Extracting the Range of cps from Affine Typing Extended Abstract

Q1126pis Rev 01/221Product InformationQ Sepharose ® Fast FlowQ1126Product DescriptionQ Sepharose ® Fast Flow is an ion exchangechromatography resin with a quaternary amine (Q) functional group [-CH 2-N +(CH 3)3] attached to Sepharose ® Fast Flow. The Q group serves as astrong anion exchanger, which is completely ionized over a broad pH range. The terms “s trong" and"weak" in ion exchange chromatography refer to the extent of ionization with pH, and not to the binding strength of the functional group to the target species. The parent Sepharose ® Fast Flow is a cross-linked derivative of Sepharose ®. The particle size range is 45-165 µm. The average bead diameter is ~90 µm. The counterion in the product is sulfate (SO 4-2). Recommended cation buffers to use with Q Sepharose ® Fast Flow include alkylamines,ammonium, ethylenediamine, imidazole, pyridine, or Tris. In terms of pH, it is suggested to operate within 0.5 pH unit of the buffer's pK a . With proteins, it is suggested to operate at least 1 pH unit above the pI of the protein, to facilitate binding. Oxidizing agents, and anionic detergents and buffers, should not be used with Q Sepharose ® Fast Flow. Likewise,extended exposure of Q1126 to pH < 4 should be avoided. Several publications 1,2 and dissertations 3-5 cite use of product Q1126 in their research.ReagentQ Sepharose ® Fast Flow is offered as a suspension in 20% ethanol.Approximate Exclusion Limit: average molecular mass of ~4 × 106 DaltonsIonic Capacity: 0.18-0.24 mmol Cl -/mL gel Binding Capacity: ~42 mg BSA per mL gel pH Stability: 2-12Working temperature: 4-40 °CPrecautions and DisclaimerFor R&D use only. Not for drug, household, or other uses. Please consult the Safety Data Sheet for information regarding hazards and safe handling practices. General Resin Preparation Procedure1. Allow the ion exchange medium and ~10 columnvolumes (CV) of buffer to equilibrate to thetemperature chosen for the chromatographic run. 2. Mix the pre-swollen suspension with startingbuffer to form a moderately thick slurry, which consists of ~75% settled gel and 25% liquid. 3. Degas the gel under vacuum at the temperatureof column operation.4. Mount the column vertically on a suitable stand,out of the way of direct sunlight or drafts, which may cause temperature fluctuations.5. Pour a small amount of buffer into the emptycolumn. Allow the buffer to flow through spaces to eliminate air pockets.6. Pour the suspension of ion exchange mediumprepared in Step 3 into the column by allowing it to flow gently down the side of the tube, to avoid bubble formation.7. For consistent flow rates and reproducibleseparations, connect a pump to the column. 8. Fill the remainder of the column to the top withbuffer. Allow ~5 CV of buffer to drain through the bed at a flow rate at least 133% of the flow rate to be used in the procedure. The bed height should have settled to a constant height.9. Using a syringe or similar instrument, apply thesample dissolved in starting buffer to the column. For isocratic separations, the sample volumeshould range from 1-5% of the column volume. If the chromatographic run involves elution with a gradient, the applied sample mass is of much greater importance than the sample volume, and the sample should be applied in a low ionicstrength medium. Ion exchange is used both to concentrate and to fractionate the sample. 10. Elution:• If only unwanted substances in the sample areadsorbed, or if sample components aredifferentially retarded under isocratic conditions, the starting buffer can also be used as the eluent.The life science business of Merck operates as MilliporeSigma in the U.S. and Canada.Merck and Sigma-Aldrich are trademarks of Merck KGaA, Darmstadt, Germany or its affiliates. All other trademarks are the property of their respective owners. Detailed information on trademarks is available via publicly accessible resources.© 2022 Merck KGaA, Darmstadt, Germany and/or its affiliates. All Rights Reserved. Q1126pis Rev 01/22 JJJ,MAM,GCY2•Normally, however, separation and elution are achieved by selectively decreasing the affinity of the molecules for the charged groups on the resin by changing the pH and/or ionic strength of the eluent. This procedure is termed gradient elution. 11. Regeneration: •Either (a) washing the column with a high ionic strength salt solution, such as 1 M NaCl, or (b) changing the pH to the tolerable low and high pH extremes, is usually sufficient to remove reversibly bound material.• When needed, lipids and precipitated proteins canbe removed by washing with 1 CV of 1-2 M NaCl, followed by 1 CV of 0.1 M NaOH in 0.5 M NaCl. • Rinse with several CV of water. Thenre-equilibrate the resin with starting buffer.• If base such as NaOH was used, adjust the pH ofthe resin to neutral before storing or using.12. Storage: Q Sepharose ® Fast Flow may be storedat 2-8 °C in water with 20% ethanol added as an antibacterial agent.General NotesCation versus Anion Exchanger• If sample components are most stable below their pI values, a cation exchanger should be used. • If sample components are most stable above their pI values, an anion exchanger should be used. •If stability is good over a wide pH range on both sides of the pI, either or both types of ion exchanger may be used.Strong versus Weak Ion Exchanger•Most proteins have pI values within the range 5.5-7.5, and can thus be separated on both strong and weak ion exchangers.•When maximum resolution occurs at an extreme pH and the molecules of interest are stable at that pH, a strong ion exchanger should be used. Choice of Buffer, pH, and Ionic Strength• The highest ionic strength which permits binding should normally be used.•The required buffer concentration varies fromsubstance to substance. Usually, an ionic strength of at least 10 mM is required to ensure adequate buffering capacity.•As salts (such as buffers) help to stabilize proteins in solution, their concentration should be highenough to prevent denaturation and precipitation.References1. López, G. et al ., Eukaryot. Cell , 14(6), 564-577(2015).2. Bhargava, V. et al ., Dev. Cell., 52(1), 38-52.e10(2020).3. Fu , Yinan, “Structure and dynamics ofPseudomonas aeruginosa ICP”. University ofGlasgow, Ph.D. dissertation, p. 126 (April 2009). 4. Redmond, Miranda , “The Role of N-TerminalAcidic Inserts on the Dynamics of the Tau Protein ”. University of Vermont, Ph.D. dissertation, p. 22 (May 2017).5. Taylor-Whiteley, Teresa Rachel , “RecapitulatingParkinson’s disease pathology in athree-dimensional neural cell culture mode ”. Sheffield Hallam University, Ph.D. dissertation, p. 58 (September 2019).NoticeWe provide information and advice to our customers on application technologies and regulatory matters to the best of our knowledge and ability, but without obligation or liability. Existing laws and regulations are to be observed in all cases by our customers. This also applies in respect to any rights of third parties. Our information and advice do not relieve ourcustomers of their own responsibility for checking the suitability of our products for the envisaged purpose. The information in this document is subject to change without notice and should not be construed as acommitment by the manufacturing or selling entity, or an affiliate. We assume no responsibility for any errors that may appear in this document.Technical AssistanceVisit the tech service page at /techservice .Standard WarrantyThe applicable warranty for the products listed in this publication may be found at /terms .Contact InformationFor the location of the office nearest you, go to /offices .。

数据挖掘与数据分析，数据可视化试题1. Data Mining is also referred to as ……………………..data analysisdata discovery(正确答案)data recoveryData visualization2. Data Mining is a method and technique inclusive of …………………………. data analysis.(正确答案)data discoveryData visualizationdata recovery3. In which step of Data Science consume Almost 80% of the work period of the procedure.Accumulating the dataAnalyzing the dataWrangling the data(正确答案)Recapitulation of the Data4. Which Step of Data Science allows the model to consistently improve and provide punctual performance and deliverapproximate results.Wrangling the dataAccumulating the dataRecapitulation of the Data(正确答案)Analyzing the data5. Which tool of Data Science is robust machine learning library, which allows the implementation of deep learning ?algorithms. STableauD3.jsApache SparkTensorFlow(正确答案)6. What is the main aim of Data Mining ?to obtain data from a less number of sources and to transform it into a more useful version of itself.to obtain data from a less number of sources and to transform it into a less useful version of itself.to obtain data from a great number of sources and to transform it into a less useful version of itself.to obtain data from a great number of sources and to transform it into a more useful version of itself.(正确答案)7. In which step of data mining the irrelevant patterns are eliminated to avoid cluttering ? Cleaning the data(正确答案)Evaluating the dataConversion of the dataIntegration of data8. Data Science t is mainly used for ………………. purposes. Data mining is mainly used for ……………………. purposes.scientific,business(正确答案)business,scientificscientific,scientificNone9. Pandas ………………... is a one dimensional labeled array capable of holding data of any type （integer, string, float, python objects, etc.）.Series(正确答案)FramePanelNone10. How many principal components Pandas DataFrame consists of ?4213(正确答案)11. Important data structure of pandas is/are ___________SeriesData FrameBoth(正确答案)None of the above12. Which of the following command is used to install pandas?pip install pandas(正确答案)install pandaspip pandasNone of the above13. Which of the following function/method help to create Series? series（）Series（）(正确答案)createSeries（）None of the above14. NumPY stands for?Numbering PythonNumber In PythonNumerical Python(正确答案)None Of the above15. Which of the following is not correct sub-packages of SciPy? scipy.integratescipy.source(正确答案)scipy.interpolatescipy.signal16. How to import Constants Package in SciPy?import scipy.constantsfrom scipy.constants(正确答案)import scipy.constants.packagefrom scipy.constants.package17. ………………….. involveslooking at and describing the data set from different angles and then summarizing it ?Data FrameData VisualizationEDA(正确答案)All of the above18. what involves the preparation of data sets for analysis by removing irregularities in the data so that these irregularities do not affect further steps in the process of data analysis and machine learning model building ?Data AnalysisEDA(正确答案)Data FrameNone of the above19. What is not Utility of EDA ?Maximize the insight in the data setDetect outliers and anomaliesVisualization of dataTest underlying assumptions(正确答案)20. what can hamper the further steps in the machine learning model building process If not performed properly ?Recapitulation of the DataAccumulating the dataEDA(正确答案)None of the above21. Which plot for EDA to check the dependency between two variables ? HistogramsScatter plots(正确答案)MapsTime series plots22. What function will tell you the top records in the data set?shapehead(正确答案)showall of the aboce23. what type of data is useful for internal policymaking and business strategy building for an organization ?public dataprivate data(正确答案)bothNone of the above24. The ………… function can “fill in” NA valueswith non-null data ?headfillna(正确答案)shapeall of the above25. If you want to simply exclude the missing values, then what function along with the axis argument will be use?fillnareplacedropna(正确答案)isnull26. Which of the following attribute of DataFrame is used to display data type of each column in DataFrame?DtypesDTypesdtypes(正确答案)datatypes27. Which of the following function is used to load the data from the CSV file into a DataFrame?read.csv（）readcsv（）read_csv（）(正确答案)Read_csv（）28. how to Display first row of dataframe ‘DF’ ?print（DF.head（1））print（DF[0 : 1]）print（DF.iloc[0 : 1]）All of the above(正确答案)29. Spread function is known as ................ in spreadsheets ?pivotunpivot(正确答案)castorder30. ................. extract a subset of rows from a data fram based on logical conditions ? renamefilter(正确答案)setsubset31. We can shift the DataFrame’s index by a certain number of periods usingthe …………. Method ?melt（）merge（）tail（）shift（）(正确答案)32. We can join melted DataFrames into one Analytical Base Table using the ……….. function.join（）append（）merge（）(正确答案)truncate（）33. What methos is used to concatenate datasets along an axis ?concatenate（）concat（）(正确答案)add（）merge（）34. Rows can be …………….. if the number of missing values is insignificant, as thiswould not impact the overall analysis results.deleted(正确答案)updatedaddedall35. There is a specific reason behind the missing value.What stands for Missing not at randomMCARMARMNAR(正确答案)None of the above36. While plotting data, some values of one variable may not lie beyond the expectedrange, but when you plot the data with some other variable, these values may lie far from the expected value.Identify the type of outliers?Univariate outliersMultivariate outliers(正确答案)ManyVariate outlinersNone of the above37. if numeric values are stored as strings, then it would not be possible to calculatemetrics such as mean, median, etc.Then what type of data cleaning exercises you will perform ?Convert incorrect data types:(正确答案)Correct the values that lie beyond the rangeCorrect the values not belonging in the listFix incorrect structure:38. Rows that are not required in the analysis. E.g ifobservations before or after a particular date only are required for analysis.What steps we will do when perform data filering ?Deduplicate Data/Remove duplicateddataFilter rows tokeep only therelevant data.(正确答案)Filter columns Pick columnsrelevant toanalysisBring the datatogether, Groupby required keys,aggregate therest39. you need to…………... the data in order to get what you need for your analysis. searchlengthorderfilter(正确答案)40. Write the output of the following ?>>> import pandas as pd >>> series1 =pd.Series（[10,20,30]）>>> print（series1）0 101 202 30dtype: int64(正确答案)102030dtype: int640 1 2 dtype: int64None of the above41. What will be output for the following code?import numpy as np a = np.array（[1, 2, 3], dtype = complex） print a[[ 1.+0.j, 2.+0.j, 3.+0.j]][ 1.+0.j]Error[ 1.+0.j, 2.+0.j, 3.+0.j](正确答案)42. What will be output for the following code?import numpy as np a =np.array（[1,2,3]） print a[[1, 2, 3]][1][1, 2, 3](正确答案)Error43. What will be output for the following code?import numpy as np dt = dt =np.dtype（'i4'） print dtint32(正确答案)int64int128int1644. What will be output for the following code?import numpy as np dt =np.dtype（[（'age',np.int8）]） a = np.array（[（10,）,（20,）,（30,）], dtype = dt）print a['age'][[10 20 30]][10 20 30](正确答案)[10]Error45. We can add a new row to a DataFrame using the _____________ methodrloc[ ]iloc[ ]loc[ ](正确答案)None of the above46. Function _____ can be used to drop missing values.fillna（）isnull（）dropna（）(正确答案)delna（）47. The function to perform pivoting with dataframes having duplicate values is _____ ? pivot（unique = True）pivot（）pivot_table（unique = True）pivot_table（）(正确答案)48. A technique, which when performed on a dataframe, rearranges the data from rows and columns in a report form, is called _____ ?summarisingreportinggroupingpivoting(正确答案)49. Normal Distribution is symmetric is about ___________ ?VarianceMean(正确答案)Standard deviationCovariance50. Write a statement to display “Amount” as x-axis label. （consider plt as an alias name of matplotlib.pyplot）bel（“Amount”）plt.xlabel（“Amount”）(正确答案)plt.xlabel（Amount）None of the above51. Fill in the blank in the given code, if we want to plot a line chart for values of list ‘a’ vs values of list ‘b’.a = [1, 2, 3, 4, 5]b = [10, 20, 30, 40, 50]import matplotlib.pyplot as pltplt.plot __________（a, b）(正确答案)（b, a）[a, b]None of the above52. #Loading the datasetimport seaborn as snstips =sns.load_dataset（"tips"）tips.head（）In this code what is tips ?plotdataset name(正确答案)paletteNone of the above53. Visualization can make sense of information by helping to find relationships in the data and support （or disproving） ideas about the dataAnalyzeRelationShip(正确答案)AccessiblePrecise54. In which option provides A detailed data analysis tool that has an easy-to-use tool interface and graphical designoptions for visuals.Jupyter NotebookSisenseTableau DesktopMATLAB(正确答案)55. Consider a bank having thousands of ATMs across China. In every transaction, Many variables are recorded.Which among the following are not fact variables.Transaction charge amountWithdrawal amountAccount balance after withdrawalATM ID(正确答案)56. Which module of matplotlib library is required for plotting of graph?plotmatplotpyplot(正确答案)None of the above57. Write a statement to display “Amount” as x-axis label. （consider plt as an alias name of matplotlib.pyplot）bel（“Amount”）plt.xlabel（“Amount”）(正确答案)plt.xlabel（Amount）None of the above58. What will happen when you pass ‘h’ as as a value to orient parameter of the barplot function?It will make the orientation vertical.It will make the orientation horizontal.(正确答案)It will make line graphNone of the above59. what is the name of the function to display Parameters available are viewed .set_style（）axes_style（）(正确答案)despine（）show_style（）60. In stacked barplot, subgroups are displayed as bars on top of each other. How many parameters barplot（） functionhave to draw stacked bars?OneTwoNone(正确答案)three61. In Line Chart or Line Plot which parameter is an object determining how to draw the markers for differentlevels of the style variable.?x.yhuemarkers(正确答案)legend62. …………………..similar to Box Plot but with a rotated plot on each side, giving more information about the density estimate on the y axis.Pie ChartLine ChartViolin Chart(正确答案)None63. By default plot（） function plots a ________________HistogramBar graphLine chart(正确答案)Pie chart64. ____________ are column-charts, where each column represents a range of values, and the height of a column corresponds to how many values are in that range.Bar graphHistograms(正确答案)Line chartpie chart65. The ________ project builds on top of pandas and matplotlib to provide easy plotting of data.yhatSeaborn(正确答案)VincentPychart66. A palette means a ________.. surface on which a painter arranges and mixed paints. circlerectangularflat(正确答案)all67. The default theme of the plotwill be ________?Darkgrid(正确答案)WhitegridDarkTicks68. Outliers should be treated after investigating data and drawing insights from a dataset.在调查数据并从数据集中得出见解后，应对异常值进行处理。

【Python】extract及contains⽅法（正则提取筛选数据）⼀，extract⽅法的使⽤extract函数主要是对于数据进⾏提取。

场景⼀般对于DataFrame中的⼀列中的数据进⾏提取的场合⽐较多。

例如⼀列中包含了很长的字段，我们希望在这些字段中提取出我们想要的字段时，就可以通过extract⽅法进⾏数据的提取了。

好了，废话不多说直接上代码。

数据源序号姓名服务卡卡号消费地点消费时间理赔⾦额（元）交易明细数量1 张三 8100001 我爱花钱连锁有限公司 2020/3/1 8:02 605 珍牡肾⾻胶囊（珍泉）0.63g*48粒*3盒 12 张三 8100001 我爱花钱连锁有限公司 2020/3/1 8:02 1225 桂龙药膏（葛洪）202g*6瓶 13 张三 8100001 我爱花钱连锁有限公司 2020/3/2 10:58 27 胆宁⽚（上药牌）0.36g*60⽚/瓶 14 李四 8100002 我爱花钱连锁有限公司 2020/3/1 9:20 30 阿莫西林胶囊0.5g*24粒/盒 35 李四 8100002 我爱花钱连锁有限公司 2020/3/1 9:20 5 氨咖黄敏胶囊（康麦尔）12粒/盒 16 李四 8100002 我爱花钱连锁有限公司 2020/3/4 14:26 51 阿归养⾎⼝服液（中联）10ml*24⽀/盒 17 李四 8100002 我爱花钱连锁有限公司 2020/3/4 14:26 5 氨咖黄敏胶囊（康麦尔）12粒/盒 18 李四 8100002 我爱花钱连锁有限公司 2020/3/9 17:56 28 胆宁⽚（上药牌）0.36g*60⽚/瓶 19 李四 8100002 我爱花钱连锁有限公司 2020/3/19 11:19 56 柴⽯退热颗粒（德众）8g*6袋/盒 110 李四 8100002 我爱花钱连锁有限公司 2020/3/21 16:04 68 醒脾胶囊0.3g*30粒 111 李四 8100002 我爱花钱连锁有限公司 2020/3/31 10:00 60 ⼩败毒膏（东⽅博爱）10g*8袋 112 王五 8100003 我爱花钱连锁有限公司 2020/3/1 10:43 114 枣仁安神液10ml*7⽀ 113 王五 8100003 我爱花钱连锁有限公司 2020/3/17 10:40 118 益⽓维⾎颗粒(红珊瑚)10g*15袋 114 王五 8100003 我爱花钱连锁有限公司 2020/3/21 8:19 615 ⽐卡鲁胺⽚(双益安)50mg*14s*2板 115 王五 8100003 我爱花钱连锁有限公司 2020/3/1 10:56 120 消痛贴膏（奇正）1.2g:2.5ml*10贴/盒 116 王五 8100003 我爱花钱连锁有限公司 2020/3/1 12:56 198 复⽅⾸乌地黄丸（修正）3g*10袋*3⼩盒 117 王五 8100003 我爱花钱连锁有限公司 2020/3/1 12:56 28 胆宁⽚（上药牌）0.36g*60⽚/瓶 118 王五 8100003 我爱花钱连锁有限公司 2020/3/1 13:53 256 河车⼤造丸（同仁堂）9g*10丸/盒 119 赵六 8100004 我爱花钱连锁有限公司 2020/3/1 14:52 7 复⽅氨酚烷胺⽚（新迪）12⽚/盒 120 赵六 8100004 我爱花钱连锁有限公司 2020/3/1 14:52 149 法莫替丁分散⽚20mg*36⽚/盒 121 赵六 8100004 我爱花钱连锁有限公司 2020/3/9 19:56 100 朱砂安神丸6g*10袋 122 赵六 8100004 我爱花钱连锁有限公司 2020/3/9 19:56 23 清热消炎宁⽚0.4g*24⽚/盒 123 赵六 8100004 我爱花钱连锁有限公司 2020/3/1 15:16 30 多酶⽚100s/盒 124 赵六 8100004 我爱花钱连锁有限公司 2020/3/1 15:16 1139 补肺丸（养⽆极）9g*10丸*16板 125 赵六 8100004 我爱花钱连锁有限公司 2020/3/5 17:25 170 补肾益寿⽚（恒修堂）0.4g*100⽚ 126 赵六 8100004 我爱花钱连锁有限公司 2020/3/5 17:25 800 益安宁丸72丸*2瓶(每18丸重3.1g) 127 赵六 8100004 我爱花钱连锁有限公司 2020/3/9 17:39 800 益安宁丸72丸*2瓶(每18丸重3.1g) 128 赵六 8100004 我爱花钱连锁有限公司 2020/3/11 17:30 480 七⼗味珍珠丸(⽢露)1g*6s 129 赵六 8100004 我爱花钱连锁有限公司 2020/3/22 16:58 1154 双参龙胶囊45盒装0.3g*24s*45盒 130 杨七 8100005 我爱花钱连锁有限公司 2020/3/1 16:54 100 朱砂安神丸6g*10袋 131 杨七 8100005 我爱花钱连锁有限公司 2020/3/12 20:53 14 消痔灵⽚0.3g*24⽚ 132 杨七 8100005 我爱花钱连锁有限公司 2020/3/18 10:04 402 回元堂固本回元⼝服液 20ml*24瓶20ml*24瓶 133 杨七 8100005 我爱花钱连锁有限公司 2020/3/21 11:18 847 伏⽴康唑分散⽚(复锐)0.2g*6s 134 杨七 8100005 我爱花钱连锁有限公司 2020/3/1 17:36 30 多酶⽚100s/盒 1View Code代码这⾥是通过jupyter来分段显⽰的。

第1篇---IntroductionIn today's globalized world, the ability to communicate effectively across languages is a crucial skill for professionals in multinational corporations. This interview question aims to assess the candidate's proficiency in English to Chinese translation, a skill that is essential for roles that involve cross-cultural communication, marketing, and documentation. The question provided below is designed to gauge the candidate's understanding of the source text, their ability to convey the intended meaning accurately, and their attention to detail and cultural appropriateness.---Interview Question:As a marketing manager for a global technology company, you have been tasked with translating a press release about a new software productthat is set to revolutionize the way businesses manage their data. The press release is written in English and contains technical jargon, industry-specific terminology, and references to cultural nuances that are unique to the English-speaking market. Below is the English text of the press release. Your task is to translate it into Chinese, ensuring that the translation is accurate, culturally appropriate, and maintains the original tone and intent.---English Text:---FOR IMMEDIATE RELEASEGlobalTech Announces the Launch of DataXpress, the Ultimate Solution for Data Management[City, Country] – GlobalTech, a leading provider of innovative data management solutions, is proud to announce the launch of DataXpress, the latest addition to its suite of cutting-edge products. DataXpress is designed to transform the way businesses store, analyze, and securetheir data, offering a comprehensive solution that addresses the evolving challenges of the digital age.A Game-Changer for Data ManagementDataXpress is a revolutionary software platform that leverages advanced machine learning algorithms to optimize data storage and retrieval processes. With its intuitive user interface and robust security features, DataXpress empowers businesses to manage their data more efficiently and securely than ever before.“DataXpress is a game-changer for data management,” says John Smith, Chief Technology Officer at GlobalTech. “Our team has poured years of research and development into creating a product that not only meets the demands of today’s data-intensive businesses but also prepares them for the challenges of tomorrow.”Key Features of DataXpress:- Intelligent Data Storage: Utilizes machine learning to analyze and categorize data, ensuring optimal storage solutions.- Advanced Analytics: Offers powerful tools for data analysis, allowing businesses to gain actionable insights from their data.- Enhanced Security: Implements cutting-edge encryption techniques to protect sensitive data from unauthorized access.- Scalable Architecture: Designed to handle large volumes of data and scale with the growth of the business.- Comprehensive Support: Provides 24/7 customer support to ensure smooth implementation and ongoing assistance.GlobalTech’s Commitment to InnovationGlobalTech has a long-standing reputation for innovation and excellence in data management. With DataXpress, the company continues its commitment to providing cutting-edge solutions that empower businesses to thrive in the digital era.“DataXpress is the result of our dedica tion to driving technological advancements in data management,” says Sarah Johnson, President of GlobalTech. “We are confident that this product will become anessential tool for businesses worldwide.”Availability and PricingDataXpress is now available f or purchase through GlobalTech’s official website. Pricing starts at $99 per month for a basic subscription, with discounts available for annual commitments.About GlobalTechGlobalTech is a global leader in data management solutions, offering a wide range of products and services designed to help businesses manage their data effectively. With a focus on innovation and customer satisfaction, GlobalTech has become a trusted partner for businesses around the world.---Instructions for the Candidate:1. Read the entire press release carefully to ensure you understand the context and the intended message.2. Pay close attention to technical jargon, industry-specific terminology, and cultural nuances.3. Translate the press release into Chinese, ensuring that the translation is accurate and maintains the original tone and intent.4. Your translation should be clear, concise, and culturally appropriate.5. Pay attention to grammar, punctuation, and formatting.6. Submit your translation in a separate document.---Evaluation Criteria:- Accuracy: The translation should accurately reflect the original text, including technical terms and industry-specific jargon.- Cultural Appropriateness: The translation should be culturally appropriate, taking into account the target audience and cultural nuances.- Tone and Intent: The translation should maintain the original tone and intent of the press release.- Clarity and Conciseness: The translation should be clear and concise, avoiding unnecessary wordiness or ambiguity.- Grammar and Punctuation: The translation should be grammatically correct and punctuated accurately.---This interview question is designed to test the candidate's proficiency in English to Chinese translation, their attention to detail, and their ability to adapt to the specific requirements of the target language and culture.第2篇IntroductionThe role of a translator is pivotal in the globalized world, where communication across languages is essential for business, culture, and education. This document outlines a comprehensive set of interview questions designed to assess the skills, knowledge, and personality of candidates applying for a translator position. The questions are categorized into different sections to provide a structured approach to evaluating the candidate's suitability for the role.Section 1: Language Proficiency and Translation Skills1. Tell us about your language background. What languages do youfluently speak and write?2. Can you describe a challenging translation project you have worked on and how you overcame the difficulties?3. How do you ensure the accuracy and consistency of your translations?4. What tools and software do you use for translation work? Explain how you utilize them effectively.5. Discuss the importance of context in translation. Give an example of how you handled a contextually challenging translation.6. How do you maintain the tone and style of the original text in your translations?7. Describe a time when you had to translate a technical term or concept. How did you approach it?8. What is your approach to translating idiomatic expressions?9. How do you handle cultural differences in your translations?10. Can you explain the difference between literal translation and free translation? Give an example of each.Section 2: Specialization and Industry Knowledge11. What is your area of specialization in translation (e.g., legal, medical, technical, literary)?12. Can you provide examples of specialized terminology in your fieldand how you handle them?13. How do you stay updated with the latest developments in your specialized field?14. What experience do you have in translating documents related to [specific industry or field]?15. How do you ensure the cultural relevance of your translations withina specific industry?16. Can you describe a situation where you had to adapt your translation style to suit a specific audience within an industry?17. What are the key challenges you face when translating documents from [specific source language] to [specific target language]?18. How do you ensure the confidentiality of sensitive information in your translations?19. What are the legal and ethical considerations you take into account when translating documents?Section 3: Project Management and Work Style20. How do you prioritize and manage multiple translation projects simultaneously?21. Can you describe your workflow for a typical translation project?22. What is your approach to meeting tight deadlines?23. How do you ensure quality control in your translations?24. What feedback mechanisms do you use to improve your translation work?25. How do you handle client queries and revisions?26. What experience do you have with project management tools and software?27. How do you ensure effective communication with clients and colleagues?28. What is your approach to working in a team on translation projects?29. How do you handle pressure and stress in your work environment?30. What are your long-term career goals in the field of translation?Section 4: Professional Development and Learning31. How do you stay motivated in your translation work?32. What professional development opportunities have you pursued in the past year?33. How do you stay current with industry trends and advancements in translation technology?34. What are your preferred methods for learning new languages and terminology?35. How do you keep your language skills sharp and up-to-date?36. What certifications or qualifications do you hold in translation or related fields?37. What professional organizations or networks are you a part of in the translation industry?38. How do you approach continuous learning and improvement in your work?39. What advice would you give to someone starting their career in translation?40. How do you envision your professional growth over the next five years?ConclusionThese interview questions are designed to provide a comprehensive evaluation of a candidate's suitability for a translator position. By asking a wide range of questions, employers can gain insights into the candidate's language proficiency, translation skills, specialization knowledge, project management abilities, work style, and professional development aspirations. It is important to tailor these questions to the specific requirements of the role and the company to ensure the best fit for the position.第3篇Introduction:As a professional Chinese-English interpreter, you are expected to possess not only linguistic proficiency but also cultural understanding, quick thinking, and the ability to adapt to various communication scenarios. This comprehensive set of interview questions is designed to assess your skills, experience, and suitability for a Chinese-English interpreter position.1. Personal Background and Language SkillsQuestion 1: Can you please introduce yourself and tell us about your background in language learning and interpretation?Answer:[Your name] is a dedicated and highly motivated individual with a strong passion for language and cross-cultural communication. I hold a Bachelor’s degree in Translation and Interpretation from [University Name], where I majored in Chinese-English translation and interpretation. Throughout my academic journey, I have consistently achieved top gradesin both language courses and practical interpretation exercises.My interest in languages began at a young age, and I have sincededicated myself to mastering both Chinese and English. I have completed numerous translation and interpretation projects, including conferences, business meetings, and cultural events. My proficiency in both languages is not only linguistic but also cultural, as I have lived and worked in both China and English-speaking countries, providing me with a deep understanding of the nuances of both languages and cultures.Question 2: What are the main differences between Chinese and English in terms of grammar, vocabulary, and usage? How do you handle these differences when interpreting?Answer:The main differences between Chinese and English lie in their grammatical structures, vocabulary, and usage. For example, Chinese has no articles, while English requires articles in certain contexts.Additionally, Chinese tends to use more idiomatic expressions and proverbs, which can be challenging to translate directly into English.To handle these differences, I approach each interpretation task with a keen awareness of the cultural and linguistic nuances involved. I focus on understanding the context of the conversation, identifying the intended meaning behind the words, and then conveying that meaning in a way that is natural and appropriate for the target language. This often involves using synonyms, paraphrasing, or even creating new expressions to ensure the message is accurately and effectively communicated.2. Professional Experience and SkillsQuestion 3: Can you describe your experience in interpreting at conferences and business meetings? What were some of the challenges you faced, and how did you overcome them?Answer:Throughout my career, I have had the opportunity to interpret at numerous conferences and business meetings, including international trade fairs, seminars, and corporate events. One of the challenges I often face is the need to quickly adapt to the specific terminology and industry jargon used by the participants.To overcome this challenge, I spend time researching the relevant subject matter before the event and familiarize myself with the key terms and concepts. I also actively seek feedback from the participants to ensure that my interpretations are accurate and clear. Additionally, I maintain a calm and professional demeanor to manage the pressure and ensure a smooth flow of communication.Question 4: What is your approach to consecutive interpretation? Can you give an example of a situation where you used consecutive interpretation effectively?Answer:Consecutive interpretation requires a high level of concentration, memory, and language skills. My approach to consecutive interpretationinvolves listening carefully to the speaker, mentally processing the information, and then conveying the message in the target language in a coherent and concise manner.One example of a situation where I used consecutive interpretation effectively was during a business negotiation between a Chinese company and an international client. The negotiation involved complex technical terms and required a deep understanding of both the business context and the cultural nuances of the conversation. By maintaining a calm demeanor and focusing on the key points, I was able to convey the message accurately and facilitate a successful negotiation.Question 5: How do you prepare for a major interpreting assignment? What are some of the resources you use?Answer:Preparing for a major interpreting assignment involves several steps. First, I research the topic and the participants to understand the context and the key issues at stake. I then familiarize myself with the relevant terminology and industry jargon, using dictionaries, glossaries, and online resources.I also prepare by practicing the interpretation of sample text and role-playing scenarios to improve my timing and delivery. Additionally, I ensure that I am well-rested and hydrated on the day of the event to maintain peak performance.3. Adaptability and Problem-SolvingQuestion 6: Describe a time when you had to interpret in a challengingor unfamiliar environment. How did you handle the situation?Answer:During a recent conference, I was asked to interpret in a venue that was extremely noisy due to construction work. This made it difficult to hear the speakers clearly and to convey the message accurately to the participants.To handle the situation, I asked the organizers to move the interpreter booth closer to the speakers and to provide noise-cancelling headphones.I also increased my focus and concentration, and made a conscious effort to repeat key points and ask for clarifications when necessary. Despite the challenging environment, I was able to maintain the quality of my interpretation and ensure that the event ran smoothly.Question 7: How do you handle situations where there is a cultural misunderstanding or miscommunication during an interpretation?Answer:Cultural misunderstandings can occur at any time during an interpretation, and it is important to address them promptly and effectively. When I encounter a cultural misunderstanding, I take a few moments to pause and reflect on the context and the likely source of the misunderstanding.I then clarify the point with the speaker, ensuring that I have a clear understanding of their intentions. If necessary, I seek additional information from the participants to facilitate a more accurate interpretation. By maintaining open communication and showing empathy, I can often resolve cultural misunderstandings and ensure a successful interpretation.4. Ethics and ProfessionalismQuestion 8: What are your ethical considerations when working as an interpreter? Can you give an example of a situation where you had to adhere to an ethical guideline?Answer:As an interpreter, I am bound by a set of ethical guidelines that emphasize confidentiality, neutrality, and professionalism. These guidelines ensure that I maintain the integrity of the communication process and protect the interests of all parties involved.One example of a situation where I had to adhere to an ethical guideline was during a legal deposition. I was required to remain neutral andimpartial, ensuring that the interpretation accurately reflected the statements of both the plaintiff and the defendant. By adhering to these ethical principles, I was able to maintain the integrity of the legal process and provide a fair and accurate account of the proceedings.Question 9: How do you ensure the confidentiality of sensitive information during an interpretation?Answer:Confidentiality is a crucial aspect of interpretation, and I take it very seriously. To ensure the confidentiality of sensitive information, I follow these steps:1. Understand the context: Before beginning the interpretation, Iclarify the nature of the information being shared and anyconfidentiality requirements.2. Establish trust: I build a strong rapport with the participants, ensuring that they trust me to handle sensitive information with care.3. Maintain confidentiality: I do not discuss the interpretation with anyone outside of the assignment and take steps to secure any physical or digital materials related to the interpretation.4. Legal compliance: I am aware of the legal requirements for confidentiality in my jurisdiction and ensure that I comply with all relevant laws and regulations.5. ConclusionAs a professional Chinese-English interpreter, I am committed to providing high-quality, accurate, and culturally sensitiveinterpretation services. I am confident that my language skills, professional experience, and ethical standards make me a suitable candidate for this position. I am eager to contribute to your team and help facilitate effective communication between Chinese and English-speaking parties. Thank you for considering my application.。

Journal of Ethnopharmacology 93(2004)409–415Antioxidant and anticancer activities of organic extracts from Platycodon grandiflorum A.De Candolle rootsJi-Young Lee a ,Woo-Ik Hwang b ,Seung-Taik Lim a ,∗aGraduate School of Biotechnology,Korea University,Anam-dong,Sungbuk-ku,Seoul 136-701,Republic of KoreabDepartment of Biochemistry,College of Medicine,Korea University,Anam-dong,Sungbuk-ku,Seoul 136-701,Republic of KoreaReceived 21May 2003;received in revised form 20March 2004;accepted 26April 2004AbstractThis study examined the antioxidant and anticancer activities of the petroleum ether extracts from the roots of Platycodon grandiflorum A.DC,which is a plant used as both a herbal medicine and food in Asia.Extracts from Platycodon grandiflorum in petroleum ether were fractionated (fractions I –V )by silica gel column chromatography using gradient solvents (petroleum ether:ethyl ether,9:1–5:5,v/v).The antioxidant activities of the fractions were evaluated in terms of their inhibition of lipid peroxidation as well as their free radical scavenging activity.Fraction II ,which was extracted at an 8:2mixture of petroleum ether and ethyl ether,exhibited the greatest antioxidant activity among the fractions.On the other hand,the cytotoxicity of each fraction,which was evaluated by the MTT assay using human cancer cell lines (HT-29,HRT-18and HepG2),was greatest in fraction III ,which was extracted with a 7:3petroleum ether and ethyl ether mixture.Both fractions,II and III ,were sub-fractionated by thin layer chromatography,and the sub-fractions each were screened for their antioxidant and anticancer activities.In addition,the antioxidant activity was closely related to the content of phenolic compounds,and the anticancer active fraction exhibited a typical UV absorbance spectrum of polyacetylene.©2004Elsevier Ireland Ltd.All rights reserved.Keywords:Antioxidant activity;Cytotoxicity;Platycodon grandiflorum ;DPPH;MTT1.IntroductionAntioxidants are added to a variety of foods to prevent or deter free radical-induced lipid oxidation,which is respon-sible for the development of off-flavors and the undesirable chemical compounds in food (Angelo,1996).The free radi-cals can also be generated in biological systems in the form of reactive oxygen species (ROS),such as superoxide anion radicals (O 2•−),hydrogen peroxide (H 2O 2),hydroxyl rad-icals (OH •),and the singlet oxygen (1O 2)(Halliwell et al.,1995).These reactive ROS cause destructive and irreversible damage to the components of a cell,such as lipids,proteins and DNA (Lopaczyski and Zeisel,2001).Although normal cells possess antioxidant defense systems against ROS,the continuous accumulation of damage to the cells induces dis-eases such as cancer and aging (Matés and Sánchez-Jiménez,2000).The continuous antioxidant dose also plays a pre-ventive role against these diseases by removing the ROS in biological systems (Sgambato et al.,2001).∗Correspondingauthor.Tel.:+82232903435;fax:+8229275201.E-mail address:limst@korea.ac.kr (S.-T.Lim).Anticancer agents,on the other hand,are mainly related to their curative role in a damaged system.Under normal con-ditions,the cells in which the DNA or other components are irreversibly damaged by various causes undergo apoptotic cell death,which is a self-destructive metabolism accord-ing to the genetically encoded cell death-signal (Korsmeyer,1995;Hooper et al.,1999).However,cancer cells,which are already irreversibly developed,obtain the capability to evade apoptosis by various ways.The aim of anticancer agents is to trigger the apoptosis signaling system in these cancer cells whilst disturbing their proliferation (Bold et al.,1997).Plants have many phytochemicals with various bioactivi-ties,including antioxidant,anti-inflammatory and anticancer activities.For example,some studies have reported that ex-tracts from natural products,such as fruits,vegetables and medicinal herbs,have positive effects against cancer,com-pared with chemotherapy or recent hormonal treatments (Pezzuto,1997;Wu et al.,2002).Therefore,many plants have been examined to identify new and effective antioxi-dant and anticancer compounds,as well as to elucidate the mechanisms of cancer prevention and apoptosis (Pietta et al.,1998;Kim et al.,1998;Swamy and Tan,2000).In particu-0378-8741/$–see front matter ©2004Elsevier Ireland Ltd.All rights reserved.doi:10.1016/j.jep.2004.04.017410J.-Y.Lee et al./Journal of Ethnopharmacology93(2004)409–415lar,oriental medicinal plants are considered to be one of the most promising sources due to their variety of species and applications.In addition,their therapeutic effect has been demonstrated by their clinical uses in Asia for many decades. The roots of Platycodon grandiflorum A.De Candolle (Korean name,‘Doraji’,Japanese name,‘Kikyo’,and Chi-nese name,‘Jiegeng’),which belongs to the Campanulaceae family,have been used as either a food material or a tradi-tional oriental medicine.The extracts from Platycodon gran-diflorum have been reported to have a wide range of health benefits.In particular,in Korea,the roots grown for4years have been used to treat bronchitis,asthma,pulmonary tu-berculosis,diabetes and inflammatory diseases(Takagi and Lee,1972;Lee,1973).Recently,its immunopharmacologi-cal effects have been studied(Nagao et al.,1986),and some active compounds,such as triterpenoid(Nikaido et al.,1999) and saponin(Ishii et al.,1984)have been identified.Some studies even extended the cultivation period of Platycodon grandiflorum to22years using a patented method(Lee, 1991),and reported that its aqueous extracts were effec-tive in preventing hypercholesterolemia,hyperlipidemia,and CCl4-induced hepatotoxicity(Lee and Jeong,2002).How-ever,there are few reports on the antioxidant and anticancer activity of the organic extract from Platycodon grandiflo-rum.In a previous study,it was reported that the crude petroleum ether extract from Platycodon grandiflorum ex-hibited strong inhibitory activity against human cancer cell growth,and the activity of the organic extract was greater than that of the aqueous extract(Lee et al.,1998).In this study,the petroleum ether extract of Platycodon grandi-florum root was fractionated using gradient solvents,and their antioxidant activity was compared with commercial antioxidant agents.In addition,the anticancer activity of the fractions was also examined.2.Materials and methods2.1.MaterialThe chopped and dried roots of Platycodon grandiflo-rum A.DC(Campanulaceae family)cultivated in Youngju, Korea,were purchased from the oriental herbal market, and the Korea Molecular Medicine and Nutrition Re-search Institute confirmed the identity.The human rectal (HRT-18),hepatoma(HepG2)and colon(HT-29)can-cer cell lines were purchased from the American Type Culture Collection(Maryland,USA).Dulbecos Modi-fied Eagle Medium(DMEM),fetal bovine serum and trypsin–EDTA were acquired from Gibco BRL(Grand Island,NY,USA),and the culture supplies such as the 48-well plates were obtained from Nunclon Brand Prod-ucts.3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide(MTT)and1,1-diphenyl-2-picrylhydrazyl(DPPH) were purchased from the Sigma-Aldrich Company(St.Louis,MO,USA).Silicic acid(BIO-SIL A100–200mesh) was a product from Bio-rad Lab.(Richmond,CA,USA), and the analytical and preparative thin layer chromatogra-phy(TLC)was performed using silica gel60F254(Merck, Darmstadt,Germany).2.2.Extraction and fractionationThe dried roots of Platycodon grandiflorum(600g)were ground into powder,and extracted with petroleum ether(4L) by shaking for72h at room temperature.After the powder particles had settled down,the clear yellow supernatant was filtered with a0.22␮m pore size PTFEfilter(Milipore Co., Billerica,USA),and concentrated(10.3g,dry weight)by vacuum-evaporation.The concentrate was then fractionated (Fractions I–V)using a silica gel column with a solvent gradient of petroleum ether and ethyl ether(9:1–5:5),and the fractions were concentrated under reduced pressure. 2.3.Measurement of the antioxidant activity2.3.1.Ferric thiocyanate test(FTC)The antioxidant activity analysis using ferric thiocyanate was performed according to the method reported by Osawa and Namiki(1981).Six hundred micrograms of the dried solids from each fraction were dissolved in0.12mL of98% ethanol,and2.88mL of a2.51%linoleic acid solution in EtOH and9mL of a40mM phosphate buffer(pH7.0) were added.The mixture was incubated at40◦C in a dark screw-cap vial.During the incubation,a0.1mL aliquot was taken from the mixture,and diluted with9.7mL of75% ethanol,followed by the addition of0.1mL of30%ammo-nium thiocyanate.Precisely3min after adding the0.1mL of20mM ferrous chloride in3.5%hydrochloric acid,the absorbance for the red color was measured at500nm.The level of lipid peroxidation inhibition by each fraction was calculated from the absorbance ratio to that of a blank with-out any sample.2.3.2.Thiobarbituric acid test(TBA)This assay was performed according to the method re-ported by Kikuzaki and Nakatani(1993).Two milliliters of 20%trichloroacetic acid and2mL of thiobarbituric acid so-lutions were added to1mL of the mixture solution contain-ing linoleic acid,which was prepared according to the FTC procedure.The mixture was then placed in a boiling water bath for10min.After cooling,the mixture was centrifuged at3000rpm for20min,and the absorbance of the super-natant was measured at532nm.2.3.3.DPPH radical scavenging testThis test was measured as described by Blois(1958).One milliliter of the fraction solutions(50,100,and200␮g/mL in ethanol)was added to1mL of a DPPH solution(0.2mM in ethanol).After a30min of reaction at room temperature, the absorbance of the solution was measured at517nm.J.-Y.Lee et al./Journal of Ethnopharmacology93(2004)409–415411The free radical scavenging activity of each fraction was determined by comparing its absorbance with that of a blank solution(no sample).2.4.Cytotoxicity on cancer cells(MTT test)This assay was performed according to a slight modifi-cation of the procedure reported by Mosmann(1983).In 48-well plates,a human cancer cell suspension(3×104 cells/well)was incubated for24h at37◦C.The cells were then rinsed and grown in a new DMEM containing each frac-tion(300␮g/mL).After incubation for24or48h at37◦C, the DMEM was removed,and the cells were again incubated again with0.25mL of DMEM and0.05mL of a MTT solu-tion(0.5␮g/mL)for4h.0.7mL of the lysing buffer(20% sodium dodecyl sulfate in50%N,N-dimethylformamide,pH 4.6)was then added to each well to dissolve the purple for-mazan produced by the MTT,and the cells were incubated for a further2h.The plate was read using a spectrophotome-ter(Beckman model DU-64)at a wavelength of540nm. The cytotoxicity was obtained by comparing the absorbance between the samples and the control.2.5.Total phenolic contentThe total phenolic content was determined using a Folin–Ciocalteu reagent according to the procedure reported by Singleton and Rossi(1965).The fractions(400␮g/mL in ethanol)were mixed with0.75mL of a Folin–Ciocalteu reagent,which was diluted10-fold with distilled water im-mediately before use,which was followed by standing at room temperature for5min.Subsequently,0.75mL of a sodium bicarbonate solution(60mg/mL)was added.This mixture was stored for2h at room temperature,and its absorbance was measured at725nm.The analysis was per-formed in triplicate,and the results are expressed as the ferulic acid equivalents.2.6.Thin layer chromatography(TLC)The fractions from the silica gel column were an-alyzed by TLC with a mobile phase of petroleum ether:chloroform:methanol(15:7:3,v/v/v)(A)or petroleum ether:diethyl ether:acetic acid(80:20:1,v/v/v)(B),accord-ing to a slight modification of the procedure reported by Amarowicz et al.(2000).The separated spots on the TLC plate were identified under UV lights of a short(254nm) and long(365nm)wavelength,and also by spraying with H2SO4.The phenolic compounds could be visualized by spraying the plates with a1%FeCl3solution in1M HCl (Reio,1958).For the rapid detection of the antioxidant activity of the spots,the plates were stained with a DPPH solution(Soler-Rivas et al.,2000).After discerning the most active spot on the plates,a preparative TLC plate was used to scrape and collect—it’s a large amount for a quantitative DPPH assay of the antioxidant activity.3.Results and discussion3.1.Yield and total phenolic contentFractions I–V were separated from the crude petroleum ether extract using a silica gel column and gradient solvents (9:1–5:5),yielding0.02–0.33g/g,based on the initial weight of the crude extract(Table1).The total phenolic content in the fractions ranged from1.66to4.80mg/g,and fraction II,which was eluted with a8:2mixture of petroleum ether and ethyl ether,contained the highest level of the phenolic compounds.3.2.Inhibition of lipid peroxidationThe antioxidant activity of the crude extract and its frac-tions were measured using ferric thiocyanate(FTC)and thio-barbituric acid(TBA)tests.In the FTC test,which deter-mines the amount of peroxide produced at the initial stage of lipid peroxidation,a lower absorbance indicates a higher level of antioxidant activity.Fig.1shows the changes in the absorbance for each fraction during3days of incuba-tion at40◦C,in comparison with BHA and␣-tocopherol. The absorbance of the control increased in proportion to the incubation time,and the absorbance of the other sam-ples also increased with increasing incubation time.How-ever,most samples,with the exception of fraction I,showed a significantly lower increment in the rate compared to the control after48h(P<0.01).Although the differences be-tween the samples were not so significant until48h,frac-tion II showed a slightly higher inhibition effect after72h than the others(P<0.01).However,the differences in the absorbance between the fractions and commercial antioxi-dants,␣-tocopherol and BHA,also increased as incubation continued.Different from the FTC test,which is related to the per-oxide formation in the initial stage of lipid oxidation,the TBA test measures the amount of malondialdehyde(MDA) produced after the decomposition of the lipid peroxide dur-ing the oxidation process.MDA is a very unstable com-pound causing mutagenic and cytotoxic events(Zin et al., 2002).At a low pH and high temperature(100◦C),MDA binds TBA to form a red complex that can be measured at Table1Extraction yields and phenolic contents of each fraction from petroleum ether extract of Platycodon grandiflorumFraction Yields(g/g)a Total phenolic content(mg/g)b I(9:1)0.33 1.66±0.42II(8:2)0.11 4.80±0.26III(7:3)0.26 2.91±0.24IV(6:4)0.05 3.45±0.17V(5:5)0.02 3.79±0.10a g fractions/g solids of petroleum ether extracts.b g total phenolic/g fractions:Ferulic acid equivalents(mean±S.D.; n=3).412J.-Y.Lee et al./Journal of Ethnopharmacology 93(2004)409–41500.51244872Time (h)A b s o r b a n c e a t 500 n mFig.1.Absorbance of the fractions (F )from Platycodon grandiflorum by FTC method with increasing incubation time,compared with BHA and ␣-tocopherol (mean ±S.D.;n =3).532nm after incubation for 72h.The results from the TBA test (Fig.2)strongly correlated with the FTC data,and most fractions,except for fraction I ,showed a significantly lower absorbance than the control (P <0.01).However,in the FTC test,fraction II ,III and V showed significantly higher inhibition activities than ␣-tocopherol (P <0.01),and frac-tion II was second only to BHA in activity.Therefore,from the results of both tests,fraction II was the mosteffective in inhibiting the lipid peroxidation than the other separated0.10.20.30.40.50.60.70.8Control CrudeF IF IIF IIIF IVF VBHAToco-pherolA b s o r b a n c e a t 532 n mFig.2.Absorbance at 532nm of the fractions (F )from Platycodon grandiflorum extract by TBA method,compared with BHA and ´a-tocopherol (mean ±S.D.;n =3).fractions,which was slightly lower than the activity of BHA.The slightly higher value of fraction I than the control in the TBA test (P <0.05)was expected from the co-oxidation of oil or fat,which may have been eluted early from the silica gel column.3.3.Scavenging activity of free radicalFree radicals are known to be a major factor in bio-logical damages,and DPPH has been used to evaluate the free radical-scavenging activity of natural antioxidants (Yokozawa et al.,1998;Zhu et al.,2001).DPPH,which is a radical itself with a purple color,changes into a stable compound with a yellow color by reacting with an antioxi-dant,and the extent of the reaction depends on the hydrogen donating ability of the antioxidant (Bondent et al.,1997).Fig.3A shows the DPPH free radical scavenging activity of each fraction at three different concentrations,50,100and 200␮g/mL.All the fractions showed dose-dependant increase in activity.Fraction II exhibited the strongest an-tioxidant activity in accordance with the other tests (P <0.01),and the activities decreased in the order of fraction III >crude >V >I >IV at a concentration of 200␮g/mL.The IC 50of fraction II for the DPPH radical scavenging activity was calculated to be approximately 130g/mL.Since fraction II had the highest antioxidant activ-ity in the three antioxidant activity tests,it was further sub-fractionated by TLC.Five different spots from frac-tion II were detected under the short and long wavelength of UV light,and showed different colors by H 2SO 4:R f =0.45(yellow-brown),0.56(violet),0.64(green-yellow),0.68(dark brown)and 0.81(brown)for sub-fraction II-1,2,3,4and 5,respectively.From a rapid DPPH test on the TLC plate,all the sub-fractions,except for II-5,showed a bright yellow color,and in particular,sub-fraction II-2had a relatively stronger free radical scavenging activityJ.-Y.Lee et al./Journal of Ethnopharmacology93(2004)409–415413Fig.3.DPPH free-radical scavenging activity(%)of each fraction(F) with increasing concentrations(A),and of the sub-fractions(SF)isolated from fraction II(B)compared with BHA and␣-tocopherol(mean±S.D.;n=3).than the other sub-fractions.Since it was reported that the antioxidant activity of a plant extract often originates from phenolic compounds(Velioglu et al.,1998;Amarowicz et al.,2000),a phenolic spot test was performed directly on the TLC plate.Similar to the previous phenolic test re-sults of fraction II,sub-fraction II-2showed a strong blue color,indicating that it has a high concentration of phenolic compounds which are responsible for its high antioxidant activity.According to the results of analytical TLC,all thefive sub-fractions were obtained using preparative TLC,and the DPPH free radical scavenging activities of the sub-fractions were measured quantitatively(Fig.3B).The radical scaveng-ing activity of sub-fraction II-2was significantly stronger than those of the other sub-fractions and␣-tocopherol,but was still lower than that of BHA(P<0.01).However,con-sidering that the sub-fraction is not a pure compound,the active compound can be expected to be comparable to the strong antioxidant,BHA.3.4.Cytotoxicity activity on cancer cellsThe anticancer activities of the Platycodon grandiflorum extracts and its fractions were investigated using a MTT assay on three human cancer cell lines,HT-29,HepG2 and HRT-18.A mitochondrial enzyme in living cells, succinate-dehydrogenase,cleaves the tetrazolium ring,con-verting the MTT to an insoluble purple formazan.Therefore,Fig.4.Cytotoxicity of each fraction(F)(300␮g/mL)on three human can-cer cells(HT-29,HRT-18and HepG2)(A),and of the sub-fractions(SF) from fraction III on human colon cancer cells(HT-29)with increasing concentration(100and200␮g/mL)(B)after24h incubation,measured by MTT test(mean±S.D.;n=4).the amount of formazan produced is directly proportional to the number of viable cells(Mosmann,1983).Fig.4A shows that fractions II,III and V significantly inhibited cancer cell growth at a concentration of300␮g/mL(P< 0.01),and in particular fraction III exhibited the highest cytotoxicity(>50%)in all three cell lines.Among the cell lines,the cytotoxic susceptibility to fraction III was greater in the HepG2(69.1±0.52%)than in HT-29(53.0±2.22%)or HRT-18(56.2±0.50%)cells(P<0.01),but this difference was not as significant for the other fractions.The significant negative activities(P<0.01)of some fractions to specific cell lines means that they increased the growth rate of cancer cell,but more confirmative studies will be needed in the future to confirm this.Fraction III was also examined by analytical TLC, and six sub-fractions were obtained by preparative TLC (III-1–III-6).The anticancer activities of the sub-fractions were assayed using one of the cell lines previously used, HT-29,at a concentration of100and200␮g/mL after24h incubation.As shown in Fig.4B,sub-fractions III-1and III-2had a significantly higher cytotoxicity on HT-29than the other sub-fractions(P<0.01),in a dose-dependent man-ner.The estimated IC50for the cytotoxicity of sub-fractions III-1and III-2were approximately340and390␮g/mL, respectively.The UV absorbance spectra of sub-fractions III-1and III-2revealed that they have a similarλmax at 238,253,268and283nm,which is a typical spectrum for the diyn-ene chromophore of polyacetylene.Polyacetylenes414J.-Y.Lee et al./Journal of Ethnopharmacology93(2004)409–415found in ginseng(Matsunaga et al.,1990)and other medic-inal plants(Jung et al.,2002)have been reported to exhibit anticancer activity.A few polyacetylene compounds have also been reported from the Platycodon grandiflorum or-ganic extracts(Tada et al.,1995),but they are believed to be different from the polyacetylene in this study because of the different UV spectra.4.ConclusionThe petroleum ether extract of Platycodon grandiflo-rum was confirmed to exhibit antioxidant and anticancer activities.The lipid peroxidation and free radical scav-enging assays on the fractions from the silica gel column and TLC suggest that the antioxidant active and proba-bly phenolic compound in this study has a high activity, which is comparable to BHA.Their MTT assay revealed that Platycodon grandiflorum also contains a strong poly-acetylenic anticancer compound,which exhibited cyto-toxicity on the three human cancer cell lines.However, further studies will be needed to identify the exact molec-ular structures of both the antioxidant and anticancer 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Non-invasive prenatal testing for Down syndromePhilip Twiss a,Melissa Hill a,Rebecca Daley a,Lyn S.Chitty a,b,*a NE Thames Regional Genetics Service,Great Ormond Street Hospital for Children NHS Foundation Trust,37Queen Square,London WC1N3BH,UKb UCL Institute of Child Health,30Guilford Street,London WC1N1EH,UKKeywords:Cell-free fetal DNADown syndromeFetal aneuploidyNon-invasive prenatal testing Prenatal diagnosis s u m m a r yPrenatal screening and diagnosis of Down syndrome and other major aneuploidies may be transformed following the identification of cell-free fetal DNA in maternal plasma at the end of the last millennium. Next generation sequencing has enabled the development of tests that accurately predict the presence of fetal trisomies by analysis of cell-free DNA in maternal blood from as early as10weeks of gestation. These tests are now widely available in the commercial sector but are yet to be implemented in publicly led health services.In this article we discuss the technical,social,and ethical challenges that these new tests bring.Ó2013Elsevier Ltd.All rights reserved.IntroductionDown syndrome(DS)or trisomy21is the most frequently observed aneuploidy associated with long-term survival,with an incidence of1in800live births.Antenatal screening for DS is routinely offered to all pregnant women in the UK and many parts of the developed world.This is usually performed using a combi-nation of maternal age,ultrasound,and maternal serum bio-markers to estimate a pregnancy-specific individual risk of carrying a DS fetus[1].Traditionally,definitive diagnosis in pregnancies identified as being at high risk is then offered by amniocentesis or chorionic villus sampling(CVS),both of which are invasive pro-cedures and have miscarriage risk rates of around0.5e1%[2].Over the last few decades research has focused on identifying a less invasive approach to prenatal diagnosis.This was initially based on the isolation of fetal cells in the maternal circulation[3]but, following the identification of cell-free fetal DNA(cffDNA)in maternal plasma[4],efforts to develop non-invasive prenatal testing(NIPT)turned towards the analysis of cell-free DNA(cfDNA) [5].Cell-free fetal DNA is a useful potential source of fetal genetic material to use for prenatal diagnosis as it is present in the maternal circulation from early in pregnancy and is rapidly cleared from maternal plasma shortly after delivery[6],making it pregnancy specific.However,the majority of cell-free DNA in a mother’s blood is maternal in origin[7],which makes analysis of cffDNA challenging.Early clinical applications for cffDNA included the polymerase chain reaction(PCR)-based detection or exclusion of paternally inherited alleles for fetal sex determination in preg-nancies at high risk of sex-linked genetic disorders[8],fetal RHD typing in RhD-negative mothers[9]and,more recently,for the diagnosis of some single gene disorders,which have arisen de novo or are paternally inherited[10,11].NIPT for DS poses different challenges because of the high background levels of maternal chromosome21cfDNA.It is not feasible to use the PCR methods described above,as these are not sufficiently sensitive to detect the relatively small changes in level of chromosome21when the fetus has DS as most of the cfDNA is maternal in origin.Detection and quantification of this small dif-ference requires either the analysis of targets that are free from maternal background interference,i.e.are fetal specific,or the use of technologies that enable extremely accurate copy number ‘counting’.Initial attempts at NIPT for DS targeted a fetal-specific marker in mRNA in maternal plasma rather than cffDNA.This approach was based on testing cell-free mRNA from PLAC4,a gene located on chromosome21,which is expressed in the placenta but not in maternal blood(i.e.it is fetal specific)[12].By extracting cfRNA(rather than cfDNA)from maternal plasma and testing a single nucleotide polymorphism(SNP,a common sequence varia-tion found in the normal population)located in the PLAC4fetal mRNA sequence,the chromosome21allelic ratio was determined to infer chromosome21dosage[12].Named the‘RNA-SNP’method, this represented thefirst demonstration of NIPT for DS,achieving a sensitivity and specificity of90%and96.5%,respectively.However, a major drawback to SNP-based approaches is the reliance on polymorphisms within the DNA carrying the placenta-specific expression,thus limiting their use to families where parents carry*Corresponding author.Address:NE Thames Regional Genetics Service,York House,37Queen Square,London WC1N3BH,UK.Tel.:þ44(0)2078138533.E-mail address:l.chitty@(L.S.Chitty).Contents lists available at ScienceDirectSeminars in Fetal&Neonatal Medicine journal h omepage:w ww.el /locate/siny1744-165X/$e see front matterÓ2013Elsevier Ltd.All rights reserved./10.1016/j.siny.2013.10.003Seminars in Fetal&Neonatal Medicine19(2014)9e14different alleles and whose fetuses are therefore heterozygous.For the PLAC4RNA-SNP method this was estimated to apply to around 40%of pregnancies [12],rendering this approach impractical for routine clinical use.Alternative approaches to NIPT for DS have been based on epigenetic differences between the maternal and fetal DNA,fetal DNA from the placenta being hypermethylated compared to maternal DNA,which is hypomethylated.The basis of this approach is that by using methylation-sensitive restriction enzymes,hypo-methylated maternal sequences can be digested leaving only hypermethylated fetal sequences available for analysis by real-time PCR.Papageorgiou and colleagues published a set of fetal-speci fic epigenetic markers for all common aneuploidy chromosomes [13],and subsequently reported accurate NIPT for DS using meth-ylated DNA immunoprecipitation (MeDIP)real-time PCR [14].However,to date no large-scale validation study has been reported using this method.Hypermethylation of the HLCS gene promoter on chromosome 21has also been successfully reported for NIPT of T21by comparing to dosage of the ZFY gene.However,this test is restricted to male-bearing pregnancies [15].NIPT based on differ-ential methylation has yet to find a place in clinical practice,not least because the use of epigenetic markers is limited by relatively labour-intensive and time-consuming bisulphite conversion or re-striction enzyme digestion,making them less practical for use in a routine service laboratory.The introduction of technologies such as digital PCR (dPCR)and next generation sequencing (NGS)have enabled accurate estima-tion of very small differences in chromosome-speci fic sequences in maternal blood,thus delivering an approach to NIPT that can be used in clinical practice.Non-invasive prenatal testing for DS using NGSTwo seminal proof-of-principle experiments published in 2008[16,17]demonstrated that massively parallel shotgun sequencing (MPSS)of cfDNA in maternal plasma had the potential to be an effective method for fetal T21detection.In brief,whole genome cfDNA extracted from maternal plasma is sequenced to generate millions of short sequence reads or ‘tags ’.These tags are then aligned and uniquely mapped to the reference human genome sequence.Individual uniquely mapped reads to chromosome 21are then counted,and compared to the number of counts obtained from a reference euploid sample.Fan et al.[16]successfully clas-si fied all nine trisomy 21cases in a cohort of 18samples,and Chui et al.[17]correctly detected all 14T21cases in a cohort of 28,with neither study producing false-positive results.Other groups havereproduced these findings in large validation studies (Table 1)with similarly high detection levels across a range of sequencing in-struments and chemistries,using a variety of bioinformatics algo-rithms to open the door to the wider application of NGS for the NIPT of DS [18e 28].Two approaches to NIPT for DS using NGS are now in common use in the USA,Asia,and some parts of Europe [29].The first uses the whole genome MPS approach described above (Table 1),which requires sequencing of many millions of DNA fragments in order to generate suf ficient reads to detect differences in level of reads from chromosome 21,which constitutes around 1.5%of sequenced fragments.The alternative approach has been to target the sequencing to selected genomic loci on the chromosome of interest,e.g.chromosome 21for NIPT for DS (Table 1)[30e 36].This signif-icantly reduces the amount of sequencing required and is primarily aimed at reducing costs while increasing throughput and test performance.Regardless of the approach taken,the sensitivity and speci ficity of these methods are high,ranging from 98.6to 100%and from 99.7to 100%,respectively (Table 1).False-negative results may be related to low fetal fraction of cffDNA and have been shown to be more common in obese women [37,38],where it is thought that there is a higher than average level of circulating maternal cfDNA because of increased release of cfDNA from adipose tissue.The small,but regularly reported,false-positive rate results from a variety of factors and re flects the fact NIPT analyses both maternal and fetal cfDNA,and that the cffDNA emanates from the placenta.Thus,the aetiology of reported discordant results includes con fined placental mosaicism [39,40],maternal chromosome abnormalities [41],and the presence of maternal malignancy [42].NIPT for other common chromosomal abnormalitiesNIPT for other common aneuploidies,trisomies 13and 18,have been reported with lower detection rates,which some reports suggest is because of the larger chromosome size and higher GC content [20,28,31e 33,43].Combined data from five studies report a sensitivity of 97.4%(188/193)for trisomy 18(Edwards syndrome)[20,28,31e 33].However,only three of these studies [20,28,43]include data for trisomy 13(Patau syndrome)and report a lower sensitivity of 83.3%(30/38).However,more recent studies report improved detection rates [22,23],although the outcome data are not always reported in detail.False-positive rates are broadly similar,with trisomy 18being consistent with those seen for tri-somy 21,and slightly higher for NIPT of trisomy 13(0.41%),but as the numbers reported are small,it is dif ficult to draw de finitive conclusions at this time.Table 1Studies reporting the use of next generation sequencing for non-invasive prenatal testing for Down syndrome.Type of approachTest results Sensitivity Speci ficity TPFN TN FP Total %95%CI %95%CI MPS whole genome Enrich et al.[18]390409144910089e 10099.798.5e 99.9Palomaki et al.[19]209314683168398.695.9e 99.599.899.4e 99.9Bianchi et al.[20]890404049310095.9e 10010099.1e 100Dan et al.[21]139028191295910097.3e 10099.9699.8e 99.99Futch et al.[22]154255151567298.795.5e 99.799.9899.9e 100Liang et al.[23]400372041210091.2e 10010098.98e 100Targeted MPSSparks et al.[30]390252029110091.0e 10010098.5e 100Sparks et al.[31]360123015910090.4e 10010097.0e 100Ashoor et al.[32]500297034710092.9e 10010098.7e 100Norton et al.[33]81028871296910095.5e 10099.9799.8e 99.99Nicolaides et al.[34]8019390194710067.6e 10010099.8e 100Zimmerman et al.[35]110126013710074.1e 10010097.0e 100Nicolaides et al.[36]2519722210086.7e 10010098.1e 100TP,true positive;FN,false negative;TN,true negative;FP,false positive;CI,con fidence interval;MPS,massively parallel sequencing.P.Twiss et al./Seminars in Fetal &Neonatal Medicine 19(2014)9e 1410Transition to clinical practiceThe series of successful validation studies has paved the way for the clinical implementation of NIPT for DS.However,the low false-positive rate means that NIPT is not considered fully diagnostic and is considered to be a highly accurate screening test where invasive testing is recommended to confirm a positive NIPT result[44,45]. Nonetheless,the clinical implementation of NIPT for DS has moved rapidly,being wholly commercially driven.It wasfirst launched through commercial providers in the USA and China/Hong Kong in 2011.Other companies have been quick to follow and several different providers are currently offering tests for trisomies21,18, 13and sex aneuploidies,with more companies likely to enter the market in the near future[46].Currently,NIPT is only available in the private sector in most countries,with public sector imple-mentation awaiting further evaluation in medium or low-risk pregnancies.There is ongoing debate as to how NIPT may bestfit into existing care pathways for the routine screening and diagnosis of DS.The initial validation studies were performed in high-risk populations,and the current approach supported by a variety of professional bodies worldwide is to offer NIPT to women consid-ered at high risk because of past history or other screening results. Studies showing clinical efficacy in average and low-risk pop-ulations are now being published[34],which may influence de-cisions on implementation,including whether NIPT should be offered as afirst-line screening test to all pregnant women,thus replacing current screening,or as a second tier screening test, contingent on the results of a traditional screening test.Regardless of the ultimate method of delivery,for national-or state-based prenatal screening programmes,consideration needs to be given to issues such as accuracy in the population being tested,test up-take,costs and benefits derived from existing care pathways,and maintenance of informed parental choice[47].Counselling issuesRegardless of potential changes in the care pathway,in view of the false-positive rate described above,those offering post-test counselling following positive results should ensure that the need for a confirmatory invasive diagnostic test is discussed.Interpre-tation of results in the absence of definitive confirmation by traditional testing of amniocytes or chorionic villi obtained after amniocentesis or chorionic villus sampling may be complicated, particularly in the absence of ultrasound abnormalities indicative of the specific chromosomal abnormality in question.Economic considerations for implementationCost is a major factor in determining how NIPT shouldfit into existing care pathways,especially for state-funded healthcare systems.Several studies have undertaken model-based cost and outcome analyses of offering NIPT in a variety of ways from both a US[28,48e51]and UK[52,53]perspective.Morris et al.[52]have evaluated NIPT as a contingent screening test and as afirst-line screening test with reference to current screening pathways in the UK’s National Health Service(NHS).Contingent screening gave favourable clinical outcomes in terms of the number of DS cases detected and fewer procedure related-miscarriages.It was also cheaper than existing pathways if NIPT was to cost less than£500. When used as afirst-line test,NIPT detects more cases of DS and has fewer procedure-related miscarriages,but it is considerably more expensive than current screening even if NIPT was to cost just £50.Other studies have also favoured contingent screening in terms of costs,cases detected,and miscarriages avoided compared to first-line testing,leading to suggestions that contingent screening is an appropriate approach until costs of NIPT fall[28,48,51,53]. However,an accurate evaluation of economic costs and benefits not only depends on the cost testing and mode of implementation,but also on the uptake of,and reasons for,testing and thus further evaluation following implementation is required.Uptake of NIPT for DSNIPT reduces the risk of miscarriage associated with invasive diagnostic testing,and this is reported by women to be one of the greatest advantages of NIPT.Studies based on hypothetical sce-narios of offering NIPT for DS have indicated that uptake will be high[54],and are likely to be significantly greater than the uptake of current of DS screening and invasive testing.It is also clear from some of these studies that an additional group of women,who would decline current screening and diagnosis because of the risk of miscarriage,will undergo NIPT to plan and prepare for the birth of an affected child.Both uptake and clinical utility will clearly influence the economic aspects of implementation.Thefirst reports of clinical experience and uptake following the implementation of NIPT in the private sector in the USA are now beginning to appear [55e57].These confirm the positive attitude towards NIPT,but they indicate that uptake is not as great as hypothetical studies have suggested[55e57].It appears that cost was an important factor in test uptake in all studies,as insurance coverage is variable;some people had out-of-pocket expenses for NIPT but not other types of testing[55e57].Other factors thought to contribute to NIPT uptake in these studies include having certainty and additional informa-tion from invasive testing(e.g.pathogenic chromosomal rear-rangements,microdeletions,etc.),later gestational age at the time of being offered the test,ethnic background,and opportunities for ultrasonography[55,56].Potential impact of patents and licensingPatents and licensing is a complex and contentious area for NIPT implementation that has yet to be resolved,but which may impact significantly on both the cost and type of NIPT offered.There are more than100patents and applications relating to cffDNA testing, with the basic technologies for isolating and genetic analysis of cffDNA being patented or licensed to just a small number of com-panies or institutions[46].Several lawsuits are currently in prog-ress regarding enforcement and infringement of patents and licensing,and until these are resolved it is difficult to assess what the impact will be.If the current claims are upheld and a single company holds all intellectual property relating to NIPT,there are concerns that costs of tests will increase,access to alternative tests will be limited,test improvement and quality assurance measures will be restricted,and that there will be obstacles imposed on research and development.All of this could result in reduced quality of care for patients and limitations on access to tests[46].A detailed explanation of the commercial and patenting issues is beyond the scope of this review,but Agarwal et al.[46]provide an overview of the patenting landscape in the USA.Formal regulation and guidance of testing is essential for successful implementationIn their recent review,Hahn et al.[58]suggest that the imple-mentation of NIPT through multiple companies competing for marketplace share raises concerns that NIPT has come into practice too rapidly and that appropriate safeguards for accuracy,clinical utility,and patient awareness have not been met.Guidance for of-fering prenatal testing and regulation of laboratories conducting NIPT will vary widely between countries.Formal guidance fromP.Twiss et al./Seminars in Fetal&Neonatal Medicine19(2014)9e1411professional bodies and other expert groups has an important role to play in the successful and ethically sound implementation of NIPT [59].Health professionals in both the USA[60]and the UK[61]are reported to value formal guidance on how best to offer NIPT.There is some evidence that,although implementation of NIPT has been driven by commercial providers,guidance from professional bodies has played a major part in how testing has been implemented, particularly in the USA[62].For example,guidelines describing NIPT as an advanced screening test that needs to be confirmed by invasive testing and support for tests being offered through health care providers to promote informed choice[44,45]are being upheld by commercial companies offering NIPT in the USA.Addressing ethical issues through appropriate counselling and supportThere is ongoing debate about how best to circumvent key ethical concerns associated with offering NIPT,including difficulties facilitating informed choice,increased pressure to take up prenatal testing,and equity of access[63,64].Concerns around informed choice are not new for prenatal testing for DS,as research indicates that women do not always make informed decisions when un-dergoing screening[65].However,it has been suggested that because NIPT for DS generates a highly accurate screening result,it is especially important that we address this issue and ensure that informed consent is obtained through detailed pre-test counselling [64].Yet,two of the key clinical benefits of NIPT e that it is easy to perform and that it carries no risk of miscarriage e are also the factors that make offering NIPT susceptible to difficulties in safe-guarding informed choice.For example,parents may not give full consideration to the implications of results,as NIPT is‘just a blood test,’[63]especially if it is offered as one of many other antenatal blood tests.Similarly,without the miscarriage risk,parents may see no downside to testing,and NIPT could be viewed as routine or expected[63],which makes the possibility of informed decisions less likely than when tests are viewed as optional[65].There is also evidence that both health care professionals and women view NIPT much more like a screening test than an invasive test in terms of a need for written consent or time for reflection about testing,and consequently both parties may be less concerned about reaching informed consent than they would with an invasive diagnostic test.Increased societal pressure for testing and termination as tests become easier to access,safer,and easier to perform is a concern that has been raised by health care professionals,pregnant women,and the general public[54].There is also concern that any increases in testing and terminations from NIPT have the potential to result in a reduction in support structures for children with disabilities and a society that may be less tolerant in their attitudes to people who have children with DS[54],all of which have the potential to result in women feeling more pressure to undertake testing.In addition, without the risk of miscarriage women may feel they cannot justify their decision not to have a test,and clinicians need to be sensitive and aware that some women will prefer not to have prenatal testing.Another issue of major concern is equity of access.In the USA, the costs of NIPT are highly variable and coverage by insurers dif-fers,so out-of-pocket expenses vary widely.In the UK’s private sector the cost of NIPT is also variable.This is a major drawback of testing being offered solely through commercial providers,as the associated costs prevent equity of access with low-income families being unable to afford testing[46].ConclusionsThere is no doubt that NIPT for DS and other major trisomies is highly accurate when using NGS.NIPT is currently restricted to the major trisomies and sex chromosome anomalies.Recent reports of the detection of subchromosome abnormalities[66,67]indicate that it may become more comprehensive over time,particularly as sequencing costs fall.Current application is limited to the private sector,but it is hoped that more widespread implementation into public sector health care will follow soon.Many thousands of tests have now been carried out across the globe and factors affecting test performance are becoming clearer.What is certain is that routine implementation of NIPT will require health care profes-sional and patient education,with new strategies for pre-and post-test counselling in order to maintain ethically-sound levels of informed parental choice and to ensure that parents understand the implications and limitations of results and have personalised support and information for making decisions about the next steps.NIPT is an exciting and rapidly developing area which is set to transform antenatal care.The challenge now is to translate this technology into an accurate and affordable test that can be made available to all women within current healthcarebudgets.P.Twiss et al./Seminars in Fetal&Neonatal Medicine19(2014)9e14 12Conflict of interest statementNone declared.Funding sourcesP.T.is funded by the NIHR Biomedical Research Centre at Great Ormond Street Hospital,and L.S.C.is partially funded by the Great Ormond Street Hospital Children’s Charity and the NIHR Biomed-ical 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extraction 翻译"Extraction"翻译成中文可以是"提取"或"萃取"。

以下是一些关于"extraction"的用法和中英文对照例句：1. Chemical Extraction: 化学提取- The chemical extraction process involves extracting the desired compound from a mixture using solvents. (化学提取过程涉及使用溶剂从混合物中提取所需的化合物。

)2. Data Extraction: 数据提取- The software allows for easy data extraction from various file formats. (该软件可以轻松从不同的文件格式中提取数据。

)3. Tooth Extraction: 牙齿拔除- The dentist recommended tooth extraction to address the severe tooth decay. (牙医建议拔除牙齿以解决严重的蛀牙问题。

)4. Oil Extraction: 石油提取- The country relies heavily on oil extraction as a major source of revenue. (该国在石油提取方面依赖较重，作为主要的收入来源。

)5. DNA Extraction: DNA提取- The scientist developed a new method for DNA extractionfrom blood samples. (科学家开发了一种从血样中提取DNA的新方法。

)6. Extraction of Resources: 资源开采- The extraction of natural resources can have both positive and negative impacts on the environment. (资源开采对环境既有积极的影响，也有负面的影响。