||
“方法”部分应包含足够的信息以供其他研究者准确重复你描述的试验;如果其中有关键信息遗漏,别人就无法完全重复你的实验条件;这会引起结果不一致,有可能造成误会,甚至还会被人指责造假。所以“方法”部分要力求全面。
“方法”部分应该使用过去时态,例如:“sections were stained with…” and “data were analyzedusing…”。但是在提及图表时应使用现在时,例如:“The patients’ clinical characteristics arelisted in Table 1”。 此外,当你在叙述某个事物的定义或当前对它公认的看法时也要用现在时,例如:“the cells weresubjected to hypoxia, which induces HIF-1expression…”。这句话中,虽然实验部分是用的过去时,但由于缺氧(hypoxia)导致HIF-1是一个普遍现象而不是限定于本文的结果,因此后面半句应该用现在时。
要列出所有试剂的供应商以及设备的厂家;有的期刊还要求列出其地址,即国家、州(如为美国)和市。叙述设备、试剂盒、试剂的时候应该用常用术语来具体描述,不要只用厂商的专门术语或只写型号。比如,不要写成:“Absorbance in each well was measured at a wavelength of 492 nm usinga Beckman Coulter AD 340C”,因为大多数人都对Beckman Coulter AD340C没有任何概念;应该写成:“Absorbance in each well was measured at a wavelengthof 492 nm using a multi-well plate reader (AD 340C, BeckmanCoulter)”,或者“Absorbance in each well was measured at a wavelength of492 nm using an AD 340C multi-well plate reader (Beckman Coulter Inc,Fullerton, CA, USA)”。
“方法”部分只能包括最终得出结果的实验方法。如果某个试验失败了或者没能提供你需要的结果,而且你已经决定论文中不提这些结果,那么也没有必要去谈其试验方法。用适当的子标题把各种不同目的的材料和方法分类。如果期刊设有“补充方法”(SupplementaryMethods)部分,则可用这部分来详述细节,并让纸面刊出的“方法”部分保持简短。新方法应该详细叙述以便他人重复;标准和常用技术只须引用文献即可,但如果你的方法和文献有差异之处应予说明。尤其要保证所有单位都正确,实验条件(如时间、温度)都清楚。最后,如果开展了统计学分析来评价研究结果的意义,则应在“方法”的最后一段叙述你的统计学方法,包括所选择的显著性阈值。
实例
“…homogenates were spun at 10,000 × g and 4 °C for 12 min”
这句话包含了时间、温度两个重要细节。而:
“…homogenates were spun at 10,000 × g” 和更简化的 “homogenates were centrifuged”
两个句子中就遗漏这些细节。这些细节有可能对得到你的结果很重要,所以应该给出。
同理,不要只写:“Then, 10 μl of a propidium iodide solution was added to thecells”,因为这对读者毫无意义,除非他们知道该溶液的浓度。应该写成:“Propidium iodide was added to thewells to a final concentration of 0.5 μg/ml”。
下图节选自《The Journal of Clinical Investigation》所发表的一篇论文(doi:10.1172/JCI37155;经同意转载)的方法部分。它显示了“方法”部分的各种要素以及他们如何组合的。
核查清单
1. 用清楚的子标题列出用于不同目的的方法和材料。
2. 研究方法用过去时。
3. 新方法给出充足的细节以便他人重复。
4. 已有方法可用参考文献。
5. 写明厂家/供应商,必要时应提供地址。
6. 说明所采用的统计学方法。
英文原文
Methods: what you did
Themethods section of your manuscript should contain sufficientinformation for a capable researcher to accurately repeat theexperiments you describe; if essential information is left out, theexact conditions might not be replicated, leading to different results,potential misunderstandings, or worse, accusations of falsification.Thus, the methods section needs to be comprehensive.
The methodssection should be written in the past tense; for example, “sectionswere stained with…” and “data were analyzed using…”. An exception tothis is references to tables or figures in the manuscript, for example“The patients’ clinical characteristics are listed in Table 1”. Anotherexception is when providing a definition or describing the currentconsensus on something: for example, “the cells were subjected tohypoxia, which induces HIF-1 expression…”. Here, although what was doneis described in the past tense, the fact that hypoxia induces HIF-1 isdescribed in the present tense because it is a general phenomenon notlimited to the present paper.
The suppliers of all reagents andthe manufacturers of all equipment used should be listed; some journalsalso request that the locations, that is, city, state (if in the USA)and country, of these companies are provided. When describingequipment, kits, or reagents, you should use familiar terms to definethe particular item you are describing, rather than just amanufacturer-specific term or model number. For example rather thanwriting “Absorbance in each well was measured at a wavelength of 492 nmusing a Beckman Coulter AD 340C”, which would be meaningless to themajority of readers, you should write “Absorbance in each well wasmeasured at a wavelength of 492 nm using a multi-well plate reader (AD340C, Beckman Coulter)” or perhaps “Absorbance in each well wasmeasured at a wavelength of 492 nm using an AD 340C multi-well platereader (Beckman Coulter Inc, Fullerton, CA, USA)”.
Methodsshould only be included if the results of the described experiments areprovided; if an experiment you performed didn’t work, or didn’t providethe results you needed, and you have opted to leave the results out ofyour paper, then there is no need to describe the associated methods.Use appropriate subheadings to separate materials and methods withdifferent purposes. If available, use a Supplementary Methods sectionto provide detailed information so that the printed methods section canbe kept brief. Novel techniques need to be described in detail so thatthey can easily be replicated, but established and commonly usedtechniques can be referenced as long as any variations between themethod used in the present study and that described in the cited studyare clearly described. Above all, be precise and ensure that all unitsare correct and all conditions (for example, times and temperatures)are clear. Finally, if any statistical analysis was performed to assessthe significance of your data, describe the statistical methods used,including the threshold(s) selected for significance, at the end of themethods section.
Examples
The sentence “…homogenates werespun at 10,000 × g and 4 °C for 12 min” includes the important detailsof time and temperature that would have been missing if the authorsimply wrote “…homogenates were spun at 10,000 × g”, or even moresimply “homogenates were centrifuged”. These details could have beenessential to obtaining the result you did, and so should be explained.
Similarly,rather than saying “Then, 10 μl of a propidium iodide solution wasadded to the cells”, which is meaningless unless the reader knows theconcentration of the propidium iodide solution, you should write“Propidium iodide was added to the wells to a final concentration of0.5 μg/ml”.
The figure below, showing a couple of excerpts from themethods section of paper published in The Journal of ClinicalInvestigation (doi:10.1172/JCI37155; reproduced with permission),indicates the important components of a methods section and how thesefit together.
Checklist
1. Clear subheadings for methods/materials with differentpurposes, with materials described first
2. Methods described in past tense
3. Novel methods described in full detail, sufficient for acapable researcher to reproduce
4. Established methods referenced to previous literature
5. Suppliers/manufacturers provided, including locations ifrequested
6. Statistical methods described
Dr Daniel McGowan
分子神经学博士
理文编辑学术总监
Archiver|手机版|科学网 ( 京ICP备07017567号-12 )
GMT+8, 2024-9-1 08:48
Powered by ScienceNet.cn
Copyright © 2007- 中国科学报社