文章的introduction是作为全文的开头部分，从论文读者角度它是读者最先看到的部分；从编辑和审稿人角度看，它能让编辑和审稿人更进一步了解文章研究意义。
在著名的杂志Science官网我们可以看到它对于introduction的要求如下：
它这段话可以浓缩为两点：清楚易懂（intelligible）和研究意义（significance），即introduction部分既要写得清楚易懂，逻辑通顺，又要展示出研究的意义和重要性。在写introduction之前，需要确定的两点是：1. 工作的创新点是什么？这是一个introduction重中之重的部分。只有确定了这点，才可以着手准备写。可以说这也是决定了文章档次的部分。2. Introduction 的逻辑需要用一个大致的提纲来确定。大家不要小看这一步，因为打好提纲，再开始写作，可以极大减少写作的时间。建议大家每篇论文在写作之前都要仔细和导师谈论好这两点，再开始入手，这样可以节省很多前期写作和后期修改耗费的时间。1. 在阐明工作创新点的时候，要紧紧围绕过去研究的缺陷性来描述，清晰而完整地描述自己的解决思路。2. 在提出自己观点的时候，通常需要介绍到别人工作。而这里需要客观公正地评价别人的工作。千万不要把抬高自己研究的价值建立在贬低别人的工作之上，这是SCI论文的写作中最忌讳的，也是最容易犯的错误。3. 要注意文章的论点不要太大太广，只需要抓住其中一个点来深入阐述即可。论述的面太广会让审稿人找不到重点，从而文章的重点就不够突出，每个问题的阐释也很难全面。事实上一个可以清楚地解决目前研究中任何一个问题的工作，就是一篇极好的SCI论文。这篇是新英格兰发表的第三代ALK抑制剂劳拉替尼（Lorlatinib）与第一代ALK抑制剂克唑替尼（crizotinib）治疗晚期ALK阳性的非小细胞肺癌的疗效对比的III期临床试验结果，该研究结果显示，劳拉替尼相比于克唑替尼治疗晚期ALK阳性的非小细胞肺癌具有更好的无进展生存期和更好的颅内治疗反应。Chromosomal rearrangements involving the anaplastic lymphoma kinase (ALK) gene define a subset of non–small-cell lung cancers (NSCLCs) that are highly sensitive to small-molecule ALK tyrosine kinase inhibitors. （大背景：在肺癌治疗中ALK和ALK抑制剂是什么）One trial showed that the efficacy of the first-generation ALK inhibitor crizotinib as first-line therapy was superior to that of platinum–pemetrexed chemotherapy; this finding established crizotinib as a standard first-line treatment for advanced ALK-positive NSCLC. （既往研究回顾，第一代ALK抑制剂在治疗晚期ALK阳性非小细胞肺癌的意义）Subsequently, several randomized, phase 3 studies showed that more potent second-generation ALK inhibitors, including alectinib, brigatinib, and ensartinib, were superior to crizotinib as first-line therapy; these findings led to the adoption of second-generation inhibitors as standard first-line treatments. （第二代ALK抑制剂在治疗晚期ALK阳性非小细胞肺癌的意义）However, despite the improved efficacy of second-generation inhibitors, drug resistance and recurrent disease — including central nervous system (CNS) progression, a major cause of illness and death — still develop.（小背景：指出现有的问题所在，耐药和疾病复发，尤其是神经系统进展仍然是亟待解决的难题）
Lorlatinib (Pfizer) is a novel third-generation ALK inhibitor that is more potent than second-generation inhibitors in biochemical and cellular assays and has the broadest coverage of ALK resistance mutations that have been identified. （自然而然地既然有上述问题，第三代ALK抑制剂劳拉替尼就来了）Lorlatinib was designed to cross the blood–brain barrier in order to achieve high exposures in the CNS.（跨血脑屏障，为CNS进展而生，呼应以上难题）In phase 1 and 2 studies, lorlatinib had potent antitumor activity after the failure of previous ALK inhibitors (first-generation, second-generation, or both). （已经有了研究基础，1期和2期研究都发在柳叶刀肿瘤上，有兴趣的读者可以自己去查查）In particular, lorlatinib had marked intracranial activity in previously treated patients with baseline CNS disease, including leptomeningeal disease. （重要的研究结局告诉我们，颅内治疗反应很好）Because of its efficacy and safety, lorlatinib is a standard treatment option for ALK-positive patients in whom one or more ALK inhibitors have failed.（基于lorlatinib的优点，我们推荐用于相关患者的治疗）
The CROWN trial is a global, randomized, phase 3 trial comparing lorlatinib with crizotinib (the standard-of-care first-line treatment at the time of trial initiation) in patients with previously untreated advanced ALK-positive NSCLC. Here, we report the results of a planned interim analysis of the CROWN trial.（这段重申一下这次研究的目的和内容，报告这次三期临床的结果）A major current focus in __ is how to ensure sustainability of…__ 当前的一个主要重点是如何确保...的可持续性 Much research in recent years has focused on __ Analysis of change in __ is vital for two important reasons: …It is of interest to know whether __still hold true.The past decade has seen the rapid development of X in many ...The issue of__has received considerable critical attention.The importance of __has been demonstrated by…Evidence suggests that X is among the most important factors for ...02、早前、当前的研究贡献There is no previous research using __ approach.As far as we know, no previous research has investigated __There has been less previous evidence for __Other studies have failed to __To our knowledge, no study has yielded __No study to date has examined __Only a few studies have shown __However, __ has rarely been studied directly.
03、差距/疑问/难题/评论The main challenge faced by many experiments is the ...__ is one of the most frequently stated problems with ... __ is a major public problem, and the main cause of ...Unfortunately, these methods do not always guarantee… There remains a need for an efficient method that can…Although this approach improves performance, it results in an unacceptablenumber of…虽然这种方法提高了性能，但它导致了一个不可接受的…The function of__ remains unclear.However, the experimental configuration was far from optimal.With this aim in mind, in this paper we present a new method for __基于这一目的，我们在本文中提出了一种研究__的新方法。Our research aims at finding a solution for this challenging problem of__In this paper we present…New correlations were developed with excellent results…In the present study we performed…This paper introduces a scheme which solves these problems.The approach we have used in this study aims to…This study investigated the use of…