英语医学论文格式要求

英语医学科研论文的格式和要求
打开一本医学专业期刊，可以看到不同文体的文章。

除了综述(review)或述评（comments）、编者按（editorials）和个例报告（case reports）外，大量的是医学科研论文，即原始报告（original articles）。

医学科研论文有许多不同的类型，常见的有两大类：医学基础研究报告和临床研究报告。

I．格式
根据国际医学杂志编辑委员会 (The International Committee of Medical Journal Editors, ICMJE) 制定的《生物医学杂志投稿统一要求》（The Uniform Requirements for Manuscripts Submitted to Biomedical Journals, 5th Ed., 1997，URMSBJ）(国际——温哥华格式1979年创建, 2006年2月最新版本)
*, 一篇生物医学科研论文（以下简称"论文"）应包括以下12个部分：
1．标题（Title） 7．致谢（Acknowledgements）
2．摘要（Abstract）8．参考文献（References）
3．引言（Introduction）9．插图说明（Legends）
4．材料与方法（Materials and Methods ） 10．插图（Figures）
5．结果（Results）11．表格（Tables）
6．讨论（Discussion） 12．照片和说明（Plates and Explanations）以上除7、9、10、11、12部分因实际情况不需要外，其他各部分是一篇论文必不可少的内容。

下面分别介绍对各部分的基本要求，其中"标题"和"摘要"两部分将在以后单元另行讨论。

II．要求
1．标题
A. 标题的要求
Titles are to be written to be understood by those in your field, telling them exactly what you have done in your work.（告诉你的同行确切研究了什么）
要求：
（1） Short and concise（简明扼要）：Write in one line (not a sentence); not containing an active verb; not exceeding 25 words or 120-140 letters and spaces; no abbreviations or chemical symbols except those that are generally accepted, e.g. DNA, RNA, AIDS, CT, etc.; 中文标题常见的“试论”，“浅谈”，“初探”等词在英文标题中一般不用。

我国的国家标准（GB－7713－87）要求将一般英文标题的实词控制在10个词以内。

例：Association between Duration of Obesity and Risk of Non-insulin-Dependent Diabetes Mellitus 肥胖期与非依赖胰岛素糖尿病之关系
（2）Informative（信息丰富）：State exactly what you want the reader to know about your paper and your work;
（3）Indexing（便于索引）：Pack as many key words or indexing terms as possible into the title without overloading it; key words not in the title will be in the abstract or can go in the "Key Words" section of the paper; key words are usually in the beginning or ending place of the title. 标题是读者检索文献的重要标识，是著录题录和索引等第二次文献的重要内容。

标题中所选每一个实词必须是正确通用的术语，能提供文献检索，尽量包含关键词。

要求尽量把关键词（索引词）安排在标题最前面或最后面的位置上
（4）Highlighting the head word. (突出中心词): 每条标题都有中心词，它们是能
高度概括论文中心内容和主题的单词，要将其放在最显著突出的位置。

中心词的内容一般是
研究方法，研究对象，研究目的或效果，一般为名词，名词短语，分词短语或动名词短语。

例：Knowledge-based Technology in the Service of Health 论卫生事业中的知识技术Cognitive Impairment and Intracranial Calcification in Chronic Hyparathyroidism 鉴
别力受损与颅内钙化——甲状旁腺功能逐渐减退
B. 标题的结构
标题的结构一般都用名词作主干的名词短语型，这类标题结构中作为主干词的名词一般带有
动词意义，有时也用完整句，以陈述句较多，偶尔也用疑问句。

例：
Resolution of Adult Respiratory Distress Syndrome after Recovery from Fulminant Hepatic Failure 治疗成年人突发性肝衰竭康复后呼吸窘迫综合症
Using a Title Table to Evaluate Syncope 列表诊断晕厥
1)表示诊断，治疗方式或药物治疗的标题结构
这类标题中的diagnosis, treatment, therapy 等作主干的名词都带有动词意义，后跟for, in, to, with 等引导的介词短语引出病名或接受诊治的部位及所使用的药物。

例：Adjunctive Therapy with Aspirin in Vernal Conjunctivitis 用阿司匹林辅助治疗春季
结膜炎
Basic Approach in the Management of Intraocular Foreign Bodies 眼内异物的基本处
理方法
2)表示研究，分析，实验调查，观察，评估等的标题结构
study (analysis /trial/appraisal/ observation / evaluation / assessment/survey/estimation/test) of (on) … (by) using (by 方法 / with工具)…Assessment of Liver Function 肝功能的鉴定
Presurgical Evaluation of Eyes with Opaque Media 用不透明介质进行眼术前检查
3)表示关系，相关，比较，对照等的标题结构
这类标题结构一般用 (the) correlation, relationship, association, comparison, contrast等词为主体词干，加of…and, of…with, of…with…and, between…and 等表示
范围，比较对象等。

例：Correlation of Histology and Sensibility after Nerve Repair
神经修补后组织结构与感官能力间的关系
A Comparison of Digoxin and Dobutamine in Patients with Acute Infarction and Cardiac Failure 用DIGOXIN 和DOBUTAMINE治疗急性梗塞和心衰之比较
常用修饰词: positively (正) / negatively (负) / significantly (明显) / insignificantly (不明显) / strongly (很大) / little (很小)
e.g. Positive correlation of CD44v6 expression with invasion and metastasis of human gastric cancer
4)表示技术，使用，特点，结果，方法，模式，证据，测定，介绍等的标题结构
这类标题结构一般用（A或The）technique, use, properties, characteristics, introduction, method, result, evidence, essay 等词，加for, in, to, in 等介词引
导的短语，或带to不定式短语，表示方面，范围，类型等。

例：
Use of sulphamethizole in the treatment of urinary tract infection in the elderly 用磺胺甲噻二唑治疗老年泌尿道感染
Biological Properties of the Human Colonic Adenocarcinoma Cell Lines SW620
结肠腺癌细胞系SW620 的生物特征
5)标题中分词短语的用法
医学英语论文中分词短语一般作定语，大多放在被修饰词的后面，必要时与名词一起构成复合分词作定语。

例：
Analysis of Surface Protein of Mouse Lung Carcinoma Using Monolconal Antibiotics 分析使用单克隆抗生素的鼠肺癌表面蛋白
C．标题页
根据URMSBJ要求，论文标题及有关著录内容应单独双行打印，称为"标题页"（Title page），其内容包括：
1）标题（the title of the article）；
2）所有作者的姓名及其最高学位、所属单位（the name by which each author is known, with his or her highest academic degree(s) and institutional affiliation）；
3）研究工作的归属部门或单位名称（the name of the department(s) and institution(s) to which the work should be attributed）；
4）弃权者（若有）（disclaimers, if any）；
5）负责通讯和校稿作者的姓名能够和详细地址（the name and address of the author responsible for correspondence and proof about the manuscript）；
6）申请副本联系人姓名和地址（the name and address of the author to whom requests for reprints should be addressed）；
7）资助、设备、药品来源（sources of support in the form of grants, equipment, drugs, or all of these）；
8）不超过40个字母（包括间隔）的页眉标题（a short running head of no more than 40 letters and spaces at the foot of the title page）；
D．著录部分写法示例
1) 标题：
Use of steroid in the treatment of clinical septic shock
Unstable angina pectoris: Clinical, angiographic and myocadial scintigrapgic observations
2) 姓名：
标准式：Yang Jianguo, Guo Xiao'an *, Ouyang Kunpeng, and Lin Li
变式：YANG Jianguo；OUYANG Kunpeng; Yang, Jianguo, Jiangguo Yang
3) 单位：（From）Microbiology Department of Second Military Medical University, Shanghai
许多英美医学刊物中，单位置于标题页下方以脚注形式表示，这时工作单位前一般要用from
4) 地址：800 Xiang Yin Road, Shanghai 200433, P. R. China
5) 副本联系：Address reprint requests to: Cai Guangwen, Microbiology of Second Military Medical University, 800 Xiang Yin Road, Shanghai 200433, P. R. China 6) 资助：Supported / funded / granted / sponsored by the National Natural Science Foundation （标书号、合同号等）// A projected funded by the National "863" Program 7) 页眉标题：angina pectoris [原标题Unstable angina pectoris: Clinical, angiographic and myocardial scintigraphic observations] 对不稳定心绞痛的临床，血管造影和心肌闪烁法观察
2. 引言部分
总的要求是：The purpose of an introduction is to bring the reader into the general area of your study and then state the specific area of study (move from the general to the specific). The introduction shows the scope of your investigation efforts.** 即：说明研究的总体范围和目的。

具体内容包括：
A．背景 - 说明所研究问题的目前总体情况或历史（statement of general area or history of problem）
B．意义 - 说明研究的意义或必要性（statement of importance or need）
C．进展 - 说明有关该问题的先有发现、报告或研究（statement of previous findings, reports or studies）。

陈述这部分内容时一般要有引文（citations）
D．目的 - 说明本研究的目的（statement of purpose of current study）
E．范围 - 说明要研究问题的具体范围（statement of specific area of problem to be studied）
示例：
In the military, it has been common to treat hyperthermic heat casualties by immersion in ice-containing water. 【研究背景】 This method is highly unphysiologic, because the secondary profound cutaneous vasoconstriction shunts blood away from the skin, which greatly slows heat loss from the body core. In addition, shivering occurs soon after immersion, even though core temperature has decreased very little; and this is counterproductive by virtue of muscular heat production. Finally, immersion cooling is extremely unpleasant to the alert patient. 【本研究意义】Recently Weiner and Khogali [7] have developed a method for cooling hyperthermic patients based on the principle of vaporization of warm water from the body surface by blowing warm dry air over the skin. Their method is an improvement on previous experience with vaporization of cold water from the body surface. [3,4] 【研究进展】
Based on their experience, we have utilized the same physiologic principles in treating heat casualties during a two-week period of desert training (44th MAU,CAX 9-82,MCAGCC,29 Palms, Calif.). In addition, we have applied these principles to normothermic volunteers to study the difference of the method and evaluate untoward effects. 【本研究的目的】
3. 材料与方法部分
总的要求是：Readers must be able to reproduce your results, evaluate the validity of your results and the soundness of your methods, and follow the logic in the paper. 即：结果的可重演性、方法的可靠性以及前后的逻辑性。

具体内容包括：
简要说明研究设计（study design / protocol），如：回顾（retrospective / review），前瞻（prospective），临床（clinical），动物（animal），实验（experimental），活体内（in vivo）活体外（in vitro），原位（in situ）随访（follow-up），对照（controlled），随机（random / randomized），双盲交叉（double-blind crossover），人群（population / cohort / migrant），对比（comparative），流行病学（epidemiological）等研究性质；
详细说明研究对象（subject）情况，包括动物（animal）的性别（sex）、年龄（age）、物种（species）、品种（breed）、生理状态（physiological state）; 微生物菌株（strain）、血清型（serotype）及其他区别特性（identity characteristics）；随机分组方法（methods of any random assignment of subjects to groups）和选择标准（criteria for admission to study groups）；
详细说明所用的药物（drug），激素（hormone），试剂（reagent）和其他化学品（chemical）的名称、商标（trademark）、生产厂家（manufacturer）及所在地（location）；
简要说明测定方法（method of measurement），包括名称，引文和偏差（variations）；简要说明统计学分析方法（method of statistic analysis）
这部分的陈述程序一般为：研究设计→ 研究对象性质→ 处理 / 干预方法→ 测定/ 观察手段→ 统计分析
除指示性说明外，如："病人资料见表1"（Data of the patients are shown in Table 1）"材料与方法"和"结果"两部分一律用过去时表达。

示例：A retrospective analysis was conducted of all adults and pediatric patients (age less than 18 years) who received a prolonged course of parenteral nutrition at UCLA Medical Center from January 1976 through December 1983. [研究设计：性质、时间、地点、对象] Criteria for patient selection included a minimum course of a months and development of calculous or acalculous cholecystitis requiring cholecystectomy. From 1976 through 1983 136 patients underwent a prolonged course of TPN at the UCLA Medical Center. Sixty-two of these patients were found to have gallbladder disease. Cholecystectomy was performed in 21 of these patients before the initiation of TPN, and in 35 patients during or after administration of long term TPN. This latter group of 35 patients forms the basis for this report. [选择标准] Specific data regarding age, sex, length of time receiving TPN, underlying disorders, indication for TPN, number of previous operations, preoperative assessment, and the operative biliary procedure, findings and outcomes were all recorded.[研究对象性质] Patient data are summarized in Table 1. [指示性说明] (以下详细说明所选35个研究对象的情况，表格等内容，略)
4.结果部分
总的要求：This section tells the reader what happened in your work. Remember: let your results speak for themselves and don't embellish (leave that for the Discussion section), 即：让研究的客观结果说话，不要添枝加叶。

具体要求：
1）对所获结果进行概述（overview of the results）；
2）说明所获资料或数据的统计意义（statistical significance）；
3）统计支持（statistical support），包括图，表，照片等（凡用图表表示的内容不再用文字详述）。

注意：不要用模棱两可的词或短语表述结果，如： " The results tended to be greater than…", "… showed no promising trends", "It could / might be inhibited by …"。

示例：
Clinical and laboratory findings
Although the findings of abdominal pain, nausea, emesis, fever, and chills were present alone or in combination in 31 of 35 patients (88 percent), the diagnosis
of biliary disease was often delayed. The initial diagnosis in five of the seven children less than 6 years of age was catheter sepsis. Results of preoperative liver function tests were available in 27 patients. Twenty-five of these 27 patients (93%) had some evidence of hepatic dysfunction. Hyperbilirubinemia was present in 8 patient (30 percent), elevated alkaline phosphatase levels in 25 (93 percent), and elevated transminase levels in 13 patients (48 percent). In almost all these patients, the abnormal results of liver function tests had been noted early after the initiation of TPN and before the diagnosis of biliary tract disease. Either hepatosplenomegaly or laboratory evidence of a coagulation abnormality (prolonged prothrombin or partial thromboplastin time) or both were present in 19 patients (54 percent). Hepatobiliary scans (HIDA or PIPIDA) were performed in eighth patients and were suggestive of cystic duct obstruction in six. Abdominal ultrasonography was performed in 24 patients and correctly identified biliary sludge, gallstones, or both in 22 (92 percent). Gallstones were documented in two additional patients by oral cholecystogram in one and endoscopic retrograde cholangiography in the other. The remaining patient was explored with a presumptive diagnosis of cholecystitis without the benefit of any of these diagnostic tests. Although the clinical diagnosis was delayed in many of these patients, a correct preoperative diagnosis of calculous or acalculous cholecytitis was made in all but two patients who were thought to have some other focus of intraabdominal sepsis. [用统计数字说明临床和实验室发现] Operative findings (略) Complications （略）
Four of the 35 patients (11 percent) died after their biliary operation. Two adults and one child died within 30 days of operation, and a second child died as a result of progressive respiratory and hepatic failure. He had previously undergone two attempts at cholecystectomy that had to be aborted because of massive hemorrhage and was being prepared for a third attempt when he died. The other child died as a result of persistent sepsis and respiratory failure. A 75 year-old patient with previously documented carcinoma of the colon and short bowel syndrome secondary to multiple resections for radiation enteritis died 23 days after emergent cholecystectomy for acalculous cholecystitis. His immediate preoperative and postoperative course were complicated by progressive hepatic insufficiency and renal failure. He died on the eighth postoperative day. Hospital mortality was 24 percent in the 14 patients who required urgent operqtions. [死亡率及死亡原因]
5. 讨论部分
总的要求：The author should tell the reader what the results mean by placing them in the context of previous published studies of the problem, 即：与先有研究相比，本研究有何意义。

具体要求：
A．简要说明研究背景（background）
B．简要介绍总的发现（general findings）
C．介绍具体要点（introduction of points）
D．与现有发现（若有）进行比较（comparison in the context of other studies）E．意义（suggested meaning）
F．结论（conclusion）
G．前瞻研究（future studies）
结论往往是论文中最长也是最难写的部分，主要原因是作者要对研究结果和发现进行分析、推断、演绎和推理，要求作者具有很强逻辑思维能力和英语文字组织能力。

此外，这部分时态比较复杂，要分清实验过程和结果（过去时）与分析意见（确定：现在时；不确定或假设：过去时）的区别；他人研究结果（过去时或现在完成时）与本研究结果（过去时）的区别；普遍适用的结论（现在时）与只适用本研究的结论（过去时）的其别等。

因此，对于however, may, might, could, would, possibly, probably, be likely to 等词（组）的使用以及we believe (think / consider) that, to our knowledge, in our experience (practice) 等插入语的使用就显得格外重要。

示例：
Parenteral nutrition is being used with increasing frequency as a primary source of caloric support in adult and pediatric patients with gastrointestinal problems. Numerous complications have been associated with the administration of TPN, including a significantly increased incidence of gallbladder disease [3-5,7]. The data here suggest that cholecystectomy is often required for the management of symptomatic gallbladder disease in this group of patients, and is associated with significant risks.【说明研究背景，包括意义】
Of the 35 patients who required cholecystectomy for TPN-induced gallbladder disease, operative morbidity and mortality were 54 percent and 11 percent, respectively. Maingot [8] has stated that cholecystectomy "is one of the simplest and safest of the abdominal operations, and is associated with a low operative mortality rate (about 0.5 percent). A review of the pediatric literature suggests that when cholecystectomy is performed in children, the operative morbidity is less than 10 percent, and the mortality is less than 1 percent. [8,9] Glenn [11] has reported a mortality rate of less than 0.1 percent in over 5,000 patients under the age of 50 years who underwent cholecystectomy. The morbidity and mortality observed in our group of receiving long-term TPN, therefore, were far in excess of what would be expected for a population of patients whose mean age was 29 years. 【提出本研究主要发现并将其与其他研究发现相比较】
Our data suggest that are specific factors unique to patients who require long-term TPN that contribute to the increased mortality and morbidity associated with cholecystectomy in this select group.[以下，作者用较大篇幅分析了这类病人死亡率和并发症增高的临床、实验室和手术等方面的原因，说明为什么本研究报告的手术发病率和死亡率比其他研究报告的要高，原文从略]
Based on the results of our studies, we believe that early cholecystectomy is indicated in patients with TPN-induced gallbladder disease. Obviously, all patients with symptomatic disease should undergo cholecystectomy unless there specific medical contraindications. These operations should be performed in a timely, elective fashion because delay may result in the need for urgent surgery and thereby, increase an already high risk. Although recent studies have suggested that cholecystectomy may not be warranted in otherwise healthy patients with asymptomatic gallbladder disease [20], we believe that this axiom does not apply to patients with TPN-induced gallbladder disease. Out data suggest that the natural history of
gallbladder disease in patients receiving TPN is considerably different from that of their counterparts not receiving TPN. Based on our findings, we recommend elective cholecystectomy in patients receiving TPN when gallstones first appear. Furthermore, cholecystectomy should be considered, especially in children without stones who are undergoing laparotomy for other reasons. 【从对结果的分析及与其他研究的比较得出结论性意见，这是讨论部分最重要的内容，也是摘要结论部分的基础】Whether TPN-induced gallstones can be prevented through daily stimulated gallbladder emptying awaits the results of further studies. 【前瞻研究，即对研究存在或新发现的问题】
6. 致谢部分
总的要求：Always get approval of your intention to mention someone in the acknowledgement and approval of the form in which you will present the acknowledgement, 即：致谢词和致谢方式必须征得受谢人或单位的同意。

7. 参考文献
总的要求：Reference styles should be specific to each journal, 即：根据各杂志的具体要求，因为各杂志对参考文献部分的编排顺序和格式不尽统一。

现将URMSBJ要求的20多种参考文献中最常见的6种格式列举如下：
1.Vega KJ, Pina I, Krevsky B. Heart transplantation is associated with an increased risk for pancreatobiliary disease. Ann Intern Med 1996 Jun 1; 124(11): 980-3. [标准杂志文章]
如期刊名称用缩写，应按照<医学文献索引>中的方式缩写。

可查阅<医学文献索引>中收录的期刊目录——由美国国立医学图书馆每年作为<医学文献索引>的1月号单独出版。

2.The Cardiac Society of Australia and New Zealand. Clinical excise stress testing:Safety and performance guidelines. Med J Aust 1996; 164: 282-4. [作者是个组织]
3.Cancer in South Africa [editorial]. S Afr Med J 1984; 84: 15. [无作者名]
4.Shen HM, Zhang QF. Risk assessment of nickel cardiogenicity and occupational lung cancer. Environ Health Perspect 1994; 102 Suppl 1: 275-82. [某杂志增刊]
5.Browell DA, Lennard TW. Immunologic status of the cancer patient and the effects of blood transfusion on antitumor responses. Curr Opin Gen Surg 1993; 325-33 [无期无卷]
6. Lindenbaum J, Allen RH. Clinical spectrum and diagnosis of folate deficiency. In: Bailey LB, ed. Folate in Heath and Disease. New York: Marcel-Deker; 1995: 43-74.[专著类文章]
至于参考文献的排列顺序基本上都采用顺序编码标注方法，即参考文献表标注法。

它是在论文正文部分按所引文献首次出现的次序，以数码标注出其序号，有时加方括号，注在所引文字的结尾处和适当词语的右上方。

8. 插图说明
总的要求：Type or point out legends for illustrations using double spacing, starting on a separate page, 即：插图说明要另页双行打印。

当插图中有箭头（arrow）、符号（symbol）、数字（number）或字母（letter）时，要在这部分（不是在插图页上）对
其方向、位置等作出非常明确的说明。

9. 插图
总的要求：Design your figures for the appropriate reduction, 即：插图要按杂志的版面大小比例进行压缩；不要把插图拍成照片。

10. 表格
总的要求：A table should be a totally self-contained unit of information, 即：表格要作为一个独立的信息单位另页打印。

表格要简明清楚，完整（标题、内容和脚注），即使只有一张表格也要标Table 1。

11. 照片和说明
总的要求：与7）、8）部分相同。

III. Exercise 修改以下标题
（1）视网膜小血管变化是冠状动脉疾病的一个指标
Original:Retinal arteriolar changes are an indicator of coronary artery disease 问题：标题中应尽量避免使用活用动词 (active verb), 即谓语动词，一般采用名词短语型结构。

Revised:Retinal arteriolar changes as an indicator of coronary artery disease （2) 用大剂量氨甲喋呤治疗急性淋巴细胞白血病的初步体会
Original: Preliminary experience in using high dose of methotrexate to treat ALL 问题：1) 应尽量避免使用"初步体会"，"初步研究"，"初步经验"之类没有实际意义的词; 2) 除了像AIDS, DNA等已通用的缩略语外，标题中应尽量避免使用缩略语，如ALL应写全称；3）尽量避免使用动词
Revised:High dose methotrexate therapy in acute lymphocytic leukemia 或：Use of high dose methotrexate in (the) treatment of acute lymphocytic leukemia
（3) 关于饮食中钾含量与血压关系的研究
Original:A research of the relationship between the content of potassium in diet and blood pressure
问题：（1）具体的研究一般用study表述 (research一般作不可数名词处理，如much research has been done on…)；标题中如果"研究"一词前没有限定词，一般都省略，比较：A prospective clinical study of isoniazid-refampicin-pyrazinamide-induced liver injury in an area endemic for hepatitis；（2）表述过于繁琐
Revised: Dietary potassium and blood pressure
为了满足标题写作的上述，有时对较长标题可采用副标题（subtitle）处理，如出现：（4)病例数时，如：对急症室连续170例腹痛病例的回顾性研究
Original: A retrospective study on 170 consecutive cases of abdominal pain in the emergency room
问题：关键词不突出
Revised:Abdominal pain in the emergency room: Retrospective study of 170 consecutive cases
（5) 研究性质/方法时，如：用磁共振成象术对正常怀孕期间垂体增大进行活体内研究Original: Use MRI to conduct an in vivo study on the enlargement of the pituitary gland during normal pregnancy
问题：1）关键词不突出；2）过多使用了动词
Revised:Pituitary gland growth during normal pregnancy: An in vivo study using magnetic resonance imaging
（6) 并列结构时，如：军队卫生防疫工作中出现的问题、原因与对策的初探
Original:A preliminary study on the problems, causes and countermeasures in health and epidemic prevention work of CPLA
问题：（1）"初探"是多余的；（2）外国人知道CPLA吗？（3）主题不够突出
Revised:Military health and epidemic prevention: Problems, causes and countermeasures
（7) 解释性用词时，如：一例系统性红斑狼疮出现胰腺炎病例报告及文献综述
Original: A case report of SLE appearing pancreatitis and review of literatures 问题：1）"appear"为不及物动词，不能跟宾语；2)SLE应使用全称; 3)关键词不够突出；4）literature一般为不可数名词
Revised:Pancreatitis in systemic lupus erythematosus (SLE): A case report and review of the literature
（8) 提问或选择时，如：听诊器是潜在的医院感染源吗？
Original:Is stethoscope a potential source of nosocomial infection?
Revised:Stethoscope: a potential source of nosocomial infection?。