一、常见的语法问题
1. 这是最容易忽视的错误，它在经典的The Elements of Style书中名列第二。In a series of three or more terms with a single conjunction, use a comma after each term except the last （在一系列三个或三个以上带有单个连词的术语中，除最后一个术语外，在每个术语后面应使用逗号），尤其是倒数第二的逗号常常被忽视。
例句： However, HB, HCT and PT in the autologous transfusion group were better than those in the allogeneic transfusion group.
改正： However, HB, HCT, and PT in the autologous transfusion group were better than those in the allogeneic transfusion group.
2. 这也是最容易出现的错误，尤其在长句中（带有修饰性的从句时）主语是单数第三人称或复数，而谓语动词不配合。
例句： The procedure for collecting the unlabeled pre-enriched CD4+T cells were the same as mentioned above.
改正： The procedure for collecting the unlabeled pre-enriched CD4+T cells was the same as mentioned above.
例句： The number of Nab positive subjects (%) in the BAT2206 group, ustekinumab (EU) group, and ustekinumab (US) group were 8 (8.9%), 5 (5.7%), and 6 (6.7%), respectively.
改正： The number of Nab positive subjects (%) in the BAT2206 group, ustekinumab (EU) group, and ustekinumab (US) group was 8 (8.9%), 5 (5.7%), and 6 (6.7%), respectively.
3. And 连接的两个并列句，如果缺乏逻辑的联系，应拆成两个句子。
例句： These patients did not receive any corticosteroids and immunosuppressive drugs in the three months before and during the baseline measurement and were excluded from other autoimmune diseases, infectious diseases, and respiratory system, circulatory diseases.
改正： Those patients did not receive any corticosteroids and immunosuppressive drugs in the three months before and during the baseline measurement. If patients have other autoimmune diseases, infectious diseases, respiratory system, or circulatory diseases, they were excluded from this study.
二、如何提高医学英语的写作水平，像native speaker一样写出地道的英语医学文章
我的建议是多读经典的医学教科书，如CECIL Essentials of MEDICINE, 最好手头有一本，经常翻翻，体会一下西人是如何用书面语言表达和阐述自己的观点。再则，就是模仿用英语表达同样的事情或观点。久而久之，英语的写作水平就会提高，语法错误也少了。更重要的是，自己学会了英语写作，不用再大段大段地拷贝别人的文章，以免Cross-check通不过。下面从CECIL Essentials of MEDICINE一书中摘出两个句子，看看西人是怎样写长句的。
例句1： The process of splicing, or removing intronic sequences to produce the mature mRNA, is an exquisitely choreographed event that involves the intermediate formation of a spliceosome, a large complex consisting of small nuclear RNAs and specific proteins, which contains a loop or lariat-like structure that includes the intron targeted for removal.
从此例句中，可以看出各层的意思表达得很清晰，从句的谓语动词指向明确，不会产生歧义。
例句2： Because prosthetic heart valves are associated with a number of complications, including thrombosis, endocarditis, and hemolysis, the decision to proceed with valve surgery should only be made after the risks of valve replacement are weighed against the potential benefits of symptom relief and improved survival.
从此例句中，可以看出各层的逻辑关系表达分明，重点突出。
三、机器翻译的译文需人工修改
机器翻译是指由计算机进行自动翻译的过程，如今人工智能技术的发展极大地推动了机器翻译的进步。虽然人工翻译的精度很高，但是费时费力。机器翻译的特点是译文生成的速度快且成本低廉，特别适用于翻译大量的文本。长期以来，机器翻译都是指句子级的翻译。主要原因是可以大大简化计算机翻译建模的过程。但是人类的语言交流并不是孤立地在一个个句子上进行的，所以基于上下文的翻译是机器翻译的一个重要分支。目前，大多数机器翻译系统的功能主要是句子级的翻译。由于缺乏对篇章上下文信息的建模，往往对篇章级的翻译效果不尽人意。因此经常需要人工修改后才能使用，例如译后编辑（Post-editing）,另一种方法是让人和机器翻译系统进行互相交流，在不断的修正中生成更好的译文，这个过程也称作交互式机器翻译（Interactive machine translation， IMT）。下面举例说明之。
中文原文：病人的私人物品在留尿时要先检查过，防止其留尿时将其他物品带入洗手间，导致尿液标本被稀释或污染，对物品检查合格者，可以发给尿杯。护士将打印的样本号码预先粘贴到尿杯上，收集尿样的当天，护士先检查尿杯上的样本号码，再核实病人的身份号码，两者信息匹配后，即将尿杯发给需留尿的病人，他们应逐一进入洗手间留尿。留尿完成后，尿液样本的检查很重要，必须根据尿液的颜色和温度来判断尿样是否是该病人本人留取或已经被稀释或污染。对于被稀释或污染的尿液样本，应如实记录并将样本丢弃，而样本判断合格后，护士还要再次核实尿杯上的样本号码和病人的身份号码。
机器翻译的译文：
The patient's personal belongings should be checked first before leaving urine, so as to prevent other items from being brought into the bathroom when leaving urine, which may lead to dilution or contamination of urine specimens. The person who passes the inspection of the articles can be issued a urine cup. The nurse pasted the printed sample number onto the urine cup in advance. On the day of urine sample collection, the nurse first checked the sample number on the urine cup and then checked the patient's identity number. After the two information matched, the urine cup was given to the patients who needed to leave urine. After urine retention is complete, it is important to examine the urine sample, and the color and temperature of the urine must be used to determine whether the urine sample has been collected by the patient or has been diluted or contaminated. For diluted or contaminated urine samples, the sample should be recorded truthfully and discarded. After the sample is judged to be qualified, the nurse should double-check the sample number on the urine cup and the patient's identity number.
人工修改后的译文：
To avoid a contrived urine sample that is diluted or contaminated on purpose, the nurse should check the items the patient carried and indicate those which are not allowed to take into the toilet when collecting urine samples. After checking, the qualified person will receive a urine collection cup, in which a printed barcode has been affixed by the nurse. Once the information presented in both of urine collection cup and the patient’s wristband is matched, that person is allowed to enter the toilet for collecting a urine sample. Once a cup of urine sample is received, the nurse should judge whether it is the original one or diluted or contaminated, based on the color and temperature of this sample. If the urine sample is found to be diluted or contaminated, it will be discarded with a truthful record. Only the qualified samples could be taken by the nurse who will verify the barcode on the urine collection cup and patient’s ID again.
回译：为避免人为尿样被故意稀释或污染，护士在收集尿样时应检查患者携带的物品，并指明不允许带入厕所的物品。经检查合格的人将获得一个尿液收集杯，此杯上有打印好的条形码，由护士提前粘贴好的。一旦尿液收集杯和患者手环上显示的信息匹配，该患者就可以进入厕所收集尿液样本。当收到一杯尿样时，护士应根据尿样的颜色和温度判断是原尿样还是稀释尿样或被污染尿样。如发现尿液样本被稀释或污染，将予以丢弃，并如实记录。只有收到合格的样本，护士才会再次核实尿液收集杯上的条形码和患者的身份。
从上面的例子可以看出人工修改后的译文更贴近中文原文，而且更符合英语的表达方式，便于读者理解。