首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   1632篇
  免费   85篇
  国内免费   17篇
耳鼻咽喉   18篇
儿科学   26篇
妇产科学   18篇
基础医学   326篇
口腔科学   9篇
临床医学   104篇
内科学   485篇
皮肤病学   63篇
神经病学   99篇
特种医学   24篇
外科学   206篇
综合类   10篇
一般理论   1篇
预防医学   40篇
眼科学   48篇
药学   79篇
中国医学   12篇
肿瘤学   166篇
  2023年   17篇
  2022年   32篇
  2021年   36篇
  2020年   21篇
  2019年   38篇
  2018年   40篇
  2017年   43篇
  2016年   38篇
  2015年   57篇
  2014年   78篇
  2013年   75篇
  2012年   94篇
  2011年   122篇
  2010年   79篇
  2009年   65篇
  2008年   92篇
  2007年   112篇
  2006年   75篇
  2005年   94篇
  2004年   75篇
  2003年   69篇
  2002年   63篇
  2001年   26篇
  2000年   29篇
  1999年   30篇
  1998年   18篇
  1997年   13篇
  1996年   4篇
  1995年   9篇
  1994年   8篇
  1993年   10篇
  1992年   16篇
  1991年   12篇
  1990年   14篇
  1989年   13篇
  1988年   5篇
  1987年   13篇
  1986年   15篇
  1985年   11篇
  1983年   5篇
  1982年   5篇
  1981年   5篇
  1979年   5篇
  1978年   5篇
  1975年   5篇
  1970年   4篇
  1969年   3篇
  1968年   5篇
  1967年   3篇
  1966年   6篇
排序方式: 共有1734条查询结果,搜索用时 15 毫秒
21.
We evaluated somatic genetic alterations in the kinase domain of the EGFR gene in the tumors of 219 non-small cell lung cancer patients of primarily Caucasian and African American origins. We identified 26 patients (12%) whose tumors had a mutation in the EGFR gene, and 11 (5%) patients carried novel genomic variations consistent with germ-line polymorphisms. All but one mutation were identified in Caucasian patients affected with adenocarcinoma. EGFR mutations were more frequent in women and in nonsmokers, but a significant portion of the affected patients were men (12 of 26) and current or past smokers accounted for half of the patients affected (13 of 26). Screening subjects with EGFR mutations may identify patients whose tumors could respond to targeted therapy using tyrosine kinase inhibitors.  相似文献   
22.
23.
AIM OF THE STUDY: Hypoglycaemic and hypolipidemic properties of the ethanolic and aqueous extracts, respectively, from Chinese juniper (Juniperus chinensis L.) berries were investigated in alloxan-induced diabetic rats. MATERIALS AND METHODS: After oral administration of each extract singly or repeatedly to alloxan-induced diabetic rats, the blood glucose, glutamate-pyruvate transferase (GPT), glutamate-oxaloacetate transaminase (GOT), total cholesterol (TC) and triglyceride (TG) levels were assayed. RESULTS: The blood glucose levels after a single oral administration of the ethanolic extract significantly reduced in a time-dependent manner, which is much faster and more than that of glibenclamide. The blood glucose levels of alloxan-induced diabetic rats treated with the ethanolic extract were reduced to 94, 81%, 66%, 45% and 40% at 1, 3, 5, 7 and 9h, respectively (p<0.05), while the aqueous extract had no effect at all. Repeated oral administration of the ethanolic extract also effectively reduced the GPT value to 58% of the diabetic rats, but slightly reduced the GOT value to 87% of the diabetic rats (p<0.05). On the other hand, the repeated oral administration of aqueous extract effectively reduced the GOT value to 43% of the diabetic rats, without affecting the GPT level. Effects of both extracts on the TC and TG levels were different. There was no significant difference in the TC and TG levels between diabetic control and diabetic groups when repeatedly administered orally with ethanolic extract. On the other hand, the aqueous extract brought down the TC value to 57% and the TG value to 37% of the diabetic control rats (p<0.05). CONCLUSIONS: The results suggested that the ethanolic extract of Chinese juniper berries possesses a potential hypoglycaemic effect while the aqueous extract has a potential hypolipidemic effect.  相似文献   
24.
25.
Lung cancer is the primary cause of cancer-related deaths worldwide. Recently, although the microbiome has emerged as the key modulator of the carcinogenesis, it has not been evaluated in lung cancer. Here, we evaluated the microbial composition of lung cancer tissues according to the histologic type and genetic mutation, compared it with that of the adjacent normal lung tissues, and investigated the association between the lung microbiome and clinical parameters. We collected lung tissue samples from 162 patients with non-small cell lung cancer (NSCLC, 162 cancer and 54 adjacent normal tissues), surgically resected between January 2018 and December 2019, and analyzed their microbiome using 16S rRNA gene amplicon sequencing, the QIIME2 pipeline, and statistical analyses. NSCLC tissues had significantly lower alpha diversity than the normal tissues, and their microbial composition differed according to the histologic type and cancer genetic mutation. The genera Romboutsia, Novosphingobium, Acinetobacter, and Prevotella were significantly overrepresented in NSCLC tissues. Alpha diversity steadily declined from a normal to a more advanced stage, and microbial compositional differences were noted along with recurrence. Stenotrophomonas was the most predominant genus in the NSCLC tissues of patients with recurrence. The pathways related to the tricarboxylic acid cycle and L-glutamate and L-glutamine biosynthesis were predominant in adenocarcinoma, whereas those related to purine and pyrimidine nucleotide degradation and formaldehyde assimilation were predominant in squamous cell carcinoma. Our findings suggest that the altered lung cancer microbial composition might be associated with cancer initiation and/or progression.  相似文献   
26.
27.
28.
29.
30.
Kihara  Mari  Sugihara  Takahiko  Asano  Junichi  Sato  Midori  Kaneko  Hiroshi  Muraoka  Sei  Ohshima  Shiro  Nanki  Toshihiro 《Clinical rheumatology》2022,41(12):3661-3673
Clinical Rheumatology - To describe clinical characteristics of patients in Japan with coronavirus disease 19 (COVID-19) and pre-existing rheumatic disease and examine the possible risk factors...  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号