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   7917篇
  免费   479篇
  国内免费   31篇
耳鼻咽喉   120篇
儿科学   244篇
妇产科学   102篇
基础医学   1096篇
口腔科学   805篇
临床医学   545篇
内科学   1912篇
皮肤病学   122篇
神经病学   526篇
特种医学   227篇
外国民族医学   2篇
外科学   726篇
综合类   46篇
一般理论   3篇
预防医学   823篇
眼科学   117篇
药学   566篇
中国医学   42篇
肿瘤学   403篇
  2023年   71篇
  2022年   180篇
  2021年   265篇
  2020年   170篇
  2019年   223篇
  2018年   273篇
  2017年   190篇
  2016年   230篇
  2015年   263篇
  2014年   335篇
  2013年   416篇
  2012年   655篇
  2011年   644篇
  2010年   373篇
  2009年   310篇
  2008年   473篇
  2007年   471篇
  2006年   412篇
  2005年   347篇
  2004年   294篇
  2003年   250篇
  2002年   228篇
  2001年   135篇
  2000年   153篇
  1999年   138篇
  1998年   68篇
  1997年   61篇
  1996年   49篇
  1995年   31篇
  1994年   31篇
  1993年   22篇
  1992年   63篇
  1991年   52篇
  1990年   50篇
  1989年   54篇
  1988年   54篇
  1987年   38篇
  1986年   40篇
  1985年   47篇
  1984年   37篇
  1983年   21篇
  1982年   15篇
  1981年   20篇
  1980年   20篇
  1979年   14篇
  1978年   14篇
  1977年   15篇
  1976年   18篇
  1975年   17篇
  1968年   12篇
排序方式: 共有8427条查询结果,搜索用时 15 毫秒
91.
OBJECTIVES: To evaluate operative time, blood loss and inflammatory response in patients submitted to hysterectomy. METHODS: Sixty patients referred for hysterectomy were prospectively randomized to total abdominal hysterectomy (n=20), vaginal hysterectomy (n=20), or laparoscopic hysterectomy (n=20). The operative time, blood loss (variation in erythrocyte and hemoglobin) and inflammatory answer (CRP and interleukin-6 dosages) were compared by using Kruskal-Wallis, Dunn non-parametric test and variance analysis with repeated measurements. RESULTS: Operative time was shorter for vaginal hysterectomy, and there was no significant difference between total abdominal hysterectomy and laparoscopic hysterectomy. Reduction in erythrocyte and hemoglobin was more noticeable after vaginal hysterectomy, followed by total abdominal hysterectomy and laparoscopic hysterectomy. CRP levels increased steadily from vaginal hysterectomy to laparoscopic hysterectomy and then to total abdominal hysterectomy. The increase in interleukin-6 was substantially higher in total abdominal hysterectomy, whereas no difference was noted between vaginal and laparoscopic hysterectomy. CONCLUSIONS: Vaginal hysterectomy presents superior results in terms of operative time and inflammatory response when compared with total abdominal and laparoscopic hysterectomy and it should be the first option for hysterectomy. Laparoscopic hysterectomy should be considered when the vaginal approach is unfeasible, showing clear advantages over abdominal hysterectomy.  相似文献   
92.
In order to obtain basic data on the effect of broad-spectrum protease inhibitor against local symptoms of Viperidae snake envenomation, inhibitory capacity of rat murinoglobulin on local hemorrhagic and edematogenic activities of venoms from Crotalus atrox, Bothrops jararaca, Lachesis muta muta, Trimeresurus flavoviridis and Echis carinatus sochureki were examined. Murinoglobulin, pre-incubated with the crude venoms at 37 degrees C for 15 min, inhibited hemorrhagic activity of all five venoms to various extents. The activity of C. atrox was almost completely inhibited at the murinoglobulin/venom ratio (w/w) of 20. The activity of B. jararaca, Lachesis muta muta and T. flavoviridis venoms was considerably inhibited at the ratio of 20 (77.2, 80.0 and 86.2% inhibition, respectively), however some of the activity still remained even at the ratio of 40 (84.2, 79.8 and 86.2% inhibition, respectively). Among the five venoms, E. c. sochureki venom is quite resistant to murinoglobulin treatment and statistically significant inhibition was only found at the ratio of 40 (64.1% inhibition). Fibrinolytic and gelatinase activities were more susceptible to murinoglobulin inhibition. The treatment at the ratios of 10 and 20 almost completely inhibited respectively the fibrinolytic and the gelatinase activities of all the venoms. Murinoglobulin treatment also significantly inhibited the edematogenic activity of L. muta muta, T. flavoviridis and Echis carinatus sochureki. The treatment of murinoglobulin at the ratio of 40 considerably suppressed the swelling up to 60 min after subcutaneous injection of L. muta muta and E. c. sochureki venoms, and up to 30 min after T. flavoviridis venom injection. Murinoglobulin is a potent inhibitor against local effects of multiple snake venoms in Viperidae family.  相似文献   
93.
The Brucella abortus ribosomal protein L7/L12 is an immunodominant antigen and an interesting candidate for the development of oral live vaccines against brucellosis. Here, a recombinant Lactococcus lactis strain producing L7/L12 under the control of nisin inducible promoter was orally administered to BALB/c mice. Significant levels of anti-L7/L12 specific IgA detected in feces revealed an induced local humoral immune response. However, serum analysis did not reveal any anti-L7/L12 antibodies suggesting the absence of a systemic response. Nevertheless, the vaccinated mice showed a partial protective immunity against B. abortus virulent strain (S2308) challenged by intraperitoneal inoculation.  相似文献   
94.
The glutathione S-transferase (GST) genes are involved in the metabolism of various carcinogens. Deletion polymorphisms in the genes GSTM1 and GSTT1 and a base transition polymorphism at codon 105 (Ile-->Val) in GSTP1 were investigated in relation to breast cancer risk. Tobacco smoking and reproductive factors were examined as potential effect modifiers. Individual data from seven case-control studies were pooled within the International Collaborative Study on Genetic Susceptibility to Environmental Carcinogens. To measure the effect of GSTs on breast cancer risk, odds ratios and 95% confidence intervals were computed adjusting for study center and age. The modifying effect was investigated by stratification on variables of smoking habits and reproductive history. A total of 2,048 cases with breast cancer and 1,969 controls were analyzed. The relative odds ratio (95% confidence interval) of breast cancer was 0.98 (0.86-1.12) with the GSTM1 null, 1.11 (0.87-1.41) with the GSTT1 null, 1.01 (0.79-1.28) with GSTP1 heterozygous mutants, and 0.93 (0.62-1.38) with GSTP1 homozygous mutants. Stratification by smoking or reproductive factors did not reveal a modifying effect of these variables, nor was there any association between GSTM1 and age at diagnosis of breast cancer. This is the largest study investigating susceptibility to breast cancer due to polymorphisms in the GST genes. The results conclusively show that single gene GST polymorphisms do not confer a substantial risk of breast cancer to its carriers. Furthermore, GSTs did not interact with smoking or reproductive history to modify cancer risk.  相似文献   
95.
96.
97.
98.
99.
Immune deficiencies in chronic intestinal pseudo-obstruction   总被引:1,自引:0,他引:1  
Aim: Chronic intestinal pseudo-obstruction has been associated with urinary disorders, myopathy, and ophthalmoplegia in adults and cholelithiasis in children. We observed a high percentage of total-parenteral-nutrition-dependent patients with pseudo-obstruction and recurrent infections requiring gammaglobulin infusions. Methods: AH records for 23 children with chronic intestinal pseudo-obstruction (10 females and 13 males, mean age 9.8 y ± 4.9 y, range 4–24 y) referred for a nutritional evaluation from 1992 to 1995 were reviewed. Chronic intestinal pseudo-obstruction was diagnosed by clinical, radiographic findings and antroduodenal manometry. Intestinal full-thickness biopsies were performed in seven children. Results: Hypogammaglobulinemia was diagnosed in 18 patients (78%): 16 patients had various immunoglobulin deficiencies and 2 had selective antibody deficiency. Intravenous gammaglobulin was administered in 14 patients. Other medical conditions affecting the children are summarized as follows: autonomic dysfunction in 10 patients (43%), recurrent hypoglycemia in 9 (39%), asthma in 9 (39%), cholecystitis in 7 (30%), low serum carnitine level in 6 (26%), urinary dysfunction in 6 (26%), pancreatitis in 5 (22%), behavioral problems in 5 (22%), myopathy in 2 (9%), idiopathic thrombocytopenia in 2 (8%), velopharyngeal insufficiency in 1 (4%), oculocutaneous albinism in 1 (4%), Pierre-Robin syndrome in 1 (4%), and protein C deficiency in 1 (4%). Munchausen syndrome was suspected in two patients. Conclusions: Chronic intestinal pseudo-obstruction appears to be associated with immune deficiencies. It is unclear if the immune deficiencies, intestinal pseudo-obstruction, and the other medical conditions have a common underlying etiology. Repeated infections may be due to impaired immune function in children with chronic intestinal pseudo-obstruction. We recommend screening for immune deficiencies in children with chronic intestinal pseudo-obstruction.  相似文献   
100.
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