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   14539篇
  免费   1137篇
  国内免费   106篇
耳鼻咽喉   125篇
儿科学   377篇
妇产科学   346篇
基础医学   2010篇
口腔科学   385篇
临床医学   1595篇
内科学   3075篇
皮肤病学   266篇
神经病学   1028篇
特种医学   877篇
外国民族医学   17篇
外科学   1849篇
综合类   159篇
一般理论   6篇
预防医学   1321篇
眼科学   190篇
药学   957篇
中国医学   20篇
肿瘤学   1179篇
  2021年   175篇
  2020年   129篇
  2019年   194篇
  2018年   254篇
  2017年   161篇
  2016年   239篇
  2015年   268篇
  2014年   339篇
  2013年   470篇
  2012年   631篇
  2011年   617篇
  2010年   376篇
  2009年   394篇
  2008年   596篇
  2007年   633篇
  2006年   601篇
  2005年   569篇
  2004年   547篇
  2003年   555篇
  2002年   530篇
  2001年   521篇
  2000年   556篇
  1999年   498篇
  1998年   249篇
  1997年   226篇
  1996年   222篇
  1995年   187篇
  1994年   154篇
  1993年   163篇
  1992年   365篇
  1991年   321篇
  1990年   306篇
  1989年   293篇
  1988年   289篇
  1987年   261篇
  1986年   267篇
  1985年   254篇
  1984年   201篇
  1983年   195篇
  1982年   115篇
  1981年   110篇
  1980年   119篇
  1979年   152篇
  1978年   116篇
  1977年   104篇
  1976年   80篇
  1975年   91篇
  1974年   105篇
  1973年   116篇
  1971年   86篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
31.
Young rats were injected with either ethanol (75 mmol/kg), acetaldehyde (2.8 mmol/kg) or isovolumetric amounts of NaCl (0.15 mol/l, i.e. controls) with or without inhibitors of alcohol dehydrogenase (4-methylpyrazole) or aldehyde dehydrogenase (cyanamide). After 2.5 hr, fractional rates of protein synthesis (i.e. ks) in the soleus (Type I fibre-rich) and plantaris (Type II fibre-rich) muscles were measured. Ethanol alone reduced ks in both soleus and plantaris muscles, by approx. 25%. Pretreatment of ethanol-dosed rats with 4-methylpyrazole raised plasma ethanol levels and reduced ks in the soleus and plantaris by approx. 35%. Pretreatment of ethanol-dosed rats with cyanamide also increased plasma ethanol and further potentiated the effects of ethanol by reducing ks in the soleus and plantaris by approx. 65%. Acetaldehyde alone reduced ks by approx. 15%, and this effect was not significantly altered by 4-methylpyrazole pretreatment. In some instances, the plantaris was slightly more sensitive to ethanol and acetaldehyde than the soleus. Similar conclusions were derived when data were expressed relative to either RNA or DNA. The data thus suggest that the ethanol-induced inhibition of skeletal muscle protein synthesis may possibly be independently mediated by both ethanol and acetaldehyde.  相似文献   
32.
Foreign-body granulomas in the hand can appear secondary to an unrecognized foreign material. In a six-year-old boy, an extensive sterile osteitis of the second metacarpal bone appeared adjacent to a wood splinter.  相似文献   
33.
The activity of P-glycoprotein (Pgp/MDR1/ABCB1) and multidrug resistance proteins (MRP/ABCC) influence the pharmacokinetics and bioavailability of many drugs. Few suitable cell lines for the study of drug transport exist. Additional non-human cell lines may help clarify species differences and contribute to the current knowledge of drug transport. The aim of the present study was to characterize three rat epithelial cell lines for transporter expression and activity. Transporter expression was assessed in intestinal IEC-6 and renal GERP and NRK-52E cells using RT-PCR and Western blot analysis. Pgp and Mrp transport activity were analyzed by measuring calcein accumulation and glutathione-S-bimane efflux, respectively. The three cell lines showed Pgp expression and Pgp-dependent transport, both decreasing with culture time after reaching confluency. Besides Pgp, cells expressed Mrp1, Mrp3, Mrp4, and Mrp5, while Mrp2 and Mrp6 were absent. In addition, they showed temperature- and Mrp-dependent efflux of glutathione-S-bimane. Exposure to a panel of different inhibitors showed that this efflux was probably mediated by Mrp4. In conclusion, the three rat epithelial cell lines investigated showed Pgp and Mrp expression and transport. Mrp dependent transport was most likely mediated by Mrp4. In future, these cell lines may be used as in vitro models to study drug transport.  相似文献   
34.
35.
We report a metallic foreign body that entered through the anterior table of the frontal sinus, and rolled down to lodge in the nasofrontal duct. An electromagnet was used to remove the foreign body through a trephination.  相似文献   
36.
37.
38.
39.
OBJECTIVE: To investigate child restraint/seatbelt use by the indigenous (Maori) population in Northland New Zealand. METHOD: Observational surveys were conducted at the two main car parks (McDonald's and the largest supermarket) to determine the number of passengers restrained, the type of restraints, and correct use. Observations were restricted to those who were obviously Maori, based upon the local knowledge of the observer. In addition, face to face questionnaires were administered to Maori whanau/caregivers involved in the care of two or more children for more than three days a week. RESULTS: A total of 788 participants were observed. Babies were those most likely to have all occupants restrained correctly (97%), followed by toddlers (66%), adults (56%), and school age children (48%); 138 interviews were conducted. Females (86%) were significantly more likely to ensure that all passengers were restrained on short journeys compared to males (67%; p<0.05). Respondents under 45 (80%) were significantly less likely to restrain child passengers compared to people aged 45 or older (91%; p<0.05). DISCUSSION: This study highlights the problem that larger families in this study had in providing correct child restraints for all their children.  相似文献   
40.
HIV-1 and HIV-2 antibodies, erythrocyte sedimentation rate, leucocytes and additionally serum neopterin levels were measured in 100 potential spongiosa donors. HIV antibodies were negative in all patients, whereas in 24% neopterin levels were elevated (greater than 10 nmol/l). Enhanced neopterin production is related to activity in cell-mediated immune response. In further investigations of these patients we found in 29% infections, 38% tumor diseases and 13% autoimmune diseases, all being exclusion criteria for spongiosa transplantation. In 3 patients increased neopterin values were the only pathological screening parameters. The measurement of serum neopterin levels showed to be a helpful parameter for the selection of spongiosa donors.  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