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   398260篇
  免费   36541篇
  国内免费   27161篇
耳鼻咽喉   3620篇
儿科学   4993篇
妇产科学   5711篇
基础医学   45703篇
口腔科学   6687篇
临床医学   55719篇
内科学   57314篇
皮肤病学   3875篇
神经病学   20643篇
特种医学   14321篇
外国民族医学   225篇
外科学   37833篇
综合类   67658篇
现状与发展   93篇
一般理论   24篇
预防医学   27716篇
眼科学   11261篇
药学   41938篇
  471篇
中国医学   24205篇
肿瘤学   31952篇
  2024年   1330篇
  2023年   6065篇
  2022年   15644篇
  2021年   19742篇
  2020年   14909篇
  2019年   12903篇
  2018年   13384篇
  2017年   12300篇
  2016年   11431篇
  2015年   17602篇
  2014年   21888篇
  2013年   20103篇
  2012年   29570篇
  2011年   32793篇
  2010年   21496篇
  2009年   17123篇
  2008年   22325篇
  2007年   22146篇
  2006年   21574篇
  2005年   20444篇
  2004年   13282篇
  2003年   12085篇
  2002年   10319篇
  2001年   8944篇
  2000年   9401篇
  1999年   9715篇
  1998年   5822篇
  1997年   5844篇
  1996年   4606篇
  1995年   4126篇
  1994年   3433篇
  1993年   2228篇
  1992年   2914篇
  1991年   2501篇
  1990年   2193篇
  1989年   1931篇
  1988年   1620篇
  1987年   1388篇
  1986年   1142篇
  1985年   942篇
  1984年   541篇
  1983年   378篇
  1982年   250篇
  1981年   247篇
  1980年   192篇
  1979年   223篇
  1977年   94篇
  1974年   107篇
  1973年   86篇
  1972年   86篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
71.
72.
BACKGROUND AND PURPOSE: Health-related quality of life (HRQOL) is primarily an assessment of how domains of life are affected by health. This study investigated the factors influencing HRQOL of Taiwanese patients with bronchial asthma. METHODS: A cross-sectional study was conducted to assess the factors influencing HRQOL. The sample consisted of 242 outpatients with bronchial asthma. The Chinese language version of the St. George's Respiratory Questionnaire was used to measure HRQOL. Data were analyzed using simple regression and multiple regression. RESULTS: Age, marital status, level of education, asthma severity, peak expiratory flow, and previous hospital admissions were found to be predictors of HRQOL. Gender, duration of disease, and history of emergency visits were not correlated with HRQOL. The variables entered in the HRQOL model accounted for 17.4% of the total variance (adjusted R(2)). The regression coefficients indicated that the mean scores increased 7.68 in patients with moderate to severe disease severity, and increased 7.34 in patients with a history of hospital admissions. The mean scores decreased 7.60 in married patients. CONCLUSION: This study found that marital status, asthma severity, and history of hospital admissions were major predictors of HRQOL in Taiwanese patients with bronchial asthma.  相似文献   
73.
薛颖 《中华现代护理杂志》2007,13(15):1385-1386
总结2例腹腔镜下阴道癌根治及阴道重建手术的手术配合经验.提出术前做好心理护理、肠道准备,熟悉手术步骤、手术者的手术特点,熟练掌握手术器械的使用方法,与术者默契配合,是保证手术成功的关键措施.  相似文献   
74.
As an ongoing effort to elucidate the mechanisms involved in the calcium-dependent fertility regulation process, the viscoelastic properties of the mucus obtained from lamb cervix and human semen, as well as their water and total protein contents after exposure to EDTA, a chelating agent, or Nonoxynol-9 (N-9), a spermicidal agent, were examined. The viscosity was measured using a Cone Plate Digital Viscometer, while the water and total protein contents were determined by the lyophilization process and the Lowry method, respectively. The significant changes in the rheological properties of mucus, such as its viscosity and the water content, upon exposure to EDTA were demonstrated. The viscosity of cervical mucus and human semen were significantly increased by EDTA treatment (as compared to the controls): lamb cervical mucus (2.9 ± 0.3 vs. 2.2 ± 0.3 cps) and human semen (5.0 ± 0.3 vs. 4.3 ± 0.3 cps), respectively. The hydration rate was decreased by EDTA treatment as compared with the control (93.6 ± 0.7 vs. 96.8 ± 0.8%). Among tested samples, the reduction in the percentage of sperm penetration through the cervical mucus was the highest in the mucus containing EDTA, which had the lowest water content (93.6 ± 0.7%), indicating that there is a positive relationship between the hydration rate of the cervical mucus and its ability to permit the penetration of spermatozoa. This result indicates that spermicidal activity exerted by high concentrations of EDTA is in part due to its effect on the rheological properties of cervical mucus or semen.  相似文献   
75.
Since the beginning of this century, trans- naso-sphenoidal resection of the pituitary fossa tumors has been widely used clinically. It has more merits than other operative approaches used before. In China it has been adopted by both ENT doctors and neurosurgeons since 1959.1 In order to afford some relevant anatomical data, we measured 137 adult sagittal plane skulls with distinct landmarks.  相似文献   
76.
OBJECTIVE: To examine the distribution of rat facial motoneurons contributing different branches under normal situation and when nerve reinnervation occurred following facial nerve axotomy. METHODS: The normal distribution of motoneurons innervated both buccal and marginal mandibular branches and its reorganization after facial nerve reinnervation was observed using retrograde labeling with fluorescein. RESULTS: Under normal situation, the motoneurons contributing buccall and marginal mandibular branches were primarily distributed in the intermedial and lateral subnucleus in facial nucleus and almost completely overlapped. The two types labeled neurons organized closely, but there were no double-labeled neurons. Although the motoneurons contributing buccall and marginal mandibular branches were primarily overlapped 4 month post-anastomosis, the number of the labeled neurons obviously decreased and the organization got more scattered. There were 10% of buccall branches, 5% of marginal mandibular motoneurons in the dorsal subnuleus, 1% of buccall and 4% of marginal mandibular in dorsal ventral and medial subnucleus. The distribution pattern of the motoneurons 6 month post-anastomosis was similar to that of 4 month post-anastomosis, but the number of the labeled neurons increased, and there were 1%-2% double-labeled neurons. CONCLUSION: The distribution pattern of motoneurons innervated both buccal and marginal mandibular branches indicates that it should exist wide-spread communicating branches, and its reorganization after facial nerve reinnervation suggests that misdirected regeneration occurs among motoneurons innervating different branches.  相似文献   
77.
78.
79.
The effect of lowered estradiol levels on periodontal tissue   总被引:1,自引:0,他引:1  
  相似文献   
80.
The firing rate of locus coeruleus (LC) neurons in rat brain slices was increased reversibly by agents that either elevate intracellular levels of adenosine 3',5'-cyclic monophosphate (cAMP) or mimic its actions (e.g., forskolin, and activator of adenylate cyclase, 8-Br-cAMP, a membrane permeable analog of cAMP, and Ro20-1724, a preferential inhibitor of cAMP-phosphodiesterase). Intracellular recordings showed that 8-Br-cAMP and forskolin induce a depolarization of LC neurons, accompanied by a decrease in input resistance. The 8-Br-cAMP- and forskolin-elicited depolarization persisted in the presence of cobalt, a calcium channel blocker. Steady-state current-voltage curves revealed that in the voltage range of -50 to -120 mV, 8-Br-cAMP and forskolin induced an inward current, which did not reverse at the potassium equilibrium potential and could not be blocked by tetrodotoxin. Partial replacement of sodium with Tris or choline markedly reduced the depolarization elicited by 8-Br-cAMP. We conclude that 8-Br-cAMP and forskolin act through a common mechanism to increase the firing rate of locus coeruleus neurons by inducing a cAMP-activated inward current, carried out at least in part by sodium ions.  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