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   17740篇
  免费   1803篇
  国内免费   979篇
耳鼻咽喉   159篇
儿科学   262篇
妇产科学   302篇
基础医学   2089篇
口腔科学   291篇
临床医学   2419篇
内科学   3176篇
皮肤病学   242篇
神经病学   1012篇
特种医学   840篇
外国民族医学   5篇
外科学   2087篇
综合类   2162篇
现状与发展   1篇
一般理论   6篇
预防医学   1125篇
眼科学   499篇
药学   1697篇
  15篇
中国医学   742篇
肿瘤学   1391篇
  2024年   54篇
  2023年   293篇
  2022年   588篇
  2021年   814篇
  2020年   641篇
  2019年   557篇
  2018年   642篇
  2017年   571篇
  2016年   558篇
  2015年   773篇
  2014年   962篇
  2013年   920篇
  2012年   1206篇
  2011年   1201篇
  2010年   919篇
  2009年   764篇
  2008年   811篇
  2007年   829篇
  2006年   862篇
  2005年   787篇
  2004年   648篇
  2003年   620篇
  2002年   579篇
  2001年   474篇
  2000年   397篇
  1999年   416篇
  1998年   352篇
  1997年   335篇
  1996年   257篇
  1995年   249篇
  1994年   163篇
  1993年   149篇
  1992年   134篇
  1991年   107篇
  1990年   97篇
  1989年   121篇
  1988年   107篇
  1987年   88篇
  1986年   62篇
  1985年   62篇
  1984年   38篇
  1983年   23篇
  1982年   22篇
  1981年   28篇
  1980年   26篇
  1979年   29篇
  1978年   18篇
  1977年   19篇
  1976年   20篇
  1974年   18篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
11.
报道并分析20例小儿糖尿病患儿的临床资料及血胰岛细胞抗体(ICA)及胰岛素自身抗体(IAA)的测定资料。在20例患儿中,临床表现多不典型。在酮症酸中毒的治疗中小剂量胰岛素疗法方法简便,安全可靠,并发症少。本组患儿ICA阳性率55%,IAA阳性率30%,经卡方检验均显著高于对照组,推测病毒感染引起自身免疫反应,产生ICA及IAA而致本病发生。  相似文献   
12.
Clinical data of 192 patients with breast cancer with a primary lesion of 2-5 cm (stage II according to the criteria recommended by the UICC) and with histopathologically confirmed positive axillary lymph nodes were analyzed. The patients were divided into three groups: 1) surgical excision alone; 2) surgery plus irradiation; and 3) surgery plus chemotherapy. It was shown that the 5-year survival rates for these groups were 40.5%, 61.0%, and 62.0%, respectively (P less than .05).  相似文献   
13.
We provide further evidence for the two-factor structure of the 9-item Academic Expectations Stress Inventory (AESI) using confirmatory factor analysis on a sample of 289 Canadian adolescents and 310 Singaporean adolescents. Examination of measurement invariance tests the assumption that the model underlying a set of scores is directly comparable across groups. This study also examined the cross-cultural validity of the AESI using multigroup confirmatory factor analysis across both the Canadian and Singaporean adolescent samples. The results suggested cross-cultural invariance of form, factor loadings, and factor variances and covariances of the AESI across both samples. Evidence of AESI's convergent and discriminant validity was also reported. Findings from t-tests revealed that Singaporean adolescents reported a significantly higher level of academic stress arising from self expectations, other expectations, and overall academic stress, compared to Canadian adolescents. Also, a larger cross-cultural effect was associated with academic stress arising from other expectations compared with academic stress arising from self expectations.  相似文献   
14.
15.
Changes in T .lymphocyte subsets after severe traumatic brain inJury   总被引:2,自引:0,他引:2  
BACKGROUND: Besides local changes of cranial parenchymal cells, hemorrhage, etc., severe traumatic brain injuries also cause the changes of total body fluid and various functions, and the changes of lymphocytes and T lymphocyte subsets should be paid more attention to. OBJECTIVE: To reveal the changing laws of T lymphocyte subsets after severe traumatic brain injury, and compare with mild to moderate brain injury. DESIGN: A comparative observation. SETTINGS: Department of Neurosurgery, Longgang District Buji People's Hospital of Shenzhen City; Central Laboratory of Shenzhen Hospital of Prevention and Cure for Chronic Disease. PARTICIPANTS: All the subjects were selected from the Department of Neurosurgery, Longgang District Buji People's Hospital of Shenzhen City from August 2002 to August 2005. Thirty patients with severe brain injury, whose Glasgow coma score (GCS) was ≤ 8 points, were taken as the experimental group, including 21 males and 9 females, aging 16 - 62 years. Meanwhile, 30 patients with mild traumatic brain injury were taken as the control group (GCS ranged 14- 15 points), including 18 males and 12 females, aging 15 -58 years. All the subjects were in admission at 6 hours after injury, without disease of major organs before injury Informed consents were obtained from all the patients or their relatives. METHODS: (1) The T lymphocytes and the subsets in peripheral blood were detected with immunofluorescent tricolor flow cytometry at l, 3, 7 and 14 days after injury in both groups. (2) The conditions of pulmonary infections were observed at 4 days after injury. The differences of measurement data were compared with the t test. MAIN OUTCOME MEASURES: Changes of T lymphocytes subsets at 1 - 14 days after severe and mild or moderate traumatic injury. RESULTS: Finally, 28 and 25 patients with mild to moderate traumatic brain injury, whereas 25 and 21 patients with severe traumatic brain injury were analyzed at 7 and 14 days respectively, and the missed ones died due to the development of disease. (1) Changes of T lymphocyte subsets: At 1 and 3 days after injury, CD3, CD4, CD8, CD4/CD8 began to decrease, whereas CD8 increased in the experimental group, which were very significantly different from those in the control group (t =2.77 - 3.26, P 〈 0.01), and began to recover at 7 days, which were significantly different from those in the control group (t = 2.06 - 2.24, P 〈 0.05), and generally recovered to the normal levels at 14 days (P 〉 0.05). (2) Conditions of pulmonary infections: At 4 days after injury, the rate of pulmonary infection was significantly different between the experimental group and control group [73% (22/30), 0, x2=37.29, P 〈 0.01]. CONCLUSION: Patients with severe traumatic brain injury suffer from damages of cellular immune function at early period (within 7 days), and they are easily to be accompanied by pulmonary infections.  相似文献   
16.
17.
The melt agglomeration process of lactose powder with hydrogenated cottonseed oil (HCO) as the hydrophobic meltable binder was investigated by studying the physicochemical properties of molten HCO modified by sucrose stearates S170, S770 and S1570. The size, size distribution, micromeritic and adhesion properties of agglomerates as well as surface tension, contact angle, viscosity and specific volume of molten HCO, with and without sucrose stearates, were examined. The viscosity, specific volume and surface tension of molten HCO were found to be modified to varying extents by sucrose stearates which are available in different HLB values and melt properties. The growth of melt agglomerates was promoted predominantly by an increase in viscosity, an increase in specific volume or a decrease in surface tension of the molten binding liquid. The agglomerate growth propensity was higher with an increase in inter-particulate binding strength, agglomerate surface wetness and extent of agglomerate consolidation which enhanced the liquid migration from agglomerate core to periphery leading to an increased surface plasticity for coalescence. The inclusion of high concentrations of completely meltable sucrose stearate S170 greatly induced the growth of agglomerates through increased specific volume and viscosity of the molten binding liquid. On the other hand, the inclusion of incompletely meltable sucrose stearates S770 and S1570 promoted the agglomeration mainly via the reduction in surface tension of the molten binding liquid with declining agglomerate growth propensity at high sucrose stearate concentrations. In addition to being an agglomeration modifier, sucrose stearate demonstrated anti-adherent property in melt agglomeration process. The properties of molten HCO and melt agglomerates were dependent on the type and concentration of sucrose stearate added.  相似文献   
18.
Cooking processes that gelatinize granules or disrupt structure might increase the glucose and insulin responses because a disruption of the structure of starch by gelatinization increases its availability for digestion and absorption in the small intestine. We hypothesized that the uncooked form of rice, which has a relatively low degree of gelatinization even though in powder form, would result in lower metabolic glucose and insulin responses compared with cooked rice (CR). To assess the effects of the gelatinization of rice on metabolic response of glucose and insulin, we investigated the glucose and insulin responses to 3 rice meals of different gelatinization degree in female college students (n = 12): CR (76.9% gelatinized), uncooked rice powder (UP; 3.5% gelatinized), and uncooked freeze-dried rice powder (UFP; 5.4% gelatinized). Uncooked rice powders (UP and UFP) induced lower glucose and insulin responses compared with CR. The relatively low gelatinization degree of UPs resulted in low metabolic responses in terms of the glycemic index (CR: 72.4% vs UP: 49.7%, UFP: 59.8%) and insulin index (CR: 94.8% vs UP: 74.4%, UFP: 68.0%). In summary, UPs that were less gelatinized than CR induced low postprandial glucose and insulin responses.  相似文献   
19.
大学生心理健康教育干预研究   总被引:11,自引:2,他引:9  
目的 研究高校心理健康干预模式 ,提高大学生心理健康水平。方法 采取分层整群抽样的方法 ,运用SCL - 90自评量表对该院学生测试评分 ,分别进行实施心理健康干预模式 (心理教育、心理预防、心理训练 )前后状况调查 ,比较学生心理测试总体水平。结果 学校心理健康教育干预实施后一年 ,学生心理测试 8项因子分均值低于心理健康干预实施前 ,其中强迫、人际关系、焦虑、恐怖、偏执因子分实施前后有显著性差异 (P <0 0 5 )。结论 学校实施心理健康教育干预能有效地维护大学生心理健康 ,促进大学生心理发展 ,提高大学生心理素质  相似文献   
20.
Deoxycholic acid (DA) caused a dose-related release of histamine (HR) from mast cells of rat peritoneum (RPMC) and mucosal cells of guinea pig rectocolon (RCMC). In both cell populations, DA-induced HR was: (1) accompared by a parallel release of lactate dehydrogenase (LDH), (2) not affected by metabolic inhibitors, (3) dependent on time of incubation, temperature and pH, and affected by Ca++ concentration in RPMC but not in RCMC. DA-induced HR from RCMC may be involved in certain functional disorders of the colon.  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