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   14948篇
  免费   963篇
  国内免费   37篇
耳鼻咽喉   126篇
儿科学   607篇
妇产科学   469篇
基础医学   2137篇
口腔科学   257篇
临床医学   2060篇
内科学   2397篇
皮肤病学   284篇
神经病学   1656篇
特种医学   272篇
外科学   1118篇
综合类   156篇
现状与发展   1篇
一般理论   37篇
预防医学   2195篇
眼科学   210篇
药学   810篇
中国医学   11篇
肿瘤学   1145篇
  2023年   144篇
  2022年   181篇
  2021年   343篇
  2020年   253篇
  2019年   377篇
  2018年   375篇
  2017年   336篇
  2016年   293篇
  2015年   356篇
  2014年   510篇
  2013年   801篇
  2012年   1111篇
  2011年   1150篇
  2010年   585篇
  2009年   545篇
  2008年   995篇
  2007年   984篇
  2006年   1021篇
  2005年   1010篇
  2004年   913篇
  2003年   843篇
  2002年   829篇
  2001年   113篇
  2000年   67篇
  1999年   112篇
  1998年   190篇
  1997年   149篇
  1996年   108篇
  1995年   110篇
  1994年   92篇
  1993年   78篇
  1992年   86篇
  1991年   52篇
  1990年   55篇
  1989年   47篇
  1988年   39篇
  1987年   27篇
  1986年   47篇
  1985年   46篇
  1984年   53篇
  1983年   65篇
  1982年   82篇
  1981年   53篇
  1980年   50篇
  1979年   31篇
  1978年   34篇
  1977年   21篇
  1976年   19篇
  1974年   22篇
  1972年   14篇
排序方式: 共有10000条查询结果,搜索用时 46 毫秒
91.
78 rats weighing 180–200 g were used to assess the bone tissue responses to three periodontal dressings (Coe-pak, Peripac and Ward's Wondrpak). The dressings were implanted subscutaneously on periosteal covered and denuded bone. Sham operated animals served as controls and a comparison btween the responses produced by the three dressngs were made.
In one series the dressings remained in situ for 3, 7, 14, 30 and 90 days. Osteocyte damage of varying extent was recorded for all materials. Remodelling of the bone surface adjacent to the dressing was observed. Bone resorption was never foud in the gournd defect produced to denude the bone tissue, but repair of the defect by bone formation was observed after long observation periods. This repair was retarded in some animals were Ward's Wondrpak had been implanted.
In another seiries Ward's Waondrpak was implanted against bone for three days, then re-operated to remove the dressing and the defect allowed to heal for 30 days. The test group exhibited empty bone lacunae and the repair of the defect was retarded or lacking.  相似文献   
92.
Neuropathological features in brainstem, cerebellum and spinal cord. In addition to cerebellar, vestibullar nuclei and spinal cord posterior columns involvement, a moderate reduction of motor neurons in hypoglossal nucleus and anterior horn of the thoracic spinal cord was present.  相似文献   
93.
目的探讨血清胸苷激酶1(TK1)作为肿瘤细胞增殖标志物对恶性肿瘤诊断及疗效评估的意义。方法应用免疫印迹-增强化学发光法检测恶性肿瘤组(53例)治疗前后、体格检查组(49例)以及健康对照组(18名)的血清TK1水平。治疗前与治疗后比较用配对t检验,治疗前和后分别与健康对照组、体格检查组比较采用两独立样本均数比较t检验。结果恶性肿瘤组治疗前STK1为0.3—11.3(2.4±2.0)pmol/L;恶性肿瘤组治疗后STK1为0.3~5.0(0.9±0.8)pmol/L;体格检查组STK1为0.1~2.1(0.8±0.3)pmol/L;健康对照组STK1为0.5~1.2(0.7±0.2)pmol/L。恶性肿瘤组治疗前与治疗后之间STK1水平差异有统计学意义(t=5.257,P〈0.0001)。恶性肿瘤组治疗前与健康对照组和体格检查组STK1水平比较,差异均有统计学意义(t=3.568和5.460,P=0.001和〈0.0001),而恶性肿瘤组治疗后与健康对照组和体格检查组STK1水平比较,差异均无统计学意义(t=1.056和0.715,P均〉0.05)。结论血清TK1检测细胞增殖有较高的特异性和灵敏度,对临床监测恶性肿瘤疗效和在体格检查中进行恶性肿瘤风险筛查具有重要意义。  相似文献   
94.
ObjectiveTo evaluate predictors for patient preference regarding multifetal or singleton gestation among women presenting for infertility care.DesignCross-sectional study.SettingAcademic university hospital-based infertility clinic.Patient(s)Five hundred thirty-nine female patients with infertility who presented for their initial visit.Main outcome measure(s)Demographic characteristics, infertility history, insurance coverage, desired treatment outcome, acceptability of multifetal reduction, and knowledge of the risks of multifetal pregnancies were assessed using a previously published 41-question survey. Univariate analysis was performed to assess patient factors associated with the desire for multiple births. Independent factors associated with this desire were subsequently assessed by multivariate logistic regression analysis.Result(s)Nearly a third of women preferred multiples over a singleton gestation. Nulliparity, lower annual household income, older maternal age, marital status, larger ideal family size, openness to multifetal reduction, and lack of knowledge of the maternal/fetal risks of twin pregnancies were associated with pregnancy desire. Older age (OR (95% CI) 1.66 (1.20–2.29)), nulliparity (OR (95% CI) 0.34 (0.20–0.58)), larger ideal family size (OR (95% CI) 2.34 (1.73–3.14)), and lesser knowledge of multifetal pregnancy risk (OR (95% CI) 0.67 (0.55–0.83)) were independently associated with desire.Conclusion(s)A large number of patients undergoing fertility treatment desire multifetal gestation. Although a lack of understanding of the risks associated with higher order pregnancies contributes to this desire, additional individual specific variables also contribute to this trend. Efforts to reduce the incidence of multiples should focus not only on patient education on comparative risks of multiples vs singleton pregnancies but also account for individual specific reservations.  相似文献   
95.
Behavioural sciences have complemented medical and epidemiological sciences in the response to the SARS-CoV-2 pandemic. As vaccination uptake continues to increase across the EU/EEA – including booster vaccinations – behavioural science research remains important for both pandemic policy, planning of services and communication. From a behavioural perspective, the following three areas are key as the pandemic progresses: (i) attaining and maintaining high levels of vaccination including booster doses across all groups in society, including socially vulnerable populations, (ii) informing sustainable pandemic policies and ensuring adherence to basic prevention measures to protect the most vulnerable population, and (iii) facilitating population preparedness and willingness to support and adhere to the reimposition of restrictions locally or regionally whenever outbreaks may occur. Based on mixed-methods research, expert consultations, and engagement with communities, behavioural data and interventions can thus be important to prevent and effectively respond to local or regional outbreaks, and to minimise socioeconomic and health disparities. In this Perspective, we briefly outline these topics from a European viewpoint, while recognising the importance of considering the specific context in individual countries.  相似文献   
96.
97.
98.
99.
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