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   241833篇
  免费   20851篇
  国内免费   14360篇
耳鼻咽喉   2174篇
儿科学   3046篇
妇产科学   4879篇
基础医学   28291篇
口腔科学   4217篇
临床医学   30909篇
内科学   39892篇
皮肤病学   2818篇
神经病学   13532篇
特种医学   8611篇
外国民族医学   96篇
外科学   26656篇
综合类   34070篇
现状与发展   48篇
一般理论   45篇
预防医学   15096篇
眼科学   6678篇
药学   24200篇
  164篇
中国医学   10889篇
肿瘤学   20733篇
  2024年   697篇
  2023年   3476篇
  2022年   8663篇
  2021年   11374篇
  2020年   8382篇
  2019年   7549篇
  2018年   7989篇
  2017年   6972篇
  2016年   6674篇
  2015年   10092篇
  2014年   12698篇
  2013年   11888篇
  2012年   17531篇
  2011年   19215篇
  2010年   11723篇
  2009年   9379篇
  2008年   12759篇
  2007年   12823篇
  2006年   12362篇
  2005年   12444篇
  2004年   8599篇
  2003年   7637篇
  2002年   6611篇
  2001年   5997篇
  2000年   6109篇
  1999年   6416篇
  1998年   3671篇
  1997年   3693篇
  1996年   2804篇
  1995年   2602篇
  1994年   2243篇
  1993年   1511篇
  1992年   2293篇
  1991年   2003篇
  1990年   1668篇
  1989年   1467篇
  1988年   1276篇
  1987年   1183篇
  1986年   953篇
  1985年   759篇
  1984年   501篇
  1983年   382篇
  1982年   232篇
  1981年   208篇
  1980年   196篇
  1979年   249篇
  1978年   141篇
  1977年   119篇
  1976年   105篇
  1974年   116篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
991.
人工心脏瓣膜置换术后患者口服抗凝治疗不当所致的出血与栓塞占远期并发症的首位。血浆凝血酶原时间(PT)是对人工心脏瓣膜置换术后患者口服抗凝药监测简便、敏感、快速、实用的实验室首选指标,其报告方式的标准化对临床医生有着非常重要的指导意义,国际标准化比率(PT-INR)作为一个较好的监测抗凝药物水平的表示方法,已被WHO推荐使用,但对于人工心脏瓣膜置换术后患者口服抗凝药治疗时PT-INR值的允许范围各地报告不一,为此,我们对我院收治的行人工心脏瓣膜置换术后患者口服华法令治疗时PT监测的情况进行了总结和研究,以探讨适合本地区人工心脏瓣膜置换术后患者口服抗凝药治疗监测中PT-INR的允许范围,为临床合理用药提供安全可靠的实验室监测指标。现报告如下。  相似文献   
992.
目的 探讨外伤性白内障术后二期植入后房型人工晶状体的时机和手术方式。方法 对34例(34只眼)外伤性白内障术后无晶状体眼根据不同情况采用直接睫状沟植入法或缝线固定法进行二期植入后房型人工晶状体,观察两组患者的术后反应和治疗效果。结果 直接睫状沟植入法14只眼(41.2%),缝线固定法20只眼(58.8%),31只眼(91.2%)视力达到0.1以上,21只眼(61.76%)视力达0.3以上,28只眼(82.4%)术后矫正视力等于或高于术前最佳矫正视力。结论 选取合适的时机和方式二期植入人工晶状体,有助于减少术后并发症,提高视功能的恢复。  相似文献   
993.
This was a 6-week, parallel, randomized, double-blind study comparing the efficacy and safety of the 0.5% timolol/2.0% MK-507 combination b.i.d. to the concomitant administration of 0.5% timolol b.i.d. and 2.0% MK-507 b.i.d. Patients with ocular hypertension or open-angle glaucoma from 21 to 85 years of age were enrolled in this study. Each of them should have intraocular pressure (IOP) of 20 mmHg or more in the study eye after they completed the wash-out period. The patients enrolled were randomly assigned to either combination (0.5% timolol/2.0% MK-507 b.i.d. and placebo b.i.d.) or concomitant (0.5% timolol b.i.d. and 2.0% MK-507 b.i.d.) treatment. During the study, no systemic or topical medication affecting IOP other than test drugs were allowed. A total of 20 randomized patients were included in the intention-to-treat population for analysis of data. The ten were assigned to the combination treatment and others were assigned to the concomitant treatment. There was no statistically significant difference between the two study treatments in terms of gender distribution, average age, and average IOP at the trough and the peak before starting the test medications. Mean reduction of the IOP from baseline to the final visit at the trough was 5.04 mmHg in the combination treatment and was 2.73 mmHg in the concomitant treatment. Mean reduction of the IOP at the peak was 2.19 mmHg in the combination treatment and was 2.53 mmHg in the concomitant treatment. There were no statistically significant differences in the above analyses between the two treatments. Safety evaluation was carried out, and number of adverse events in each treatment group did not differ substantially. Ocular signs and symptoms were evaluated in each visit, and all of the between-treatment values were not different significantly, either. Laboratory tests were performed, and showed no significant differences between pre- and post-treatment periods. None of these was found to be clinically serious, either. We concluded that the 0.5% timolol/2.0% MK-507 combination b.i.d. is equivalent in the efficacy of lowering IOP as well as safety compared to the concomitant administration of 0.5% timolol b.i.d. and 2.0% MK-507 b.i.d. in patients with ocular hypertension or open-angle glaucoma.  相似文献   
994.
目的 了解我院医院感染发生及漏报率。方法 将我院 2 0 0 3年 1~ 12月出院的所有病例进行回顾性调查。结果 医院感染率 7.3 2 %、漏报率 14 .93 %,均符合国家卫生部要求。结论 做好医院感染监测工作 ,严格执行各项工作制度 ,掌握医院感染与手术并发症的鉴别诊断 ,提高医院感染诊断的准确率  相似文献   
995.
2006年10月开始上主班,通过近2个月的主班工作及与前两任主班的共同经验交流,探讨泌尿科主班工作制在临床工作中的应用,现介绍如下。  相似文献   
996.
997.
BACKGROUND AND PURPOSE: Etanercept (Enbrel), a recombinant tumor necrosis factor receptor fusion protein, has been shown to be effective in the treatment of patients with rheumatoid arthritis (RA). The purpose of this study was to compare the efficacy and safety of etanercept in combination with methotrexate (MTX) and MTX alone in Taiwanese patients with active RA. METHODS: In this double-blind study, 58 patients with active RA who were maintained on MTX therapy at a stable dose of 12.5 to 20 mg per week for 4 weeks were randomized to receive either etanercept 25 mg (n = 29) or placebo (n = 29) by subcutaneous injection twice weekly over a period of 12 weeks. The primary endpoint was the reduction of tender and swollen joint counts by 20% (ACR 20), 50% (ACR 50), and 70% (ACR 70) as determined by the American College of Rheumatology criteria at the 12th week. RESULTS: The addition of etanercept to MTX resulted in a greater reduction in the number of tender (7.00 vs 2.45, p = 0.012) and swollen joints (8.55 vs 3.86, p = 0.017), and in serum levels of C-reactive protein (1.26 mg/dL vs 0.45 mg/dL, p = 0.014) compared to MTX alone after 12 weeks of therapy. In addition, the global assessment of disease activity by both physicians and patients, duration of morning stiffness, pain visual analog scale score, and Health Assessment Questionnaire were all improved by etanercept plus MTX therapy. Results for the overall improvement in disease activity assessed by ACR 20 (90% vs 34%), ACR 50 (66% vs 10%) and ACR 70 (24% vs 0%) all favored the etanercept plus MTX group. However, the adverse events were comparable between the 2 treatment groups. CONCLUSION: Etanercept in combination with MTX was well tolerated and provided significantly more clinical benefit than MTX alone in Taiwanese patients with active RA.  相似文献   
998.
BACKGROUND AND PURPOSE: In hospitals, preterm infants are routinely fed specified amounts of formula on a fixed schedule. This results in the baby's intake volume being regular and easily confirmed, but does not consider the individual baby's needs. The purpose of this study was to compare the effects of demand feeding and fixed schedule feeding for healthy premature newborn babies. METHODS: A 2-feeding-type, 2-period crossover study design was employed, in which each period consisted of 2 days, the first of which was a washout period, comprising a self-comparison protocol designed to identify any differences in the feeding characteristics of premature infants on demand or scheduled bottle-feeding. Eleven preterm infants were included. The sample size was monitored during the observation period by power calculation. The mean weight at study entry was 1897.27 +/- 175.94 g and the mean postconceptional age was 35.34 +/- 1.54 weeks. RESULTS: Compared with scheduled feeding, demand feeding was associated with a longer daily mean interval (4.17 vs 3.02 hours; p = 0.00), greater volume per feed for demand feeding (67.28 vs 51.11; p = 0.00), greater feeding speed (5.73 vs 4.51 mL/min; p = 0.00), but a similar daily total duration of feeding. There was no significant difference in the daily total feeding volume. CONCLUSIONS: Demand feeding provides superior volume per feed, and feeding speed and shortens the duration of feeding compared to feeding on a routine schedule. It is suitable and feasible for healthy premature newborns.  相似文献   
999.
This study used the indices of the temporomandibular glenoid and posterior slope of the eminence by tomography to determine the effect of severe dental attrition on temporomandibular glenoid morphology. The results showed: the temporomandibular glenoid indexes in the group with dental severe attrition and in the control group were respectively 91.49 +/- 8.20 and 92.54 +/- 8.38 (P > 0.05), and the indices of posterior slope of the eminence were 49.79 +/- 5.84 and 50.38 +/- 4.58 (P > 0.05), the difference was not statistical. It was concluded that severe dental attrition would not certainly cause abnormal temporomandibular glenoid.  相似文献   
1000.
目的:评价酸蚀及化学偶联剂对树脂—烤瓷粘结强度的影响。方法:烤瓷试件分7组用5%氟氢酸分别酸蚀0~180s,然后一半使用偶联剂,另一半不使用偶联剂,与树脂粘结后测试剪切粘结强度。结果:无偶联剂组酸蚀后可使瓷—树脂粘结强度达到30MPa(150s),对照组为3MPa;单独使用偶联剂可使粘结强度达25.2MPa,若结合酸蚀剂最高可达34.3MPa,但酸蚀后使用偶联剂,酸蚀时间对粘结强度无明显影响;结论:瓷酸蚀是瓷粘结修复中重要的处理方法;偶联剂的使用有利于提高粘结强度,并可用较短的酸蚀时间获得理想的粘结强度。  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