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   344850篇
  免费   22509篇
  国内免费   7616篇
耳鼻咽喉   4120篇
儿科学   9620篇
妇产科学   6580篇
基础医学   27898篇
口腔科学   8038篇
临床医学   37674篇
内科学   43116篇
皮肤病学   4587篇
神经病学   19472篇
特种医学   7943篇
外国民族医学   31篇
外科学   36733篇
综合类   51610篇
现状与发展   12篇
一般理论   29篇
预防医学   36796篇
眼科学   5312篇
药学   30507篇
  388篇
中国医学   30902篇
肿瘤学   13607篇
  2023年   5561篇
  2022年   9869篇
  2021年   13516篇
  2020年   12535篇
  2019年   18469篇
  2018年   15991篇
  2017年   12878篇
  2016年   10351篇
  2015年   9719篇
  2014年   20102篇
  2013年   21588篇
  2012年   18414篇
  2011年   19952篇
  2010年   16061篇
  2009年   14723篇
  2008年   14343篇
  2007年   14775篇
  2006年   12849篇
  2005年   11143篇
  2004年   9065篇
  2003年   7997篇
  2002年   6253篇
  2001年   5620篇
  2000年   4629篇
  1999年   4034篇
  1998年   3272篇
  1997年   3124篇
  1996年   2701篇
  1995年   2585篇
  1994年   2502篇
  1993年   1994篇
  1992年   2024篇
  1991年   1736篇
  1990年   1552篇
  1989年   1379篇
  1988年   1315篇
  1987年   1123篇
  1985年   3792篇
  1984年   4800篇
  1983年   3344篇
  1982年   3805篇
  1981年   3551篇
  1980年   3158篇
  1979年   2909篇
  1978年   2535篇
  1977年   1911篇
  1976年   2154篇
  1975年   1638篇
  1974年   1446篇
  1973年   1291篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
71.
目的:探讨铲状电极经尿道前列腺电汽化切割术中的手术经验及疗效。方法:总结了120例经尿道前列腺电汽化切割手术的治疗资料。结果:术后随访1月~2年,120倒手术患者118例治愈,2例于术后出现急性肾衰,经保守对症治疗痊愈,2例出现压力性尿失禁,经对症治疗好转。结论:铲状电极行前列腺组织的汽化切割,优于滚轮汽化电极或电极弧,术中术后出血少,术中术野清晰,安全可靠。  相似文献   
72.
Ciclesonide is an onsite-activated inhaled corticosteroid (ICS) for the treatment of asthma. This study compared the efficacy, safety and effect on quality of life (QOL) of ciclesonide 160 microg (ex-actuator; nominal dose 200 microg) vs. budesonide 400 microg (nominal dose) in children with asthma. Six hundred and twenty-one children (aged 6-11 yr) with asthma were randomized to receive ciclesonide 160 microg (ex-actuator) once daily (via hydrofluoroalkane metered-dose inhaler and AeroChamber Plus spacer) or budesonide 400 microg once daily (via Turbohaler) both given in the evening for 12 wk. The primary efficacy end-point was change in forced expiratory volume in 1 s (FEV1). Additional measurements included change in daily peak expiratory flow (PEF), change in asthma symptom score sum, change in use of rescue medication, paediatric and caregiver asthma QOL questionnaire [PAQLQ(S) and PACQLQ, respectively] scores, change in body height assessed by stadiometry, change in 24-h urinary cortisol adjusted for creatinine and adverse events. Both ciclesonide and budesonide increased FEV1, morning PEF and PAQLQ(S) and PACQLQ scores, and improved asthma symptom score sums and the need for rescue medication after 12 wk vs. baseline. The non-inferiority of ciclesonide vs. budesonide was demonstrated for the change in FEV1 (95% confidence interval: -75, 10 ml, p = 0.0009, one-sided non-inferiority, per-protocol). In addition, ciclesonide and budesonide showed similar efficacy in improving asthma symptoms, morning PEF, use of rescue medication and QOL. Ciclesonide was superior to budesonide with regard to increases in body height (p = 0.003, two-sided). The effect on the hypothalamic-pituitary-adrenal axis was significantly different in favor of ciclesonide treatment (p < 0.001, one-sided). Both ciclesonide and budesonide were well tolerated. Ciclesonide 160 microg once daily and budesonide 400 microg once daily were effective in children with asthma. In addition, in children treated with ciclesonide there was significantly less reduction in body height and suppression of 24-h urinary cortisol excretion compared with children treated with budesonide after 12 wk.  相似文献   
73.
Abstract Pericardial tamponade remains a diagnostic challenge to the clinician especially when the patient is well compensated hemodynamically. We report an unusual case who sought medical help 1 month after having been stabbed in his chest. An investigation revealed a perforation of the myocardium and a pericardial tamponade. The patient survived thanks to a large organized clot that plugged the perforation. The patient was exposed to increased risk due to delayed onset, recognition, and therapy of the tamponade. Most reports on this subject deal with acute pericardial tamponade. Only few cases of delayed pericardial tamponade have been reported. A review of the relevant literature and the therapeutic approaches are discussed.  相似文献   
74.
本文作者比较了不同时期的纸质病案的使用率,讨论了旧病案的缺点,如难于保存,占用空间及实用价值不大.作者提出了改进保存病案的办法.  相似文献   
75.
目的 探讨提高上尿路结石碎石成功率的微创治疗方法。方法 采用经皮肾穿微造瘘输尿管镜气压弹道碎石,术中放置双J管,术后配合体外冲击波碎石术(ESWL)治疗上尿路结石48例。结果 结石总排净率为89.1%,结石最小排净率79.2%,无严重并发症发生。结论 该方法结石排净率高,创伤较小,手术并发症少,是上尿路结石较为理想的微创治疗方法。  相似文献   
76.
After removal of intraductal stones, a 10‐Fr or 7‐Fr pancreatic stent was placed in 16 patients with upstream ductal dilation proximal to a stricture of the main pancreatic duct. Stents were removed after a mean duration of 52.5 days. Nine patients underwent repeated stenting. About one year after removal of the initial stent, when the remaining upstream ductal dilation was found on follow‐up pancreatograms, the next stent was replaced. Repeated stenting improved outflow of pancreatic juice more effectively than one‐time stenting. Correlation between long‐term pain relief without recurrence of intraductal stones and reduction of duct diameter was also shown. Stent occlusion was observed in 14 of 30 stents. Stent occlusion was frequently associated with recurrence of pancreatitis and intraductal stones, and was also associated with morphologic changes in the pancreatic ductal system. Although there were no significant differences between stent patency of the initial stents and that of the next stents, stent patency of 10‐Fr stents was superior to that of 7‐Fr stents. 10‐Fr stents should be removed within 8 weeks and 7‐Fr stents should be removed within 4 weeks for the prevention of stent occlusion. Repeated stenting with short‐term stenting is therefore considered a safe and effective protocol of endoscopic pancreatic stenting.  相似文献   
77.
The naevus of Ota (naevus fusculocoeruleus ophthalmomaxillaris) was first described by the Japanese dermatologist M. T. Ota in 1939. It has a reported incidence of 0.2% to 1% in the Japanese population. It usually occurs in the skin innervated by the first or second branch of the trigeminal nerve. The naevus comprises dermal melanocytes and is congenital or acquired during adolescence. Commonly associated lesions include scleral melanocytosis and other ocular manifestations as well as lesions of the tympanic membrane, oral and intranasal mucosa and leptomeninges. Diseases associated with Ota's naevus in rare cases are open-angle glaucomas and melanoma. The naevus of Ota in Europeans is a rare manifestation. We report the very rare case of a bilateral naevus of Ota associated with enoral melanocytosis in a white European person.  相似文献   
78.
目的:探讨股骨头缺血坏死的病理和影像学研究进展情况。方法:阅读并分析关于股骨头缺血坏死的文献。结果:影像学检查反映疾病的病理改变,在诊断中占有重要地位。结论:磁共振成像具有很高的敏感性和准确性,不仅能发现股骨头坏死的早期病变,且能反映病变的范围和程度,对早期诊断和治疗具有积极意义。  相似文献   
79.
Summary Quantitative aspects of the microanatomy of the pineal gland and other neuroendocrine and circumventricular structures were studied in a small, reproductively suppressed, female Naked Mole-rat from central Kenya, Africa. The atrophic pineal is the smallest in absolute size (0.002135 mm3) of any so far described in a species of rodent, and in size relative to body weight is second only to that of another tropical species. The subcommissural organ and posterior collicular recess are also relatively small and less well differentiated than those in most other examined rodent species. In contrast, the subfornical organ, OVLT and median eminence are large and well vascularized. It is concluded that the pineal in this species follows the previously described trend among rodents of relatively smaller size in species whose centers of distribution are in lower latitudes. Although the pineal is atrophic, the Naked Mole-rat still exhibits 24-hour and seasonally timed patterns of behavior and seasonal reproduction. However, in this species these events are probably cued by moisture, temperature and social factors rather than by photic information.  相似文献   
80.
While an exacerbation in allergic symptoms corresponding to seasons has long been reported, few studies have investigated the association between the season of birth and allergic disorders. The aim of this study was to investigate whether the climatologic data before and after birth affected the incidence of atopic dermatitis (AD) and the results of allergy-related blood tests in early infancy. From February 1995 to January 2000, 2136 infants were tested for AD and followed for 12 months. AD patients were tested by using allergy-related blood tests. Data were compared according to the month of birth and the climatologic data using a computed statistical software package. Six hundred and thirty infants had AD before 12 months old, and significant differences were found according to the season of birth (p < 0.0001). Infants born in spring showed the lowest (22.3%) incidence, while those born in autumn showed the highest (34.6%). In 369 patients, total serum IgE levels, and serum specific IgE levels with egg white at 3 months old were also different according to the season of birth. All of these levels were lower in patients born in spring and summer, and higher in patients born in autumn and winter. Furthermore, the cumulative sunshine amount during the 3 months before and after birth was inversely correlated, while the average temperature over the 3 months before birth was positively correlated to the incidence of AD according to the month of birth. The climatologic data around birth may play an important role in whether an infant develops allergies.  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