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   9501篇
  免费   1019篇
  国内免费   25篇
耳鼻咽喉   174篇
儿科学   274篇
妇产科学   151篇
基础医学   1388篇
口腔科学   275篇
临床医学   1157篇
内科学   1940篇
皮肤病学   120篇
神经病学   665篇
特种医学   471篇
外国民族医学   1篇
外科学   1297篇
综合类   181篇
一般理论   6篇
预防医学   1077篇
眼科学   115篇
药学   691篇
中国医学   3篇
肿瘤学   559篇
  2021年   161篇
  2020年   92篇
  2019年   131篇
  2018年   137篇
  2017年   114篇
  2016年   141篇
  2015年   168篇
  2014年   216篇
  2013年   280篇
  2012年   419篇
  2011年   420篇
  2010年   284篇
  2009年   253篇
  2008年   396篇
  2007年   408篇
  2006年   416篇
  2005年   413篇
  2004年   413篇
  2003年   384篇
  2002年   327篇
  2001年   305篇
  2000年   340篇
  1999年   312篇
  1998年   167篇
  1997年   144篇
  1996年   136篇
  1995年   141篇
  1994年   86篇
  1993年   93篇
  1992年   184篇
  1991年   199篇
  1990年   181篇
  1989年   203篇
  1988年   165篇
  1987年   166篇
  1986年   142篇
  1985年   187篇
  1984年   140篇
  1983年   124篇
  1982年   96篇
  1981年   86篇
  1980年   70篇
  1979年   119篇
  1978年   97篇
  1977年   68篇
  1976年   82篇
  1975年   68篇
  1974年   93篇
  1973年   76篇
  1970年   61篇
排序方式: 共有10000条查询结果,搜索用时 234 毫秒
41.
Melioidosis. Forgotten, but not gone!   总被引:3,自引:0,他引:3  
Melioidosis, infection by the soil bacterium Pseudomonas pseudomallei, has the potential for prolonged latency with recrudescence into an acute, often fulminating, and fatal infection. Although the organism is never found in North America, infection is endemic in areas of southeast Asia, and populations of service personnel exposed during the Vietnam war and southeast Asian immigrants are at risk of severe recrudescent disease. Diagnosis, however, has been missed or delayed because of lack of familiarity with this disease. We present a case of recrudescent melioidosis that illustrates the difficulties encountered in diagnosis and treatment. This case involves a 76-year-old Vietnam veteran who presented with melioidosis of the bone 18 years after exposure to the organism and 10 years after a missed diagnosis of latent pulmonary disease. This case illustrates the protean nature of latent infection and the difficulty of selecting successful antibiotic therapy.  相似文献   
42.
43.
This review is intended to provide a balanced view of the role of surgical burn wound excision and closure within the larger context of the total care and rehabilitation of patients with burn injury. The historical background leading to present practice is outlined. The salient technical and logistical problems associated with the performance of wound excision are discussed, with emphasis on the necessity for expeditiously completing these procedures which are associated with major blood loss. A realistic analysis of the results of excisional therapy in patients with burns of varying severity is presented. Benefits attributable to the surgical phase of therapy become progressively more difficult to identify as the size of deep burns increases beyond 20% of total body surface area.
Resumen La presente revisión propone proveer una visión equilibrada del papel de la resección tangencial quirúrgica de la quemadura y su cierre en el contexto más amplio del cuidado total y la rehabilitación de pacientes con lesiones térmicas. Se hace un recuento de los antecedentes históricos y se discuten los más prominentes problemas técnicos y logísticos relacionados con la resección tangencial de la quemadura con énfasis en la necesidad de implementar en forma expedita estos procedimientos, los cuales se asocian con pérdidas mayores de sangre. Se presenta el análisis realista de los resultados de la resección tangencial en pacientes con quemaduras de gravedad variable. Los beneficios atribuibles a la fase quirúrgica de la terapia se hacen progresivamente más difíciles de identificar en cuanto la extensión y profundidad sobrepasan el 20% de la superficie corporal.

Résumé Cette article fait le point sur les avantages et inconvénients respectifs de l'excision et la suture dans le cadre du traitement et la rééducation des grands brûlés. L'historique de cette technique est résumée. Les principaux problèmes de technique et de logistique de l'excision des brûlures sont discutés, en soulignant la nécessité d'assurer un geste rapide enfin de réduire les pertes sanguines. Une analyse réaliste des résultats de la technique excisionnelle des brûlures de sévérité variable est présentée. Les bénéfices directement en rapport avec la chirurgie deviennent plus difficiles à apprécier lorsque la surface brûlée dépasse 20 % de la surface corporéelle.
  相似文献   
44.
The relative effectiveness of intermittent infusions and primed continuous infusions of cimetidine in the maintenance of intragastric pH greater than or equal to 4.0 was evaluated in a double-blind crossover trial in 26 patients who had active or healed gastroduodenal ulcers. During the intermittent phase, each patient received 300 mg cimetidine intravenously every 6 hours. During the continuous infusion phase, each patient was given a continuous infusion of 37.5 mg cimetidine per hour, preceded by a priming dose of 300 mg cimetidine that was given for 15 minutes. Intragastric pH was monitored continuously. During the last 12 hours of the study, the continuous infusion regimen provided 20% more time in which the pH was more [corrected] than 4.0 with 25% less medication than did the intermittent infusion regimen.  相似文献   
45.
Fine needle aspiration cytology: an in vitro study of cell yield   总被引:1,自引:0,他引:1  
To investigate the effect of needle size and number of passes into a tumour mass on the cell yield from a fine needle aspirate, an in vitro study was undertaken in 19 consecutive tumours removed surgically for biopsy. Different needle sizes (23G, 21G, 19G) passed in random order, five, ten and fifteen times into the tumours, were compared. The type of tumour, needle size and number of passes independently and significantly influenced cell yield. A 21G(green) needle passed into the tumour at least 10 times was the most efficient in obtaining cells. This in vitro study could explain the variation in the reported accuracy of fine needle aspiration cytology from groups using different techniques and is perhaps one reason why the highest diagnostic accuracy and the lowest rate of unsatisfactory aspirates comes from a centre which uses a 21G needle and at least 10 passes through the tumour.  相似文献   
46.
Beh?et's disease is characterized by recurrent ulcers of the mouth and genitalia and relapsing iritis. It is now recognized as a chronic multisystem disease affecting the skin, mucous membranes, eye, joints, central nervous system, and blood vessels. One of the known vascular complications of Beh?et's disease is aneurysm formation or venous thrombosis. The two patients with Beh?et's disease in this report developed multiple aneurysms over a short time span. Vascular surgeons dealing with young adults with peripheral aneurysms must be aware of this uncommon yet challenging clinical entity.  相似文献   
47.
OBJECTIVE: This analysis examined whether patients with Alzheimer disease (AD) tolerate continuous positive airway pressure (CPAP). METHOD: Thirty patients with AD were randomized to CPAP or sham CPAP and completed sleep, depression, and quality-of-life questionnaires. Participants could choose to continue treatment after the trial. RESULTS: Patients wore CPAP for 4.8 hours per night. More depressive symptoms were associated with worse adherence (rS=-0.37; N=30, p<0.04). Patients who continued using CPAP had fewer depressive symptoms (t [19]=2.45, p=0.02) and better adherence (t [19]=2.32, p=0.03) during the trial. CONCLUSION: Patients with AD with obstructive sleep apnea can tolerate CPAP. Adherence and long-term use may be more difficult among those patients with more depressive symptoms.  相似文献   
48.
Malignant fibrous histiocytoma of the lung   总被引:1,自引:0,他引:1  
  相似文献   
49.
1. The activation of the L-arginine: nitric oxide (NO) pathway during aggregation of human platelets by adenosine 5'-diphosphate (ADP), arachidonic acid, thrombin and the calcium ionophore A23187 and its inhibition by NG-monomethyl-L-arginine (L-NMMA), NG-nitro-L-arginine methyl ester (L-NAME) and N-iminoethyl-L-ornithine (L-NIO) were studied. The inhibition of the cytosolic platelet NO synthase by these compounds was also examined. 2. Platelet aggregation induced by ADP (1-10 microM) and arachidonic acid (0.1-10 microM), but not that induced by thrombin (1-30 mu ml-1) or A23187 (1-10 nM), was inhibited by L-, but not D-arginine (1-30 microM). However, in the presence of a subthreshold concentration of prostacyclin (0.1 nM) or of M & B 22948 (1 microM), a selective inhibitor of guanosine 3':5'-cyclic monophosphate (cyclic GMP) phosphodiesterase, L-arginine caused concentration-dependent inhibition of aggregation induced by all of these aggregating agents. 3. L-NMMA, L-NAME and L-NIO (all at 1-30 microM), but not their D-enantiomers, enhanced to the same extent platelet aggregation induced by ADP, arachidonic acid and thrombin without affecting that induced by A23187. 4. In the presence of 300 microM L-arginine, the NO synthase in platelet cytosol was inhibited by L-NMMA, L-NAME and L-NIO with IC50s of 74 +/- 9, 79 +/- 8 and 8.5 +/- 1.5 microM (n = 3), respectively. 5. These results indicate that the L-arginine: NO pathway in human platelets plays a role in the modulation of platelet aggregation.  相似文献   
50.
Neuropsychological tests of frontal lobe functions were undertaken in 46 chronic schizophrenic patients who were also rated for movement disorders. Tardive dyskinesia was found to have significant associations with most of these psychological tests. The possible mechanisms are discussed within the context of known neostriatal psychological functions.  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