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   33399篇
  免费   1858篇
  国内免费   125篇
耳鼻咽喉   378篇
儿科学   1663篇
妇产科学   919篇
基础医学   4036篇
口腔科学   675篇
临床医学   2286篇
内科学   7246篇
皮肤病学   945篇
神经病学   2378篇
特种医学   886篇
外科学   3935篇
综合类   822篇
一般理论   23篇
预防医学   2234篇
眼科学   1620篇
药学   2876篇
中国医学   217篇
肿瘤学   2243篇
  2023年   206篇
  2022年   476篇
  2021年   1203篇
  2020年   623篇
  2019年   830篇
  2018年   998篇
  2017年   704篇
  2016年   841篇
  2015年   874篇
  2014年   1310篇
  2013年   1596篇
  2012年   2341篇
  2011年   2525篇
  2010年   1360篇
  2009年   1135篇
  2008年   1833篇
  2007年   1888篇
  2006年   1827篇
  2005年   1588篇
  2004年   1404篇
  2003年   1228篇
  2002年   1159篇
  2001年   745篇
  2000年   724篇
  1999年   595篇
  1998年   279篇
  1997年   197篇
  1996年   166篇
  1995年   179篇
  1994年   131篇
  1993年   123篇
  1992年   379篇
  1991年   382篇
  1990年   347篇
  1989年   337篇
  1988年   289篇
  1987年   262篇
  1986年   241篇
  1985年   236篇
  1984年   178篇
  1983年   142篇
  1981年   103篇
  1979年   159篇
  1978年   102篇
  1977年   88篇
  1975年   84篇
  1974年   101篇
  1973年   96篇
  1972年   121篇
  1970年   81篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
91.
Secondary tuberculosis of pharynx is a rare condition as pharynx is not a common site for clinically manifest tuberculosis. A rare and unusual case of secondary oropharyngeal tuberculosis in a 40 years male patient, who presented with an ulceroproliferative lesion of oropharynx extending to nasopharynx and laryngopharynx is being reported.  相似文献   
92.
OBJECTIVES: Despite longstanding national guidelines, many children with asthma do not receive annual influenza vaccinations. Information from Medicaid-administrative claims data was integrated into the Michigan Care Improvement Registry (MCIR) to prompt providers regarding influenza vaccination among children with high-risk conditions such as asthma. The attitudes of pediatric primary care providers regarding the implementation of this system were assessed. METHODS: A survey was sent in February 2006 to office-based general pediatricians (n = 300) and family physicians (n = 300) in Michigan. The survey focused on influenza vaccination during the 2005-2006 influenza season and attitudes regarding a reminder system for providers using the MCIR. RESULTS: Overall response rate was 67 percent. MCIR participation was high (91%) among respondents, and most (83%) had MCIR information available to them prior to visits with pediatric patients. Most physicians (75%) considered the MCIR high-risk indicator for influenza vaccination a feature that they would find helpful. Some respondents reported concerns that the reminder system is limited to Medicaid patients only (44%) and regarding the completeness of Medicaid data to identify children with asthma (24%). CONCLUSIONS: Physicians have a positive overall view of a statewide registry-based automated reminder system to assist in identifying children with asthma for influenza vaccination, albeit with specific areas of concern.  相似文献   
93.
Reticulate acropigmentation of Kitamura in a mother and her daughter is reported. Both demonstrated peri-orbital involvement in addition to involvement of acral areas, face and eyelids which has not been recorded before.  相似文献   
94.
A new patellar angle is described in lateral radiographs of the knee joint. One line is drawn along the articular surface of the patella and another from the end of the inferior articular cartilage to the patellar apex. The angle formed by these two lines averaged 33° in 68 knees joints afflicted with Osgood-Schlatter disease and 47° in 71 age-matched controls and 198 adult controls. The small angle in Osgood-Schlatter disease is proposed to be an important factor in the pathogenesis of the traction apophysitis.  相似文献   
95.
The effects of continuous therapy with hydrochlorothiazide and spironolactone on pulmonary function in 34 premature infants with severe bronchopulmonary dysplasia were assessed in a randomized double-blind controlled trial. Subjects were greater than or equal to 30 days old, were supported by mechanical ventilation in greater than or equal to 30% oxygen, and had radiographic evidence of bronchopulmonary dysplasia. The treatment group (n = 19) and the placebo group (n = 15) were similar in all respects except for distribution of gender. Anthropometrics, ventilatory measurements, and the results of pulmonary function tests were evaluated at study entry and at 1, 4, and 8 weeks into therapy. Poststudy chest radiographs were compared with those obtained before the study. The proportion of infants alive at discharge was significantly increased (84%) in the treatment group compared with the placebo group (47%) (p = 0.05). There were no statistically significant differences in total hospital days or in total ventilator days. Total respiratory system compliance at 4 weeks was higher in the treatment group (0.61 +/- 0.18) than in the placebo group (0.45 +/- 0.13) (p = 0.016). No difference in outcome was detected between male and female infants in the treatment group. These results suggest that long-term diuretic therapy improves outcome in infants with bronchopulmonary dysplasia.  相似文献   
96.
Clinical utilisation of positron emission tomography could be enhanced by the availability of short-lived radionuclides derived from generator systems. The zinc-62/copper-62 combination is one such system which could be used as a source for a number of copper-62 radiopharmaceuticals. We have developed and optimised a high activity (5.6 GBq, 150 mCi) zinc-62/copper-62 generator to provide 62Cu in a form that is suitable for direct labelling of pyruvaldehyde-bis-(N4-methylthiosemicarbazone)-copper(II), Cu(PTSM). The distribution coefficients of Zn(II) and Cu(II) between anion-exchange resin and various hydrochloric acid/organic solvent mixtures were measured. Based on these measurements a generator eluent of 0.3 M HCl/40% ethanol provided 62Cu in greater than 90% yield in a 3-ml volume. A very low 62Zn breakthrough of less than 3 x 10(-7)% was achieved. Copper-PTSM was successfully labelled with the no-carrier-added 62Cu eluent directly from the generator with 94% radiochemical yield.  相似文献   
97.
Neurosarcoidosis     
O P Sharma 《Chest》1991,100(2):301-302
  相似文献   
98.
Water-suppressed 1H magnetic resonance spectra were recorded from two brain regions of psychiatric patients and normal volunteers. The two regions studied were (a) the basal ganglia structures surrounding the anterior horn of the lateral ventricle and (b) the occipital cortex. N-Acetylaspartate (NAA), phosphocreatine-creatine (PCr-Cr), choline and inositol resonances were seen in both regions. Ratios of metabolite peak integrals to PCr-Cr peak integral were calculated for each spectrum. To control for partial volume effects, comparisons between patients and controls were made only from identical regions i.e. basal ganglia vs basal ganglia, and likewise for occipital cortex. Metabolite ratios from the occipital region of patients were similar to those from the occipital region of normal subjects. Bipolar patients being treated with lithium had elevated NAA/PCr-Cr in the basal ganglia region when compared to normals. These patients also demonstrated elevated choline/PCr-Cr and inositol/PCr-Cr ratios in the basal ganglia region.  相似文献   
99.
100.
A total of 675 strains of Salmonella bareilly received from different parts of India and France during 1959-92 were phage typed using six bacteriophages. Overall typability achieved was 90.8% with 23 distinct phage types excluding a group of untypable strains. Phage types have been defined in octal code. Simpson''s coefficient was applied for diversity index having a value of 0.839. This system was found to be reproducible, stable and epidemiologically useful.  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