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   97948篇
  免费   7738篇
  国内免费   4400篇
耳鼻咽喉   1132篇
儿科学   1272篇
妇产科学   1540篇
基础医学   12274篇
口腔科学   1986篇
临床医学   10247篇
内科学   15369篇
皮肤病学   1514篇
神经病学   5655篇
特种医学   3326篇
外国民族医学   22篇
外科学   11150篇
综合类   14175篇
现状与发展   9篇
一般理论   6篇
预防医学   7067篇
眼科学   2603篇
药学   10124篇
  54篇
中国医学   3360篇
肿瘤学   7201篇
  2023年   516篇
  2022年   1388篇
  2021年   2103篇
  2020年   1655篇
  2019年   1656篇
  2018年   2191篇
  2017年   2165篇
  2016年   1947篇
  2015年   2839篇
  2014年   3810篇
  2013年   4251篇
  2012年   6039篇
  2011年   6452篇
  2010年   4637篇
  2009年   4098篇
  2008年   5211篇
  2007年   5001篇
  2006年   4788篇
  2005年   3917篇
  2004年   3242篇
  2003年   3057篇
  2002年   2704篇
  2001年   5708篇
  2000年   5363篇
  1999年   4517篇
  1998年   1765篇
  1997年   1380篇
  1996年   900篇
  1995年   740篇
  1994年   691篇
  1993年   530篇
  1992年   2051篇
  1991年   1777篇
  1990年   1581篇
  1989年   1534篇
  1988年   1348篇
  1987年   1225篇
  1986年   1082篇
  1985年   919篇
  1984年   601篇
  1983年   470篇
  1982年   253篇
  1981年   182篇
  1980年   143篇
  1979年   282篇
  1978年   80篇
  1974年   80篇
  1973年   97篇
  1972年   73篇
  1969年   66篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
71.
72.
This paper is a summary of our observations on 105 cases of infantile spasms. The age of onset was around six months after birth, but the patients came for treatment mainly about one year after onset. Fever of unknown cause, asphyxia, birth injury, infection of the central nervous system, tuberous sclerosis, phenylketonuria and recent immunization etc. were complained. Clinically, it is characterized by head nodding, mental retardation, myoclonic jerks and various neurologic deficits. EEG findings showed classical or modified arrythmia or other epileptiform patterns. About one third of 22 cases examined had abnormal brain stem auditory evoked potentials. Among 42 patients who underwent CT scanning before ACTH treatment, 18 were normal and 7 abnormal; during ACTH treatment 3 normal and 4 abnormal; after completion of treatment, 4 normal and 6 abnormal, suggesting no further atrophy of the brain. Examination of trace elements of the hair by particle-induced X-ray emission (PIXE) method in 23 patients revealed a significant difference in lead, calcium and zinc contents between patients and 101 controls, but no statistical difference in iron and copper contents between the two groups. Sodium valproate, prednisone and ACTH appear to be effective in the treatment of infantile spasms. Eight patients fully recovered, and they can go to school without difficulty. Many patients derived various degrees of improvement to the satisfaction of their parents. Two patients were still amented and often attacked by myoclonus. The effects, side effects of these drugs, and the possible pathogenesis were discussed.
  相似文献   
73.
The effects of some antirheumatics on the formation and retraction of collagen lattices seeded with fibroblasts have been studied. Among the antirheumatics, diclofenac was the most active inhibitor of lattice retraction, then tropesin and to a lesser extent indomethacin. Ibuprofen which is known as a very slight inhibitor of protein synthesis was able to significantly enhance lattice retraction when 10 micrograms/ml (48.5 microM) and 50 micrograms/ml (242 microM) were used.  相似文献   
74.
A role for type II interferon (IFN-gamma) in resolving viral infection is suggested by the correlation of hepatitis C virus (HCV) clearance with enhancement of IFN-gamma-producing activated T cells in the resolution of acute HCV infection. Using vesicular stomatitis virus (VSV), a synergistic direct antiviral effect was documented using IFN-gamma1b and a potent, consensus type I IFN (IFN alfacon-1). Global expression profiling following EC50 exposure to IFN alfacon-1, IFN-gamma1b, or a cocktail of the two allowed the antiviral state to be correlated with induction of a subset of IFN-stimulated genes (ISGs). Genes identified through this analysis corresponded to classic antiviral components, ISGs more recently associated with direct antiviral functions, as well as expressed sequence tags (ESTs) and hypothetical proteins. The magnitude of these antiviral EC50-correlated expression events in human hepatoma (Huh7) cells exposed to clinically relevant doses of IFN alfacon-1, IFN-gamma1b, or a cocktail of the two was also probed because the standard of care for patients with chronic hepatitis C is type I IFN-containing regimens. Relative to type I IFNs used alone, the addition of type II IFN caused enhanced expression not only of many of the genes correlated with the direct antiviral state but also of genes involved in (1) antigen presentation to cytotoxic T lymphocytes (CTLs), (2) macrophage, natural killer (NK), and T helper 1 (Th1) cell recruitment and activation, (3) complement system function, (4) apoptosis, and (5) ISGs with unknown functions. As many of these processes are correlated clinically with resolution of chronic HCV infection, the combined use of these IFNs could display a beneficial effect on viral clearance in patients infected with HCV and other viruses through enhancement of one of these processes or of the direct antiviral state.  相似文献   
75.
76.
FOLFOX4与替加氟替代方案对晚期胃癌疗效的对比研究   总被引:1,自引:0,他引:1  
目的:对比观察FOLFOX4方案与替加氟替代方案治疗晚期胃癌的疗效和不良反应.方法:经病理或细胞学确诊的晚期胃癌患者75例,按收治的时间顺序交叉分入FOLFOX4组(A组)或替加氟替代组(B组),两方案均至少连用3周期评价疗效.A组:OXA 85mg/m2,静滴2h,第1天;LV 200mg/m2,静滴2h,第1、2天;5-FU 400mg/m2,静推,然后600mg/m2,22h静脉维持,第1、2天;2周重复,14天为1个周期.B组:OXA 130mg/m2,静滴2h,第1天;LV 200mg/m2,静滴2h,第1-5天;FT-207 800mg/m2,静滴3h,第1-5天;3周重复,21天为1个周期.结果:研究对象共75例.A组39例,总有效率(CR + PR)41.0%,其中初治患者总有效率55.6%;复治患者的总有效率28.6%.B组36例, 总有效率38.9%,其中初治患者总有效率 50.0%;复治患者的总有效率30.0%.两组总有效率比较均无统计学差异.不良反应主要是白细胞减少、恶心呕吐、神经感觉毒性等,A组白细胞下降发生率和消化系统不良反应发生率均明显高于B组(P均<0.05).两组均无化疗相关死亡.结论:FOLFOX4方案与替加氟替代方案均为治疗晚期胃癌有效的方案,FOLFOX4方案总有效率稍高,不良反应较替加氟替代方案重,但可耐受.建议晚期胃癌初治可选用FOLFOX4方案,而其中年龄偏大,体质欠佳的患者宜选替加氟替代方案.  相似文献   
77.
BACKGROUND: Wireless pH studies can offer prolonged pH monitoring, which may potentially facilitate the diagnosis and management of patients with gastroesophageal reflux disease (GERD). The aim of the present study was to evaluate the detection rate of abnormal esophageal acid exposure using prolonged pH monitoring in patients with suspected or refractory GERD symptoms. METHODS: Patients undergoing prolonged ambulatory pH studies for the evaluation of GERD-related symptoms were assessed. Patients with a known diagnosis of GERD were tested on medical therapy, while patients with suspected GERD were tested off therapy. The wireless pH capsules were placed during upper endoscopy 6 cm above the squamocolumnar junction. RESULTS: One hundred ninety-one patients underwent a total of 198 pH studies. Fifty ambulatory pH studies (25%) were excluded from the analysis: 27 patients (14%) had insufficient data capture (less than 18 h on at least one day of monitoring), 15 patients had premature capsule release (7%), seven were repeat studies (3.5%) and one had intolerable pain requiring capsule removal (0.5%). There were 115 patients undergoing pH studies who were off medication, and 33 patients were on therapy. For the two groups of patients, results were as follows: 32 (28%) and 22 (67%) patients with normal studies on both days; 58 (50%) and five (15%) patients with abnormal studies on both days; 18 (16%) and three (9%) patients with abnormal studies on day 1 only; and seven (6%) and three (9%) patients with abnormal studies on day 2 only, respectively. CONCLUSIONS: Prolonged 48 h pH monitoring can detect more abnormal esophageal acid exposure but is associated with a significant rate of incomplete studies.  相似文献   
78.
目的:探讨靶重建放大扫描技术对肺孤立性结节病变的诊断价值。方法:对63例患者先行常规CT平扫,选定结节处为兴趣区,行薄层靶重建放大扫描,层厚、层距为2mm,FOV为160。结果:42例恶性病变中有37例表现为深分叶,占88.1%;21例良性病变中有15例表现为浅分叶,占71.4%。恶性结节中15例内部出现条状低密度支气管征;7例出现血管集中征;8例出现空泡征;病变内部出现液化坏死13例,其中恶性病变ll例。22例出现钙化,包括12例良性病变和10例恶性病变。2例错构瘤内均见小面积脂肪性低密度影。结论:靶重建放大扫描比普通CT扫描可提供更多的信息,对良恶性病变的鉴别诊断有一定价值。恶性病变大多数为深分叶,良性病变大多数为浅分叶或无分叶。  相似文献   
79.
80.
2008年连云港市“手足口病”流行特征及病原学分型   总被引:1,自引:0,他引:1  
宋华 《职业与健康》2010,26(2):191-193
目的分析连云港市2008年手足口病的流行特征及病原学分型情况。方法应用流行病学方法对2008年该市的手足口病流行资料进行分析。结果依据疫情报告,实验室诊断病例45例,其中CoxA1638例,EV71型7例,其他肠道病毒0例。2008年该市临床报告手足口病例1067例,报告发病率为23.19/10万,比2007年上升442.34%,男女发病比为3.1∶1。发病年龄最小的为0岁组,最大的为8岁;0~5岁组,共计发病976例,占总发数的91.47%。发病数的构成以散居儿童最多,占76.66%。地区分布:全市各个区县均有手足口病病例报告,但城区的总体发病率高于县。结论连云港市手足口病发病率有上升趋势;控制传染源是有效防止该病流行的关键。  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