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   371227篇
  免费   33180篇
  国内免费   26020篇
耳鼻咽喉   3461篇
儿科学   3853篇
妇产科学   5387篇
基础医学   45116篇
口腔科学   6459篇
临床医学   51379篇
内科学   55845篇
皮肤病学   3608篇
神经病学   20305篇
特种医学   13474篇
外国民族医学   244篇
外科学   37786篇
综合类   58822篇
现状与发展   90篇
一般理论   34篇
预防医学   23394篇
眼科学   10884篇
药学   37936篇
  378篇
中国医学   20386篇
肿瘤学   31586篇
  2024年   1168篇
  2023年   5636篇
  2022年   14623篇
  2021年   18554篇
  2020年   13696篇
  2019年   12220篇
  2018年   12834篇
  2017年   11276篇
  2016年   10584篇
  2015年   16388篇
  2014年   20320篇
  2013年   17615篇
  2012年   26084篇
  2011年   29471篇
  2010年   18546篇
  2009年   14419篇
  2008年   19611篇
  2007年   19628篇
  2006年   19654篇
  2005年   19239篇
  2004年   12563篇
  2003年   11566篇
  2002年   9903篇
  2001年   8748篇
  2000年   9446篇
  1999年   10178篇
  1998年   6258篇
  1997年   6219篇
  1996年   4860篇
  1995年   4473篇
  1994年   3672篇
  1993年   2369篇
  1992年   3136篇
  1991年   2702篇
  1990年   2373篇
  1989年   2072篇
  1988年   1738篇
  1987年   1508篇
  1986年   1225篇
  1985年   1014篇
  1984年   583篇
  1983年   406篇
  1982年   263篇
  1981年   260篇
  1980年   196篇
  1979年   240篇
  1978年   82篇
  1977年   90篇
  1974年   102篇
  1973年   83篇
排序方式: 共有10000条查询结果,搜索用时 62 毫秒
11.
CONTEXT: Although the nonmedical use of stimulant drugs such as cocaine and methamphetamine is increasingly common in many rural areas of the United States, little is known about the health beliefs of people who use these drugs. PURPOSE: This research describes illicit stimulant drug users' views on health and health-related concepts that may affect their utilization of health care services. METHODS: A respondent-driven sampling plan was used to recruit 249 not-in-treatment, nonmedical stimulant drug users who were residing in 3 rural counties in west central Ohio. A structured questionnaire administered by trained interviewers was used to collect information on a range of topics, including current drug use, self-reported health status, perceived need for substance abuse treatment, and beliefs about health and health services. FINDINGS: Participants reported using a wide variety of drugs nonmedically, some by injection. Alcohol and marijuana were the most commonly used drugs in the 30 days prior to the interview. Powder cocaine was used by 72.3% of the sample, crack by 68.3%, and methamphetamine by 29.7%. Fair or poor health status was reported by 41.3% of the participants. Only 20.9% of the sample felt they needed drug abuse treatment. Less than one third of the sample reported that they would feel comfortable talking to a physician about their drug use, and 65.1% said they preferred taking care of their problems without getting professional help. CONCLUSIONS: Stimulant drug users in rural Ohio are involved with a range of substances and hold health beliefs that may impede health services utilization.  相似文献   
12.
We report clinical, neuroradiologic features, and neuropathologic findings of a 76‐year‐old man with coexistent Pick’s disease and progressive supranuclear palsy. The patient presented with loss of recent memory, abnormal behavior and change in personality at the age of 60. The symptoms were progressive. Three years later, repetitive or compulsive behavior became prominent. About 9 years after onset, he had difficulty moving and became bed‐ridden because of a fracture of his left leg. His condition gradually deteriorated and he developed mutism and became vegetative. The patient died from pneumonia 16 years after the onset of symptoms. Serial MRI scans showed progressive cortex atrophy, especially in the bilateral frontal and temporal lobes. Macroscopic inspection showed severe atrophy of the whole brain, including cerebrum, brainstem and cerebellum. Microscopic observations showed extensive superficial spongiosis and severe neuronal loss with gliosis in the second and third cortical layers in the frontal, temporal and parietal cortex. There were Pick cells and argyrophilic Pick bodies, which were tau‐ and ubiquitin‐positive in neurons of layers II–III of the above‐mentioned cortex. Numerous argyrophilic Pick bodies were observed in the hippocampus, especially in the dentate fascia. In addition, moderate to severe loss of neurons was found with gliosis and a lot of Gallyas/tau‐positive globus neurofibrillary tangles in the caudate nucleus, globus pallidus, thalamus, substantia nigra, locus coeruleus and dentate nucleus. Numerous thorned‐astrocytes and coiled bodies but no‐tuft shaped astrocytes were noted in the basal ganglion, brainstem and cerebellar white matter. In conclusion, these histopathological features were compatible with classical Pick’s disease and coexistence with progressive supranuclear palsy without tuft‐shaped astrocytes.  相似文献   
13.
Finding appropriate soft-tissue to cover a wound located over the middle or distal portion of the foot can be challenging. A distally based sural fasciomusculocutaneous flap including the sural nerve and a midline cuff of the gastrocnemius muscle can be used for this purpose. This flap is designed on the proximal third of the posterior calf and is nourished in a retrograde manner by the lower peroneal septocutaneous perforators, through the vascular axis of the sural nerve to the musculocutaneous perforators of the gastrocnemius muscle. Between October of 2002 and January of 2004, this flap was applied in nine individuals, including four diabetic patients. The skin defects all resulted from trauma, osteomyelitis or chronic ulcer, and combined with bone or tendon exposure. One flap developed distal necrosis. The other flaps survived fully and provided good contour. In our series, diabetes mellitus seemed not to compromise the vascularity of the flap. The distally based sural fasciomusculocutaneous flap is very useful for lower limb reconstruction, particularly for the foot, because of its long vascular pedicle and the availability of the skin portion of the proximal calf based on direct branches between the musculocutaneous perforators and the neurovascular axis of the sural nerve. This is an important variant of the sural neurocutaneous flap and it appears to be a good alternative to free flaps for resurfacing the foot.  相似文献   
14.
置身RAIN CLUB的超凡境地中,美食、美酒和美妙的音乐是智灵的洗净,像干燥的北京城迎来第一场春天的“润”——稍显奢华。[编者按]  相似文献   
15.
目的用腔内注药法治疗颌骨囊肿代替手术摘除法,不破坏周围正常组织结构,不影响正常生理功能,不遗留疤痕畸形,不影响美容.即使巨大骨囊肿也无须植骨,不遗留骨质缺陷畸形.方法囊腔穿刺冲洗,注入复方磷酸液(Composite Phosphoric,CP液),5~10分钟后冲洗.结果注药后功能及生活无影响;囊腔愈合、骨化;松动牙固定;无感觉运动异常、功能障碍、残留疤痕及缺陷畸形.结论 CP液能使上皮细胞层凝固坏死,使之失去分泌与隔离功能,肉芽组织增生充满囊腔,骨腔骨化,恢复功能.  相似文献   
16.
Inter-individual variations in the development of silicosis, even within the same environments, have been reported, which suggest the contribution of genetic factors in silicosis aetiology. The aim of the present study was to determine whether there is any significant genetic influence on the development of silicosis. Furthermore, which genetic loci are responsible for the pulmonary response to silica exposure? Eight strains of inbred mice were used to examine the genetic influence on the lung fibrotic response to silica exposure. After intercross-breeding between the most susceptible and most resistant strains, a genome-wide linkage analysis of quantitative trait loci (QTL) was performed. Hydroxyproline was applied as an index, and genotypes of 167 marker genes were analysed by fragment analysis using a capillary-type sequencer. There was significant inter-strain difference in the mean concentration of hydroxyproline contents among the eight strains of mice. Breeding studies were conducted between the most susceptible, C57BL/6J, and the most resistant strain, CBA/J. A genome-wide linkage analysis of silica-exposed intercrossed cohorts identified significant QTL on chromosome 4 and suggestive QTL on chromosomes 3 and 18. The present study demonstrates that genetic factors may play a significant role in fibrotic-lung responses to silica; one significant and two suggestive quantitative trait loci were identified.  相似文献   
17.
18.
晶体玻璃体视网膜联合手术治疗复杂性视网膜脱离   总被引:6,自引:2,他引:4  
目的探讨玻璃体视网膜手术(vitreretinalsurgery,VR术)联合晶体切除/超声粉碎的效果。方法对81例(81只眼)应用晶体玻璃体视网膜联合手术(lenticular-vitreoretinalsurgery,LVR术)治疗的复杂性视网膜脱离进行回顾性分析。结果解剖性成功者64只眼(79.01%),功能性成功者45只眼(55.56%);手术成功率显著降低的原因是前部增殖性玻璃体视网膜病变(proliferativevitreo-retinopathy,PVR)(成功率42.86%,P<0.01)和术中/术后眼内出血(成功率58.82%,P<0.025)。结论LVR术是治疗复杂性视网膜脱离的主要方法;显著影响手术预后的因素是前部PVR和术中/术后眼内出血。  相似文献   
19.
外阴汗腺癌七例临床分析   总被引:2,自引:0,他引:2  
目的:总结外阴汗腺癌的临床特点及治疗方法。方法:对7例外阴汗腺癌病例进行回顾性分析。结果:外阴汗腺癌的发病年龄为40~58岁。7例患者的治疗为局部扩大切除或根治性外阴广泛切除,2例辅以术后放疗。7例中5例存活5年以上,其中1例曾在首次治疗后第7年、11年2次复发并于第17年死于肿瘤。2例存活<5年,1例在术后2年半死于脑出血,1例因脊椎广泛转移在术后1年零9个月死亡。结论:外阴汗腺癌的预后较好,局部扩大切除或根治性外阴切除,是首选治疗方法。  相似文献   
20.
人体蠕形螨的生物学研究   总被引:4,自引:0,他引:4  
用透明胶带法观察蠕形螨在人体面部的寄生、逸出及其在体外的存活能力。结果表明:毛囊蠕形螨(Demod-exfoliculorum,D.f.)主要以颚体朝向毛囊底部寄生,且常常有多条群居现象,而皮脂蠕形螨,(Demodexbrevis,D.b.)一般为单条独居生活。两种人体蠕形螨昼夜均可主动爬出毛囊口出现在皮肤表面,D.f.以白天1000~1800为逸出高峰;D.b.则以夜间2200~200逸出最多。此外,蠕形螨在体外有较强的活动力和存活力。透明胶带法在人体蠕形螨的流行病学调查和生物学研究方面具有较高的应用价值  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