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   1040989篇
  免费   342917篇
  国内免费   71854篇
耳鼻咽喉   10439篇
儿科学   17152篇
妇产科学   7646篇
基础医学   139876篇
口腔科学   17948篇
临床医学   151747篇
内科学   161845篇
皮肤病学   13857篇
神经病学   41335篇
特种医学   39554篇
外国民族医学   67篇
外科学   107644篇
综合类   266770篇
现状与发展   192篇
一般理论   18篇
预防医学   134469篇
眼科学   29408篇
药学   151746篇
  1374篇
中国医学   109355篇
肿瘤学   53318篇
  2023年   12567篇
  2022年   29774篇
  2021年   37175篇
  2020年   33844篇
  2019年   25107篇
  2018年   26365篇
  2017年   32213篇
  2016年   26013篇
  2015年   41488篇
  2014年   51225篇
  2013年   60129篇
  2012年   83449篇
  2011年   90510篇
  2010年   84548篇
  2009年   84798篇
  2008年   75806篇
  2007年   70852篇
  2006年   63355篇
  2005年   51769篇
  2004年   39955篇
  2003年   33960篇
  2002年   28843篇
  2001年   28871篇
  2000年   20559篇
  1999年   18199篇
  1998年   15683篇
  1997年   15419篇
  1996年   16226篇
  1995年   16266篇
  1994年   15890篇
  1993年   14126篇
  1992年   13334篇
  1991年   12638篇
  1990年   11544篇
  1989年   11321篇
  1988年   10837篇
  1987年   10160篇
  1986年   9620篇
  1985年   8630篇
  1984年   6613篇
  1983年   6609篇
  1982年   7640篇
  1981年   7166篇
  1980年   6827篇
  1979年   6670篇
  1978年   5824篇
  1977年   6127篇
  1976年   5758篇
  1975年   5486篇
  1974年   5037篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
91.
The objective of this review is to identify and review publications describing the impact of reduced somatosensation on balance. Based on knowledge of the association between specific somatosensory loss and deterioration of balance, conclusions can be made about role of somatosensation in standing balance.A systematic literature review is presented in which publications from the years 1993 through 2007 were searched in Medline and Embase. Medical Subject Headings (MESH) terms and free text words (related to balance, somatosensory loss, and lower limb) were used to perform the searches. Fifteen articles were selected for detailed review based on predetermined inclusion criteria, and three of the included articles described the effect of experimentally reduced somatosensation on balance in healthy subjects. Ten of the articles described balance in diabetic neuropathy (DN). The last two included articles described balance in Charcot-Marie-Tooth (CMT) disease type 1A (CMT1A) or type 2 (CMT2).The literature indicates that the tactile sensation is reduced in DN, CMT1A, and CMT2 and when the plantar surface of the feet was hypothermically anesthetized. Joint motion sensation seems to be impaired in patients with DN, and passive joint position sensation appears to be reduced in healthy subjects with anesthesia of ankle and foot from prolonged ischemia. This reduced somatosensation seems to have a negative effect on balance in patients with DN and CMT2; however, this appeared not to be the case in patients with CMT1A and in healthy subjects.  相似文献   
92.
Background:  The term 'pigmented epithelioid melanocytoma (PEM)' was recently used for borderline melanocytic tumor/low-grade melanoma including cases previously diagnosed as human animal-type melanoma and epithelioid blue nevus. No Japanese cases have been reported.
Methods:  We reviewed 219 cases previously diagnosed as blue nevus in Japan. Common blue nevus was identified in 154 cases and cellular blue nevus in 65 cases.
Results:  We have found two Japanese cases of PEM previously diagnosed as cellular blue nevus. Two patients were female. The age at presentation was 32 and 28 years. Two lesions were on the buttock. Two cases fulfilled histological criteria proposed for PEM. There is no evidence of recurrence or metastases.
Conclusions:  PEM is a distinct melanocytic tumor and the unifying diagnostic term. PEM is present in Japanese, but these cases may be previously diagnosed as cellular blue nevus. Japanese pathologists should recognize a new concept of PEM, and when they make a diagnosis of PEM, they should be recommended sentinel lymph node sampling.  相似文献   
93.
Ehlers-Danlos syndrome – vascular type, the only lethal form, is rarely reported in dermatology literature. It is characterized by translucent, atrophic skin, easy bruising, arterial, intestinal and/or uterine fragility manifesting as varicose veins, aneurysms and vascular/visceral/uterine rupture. As its dermatopathologic features are not well elucidated, diagnosis is often made after a catastrophic complication or at autopsy. This 36 year-old non-consanguineous male had brown-black plaques with atrophy and frequent ulceration over legs and dorsal feet and tortuous varicose veins around ankles for the past 15 years. Perivenous skin was translucent and hypopigmented. He had multiple and ecchymotic keloids and small atrophic, pityriasis versicolor-like lesions over trunk. He did not have hypermobile/hyperextensible skin and joints and showed no systemic or investigative abnormality. Histopathologic features of atrophic lesion included blood extravasation in atrophic epidermis/dermis, focal clustering and dilatation of blood vessels, malformed vessel walls, abundant hemosiderin in the dermis and homogenously stained/whorled patterned collagen especially around blood vessels. Pathology of keloidal lesion showed new collagen and vascular fragility. These histopathologic features appear of diagnostic value especially in patients who have compatible clinical findings but cannot afford confirmation by biochemical testing for abnormal synthesis of type III procollagen or identification of mutations in the COL3A1 gene.  相似文献   
94.
Background:  Nucleolin is a major nucleolar argyrophilic protein involved in carcinogenesis. There are only few studies on its tissue expression in human cancer and none in melanoma. We aimed at exploring this protein and its prognostic impact in cutaneous melanocytic lesions.
Methods:  We studied 193 cases including benign, dysplastic and malignant melanocytic lesions. Nuclear positivity was evaluated by immunohistochemistry and quantified by automated image analysis.
Results:  Most dysplastic and malignant lesions showed high percentages of cells with abnormal patterns of nuclear positivity (Abn+N) consisting in multiple, irregular, positive dots (ID+) and a coarse, irregularly positive nucleoplasm (CNpl+) or both (ID+CNpl+). The patterns CNpl+ and/or ID+CNpl+ were never observed in benign lesions, in which ID+ were also virtually absent. Abn+N% was significantly lower in dysplastic nevi than in primary melanomas and metastases and in primary melanomas than in metastases (p < 0.05). Furthermore, Abn+N was the second powerful prognostic discriminator, after melanoma thickness, and a significantly lower survival was observed in vertical growth phase melanoma patients showing Abn+N in more than 50% of melanoma cells.
Conclusion:  An altered nuclear nucleolin expression seems to accompany melanoma progression. Further investigation on nucleolin functionality and subcellular trafficking could add information on its altered role in melanoma.  相似文献   
95.
96.
97.
98.

Introduction  

Ethanol has a suppressive effect on inflammation and the immune system, but the effect of ethanol on tendon healing in vivo has not been studied. The purpose of this study was to investigate the histological and biomechanical effects of ethanol intake on tendon healing in a rat tendon injury model.  相似文献   
99.
膀胱肿瘤2350例临床病理学特点分析   总被引:1,自引:0,他引:1  
目的 探讨膀胱肿瘤的发病现状、总体趋势和病理特点.方法 整理1980-2007年2350例膀胱肿瘤病理档案,分为1980-1989、1990-1999和2000-2007年3个时间段.应用SPSS 13.0软件分析3时间段患者性别、年龄及肿瘤组织学类型间的关系.结果 2350例膀胱肿瘤中男1854例,女496例.良性92例,恶性2258例,膀胱恶性肿瘤的发病人数逐年上升.发病高峰年龄从50~69岁推迟到60~79岁.1980-1989、1990-1999和2000-2007年3个时间段中男、女恶性肿瘤病例数分别为524例和113例(4.64:11 00)、589例和164例(3.59:1.00)、675例和193例(3.50:1.00),男性约为女性的3.80倍;3时间段男性发生膀胱尿路上皮癌年龄分别为(57.5±11.7)、(62.6±12.3)、(65.9±11.3)岁,女性分别为(58.7±13.6)、(60.7±12.1)、(65.8±12.0)岁,男女各年龄段分别比较差异有统计学意义(P<0.05).男性发生鳞状细胞癌、尿路上皮癌和腺癌年龄分别为(68.05±9.7)、(59.85±14.1)、(63.4±9.9)岁,差异有统计学意义(P相似文献   
100.
目的探讨穴位按压对健康体检者静脉采血中晕厥的护理干预效果。方法将59例发生晕厥的健康体检者随机分为观察组(31人)和对照组(28人)。对照组采用常规处理方法,予10%葡萄糖注射液饮服或静脉注射;观察组予以指压舍谷、内关、足三里穴。结果两组治疗效果比较,差异有统计学意义(P〈0.01)。结论指压合谷、内关、足三里穴能有效治疗静脉采血所致的晕厥,且方法简单、安全。  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