全文获取类型
收费全文 | 40099篇 |
免费 | 2189篇 |
国内免费 | 143篇 |
专业分类
耳鼻咽喉 | 529篇 |
儿科学 | 2580篇 |
妇产科学 | 709篇 |
基础医学 | 4773篇 |
口腔科学 | 1118篇 |
临床医学 | 2936篇 |
内科学 | 7230篇 |
皮肤病学 | 1137篇 |
神经病学 | 2354篇 |
特种医学 | 1273篇 |
外科学 | 6002篇 |
综合类 | 1295篇 |
一般理论 | 17篇 |
预防医学 | 2052篇 |
眼科学 | 1431篇 |
药学 | 3988篇 |
1篇 | |
中国医学 | 349篇 |
肿瘤学 | 2657篇 |
出版年
2023年 | 330篇 |
2022年 | 952篇 |
2021年 | 1611篇 |
2020年 | 886篇 |
2019年 | 972篇 |
2018年 | 1385篇 |
2017年 | 1016篇 |
2016年 | 1330篇 |
2015年 | 1339篇 |
2014年 | 1981篇 |
2013年 | 2253篇 |
2012年 | 3112篇 |
2011年 | 3035篇 |
2010年 | 1849篇 |
2009年 | 1446篇 |
2008年 | 2050篇 |
2007年 | 2072篇 |
2006年 | 1883篇 |
2005年 | 1668篇 |
2004年 | 1553篇 |
2003年 | 1315篇 |
2002年 | 1135篇 |
2001年 | 785篇 |
2000年 | 711篇 |
1999年 | 601篇 |
1998年 | 288篇 |
1997年 | 244篇 |
1996年 | 247篇 |
1995年 | 201篇 |
1994年 | 173篇 |
1993年 | 142篇 |
1992年 | 358篇 |
1991年 | 337篇 |
1990年 | 363篇 |
1989年 | 338篇 |
1988年 | 293篇 |
1987年 | 249篇 |
1986年 | 242篇 |
1985年 | 238篇 |
1984年 | 183篇 |
1983年 | 127篇 |
1982年 | 81篇 |
1981年 | 82篇 |
1980年 | 80篇 |
1979年 | 114篇 |
1978年 | 77篇 |
1977年 | 95篇 |
1976年 | 71篇 |
1973年 | 65篇 |
1971年 | 61篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
71.
Prasanna Kumar Reddy R Venkata Subramanian S Yuvaraja 《JSLS, Journal of the Society of Laparoendoscopic Surgeons》2005,9(3):356-357
Transposition of the gallbladder to the left side without situs inversus viscerum is rare. These gallbladders are situated under the left lobe of the liver between Segment III and IV or on Segment III to the left of the falciform ligament. Because routine preoperative studies may not detect the anomaly, it may provide the surgeons with an unusual surprise during laparoscopy. Awareness of the unpredictable confluence of the cystic duct into the common bile duct and selective use of intraoperative cholangiography aid in the safe laparoscopic management of this unusual problem. 相似文献
72.
73.
74.
75.
Muraleedharan P. Nampoothiri K. P. Sunil Kumar V. K. Sajina 《Indian journal of otolaryngology and head and neck surgery》2006,58(1):111-112
Extrame dullary plasmacytoma of larynx is extremely rare. We report a case of multiple myeloma which presented as extrame dullary manifestation in larynx. The rarity of incidence and difficulty in diagnosis of the disease is discussed. 相似文献
76.
R Jeyamani N K Shyamkumar Kumar Narayanan H S Subhash Biju George George Kurian 《Indian journal of gastroenterology》2003,22(4):147-148
We report a 40-year-old man with rheumatic heart disease who presented with abdominal pain for three weeks and hematemesis for 24 hours. CT scan showed a large splenic artery aneurysm without evidence of pancreatitis. Mycotic aneurysm due to infective endocarditis was considered and confirmed by echocardiogram, which showed aortic and mitral valve regurgitation and vegetations. He was managed successfully with coil embolization of the aneurysm and antibiotics. 相似文献
77.
Martina Ballmaier Elizabeth R Sowell Paul M Thompson Anand Kumar Katherine L Narr Helen Lavretsky Suzanne E Welcome Heather DeLuca Arthur W Toga 《Neuropsychopharmacology》2004,55(4):382-389
BACKGROUND: In elderly depression, volumetric brain imaging findings suggest abnormalities of the frontal lobe, particularly the orbitofrontal cortex, and the hippocampus. No studies to date have mapped cortical abnormalities over the entire brain surface in major depression. Here, we conducted detailed spatial analyses of brain size and gray matter within the cortical mantle in elderly patients with major depression. METHODS: High-resolution, three-dimensional, structural magnetic resonance imaging data and cortical pattern matching methods were used in 24 depressed elderly patients and 19 group-matched controls to measure local brain size and proportions of gray matter at thousands of homologous cortical surface locations. RESULTS: Prominent brain size reductions were observed in the depressed subjects in the orbitofrontal cortex bilaterally. Cortical gray matter measurements revealed significant gray matter increases in the orbitofrontal cortex, adjacent to focal trend level significant decreases of gray matter in the same region. Depressed patients also exhibited significant gray matter increases in parietal cortices, as well as the left temporal cortex. CONCLUSIONS: Complex cortical changes may contribute to the brain size reduction of the orbitofrontal cortex and to the gray matter abnormalities detected in orbitofrontal cortex and temporoparietal cortices, thereby providing a potentially new window into the pathophysiology of elderly depression. 相似文献
78.
We report a seven-year-old girl who presented with a sudden tumor apoplexy due to a parasagittal hemangiopericytoma. Following tumor excision, the child was noted to have bilateral optic nerve dysfunction and progressive papilledema, despite rapid overall neurological improvement. Based on the clinical features, we feel that this case represents an unusual form of visual deterioration related to impaired CSF absorption somehow precipitated by the acute tumour apoplexy. This unusual case of blindness responded significantly to CSF shunting. Several reports exist describing raised intracranial pressure with papilledema caused by nonthrombotic sinus occlusion due to tumors in proximity to the posterior superior sagittal sinus, torcular herophili and the jugular outlet. Communicating hydrocephalus, pseudotumor syndrome or intracranial venous sinus obstruction should be considered when otherwise inexplicable visual loss coexists with optic nerve dysfunction and papilledema. We emphasize the importance of a thorough search for the cause of visual loss. 相似文献
79.
Identification and functional significance of troponin I isoforms in neonatal rat heart myofibrils 总被引:6,自引:0,他引:6
We investigated the mechanism(s) responsible for differences in the effects of acidic pH on Ca2+ activation of the activity of adult and neonatal rat heart myofilaments. Studies on preparations of myofilaments reconstituted with adult troponin-tropomyosin (Tn-Tm) and either adult or neonatal thick filaments indicated that the difference in effect of acidic pH is related to differences in Tn-Tm and not other myofilament proteins. Immunoblotting analysis showed that development of the rat heart myofibrils is associated with isoform switching from slow skeletal TnI to cardiac TnI and from a slow mobility isoform of TnT (TnT1) to a faster Mr isoform (TnT2. Expression of slow skeletal TnI was associated with a relative insensitivity of myofilament Ca2+ activation to deactivation by acidic pH. Moreover, the effect of acidic pH on Ca2+ activation of ATPase activity of soleus myofibrils, which contain cardiac TnC and slow skeletal TnI, was essentially the same as the effect of acidic pH on rat cardiac myofibrils in the early neonatal period. Neonatal myofilaments also contained a relative abundance of a set of polypeptides copurifying with the thin filaments. We have identified these proteins as histones. The relative amount of histones among a variety of preparations from different species was not correlated with the pH sensitivity of myofibrillar Ca2+ activation. Shifts in TnT isoforms among these species were also not correlated with an altered response to acidic pH. Our data provide evidence in support of the hypothesis that the relative insensitivity of neonatal myofilament activity to acidic pH is due to the presence of slow skeletal TnI in the thin-filament regulatory complex. 相似文献
80.
Jones DL Weiss SM Chitalu N Villar O Kumar M Bwalya V Mumbi M 《American journal of infectious diseases》2007,3(4):169-176
An estimated 38.6 million persons globally are living with HIV, of whom over 1.1 million reside in Zambia. Of the 2 million cases in the US, 64% of new cases among women are among African Americans. Alcohol and drug use represents a significant risk factor for HIV transmission among both Zambians and African Americans. In addition, gender dynamics in both the US and Zambia promote transmission. This study examines two interventions targeting HIV risk behavior among HIV positive substance users, women in Miami, USA (the New Opportunities for Women (NOW) Project) and men in Lusaka, Zambia (the Partner Project). The study compares the efficacy of these two culturally tailored sexual behavior interventions provided in group and individual session formats. US and Zambian participants increased sexual barrier use and reduced substance-related sexual risk. Comparatively greater gains were made by higher risk Zambian males than US females in both group and individual conditions. Among lower risk participants, women in the group condition achieved and sustained the greatest comparative risk reductions. Results suggest that cost effective group HIV transmission risk reduction interventions for multiethnic individuals can be successfully implemented among both female and male drug and alcohol users in multinational settings. 相似文献