全文获取类型
收费全文 | 86898篇 |
免费 | 7715篇 |
国内免费 | 2505篇 |
专业分类
耳鼻咽喉 | 974篇 |
儿科学 | 2367篇 |
妇产科学 | 885篇 |
基础医学 | 6181篇 |
口腔科学 | 1938篇 |
临床医学 | 12258篇 |
内科学 | 14144篇 |
皮肤病学 | 638篇 |
神经病学 | 5938篇 |
特种医学 | 3359篇 |
外国民族医学 | 2篇 |
外科学 | 11462篇 |
综合类 | 15779篇 |
现状与发展 | 3篇 |
预防医学 | 5693篇 |
眼科学 | 1399篇 |
药学 | 7495篇 |
119篇 | |
中国医学 | 4926篇 |
肿瘤学 | 1558篇 |
出版年
2024年 | 380篇 |
2023年 | 1448篇 |
2022年 | 2934篇 |
2021年 | 4094篇 |
2020年 | 4001篇 |
2019年 | 3154篇 |
2018年 | 2923篇 |
2017年 | 3378篇 |
2016年 | 3361篇 |
2015年 | 3061篇 |
2014年 | 5785篇 |
2013年 | 5778篇 |
2012年 | 4821篇 |
2011年 | 5225篇 |
2010年 | 4385篇 |
2009年 | 4028篇 |
2008年 | 4089篇 |
2007年 | 4372篇 |
2006年 | 3864篇 |
2005年 | 3398篇 |
2004年 | 2795篇 |
2003年 | 2369篇 |
2002年 | 2047篇 |
2001年 | 1905篇 |
2000年 | 1541篇 |
1999年 | 1402篇 |
1998年 | 1140篇 |
1997年 | 1066篇 |
1996年 | 935篇 |
1995年 | 923篇 |
1994年 | 807篇 |
1993年 | 637篇 |
1992年 | 677篇 |
1991年 | 531篇 |
1990年 | 459篇 |
1989年 | 397篇 |
1988年 | 373篇 |
1987年 | 373篇 |
1986年 | 281篇 |
1985年 | 317篇 |
1984年 | 291篇 |
1983年 | 175篇 |
1982年 | 228篇 |
1981年 | 158篇 |
1980年 | 129篇 |
1979年 | 139篇 |
1978年 | 123篇 |
1977年 | 72篇 |
1976年 | 86篇 |
1975年 | 56篇 |
排序方式: 共有10000条查询结果,搜索用时 11 毫秒
41.
Schistosoma mansoni infection, both in humans and in animal models, is known to induce granulomas in the liver and intestine. It has also been
reported that in humans the eggs of this parasite can reach the brain, causing psychiatric and neuropathological disorders.
Whether this also occurs in rodents is unknown. To answer this question, mice were infected with this parasite and the central
nervous system (CNS) examined at various time intervals. The results show that schistosomiasis induced granulomas in several
regions of the CNS and increased nerve growth factor (NGF) levels in the cortex, hypothalamus and brain stem, but not in the
hippocampus. The infection also caused paw hyperalgesia, as determined by the hot-plate test, and a local increase in NGF,
but not in substance P. These findings indicate that the murine model of infection can be used for studying mechanisms leading
to human neuroschistosomiasis and suggest that the neuropathological disorders and the sensory deficits observed in human
schistosomiasis are associated with impaired levels of NGF in the peripheral and central nervous system.
Received: 18 January 1996 / Revised, accepted: 16 April 1996 相似文献
42.
Summary Methods in current practice for ascertaining time of death are largely based on the cooling of the body after death and are
somewhat unreliable. A theoretica relationship is known to exist between the decline in the properties defining nerve conduction
and time after death caused by the gradual cessation of metabolic activity in nerves. A number of such properties were measured
in rats during life and after death. In most cases the relationship was found to be inconsistent. The chronaxie of the strength
duration curve for the sciatic nerve was, however, found to increase consistently and reproducibly in a linear fashion over
the first 90 min after death to a plateau value which was maintained beyond 135 min. These findings are discussed as the possible
basis of a forensic method of determining the duration of the “post mortem interval” within the first few hours after death.
相似文献
43.
The use of glutamate antagonists and GABA agonists may protect neurons from the effects of transient ischemia. Felbamate is a new antiepileptic drug with glutamate antagonist and GABA agonist properties, We tested the efficacy of felbamate in a gerbil model of transient forebrain ischemia. Damage assessment was done with silver staining at 7 and 28 days after 5 min of bilateral carotid occlusion, Cerebral cortex, hippocampus (CA1 and CA4), thalamus and striatum were evaluated on a 4-point scoring system, The animals sacrificed at 28 days were also tested in a water-maze task to assess recovery of function, The initial dose of felbamate (300 mg/kg) was given 30 min before the ischemic insult in one set of animals and 30 min after the insult in another set of animals. There were 8 animals tested per group (total: 48 animals). There was significant neuronal protection with the use of felbamate, both before and after ischemia in all regions of the brain. Protection was seen in animals sacrificed at 7 and 28 days, Protection was moderate when felbamate was used before ischemia. It was highly significant when felbamate was given 30 min after the insult. Behavioral studies however did not show any difference in the felbamate treated animals versus the saline treated controls. The structural protection with felbamate was very significant when used in the post-ischemic period. This window for protection merits further evaluation in relation to the clinical setting of stroke. 相似文献
44.
45.
Anne B. Fulton Ronald M. Hansen 《Documenta ophthalmologica. Advances in ophthalmology》1988,68(3-4):293-304
Scotopic b-wave stimulus/response (S/R) functions are abnormal in several human retinal degenerative disorders. However, the mechanisms by which diseases affect the S/R parameters are not yet fully known. Three experiments were done to simulate functional pathologies known to occur in retinal degenerations: 1) attenuated sensitivity of retinal units, 2) loss of rhodopsin, 3) loss of sensitivity with little or no loss of rhodopsin. None of the experimental perturbations of normal function replicated the pattern of S/R abnormalities caused by retinal degenerations. Thus, in the retinal degenerative disorders intrinsic abnormalities of cellular processing must affect the organization of distal retinal function indexed by the b-wave. 相似文献
46.
NAVIN C. NANDA M.D. SAYED MOHAMMED ABD-EL RAHMAN M.D. GAJENDRA KHATRI M.D. GOPAL AGRAWAL M.D. ADEL A. EL-SAYED M.D. HASSAN A. SHEHATA HASSANIAN M.D. MOHAMMAD KAMRAN M.D. JAMES KIRKLIN M.D. DAVID C. McGIFFIN M.D. WILLIAM L. HOLMAN M.D. ALBERT D. PACIFICO M.D. 《Echocardiography (Mount Kisco, N.Y.)》1995,12(6):619-628
In the present study, we compared three-dimensionally (3-D) reconstructed images with multiplane two-dimensional (2-D) transesophageal echocardiographic (TEE) images in 17 patients with various cardiac masses and defects. To overcome the problem of making measurements from 3-D reconstructed images, we carefully "dissected" the 3-D dataset using paraplane and anyplane 2-D sections, which were then used to obtain the maximum sizes of the cardiac masses and defects. Of the 15 vegetations and 9 abscesses detected by 3-D TEE in 7 patients, only 8 (53%) vegetations and 4 (44%) abscesses were detected by multiplane 2-D TEE (P < 0.02). Also, the exact anatomical location, shape, geometry, and extent of various cardiac masses and defects were more clearly delineated by 3-D than 2-D TEE. The maximum dimensions of cardiac masses and defects were larger by 3-D than by 2-D TEE in 17 (89%) of the 19 lesions available for comparison (P < 0.002). In addition, 3-D TEE correlated more closely than 2-D TEE when compared to surgical measurements in three patients in whom they were available. Thus, it would appear that in several instances, the exact size of the cardiac lesion could only be assessed by analysis of the 3-D volumetric dataset. Out preliminary study has demonstrated the superiority of transesophageal 3-D reconstruction over multiplane 2-D TEE in both qualitative and quantitative assessment of various cardiac mass lesions and pathological defects. 相似文献
47.
观察了食饵性高血脂对新西兰兔血小板功能、纤溶系统和血液流变学的影响以及去纤酶的调节作用,并动态观察了指标的变化.结果发现,高血脂能引起兔的血小板数增加,粘附力增强,血液粘滞性增加,红细胞流动变慢,呈现高凝和低纤溶状态,且主动脉形成明显粥样斑块.去纤酶在降低血脂的同时,可明显降低血小板的粘附力,降低血液粘滞性,呈现低凝和高纤溶状态,其主动脉粥样斑块亦明显减轻和缩小.提示去纤酶既能降低血脂又能降低血粘稠度,促进纤溶,起到抗凝及防止血栓形成,抑制动脉硬化的形成和发展. 相似文献
48.
M. Burdelski M. Oellerich J. Düwel H. Raith M. Scheruhn B. Ringe B. Rodeck A. Latta R. Pichlmayr J. Brodehl 《European journal of pediatrics》1992,151(Z1):S39-S43
The pre-operative risk of paediatric liver transplantation candidates (n=41) was assessed in a prospective study by means of clinical symptoms, conventional static and liver blood flow dependent dynamic liver function tests. Nine patients died during the 365-day waiting period. The data were subjected as covariates to a survival analysis in the Cox proportional hazards model. There was a significant relationsship between the results of mono-ethylglycinexylidide (MEGX) formation and ICG test and the 365-day survival rate. In the stepwise analysis, none of the remaining parameters improved the predictive ability when added to the dynamic liver function test results. The assessment of post-transplantation liver function was studied in 27 patients during the first 28 postoperative-day period. In addition, liver function was studied in a cross-sectional study 1–7 years after successful liver transplantation in children with complete or partial rehabilitation. In the early postoperative period severe organ damage was indicated by both static and dynamic liver function tests. In the later course after transplantation no deterioration of liver function measured with MEGX formation was to be observed. These findings demonstrate the usefulness of dynamic liver function tests in the pre- and post-transplant assessment of liver function. 相似文献
49.
腧穴针感在针刺防治疾病过程中发挥着重要作用。本文从针刺作用的感受器,腧穴针感的外周传入神经,以及针感与中枢神经的关系,诸方面,列举大量实验结果和理论,阐明针感形成的物质基础是神经系统。 相似文献
50.
R S Nanra 《Nephrology, dialysis, transplantation》1992,7(5):384-390
Comprehensive renal function tests were performed in 84 patients with analgesic nephropathy, 33 glomerulonephritis patients matched for creatinine clearance, and 30 control subjects. A system of 1-day renal function tests including urine microscopy, creatinine clearance, phenolsulphonphthalein excretion, urine concentration and acidification, and electrolyte excretion, was used. Patients with analgesic nephropathy were found to have significant sterile pyuria and haematuria, even those with mild renal insufficiency, significantly reduced concentrating ability and a distal acidifying defect, and a tendency to impaired sodium conservation. These function defects are consistent with the primary lesion of renal papillary necrosis in analgesic nephropathy; the detection of these defects have implications in patient management. 相似文献