全文获取类型
收费全文 | 7677篇 |
免费 | 469篇 |
国内免费 | 44篇 |
专业分类
耳鼻咽喉 | 138篇 |
儿科学 | 173篇 |
妇产科学 | 120篇 |
基础医学 | 923篇 |
口腔科学 | 219篇 |
临床医学 | 757篇 |
内科学 | 1613篇 |
皮肤病学 | 108篇 |
神经病学 | 949篇 |
特种医学 | 256篇 |
外科学 | 1330篇 |
综合类 | 83篇 |
一般理论 | 1篇 |
预防医学 | 409篇 |
眼科学 | 76篇 |
药学 | 424篇 |
中国医学 | 12篇 |
肿瘤学 | 599篇 |
出版年
2023年 | 58篇 |
2022年 | 118篇 |
2021年 | 194篇 |
2020年 | 126篇 |
2019年 | 153篇 |
2018年 | 176篇 |
2017年 | 125篇 |
2016年 | 185篇 |
2015年 | 170篇 |
2014年 | 243篇 |
2013年 | 312篇 |
2012年 | 492篇 |
2011年 | 498篇 |
2010年 | 270篇 |
2009年 | 251篇 |
2008年 | 398篇 |
2007年 | 378篇 |
2006年 | 394篇 |
2005年 | 360篇 |
2004年 | 361篇 |
2003年 | 348篇 |
2002年 | 290篇 |
2001年 | 206篇 |
2000年 | 188篇 |
1999年 | 178篇 |
1998年 | 72篇 |
1997年 | 76篇 |
1996年 | 63篇 |
1995年 | 52篇 |
1994年 | 51篇 |
1993年 | 49篇 |
1992年 | 103篇 |
1991年 | 88篇 |
1990年 | 82篇 |
1989年 | 84篇 |
1988年 | 65篇 |
1987年 | 67篇 |
1986年 | 77篇 |
1985年 | 61篇 |
1984年 | 47篇 |
1983年 | 45篇 |
1982年 | 36篇 |
1981年 | 40篇 |
1978年 | 36篇 |
1977年 | 36篇 |
1976年 | 42篇 |
1975年 | 51篇 |
1974年 | 40篇 |
1973年 | 40篇 |
1972年 | 35篇 |
排序方式: 共有8190条查询结果,搜索用时 15 毫秒
11.
One hundred nine percutaneous catheterizations of synthetic vascular grafts in 89 patients who had angiographic procedures were reviewed to determine the risk of major complications. Ninety-six of the catheterizations were inserted into the inguinal portion of aortofemoral grafts. There were no instances of hematoma, graft infection, aneurysm formation, suture line disruption, or embolic events distal to the puncture site. One local thrombus developed within a vascular graft that was corrected by a simple thrombectomy performed with a surgical catheter. One puncture site required 2 hours of compression to maintain hemostasis. Because of the extremely low risk of complications from catheterization of synthetic vascular grafts, it is the preferred route for angiographic procedures when the native femoral arterial route is unavailable. 相似文献
12.
Sundaram Hariharan Eric P. Cohen Brahm Vasudev Rimas Orentas Raphael P. Viscidi Justin Kakela Brian DuChateau 《American journal of transplantation》2005,5(11):2719-2724
We evaluated twenty renal transplant subjects at various stages of BKV nephritis (BKVN) for BKV-specific IgG and IgM antibodies using ELISA technique and BKV-DNA using PCR. They were divided as early onset (n = 7), stabilizing (n = 3), resolved (n = 8) and late onset (n = 2) BKVN. BKV-specific antibodies and BKV-DNA were simultaneously determined. The mean BKV-specific IgG level in early onset and stabilizing BKVN were 64 and 39 EIA units, and were significantly lower than 138 EIA units seen in resolved BKVN, P = 0.007, P = 0.008. The mean BKV-specific IgM levels in stabilizing BKVN was higher than resolved BKVN (130 vs 51 EIA units), P = 0.006. Mean plasma BKV loads for each group were 955,925, 5642 and 42 copies/mL of plasma, respectively. Prospective study in six BKVN cases revealed mean IgG, IgM levels and BKV-DNA at the time of diagnosis of BKVN as 39, 110 EIA units and 586,758 copies/mL of plasma, respectively. After a mean period of 5.2 months, IgG level increased to 120 EIA units (p = 0.0058) and had no detectable viral copies in circulation. Recovery from BKVN and elimination of BKV is associated with the development of BKV-specific IgG antibodies and this provides insight into the role of humoral immunity to BKV in the pathogenesis of BKVN. 相似文献
13.
Thomas A. Luger Harald Gollnick Thomas Schwennesen Raphael Bextermller Siegfried Freytag Matthias Brutigam 《Journal der Deutschen Dermatologischen Gesellschaft》2007,5(10):908-914
Background: Pimecrolimus cream 1% has proven to be well‐tolerated and effective in controlled clinical studies in patients with atopic dermatitis (AD). In a 15‐week patient self‐observation study, safety and efficacy was investigated in the daily practice. Patients and methods: 3502 patients with AD (mean age 26.2 ± 18 years, 62% female) received pimecrolimus cream 1% from 810 physicians in the German Federal Republic.The severity of the disease was assessed at baseline, two times during the 15‐week observation period and at the end of treatment.Patients recorded daily the degree of erythema and pruritus. At the end of treatment, safety and efficacy were assessed by the physician based on patient's daily records and by the patient. Results: The percentage of patients with severe or massive AD decreased from 25% to 7%, whereas the percentage of patients without or with mild symptoms increased from 9% to 55%.The efficacy of treatment was rated by physicians as good or very good in 83.5% of cases and by 79% of patients.At baseline 35% of the patients were free of flares as compared to 75% at the end of therapy. Disease control was better in patients who followed the recommended treatment algorithm for pimecrolimus cream.Tolerability was mostly rated as good or very good. Conclusion: Treatment with pimecrolimus cream 1% for patients with AD is well‐tolerated and effective in daily practice. 相似文献
14.
Jens Garbade Andreas Schubert Ardawan Julian Rastan Dominik Lenz Thomas Walther Jan Fritz Gummert Stefan Dhein Friedrich-Wilhelm Mohr 《European journal of cardio-thoracic surgery》2005,28(5):685-691
OBJECTIVE: Recent studies have demonstrated that transplanted bone marrow-derived stem cells (BMCs) possess a broad differentiation potential and are able to form new cardiomyocytes. However, the identity of BMCs as true cardiomyocytes is still ambiguous. Therefore, we investigated the fate of transplanted fluorescence labeled BMCs and cardiomyocytes in co-culture. METHODS: For cell tracking we used two different fluorescent probes, Vybrant/DiO and Vybrant/DiI. BMCs were taken from human sternal marrow, purified using a Ficoll-gradient-centrifugation, treated with 5-azacytidine and stained with Vybrant/DiO. Furthermore, isolated spontaneous beating cardiomyocytes of neonatal rats (CM) were labeled with Vybrant/DiI. Thereafter, the BMCs were transplanted into CM-cultures and investigated on day 1, 4, 7, 14 and 28 using two-color fluorescence phenotyping by laser-scanning-cytometry (LSC). Two-color positive cells were harvested by patch-clamp technique and beta-MHC mRNA expression was analyzed by single-cell PCR. RESULTS: Two different morphological phenotypes were observed by LSC. First, isolated DiO labeled BMCs without contact or with direct cell contact to DiI labeled CMs. Second, some BMCs and CMs were double positive for DiO/DiI spontaneously forming hybrids. This population increased by 18% from day 1 to 4 and decreased only slightly until day 28. Additionally, few two-color positive cell formations expressed both human and rat specific beta-MHC mRNA as well as only human beta-MHC mRNA indicating that cell-fusion and transdifferentiation has occurred. CONCLUSION: These observations provide in vitro evidence for spontaneous cell fusion and transdifferentiation of BMCs in co-culture, raising the possibility that the observed phenomenons may contribute to development or maintenance of these cell types. 相似文献
15.
Evan S. Siegelman Eric K. Outwater Emma E. Furth Raphael Rubin 《Journal of magnetic resonance imaging : JMRI》1995,5(6):730-732
Nodular regenerative hyperplasia (NRH), a rare condition that is commonly associated with noncirrhotic portal hypertension, is not well described in the MR literature. Three patients at two institutions were identified who had both abdominal MR imaging and pathologic evidence of NRH. All examinations were performed at 1.5 T and included axial T1- and T2-weighted spin-echo (SE) images. The MR studies were reviewed by two radiologists in consensus. Two patients had multiple liver lesions that had high signal components on T1-weighted images and were predominantly isointense with liver on the T2-weighted images. One patient had no focal lesions identified. NRH, when visualized on MR images, appears as multifocal masses with shortened Tl and T2 similar to liver. NRH should be considered in the differential diagnosis of hepatocellular tumors, especially in patients with a predisposing condition. 相似文献
16.
17.
18.
OBJECTIVE: Restraint use is not monitored in the US, and only institutions that choose to do so collect statistics. In 1999, investigative journalists reported lethal consequences proximal to restraint use, making it a life-and-death matter that demands attention from professionals. This paper reviews the literature concerning actual and potential causes of deaths proximal to the use of physical restraint. METHOD: Searching the electronic databases Medline, Cinahl, and PsycINFO, we reviewed the areas of forensics and pathology, nursing, cardiology, immunology, psychology, neurosciences, psychiatry, emergency medicine, and sports medicine. CONCLUSIONS: Research is needed to provide clinicians with data on the risk factors and adverse effects associated with restraint use, as well as data on procedures that will lead to reduced use. Research is needed to determine what individual risk factors and combinations thereof contribute to injury and death. 相似文献
19.
I.J. Namer J. Steibel S.J. Piddlesden M. Mohr P. Poulet J. Chambron 《Journal of neuroimmunology》1994,54(1-2)
Two models of demyelinating experimental allergic encephalomyelitis (EAE) were studied on Lewis rats in whom the disease was induced by injections of either (i) lentil-lectine binding myelin glycoproteins plus myelin basic protein (MBP)-specific T cells (36 rats), or (ii) myelin/oligodendrocyte glycoprotein-specific monoclonal antibody plus MBP-specific T cells (16 rats). In our 24 control rats, 20 received MBP-specific T cells only, and four received myelin glycoproteins plus purified protein derivative-specific T cells. The extent of the resulting blood-brain barrier (BBB) permeability, vasogenic oedema and/or demyelination was assessed in vivo using magnetic resonance imaging (MRI) techniques. The results show that in both demyelinating EAE models the disease appeared more quickly, progressed very rapidly and was more severe than when induced with a similar number of MBP-specific T cells alone. Almost all animals developed hypercute EAE, with a very high mortality rate. MRI showed a very intense BBB breakdown and vasogenic oedema in all the normally ‘leaky’ areas of the central nervous system, and focal lesions corresponding to plaque formation in the brain stem or spinal cord near the ‘leaky’ areas. During the 40-day observation period, the rare survivors of this hyperacute form of EAE presented a chronic form of EAE with serious sequelae. Our results demonstrate that the synergistic effect observed between MBP-specific T cells and antibodies to myelin glycoproteins, especially to myelin/oligodendrocyte glycoprotein, does not only induced demyelinating lesions and chronic clinical signs, but is further responsible, via the normally ‘leaky areas’, for the fatal increase of the BBB breakdown and vasogenic oedema of which there are ample acute clinical signs. 相似文献
20.
Alcohol and Platelet Function 总被引:3,自引:0,他引:3
Epidemiological studies have shown that moderate consumption of alcoholic beverages is inversely related to the incidence of the complications of coronary artery disease. The protective effect of ethanol may be partially attributable to an inhibitory effect of ethanol on platelets. This article summarizes the experimental observations that ethanol inhibits platelet responses to specific physiological agonists. In alcoholics, various platelet defects have been observed, but these may be influenced by metabolic factors rather than the presence of ethanol alone. The acute effects of ethanol on platelet functions both in vivo and ex vivo will be reviewed. Evidence will be presented demonstrating that ethanol added acutely in vitro inhibits phospholipase A2 in stimulated platelets. The interaction of ethanol with other signal transduction pathways will also be discussed. 相似文献