全文获取类型
收费全文 | 20014篇 |
免费 | 1320篇 |
国内免费 | 80篇 |
专业分类
耳鼻咽喉 | 223篇 |
儿科学 | 449篇 |
妇产科学 | 360篇 |
基础医学 | 2823篇 |
口腔科学 | 328篇 |
临床医学 | 1768篇 |
内科学 | 5128篇 |
皮肤病学 | 418篇 |
神经病学 | 1730篇 |
特种医学 | 651篇 |
外国民族医学 | 8篇 |
外科学 | 2806篇 |
综合类 | 240篇 |
一般理论 | 8篇 |
预防医学 | 1463篇 |
眼科学 | 445篇 |
药学 | 1209篇 |
中国医学 | 78篇 |
肿瘤学 | 1279篇 |
出版年
2023年 | 137篇 |
2022年 | 335篇 |
2021年 | 572篇 |
2020年 | 318篇 |
2019年 | 476篇 |
2018年 | 548篇 |
2017年 | 353篇 |
2016年 | 379篇 |
2015年 | 472篇 |
2014年 | 643篇 |
2013年 | 883篇 |
2012年 | 1399篇 |
2011年 | 1415篇 |
2010年 | 801篇 |
2009年 | 696篇 |
2008年 | 1175篇 |
2007年 | 1258篇 |
2006年 | 1229篇 |
2005年 | 1157篇 |
2004年 | 1062篇 |
2003年 | 1003篇 |
2002年 | 994篇 |
2001年 | 184篇 |
2000年 | 159篇 |
1999年 | 212篇 |
1998年 | 209篇 |
1997年 | 181篇 |
1996年 | 176篇 |
1995年 | 130篇 |
1994年 | 120篇 |
1993年 | 106篇 |
1992年 | 125篇 |
1991年 | 126篇 |
1990年 | 125篇 |
1989年 | 90篇 |
1988年 | 103篇 |
1987年 | 102篇 |
1986年 | 89篇 |
1985年 | 110篇 |
1984年 | 112篇 |
1983年 | 109篇 |
1982年 | 123篇 |
1981年 | 135篇 |
1980年 | 110篇 |
1979年 | 78篇 |
1978年 | 87篇 |
1977年 | 95篇 |
1976年 | 67篇 |
1974年 | 62篇 |
1973年 | 57篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
91.
Mutual inhibition of the binding of Clq and protein A to rabbit IgG immune complexes 总被引:1,自引:0,他引:1
A complex of rabbit IgG antibody with horseradish peroxidase covalently linked to Sepharose 4B was used as an insoluble immune complex for studying the binding of complement factor C1q protein A from Staphylococcus aureus, and its IgG-binding fragments AB and B, to rabbit IgG. It was shown that protein A (mol. wt approx. 42,000) and fragments AB and B (mol. wts approx. 14,000 and 7000, respectively) inhibited the binding of C1q to insoluble immune complex at 4 degrees C. However, at 37 degrees C fragment B did not inhibit this binding. On the other hand, C1q, when bound to an insoluble immune complex, almost completely blocked the binding of protein A and fragment B at both temps. The higher affinity of C1q for its CH2-binding site than of fragment B for its CH2-binding site may explain the displacement of the latter from the CH2 domain. The mutual inhibition of the binding of C1q and protein A (and its smaller fragments) indicates that the binding sites for C1q and protein A are closely located in the CH2 domain. 相似文献
92.
L. Gazaigne P. Legrand B. Renaud B. Bourra E. Taillandier C. Brun-Buisson P. Lesprit 《European journal of clinical microbiology & infectious diseases》2008,27(3):185-189
In this paper, we report 21 cases of Campylobacter fetus bloodstream infection observed in our institution over a 9-year period. The median age of the patients was 78 years. Most
of them (62%) had a significant underlying disease, such as diabetes, immunodeficiency or cardiovascular disease. The main
clinical features were fever with (62% of cases) or without (38%) extra-intestinal symptoms. These included mycotic aneurysm
of the abdominal aorta (24%) and cellulitis (19%). Antibiotic treatment was mainly based on amoxicilline-clavulanate (57%)
or imipenem (21%), for a median duration of 28 days. A favourable outcome was observed in 72% of cases. Death directly attributable
to infection was observed for three patients, due to the rupture of an infected aneurysm or relapsing bloodstream infection
with septic shock. All patients initially treated with imipenem had a favourable outcome. This report adds evidence that C. fetus bloodstream infection should be suspected in elderly patients with fever, immunodeficiency and cardiovascular damages. Imipenem
seems to be the most active drug, especially in severe cases. 相似文献
93.
On the classification of the acrocephalosyndactyly syndromes 总被引:2,自引:0,他引:2
This report describes a family in which two different types of acrocephalosyndactyly (ACS) were clinically identified. The proband presented with the classic stigmata of Pfeiffer syndrome, while her cousin was considered to be a typical case of Apert syndrome. Seven other family members also have unusually shaped heads and the facial appearance reminiscent of Crouzon disease.
Observations made in this family and from previous reports in the literature, we feel there is substantial reason to re-evaluate the ACS classification and to consider that the Apert and Pfeiffer types of ACS may be one and the same. 相似文献
Observations made in this family and from previous reports in the literature, we feel there is substantial reason to re-evaluate the ACS classification and to consider that the Apert and Pfeiffer types of ACS may be one and the same. 相似文献
94.
Jin-Kyoo Kim May-Fang Tsen Victor Ghetie E. Sally Ward 《European journal of immunology》1994,24(3):542-548
Site-directed mutagenesis has been used to change amino acid residues of a recombinant Fc-hinge fragment derived from the murine immunoglobulin (Ig)G1 molecule, and the effects of these mutations on the pharmacokinetics of the Fc-hinge fragment have been determined. Specifically, Ile-253, His-310 and Gln-311 of the CH2 domain and His-433 and Asn-434 of the CH3 domain have been changed. In the three dimensional structure of an antibody, these amino acids are in close proximity to each other at the CH2-CH3 domain interface. The mutated Fc-hinge fragments have been purified from recombinant Escherichia coli cells and their pharmacokinetic parameters determined in mice and compared with those of the wild-type Fc-hinge fragment. The results show that the site of the IgG1 molecule that controls the catabolic rate (the ‘catabolic site’) is located at the CH2-CH3 domain interface and overlaps with the Staphylococcal protein A binding site. 相似文献
95.
Zuber B Levitsky V Jönsson G Paulie S Samarina A Grundström S Metkar S Norell H Callender GG Froelich C Ahlborg N 《Journal of immunological methods》2005,302(1-2):13-25
The perforin (PFN) protein is essential for the elimination of target cells by cytotoxic T lymphocytes (CTL) and natural killer (NK) cells. The study of cells releasing PFN has been hampered by a lack of sensitive methods. We therefore produced PFN-reactive monoclonal antibodies (mAb) and developed capture enzyme-linked immunosorbent (ELISA) and enzyme-linked immunospot (ELISpot) assays. Three mAbs were generated and shown to react with unique determinants of PFN. All mAbs recognized intracellular PFN in human peripheral blood mononuclear cell (PBMC) as assessed by flow cytometry and immunohistochemistry. Functional PFN capture ELISA and ELISpot assays were developed utilizing two of the mAbs for capture and the third mAb for detection. When examining PFN release by the YT lymphoma cell line, the ELISpot displayed a greater detection sensitivity than the ELISA. Assessment of PFN release by a CTL clone using ELISpot gave results consistent with a parallel (51)Cr-release cytotoxicity assay. Moreover, PFN release by PBMC could be quantified by ELISpot and ELISA after ex vivo stimulation with defined CTL epitopes from common viruses. These novel immunoassays will be valuable for further investigations of the mechanisms underlying granule-mediated apoptosis. In addition, the capture immunoassays could provide tools for studying CTL responses in infectious and tumor diseases as well as for vaccine development. 相似文献
96.
Carol A Mathews Caroline M Nievergelt Amin Azzam Helena Garrido Denise A Chavira Jennifer Wessel Monica Bagnarello Victor I Reus Nicholas J Schork 《American journal of medical genetics. Part B, Neuropsychiatric genetics》2007,(2):174-182
To date, only one complete genome screen for obsessive-compulsive disorder (OCD) has been published. That study identified a region of suggestive linkage (maximum lod score of 2.25) with a relatively small sample size (N = 56; 27 with OCD). Additional complete genome screens are needed to confirm this finding and identify other regions of linkage. We present the clinical characteristics and power to detect linkage of 11 multigenerational families with OCD and hoarding (N = 92; 44 with OCD), as well as heritability estimates for several quantitative traits. Families with at least two individuals with OCD were identified through probands with childhood-onset OCD. Expected lod scores were calculated for simulated genetic marker data under an additive and two dominant models assuming a dense SNP marker map. All affected individuals had an early age of onset (18 or younger). Hoarding was present in 46% of subjects. Obsessive-compulsive symptoms and hoarding were highly heritable. The maximum mean expected lod score was 3.31 for OCD and 1.39 for hoarding. We found reasonable power to detect regions of interest (lod = 2) for OCD in these families, but will need to expand our family collection to have adequate power to detect regions of interest for hoarding. 相似文献
97.
BACKGROUND: Rates of remission and relapse were studied over more than 2 years in a sample of Spanish outpatients with DSM-III-R criteria of unipolar major depressive episodes. METHODS: Patients were treated following standardised pharmacological protocols at our centre. In the first visit, the structured clinical interview for DSM-III-R (SCID) was used. The following visits were held monthly. Phases of evolution were recorded using the Hamilton Depression Rating Scale (HDRS), applying the Frank criteria. RESULTS: A significantly greater proportion of relapse was observed in the partial remission group compared to the complete remission one. The rate of relapses for patients in complete remission was 15.18%, while for patients in partial remission was 67.61%. Partial remission was significantly associated with relapses. LIMITATIONS: The short duration of the study and the decreasing sample size during the follow-up. CONCLUSIONS: Partial remission after a depressive episode seems to be strongly associated with relapses. Moreover, this clinical factor could by itself fully predict short-term relapses. CLINICAL RELEVANCE: The study shows the importance of reaching complete remission to decrease the rate of short-term relapses. 相似文献
98.
Zhang J Herman EH Knapton A Chadwick DP Whitehurst VE Koerner JE Papoian T Ferrans VJ Sistare FD 《Toxicologic pathology》2002,30(1):28-40
The characteristics and pathogenesis of the cardiovascular toxicity induced by the type III selective phosphodiesterase inhibitor SK&F 95654 were examined in 2 studies. Sprague-Dawley rats received either a single sc injection of 50, 100, or 200 mg/kg SK&F 95654 and were euthanized at 24 hours after administration of the drug (Study 1), or were given a single subcutaneous (sc) injection of 100 mg/kg SK&F 95654 and euthanized at 1, 2, 4, 6, 8,12, 24 hours, or 2 weeks after treatment (Study 2). Control rats received either DMSO or saline. Myocardial lesions and vascular lesions of the mesentery, spleen, and pancreas were seen 24 hours after dosing with either 50,100, or 200 mg/kg SK&F 95654. The frequency and severity of these lesions (evaluated after the 100 mg/kg dose) increased with time over a period of 1 to 24 hours. By 2 weeks, the lesions subsided. Cardiac lesions consisted of myocyte necrosis with hypercontraction bands, inflammatory cell infiltration, interstitial hemorrhage, and interstitial edema. Vascular lesions of the mesentery were most prominent and consisted of vasodilatation and inflammation in the small-sized vessels, arterial medial necrosis and hemorrhage, and venous thrombosis. The vascular lesions included: leukocyte adhesion to endothelial cells, transendothelial migration of leukocytes, and inflammatory cell infiltration into vessel walls. Affected vessels included arteries, terminal arterioles, capillaries, postcapillary venules, and veins. Apoptosis of endothelial and smooth muscle cells was detected in the mesenteric vasculature by both TUNEL assay and electron microscopy. Evidence of endothelial cell activation in the mesenteric arteries and veins was also observed by electron microscopy. Immunohistochemical staining detected enhanced endothelial cell expression of intercellular adhesion molecule- 1 (ICAM- 1) and von Willebrand factor (vWF) in the mesenteric arteries and veins. Mast cells were noted to be more prevalent in affected mesenteric tissue from drug-treated animals. The present findings suggest that apoptosis of endothelial and smooth muscle cells, activation of endothelial cells, recruitment of mast cells, and increased expression of adhesion molecules are important factors to the overall pathogenesis of SK&F 95654-induced vasculitis. 相似文献
99.
100.