全文获取类型
收费全文 | 579篇 |
免费 | 44篇 |
国内免费 | 8篇 |
专业分类
儿科学 | 10篇 |
妇产科学 | 9篇 |
基础医学 | 60篇 |
口腔科学 | 7篇 |
临床医学 | 62篇 |
内科学 | 157篇 |
皮肤病学 | 9篇 |
神经病学 | 4篇 |
特种医学 | 154篇 |
外科学 | 30篇 |
综合类 | 7篇 |
预防医学 | 73篇 |
眼科学 | 2篇 |
药学 | 28篇 |
肿瘤学 | 19篇 |
出版年
2020年 | 4篇 |
2019年 | 5篇 |
2018年 | 11篇 |
2014年 | 7篇 |
2013年 | 10篇 |
2012年 | 10篇 |
2011年 | 13篇 |
2010年 | 12篇 |
2009年 | 14篇 |
2008年 | 14篇 |
2007年 | 13篇 |
2006年 | 29篇 |
2005年 | 17篇 |
2004年 | 10篇 |
2003年 | 12篇 |
2002年 | 15篇 |
2001年 | 9篇 |
2000年 | 9篇 |
1999年 | 10篇 |
1998年 | 17篇 |
1997年 | 23篇 |
1996年 | 24篇 |
1995年 | 16篇 |
1994年 | 25篇 |
1993年 | 15篇 |
1992年 | 7篇 |
1991年 | 11篇 |
1990年 | 8篇 |
1989年 | 26篇 |
1988年 | 20篇 |
1987年 | 13篇 |
1986年 | 22篇 |
1985年 | 16篇 |
1984年 | 17篇 |
1983年 | 8篇 |
1982年 | 13篇 |
1981年 | 9篇 |
1980年 | 6篇 |
1979年 | 4篇 |
1978年 | 9篇 |
1977年 | 10篇 |
1976年 | 7篇 |
1975年 | 10篇 |
1974年 | 5篇 |
1973年 | 5篇 |
1972年 | 5篇 |
1971年 | 4篇 |
1970年 | 8篇 |
1969年 | 6篇 |
1968年 | 6篇 |
排序方式: 共有631条查询结果,搜索用时 15 毫秒
1.
Rhinovirus infections in Tecumseh, Michigan: frequency of illness and number of serotypes 总被引:4,自引:0,他引:4
We studied rhinovirus-associated illnesses from 1976 to 1981 among residents of the community of Tecumseh, Michigan, in a continuation of similar studies done in 1966-1971. Rhinoviruses were the most frequently isolated respiratory pathogen in all age groups, including young children. The pattern of age-specific isolation rates was similar to that for total respiratory illness. Rhinovirus-associated illnesses were generally mild but of relatively long duration; restriction of daily activity was frequent, especially in certain age groups. Typing of all isolates has been completed; with high-quality antisera nearly all isolates could be typed. Thus, new serotypes are probably not evolving, and most have already been identified. Differences in frequency of occurrences of different serotypes were evident, but ranking in order of importance was difficult based on existing data. 相似文献
2.
3.
4.
5.
6.
Life expectancy in British Marfan syndrome populations 总被引:2,自引:0,他引:2
JR Gray AB Bridges RR West L. McLeish AG Stuart JCS Dean MEM Porteous M. Boxer SJ Davies 《Clinical genetics》1998,54(2):124-128
A total of 206 patients with Marfan syndrome were ascertained throughout genetic clinics in Wales and Scotland during the period 1970–1990. There were 45 deaths representing 22% of the cohort. Mean age at death was 45.3 ± 16.5 years. 50% median cumulative survival in the total cohort (n = 206) was 53 years for males and 72 years for females. Multivariate analysis confirmed severity as the best independent indicator of survival. These findings and survival curves will assist in the counselling of British families and individuals with Marfan syndrome. 相似文献
7.
Chee-Kin Hui Eva Lau Helen Wu Alexander Monto Michael Kim John M Luk George K K Lau Teresa Lyn Wright 《Journal of clinical virology》2006,35(2):185-192
Occult hepatitis B virus (HBV) infection in individuals without hepatitis B surface antigen (HBsAg) can be identified in hepatitis C virus (HCV) infected patients. However, its role in fibrosis progression remains uncertain. This retrospective study compared the fibrosis progression (defined as fibrosis progression by at least one stage) and progression to severe fibrosis (fibrosis stage 3 or 4) in HCV patients with occult HBV infection. Occult HBV infection was diagnosed by the detection of HBV DNA in the serum of 74 consecutive anti-HCV positive patients by PCR. Thirty-one patients (41.9%) had occult HBV infection. All 74 patients had a median of 2 (range 2-3) liver biopsies. The median time between the first and last liver biopsy was 57.7 (range 15.0-132.8) months. Eleven of the 31 patients with occult HBV infection compared with 12 of the 43 patients without occult HBV infection had fibrosis progression (35.5% versus 27.9%, respectively, p=0.608). Six of the 31 patients with occult HBV infection compared with 8 of the 43 patients without occult HBV infection developed severe fibrosis (19.4% versus 18.6%, respectively, p=0.946). In conclusion, chronic HCV patients with occult HBV co-infection does not seem to progress more than patients without occult HBV infection. However, more large-scale studies are needed before a definite conclusion can be obtained. 相似文献
8.
9.
Monocytoid B-cell lymphoma: its evolution and relationship to other low- grade B-cell neoplasms 总被引:3,自引:0,他引:3
Monocytoid B-cell lymphoma (MBCL) is a newly recognized B-cell neoplasm of uncertain histogenesis. The cytologic features of the neoplastic monocytoid B lymphocytes are virtually identical to those of hairy cell leukemia (HCL). As with HCL, progression of MBCL to a higher histologic grade is very unusual. However, whereas circulating leukemic cells are a characteristic feature of HCL, peripheral blood involvement has not been reported in MBCL. We recently studied a patient with MBCL of the spleen and axillary lymph nodes who developed peripheral blood involvement by MBCL cells. Unlike the cells of HCL, the circulating MBCL cells exhibited strong acid phosphatase activity that was tartrate sensitive. The leukemic cells had the antigenic phenotype IgM lambda, CD20+, CD11c+, CD5-, CD25(TAC)-, and PCA-1-. Immunogenetic studies of both lymph node and peripheral blood cells revealed identical immunoglobulin heavy-chain gene rearrangements. When compared with a series of HCL, the immunophenotype was similar except for the absence of PCA-1 and TAC. Progression of the MBCL to a large cell lymphoma, also expressing IgM lambda, was documented in an abdominal lymph node of this patient. Therefore, although rare, peripheral blood involvement by lymphoma cells may occur during the course of MBCL and should be distinguished from HCL with cytochemical and immunophenotypic studies. In addition, comparison of the clinical, pathologic, and immunologic features of MBCL with those of other low-grade B-cell neoplasms suggests that a close lineage relationship exists between MBCL and HCL. 相似文献
10.
Thrombospondin mediates the cytoadherence of Plasmodium falciparum- infected red cells to vascular endothelium in shear flow conditions 总被引:3,自引:0,他引:3
Rock EP; Roth EF Jr; Rojas-Corona RR; Sherwood JA; Nagel RL; Howard RJ; Kaul DK 《Blood》1988,71(1):71-75
Cerebral malaria is thought to involve specific attachment of Plasmodium falciparum-infected knobby red cells to venular endothelium. The nature of surface ligands on host endothelial cells that may mediate cytoadherence is poorly understood. We have investigated the effects of soluble thrombospondin, rabbit antiserum raised against thrombospondin, and human immune serum on cytoadherence of parasitized erythrocytes in ex vivo mesocecum vasculature. Preincubation of infected red cells with soluble thrombospondin or human immune serum inhibits binding of infected red cells to rat venular endothelium. Infusion of the microcirculatory preparation with rabbit antithrombospondin antibodies before perfusion of parasitized erythrocytes also resulted in decreased cytoadherence. In addition, incubation of infected cells with human immune sera obtained from malaria patients significantly inhibited the observed cytoadherence. Our results indicate that thrombospondin mediates binding of infected red cells to venular endothelium and may thus be involved in the pathogenesis of cerebral malaria. 相似文献