全文获取类型
收费全文 | 639篇 |
免费 | 26篇 |
国内免费 | 13篇 |
专业分类
耳鼻咽喉 | 21篇 |
儿科学 | 15篇 |
妇产科学 | 12篇 |
基础医学 | 75篇 |
口腔科学 | 17篇 |
临床医学 | 32篇 |
内科学 | 119篇 |
皮肤病学 | 21篇 |
神经病学 | 36篇 |
特种医学 | 173篇 |
外科学 | 16篇 |
综合类 | 4篇 |
预防医学 | 30篇 |
眼科学 | 75篇 |
药学 | 12篇 |
中国医学 | 1篇 |
肿瘤学 | 19篇 |
出版年
2018年 | 4篇 |
2017年 | 4篇 |
2016年 | 11篇 |
2015年 | 5篇 |
2014年 | 9篇 |
2013年 | 19篇 |
2012年 | 32篇 |
2011年 | 20篇 |
2010年 | 23篇 |
2009年 | 12篇 |
2008年 | 13篇 |
2007年 | 23篇 |
2006年 | 12篇 |
2005年 | 11篇 |
2004年 | 11篇 |
2003年 | 8篇 |
2002年 | 9篇 |
2001年 | 8篇 |
2000年 | 5篇 |
1999年 | 5篇 |
1998年 | 14篇 |
1997年 | 22篇 |
1996年 | 25篇 |
1995年 | 16篇 |
1994年 | 17篇 |
1993年 | 11篇 |
1992年 | 14篇 |
1991年 | 8篇 |
1990年 | 11篇 |
1989年 | 31篇 |
1988年 | 24篇 |
1987年 | 27篇 |
1986年 | 21篇 |
1985年 | 25篇 |
1984年 | 15篇 |
1983年 | 10篇 |
1982年 | 9篇 |
1981年 | 5篇 |
1979年 | 9篇 |
1978年 | 12篇 |
1977年 | 10篇 |
1976年 | 6篇 |
1975年 | 9篇 |
1974年 | 8篇 |
1973年 | 4篇 |
1970年 | 4篇 |
1968年 | 14篇 |
1967年 | 5篇 |
1966年 | 5篇 |
1965年 | 4篇 |
排序方式: 共有678条查询结果,搜索用时 31 毫秒
1.
PADGEM (GMP140) is a component of Weibel-Palade bodies of human endothelial cells 总被引:65,自引:10,他引:55
PADGEM protein (PADGEM), also known as GMP140, is a platelet alpha- granule membrane protein that is translocated to the external membrane after platelet activation. Although the biosynthesis of this protein was originally thought to be confined to megakaryocytes, the synthesis of PADGEM in endothelial cells was recently demonstrated (McEver et al: Blood 70:1974a, 1987). We now describe the subcellular localization of this protein in endothelial cells. Immunofluorescence staining of permeabilized human umbilical vein endothelial cells with KC4, a well characterized monoclonal antibody to PADGEM, showed positively stained elongated structures similar in distribution and shape to Weibel-Palade bodies. Their identity as Weibel-Palade bodies was confirmed by double label immunofluorescence using KC4 and a polyclonal antiserum to von Willebrand factor (vWf), a protein known to be specifically stored in these organelles. All Weibel-Palade bodies were found to contain PADGEM. In contrast to strong perinuclear staining produced with anti- vWf antibodies, no significant perinuclear staining was obtained with KC4, indicating that relatively little PADGEM is present in the endoplasmic reticulum and in the Golgi apparatus. In endothelial cells treated with secretagogues that stimulate vWf release the elongated structures positive for PADGEM disappeared, further identifying these structures as Weibel-Palade bodies. This observation extends the parallels between Weibel-Palade bodies and alpha-granules and suggests a possible functional association between vWf and PADGEM. 相似文献
2.
Occurrence of the t(2;5)(p23;q35) in non-Hodgkin's lymphoma 总被引:9,自引:3,他引:6
Weisenburger DD; Gordon BG; Vose JM; Bast MA; Chan WC; Greiner TC; Anderson JR; Sanger WG 《Blood》1996,87(9):3860-3868
Primary CD30(Ki-1)-positive anaplastic large-cell lymphoma (ALCL) is considered by some to be a distinct clinicopathologic entity associated with the t(2;5) (p23;q35). However, the specificity of t(2;5) for ALCL has not been carefully studied. Therefore, we performed a detailed analysis of all cases of ALCL with abnormal cytogenetics results in the Nebraska Lymphoma Study Group registry, as well as all other cases of non-Hodgkin's lymphoma with t(2;5) in the registry. We found the t(2;5) in only five of 10 cases of ALCL, four of whom were young patients. However, we also found the t(2;5) in 11 other cases of nonanaplastic lymphoma, including eight children with typical peripheral T-cell lymphomas of various types. The t(2;5) was also found in three older adults with B-cell lymphomas of various types. Thus, the t(2;5) was not specific for CD30+ ALCL. However, t(2;5) may define a clinicopathologic entity in children and young adults characterized by variable morphologies with a T-cell or indeterminate phenotype, CD30-positivity, nodal disease with frequent extranodal involvement, advanced stage, and an excellent response to therapy, including bone marrow transplantation for relapsed disease. The clinical relevance of the t(2;5) in older patients requires further study. 相似文献
3.
4.
Virus-like particles were found in the brain and salivary glands of Dermacentor reticulatus ticks double infected with Coxiella burnetii and Rickettsiella phytoseiuli. The particles were spherical (diameter of about 70 nm) and consisted of an electron-dense inner core and a dense external coat. 相似文献
5.
6.
Advanced primary breast cancer: assessment at mammography of response to induction chemotherapy 总被引:2,自引:0,他引:2
The response to induction chemotherapy is an important prognostic factor in patients with nonmetastatic, locally advanced breast carcinomas. Assessment at mammography of the response of 60 breast cancers in 59 women was performed between 1974 and 1986. Responses were excellent in 13 tumors, moderate in 34, and poor in 13 (excellent moderate = 78%). Assessment of response of discrete masses in a fatty breast was easiest; assessment of response of tumor areas that were poorly defined-such as a focal area of architectural distortion or mass in dense breast parenchyma-was more difficult. Of 17 patients with excellent pathologic responses-that is, minimal or no residual tumor-15 (88%) had complete responses (no residual tumor) as determined with mammography, physical examination, or both. Mammography provides information complementary to physical examination and is essential in the accurate assessment of the response to chemotherapy of locally advanced breast cancer. 相似文献
7.
The authors present an account on a 12-year-old girl with ectomesodermal dysgenesis of the Rieger type syndrome. The disease was manifested at the age of nine months by transient diffuse corneal opacity, while the intraocular pressure was normal. In addition to typical corneal changes and changes in the angle of the chamber other associated somatic symptoms included megalocornea, high myoptic astigmatism, cleft soft palate, hypoplasia of the upper jaw, partial anodontia, marked thoracic kyphosis, scoliosis, generalized hypermobility and taxicity of the joints and torticollis. Examination revealed an uncommon pathological karyotype 46, XX, t/1,4 (p36, q23). Cytogenetic examination of the parents and siblings of the proband did not disclose any numerical or structural aberrations. The authors reflect on possible causes of the development of the disease and on the differential diagnosis. 相似文献
8.
9.
The effects of co-culture with human fibroblasts on human embryo development in vitro and implantation 总被引:5,自引:0,他引:5
Wetzels AM; Bastiaans BA; Hendriks JC; Goverde HJ; Punt-van der Zalm AP; Verbeet JG; Braat DD 《Human reproduction (Oxford, England)》1998,13(5):1325-1330
In a human in-vitro fertilization (IVF) programme, the effect of co-
culture of embryos with human fibroblasts was evaluated with respect to
pregnancy rate and embryo development. Patients were included in the study
after giving informed written consent. The IVF treatments were randomly
assigned by stratification of both age (<36 versus > or =36 years)
and previous IVF attempts (yes versus no). After fertilization was
established, the zygotes were transferred to a 4-well dish with or without
fibroblasts and cultured for 2 days. On the third day after ovum pick-up
(OPU), cell number and quality [5 (good) to 1 (poor)] of the embryos were
scored and a maximum of three embryos was transferred. Supernumerary
embryos of good quality were cryopreserved. The design of this study was a
group sequential trial with the objective of detecting differences between
pregnancy rates following IVF with conventional incubation or incubation in
co-culture with fibroblasts. This design included one evaluation at
half-way data collection. In the study, 148 patients had an OPU, of whom 77
were allocated to the co-culture group. There was no statistically
significant difference in pregnancy rate, cell number and embryo quality
between the two groups. The ongoing pregnancy rate per embryo transfer was
27% in co-culture and 30% in the conventional culture group. The
implantation rates per transferred embryo were 17 and 18% respectively.
Using a multivariate logistic regression model for the probability of
ongoing pregnancies, the odds ratio of co-culture, adjusted for age and
previous IVF attempts, was not statistically significant. In conclusion,
co-culture with human fibroblasts does not contribute to an improvement of
embryo quality nor to a higher pregnancy rate after IVF in an unselected
group of patients.
相似文献
10.
Byron H Hartman Toshinori Hayashi Branden R Nelson Olivia Bermingham-McDonogh Thomas A Reh 《Developmental dynamics》2007,236(10):2875-2883
Notch mediates the process of lateral inhibition that controls the production of hair cells in the inner ear. Hair cells are known to express Notch ligands Dll1 and Jag2, which signal through Notch1 in adjacent supporting cells. However, recent genetic and pharmacological studies indicate that the level of Notch-mediated lateral inhibition is greater than can be accounted for by Dll1 and Jag2. Here, we report that another Notch ligand, Dll3, is expressed in developing hair cells, in a pattern that overlaps that of Dll1 and Jag2. We analyzed the cochleae of Dll3(pu) mutant mice, but did not detect any abnormalities. However, earlier studies have demonstrated that there is functional redundancy among Notch ligands in cochlear development and loss of one ligand can be at least partially compensated for by another. Thus Dll3 may play a role in lateral inhibition similar to that of Dll1 and Jag2. 相似文献