全文获取类型
收费全文 | 436篇 |
免费 | 43篇 |
国内免费 | 10篇 |
专业分类
耳鼻咽喉 | 2篇 |
儿科学 | 36篇 |
妇产科学 | 3篇 |
基础医学 | 52篇 |
口腔科学 | 11篇 |
临床医学 | 44篇 |
内科学 | 124篇 |
皮肤病学 | 8篇 |
神经病学 | 14篇 |
特种医学 | 49篇 |
外科学 | 52篇 |
综合类 | 11篇 |
一般理论 | 1篇 |
预防医学 | 31篇 |
眼科学 | 2篇 |
药学 | 17篇 |
中国医学 | 6篇 |
肿瘤学 | 26篇 |
出版年
2023年 | 6篇 |
2022年 | 15篇 |
2021年 | 15篇 |
2020年 | 13篇 |
2019年 | 8篇 |
2018年 | 19篇 |
2017年 | 11篇 |
2016年 | 7篇 |
2015年 | 16篇 |
2014年 | 17篇 |
2013年 | 16篇 |
2012年 | 13篇 |
2011年 | 9篇 |
2010年 | 10篇 |
2009年 | 15篇 |
2008年 | 11篇 |
2007年 | 13篇 |
2006年 | 14篇 |
2005年 | 18篇 |
2004年 | 17篇 |
2003年 | 15篇 |
2002年 | 5篇 |
2001年 | 6篇 |
2000年 | 5篇 |
1999年 | 4篇 |
1998年 | 20篇 |
1997年 | 17篇 |
1996年 | 19篇 |
1995年 | 17篇 |
1994年 | 15篇 |
1993年 | 15篇 |
1992年 | 1篇 |
1991年 | 4篇 |
1990年 | 7篇 |
1989年 | 12篇 |
1988年 | 9篇 |
1987年 | 8篇 |
1986年 | 6篇 |
1985年 | 6篇 |
1984年 | 4篇 |
1983年 | 3篇 |
1982年 | 4篇 |
1981年 | 6篇 |
1980年 | 3篇 |
1979年 | 2篇 |
1978年 | 3篇 |
1977年 | 7篇 |
1976年 | 1篇 |
1972年 | 1篇 |
1935年 | 1篇 |
排序方式: 共有489条查询结果,搜索用时 906 毫秒
1.
2.
Marie-Louise Muff Christensen Umbreen Yousaf Gerda Engholm Hans Henrik Storm 《European journal of cancer prevention》2006,15(3):266-268
More suicides than expected (standardized mortality ratio=1.3; 95% confidence interval=1.1-1.6) compared to the population risk were found among Danish women with a diagnosis of non-melanoma skin cancer in the period 1971-1999 but not among men. The increased risk might be associated with a different personality type in this cancer group. 相似文献
3.
4.
Nasim Yousaf Jonathan C. Howard Bryan D. Williams 《European journal of immunology》1993,23(2):369-375
We describe studies aimed at maximizing the effector mechanisms responsible for eliminating target erythrocytes from the circulation in a fully homologous opsonization system in vivo. The effects on the subsequent fate of target erythrocytes were examined in both normal and decomplemented rats preinjected with a variety of rat IgG monoclonal antibodies (mAb) directed against different epitopes on the RTlAa, the classical class I major histocompatibiliy complex antigen of the DA rat. In general, the clearance of both DA and (DA × PVG)F1 erythrocytes in normal rats preinjected with various pairs of noncompetitive mAb was very rapid when compared with the overall clearance patterns seen with individual antibodies. With all mAb combinations containing IgG2b or IgG2a, an intact complement system was an essential requirement for augmenting the initial clearance and promoting hepatic sequestration of these target cells. The removal of (DA × PVG)F1 erythrocytes, expressing half as much antigen, was considerably slower than the DA cells for each antibody pair tested although a notable degree of heterogeneity was observed in the overall behavior of both types of target cells with different mAb combinations. Our results suggest that the limiting effects of low antigen density on the target cells combined with the use of mAb of an isotype like the rat IgG2a can be overcome using pairs of mAb that recognize different epitopes on the same target antigen. 相似文献
5.
Hydrosalpinges adversely affect markers of endometrial receptivity 总被引:22,自引:10,他引:22
Meyer WR; Castelbaum AJ; Somkuti S; Sagoskin AW; Doyle M; Harris JE; Lessey BA 《Human reproduction (Oxford, England)》1997,12(7):1393-1398
While in-vitro fertilization (IVF) was initially developed in women with
tubal factor infertility, recent clinical studies have suggested that the
presence of hydrosalpinges lowers implantation and pregnancy rates. We
postulated that these hydrosalpinges cause impaired endometrial
receptivity. A total of 103 women with hydrosalpinges were prospectively
evaluated, and compared with 55 infertile and 44 fertile controls. All
women had endometrial biopsies during the window of implantation, analysed
by conventional histological criteria, and also stained for three integrin
markers of endometrial receptivity (alpha1beta1, alpha4beta1 and alpha
vbeta3). Women with hydrosalpinges (cases) expressed significantly less of
the alpha vbeta3 integrin compared with controls. There was no difference
in expression of alpha1beta1 or alpha4beta1 among groups. A significantly
greater number of cases had out of phase histology and missing alpha vbeta3
(type I defects) and absent integrin expression despite normal histological
maturation (type II) defects, compared with controls. Of 20 women with
impaired endometrial receptivity who were also biopsied after hydrosalpinx
surgery, 70% demonstrated increased alpha vbeta3 expression. Seventy-seven
percent of type I and 57% of type II defects were corrected
postoperatively. Using markers of endometrial receptivity, this study
demonstrates that inflammatory hydrosalpinges have an adverse effect on
endometrial receptivity, which in some cases may be overcome by surgical
treatment of the hydrosalpinx.
相似文献
6.
bcl-2 transgene expression promotes survival and reduces proliferation of CD3-CD4-CD8- T cell progenitors 总被引:16,自引:0,他引:16
Proliferative expansion and apoptotic cell death play prominent roles in T
cell development. The molecular control of cell cycle progression and
apoptosis appear to be inter-connected since the Bcl-2 protein can inhibit
apoptosis and slow cell cycle progression in cortical thymocytes and mature
T cells, particularly during the transition from the quiescent state into
the cell cycle. Here the impact of bcl-2 transgene expression on
CD3-CD4-CD8- T cell progenitors was assessed. Bcl-2 enhanced the survival
of these progenitors at all of the four major differentiation stages, CD25-
CD44+ (pro-T1), CD25 + CD44+ (pro- T2), CD25 + CD44- (pro-T3) and
CD25-CD44- (pro-T4). However, it reduced cell cycling and slowed turnover
only in the pro-T4 subset. From an analysis of bcl-2 transgenic mice
expressing a TCR transgene or bearing a mutation in the scid or rag-1 gene
we conclude that Bcl-2 inhibits proliferation only of T cell progenitors
that are activated via the pre- TCR, not those stimulated via c-Kit and the
IL-7 receptor.
相似文献
7.
Mutations in the Ca(2+)-sensing receptor gene cause autosomal dominant and sporadic hypoparathyroidism 总被引:3,自引:0,他引:3
Baron J; Winer KK; Yanovski JA; Cunningham AW; Laue L; Zimmerman D; Cutler GB Jr 《Human molecular genetics》1996,5(5):601-606
Parathyroid hormone secretion is negatively regulated by a 7- transmembrane
domain, G-protein coupled Ca(2+)-sensing receptor. We hypothesized that
activating mutations in this receptor might cause autosomal dominant
hypoparathyroidism (ADHP). Consistent with this hypothesis, we identified,
in two families with ADHP, heterozygous missense mutations in the
Ca(2+)-sensing receptor gene that cosegregated with the disorder. None of
50 normal controls had either mutation. We also identified a de novo,
missense Ca(2+)-sensing receptor mutation in a child with severe sporadic
hypoparathyroidism. The amino acid substitution in one ADHP family affected
the N-terminal, extracellular domain of the receptor. The other mutations
involved the transmembrane region. Unlike patients with acquired
hypoparathyroidism, patients with these mutations had hypercalciuria even
at low serum calcium concentrations. Their greater hypercalciuria
presumably reflected activation of Ca(2+)-sensing receptors in kidney
cells, where the receptor negatively regulates calcium reabsorption. This
augmented hypercalciuria increases the risk of renal complications and thus
has implications for the choice of therapy.
相似文献
8.
Symptomatic peripheral arterial disease: the value of a validated questionnaire and a clinical decision rule 下载免费PDF全文
Bianca LW Bendermacher Joep AW Teijink Edith M Willigendael Marie-Louise Bartelink Harry R Büller Ron JG Peters Jelis Boiten Machteld Langenberg Martin H Prins 《The British journal of general practice》2006,56(533):932-937
BACKGROUND: If a validated questionnaire, when applied to patients reporting with symptoms of intermittent claudication, could adequately discriminate between those with and without peripheral arterial disease, GPs could avoid the diagnostic measurement of the ankle brachial index. AIM: To investigate the Edinburgh Claudication Questionnaire (ECQ) in general practice and to develop a clinical decision rule based on risk factors to enable GPs to easily assess the likelihood of peripheral arterial disease. DESIGN OF STUDY: An observational study. SETTING: General practice in The Netherlands. METHOD: This observational study included patients of > or =55 years visiting their GP for symptoms suggestive of intermittent claudication or with one risk factor. The ECQ and the ankle brachial index were performed. The prevalence of peripheral arterial disease, defined as an ankle brachial index <0.9, was related to risk factors using logistic regression analyses, on which a clinical decision rule was developed and related to the presence of peripheral arterial disease. RESULTS: Of the 4790 included patients visiting their GP with symptoms suggestive of intermittent claudication, 4527 were eligible for analyses. The prevalence of peripheral arterial disease in this group was 48.3%. The sensitivity of the ECQ was only 56.2%. The prevalence of peripheral arterial disease in a clinical decision rule that included age, male sex, smoking, hypertension, hypercholesterolemia, and a positive ECQ, increased from 14% in the lowest to 76% in the highest category. CONCLUSION: This study indicates that the ECQ alone has an inadequate diagnostic value in detecting patients with peripheral arterial disease. The ankle brachial index should be performed to diagnose peripheral arterial disease in patients with complaints suggestive of intermittent claudication, although our clinical decision rule could help to differentiate between extremely high and lower prevalence of peripheral arterial disease. 相似文献
9.
10.
Rabia Faridi Rizwan Yousaf Shoujun Gu Sayaka Inagaki Amy E. Turriff Keith Pelstring Bin Guan Amelia Naik Andrew J. Griffith Samuel Mawuli Adadey Elvis Twumasi Aboagye Gordon A. Awandare Robert J. Morell Ekaterini Tsilou Amanda G. Noyes Laura A. G. Sulmonte Ambroise Wonkam Isabelle Schrauwen Suzanne M. Leal Hela Azaiez Carmen C. Brewer Sheikh Riazuddin Robert B. Hufnagel Michael Hoa Wadih M. Zein J. Karl de Dios Thomas B. Friedman 《Clinical genetics》2023,103(6):699-703