全文获取类型
收费全文 | 1599篇 |
免费 | 76篇 |
国内免费 | 40篇 |
专业分类
耳鼻咽喉 | 4篇 |
儿科学 | 70篇 |
妇产科学 | 27篇 |
基础医学 | 245篇 |
口腔科学 | 36篇 |
临床医学 | 181篇 |
内科学 | 381篇 |
皮肤病学 | 17篇 |
神经病学 | 96篇 |
特种医学 | 195篇 |
外科学 | 111篇 |
综合类 | 20篇 |
预防医学 | 120篇 |
眼科学 | 5篇 |
药学 | 110篇 |
中国医学 | 1篇 |
肿瘤学 | 96篇 |
出版年
2022年 | 8篇 |
2021年 | 32篇 |
2020年 | 16篇 |
2019年 | 18篇 |
2018年 | 29篇 |
2017年 | 26篇 |
2016年 | 21篇 |
2015年 | 41篇 |
2014年 | 48篇 |
2013年 | 56篇 |
2012年 | 69篇 |
2011年 | 63篇 |
2010年 | 60篇 |
2009年 | 59篇 |
2008年 | 53篇 |
2007年 | 69篇 |
2006年 | 47篇 |
2005年 | 40篇 |
2004年 | 33篇 |
2003年 | 29篇 |
2002年 | 32篇 |
2001年 | 41篇 |
2000年 | 38篇 |
1999年 | 40篇 |
1998年 | 61篇 |
1997年 | 56篇 |
1996年 | 55篇 |
1995年 | 33篇 |
1994年 | 27篇 |
1993年 | 39篇 |
1992年 | 29篇 |
1991年 | 28篇 |
1990年 | 33篇 |
1989年 | 43篇 |
1988年 | 35篇 |
1987年 | 39篇 |
1986年 | 22篇 |
1985年 | 27篇 |
1984年 | 22篇 |
1983年 | 24篇 |
1982年 | 19篇 |
1981年 | 22篇 |
1980年 | 22篇 |
1979年 | 5篇 |
1978年 | 13篇 |
1977年 | 9篇 |
1976年 | 9篇 |
1975年 | 6篇 |
1926年 | 6篇 |
1925年 | 6篇 |
排序方式: 共有1715条查询结果,搜索用时 15 毫秒
21.
22.
23.
Background
Genetic polymorphisms of the TCF7L2 gene are strongly associated with large increments in type 2 diabetes risk in different populations worldwide. In this study, we aimed to confirm the effect of the TCF7L2 polymorphism rs7903146 on diabetes risk in a Brazilian population and to assess the use of this genetic marker in improving diabetes risk prediction in the general population. 相似文献24.
Romieu R; Lacabanne V; Kayibanda M; Antoine B; Bennoun M; Chouaib S; Guillet JG; Viguier M 《International immunology》1997,9(10):1405-1413
There is now good evidence that cytokines contribute to the regulation of
tumor growth. The cytokine-driven modulation of tumor growth was
investigated during the progression of a hepatocellular carcinoma (HCC) in
SV40 large T tumor antigen transgenic mice. In vivo, an increased rate of
liver growth correlated with increased transforming growth factor
(TGF)-beta 1 mRNA expression, while the greatest amounts of tumor necrosis
factor (TNF)-alpha mRNA were detected earlier during tumor development.
Conversely, no particular alteration of IL-1 alpha, IL-1 beta, IL-6, IL-2,
IL-4 and IFN-gamma mRNA production could be reported. In vitro,
hepatocyte-like tumor cell lines established at two stages, either before
or after HCC differentiation, were characterized. The early-stage-derived
cell line produced TNF-alpha mRNA, but had barely detectable expression of
TGF-beta 1 mRNA, while later-stage- derived cell lines showed the
reciprocal pattern. All cell lines displayed a lack of sensitivity to
TNF-alpha, although some degree of sensitivity to TNF-alpha could be
observed in the presence of actinomycin-D or after treatment with
IFN-gamma. The early-stage- derived cell line was sensitive to the growth
inhibitory effects of TGF- beta 1, but late-stage-derived tumor cell lines
displayed a loss of sensitivity to TGF-beta 1 which correlated with the
increased expression of TGF-beta 1 mRNA. Altogether, this suggests that
tumor cells contribute to the discrete TNF-alpha and TGF-beta 1 expression
patterns during HCC progression. This model of HCC could be of valuable
interest to assess the impact of various immunotherapeutic strategies on
modulation of tumor growth.
相似文献
25.
Only target-conformal treatment allows one to exploit the advantages of ion beams (the increased dose and high biological efficiency at the end of the particle range) to a maximum extent. Up to now, target-conformal treatments such as spot scanning or intensity-controlled raster scanning have used fast magnetic lateral deflection in one or two directions perpendicular to the beam axis and a slow range variation in the longitudinal axis by active or passive energy variation. The present paper describes a new method for conformal irradiation with a fast intensity-controlled longitudinal scan in the beam direction, called 'depth scanning'. Its advantages and disadvantages will be discussed. First experimental results from depth scanning will be presented. 相似文献
26.
Stefanie Kreutmair Susanne Unger Nicolás Gonzalo Núñez Florian Ingelfinger Chiara Alberti Donatella De Feo Sinduya Krishnarajah Manuel Kauffmann Ekaterina Friebel Sepideh Babaei Benjamin Gaborit Mirjam Lutz Nicole Puertas Jurado Nisar P. Malek Siri Goepel Peter Rosenberger Helene A. Häberle Ikram Ayoub Burkhard Becher 《Immunity》2021,54(7):1578-1593.e5
- Download : Download high-res image (233KB)
- Download : Download full-size image
27.
Symptomatic peripheral arterial disease: the value of a validated questionnaire and a clinical decision rule
下载免费PDF全文
![点击此处可从《The British journal of general practice》网站下载免费的PDF全文](/ch/ext_images/free.gif)
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
28.
Mutational analysis of the SOX9 gene in campomelic dysplasia and autosomal sex reversal: lack of genotype/phenotype correlations 总被引:9,自引:1,他引:9
Meyer J; Sudbeck P; Held M; Wagner T; Schmitz ML; Bricarelli FD; Eggermont E; Friedrich U; Haas OA; Kobelt A; Leroy JG; Van Maldergem L; Michel E; Mitulla B; Pfeiffer RA; Schinzel A; Schmidt H; Scherer G 《Human molecular genetics》1997,6(1):91-98
It has previously been shown that, in the heterozygous state, mutations in
the SOX9 gene cause campomelic dysplasia (CD) and the often associated
autosomal XY sex reversal. In 12 CD patients, 10 novel mutations and one
recurrent mutation were characterized in one SOX9 allele each, and in one
case, no mutation was found. Four missense mutations are all located within
the high mobility group (HMG) domain. They either reduce or abolish the
DNA-binding ability of the mutant SOX9 proteins. Among the five nonsense
and three frameshift mutations identified, two leave the C-terminal
transactivation (TA) domain encompassing residues 402-509 of SOX9 partly or
almost completely intact. When tested in cell transfection experiments, the
recurrent nonsense mutation Y440X, found in two patients who survived for
four and more than 9 years, respectively, exhibits some residual
transactivation ability. In contrast, a frameshift mutation extending the
protein by 70 residues at codon 507, found in a patient who died shortly
after birth, showed no transactivation. This is apparently due to
instability of the mutant SOX9 protein as demonstrated by Western blotting.
Amino acid substitutions and nonsense mutations are found in patients with
and without XY sex reversal, indicating that sex reversal in CD is subject
to variable penetrance. Finally, none of 18 female patients with XY gonadal
dysgenesis (Swyer syndrome) showed an altered SOX9 banding pattern in SSCP
assays, providing evidence that SOX9 mutations do not usually result in XY
sex reversal without skeletal malformations.
相似文献
29.
Summary The enzyme inosinic acid dehydrogenase (EC 1.2.1. [14]) was measured and partially purified (10- to 15-fold) from normal and leukemic leukocytes. From the normal blood cells, the highest activities could be detected in lymphocytes and bone marrow cells. Dependent on the blast cell count, the leukemic IMP dehydrogenase had a higher mean specific activity than the enzymes of fractionated, immature bone marrow cells, or normal granulocytes. The partially purified enzymes from the various blood cells were apparently identical; they exhibited hyperbolic substrate saturation kinetics and were inhibited by a number of purine nucleotides. For the leukemic blast cell enzyme, theK
m values for the substrates, IMP and NAD+, were 28±11; 227±98 µM, and 34±10; 240±67 µM for the partially purified enzyme from normal, immature bone marrow cells.The hypoxanthine-guanine and adenine phosphoribosyltransferase activities increased in the leukemic cells when compared with mature granulocytes, but nearly always showed similar activities when compared with the fractionated bone marrow cells. Only one of the 30 investigated leukemic patients exhibited a marked decrease in hypoxanthine phosphoribosyltransferase activity of 0.5 nmol/mg/h. The phosphoribosyltransferase-specific activities of the leukemic cells are more variable than for the normal ones and no correlation of enzyme activities and blast cell count was apparent.
Abbreviations A-PRT adenine phosphoribosyltransferase - HG-PRT hypoxanthine-guanine phosphoribosyltransferase - PRPP 5-phosphoribosyl-1-pyrophosphate - ALL acute lymphocytic leukemia - AML acute myelogenous leukemia - CLL chronic lymphatic leukemia - CML chronic myelogenous leukemia - AMMOL acute myelomonocytic leukemia This study was supported by the Deutsche forschungsgemeinschaft Be 458/4 相似文献
Abbreviations A-PRT adenine phosphoribosyltransferase - HG-PRT hypoxanthine-guanine phosphoribosyltransferase - PRPP 5-phosphoribosyl-1-pyrophosphate - ALL acute lymphocytic leukemia - AML acute myelogenous leukemia - CLL chronic lymphatic leukemia - CML chronic myelogenous leukemia - AMMOL acute myelomonocytic leukemia This study was supported by the Deutsche forschungsgemeinschaft Be 458/4 相似文献
30.
The effect of supervised rehabilitation on strength, postural sway, position sense and re-injury risk after acute ankle ligament sprain 总被引:2,自引:0,他引:2
Holme E Magnusson SP Becher K Bieler T Aagaard P Kjaer M 《Scandinavian journal of medicine & science in sports》1999,9(2):104-109
The effect of an early rehabilitation program, including postural training, on ankle joint function after an ankle ligament sprain was investigated prospectively. Ninety-two subjects, matched for age, sex, and level of sports activity, were randomized to a control or training group. All subject received the same standard information regarding early ankle mobilization. In addition, the training group participated in supervised physical therapy rehabilitation (1 h, twice weekly) with emphasis on balance training. Postural sway, position sense and isometric ankle strength were measured 6 weeks and 4 months after the injury, and at 12 months re-injury data were obtained. In the training group, there was a significant difference between the injured and uninjured side for plantar flexion (P < 0.01), eversion (P < 0.01) and inversion (P < 0.05), but not for dorsiflexion at 6 weeks. In the control group, there was a significant difference between the injured and uninjured side for plantar flexion (P < 0.01), eversion (P < 0.01), inversion (P < 0.01), and dorsiflexion (P < 0.05) at 6 weeks. Postural sway, but not position sense, differed between the injured and uninjured side in both groups (P < 0.01) at 6 weeks. The side-to-side percent differences were similar in both groups for all variables (P > 0.05) at 6 weeks, and there were no side-to-side differences at 4 months in either group. In the control group, 11/38 (29%) suffered a re-injury, while this number was only 2/29 (7%) in the training group (P < 0.05). These data showed that an ankle injury resulted in reduced ankle strength and postural control at 6 weeks, but that these variables had normalized at 4 months, independent of the supervised rehabilitation. However, the findings also demonstrated that supervised rehabilitation may reduce the number of re-injuries, and therefore may play a role in injury prevention. 相似文献