全文获取类型
收费全文 | 1187篇 |
免费 | 88篇 |
国内免费 | 27篇 |
专业分类
耳鼻咽喉 | 1篇 |
儿科学 | 73篇 |
妇产科学 | 13篇 |
基础医学 | 183篇 |
口腔科学 | 25篇 |
临床医学 | 94篇 |
内科学 | 212篇 |
皮肤病学 | 61篇 |
神经病学 | 62篇 |
特种医学 | 159篇 |
外科学 | 100篇 |
综合类 | 7篇 |
预防医学 | 142篇 |
眼科学 | 13篇 |
药学 | 94篇 |
肿瘤学 | 63篇 |
出版年
2023年 | 4篇 |
2022年 | 6篇 |
2021年 | 23篇 |
2020年 | 13篇 |
2019年 | 17篇 |
2018年 | 25篇 |
2017年 | 12篇 |
2016年 | 22篇 |
2015年 | 25篇 |
2014年 | 28篇 |
2013年 | 44篇 |
2012年 | 62篇 |
2011年 | 60篇 |
2010年 | 45篇 |
2009年 | 50篇 |
2008年 | 50篇 |
2007年 | 80篇 |
2006年 | 50篇 |
2005年 | 51篇 |
2004年 | 30篇 |
2003年 | 27篇 |
2002年 | 16篇 |
2001年 | 27篇 |
2000年 | 17篇 |
1999年 | 14篇 |
1998年 | 42篇 |
1997年 | 49篇 |
1996年 | 56篇 |
1995年 | 42篇 |
1994年 | 32篇 |
1993年 | 30篇 |
1992年 | 15篇 |
1991年 | 19篇 |
1990年 | 19篇 |
1989年 | 39篇 |
1988年 | 29篇 |
1987年 | 20篇 |
1986年 | 17篇 |
1985年 | 15篇 |
1984年 | 17篇 |
1983年 | 9篇 |
1982年 | 8篇 |
1981年 | 7篇 |
1980年 | 5篇 |
1979年 | 6篇 |
1978年 | 2篇 |
1977年 | 6篇 |
1976年 | 6篇 |
1975年 | 8篇 |
1974年 | 2篇 |
排序方式: 共有1302条查询结果,搜索用时 31 毫秒
1.
2.
N. M. van Schoor D. L. Knol C. A. W. Glas R. W. J. G. Ostelo A. Leplège C. Cooper O. Johnell P. Lips 《Osteoporosis international》2006,17(4):543-551
Introduction Vertebral deformities are a common consequence of osteoporosis and are known to decrease quality of life. The Qualeffo–41
is a quality-of-life questionnaire especially developed for measuring quality of life in patients with vertebral deformities.
It consists of 41 questions arranged in five domains: pain, physical function, social function, general health perception,
and mental function. The objectives of this study were: (1) to develop a shorter version of the Qualeffo–41 by removing redundant
questions; and (2) to investigate the scale characteristics, reliability, and validity of this shorter version.
Methods The study was performed using data from the Qualeffo validation study and the Multiple Outcomes of Raloxifene Evaluation (MORE)
study. The analyses were performed in patients with vertebral deformities (n=579). Factor analysis on polychoric correlations and an item response theory (IRT) model, i.e., the generalized partial credit
model (GPCM), were used to create a shorter version of Qualeffo–41. Using GPCM, scoring weights were computed for all items.
Results Three items were removed from the data set because of too many missing values. Factor analysis identified three instead of
five domains: (1) pain, (2) physical function, and (3) mental function. Five items had factor loadings <0.4 and were not included
in the GPCM. After excluding several items, the domains pain (four items), physical function (18 items), and mental function
(nine items) showed a good, reasonable, and excellent fit, respectively. This indicates that the mental function domain and
the pain domain are more unidimensional than the physical function domain. All three domains showed a very high correlation
(r ≥0.95) with the corresponding domains of the Qualeffo–41.
Conclusions Qualeffo–31 was developed, consisting of three domains with a reasonable to excellent fit to the GPCM. Although the fit to
the GPCM supports the construct validity of the Qualeffo–31, validation in a new study should be performed before using it
in practice. 相似文献
3.
Repair of large midline incisional hernias with polypropylene mesh: Comparison of three operative techniques 总被引:9,自引:0,他引:9
de Vries Reilingh TS van Geldere D Langenhorst BLAM de Jong D van der Wilt GJ van Goor H Bleichrodt RP 《Hernia》2004,8(1):56-59
Polypropylene mesh is widely used for the reconstruction of incisional hernias that cannot be closed primarily. Several techniques have been advocated to implant the mesh. The objective of this study was to evaluate, retrospectively, early and late results of three different techniques, onlay, inlay, and underlay. The records of 53 consecutive patients with a large midline incisional hernia — 25 women and 28 men, mean age 60.4 (range 28–94) — were reviewed. Polypropylene mesh was implanted using the onlay technique in 13 patients, inlay in 23 patients, and underlay in 17 patients. Either the greater omentum or a polyglactin mesh was interponated between the mesh and the viscera. The records of these 53 patients were reviewed with respect to: size and cause of the hernia, pre- and postoperative mortality and morbidity, with special attention to wound complications. Patients were invited to attend the outpatient clinic at least 12 months after implantation of the mesh for physical examination of the abdominal wall. Postoperative complications occurred in 14 (26.4%) patients. The onlay technique had significantly more complications, as compared to both other techniques. Reherniation occurred in 15 (28.3%) patients. The reherniation rate of the inlay technique was significantly higher than after the underlay technique (44% vs 12%, P=0.03) and tended to be higher than the onlay technique (44% vs 23%, P=0.22). Repair of large midline incisional hernias with the use of a polypropylene mesh carries a high risk of complications and has a high reherniation rate. The underlay technique seems to be the better technique. 相似文献
4.
5.
An anomalous pulmonary vein draining into the subdiaphragmatic inferior vena cava was initially demonstrated on computed tomographic (CT) scans. The diagnosis of scimitar syndrome was confirmed with digital subtraction angiography. In retrospect, the anomalous vein and dextroposition of the heart were shown on chest radiographs. 相似文献
6.
B. Ruiter V. Trégoat L. M''Rabet J. Garssen C. A. F. M. Bruijnzeel-Koomen E. F. Knol E. van Hoffen 《Clinical and experimental allergy》2006,36(3):303-310
BACKGROUND: One to two percent of infants suffer from IgE-mediated allergic reactions against cow's milk proteins. Most children develop clinical tolerance, but approximately 15% are still allergic by the age of 10 years. Little is known about the T cell epitopes in individual cow's milk protein in relation to allergy and tolerance. OBJECTIVE: To identify T cell epitopes in alphas1-casein, the most abundant milk protein, and to investigate T cell responses toward these epitopes in allergic, atopic and non-atopic children. METHODS: Allergen-specific T cell lines (TCLs) were derived from peripheral blood mononuclear cells of 11 cow's milk allergic, nine atopic and nine non-atopic children. T cell responses were measured to alphas1-casein and to overlapping peptides (18-mers), spanning the alphas1-casein molecule. Proliferation was determined by incorporation of (3)H-thymidine, and cytokine production (IL-10, IL-13 and IFN-gamma) was measured by ELISA. RESULTS: Four main regions (amino acid (AA) residues 43-66, 73-96, 91-114 and 127-180) in the alphas1-casein molecule were immunogenic to T cells, among which the AA residues 133-156 spanned the immunodominant part. Only subtle differences were found in peptide recognition between the subject groups. Some of the peptides induced slightly Th1- or Th2-skewed cytokine responses. The increased levels of IL-10 in response to alphas1-casein observed in TCLs from atopic children appeared not to be linked to recognition of specific IL-10-inducing epitopes. CONCLUSIONS: The immunodominant sequence in alphas1-casein is spanned by AA residues 133-156. Tolerance towards alphas1-casein in atopic children may be mediated by an overall induction of IL-10 and not by recognition of certain T cell epitopes. The identified T cell epitopes in children with cow's milk allergy may be useful targets in developing peptide immunotherapy. 相似文献
7.
Arne Popma Robert Vermeiren Charlotte A M L Geluk Thomas Rinne Wim van den Brink Dirk L Knol Lucres M C Jansen Herman van Engeland Theo A H Doreleijers 《Neuropsychopharmacology》2007,61(3):405-411
BACKGROUND: In animals, strong evidence exists for an association between testosterone and aggression. In humans, and particularly in children and adolescents, findings have been less consistent. Previous research has suggested that this may partly be due to moderating effects of other factors, e.g., hormones. This study aims to investigate the moderating effect of cortisol on the relationship between testosterone and subtypes of aggression in delinquent male adolescents. METHODS: Participants were 103 boys (mean age 13.7) referred to a delinquency diversion program. Testosterone and cortisol levels were determined from saliva samples collected during resting conditions and related to self-report scores on overt and covert aggression. RESULTS: Linear regression analyses revealed a significant interaction between cortisol and testosterone in relation to overt aggression, with a significant positive relationship between testosterone and overt aggression in subjects with low cortisol levels but not in subjects with high cortisol levels. Using the same model for covert aggression, no significant effects of testosterone, cortisol, or testosterone x cortisol interaction were found. CONCLUSIONS: These results indicate a moderating effect of cortisol on the relationship between testosterone and overt aggression in delinquent male adolescents. Implications and directions for future research are discussed. 相似文献
8.
D Mahalanabis H Ashraf MM Rahman GJ Fuchs 《Acta paediatrica (Oslo, Norway : 1992)》1998,87(11):1113-1115
One-hundred and six male children aged 6-23 months with a history of acute watery diarrhoea of less than 72 h duration were randomized to receive either folic acid in a dose of 5 mg at 8-h intervals or placebo for 5 d. There were 54 children in the folic acid group and 52 in the placebo group. The admission characteristics were comparable between the two groups. No significant differences were observed in the intake of oral rehydration solution or stool output between the groups. The mean ± SD of total stool output (g kg−1 ) was 532 ± 476 vs 479 ± 354 and the duration (h) of diarrhoea was 108 ± 68 vs 103 ± 53 in the folic acid vs placebo group, respectively. The findings, therefore, should have a positive influence on preventing the inappropriate use of folic acid in acute diarrhoea. 相似文献
9.
Studies of proteins that inhibit tissue factor activity have generally been conducted using either an extracted tissue homogenate ("thromboplastin") or tissue factor protein reconstituted into phospholipid vesicles rather than with tissue factor expressed in cell membranes (its physiological environment). In the present study, a human fibroblast cell strain was used to evaluate the effects of lipoprotein associated coagulation inhibitor (LACI), placental anticoagulant protein (PAP), and apolipoprotein A-II (apo A-II) on human tissue factor in cell membranes. LACI was tested from 7.8 to 500 pmol/L on fibroblasts cultured at cell densities ranging from 3,500 to 9,925 cells/well, and caused a progressive inhibition of tissue factor activity. PAP was tested from 3.9 nmol/L to 1 mumol/L at cell densities ranging from 4,500 to 15,400 cells/well and caused up to 83% inhibition of tissue factor activity. Inhibition by these proteins appeared to be influenced by cell density as well as whether the cells were intact or disrupted. Apo A-II, up to 1 mumol/L, did not inhibit the tissue factor activity of intact or disrupted fibroblasts at any cell density examined even though it did inhibit the activity of tissue factor in phospholipid vesicles. Of these inhibitors of tissue factor-dependent activation of factor X, LACI was the most effective in suppressing the generation of factor Xa activity. The effects obtained with apo A-II are clearly dependent on the nature of the tissue factor preparation with which it is tested. The disparity between the inhibitory effect of apo A-II on the activity of tissue factor reconstituted into lipid vesicles and the absence of effect on the activity of tissue factor remaining in cell membranes serves to reemphasize the necessity of reexamining results obtained with model systems using as nearly physiological reagents as possible. 相似文献
10.
R A Pomerantz F E Eckhauser J A Knol K Guirre S E Raper J G Turcotte 《The American surgeon》1989,55(6):333-337
The importance of "operative timing" in cirrhotic patients with variceal hemorrhage is often underemphasized. To evaluate the effects of immediate versus delayed selective portasystemic decompression on hepatic function, operative mortality, and long-term patient survival, we reviewed the records of 77 patients who underwent distal splenorenal shunts (DSRS) over a 14-year period. A hepatic risk status score was calculated at the time of the index bleed (HRS1) or presentation and again just prior to operation (HRS2). Variables analyzed included age, sex, prior bleeding episodes, time from index bleed to operation, transfusion requirements, and etiology of cirrhosis. Operative mortality rates for immediate versus delayed DSRS were 46.2 per cent and 17 per cent, respectively. HRS improved significantly in elective DSRS patients from 1.46 to 1.30. Predictors of HRS2 included HRS1 and time in days from the index bleed to operation. The most important predictor of early survival for all patients after elective DSRS was the HRS2; however, for patients who underwent elective DSRS and survived, HRS1 was a better predictor of length of survival than HRS2. No other variable analyzed accurately predicted survival. We conclude that HRS can be expected to improve with supportive inhospital therapy; improved HRS at the time of operation is associated with decreased operative mortality; and the extent of liver disease as determined by HRS1 appears to be the chief determinant of long-term patient survival. 相似文献