全文获取类型
收费全文 | 5409篇 |
免费 | 305篇 |
国内免费 | 18篇 |
专业分类
耳鼻咽喉 | 16篇 |
儿科学 | 122篇 |
妇产科学 | 59篇 |
基础医学 | 708篇 |
口腔科学 | 154篇 |
临床医学 | 493篇 |
内科学 | 1150篇 |
皮肤病学 | 48篇 |
神经病学 | 550篇 |
特种医学 | 240篇 |
外科学 | 647篇 |
综合类 | 10篇 |
一般理论 | 7篇 |
预防医学 | 553篇 |
眼科学 | 16篇 |
药学 | 527篇 |
中国医学 | 6篇 |
肿瘤学 | 426篇 |
出版年
2024年 | 6篇 |
2023年 | 25篇 |
2022年 | 35篇 |
2021年 | 75篇 |
2020年 | 63篇 |
2019年 | 98篇 |
2018年 | 97篇 |
2017年 | 92篇 |
2016年 | 97篇 |
2015年 | 116篇 |
2014年 | 192篇 |
2013年 | 245篇 |
2012年 | 419篇 |
2011年 | 453篇 |
2010年 | 266篇 |
2009年 | 230篇 |
2008年 | 405篇 |
2007年 | 462篇 |
2006年 | 380篇 |
2005年 | 406篇 |
2004年 | 344篇 |
2003年 | 327篇 |
2002年 | 290篇 |
2001年 | 61篇 |
2000年 | 33篇 |
1999年 | 53篇 |
1998年 | 77篇 |
1997年 | 64篇 |
1996年 | 51篇 |
1995年 | 41篇 |
1994年 | 37篇 |
1993年 | 49篇 |
1992年 | 15篇 |
1991年 | 17篇 |
1990年 | 23篇 |
1989年 | 10篇 |
1988年 | 9篇 |
1987年 | 7篇 |
1986年 | 9篇 |
1985年 | 6篇 |
1984年 | 10篇 |
1983年 | 7篇 |
1982年 | 10篇 |
1981年 | 8篇 |
1980年 | 5篇 |
1976年 | 1篇 |
1975年 | 1篇 |
1974年 | 1篇 |
1966年 | 1篇 |
1964年 | 1篇 |
排序方式: 共有5732条查询结果,搜索用时 15 毫秒
81.
Joris W J Vriend Wim Drenthen Petronella G Pieper Jolien W Roos-Hesselink Aeiko H Zwinderman Dirk J van Veldhuisen Barbara J M Mulder 《European heart journal》2005,26(20):2173-2178
AIMS: Nowadays, most women born with aortic coarctation reach childbearing age. However, data on outcome of pregnancy in women after repair of aortic coarctation are scarce. The aim of this study was to report on maternal and neonatal outcome of pregnancy in women after aortic coarctation repair. METHODS AND RESULTS: The CONCOR national registry on congenital heart disease in The Netherlands was reviewed for women of childbearing age (> or =18 years old) with a history of aortic coarctation repair. Medical history and maternal, obstetrical, and neonatal outcome were determined. Fifty-four of the 100 women included had a history of pregnancy. The 54 women had 126 pregnancies resulting in 98 successful pregnancies, 22 miscarriages, and six abortions. The success rate was estimated as 0.778 (SE 0.002) including abortions and 0.817 (SE 0.002) excluding abortions. There were 85 vaginal deliveries, seven vaginal deliveries with epidural analgesia, and six caesarean sections. There were two neonatal deaths. A total of 26 pregnancies were complicated by a hypertensive disorder of pregnancy. There were 21 pregnancies in 14 women complicated by hypertension and five pregnancies in four women complicated by pre-eclampsia. The hypertension- and pre-eclampsia-probabilities were estimated as 0.183 (SE 0.285) and 0.061 (SE 0.211), respectively. During pregnancy, five patients had an increase > or =15 mmHg across the site of repair at echocardiography, but only one patient required reintervention for recoarctation after delivery. Four of the 98 children (4%) had a congenital heart defect. CONCLUSION: Pregnancy is well tolerated in women after repair of aortic coarctation. However, an excess of miscarriages and hypertensive disorders of pregnancy were found. 相似文献
82.
Kaluzay J Vandenberghe K Fontaine D Ganame J Anné W Van der Merwe N Van de Werf F Heidbüchel H 《International journal of cardiology》2005,98(3):431-437
BACKGROUND: Determination of ST-segment deviation (STdev) and its resolution (STR) by reperfusion strategies have become important tools in the assessment of patients with acute myocardial infarction (AMI). STdev has been measured at different time-points, i.e. at 20-80 ms after the J-point. There are no data comparing STR at different time-points. METHODS AND RESULTS: STdev was measured using a new computer-assisted workflow. The intraclass correlation coefficients (ICC) for validity and agreement vs. classical manual measurements (n=1020) were both 0.996 (p<0.0001). The reliability indices were 0.991 (95% CI 0.990-0.992) for the manual vs. 0.995 (95% CI 0.995-0.996) for the computer-assisted method, indicating superiority of the latter. 12-lead STdev were determined on ECGs before (baseline) and 180 min after start of thrombolytic therapy, measured both at the J-point (STdev(J)) and 20 ms after the J-point (STdev(J20); n=2400). STdev(J20) was on average 0.01+/-0.03 mV higher than STdev(J) (p<0.0001) with a tendency towards larger differences for higher ST-elevations (p<0.001). Although the average STR calculated from STdev(J20) and STdev(J) was not statistically different in any infarct location group, in 26% of the patients the difference was >10%, and 11% of the patients were classified into another ST-resolution group. Analysing STdev only in the single lead with the highest ST-elevation at baseline (a simplified measurement which may eliminate the confounding effect of ST-depressions) showed an even higher classification discordance (14% of the patients). CONCLUSIONS: The time-point of STdev measurement is an important variable to be accounted for when evaluating ST resolution data. Uncontrolled extrapolation of classification schemes based on STdev(J20) to other time-points cannot be justified. 相似文献
83.
BACKGROUND: Acute exacerbations of asthma and chronic obstructive pulmonary disease (COPD) are associated with increased airflow Limitation, hyperinflation and respiratory muscle fatigue. It is unclear, whether patients are able to perform adequate inhalations through various inhalation devices with different orfices during an exacerbation. The aim of this study was to examine the evolution of inhalation profiles of patients inhaling through Diskus, Turbuhaler, pressurized metered dose inhaler (pMDI) and Volumatic and consequently the appropriateness of using the various devices during an exacerbation. MEASUREMENTS: 15 hospitalized patients participated in this randomized comparison of inhalation profiles through the four placebo-devices. For each device, triplicate inhalation profiles were recorded during day 1-9 of admission and in stable phase (day 50). RESULTS: The mean percentage of patients performing optimum inhalation profiles was 100% for Diskus, 60% for Turbuhaler, 14% for pMDI and 87% for Volumatic over the interval of day 1-9 and day 50. Patients with an inspiratory muscle strength (MIP) of less than 6kPa were generally unable to generate the optimum flow through the Turbuhaler (>60 l/min). CONCLUSION: The Diskus and Volumatic can be used effectively in the acute phase of an exacerbation of asthma or COPD. The Turbuhaler could be optimally used after the fifth day of convalescence. The pMDI is rather unsuitable during an exacerbation. 相似文献
84.
Rodrigo San-Cristobal Santiago Navas-Carretero Carlos Celis-Morales Lorraine Brennan Marianne Walsh Julie A. Lovegrove Hannelore Daniel Wim H. M. Saris Iwonna Traczyk Yannis Manios Eileen R. Gibney Michael J. Gibney John C. Mathers J. Alfredo Martinez 《Nutrients》2015,7(11):9523-9537
Obesity prevalence is increasing. The management of this condition requires a detailed analysis of the global risk factors in order to develop personalised advice. This study is aimed to identify current dietary patterns and habits in Spanish population interested in personalised nutrition and investigate associations with weight status. Self-reported dietary and anthropometrical data from the Spanish participants in the Food4Me study, were used in a multidimensional exploratory analysis to define specific dietary profiles. Two opposing factors were obtained according to food groups’ intake: Factor 1 characterised by a more frequent consumption of traditionally considered unhealthy foods; and Factor 2, where the consumption of “Mediterranean diet” foods was prevalent. Factor 1 showed a direct relationship with BMI (β = 0.226; r2 = 0.259; p < 0.001), while the association with Factor 2 was inverse (β = −0.037; r2 = 0.230; p = 0.348). A total of four categories were defined (Prudent, Healthy, Western, and Compensatory) through classification of the sample in higher or lower adherence to each factor and combining the possibilities. Western and Compensatory dietary patterns, which were characterized by high-density foods consumption, showed positive associations with overweight prevalence. Further analysis showed that prevention of overweight must focus on limiting the intake of known deleterious foods rather than exclusively enhance healthy products. 相似文献
85.
Jennes W Sawadogo S Koblavi-Dème S Vuylsteke B Maurice C Roels TH Chorba T Nkengasong JN Kestens L 《AIDS research and human retroviruses》2002,18(3):171-177
The role of beta-chemokines in controlling HIV replication in vivo is still controversial. Therefore, the association between HIV-1 plasma viral load and the capacity of CD4(+) and CD8(+) T cells to produce beta-chemokines was studied in 28 antiretroviral drug-na?ve HIV-1-infected female sex workers in Abidjan, C?te d'Ivoire. Percentages of beta-chemokine-positive T cells were measured in peripheral blood mononuclear cells by flow cytometry after intracellular staining for RANTES (regulated on activation, normal T expressed and secreted), macrophage inflammatory protein (MIP)-1alpha, and MIP-1beta. HIV-1-infected subjects had higher percentages of MIP-1alpha- and MIP-1beta-positive CD4(+) and CD8(+) T cells (p < 0.02) and of RANTES-positive CD8(+) T cells (p = 0.054) than uninfected controls. Percentages of RANTES- and MIP-1beta-positive CD8(+) T cells correlated directly with HIV-1 plasma viral load (p < 0.02). Percentages of beta-chemokine-positive CD4(+) and CD8(+) T cells correlated directly with percentages of HLA-DR-positive T cells (p < 0.02) and inversely (except RANTES in CD4(+) T cells) with absolute numbers of CD4(+) T cells (p < 0.05) in peripheral blood. These data indicate that increased percentages of beta-chemokine-producing T cells in HIV-1-infected subjects correlate with disease progression and are a sign of viremia-driven chronic T cell activation. 相似文献
86.
Matrix metalloproteinases and atrial remodeling in patients with mitral valve disease and atrial fibrillation 总被引:2,自引:0,他引:2
Anné W Willems R Roskams T Sergeant P Herijgers P Holemans P Ector H Heidbüchel H 《Cardiovascular research》2005,67(4):655-666
BACKGROUND: Atrial fibrillation (AF) is associated with extracellular matrix remodeling involving atrial fibrosis and atrial dilatation. Angiotensin II mediated pathways and matrix metalloproteinases (MMPs) have been implicated in these processes. Our aim was to study atrial structural remodeling and the expression of the angiotensin receptor subtypes and MMPs and their inhibitors (TIMPs) in patients with mitral valve disease with and without AF. METHODS AND RESULTS: Biopsies from right and left atrial appendages (RA and LA) were taken from patients undergoing CABG (n=9, all in sinus rhythm (SR)) or mitral valve surgery (MVS; n=19; 9 with permanent AF and 10 in SR). Patients with MVS and AF had significantly larger atria (versus MVS and SR: p=0.02; versus CABG: p<0.01). The MVS patients had significantly more fibrosis than the control CABG group. Fibrosis was increased in both the AF and SR MVS groups in the LA, but only in the MVS-AF group in the RA. These AF patients had significantly more tricuspid regurgitation than SR patients. MMP-1 was down-regulated in LA of MVS patients (p=0.02) independent of the underlying rhythm (SR or AF; p=0.95). In RA biopsies, MMP-1 was down-regulated only in the MVS and AF group. MMP-9 was down-regulated in the MVS patients compared to CABG both in the RA and LA, and without a difference between the SR and AF groups. Protein expression of AT-1, AT-2, MMP-2, TIMP-1, -2 and -4, TNF-alpha, and TNF-alpha-converting enzyme did not differ significantly between the 3 groups. CONCLUSIONS: Concordant changes between MMP-expression and fibrosis during mitral valve disease, both in LA and RA, suggest involvement of MMPs in structural atrial remodeling. AF itself did not contribute to altered fibrosis or MMP-expression in the LA. The association between AF and RA changes may be precipitated by greater hemodynamic load due to tricuspid regurgitation in these patients. 相似文献
87.
Wim Huysmans MD Werner Budts MD PhD 《Catheterization and cardiovascular interventions》2008,72(2):286-288
We report a remarkable case of right atrial rupture, 3 years after transcatheter closure of a secundum atrial septal defect, and 7 months after permanent transvenous two‐chamber pacemaker implantation. The etiology of the rupture remains unclear, but the presence of the two intracardiac devices is probably not coincidental. © 2008 Wiley‐Liss, Inc. 相似文献
88.
Robert W. A. M. Kuijpers John N. van den Anker Wim Baerts Albert E. G. Kr. von dem Borne 《British journal of haematology》1994,87(3):576-579
We report a family with a neonate who was severely damaged by intracranial haemorrhages. These probably occurred before the 20th week of gestation. The neonate had a moderate thrombocytopenia. In the maternal serum anti-HPA-1b and anti-HPA-2a alloantibodies were detected. Third-generation assays were applied to identify the alloantibodies. No other cause for the bleeding was found. Probably the combination of anti-HPA-1b and anti-HPA-2a alloantibodies, directed against the platelet fibrinogen receptor and the von Willebrand receptor, respectively, induced a thrombocytopenia and a thrombocytopathy. 相似文献
89.
Jennes W Sawadogo S Koblavi-Dème S Vuylsteke B Maurice C Roels TH Chorba T Nkengasong JN Kestens L 《The Journal of infectious diseases》2003,187(2):206-214
Cellular factors that may protect against human immunodeficiency virus (HIV) infection were investigated in 27 HIV-exposed seronegative (ESN) female sex workers (FSWs) and 27 HIV-seronegative female blood donors. Compared with blood donors, ESN FSWs had significantly decreased expression levels of C-X-C chemokine receptor 4 (CXCR4), but not of C-C chemokine receptor 5, on both memory (P<.001) and naive (P=.041) CD4(+) T cells. CXCR4 down-regulation was associated with prolonged duration of commercial sex work by ESN FSWs. CD38 expression on CD8(+) T cells was significantly increased among ESN FSWs, compared with that among blood donors (P=.017). There were no differences in HLA-DR and CD62L expression between blood donors and ESN FSWs. Proportions of T cells producing the beta-chemokines RANTES (regulated on activation, normally T cell-expressed and -secreted), macrophage inflammatory protein (MIP)-1alpha, and MIP-1beta or the cytokines interleukin (IL)-2, IL-4, interferon-gamma, and tumor necrosis factor-alpha, were similar in the 2 groups. These data indicate that ESN FSWs differ from HIV-seronegative female blood donors with respect to immunological factors that have no clear protective potential against HIV transmission. 相似文献
90.
Kerstens MN van der Kleij FG Boonstra AH Sluiter WJ Koerts J Navis G Dullaart RP 《The Journal of clinical endocrinology and metabolism》2003,88(9):4180-4185
We studied cortisol metabolism together with insulin sensitivity [homeostatic model assessment (HOMA)] and renal hemodynamics in 19 salt-resistant (sr) and nine salt-sensitive (ss) normotensive subjects after a low- and high-salt diet. Results are described as high- vs. low-salt diet. Sum of urinary cortisol metabolite excretion (sum(metabolites)) increased in sr subjects (3.8 +/- 1.6 vs. 3.1 +/- 1.1 microg/min per square meter, P < 0.05) and decreased in ss subjects (2.3 +/- 1.0 vs. 2.9 +/- 1.1 microg/min per square meter, P < 0.05). Plasma 0830 h cortisol decreased in sr subjects but did not change significantly in ss subjects. In all subjects, the absolute blood pressure change correlated negatively with the percentage change in sum(metabolites) (P < 0.05) and positively with the percentage change in renal vascular resistance (P < 0.05). Sum(metabolites) during high-salt diet correlated negatively with the percentage changes in plasma 0830 h cortisol (P < 0.05) and renal vascular resistance (P = 0.05). HOMA did not change in either group, but the percentage change in HOMA correlated positively with the percentage change in plasma cortisol (P = 0.001) and negatively with the percentage change in sum(metabolites) (P < 0.01). Parameters of 11 beta-hydroxysteroid dehydrogenase activity were not different between groups and did not change. In conclusion, these data suggest that cortisol elimination is affected differently after salt loading in sr and ss subjects. Changes in circulating cortisol might contribute to individual sodium-induced alterations in insulin sensitivity. 相似文献