全文获取类型
收费全文 | 11008篇 |
免费 | 684篇 |
国内免费 | 53篇 |
专业分类
耳鼻咽喉 | 302篇 |
儿科学 | 273篇 |
妇产科学 | 299篇 |
基础医学 | 1550篇 |
口腔科学 | 419篇 |
临床医学 | 906篇 |
内科学 | 2570篇 |
皮肤病学 | 202篇 |
神经病学 | 1252篇 |
特种医学 | 220篇 |
外科学 | 1003篇 |
综合类 | 21篇 |
一般理论 | 5篇 |
预防医学 | 644篇 |
眼科学 | 132篇 |
药学 | 689篇 |
中国医学 | 36篇 |
肿瘤学 | 1222篇 |
出版年
2024年 | 19篇 |
2023年 | 116篇 |
2022年 | 274篇 |
2021年 | 420篇 |
2020年 | 267篇 |
2019年 | 316篇 |
2018年 | 349篇 |
2017年 | 288篇 |
2016年 | 347篇 |
2015年 | 369篇 |
2014年 | 494篇 |
2013年 | 601篇 |
2012年 | 924篇 |
2011年 | 1036篇 |
2010年 | 513篇 |
2009年 | 448篇 |
2008年 | 782篇 |
2007年 | 712篇 |
2006年 | 639篇 |
2005年 | 666篇 |
2004年 | 599篇 |
2003年 | 545篇 |
2002年 | 478篇 |
2001年 | 55篇 |
2000年 | 33篇 |
1999年 | 50篇 |
1998年 | 86篇 |
1997年 | 59篇 |
1996年 | 43篇 |
1995年 | 46篇 |
1994年 | 33篇 |
1993年 | 32篇 |
1992年 | 19篇 |
1991年 | 10篇 |
1990年 | 7篇 |
1989年 | 12篇 |
1988年 | 7篇 |
1987年 | 2篇 |
1986年 | 13篇 |
1985年 | 3篇 |
1984年 | 5篇 |
1983年 | 4篇 |
1982年 | 5篇 |
1980年 | 4篇 |
1979年 | 2篇 |
1978年 | 2篇 |
1976年 | 3篇 |
1974年 | 2篇 |
1973年 | 2篇 |
1968年 | 1篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
961.
Darze ES Latado AL Guimarães AG Guedes RA Santos AB de Moura SS Passos LC 《Chest》2007,131(6):1838-1843
BACKGROUND: Congestive heart failure (CHF) is a well-recognized risk factor for venous thromboembolism (VTE) and is associated with higher mortality in patients with an acute pulmonary embolism (PE). There are very few data on how acute PE affects the clinical course of patients with heart failure. The purpose of this study was to determine the impact of an acute PE on the short-term prognosis of patients hospitalized for decompensated CHF. METHODS: This was a prospective cohort study of 198 patients admitted to a coronary care unit between July 2001 and March 2003 with severe decompensated CHF. The primary outcome measure was death or rehospitalization at 3 months. RESULTS: PE was confirmed in 18 of 198 patients enrolled (9.1%). The groups with and without PE were comparable with regards to demographics, the prevalence of comorbid conditions, and severity of CHF (p > 0.05). The prevalence of cancer (p = 0.0001), previous VTE (p = 0.003), and right ventricular overload (p = 0.006) was higher in the PE group. The presence of PE was also associated with a longer hospital stay (37.5 +/- 71.6 days vs 15.4 +/- 15.0 days, p = 0.001) [mean +/- SD] and a higher incidence of death or rehospitalization at 3 months (72.2% vs 43.9%, p = 0.02). In a multiple logistic regression analysis, PE remained an independent predictor of death or rehospitalization at 3 months (odds ratio, 4.0; 95% confidence interval, 1.1 to 15.1; p = 0.038). CONCLUSIONS: Acute PE commonly complicates the hospital course of patients with severe CHF, increasing the length of hospital stay and the chance of death or rehospitalization at 3 months. 相似文献
962.
Atteritano M Marini H Minutoli L Polito F Bitto A Altavilla D Mazzaferro S D'Anna R Cannata ML Gaudio A Frisina A Frisina N Corrado F Cancellieri F Lubrano C Bonaiuto M Adamo EB Squadrito F 《The Journal of clinical endocrinology and metabolism》2007,92(8):3068-3075
CONTEXT: Genistein, a soy isoflavone, has received wide attention over the last few years because of its potential preventive role for cardiovascular disease. OBJECTIVE: Our objective was to assess the effects of genistein administration (54 mg/d) on some predictors of cardiovascular risk in osteopenic, postmenopausal women. DESIGN AND SETTING: We conducted a randomized, double-blind, placebo-controlled trial at three Italian university medical centers. INTERVENTION: After a 4-wk stabilization on a standard isocaloric, fat-reduced diet, participants were randomly assigned to receive genistein (n = 198) or placebo (n = 191) daily for 24 months. Both intervention and placebo contained calcium and vitamin D(3). OUTCOME MEASURES: Blood lipid profiles, fasting glucose and insulin, homeostasis model assessment for insulin resistance, fibrinogen, soluble intercellular adhesion molecule-1, soluble vascular cellular adhesion molecule-1, F2-isoprostanes, and osteoprotegerin at baseline and after 12 and 24 months of treatment were measured. RESULTS: Compared with placebo, genistein significantly reduced fasting glucose and insulin as well as homeostasis model assessment for insulin resistance after both 12 and 24 months of treatment. By contrast, genistein administration did not affect blood lipid levels although fibrinogen, F2-isoprostanes, soluble intercellular adhesion molecule-1, and soluble vascular cellular adhesion molecule-1 decreased significantly compared with placebo after 24 months. Serum osteoprotegerin was higher in the genistein group compared with placebo. At 24 months, the genistein group showed no change in endometrial thickness compared with placebo. Most treatment-related adverse events were moderate and composed of gastrointestinal side effects [genistein, n = 37 (19%); placebo, n = 15 (8%)]. CONCLUSIONS: These results suggest that 54 mg genistein plus calcium, vitamin D(3), and a healthy diet was associated with favorable effects on both glycemic control and some cardiovascular risk markers in a cohort of osteopenic, postmenopausal women. 相似文献
963.
Marchesi S Lupattelli G Sensini A Lombardini R Brozzetti M Roscini AR Siepi D Mannarino E Vaudo G 《Atherosclerosis》2007,191(1):227-234
There is much evidence to suggest the existence of racial differences between blacks and whites in the behaviour of endothelial function. Infective state, sustained by viral or bacterial agents, may injure the endothelial surface favouring the onset and progression of atherosclerotic process, mainly by an inflammatory mechanism. The aim of the study was to investigate endothelial function, expressed as brachial flow-mediated vasodilation (FMV), in black and white healthy subjects, along with antibody titer to cytomegalovirus, hepatitis virus (B, C), herpes virus-1 and 2, Epstein-Barr, Chlamydia pneumoniae and the expression of adhesion molecules. We enrolled 22 young (mean age 27+/-8 years) healthy subjects of black race (10 males) and 20 healthy young subjects (10 males, mean age 28+/-9 years) of white race. Total infectious burden (TIB) was defined as the number of serological positive infections. Black subjects have a reduced brachial FMV (6.9+/-3.5% versus 11.6+/-3.0%, p<0.01) and increased values of hsCRP (0.35+/-0.15 mg/dL versus 0.07+/-0.08 mg/dL, p<0.05), white cells (8578+/-1041/mmc versus 5833+/-998/mmc, p<0.01) and adhesion molecules (respectively: sVCAM-1 945+/-142 versus 779+/-93, sICAM-1 534+/-107 ng/mL versus 325+/-80 ng/mL; both p<0.01) in comparison to white subjects. The total infectious burden in black race was significantly higher than in white race (5+/-1 versus 2+/-1, p<0.01). At the univariate analysis, brachial FMV was significantly related to the levels of adhesion molecules (respectively: sVCAM-1 r=-0.49; sICAM-1 r=-0.50, both p<0.05), hsCRP (r=-0.47, p<0.05) and white blood cells (r=-0.43, p<0.05). TIB was associated with brachial FMV (r=-0.64, p<0.05), sVCAM-1 (r=0.55, p<0.05) and hsCRP (r=0.47, p<0.05). At the multivariate analysis the only predictive variables for brachial FMV were hsCRP, TIB and brachial diameter (respectively: beta=-0.49, -0.19, -0.54, all p<0.05). This study confirms that endothelial reactivity is impaired in young African black patients; moreover its behavior is strictly related to the inflammatory state and to the total infectious burden. 相似文献
964.
Kouri V Marini A Nambiar S Rodriguez ME Capo V Resik S Mantecon B Martinez A Köhler-Hansner KJ Hengge UR 《AIDS (London, England)》2007,21(6):765-768
Transmission of human herpesvirus 8 (HHV-8) may occur through various routes including breastfeeding and sexual intercourse. We attempted to detect HHV-8 infection in nine HIV-positive couples discordant for Kaposi's sarcoma who maintained a monogamous sexual relationship for at least one year. By quantitative real-time polymerase chain reaction and HHV-8 genotyping we provide strong evidence for the sexual transmission of HHV-8 in this unique cohort. 相似文献
965.
Dysfunction and functional restoration of HCV-specific CD8 responses in chronic hepatitis C virus infection 总被引:17,自引:0,他引:17
Penna A Pilli M Zerbini A Orlandini A Mezzadri S Sacchelli L Missale G Ferrari C 《Hepatology (Baltimore, Md.)》2007,45(3):588-601
The functional impairment of HCV-specific T cell responses is believed to be an important determinant of HCV persistence, but the functional T cell defects of patients with chronic hepatitis C (CH-C) are only partially defined. CD8 responses to HLA-A2-restricted epitopes of HCV and other unrelated viruses were studied in 23 HLA-A2-positive patients both ex vivo and after in vitro culture. Degranulation capacity, intracellular perforin, and granzyme-A content and cytokine production (IFN-gamma, TNF-alpha) by HCV- and non-HCV-specific CD8 cells were tested both ex vivo and in vitro, whereas cytolytic activity was studied after 10 days' expansion in vitro. Memory maturation and role of exhaustion were assessed ex vivo by HCV-specific CD8 staining for CD127 and PD-1, and in vitro after peripheral blood mononuclear cells (PBMC) culture in the presence of anti-PD-L1 monoclonal antibodies. IFN-gamma production and cytolytic activity were expressed less efficiently by HCV-specific than by non-HCV specific CD8 cells derived from the same CH-C patients. The amount of stored granzyme-A within single cells was always lower in HCV-specific CD8 cells, which were less efficient also in the release of lytic granules and in the production of TNF-alpha. The CD8 dysfunction was associated with high PD-1 expression by most HCV-specific CD8 cells, and PD-1/PD-L1 blockade by anti-PD-L1 antibodies in vitro was able to improve the HCV-specific CD8 function. CONCLUSION: Our study characterizes CD8 defects that may be important in maintaining HCV persistence; identification of strategies to correct these defects may help to define novel approaches to treat HCV infection. 相似文献
966.
Bosutti A Scaggiante B Grassi G Guarnieri G Biolo G 《Metabolism: clinical and experimental》2007,56(12):1629-1634
The eukaryotic elongation factors (eEF1A2 and eEF1A1) play a key role in translation of messenger RNA (mRNA) to protein. In skeletal muscle of healthy humans, EEF1A2 is overexpressed and selected over EEF1A1. In cellular stress models, muscle EEF1A1 expression increased and was associated with apoptosis and catabolism. We have determined mRNA levels of EEF1A1 and EEF1A2, as well as those of other proapoptotic genes, such as p66(ShcA) and c-MYC, in skeletal muscle of severely traumatized patients and healthy volunteers. Muscle protein kinetic was determined by stable isotopes and the arteriovenous technique. The patients were in a hypercatabolic condition because the rate of muscle proteolysis exceeded that of synthesis. Mean mRNA levels of EEF1A1 and EEF1A2 were 165- and 29-fold greater (P < .01) in patients than in the control group, respectively. Mean p66(ShcA) mRNA levels were 3-fold greater (P < .05) in patients than in the controls. In contrast, c-MYC mRNA levels were not significantly different in patients and healthy controls. In patients, muscle mRNA levels of EEF1A1 and p66(ShcA) directly correlated (P < .05) with the rate of proteolysis (R = 0.901 and R = 0.826, respectively). This is in agreement with a reduction in actin and tubulin protein content, both markers of cytoskeletal and sarcomeric disorganization, and with an increased poly(adenosine diphosphate-ribose) polymerase cleavage, a marker of apoptosis. In conclusion, in hypercatabolic traumatized patients, an up-regulation of muscle EEF1A1 and p66(ShcA) relates to proteolysis rate, suggesting an involvement of these genes in muscle catabolic response. 相似文献
967.
Siragusa S Malato A Falaschi F Porro F Anastasio R Giarratano A Lo Coco L Buonanno MC Maggi E Bressan MA Mariani G 《Haematologica》2007,92(3):410-413
We evaluated a simplified algorithm for safely postponing diagnostic imaging for pulmonary embolism (PE). At the index visit, patients were identified as being at high or low risk of PE; the former received full dosage low molecular weight heparin while the latter were left untreated until performance of diagnostic imaging (max 72 hours). During this period, no thromboembolic events occurred in low-risk patients (0/211, 0.% [upper 95% CI 0.9%]); only one event occurred in those at high-risk (1/125, 0.8% [upper 95% CI, 1.2]). Our study demonstrates that diagnostic imaging for PE can be safely deferred for up to 3 days. 相似文献
968.
969.
Rosenthal-Allieri MA Tran A Halfon P Imbert-Bismut F Munteanu M Messous D Peritore ML Poynard T Bernard A 《Gastroentérologie clinique et biologique》2007,31(10):815-821
OBJECTIVES: Combination of alpha 2-macroglobulin, haptoglobin, apolipoprotein-A1, gamma-glutamyl transpeptidase, total bilirubin and alanine aminotransferase measurements allows to determine the Fibrotest-Actitest score, an alternative to liver biopsy in hepatitis C virus infection. The aims of this study were to evaluate the analytical variability of the Fibrotest-Actitest proteins alpha 2-macroglobulin, haptoglobin and apolipoprotein-A1, and to assess their impact on the Fibrotest-Actitest scores.METHODS: We compared 129 sera from hepatitis C virus infected patients for alpha 2-macroglobulin, haptoglobin and apolipoprotein-A1 levels obtained with the Immage (Beckman-Coulter) and the BNProspec (Dade-Berhing) automates. We evaluated Fibrotest-Actitest results obtained with the two nephelemeters.RESULTS: Optimal correlation was found for alpha 2-macroglobulin (Y=1.05X + 0.01, correlation coefficient: 0.98) and haptoglobin (Y=1.05X - 0.07, correlation coefficient: 0.98). Apolipoprotein-A1 levels, as determined by Immage, were slightly lower than those obtained by BNProspec (Y=0.86X - 0.02, CC=0.95). When Fibrotest-Actitest scores obtained with the two protein measurements were compared adjusting for apolipoprotein-A1 from Immage, the concordance rate was 0.903+/-0.096, with only 2/107 patients showing minimal discordance>0.10 for Fibrotest, and 1.00+/-0.06 for Actitest, with no discordance>0.10.CONCLUSIONS: Measurement of apolipoprotein-A1, included in the Fibrotest-Actitest score, depends on the equipment used. Such discordance is of little clinical consequence for liver fibrosis evaluation in hepatitis C virus patients. 相似文献
970.
Beretta L Caronni M Raimondi M Ponti A Viscuso T Origgi L Scorza R 《Clinical rheumatology》2007,26(2):168-172
Lung involvement constitutes nowadays the major cause of morbidity and mortality in scleroderma patients. Pulmonary fibrosis
in systemic sclerosis (SSc) is thought to be the consequence of interstitial inflammation. Early diagnosis and treatment of
active alveolitis is essential to prevent the deterioration of pulmonary function, improving outcome in SSc patients. The
aim of the study was to investigate the effect of 1-year treatment with oral cyclophosphamide (CYC) on the evolution of interstitial
lung disease in scleroderma patients with a diagnosis of active alveolitis. An open-label one-arm monocenteric study was conducted
on 33 scleroderma patients with active alveolitis—defined as the presence of areas of ‘ground-glass attenuation’ on high-resolution
computed tomography and a recent deterioration in lung function—treated with oral CYC 2 mg kg−1 day−1 for 1 year and medium-low dose steroids (prednisone 25 mg for 3 months and then tapered to 5 mg/day). Results showed that
diffusing capacity for carbon monoxide (DLco) values remained stable after 6 months of treatment and significantly increased
after 12 months (2.06±1.38, 2.21±1.62 and 2.39±1.64 mmol/min/kPa, at baseline/6/12 months, respectively; p<0.001 12th month vs baseline) vital capacity (VC) values slightly increased (i.e. stabilised) in the same time frame (2.46±0.71,
2.41±0.76 and 2.56±0.75 l). Accordingly, the vast majority of our patients (n=29, 87.9%) presented a DLco and/or a VC improvement or stabilisation with respect to baseline. Favourable results were more
likely to be observed in patients with a lower Wells’ radiological grade (grade I). In 25 patients followed up for further
12 months after the interruption of therapy, VC and DLco remained stable. Thus, long-term therapy with oral CYC is effective
in ameliorating and/or stabilising lung function in scleroderma patients with active alveolitis, with beneficial effects lasting
up to 1 year after interruption. The higher efficacy in those patients with an early pulmonary disease stage and a lower radiological
grade underlies the importance of an early diagnosis and intervention. 相似文献