全文获取类型
收费全文 | 1482篇 |
免费 | 144篇 |
国内免费 | 6篇 |
专业分类
耳鼻咽喉 | 11篇 |
儿科学 | 48篇 |
妇产科学 | 23篇 |
基础医学 | 115篇 |
口腔科学 | 40篇 |
临床医学 | 171篇 |
内科学 | 376篇 |
皮肤病学 | 34篇 |
神经病学 | 41篇 |
特种医学 | 364篇 |
外科学 | 98篇 |
综合类 | 45篇 |
预防医学 | 138篇 |
眼科学 | 10篇 |
药学 | 55篇 |
中国医学 | 1篇 |
肿瘤学 | 62篇 |
出版年
2021年 | 27篇 |
2020年 | 13篇 |
2019年 | 20篇 |
2018年 | 32篇 |
2017年 | 24篇 |
2016年 | 24篇 |
2015年 | 32篇 |
2014年 | 68篇 |
2013年 | 47篇 |
2012年 | 53篇 |
2011年 | 47篇 |
2010年 | 58篇 |
2009年 | 53篇 |
2008年 | 57篇 |
2007年 | 45篇 |
2006年 | 45篇 |
2005年 | 47篇 |
2004年 | 58篇 |
2003年 | 54篇 |
2002年 | 32篇 |
2001年 | 40篇 |
2000年 | 44篇 |
1999年 | 35篇 |
1998年 | 35篇 |
1997年 | 45篇 |
1996年 | 53篇 |
1995年 | 38篇 |
1994年 | 31篇 |
1993年 | 40篇 |
1992年 | 26篇 |
1991年 | 17篇 |
1990年 | 27篇 |
1989年 | 30篇 |
1988年 | 29篇 |
1987年 | 28篇 |
1986年 | 34篇 |
1985年 | 27篇 |
1984年 | 22篇 |
1983年 | 15篇 |
1982年 | 26篇 |
1981年 | 9篇 |
1980年 | 9篇 |
1977年 | 17篇 |
1976年 | 11篇 |
1975年 | 22篇 |
1974年 | 16篇 |
1973年 | 15篇 |
1972年 | 11篇 |
1970年 | 6篇 |
1969年 | 7篇 |
排序方式: 共有1632条查询结果,搜索用时 46 毫秒
51.
MJ Hwang A Bhangu CE Webster DM Bowley MX Gannon SS Karandikar 《Annals of the Royal College of Surgeons of England》2014,96(5):343-347
Introduction
In 2009 the Department of Health instructed McKinsey & Company to provide advice on how commissioners might achieve world class National Health Service productivity. Asymptomatic inguinal hernia repair was identified as a potentially cosmetic procedure, with limited clinical benefit. The Birmingham and Solihull primary care trust cluster introduced a policy of watchful waiting for asymptomatic inguinal hernia, which was implemented across the health economy in December 2010. This retrospective cohort study aimed to examine the effect of a change in clinical commissioning policy concerning elective surgical repair of asymptomatic inguinal hernias.Methods
A total of 1,032 patients undergoing inguinal hernia repair in the 16 months after the policy change were compared with 978 patients in the 16 months before. The main outcome measure was relative proportion of emergency repair in groups before and after the policy change. Multivariate binary logistic regression was used to adjust the main outcome for age, sex and hernia type.Results
The period after the policy change was associated with 59% higher odds of emergency repair (3.6% vs 5.5%, adjusted odds ratio [OR]: 1.59, 95% confidence interval [CI]: 1.03–2.47). In turn, emergency repair was associated with higher odds of adverse events (4.7% vs 18.5%, adjusted OR: 3.68, 95% CI: 2.04–6.63) and mortality (0.1% vs 5.4%, p<0.001, Fisher’s exact test).Conclusions
Introduction of a watchful waiting policy for asymptomatic inguinal hernias was associated with a significant increase in need for emergency repair, which was in turn associated with an increased risk of adverse events. Current policies may be placing patients at risk. 相似文献52.
R. Zachariah A. M. V. Kumar A. J. Reid R. Van den Bergh P. Isaakidis B. Draguez P. Delaunois S. B. Nagaraja A. Ramsay J. C. Reeder O. Denisiuk E. Ali M. Khogali S. G. Hinderaker R. J. Kosgei J. van Griensven G. L. Quaglio D. Maher N. E. Billo R. F. Terry A. D. Harries 《Public Health Action》2014,4(3):142-144
Open-access journal publications aim to ensure that new knowledge is widely disseminated and made freely accessible in a timely manner so that it can be used to improve people''s health, particularly those in low- and middle-income countries. In this paper, we briefly explain the differences between closed- and open-access journals, including the evolving idea of the ‘open-access spectrum’. We highlight the potential benefits of supporting open access for operational research, and discuss the conundrum and ways forward as regards who pays for open access. 相似文献
53.
54.
55.
The effect of thoracic lymph diversion on gastric secretion has been studied in dogs. In addition, the concentration of gastrin in thoracic duct lymph of nine dogs and two patients has been measured before and during antral stimulation with either food or acetylcholine. The secretory studies do not support the concept that there is a significant gastric secretagogue in thoracic duct lymph. The amount of gastrin carried in thoracic duct lymph as determined by radioimmunoassay is far less than that necessary to evoke a gastric secretory response. 相似文献
56.
Hellermann JP Jacobsen SJ Redfield MM Reeder GS Weston SA Roger VL 《European journal of heart failure》2005,7(1):119-125
OBJECTIVES: To characterize the presentation and outcome of patients with heart failure (HF) after myocardial infarction (MI) according to left ventricular ejection fraction (LVEF) and test the hypothesis that the outcome of HF did not change over time. BACKGROUND: Little is known about the presentation and outcome of HF post-MI and how these may have changed over time. METHODS: Using the Rochester Epidemiology Project, all residents of Olmsted County, Minnesota who experienced an incident MI between 1979 and 1998 were identified; MI and HF were validated using standardized criteria. Subjects were followed through their community medical record. RESULTS: Between 1979 and 1998, 1915 patients with incident MI and no prior history of HF were identified. Of these, 791(41%) experienced new onset HF as defined by Framingham criteria during 6.6+/-5.0 years of follow-up. Forty-seven percent were men, mean age was 73+/-12 years. Forty-four percent had impaired LVEF, 18% preserved LVEF and 38% had no LVEF measurement within 60 days after the HF event. Median survival after HF onset was 4 years and at 5 years after HF onset, only 45% were alive. Older age, male sex, comorbidity, hypertension and no LVEF assessment were associated with increased risk of death, however, patients with impaired LVEF had the worst outcome. Over time, survival did not improve (HR for year: 1.00; 95% CI 0.99, 1.02; P=0.919) even after adjustment for baseline characteristics. CONCLUSION: In this geographically defined cohort of patients with MI, new onset HF after the MI was frequent. When measured, LVEF was most frequently reduced, consistent with systolic heart failure. Mortality was high and did not decline over time and death was independently associated with male sex, older age, hypertension and comorbidity. It also differed according to LVEF, which was inconsistently ascertained in this setting, potentially representing practice opportunities. 相似文献
57.
G S Reeder P J Currie D A Fyfe D J Hagler J B Seward A J Tajik 《Journal of the American College of Cardiology》1984,4(5):1006-1011
Extracardiac valved conduits are often employed in the repair of certain complex congenital heart defects; late obstruction is a well recognized problem that usually requires catheterization for definitive diagnosis. A reliable noninvasive method for detecting conduit stenosis would be clinically useful in identifying the small proportion of patients who develop this problem. Continuous wave Doppler echocardiography has been used successfully to estimate cardiac valvular obstructive lesions noninvasively. Twenty-three patients with prior extracardiac conduit placement for complex congenital heart disease underwent echocardiographic and continuous wave Doppler echocardiographic examinations to determine the presence and severity of conduit stenosis. In 20 of the 23 patients, an adequate conduit flow velocity profile was obtained, and in 10 an abnormally increased conduit flow velocity was present. All but one patient had significant obstruction proven at surgery and in one patient, surgery was planned. In three patients, an adequate conduit flow velocity profile could not be obtained but obstruction was still suspected based on high velocity tricuspid regurgitant Doppler signals. In these three patients, subsequent surgery also proved that conduit stenosis was present. Doppler-predicted gradients and right ventricular pressures showed an overall good correlation (r = 0.90) with measurements at subsequent cardiac catheterization. Continuous wave Doppler echocardiography appears to be a useful noninvasive tool for the detection and semiquantitation of extracardiac conduit stenosis. 相似文献
58.
Crist WM; Shuster JJ; Falletta J; Pullen DJ; Berard CW; Vietti TJ; Alvarado CS; Roper MA; Prasthofer E; Grossi CE 《Blood》1988,72(6):1891-1897
The immunophenotypes of lymphoblasts from children with newly diagnosed T-cell acute lymphoid leukemia (T-ALL, n = 101) or T-cell non-Hodgkin lymphoma (T-NHL, n = 31) were analyzed to correlate stage of thymocyte differentiation with clinical features and outcome. The 67 boys and 34 girls with T-ALL were 1 month to 18 years old (median, 8 years) with leukocyte counts ranging from 2 to 810 x 10(9)/L (median, 55 x 10(9)/L). Eighteen of these patients were black, and 70 had a mediastinal mass. Twenty-six boys and five girls with a median age of 9 years (range, 1 to 20 years) had T-NHL. Seven of these patients were black, and 24 had a mediastinal mass. The distributions of thymocyte developmental stages (early [CD7+], intermediate [CD1+ and/or CD4+ and/or CD8+], and mature [CD3+]) in cases of T-ALL and T-NHL were significantly different: 34%, 43%, and 23% v 6%, 62%, and 32% (P = .02). A comparison of the patients' clinical features according to the maturational stage of thymocytes failed to disclose significant differences in the majority of characteristics studied. However, patients with mature-stage T-NHL, with or without the addition of subjects with mature-stage T-ALL, were less likely to have a mediastinal mass (P = .02 for both comparisons). Those with intermediate-stage T-cell malignancy (T-ALL and T-NHL combined) were the subgroup most likely to have a mediastinal mass (P = .01). Response to remission induction therapy was significantly worse in the T-ALL subgroup with an early-stage phenotype: a failure rate of 21% v 0% and 6% for the two more differentiated phenotypic subgroups (P = .007). Event-free survival was not affected by thymocyte maturational stage in cases of either T-ALL or T-NHL. Despite evidence of clinical heterogeneity among the maturational stages of T-cell malignancies in children, these developmental subdivisions do not appear to be critical determinants of outcome once remission is achieved. We conclude that such phenotypes need not be included in the stratification plans for clinical trials using common induction treatment. 相似文献
59.
Retrovirally marked CD34-enriched peripheral blood and bone marrow cells contribute to long-term engraftment after autologous transplantation 总被引:16,自引:17,他引:16
Dunbar CE; Cottler-Fox M; O'Shaughnessy JA; Doren S; Carter C; Berenson R; Brown S; Moen RC; Greenblatt J; Stewart FM 《Blood》1995,85(11):3048-3057
We report here on a preliminary human autologous transplantation study of retroviral gene transfer to bone marrow (BM) and peripheral blood (PB)-derived CD34-enriched cells. Eleven patients with multiple myeloma or breast cancer had cyclophosphamide and filgrastim-mobilized PB cells CD34-enriched and transduced with a retroviral marking vector containing the neomycin resistance gene, and CD34-enriched BM cells transduced with a second marking vector also containing a neomycin resistance gene. After high-dose conditioning therapy, both transduced cell populations were reinfused and patients were followed over time for the presence of the marker gene and any adverse effects related to the gene-transfer procedure. All 10 evaluable patients had the marker gene detected at the time of engraftment, and 3 of 9 patients had persistence of the marker gene for greater than 18 months posttransplantation. The marker gene was detected in multiple lineages, including granulocytes, T cells, and B cells. The source of the marking was both the transduced PB graft and the BM graft, with a suggestion of better long-term marking originating from the PB graft. The steady- state levels of marking were low, with only 1:1000 to 1:10,000 cells positive. There was no toxicity noted, and patients did not develop detectable replication-competent helper virus at any time posttransplantation. These results suggest that mobilized PB cells may be preferable to BM for gene therapy applications and that progeny of mobilized peripheral blood cells can contribute long-term to engraftment of multiple lineages. 相似文献
60.