全文获取类型
收费全文 | 5113篇 |
免费 | 404篇 |
国内免费 | 36篇 |
专业分类
耳鼻咽喉 | 46篇 |
儿科学 | 128篇 |
妇产科学 | 139篇 |
基础医学 | 707篇 |
口腔科学 | 61篇 |
临床医学 | 715篇 |
内科学 | 867篇 |
皮肤病学 | 329篇 |
神经病学 | 501篇 |
特种医学 | 148篇 |
外科学 | 554篇 |
综合类 | 64篇 |
一般理论 | 6篇 |
预防医学 | 502篇 |
眼科学 | 165篇 |
药学 | 289篇 |
中国医学 | 9篇 |
肿瘤学 | 323篇 |
出版年
2023年 | 39篇 |
2022年 | 45篇 |
2021年 | 126篇 |
2020年 | 114篇 |
2019年 | 127篇 |
2018年 | 131篇 |
2017年 | 106篇 |
2016年 | 159篇 |
2015年 | 121篇 |
2014年 | 151篇 |
2013年 | 237篇 |
2012年 | 318篇 |
2011年 | 351篇 |
2010年 | 203篇 |
2009年 | 179篇 |
2008年 | 275篇 |
2007年 | 302篇 |
2006年 | 282篇 |
2005年 | 298篇 |
2004年 | 257篇 |
2003年 | 311篇 |
2002年 | 246篇 |
2001年 | 87篇 |
2000年 | 61篇 |
1999年 | 66篇 |
1998年 | 60篇 |
1997年 | 51篇 |
1996年 | 28篇 |
1995年 | 47篇 |
1994年 | 38篇 |
1993年 | 33篇 |
1992年 | 30篇 |
1991年 | 17篇 |
1990年 | 21篇 |
1989年 | 21篇 |
1988年 | 25篇 |
1987年 | 27篇 |
1986年 | 30篇 |
1985年 | 32篇 |
1984年 | 30篇 |
1983年 | 25篇 |
1982年 | 30篇 |
1981年 | 31篇 |
1980年 | 35篇 |
1979年 | 34篇 |
1978年 | 30篇 |
1977年 | 24篇 |
1976年 | 27篇 |
1970年 | 16篇 |
1966年 | 16篇 |
排序方式: 共有5553条查询结果,搜索用时 31 毫秒
1.
Stephan Koter Tina U. Cohnert Korbinian B. Hindermayr Jörg Lindenmann Maximilian Brückner Wolfgang K. Oswald Georg Werkgartner Doris Wagner 《Journal of vascular surgery》2019,69(4):1227-1232
Objective
Low psoas muscle area is shown to be an indicator for worse postoperative outcome in patients undergoing vascular surgical. Additionally, it has been associated with longer durations of hospital stay in patients with cancer who undergo surgery and subsequently greater health care costs in Europe and the United States. We sought to evaluate this effect on hospital expenditure for patients undergoing vascular repair in a health care system with universal access.Methods
Skeletal muscle mass was assessed on preoperative abdominal computed tomography scans of patients undergoing open aortic aneurysm repair in a retrospective fashion. The skeletal muscle index (SMI) was used to define low muscle mass. Health care costs were obtained for all patients and the relationship between a low SMI and higher costs was explored using linear regression and cross-sectional analysis.Results
We included 156 patients (81.5% male) with a median age of 72 years undergoing elective surgery for infrarenal abdominal aortic aneurysm in this analysis. The median SMI for patients with low skeletal muscle mass was 53.21 cm2/kg and for patients without, 70.07 cm2/kg. Hospital duration of stay was 2 days longer in patients with low skeletal muscle mass as compared with patients with normal (14 days vs 11 days; P = .001), as was duration of intensive care stay (3 days vs 1 day; P = .01). The median overall hospital costs were €10,460 higher for patients with a low SMI as compared with patients with a normal physical constitution (€53,739 [interquartile range, €45,007-€62,471] vs €43,279 [interquartile range, €39,509-€47,049]; P = .001). After confounder adjustment, a low SMI was associated with a 14.68% cost increase in overall hospital costs, for a cost increase of €6521.Conclusions
Low skeletal muscle mass is independently associated with higher hospital as well as intensive care costs in patients undergoing elective aortic aneurysm repair. Strategies to reduce this risk factor are warranted for these patients. 相似文献2.
Julie A. Schmidt Georgina K. Fensom Sabina Rinaldi Augustin Scalbert Paul N. Appleby David Achaintre Audrey Gicquiau Marc J. Gunter Pietro Ferrari Rudolf Kaaks Tilman Kühn Heiner Boeing Antonia Trichopoulou Anna Karakatsani Eleni Peppa Domenico Palli Sabina Sieri Rosario Tumino Bas Bueno-de-Mesquita Antonio Agudo Maria-Jose Sánchez María-Dolores Chirlaque Eva Ardanaz Nerea Larrañaga Aurora Perez-Cornago Nada Assi Elio Riboli Konstantinos K. Tsilidis Timothy J. Key Ruth C. Travis 《International journal of cancer. Journal international du cancer》2020,146(3):720-730
Metabolomics may reveal novel insights into the etiology of prostate cancer, for which few risk factors are established. We investigated the association between patterns in baseline plasma metabolite profile and subsequent prostate cancer risk, using data from 3,057 matched case–control sets from the European Prospective Investigation into Cancer and Nutrition (EPIC). We measured 119 metabolite concentrations in plasma samples, collected on average 9.4 years before diagnosis, by mass spectrometry (AbsoluteIDQ p180 Kit, Biocrates Life Sciences AG). Metabolite patterns were identified using treelet transform, a statistical method for identification of groups of correlated metabolites. Associations of metabolite patterns with prostate cancer risk (OR1SD) were estimated by conditional logistic regression. Supplementary analyses were conducted for metabolite patterns derived using principal component analysis and for individual metabolites. Men with metabolite profiles characterized by higher concentrations of either phosphatidylcholines or hydroxysphingomyelins (OR1SD = 0.77, 95% confidence interval 0.66–0.89), acylcarnitines C18:1 and C18:2, glutamate, ornithine and taurine (OR1SD = 0.72, 0.57–0.90), or lysophosphatidylcholines (OR1SD = 0.81, 0.69–0.95) had lower risk of advanced stage prostate cancer at diagnosis, with no evidence of heterogeneity by follow-up time. Similar associations were observed for the two former patterns with aggressive disease risk (the more aggressive subset of advanced stage), while the latter pattern was inversely related to risk of prostate cancer death (OR1SD = 0.77, 0.61–0.96). No associations were observed for prostate cancer overall or less aggressive tumor subtypes. In conclusion, metabolite patterns may be related to lower risk of more aggressive prostate tumors and prostate cancer death, and might be relevant to etiology of advanced stage prostate cancer. 相似文献
3.
Prof. Dr. Doris Balogh 《European Surgery》1997,29(6):309-311
4.
Richard B Thompson Ewout J van den Bos Bryce H Davis Yoshihisa Morimoto Damian Craig Brad S Sutton Donald D Glower Doris A Taylor 《The Journal of heart and lung transplantation》2005,24(2):205-214
BACKGROUND: Pre-clinical and clinical studies suggest that transplantation of bone marrow-derived stem cells can improve global cardiac function. However, no quantitative assessment of regional systolic contraction and correlation with phenotype has been made. Therefore, we used our model of cryoinfarcted rabbit myocardium for intracardiac transplantation of a mixed population of bone marrow-derived cells and assessed both regional function and myogenic conversion of the cells. METHODS: Nineteen New Zealand white rabbits underwent cryoinjury of the left ventricle. Autologous bone marrow (BM) cells were expanded in vitro. After 2 weeks, either 1 x 10(8) mixed BM-derived progenitor cells (BM group, n = 11) or vehicle (control group, n = 8) were injected into the cryoinjured region. Regional systolic function was measured using micromanometry and sonomicrometry before and 4 weeks after cell injection; cell phenotype was evaluated histologically. RESULTS: All animals in the BM group significantly improved both systolic shortening (0.11 +/- 0.7 vs -0.05 +/- 0.05 mm in the control group, p < 0.05) and regional stroke work when compared with control (9.6 +/- 2.4 vs -1.2 +/- 1.2 mm . mm Hg, p < 0.003). In addition, the BM group had improved global diastolic function, as measured by minimum dP/dt and end-diastolic pressure. On histologic assessment, BM cells differentiated toward a myogenic phenotype. CONCLUSIONS: Transplanting a mixed population of marrow-derived cells that can adopt a myogenic phenotype improves regional contractility and diastolic relaxation after myocardial infarction. 相似文献
5.
6.
Doris Cerecedo Sirenia González Mónica Mondragón Elba Reyes Ricardo Mondragón 《Blood coagulation & fibrinolysis》2006,17(2):161-164
Platelets are cell fragments with dynamic properties involved in clot formation after tissue damage. Platelet activation causes a change in shape, secretion of intracellular granules and aggregation with each other through the cytoskeleton components and biochemical changes. Platelet adhesion, considered as the major event in haemostasis, has been studied in several in-vitro and in-vivo models to evaluate the feasible thrombogenicity of some materials, the dynamics of specific receptors, as well as the effect of different buffers and inhibitors in this process. In spite of the numerous reports about platelet activation, to date there is no information available about the fine structure of the platelet-platelet and platelet-substrate interactions. In the present report we describe an in-vitro system that allows the visualization of these interactions: platelets are adhered to an inert substrate, and interactions with suspended platelets as a process to initiate the formation of thrombi was followed by ultramicrotomy and transmission electron microscopy. 相似文献
7.
Mark S. Scher Marisha Y. Hamid Doris A. Steppe Marquita E. Beggarly Michael J. Painter 《Epilepsia》1993,34(2):284-288
Summary: The effect of gestational age on neonatal ictal and interictal durations has not been investigated. Sixty-eight neonates with 644 electrographic seizures were identified retrospectively. Thirty-five full-term (FT) neonates were compared with 33 preterm (PT) neonates. Eighteen older preterm infants (OPT) [>31 weeks estimated gestational age (EGA)] were also compared with 15 young preterm infants (YPT) of ≤31 weeks EGA. Ictal/ interictal durations were calculated for the total cohort with and without status epilepticus (SE). Statistical analyses were two-tailed t tests, chi-square calculations, and one-way analysis of variance (ANOVA) with Duncan's multiple-range test. Eleven of 35 (33%) FT had SE as compared with 3 of 33 (9%) PT (chi-square = 7.8, p < 0.05). The mean ictal duration was 14.2 min for FT infants as compared with 3.1 min for PT infants (p < 0.01); only borderline differences were noted after those with SE were excluded. Interictal durations were longer for OPT than YPT (p < 0.05). By ANOVA and Duncan's multiple-range tests, group differences included longer mean ictal durations for FT infants as compared with OPT infants (p = 0.06, ANOVA; p < 0.05, Duncan's), and longer mean interictal durations for FT infants versus OPT and OPT versus YPT (p = 0.02, ANOVA; p < 0.05, Duncan's). More developed neuronal networks result in longer ictal durations in FT than in PT neonates, including FT infants with SE. Inhibitory networks responsible for longer interictal periods are more dominant in OPT infants than in YPT infants, reflecting maturational changes that suppress seizure activity during the latter part of the third trimester before the infant reaches an FT corrected age. 相似文献
8.
Parminder Suchdev Kym Ahrens Eleanor Click Lori Macklin Doris Evangelista Elinor Graham 《Ambulatory Pediatrics》2007,7(4):317-320
The health status of many people in developing countries is often dismal compared with the norms in industrialized countries. Increasingly, medical practitioners in the United States and other industrialized countries have become interested in global health issues, an interest that often takes the form of short-term international medical trips. We discuss several ethical issues associated with participation in such trips and use our experiences in developing the Children's Health International Medical Project of Seattle (CHIMPS) to outline and illustrate a set of 7 guiding principles for making these trips. CHIMPS is a resident-run, faculty-supported international medical program founded in 2002 by pediatric residents at the University of Washington in Seattle. Members of CHIMPS work with a rural community in El Salvador to support ongoing public health interventions there and provide sustainable medical care in collaboration with the community and a local nongovernmental organization. The 7 principles developed as a result of this work-mission, collaboration, education, service, teamwork, sustainability, and evaluation-can be used as a model for health practitioners as they develop or select international medical trips. The importance of partnering with the community and working within the existing medical and public health infrastructure is emphasized. Many of the challenges of doing international medical work can be overcome when efforts are guided by a few specific principles, such as those we have outlined. 相似文献
9.
10.
Frances Chung Doris Tong Paula C. Miceli Joseph Reiz Zoltan Harsanyi Andrew C. Darke Lance W. Payne 《Journal canadien d'anesthésie》2004,51(3):216-221
PURPOSE: Following ambulatory surgery, long-acting analgesics may provide advantages over short-acting analgesics. This study compared controlled-release codeine (CC) and acetaminophen plus codeine (A/C; 300 mg/30 mg) for pain control in the 48-hr period following laparoscopic cholecystectomy. METHODS: Eligible patients were randomized to CC or A/C in a double-blind, double-dummy parallel group study. Unrelieved pain in hospital was treated with fentanyl i.v. bolus. Pain [100 mm visual analogue scale (VAS)] was assessed before the first dose of medication; at 0.5, one, two, three, and four hours post-dose; at discharge; and three times a day for 48 hr. Adverse events were recorded and measures of patient satisfaction were assessed at the end of the study. RESULTS: Eighty-four patients were enrolled in the study; 42 patients in each group. There were no statistically significant differences between CC and A/C treatment. Mean VAS baseline pain was similar in both groups (P = 0.49) and there was no significant difference in the time to onset of analgesia (P = 0.17). At 0.5 hr, the mean VAS pain score was significantly reduced from baseline in both groups (P = 0.0001). The VAS pain scores at discharge were reduced 59% and 56% from baseline, respectively (P = 0.61). There was no difference between treatments in the incidence of adverse events and patients reported similar levels of satisfaction. CONCLUSIONS: Controlled-release codeine provides an equivalent onset of analgesia, reduction in postoperative pain, and level of patient satisfaction, to acetaminophen plus codeine, over 48 hr following cholecystectomy, with the advantage of less frequent dosing. 相似文献