全文获取类型
收费全文 | 2176篇 |
免费 | 152篇 |
国内免费 | 63篇 |
专业分类
耳鼻咽喉 | 5篇 |
儿科学 | 83篇 |
妇产科学 | 63篇 |
基础医学 | 224篇 |
口腔科学 | 31篇 |
临床医学 | 248篇 |
内科学 | 360篇 |
皮肤病学 | 52篇 |
神经病学 | 92篇 |
特种医学 | 284篇 |
外科学 | 348篇 |
综合类 | 72篇 |
一般理论 | 1篇 |
预防医学 | 246篇 |
眼科学 | 35篇 |
药学 | 163篇 |
肿瘤学 | 84篇 |
出版年
2022年 | 10篇 |
2021年 | 37篇 |
2020年 | 14篇 |
2019年 | 21篇 |
2018年 | 38篇 |
2017年 | 19篇 |
2016年 | 22篇 |
2015年 | 34篇 |
2014年 | 45篇 |
2013年 | 48篇 |
2012年 | 77篇 |
2011年 | 103篇 |
2010年 | 51篇 |
2009年 | 74篇 |
2008年 | 97篇 |
2007年 | 93篇 |
2006年 | 84篇 |
2005年 | 91篇 |
2004年 | 51篇 |
2003年 | 80篇 |
2002年 | 71篇 |
2001年 | 85篇 |
2000年 | 75篇 |
1999年 | 72篇 |
1998年 | 68篇 |
1997年 | 79篇 |
1996年 | 66篇 |
1995年 | 71篇 |
1994年 | 43篇 |
1993年 | 50篇 |
1992年 | 53篇 |
1991年 | 51篇 |
1990年 | 40篇 |
1989年 | 69篇 |
1988年 | 52篇 |
1987年 | 61篇 |
1986年 | 37篇 |
1985年 | 30篇 |
1984年 | 22篇 |
1983年 | 16篇 |
1982年 | 22篇 |
1981年 | 22篇 |
1980年 | 22篇 |
1979年 | 16篇 |
1978年 | 14篇 |
1977年 | 19篇 |
1976年 | 14篇 |
1975年 | 11篇 |
1974年 | 7篇 |
1967年 | 6篇 |
排序方式: 共有2391条查询结果,搜索用时 15 毫秒
31.
32.
Debelenko LV; Brambilla E; Agarwal SK; Swalwell JI; Kester MB; Lubensky IA; Zhuang Z; Guru SC; Manickam P; Olufemi SE; Chandrasekharappa SC; Crabtree JS; Kim YS; Heppner C; Burns AL; Spiegel AM; Marx SJ; Liotta LA; Collins FS; Travis WD; Emmert-Buck MR 《Human molecular genetics》1997,6(13):2285-2290
Lung carcinoids occur sporadically and rarely in association with multiple
endocrine neoplasia type 1 (MEN1). There are no well defined genetic
abnormalities known to occur in these tumors. We studied 11 sporadic lung
carcinoids for loss of heterozygosity (LOH) at the locus of the MEN1 gene
on chromosome 11q13, and for mutations of the MEN1 gene using dideoxy
fingerprinting. Additionally, a lung carcinoid from a MEN1 patient was
studied. In four of 11 (36%) sporadic tumors, both copies of the MEN1 gene
were inactivated. All four tumors showed the presence of a MEN1 gene
mutation and loss of the other allele. Observed mutations included a 1 bp
insertion, a 1 bp deletion, a 13 bp deletion and a single nucleotide
substitution affecting a donor splice site. Each mutation predicts
truncation or potentially complete loss of menin. The remaining seven
tumors showed neither the presence of a MEN1 gene mutation nor 11q13 LOH.
The tumor from the MEN1 patient showed LOH at chromosome 11q13 and a
complex germline MEN1 gene mutation. The data implicate the MEN1 gene in
the pathogenesis of sporadic lung carcinoids, representing the first
defined genetic alteration in these tumors.
相似文献
33.
Projected Economic Burden of Periprosthetic Joint Infection of the Hip and Knee in the United States
Ajay Premkumar David A. Kolin Kevin X. Farley Jacob M. Wilson Alexander S. McLawhorn Michael B. Cross Peter K. Sculco 《The Journal of arthroplasty》2021,36(5):1484-1489.e3
BackgroundIn addition to the significant morbidity and mortality associated with periprosthetic joint infection (PJI), the cost of treating PJI is substantial. Prior high-quality national estimates of the economic burden of PJI utilize data up to 2009 to project PJI growth in the United States through 2020. Now in the year 2020, it is appropriate to evaluate these past projections and incorporate the latest available data to better understand the current scale and burden of PJI in the United States.MethodsThe Nationwide Inpatient Sample (2002-2017) was used to identify rates and associated inpatient costs for primary total knee arthroplasty (TKA) and total hip arthroplasty (THA) and PJI-related revision TKA and THA. Poisson regression was utilized to model past growth and project future rates and cost of PJI of the hip and knee.ResultsUsing the most recent data, the combined annual hospital costs related to PJI of the hip and knee were estimated to be $1.85 billion by 2030. This includes $753.4 million for THA PJI and $1.1 billion for TKA PJI, in that year. Increases in PJI costs are mainly attributable to increases in volume. Although the growth in incidence of primary THA and TKA has slowed in recent years, the incidence of PJI and the cost per case of PJI remained relatively constant from 2002 to 2017.DiscussionUnderstanding the current and potential future financial burden of PJI for surgeons, patients, and healthcare systems is essential. There is an urgent need for efficacious preventive strategies in reducing rates of PJI after THA and TKA. 相似文献
34.
Omair A. Shariq Katherine A. Bews Nicholas P. McKenna Benzon M. Dy Melanie L. Lyden David R. Farley Geoffrey B. Thompson Travis J. McKenzie Elizabeth B. Habermann 《Surgery》2021,169(2):289-297
BackgroundAdvances in minimally invasive surgery and perioperative care have decreased substantially the duration of time that patients spend recovering in hospital, with many laparoscopic procedures now being performed on an ambulatory basis. There are limited studies, however, on same-day discharge after laparoscopic adrenalectomy. The objectives of this study were to investigate the outcomes and trends of ambulatory laparoscopic adrenalectomy in a multicenter cohort of patients.MethodsAdult patients who underwent elective laparoscopic adrenalectomy between 2005 and 2016 were identified in the database of the American College of Surgeons National Surgical Quality Improvement Program (ACS NSQIP). Baseline demographics and 30-day outcomes were compared between patients who underwent ambulatory laparoscopic adrenalectomy and those who were discharged after an inpatient stay. Multivariable logistic regression and Cox proportional hazards modelling were used to investigate the association between same-day discharge and 30-day complications and unplanned readmissions.ResultsOf the 4,807 patients included in the study, 88 (1.8%) underwent ambulatory laparoscopic adrenalectomy and 4,719 (98.2%) were admitted after the adrenalectomy. The same-day discharge group contained fewer obese patients (37.2% vs 50%; P = .04), a lesser proportion of American Society of Anesthesiologists class III patients (45.5% vs 61%; P = .003), and more patients with primary aldosteronism (14.8% vs 6%; P = .002) compared with the inpatient group. After adjustment for confounders, same-day discharge was not associated with 30-day overall complications (OR 1.17, 95% CI 0.35–3.85; P = .80) or unplanned readmissions (HR 2.77, 95% CI 0.86–8.96; P = .09). The percentage of laparoscopic adrenalectomies performed on an ambulatory basis at hospitals participating in the ACS NSQIP remained low throughout the study period (0–3.1% per year) with no evidence of an increasing trend over time (P = .21).ConclusionAmbulatory laparoscopic adrenalectomy is a safe and feasible alternative to inpatient hospitalization in selected patients. Further study is needed to determine the cost savings, barriers to uptake, and optimal selection criteria for this approach. 相似文献
35.
36.
JS Tsang Chi Chung Foo Jeremy Yip Hok Kwok Choi Wai Lun Law Oswens Siu Hung Lo 《The surgeon》2021,19(3):150-155
IntroductionThe difference in outcome between right (RCD) and left colonic diverticulitis (LCD) is not well established. The aim of this study was to analyse the presentation and surgical outcome of RCD versus left-sided disease following emergency surgery.MethodWe conducted a retrospective review of patients presenting with acute diverticulitis over a 10-year period from 2004 to 2014 to a tertiary unit. Patient demographics, Hinchey classification, need for emergency surgery, perioperative outcome and recurrence were evaluated.ResultsIn total 360 patients presented with acute diverticulitis, 218 (61%) were right-sided and 142 (39%) were left-sided. The mean age (57 yrs vs 68 yrs) and median length of stay (4 days vs 5 days) were significantly less in RCD (p < 0.001). The need for emergency surgery was similar between RCD and LCD (30.7% vs 23.2%, p = 0.12). Sixty-seven (31%) patients with RCD required emergency surgery, 42 (62.7%) of these were based on a presumptive diagnosis of appendicitis and underwent laparoscopic appendicectomy only. Operative morbidity (10.4% vs 51.5%, p < 0.001) and mortality were significantly higher in LCD (1.5% v 15.2%, p = 0.007). Subgroup analysis of non-appendicectomy, RCD patients, showed LCD were more likely to require surgery (11.5% vs 23.2%, p = 0.003). There was no difference in recurrence (p = 0.6).ConclusionRight colonic diverticulitis patients are younger and disease course is more benign compared to LCD. Presentation can be confused with appendicitis without proper imaging. In the rare cases where emergency surgery is required, RCD is associated with a lower operative morbidity and mortality compared to left-sided disease. 相似文献
37.
38.
39.
Paré Farley Romãozinho Bardhan French & Roberts 《Alimentary pharmacology & therapeutics》1999,13(8):1071-1078
BACKGROUND: Many dual and triple therapy treatment regimens have been proposed for the eradication of Helicobacter pylori. However, assessing the relative efficacy of these regimens is complicated by differences in study design, and few well-controlled comparative studies have been reported. METHODS: This multicentre, randomized, double-blind study involved 530 duodenal ulcer patients, of whom 520 had confirmed H. pylori infection. Patients received 14 days b.d. dual therapy of either ranitidine bismuth citrate (RBC) 400 mg or omeprazole 20 mg, both with clarithromycin 500 mg to eradicate H. pylori, followed by a further 14 days of treatment with RBC 400 mg b. d. or omeprazole 20 mg o.d. to facilitate ulcer healing. H. pylori eradication and ulcer healing were assessed at least 26 days after the end of treatment. Adverse events were recorded throughout the study. RESULTS: H. pylori was eradicated in 90% of patients who received RBC with clarithromycin and in 66% of patients who received omeprazole with clarithromycin (per protocol; P<0.001). intention-to-treat eradication rates were 77% and 60%, respectively (P<0.001). Ulcer healing rates were 97% in the RBC treatment group and 95% in the omeprazole treatment group. Only 3% and 1% of patients in the RBC and omeprazole treatment groups, respectively, were withdrawn due to adverse events. CONCLUSIONS: RBC with clarithromycin is a simple and highly effective dual therapy regimen for the eradication of H. pylori, and is significantly more effective than omeprazole with clarithromycin. Both treatment regimens are well tolerated and effectively heal duodenal ulcers. 相似文献
40.
The prevalence of microalbuminuria was assessed in 50 patients of non-insulin dependent diabetes mellitus. The mean age of patients was 52.1 ± 11.6 years and the duration of diabetes was 8.3 ± 6.8 years. Twenty (40%) patients had microalbuminuria. Microalbuminuria was more common in patients with a longer duration of diabetes (more than 5 years), a poor glycaemic control, and higher systolic blood pressure.KEY WORDS: Microalbuminuria, Diabetes mellitus, Diabetic nephropathy, Chronic renal failure 相似文献