首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   11723篇
  免费   807篇
  国内免费   96篇
耳鼻咽喉   117篇
儿科学   254篇
妇产科学   436篇
基础医学   1536篇
口腔科学   399篇
临床医学   1071篇
内科学   2575篇
皮肤病学   198篇
神经病学   933篇
特种医学   412篇
外国民族医学   3篇
外科学   1888篇
综合类   251篇
一般理论   4篇
预防医学   616篇
眼科学   115篇
药学   607篇
  1篇
中国医学   47篇
肿瘤学   1163篇
  2023年   74篇
  2022年   128篇
  2021年   349篇
  2020年   187篇
  2019年   255篇
  2018年   320篇
  2017年   220篇
  2016年   265篇
  2015年   301篇
  2014年   391篇
  2013年   493篇
  2012年   826篇
  2011年   809篇
  2010年   444篇
  2009年   380篇
  2008年   661篇
  2007年   730篇
  2006年   601篇
  2005年   617篇
  2004年   601篇
  2003年   513篇
  2002年   517篇
  2001年   343篇
  2000年   341篇
  1999年   338篇
  1998年   109篇
  1997年   114篇
  1996年   79篇
  1995年   66篇
  1994年   77篇
  1993年   62篇
  1992年   164篇
  1991年   153篇
  1990年   123篇
  1989年   143篇
  1988年   76篇
  1987年   118篇
  1986年   80篇
  1985年   55篇
  1984年   67篇
  1983年   42篇
  1982年   26篇
  1981年   30篇
  1980年   26篇
  1979年   46篇
  1976年   30篇
  1975年   22篇
  1974年   29篇
  1972年   25篇
  1971年   21篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
71.
72.
BackgroundThe aim of this study is to compare the long-term functional outcome and quality of life between total knee arthroplasty (TKA) and fixed-bearing unicompartmental knee arthroplasty (UKA) for the treatment of isolated medial compartment osteoarthritis.MethodsBetween 2000 and 2008, a total of 218 patients underwent primary UKA at our tertiary hospital. A TKA group was matched through 1:1 propensity score matching and adjusted for age, gender, body mass index, preoperative knee flexion, and function scores. All patients had medial compartment osteoarthritis. The patients were assessed with the range of motion, Knee Society Knee Score and Knee Society Function Score, Oxford Knee Score, Short Form-36 physical component score (PCS) and mental component score preoperatively, at 6 months, 2 years, and 10 years. Patients’ satisfaction, expectation fulfillment, and minimal clinically important difference were analyzed.ResultsThere were no differences in baseline characteristics between groups after propensity score matching (P > .05). UKA had greater knee flexion at all time points. Although the Knee Society Function Score was superior in UKA by 5.5, 3, and 4.3 points at 6 months, 2 years, and 10 years, respectively (P < .001), these differences did not exceed the minimal clinically important difference (Knee Society Knee Score 6.1). There were no significant differences in the Oxford Knee Score and Short Form-36 physical component score/mental component score. At 10 years, similar proportions of UKA and TKA were satisfied (90.8% vs 89.9%, P = .44) and had expectation fulfillment (89.4% vs 88.5%, P = .46). Between 2 and 10 years, all function scores deteriorated significantly for both groups (P < .01).ConclusionUKA and TKA are excellent treatment modalities for isolated medial compartment osteoarthritis, with similar functional outcomes, quality of life, and satisfaction at 10 years.  相似文献   
73.
74.
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   
75.
BackgroundSleeve gastrectomy (SG) has become the most prevalent bariatric-metabolic surgical approach in the United States. Its popularity among surgeons and patients is mainly due to a better safety profile and less overall morbidity, with broad benefits from a systemic and metabolic perspective.ObjectiveComprehensively describe the short-term multiorgan metabolic effects of rapid weight loss after SG.SettingAcademic hospital, United States.MethodsWe retrospectively reviewed the charts of patients that underwent SG at our institution between 2012 and 2016. We analyzed the required variables to calculate multiple risk scores, such as cardiovascular, hypertension, and diabetes risk scores. Furthermore, the renal and hepatic functions and the metabolic and hematologic profiles were assessed at 12 months of follow-up.ResultsA total of 1002 patients were included in the analysis. The percentage of excess body mass index loss was, on average, 65% at 12 months of follow-up. We observed a positive cardio-renal-hepatic improvement, demonstrated by a substantial reduction of the 10-year cardiovascular risk. We noticed an improvement of renal function, which was more significant in chronic kidney disease (stage ≥2), and a significant improvement on liver function tests (measured by decreased aspartate aminotransferase and alanine transaminase) at 12 months of follow-up. Our data also show a positive impact on decreasing the risk of developing hypertension and type 2 diabetes. There was a positive impact on the lipid profile, with the exception of low-density lipoprotein.ConclusionThere are significant short-term benefits on multiorgan metabolic parameters after rapid weight loss in severely obese patients undergoing sleeve gastrectomy.  相似文献   
76.
BackgroundObesity is a well-known risk factor for heart disease, resulting in a broad spectrum of cardiovascular changes. Left ventricular mass (LVM) and contractility are recognized markers of cardiac function.ObjectivesTo determine the changes of LVM and contractility after bariatric surgery (BaS).SettingUniversity hospital, United StatesMethodsTo determine the cardiac changes in ventricular mass, ventricular contractility, and left ventricular shortening fraction (LVSF), we retrospectively reviewed the 2-dimensional echocardiographic parameters of patients with obesity who underwent BaS at our institution. We compared these results before and after BaS.ResultsA total of 40 patients met the inclusion criteria. The majority were females (57.5%; n = 23), with an average age of 63.5 ± 12.1. The excess body mass index (BMI) lost at 12 months was 48.9 ± 28.9%. The percent total weight loss after BaS was 16.46 ± 9.9%. The left ventricular mass was 234.9 ± 88.1 grams before and 181.5 ± 52.7 grams after BaS (P = .002). The LVM index was 101.3 ± 38.3 g/m2 before versus 86.7 ± 26.6 g/m2 after BaS (P = .005). The LVSF was 31% ± 8.8% before and 36.3% ± 8.2% after BaS (P = .007). We found a good correlation between the decrease in LVM index and the BMI after BaS (P = .03).ConclusionRapid weight loss results in a decrease of the LVM index, as well as improvement in the left ventricular muscle contractility. Our results suggest that there is left ventricular remodeling and an improvement of heart dynamics following bariatric surgery. Further studies are needed to better assess these findings.  相似文献   
77.
Kidney transplant program performance in the United States is commonly measured by posttransplant outcomes. Inclusion of pretransplant measures could provide a more comprehensive assessment of transplant program performance and necessary information for patient decision-making. In this study, we propose a new metric, the waitlisting rate, defined as the ratio of patients who are waitlisted in a center relative to the person-years referred for evaluation to a program. Furthermore, we standardize the waitlisting rate relative to the state average in Georgia, North Carolina, and South Carolina. The new metric was used as a proof-of-concept to assess transplant-program access compared to the existing transplant rate metric. The study cohorts were defined by linking 2017 United States Renal Data System (USRDS) data with transplant-program referral data from the Southeastern United States between January 1, 2012 and December 31, 2016. Waitlisting rate varied across the 9 Southeastern transplant programs, ranging from 10 to 22 events per 100 patient-years, whereas the program-specific waitlisting rate ratio ranged between 0.76 and 1.33. Program-specific waitlisting rate ratio was uncorrelated with the transplant rate ratio (r = −.15, 95% CI, −0.83 to 0.57). Findings warrant collection of national data on early transplant steps, such as referral, for a more comprehensive assessment of transplant program performance and pretransplant access.  相似文献   
78.
79.
Using monoclonal antibodies, we have examined the expression pattern of MASH1, a basic helix-loop-helix protein that is a mammalian homolog of the Drosophila achaete-scute proteins. In Drosophila, achaete-scute genes are required for the determination of a subset of neurons. In the rat embryo, MASH1 expression is confined to subpopulations of neural precursor cells. The induction of MASH1 precedes, but is extinguished upon, overt neuronal differentiation. MASH1 is expressed in the forebrain by spatially restricted domains of neuroepithelium and in the peripheral nervous system exclusively by precursors of sympathetic and enteric neurons. The features of early and transient expression, in spatially restricted subpopulations of neural precursors, are similar to those observed for achaete-scute. Thus, the amino acid sequence conservation between MASH1 and achaete-scute is reflected in a parallel conservation of cell type specificity of expression, similar to the case of mammalian MyoD and Drosophila nautilus. These data support the idea that helix-loop-helix proteins may represent an evolutionarily conserved family of cell-type determination genes, of which MASH1 is the first neural-specific member identified in vertebrates.  相似文献   
80.
In a recent, thought-provoking novel by Elizabeth McCracken (The Giant's House. Avon Books, New York, 1997), two characters discuss love and its impossibilities. One brashly claims to be "immune to love", explaining the concept to his perplexed interlocutor, "...people become immune to love like they become immune to any disease. Either they had it bad early in life, like chicken pox and that's that; or they keep getting exposed to it in little doses and build up an immunity; or somehow they just don't catch it, something in'em is born resistant. I'm the last type. I'm immune to love and poison ivy". (p. 275) (E. McCracken, The Giant's House. Avon Books, New York, 1997). Substitute the words 'HIV infection' for 'love' and this intriguing metaphor summarizes the state of the art working hypotheses for the phenomenon of resistance to HIV infection in HIV-exposed individuals who, against all odds, do not seroconvert. These hypotheses will be discussed hereafter and particular emphasis will be placed upon a possible role for mucosal immunity in this phenomenon.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号