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   2928篇
  免费   176篇
  国内免费   8篇
耳鼻咽喉   31篇
儿科学   210篇
妇产科学   52篇
基础医学   276篇
口腔科学   64篇
临床医学   217篇
内科学   591篇
皮肤病学   128篇
神经病学   234篇
特种医学   37篇
外科学   417篇
综合类   38篇
一般理论   4篇
预防医学   122篇
眼科学   139篇
药学   318篇
中国医学   15篇
肿瘤学   219篇
  2023年   12篇
  2022年   45篇
  2021年   95篇
  2020年   61篇
  2019年   84篇
  2018年   117篇
  2017年   87篇
  2016年   95篇
  2015年   87篇
  2014年   134篇
  2013年   163篇
  2012年   230篇
  2011年   226篇
  2010年   165篇
  2009年   109篇
  2008年   205篇
  2007年   177篇
  2006年   154篇
  2005年   168篇
  2004年   180篇
  2003年   123篇
  2002年   107篇
  2001年   32篇
  2000年   24篇
  1999年   19篇
  1998年   36篇
  1997年   19篇
  1996年   23篇
  1995年   19篇
  1994年   12篇
  1993年   7篇
  1992年   9篇
  1991年   19篇
  1990年   6篇
  1989年   9篇
  1988年   5篇
  1987年   6篇
  1986年   3篇
  1984年   3篇
  1983年   6篇
  1982年   4篇
  1981年   6篇
  1980年   4篇
  1979年   2篇
  1978年   3篇
  1977年   4篇
  1974年   2篇
  1972年   1篇
  1968年   1篇
  1966年   1篇
排序方式: 共有3112条查询结果,搜索用时 15 毫秒
81.

Background

Surgical site infections (SSIs) are a major cause of morbidity, mortality, and healthcare costs, and patients undergoing simultaneous colorectal/liver resections are at an especially high SSI risk.

Methods

Data were collected on all patients undergoing synchronous colorectal/liver resection from 2011 to 2016 (n = 424). The intervention, implemented in 2013, included 13 multidisciplinary perioperative components. The primary endpoints were superficial/deep and organ space SSIs. Secondary endpoints were hospital length of stay (LOS) and 30-day readmission rate. To control for changes in SSI rates independent of the intervention, interrupted time series analysis was conducted.

Results

Overall, superficial/deep, and organ space SSIs decreased by 60.5% (p < 0.001), 80.6% (p < 0.001), and 47.6% (p = 0.008), respectively. In the pre-intervention cohort (n = 231), there were 79 (34.2%), 31 (13.4%), and 48 (20.8%) total, superficial/deep, and organs space SSIs, respectively. In the post-intervention cohort (n = 193), there were 26 (13.5%), 5 (2.6%), and 21 (10.9%) total, superficial/deep, and organs space SSIs, respectively. Median LOS decreased from 9 to 8 days (p < 0.001). Readmission rates did not change (p = 0.6). Interrupted time series analysis found no significant trends in SSI rate within the pre-intervention (p = 0.35) and post-intervention (p = 0.55) periods.

Conclusion

In combined colorectal/liver resection patients, implementation of a multidisciplinary care bundle was associated with a 61% reduction in SSIs, with the greatest impact on superficial/deep SSI, and modest reduction in LOS. The absence of trends within each time period indicated that the intervention was likely responsible for SSI reduction. Future efforts should target further reduction in organ space SSI.  相似文献   
82.
83.
84.
85.
Genetic polymorphisms in the methylene tetrahydrofolate reductase (MTHFR) gene have been associated with the development of acute leukemias and various malignancies. The role of MTHFR polymorphism in the development of pediatric acute lymphoblastic leukemia (ALL) has been extensively studied among north Indians in various settings, yet its association with acute leukemias remains unresolved. To evaluate the relationship between functional MTHFR polymorphisms, C677T and A1298C and possible effect on risk of ALL in adults and children in North Indian population by comparing them with healthy controls. DNA was isolated from peripheral blood of 184 ALL patients (33 adults, 151 children) and 155 controls and analyzed by a PCR-restriction fragment length polymorphism assay. The frequency of MTHFR 677CT and 1298 AC genotypes were significantly lower among adult ALL cases when compared to the controls. We found a 1.74-fold reduced risk of ALL in individuals with 1298AC polymorphic variant and a 9.17-fold decreased risk of adult ALL. However, no statistically significant difference was evident between the above polymorphisms and susceptibility to ALL in children. Polymorphisms in the MTHFR gene possibly modulate risk of ALL in north Indian adults but not in children, although larger studies are needed.  相似文献   
86.
87.
A simple one-pot polyol-assisted pyro-technique has been adopted to synthesize highly crystalline, carbon-coated LiMn2O4 (LMO/C) nanoparticles for use as a cathode material in rechargeable Li-ion battery (LIB) applications. The phase purity, structure and stoichiometry of the prepared cathode was confirmed using X-ray techniques that included high-resolution powder X-ray diffraction and X-ray absorption fine structure spectroscopy. Electron microscopy studies established that the synthetic technique facilitated the production of nano-sized LMO particles with uniform carbon coating. The prepared LMO/C cathode demonstrates excellent electrochemical properties (cycling stabilities of 86% and 77.5% and high rate capabilities of 79% and 36% within the potential windows of 3.3–4.3 V and 2.5–4.3 V, respectively). The high electrochemical performance of the LMO/C cathode is attributed to the nano-size of the LiMn2O4 particles enabling high surface area and hence greater lithium insertion and also the uniform amorphous carbon coating facilitating effective reduction in manganese dissolution and volume expansion during the lithium de-intercalation/intercalation reactions. In addition, cyclic voltametry and impedance characterization confirm the reversible Li-intercalation and the role of the solid electrolyte interface layer (SEI) in the stable electrochemical reaction of the LMO/C electrode. Furthermore, this study shows the efficacy of a simple and low-cost pyro-synthetic method to realize high performance nano-sized particle electrodes with uniform carbon coating for useful energy storage applications.

A simple one-pot polyol-assisted pyro-synthesized LiMn2O4/C cathode demonstrated remarkable lithium cycling stabilities of 86% and 19% and high rate capabilities of 77.5% and 36% at 3.3–4.3 V and 2.5–4.3V, respectively.  相似文献   
88.
FMS-like tyrosine kinase 3 (FLT3) mutations are prevalent in acute myeloid leukemia (AML), and their presence confers adverse risk. FLT3-mutated (FLT3m) AML is a challenging leukemia to manage, particularly in older and unfit patients as well as patients with relapsed/refractory (r/r) disease. We retrospectively analyzed the outcomes of 50 FLT3m AML patients (17 treatment-naïve, 33 r/r) treated with venetoclax (VEN) and hypomethylating agents (HMA). The overall CR/CRi rate with VEN-HMA was 60% (94% in treatment-naïve AML and 42% in r/r AML). Early (60-days) treatment related mortality was 2%. The r/r AML setting was an independent predictor of lower complete response (OR: 0.08; 95%CI: 0.00-0.60, P = .03). Cytogenetics-molecular risk, concurrent mutations, the type of FLT3 mutation (ITD vs TKD), the ITD allelic ratio, the type of HMA, age, prior exposure to HMA and receipt of prior allogeneic transplant did not independently impact response or leukemia-free survival (LFS). Concurrent IDH mutations were associated with lower CR/CRi (P = .01), while ASXL1 or TET2 mutations showed a non-significant association toward higher CR/CRi (P = .07, for both). However, none of the concurrent mutations were an independent predictor for response when adjusted to AML setting. In conclusion, VEN-HMA is associated with encouraging efficacy in FLT3m AML among both newly diagnosed unfit and r/r patients.  相似文献   
89.
Elmamoun  M.  Eraso  M.  Anderson  M.  Maharaj  A.  Coates  L.  Chandran  Vinod  Abogamal  A.  Adebajo  A. O.  Ajibade  A.  Ayanlowo  O.  Azevedo  V.  Bautista-Molano  W.  Carneiro  S.  Goldenstein-Schainberg  C.  Hernandez-Velasco  F.  Ima-Edomwonyi  U.  Lima  A.  Medina-Rosas  J.  Mody  G. M.  Narang  T.  Ortega-Loayza  A. G.  Ranza  R.  Sharma  A.  Toloza  S.  Vega-Espinoza  L.  Vega-Hinojosa  O. 《Clinical rheumatology》2020,39(6):1839-1850
Clinical Rheumatology - Psoriatic arthritis (PsA) is a challenging heterogeneous disease. The European League Against Rheumatism (EULAR) and the Group for Research and Assessment of Psoriasis and...  相似文献   
90.
Salmonella enteritidis ghosts (SEGs), non-living empty bacterial cell envelopes were generated by using the minimum inhibitory concentration (MIC) of sodium hydroxide (NaOH) and investigated as a vaccine candidate in rats. To determine the immunogenicity and protective efficacy of SEG vaccine, rats were divided into four groups: group A (non-vaccinated control), group B (orally vaccinated), group C (intramuscularly vaccinated) and group D (intramuscularly vaccinated with complete Freund's adjuvant). Vaccination of rats with SEGs induced significant immune responses before and after virulent challenge. Rats vaccinated with SEGs showed significant increases in serum IgG antibodies after challenging with virulent S. enteritidis on week 8 and week 10 (P < 0.01). During the vaccination period, groups B, C and D showed significantly higher serum bactericidal activity (SBA) compared to group A (P < 0.01). Most importantly, bacterial loads in vaccinated groups were significantly lower than in the non-vaccinated group (P < 0.01). In conclusion, these results show that the chemically induced SEGs as a vaccine candidate against virulent challenge.  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