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   647篇
  免费   55篇
  国内免费   29篇
耳鼻咽喉   15篇
儿科学   17篇
妇产科学   1篇
基础医学   46篇
口腔科学   25篇
临床医学   69篇
内科学   72篇
皮肤病学   61篇
神经病学   89篇
特种医学   114篇
外科学   104篇
综合类   26篇
预防医学   18篇
眼科学   2篇
药学   53篇
肿瘤学   19篇
  2024年   4篇
  2023年   13篇
  2021年   11篇
  2020年   6篇
  2019年   12篇
  2018年   19篇
  2017年   9篇
  2016年   11篇
  2015年   12篇
  2014年   21篇
  2013年   19篇
  2012年   16篇
  2011年   19篇
  2010年   22篇
  2009年   16篇
  2008年   13篇
  2007年   27篇
  2006年   23篇
  2005年   30篇
  2004年   15篇
  2003年   18篇
  2002年   21篇
  2001年   19篇
  2000年   10篇
  1999年   17篇
  1998年   24篇
  1997年   26篇
  1996年   23篇
  1995年   9篇
  1994年   25篇
  1993年   24篇
  1992年   8篇
  1991年   11篇
  1990年   12篇
  1989年   22篇
  1988年   17篇
  1987年   14篇
  1986年   8篇
  1985年   19篇
  1984年   13篇
  1983年   15篇
  1982年   10篇
  1981年   16篇
  1980年   5篇
  1979年   4篇
  1978年   5篇
  1977年   6篇
  1976年   5篇
  1975年   5篇
  1930年   1篇
排序方式: 共有731条查询结果,搜索用时 15 毫秒
1.
BACKGROUND: Nurse leaders in Fiji are currently involved in meeting the challenges of being at the forefront of an AusAID supported Health Sector Improvement process. Fiji is experiencing the same shortages of health professionals (including nurses) as is occurring internationally, while simultaneously striving to improve the quality of its health services. PRIMARY ARGUMENT: This paper provides information about the current situation in relation to health services in Fiji, and describes strategies being undertaken by the nurse leaders of Fiji to meet the challenge of leading an exciting reform process. James Cook University, School of Nursing Sciences, has been privileged to support the provision of contemporary leadership and management education for current and future nurse leaders in the Fiji Health Sector as a component of a current education program to educate registered nurses to bachelor level. This paper will provide an overview of the current Fiji Health Sector Improvement Program, with a particular focus on the preparation of nurse leaders. CONCLUSION: There is an ongoing need to understand beliefs and values, and styles of interaction and communication, and indeed, ideas about time. With collaboration between Australian academics and Fiji tutors from the Fiji School of Nursing, the program appears to be remarkably successful.  相似文献   
2.
以18-甲基-17β-羟基-17α-乙炔基-雌甾-4-烯-3-酮(18-甲基炔诺酮),17β-羟基-17α-乙缺基-雌甾-4-烯-3-酮(炔诺酮),17β-羟基-17α-乙炔基-雄甾-4-烯-3-酮(妊娠素)和17a-羟基孕甾-4-烯-3,20二酮(17α-羟基黄体酮)为原料,经NaBH,还原、脱水、双键转位和酯化等反应合成一系列3,5-甾二烯化合物,用1HNMR和MS证明了它们的结构。动物筛选结果表明,17β-丙酰氧基-17α-乙炔基-雌甾-3,5-二烯(IVb2有明显的抗早孕活性。中断早期妊娠的作用似与其雌激素活性有关。  相似文献   
3.
Bile duct calculi in patients with primary sclerosing cholangitis   总被引:1,自引:0,他引:1  
  相似文献   
4.
5.
GP73 is a novel type II Golgi transmembrane protein that is expressed at high levels in the hepatocytes of patients with viral hepatitis (R. D. Kladney, G. A. Bulla, L. Guo, A. L. Mason, A. E. Tollefson, D. J. Simon, Z. Koutoubi, and C. J. Fimmel, 2000, Gene 249, 53-65) and is induced in cultured cells by infection with viruses including adenoviruses. Its biological function and the mechanisms by which its expression may be regulated by viral infection are unknown. Here we report that GP73 is induced at the RNA and protein level in human Hep3B hepatoma cells infected by human Ad5 and Ad2. Hep3B cells were infected with wild-type or mutant adenoviruses. GP73 expression was measured by RNase protection assay, immunoblotting, or immunofluorescence microscopy. GP73 RNA and protein levels were strikingly induced following infection. The rise in GP73 expression coincided with the appearance of the adenovirus E1A and DBP proteins and preceded the expression of the fiber protein, a marker of the late phase of infection. Infection did not affect the expression of giantin, GPP130, or golgin-84, three integral Golgi membrane proteins with structural similarities to GP73. Mapping studies using a panel of mutant adenoviruses demonstrated that the E1A C-terminus, specifically its CtBP interaction domain (CID), is required for GP73 expression. Subsequently, Hep3B cells were transiently transfected with plasmids expressing wild-type or mutant E1A proteins. These studies confirmed that E1A induced GP73 expression via the CID. Our studies establish GP73 as a novel adenovirus-induced cellular protein whose expression is regulated through the CID of the E1A protein.  相似文献   
6.
Summary Accurate volume determination of the encephalic ventricles is of importance in several clinical conditions, including Alzheimer's presenile dementia, schizophrenia, and benign intracranial hypertension. Previous studies have investigated the accuracy with which magnetic resonance imaging (MRI) can be used in clinical practice to evaluate the encephalic ventricles. However, adequate evaluation of pathological conditions depends on a sufficient amount of morphometric data from normal subjects. To begin establishing this data base for normal subjects, we evaluated the MRI scans of 38 subjects found to have no apparent pathology and calculated the ventricular volume in each case by using methods previously developed in our laboratory. The results were then compared with published volumes determined from studies that used either ventricular casts or computerized tomographic scans. The average total ventricular volume for all 38 subjects was 17.4 cm3, while that for males was 16.3 cm3 and that for females was 18.0 cm3. A small but significant correlation was found between age of subject and ventricular volume, with ventricular size increasing with age.
Evaluation du volume des ventricules cérébraux à partir des images obtenues en résonance magnétique nucléaire chez 38 sujets humains
Résumé La détermination exacte du volume des ventricules cérébraux est importante en clinique comme par exemple dans la démence présénile d'Alzheimer, la schizophrénie et l'hypertension intracrânienne bénigne. Des études antérieures ont étudié la fiabilité de la résonance magnétique nucléaire en pratique clinique pour évaluer le volume des ventricules cérébraux. Toutefois une évaluation correcte dans les conditions pathologiques implique une bonne connaissance des données morphométriques du sujet normal. Pour établir ces données sur « le sujet normal », nous avons étudié les coupes obtenues en IRM chez 38 sujets apparemment indemnes de toute pathologie; nous avons calculé le volume ventriculaire dans chaque cas en utilisant des méthodes mises au point auparavant dans notre laboratoire. Les résultats ont été ensuite comparés avec ceux obtenus par d'autres études utilisant soit des moules ventriculaires, soit des coupes tomographiques computérisées. Le volume ventriculaire total moyen chez 38 sujets est de 17,4 cm3, mais il est chez les sujets masculins de 16,3 cm3 et chez les sujets de sexe féminin de 18 cm3. Une corrélation faible mais significative a été trouvée entre l'âge du sujet et le volume ventriculaire, étant entendu que la taille du ventricule augmente avec l'âge.
  相似文献   
7.
8.
A Scaria  A E Tollefson  S K Saha  W S Wold 《Virology》1992,191(2):743-753
The 11,600 MW (101 amino acids; 11.6K) protein of adenovirus 2 (Ad2) is a protein of unknown function which is synthesized in low amounts during early stages of infection but in very high amounts at late stages. The 11.6K protein migrates as three major groupings of diffuse bands of ca. 14K, 21K, and 31K on SDS-PAGE, indicating that 11.6K undergoes post-translational modification. We show here that 11.6K is Asn-glycosylated with complex (endo H-resistant) oligosaccharides and that 11.6K is an integral membrane protein. Immunofluorescence indicated that 11.6K initially is associated with the endoplasmic reticulum and Golgi apparatus and that it ultimately localizes to the nuclear membrane. The 11.6K protein is predicted to have a single signal-anchor sequence at residues 41-62 and only one potential Asn-linked glycosylation site at residue 14; thus, 11.6K must be oriented in the membranes with its NH2-terminus in the lumen and its COOH-terminus in the cytoplasm. The signal-anchor and glycosylation features of 11.6K are preserved in Ad2 and Ad5 (group C), and in Ad3 and Ad7 (group B), but the sequence of 11.6K is more diverged among these serotypes than is the sequence of most other adenovirus proteins.  相似文献   
9.
IntroductionIntraoperative hypothermia (IOH) has been suggested to adversely impact outcomes following surgery. The objective of this study was to evaluate the association between IOH and survival following radical cystectomy (RC).MethodsPatients who underwent RC for bladder cancer from 2003 to 2018 were identified in our cystectomy registry. Intraoperative temperatures were extracted from the anesthesia record. IOH was defined as a median intraoperative temperature <36°C, and severe IOH as ≤ 35°C. Time under 36°C was assessed as a continuous variable. Recurrence-free survival (RFS), cancer-specific survival (CSS), and overall survival (OS) were estimated using the Kaplan-Meier method. Associations between IOH and outcomes were assessed with multivariable Cox proportional hazards models.ResultsA total of 852 patients were identified, among whom 274 (32%) had IOH. Median follow up among survivors was 4.9 years (IQR 2.4–8.7), during which time 483 patients died, including 343 from bladder cancer. Two-year survival was not significantly different between patients with and without IOH (CSS: 74% vs. 71%, P= 0.31; OS: 68% vs. 67%, P= 0.13). Following multivariable adjustment, neither IOH nor time under 36°C was significantly associated with survival. A total of 37 patients (4.3%) had severe IOH. These patients were observed to have significantly lower 2-year OS (56% vs. 68%, P= 0.005); however, this association did not remain statistically significant after multivariable adjustment (P= 0.92).ConclusionIOH was not independently associated with survival following RC. These data do not support IOH as a prognostic factor for cancer outcomes among patients undergoing RC.  相似文献   
10.
IntroductionWhile numerous current clinical trials are testing novel salvage therapies (ST) for patients with recurrent nonmuscle invasive bladder cancer (NMIBC) after bacillus Calmette-Guérin (BCG), the natural history of this disease state has been poorly defined to date. Herein, we evaluated oncologic outcomes in patients previously treated with BCG and ST who subsequently underwent radical cystectomy (RC).MethodsWe identified 378 patients with high-grade NMIBC who received at least one complete induction course of BCG (n = 378) with (n = 62) or without (n = 316) additional ST and who then underwent RC between 2000 and 2018. Oncologic outcomes were compared using the Kaplan-Meier method and Cox proportional hazards models. Sensitivity analyses were conducted stratifying by presenting tumor stage, matched 1:3 for receipt vs. no receipt of ST.ResultsPatients receiving ST were more likely to initially present with CIS (26% vs. 17%) and less likely with T1 disease (34% vs. 50%, P = 0.06) compared to patients not treated with ST. Receipt of ST was not associated with increased risk of adverse pathology (≥pT2 or pN+) at RC (31% vs. 41%, P = 0.14). Likewise, 5-year cancer-specific survival did not significantly differ between groups on univariable Kaplan-Meier analysis (73% for ST and 74% for no ST, P = 0.7). Moreover, on multivariable analysis, receipt of ST was not significantly associated the risk of death from bladder cancer (HR 1.12; 95% CI 0.60–2.09, P = 0.7). Results were unchanged on sensitivity analysis.ConclusionsThese data suggest that, in carefully selected patients, ST following BCG for high grade NMIBC does not compromise oncologic outcomes for patients who ultimately undergo RC.  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