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   2853篇
  免费   135篇
  国内免费   27篇
耳鼻咽喉   5篇
儿科学   120篇
妇产科学   61篇
基础医学   401篇
口腔科学   33篇
临床医学   278篇
内科学   747篇
皮肤病学   31篇
神经病学   177篇
特种医学   82篇
外科学   388篇
综合类   13篇
一般理论   1篇
预防医学   179篇
眼科学   95篇
药学   240篇
中国医学   10篇
肿瘤学   154篇
  2023年   13篇
  2022年   32篇
  2021年   75篇
  2020年   42篇
  2019年   55篇
  2018年   70篇
  2017年   58篇
  2016年   64篇
  2015年   73篇
  2014年   90篇
  2013年   121篇
  2012年   213篇
  2011年   213篇
  2010年   120篇
  2009年   96篇
  2008年   163篇
  2007年   203篇
  2006年   208篇
  2005年   173篇
  2004年   172篇
  2003年   176篇
  2002年   143篇
  2001年   28篇
  2000年   17篇
  1999年   21篇
  1998年   21篇
  1997年   23篇
  1996年   24篇
  1995年   12篇
  1994年   9篇
  1993年   13篇
  1992年   11篇
  1991年   17篇
  1990年   11篇
  1989年   11篇
  1987年   14篇
  1986年   16篇
  1985年   17篇
  1984年   16篇
  1983年   12篇
  1982年   12篇
  1981年   10篇
  1980年   14篇
  1979年   8篇
  1977年   10篇
  1976年   10篇
  1975年   8篇
  1974年   7篇
  1973年   13篇
  1972年   8篇
排序方式: 共有3015条查询结果,搜索用时 15 毫秒
41.
ObjectiveTo assess the predictors for the initiation of a basal supported oral therapy (BOT) in type 2 diabetic patients under real-life conditions in Germany.Research design and methodsA historical cohort study based on representative German real life data (IMS® Disease Analyzer) was performed. The study included patients with type 2 diabetes who started an oral antidiabetic drug (OAD) treatment between 01/1995 and 12/2011. Patients with consecutive treatment data for at least 12 months before the initiation of an OAD treatment were eligible for the analysis. The time-dependent rate of patients starting an insulin therapy with a long-acting insulin was calculated by use of the Kaplan–Meier method. Multivariate Cox regression analyses were applied to identify associated factors.ResultsThe study included 194,967 patients with type 2 diabetes mellitus being on OAD therapy. 24,964 patients were switched to BOT during the observational period. The probability of switching to insulin therapy was associated with three main predictors such as (1) poor metabolic control, (2) midlife age and (3) number and type of the OAD before insulinization. The variation of the HbA1c threshold to HbA1c  7.5 leads to comparable outcomes with significant HR.ConclusionThe highest probability of initiating a basal supported oral therapy (BOT) under real life conditions was found for patients with poor metabolic control, midlife age and pre-treatment with specific OADs such as SU, GLI or AGI before initiation of insulin therapy.  相似文献   
42.
Chemical exchange saturation transfer (CEST) is an MRI technique that allows mapping of biomolecules (small metabolites, proteins) with nearly the sensitivity of conventional water proton MRI. In living organisms, several tissue‐specific CEST effects have been observed and successfully applied to diagnostic imaging. In these studies, particularly the signals of proteins showed a distinct correlation with pathological changes. However, as CEST effects depend on various properties that determine and affect the chemical exchange processes, the origins of the observed signal changes remain to be understood. In this study, protein aggregation was identified as an additional process that is encoded in the CEST signals of proteins. Investigation of distinct proteins that are involved in pathological disorders, namely amyloid beta and huntingtin, revealed a significant decrease of all protein CEST signals upon controlled aggregation. This finding is of particular interest with regard to diagnostic imaging of patients with neurodegenerative diseases that involve amyloidogenesis, such as Alzheimer's or Huntington's disease. To investigate whether the observed CEST signal decrease also occurs in heterogeneous mixtures of aggregated cellular proteins, and thus prospectively in tissue, heat‐shocked yeast cell lysates were employed. Additionally, investigation of different cell compartments verified the assignment of the protein CEST signals to the soluble part of the proteome. The results of in vitro experiments demonstrate that aggregation affects the CEST signals of proteins. This observation can enable hypotheses for CEST imaging as a non‐invasive diagnostic tool for monitoring pathological alterations of the proteome in vivo.  相似文献   
43.
44.
IntroductionThe free radial forearm (FRFA) flap is universally still considered as the gold standard technique in penile reconstruction. Typically, a considerably large flap is required, often involving almost the entire circumference of the forearm. Partial necrosis may occur at the distal-most (dorsoradial) part of the flap as a result of insufficient perfusion.AimTo describe a new technique using the posterior interosseous artery (PIOA) to supercharge FRFA phalloplasty.MethodsIn a 12-month period, all patients having FRFA flap phalloplasty were enrolled. Perioperative, after complete flap dissection, an indocyanine green perfusion scan was performed. In case of insufficient perfusion at the distalmost part of the flap, a supramicrosurgical anastomosis was performed between the FRFA pedicle and the PIOA (artery only).Main Outcome MeasuresStudied outcomes included the rate of marginal necrosis, surgical time, postoperative posterior interosseous nerve damage and urethral complications (fistula, stenosis or necrosis).ResultsA total of 27 FRFA flap phalloplasties was performed. Anastomosis of the PIOA was needed in 15 cases. No marginal necrosis was observed in these cases. There were no cases of postoperative posterior interosseous nerve damage. There were no significant differences in urethral complications (fistula, stenosis or necrosis) between the 2 groups.Clinical ImplicationsIn selected cases where insufficient perfusion of the dorsoradial part of the flap is present, patients may benefit from arterial supercharging to prevent postoperative marginal necrosis.Strength & LimitationsStrengths include a single surgeon, thus lending continuity of skill and technique, a consecutive series, and 100% short-term follow-up. Limitations include single institution series and a limited number of patients.ConclusionArterial supercharging is effective in improving perfusion of large FRFA flaps used in phalloplasty when dorsoradial hypoperfusion is detected on an indocyanine green perfusion scan. It is a technically challenging addition to the standard technique because of the small size of the vessels, the close relationship between the PIOA and the posterior interosseous nerve, and the vulnerability of the newly constructed intra-flap anastomosis.De Wolf E, Claes K, Sommeling CE, et al. Free Bipedicled Radial Forearm and Posterior Interosseous Artery Perforator Flap Phalloplasty. J Sex Med 2019;16:1111–1117.  相似文献   
45.
46.
Clinical Rheumatology - The original publication contains two areas which require correcting. None of these errors change the results or conclusions of the article, but the authors wish to...  相似文献   
47.
48.
49.
Geriatric educators face the challenge of attracting more clinicians, scientists, and educators into geriatrics and gerontology, and promoting involvement in gerontological societies. A survey of psychologists (N = 100) examined factors that attract students in clinical/counseling psychology to practice with older adults, as well as experiences in organizational service. For 58%, interest in aging began at the undergraduate level, but for others interest developed later. About one half cited academic exposure such as mentorship (51%), research (47%), or coursework (45%) as sparking interest, along with family (68%) or work experience (61%). Involvement in professional organizations lags (58%), in part owing to misperceptions about what those activities require. A continued targeted effort at the undergraduate and graduate level is essential to attract students to careers in aging. To preserve vital professional organizations, enhanced outreach may be useful to dispel myths about service and encourage engagement.  相似文献   
50.
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