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   2780篇
  免费   265篇
  国内免费   9篇
耳鼻咽喉   18篇
儿科学   161篇
妇产科学   29篇
基础医学   377篇
口腔科学   80篇
临床医学   296篇
内科学   632篇
皮肤病学   34篇
神经病学   181篇
特种医学   123篇
外科学   396篇
综合类   86篇
一般理论   1篇
预防医学   212篇
眼科学   14篇
药学   272篇
中国医学   1篇
肿瘤学   141篇
  2021年   35篇
  2019年   43篇
  2018年   43篇
  2017年   32篇
  2016年   39篇
  2015年   41篇
  2014年   63篇
  2013年   88篇
  2012年   116篇
  2011年   123篇
  2010年   90篇
  2009年   85篇
  2008年   114篇
  2007年   114篇
  2006年   107篇
  2005年   107篇
  2004年   82篇
  2003年   95篇
  2002年   82篇
  2001年   85篇
  2000年   89篇
  1999年   84篇
  1998年   47篇
  1997年   54篇
  1996年   43篇
  1995年   54篇
  1994年   44篇
  1993年   35篇
  1992年   67篇
  1991年   42篇
  1990年   48篇
  1989年   79篇
  1988年   66篇
  1987年   61篇
  1986年   51篇
  1985年   41篇
  1984年   33篇
  1983年   23篇
  1982年   28篇
  1981年   26篇
  1980年   21篇
  1977年   28篇
  1976年   21篇
  1974年   34篇
  1973年   32篇
  1972年   26篇
  1971年   26篇
  1970年   27篇
  1969年   23篇
  1967年   26篇
排序方式: 共有3054条查询结果,搜索用时 0 毫秒
51.
Heart Failure Reviews - Methamphetamine abuse is a global epidemic associated with a wide-ranging array of adverse effects on the cardiovascular system including dilated cardiomyopathy, malignant...  相似文献   
52.
53.
Stimulation of beta-adrenergic receptors (betaARs) causes apoptosis in adult rat ventricular myocytes (ARVMs). The role of reactive oxygen species (ROS) in mediating betaAR-stimulated apoptosis is not known. Stimulation of betaARs with norepinephrine (10 micromol/L) in the presence of prazosin (100 nmol/L) for 24 hours increased the number of apoptotic myocytes as determined by TUNEL staining by 3.6- fold. The superoxide dismutase/catalase mimetics Mn(III)tetrakis(1-methyl-4-pyridyl)porphyrin pentachloride (MnTMPyP; 10 micromol/L) and Euk-134 decreased betaAR-stimulated apoptosis by 89+/-6% and 76+/-10%, respectively. Infection with an adenovirus expressing catalase decreased betaAR-stimulated apoptosis by 82+/-15%. The mitochondrial permeability transition pore inhibitor bongkrekic acid (50 micromol/L) decreased betaAR-stimulated apoptosis by 76+/-8%, and the caspase inhibitor zVAD-fmk (25 micromol/L) decreased betaAR-stimulated apoptosis by 62+/-11%. betaAR-stimulated cytochrome c release was inhibited by MnTMPyP. betaAR stimulation caused c-Jun NH2-terminal kinase (JNK) activation, which was abolished by MnTMPyP. Transfection with an adenovirus expressing dominant-negative JNK inhibited betaAR-stimulated apoptosis by 81+/-12%, and the JNK inhibitor SP600125 inhibited both betaAR-stimulated apoptosis and cytochrome c release. Thus, betaAR-stimulated apoptosis in ARVMs involves ROS/JNK-dependent activation of the mitochondrial death pathway.  相似文献   
54.

The T2 Candida Panel (T2CP) has high sensitivity and specificity to detect candidemia. Its role in the diagnosis and management of candidemia compared to blood cultures (BC) remains unclear. The purpose of this study was to evaluate the T2CP versus BC in detecting and treating candidemia. A retrospective, observational cohort study was conducted to compare clinical outcomes in patients with candidemia identified by BC versus T2CP. Patients with a positive BC or T2CP for Candida spp. from January 2012 to August 2020 were grouped by initial method of detection (BC vs T2CP). Co-primary endpoints assessed included time to detection of candidemia and time to antifungal therapy. Key secondary endpoints included length of stay (LOS), ICU LOS, and mortality. One hundred sixty-three patients with a positive BC and 89 patients with a positive T2CP were included in the evaluation. The average time to detection of candidemia was significantly shorter in the T2CP group compared to BC group (9 vs 41 h, p <?0.001). The time to antifungal was also significantly shorter in the T2CP group compared to the BC group (4 vs 37 h, p?<?0.001). However, LOS was significantly shorter in the BC positive group than the T2CP group with no difference in ICU LOS. There was no difference in in-hospital or 30-day mortality between the two groups. Of patients diagnosed with candidemia at our large community hospital, identification by T2CP led to faster detection and initiation of antifungal compared to blood cultures without improvement in LOS or mortality.

  相似文献   
55.
56.
The menstrual cycle has been implicated as a sex‐specific biological process influencing psychological symptoms across a variety of disorders. Limited research exists regarding the role of the menstrual cycle in psychological symptoms among women with posttraumatic stress disorder (PTSD). The current study examined the severity of a broad range of psychological symptoms in both the early follicular (Days 2–6) and midluteal (6–10 days postlutenizing hormone surge) phases of the menstrual cycle in a sample of trauma‐exposed women with and without PTSD (N = 49). In the sample overall, total psychological symptoms (d = 0.63), as well as depression (d = 0.81) and phobic anxiety (d = 0.81) symptoms, specifically, were increased in the early follicular compared to midluteal phase. The impact of menstrual cycle phase on phobic anxiety was modified by a significant PTSD × Menstrual Phase interaction (d = 0.63). Women with PTSD reported more severe phobic anxiety during the early follicular versus midluteal phase, whereas phobic anxiety did not differ across the menstrual cycle in women without PTSD. Thus, the menstrual cycle appears to impact fear‐related symptoms in women with PTSD. The clinical implications of the findings and future research directions are discussed.  相似文献   
57.
Heat-alkali treatment of synthetic alpha- and beta-melanocyte-stimulating hormones (MSH), known to cause racemization of amino acids within the peptides, results in prolongation of the darkening (melanophore dispersion) effect of these hormones on frog and lizard skins in vitro. Skins remain darkened for hours or even days if supramaximal concentrations of the racemized hormones are used. This response can be partially reversed by melatonin or noradrenaline. Heat-alkali treatment of alpha-MSH at either 60 or 97 degrees C results in a retardation of the response of the skins to the racemized peptides. In contrast, the response of frog skins to heat-alkali-treated beta-MSH is immediately enhanced and potentiated. Heat-alkali treatment also prolongs and potentiates the activity of synthetic [des-acetyl]-alpha-MSH (in contrast to the retardation effect on the natural acetylated peptide). These data suggest a role for the N-acetyl group in the retardation phenomenon. The activity of synthetic [2-D-tyrosine]-alpha-MSh is much lower than that of alpha-MSH itself, indicating that heat-alkali treatment of the hormone may produce either potentiation or partial inactivation of the peptide, depending on the site of racemization.  相似文献   
58.
Assiduous surveillance for genetic aberrations is necessary in patients on cytotoxic therapies to detect therapy‐related myeloid neoplasms (t‐MN). Current modalities include metaphase cytogenetics and FISH. Since t‐MN may develop abruptly in cytogenetically normal patients, a discussion exploring additional methods such as SNP‐array and targeted‐deep‐sequencing to detect subchromosomal abnormalities is needed.  相似文献   
59.
60.
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