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   1024篇
  免费   40篇
  国内免费   3篇
耳鼻咽喉   9篇
儿科学   49篇
妇产科学   9篇
基础医学   104篇
口腔科学   46篇
临床医学   55篇
内科学   119篇
皮肤病学   37篇
神经病学   17篇
特种医学   57篇
外科学   102篇
综合类   303篇
预防医学   72篇
眼科学   10篇
药学   39篇
  1篇
中国医学   3篇
肿瘤学   35篇
  2023年   4篇
  2022年   16篇
  2021年   30篇
  2020年   17篇
  2019年   15篇
  2018年   16篇
  2017年   10篇
  2016年   11篇
  2015年   38篇
  2014年   38篇
  2013年   46篇
  2012年   45篇
  2011年   41篇
  2010年   75篇
  2009年   57篇
  2008年   55篇
  2007年   51篇
  2006年   52篇
  2005年   32篇
  2004年   51篇
  2003年   22篇
  2002年   29篇
  2001年   29篇
  2000年   20篇
  1999年   27篇
  1998年   29篇
  1997年   30篇
  1996年   28篇
  1995年   17篇
  1994年   21篇
  1993年   8篇
  1992年   8篇
  1990年   7篇
  1989年   8篇
  1988年   10篇
  1987年   10篇
  1986年   9篇
  1985年   7篇
  1984年   5篇
  1983年   2篇
  1982年   6篇
  1981年   4篇
  1980年   4篇
  1978年   6篇
  1977年   3篇
  1976年   5篇
  1974年   2篇
  1973年   4篇
  1972年   2篇
  1953年   1篇
排序方式: 共有1067条查询结果,搜索用时 15 毫秒
11.
12.
13.
14.
It is known that BK does play a role in the cardioprotective effect of angiotensin converting enzyme (ACE) inhibitors. The present study therefore was conducted to examine the effects of bradykinin (BK) and its antagonist on survival time in spontaneously hypertensive rats (SHR) with coronary artery ligation for 15 min and continuously. We also evaluated the heart rate and blood pressure (BP) in the presence and absence of BK and BK2 receptor antagonist, D-Arg-[Hyp-D-Phe7]BK. Coronary artery was ligated in anaesthetized rats and they were artificially ventilated with room air (stroke volume, 4 ml; 48 strokes/min) as described by the previous investigators. Lead II elecrocardiogram (ECG) was recorded from subcutaneous steel needle electrodes. Results of this investigation indicated that BK treatment 4 microg/kg (i.v.) and 8 microg/kg (i.v.) caused significant (P < 0.05) increase in survival time in SHR with coronary artery ligation for 15 min and continuously as compare to their respective saline-treated controls. However, BK antagonist treatment 4 microg/kg (i.v.) abolished the increase in survival time caused by BK treatment. The mean values of survival time between the saline-treated and BK antagonist plus BK-treated rats did not differ significantly (P > 0.05). The heart rate and BP responses were greatly reduced (P < 0.001) in the presence of coronary artery ligation. These findings suggest that BK might have cardioprotective effect to increase the survival time in rats by activating BK2 receptors after coronary artery ligation.  相似文献   
15.
16.
Dibenzo[a,l]pyrene (DB[a,l]P), an environmental polycyclic aromatic hydrocarbon, is the most potent carcinogen ever tested in mouse skin and rat mammary gland. In this study, DB[a,l]P was examined for DNA adduction, tumorigenicity, and induction of Ki-ras oncogene mutations in tumor DNA in strain A/J mouse lung. Groups of mice received a single i.p. injection of 0.3, 1.5, 3.0, or 6.0 mg/kg DB[a,l]P in tricaprylin. Following treatment, DNA adducts were measured at times between 1 and 28 days, while tumors were counted at 250 days and analyzed for the occurrence of point mutations in codons 12 and 61 of the Ki-ras oncogene. DB[a,l]P in strain A/J mouse lung induced six major and four minor DNA adducts. Maximal levels of adduction occurred between 5 and 10 days after injection followed by a gradual decrease. DB[a,l]P-DNA adducts in lung tissue were derived from both anti- and syn-11,12- dihydroxy-13,14-epoxy- 11,12,13,14-tetrahydrodibenzo[a,l]pyrene (DB[a,l]PDE) and both deoxyadenosine (dAdo) and deoxyguanosine (dGuo) residues in DNA as revealed by cochromatography. The major adduct was identified as a product of the reaction of an anti-DB[a,l]PDE with dAdo in DNA. DB[a,l]P induced significant numbers of lung adenomas in a dose- dependent manner, with the highest dose (6.0 mg/kg) yielding 16.1 adenomas/mouse. In tricaprylin-treated control animals, there were 0.67 adenomas/mouse. Based on the administered dose, DB[a,l]P was more active than other environmental carcinogens including benzo[a]pyrene. As a function of time-integrated DNA adduct levels, DB[a,l]P induced lung adenomas with about the same potency as other PAHs, suggesting that the adducts formed by DB[a,l]P are similar in carcinogenic potency to other PAHs in the strain A/J mouse lung model. Analysis of the Ki- ras mutation spectrum in DB[a,l]P-induced lung tumors revealed the predominant mutations to be G-->T transversions in the first base of codon 12, A-->G transitions in the second base of codon 12, and A-->T transversions in the second or third base of codon 61, concordant with the DNA adduct profile.   相似文献   
17.
Twenty-seven patients with idiopathic palmoplanter hyperhidrosis were treated with Iontotherapy over a one year period. In twenty-four cases there was a good response but maintenance therapy was required every 3-4 weeks.KEY WORDS: Iontophoresis, Palmoplanter hyperhidrosis  相似文献   
18.
19.
BackgroundCoronavirus disease 2019 (covid-19), which causes a pandemic in the world, has started to appear in turkey since march 2020. Healthcare workers are at the top of the groups most at risk for covid-19 infection, which can have a negative impact on psychological state.ObjectivesIt was aimed to evaluate anxiety and depression levels among healthcare workers.Methodsthis cross-sectional study performed via an online survey in april 2020. Participants answered questions about sociodemographic features, personal views and experiences about covid-19 and the hospital anxiety and depression scale (hads).ResultsA total of 300 healthcare workers,193 men and 107 women, participated in the survey. According to hads, 44.6% of participants scored above anxiety and 68.2% scored above depression cut-off points. Being younger than 50 and taking care of covid-19 patients in hospitals were independently associated with anxiety risk. Female gender, young age (less than 50) and having comorbidity were independent risk factors for depression.ConclusionHealthcare workers were at high risk of anxiety and depression during covid-19 outbreak. For this reason, psychological support should be given, especially to the group with high risk.  相似文献   
20.
Ermin is an actin‐binding protein found almost exclusively in the central nervous system (CNS) as a component of myelin sheaths. Although Ermin has been predicted to play a role in the formation and stability of myelin sheaths, this has not been directly examined in vivo. Here, we show that Ermin is essential for myelin sheath integrity and normal saltatory conduction. Loss of Ermin in mice caused de‐compacted and fragmented myelin sheaths and led to slower conduction along with progressive neurological deficits. RNA sequencing of the corpus callosum, the largest white matter structure in the CNS, pointed to inflammatory activation in aged Ermin‐deficient mice, which was corroborated by increased levels of microgliosis and astrogliosis. The inflammatory milieu and myelin abnormalities were further associated with increased susceptibility to immune‐mediated demyelination insult in Ermin knockout mice. Supporting a possible role of Ermin deficiency in inflammatory white matter disorders, a rare inactivating mutation in the ERMN gene was identified in multiple sclerosis patients. Our findings demonstrate a critical role for Ermin in maintaining myelin integrity. Given its near‐exclusive expression in myelinating oligodendrocytes, Ermin deficiency represents a compelling “inside‐out” model of inflammatory dysmyelination and may offer a new paradigm for the development of myelin stability‐targeted therapies.  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