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   32203篇
  免费   1307篇
  国内免费   2143篇
耳鼻咽喉   296篇
儿科学   589篇
妇产科学   707篇
基础医学   4633篇
口腔科学   365篇
临床医学   2573篇
内科学   6512篇
皮肤病学   383篇
神经病学   2047篇
特种医学   732篇
外国民族医学   4篇
外科学   3658篇
综合类   2948篇
现状与发展   24篇
一般理论   3篇
预防医学   1658篇
眼科学   1164篇
药学   3235篇
  2篇
中国医学   733篇
肿瘤学   3387篇
  2024年   51篇
  2023年   237篇
  2022年   167篇
  2021年   125篇
  2020年   104篇
  2019年   61篇
  2018年   55篇
  2017年   45篇
  2016年   60篇
  2015年   79篇
  2014年   240篇
  2013年   108篇
  2012年   4990篇
  2011年   5503篇
  2010年   957篇
  2009年   431篇
  2008年   3287篇
  2007年   3381篇
  2006年   3132篇
  2005年   2730篇
  2004年   2422篇
  2003年   2095篇
  2002年   1684篇
  2001年   1042篇
  2000年   1324篇
  1999年   590篇
  1998年   208篇
  1997年   96篇
  1996年   37篇
  1995年   30篇
  1994年   24篇
  1993年   26篇
  1992年   21篇
  1989年   23篇
  1988年   16篇
  1987年   26篇
  1986年   14篇
  1985年   23篇
  1984年   25篇
  1983年   17篇
  1982年   13篇
  1981年   19篇
  1980年   9篇
  1979年   7篇
  1965年   13篇
  1964年   10篇
  1963年   13篇
  1962年   13篇
  1960年   7篇
  1941年   8篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
Age-related neurodegenerative disorders such as Alzheimer’s disease(AD)have become a critical public health issue due to the significantly extended human lifespan,leading to considerable economic and social burdens.Traditional therapies for AD such as medicine and surgery remain ineffective,impractical,and expensive.Many studies have shown that a variety of bioactive substances released by physical exercise(called“exerkines”)help to maintain and improve the normal functions of the brain in terms of cognition,emotion,and psychomotor coordination.Increasing evidence suggests that exerkines may exert beneficial effects in AD as well.This review summarizes the neuroprotective effects of exerkines in AD,focusing on the underlying molecular mechanism and the dynamic expression of exerkines after physical exercise.The findings described in this review will help direct research into novel targets for the treatment of AD and develop customized exercise therapy for individuals of different ages,genders,and health conditions.  相似文献   
2.
Abnormal accumulation ofα-synuclein contributes to the formation of Lewy bodies in the substantia nigra,which is considered the typical pathological hallmark of Parkinson's disease.Recent research indicates that angiotensin-(1-7)plays a crucial role in several neurodegenerative disorders,including Parkinson's disease,but the underlying mechanisms remain elusive.In this study,we used intraperitoneal administration of rotenone to male Sprague-Dawley rats for 4 weeks to establish a Parkinson's disease model.We investigated whether angiotensin-(1-7)is neuroprotective in this model by continuous administration of angiotensin-(1-7)into the right substantia nigra for 4 weeks.We found that angiotensin-(1-7)infusion relieved characteristic parkinsonian behaviors and reducedα-synuclein aggregation in the substantia nigra.Primary dopaminergic neurons were extracted from newborn Sprague-Dawley rat substantia nigras and treated with rotenone,angiotensin-(1-7),and/or the Mas receptor blocker A-779 for 24 hours.After binding to the Mas receptor,angiotensin-(1-7)attenuated apoptosis andα-synuclein aggregation in rotenone-treated cells.Primary dopaminergic neurons were also treated with angiotensin-(1-7)and/or the autophagy inhibitor 3-methyladenine for 24 hours.Angiotensin-(1-7)increasedα-synuclein removal and increased the autophagy of rotenone-treated cells.We conclude that angiotensin-(1-7)reducesα-synuclein aggregation by alleviating autophagy dysfunction in Parkinson's disease.Therefore,the angiotensin-(1-7)/Mas receptor axis plays an important role in the pathogenesis of Parkinson's disease and angiotensin-(1-7)has potential therapeutic value for Parkinson's disease.All experiments were approved by the Biological Research Ethics Committee of Nanjing First Hospital(approval No.DWSY-2000932)in January 2020.  相似文献   
3.
重症胰腺炎(SAP)是临床上常见的急腹症之一,它不仅仅是胰腺的局部炎症改变,而且常常涉及多个脏器损伤,甚至造成多器官功能衰竭.目前临床上治疗主要以抑制胰酶、维持水电酸碱平衡和预防并发症,甚至手术治疗等综合性措施为主.但疗效并非完全满意.为此,作者开展了对SAP患者的连续性肾脏替代治疗(CRRT),以探讨CRRT对患者机体组织器官的保护作用.  相似文献   
4.
我们现在要尽量使这些治疗方法进入临床试验证明他们的可行性现在脊髓损伤的临床试验基金很有限,所以只有很少的这些治疗方法真正用于病人主要的制药厂开始对脊髓损伤治疗产生兴趣,我们现在还有很多工作要做,但是前景方向十分清楚,我们需要努力快速的工作。  相似文献   
5.
BACKGROUND: Hepatocellular carcinoma (HCC) is one of the most prevalent fatal cancers in the world. Despite advances in early diagnosis and improvements in surgical techniques, the survival of patients with HCC even after resection is poor because of the high incidence of recurrences. Therefore, the identification of prognostic factors may be helpful in the development of new treatment protocols. AIMS: To investigate HER-2/neu status in HCC by immunohistochemistry (IHC) and fluorescence in situ hybridisation (FISH), and to explore the possibility of using trastuzumab in the treatment of HCC. METH ODS: Eight hundred and sixty eight surgical samples from patients with primary HCC were examined for their HER-2/neu status. IHC for HER-2/neu was performed with the HercepTest kit; FISH analysis was performed with the PathVysion HER-2 DNA probe kit. The correlations between HER-2/neu overexpression and clinicopathological characteristics were analysed statistically. RESULTS: HER-2/neu overexpression was detected in 21 (2.42%) of the 868 primary HCCs. Only one specimen showed HER-2/neu gene amplification by FISH. No significant associations were found between HER-2/neu overexpression and the clinicopathological parameters. CONCLUSIONS: There is a low frequency of HER-2/neu overexpression/amplification in HCC. There appears to be no role for HER-2/neu as a prognostic marker and no benefit of anti-HER-2/neu trastuzumab treatment in patients with HCC.  相似文献   
6.
Wehavereported previouslythatligustrazinecouldpromotehematopoiesisthroughimprovingbonemarrowmicroenvironmentandenhancingadhesive  相似文献   
7.
目的探讨胰头癌侵犯门静脉和/或肠系膜上静脉(PV/SMV)时的根治切除的可行性。方法回顾分析包括受侵PV/SMV在内的扩大胰头十二指肠切除术16例的临床资料。16例均行胰头十二指肠切除术,其中9例行血管壁部分切除,5例行血管节段性切除及对端吻合,2例行受侵血管切除+自体静脉移植。结果全组患者术后均未发生血管栓塞、肠坏死、肝衰竭等并发症。除1例并发多器官衰竭于术后2d死亡外,均康复出院。15例均随访。存活超过3年者3例,超过5年者1例,存活3~26个月4例。结论对单纯侵犯PV/SMV的胰头癌施行联合PV/SMV住内的胰头癌扩大根治术是可行的。  相似文献   
8.
9.
Purpose:To report a rare sign, paracentral corneal dellen that developed in a middleaged female patient with Graves ophthalmopathy.Methods:A paracentral corneal dellen developed in the left eye in a 42-year-old woman who was diagnosed as Graves ophthalmopathy. The patient had remarkable upper eyelid retraction, upper eyelid lag and upward motility restriction. The Graves ophthalmopathy was classified as Grade Ⅳ according to NOSPECS classification.Results:Local artificial tear film and 0.3% Tobramycin eye drops were administered to both eyes.Twenty-four hours later, the left corneal dellen disappeared.Conclusions:Graves ophthalmopathy can lead to paracentral corneal dellen because of severe upper eyelid retraction and upward motility restriction of the eye in spite of the lack of lagophthalmos. Artificial tear drop and antibiotic eye drop therapy helped even though the patient did not have corneal exposure. Eye Science 2003;19:174-175.  相似文献   
10.
本文研究了在使用菌苗预防前后的流行性脑脊髓膜炎流行强度的变迁,年龄、地区及季节分布特点,人群的易感性及带菌率之间的关系,并讨论了今后的预防措施。  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