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   4738篇
  免费   582篇
  国内免费   175篇
耳鼻咽喉   26篇
儿科学   138篇
妇产科学   39篇
基础医学   567篇
口腔科学   187篇
临床医学   228篇
内科学   744篇
皮肤病学   150篇
神经病学   184篇
特种医学   32篇
外国民族医学   1篇
外科学   206篇
综合类   1095篇
现状与发展   3篇
预防医学   135篇
眼科学   245篇
药学   163篇
  3篇
中国医学   1225篇
肿瘤学   124篇
  2024年   33篇
  2023年   95篇
  2022年   190篇
  2021年   265篇
  2020年   267篇
  2019年   192篇
  2018年   122篇
  2017年   198篇
  2016年   205篇
  2015年   173篇
  2014年   324篇
  2013年   382篇
  2012年   327篇
  2011年   335篇
  2010年   321篇
  2009年   221篇
  2008年   218篇
  2007年   207篇
  2006年   211篇
  2005年   187篇
  2004年   150篇
  2003年   123篇
  2002年   113篇
  2001年   89篇
  2000年   63篇
  1999年   53篇
  1998年   60篇
  1997年   37篇
  1996年   45篇
  1995年   40篇
  1994年   30篇
  1993年   34篇
  1992年   25篇
  1991年   32篇
  1990年   20篇
  1989年   22篇
  1988年   8篇
  1987年   15篇
  1986年   11篇
  1985年   9篇
  1984年   3篇
  1983年   7篇
  1982年   7篇
  1981年   5篇
  1980年   4篇
  1979年   2篇
  1978年   3篇
  1976年   5篇
  1975年   2篇
  1967年   2篇
排序方式: 共有5495条查询结果,搜索用时 15 毫秒
1.
肠易激综合征(IBS)是一种常见的功能性疾病,中医病名为"肠郁"。郭朋教授根据IBS生理、病理特点,以疏肝健脾法调和肝脾,辨证施治,取得良好疗效。文章从病因病机、辨证论治及经典案例介绍等几个方面对郭教授治疗IBS经验进行系统阐述,以期为中医药治疗IBS提供理论和方法学参考。  相似文献   
2.
室管膜瘤是一种原发于神经上皮的中枢神经系统肿瘤,病变累及脑和脊髓,多发于儿童。基因分型的新分类方法,为室管膜瘤的治疗和预后评估提供了更为可靠的依据。室管膜瘤对辅助治疗的敏感性低是造成患儿预后较差的重要原因之一。该文对近年来儿童室管膜瘤的分型、诊断、治疗策略等进行综述。  相似文献   
3.
4.
Permissive herpes simplex virus (HSV) infection in tissue culture results in host cell destruction. Latent HSV infection in vivo occurs in neurons of peripheral sensory ganglia (PSG) and it therefore can not take place in neurons in which the virus has completed a lytic replication cycle similar to that present in vitro. Our hypothesis, based on experimental data and observations in humans, suggests that establishment of latent infection and reactivation of HSV-1 does not involve neuronal cell loss. Latency is established in neurons in which the virus does not replicate and is determined, in part, by the tissue levels of a herpes transactivating protein (Vmw65) that is a component of the viral tegument. We also suggest that reactivation of latent infection does not involve destruction of neurons and is due to replication of virus at the peripheral mucocutaneous tissues to where virus or viral DNA have been transported from the nervous tissue. Alternatively, reactivation is initiated in the PSG using a replication cycle which does not involve irreversible damage to neurons. This model explains the lack of damage to neurons which continue to serve as permanent reservoirs of latent virus for the entire life of the host.  相似文献   
5.
Background  Psoriasis is a chronic disease characterized by abnormal epidermal proliferation, inflammation and angiogenesis. It has been reported that vascular endothelial growth factor (VEGF) is overexpressed in lesional psoriatic skin and its serum levels are significantly elevated in patients with moderate to severe disease.
Objective  This study aims to evaluate the possible role of VEGF in the pathogenesis of psoriasis, and its significance as an indicator of disease severity and control.
Methods  Thirty patients with moderate to severe psoriasis and 10 healthy controls were subjected to baseline evaluation of VEGF. Patients were divided into three groups according to the received treatment: psoralen plus ultraviolet A (PUVA) thrice weekly (group 1), acitretin 50 mg daily (group 2), and combined PUVA twice weekly and acitretin 25 mg daily (group 3).Treatment continued for 16 weeks or up to clinical cure. Every patient was subjected to severity evaluation by Psoriasis Area and Severity Index (PASI) and measurement of serum VEGF before and after treatment.
Results  Mean serum levels of VEGF were significantly elevated in patients (327 ± 66.2 pg/mL) than control subjects (178 ± 83.4 pg/mL). A highly significant correlation was found between VEGF and PASI score, but not with other variables. The best clinical response, the least side-effects and the highest reduction of VEGF serum levels were achieved by the combined therapy.
Conclusion  The present study supported the proposed role of VEGF in the pathogenesis of psoriasis, and suggested that it could serve as a good indicator of disease severity and control.  相似文献   
6.
Retinopathy of prematurity (ROP) is a vaso-proliferative disease with infiltration of the vitreous gel. Contraction of the infiltrate results in traction detachment with typical peripheral trough formation. Cryotherapy inhibits proliferation in the active stages of the disease (Stage 3, 'plus'). With development of traction detachment involving the macula (Stage 48) encircling buckling procedures should first be tried. Closed vitrectomy is considered when high retinal detachment and opacification by vitreous strands occur. The surgical technique is described. Anatomical (64%) and functional (43%) successes are reasonably high for Stage 4 cases, but disappointing (anatomical 40%, functional 16%) for Stage 5 ROP. Open funnels of detached retina fare better than closed ones. It is probably best to perform surgery not before the cicatricial stage, i.e. six months after birth.  相似文献   
7.
本文报告动脉粥样硬化(AS)形成和消退研究的部分工作。在复制AS形成和消退模型的基础上,研究了AS形成和消退中的内皮细胞、平滑肌细胞和单核细胞的改变。  相似文献   
8.
Abstract Human immunodeficiency virus (HIV)-l neuropathogenesis can be divided into three important components: (i) virus entry into the nervous system; (ii) the role of viral proteins and/or cellular products in neural tissue damage; and (iii) the mechanisms of neuronal injury/death. Both blood derived macrophages or trafficking HIV-1 infected T-lymphocytes have been implicated in viral entry to the central nervous system (CNS). The major cell type harboring productive HIV-1 infection in the nervous system is the perivascular macrophage/ microglia. The HIV-1 infection of brain astrocytes, restricted to the expression of regulatory gene products, may cause astrocyte dysfunction and contribute to neuronal injury or to disruption of the blood-brain barrier (BBB). Studies of cerebrospinal fluid and postmortem tissues reveal chronic inflammation/immune activation in the nervous system during the later stages of HIV-1 infection associated with disruption of BBB integrity. Blood-brain barrier damage may underlie the white matter pallor described in HIV-1 infection and could result in further entry into the CNS of toxic viral or cellular products, or additional HIV-1 infected cells. The HIV infected and activated macrophages/microglia produce excessive amounts of pro-inflammatory cytokines, including tumor necrosis factor alpha, and platelet activating factor. These products are directly toxic to human neurons in vitro. The HIV-1 envelope glycoprotein, gp 120 may stimulate the release of toxic factors from brain macrophages. Blocking N-methyl-D-aspartate (NMDA; or AMPA) glutamate receptors can antagonize candidate toxins of both viral and cellular origin. It has been postulated that (weak) excitotoxicity leads to oxidative stress in neurons and ultimately to apoptosis. Neuronal apoptosis occurs in the brains of both children and adults with HIV-1 infection. This understanding of HIV neuropathogenesis implies that therapeutic strategies should include: (i) anti-retroviral medications to decrease systemic and CNS virus load, and possibly to prevent perinatal transmission of HIV; (ii) anti-inflammatory compounds to decrease the chronic immune activation in microglia and allow the restoration of BBB integrity; and (iii) neuroprotective compounds to reduce neuronal injury and apoptotic death.  相似文献   
9.
Eighteen trabeculectomy specimens of congenital glaucoma were examined by light and transimssion electron microscopy. The results showed that the primary anomalies in congenital glaucoma included the developmental defects of trabecular meshwork, excessive collagen fibrils in the trabecular matrix, shifting forward of ciliary muscle fibres and persistent mesenchymal tissues in the anterior-chamber angle. The authors also pointed out the importance of the secondary lesions of the trabecular meshwork in the pathogenesis of congenital glaucoma. Eye Science 1994; 10:50-56.  相似文献   
10.
跟痛症的发病机制与临床诊断方法   总被引:10,自引:0,他引:10  
跟痛症是一种临床常见多发疾病,以中老年患者居多,对于其发病机制与临床诊断鉴别方法不同的学者有着不同的见解。结合周福贻教授的理论与临床经验从发病机制、诊断、鉴别诊断及辅助检查等方面对跟痛症加以阐述。  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