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   579篇
  免费   45篇
耳鼻咽喉   8篇
儿科学   35篇
妇产科学   14篇
基础医学   89篇
口腔科学   6篇
临床医学   40篇
内科学   96篇
皮肤病学   50篇
神经病学   14篇
特种医学   5篇
外科学   42篇
综合类   11篇
一般理论   2篇
预防医学   39篇
眼科学   3篇
药学   39篇
中国医学   2篇
肿瘤学   129篇
  2023年   3篇
  2022年   16篇
  2021年   23篇
  2020年   16篇
  2019年   28篇
  2018年   42篇
  2017年   26篇
  2016年   19篇
  2015年   15篇
  2014年   22篇
  2013年   27篇
  2012年   49篇
  2011年   47篇
  2010年   36篇
  2009年   16篇
  2008年   34篇
  2007年   30篇
  2006年   35篇
  2005年   30篇
  2004年   21篇
  2003年   24篇
  2002年   16篇
  2001年   7篇
  2000年   1篇
  1999年   2篇
  1998年   2篇
  1997年   1篇
  1996年   2篇
  1994年   2篇
  1993年   2篇
  1992年   3篇
  1990年   5篇
  1989年   4篇
  1988年   6篇
  1987年   3篇
  1986年   4篇
  1985年   3篇
  1982年   1篇
  1978年   1篇
排序方式: 共有624条查询结果,搜索用时 31 毫秒
81.

Objectives:

The present study was undertaken to evaluate the radioprotective and cytoprotective potential of cordifolioside-A, a primary active constituent of n-butanol fraction of Tinospora Cordifolia (NBTC) against 4 Gy-γ radiation in mice and cyclophosphamide induced genotoxicity.

Materials and Methods:

Presence of cordifolioside-A in NBTC stem ethanolic extract was confirmed by high performance thin layer chromatography (HPTLC) analysis. Radioprotective activity was evaluated at 80 and 120 mg/kg, intraperitoneal (i.p.) dose of NBTC administered 15 days prior to whole body radiation exposure by observing survival rate, change in body weight, hematology, spleen colony forming unit (CFU), and micronucleus (MN) expression. Cytoprotective activity of NBTC was evaluated at 5, 10, and 15 mg/ml concentrations on Allium cepa root meristem growth against cyclophosphamide.

Results:

HPTLC analysis of standard cordifolioside A, and NBTC confirmed the presence of cordifolioside-A in NBTC with the retention factor value of 0.86. Administration of NBTC (120 mg/kg, i.p.) produced significant protection against radiation in terms of increased survival rate, body weight retention, hematological parameters, spleen CFU assay (P < 0.01), and decreased MN expression (P < 0.01). Cytoprotectivity was observed maximally at 10 mg/ml NBTC concentration with significant increase in root growth (P < 0.01), non-toxic mitotic index (MI) (65.9%) and lesser chromosomal aberrations (15.4%). NBTC at 10 mg/ml concentration showed very few C-anaphase compared to aberrations like fragmentation, C-anaphase, multipolarity and sticky chromosome in cyclophosphamide alone.

Conclusion:

The results suggest that enriched NBTC containing cordifolioside-A has a potential in vivo radioprotective effect as well as in vitro cytoprotective activity.KEY WORDS: Cordifolioside-A, cytoprotective activity, radioprotective activity, Tinospora cordifolia  相似文献   
82.
Though tuberculosis (TB) primarily affects lungs, extra pulmonary tuberculosis (EPTB) is also common, especially in high disease load areas and mainly manifests in ENT region. To study the different manifestations of tuberculosis in ENT region in terms of presentation, disease process, treatment and outcome. Records of patients diagnosed and treated for TB in the ENT region at our institute’s DOTS centre for a two and half year period were analysed for presenting complaints, examination findings, diagnostic features, treatment modes and outcome. Out of 3750 cases diagnosed as TB, 230 had EPTB. 211 cases had ENT manifestations. Majority of the cases were male and in the fourth decade of life. Commonest manifestation was cervical lymphadenopathy with 201 cases. Fine needle aspiration cytology was mostly diagnostic and category I anti TB treatment (AKT) achieved cure. The six cases of TB otitis media presented with ear discharge, sometimes bloody and had varied tympanic membrane findings and facial palsy in two cases with different types and degrees of hearing loss. Diagnosis was confirmed by histology of tissue removed during surgery. Patients completed category I AKT. Hearing and facial palsy did not improve. There were three cases of TB laryngitis and one of nasal TB both of which were confirmed by tissue diagnosis and responded well to AKT. Most of the results in the present study conform to findings of other studies. High degree of suspicion is necessary to reach diagnosis. Category I AKT is effective. Some cases may require surgery.  相似文献   
83.
The mechanisms of ethanol addiction are not completely understood. The mesolimbic dopaminergic system is involved in many drug-related behaviors, including ethanol self-administration. The dopaminergic neurons in this system originate in the ventral tegmental area (VTA) and are under the control of GABAergic transmission. Our previous in vitro electrophysiological data indicate that glycine receptors (GlyRs) exist on the GABAergic terminals, which make synapses on VTA dopaminergic neurons, and activation of these GlyRs reduces GABAergic transmission and increases the activity of VTA dopaminergic neurons. In the current study, we tested the hypothesis that the activation of the presynaptic GlyRs in the VTA might interfere with ethanol self-administration. Glycine and strychnine, the selective antagonist of GlyRs, were injected, either alone or in combination, into the VTA of rats. Ethanol self-administration by rats was evaluated by using three different drinking models: intermittent access, continuous access, and operant self-administration. We found that the infusion of glycine into the VTA selectively reduced the intake of ethanol but not sucrose or water in rats chronically exposed to ethanol under the intermittent-access and continuous-access procedures and decreased lever-press responding for ethanol under an operant self-administration procedure. The effects of glycine probably were mediated by strychnine-sensitive GlyRs, because the coinjection of glycine and strychnine reduced neither ethanol intake in the home cages nor lever-press responding for ethanol in the operant chambers. Thus, GlyRs in the VTA may play a critical role in ethanol self-administration in animals chronically exposed to ethanol. Therefore, drugs targeting GlyRs may be beneficial for alcoholics.  相似文献   
84.
Gap junctional coupling is important for functional integration of transplanted cells with host myocardium. However, the role of gap junctions in cardiomyogenic differentiation of transplanted cells has not been directly investigated. The objective of this work is to study the role of connexin43 (Cx43) in cardiomyogenic differentiation of human mesenchymal stem cells (hMSCs). Knockdown of Cx43 gene expression (Cx43↓) was established in naturally Cx43-rich fetal amniotic membrane (AM) hMSCs, while Cx43 was overexpressed (Cx43↑) in inherently Cx43-poor adult adipose tissue (AT) hMSCs. The hMSCs were exposed to cardiomyogenic stimuli by coincubation with neonatal rat ventricular cardiomyocytes (nrCMCs) for 10 days. Differentiation was assessed by immunostaining and whole-cell current clamping. To establish whether the effects of Cx43 knockdown could be rescued, Cx45 was overexpressed in Cx43↓ fetal AM hMSCs. Ten days after coincubation, not a single Cx43↓ fetal AM hMSC, control adult AT MSC, or Cx43↑ adult AT mesenchymal stem cell (MSC) expressed α-actinin, while control fetal AM hMSCs did (2.2% ± 0.4%, n = 5,000). Moreover, functional cardiomyogenic differentiation, based on action potential recordings, occurred only in control fetal AM hMSCs. Of interest, Cx45 overexpression in Cx43↓ fetal AM hMSCs restored their ability to undergo cardiomyogenesis (1.6% ± 0.4%, n = 2,500) in coculture with nrCMCs. Gap junctional coupling is required for differentiation of fetal AM hMSCs into functional CMCs after coincubation with nrCMCs. Heterocellular gap junctional coupling thus plays an important role in the transfer of cardiomyogenic signals from nrCMCs to fetal hMSCs but is not sufficient to induce cardiomyogenic differentiation in adult AT hMSCs.  相似文献   
85.
86.
87.
88.
Chronic hyperglycaemia is a peculiar feature of diabetes mellitus (DM). Sequential metabolic abnormalities accompanying glucotoxicity are some of its implications. Glucotoxicity most likely corresponds to the vascular intricacy and metabolic alterations, such as increased oxidation of free fatty acids and reduced glucose oxidation. More than half of those with diabetes also develop cardiac abnormalities due to unknown causes, posing a major threat to the currently available marketed preparations which are being used for treating these cardiac complications. Even though impairment in cardiac functioning is the principal cause of death in individuals with type 2 diabetes (T2D), reducing plasma glucose levels has little effect on cardiovascular disease (CVD) risk. In vitro and in vivo studies have demonstrated that inhibitors of sodium glucose transporter (SGLT) represent a putative therapeutic intervention for these pathological conditions. Several clinical trials have reported the efficacy of SGLT inhibitors as a novel and potent antidiabetic agent which along with its antihyperglycaemic activity possesses the potential of effectively treating its associated cardiac abnormalities. Thus, hereby, the present review highlights the role of SGLT inhibitors as a successful drug candidate for correcting the shifts in deregulation of cardiac energy substrate metabolism together with its role in treating diabetes-related cardiac perturbations.  相似文献   
89.
Neutrophilic panniculitis (NP) with myelodysplasia has been described in adults but not in children. We report a case of NP associated with myelodysplasia in a child with MYSM1 deficiency, a newly described syndrome with primary immunodeficiency (PI), bone marrow failure, and developmental aberrations.  相似文献   
90.
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