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   366篇
  免费   32篇
  国内免费   9篇
耳鼻咽喉   1篇
儿科学   9篇
妇产科学   5篇
基础医学   71篇
口腔科学   6篇
临床医学   40篇
内科学   115篇
皮肤病学   7篇
神经病学   41篇
特种医学   9篇
外科学   30篇
综合类   1篇
预防医学   27篇
眼科学   4篇
药学   13篇
肿瘤学   28篇
  2024年   2篇
  2023年   3篇
  2022年   5篇
  2021年   20篇
  2020年   14篇
  2019年   9篇
  2018年   14篇
  2017年   16篇
  2016年   12篇
  2015年   12篇
  2014年   18篇
  2013年   22篇
  2012年   32篇
  2011年   19篇
  2010年   15篇
  2009年   14篇
  2008年   17篇
  2007年   18篇
  2006年   21篇
  2005年   17篇
  2004年   16篇
  2003年   11篇
  2002年   7篇
  2000年   1篇
  1999年   1篇
  1998年   2篇
  1997年   3篇
  1996年   2篇
  1995年   1篇
  1994年   2篇
  1993年   2篇
  1992年   5篇
  1991年   1篇
  1990年   8篇
  1989年   4篇
  1988年   2篇
  1987年   3篇
  1986年   5篇
  1985年   6篇
  1984年   4篇
  1983年   4篇
  1982年   2篇
  1980年   1篇
  1979年   2篇
  1976年   1篇
  1975年   2篇
  1973年   4篇
  1972年   1篇
  1971年   2篇
  1970年   1篇
排序方式: 共有407条查询结果,搜索用时 15 毫秒
101.
Objectives:To compare the prevalence of clinical complications between two different telescopic Herbst systems: the conventional telescopic system, with traditional rod and tube (RMS), and the Manni telescopic Herbst appliance (MTH).Materials and Methods:Ninety subjects treated with RMS were compared to 89 patients treated with MTH. All of the complications that occurred were reported, and percentages of prevalence were calculated.Results:MTH showed a significantly lower percentage of reversible complications (that did not require appliance removal) when compared to the reversible complications during RMS treatment (20.2% vs 51.1%). No statistically significant differences were found between RMS and MTH regarding irreversible complications (that required appliance removal and full re-make). All of the irreversible complications occurred after reversible complications in the RMS group, while most of the irreversible complications in the MTH group occurred without any previous reversible complication.Conclusions:MTH exhibited a smaller number of clinical complications during Class II skeletal malocclusion therapy.  相似文献   
102.
In this study we report on the establishment and characterization of two novel lymphoma cell lines (CRO-AP/3 and CRO-AP/5) which carry infection by human herpesvirus type-8 (HHV-8) and have derived from AIDS-related primary effusion lymphoma (PEL). These two cell lines are representative of different virologic subtypes of PEL, i.e. HHV-8+/EBV? PEL in the case of CRO-AP/3 and HHV-8+/EBV+ PEL in the case of CRO-AP/5. Consistent with the diagnosis of PEL, both CRO-AP/3 and CRO-AP/5 expressed indeterminate (i.e. non-B, non-T) phenotypes although immunogenotypic studies documented their B-cell origin. Both cell lines are devoid of genetic lesions of c-MYC, BCL-2 and p53 as well as gross rearrangements of BCL-6. Detailed histogenetic characterization of these novel PEL cell lines suggests that PEL may derive from a post-germinal centre B cell which has undergone pre-terminal differentiation. The CRO-AP/3 and CRO-AP/5 cell lines may provide a valuable model for clarifying the pathogenesis of PEL. In particular, these cell lines may help understand the relative contribution of HHV-8 and EBV to PEL growth and development and may facilitate the identification of recurrent cytogenetic abnormalities highlighting putative novel cancer related loci relevant to PEL.  相似文献   
103.
104.
105.
106.

Purpose  

To identify a cohort of subjects without treatment for any cardiovascular risk and analyze the potential causative role of treatment for depression on the development of major cardiovascular outcomes during 2 years of follow-up.  相似文献   
107.
Objective: The aim of this review is to evaluate and summarize the available scientific information on the commonest plant extracts marketed in Western countries. In view of the intense, ongoing search for new plant extracts with powerful anti‐inflammatory activity, we paid particular attention to this topic. The aim is to provide broad coverage of as many potentially useful plants as possible and then to focus on those with the greatest therapeutic potential. Methods: Our bibliographic sources were the SciFinder databases: CAPLUS, MEDLINE, REGISTRY, CASREACT, CHEMLIST, CHEMCATS (update to October 2007). In order to assess the value of clinical trials, we focused a specific search on clinical investigations concerning nine plants with the most trial data, viz., Althaea officinalis, Calendula officinalis, Centella asiatica, Echinacea purpurea, Passiflora incarnata, Punica granatum, Vaccinium macrocarpon, Vaccinium myrtillus, Valeriana officinalis. This was carried out in several databases (update to June 2008): ISI Web of KnowledgeSM (ISI WoK), SciFinder (CAPLUS, MEDLINE, REGISTRY, CASREACT, CHEMLIST, CHEMCATS) and PubMed (indexed for MEDLINE). Results: Our survey covers roughly a 1000 plants, although clinical trials have been published only for 156 plants supporting specific pharmacological activities and therapeutic applications. However, for about half of the plants, in vitro and in vivo studies provide some support for therapeutic use. For one‐fifth of the plants included in our search, only phytochemical studies were found. Their properties and indications were often attributed to the presence of certain compounds, but no evidence concerning the activities of the whole extracts was presented. We found that for about 12% of the plants, currently available on the Western market, no substantial studies on their properties had been published, while there was strong evidence that 1 in 200 were toxic or allergenic, so that their use ought to be discouraged or forbidden. Nine plants had considerable evidence of therapeutic effect, viz., A. officinalis, Calendula officinalis, Centella asiatica, E. purpurea, Passiflora incarnata, Punica granatum, Vaccinium macrocarpon, Vaccinium myrtillus, Valeriana officinalis. Conclusion: The present review provides a baseline on the level of evidence available on many herbal preparations and should be of help to those intending to research further on these topics.  相似文献   
108.
109.
Polycystic ovary syndrome (PCOS) is the most common endocrine disorder in young reproductive-aged women. PCOS is often associated with obesity and impairs reproductive health. Even though several theories have been proposed to explain the pathogenic mechanism of PCOS, the role of insulin resistance (IR) as a key etiological component, independently of (but amplified by) obesity, is well recognized. The consequent hyperinsulinemia activates excessive ovarian androgen production, leading to PCOS. Additionally, the state of chronic inflammation related to obesity impacts ovarian physiology due to insulin sensitivity impairment. The first-line treatment for adolescents with obesity and PCOS includes lifestyle changes; personalized dietary interventions; and, when needed, weight loss. Medical nutrition therapy (MNT) and the use of specific food supplements in these patients aim at improving symptoms and signs, including insulin resistance and metabolic and reproductive functions. The purpose of this narrative review is to present and discuss PCOS in adolescents with obesity, its relationship with IR and the role of MNT and food supplements in treatment. Appropriate early dietary intervention for the management of adolescents with obesity and PCOS should be considered as the recommended approach to restore ovulation and to protect fertility.  相似文献   
110.
Increased intramyocellular lipid concentrations are thought to play a role in insulin resistance, but the precise nature of the lipid species that produce insulin resistance in human muscle are unknown. Ceramides, either generated via activation of sphingomyelinase or produced by de novo synthesis, induce insulin resistance in cultured cells by inhibitory effects on insulin signaling. The present study was undertaken to determine whether ceramides or other sphingolipids are increased in muscle from obese insulin-resistant subjects and to assess whether ceramide plays a role in the insulin resistance of Akt in human muscle. Lean insulin-sensitive and obese insulin-resistant subjects (n = 10 each) received euglycemic-hyperinsulinemic clamps with muscle biopsies basally and after 30, 45, or 60 min of insulin infusion. The rate of glucose infusion required to maintain euglycemia (reflecting glucose uptake) was reduced by >50%, as expected, in the obese subjects at each time point (P < 0.01). Under basal conditions, total muscle ceramide content was increased nearly twofold in the obese subjects (46 +/- 9 vs. 25 +/- 2 pmol/2 mg muscle, P < 0.05). All species of ceramides were increased similarly in the obese subjects; in contrast, no other sphingolipid was increased. Stimulation of Akt phosphorylation by insulin in the obese subjects was significantly reduced after 30 min (0.96 +/- 0.11 vs. 1.84 +/- 0.38 arbitrary units) or 45-60 min (0.68 +/- 0.17 vs. 1.52 +/- 0.26) of insulin infusion (P < 0.05 for both). Muscle ceramide content was significantly correlated with the plasma free fatty acid concentration (r = 0.51, P < 0.05). We conclude that obesity is associated with increased intramyocellular ceramide content. This twofold increase in ceramide may be involved in the decrease in Akt phosphorylation observed after insulin infusion and could theoretically play a role in the reduced ability of insulin to stimulate glucose uptake in skeletal muscle from obese subjects.  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