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   629篇
  免费   46篇
  国内免费   13篇
耳鼻咽喉   2篇
儿科学   11篇
妇产科学   15篇
基础医学   53篇
口腔科学   5篇
临床医学   65篇
内科学   66篇
皮肤病学   2篇
神经病学   33篇
特种医学   65篇
外科学   93篇
综合类   96篇
预防医学   92篇
眼科学   11篇
药学   46篇
  2篇
中国医学   11篇
肿瘤学   20篇
  2024年   1篇
  2023年   50篇
  2022年   77篇
  2021年   57篇
  2020年   65篇
  2019年   32篇
  2018年   14篇
  2017年   24篇
  2016年   23篇
  2015年   21篇
  2014年   63篇
  2013年   41篇
  2012年   34篇
  2011年   34篇
  2010年   33篇
  2009年   29篇
  2008年   8篇
  2007年   9篇
  2006年   15篇
  2005年   7篇
  2004年   2篇
  2003年   5篇
  2002年   2篇
  2001年   1篇
  2000年   1篇
  1999年   4篇
  1998年   4篇
  1997年   6篇
  1996年   10篇
  1995年   3篇
  1994年   3篇
  1993年   1篇
  1992年   1篇
  1991年   3篇
  1990年   1篇
  1989年   1篇
  1988年   3篇
排序方式: 共有688条查询结果,搜索用时 31 毫秒
11.
12.
13.
Aiming to identify genomic variants associated with osteoporosis, we performed a genome-wide association meta-analysis of bone mineral density (BMD) at Ward's triangle of the hip in 7175 subjects from 6 samples. We performed in silico replications with femoral neck, trochanter, and inter-trochanter BMDs in 6912 subjects from the Framingham heart study (FHS), and with forearm, femoral neck and lumbar spine BMDs in 32965 subjects from the GEFOS summary results. Combining the evidence from all samples, we identified 2 novel loci for areal BMD: 1q43 (rs1414660, discovery p = 1.20 × 10 8, FHS p = 0.05 for trochanter BMD; rs9287237, discovery p = 3.55 × 10 7, FHS p = 9.20 × 10 3 for trochanter BMD, GEFOS p = 0.02 for forearm BMD, nearest gene FMN2) and 2q32.2 (rs56346965, discovery p = 7.48 × 10 7, FHS p = 0.10 for inter-trochanter BMD, GEFOS p = 0.02 for spine BMD, nearest gene NAB1). The two lead SNPs rs1414660 and rs56346965 are eQTL sites for the genes GREM2 and NAB1 respectively. Functional annotation of GREM2 and NAB1 illustrated their involvement in BMP signaling pathway and in bone development. We also replicated three previously reported loci: 5q14.3 (rs10037512, discovery p = 3.09 × 10 6, FHS p = 8.50 × 10 3, GEFOS p = 1.23 × 10 24 for femoral neck BMD, nearest gene MEF2C), 6q25.1 (rs3020340, discovery p = 1.64 × 10 6, GEFOS p = 1.69 × 10 3 for SPN-BMD, nearest gene ESR1) and 7q21.3 (rs13310130, discovery p = 8.79 × 10 7, GEFOS p = 2.61 × 10 7 for spine BMD, nearest gene SHFM1). Our findings provide additional insights that further enhance our understanding of bone development, osteoporosis, and fracture pathogenesis.  相似文献   
14.
15.
Newcastle disease virus (NDV) is the causative agent of Newcastle disease, which is characterized by inflammatory pathological changes in the organs of chickens. The inflammatory response to this disease has not been well characterized. Previous reports showed that the sphingosine-1-phosphate-1 receptor (S1PR1), a G protein-coupled receptor, is important to the activation of inflammatory responses. To understand better the viral pathogenesis and host inflammatory response, we analyzed S1PR1 expression during NDV infection. We observed a direct correlation between chicken embryo fibroblast (CEF) cellular inflammatory responses and S1PR1 expression. Virulent NDV-infected CEF cells also had elevated levels of pro-inflammatory cytokines (IL-1β, IL-6 and IL-18). When S1PR1 was inhibited by using the specific antagonist W146, pro-inflammatory cytokine production declined. Overexpression of S1PR1 resulted in increased virus-induced IL-1β production. S1PR1 expression levels did not impact significantly NDV replication. These findings highlight the important role of S1PR1 in inflammatory responses in NDV infection.  相似文献   
16.
Y-chromosomal SNP (Y-SNP), with its stable inheritance and low mutation, can provide Supplementary information in forensic investigation. While commonly used Y-chromosomal STR haplotypes show their limitations, typing of Y-SNP would become a powerful complement. In this study, a 16-plex Y-SNP typing system based on allele-specific PCR (AS-PCR) was developed to discriminate four dominant Y-chromosomal haplogroups (C-M130, D-CTS3946, N-M231, and O-M175) and 12 predominant sub-haplogroups of O-M175 (O1a-M119, O1a1a1a-CTS3265, O1b-M268, O1b1a2-Page59, O2-M122, O2a1-L127.1, O2a1b-F240, O2a1b1a1-CTS5820, O2a2-P201, O2a2b1a1-M177, O2a2b1a1a1a-Y17728, O2a2b1a2-F114). A series of experimental validation studies including sensitivity, species specificity, male-female mixture and inhibition were performed. The discrimination of the typing system was preliminarily proved with a haplogroup diversity of 0.9239. Altogether, the Y-SNP typing system based on AS-PCR should be capable of distinguishing China’s dominant Y-chromosomal haplogroups in a rapid and reliable manner, thus can be employed as a useful complement in forensic casework.  相似文献   
17.
Essential polyunsaturated fatty acids (PUFA) from the n-3 and n-6 series constitute the building blocks of brain cell membranes where they regulate most aspects of cell physiology. They are either biosynthesized from their dietary precursors or can be directly sourced from the diet. An overall increase in the dietary n-6/n-3 PUFA ratio, as observed in the Western diet, leads to reduced n-3 PUFAs in tissues that include the brain. Some clinical studies have shown a positive correlation between dietary n-3 PUFA intake and sleep quantity, yet evidence is still sparse. We here used a preclinical model of dietary n-3 PUFA deficiency to assess the precise relationship between dietary PUFA intake and sleep/wake activity. Using electroencephalography (EEG)/electromyography (EMG) recordings on n-3 PUFA deficient or sufficient mice, we showed that dietary PUFA deficiency affects the architecture of sleep-wake activity and the oscillatory activity of cortical neurons during sleep. In a second part of the study, and since PUFAs are a potent modulator of inflammation, we assessed the effect of dietary n-3 PUFA deficiency on the sleep response to an inflammatory stimulus known to modulate sleep/wake activity. We injected mice with the endotoxin lipopolysaccharide (LPS) and quantified the sleep response across the following 12 h. Our results revealed that n-3 PUFA deficiency affects the sleep response in basal condition and after a peripheral immune challenge. More studies are now required aimed at deciphering the molecular mechanisms underlying the intimate relationship between n-3 PUFAs and sleep/wake activity.  相似文献   
18.
Tang  Xin-Ying  Ru  Nan  Li  Qing  Qian  Yang-Yang  Sun  Hui  Zhu  Jia-Hui  He  Lin  Wang  Yuan-Chen  Hu  Liang-Hao  Li  Zhao-Shen  Zou  Wen-Bin  Liao  Zhuan 《Digestive diseases and sciences》2021,66(11):4008-4016
Digestive Diseases and Sciences - The high incidence of osteopathy among patients with chronic pancreatitis (CP) has garnered increased attention over recent years. The aims of this study were to...  相似文献   
19.
幼年特发性关节炎(JIA)临床上常见亚型包括全身型JIA、少关节型/多关节型JIA和幼年脊柱关节炎。本病无特异性诊断指标, 需与感染性疾病和恶性病相鉴别。全身型JIA起病多急骤, 病情进展快, 易合并巨噬细胞活化综合征而危及生命。儿童风湿科医生对JIA的诊断及治疗经验仍不足, 规范化诊疗水平有待进一步提高。中华医学会风湿病学分会组织有关专家, 在借鉴国内外诊疗规范和分类标准的基础上, 制定本规范, 旨在规范JIA各亚型及全身型JIA合并巨噬细胞活化综合征的诊断和治疗方案, 以降低致死率和严重并发症的发生率, 从而改善患儿预后。  相似文献   
20.
The effect of consumers’ compliance with nutritional recommendations is uncertain because of potentially complex substitutions. To lift this uncertainty, we adapt a model of consumer behaviour under rationing to the case of linear nutritional constraints. Dietary adjustments are derived from information on consumer preferences, consumption levels, and nutritional contents of foods. A calibration exercise simulates, for different income groups, how the French diet would respond to various nutrition recommendations, and those behavioural adjustments are translated into health outcomes through the DIETRON epidemiological model. This allows for the ex-ante comparison of the efficiency, equity and health effects of ten nutritional recommendations. Although most recommendations impose significant taste costs on consumers, they are highly cost-effective, with the recommendations targeting salt, saturated fat, and fruits and vegetables (F&V) ranking highest in terms of efficiency. Most recommendations are also economically progressive, with the exception of that targeting F&V.  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