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   131篇
  免费   8篇
  国内免费   6篇
儿科学   4篇
妇产科学   2篇
基础医学   21篇
口腔科学   3篇
临床医学   14篇
内科学   26篇
皮肤病学   7篇
神经病学   17篇
特种医学   3篇
外科学   24篇
预防医学   9篇
眼科学   4篇
药学   4篇
肿瘤学   7篇
  2023年   3篇
  2022年   2篇
  2021年   3篇
  2019年   4篇
  2018年   1篇
  2017年   3篇
  2016年   3篇
  2015年   4篇
  2014年   7篇
  2013年   11篇
  2012年   21篇
  2011年   13篇
  2010年   7篇
  2009年   4篇
  2008年   13篇
  2007年   9篇
  2006年   4篇
  2005年   7篇
  2004年   8篇
  2003年   7篇
  2002年   3篇
  1999年   1篇
  1995年   1篇
  1991年   1篇
  1990年   1篇
  1987年   1篇
  1979年   1篇
  1976年   1篇
  1974年   1篇
排序方式: 共有145条查询结果,搜索用时 31 毫秒
71.
Histological diagnosis of burn depth lacks consensus. The purpose of this study was to determine whether Ki-67, a cell proliferation marker, provides an index of integument viability after burn injury. Induction of thermal burn injuries (3, 12, 20, 30, 75, 90, and 120 seconds) were made with a brass rod heated to 100°C on the dorsal trunk of the swine. Controls were created with a brass rod heated to 37.5°C. Four 6-mm biopsies were obtained from each site for histological analysis of Ki-67. Biopsies were taken at the following times postinjury: 1, 12, 24, 36, 48, 72, and 96 hours. The results illustrate a characteristic Ki-67 nuclear staining in the basal layer of the epidermis and in the hair follicle. With increasing thermal injury, the nuclei of the cells changed morphology: condensing, fragmenting, and elongating. The uniqueness of the labeling index was to include only morphologically intact nuclei as having capacity to proliferation. Quantitative analysis showed a reduction in the mean number of Ki-67-positive cells, suggesting a reduced regenerative capacity. This study supports using this index as a means of performing histology for burn depth analysis. In future studies, determining viability of partial-thickness burns will require multiple histological markers such as Ki-67 in addition to hematoxylin and eosin staining.  相似文献   
72.
The insulin receptor (IR) is a protein tyrosine kinase playing a pivotal role in the regulation of peripheral glucose metabolism and energy homoeostasis. IRs are also abundantly distributed in the cerebral cortex and hippocampus, where they regulate synaptic activity required for learning and memory. As the major anabolic hormone in mammals, insulin stimulates protein synthesis partially through the activation of the PI3K/Akt/mTOR pathway, playing fundamental roles in neuronal development, synaptic plasticity and memory. Here, by means of a multidisciplinary approach, we report that long-term synaptic plasticity and recognition memory are impaired in IR ??-subunit heterozygous mice. Since IR expression is diminished in type-2 diabetes as well as in Alzheimer??s disease (AD) patients, these data may provide a mechanistic link between insulin resistance, impaired synaptic transmission and cognitive decline in humans with metabolic disorders.  相似文献   
73.
74.
BackgroundMerkel cell carcinoma (MCC) is a rare malignancy of the skin, and its incidence is reported to be rising. The purpose of this study was to calculate its incidence and survival ratios, and to describe the clinical characteristics of Merkel cell carcinoma patients in Finland.MethodsWe calculated the incidence of MCC based on data from the Finnish Cancer Registry. In addition, patient files from hospitals and primary health care centres were reviewed for detailed data on the treatment and disease recurrence of 181 patients diagnosed with MCC in Finland during 1983–2004, and relative survival ratios were calculated for them.ResultsThe incidence (per 100,000) of MCC in Finland in 1989–2008 was 0.11 for men and 0.12 for women, adjusted for age to the world standard population. The mean age at diagnosis was 76 years (range 27–100), and 69% of the patients were women. The most common site of the primary tumour was the head and neck (53%). No extra benefit was gained from a wide surgical margin (⩾2 cm) compared to a margin of 0.1–0.19 cm, but an intralesional excision was more often associated with local recurrence. None of the patients with Stage I–II disease who had received postoperative radiotherapy to the tumour bed had a local recurrence. The 5-year relative survival ratio amongst men was 36% (95% confidence interval 20–54%), and amongst women 69% (56 to −82%).ConclusionsMCC is a rare disease in Finland, with incidence rates similar to those in the other Nordic countries. Our results support the view that complete excision with clear margins and post operative radiotherapy decrease local recurrences.  相似文献   
75.
AIM: To analyze the ability of nine different potentially probiotic bacteria to induce maturation and cytokine production in human monocyte-derived dendritic cells (moDCs).
METHODS: Cytokine production and maturation of moDCs in response to bacterial stimulation was analyzed with enzyme-linked immunosorbent assay (ELISA) and flow cytometric analysis (FACS), respectively. The kinetics of mRNA expression of cytokine genes was determined by Northern blotting. The involvement of different signaling pathways in cytokine gene expression was studied using specific pharmacological signaling inhibitors.
RESULTS: All studied bacteria induced the maturation of moDCs in a dose-dependent manner. More detailed analysis with S. thermophilus THS, B. breve Bb99, and L. lactis subsp, cremoris ARH74 indicated that these bacteria induced the expression of moDC maturation markers HLA class Ⅱ and CD86 as efficiently as pathogenic bacteria. However, these bacteria differed in their ability to induce moDC cytokine gene expression. S. thermophilus induced the expression of pro-inflammatory (TNF-α, IL-12, IL-6, and CCL20) and Thl type (IL-12 and IFN-γ) cytokines, while B. breve and L. lactis were also potent inducers of antiinflammatory IL-10. Mitogen-activated protein kinase (MAPK) p38, phosphatidylinositol 3 (PI3) kinase, and nuclear factor-kappa B (NF-κB) signaling pathways were shown to be involved in bacteria-induced cytokine production. CONCLUSION: Our results indicate that potentially probiotic bacteria are able to induce moDC maturation, but their ability to induce cytokine gene expression varies significantly from one bacterial strain to another,  相似文献   
76.
AIM: To investigate the capacity of potentially probiotic strains from six bacterial genera to induce cytokine production alone or in combinations in order to identify potential enhancing or synergistic effects in order to select probiotic bacteria for in vivo purposes.
METHODS: Cytokine production in human peripheral blood mononuclear cells (PBMC) in response to stimulation with eleven different potentially probiotic bacterial strains from Streptococcus, Lactobacillus, Bifidobacterium, Lactococcus, L euconostoc a n d Propionibacterium genera was analysed. Production and mRNA expression of TNF-α, IL-12, IFN-y and IL-10 were determined by ELISA and Northern blotting, respectively.
RESULTS: All tested bacteria induced TNF-α production. The best inducers of Thl type cytokines IL-12 and IFN-y were Streptococcus and Leuconostoc strains. All BiHdobacterium and Propionibacterium strains induced higher IL-IO production than other studied bacteria. Stimulation of PBMC with any bacterial combinations did not result in enhanced cytokine production suggesting that different bacteria whether gram-positive or gram- negative compete with each other during host cell interactions.
CONCLUSION: The probiotic S. thermophilus and Leuconostoc strains are more potent inducers of Thl type cytokines IL-12 and IFN-γ than the probiotic Lactobacillus strains. Bacterial combinations did not result in enhanced cytokine production.  相似文献   
77.

Objective

The objective was to examine the effect of a solvent dimethyl sulfoxide (DMSO) on resin–dentin bond durability, as well as potential functional mechanisms behind the effect.

Methods

Microtensile bond strength (μTBS) was evaluated in extracted human teeth in two separate experiments. Dentin specimens were acid-etched and assigned to pre-treatment with 0.5 mM (0.004%) DMSO as additional primer for 30 s and to controls with water pre-treatment. Two-step etch-and-rinse adhesive (Scotchbond 1XT, 3M ESPE) was applied and resin composite build-ups were created. Specimens were immediately tested for μTBS or stored in artificial saliva for 6 and 12 months prior to testing. Additional immediate and 6-month specimens were examined for interfacial nanoleakage analysis under SEM. Matrix metalloproteinase (MMP) inhibition by DMSO was examined with gelatin zymography. Demineralized dentin disks were incubated in 100% DMSO to observe the optical clearing effect.

Results

The use of 0.5 mM DMSO had no effect on immediate bond strength or nanoleakage. In controls, μTBS decreased significantly after storage, but increased significantly in DMSO-treated group. The control group had significantly lower μTBS than DMSO-group after 6 and 12 months. DMSO also eliminated the increase in nanoleakage seen in controls. 5% and higher DMSO concentrations significantly inhibited the gelatinases. DMSO induced optical clearing effect demonstrating collagen dissociation.

Significance

DMSO as a solvent may be useful in improving the preservation of long-term dentin–adhesive bond strength. The effect may relate to dentinal enzyme inhibition or improved wetting of collagen by adhesives. The collagen dissociation required much higher DMSO concentrations than the 0.5 mM DMSO used for bonding.  相似文献   
78.
The present study investigated the development of executive functions (EFs) and their associations with performance and behavior at school in 8–12-year-old children. The EFs were measured by computer-based n-back, Continuous Performance and Go/Nogo tasks. School performance was evaluated by Teacher Report Form (TRF) and behavior by TRF and Child Behavior Checklist. The studied dimensions of EF were cognitive efficiency/speed, working memory/attention and inhibitory control. Strong age effects were found for these cognitive abilities (p values <0.01). Inhibitory control was associated with better adaptive functioning (learning, working hard and behaving well), academic performance and less psychiatric symptoms (p values <0.05), specially in 8–9-year-old children. In this youngest age group low inhibitory control was also associated with teacher-reported inattention (p = 0.042). Low inhibitory control was associated with teacher- and parent-reported internalizing symptoms (p < 0.01). These results suggest that maturational factors may underlie low adaptive functioning and psychiatric symptoms during early school years. Further studies are needed to evaluate the association between inhibition and emotional symptoms.  相似文献   
79.
Background/Objectives:To determine whether long-term daily consumption of milk containing probiotic Lactobacillus rhamnosus GG (GG) decreases respiratory illness in children.Subjects/Methods:A randomized, double-blind, placebo-controlled trial was conducted with 523 children aged 2-6 years attending day care centers in Finland. Subjects received either normal milk or the same milk with GG on three daily meals for 28 weeks. Daily recording of childrens' symptoms was done by parents. Primary outcome data from 501 subjects were available for analysis, and data from 128 subjects were analyzed as completed cases in terms of recovery of GG in fecal samples.Results:Number of days with at least one respiratory symptom in all subjects was 5.03/month (95% confidence interval (CI): 4.92-5.15) in the GG group and 5.17/month (95% CI: 5.05-5.29) in the placebo group incidence rate ratio (IRR) 0.97; 95% CI: 0.94-1.00; P=0.098). In the completed cases, the figures were 4.71 days/month (95% CI: 4.52-4.90) in the GG group and 5.67 days/month (95% CI: 5.40-5.94) in the placebo group (IRR 0.83; 95% CI: 0.78-0.88; P<0.001).Conclusions:Consumption of GG reduced the occurence of respiratory illness in children attending day care centers in the completed cases subgroup, but not in the total population. Thus, future clinical trials are warranted to clarify the association between fecal recovery of a probiotic and the symptom prevalence.  相似文献   
80.
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