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   285篇
  免费   29篇
  2024年   1篇
  2023年   9篇
  2022年   9篇
  2021年   10篇
  2020年   15篇
  2019年   29篇
  2018年   21篇
  2017年   21篇
  2016年   17篇
  2015年   12篇
  2014年   18篇
  2013年   40篇
  2012年   22篇
  2011年   24篇
  2010年   11篇
  2009年   7篇
  2008年   5篇
  2007年   10篇
  2006年   6篇
  2005年   4篇
  2004年   5篇
  2003年   2篇
  2002年   3篇
  2001年   3篇
  2000年   2篇
  1999年   4篇
  1987年   1篇
  1984年   1篇
  1981年   2篇
排序方式: 共有314条查询结果,搜索用时 250 毫秒
101.
102.
103.
Chemokines, a subclass of cytokine superfamily have both pro-inflammatory and migratory role and serve as chemoattractant of immune cells during the inflammatory responses ensuing spinal cord injury (SCI). The chemokines, especially CXCL-1, CXCL-9, CXCL-10 and CXCL-12 contribute significant part in the inflammatory secondary damage of SCI. Inhibiting chemokine’s activity and thereby the secondary damage cascades has been suggested as a chemokine-targeted therapeutic approach to SCI. To optimize the inhibition of secondary injury through targeted chemokine therapy, accurate knowledge about the temporal profile of these cytokines following SCI is required. Hence, the present study was planned to determine the serum levels of CXCL-1, CXCL-9, CXCL-10 and CXCL-12 at 3–6 h, 7 and 28 days and 3 m after SCI in male and female SCI patients (n = 78) and compare with age- and sex-matched patients with non-spinal cord injuries (NSCI, n = 70) and healthy volunteers (n = 100). ANOVA with Tukey post hoc analysis was used to determine the differences between the groups. The data from the present study show that the serum level of CXCL-1, CXCL-9 and CXCL-10 peaked on day 7 post-SCI and then declined to the control level. In contrast, significantly elevated level of CXCL-12 persisted for 28 days post SCI. In addition, post-SCI expression of CXCL-12 was found to be sex-dependent. Male SCI patients expressed significantly higher CXCL-12 when compared to control and SCI female. We did not observe any change in chemokines level of NSCI. Further, the age of the patients did not influence chemokines expression after SCI. These observations along with SCI-induced CSF-chemokine level should contribute to the identification of selective and temporal chemokine targeted therapy after SCI.  相似文献   
104.
ABSTRACT

The aim of the present study was to examine the effect of a nap opportunity during the daytime realized at different times of day on physical and mental performance. Eighteen physically active males (age: 20.5 ± 3.0 years, height: 175.3 ± 5.9 cm, body-mass: 70.0 ± 8.6 kg) were tested under four experimental conditions: no-nap condition, nap at 13h00, nap at 14h00 and nap at 15h00. All nap durations were of 25-min and all tests were performed at 17h00. They performed a 5-m shuttle run test, which generated measures of the highest distance (HD) and total distance (TD). The rating of perceived exertion (RPE) was recorded after each of the six sprints in the 5-m shuttle run test. Vigilance was measured using a digit cancellation test. The results showed that TD at 17h00 was 4% greater after a nap at 14h00 than in the no-nap condition (+28 m, p < .05) or after the nap at 13h00 (+29 m, p < .05). HD was 8% higher (+9 m, p < .001) after a nap at 14h00 than in the no-nap condition and 7% higher after nap at 15h00 than in the no-nap condition (+7 m, p < .05). In addition, HD was 6% higher after nap at 14h00 (+7 m, p < .01) and 5% higher after nap at 15h00 (+9 m, p < .01) than HD after a nap at 13h00. Napping at 13h00 had no effect on physical performance at 17h00. No significant differences were observed between RPE and vigilance scores in the nap and no-nap conditions. In conclusion, napping for 25 min at 14h00 and 15h00 produces meaningful improvements in responses during repeated short-term maximal exercise tests performed at 17h00. Napping at 13h00 does not. Vigilance, as measured using a digit cancellation test, and RPE scores are not influenced by any of the nap opportunities.  相似文献   
105.

Background

The rising challenge of diabetes requires novel service delivery approaches. In the UK, Local Enhanced Services (LES) have been commissioned for diabetes. Health professionals from general practices (GPs) who signed up to LES were given additional training (and a monetary incentive) to improve management of patients with diabetes. All practices in the PCT were invited to the LES initiative, which ensured avoiding selection bias. The aim of the study was to examine the impact of LES in terms of diabetes Quality Outcome Framework (QOF) indicators: DM23(glycaemia), DM17(lipid) and DM12(blood pressure; BP).

Methods

QOF diabetes indicators were examined using data from 76 general practices for 2009–2010 in a large primary care trust area in Birmingham, UK. Data were extracted from Quality Management Analysis System. The primary outcome was a difference in achievement of QOF indicators between LES and NLES practices. A secondary outcome was the difference between LES and non-LES practices for hospital first and follow-up appointments.

Results

We did not find any difference for DM12(BP) and DM17(lipid) outcomes between LES and NLES practices. However, LES practices were more likely to achieve the DM23(glycaemia) outcome (estimated odds 1.459;95% CI:1.378-1.544; P=0.0001). The probability of achieving satisfactory level of DM23(glycaemia) increased by almost 10% when GPs belonged to LES groups compared with GPs in NLES group. LES practices were less likely to refer patients to secondary care.

Conclusion

Overall, LES practices performed better in the achievement of DM23(glycaemia) and also referred fewer patients to hospital, thereby meeting their objectives. This suggests that the LES approach is beneficial and needs to be further explored in order to ascertain whether the impact exerted was due to LES.  相似文献   
106.
Fas/Fas ligand (FasL) system is one of the key apoptotic signaling entities in the extrinsic apoptotic pathway. De-regulation of this pathway, i.e. by mutations may prevent the immune system from the removal of newly-formed tumor cells, and thus lead to tumor formation. The present study investigated the association between −1377 G/A (rs2234767) and −670 A/G (rs1800682) polymorphisms in Fas as well as single nucleotide polymorphisms INV2nt −124 A/G (rs5030772) and −844 C/T (rs763110) in FasL in a sample of Iranian patients with breast cancer. This case-control study was done on 134 breast cancer patients and 152 normal women. Genomic DNA was extracted from whole blood samples. The polymorphisms were determined by using tetra-ARMS-PCR method. There was no significant difference in the genotype distribution of FAS rs2234767 polymorphism between cases and controls. FAS rs1800682, FASL rs5030772, and FASL rs763110 genotypes showed significant associations with an increasing risk of breast cancer (odds ratio OR = 3.18, P = 0.019; OR = 5.08, P = 0.012; OR = 2.40, P = 0.024, respectively). In conclusion, FAS rs2234767 was not associated with breast cancer risk. Though, FAS rs1800682, FASL rs5030772, and FASL rs763110 polymorphisms were associated with the risk of breast cancer in the examined population.  相似文献   
107.
  相似文献   
108.

PURPOSE:

This study aims to assess a meta-analysis of the association of X-ray repair cross-complementing group 1 (XRCC1) polymorphisms with the risk of various non-carcinogenic diseases in different population.

MATERIALS AND METHODS:

This meta-analysis was performed by critically reviewing reveals 38 studies involving 10043 cases and 11037 controls. Among all the eligible studies, 14 focused on Arg194Trp polymorphism, 33 described the Arg399Gln and three articles investigated on Arg280His. Populations were divided into three different ethnic subgroups include Caucasians, Asians and other (Turkish and Iranian).

RESULTS:

Pooled results showed no correlation between Arg194Trp and non-carcinogenic disease. There was only weak relation in the recessive (odds ratio [OR] =1.11, 95% confidence interval [CI]: 0.86-1.44) model in Asian population and dominant (OR = 1.04, 95% CI: 0.66-1.63) model of other populations. In Arg399Gln polymorphism, there was no relation with diseases of interest generally. In the pooled analysis, there were weak relation in the dominant (OR = 1.08, 95% CI: 0.86-1.35) model of Asian population and quite well-correlation with recessive (OR = 1.49, 95% CI: 1.19-1.88), dominant (OR = 1.23, 95% CI: 0.94-1.62), and additive (OR = 1.23, 95% CI: 0.94-1.62) models of other subgroup. For Arg280His, there was a weak relation only in the dominant model (OR = 1.06, 95% CI: 0.74-1.51).

CONCLUSION:

The present meta-analysis correspondingly shows that Arg399Gln variant to be associated with increased non-carcinogenic diseases risk through dominant and recessive modes among Iranian and Turkish population. It also suggests a trend of dominant and recessive effect of Arg280His variant in all population and its possible protective effect on non-carcinogenic diseases.  相似文献   
109.
This study was performed to investigate the constituents, in vitro antifungal activity and phytotoxicity potential of the essential oil from Juniperus polycarpos var. turcomanica leaves. The essential oil was analyzed by GC–FID, and GC/MS, which predominantly contains α-pinene (51.21%), germacrene–B (4.80%), and ∆-cadinene (2.56%). The antifungal activity of the essential oil against some phytopathogenic fungi, including Alternaria alternata, Colletotrichum trichellum, Curvularia fallax, Cytospora sacchari, Fusarium oxysporum, and Macrophomina phaseolina was performed through disk diffusion and agar dilution assays. The essential oil of J. polycarpos var. turcomanica had high antifungal activity against tested phytopathogenic fungi. The most susceptible fungi to the essential oil were C. trichellum in agar dilution and M. phaseolina and C. fallax in disk diffusion methods, whereas, the most resistant fungus to the essential oil was obtained from A. alternata in both assays. Screening methods had an influence on antifungal activity of the essential oil as most of the tested fungi in this study were shown to be more resistant in disc diffusion methods. According to the phytotoxic assay results, the essential oil from J. polycarpos var. turcomanica had high phytotoxicity against three species of weeds, including P. oleracea L., A. retroflexus L., and D. stramonium L. The results of this research suggest that the herbicidal and antifungal activities of the essential oil from J. polycarpos var. turcomanica can be attributed to its major group of constituents, monoterpenes hydrocarbons.  相似文献   
110.
Reporter genes have proved to be an excellent tool for studying disease progression. Recently, the green fluorescent protein (GFP) ability to quantitatively monitor gene expression has been demonstrated in different organisms. This report describes the use of Leishmania tarentolae (L. tarentolae) expression system (LEXSY) for high and stable levels of GFP production in different Leishmania species including L. tarentolae, L. major and L. infantum. The DNA expression cassette (pLEXSY-EGFP) was integrated into the chromosomal ssu locus of Leishmania strains through homologous recombination. Fluorescent microscopic image showed that GFP transgenes can be abundantly and stably expressed in promastigote and amastigote stages of parasites. Furthermore, flow cytometry analysis indicated a clear quantitative distinction between wild type and transgenic Leishmania strains at both promastigote and amastigote forms. Our data showed that the footpad lesions with GFP-transfected L. major are progressive over time by using fluorescence small-animal imaging system. Consequently, the utilization of stable GFP-transfected Leishmania species will be appropriate for in vitro and in vivo screening of anti-leishmanial drugs and vaccine development as well as understanding the biology of the host–parasite interactions at the cellular level.  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