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   125篇
  免费   4篇
  129篇
  2022年   2篇
  2021年   9篇
  2020年   1篇
  2019年   1篇
  2018年   6篇
  2017年   3篇
  2015年   7篇
  2014年   11篇
  2013年   14篇
  2012年   11篇
  2011年   13篇
  2010年   10篇
  2009年   5篇
  2008年   8篇
  2007年   5篇
  2006年   5篇
  2005年   3篇
  2004年   3篇
  2003年   4篇
  2002年   4篇
  1997年   1篇
  1996年   2篇
  1986年   1篇
排序方式: 共有129条查询结果,搜索用时 15 毫秒
121.
In the present study, the relationship between total bulk milk somatic cell counts (BMSCC), differential BMSCC (macrophage, lymphocyte, and polymorphonuclear leukocytes), and antioxidant enzymes was investigated. Forty-three samples of bulk milk were selected randomly from eight dairy farms in the region of Sfax (Tunisia) in winter, from November 2005 to February 2006. Bulk milk samples were analyzed for antioxidant enzymes such as catalase, SOD and GSHPx activity and differential SCC. After that, milks were allotted according to their total SCC to: group 1, bulk milk with SCC below 1000x10(3) ml(-1); group 2, bulk milk with SCC from 1000x10(3) to 1500x10(3) ml(-1); group 3, bulk milk with SCC above 1500x10(3) ml(-1). BMSCC levels ranged from 400x10(3) to nearly 4000x10(3) ml(-1). Lymphocytes were the predominant cell type in all groups, but their proportion declined with the total BMSCC. Catalase and GSHPx activities were found to be significantly (P<0.001) correlated with total BMSCC and with the PMN population. In contrast, a weak correlation between the activity of the SOD and total or differential bulk milk somatic cells was observed. It has been suggested that milk cells, especially PMN, could generate a situation of oxidative stress in the mammary gland. Specifically, hydrogen peroxide and hydroxyl radicals were probably the most important reactive oxygen metabolites released by PMN. To cite this article: H. Hamed et al., C. R. Biologies 331 (2008).  相似文献   
122.
Spontaneous fetal swallowing occurs at a markedly higher rate compared with spontaneous adult drinking activity. This high rate of fetal swallowing is critical for amniotic fluid volume regulation. Central NO is critical for maintaining the normal rate of fetal swallowing, as nonselective inhibition of NO (with central N(G)-nitro-L-arginine methyl ester) suppresses spontaneous and angiotensin II (ANG II)-stimulated swallowing. We sought to differentiate the contributions of central endothelial vs. neuronal NO in the regulation of spontaneous and stimulated fetal swallowing, using a selective neuronal NO synthase (nNOS) inhibitor. Six time-dated pregnant ewes and fetuses were chronically prepared with fetal vascular and intracerebroventricular (i.c.v.) catheters and electrocorticogram (ECoG) and esophageal electromyogram electrodes and studied at 130 +/- 1 days of gestation. After an initial 2-h baseline period (0-2 h), the selective nNOS inhibitor N-propyl-L-arginine (NPLA) was injected i.c.v. (2-4 h). At 4 h, the dose of NPLA was repeated, together with ANG II, and fetal swallowing was monitored for a final 2 h. Four fetuses also received an identical control study (on an alternate day) in which NPLA was replaced with artificial cerebrospinal fluid (aCSF). Suppression of nNOS by i.c.v. NPLA significantly reduced mean (+/- SE) spontaneous fetal swallowing (1.35 +/- 0.12 to 0.50 +/- 0.07 swallows/min; P < 0.001). Injection of ANG II in the presence of NPLA had no dipsogenic effect on fetal swallowing (0.68 +/- 0.09 swallows/min). In the aCSF study, i.c.v. aCSF did not change fetal swallowing (0.93 +/- 0.10 vs. 0.95 +/- 0.09 swallows/min), whereas i.c.v. ANG II resulted in a significant increase in the rate of fetal swallowing (2.0 +/- 0.04 swallows/min; P = 0.001). We speculate that the suppressive dipsogenic effects of central NPLA indicate that spontaneous and ANG II- stimulated fetal swallowing is dependent on central nNOS activity.  相似文献   
123.
124.
Etanercept is a soluble fusion protein of the tumor necrosis factor receptor (TNFR) extracellular domain, linked to an Fc part of IgG1. It possesses three N- and 13 O-glycosylation sites. Due to its complex structure, an analytical challenge is facing the development and approval of biosimilars. In the current study, physicochemical characterization using state-of-the-art analytics was performed to analyze intact and subunit masses, post-translational modifications (PTMs), higher order structure and potency of Etanercept originator Enbrel® and its biosimilar Altebrel? (AryoGen Pharmed) in accordance to critical quality attributes of biopharmaceuticals. Intact mass and subunit analysis revealed a size of about 126 kDa for both biologicals. Similar glycoprotein species for the complete monomer and the Fc domain of originator and follow-on product were observed, however, small differences in lysine variants and oxidation were found. N-Glycopeptide analysis with UHPLC-QTOF-MSE confirmed the N-glycosylation sites (N149, N171 and N317) as well as Fc-specific glycosylation on N317, and TNFR-specific highly sialylated glycans on N149 and N171 on both investigated products. Small quantitative variations in the N-glycan profile were detected, although the N-glycans were qualitatively similar. Four different O-glycopeptides bearing core 1-type glycans were detected. For both, N- and O-glycopeptide analysis, determination was achieved without prior cleavage of the sialic acid residues for the first time. In addition, ion mobility spectrometry data confirmed close similarity of higher-order structure of both biologics. Furthermore, a neutralization assay, investigating the impact of altered PTMs on potency, indicated that the differences within all batches are still in the acceptable range for biosimilarity.  相似文献   
125.

Background

Behçet’s disease is a multisystem disease. It stands at the crossroad between the autoimmunity and auto-inflammatory disorders. In this study, we sought to address a relationship that might exist between interleukin-1β (IL-1β) and the oxidants/antioxidants markers in Behçet’s patients.

Methods

Behçet’s disease patients (n = 78: active stage, n = 28; inactive stage, n = 50) and 41 healthy controls have been included in our study. In this context, we investigated the plasma levels of IL-1β and the nitrosative/oxidative markers: nitric oxide (NO), advanced oxidative protein products (AOPP) and fatty acids peroxidation-malondialdehyde (MDA). The antioxidant system was assessed by measuring the plasma level of superoxide dismutase (SOD) activity. The Mann-Whitney’s U and Pearson’s correlation tests were used for statistical analyses.

Results

Our case-control study showed that patients in active stage displayed higher plasma levels of IL-1β, NO, AOPP and MDA versus healthy controls and patients in inactive stage. Patients in active stage showed significantly lower SOD levels related to patients in inactive stage and healthy controls respectively, whereas patients in inactive stage showed statistically insignificant SOD level versus healthy controls. Correlation studies showed a significant positive correlation between IL-1β and AOPP, IL-1β and NO, and negative correlation between IL-1β and SOD among Behçet’s disease patients. In addition, we showed positive correlation between AOPP and NO, AOPP and MDA and negative correlation between NO and SOD, AOPP and SOD in Behçet’s disease patients.

Conclusion

Interestingly, our study revealed that IL-1β levels increased and correlated with an imbalance of oxidants/antioxidants system, especially during active stage of Behçet disease. Collectively, our study indicates a possible link between IL-1β production and nitrosative/oxidative markers during Behçet’s disease. Exploiting this relationship might provide valuable outputs in the follow-up and prognosis of Behçet’s disease with a potential therapeutic value.
  相似文献   
126.
Associations with type 2 diabetes mellitus have been identified for variants CDKAL1 rs7756992, KCNJ11 rs5219, and IGF2BP2 rs4402960 in different populations. In a case–control study of 250 unrelated Moroccan diabetic patients and 250 healthy controls, we used TaqMan allelic discrimination assays to genotype the three SNPs and meta-analysis to investigate the association between the polymorphisms and diabetes in Arab populations. The results showed a significant diabetes association only with the variant rs4402960 of the IGF2BP2 gene under additive 2 (GG vs. TT; p = 0.009) and recessive (TT vs. GG+GT; p = 0.003) models. Meta-analysis indicated significant association between the IGF2BP2 rs4402960 and CDKAL1 rs7756992 polymorphisms and increased risk of diabetes in Arab populations. According to our results, the case–control study and meta-analysis revealed a significant association between the IGF2BP2 rs4402960 variant and type 2 diabetes in Moroccan and Arab populations.  相似文献   
127.
Primary hyperoxaluria type 1 (PH1) is a severe autosomal recessive inherited disorder of glyoxylate metabolism caused by mutations in the AGXT gene on chromosome 2q37.3 that encodes the hepatic peroxisomal enzyme alanine:glyoxylate aminotransferase. These mutations are found throughout the entire gene and cause a wide spectrum of clinical severity. Rare in Europe, PH1 is responsible for 13% of the end stage renal failure in the Tunisian child. In the present work, we identified the double mutation c.32C>T (Pro11Leu) and c.731T>C (p.Ile244Thr) in AGXT gene in five unrelated Tunisian families with PH1 disease. Our results provide evidence regarding the potential involvement of c.32C>T, originally described as common polymorphism, on the resulting phenotype. We also reported an extreme intrafamilial heterogeneity in clinical presentation of PH1. Despite the same genetic background, the outcome of the affected members differs widely. The significant phenotypic heterogeneity observed within a same family, with a same genotype, suggests the existence of relevant modifier factors.  相似文献   
128.
129.
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