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   8篇
  免费   1篇
  2015年   1篇
  2013年   2篇
  2012年   1篇
  2011年   1篇
  2008年   1篇
  2002年   1篇
  1991年   1篇
  1975年   1篇
排序方式: 共有9条查询结果,搜索用时 555 毫秒
1
1.
The purpose of this work was to study the quantitative modifications of the hepatic lipids in adult thyroidectomized rats after administration of tetracycline or ethanol (acute dose or prolonged ingestion). 1. - Thyroidectomy did not inhibit the accumulation of fat in the liver of fed euthyroid or hypothyroid rats after intraperitoneal infusion of tetracycline (320 mg/body weight in 2 injections at an interval of 16 h, the diet containing 6% of lipids). 2. - Sixteen hours after the oral administration of a single large dose of ethanol (5 g/kg body weight), there were only found some small modifications of the lipid composition of the liver in fasting euthyroid or thyroidectomized rats, receiving a diet with 6% of lipids before the experiment; on the contrary, when the diet contained 19% of lipids, a fatty liver occurred in the intact rat, but not in the thyroidectomized rat. 3. - The prolonged ethanol intake (in a 20% solution in water) for 5 months with a diet containing 19% of lipids did not induce a fatty liver in intact rats but produced a decrease of hepatic non-phosphorus lipid and an increase of the cholesterol amounts. After the administration of L-thyroxin (10 mug/100 g body weight per day) to these alcoholic thyroidectomized rats during 2 weeks, it was found an increase of the hepatic non phosphorus lipids till an higher amount than in the euthyroid rats. 4. - The hepatic phospholipid amounts were relatively constant in the different experiments. These results accounting for this differential effects were discussed.  相似文献   
2.
The current study aims to update the range of Aphanius fasciatus occurring in inland aquatic systems, and to characterise the length–weight relationship of specimens caught in inland waters of the Northern Sahara of Algeria. Although the known distribution of Afasciatus is restricted to coastal waters including islands of the Mediterranean region, visits to 39 hydrosystems in Northeast Algeria revealed the presence of the species at two sites: Oued Still and Lake Temacine. Both sites are in the Sahara Desert of Algeria, where the climate is hot and hyperarid. The surveyed populations perform their entire life cycle at the same sites. Analysis of a sample composed of 27 individuals captured in Oued Still allowed determination of the length–weight relationship. On average, females measured 4.2 ± 0.6 cm in length and weighed 1.1 ± 0.5 g; males were 3.2 ± 0.6 cm and 0.5 ± 0.2 g. Growth parameters of the von Bertalanffy equation for Afasciatus were estimated at Lt = 5.5145 (1?exp (?0.341(t?0.0049))), Wt = 2.6692 (1?exp (?0.271t))3.  相似文献   
3.
In clinical routine, lower limb analysis relies on conventional X-ray (2D view) or computerised tomography (CT) Scan (lying position). However, these methods do not allow 3D analysis in standing position. The aim of this study is to propose a fast and accurate 3D-reconstruction-method based on parametric models and statistical inferences from biplanar X-rays with clinical measurements' (CM) assessment in standing position for a clinical routine use. For the reproducibility study, the 95% CI was under 2.7° for all lower limbs' angular measurements except for tibial torsion, femoral torsion and tibiofemoral rotation (?相似文献   
4.
The effects of cadmium (Cd) on cellular proteolytic responses were investigated in the roots and leaves of tomato (Solanum lycopersicum L., var Ibiza) plants. Three-week-old plants were grown for 3 and 10 days in the presence of 0.3–300 μM Cd and compared to control plants grown in the absence of Cd. Roots of Cd treated plants accumulated four to fivefold Cd as much as mature leaves. Although 10 days of culture at high Cd concentrations inhibited plant growth, tomato plants recovered and were still able to grow again after Cd removal. Tomato roots and leaves are not modified in their proteolytic response with low Cd concentrations (≤3 μM) in the incubation medium. At higher Cd concentration, protein oxidation state and protease activities are modified in roots and leaves although in different ways. The soluble protein content of leaves decreased and protein carbonylation level increased indicative of an oxidative stress. Conversely, protein content of roots increased from 30 to 50%, but the amount of oxidized proteins decreased by two to threefold. Proteolysis responded earlier in leaves than in root to Cd stress. Additionally, whereas cysteine- and metallo-endopeptidase activities, as well as proteasome chymotrypsin activity and subunit expression level, increased in roots and leaves, serine-endopeptidase activities increased only in leaves. This contrasted response between roots and leaves may reflect differences in Cd compartmentation and/or complexation, antioxidant responses and metabolic sensitivity to Cd between plant tissues. The up-regulation of the 20S proteasome gene expression and proteolytic activity argues in favor of the involvement of the 20S proteasome in the degradation of oxidized proteins in plants. This paper is dedicated to Nathalie Galtier (1964–2005), who was senior researcher at the INRA Research Center, Villenave d’Ornon, France.  相似文献   
5.
Alfalfa, the most widely grown leguminous crop in the world, is generally exposed to severe salinity stress in Tunisia, notably affecting its germination performance. Toward a better understanding of alfalfa seed vigor, we have used proteomics to characterize protein changes occurring during germination and osmopriming, a pretreatment that accelerates germination and improves seedling uniformity particularly under stress conditions. The data revealed that germination was accompanied by dynamic changes of 79 proteins, which are mainly involved in protein metabolism, cell structure, metabolism, and defense. Comparative proteomic analysis also revealed 63 proteins specific to osmopriming, 65 proteins preferentially varying during germination, and 14 proteins common to both conditions. Thus, the present study unveiled the unexpected finding that osmopriming cannot simply be considered as an advance of germination-related processes but involves other mechanisms improving germination such as the mounting of defense mechanisms enabling osmoprimed seeds to surmount environmental stresses potentially occurring during germination. The present results therefore provide novel avenues toward understanding the mechanisms of invigoration of low vigor seeds by priming treatments that are widely used both in commercial applications and in developing countries (on farm seed priming) to better control crop yields.  相似文献   
6.
In clinical routine, lower limb analysis relies on conventional X-ray (2D view) or computerised tomography (CT) Scan (lying position). However, these methods do not allow 3D analysis in standing position. The aim of this study is to propose a fast and accurate 3D-reconstruction-method based on parametric models and statistical inferences from biplanar X-rays with clinical measurements' (CM) assessment in standing position for a clinical routine use. For the reproducibility study, the 95% CI was under 2.7° for all lower limbs' angular measurements except for tibial torsion, femoral torsion and tibiofemoral rotation ( < 5°). The 95% CI were under 2.5 mm for lower limbs' lengths and 1.5 to 3° for the pelvis' CM. Comparisons between X-rays and CT-scan based 3D shapes in vitro showed mean differences of 1.0 mm (95% CI = 2.4 mm). Comparisons of 2D lower limbs' and 3D pelvis' CM between standing ‘Shifted-Feet’ and ‘Non-Shifted-Feet’ position showed means differences of 0.0 to 1.4°. Significant differences were found only for pelvic obliquity and rotation. The reconstruction time was about 5 min.  相似文献   
7.
In some inhibitor-resistant TEM-derived beta-lactamases, Met-69 is substituted by Leu, Ile or Val. Residue 69 is located in a region of strong structural constraints, at the beginning of H2 alpha-helix, and in the vicinity of B3 and B4 beta-strands. Analysis of the three-dimensional structure of TEM-1 beta-lactamase suggests that alteration of the substrate-binding site can be produced by changes of the size of residue 69 side chain. Met-69 was substituted by alanine or glycine in TEM-Bs beta-lactamase (a TEM-1-related enzyme) using site-directed mutagenesis. The minimum inhibitory concentrations of the mutants compared with the wild-type revealed an increased susceptibility to beta-lactamase inhibitor-beta-lactam combinations and to first-generation cephalosporins. Comparing the Met69Ala and Met69Gly beta-lactamases with TEM-Bs, K(m) constants of the mutants showed an increased affinity for most beta-lactams but the kcat for most substrates did not change substantially. Mutants also demonstrated lower IC50 for the three inhibitors (clavulanic acid, tazobactam and sulbactam). The two substitutions of the residue 69 by alanine and glycine had a noticeable effect on K(m) values of TEM-Bs beta-lactamase, and on affinity for beta-lactamase inhibitors.  相似文献   
8.
9.
Discrete high-frequency oscillations (HFOs) in the range of 80–500 Hz have previously been recorded from human epileptic brains using intracereberal EEG and seem to be a reliable biomarker of seizure onset zone in patients with intractable epilepsy. Visual marking of HFOs bursts is tedious, highly time-consuming particularly for analyzing long-term multichannel EEG recordings, inevitably subjective and can be error prone. Thus, the development of automatic, fast and robust detectors is necessary and crucial for HFOs investigation and for propelling their eventual clinical applications. This paper presents a proposed algorithm for detection and classification of HFOs, which is a combination of both smoothed Hilbert Huang Transform (HHT) and root mean square (RMS) feature. Performance evaluation in terms of sensitivity and false discovery rate (FDR) were respectively 90.72% and 8.23% related to process validation. Indeed, the proposed method was efficient in terms of high sensitivity in which the majority of HFOs visually identified by experienced reviewers was correctly detected, and had a lower FDR. This would mean that only a low rate of detected events was misclassified as candidate HFOs events. The presented software is extremely fast, suitable and can be considered a valuable clinical tool for HFOs investigation.  相似文献   
1
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