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排序方式: 共有116条查询结果,搜索用时 78 毫秒
21.
Achraf Ammar Omar Boukhris Hsen Hsouna Imen Ben Dhia Khaled Trabelsi Tariq Ali Gujar Cain C.T Clark Hamdi Chtourou Tarak Driss Anita Hoekelmann 《Biology of sport / Institute of Sport》2021,38(4):683
Although napping is commonly used as a strategy to improve numerous physical and cognitive performances, the efficacy of this strategy for improving postural balance has not yet been elucidated. Thus, the aim of this study was to conduct a comprehensive examination of the effect of a 60 min nap opportunity (N60) on different components of postural control. Ten highly active individuals (age = 27 ± 3.5 y, height = 1.75 ± 0.52 m, weight = 66.02 ± 8.63 kg) performed, in a randomized order, two afternoon test sessions following no nap (NN) and N60. Postural balance was assessed using the sensory organisation test (SOT), the unilateral stance test (UST), and the limits of Stability Test performed on NeuroCom® Smart Balance Master. The subjective rating of sleepiness before and after the nap conditions was also assessed. Compared to NN, N60 improved the composite balance score (p < 0.05, ES = 0.75, Δ = 5.3%) and the average and maximum percentage balance in the most challenging postural conditions of the SOT (p < 0.05 for SOT-4 and 5 and p < 0.0005 for SOT-6; ES range between 0.58 and 1.1). This enhanced postural balance in N60 was accompanied with improved visual (p < 0.05; ES = 0.93; Δ = 8.9%) and vestibular (p < 0.05; ES = 0.81; Δ = 10.5%) ratios and a reduced level of sleepiness perception (p < 0.001, ES = 0.87). However, no significant differences were found in any of the UST and LOS components’ scores (p > 0.05). Overall, a 60 min post lunch nap opportunity may be viable for improving static balance, although further work, involving larger samples and more complex motor activities, is warranted. 相似文献
22.
Olfa Frikha-Gargouri Radhouane Gdoura Abir Znazen Boutheina Gargouri Jalel Gargouri Ahmed Rebai Adnene Hammami 《BMC microbiology》2008,8(1):217
Background
The OmcB protein is one of the most immunogenic proteins in C. trachomatis and C. pneumoniae infections. This protein is highly conserved leading to serum cross reactivity between the various chlamydial species. Since previous studies based on recombinant proteins failed to identify a species specific immune response against the OmcB protein, this study evaluated an in silico predicted specific and immunogenic antigen from the OmcB protein for the serodiagnosis of C. trachomatis infections. 相似文献23.
I. Hammami A. Rhouma B. Jaouadi A. Rebai X. Nesme 《Letters in applied microbiology》2009,48(2):253-260
Aims: The identification of a new compound active against Agrobacterium tumefaciens .
Methods and Results: The culture conditions of a newly isolated Bacillus subtilis strain, designed 14B, were optimized, as a first step, to produce its bacteriocin (termed Bac 14B) for the biocontrol of Agrobacterium spp., the causal agents of the crown gall disease. Bac 14B was then partially purified and biochemically characterized. Bacillus subtilis 14B was observed to produce an antibacterial compound having a protinaceous nature. As estimated by sodium dodecyl sulfate-polyacrilamide gel electrophoresis (SDS-PAGE), the semi-purified bacteriocin substance was found to be a monomeric protein with a molecular weight of 21 kDa. While the latter's antimicrobial activity was completely stable during exposure to a temperature range of up to 100°C for 2 h, its initial activity was totally lost at 121°C for 20 min. The maximum bacteriocin production (4096 AU ml−1 ) was recorded after 96 h-incubation in an optimized Luria Bertani medium supplemented with 10 g l−1 glucose, 15 g l−1 K2 HPO4 and 5 g l−1 MgSO4 7H2 O at 30°C in a shaking flask culture. Interestingly, the B. subtilis 14B culture supernatant that contained the bacteriocin under study was proved efficient in reducing both the percentage of galled plants and the number of galls in tomato.
Conclusion: The findings revealed that B. subtilis 14B and its bacteriocin are efficient in reducing the percentage of infections in plants caused by Ag. tumefaciens .
Significance and Impact of the Study: The results could be useful for the nurserymen who are particularly interested in the biocontrol of the crown gall disease. 相似文献
Methods and Results: The culture conditions of a newly isolated Bacillus subtilis strain, designed 14B, were optimized, as a first step, to produce its bacteriocin (termed Bac 14B) for the biocontrol of Agrobacterium spp., the causal agents of the crown gall disease. Bac 14B was then partially purified and biochemically characterized. Bacillus subtilis 14B was observed to produce an antibacterial compound having a protinaceous nature. As estimated by sodium dodecyl sulfate-polyacrilamide gel electrophoresis (SDS-PAGE), the semi-purified bacteriocin substance was found to be a monomeric protein with a molecular weight of 21 kDa. While the latter's antimicrobial activity was completely stable during exposure to a temperature range of up to 100°C for 2 h, its initial activity was totally lost at 121°C for 20 min. The maximum bacteriocin production (4096 AU ml
Conclusion: The findings revealed that B. subtilis 14B and its bacteriocin are efficient in reducing the percentage of infections in plants caused by Ag. tumefaciens .
Significance and Impact of the Study: The results could be useful for the nurserymen who are particularly interested in the biocontrol of the crown gall disease. 相似文献
24.
Failli AA Shumsky JS Steffan RJ Caggiano TJ Williams DK Trybulski EJ Ning X Lock Y Tanikella T Hartmann D Chan PS Park CH 《Bioorganic & medicinal chemistry letters》2006,16(4):954-959
Our efforts in seeking low molecular weight agonists of the antidiuretic peptide hormone arginine vasopressin (AVP) have led to the identification of the clinical candidate WAY-151932 (VNA-932). Further exploration of the structural requirements for agonist activity has provided another class of potent, orally active, non-peptidic vasopressin V2 receptor selective agonists exemplified by the 5,11-dihydro-pyrido[2,3-b][1,5]benzodiazepine as a candidate for further development. 相似文献
25.
Structural basis for the hyperthermostability of an archaeal enzyme induced by succinimide formation
Aparna Vilas Dongre Sudip Das Asutosh Bellur Sanjeev Kumar Anusha Chandrashekarmath Tarak Karmakar Padmanabhan Balaram Sundaram Balasubramanian Hemalatha Balaram 《Biophysical journal》2021,120(17):3732-3746
Stability of proteins from hyperthermophiles (organisms existing under boiling water conditions) enabled by a reduction of conformational flexibility is realized through various mechanisms. A succinimide (SNN) arising from the post-translational cyclization of the side chains of aspartyl/asparaginyl residues with the backbone amide -NH of the succeeding residue would restrain the torsion angle Ψ and can serve as a new route for hyperthermostability. However, such a succinimide is typically prone to hydrolysis, transforming to either an aspartyl or β-isoaspartyl residue. Here, we present the crystal structure of Methanocaldococcus jannaschii glutamine amidotransferase and, using enhanced sampling molecular dynamics simulations, address the mechanism of its increased thermostability, up to 100°C, imparted by an unexpectedly stable succinimidyl residue at position 109. The stability of SNN109 to hydrolysis is seen to arise from its electrostatic shielding by the side-chain carboxylate group of its succeeding residue Asp110, as well as through n → π1 interactions between SNN109 and its preceding residue Glu108, both of which prevent water access to SNN. The stable succinimidyl residue induces the formation of an α-turn structure involving 13-atom hydrogen bonding, which locks the local conformation, reducing protein flexibility. The destabilization of the protein upon replacement of SNN with a Φ-restricted prolyl residue highlights the specificity of the succinimidyl residue in imparting hyperthermostability to the enzyme. The conservation of the succinimide-forming tripeptide sequence (E(N/D)(E/D)) in several archaeal GATases strongly suggests an adaptation of this otherwise detrimental post-translational modification as a harbinger of thermostability. 相似文献
26.
Thanks to its good corrosion resistance and biocompatibility, superelastic Ni–Ti wire alloys have been successfully used in orthodontic treatment. Therefore, it is important to quantify and evaluate the level of orthodontic force applied to the bracket and teeth in order to achieve tooth movement. In this study, three dimensional finite element models with a Gibbs-potential-based-formulation and thermodynamic principles were used. The aim was to evaluate the influence of possible intraoral temperature differences on the forces exerted by NiTi orthodontic arch wires with different cross sectional shapes and sizes. The prediction made by this phenomenological model, for superelastic tensile and bending tests, shows good agreement with the experimental data. A bending test is simulated to study the force variation of an orthodontic NiTi arch wire when it loaded up to the deflection of 3 mm, for this task one half of the arch wire and the 3 adjacent brackets were modeled. The results showed that the stress required for the martensite transformation increases with the increase of cross-sectional dimensions and temperature. Associated with this increase in stress, the plateau of this transformation becomes steeper. In addition, the area of the mechanical hysteresis, measured as the difference between the forces of the upper and lower plateau, increases. 相似文献
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29.
Ketata I Smaoui-Damak W Guermazi F Rebai T Hamza-Chaffai A 《Comparative biochemistry and physiology. Toxicology & pharmacology : CBP》2007,146(3):415-430
The gulf of Gabès is well known for its multiple contaminations which are closely associated with the past and present industrial and anthropogenic activity. In order to evaluate in situ the cadmium bioaccumulation in the clam Ruditapes decussatus sampled in this area, we measured cadmium concentrations in the whole soft tissues and in the digestive gland during one year. Energy reserves (proteins, glycogen, lipids) were monitored during gametogenesis in the remainder (mantle, adductor muscle, foot, siphons) of clams. Sex steroids (progesterone, testosterone, estradiol-17beta) were also measured by radio-immunoassay (RIA) in the gonads. The results showed that cadmium varied according to the reproductive cycle. High values were recorded at the resting stage in both sexes, during the gamete development and maturation in males and at the ripening and partially spawn stages in females. No significant changes in protein levels were observed in both females and males. However, high levels of glycogen and lipid reserves were recorded during the gametogenesis activity (from the development to the partially spawn stages). For steroid analyses, the results showed no important changes in testosterone levels all along the reproductive cycle. Fluctuations of sex steroids (especially progesterone and estradiol-17beta) could suggest their possible role as endogenous modulators of gametogenesis in R. decussatus. Correlation matrix and multiple regression models were also proposed to describe negative and significant relationship between cadmium and (glycogen, progesterone, testosterone and estradiol-17beta). These correlations may suggest the involvement of cadmium in the dysfunction of energy status and the endocrine disruption which could impede reproduction. 相似文献
30.
Leila Ammar-Keskes Nozha Chakroun Afifa Sellami Ben Hamida Lobna Hadj-Kacem Nouha Bouayed-Abdelmoula Hammadi Ayadi Mohamed Nabil Mhiri Tarek Rebai Ali Bahloul 《Andrologie》2007,17(1):71-79