168 research outputs found

    Effects of butylated hydroxytoluene on blood liver enzymes and liver glutathione and glutathione-dependent enzymes in rats

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    This study was aimed to detect the effect of butylated hydroxytoluene (BHT) on the liver glutathione level and glutathione-dependent enzyme activities in female Wistar albino rats. BHT was adminis-tered by oral gavage at a dose of 250 mg/kg (Group I) and 500 mg/kg (Group II) for 28 days, 1000 mg/kg (Group III) and 1500 mg/kg (Group IV) for 4 days. The serum ALT, AST and LDH activities were measured on an autoanalyzer, and liver gluthathione (GSH), gluthathione peroxidase (GPx), gluthathione S-transferase (GST), and gluthathione reductase (GR) activities were analysed with commercial ELISA kits. The ALT activity was significantly higher in Groups III and IV (P<0.05 and P<0.001, respectively) compared to the control group. Blood AST and LDH activities were signifi-cantly increased in Group IV (P<0.05). The GSH, GPx, GST and GR in the liver tissue were deter-mined to be statistically low in Groups II, III and IV (P<0.001) in comparison with control group. In microscopic examination, BHT caused histopathological changes in the rat liver tissue in Groups II, III and IV depending on the dose and duration of exposure. It can be concluded that BHT plays a role in producing liver damage in rats with depressed hepatic antioxidant defense. The hepatotoxic re-sponse seemed to be dose- and time-dependent

    Substitutional effect of Ti-based AB2 hydrogen storage alloys: A density functional theory study

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    Stability of AB2 alloy in Laves phases C14 and C15 were studied by first-principle density functional theory simulations. A range of different combinations of B and C elements in the Ti1−xCxB2 alloys were considered. The formation energies of these alloys generally increase with the unit cell volumes of alloys. The volume also affects the stability of the corresponding metal hydride. We find that the formation energies and the hydrogenation enthalpies of AB2 alloys are likely to be determined by at least three factors: electronegativity, atomic radius and covalent radius. The enthalpies of AB2 hydrides increase with increasing compositionally-averaged electronegativity and volume change upon hydrogenation. However, the enthalpies of AB2 hydrides decrease with increasing compositionally-averaged atomic and covalent radii. This study provides useful insights for future exploration of AB2-type alloys for hydrogen storage applications

    Sox1 is required for the specification of a novel p2-derived interneuron subtype in the mouse ventral spinal cord

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    During mouse development, the ventral spinal cord becomes organized into five progenitor domains that express different combinations of transcription factors and generate different subsets of neurons and glia. One of these domains, known as the p2 domain, generates two subtypes of interneurons, V2a and V2b. Here we have used genetic fate mapping and loss-of-function analysis to show that the transcription factor Sox1 is expressed in, and is required for, a third type of p2-derived interneuron, which we named V2c. These are close relatives of V2b interneurons, and, in the absence of Sox1, they switch to the V2b fate. In addition, we show that late-born V2a and V2b interneurons are heterogeneous, and subsets of these cells express the transcription factor Pax6. Our data demonstrate that interneuron diversification in the p2 domain is more complex than previously thought and directly implicate Sox1 in this proces

    Analisis Hidrolika Bangunan Krib Permeabel pada Saluran Tanah (Uji Model Laboratorium)

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    One of the structures to protect river bank erosion is groyne. Groyne can serve and control water flow, reducing flow velocity and scour of river bank. The purposes of this study is to analyze the changes in the river bed elevation (morphology) and the depth of scour in the upstream groyne caused by the permeable groyne installed at the river meanders. The experiment was conducted at Fluid Mechanics and Hydraulics Laboratory, Sriwijaya University. The study tested the hydraulics models, a trapezoidal channel, meanders angle of 90˚, five permeable groynes at meanders, and the water flowing in the channels was clear water. The observations were carried out with a flow rate was 63,32 Lt / min, three variations of permeable groynes angle were 45˚, 90˚ and 135˚ to the upstream within 1 hour, 2,5 hours and 4 hours for each angle variations . The results of this study showed that the flow velocity of meanders was decreasing to the end of the meanders, and the changes of channel only occurred at the riverbed. Maximum riverbed changes (Bt / Bo) for permeable groyne angle of 45˚, 90˚ and 135 ˚ were 1,376 cm, 1,346 cm dan 1,452 cm. The maximum depth of scour (ds/y) for permeable groyne angle of 45˚, 90˚ and 135˚ were 1,05 cm, 0,95 cm dan 1,17 cm. Thus, permeable groyne with angle of 90 proved to be the best with the smallest riverbed changes (Bt /Bo) was 1,346 cm and the coefficient of determination (R2) was 0,9384, and also the smallest scour depth (ds/y) was 0,95 cm and the coefficient of determination (R2) was 0,8317 compared to other groyne permeable angles

    Vision-based relative navigation for formation flying of spacecraft

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    The objective of this paper is to develop a robust and efficient approach for relative navigation and at-titude estimation of spacecraft flying in formation. The approach developed here uses information from a new optical sensor that provides a line of sight vector from the master spacecraft to the secondary satel-lite. The overall system provides a novel, reliable, and autonomous relative navigation and attitude determi-nation system, employing relatively simple electronic circuits with modest digital signal processing require-ments and is fully independent of any external systems. State estimation is achieved through an optimal ob-server design, which is analyzed using a Lyapunov and contraction mapping approach. Simulation results in-dicate that the combined sensor/estimator approach provides accurate relative position and attitude esti-mates

    A high Gas6 level in plasma predicts venous thromboembolism recurrence, major bleeding and mortality in the elderly: a prospective multicenter cohort study.

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    Essentials Predictive ability of pro-hemostatic Gas6 for recurrent venous thromboembolism (VTE) is unknown. We measured Gas6 levels in 864 patients with VTE over 3 years. High Gas6 (&gt; 157%) at diagnosis is associated with VTE recurrence, major bleeding and mortality. Gas6 plasma levels measured 12 months after the index VTE are discriminatory for VTE recurrence. SUMMARY: Background Growth arrest-specific gene 6 (Gas6) is a prohemostatic protein with an unknown predictive ability for recurrent venous thromboembolism (VTE). In the elderly, VTE results in higher mortality but does not have a higher rate of recurrence than in younger patients. Consequently, anticoagulation management in the elderly is challenging. Objective To prospectively investigate the performance of Gas6 in predicting VTE recurrence, major bleeding and mortality in the elderly. Methods Consecutive patients aged ≥ 65 years with acute VTE were followed for a period of 3 years. Primary outcomes were symptomatic VTE recurrence, major bleeding, and mortality. Plasma Gas6 was measured with ELISA. Results Gas6 levels were measured in 864 patients at the time of the index VTE (T1) and, in 70% of them, also 12 months later (T2). The Gas6 level at T1 was discriminatory for VTE recurrence (C-statistic, 0.56; 95% confidence interval [CI] 0.51-0.62), major bleeding (0.60, 95% CI 0.55-0.65) and mortality (0.69, 95% CI 0.65-0.73) up to 36 months. VTE recurrence up to 24 months after T2 was discriminated by the Gas6 level at T2 (0.62, 95% CI 0.54-0.71). High Gas6 levels (&gt; 157%) and continuous Gas6 levels at T1 were associated with VTE recurrence up to 6 months and 12 months, respectively. Conclusions In elderly patients, a high Gas6 level is associated with higher risks of VTE recurrence, major bleeding, and death. These findings support further studies to assess the performance of Gas6 in adjusting the length of anticoagulation

    Broad and narrow personality traits as markers of one-time and repeated suicide attempts: A population-based study

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    <p>Abstract</p> <p>Background</p> <p>Studying personality traits with the potential to differentiate between individuals engaging in suicide attempts of different degrees of severity could help us to understand the processes underlying the link of personality and nonfatal suicidal behaviours and to identify at-risk groups. One approach may be to examine whether narrow, i.e., lower-order personality traits may be more useful than their underlying, broad personality trait dimensions.</p> <p>Methods</p> <p>We investigated qualitative and quantitative differences in broad and narrow personality traits between one-time and repeated suicide attempters in a longitudinal, population-based sample of young French Canadian adults using two multivariate regression models.</p> <p>Results</p> <p>One broad (Compulsivity: OR = 2.0; 95% CI 1.2–3.5) and one narrow personality trait (anxiousness: OR = 1.1; 95% CI 1.01–1.1) differentiated between individuals with histories of repeated and one-time suicide attempts. Affective instability [(OR = 1.1; 95% CI 1.04–1.1)] and anxiousness [(OR = .92; 95% CI .88–.95)], on the other hand, differentiated between nonattempters and one-time suicide attempters.</p> <p>Conclusion</p> <p>Emotional and cognitive dysregulation and associated behavioural manifestations may be associated with suicide attempts of different severity. While findings associated with narrow traits may be easier to interpret and link to existing sociobiological theories, larger effect sizes associated with broad traits such as Compulsivity may be better suited to objectives with a more clinical focus.</p
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