Laser-driven lepton polarization in the quantum radiation-dominated reflection regime

Generation of ultrarelativistic polarized leptons during interaction of an ultrarelativistic electron beam with a counterpropagating ultraintense laser pulse is investigated in the quantum radiation-dominated domain. While the symmetry of the laser field tends to average the radiative polarization of leptons to zero, we demonstrate the feasibility of sizable radiative polarization through breaking the symmetry of the process in the reflection regime. After the reflection, the off-axis particles escape the tightly focused beam with polarization correlated to the emission angle, while the particles at the beam center are more likely to be captured in the laser field with unmatched polarization and kinetic motion. Meanwhile, polarization along the electric field emerges due to the spin rotation in the transverse plane via precession. In this way, the combined effects of radiative polarization, spin precession and the laser field focusing are shaping the angle-dependent polarization for outgoing leptons. Our spin-resolved Monte Carlo simulations demonstrate an angle-dependent polarization degree up to $\sim20\%$ for both electrons and positrons, with a yield of one pair per seed electron. It provides a new approach for producing polarized high density electron and positron jets at ultraintense laser facilities

Validity of self-reported weight, height and resultant body mass index in Chinese adolescents and factors associated with errors in self-reports

<p>Abstract</p> <p>Background</p> <p>Validity of self-reported height and weight has not been adequately evaluated in diverse adolescent populations. In fact there are no reported validity studies conducted in Asian children and adolescents. This study aims to examine the accuracy of self-reported weight, height, and resultant BMI values in Chinese adolescents, and of the adolescents' subsequent classification into overweight categories.</p> <p>Methods</p> <p>Weight and height were self-reported and measured in 1761 adolescents aged 12-16 years in a cross-sectional survey in Xi'an city, China. BMI was calculated from both reported values and measured values. Bland-Altman plots with 95% limits of agreement, Pearson's correlation and Kappa statistics were calculated to assess the agreement.</p> <p>Results</p> <p>The 95% limits of agreement were -11.16 and 6.46 kg for weight, -4.73 and 7.45 cm for height, and -4.93 and 2.47 kg/m²for BMI. Pearson correlation between measured and self-reported values was 0.912 for weight, 0.935 for height and 0.809 for BMI. Weighted Kappa was 0.859 for weight, 0.906 for height and 0.754 for BMI. Sensitivity for detecting overweight (includes obese) in adolescents was 56.1%, and specificity was 98.6%. Subjects' area of residence, age and BMI were significant factors associated with the errors in self-reporting weight, height and relative BMI.</p> <p>Conclusions</p> <p>Reported weight and height does not have an acceptable agreement with measured data. Therefore, we do not recommend the application of self-reported weight and height to screen for overweight adolescents in China. Alternatively, self-reported data could be considered for use, with caution, in surveillance systems and epidemiology studies.</p

Experimental Study of Impact of Dock Structures on Water Level in Mountainous Waterway

Source: ICHE Conference Archive - https://mdi-de.baw.de/icheArchive

Dexmedetomidine preconditioning alleviates apoptosis in rat cardiomyocytes by suppressing programmed cell death 4 (PDCD4) after myocardial ischemia-reperfusion injury

Purpose: To determine the role of dexmedetomidine (Dex) in hypoxia/reoxygenation (H/R)-induced myocardial cell injury and the possible involvement of the programmed cell death 4 (Pdcd4) gene in Dex-mediated myocardial cell apoptosis after ischemia-reperfusion (I/R) injury. Methods: An in vivo I/R-injured rat model and in vitro H/R rat cell model were evaluated to ascertain the role of Dex in apoptosis. Programmed cell death 4 (PDCD4) gene expression levels were measured after Dex preconditioning. The effects of Pdcd4 knockdown or overexpression on Dex-mediated apoptosis during H/R injury were determined. Results: Dex pretreatment alleviated myocardial infarction in rats, suppressed myocardial cell apoptosis, and inhibited PDCD4 expression (p &lt; 0.05). Treatment with Dex also alleviated H/R-induced apoptosis in rat cardiomyocytes, while PDCD4 expression decreased after Dex treatment (p &lt; 0.05). Moreover, PDCD4 overexpression reversed the inhibitory effect of Dex on H/R myocardial cell apoptosis. Conclusion: Dex alleviates myocardial infarction in rats via its effect on PDCD4 expression. Therefore, Dex can potentially be used for the treatment but this has to clinical studies

Molecular simulation and spectroscopic studies on the interaction between perfluorohexadecanoic acid and human serum albumin

185-192In the present study, the interaction between Perfluorohexadecanoic acid (PFHxDA) and human serum albumin (HAS) was studied by fluorescence spectroscopy, molecular docking, dynamic simulation and circular dichroism (CD). The interaction character and the effect on human serum albumin conformation were measured by simulating the physiological condition (pH= 7.4). Experiments and simulation results revealed that PFHxDA molecules and HSA have regular fluorescence quenching, and the quenching mechanism is static quenching and non-radiative energy transfer. Thermodynamic analysis revealed the binding behavior was mainly governed by hydrophobic forces. Specific binding site experiments showed that the binding site of PFHxDA was a site I of HSA. The results from the CD spectrum demonstrated that PFHxDA changed the molecular conformation of HSA, which is consistent with the results obtained by molecular docking and dynamic simulation

Molecular simulation and spectroscopic studies on the interaction between perfluorohexadecanoic acid and human serum albumin

In the present study, the interaction between Perfluorohexadecanoic acid (PFHxDA) and human serum albumin (HAS) was studied by fluorescence spectroscopy, molecular docking, dynamic simulation and circular dichroism (CD). The interaction character and the effect on human serum albumin conformation were measured by simulating the physiological condition (pH= 7.4). Experiments and simulation results revealed that PFHxDA molecules and HSA have regular fluorescence quenching, and the quenching mechanism is static quenching and non-radiative energy transfer. Thermodynamic analysis revealed the binding behavior was mainly governed by hydrophobic forces. Specific binding site experiments showed that the binding site of PFHxDA was a site I of HSA. The results from the CD spectrum demonstrated that PFHxDA changed the molecular conformation of HSA, which is consistent with the results obtained by molecular docking and dynamic simulation