Causal relationship between circulating vitamin C and 25-hydroxyvitamin D concentrations and common mental disorders-a Mendelian randomization study

Mental disorders seriously affect people’s health and social stability.This Mendelian randomization(MR)study was designed to investigate the causal relationship between circulating vitamin C(VC)or 25-hydroxyvitamin D(25(OH)D)levels and mental disorders.The data used for the MR analysis were derived from the summary genome-wide association studies(GWAS)database for VC and 25(OH)D and from the Finn Gen consortium for fourteen mental disorders.Based on the inverse variance weighted(IVW)method,we found a potential causal association between circulating VC and anxiety disorders(IVW:OR=1.139,95%CI:1.023-1.269,P=0.018).However,no causal association was found between VC or 25(OH)D and other mental disorders(P>0.05).In the reverse MR analysis,individuals with Alzheimer’s disease was causally associated with higher concentrations of circulating VC(P=0.012),while individuals with anxiety disorders had a negative association between the concentrations of 25(OH)D(P=0.012).However,the current evidence does not support a causal relationship between VC or 25(OH)D and other mental disorders.In addition,there was no causal association between circulating VC and 25(OH)D(P>0.05).Future studies are needed to confirm these findings and to elucidate the mechanisms of potential causality.

Different n-6/n-3 polyunsaturated fatty acid ratios affect postprandial metabolism in normal and hypertriglyceridemic rats

Postprandial metabolism plays major roles in many pathological conditions.The n-6/n-3 polyunsaturated fatty acid(PUFA)ratio is closely related to various physiological disorders.This study aimed to investigate the effects of high fat meals with different n-6/n-3 PUFA ratios on postprandial metabolism in normal control(NC)and hypertriglyceridemia(HTG)rats.The postprandial response of triglyceride(TG)in HTG groups was higher than that in NC groups after different n-6/n-3 PUFA ratio meals.The HTG groups showed higher postprandial total cholesterol(TC)responses than NC groups after 1:1 and 20:1 ratio meals.The 5:1 n-6/n-3 PUFA ratio elicited lower postprandial responses of tumor necrosis factorα(TNF-α)than 1:1 and 10:1 ratios in HTG groups.The postprandial malondialdehyde(MDA)response was lower after a 5:1 n-6/n-3 PUFA ratio meal than 1:1 and 20:1 ratio meals in HTG groups.The 1:1 ratio resulted in a lower postprandial reactive oxygen species(ROS)level than 5:1 and 10:1 n-6/n-3 PUFA ratios in NC groups.The results showed that a low n-6/n-3 PUFA ratio improved postprandial dysmetabolism induced by a high fat meal in NC and HTG rats.A high n-6/n-3 PUFA ratio increased the difference in postprandial metabolism between NC and HTG rats.

Investigation of gyrotron-based collective Thomson scattering for fast ion diagnostics in a compact high-field tokamak

As a promising method for fast ion diagnostics,collective Thomson scattering(CTS)can measure the one-dimensional velocity distribution of fast ions with high spatial and temporal resolution.The feasibility of diagnosing fast ions in a compact high-field tokamak by CTS was studied in this work,and the results showed that a wide range of probing frequencies could be applied.A high-frequency case and a low-frequency case were mainly considered for fast ion diagnostics in a compact high-field tokamak.The use of a high probing frequency could effectively avoid the refraction effect of the beams,while the application of a low probing frequency allows greater flexibility in the selection of scattering angle which may help to improve the spatial resolution.Based on typical plasma conditions(B_(0)=12.2 T,n_(e0)=4.3×10^(20)m^(-3),T_(e0)=22.2 keV,T_(i0)=19.8 keV)for a compact high-field tokamak,a220 GHz CTS diagnostic that utilizes a small scattering angle ofθ=30°and a 160 GHz CTS diagnostic that utilizes an orthogonal geometry were proposed.Further study showed that the high-frequency case could operate in a wider range of plasma conditions and provide more information on fast ions while the low-frequency case could achieve higher spatial resolution of the poloidal direction.

Recent progress of the ECRH system and initial experimental results on the J-TEXT tokamak

In order to broaden the range of the plasma parameters and provide experimental conditions for physical research into high-performance plasma,the development of the electron cyclotron resonance heating(ECRH) system for the J-TEXT tokamak was initiated in 2017.For the first stage,the ECRH system operated successfully with one 105 GHz/500 kW/1 s gyrotron in 2019.More than 400 kW electron cyclotron(EC) wave power has been injected into the plasma successfully,raising the core electron temperature to 1.5 keV.In 2022,another 105 GHz/500 kW/1 s gyrotron completed commissioning tests which signifies that the ECRH system could generate an EC wave power of 1 MW in total.Under the support of the ECRH system,various physical experiments have been carried out on J-TEXT.The electron thermal transport in ECRH plasmas has been investigated.When ECRH is turned on,the electron thermal diffusivity significantly increases.The runaway current is elevated when a disruption occurs during ECRH heating.When the injected EC wave power is 400 kW,the conversion efficiency of runaway current increases from 35% to 75%.Fast electron behavior is observed in electron cyclotron current drive(ECCD) plasma by the fast electron bremsstrahlung diagnostic(FEB).The increase in the FEB intensity implies that ECCD could generate fast electrons.A successful startup with a 200 kW ECW is achieved.With the upgrade of the ECRH system,the J-TEXT operational range could be expanded and further relevant research could be conducted.

Error Analysis on the Positioning Accuracy of a Pneumatic Vibration Isolator

A method of error analysis on the positioning accuracy of a pneumatic vibration isolator was proposed.First,the necessity of positioning accuracy was studied,in addition to the key factors associated with positioning accuracy.These analyses indicated that the positioning accuracy of the pneumatic vibration isolator was mainly attributed to the position error of the push button and the gap between the spindle and valve stem.Second,the error model of the positioning accuracy of the pneumatic vibration isolator was established through geometric simplification and geometric calculation.There are different methods used to calculate the position error of the push button for the different valves.Finally,an example analysis evaluating the impact of a specific two-position three-way valve on the positioning accuracy was given by means of error distribution.Experimental results validated the accuracy of the error model and the example analysis.This error model can be used to guide the structural parameter optimization design according to the requirements for positioning accuracy.

Energy Cycle Insingle Degree of Freedom Conservative Vibration Isolation Systems

To obtain a longer natural period in single degree of freedom(SDF) conservative vibration isolation systems, many scholars have proposed different methods. This paper uncovers a clockwise energy cycle existing in a mass-spring system, in which the potential energy and kinetic energy convert with each other, and the natural period is determined by the magnitude of the energy cycle. Compared to water flow inside a pipe, the previous methods can be consolidated into two methods to make the energy cycle narrower;one is to optimize the parameters directly, the other is to indirectly add an anticlockwise energy cycle to the original one. The anticlockwise energy cycle has the characteristic of gravitational potential energy or elastic potential energy that reduces with displacement. The highly abstract method can provide a better optimization tool to design a practice system.

Design and Analysis of a Horizontal Quasi-Zero Stiffness Vibration Isolator by Combining Rolling-Ball and Disk Springs in Parallel

Combining disk springs having negative stiffness with a rolling-ball in parallel is proposed in this paper. It is used to reduce the system stiffness and the positioning error in a non-ideal environment.The characteristics of a disk spring are analyzed. The dynamic equation of its motion has been obtained based on Newton＇s second law. After definition of a error margin,the dynamic equation of the motion can be treated as a Duffing oscillator,and the influences of non-dimensional parameters on the stiffness and transmissibility are studied. The natural frequency and transmissibility are achieved in a linearization range,where the ratio of linear to nonlinear items is small enough.The influence of mass ratio and non-dimensional parameters on natural frequency are analyzed. Finally,a comparison of numerical example demonstrates that the QZS system can realize a lower stiffness within an increased range.