从“未病学”思想谈糖尿病前期防治

未病先防,就是要全民普及糖尿病预防知识,密切监控糖尿病的高危人群;既病防变,就是要促进糖耐量低减人群向正常糖耐量转化,阻断糖尿病的蔓延。

Effective Potential of a Two-State Model for Molecular Motor

We study force generation and motion of molecular motors using a simple two-state model in the paper.Asymmetric and periodic potential is adopted to describe the interaction between motor proteins and filaments that are periodic and polar. The current and the slope of the effective potential as functions of the temperature and transition rates are calculated in the two-state model. The ratio of the slope of the effective potential to the current is also calculated. It is shown that the directed motion of motor proteins is relevant to the effective potential. The slope of the effective potential corresponds to an average force. The non-vanishing force therefore implies that detailed balance is broken in the process of transition between different states.

Effects of aerobic training on serum paraoxonase activity and its relationship with PON1-192 phenotypes in women

Background：Paraoxonase 1（PON1） is an antioxidant enzyme that protects high-density lipoprotein（HDL） and low-density lipoprotein against oxidation.Limited studies have addressed the influenc of exercise on PON1 activity and its relationship with PON1 phenotypes.We investigated relationships between PON1-192 phenotypes,PON1 activity,aerobic exercise,and blood lipid and lipoprotein concentrations in middle-aged women.Methods：An exercise group（n=50） engaging in regular aerobic exercise and a control group（n=41） were selected from a subset of 300 Caucasian women that met the inclusion criteria.Serum PON1,salt-stimulated PON1（SSPON1）,and arylesterase（ARE） activities;cholesterol levels and ARE activities of total HDL and HDL subgroups（HDLs）（supernatants obtained by polyethylene glycol）;and blood lipid and lipoprotein concentrations were determined by standardized enzymatic methods.PON1-192 QQ（low activity）,QR（moderate activity）,and RR（high activity） phenotype groups were define using serum SSPON1/ARE activity ratios.The R-carries（RC） phenotype group consisted of the QR and RR groups combined.Results：All lipid and lipoprotein concentrations were greater in the exercise group than in the control group.Regardless of phenotype,no significan differences were observed between the exercise and control groups in terms of serum PON1,SSPON1,or ARE activity associated with HDLs（p〉 0.05）,whereas PON1 activities in QQ-phenotyped women in the exercise group were significant y higher than those in the control group（p〈0.01）,but not the RC group.A statistically significan interaction between PON1 phenotypes（QQ and RC groups） and exercise（exercise and control groups） on PON1 activity was found.Conclusion：These results showed that a regular aerobic exercise program can improve PON1 activity depending on PON1-192 phenotype,but not on lipid and lipoprotein levels,in middle-aged Turkish women.

Failure to identify an acute exercise effect on executive function assessed by the Wisconsin Card Sorting Test

Purpose： Acute exercise has been linked to the facilitation of executive function, but little is known regarding executive function assessed by the Wisconsin Card Sorting Test （WCST）. The present research consisted of two experiments aimed to determine whether acute aerobic exercise influences successive WCST performance. Methods： In Study 1, 27 young adults were randomly assigned to the exercise or reading control group and then instiucted to perform the WCST before and after assigned treatment. In exercise group, participants completed a single bout aerobic exercise with moderate intensity for 20 min on a stationary bike. A similar experimental protocol was replicated in Study 2 with 24 late middle-aged adults to look for age differences during adulthood and control for a potential ceiling effect at young adult age. Results： Although a significant time effect was observed in young adults, both studies revealed that there was no main effect for treatment or an interaction between treatment and time on any of the WCST indices. Conclusion： Acute aerobic exercise failed to influence executive function as assessed by the WCST, revealing that this classical neuropsy- chological test tapping executive function may not be sensitive to acute exercise. Our findings suggest that acute exercise does not broadly affect the entire family of executive functions, or its effect on a specific aspect of executive function may be task-dependent, as proposed by Etnier and Chanj~ （2009）.

Structure reliability analysis based on supercavity vehicle steady motion

Taking the steady motion status as a starting point,according to the modeling of actual state of theoretical analysis,a predigested model of supercavity vehicle was established,and relationship expressions of these angles were obtained when the movement of supercavity vehicle was stable.A theoretical analysis on the stability of underwater high-speed movement in the movement simulation program was conducted and the simulation results were given.Then the force status of the supercavity vehicle was elicited from the results.The finite element analysis was carried out based on the stability at all angles obtained from simulation results.Taking a pilot model as example,the Monte Carlo method was adopting to analyze the reliability with the given state of force and displacement.The result indicates that this method is feasible.

Directivity Effect on PGV Attenuation Relationships in Silakhor Earthquake （2006, Mw6.1）

Rupture directivity effect causes spatial variation in strong ground motion parameters. It causes difference between the strike- normal （V.） and strike-parallel （Vp） components of horizontal ground motion amplitudes. These variations become significant for strong ground motion velocity and the authors have developed a modification to define directivity effect factor to account for the effect of rupture directivity in empirical velocity attenuation relations which are based on modeling Silakhor earthquake, using finite element method by ANSYS. The ground motion parameters that are modified include ratio of Vn/Vp component of horizontal velocity and Vn component to average horizontal velocity （V）. The ratio of Vn to Vp is large in both the forward directivity direction, where velocity is larger, and in the backward directivity direction, where velocity is smaller. Therefore the authors expected that the Vn/Vp was mainly controlled by directivity angle. Also the variation of fault normal velocity to average horizontal velocity ratio by directivity angle （0） is defined from earthquake modeling. It shows Vn/V is controlled by directivity angle, distance between the site, epicenter and rupture length. This ratio has the same trend in Silakhor earthquake strong ground velocity data. In this paper the equation for Vn/Vp variations by directivity angle is recommended. The authors used Somervill et al. （1997） directivity model parameters as （R/L） cos2 ~ to define directivity effect on Vn/V ratio and therefore directivity factor is determined to account in near field empirical strong ground velocity attenuation relationships.

Stochastic H_2/H_∞ Control for Poisson Jump-Diffusion Systems

This paper is concerned with stochastic H_2/H_∞ control problem for Poisson jump-diffusion systems with(x, u, v)-dependent noise, which are driven by Brownian motion and Poisson random jumps. A stochastic bounded real lemma(SBRL for short) for Poisson jump-diffusion systems is firstly established, which stands out on its own as a very interesting theoretical problem. Further, sufficient and necessary conditions for the existence of a state feedback H_2/H_∞ control are given based on four coupled matrix Riccati equations. Finally, a discrete approximation algorithm and an example are presented.