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INTRODUCTION: Intracellular reactive oxygen species (ROS) and nitric oxide (NO) levels are associated with vascular homeostasis and diseases. Exercise can modulate ROS and NO production through increasing frequency and magnitude of wall shear stress (WSS). However, the details of ROS and NO production in endothelial cells and their interplay under WSS induced by exercise at different intensities remain unclear. METHODS: In this study, we developed an in vitro multicomponent nonrectangular flow chamber system to simulate pulsatile WSS waveforms induced by moderate and high intensity exercise. Furthermore, the dynamic responses of ROS and NO in endothelial cells and the relationship between ROS and NO were investigated under the WSS induced by different intensity exercise. RESULTS: After exposing to WSS induced by moderate intensity exercise, endothelial cells produced more NO than those under high intensity exercise-induced WSS. In this process, ROS was found to play a dual role in the generation of intracellular NO. Under WSS induced by moderate intensity exercise, modest elevated ROS promoted NO production, whereas excessive ROS in endothelial cells exposed to WSS induced by high intensity exercise attenuated NO bioavailability. Interestingly, antioxidant N-acetylcysteine (NAC) could increase NO production under WSS induced by high intensity exercise. CONCLUSIONS: Our results provide some cues for selecting appropriate exercise intensities and elevating benefits of exercise on endothelial function. Additionally, owing to the consistency of our results and some in vivo phenomena, this flow chamber system may serve as an in vitro exercise model of arterial vessel for future studies.

Objective To investigate the effect of tuina along the pathways of meridians on lower limb swelling after surgical repair of fracture.

Background In vivo studies have demonstrated that reasonable exercise training can improve endothelial function. To confirm the key role of wall shear stress induced by exercise on endothelial cells, and to understand how wall shear stress affects the structure and the function of endothelial cells, it is crucial to design and fabricate an in vitro multi-component parallel-plate flow chamber system which can closely replicate exercise-induced wall shear stress waveforms in artery. Methods The in vivo wall shear stress waveforms from the common carotid artery of a healthy volunteer in resting and immediately after 30 min acute aerobic cycling exercise were first calculated by measuring the inner diameter and the center-line blood flow velocity with a color Doppler ultrasound. According to the above in vivo wall shear stress waveforms, we designed and fabricated a parallel-plate flow chamber system with appropriate components based on a lumped parameter hemodynamics model. To validate the feasibility of this system, human umbilical vein endothelial cells (HUVECs) line were cultured within the parallel-plate flow chamber under abovementioned two types of wall shear stress waveforms and the intracellular actin microfilaments and nitric oxide (NO) production level were evaluated using fluorescence microscope. Results Our results show that the trends of resting and exercise-induced wall shear stress waveforms, especially the maximal, minimal and mean wall shear stress as well as oscillatory shear index, generated by the parallel-plate flow chamber system are similar to those acquired from the common carotid artery. In addition, the cellular experiments demonstrate that the actin microfilaments and the production of NO within cells exposed to the two different wall shear stress waveforms exhibit different dynamic behaviors; there are larger numbers of actin microfilaments and higher level NO in cells exposed in exercise-induced wall shear stress condition than resting wall shear stress condition. Conclusion The parallel-plate flow chamber system can well reproduce wall shear stress waveforms acquired from the common carotid artery in resting and immediately after exercise states. Furthermore, it can be used for studying the endothelial cells responses under resting and exercise-induced wall shear stress environments in vitro.

Objective To observe the clinical effects of comprehensive treatment on cutaneous region for low back pain.

Based on bayesian statistics theory and reliability-based optimization design, the research presents a new reliability-based optimization design approach that solves the form of finite test samples. In the article, the bayesian reliability-based optimization mathematical model is established and the bayesian reliability-based optimization approach of torsion bar is proposed. The method adopts a bayesian inference technique to estimate reliability, gives definition of bayesian reliability. The results illustrates the method presented is an efficient and practical reliability-based optimization approach of torsion bar.

Recently, a continuous method has been proposed by Golub and Liao as an alternative way to solve the minimum and interior eigenvalue problems. According to their numerical results, their method seems promising. This article is an extension along this line. In this article, firstly, we convert an eigenvalue problem to an equivalent constrained optimization problem. Secondly, using the Karush–Kuhn–Tucker conditions of this equivalent optimization problem, we obtain a variant of the Rayleigh quotient gradient flow, which is formulated by a system of differential-algebraic equations. Thirdly, based on the Rayleigh quotient gradient flow, we give a practical numerical method for the minimum and interior eigenvalue problems. Finally, we also give some numerical experiments of our method, the Golub and Liao method, and EIGS (a Matlab implementation for computing eigenvalues using restarted Arnoldi’s method) for some typical eigenvalue problems. Our numerical experiments indicate that our method seems promising for most test problems.

In the present paper, some types of general solutions of a first-order nonlinear ordinary differential equation with six degree are given and a new generalized algebra method is presented to find more exact solutions of nonlinear differential equations. As an application of the method and the solutions of this equation, we choose the (2 + 1) dimensional Boiti Leon Pempinelli equation to illustrate the validity and advantages of the method. As a consequence, more new types and general solutions are found which include rational solutions and irrational solutions and so on. The new method can also be applied to other nonlinear differential equations in mathematical physics.

Summary A cylindrical microlens for implementing both functions of beam-splitting and focusing on the preset positions is proposed. Phase functions of the microlenses are determined by the ray-tracing method. The performance of the microlenses is investigated based on rigorous electromagnetic theory and the boundary element method. Numerical results show that the designed microlenses basically can realize beam-splitting and focusing on the preassigned positions simultaneously. Dual and triple beam-splitting and focusing on the expected positions by the designed microlenses are demonstrated. Diffraction efficiency of the the beam-splitting and focusing is evaluated.

Aging process is a key factor influencing the availability and toxicity of heavy metals in soil. However, the aging of chromium (Cr) in soils and its influence factors are still unclear, as a result of complexity of soils in China. This study was conducted to investigate the aging process of Cr(Ill) in 22 typical soils of China by using 0.01 mol.L-1 CaCl2 as the extractant for available Cr. The results manifested that Cr spiked in the soil was time-dependently transferred from the available fraction into less labile fractions. Two regions could be distinguished: the first one for short extraction time (t21 days), corresponding to a faster transformation of metals and the second for longer extraction time (t21 days) where the transformation was relatively slower. The decrease of Cr in available fraction during the incubation could be simulated by the Elovich equation, and decrease rates were applied to reflect the transformation rates of aging process among various soils. Multiple regression analysis showed that decrease rates might be related to the organic matter, pH and amorphous Fe oxides of soil, and organic matter was the key factor to the aging process.

To observe the therapeutic effects of acupuncture at Neiguan (PC 6) on silent myocardial ischemia (SMI).Forty patients with SMI were randomly divided into an electroacupuncture group and a medicine group, 20 cases in each group. The Electroacupuncture group was treated with electroacupuncture and Neiguan (PC 6) was selected as the main acupoint, and the other acupoints were selected by syndrome differentiation. The medicine group was treated with oral administration of compound Danshen dripping pill. The total effective rate, heart rate, blood pressure and dynamic electrocardiogram in 24 h were compared.The total effective rate of 95.0% (19/20) in the electroacupuncture group was better than that of 75.0% (15/20) in the medicine group (P0.05). After treatment, the heart rate, systolic blood pressure and diastolic blood pressure in the two groups were decreased significantly (P0.01, P0.05) and the electroacupuncture group was superior to the medicine group (all P0.05). The SMI duration and the number of ST segment depression were decreased significantly in both groups after treatment (P0.01, P0.05) and the electroacupuncture group was superior to the medicine group (P0.05).Acupuncture at Neiguan (PC 6) has a good therapeutic effect on SMI. It can decrease the heart rate and blood pressure, reduce the afterload in left ventricular and is superior to that of compound Danshen dripping pill.

The optical properties of silicon nanowires (Si NWs) coated with metallic nanoparticles (NPs) were theoretically investigated. A three dimensional (3D) model of a solar cell has been proposed, in which the Si NWs were geometrically modeled to be periodically aligned nano-pillars in a square lattice. Hemispherical metallic NPs were coated onto a sidewall of Si NWs. We numerically studied the optical properties of the structure with the finite element method (FEM) by using the commercial software COMSOL Multiphysics. It is demonstrated that the electromagnetic field is strongly localized around the metallic NPs as well as between the metallic NPs and Si NWs. Localized surface plasmons (LSPs) are generated around the metallic NPs, coupling and scattering a large amount of light into the Si NWs. A significant enhancement of the light absorption is observed, especially in the long wavelength range of the solar spectrum. These theoretical investigations agree well with our experimental data while providing a fundamental background for improving the efficiency of Si NWs solar cells.

A new system for simultaneous electrodeposition of U, Np, Pu, Am and Cm has been developed. The system consists of (NH4)2C2O4−H2SO4−HCl. The effects on recovery of pH, current density, interfering ions and the amount of added HCl have been studied. The optimum condition for simultaneous electrodeposition of actinides has been recommended. Under the recommended condition recoveries of U, Np, Pu, Am and Cm have been obtained by using232U,237Np,241Am,242Pu and244Cm. The counting sources prepared are uniform, adherent and suitable for α-spectrometry.