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Background Myocardial infarction (MI) is an acute and fatal condition that threatens human health. Dl-3-n-butylphthalide (NBP) has been used for the treatment of acute ischemic stroke. Mitochondria may play a protective role in MI injury. However, there are few reports on the cardioprotective effect of NBP or the potential mitochondrial mechanism for the NBP-induced protection against cardiac ischemia injury. We investigated the therapeutic effects of NBP in an in vivo MI model and an in vitro oxidative stress model, as well as the potential mitochondrial mechanism. Methods This study comprised two different experiments. The aim of experiment 1 was to determine the protective effects of NBP on MI and the underlying mechanisms in vivo. In part 1, myocardial infarct size was measured by staining with 2,3,5-triphenyltetrazoliumchloride (TTC). Myocardial enzymes and mitochondrial enzymes were assayed. The aim of experiment 2 was to investigate the role of NBP in H 2 O 2 -induced myocardial ischemic injury in H9c2 cells and to determine the potential mechanism. In part 2, H9c2 cell viability was evaluated. ROS levels, mitochondrial morphology, and mitochondrial membrane potential of H9c2 cells were measured. ATP levels were evaluated using an assay kit; mitochondrial DNA (mtDNA), the expressions of NRF-1 and TFAM, and mitochondrial biogenesis factors were determined. Results NBP treatment significantly reduced the infarct ratio, as observed by TTC staining, decreased serum myocardial enzymes in MI, and restored heart mitochondrial enzymes (isocitrate dehydrogenase (ICDH), succinate dehydrogenase (SDH), malate dehydrogenase (MDH), and a-ketoglutarate dehydrogenase (a-KGDH) activities after MI. Moreover, in in vitro studies, NBP significantly increased the viability of H9c2 cells in a dose-dependent manner, reduced cell apoptosis, protected mitochondrial functions, elevated the cellular ATP levels, and promoted H 2 O 2 -induced mitochondrial biogenesis in H9c2 cardiomyoblasts. Conclusion Collectively, the results from both the in vivo and in vitro experiments suggested that NBP exerted a cardioprotective effect on cardiac ischemic injury via the regulation of mitochondrial function and biogenesis.

To increase the accuracy of reservoir evaluation, a new type of seismoelectric logging instrument was designed. The designed tool comprises the invented sonde-structured array complex. The tool includes several modules, including a signal excitation module, data acquisition module, phased array transmitting module, impedance matching module and a main system control circuit, which are interconnected through high-speed tool bus to form a distributed architecture. UC/OS-II was used for the real-time system control. After constructing the experimental measurement system prototype of the seismoelectric logging detector, its performance was verified in the laboratory. The obtained results showed that the consistency between the multi-channel received waveform amplitude and benchmark spectrum was more than 97%. The binary phased linear array transmitting module of the instrument can realize 0° to 20° deflection and directional radiation. In the end, a field test was conducted to verify the tool’s performance in downhole conditions. The results of this test proved the effectiveness of the developed seismoelectric logging tool.

A novel approach for simulating the process is proposed in this work, which studies the influences of shot peening parameters such as peening angle, the size of balls on the surface roughness, and residual compressive stress material. An attempt has been made to address this issue by indicating a finite element model with randomly distributed balls developed with ABAQUS python program. A Johnson–Cook material model coupling the random ball theory is implemented into the FEM model to characterize the dynamic process of shot peening and surface modification properties of materials. In the proposed approach, the shot peeing parameters including the shot size, incidence angle, and velocity are estimated by parametric modeling to determine peening coverage precisely; furthermore, the effects of shot peening parameters on the residual compressive stress (RCS) and roughness are investigated. The shot peening simulations for AISI 4340 steel are carried out to validate the random balls model. The results show that the RCS distribution and surface roughness obtained by using the proposed method are in agreement with the experimental results in references.

42CrMo high-strength steel is a material that is difficult to machine and has difficulties controlling the quality of the machined surface. To ensure the stability of surface quality during cutting, lead the adjustment of cutting parameters to accurately predict the 42CrMo steel's machined surface roughness ( Ra ). Single factor cutting, orthogonal cutting, and response surface cutting experiments were conducted based on the experimental platform, and single factor, range, and grey correlation analyses were performed on the surface roughness measurement results. It can be concluded that within a given range, the feed per tooth has the greatest impact on surface roughness, and the cutting depth has the least impact on surface roughness. The PSO-SVM surface roughness prediction model was developed and compared with other widely used surface roughness prediction models (BP, SVM, GA-BP, PSO-BP) by using experimental data on the machined surface roughness of cutting 42CrMo steel. It can be concluded that the PSO-SVM training set prediction model has an average relative prediction error of 4.76% and a goodness of fit R 2  = 0.87198, which is quite near to 1. The PSO-SVM testing set prediction model has an average relative prediction error of 12.65% and a goodness of fit of R 2  = 0.86406, which is quite near to 1. Since it can effectively guide the selection and adjustment of cutting parameters, the PSO-SVM surface roughness prediction model has high prediction accuracy, good fitting degree, and stability. It also has a specific reference value for the study of the cutting process and surface quality of 42CrMo steel.

Background This review aims to evaluate the performance and clinical applicability of the A2DS2 scale via systematic review and meta-analysis. Methods The Medline, Embase, Cochrane Library, CBM, CNKI, and Wanfang databases were searched. The risk of bias was assessed using the Quality Assessment of Diagnostic Accuracy Studies (QUADAS-2). Funnel plots and Egger’s test were used to evaluate publication bias. The bivariate random-effect model was used for calculating the sensitivity, specificity, positive likelihood ratio, negative likelihood ratio, diagnostic odds ratio, and area under the curve (AUC). A Fagan nomogram was applied to evaluate the clinical applicability of the A2DS2 scale. Results A total of 29 full-text articles met the inclusion criteria, including 19,056 patients. Bivariate mixed-effects regression models yielded a mean sensitivity of 0.78 (95 % CI: 0.73–0.83), a specificity of 0.79 (95 % CI: 0.73–0.84), a positive likelihood ratio of 3.7 (95 % CI: 2.9–4.6), and a negative likelihood ratio of 0.27 (95 % CI: 0.23–0.33). The area under the receiver operating characteristic curve was 0.85 (95 % CI: 0.82–0.88). If given a pre-test probability of 50 %, the Fagan nomogram showed that when A2DS2 was positive, the post-test probability improved to 79 %. In contrast, when A2DS2 was negative, it decreased to 22 %. The results of the subgroup analysis showed no effect on the diagnostic accuracy of the A2DS2 scale in predicting stroke-associated pneumonia, except for the optimal cut-off value. Conclusions The A2DS2 scale demonstrates high clinical applicability and could be a valid scale for the early prediction of stroke-associated pneumonia in stroke patients.

In current industrial practice, the finite element modeling of the metal cutting process is essential. In this paper, finite element analysis of conventional and high-speed cutting of 7075-T6 aluminum alloy is carried out. A finite element model of the 7075-T6 aluminum alloy was developed using the Johnson Cook instant on equation to investigate the milling behavior of the alloy under conventional and high-speed conditions. The cutting forces in the X-direction, Y-direction, and Z-direction were predicted analytically for five groups of different Johnson Cook models with different material constants, and the predicted results were compared with the experimentally determined cutting forces to investigate the influence of the Johnson Cook constitutive model parameters on the simulation of the cutting forces of the 7075-T6 aluminum alloy. The results showed that the constitutive model parameters are inconsistent for conventional and higher speed cutting conditions. Under conventional cutting conditions, the JC4 model predicts the material factor cutting forces in good agreement with the experimental results, while under high-speed cutting conditions, the JC5 model predicts the material factor cutting forces in good agreement with the experimental results, but that the finite element model has good applicability in predicting machining performance. Only the experimental data obtained by covering the real strain, strain rate and temperature range to determine the material constant of the Johnson Cook constitutive equation can accurately predict the cutting force in all directions.

Neurogenesis, especially neurite outgrowth is an essential element of neuroplasticity after cerebral ischemic injury. Mitochondria may supply ATP to power fundamental developmental processes including neuroplasticity. Although rosuvastatin (RSV) displays a potential protective effect against cerebral ischemia, it remains unknown whether it modulates mitochondrial biogenesis and function during neurite outgrowth. Here, the oxygen-glucose deprivation (OGD) model was used to induce ischemic injury. We demonstrate that RSV treatment significantly increases neurite outgrowth in cortical neurons after OGD-induced damage. Moreover, we show that RSV reduces the generation of reactive oxygen species (ROS), protects mitochondrial function, and elevates the ATP levels in cortical neurons injured by OGD. In addition, we found that, under these conditions, RSV treatment increases the mitochondrial DNA (mtDNA) content and the mRNA levels of mitochondrial transcription factor A (TFAM) and nuclear respiratory factor 1 (NRF-1). Furthermore, blocking Notch1, which is expressed in primary cortical neurons, reverses the RSV-dependent induction of mitochondrial biogenesis and function under OGD conditions. Collectively, these results suggest that RSV could restore neurite outgrowth in cortical neurons damaged by OGD , by preserving mitochondrial function and improving mitochondrial biogenesis, possibly through the Notch1 pathway.

Class function/shape function transformation (CST) is an advanced geometry representation method employed to generate airfoil coordinates. Aiming at the morbidity of the CST coefficient matrix, the pivot element weighting iterative (PEWI) method is proposed to improve the condition number of the ill-conditioned matrix in the CST. The feasibility of the PEWI method is evaluated by using the RAE2822 and S1223 airfoil. The aerodynamic optimization of the S1223 airfoil is conducted based on the Isight software platform. First, the S1223 airfoil is parameterized by the CST with the PEWI method. It is very significant to confirm the range of variables for the airfoil optimization design. So the normalization method of design variables is put forward in the paper. Optimal Latin Hypercube sampling is applied to generate the samples, whose aerodynamic performances are calculated by the numerical simulation. Then the Radial Basis Functions (RBF) neural network model is trained by these aerodynamic performance data. Finally, the multi-island genetic algorithm is performed to achieve the maximum lift-drag ratio of S1223. The results show that the robustness of the CST can be improved. Moreover, the lift-drag ratio of S1223 increases by 2.27% and the drag coefficient decreases by 1.4%.

The biological mechanisms behind health effects of air pollution have not been well known. Inflammation plays an important role in occurrence and development of a wide range of diseases. In this study, we assessed the effects of short-term exposure to ambient air pollution on systemic inflammatory biomarkers among 12 508 participants who underwent routine physical examination annually at the Hebei General Hospital in Shijiazhuang, China. For each participant, white blood cell count (WBC), lymphocytes, neutrophils and eosinophils were measured for two or three times during September 2016 to December 2018. Daily concentrations of nitrogen dioxide (NO2), sulfur dioxide (SO2), ozone (O3) and particulate matter less than 2.5 µm in aerodynamic diameter (PM2.5) were interpolated to each district, where the participants worked. The linear mixed-effects regression with a constrained distributed lag model was applied to examine the associations between air pollution and inflammatory biomarkers during lag 0-14 d. It was observed that WBC, neutrophils and eosinophils [percent change (%Δ) and 95% confidence interval (95%CI)] significantly decreased by −0.07 (−0.11, −0.04), −0.08 (−0.12, −0.03) and −0.15 (−0.25, −0.05) at lag 14 d, associated with per 10 µg m−3 increase in O3. WBC, lymphocytes and eosinophils (%Δ and 95%CI) significantly elevated by 0.08 (0.04, 0.12), 0.16 (0.11, 0.21) and 0.22 (0.10, 0.35) at lag 0 d, associated with per 10 µg m−3 increase in PM2.5. This study reveals short-term effects of air pollution on systemic inflammatory biomarkers in routine blood test, which is helpful for further study to explore the biological mechanisms.

This study focuses on the cell bump distortion and bearing capacity of parafoil structure. Based on the mechanical properties of the membrane structure, the spanwise model of parafoil inflation was established and verified by comparing with the fluid-structure interaction (FSI) results. Because the internal pressure is very low, the chordwise stiffness is mainly generated by suspending lines. The chordwise model of inflated parafoil was established in consideration of elastic force and aerodynamic force. The results show that the cell is slenderer; the canopy surface is smoother; the aerodynamic load has a light effect on the shrinkage and bump ratios; when the cell width is constant, the critical dynamic pressure reduces k times with the k times increasing in parafoil area; and the design parameters of the first-row line OA have significant effects on the structural stiffness of inflated parafoil. The analytical model is useful for the weakening deformation design and the safety discussion of large parafoil for rocket booster recovery.