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Aiming at the demand for reliability evaluation of RV reducers, the Gamma models, which can represent the performance degenerate process of reducers, are established respectively combining with transmission error data and backlash data of reducer performance degenerate test. A maximum likelihood estimation method is applied to estimate the parameters of degenerate models. Taking the models above as marginal distribution functions, a binary degenerate model of RV reducers is established through Copula function. The reliability and expected failure life of RV reducers are evaluated. The results show that the reliability evaluated by degenerate models based on transmission error and backlash is essentially in agree with the test results. The models can represent the degenerate process of RV reducers accurately. Gaussian Copula function is more suitable for representing the correlation between transmission error degenerate data and backlash degenerate data. Through the binary degenerate model, the expected failure life of RV reducers can be evaluated at different reliability under this working condition.

Accurate location information can offer huge commercial and social value and has become a key research topic. Acoustic-based positioning has high positioning accuracy, although some anomalies that affect the positioning performance arise. Inertia-assisted positioning has excellent autonomous characteristics, but its localization errors accumulate over time. To address these issues, we propose a novel positioning navigation system that integrates acoustic estimation and dead reckoning with a novel step-length model. First, the features that include acceleration peak-to-valley amplitude difference, walk frequency, variance of acceleration, mean acceleration, peak median, and valley median are extracted from the collected motion data. The previous three steps and the maximum and minimum values of the acceleration measurement at the current step are extracted to predict step length. Then, the LASSO regularization spatial constraint under the extracted features optimizes and solves for the accurate step length. The acoustic estimation is determined by a hybrid CHAN–Taylor algorithm. Finally, the location is determined using an extended Kalman filter (EKF) merged with the improved pedestrian dead reckoning (PDR) estimation and acoustic estimation. We conducted some comparative experiments in two different scenarios using two heterogeneous devices. The experimental results show that the proposed fusion positioning navigation method achieves 8~56.28 cm localization accuracy. The proposed method can significantly migrate the cumulative error of PDR and high-robustness localization under different experimental conditions. [ABSTRACT FROM AUTHOR]

The Zn2+ content of purified human immunodeficiency virus type-1 (HIV-1) integrase was studied by atomic absorption spectroscopy and by the use of a thiol modification reagent, p-(hydroxymercuri)benzenesulfonate, with a metallochromic indicator, 4-(2-pyhridylazo)resorcinol. Findings indicated that the Zn2+ content of HIV-1 integrase ranges from 0.1 to 0.92 equiv of Zn2+ per monomer depending on the conditions of protein purification. Also, Zn2+ promotes a conformation with enhanced oligomerization and thereby stimulates Mg2+-dependent 3'-processing.

Abstract Background The complications of hypertension cause severe health problems in rural areas in China. We (i) screened the major factors inducing hypertensive complications and provided intervention measures; and (ii) verified the efficacy of the New Rural Cooperative Medical Scheme (NRCMS; a medical insurance scheme for rural residents) for hypertension management. Methods A survey was conducted in the villages of Yunnan (an underdeveloped province in southwest China). The NRCMS was initiated there in 2005. Data were collected through questionnaires, physical examination, electrocardiography, as well as blood and urine tests. To detect factors inducing hypertension complications, a generalized estimating equations model was developed. Multivariable logistic regression was used to analyze influencing factors for hypertension control. Results Poor management of hypertension was observed in women. Being female, old, poorly educated, a smoker, ignorant of the dangerousness of hypertension, and having uncontrolled hypertension made patients more prone to hypertension complications. Combination therapy with ≥2 drugs helped control hypertension, but most rural patients disliked multidrug therapy because they considered it to be expensive and inconvenient. The NRCMS contributed little to reduce the prevalence of complications and improve control of hypertension. Conclusions The present study suggested that the NRCMS needs to be reformed to concentrate on early intervention in hypertension and to concentrate on women. To increase hypertension control in rural areas in China, compound products containing effective and inexpensive drugs (and not multidrug therapy) are needed.

Abstract Background Peroxisome proliferator-activated receptor γ (PPARγ) is a ligand-activated transcription factor, which regulates gene expression of the key proteins involved in lipid metabolism, vascular inflammation, and proliferation. PPARγ may contribute to attenuating atherogenesis and postangioplasty restenosis. PPARγ C161→T substitution is associated with a reduced risk of coronary artery disease (CAD). Whether or not the gene substitution alters the risk of CAD in type 2 diabetes mellitus (T2DM) patients remains unclear. Methods A total of 556 unrelated subjects from a Chinese Han population, including 89 healthy subjects, 78 CAD patients, 86 T2DM patients, and 303 CAD combined with T2DM patients, were recruited to enroll in this study. PPARγC161→T gene polymorphism was determined by polymerase chain reaction and restriction fragment length polymorphisms. Plasma levels of lipoproteins, apolipoproteins, glucose, and insulin were measured by ELISA or radioimmunoassay (RIA). The coronary artery lesions were evaluated by coronary angiography. Results The frequency of the 161T allele in CAD, T2DM, and CAD combined with T2DM patients was similar to that observed in the healthy control group. However, in CAD combined with T2DM patients, the group with angiographically documented moderate stenoses had a higher frequency of the 161T allele in comparison to the group with severe stenoses (P < 0.05). Moreover, in CAD with T2DM patients, the triglyceride levels and apoB in CC homozygote carriers were significantly higher than those in "T" allele carriers. Conclusions PPARγC161→T genotypes weren't significantly associated with the risk of CAD, but were markedly correlated with severity of disease vessels in patients with CAD and T2DM. Furthermore, PPARγC161→T substitution was associated with an altered adipose, but not glucose metabolism. These results indicate that the PPARγ C161→T polymorphism may reduce the risk of severe atherogenesis by modulation of adipose metabolism, especially triglycerides and apoB, in Chinese patients with CAD and T2DM.

To determine the stable homotopy groups of spheres π*(S) is one of the central problems in homotopy theory. Let p be a prime greater than 5. The authors make use of the May spectral sequence and the Adams spectral sequence to prove the existence of a ϖn-related family of homotopy elements, β1ωnγs, in the stable homotopy groups of spheres, where n > 3, 3 ≤ s < p − 2 and the ϖn-element was detected by X. Liu. [ABSTRACT FROM AUTHOR]

A simple hydrothermal procedure is introduced, which leads to the successful synthesis of a new composite material with fine CeO2-ZrO2 nanocrystallites embedded in amorphous and porous SiO2 matrices. The composite material possesses an extraordinary high thermal stability. After being calcined at 1000 °C, it retains CeO2-ZrO2 nanocrystallites of the size around 5 nm, a BET-specific surface area of 165 m2/g, and an oxygen storage capacity of 468 μmol/g. No phase segregation for CeO2-ZrO2 nanocrystallites is detected and the SiO2 matrices remain not crystallized. The composite material shows a great potential as a support of three-way catalyst, as evidenced in catalytic tests with supported Pt. [ABSTRACT FROM AUTHOR]

Dual channel photo-driven H 2 O 2 production in pure water on small-scale on-site setups is a promising strategy to provide low-concentrated H 2 O 2 whenever needed. This process suffers, however, strongly from the fast recombination of photo-generated charge carriers and the sluggish oxidation process. Here, insoluble Keggin-type cesium phosphomolybdate Cs 3 PMo 12 O 40 (abbreviated to Cs 3 PMo 12 ) is introduced to carbonized cellulose (CC) to construct S-scheme heterojunction Cs 3 PMo 12 /CC. Dual channel H 2 O 2 photosynthesis from both H 2 O oxidation and O 2 reduction in pure water has been thus achieved with the production rate of 20.1 mmol L -1  g cat. -1  h -1 , apparent quantum yield (AQY) of 2.1% and solar-to-chemical conversion (SCC) efficiency of 0.050%. H 2 O 2 accumulative concentration reaches 4.9 mmol L -1 . This high photocatalytic activity is guaranteed by unique features of Cs 3 PMo 12 /CC, namely, S-scheme heterojunction, electron reservoir, and proton reservoir. The former two enhance the separation of photo-generated charge carriers, while the latter speeds up the torpid oxidation process. In situ experiments reveal that H 2 O 2 is formed via successive single-electron transfer in both channels. In real practice, exposing the reaction system under natural sunlight outdoors successfully results in 0.24 mmol L -1 H 2 O 2 . This work provides a key practical strategy for designing photocatalysts in modulating redox half-reactions in photosynthesis., (© 2024 Wiley‐VCH GmbH.)

Previous studies have demonstrated extracorporeal cardiac shock waves (ECSW) could induce angiogenesis and improves myocardial function in patients with coronary heart diseases as a safe, effective, and non-invasive angiogenic approach. The endothelial progenitor cells (EPCs) can migrate to the ischemic myocardium and differentiate into vascular endothelial cells, thus promoting the angiogenesis. Whether ECSW can improve the angiogenic ability of EPCs is unclear. This topic studied the effects of ECSW Therapy on EPCs functions and related signal transduction pathways. The bone marrow-derived EPCs of SD rats were isolated by the density centrifugation method. After treatment with ECSW (500 shots at 0.09 mJ/mm 2 ), the cell viability, anti-apoptosis, migration, and tube formation of EPCs were significantly improved. In addition, the expressions of phosphorylated AKT and ERK were increased after ECSW treatment, the expressions of downstream signaling molecules eNOS and Bcl-2 were also increased, but the expressions of Bax and Caspase3 were decreased. However, these beneficial effects can be inhibited by PI3K/AKT inhibitor LY294002 and MEK/ERK inhibitor PD98059. Together, ECSW can promote the cell viability, migration, and angiogenic ability of EPCs and inhibit the apoptosis of EPCs through the PI3K/AKT and MEK/ERK signaling pathways. The mechanism may be related to promoting the expressions of downstream p-eNOS and anti-apoptotic protein Bcl-2 and inhibiting the expressions of pro-apoptotic protein Bax and Caspase3 through the PI3K/AKT and MEK/ERK signaling pathways., Competing Interests: None., (AJTR Copyright © 2020.)