Two-Stage Production of Multilayer Composites Containing a Heat-Resistant Superalloy and an Oxide Ceramic

Russian Engineering Research - The influence of the parameters of spark plasma sintering on the structural evolution within composites consisting of a superalloy, binder, and a zirconium-oxide...     

Natural rubber (Hevea Brasiliensis)-based quasi-solid electrolyte as a potential candidate for arresting recombination and improving performance in aqueous dye-sensitized solar cells

Journal of Materials Science: Materials in Electronics - We successfully fabricated dye sensitized solar cells (DSSCs) employing a quasi-solid state electrolyte based on pristine insulator natural...     

Effects of Mg-Coating and Boron Type on Electromechanical Properties of IMD MgB2/Fe Wires

Journal of Superconductivity and Novel Magnetism - In this study, mechanical and electrical characterization measurements were performed on non-bent and gradually bent IMD MgB2/Fe superconducting...     

Electrical Discharge Machining by Structural-Steel Electrodes

Russian Engineering Research - An approach is outlined to selecting conditions of electrical discharge machining such that coatings with the required functional properties are formed on the working...     

Dissociation of Gold Ore from Gurbey Deposit under Impact Effects

Journal of Mining Science - Dissociation of gold particles is tested in disintegration of Gurbey deposit ore samples under multiple impact effects in crusher DKD-300. It is found that in...     

Modelling Acoustic–Electric Nondestructive Testing for Defects in Dielectric Materials

Russian Journal of Nondestructive Testing - The influence of defectiveness of solid-state dielectric samples on the parameters of the electromagnetic response under deterministic acoustic action on...     

Exposure to environmental tobacco smoke during pregnancy and infancy increased the risk of upper respiratory tract infections in infants: A birth cohort study in Wuhan,China

We aimed to evaluate the association of the exposure to environmental tobacco smoke (ETS) during pregnancy and infancy with the risk of upper respiratory tract infections (URTI) in infants based on a Chinese birth cohort study. Among 4178 infants who constituted the final study population, 46.8% experienced URTI in their first year of life. The hazard ratios (HR) and 95% confidence intervals (CI) for the risk of URTI were assessed using Cox regression models. Compared with no ETS during pregnancy, continued ETS during pregnancy was independently associated with a higher risk of URTI (HR: 1.36, 95% CI: 1.13, 1.63) after adjustment for potential confounders and also associated with earlier occurrence of URTI (log-rank P = .002). The association remained consistent across the strata defined according to maternal age, number of siblings, sex, and breastfeeding. Exposure to ETS during infancy was associated with URTI only among infants who were breastfed for less than 12 months (P for interaction < 0.05).Furthermore, infants exposed to ETS during both pregnancy and infancy showed the highest HR of 1.46 (95% CI: 1.16, 1.85) for URTI. Efforts should be made to protect pregnant women and infants from the adverse effects of indoor and outdoor ETS.     

某企业不同工种的放射工作人员发生甲状腺结节风险分析

采用职业健康体检资料和问卷形式,利用单因素和多因素logistic回归模型,分析探讨某企业内不同工种的放射工作人员暴露在低剂量电离辐射环境下发生甲状腺结节的风险。结果表明,放射工作人员中以混合射线组甲状腺结节发生风险最高,随着年龄和放射工龄的增加发生风险会增加;性别不同与甲状腺结节发生风险有关。     

The Activity of Small Urea-γ-AApeptides Toward Gram-Positive Bacteria

Host Defense Peptides (HDPs) have gained considerable interest due to the omnipresent threat of bacterial infection as a serious public health concern. However, development of HDPs is impeded by several drawbacks, such as poor selectivity, susceptibility to proteolytic degradation, low-to-moderate activity and requiring complex syntheses. Herein we report a class of lipo-linear α/urea-γ-AApeptides with a hybrid backbone and low molecular weight. The heterogeneous backbone not only enhances chemodiversity, but also shows effective antimicrobial activity against Gram-positive bacteria and is capable of disrupting bacterial membranes and killing bacteria rapidly. Given their low molecular weight and ease of access via facile synthesis, they could be practical antibiotic agents.     

Effects of the biaxial orientation on the mechanical and optical properties and shrinkage of polyamide 6-66–montmorillonite–nanosilica nanocomposite films

Polyamide 6–66 (PA6-66)–montmorillonite (MMT)–nanosilica (NS) nanocomposite films were fabricated through a cast film process and then biaxially stretched on a laboratory stretcher. Uniaxial or biaxial stretching induced the elongated conformation of MMT and NS. The b axis of the α crystals and the amorphous phase were revealed to align along the machine direction (MD) after stretching, with the uniaxial orientation playing a more significant role. Furthermore, the crystallinity of PA6-66 stretching increased with the stretching ratio. Uniaxial stretching gave rise to a significantly enhanced tensile strength along the MD, whereas it slightly decreased the mechanical properties along the transverse direction (TD). In contrast, the films subjected to biaxial stretching exhibited more balanced mechanical properties. Uniaxial and biaxial stretching led to decreased transmittance and increased haze in the PA6-66–MMT–NS films; this could have been due to the elongated nanostructure of the two nanofillers, which inhibited the transmission and facilitated the scattering of visible light. The thermal shrinkage of the films increased with increasing stretching ratio, and the biaxially oriented films presented nearly equal shrinkage in the MD and TD. The addition of nanofillers decreased the shrinkage attributed to the mobility inhibition of the polymer chains during heating. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47504.