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Multiple systematic reviews on greenspace and health outcomes exist, but the overall evidence base remains unclear. Therefore, we performed an umbrella review to collect and appraise all relevant systematic reviews of epidemiological studies on greenness exposure and health. We searched PubMed, Embase, and Web of Science from inception to June 28, 2021, and screened references of relevant articles. Systematic reviews with or without meta-analyses of epidemiological studies that examined the associations of greenness with any health outcome were included. Two independent investigators performed study selection and data extraction. We also evaluated the methodological quality of the included systematic reviews using the Assessing the Methodological Quality of Systematic Reviews 2 checklist. A total of 40 systematic reviews and meta-analyses were included, of which most were cross-sectional studies conducted in high-income countries. Greenspace exposure was estimated with various objective and subjective parameters. Beneficial associations of greenspace with all-cause and stroke-specific mortality, CVD morbidity, cardiometabolic factors, mental health, low birth weight, physical activity, sleep quality, and urban crime were observed. No consistent associations between greenspace and other health outcomes (e.g., cancers) were observed. Most of the included systematic reviews and meta-analyses had one or more limitations in methodology. Our findings provide supportive evidence regarding the beneficial effects of greenspace exposure on some aspects of human health. However, the credibility of such evidence was compromised by methodological limitations. Better performed systematic reviews and meta-analyses as well as longitudinal designed primary studies are needed to validate this conclusion.

Free radical-cationic hybrid UV-curable resin applied to UV-cured 3D printing was developed with epoxy resin (EPON828) and polyurethane acrylate (RJ429) as photosensitive prepolymers. The influences of types, ratios and dosages of free radical and cationic photoinitiators on photocuring kinetics, mechanical properties and prototyping precision of hybrid UV-curing resin were investigated. The results show that cationic photoinitiator Gencure 842 and free radical photoinitiator Doracur 1173 are the most appropriate hybrid photoinitiators, with an optimum mass ratio of 0.75:1 and mass fraction of 6%. The optimum mass ratio of EPON828 and RJ429 is determined as 1:1, and the viscosity of the developed resin is 50.5Pa·s. The tensile strength, impact strength, volume shrinkage and warpage of UV-cured resin items are 6.60MPa, 8.28kJ·m-2,-3.986% and 3.62%, respectively. The hybrid UV-curing resin can basically satisfy the requirements of UV-cured 3D printing.

Objective: Despite the increasing number of genes associated with Charcot–Marie‐Tooth (CMT) disease, many patients currently still lack appropriate genetic diagnosis for this disease. Autosomal dominant mutations in aminoacyl‐tRNA synthetases (ARSs) have been implicated in CMT. Here, we describe causal missense mutations in the gene encoding seryl‐tRNA synthetase 1 (SerRS) for 3 families affected with CMT. Methods: Whole‐exome sequencing was performed in 16 patients and 14 unaffected members of 3 unrelated families. The functional impact of the genetic variants identified was investigated using bioinformatic prediction tools and confirmed using cellular and biochemical assays. Results: Combined linkage analysis for the 3 families revealed significant linkage (Zmax LOD = 6.9) between the genomic co‐ordinates on chromosome 1: 108681600–110300504. Within the linkage region, heterozygous SerRS missense variants segregated with the clinical phenotype in the 3 families. The mutant SerRS proteins exhibited reduced aminoacylation activity and abnormal SerRS dimerization, which suggests the impairment of total protein synthesis and induction of eIF2α phosphorylation. Interpretation: Our findings suggest the heterozygous SerRS variants identified represent a novel cause for autosomal dominant CMT. Mutant SerRS proteins are known to impact various molecular and cellular functions. Our findings provide significant advances on the current understanding of the molecular mechanisms associated with ARS‐related CMT. ANN NEUROL 2023;93:244–256 [ABSTRACT FROM AUTHOR]

As an alternative to the state-of-the-art Pt-based materials, MoS2 has attracted substantial attention as a hydrogen evolution reaction (HER) catalyst. In this study, density functional theory calculations reveal that negative curvature and stepped faces of MoS2 could weaken the hydrogen adsorption, leading to high intrinsic catalytic activity for HER. Based on this consideration, a MoS2 catalyst with an ultrathin eggshell-like nanostructure is designed and fabricated, where the uniform porous structure together with ultrathin layers exposes more active sites. Such a porous MoS2 catalyst exhibits an overpotential of 180 mV at a current density of −10 mA cm–2, outperforming most of the current MoS2 catalysts. [ABSTRACT FROM AUTHOR]

The UV -curable MTQ silicone resins was synthesized by hydrolysis copolymerization under acidic conditions with hexamethyldisiloxane, y-(methacryloyloxy) propyltrimethoxy-silane and tetraethyl orthosilicate as the raw materials. The obtained resin was characterized by IR, NMR, thermogravimetric analysis and UV-Vis spectroscopy. The M/T + Q values are used to discuss the structure of silicone. When the molar ratio of T chain unit to Q chain unit (T/Q) is controlled as 1: 3, the effects of different M/T + Q values hydrolysis time and condensation time on the product were investigated. It is found that with M/T + Q value of 1, hydrolyzed for 50 min and condensed for 7 h, the MTQ silicone resin has a higher conversion rate, good heat resistance and light transmittance. Moreover, the prepared MTQ silicone resin has high tensile strength and hardness after photo-curing. [ABSTRACT FROM AUTHOR]

Silicone rubber was prepared by UV-activated hydrosilylation of with DMS'Vi and PMHS as the substrates, and (Me-Cp) Pt(Me) 3 as photo catalyst. The effects of the concentration of ( Me-Cp) Pt( Me) 3, reaction conditions UV-curing kinetics and the viscosity of PDMS-Vi on the properties of silicone rubber were studied. Results show that when the mass fraction of ( Me-Cp) Pt( Me) 3 is 400 x 10-6, the conversion of the reaction is close to 100% within 5 minutes. The high viscosity of PDMS-Vi is beneficial to improve the final conversion of the reaction. The mechanical properties of the silicone rubber prepared by 5000 mm²/s PDMS-Vi system are the best. The tensile strength is 0. 528 MPa and the elongation at break of silicone rubber reaches 789% ( about 2-3 times of 500 mm²/s and 10000 mm²/s systems). The silicone rubber prepared by high viscosity PDMS-Vi system shows good thermal stability. The 10% maas loss of the rubber increases from 487°C to 496°C, and the final residue was increased from 60% to 68% . The method can prepare silicone rubber in a short time. The mechanical properties and thermal stability of silicone rubber products can be eefectively improved by increasing the viscosity of PDMS-Vi. [ABSTRACT FROM AUTHOR]