In recent years, the awareness of the seriousness of the damage caused by fugitive dust and the need to manage it have increased. In particular, construction sites comprise 84% of business places ...that have reported fugitive dust generation, and they are required to have inspection and management to prevent the occurrence of fugitive dust at construction sites. However, the number of complaints in the construction industry due to fugitive dust has increased. The reason for this increase is the fact that existing control measures are defined based on emission processes rather than construction work types, which makes it difficult to apply fugitive dust control measures to construction sites. Therefore, this research evaluated the effectiveness of fugitive dust control measures for construction sites in Korea through a Delphi study. This Delphi study was conducted in two rounds with 12 experts in an on-site panel, and the factors that were determined to be effective control measures were convergence, the content validity ratio (CVR), and stability. This study’s results will be utilized to direct the establishment of future guidelines for fugitive dust control measures based on types of construction work.
The future of electrochemical energy storage spotlights on the designed formation of highly efficient and robust bifunctional oxygen electrocatalysts that facilitate advanced rechargeable metal-air ...batteries. We introduce a scalable facile strategy for the construction of a hierarchical three-dimensional sulfur-modulated holey C2N aerogels (S-C2NA) as bifunctional catalysts for Zn-air and Li-O2 batteries. The S-C2NA exhibited ultrahigh surface area (∼1943 m2 g–1) and superb electrocatalytic activities with lowest reversible oxygen electrode index ∼0.65 V, outperforms the highly active bifunctional and commercial (Pt/C and RuO2) catalysts. Density functional theory and experimental results reveal that the favorable electronic structure and atomic coordination of holey C–N skeleton enable the reversible oxygen reactions. The resulting Zn-air batteries with liquid electrolytes and the solid-state batteries with S-C2NA air cathodes exhibit superb energy densities (958 and 862 Wh kg–1), low charge–discharge polarizations, excellent reversibility, and ultralong cycling lives (750 and 460 h) than the commercial Pt/C+RuO2 catalysts, respectively. Notably, Li-O2 batteries with S-C2NA demonstrated an outstanding specific capacity of ∼648.7 mA h g–1 and reversible charge–discharge potentials over 200 cycles, illustrating great potential for commercial next-generation rechargeable power sources of flexible electronics.
Treating the hypoxic region of the tumor remains a significant challenge. The goals of this study are to develop an exosome platform that can target regions of tumor hypoxia and that can be monitored ...in vivo using magnetic particle imaging (MPI). Four types of exosomes (generated under hypoxic or normoxic conditions, and with or without exposure to X-ray radiation) were isolated from MDA-MB-231 human breast cancer cells. Exosomes were labeled by DiO, a fluorescent lipophilic tracer, to quantify their uptake by hypoxic cancer cells. Subsequently, the exosomes were modified to carry SPIO (superparamagnetic iron oxide) nanoparticles and Olaparib (PARP inhibitor). FACS and fluorescence microscopy showed that hypoxic cells preferentially take up exosomes released by hypoxic cells, compared with other exosome formulations. In addition, the distribution of SPIO-labeled exosomes was successively imaged in vivo using MPI. Finally, the therapeutic efficacy of Olaparib-loaded exosomes was demonstrated by increased apoptosis and slower tumor growth in vivo. Our novel theranostic platform could be used as an effective strategy to monitor exosomes in vivo and deliver therapeutics to hypoxic tumors.
Abstract
Nonalcoholic fatty liver disease (NAFLD) is associated with obesity but also found in non-obese individuals. Gut microbiome profiles of 171 Asians with biopsy-proven NAFLD and 31 non-NAFLD ...controls are analyzed using 16S rRNA sequencing; an independent Western cohort is used for external validation. Subjects are classified into three subgroups according to histological spectra of NAFLD or fibrosis severity. Significant alterations in microbiome diversity are observed according to fibrosis severity in non-obese, but not obese, subjects.
Ruminococcaceae
and
Veillonellaceae
are the main microbiota associated with fibrosis severity in non-obese subjects. Furthermore, stool bile acids and propionate are elevated, especially in non-obese subjects with significant fibrosis. Fibrosis-related
Ruminococcaceae
and
Veillonellaceae
species undergo metagenome sequencing, and four representative species are administered in three mouse NAFLD models to evaluate their effects on liver damage. This study provides the evidence for the role of the microbiome in the liver fibrosis pathogenesis, especially in non-obese subjects.
Mesoscopic perovskite solar cells using stable CH3NH3PbI2Br as a light absorber and low‐cost poly(3‐hexylthiophene) (P3HT) as hole‐transporting layer were fabricated, and a power conversion ...efficiency of 6.64 % was achieved. The partial substitution of iodine with bromine in the perovskite led to remarkably prolonged charge carrier lifetime. Meanwhile, the replacement of conventional thick spiro‐MeOTAD layer with a thin P3HT layer has significantly reduced the fabrication cost. The solar cells retained their photovoltaic performance well when they were exposed to air without any encapsulation, presenting a favorable stability. The combination of CH3NH3PbI2Br and P3HT may render a practical and cost‐effective solid‐state photovoltaic system. The superior stability of CH3NH3PbI2Br is also promising for other photoconversion applications.
Cutting the cost: Mesoscopic CH3NH3PbI2Br perovskite solar cells with stable performance were fabricated. The thin hole‐transporting material layer of poly(3‐hexylthiophene) (P3HT) significantly cuts down the cost of the device.
A simple and efficient approach has been developed for synthesis of carbon-supported Pt nanoparticles (NPs) that combines homogeneous deposition (HD) of Pt complex species through a gradual increase ...of pH realized by in situ hydrolysis of urea and subsequent uniform reduction by ethylene glycol (EG) in a polyol process, giving control over the size and dispersion of Pt NPs. With increasing amount of urea in the starting Pt salt aqueous solution, the size of Pt complex species decreases and so does that of the metallic Pt NPs. The decrease in size of the Pt species is likely attributable to two determining factors: the steric contraction effect and the electrostatic charge effect. The excellent electrocatalysis ability of the Pt catalysts produced by HD-EG is demonstrated through the determination of electrochemical surface area and fuel-cell polarization performance. The Pt NPs deposited on Vulcan XC-72 (VC) carbon black by the HD-EG strategy show smaller size with more uniform dispersion, higher Pt utilization efficiency, and considerably improved fuel-cell polarization performance compared with the Pt NPs prepared by conventional sodium borohydride reduction or by a microwave-assisted polyol approach. Particularly important and significant is that this HD-EG method is very efficient for the synthesis of high Pt loading catalysts with tunable NP size and uniform particle dispersion. A high metal loading catalyst such as Pt(60 wt %)/VC fabricated by the HD-EG method outperforms ones with mid-to-low metal loadings (i.e., 40 and 20 wt %), even at a very low catalyst loading of 0.2 mg of Pt cm−2 at the cathode, which is for the first time reported for the VC-supported Pt catalysts.
Zinc–air batteries (ZABs) are vulnerable to the ambient environment (e.g., humidity and CO2), and have serious selfdischarge issues, resulting in a short shelf life. To overcome these challenges, a ...near‐neutral quaternary ammonium (QA) functionalized polyvinyl alcohol electrolyte membrane (different from conventional alkali‐type membranes) has been developed. QA functionalization leads to the formation of interconnected nanochannels by creating hydrophilic/‐phobic separations at the nanoscale. These nanochannels selectively transport OH− ions with a reduced migration barrier, while inhibiting Zn(NH3)62+ crossover. Owing to the superior water retention ability and enhanced chemical stability of the membrane, the solid‐state zinc–air battery (SZAB) displays outstanding flexibility, a promising cycle lifetime, and a large volumetric energy density. More importantly, the self‐discharge rate of SZAB is depressed to less than 7 % per month, and the fully dehydrated SZAB could recover its rechargeability upon replenishment of the solution of NH4Cl.
Bend and flex: Zinc–air batteries are vulnerable to the ambient environment and have serious self‐discharge issues, which result in a short shelf life. To overcome these challenges, a near‐neutral quaternary ammonium functionalized polyvinyl alcohol electrolyte membrane (different from conventional alkali‐type membranes) has been developed.
AbstractThe Internet of Things (IoT) has attracted attention in recent years as a way to prevent construction site accidents. Although various IoT technologies have been tested for the purpose of ...safety management, few have been implemented in actual projects. One possible reason is that the effectiveness of these technologies has rarely been calculated. In this study, a method for quantitatively evaluating the effectiveness of IoT technologies for accident prevention is presented. Taking the domino theory of accident causation into account, this method has three aspects: the degree of the causes of accidents that an IoT technology prevents, association between accident types and their causes, and frequency of each accident type. To quantify these, two different types of survey were conducted, and statistical records about construction accidents by type were used. To test the applicability of this method, the effectiveness of two IoT technologies was calculated. The method successfully quantified how much each technology contributes to preventing certain types of accident as well as the overall accident-prevention effect. The proposed method can enable practitioners to assess the effectiveness of certain IoT technologies, which will be useful in justifying investments in the technology. The method will lead to deploying more IoT technologies for safety management, which will eventually contribute to decreasing accidents in the construction industry.
We synthesized uniform pore-sized mesoporous silica spheres embedded with magnetite nanocrystal and quantum dots. The magnetic separation, luminescent detection, and controlled release of drugs were ...demonstrated using the uniform mesoporous silica spheres embedded with monodisperse nanocrystals.
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