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This paper introduces contorted hexabenzocoronene (c-HBC) derivatives as a potential universal precursor for use in synthesis of sp2-crystalline carbon materials that have dimensionalities ranging from 1-D to 3-D. Carbon products with different dimensions and high crystallinity were synthesized by controlling the assembly dimensions and intermolecular interactions of c-HBC derivatives, which are largely affected by the edge element and the deposition conditions. Further control of crystallinity was achieved by involving copper vapor; the effect is shown to be limited by the thickness of the assembled c-HBC layer. Study of the carbonization of c-HBC allowed development of an effective strategy to grow graphene-like structure on arbitrary substrates. This ability is expected to be a foundation for designed synthesis of graphitic carbons that have optimum morphology and dimensions for targeted applications. [Display omitted] [ABSTRACT FROM AUTHOR]

Abstract The source apportionment of volatile organic compounds (VOCs) was examined using receptor models (positive matrix factorization and chemical mass balance) and a chemical transport model (CTM). The receptor model-based analysis was performed using the datasets collected from four different sites from the megacity of Seoul during the years 2013–2015. The contributions of VOC emission sources to ozone (O 3) and PM 2.5 concentrations and the subsequent health effects in the study area were also assessed during a photochemically active period (June 2015) using a three-dimensional CTM, Community Multi-scale Air Quality (CMAQ), and the Environmental Benefits Mapping and Analysis Program (BenMAP). The solvent use and the on-road mobile emission sources were found to exert dominant controls on the VOC levels observed in the target city. VOCs transported from regions outside of Seoul accounted for a significant proportion (up to approximately 35%) of ambient VOC levels during the study period. The solvent use accounted for 3.4% of the ambient O 3 concentrations during the day (daily mean of 2.6%) and made insignificant contributions to PM 2.5 (<1%) during the simulation period. Biogenic VOC made insignificant contributions to O 3 (<1%) and a small contribution to PM 2.5 during the day (5.6% with a daily mean of 2.4%). The number of premature deaths attributed indirectly (O 3 and PM 2.5 formations via the oxidation of VOCs) to solvent use is expected to be significant. Graphical abstract Image 1 Highlights • The solvent use and the on-road mobile emission sources exert dominant controls on the VOC levels. • VOCs transported from regions outside of Seoul accounted for a significant proportion of ambient VOC levels. • Biogenic VOC made insignificant contributions to O 3 and PM 2.5 • The number of premature deaths attributed indirectly to solvent use is expected to be significant. [ABSTRACT FROM AUTHOR]

Introduction Short non-coding micro-RNAs (miRNAs) are post-transcriptional factors that directly regulate protein expression by degrading or inhibiting target mRNAs; however, the role of miRNAs in obesity and cardiometabolic disease remains unclarified. Based on our earlier study demonstrating that miR-150 influences lipid metabolism, we have studied effects of miR-150 on systemic metabolism and adipocyte biology. Materials and Methods Metabolic phenotypes including body weight, food intake, body composition, glucose tolerance and insulin sensitivity were assessed in WT and global miR-150 KO male mice fed a high-fat diet. Molecular changes in epididymal adipose tissue were evaluated through qRT-PCR and Western blotting. Results miR-150 KO mice displayed lower body weight characterized by a reduction in % fat mass while % lean mass was increased. Lower body weight was associated with reduced food consumption and an increase in circulating leptin concentrations, as well as enhanced insulin sensitivity and glucose tolerance compared with WT mice. Absence of miR-150 resulted in increased mTOR expression known to participate in increased leptin production leading to reduction of food intake. Expression of PGC-1α, another target gene of miR-150, was also increased together with upregulation of PPARα and glycerol kinase in adipose tissue as well as other genes participating in triglyceride degradation and lipid oxidation. Conclusion miR-150 KO mice showed metabolic benefits accompanied by reduced body weight, decreased energy intake, and enhanced lipid metabolism. miR-150 may represent both a biomarker and novel therapeutic target regarding obesity and insulin resistance. [ABSTRACT FROM AUTHOR]

Abstract: Poly(hexamethylenesebacamide) (nylon 610) nanocomposites containing well dispersed multi-walled carbon nanotubes (MWNTs) were successfully produced via the in situ interfacial polymerization of two liquid phases, one containing hexamethylenediamine in the presence of MWNTs and the other containing sebacoyl chloride. The processing consisted of dispersing acid-treated MWNTs in an aqueous phase containing a Triton X-100 surfactant. Scanning and transmittance electron microscopies showed that the individual MWNTs were uniformly dispersed in the nylon 610 matrix. Tensile tests of the composite sheet showed a 170% increase in the Young''s modulus with slight increases in the tensile strength and the elongation at break (about 40 and 25%, respectively). This suggests an interaction between the acid-treated MWNTs and nylon 610. The thermal stability of the composite was also enhanced by the incorporation of MWNT into nylon 610 matrix. [Copyright &y& Elsevier]

Emerging evidence suggests that during gestation the in utero environment programs metabolism and can increase risk of obesity in adult offspring. Our aim was to study how alterations in maternal diets during gestation might alter body weight evolution, circulating leptin levels and caloric intake in offspring, leading to changes in body composition. We fed gestating rats either a control diet (CD), high fat diet (HFD) or an isocaloric low protein diet (LPD), and examined the repercussions in offspring fed similar diets post-weaning on birth weight, body weight evolution, body composition, insulin sensitivity, glucose tolerance and in the relationship between plasma leptin concentration and caloric intake in offspring during growth and development. Offspring from dams fed LPD maintained reduced body weight with greater % lean mass and consumed fewer calories despite having leptin levels similar to controls. On the other hand, offspring from dams fed a HFD were insulin resistant and maintained increased body weight and % fat mass, while consuming more calories than controls despite elevated leptin concentrations. Therefore the uterine environment, modulated primarily through maternal nutrition, modified the relationship between circulating leptin levels, body fat, and caloric intake in the offspring, and dams fed a HFD produced offspring with excess adiposity, insulin resistance, and leptin resistance into adulthood. Our data indicates that in utero environmental factors affected by maternal diet program alterations in the set point around which leptin regulates body weight in offspring into adulthood contributing to obesity. [ABSTRACT FROM AUTHOR]

Effects of applied electric fields on downward and upward flame spreads (DFS and UFS) over polyethylene (PE) insulated electrical wires with Cu-core are investigated by varying the applied voltage (V AC) and frequency (f AC) at various inclination angles (θ). With AC electric fields, FSRs are influenced appreciably by complex dynamic behaviors of molten-PE and flame. For the DFSs, the FSR with θ exhibits increasing, decreasing, and increasing trends. For the UFSs, the FSR with θ shows an increasing tendency, along with dependencies on V AC and f AC. Further analyses are conducted at θ = ±70°. For the DFSs, the globular molten-PE size, the distance between flame front and globular molten PE, and electrospray influence FSR. For the UFSs, downward flow of molten-PE in some cases increases FSR. While the strong downward flow causes a flame detachment from the main body of the flame and/or a merging phenomenon between molten-PE drops, reducing FSR. A serious of bulged flames due to electrospray increases FSR. These FSR behaviors for DFS and UFS are well characterized with their related physical parameters. Flame extinction occurs only for DFSs with NiCr- and Cu-core. The critical extinction frequency for DFSs is characterized with log (f AC,ext) = a × V AC + b. [ABSTRACT FROM AUTHOR]

The contributions of various PM 2.5 emission sources to ambient PM 2.5 levels during 2013 in the main hub port city (Busan, South Korea) of East Asia was quantified using several receptor modeling techniques. Three receptor models of principal component analysis/absolute principal component score (PCA/APCS), positive matrix factorization (PMF), and chemical mass balance (CMB) were used to apportion the source of PM 2.5 obtained from the target city. The results of the receptor models indicated that the secondary formation of PM 2.5 was the dominant (45–60%) contributor to PM 2.5 levels in the port city of Busan. The PMF and PCA/APCS suggested that ship emission was a non-negligible contributor of PM 2.5 (up to about 10%) in the study area, whereas it was a negligible contributor based on CMB. The magnitude of source contribution estimates to PM 2.5 levels differed significantly among these three models due to their limitations (e.g., PM 2.5 emission source profiles and restrictions of the models). Potential source contribution function and concentration-weighted trajectory analyses indicated that long-range transport from sources in the eastern China and Yellow Sea contributed significantly to the level of PM 2.5 in Busan. [ABSTRACT FROM AUTHOR]

Abstract: In this study, surfactants were selected for the process of dispersing carbon nanotubes (CNTs) in water, in order to minimize the impact of the chemical modification of the individual CNTs on their inherent properties. The CNTs were sonicated in aqueous solutions of the various surfactants, viz. the anionic sodium dodecylbenzene sulfonate, the cationic cetyl trimethylammonium bromide, and the non-ionic Triton X-100, in order to stabilize the CNTs against the van der Waals attractive forces. The concentration of each surfactant was approximately 0.3wt% and the concentration of CNTs used for their homogeneous dispersions in aqueous solution was 0.02wt%. Furthermore, the stabilizing abilities of the aqueous CNT dispersions were measured using a recently developed optical analyzer (Turbiscan). This study shows that the surfactants successfully stabilized the aqueous CNT dispersions, whereas in the absence of surfactants they rapidly sedimented. [Copyright &y& Elsevier]

Abstract The global trends in sea spray aerosol (SSA) emissions, dimethyl sulfide (DMS) flux from sea to air, and aerosol optical depth (AOD) during 2000–2015 were analyzed using the satellite-based, ECMWF reanalysis, and model-predicted data. The SSA emissions were estimated using a widely used whitecap method with a sea surface temperature (SST) dependence. The sea-to-air DMS fluxes were estimated by a thin film model based on the DMS concentration in seawater and its gas transfer velocity. The yearly global mean anomaly in DMS fluxes showed a significant downward trend during the study period, whereas the SSA emissions showed an upward trend. In terms of regional trends, the increases in SSA emissions during 2000–2015 occurred over the tropical southeastern Pacific Ocean and Southern Ocean, whereas any downward trends in SSA emissions were localized. The DMS fluxes during the study period showed a clear downward trend over most oceans, except for the strong upward trend at low latitudes. In general, the AOD from the MODerate resolution Imaging SpectroRadiometer (MODIS) showed upward trends across the entire Southern Hemisphere (SH), whereas there were downward trends in most areas of the Northern Hemisphere (NH). Therefore, the upward trend of AOD in the SH were derived mainly from the SSA emission trend, due to smaller contribution of anthropogenic sources in the SH. Highlights • SSA emissions showed an upward trend over the global ocean. • DMS fluxes showed a significant downward trend. • Upward trend of AOD in the SH were derived mainly from the SSA emission. [ABSTRACT FROM AUTHOR]