Recycling of some minor but essential scarce metals used in vehicles may serve as an important strategy to strengthen sustainable management of natural resources. Accordingly, this study focused on ...five precious metals (PMs): Au, Ag, Pt, Pd, and Rh, in both end-of-life conventional and next-generation vehicles. To explore their recycling potentials in Japan, we developed substance flow and scenario analyses based on estimations of PM contents per end-of-life vehicle (ELV) and ELV generations. The study predicts that in Japan, from 2015 to 2040, the content of PMs per ELV will range from 2 to 6 g, and the annual amount of PMs in ELVs will remain largely stable, at 14–15 t, but the proportions of PMs utilized in different vehicles, parts, and components will gradually change; in particular, increased proportions will occur in the printed wiring boards (PWBs) of next-generation vehicles. The results also show that, in Japan, totals of 33–53% of PMs in ELVs were recycled in 2015, and that by selective dismantling of PWBs and heating wires in the rear windows of ELVs, the recycling potentials of PMs could be optimally increased to a maximum of 62–83% by 2040.
We prepared novel planar chiral monophosphine ligands bearing ferrocene‐triazole backbones. These ligands were produced in a series of steps that included triazole synthesis by diastereoselective ...azidation and Huisgen cycloaddition of (S)‐Ugi's amine, followed by methylation and phosphine introduction. This method was applicable to the preparation of various analogues due to the wide substrate scope of the Huisgen cycloaddition reaction. These ligands showed good catalytic activity in Suzuki–Miyaura coupling reactions, especially those involving bulky substrates. Furthermore, the optically active versions of these ligands were used in the asymmetric Suzuki–Miyaura coupling reaction to produce the axial chiral binaphthyl compound with moderate enantioselectivity. The ligand developed in this study is the first triazole‐type biaryl‐ monophosphine ligand that can be used in asymmetric reactions, and it is expected to be a new tool for the accessing chiral compounds.
Novel planar chiral monophosphine ligands bearing ferrocene‐triazole backbones were easily synthesized via diastereoselective azidation and Huisgen cycloaddition of (S)‐Ugi's amine, followed by methylation and phosphine introduction. These optically active ligands exhibited satisfactory catalytic activity in Suzuki–Miyaura coupling reactions and were used in the asymmetric Suzuki–Miyaura coupling reaction with moderate enantioselectivity.
Vertical air classification is widely used in waste separation processes, where the separation curves, i.e. the recovered percentages of the lighter and heavier fractions plotted against air ...velocity, determine the characteristics of separation. Although several different models of separation curve equations exist, the common mechanism underlying them is unknown. Here, a meta-model based on the stochastic process of particle separation is presented. Through mathematical and numerical analyses, the following findings are obtained. 1) Three typical separation curve models, i.e. a cumulative Weibull model, a Lynch-Rao model, and a cumulative normal model, are described as the different realizations of the meta-model with different settings. 2) The three separation curve models give almost identical curve-fitting results with sufficient accuracy, while the flexibility of fit slightly but distinctively differs: the best is the Lynch-Rao model, followed in order by the Weibull CDF model and the normal CDF model.
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•Existing different separation curve models can be described in a unified manner.•These separation curve models share a common stochastic process model.•The Lynch-Rao model is slightly more flexible than the cumulative Weibull model.•The cumulative normal model is a simplified version of the above two models.
Dynamically crosslinked gels are appealing materials for applications that require time‐dependent mechanical responses. DNA duplexes are ideal crosslinkers for building such gels because of their ...excellent sequence addressability and flexible tunability in bond energy. However, the mechanical responses of most DNA gels are complicated and unpredictable. Here, a DNA gel with a highly homogeneous gel network and well predictable mechanical behaviors is demonstrated by using a pair of star‐polymer–DNA precursors with presimulated DNA sequences showing the two‐state transition. The melting curve analysis of the DNA gels reveals the good correspondence between the thermodynamic potentials of the DNA crosslinkers and the presimulated values by DNA calculators. Stress‐relaxation tests and dissociation kinetics measurements show that the macroscopic relaxation time of the DNA gels is approximately equal to the lifetime of the DNA crosslinkers over 4 orders of magnitude from 0.1–2000 s. Furthermore, a series of durability tests find the DNA gels are hysteresis‐less and self‐healable after the applications of repeated temperature and mechanical stimuli. These results demonstrate the great potential of star‐polymer–DNA precursors for building gels with predictable and tunable viscoelastic properties, suitable for applications such as stress‐response extracellular matrices, injectable solids, and soft robotics.
DNA gels with predictable mechanical responses are developed using a star‐polymer strategy and a pair of presimulated DNA sequences. The macroscopic stress‐relaxation time of the DNA gel is connected directly to the microscopic lifetime of the DNA crosslinkers over an extended time range from 0.1–2000 s. In addition, the DNA gels are spatially homogeneous, hysteresis‐less, and self‐healable.
Commercial mixtures of decabromodiphenyl ether (deca-BDE), a brominated flame retardant, contain not only polybrominated diphenyl ethers (PBDEs, mainly BDE-209) as the main component but also ...dioxin-like compounds (DLCs) such as polybrominated dibenzofurans (PBDFs). Deca-BDE handling facilities (DHFs) and sewage treatment plants receiving effluent from DHFs are point sources of DLC and flame retardant (FR) pollution. Here, we examined their emission in Japan. For DHF effluents, DLCs detected by the dioxin-responsive chemically activated luciferase expression (DR-CALUX) assay were 1.3–890 pg TCDD-EQ/L (median 46 pg TCDD-EQ/L), while PBDEs and other FRs were <2.0–110,000 ng/L (610 ng/L) and 150–4,800,000 ng/L (41,000 ng/L). Risk quotients based on predicted no-effect concentrations suggested that DLCs, decabromodiphenyl ethane (DBDPE), tris(2,3-dibromopropyl) isocyanurate (TDBP-TAZTO), and bisphenol A bis(diphenyl phosphate) (BPA-BDPP) present significant risks for aquatic organisms. The concentrations of PBDFs, which are impurities in deca-BDE, were expected to decrease with the inclusion of deca-BDE in the Stockholm Convention list of persistent organic pollutants (May 2017). However, DLCs other than PBDFs and alternative FRs such as DBDPE, TDBP-TAZTO, and BPA-BDPP are likely still discharged. Additional findings indicate that strong (e.g., DLCs, DBDPE, and BPA-BDPP), but not weak (e.g., TDBP-TAZTO), hydrophobic compounds are sufficiently removed by current wastewater treatment processes in Japan.
Numerous reports have elucidated different statistical approaches to identify temporal trends in atmospheric persistent organic pollutant (POP) time series. However, the correlation of industrial ...activity with concentrations of atmospheric POPs in Japan has not yet been determined. Herein, a panel data analysis of a 16-year monitoring program (2003–2018) conducted by the Japanese Ministry of Environment was used to investigate a range of POPs in the atmosphere above Japan. This work focuses on polychlorinated biphenyls (PCBs), polychlorinated naphthalenes (PCNs), polybrominated diphenyl ethers (PBDEs), hexachlorobenzene (HCB), and pentachlorobenzene (PeCBz) collected each year at 53 sites across Japan. The panel analysis revealed that PCB, PCN, and PBDE concentrations were influenced by a combination of factors including year, industrial activity (municipal and industrial waste incinerators, cement kilns, steel industry, and secondary zinc production), population, temperature, and atmospheric boundary layer. However, HCB and PeCBz were not significantly affected by these factors. Industrial activity showed stronger positive correlations with all homologues of PCBs, PCNs, and PBDEs as compared to those demonstrated by population. Significant decreasing trends were identified for the atmospheric ∑PBDEs (half-life t1/2 = 9.4 years), ∑PCNs (t1/2 = 8.9 years), and ∑PCBs (t1/2 = 13.5 years) concentrations, while HCB and PeCBz showed slightly increasing or steady levels. As a statistical tool, panel data analysis can contribute to the assessment of spatial and temporal trends of POPs at a national scale, while elucidating different behavioral responses to numerous environmental variables.
•National-scale panel analysis of atmospheric POPs from 2003 to 2018 was performed.•POPs except CBz were influenced by year, industrial activity, temperature, and ABL.•Industrial activity showed strong positive correlations with PCBs, PCNs and PBDEs.•PCBs, PBDEs and PCNs decreased while HCB and PeCBz remained steady.•Different environmental effects and POP emission sources were revealed.
The performance of 2,5-dimethoxy-1,4-benzoquinone (DMBQ) as an active material for rechargeable lithium batteries was investigated. A positive-electrode that incorporated DMBQ showed an initial ...discharge capacity of 312
mAh
g
−1 with an average voltage of 2.6
V vs. Li
+/Li. This discharge capacity corresponds to a benzoquinone-based two-electron redox behavior, and is more than twice that of the conventional positive-electrode material lithium cobalt oxide (LiCoO
2). Furthermore, the positive-electrode with DMBQ showed fair cycle-life performance. Theoretical quantum calculations based on the density functional theory (DFT) were also performed to clarify the mechanism of the electrochemical properties of the solid state of DMBQ.
This study was a systematic review of research using the Wechsler Intelligence Scale for Children (WISC) with Autism Spectrum Disorder (ASD) to examine cognitive characteristics of children with ASD ...beyond the impact of revisions based on WISC and diagnostic criteria changes. The classic “islets of ability” was found in individuals with full-scale IQs < 100. The “right-descending profiles” were observed among high IQ score individuals. High levels on the Block Design and low Coding levels were consistently found regardless of the variation in intellectual functioning or diagnosis. This review identified patterns of cognitive characteristics in ASD individuals using empirical data that researchers may have previously been aware of, based on their experiences, owing to the increased prevalence of ASD.
This study analyzed polyhalogenated compounds (PHCs) such as brominated flame retardants (BFRs) in indoor air and dust samples from two modern homes in Japan. Concentrations of polychlorinated ...biphenyls (PCBs) and 2,4,6-tribromophenol (2,4,6-TBP) in exhaust and indoor air of two houses were detected at 10
2–10
3
pg
m
−3 order, which were well above those in outdoor air. For dust samples, the detected polybrominated diphenyl ether (PBDE) and polybrominated dibenzo-
p-dioxins/furan concentrations resembled values found in our past study. Interestingly, compared to PBDE concentrations, two orders of magnitude higher concentration (13
000
ng
g
−1) was observed for hexabromocyclododecanes (HBCDs) in a dust sample from one house. Based on the calculation of air/dust partition ratio values (
Kad), low
Kad values (log
Kad
⩽
0) were obtained for high brominated PBDEs (pentaBDEs – decaBDE), tetrabromobisphenol A (TBBPA), and HBCDs, although indoor air contained higher contents of low chlorinated PCBs, low brominated PBDEs, and 2,4,6-TBP. Attention should be given to exposure to 2,4,6-TBP through inhalation of air as well as dust ingestion. Results of X-ray fluorescence analysis show high bromine concentrations in curtain and roll screen samples possessing a high product loading factor. Furthermore, a preliminary estimation was made of the likely magnitude of inhabitants’ exposure to PHCs via inhalation and dust ingestion in the two houses.
Rab family small GTPases are master regulators of distinct steps of intracellular vesicle trafficking in eukaryotic cells. GDP‐bound cytoplasmic forms of Rab proteins are prone to aggregation due to ...the exposure of hydrophobic groups but the machinery that determines the fate of Rab species in the cytosol has not been elucidated in detail. In this study, we find that BAG6 (BAT3/Scythe) predominantly recognizes a cryptic portion of GDP‐associated Rab8a, while its major GTP‐bound active form is not recognized. The hydrophobic residues of the Switch I region of Rab8a are essential for its interaction with BAG6 and the degradation of GDP‐Rab8a via the ubiquitin‐proteasome system. BAG6 prevents the excess accumulation of inactive Rab8a, whose accumulation impairs intracellular membrane trafficking. BAG6 binds not only Rab8a but also a functionally distinct set of Rab family proteins, and is also required for the correct distribution of Golgi and endosomal markers. From these observations, we suggest that Rab proteins represent a novel set of substrates for BAG6, and the BAG6‐mediated pathway is associated with the regulation of membrane vesicle trafficking events in mammalian cells.
Synopsis
BAG6 specifically recognizes exposed hydrophobic residues in the Switch I region of inactive, GDP‐bound Rab8a. BAG6 targets GDP‐Rab8a to proteasomal degradation to maintain the integrity of the Golgi and endosomal compartments.
BAG6 is required for the correct distribution of Golgi/endosomal markers.
BAG6 recognizes the GDP‐bound form of Rab8a for ubiquitin‐mediated degradation.
The hydrophobicity of the Switch I region is essential for the instability of Rab8a.
BAG6 specifically recognizes exposed hydrophobic residues in the Switch I region of inactive, GDP‐bound Rab8a. BAG6 targets GDP‐Rab8a to proteasomal degradation to maintain the integrity of the Golgi and endosomal compartments.
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