Electrochemical or photoelectrochemcial oxidation of water to form hydrogen peroxide (H2O2) or hydroxyl radicals (•OH) offers a very attractive route to water disinfection, and the first process ...could be the basis for a clean way to produce hydrogen peroxide. A major obstacle in the development of effective catalysts for these reactions is that the electrocatalyst must suppress the thermodynamically favored four-electron pathway leading to O2 evolution. We develop a thermochemical picture of the catalyst properties that determine selectivity toward the one, two, and four electron processes leading to •OH, H2O2, and O2.
Electrochemical production of hydrogen peroxide (H
O
) from water oxidation could provide a very attractive route to locally produce a chemically valuable product from an abundant resource. Herein ...using density functional theory calculations, we predict trends in activity for water oxidation towards H
O
evolution on four different metal oxides, i.e., WO
, SnO
, TiO
and BiVO
. The density functional theory predicted trend for H
O
evolution is further confirmed by our experimental measurements. Moreover, we identify that BiVO
has the best H
O
generation amount of those oxides and can achieve a Faraday efficiency of about 98% for H
O
production.Producing hydrogen peroxide via electrochemical oxidation of water is an attractive route to this valuable product. Here the authors theoretically and experimentally investigate hydrogen peroxide production activity trends for a range of metal oxides and identify the optimal bias ranges for high Faraday efficiencies.
As green growth is considered an effective method to save energy and reduce emissions, the questions of how to achieve it and which factors drive green growth have become hot topic. Although there ...are some studies on the factors impacting the achievement of green growth, they are limited in quantity. Moreover, most of them are primarily focused on specific influencing factors, such as political factors, environmental regulation (ER), technological innovation (TI), and so on; while there is little discussion of the interaction effects in an integrated methodological framework. Accordingly, this paper develops an integrated model to investigate the relationships among ER, TI and regional green growth performance (RGGP). The model is tested using empirical data on 30 provincial administrative regions in China during 2011–2012 by employing structural equation modeling (SEM) approach that can effectively investigate the relationships between observed and latent variables and the relationships among latent variables simultaneously. The hypothesis H1 of this paper is not confirmed, and the results show that ER has a significant negative effect on RGGP. Both the hypotheses H2 and H3 are confirmed, namely, ER significantly positively influences TI, and TI has a positive impact on RGGP. This finding provides empirical evidence to support the Porter Hypothesis that properly designed ER may positively affect RGGP through motivating TI. According to the results of hypotheses H1, H2 and H3, we find that ER couldn’t directly promote RGGP, but RGGP will be positively impacted by TI driven ER. The finding supports the view of ecological modernization theory that green growth practices may be promoted by TI driven ER, but whether ER can bring green growth practices is uncertain. Furthermore, the finding indicates that TI is a bridge for linking ER and RGGP. Based on our findings, we present some important implications that can be useful for policy-makers and enterprise managers to promote green growth practices in China.
•Relationships among technological innovation, environmental regulation and regional green growth performance are studied.•Empirical study of 30 Chinese provincial regions during 2011–2012 is conducted.•Environmental regulation has a negative effect on regional green growth performance.•Regional green growth performance is improved by technological innovation driven environmental regulation.•Technological innovation plays a bridge role between environmental regulation and regional green growth performance.
We developed hydroxysulfurization and alkoxysulfurization of styrenes using a visible‐light synthetic strategy in the absence of photocatalyst and oxidant. This strategy provided the corresponding ...β‐hydroxysulfides and β‐alkoxysulfides in moderate to good yields with high regioselectivity. The reaction was tolerated by a wide range of functional groups. This is the first example of ArSSAr/CBr4 system has been introduced into organic transformation.
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•Salinity did not significantly inhibit the removal efficiency of TP and COD (p > 0.05).•Salinity (5 g/L) significantly increased power density by a factor of 4 (p < 0.05).•The ...highest power density was 16.4 mW m−2 in saline wastewater treatment.•Electrochemically active bacteria predominated in the microbial community.
The use of constructed wetlands in combination with microbial fuel cells (CW-MFC) to treat saline wastewater may enhance electricity production by increasing the ionic strength, reducing internal resistance and stimulating microbes to accelerate electron transfer. In this study, salinity did not significantly inhibit the removal of TP and COD, but TN and NH4+-N removal efficiencies during saline wastewater treatment (ST) were significantly lower than during non-saline wastewater treatment (NT). However, salinity significantly increased the power density (16.4 mW m−2 in ST and 3.9 mW m−2 in NT, a 4-fold enhancement) by increasing the electron transfer rate and reducing internal resistance (140.29 Ω in ST and 415.21 Ω in NT). The peptides in extracellular polymeric substances (EPS) acted as electron shuttles to promote the migration of electrons and protons in ST. From start-up to stable operation, though the microorganisms in ST were reduced in diversity relative to NT, the proportion of electrochemically active bacteria (EAB), such as Ochrobactrum, significantly increased (p < 0.05) and gradually predominated in the microbial community.
Fergusonite-type monoclinic BiVO
4
(fm-BiVO
4
) is an important semiconductor photocatalyst as an alternative to TiO
2
for solar energy conversion and environmental protection. Based upon density ...functional theory (DFT) calculations, we report the results of a comprehensive study of the surface properties of fm-BiVO
4
, including surface geometric/electronic structures, surface energy, work function, Bader charge, and oxygen-vacancy formation energy on the (100), (010), (001), (101), (011), (110) and (111) surfaces. The low-index surfaces of fm-BiVO
4
are characterized by surface geometric structures terminated with Bi atoms and VO
4
groups. There are strongly localized band-gap states at the (110) and (111) surfaces. The calculated surface energies of fm-BiVO
4
indicate a surface stability order of {001} > {011} ∼ {101} > {111} > {110} > {010} ∼ {100}. The equilibrium morphology of fm-BiVO
4
is predicted as a corner-cut truncated bipyramid with {001}, {101}, {011} and {111} facets exposed, in good agreement with experiments. The dramatic difference in work function may act as the driving force for photogenerated charge separation between {101}/{011} and {001} as observed in experiments. Based on our results, we provide a clue to morphology design for further enhancing the efficiency of charge separation in fm-BiVO
4
.
The predicted equilibrium morphology of fm-BiVO
4
agrees well with the experimental one. The tiny {111} facets exposed play an important role in photo(electro)catalysis.
Solid evidence has demonstrated that psychoemotional stress induced alteration of hair cycle through neuropeptide substance P (SP) mediated immune response, the role of reactive oxygen species (ROS) ...in brain-skin-axis regulation system remains unknown.
The present study aims to investigate possible mechanisms of ROS in regulation of SP-mast cell signal pathway in chronic restraint stress (CRS, a model of chronic psychoemotional stress) which induced abnormal of hair cycle.
Our results have demonstrated that CRS actually altered hair cycle by inhibiting hair follicle growth in vivo, prolonging the telogen stage and delaying subsequent anagen and catagen stage. Up-regulation of SP protein expression in cutaneous peripheral nerve fibers and activation of mast cell were observed accompanied with increase of lipid peroxidation levels and reduction of the activities of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) in CRS mice skin. In addition, SP receptor antagonist (RP67580) reduced mast cell activations and lipid peroxidation levels as well as increased GSH-Px activity and normalized hair cycle. Furthermore, antioxidant Tempol (a free radical scavenger) also restored hair cycle, reduced SP protein expression and mast cell activation.
Our study provides the first solid evidence for how ROS play a role in regulation of psychoemotional stress induced SP-Mast cell pathway which may provide a convincing rationale for antioxidant application in clinical treatment with psychological stress induced hair loss.
X-linked spinal and bulbar muscular atrophy (SBMA) is characterized by adult-onset muscle weakness and lower motor neuron degeneration. SBMA is caused by CAG-polyglutamine (polyQ) repeat expansions ...in the androgen receptor (AR) gene. Pathological findings include motor neuron loss, with polyQ-AR accumulation in intranuclear inclusions. SBMA patients exhibit myopathic features, suggesting a role for muscle in disease pathogenesis. To determine the contribution of muscle, we developed a BAC mouse model featuring a floxed first exon to permit cell-type-specific excision of human AR121Q. BAC fxAR121 mice develop systemic and neuromuscular phenotypes, including shortened survival. After validating termination of AR121 expression and full rescue with ubiquitous Cre, we crossed BAC fxAR121 mice with Human Skeletal Actin-Cre mice. Muscle-specific excision prevented weight loss, motor phenotypes, muscle pathology, and motor neuronopathy and dramatically extended survival. Our results reveal a crucial role for muscle expression of polyQ-AR in SBMA and suggest muscle-directed therapies as effective treatments.
•SBMA patients exhibit motor neuron degeneration accompanied by myopathic features•We created BAC fxAR121 mice with a floxed first exon to permit conditional excision•BAC fxAR121 mice crossed with human skeletal actin-Cre mice do not develop disease•Our results reveal a principal role for muscle in SBMA disease pathogenesis
Cortes et al. generate a BAC transgenic model for SBMA, engineered to permit cell-type-specific excision of polyglutamine-AR expression. They show that conditional termination of mutant AR in muscle prevents motor neuronopathy—establishing muscle as a principal site for SBMA pathogenesis.
An efficient and regioselective 4‐dimethylaminopyridine catalyzed 3+2 cycloaddition of isatin‐derived Morita−Baylis−Hillman adducts with azo esters was developed for the construction of ...3‐spiropyrazole‐2‐oxindoles. This protocol generated the desired spiropyrazoles in good to excellent yields with good functional group compatibility under mild reaction conditions.
Maize anthers, the male reproductive floral organs, express two classes of phased small-interfering RNAs (phasiRNAs). PhasiRNA precursors are transcribed by RNA polymerase II and map to low-copy, ...intergenic regions similar to PIWI-interacting RNAs (piRNAs) in mammalian testis. From 10 sequential cohorts of staged maize anthers plus mature pollen we find that 21-nt phased siRNAs from 463 loci appear abruptly after germinal and initial somatic cell fate specification and then diminish, whereas 24-nt phasiRNAs from 176 loci coordinately accumulate during meiosis and persist as anther somatic cells mature and haploid gametophytes differentiate into pollen. Male-sterile ocl4 anthers defective in epidermal signaling lack 21-nt phasiRNAs. Male-sterile mutants with subepidermal defects— mac1 (excess meiocytes), ms23 (defective pretapetal cells), and msca1 (no normal soma or meiocytes)—lack 24-nt phasiRNAs. ameiotic1 mutants (normal soma, no meiosis) accumulate both 21-nt and 24-nt phasiRNAs, ruling out meiotic cells as a source or regulator of phasiRNA biogenesis. By in situ hybridization, miR2118 triggers of 21-nt phasiRNA biogenesis localize to epidermis; however, 21- PHAS precursors and 21-nt phasiRNAs are abundant subepidermally. The miR2275 trigger, 24- PHAS precursors, and 24-nt phasiRNAs all accumulate preferentially in tapetum and meiocytes. Therefore, each phasiRNA type exhibits independent spatiotemporal regulation with 21-nt premeiotic phasiRNAs dependent on epidermal and 24-nt meiotic phasiRNAs dependent on tapetal cell differentiation. Maize phasiRNAs and mammalian piRNAs illustrate putative convergent evolution of small RNAs in male reproduction.
Significance By RNA profiling of 10 stages of maize anthers plus mature pollen, we found two distinct classes of phased small-interfering RNAs (phasiRNAs): 21-nt premeiotic phasiRNAs, after germinal and somatic cell specification, and 24-nt meiotic phasiRNAs coordinately accumulated during meiosis and persist into pollen. Sequencing of RNA from five male-sterile, anther developmental mutants— ocl4 , mac1 , ms23 , msca1 , and ameiotic1 —demonstrated the involvement of specific somatic layers. Premeiotic phasiRNAs require a functional epidermis, whereas meiotic phasiRNAs require a normal tapetum. Mammalian germ cells express “prepachytene” or “pachytene” PIWI-interacting RNAs (piRNAs). Whereas differences in biogenesis indicate independent origins, grass phasiRNAs and mammalian piRNAs share developmental timing, a lack of obvious targets, and an impact on male fertility, suggesting a possible evolutionary convergence.
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