Highly efficient and selective photocatalytic dehydrogenation of benzyl alcohol for simultaneous hydrogen and benzaldehyde production over Ni-decorated Zn_(0.5)Cd_(0.5)S solid solution

Photocatalytic conversion of solar energy into hydrogen and high value-added fine chemicals has attracted increasing attention. Herein, we demonstrate an efficient photocatalytic system for simultaneous hydrogen evolution and benzaldehyde production by dehydrogenation of benzyl alcohol over Nidecorated Zn_(0.5)Cd_(0.5)S solid solution under visible light. The photocatalytic system shows an excellent hydrogen production rate of 666.3 μmol h^(-1) with high stability. The optimal apparent quantum yield of52.5% is obtained at 420 nm. This noble-metal-free photocatalytic system displays much higher activity than pure Zn_(0.5)Cd_(0.5)S and Pt-loaded Zn_(0.5)Cd_(0.5)S solid solution. Further studies reveal that the metallic Ni nanocrystals play an important role in accelerating the separation of photogenerated charge carriers and the subsequent cleavage of α-C–H bond during dehydrogenation of benzyl alcohol.

First-Principles Study of Ultrathin Molybdenum Sulfides Nanowires:Electronic and Catalytic Hydrogen Evolution Properties

Molybdenum sulfides nanomaterials, such as one-dimensional (1D) nanotubes, nanoribbons, and two-dimensional (2D) nanosheets, have attracted intensive research interests for their novel electronic, optical, and catalytic properties. On the basis of first-principles calculation, here, we report a new series of 1D ultrathin molybdenum sulfides nanowires, including Mo2S6、Mo3S6 and Mo6S10 nanowires. Our results demonstrate that these ultrathin nanowires are both thermal and lattices dynamically stable, confirmed with the calculated phonon spectrum and Born-Oppenheimer molecular dynamic simulation at the temperature up to 600 K. The calculated elastic constant is 21.33, 103.22, and 163.00 eV/■ for Mo2S6, Mo3S6, and Mo6S10 nanowires, respectively. Mo2S6 and Mo3S6 nanowires are semiconductors with band gap of 1.55 and 0.46 eV, while Mo6S10 nanowires is metal, implying their potential applications in electronics and optoelectronics. In particular, ultrathin molybdenum sulfides nanowires can be used as catalysts for hydrogen evolution reaction. The calculated Gibbs free energy change for hydrogen evolution is about -0.05 eV for Mo2S6 nanowire, comparable with those of Pt and H-MoS2. The prediction of these 1D molybdenum sulfides nanowires may enrich the 1D family molybdenum sulfides and make a supplement to understand the high performance of hydrogen evolution reaction in transition-metal dichalcogenides.

Theoretical Study of Adsorption and Dehydrogenation of C2H4 on Cu（410）

Adsorption and dehydrogenation of ethylene on Cu（410） surface are investigated with first- principles calculations and micro-kinetics analysis. Ethylene dehydrogenation is found to start from the most stable π-bonded state instead of the previously proposed di〈r-bonded state. Our vibrational frequencies calculations verify the π-bonded adsorption at step sites at low coverage and low surface temperature and di-σ-bonded ethylene on C-C dimer （C2H4- CC） is proposed to be the species contributing to the vibrational peaks experimentally observed at high coverage at 193 K. The presence of C2H4-CC indicates that the dehydro- genation of ethylene on Cu（410） can proceed at temperature as low as 193 K.

Emission of Air Pollution in the Transport Sector: Case Study of the City of Campos dos Goytacazes, Brazil

The transportation sector is certainly one of the main agent’s principals and has contributed to the increase in global air pollution. In Brazil, the large-scale use of diesel for charge and passenger transport produces considerable air pollution in cities. The objectives of the study were to determine the concentrations of gas emissions (CO, NO and NO2), identify the chemical species that make up the particulates, from the exhaust of diesel vehicles and identify chemical species of particulates accumulated in air conditioning filters realized in the city of Campos dos Goytacazes located in the State of Rio de Janeiro. Thus, for the determination of the gas concentrations, electrochemical sensors were used and in the identification of chemical species, X-ray fluorescence spectroscopy was used. The results showed CO concentrations in the range of 173 to 880 ppmv, of NO in the range 52 to 240 ppmv and NO2 in the range 6 to 252 ppmv in the vehicles exhaust, and chemical species of the particulates in the exhaust identified: Ca, Si, Fe, S, Ti, P, Zn, Sc and Mn. Furthermore, Ca, Si, Fe, S, Ti, P, Zn, Mn, K, Cl, Al, Pb, V, Cu, Sr, Br and Er were in the air conditioning system. The concentration of gases and particulates is increased by the presence of a large highway that runs through the city, with one intense flow of trucks and buses, which certainly contributes to the reduction of the region’s air quality.

Solution-based Synthesis of Ni Sb Nanoparticles for Electrochemical Activity in Hydrogen Evolution Reaction

A cost-effective,facile solution-based hot-injection synthetic route has been developed to synthesize NiSb nanoparticles in oleylamine(OAm)using commercially available inexpensive precursor with reducing toxicity at a relatively low temperature of 160℃.Especially,an organic reductant of borane-tert-butylamine complex is intentionally involved in the reaction system to promote a fast reduction of metallic Ni and Sb for the formation of the NiSb nanoparticles.Structural characterizations reveal that the NiSb nanoparticles are hexagonal phase with space group P63/mmc and they are composed of small granules with size about 10 nm that tend to form agglomerates with porous-like geometries.This is the first report on the generation of transition metal antimonide via solution-based strategy,and the asfabricated nanoparticles possess actively electrocatalytic hydrogen evolution reaction(HER)property in acidic electrolytes when the long-chain ligand of OAm adhered on the surface of the nanoparticles is exchanged by ligand-removal and exchange procedure.It is found that the NiSb nanoparticles as a new kind of non-noble-metal HER electrocatalysts only require overpotentials of 437 and 531 mV to achieve high current densities of 10 and 50 mA/cm^2 respectively,as well as exhibit low charge transfer resistance and excellent HER stability.

The Origin of BC_(7) Sheet Metallicity and the Tuning of its Electronic Properties by Hydrogenation

Using first-principles calculations,we investigate the structural,electronic and hydrogenated properties of the hexagonal BC_(7) sheet.The computed energy bands and density of states indicate that the BC_(7) sheet is a metal,and its metallicity mainly originates from the non-bonding pz electrons of the diagonal carbon of the B atom.When these carbon atoms are fully passivated by H atoms,the BC_(7) sheet becomes a semiconductor with a band gap of 2.41 eV.Our studies demonstrate that changing both the proportion of the boron atoms in the boron carbon sheet and its hydrogenation can tune the electronic properties of boron carbon two-dimensional material.

Wet-Chemical Synthesis and Optical Property of ZnSe Nanowires by Ag₂Se-Catalyzed Growth Mechanism

High-quality II-VI semiconductor ZnSe nanowires were facilely prepared in the oleic acid and oleylamine mixed solution at low temperatures of 130°C-200°C through an Ag2Se-catalyzed growth mechanism. Oleylamine served as an effective reducing agent and a surfactant in the synthesis. Many of the resultant nanowires were terminated by an Ag2Se catalyst particle at one of their ends, confirming that the nanowire growth followed a catalytic mechanism. The crystal structure of Ag2Se catalyst was examined, which exhibited a metastable tetragonal phase, not the common orthorhombic phase. Meanwhile, the optical properties of as-synthesized ZnSe nanowire solid powder were evaluated by the UV-Visible diffuse reflectance and photoluminescence spectroscopy and a significant blue shift was observed compared to the bulk ZnSe with a band gap of 2.7 eV. This work would provide an alternative and effective catalytic route for the preparation of one-dimensional (1D) nanostructures of ZnSe and other metal selenides.

Enhanced Catalytic Hydrogen Evolution Reaction in Phosphorene Nanosheet via Cobalt Intercalation

Searching alternatives to Pt-based catalyst for producing hydrogen via water splitting has gathered enormous attention to develop renewable energy. Phosphorene has been investigated widely for its large surface area, low cost, and high carrier mobility, however, the poor activity in hydrogen evolution reaction (HER) and low conductivity limit its practical application. Herein, on the basis of first-principles calculations, we demonstrate that the catalytic HER in phosphorene can be enhanced significantly with cobalt intercalations. The Co-intercalated phosphorene is metallic with charge transfer from Co atoms to phosphorene, which could enhance the catalytic activity of phosphorene. In addition, the calculated Gibbs free energy of hydrogen adsorption on Co-intercalated phosphorene bilayer is comparable to that on Pt(111) surface, independent of the degree of hydrogen coverage. Our study implies that the Co intercalation provides an effective approach to enhance the catalytic HER in phosphorene.

Ferricyanide-Promoted Oxidative Activation and Ligation of Protein Thioacids in Neutral Aqueous Media

Ferricyanide-promoted oxidative activation of Nacylatedα-aminothioacids for amide bond formation withα-aminonitriles was recently shown to be a plausible pathway for prebiotic peptide synthesis.Herein we describe the finding that by adding sodium azide and thiols,ferricyanide oxidation can elicit highly efficient and clean conversion of fully unprotected peptide or protein thioacids in neutral aqueous media to the corresponding thioesters.This transformation enables the development of ferricyanide-promoted thioacid-based native chemical ligation(NCL)as a new redox-based method for chemical protein synthesis,which does not need to change pH and is therefore operationally easy for ligation at small scales.The effectiveness of the ferricyanide-promoted thioacid-based NCL was illustrated by synthesis of an ISG15-modified MDA5 segment under nondenaturing conditions and synthesis of an acetylated ubiquitin(Ub)-modified histone H2A through an N-to-C sequential ligation.This work broadens the concept of on-demand oxidative activation strategy for protein ligation and provides a new useful supplement to the repertoire of methods for chemical protein synthesis,particularly for studies on proteins carrying Ub family modifications.

A cytochrome c551 mediates the cyclic electron transport chain of the anoxygenic phototrophic bacterium Roseiflexus castenholzii

Roseiflexus castenholzii is a gram-negativefilamentous phototrophic bacterium that carries out anoxygenic photosynthesis through a cyclic electron transport chain(ETC).The ETC is composed of a reaction center(RC)–light-harvesting(LH)complex(rcRC–LH);an alternative complex III(rcACIII),which functionally re-places the cytochrome bc1/b6f complex;and the periplasmic electron acceptor auracyanin(rcAc).Although compositionally and structurally different from the bc1/b6f complex,rcACIII plays similar essential roles in oxidizing menaquinol and transferring electrons to the rcAc.However,rcACIII-mediated electron transfer(which includes both an intraprotein route and a downstream route)has not been clearly elucidated,nor have the details of cyclic ETC.Here,we identify a previously unknown monoheme cytochrome c(cyt c551)as a novel periplasmic electron acceptor of rcACIII.It reduces the light-excited rcRC–LH to complete a cyclic ETC.We also reveal the molecular mechanisms involved in the ETC using electron paramagnetic resonance(EPR),spectroelectrochemistry,and enzymatic and structural analyses.Wefind that electrons released from rcACIII-oxidized menaquinol are transferred to two alternative periplasmic electron acceptors(rcAc and cyt c551),which eventually reduce the rcRC to form the complete cyclic ETC.This work serves as a foundation for further studies of ACIII-mediated electron transfer in anoxygenic photosynthesis and broadens our under-standing of the diversity and molecular evolution of prokaryotic ETCs.

Air Pollution in the Brazilian Road Transport and Its Environmental and Social Consequences

The use of fossil fuels has been greatly increased since the eighteenth century with advent of the industrial revolution. Currently, the use of these fuels is responsible for, on average, 80% of energy generation in human society, producing large emission of pollutant gases and particulate material. Thus the transport sector is a major source of air pollution worldwide. This issue causes serious damages to the environment through phenomena such as acid rain, global warming and photochemical smog. Moreover, the emission of pollutants is also related to damages in human health. Brazil is a country with great territorial dimensions and its transport array is eminently by road, so it is a major consumer of fossil fuels, such as diesel, which has been producing serious environmental and social problems. Thus, this paper presents an analysis of the emission of gaseous pollutants and particulate matter from the transport sector (buses and trucks), gaseous pollutants such as NO2 and SO2 were detected in ppmv concentrations using electrochemical sensors. The composition constituents of the particulate materials emitted in diesel combustion and their respective concentrations were determined by X rays fluorescence spectrometry (XRF). The identified elements were: S, Fe, Si, Ca, Zn, P, Ni, Cr, Ti, Mn and Cu.

Evolution of Monkeypox C9L RNA G-Quadruplex Elevates the Translation of Its Only Kelch-like Protein by Accelerating G-Quadruplex Unfolding Kinetics

Genomic surveillance of monkeypox virus(MPXV)is essential to explore the reason of its unusual outbreak.Current phylogenomic analysis of the MPXV genome mainly focuses on the effect of amino acid mutations.Herein,we explore the evolutionary variation of RNA G-quadruplex(RG4)of MPXV and find that the genome evolution of MPXV can also produce new effects through changes in the RG4 structure.This RG4 is located in MPXV’s only Kelch-like C9L gene,which encodes for an antagonist of the innate immune response.The evolution of this virus increases the unfolding kinetic constant of C9L RG4 and promotes the C9 protein level in living cells.Importantly,all reported MPXV genomes in 2022 carry the C9L-RG4-5 pattern with the highest unfolding kinetic constant.Additionally,the RG4 ligand,RGB-1,can impede the unfolding of C9L-RG4-5 and thereby reduce the C9 protein level.These findings carve out a new path to comprehensively understanding MPXV virology.

Unconventionally anisotropic growth of PbSe nanorods:Controllable fabrication under solution-solid-solid regime over Ag2Se catalysis for broadband photodetection

Broadband optoelectronic devices intrigue enormous interests on account of their promising potential in optical communications,sensors and environmental monitoring.PbSe nanocrystals are promising candidates for the construction of next-generation photodetectors due to their fascinating intrinsic properties and solution-processed compatibility with varied substrates.Here,we report the fabrication of a broadband photodetector on the basis of high-quality solution-processed PbSe nanorods in rock-salt phase grown along unconventionally anisotropic growth direction of<112>zone axis.The rock-salt PbSe nanorods are synthesized in solution phase over the catalysis of Ag2Se with relatively high-temperature body-centered cubic phase via a solution-solid-solid growth regime using oleylamine and oleic acid as solvents and stabilizer surfactants,from which the PbSe nanorods with the unconventionally anisotropic growth direction are controllably grown in size and shape in the synthetic procedure typically with about 17 nm in diameter and 58 nm in length on average.Meanwhile,the PbSe nanorods-based photodetector exhibits a broadband response from 405 to 1,064 nm with a high responsivity of 0.78 A·W^(-1)and a fast response time of 17.5μs.The response time is much faster in comparison with most of the PbSe-based photodetectors with response time in millisecond level.

Applications of CBT-Cys click reaction: past, present, and future

Herein, we review the development, applications and potential prospects of CBT-Cys click reaction. This click condensation reaction is based on the condensation reaction between 2-cyanobenzothiazole(CBT) and D-cysteine(D-Cys) in fireflies and has high biocompatibility and controllability in physiological solutions. Under the control of p H, reduction, or enzyme, this CBTbased click reaction has been widely applied to a wide range of biomedical fields such as protein labeling, molecular imaging(e.g., optical imaging, nuclear imaging, magnetic resonance imaging and photoacoustic imaging), nanomaterial fabrication, cancer therapy, and other potentialities.

Preparation of true solutions of monomeric amyloidogenic protein/peptide:A critical prerequisite for aggregation kinetic study

Our dynamic laser light scattering(LLS) study shows that the current widely used protocols of dissolving amyloidogenic protein/peptide do not really result in a true solution;namely,there always exist a trace amount of interchain aggregates,which greatly affect the association kinetics,partially explaining why different kinetics were reported even for a solution with identical protein and solvent.Recently,using a combination of the conventional dissolution procedure and our newly developed ultra-filtration method,we have developed a novel protocol to prepare a true solution of amyloidogenic protein/peptide without any interchain aggregates.The resultant solutions remain in their monomeric state for at least one week,which is vitally important for further study of the very initial stage of the interchain association under the physiological conditions because more and more evidence suggests that it is those small oligomers rather than large fabric aggregates that are cytotoxic.In addition,this study shows that combining static and dynamic LLS can lead to more physical and microscopic information about the protein association instead of only the size distribution.

Simultaneous capture of ISG15 conjugating and deconjugating enzymes using a semi-synthetic ISG15-Dha probe

ISG15 is a ubiquitin-like(Ubl) protein attached to substrate proteins by ISG15 conjugating enzymes whose dysregulation is implicated in a multitude of disease processes, but the probing of these enzymes remains to be accomplished. Here, we describe the development of a new activity-based probe ISG15-Dha(dehydroalanine) through protein semi-synthesis. In vitro crosslinking and cell lysate proteomic profiling experiments showed that this probe can sequentially capture ISG15 conjugating enzymes including E1 enzyme UBA7, E2 enzyme UBE2L6, E3 enzyme HERC5, the previously known ISG15 deconjugating enzyme(USP18), as well as some other enzymes(USP5 and USP14) which we additionally confirmed to impart deISGylation activity. Collectively, ISG15-Dha provides a new tool that can simultaneously capture ISG15 conjugating and deconjugating enzymes for biochemical or pharmacological studies.

Conformational change of E.coli sulfurtransferase YgaP upon SCN- in intact native membrane revealed by fluorescence lifetime and anisotropy

Fluorescence lifetime and anisotropy has become a prevalent tool to detect the structure change and motility property of proteins. YgaP is the only membrane-integrated rhodanese in E. coli. The sulfur transfer process has been characterized by various studies. However, the mechanism of the outward transportation of SCN-remains unclear. In this work, we examined the fluorescence lifetime and anisotropy of site-specific incorporated unnatural amino acid 7-HC to study the conformational change of YgaP upon SCN-binding. We also compared the fluorescence changes between detergent-wrapped environment in DPC and intact native membrane environment in SMA. Our results suggested the presence of at least two different conformations in YgaP protein. Both the residues in the middle of TMH2 and the residues near extracellular side play important roles in the binding and/or output of SCN-. SMA is a good material to reflect the in situ conformation changes of protein than micelles.

In cell measurement of fluorescence lifetime imaging microscopy revealed C-terminal conformation changes of Ferroportin upon addition of Mn^2＋

Fluorescence microscopy, as a sensitive method to detect microenvironment of molecules, is widely used in protein conformation and dynamic studies in live cells. Fluorescence lifetime imaging microscopy（FLIM）, which is independent of fluorophore concentrations, scattering and bleaching, is a suitable tool to analyze membrane proteins in a single cell. Ferroportin（FPN）, a multi-ion exporter in vertebrates, was modulated by metal ions with unknown mechanism. Herein, we fused green fluorescence protein on Cterminal of FPN（FPN-eGFP） and applied fluorescence lifetime to monitor conformation changes of FPN in a live cell. The fluorescence lifetime distribution showed a shift to shorter lifetime upon Mn^（2＋） treatment,suggesting a preference conformation of FPN in Mn^（2＋） exposure. It is also observed that the lifetime（rather than intensity） measurement was not strongly influenced by laser power. The observed fluorescence lifetime changes of FPN-eGFP upon Mn^（2＋） treatments indicated that extracellular metal ions can modulate FPN through conformation exchanges between several different states.

Preparation of true solutions of monomeric amyloidogenic protein/peptide:A critical prerequisite for aggregation kinetic study

Our dynamic laser light scattering(LLS) study shows that the current widely used protocols of dissolving amyloidogenic protein/peptide do not really result in a true solution;namely,there always exist a trace amount of interchain aggregates,which greatly affect the association kinetics,partially explaining why different kinetics were reported even for a solution with identical protein and solvent.Recently,using a combination of the conventional dissolution procedure and our newly developed ultra-filtration method,we have developed a novel protocol to prepare a true solution of amyloidogenic protein/peptide without any interchain aggregates.The resultant solutions remain in their monomeric state for at least one week,which is vitally important for further study of the very initial stage of the interchain association under the physiological conditions because more and more evidence suggests that it is those small oligomers rather than large fabric aggregates that are cytotoxic.In addition,this study shows that combining static and dynamic LLS can lead to more physical and microscopic information about the protein association instead of only the size distribution.