Claudin-18.2(CLDN18.2)is a tight junction protein that is typically expressed only in normal gastric mucosal cells.When malignancy occurs,cell polarity is lost,intercellular adhesion structures are destroyed,and CLDN1...Claudin-18.2(CLDN18.2)is a tight junction protein that is typically expressed only in normal gastric mucosal cells.When malignancy occurs,cell polarity is lost,intercellular adhesion structures are destroyed,and CLDN18.2 is therefore exposed to the surface of tumor cells[1].CLDN18.2 is specifically expressed in approximately 40%of human epidermal growth factor receptor 2(HER2)-negative gastrointestinal cancers,making it a promising emerging therapeutic target.As recently reported,zolbetuximab,an CLDN18.2 targeting antibody,has shown amazing efficacy in patients with CLDN18.2-positive and HER2-negative gastric cancers[2].In clinical practice,the assessment of CLDN18.2 expression status is crucial to the determination of treatment regimen for patients.Molecular imaging can be used as a non-invasive test for diagnosis,staging,and efficacy monitoring.The results of molecular imaging of CLDN18.2 have been published continuously,and the development of CLDN18.2 molecular probe is of great significance for the development of tumor targeted therapy(Fig.1).展开更多
AIM:To evaluate the relationship between gene polymorphism(BclI,ER22/23EK,N363S)and the occurrence,progression and sensitivity to glucocorticoid of lacrimal gland benign lymphoepithelial lesion(LGBLEL).METHODS:Clinica...AIM:To evaluate the relationship between gene polymorphism(BclI,ER22/23EK,N363S)and the occurrence,progression and sensitivity to glucocorticoid of lacrimal gland benign lymphoepithelial lesion(LGBLEL).METHODS:Clinical peripheral blood samples of 52 LGBLEL patients and 10 normal volunteers were collected for DNA extraction and polymerase chain reaction sequencing to analyze single nucleotide polymorphism(SNP)genotypes.The lacrimal tissues of LGBLEL were surgically removed and made into paraffin sections for subsequent hematoxylin-eosin(HE)and Masson staining analysis.The duration of disease and hormone use of LGBLEL patients from diagnosis to surgery were also analyzed.The Meta-analysis follows PRISMA guidelines to conducted a systematic review of human studies investigating the relationship between the NR3C1 BclI polymorphism and glucocorticoids(GCs)sensitivity.RESULTS:There was no association between ER22/23EK or N363S and the occurrence of LGBLEL or GCs sensitivity(P>0.05);BclI GC genotype was closely related to GCs resistance(P=0.03)as is the minor allele C(P=0.0017).The HE staining and Masson staining showed that the GC genotype of BclI remarkably slowed down the disease progression and reduced fibrosis(P<0.05),especially for GCs-dependent patients(P<0.0001).Meta-analysis showed that BclI was not significantly associated with GCs responsiveness.CONCLUSION:The LGBLEL patients who carry the NR3C1 BclI allele C may be more sensitive to GCs and associated with lower fibrosis and slower disease progression.The results may guide the clinical treatment strategy for the LGBLEL patients.展开更多
The extremely high structural tolerance of ceria to oxygen vacancies(Ov)has made it a desirable catalytic material for the hydrocarbon oxidation to chemicals and pharmaceuticals and the reduction of gaseous pollutants...The extremely high structural tolerance of ceria to oxygen vacancies(Ov)has made it a desirable catalytic material for the hydrocarbon oxidation to chemicals and pharmaceuticals and the reduction of gaseous pollutants.It is proposed that the formation and diffusion of Ov originate from its outstanding reduction property.However,the formation and diffusion process of Ov over the surface of ceria at the atomic level is still unknown.Herein,the structural and valence evolution of CeO_(2)(111)surfaces in reductive,oxidative and vacuum environments from room temperature up to 700℃was studied with in situ aberration-corrected environmental transmission electron microscopy(ETEM)experiments.Ov is found to form under a high vacuum at elevated temperatures;however,the surface can recover to the initial state through the adsorption of oxygen atoms in an oxygen-contained environment.Furthermore,in hydrogen environment,the step-CeO_(2)(111)surface is not stable at elevated temperatures;thus,the steps tend to be eliminated with increasing temperature.Combined with first-principles density function calculations(DFT),it is proposed that O-terminated surfaces would develop in a hypoxic environment due to the dynamic diffusion of Ov from the outer surface to the subsurface.Furthermore,in a reductive environment,H2 facilitates the formation and diffusion of Ov while Ce-terminated surfaces develope.These results reveal dynamic atomic-scale interplay between the nanoceria surface and gas,thereby providing fundamental insights into the Ov-dependent reaction of nano-CeO_(2) during catalytic processes.展开更多
The nitrogen cycle plays an important role in nature,but N-containing products cannot meet human needs.The electrochemical synthesis of ammonia under ambient conditions has attracted the interest of many researchers b...The nitrogen cycle plays an important role in nature,but N-containing products cannot meet human needs.The electrochemical synthesis of ammonia under ambient conditions has attracted the interest of many researchers because it provides a clean and pollution-free synthesis method;however,it has certain difficulties,including a high activation energy,multiple electron transfer,and hydrogenation.Thermodynamic factors limit the selectivity and activity of ammonia synthesis techniques.This review summarizes progress in the electrochemical synthesis of ammonia from theory and experiment.Theoretically,the reduction of nitrogen molecules is analyzed using orbit theory and the thermodynamic reaction pathways.Experimentally,we first discuss the effect of the experimental setup on the nitrogen reduction reaction,and then the four critical of catalysts,including size,electronic,coordination,and orientation effects.These issues must be considered to produce highly-efficient catalysts for electrochemical nitrogen reduction(eNRR).This review provides an overview of the eNRR to enable future researchers to design rational catalysts.展开更多
The bone matrix plays an indispensable role in the human body,and its unique biomechanical and mechanobiological properties have received much attention.The bone matrix has unique mechanical anisotropy and exhibits bo...The bone matrix plays an indispensable role in the human body,and its unique biomechanical and mechanobiological properties have received much attention.The bone matrix has unique mechanical anisotropy and exhibits both strong toughness and high strength.These mechanical properties are closely associated with human life activities and correspond to the function of bone in the human body.None of the mechanical properties exhibited by the bone matrix is independent of its composition and structure.Studies on the biomechanics of the bone matrix can provide a reference for the preparation of more applicable bone substitute implants,bone biomimetic materials and scaffolds for bone tissue repair in humans,as well as for biomimetic applications in other fields.In providing mechanical support to the human body,bone is constantly exposed to mechanical stimuli.Through the study of the mechanobiology of the bone matrix,the response mechanism of the bone matrix to its surrounding mechanical environment can be elucidated and used for the health maintenance of bone tissue and defect regeneration.This paper summarizes the biomechanical properties of the bone matrix and their biological significance,discusses the compositional and structural basis by which the bone matrix is capable of exhibiting these mechanical properties,and studies the effects of mechanical stimuli,especially fluid shear stress,on the components of the bone matrix,cells and their interactions.The problems that occur with regard to the biomechanics and mechanobiology of the bone matrix and the corresponding challenges that may need to be faced in the future are also described.展开更多
β-Amyloid(Aβ)is a specific pathological hallmark of Alzheimer's disease(AD).Because of its neurotoxicity,AD patients exhibit multiple brain dysfunctions.Disease-modifying therapy(DMT)is the central concept in th...β-Amyloid(Aβ)is a specific pathological hallmark of Alzheimer's disease(AD).Because of its neurotoxicity,AD patients exhibit multiple brain dysfunctions.Disease-modifying therapy(DMT)is the central concept in the development of AD thera-peutics today,and most DMT drugs that are currently in clinical trials are anti-Aβdrugs,such as aducanumab and lecanemab.Therefore,understanding Aβ's neurotoxic mechanism is crucial for Aβ-targeted drug development.Despite its total length of only a few dozen amino acids,Aβis incredibly diverse.In addition to the well-known Aβ_(1-42),N-terminally truncated,glutaminyl cyclase(QC)catalyzed,and pyroglutamate-modified Aβ(pEAβ)is also highly amyloidogenic and far more cytotoxic.The extracel-lular monomeric Aβ_(x-42)(x=1-11)initiates the aggregation to form fibrils and plaques and causes many abnormal cellular responses through cell membrane receptors and receptor-coupled signal pathways.These signal cascades further influence many cel-lular metabolism-related processes,such as gene expression,cell cycle,and cell fate,and ultimately cause severe neural cell damage.However,endogenous cellular anti-Aβdefense processes always accompany the Aβ-induced microenvironment alterations.Aβ-cleaving endopeptidases,Aβ-degrading ubiquitin-proteasome system(UPS),and Aβ-engulfing glial cell immune responses are all essential self-defense mechanisms that we can leverage to develop new drugs.This review discusses some of the most recent advances in understanding Aβ-centric AD mechanisms and suggests prospects for promising anti-Aβstrategies.展开更多
Under the context of carbon neutrality of China,it is urgent to shift our energy supply towards cleaner fuels as well as to reduce the greenhouse gas emission.Currently,coal is the main fossil fuel energy source of Ch...Under the context of carbon neutrality of China,it is urgent to shift our energy supply towards cleaner fuels as well as to reduce the greenhouse gas emission.Currently,coal is the main fossil fuel energy source of China.The country is striving hard to replace it with methane,a cleaner fossil fuel.Although China has rich geological resources of methane as coal bed methane(CBM)reserves,it is quite challenging to utilize them due to low concentration.The CBM is however mainly emitted directly to atmosphere during coal mining,causing waste of the resource and huge contribution to greenhouse effect.The recent work by Yang et al.demonstrated a potential solution to extract low concentration methane selectively from CBM through using MOF materials as sorbents.Such kind of materials and associated separation technology are promising to reduce greenhouse gas emission and promote the methane production capability,which would contribute to carbon neutrality in dual pathways.展开更多
In the process of exploration and development of oil and gas fields, the acidic environment of oil reservoir, production and transport processes cause corrosion of pipelines and equipment, resulting in huge economic l...In the process of exploration and development of oil and gas fields, the acidic environment of oil reservoir, production and transport processes cause corrosion of pipelines and equipment, resulting in huge economic losses and production safety risks. Corrosion inhibitors were widely used in oil industry because of simple operation process and economical. In this study, three environmentally friendly corrosion inhibitors were synthesized based on the natural polysaccharide chitosan. Corrosion inhibition of three dendritic chitosan derivatives (We name them BH, CH and DH) on mild steel in 1 mol/L HCl solution with natural ventilation system was evaluated by weight loss experiment, electrochemical analysis and surface morphology characterization. The experimental results showed that when the three dendritic chitosan derivatives added in the corrosive medium were 500 mg L^(−1), the corrosion inhibition efficiencies were all more than 80%. Based on quantum chemical calculation, inhibition mechanisms of three dendritic chitosan derivatives were investigated according to molecular structures. The results showed that the benzene ring, Schiff base and N atom contained in the molecule were the active centers of electron exchange, which were more likely to form a film on the carbon steel surface, thereby slowing or inhibiting corrosion. The results also predicted the corrosion inhibition effect BH > DH > CH, which was consistent with the experimental conclusion.展开更多
Previous air pollution control strategies didn’t pay enough attention to regional collaboration and the spatial response sensitivities,resulting in limited control effects in China.This study proposed an effective PM...Previous air pollution control strategies didn’t pay enough attention to regional collaboration and the spatial response sensitivities,resulting in limited control effects in China.This study proposed an effective PM_(2.5)and O_(3) control strategy scheme with the integration of Self-Organizing Map(SOM),Genetic Algorithm(GA)and WRF-CAMx,emphasizing regional collaborative control and the strengthening of control in sensitive areas.This scheme embodies the idea of hierarchical management and spatial-temporally differentiated management,with SOM identifying the collaborative subregions,GA providing the optimized subregion-level priority of precursor emission reductions,and WRF-CAMx providing response sensitivities for grid-level priority of precursor emission reductions.With Beijing-Tianjin-Hebei and the surrounding area(BTHSA,“2+26”cities)as the case study area,the optimized strategy required that regions along Taihang Mountains strengthen the emission reductions of all precursors in PM_(2.5)-dominant seasons,and strengthen VOCs reductions but moderate NOx reductions in O_(3)-dominant season.The spatiotemporally differentiated control strategy,without additional emission reduction burdens than the 14th Five-Year Plan proposed,reduced the average annual PM_(2.5)and MDA8 O_(3) concentrations in 28 cities by 3.2%-8.2% and 3.9%-9.7% respectively in comparison with non-differential control strategies,with the most prominent optimization effects occurring in the heavily polluted seasons(6.9%-18.0%for PM_(2.5)and 3.3%-14.2% for MDA8 O_(3),respectively).This study proposed an effective scheme for the collaborative control of PM_(2.5)and O_(3) in BTHSA,and shows important methodological implications for other regions suffering from similar air quality problems.展开更多
Developing the alternative supported noble metal catalysts with low cost,high catalytic efficiency,and good resistance toward carbon dioxide and water vapor is critically demanded for the oxidative removal of volatile...Developing the alternative supported noble metal catalysts with low cost,high catalytic efficiency,and good resistance toward carbon dioxide and water vapor is critically demanded for the oxidative removal of volatile organic compounds(VOCs).In this work,we prepared the mesoporous chromia-supported bimetallic Co and Ni single-atom(Co_(1)Ni_(1)/meso-Cr_(2)O_(3))and bimetallic Co and Ni nanoparticle(Co_(NP)Ni_(NP)/mesoCr_(2)O_(3))catalysts adopting the one-pot polyvinyl pyrrolidone(PVP)-and polyvinyl alcohol(PVA)-protecting approaches,respectively.The results indicate that the Co_(1)Ni_(1)/meso-Cr_(2)O_(3)catalyst exhibited the best catalytic activity for n-hexane(C_(6)H_(14))combustion(T_(50%)and T_(90%)were 239 and 263℃ at a space velocity of 40,000 mL g^(-1)h^(-1);apparent activation energy and specific reaction rate at 260℃ were 54.7 kJ mol^(-1)and 4.3×10^(-7)mol g^(-1)_(cat)s^(-1),respectively),which was associated with its higher(Cr^(5+)+Cr^(6+))amount,large n-hexane adsorption capacity,and good lattice oxygen mobility that could enhance the deep oxidation of n-hexane,in which Ni_(1) was beneficial for the enhancements in surface lattice oxygen mobility and low-temperature reducibility,while Co_(1) preferred to generate higher contents of the high-valence states of chromium and surface oxygen species as well as adsorption and activation of n-hexane.n-Hexane combustion takes place via the Mars van Krevelen(MvK)mechanism,and its reaction pathways are as follows:n-hexane→olefins or 3-hexyl hydroperoxide→3-hexanone,2-hexanone or 2,5-dimethyltetrahydrofuran→2-methyloxirane or 2-ethyl-oxetane→acrylic acid→CO_x→CO_(2)and H_(2)O.展开更多
Objective To establish a sensitive,simple and rapid detection method for African swine fever virus(ASFV)B646L gene.Methods A recombinase-aided amplification-lateral flow dipstick(RAA-LFD)assay was developed in this st...Objective To establish a sensitive,simple and rapid detection method for African swine fever virus(ASFV)B646L gene.Methods A recombinase-aided amplification-lateral flow dipstick(RAA-LFD)assay was developed in this study.Recombinase-aided amplification(RAA)is used to amplify template DNA,and lateral flow dipstick(LFD)is used to interpret the results after the amplification is completed.The lower limits of detection and specificity of the RAA assay were verified using recombinant plasmid and pathogenic nucleic acid.In addition,30 clinical samples were tested to evaluate the performance of the RAA assay.Results The RAA-LFD assay was completed within 15 min at 37°C,including 10 min for nucleic acid amplification and 5 minutes for LFD reading results.The detection limit of this assay was found to be 200 copies per reaction.And there was no cross-reactivity with other swine viruses.Conclusion A highly sensitive,specific,and simple RAA-LFD method was developed for the rapid detection of the ASFV.展开更多
Exploring nonprecious electrocatalysts for water splitting with high efficiency and durability is critically important.Herein,bimetallic phosphides are encapsulated into graphitized carbon to construct a C@NiCoP compo...Exploring nonprecious electrocatalysts for water splitting with high efficiency and durability is critically important.Herein,bimetallic phosphides are encapsulated into graphitized carbon to construct a C@NiCoP composite nanoarray using bimetallic metal-organic framework(MOF) as a self-sacrificial template.The resulting C@NiCoP exhibits superior performance for pH-universal electrocatalytic hydrogen evolution reaction(HER),particularly representing a low overpotential of 46.3 mV at 10 mA cm^(-2) and Tafel slope of 44.1 mV dec^(-1) in alkaline media.The structural characterizations combined with theoretical calculation demonstrate that tailored electronic structure from bimetal atoms and the synergistic effect with graphitized carbon layer could jointly optimize the adsorption ability of hydrogen on active sites in HER process,and enhance the electrical conductivity as well.In addition,the carbon layer served as a protecting shell also prevents highly dispersed NiCoP components from agglomeration and/or loss in harsh media,finally improving the durability.This work thus provides a new insight into optimizing activity and stability of pH-universal electrocatalysts by the nanostructural design and electronic structure modulation.展开更多
BACKGROUND Patients with keloids who receive radiotherapy(RT)after surgery can develop refractory wounds that cannot be healed by the patient's own repair system.Such chronic wounds are uneven and complex due to p...BACKGROUND Patients with keloids who receive radiotherapy(RT)after surgery can develop refractory wounds that cannot be healed by the patient's own repair system.Such chronic wounds are uneven and complex due to persistent abscess and ulceration.Without external intervention,they can easily result in local tissue necrosis or,in severe cases,large area tissue resection,amputation,and even death.CASE SUMMARY This article describes the use of hydrogen to treat a 42-year-old female patient with a chronic wound on her left shoulder.The patient had a skin graft that involved implanting a dilator under the skin of her left shoulder,and then transferring excess skin from her shoulder onto scar tissue on her chest.The skin grafting was followed by two rounds of RT,after which the shoulder wound had difficulty healing.For six months,the patient was treated with 2 h of hydrogen inhalation(HI)therapy per day,in addition to application of sterile gauze on the wound and periodic debridement.We also performed one deep,large,sharp debridement to enlarge the wound area.The wound healed completely within 6 mo of beginning the HI treatment.CONCLUSION After HI therapy,the patient showed superior progress in reepithelialization and wound repair,with eventual wound closure in 6 mo,in comparison with the previous failures of hyperbaric oxygen and recombinant bovine basic fibroblast growth factor therapies.Our work showed that HI therapy could be a new strategy for wound healing that is cleaner,more convenient,and less expensive than other therapies,as well as easily accessible for further application in clinical wound care.展开更多
The ubiquity of N-heterocycles in marketed drugs makes the development of metal-free methodologies for constructing C–N bonds of considerable importance.As an environmentally friendly method,electro-oxidative intramo...The ubiquity of N-heterocycles in marketed drugs makes the development of metal-free methodologies for constructing C–N bonds of considerable importance.As an environmentally friendly method,electro-oxidative intramolecular C–H amination has emerged as a powerful platform for synthesizing nitrogen-containing heterocycles under metal-and external oxidant-free conditions.In this minireview,the main achievements in this direction since 2020 are summarized,with an emphasis on the substrate scope and mechanistic aspects.The reactions are classifi ed into two categories:direct and indirect electro-oxidative intramolecular C–H aminations.展开更多
Continuous aggravated surface O_(3) over North China Plain(NCP)has attracted widely public concern.Herein,we evaluated the effects of changes in aerosols,precursor emissions,and meteorology on O_(3) in summer(June)of ...Continuous aggravated surface O_(3) over North China Plain(NCP)has attracted widely public concern.Herein,we evaluated the effects of changes in aerosols,precursor emissions,and meteorology on O_(3) in summer(June)of 2015–2019 over NCP via 8 scenarios with WRF-Chem model.The simulated mean MDA8 O_(3) in urban areas of 13 major cities in NCP increased by 17.1%∼34.8%,which matched well with the observations(10.8%∼33.1%).Meanwhile,the model could faithfully reproduce the changes in aerosol loads,precursors,and meteorological conditions.A relatively-even O_(3) increase(+1.2%∼+3.9%for 24-h O_(3) and+1.0%∼+3.8%for MDA8 O_(3))was induced by PM_(2.5) dropping,which was consistent with the geographic distribution of regional PM_(2.5) reduction.Meanwhile,the NO_(2) reduction coupled with a nearconstant VOCs led to the elevated VOCs/NOx ratios,and then caused O_(3) rising in the areas under VOCs-limited regimes.Therein,the pronounced increases occurred in Handan,Xingtai,Shijiazhuang,Tangshan,and Langfang(+10.7%∼+13.6%for 24-h O_(3) and+10.2%∼+12.2%forMDA8 O_(3));while the increases in other citieswere 5.7%∼10.5%for 24-h O_(3) and 4.9%∼9.2%for MDA8 O_(3).Besides,the meteorological fluctuations brought about the more noticeable O_(3) increases in northern parts(+12.5%∼+13.5%for 24-h O_(3) and+11.2%∼+12.4%for MDA8 O_(3))than those in southern and central parts(+3.2%∼+9.3%for 24-h O_(3) and+3.7%∼+8.8%for MDA8 O_(3)).The sum of the impacts of the three drivers reached 16.7%∼21.9%,which were comparable to the changes of the observed O_(3).Therefore,exploring reasonable emissionsreduction strategies is essential for the ozone pollution mitigation over this region.展开更多
Lead-free bismuth-based halide perovskites and their analogues have attracted research interest for their high stability and optoelectronic properties.However,the morphology-controlled synthesis of bismuth-based perov...Lead-free bismuth-based halide perovskites and their analogues have attracted research interest for their high stability and optoelectronic properties.However,the morphology-controlled synthesis of bismuth-based perovskite nanocrystals has been rarely demonstrated.Herein,we report the colloidal synthesis of zero-dimensional(0D)Cs3BiCl6 nanosheets(NSs),Cs3Bi2Cl9 NSs/nanoplates(NPs)and Cs4MnBi2Cl12 NPs through a hot-injection method.We demonstrate that the Cs3BiCl6 NSs,as an initial product of Cs3Bi2Cl9 and Cs4MnBi2Cl12 NPs,can transform into Cs3Bi2Cl9 NSs or Cs4MnBi2Cl12 NPs via Cl-induced metal ion insertion reactions under the templating effect of Cs3BiCl6.This growth mechanism is also applicable for the synthesis of Cs4CdBi2Cl12 nanoplates.Furthermore,the alloying of Cd2+into Cs4MnBi2Cl12 lattice could weaken the strong coupling effect between Mn and Mn,which leads to a prolonged photoluminescence lifetime and an enhanced photoluminescence quantum yield(PLQY).As a proof of concept,the alloyed Cs4MnxCd1–xBi2Cl12 NPs are used as a scintillator,which show a lowest detection limit of 134.5 nGy/s.The X-ray imaging results display a high spatial resolution of over 20 line pairs per millimeter(lp/mm).These results provide new insights in the synthesis of anisotropic bismuth-based perovskite nanocrystals and their applications in radiation detection.展开更多
Road silt loading(sL)is an important parameter in the fugitive road dust(FRD)emissions.In this study,the improved Testing Re-entrained Aerosol Kinetic Emissions from Roads(TRAKER)combined with the AP-42 method was fir...Road silt loading(sL)is an important parameter in the fugitive road dust(FRD)emissions.In this study,the improved Testing Re-entrained Aerosol Kinetic Emissions from Roads(TRAKER)combined with the AP-42 method was firstly developed to quickly measure and estimate the sLs of paved roads in Beijing,China.The annual average sLs in Beijing was 0.59±0.31 g/m^(2)in 2020,and decreased by 22.4%compared with that in 2019.The seasonal variations of sLs followed the order of spring>winter>summer>autumn in the two years.The seasonal mean road sLs on the same type road in the four seasons presented a decline trend from^(2)019 to 2020,especially on the Expressway,decreasing 47.4%-72.7%.The road sLs on the different type roads in the same season followed the order of Major arterial∼Minor arterial∼Branch road>Express road,and Township road∼Country highway>Provincial highway∼National highway.The emission intensities of PM10 and PM_(2.5)from FRD in Beijing in 2020 were lower than those in 2019.The PM10 and PM_(2.5)emission intensities at the four planning areas in the two years all presented the order of the capital functional core area>the urban functional expansion area>the urban development new area>the ecological conservation and development area.The annual emissions of PM10 and PM_(2.5)from FRD in Beijing in 2020 were 74,886 ton and 18,118 ton,respectively,decreasing by∼33.3%compared with those in 2019.展开更多
An evidence-based control strategy for emission reduction of VOC sources can effectively solve the regional PM2.5and O3compound pollution in China.We estimated the anthropogenic VOC emission inventory in China in 2018...An evidence-based control strategy for emission reduction of VOC sources can effectively solve the regional PM2.5and O3compound pollution in China.We estimated the anthropogenic VOC emission inventory in China in 2018 and established a source profile database containing 129 sources based on localized detection and the latest research results.Then,the distribution of the ozone formation potential(OFP)and secondary organic aerosol formation potential(SOAFP)for emission sources was analyzed.Moreover,priority control routes for VOC emission sources were proposed for different periods.Anthropogenic VOC emissions in China reached 27,211.8 Gg in 2018,and small passenger cars,industrial protective coatings,biomass burning,heavy trucks,printing,asphalt paving,oil storage and transportation,coking,and oil refining were the main contributors.Industrial protective coatings,small passenger cars,and biomass burning all contributed significantly to OFP and SOAFP.Priority in emission reduction control should be given to industrial protective coatings,small passenger cars,heavy trucks,coking,printing,asphalt paving,chemical fibers,and basic organic chemical sources over the medium and long term in China.In addition,the priority control route for VOC emission sources should be adjusted according to the variations in VOC emission characteristics and regional differences,so as to obtain the maximum environmental benefits.展开更多
Defective layered Mn-based materials were synthesized by Li/Na ion exchange to improve their electrochemical activity and Coulombic efficiency.The annealing temperature of the Na precursors was important to control th...Defective layered Mn-based materials were synthesized by Li/Na ion exchange to improve their electrochemical activity and Coulombic efficiency.The annealing temperature of the Na precursors was important to control the P3-P2 phase transition,which directly affected the structure and electrochemical characteristics of the final products obtained by ion exchange.The O3-Li_(0.78)[Li_(0.25)Fe_(0.075)Mn_(0.675)]O_(δ) cathode made from a P3-type precursor calcined at 700℃ was analyzed using X-ray photoelectron spectrometry and electron paramagnetic resonance.The results showed that the presence of abundant trivalent manganese and defects resulted in a discharge capacity of 230 mAh/g with an initial Coulombic efficiency of about 109%.Afterward,galvanostatic intermittent titration was performed to examine the Li^(+) ion diffusion coefficients,which affected the reversible capacity.First principles calculations suggested that the charge redistribution induced by oxygen vacancies(OV_(s))greatly affected the local Mn coordination environment and enhanced the structural activity.Moreover,the Li-deficient cathode was a perfect match for the pre-lithiation anode,providing a novel approach to improve the initial Coulombic efficiency and activity of Mn-based materials in the commercial application.展开更多
The separation of C2H4from C_(2)H_(6)/C_(2)H_(4)mixture is of great importance but difficult and energy intensive. Adsorptive separation provides an alternative approach to ameliorate this situation. Here, we report a...The separation of C2H4from C_(2)H_(6)/C_(2)H_(4)mixture is of great importance but difficult and energy intensive. Adsorptive separation provides an alternative approach to ameliorate this situation. Here, we report a microporous metal–organic framework(MOF) BUT-315-a as a C_(2)H_(6)-selective adsorbent for the separation of C2H6/C2H4gas mixture. BUT-315-a combines good IAST selectivity of 2.35 with high C_(2)H_(6)uptake of 97.5 cm^(3)g^(-1), giving superior high separation potential ΔQ(2226 mmol L^(-1)) for equimolar C_(2)H_(6)/C_(2)H_(4) at 298 K. Impressively, such excellent performance can be preserved at higher temperatures of 313 and 323 K to accommodate industrial conditions. Efficient dynamic separation performance of BUT-315-a has been demonstrated by column breakthrough experiments under varied temperatures and gas ratios. Theoretical calculations further reveal multiple synergistic interactions between C_(2)H_(6) and the framework. This work highlights a new benchmark material for C_(2)H_(6)/C_(2)H_(4)separation and provides guidance for designing adsorbent for separation applications.展开更多
文摘Claudin-18.2(CLDN18.2)is a tight junction protein that is typically expressed only in normal gastric mucosal cells.When malignancy occurs,cell polarity is lost,intercellular adhesion structures are destroyed,and CLDN18.2 is therefore exposed to the surface of tumor cells[1].CLDN18.2 is specifically expressed in approximately 40%of human epidermal growth factor receptor 2(HER2)-negative gastrointestinal cancers,making it a promising emerging therapeutic target.As recently reported,zolbetuximab,an CLDN18.2 targeting antibody,has shown amazing efficacy in patients with CLDN18.2-positive and HER2-negative gastric cancers[2].In clinical practice,the assessment of CLDN18.2 expression status is crucial to the determination of treatment regimen for patients.Molecular imaging can be used as a non-invasive test for diagnosis,staging,and efficacy monitoring.The results of molecular imaging of CLDN18.2 have been published continuously,and the development of CLDN18.2 molecular probe is of great significance for the development of tumor targeted therapy(Fig.1).
基金Supported by Natural Science Foundation of Beijing(No.7222025)Beijing Hospitals Authority’Ascent Plan(No.DFL20190201)Natural Science Foundation of Beijing Projects(No.81602408).
文摘AIM:To evaluate the relationship between gene polymorphism(BclI,ER22/23EK,N363S)and the occurrence,progression and sensitivity to glucocorticoid of lacrimal gland benign lymphoepithelial lesion(LGBLEL).METHODS:Clinical peripheral blood samples of 52 LGBLEL patients and 10 normal volunteers were collected for DNA extraction and polymerase chain reaction sequencing to analyze single nucleotide polymorphism(SNP)genotypes.The lacrimal tissues of LGBLEL were surgically removed and made into paraffin sections for subsequent hematoxylin-eosin(HE)and Masson staining analysis.The duration of disease and hormone use of LGBLEL patients from diagnosis to surgery were also analyzed.The Meta-analysis follows PRISMA guidelines to conducted a systematic review of human studies investigating the relationship between the NR3C1 BclI polymorphism and glucocorticoids(GCs)sensitivity.RESULTS:There was no association between ER22/23EK or N363S and the occurrence of LGBLEL or GCs sensitivity(P>0.05);BclI GC genotype was closely related to GCs resistance(P=0.03)as is the minor allele C(P=0.0017).The HE staining and Masson staining showed that the GC genotype of BclI remarkably slowed down the disease progression and reduced fibrosis(P<0.05),especially for GCs-dependent patients(P<0.0001).Meta-analysis showed that BclI was not significantly associated with GCs responsiveness.CONCLUSION:The LGBLEL patients who carry the NR3C1 BclI allele C may be more sensitive to GCs and associated with lower fibrosis and slower disease progression.The results may guide the clinical treatment strategy for the LGBLEL patients.
基金Project supported by the National Key Research and Development Plan(2021YFA1200201)the Natural Science Foundation of China(51872008)+1 种基金the"111"Project under the DB18015 grantBeijing Outstanding Young Scientists Projects(BJJWZYJH01201910005018)。
文摘The extremely high structural tolerance of ceria to oxygen vacancies(Ov)has made it a desirable catalytic material for the hydrocarbon oxidation to chemicals and pharmaceuticals and the reduction of gaseous pollutants.It is proposed that the formation and diffusion of Ov originate from its outstanding reduction property.However,the formation and diffusion process of Ov over the surface of ceria at the atomic level is still unknown.Herein,the structural and valence evolution of CeO_(2)(111)surfaces in reductive,oxidative and vacuum environments from room temperature up to 700℃was studied with in situ aberration-corrected environmental transmission electron microscopy(ETEM)experiments.Ov is found to form under a high vacuum at elevated temperatures;however,the surface can recover to the initial state through the adsorption of oxygen atoms in an oxygen-contained environment.Furthermore,in hydrogen environment,the step-CeO_(2)(111)surface is not stable at elevated temperatures;thus,the steps tend to be eliminated with increasing temperature.Combined with first-principles density function calculations(DFT),it is proposed that O-terminated surfaces would develop in a hypoxic environment due to the dynamic diffusion of Ov from the outer surface to the subsurface.Furthermore,in a reductive environment,H2 facilitates the formation and diffusion of Ov while Ce-terminated surfaces develope.These results reveal dynamic atomic-scale interplay between the nanoceria surface and gas,thereby providing fundamental insights into the Ov-dependent reaction of nano-CeO_(2) during catalytic processes.
基金financially supported by the Beijing Municipal High Level Innovative Team Building Program(No.IDHT20180504)the Beijing Outstanding Young Scientist Program(BJJWZYJH01201910005017)+5 种基金the National Natural Science Foundation of China(No.51801006,21805004,21671011 and 21872001)the Beijing Natural Science Foundation(No.KZ201710005002 and 2192005)the Beijing Municipal Science and Natural Science Fund Project(No.KM201910005016)the China Postdoctoral Science Foundation(No.2018M641133)the Beijing Postdoctoral Research Foundation(No.2018-ZZ-021)the Chaoyang District Postdoctoral Research Foundation(No.2018-ZZ-026)。
文摘The nitrogen cycle plays an important role in nature,but N-containing products cannot meet human needs.The electrochemical synthesis of ammonia under ambient conditions has attracted the interest of many researchers because it provides a clean and pollution-free synthesis method;however,it has certain difficulties,including a high activation energy,multiple electron transfer,and hydrogenation.Thermodynamic factors limit the selectivity and activity of ammonia synthesis techniques.This review summarizes progress in the electrochemical synthesis of ammonia from theory and experiment.Theoretically,the reduction of nitrogen molecules is analyzed using orbit theory and the thermodynamic reaction pathways.Experimentally,we first discuss the effect of the experimental setup on the nitrogen reduction reaction,and then the four critical of catalysts,including size,electronic,coordination,and orientation effects.These issues must be considered to produce highly-efficient catalysts for electrochemical nitrogen reduction(eNRR).This review provides an overview of the eNRR to enable future researchers to design rational catalysts.
基金supported by the National Natural Science Foundation of China(Nos.11872097,11827803 and U20A20390)the National Key R&D Program of China(No.2020YFC0122204)the 111 Project(No.B13003).
文摘The bone matrix plays an indispensable role in the human body,and its unique biomechanical and mechanobiological properties have received much attention.The bone matrix has unique mechanical anisotropy and exhibits both strong toughness and high strength.These mechanical properties are closely associated with human life activities and correspond to the function of bone in the human body.None of the mechanical properties exhibited by the bone matrix is independent of its composition and structure.Studies on the biomechanics of the bone matrix can provide a reference for the preparation of more applicable bone substitute implants,bone biomimetic materials and scaffolds for bone tissue repair in humans,as well as for biomimetic applications in other fields.In providing mechanical support to the human body,bone is constantly exposed to mechanical stimuli.Through the study of the mechanobiology of the bone matrix,the response mechanism of the bone matrix to its surrounding mechanical environment can be elucidated and used for the health maintenance of bone tissue and defect regeneration.This paper summarizes the biomechanical properties of the bone matrix and their biological significance,discusses the compositional and structural basis by which the bone matrix is capable of exhibiting these mechanical properties,and studies the effects of mechanical stimuli,especially fluid shear stress,on the components of the bone matrix,cells and their interactions.The problems that occur with regard to the biomechanics and mechanobiology of the bone matrix and the corresponding challenges that may need to be faced in the future are also described.
基金National Institute of Neurological Disorders and Stroke,Grant/Award Number:2RF1NS095799National Natural Science Foundation of China,Grant/Award Number:31970044 and 91854115Beijing University of Technology Faculty of Environment and Life Seed Funding,Grant/Award Number:049000513202。
文摘β-Amyloid(Aβ)is a specific pathological hallmark of Alzheimer's disease(AD).Because of its neurotoxicity,AD patients exhibit multiple brain dysfunctions.Disease-modifying therapy(DMT)is the central concept in the development of AD thera-peutics today,and most DMT drugs that are currently in clinical trials are anti-Aβdrugs,such as aducanumab and lecanemab.Therefore,understanding Aβ's neurotoxic mechanism is crucial for Aβ-targeted drug development.Despite its total length of only a few dozen amino acids,Aβis incredibly diverse.In addition to the well-known Aβ_(1-42),N-terminally truncated,glutaminyl cyclase(QC)catalyzed,and pyroglutamate-modified Aβ(pEAβ)is also highly amyloidogenic and far more cytotoxic.The extracel-lular monomeric Aβ_(x-42)(x=1-11)initiates the aggregation to form fibrils and plaques and causes many abnormal cellular responses through cell membrane receptors and receptor-coupled signal pathways.These signal cascades further influence many cel-lular metabolism-related processes,such as gene expression,cell cycle,and cell fate,and ultimately cause severe neural cell damage.However,endogenous cellular anti-Aβdefense processes always accompany the Aβ-induced microenvironment alterations.Aβ-cleaving endopeptidases,Aβ-degrading ubiquitin-proteasome system(UPS),and Aβ-engulfing glial cell immune responses are all essential self-defense mechanisms that we can leverage to develop new drugs.This review discusses some of the most recent advances in understanding Aβ-centric AD mechanisms and suggests prospects for promising anti-Aβstrategies.
基金financial support from the National Natural Science Foundation of China(No.22038001,51621003,22108007)。
文摘Under the context of carbon neutrality of China,it is urgent to shift our energy supply towards cleaner fuels as well as to reduce the greenhouse gas emission.Currently,coal is the main fossil fuel energy source of China.The country is striving hard to replace it with methane,a cleaner fossil fuel.Although China has rich geological resources of methane as coal bed methane(CBM)reserves,it is quite challenging to utilize them due to low concentration.The CBM is however mainly emitted directly to atmosphere during coal mining,causing waste of the resource and huge contribution to greenhouse effect.The recent work by Yang et al.demonstrated a potential solution to extract low concentration methane selectively from CBM through using MOF materials as sorbents.Such kind of materials and associated separation technology are promising to reduce greenhouse gas emission and promote the methane production capability,which would contribute to carbon neutrality in dual pathways.
文摘In the process of exploration and development of oil and gas fields, the acidic environment of oil reservoir, production and transport processes cause corrosion of pipelines and equipment, resulting in huge economic losses and production safety risks. Corrosion inhibitors were widely used in oil industry because of simple operation process and economical. In this study, three environmentally friendly corrosion inhibitors were synthesized based on the natural polysaccharide chitosan. Corrosion inhibition of three dendritic chitosan derivatives (We name them BH, CH and DH) on mild steel in 1 mol/L HCl solution with natural ventilation system was evaluated by weight loss experiment, electrochemical analysis and surface morphology characterization. The experimental results showed that when the three dendritic chitosan derivatives added in the corrosive medium were 500 mg L^(−1), the corrosion inhibition efficiencies were all more than 80%. Based on quantum chemical calculation, inhibition mechanisms of three dendritic chitosan derivatives were investigated according to molecular structures. The results showed that the benzene ring, Schiff base and N atom contained in the molecule were the active centers of electron exchange, which were more likely to form a film on the carbon steel surface, thereby slowing or inhibiting corrosion. The results also predicted the corrosion inhibition effect BH > DH > CH, which was consistent with the experimental conclusion.
基金supported by the National Natural Science Foundation of China(Nos.51638001,52000005)。
文摘Previous air pollution control strategies didn’t pay enough attention to regional collaboration and the spatial response sensitivities,resulting in limited control effects in China.This study proposed an effective PM_(2.5)and O_(3) control strategy scheme with the integration of Self-Organizing Map(SOM),Genetic Algorithm(GA)and WRF-CAMx,emphasizing regional collaborative control and the strengthening of control in sensitive areas.This scheme embodies the idea of hierarchical management and spatial-temporally differentiated management,with SOM identifying the collaborative subregions,GA providing the optimized subregion-level priority of precursor emission reductions,and WRF-CAMx providing response sensitivities for grid-level priority of precursor emission reductions.With Beijing-Tianjin-Hebei and the surrounding area(BTHSA,“2+26”cities)as the case study area,the optimized strategy required that regions along Taihang Mountains strengthen the emission reductions of all precursors in PM_(2.5)-dominant seasons,and strengthen VOCs reductions but moderate NOx reductions in O_(3)-dominant season.The spatiotemporally differentiated control strategy,without additional emission reduction burdens than the 14th Five-Year Plan proposed,reduced the average annual PM_(2.5)and MDA8 O_(3) concentrations in 28 cities by 3.2%-8.2% and 3.9%-9.7% respectively in comparison with non-differential control strategies,with the most prominent optimization effects occurring in the heavily polluted seasons(6.9%-18.0%for PM_(2.5)and 3.3%-14.2% for MDA8 O_(3),respectively).This study proposed an effective scheme for the collaborative control of PM_(2.5)and O_(3) in BTHSA,and shows important methodological implications for other regions suffering from similar air quality problems.
基金supported by the National Natural Science Committee of China-Liaoning Provincial People's Government Joint Fund(U1908204)National Natural Science Foundation of China(21876006,21976009,and 21961160743)+2 种基金Foundation on the Creative Research Team Construction Promotion Project of Beijing Municipal Institutions(IDHT20190503)Natural Science Foundation of Beijing Municipal Commission of Education(KM201710005004)Development Program for the Youth Outstanding-Notch Talent of Beijing Municipal Commission of Education(CIT&TCD201904019)。
文摘Developing the alternative supported noble metal catalysts with low cost,high catalytic efficiency,and good resistance toward carbon dioxide and water vapor is critically demanded for the oxidative removal of volatile organic compounds(VOCs).In this work,we prepared the mesoporous chromia-supported bimetallic Co and Ni single-atom(Co_(1)Ni_(1)/meso-Cr_(2)O_(3))and bimetallic Co and Ni nanoparticle(Co_(NP)Ni_(NP)/mesoCr_(2)O_(3))catalysts adopting the one-pot polyvinyl pyrrolidone(PVP)-and polyvinyl alcohol(PVA)-protecting approaches,respectively.The results indicate that the Co_(1)Ni_(1)/meso-Cr_(2)O_(3)catalyst exhibited the best catalytic activity for n-hexane(C_(6)H_(14))combustion(T_(50%)and T_(90%)were 239 and 263℃ at a space velocity of 40,000 mL g^(-1)h^(-1);apparent activation energy and specific reaction rate at 260℃ were 54.7 kJ mol^(-1)and 4.3×10^(-7)mol g^(-1)_(cat)s^(-1),respectively),which was associated with its higher(Cr^(5+)+Cr^(6+))amount,large n-hexane adsorption capacity,and good lattice oxygen mobility that could enhance the deep oxidation of n-hexane,in which Ni_(1) was beneficial for the enhancements in surface lattice oxygen mobility and low-temperature reducibility,while Co_(1) preferred to generate higher contents of the high-valence states of chromium and surface oxygen species as well as adsorption and activation of n-hexane.n-Hexane combustion takes place via the Mars van Krevelen(MvK)mechanism,and its reaction pathways are as follows:n-hexane→olefins or 3-hexyl hydroperoxide→3-hexanone,2-hexanone or 2,5-dimethyltetrahydrofuran→2-methyloxirane or 2-ethyl-oxetane→acrylic acid→CO_x→CO_(2)and H_(2)O.
基金supported by National Key R&D Program of China[2017YFC200503]National Natural Science Foundation of China[No.42077399].
文摘Objective To establish a sensitive,simple and rapid detection method for African swine fever virus(ASFV)B646L gene.Methods A recombinase-aided amplification-lateral flow dipstick(RAA-LFD)assay was developed in this study.Recombinase-aided amplification(RAA)is used to amplify template DNA,and lateral flow dipstick(LFD)is used to interpret the results after the amplification is completed.The lower limits of detection and specificity of the RAA assay were verified using recombinant plasmid and pathogenic nucleic acid.In addition,30 clinical samples were tested to evaluate the performance of the RAA assay.Results The RAA-LFD assay was completed within 15 min at 37°C,including 10 min for nucleic acid amplification and 5 minutes for LFD reading results.The detection limit of this assay was found to be 200 copies per reaction.And there was no cross-reactivity with other swine viruses.Conclusion A highly sensitive,specific,and simple RAA-LFD method was developed for the rapid detection of the ASFV.
基金supported by the National Natural Science Foundation of China (nos. 21771012, 22038001, 51621003)。
文摘Exploring nonprecious electrocatalysts for water splitting with high efficiency and durability is critically important.Herein,bimetallic phosphides are encapsulated into graphitized carbon to construct a C@NiCoP composite nanoarray using bimetallic metal-organic framework(MOF) as a self-sacrificial template.The resulting C@NiCoP exhibits superior performance for pH-universal electrocatalytic hydrogen evolution reaction(HER),particularly representing a low overpotential of 46.3 mV at 10 mA cm^(-2) and Tafel slope of 44.1 mV dec^(-1) in alkaline media.The structural characterizations combined with theoretical calculation demonstrate that tailored electronic structure from bimetal atoms and the synergistic effect with graphitized carbon layer could jointly optimize the adsorption ability of hydrogen on active sites in HER process,and enhance the electrical conductivity as well.In addition,the carbon layer served as a protecting shell also prevents highly dispersed NiCoP components from agglomeration and/or loss in harsh media,finally improving the durability.This work thus provides a new insight into optimizing activity and stability of pH-universal electrocatalysts by the nanostructural design and electronic structure modulation.
基金Supported by National Natural Science Foundation of China,No.81602408Military Logistics Key Open Research Projects,China,No.BHJ17L018.
文摘BACKGROUND Patients with keloids who receive radiotherapy(RT)after surgery can develop refractory wounds that cannot be healed by the patient's own repair system.Such chronic wounds are uneven and complex due to persistent abscess and ulceration.Without external intervention,they can easily result in local tissue necrosis or,in severe cases,large area tissue resection,amputation,and even death.CASE SUMMARY This article describes the use of hydrogen to treat a 42-year-old female patient with a chronic wound on her left shoulder.The patient had a skin graft that involved implanting a dilator under the skin of her left shoulder,and then transferring excess skin from her shoulder onto scar tissue on her chest.The skin grafting was followed by two rounds of RT,after which the shoulder wound had difficulty healing.For six months,the patient was treated with 2 h of hydrogen inhalation(HI)therapy per day,in addition to application of sterile gauze on the wound and periodic debridement.We also performed one deep,large,sharp debridement to enlarge the wound area.The wound healed completely within 6 mo of beginning the HI treatment.CONCLUSION After HI therapy,the patient showed superior progress in reepithelialization and wound repair,with eventual wound closure in 6 mo,in comparison with the previous failures of hyperbaric oxygen and recombinant bovine basic fibroblast growth factor therapies.Our work showed that HI therapy could be a new strategy for wound healing that is cleaner,more convenient,and less expensive than other therapies,as well as easily accessible for further application in clinical wound care.
基金the funding from the Natural Science Foundation of Henan Province(No.222300420102)the start-up funding from Anyang Institute of Technology(No.BSJ2021049)Postdoctoral Innovation Practice Base in Anyang Institute of Technology(No.BHJ2021009).
文摘The ubiquity of N-heterocycles in marketed drugs makes the development of metal-free methodologies for constructing C–N bonds of considerable importance.As an environmentally friendly method,electro-oxidative intramolecular C–H amination has emerged as a powerful platform for synthesizing nitrogen-containing heterocycles under metal-and external oxidant-free conditions.In this minireview,the main achievements in this direction since 2020 are summarized,with an emphasis on the substrate scope and mechanistic aspects.The reactions are classifi ed into two categories:direct and indirect electro-oxidative intramolecular C–H aminations.
基金supported by the National Natural Science Foundation of China(Nos.51978010,52022005).
文摘Continuous aggravated surface O_(3) over North China Plain(NCP)has attracted widely public concern.Herein,we evaluated the effects of changes in aerosols,precursor emissions,and meteorology on O_(3) in summer(June)of 2015–2019 over NCP via 8 scenarios with WRF-Chem model.The simulated mean MDA8 O_(3) in urban areas of 13 major cities in NCP increased by 17.1%∼34.8%,which matched well with the observations(10.8%∼33.1%).Meanwhile,the model could faithfully reproduce the changes in aerosol loads,precursors,and meteorological conditions.A relatively-even O_(3) increase(+1.2%∼+3.9%for 24-h O_(3) and+1.0%∼+3.8%for MDA8 O_(3))was induced by PM_(2.5) dropping,which was consistent with the geographic distribution of regional PM_(2.5) reduction.Meanwhile,the NO_(2) reduction coupled with a nearconstant VOCs led to the elevated VOCs/NOx ratios,and then caused O_(3) rising in the areas under VOCs-limited regimes.Therein,the pronounced increases occurred in Handan,Xingtai,Shijiazhuang,Tangshan,and Langfang(+10.7%∼+13.6%for 24-h O_(3) and+10.2%∼+12.2%forMDA8 O_(3));while the increases in other citieswere 5.7%∼10.5%for 24-h O_(3) and 4.9%∼9.2%for MDA8 O_(3).Besides,the meteorological fluctuations brought about the more noticeable O_(3) increases in northern parts(+12.5%∼+13.5%for 24-h O_(3) and+11.2%∼+12.4%for MDA8 O_(3))than those in southern and central parts(+3.2%∼+9.3%for 24-h O_(3) and+3.7%∼+8.8%for MDA8 O_(3)).The sum of the impacts of the three drivers reached 16.7%∼21.9%,which were comparable to the changes of the observed O_(3).Therefore,exploring reasonable emissionsreduction strategies is essential for the ozone pollution mitigation over this region.
基金This work was supported by the Basic Science Center Program for Multiphase Evolution in Hypergravity of the National Natural Science Foundation of China(No.51988101)the National Natural Science Foundation of China(Nos.21701009,11674015,and 91860202)Beijing Outstanding Young Scientists Projects(No.BJJWZYJH01201910005018)and Beijing Natural Science Foundation(No.2222050).
文摘Lead-free bismuth-based halide perovskites and their analogues have attracted research interest for their high stability and optoelectronic properties.However,the morphology-controlled synthesis of bismuth-based perovskite nanocrystals has been rarely demonstrated.Herein,we report the colloidal synthesis of zero-dimensional(0D)Cs3BiCl6 nanosheets(NSs),Cs3Bi2Cl9 NSs/nanoplates(NPs)and Cs4MnBi2Cl12 NPs through a hot-injection method.We demonstrate that the Cs3BiCl6 NSs,as an initial product of Cs3Bi2Cl9 and Cs4MnBi2Cl12 NPs,can transform into Cs3Bi2Cl9 NSs or Cs4MnBi2Cl12 NPs via Cl-induced metal ion insertion reactions under the templating effect of Cs3BiCl6.This growth mechanism is also applicable for the synthesis of Cs4CdBi2Cl12 nanoplates.Furthermore,the alloying of Cd2+into Cs4MnBi2Cl12 lattice could weaken the strong coupling effect between Mn and Mn,which leads to a prolonged photoluminescence lifetime and an enhanced photoluminescence quantum yield(PLQY).As a proof of concept,the alloyed Cs4MnxCd1–xBi2Cl12 NPs are used as a scintillator,which show a lowest detection limit of 134.5 nGy/s.The X-ray imaging results display a high spatial resolution of over 20 line pairs per millimeter(lp/mm).These results provide new insights in the synthesis of anisotropic bismuth-based perovskite nanocrystals and their applications in radiation detection.
基金This research was funded by the Development and Demonstration of Road Dust Monitoring and Management System(No.Z191100009119011)the National Research Program for Key Issues in Air Pollution Control China(No.DQGG0201)the National Key Research and Development program of China(No.2018YFC0213203).
文摘Road silt loading(sL)is an important parameter in the fugitive road dust(FRD)emissions.In this study,the improved Testing Re-entrained Aerosol Kinetic Emissions from Roads(TRAKER)combined with the AP-42 method was firstly developed to quickly measure and estimate the sLs of paved roads in Beijing,China.The annual average sLs in Beijing was 0.59±0.31 g/m^(2)in 2020,and decreased by 22.4%compared with that in 2019.The seasonal variations of sLs followed the order of spring>winter>summer>autumn in the two years.The seasonal mean road sLs on the same type road in the four seasons presented a decline trend from^(2)019 to 2020,especially on the Expressway,decreasing 47.4%-72.7%.The road sLs on the different type roads in the same season followed the order of Major arterial∼Minor arterial∼Branch road>Express road,and Township road∼Country highway>Provincial highway∼National highway.The emission intensities of PM10 and PM_(2.5)from FRD in Beijing in 2020 were lower than those in 2019.The PM10 and PM_(2.5)emission intensities at the four planning areas in the two years all presented the order of the capital functional core area>the urban functional expansion area>the urban development new area>the ecological conservation and development area.The annual emissions of PM10 and PM_(2.5)from FRD in Beijing in 2020 were 74,886 ton and 18,118 ton,respectively,decreasing by∼33.3%compared with those in 2019.
基金financially supported by the National Natural Science Foundation of China (No.51638001)National Joint Center for Air Pollution Prevention and Control (No.DQGG202010)。
文摘An evidence-based control strategy for emission reduction of VOC sources can effectively solve the regional PM2.5and O3compound pollution in China.We estimated the anthropogenic VOC emission inventory in China in 2018 and established a source profile database containing 129 sources based on localized detection and the latest research results.Then,the distribution of the ozone formation potential(OFP)and secondary organic aerosol formation potential(SOAFP)for emission sources was analyzed.Moreover,priority control routes for VOC emission sources were proposed for different periods.Anthropogenic VOC emissions in China reached 27,211.8 Gg in 2018,and small passenger cars,industrial protective coatings,biomass burning,heavy trucks,printing,asphalt paving,oil storage and transportation,coking,and oil refining were the main contributors.Industrial protective coatings,small passenger cars,and biomass burning all contributed significantly to OFP and SOAFP.Priority in emission reduction control should be given to industrial protective coatings,small passenger cars,heavy trucks,coking,printing,asphalt paving,chemical fibers,and basic organic chemical sources over the medium and long term in China.In addition,the priority control route for VOC emission sources should be adjusted according to the variations in VOC emission characteristics and regional differences,so as to obtain the maximum environmental benefits.
基金The Beijing Municipal Education Commission(KZ201910005003)supported this work。
文摘Defective layered Mn-based materials were synthesized by Li/Na ion exchange to improve their electrochemical activity and Coulombic efficiency.The annealing temperature of the Na precursors was important to control the P3-P2 phase transition,which directly affected the structure and electrochemical characteristics of the final products obtained by ion exchange.The O3-Li_(0.78)[Li_(0.25)Fe_(0.075)Mn_(0.675)]O_(δ) cathode made from a P3-type precursor calcined at 700℃ was analyzed using X-ray photoelectron spectrometry and electron paramagnetic resonance.The results showed that the presence of abundant trivalent manganese and defects resulted in a discharge capacity of 230 mAh/g with an initial Coulombic efficiency of about 109%.Afterward,galvanostatic intermittent titration was performed to examine the Li^(+) ion diffusion coefficients,which affected the reversible capacity.First principles calculations suggested that the charge redistribution induced by oxygen vacancies(OV_(s))greatly affected the local Mn coordination environment and enhanced the structural activity.Moreover,the Li-deficient cathode was a perfect match for the pre-lithiation anode,providing a novel approach to improve the initial Coulombic efficiency and activity of Mn-based materials in the commercial application.
基金the financial support of the National Natural Science Foundation of China (No. 22038001)。
文摘The separation of C2H4from C_(2)H_(6)/C_(2)H_(4)mixture is of great importance but difficult and energy intensive. Adsorptive separation provides an alternative approach to ameliorate this situation. Here, we report a microporous metal–organic framework(MOF) BUT-315-a as a C_(2)H_(6)-selective adsorbent for the separation of C2H6/C2H4gas mixture. BUT-315-a combines good IAST selectivity of 2.35 with high C_(2)H_(6)uptake of 97.5 cm^(3)g^(-1), giving superior high separation potential ΔQ(2226 mmol L^(-1)) for equimolar C_(2)H_(6)/C_(2)H_(4) at 298 K. Impressively, such excellent performance can be preserved at higher temperatures of 313 and 323 K to accommodate industrial conditions. Efficient dynamic separation performance of BUT-315-a has been demonstrated by column breakthrough experiments under varied temperatures and gas ratios. Theoretical calculations further reveal multiple synergistic interactions between C_(2)H_(6) and the framework. This work highlights a new benchmark material for C_(2)H_(6)/C_(2)H_(4)separation and provides guidance for designing adsorbent for separation applications.