查看更多>>摘要：Light-driven dry reforming of methane toward syngas presents a proper solution for alleviating climate change and for the sustainable supply of transportation fuels and chemicals.Herein,Rh/InGaN1-xOx nanowires supported by silicon wafer are explored as an ideal platform for loading Rh nanoparticles,thus assembling a new nanoarchitecture for this grand topic.In combination with the remarkable photo-thermal synergy,the O atoms in Rh/InGaN1-xOx can significantly lower the apparent activation energy of dry reforming of methane from 2.96 eV downward to 1.70 eV.The as-designed Rh/InGaN1-xOx NWs nanoarchitecture thus demonstrates a measurable syngas evolution rate of 180.9 mmol g-1cat h-1 with a marked selectivity of 96.3％under concentrated light illumination of 6 W cm-2.What is more,a high turnover number(TON)of 4182 mol syngas per mole Rh has been realized after six reuse cycles without obvious activity degradation.The correlative 18O isotope labeling experiments,in-situ irradiated X-ray photoelectron spectroscopy(1SI-XPS)and in-situ diffuse reflectance Fourier transform infrared spec-troscopy characterizations,as well as density functional theory calculations reveal that under light illu-mination,Rh/InGaN1-xOx NWs facilitate releasing *CH3 and H+from CH4 by holes,followed by H2 evolution from H+reduction with electrons.Subsequently,the O atoms in Rh/InGaN1-xOx can directly participate in CO generation by reacting with the *C species from CH4 dehydrogenation and contributes to the coke elimination,in concurrent formation of O vacancies.The resultant O vacancies are then replenished by CO2,showing an ideal chemical loop.This work presents a green strategy for syngas pro-duction via light-driven dry reforming of methane.
查看更多>>摘要：Oxygen-containing species have been demonstrated to play a key role in facilitating electrocatalytic CO2 reduction(CO2RR),particularly in enhancing the selectivity towards multi-carbon(C2+)products.However,the underlying promotion mechanism is still under debate,which greatly limits the rational optimization of the catalytic performance of CO2RR.Herein,taking CO2 and O2 co-electrolysis over Cu as the prototype,we successfully clarified how O2 boosts CO2RR from a new perspective by employing comprehensive theoretical simulations.Our results demonstrated that O2 in feed gas can be rapidly reduced into *OH,leading to the partial oxidation of Cu surface under reduction conditions.Surface*OH accelerates the formation of quasi-specifically adsorbed K+due to the electrostatic interaction between *OH and K+ions,which significantly increases the concentration of K+near the Cu surface.These quasi-specifically adsorbed K+ions can not only lower the C-C coupling barriers but also promote the hydrogenation of CO2 to improve the CO yield rate,which are responsible for the remarkably enhanced efficiency of C2+products.During the whole process,O2 co-electrolysis plays an indispensable role in stabilizing surface *OH.This mechanism can be also adopted to understand the effect of high pH of electrolyte and residual O in oxide-derived Cu(OD-Cu)on the catalytic efficiency towards C2+products.Therefore,our work provides new insights into strategies for improving C2+products on the Cu-based cat-alysts,i.e.,maintaining partial oxidation of surface under reduction conditions.
查看更多>>摘要：The Zr(Ⅳ)ions are easily hydrolyzed to form oxides,which severely limits the discovery of new struc-tures and applications of Zr-based compounds.In this work,three ferrocene(Fc)-functionalized Zr-oxo clusters(ZrOCs),Zr9Fc6,Zr10Fc6 and Zr12Fc8 were synthesized through inhibiting the hydrolysis of Zr(Ⅳ)ions,which show increased nuclearity and regular structural variation.More importantly,these Fc-functionalized ZrOCs were used as heterogeneous catalysts for the transfer hydrogenation of levulinic acid(LA)and phenol oxidation reactions for the first time,and displayed outstanding catalytic activity.In particular,Zr12Fc8 with the largest number of Zr active sites and Fc groups can achieve＞95％yield for LA-to-γ-valerolactone within 4 h(130 ℃)and＞98％yield for 2,3,6-trimethylphenol-to-2,3,5-trimethyl-p-benzoquinone within 30 min(80 ℃),showing the best catalytic performance.Catalytic characterization combined with theory calculations reveal that in the Fc-functionalized ZrOCs,the Zr active sites could serve as substrate adsorption sites,while the Fc groups could act as hydrogen transfer reagent or Fenton reagent,and thus achieve effectively intramolecular metal-ligand synergistic catalysis.This work develops functionalized ZrOCs as catalysts for thermal-triggered redox reactions.
查看更多>>摘要：Developing low-power FETs holds significant importance in advancing logic circuits,especially as the fea-ture size of MOSFETs approaches sub-10 nanometers.However,this has been restricted by the thermio-nic limitation of SS,which is limited to 60 mV per decade at room temperature.Herein,we proposed a strategy that utilizes 2D semiconductors with an isolated-band feature as channels to realize sub-thermionic SS in MOSFETs.Through high-throughput calculations,we established a guiding principle that combines the atomic structure and orbital interaction to identify their sub-thermionic transport poten-tial.This guides us to screen 192 candidates from the 2D material database comprising 1608 systems.Additionally,the physical relationship between the sub-thermionic transport performances and elec-tronic structures is further revealed,which enables us to predict 15 systems with promising device per-formances for low-power applications with supply voltage below 0.5 V.This work opens a new way for the low-power electronics based on 2D materials and would inspire extensive interests in the experimen-tal exploration of intrinsic steep-slope MOSFETs.
查看更多>>摘要：Atmospheric water harvesting(AWH)is a promising solution to the water shortage problem.Current sorption-based AWH(SAWH)systems seldom obtain both wide climatic adaptability and high energy efficiency due to the lack of thermodynamic optimization.To achieve the ideal harvesting circulation in SAWH systems,the"optimal harvesting window"(OHW)design based on thermodynamic analysis was first proposed and validated by our prototype.The"OHW"theory indicates the water production rate and energy efficiency could be improved by properly reducing the adsorption temperature.As the humid-ity increases,the optimal adsorption temperature should be closer to the dew point of the environment.Experimental results revealed that,loaded with 3 kg widely adopted silica gel,the daily water production could reach 5.76-17.64 L/d with ultrahigh energy efficiency of 0.46-1.5 L/kWh.This prototype could also achieve optimal performance in wide climatic conditions in terms of 13-35 ℃ and 18％-72％RH.Lastly,the performance of photovoltaic(PV)-driven SAWH was evaluated.Results showed that a 1 m2 PV panel could generate 0.66-2 L water per day in Shanghai throughout the year,the highest in opening literature.Notably,this work introduces a promising concept that can help achieve large-scale,ultra-fast,energy-efficient AWH worldwide.
查看更多>>摘要：Liver-tissue engineering has proven valuable in treating liver diseases,but the construction of liver tis-sues with high fidelity remains challenging.Here,we present a novel three-dimensional(3D)-imprinted cell-sheet strategy for the synchronous construction of biomimetic hepatic microtissues with high accuracy in terms of cell type,density,and distribution.To achieve this,the specific composition of hepatic cells in a normal human liver was determined using a spatial proteogenomics dataset.The data and biomimetic hepatic micro-tissues with hexagonal hollow cross-sections indicate that cell informa-tion was successfully generated using a homemade 3D-imprinted device for layer-by-layer imprinting and assembling the hepatic cell sheets.By infiltrating vascular endothelial cells into the hollow section of the assembly,biomimetic hepatic microtissues with vascularized channels for nutrient diffusion and drug perfusion can be obtained.We demonstrate that the resultant vascularized biomimetic hepatic micro-tissues can not only be integrated into a microfluidic drug-screening liver-on-a-chip but also assembled into an enlarged physiological structure to promote liver regeneration.We believe that our 3D-imprinted cell sheets strategy will open new avenues for biomimetic microtissue construction.
查看更多>>摘要：Synaptic dysfunction is a core component of the pathophysiology of schizophrenia.However,the genetic risk factors and molecular mechanisms related to synaptic dysfunction are still not fully understood.The Stonin 2(STON2)gene encodes a major adaptor for clathrin-mediated endocytosis(CME)of synaptic vesi-cles.In this study,we showed that the C-C(307Pro-851Ala)haplotype of STON2 increases the suscepti-bility to schizophrenia and examined whether STON2 variations cause schizophrenia-like behaviors through the regulation of CME.We found that schizophrenia-related STON2 variations led to protein dephosphorylation,which affected its interaction with synaptotagmin 1(Syt1),a calcium sensor protein located in the presynaptic membrane that is critical for CME.STON2307Pro851Ala knockin mice exhibited deficits in synaptic transmission,short-term plasticity,and schizophrenia-like behaviors.Moreover,among seven antipsychotic drugs,patients with the C-C(307Pro-851Ala)haplotype responded better to haloperidol than did the T-A(307Ser-851Ser)carriers.The recovery of deficits in Syt1 sorting and synaptic transmission by acute administration of haloperidol effectively improved schizophrenia-like behaviors in STON2307Pro851Ala knockin mice.Our findings demonstrated the effect of schizophrenia-related STON2 variations on synaptic dysfunction through the regulation of CME,which might be attrac-tive therapeutic targets for treating schizophrenia-like phenotypes.
查看更多>>摘要：Currently,clinically available coronary CT angiography(CCTA)derived fractional flow reserve(CT-FFR)is time-consuming and complex.We propose a novel artificial intelligence-based fully-automated,on-site CT-FFR technology,which combines the automated coronary plaque segmentation and luminal extrac-tion model with reduced order 3 dimentional(3D)computational fluid dynamics.A total of 463 consec-utive patients with 600 vessels from the updated China CT-FFR study in Cohort 1 undergoing both CCTA and invasive fractional flow reserve(FFR)within 90 d were collected for diagnostic performance evalu-ation.For Cohort 2,a total of 901 chronic coronary syndromes patients with index CT-FFR and clinical outcomes at 3-year follow-up were retrospectively analyzed.In Cohort 3,the association between index CT-FFR from triple-rule-out CTA and major adverse cardiac events in patients with acute chest pain from the emergency department was further evaluated.The diagnostic accuracy of this CT-FFR in Cohort 1 was 0.82 with an area under the curve of 0.82 on a per-patient level.Compared with the manually dependent CT-FFR techniques,the operation time of this technique was substantially shortened by 3 times and the number of clicks from about 60 to 1.This CT-FFR technique has a highly successful(＞99％)calculation rate and also provides superior prediction value for major adverse cardiac events than CCTA alone both in patients with chronic coronary syndromes and acute chest pain.Thus,the novel artificial intelligence-based fully automated,on-site CT-FFR technique can function as an objective and convenient tool for coronary stenosis functional evaluation in the real-world clinical setting.
查看更多>>摘要：Sulfate reduction is an essential metabolism that maintains biogeochemical cycles in marine and terres-trial ecosystems.Sulfate reducers are exclusively prokaryotic,phylogenetically diverse,and may have evolved early in Earth's history.However,their origin is elusive and unequivocal fossils are lacking.Here we report a new microfossil,Qingjiangonema cambria,from～518-million-year-old black shales that yield the Qingjiang biota.Qingjiangonema is a long filamentous form comprising hundreds of cells filled by equimorphic and equidimensional pyrite microcrystals with a light sulfur isotope composition.Multiple lines of evidence indicate Qingjiangonema was a sulfate-reducing bacterium that exhibits similar patterns of cell organization to filamentous forms within the phylum Desulfobacterota,including the sulfate-reducing Desulfonema and sulfide-oxidizing cable bacteria.Phylogenomic analyses confirm sepa-rate,independent origins of multicellularity in Desulfonema and in cable bacteria.Molecular clock anal-yses infer that the Desulfobacterota,which encompass a majority of sulfate-reducing taxa,diverged～2.41 billion years ago during the Paleoproterozoic Great Oxygenation Event,while cable bacteria diverged～0.56 billion years ago during or immediately after the Neoproterozoic Oxygenation Event.Taken together,we interpret Qingjiangonema as a multicellular sulfate-reducing microfossil and propose that cable bacteria evolved from a multicellular filamentous sulfate-reducing ancestor.We infer that the diversification of the Desulfobacterota and the origin of cable bacteria may have been responses to oxy-genation events in Earth's history.
查看更多>>摘要：Lunar materials are overall more reducing compared with their terrestrial counterparts,but the mecha-nism remains to be elucidated.In this study,we present a possible explanation for the changes in redox state of the lunar regolith caused by impact events,based on our investigations of the impact glass beads from Chang'e-5 mission.These glass beads contain iron metal grains and show concentration gradients of FeO and K2O(with or without Na2O)from their rims to centers.The compositional profiles exhibit error-function-like shapes,which indicates a diffusion-limited mechanism.Our numerical modeling results suggest that the iron metal grains on the surface of the glass beads were generated through the reduction of FeO by elemental K and(or)Na produced during the impact events.Meanwhile,the iron metal grains inside the bead may have formed due to oxygen diffusion driven by redox potential gradients.Furthermore,our study suggests that impact processes intensify the local reducing conditions,as evi-denced by the presence of calcium sulfide particles within troilite grains that coexist with iron metal grains on the surface of the glass beads.This study provides insights into the oxygen diffusion kinetics during the formation of iron metal spherules and sheds light on the changes in redox conditions of lunar materials caused by impact events.
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