A dislocation density-based crystal plasticity finite element(CPFE)model is developed to reveal the mechanism of discontinuous dynamic recrystallization(DDRX)of the TC17 dual-phase titanium alloy during hot deformatio...A dislocation density-based crystal plasticity finite element(CPFE)model is developed to reveal the mechanism of discontinuous dynamic recrystallization(DDRX)of the TC17 dual-phase titanium alloy during hot deformation.The model incorporates the temperature and strain rate dependence of nucleation,growth and evolution during DDRX.The evolution of the dislocation densities in the matrix grains(MGs)and the recrystallized grains(RGs)is considered individually.The mechanical response and underlying microstructural evolution are systematically investigated by comparing the CPFE model predictions with experimental tests.The results indicate that at lower temperatures(700℃ and 800℃),TC17 titanium alloy exhibits a higher volume fraction of recrystallization and a notable drop in flow stress.As the temperature increases(900℃ and 1000℃),the volume fraction of recrystallization decreases,resulting in a weakened flow stress softening.The nucleation rate of DDRX increases with decreasing deformation temperature and increasing strain rate,while the size of RGs increases with higher temperature and lower strain rate.DDRX nuclei primarily occur at grain boundaries with high dislocation density.Furthermore,DDRX consumes a large number of dislocations and thus reduces the stress concentration and dislocation density at grain boundaries.This study provides a robust model that enhances the understanding of hot deformation mechanisms and informs the design of high-performance titanium alloys for future applications.展开更多
In this paper,nitrogen-doped hierarchical porous carbon(N-HPC)was prepared from polyaniline(PANI)/silica self-aggregates.H-bonding between N\\H groups in aniline/PANI and\\OH groups in nano silica template led to a se...In this paper,nitrogen-doped hierarchical porous carbon(N-HPC)was prepared from polyaniline(PANI)/silica self-aggregates.H-bonding between N\\H groups in aniline/PANI and\\OH groups in nano silica template led to a self-assembly type,which enabled the formation of uniform N-HPC nanoparticles.Silica self-aggregates provided macroporous channels resulted in a decreased diffusion distance.After removing the hard template,the N-HPC had a high surface area(899 m^2·g^(-1)).Owing to two co-existed synergetic energy-storage mechanisms and the hierarchical porous structure,the obtained N-HPC exhibited a high specific capacitance of 218.75 F·g^(-1)at 0.5 A·g^(-1),compared with the nonporous nitrogen-doped carbon(N-C)derived from pure PANI.Moreover,the N-HPC electrode demonstrated excellent cycle life,retaining 99%of its initial specific capacitance after 1000 cycles.展开更多
In-depth vocabulary knowledge plays a key role in L2(second language)vocabulary acquisition,and computer English vocabulary is vital to academic performances of students majored in Computer Science.While many Chinese ...In-depth vocabulary knowledge plays a key role in L2(second language)vocabulary acquisition,and computer English vocabulary is vital to academic performances of students majored in Computer Science.While many Chinese students cannot realize computer English vocabulary acquisition due to lacking input environment of computer English.To solve this problem,with techniques of keyword search,information retrieval,and text classification,to meet the diverse learning needs of students,it built the in-depth computer English vocabulary knowledge acquisition environment for the high frequency of computer English words,providing the depth of knowledge such as polysemy,synonyms,syntax,and pragmatics.The construction of in-depth computer English vocabulary acquisition environment helps future studies on computer English teaching applications.展开更多
Computer English plays a vital role in academic study for students majored in Computer Science.As the fast development of information technology,traditional English teaching methods cannot meet students’learning need...Computer English plays a vital role in academic study for students majored in Computer Science.As the fast development of information technology,traditional English teaching methods cannot meet students’learning needs.WeChat is the most popular mobile application of social networks in China.Its features of real-time communication,interactivity and utilization of fragmentary time attract educators’attention to its application in teaching.This paper carried out an empirical study to explore applying WeChat in Computer English teaching.With WeChat,an English interaction environment was built,and interactive learning activities were implemented.The experimental results show teaching based on WeChat is effective to improve students’Computer English skills.展开更多
Biodegradable Zn-based alloys have gained increasing attention as bone implant materials due to their moderate degradation rates,bone-like mechanical properties,and excellent biocompatibility.Selective laser melting(S...Biodegradable Zn-based alloys have gained increasing attention as bone implant materials due to their moderate degradation rates,bone-like mechanical properties,and excellent biocompatibility.Selective laser melting(SLM)has emerged as a promising technique for producing customized metallic bone im-plants,offering high-quality prints and precise geometric control.However,process optimization for SLM Zn alloys,which have only recently been developed,typically relies on trial and error.In this study,we applied machine learning to optimize the SLM parameters for a Zn-2Cu alloy for the first time.A su-pervised Gaussian Process Regression(GPR)method was used to predict the optimal high-density pro-cess window.Notably,a rarely utilized combination of high-power and low-speed(HPLS)parameters was identified and experimentally verified.The microstructures,mechanical properties,degradation perfor-mance,biological properties,and antibacterial properties of Zn-2Cu specimens fabricated using three representative SLM parameter sets were systematically compared.The SLM Zn-2Cu alloy exhibited re-fined Zn grains and randomly distributedε-CuZn5 phases.Among the parameter sets,the HPLS group demonstrated the best mechanical properties,with an ultimate tensile strength of 119.00±1.73 MPa,a tensile elongation of 3%,and an ultimate compressive strength of 681.39±7.41 MPa.The degrada-tion rate of the SLM Zn-2Cu alloy remained moderate at approximately 0.16 mm/year,with no significant differences between parameter sets.Additionally,10%and 20%diluted extracts of SLM Zn-2Cu speci-mens exhibited favorable biocompatibility and alkaline phosphatase(ALP)activity in vitro using MC-3T3 cells.Furthermore,the SLM Zn-2Cu demonstrated superior antibacterial properties compared to SLM Zn.This study highlights the potential of additively manufactured Zn-2Cu alloys as promising bone implant materials and illustrates how machine learning can enhance the process optimization of SLM Zn-based alloys.展开更多
A good method of synthesizing Ti_(3)C_(2)T_(x)(MXene)is critical for ensuring its success in practical applications,e.g.,electromagnetic interference shielding,electrochemical energy storage,catalysis,sensors,and biom...A good method of synthesizing Ti_(3)C_(2)T_(x)(MXene)is critical for ensuring its success in practical applications,e.g.,electromagnetic interference shielding,electrochemical energy storage,catalysis,sensors,and biomedicine.The main concerns focus on the moderation of the approach,yield,and product quality.Herein,a modified approach,organic solvent-assisted intercalation and collection,was developed to prepare Ti_(3)C_(2)T_(x) flakes.The new approach simultaneously solves all the concerns,featuring a low requirement for facility(centrifugation speed<4000 rpm in whole process),gram-level preparation with remarkable yield(46.3%),a good electrical conductivity(8672 S cm^(−1)),an outstanding capacitive performance(352 F g^(−1)),and easy control over the dimension of Ti_(3)C_(2)T_(x) flakes(0.47–4.60μm^(2)).This approach not only gives a superb example for the synthesis of other MXene materials in laboratory,but sheds new light for the future mass production of Ti_(3)C_(2)T_(x) MXene.展开更多
Objective:The present study aimed to investigate the effect of seasonal variation on neurotransmitter release in the hippocampus of normal rats and rats with pineal excision.Methods:Two time points,the summer and wint...Objective:The present study aimed to investigate the effect of seasonal variation on neurotransmitter release in the hippocampus of normal rats and rats with pineal excision.Methods:Two time points,the summer and winter solstice,which are the longest and shortest days of the year,respectively,were selected.Male Spraguee Dawley rats that underwent a sham operation without pineal excision were included as a control group.The concentrations of 5-hydroxytryptamine(5-HT)andγ-aminobutyric acid(GABA)were determined by radioimmunoassays and enzyme-linked immunosorbent assays,respectively.Results:In the winter,the 5-HT and GABA levels in normal rats exhibited a significant difference compared with those in the operation group(P<.01).A difference was also noted in GABA levels between the normal group and the sham operation group(P<.05).The concentrations of 5-HT and GABA in the hippocampal tissues of the normal group exhibited a seasonal rhythm consisting of elevation during the summer and reduction during the winter(P<.01),while the GABA levels in the sham operation group exhibited a significant difference,with elevation during the summer and reduction during the winter(P<.01).In the operation group,GABA showed the same trend(P<.01).Conclusion:The seasonal rhythm of neurotransmitter secretion by the hippocampus(5-HT and GABA)consisted of elevation during the summer and reduction during the winter.During the winter,the pineal gland exhibited a reverse regulatory effect on the secretion of 5-HT and GABA in the hippocampus,and it exhibited seasonal selectivity with regard to the regulation of 5-HT.展开更多
Macrophages are essential components of the innate immune system and constitute a non-specific first line of host defense against pathogens and inflammation.Mitochondria regulate macrophage activation and innate immun...Macrophages are essential components of the innate immune system and constitute a non-specific first line of host defense against pathogens and inflammation.Mitochondria regulate macrophage activation and innate immune responses in various inflammatory diseases,including cochlear inflammation.The distribution,number,and morphological characteristics of cochlear macrophages change significantly across different inner ear regions under various pathological conditions,including noise exposure,ototoxicity,and age-related degeneration.However,the exact mechanism underlying the role of mitochondria in macrophages in auditory function remains unclear.Here,we summarize the major factors and mitochondrial signaling pathways(e.g.,metabolism,mitochondrial reactive oxygen species,mitochondrial DNA,and the inflammasome)that influence macrophage activation in the innate immune response.In particular,we focus on the properties of cochlear macrophages,activated signaling pathways,and the secretion of inflammatory cytokines after acoustic injury.We hope this review will provide new perspectives and a basis for future research on cochlear inflammation.展开更多
Cropland expansion has caused the loss of soil organic carbon(SOC)and the degradation of microbial communities.Fallowing is an important strategy for soil restoration,and fungi are critical in soil fertilization.This ...Cropland expansion has caused the loss of soil organic carbon(SOC)and the degradation of microbial communities.Fallowing is an important strategy for soil restoration,and fungi are critical in soil fertilization.This study compared the soil properties and fungal assemblage in two adjacent environments(farmland vs.fallowing)using a 30-year field experiment composed of five treatments:fallowing and agricultural management under no fertilization,chemical fertilization,and chemical fertilization plus cow manure or crop straw.The fallowed soil had more diverse fungi and maintained higher SOC than the artificially managed treatments.Importantly,the relative abundance of Chaetomiaceae was positively correlated with all the carbon components(SOC,dissolved organic carbon,and microbial biomass carbon)simultaneously.An RNA-Seq of Trichocladium uniseriatum,the key fungus affiliated with Chaetomiaceae,showed that straw addition significantly upregulated the genes for T.uniseriatum melanogenesis,resulting in recalcitrant necromass formation.A remarkable carbon dioxide(CO_(2))assimilation capacity of T.uniseriatum was revealed using^(13)C-labelling assay.Therefore,T.uniseriatum improved SOC storage directly by CO_(2)fixation and indirectly by melanogenesis.Fertilization of agricultural systems can stimulate the growth of T.uniseriatum.Inoculation of T.uniseriatum promoted crop growth,facilitating carbon absorption from the roots.This study highlights that the valuable microbial species resources preserved in fallowed soils can improve farmland ecosystems.展开更多
The bifurcation regions of intracranial and extracranial arteries are common sites for atherosclerosis,predisposing to ischaemic stroke.1 Previous studies have shown that the unique haemodynamics at the bifurca-tion m...The bifurcation regions of intracranial and extracranial arteries are common sites for atherosclerosis,predisposing to ischaemic stroke.1 Previous studies have shown that the unique haemodynamics at the bifurca-tion may lead to alterations in genes and proteins in this region.2 Elastin is closely associated with the progression of athero-sclerosis.3 However,under physiological conditions,the expression and distribu-tion of elastin in bifurcation regions have not yet been elucidated.Mice are the most frequently used animal model for studying atherosclerosis.This study focuses on carotid bifurcation,optimising the iDISCO(immunolabeling-enabled three-dimensional imaging of solvent-cleared organs)technique for whole tissue clearing and staining of the carotid artery in mice.4 These techniques,along with fluorescence micro-optical sectioning tomography(FMOST)technology,have also been used in studies on ischaemic stroke and kidney diseases,4 highlighting their potential for broader applications due to their high precision and three-dimensional imaging capabilities.5 Using FMOST technology in vitro,we have made a detailed visualisation of a U-shaped expression pattern of elastin at bifurcation regions for the first time.Specifically,elastin expression is found to be lowest at the bifurcation itself compared with the regions adjacent to or proximal to the bifurcation(figures 1A,B).Further-more,we observed disorganised arrange-ment of elastic fibres within the bifurcation zone(figures 1C,D).These findings provide important evidence linking elastic fibres to the pathogenesis of atherosclerosis at bifurcations and suggest the potential for more precise local therapies for athero-sclerosis,which could significantly advance precision medicine and reduce the poten-tial side effects on normal tissues.展开更多
Cannabidiol(CBD),a non-psychoactive cannabinoid,shows great promise in treating methamphetamine(METH)addiction.Nonetheless,the molecular target and the mechanism through which CBD treats METH addiction remain unexplor...Cannabidiol(CBD),a non-psychoactive cannabinoid,shows great promise in treating methamphetamine(METH)addiction.Nonetheless,the molecular target and the mechanism through which CBD treats METH addiction remain unexplored.Herein,CBD was shown to counteract METH-induced locomotor sensitization and conditioned place preference.Additionally,CBD mitigated the adverse effects of METH,such as cristae loss,a decline in ATP content,and a reduction in membrane potential.Employing an activity-based protein profiling approach,a target fishing strategy was used to uncover CBD's direct target.ATP5A1,a subunit of ATP synthase,was identified and validated as a CBD target.Moreover,CBD demonstrated the ability to ameliorate METH-induced ubiquitination of ATP5A1 via the D376 residue,thereby reversing the METH-induced reduction of ATP5A1 and promoting the assembly of ATP synthase.Pharmacological inhibition of the ATP efflux channel pannexin 1,blockade of ATP hydrolysis by a CD39 inhibitor,and blocking the adenosine A1 receptor(A1R)all attenuated the therapeutic benefits of CBD in mitigating METH-induced behavioral sensitization and CPP.Moreover,the RNA interference of ATP5A1 in the ventral tegmental area resulted in the reversal of CBD's therapeutic efficacy against METH addiction.Collectively,these data show that ATP5A1 is a target for CBD to inhibit METH-induced addiction behaviors through the ADO-A1R signaling pathway.展开更多
The liver serves as a crucial regulatory center in the human body,orchestrating various essential physiological processes and maintaining homeostasis.This organ is heterogeneous,consisting of hepatocytes,liver sinusoi...The liver serves as a crucial regulatory center in the human body,orchestrating various essential physiological processes and maintaining homeostasis.This organ is heterogeneous,consisting of hepatocytes,liver sinusoidal endothelial cells,hepatic stellate cells,and Kupffer cells.These cells are intricately linked in structure and communicate via autocrine and paracrine signaling,playing key roles in the regulation of liver regeneration and fibrosis following injury.In this review,we provide a brief overview of the different cell types within the vascular niche.Moreover,we discuss some of the molecular mechanisms within this niche that guide liver regeneration and fibrosis,as well as hepatocellular carcinoma.It is important to highlight that developing new treatments for liver diseases necessitates a comprehensive understanding of these cellular and molecular mechanisms.展开更多
Boosting tumor immunosurveillance with vaccines has been proven to be a feasible and cost-effective strategy to fight cancer. Although major breakthroughs have been achieved in preventative tumor vaccines targeting on...Boosting tumor immunosurveillance with vaccines has been proven to be a feasible and cost-effective strategy to fight cancer. Although major breakthroughs have been achieved in preventative tumor vaccines targeting oncogenic viruses, limited advances have been made in curative vaccines for virus-irrelevant malignancies. Accumulating evidence suggests that preconditioning tumor cells with certain cytotoxic drugs can generate whole-cell tumor vaccines with strong prophylactic activities. However, the immunogenicity of these vaccines is not sufficient to restrain the outgrowth of existing tumors. In this study, we identified arsenic trioxide (ATO) as a wide-spectrum cytotoxic and highly immunogenic drug through multiparameter screening. ATO preconditioning could generate whole-cell tumor vaccines with potent antineoplastic effects in both prophylactic and therapeutic settings. The tumor-preventive or tumor-suppressive benefits of these vaccines relied on CD8^(+) T cells and type I and II interferon signaling and could be linked to the release of immunostimulatory danger molecules. Unexpectedly, following ATO-induced oxidative stress, multiple cell death pathways were activated, including autophagy, apoptosis, necroptosis, and ferroptosis. CRISPR‒Cas9-mediated knockout of cell death executors revealed that the absence of Rip3, Mlkl, or Acsl4 largely abolished the efficacy of ATO-based prophylactic and therapeutic cancer vaccines. This therapeutic failure could be rescued by coadministration of danger molecule analogs. In addition, PD-1 blockade synergistically improved the therapeutic efficacy of ATO-based cancer vaccines by augmenting local IFN-γ production.展开更多
Single-atom catalysts(SACs)with the advantages of homogeneous and heterogeneous catalysts have become a hot-spot in catalysis field.However,for lack of metal–metal bond in SACs,H_(2)has to go through heterolytic diss...Single-atom catalysts(SACs)with the advantages of homogeneous and heterogeneous catalysts have become a hot-spot in catalysis field.However,for lack of metal–metal bond in SACs,H_(2)has to go through heterolytic dissociation pathway,which has higher barrier than homolytic dissociation pathway,and thus limits the hydrogenation activity of SACs.Herein,we propose and demonstrate through constructing synergistic iridium single atoms and nanoparticles co-existed catalyst(denoted as Ir_(1+NPs)/CMK)to boost the catalytic activity of quinoline hydrogenation.Both experimental and density functional theory calculation results confirm that Ir_(1)single sites activate quinoline,while Ir nanoparticles boost hydrogen dissociation.H atoms generated at Ir nanoparticles migrate to the quinoline bounded Ir_(1)single sites to complete hydrogenation.The Ir_(1+NPs)/CMK catalyst exhibits much higher reactivity with turnover frequency of 7,800 h^(−1)than those counterpart Ir_(1)/CMK and IrNPs/CMK catalysts,and is 20,000 times higher activity of commercial Ir/C benchmark catalyst for hydrogenation of quinoline under the same reaction conditions.This synergistic catalysis strategy between single atoms and nanoparticles provides a solution to further improve the performance of SACs for hydrogenation.展开更多
Ionic liquids(ILs)have the advantages of low cost,eco-friendliness,abundant heteroatoms,excellent solubility,and coordinated ability with metal ions.These features make ILs a suitable precursor for fabricating metal s...Ionic liquids(ILs)have the advantages of low cost,eco-friendliness,abundant heteroatoms,excellent solubility,and coordinated ability with metal ions.These features make ILs a suitable precursor for fabricating metal singleatom catalysts(SACs).Herein,we prepared various metal single atoms anchored on ultrathin N-doped nanosheets(denoted as Cu_(1)/NC,Fe_(1)/NC,Co_(1)/NC,Ni_(1)/NC,and Pd_(1)/NC)by direct pyrolysis using ILs and g-C_(3)N_(4)nanosheets as templates.Taking benzene oxidation to phenol with H_(2)O_(2)as a model reaction to evaluate their catalytic performance and potential applications,Cu_(1)/NC calcined at 1000℃(denoted as Cu1/NC-1000)exhibits the highest activity with a turnover frequency of about 200 h^(-1)in the first 1 h at 60℃,which is better than that of most metal SACs reported in the literature.High benzene conversion of 82% with high phenol selectivity of 96% and excellent recyclability were achieved using the Cu_(1)/NC-1000 catalyst.This study provides an efficient general strategy for fabricating SACs using ILs for catalytic applications.展开更多
In the era of big data, the dimensionality of data is increasing dramatically in many domains. To deal with high dimensionality, online feature selection becomes critical in big data mining. Recently, online selection...In the era of big data, the dimensionality of data is increasing dramatically in many domains. To deal with high dimensionality, online feature selection becomes critical in big data mining. Recently, online selection of dynamic features has received much attention. In situations where features arrive sequentially over time, we need to perform online feature selection upon feature arrivals. Meanwhile, considering grouped features, it is necessary to deal with features arriving by groups. To handle these challenges, some state-of- the-art methods for online feature selection have been proposed. In this paper, we first give a brief review of traditional feature selection approaches. Then we discuss specific problems of online feature selection with feature streams in detail. A comprehensive review of existing online feature selection methods is presented by comparing with each other. Finally, we discuss several open issues in online feature selection.展开更多
Direct chemical oxidation and pure adsorption could not effectively remove p-Arsanilic acid(p-ASA)and the released inor-ganic arsenic.Herein,one novel biochar supported MnFe_(2)O_(4)(MFB)was synthesized and adopted fo...Direct chemical oxidation and pure adsorption could not effectively remove p-Arsanilic acid(p-ASA)and the released inor-ganic arsenic.Herein,one novel biochar supported MnFe_(2)O_(4)(MFB)was synthesized and adopted for p-ASA degradation and synchronous adsorption of the generated inorganic arsenic.The MFB/persulfate(PS)system could remain effective under a wide pH range(3.0-9.0),and the released arsenic could be removed simultaneously by MFB.Mechanism investiga-tion revealed that the functional groups of MFB(i.e.O-C=O and C=O),Fe and Mn oxides on MFB all contributed to PS activation.O_(2)^(·−)and^(1)O_(2)were the main reactive oxygen species(ROS)responsible for p-ASA degradation,and^(1)O_(2)was the predominant ROS.Besides,the MFB possessed superior reusability.Therefore,it is expected to develop a potential method for organic arsenic contaminants removal via an oxidation-adsorption process,and the results could also shed light on the better understanding of the PS activation mechanisms.展开更多
基金supported by the National Natural Science Foundation of China(Grant Nos.52105393,52305334,and U22A20186).
文摘A dislocation density-based crystal plasticity finite element(CPFE)model is developed to reveal the mechanism of discontinuous dynamic recrystallization(DDRX)of the TC17 dual-phase titanium alloy during hot deformation.The model incorporates the temperature and strain rate dependence of nucleation,growth and evolution during DDRX.The evolution of the dislocation densities in the matrix grains(MGs)and the recrystallized grains(RGs)is considered individually.The mechanical response and underlying microstructural evolution are systematically investigated by comparing the CPFE model predictions with experimental tests.The results indicate that at lower temperatures(700℃ and 800℃),TC17 titanium alloy exhibits a higher volume fraction of recrystallization and a notable drop in flow stress.As the temperature increases(900℃ and 1000℃),the volume fraction of recrystallization decreases,resulting in a weakened flow stress softening.The nucleation rate of DDRX increases with decreasing deformation temperature and increasing strain rate,while the size of RGs increases with higher temperature and lower strain rate.DDRX nuclei primarily occur at grain boundaries with high dislocation density.Furthermore,DDRX consumes a large number of dislocations and thus reduces the stress concentration and dislocation density at grain boundaries.This study provides a robust model that enhances the understanding of hot deformation mechanisms and informs the design of high-performance titanium alloys for future applications.
基金Supported by the National Natural Science Foundation of China(21401079,21501069)Fundamental Research Funds for Central Universities(JUSRP51626B)+2 种基金the Natural Science Foundation of Jiangsu Province of China(BK20140158,BK20161128,BK20161166)Natural Science Fund for Colleges and Universities in Jiangsu Province(18KJD430008,17KJD430005,17KJB430032)the Top-notch Academic Programs Project of Jiangsu Higher Education Institutions(PPZY2015B181)
文摘In this paper,nitrogen-doped hierarchical porous carbon(N-HPC)was prepared from polyaniline(PANI)/silica self-aggregates.H-bonding between N\\H groups in aniline/PANI and\\OH groups in nano silica template led to a self-assembly type,which enabled the formation of uniform N-HPC nanoparticles.Silica self-aggregates provided macroporous channels resulted in a decreased diffusion distance.After removing the hard template,the N-HPC had a high surface area(899 m^2·g^(-1)).Owing to two co-existed synergetic energy-storage mechanisms and the hierarchical porous structure,the obtained N-HPC exhibited a high specific capacitance of 218.75 F·g^(-1)at 0.5 A·g^(-1),compared with the nonporous nitrogen-doped carbon(N-C)derived from pure PANI.Moreover,the N-HPC electrode demonstrated excellent cycle life,retaining 99%of its initial specific capacitance after 1000 cycles.
基金This research is partly supported by the Ministry of Education’s Humanities and Social Science Project No.11YJC740048,Scientific planning issues of education in Heilongjiang Province No.GBC1211062,research fund for the program of new century excellent talents in Heilongjiang provincial university No.1155-ncet-008 and the National Natural Science Foundation of China under grant Nos.60903083,61502123.
文摘In-depth vocabulary knowledge plays a key role in L2(second language)vocabulary acquisition,and computer English vocabulary is vital to academic performances of students majored in Computer Science.While many Chinese students cannot realize computer English vocabulary acquisition due to lacking input environment of computer English.To solve this problem,with techniques of keyword search,information retrieval,and text classification,to meet the diverse learning needs of students,it built the in-depth computer English vocabulary knowledge acquisition environment for the high frequency of computer English words,providing the depth of knowledge such as polysemy,synonyms,syntax,and pragmatics.The construction of in-depth computer English vocabulary acquisition environment helps future studies on computer English teaching applications.
基金This research is partly supported by the Ministry of Education’s Humanities and Social Science Project No.11YJC740048,Scientific planning issues of education in Heilongjiang Province No.GBC1211062,research fund for the program of new century excellent talents in Heilongjiang provincial university No.1155-ncet-008 and the Natural Science Foundation of Heilongjiang Province under grant Nos.QC2015084,F201132.
文摘Computer English plays a vital role in academic study for students majored in Computer Science.As the fast development of information technology,traditional English teaching methods cannot meet students’learning needs.WeChat is the most popular mobile application of social networks in China.Its features of real-time communication,interactivity and utilization of fragmentary time attract educators’attention to its application in teaching.This paper carried out an empirical study to explore applying WeChat in Computer English teaching.With WeChat,an English interaction environment was built,and interactive learning activities were implemented.The experimental results show teaching based on WeChat is effective to improve students’Computer English skills.
基金financially supported by the National Key Re-search&Development Program of China(No.2023YFB3813000)the National Natural Science Foundation of China(Nos.52471260,52201294,52231010,52071028,and 52105421)+2 种基金the Natural Sci-ence Foundation of Beijing(No.L212014)the Beijing Nova Pro-gram(2022 Beijing Nova Program Cross Cooperation Program No.20220484178)the Interdisciplinary Research Project for Young Teachers of USTB(Fundamental Research Funds for the Central Universities,Contract No.FRF-IDRY-23-029).
文摘Biodegradable Zn-based alloys have gained increasing attention as bone implant materials due to their moderate degradation rates,bone-like mechanical properties,and excellent biocompatibility.Selective laser melting(SLM)has emerged as a promising technique for producing customized metallic bone im-plants,offering high-quality prints and precise geometric control.However,process optimization for SLM Zn alloys,which have only recently been developed,typically relies on trial and error.In this study,we applied machine learning to optimize the SLM parameters for a Zn-2Cu alloy for the first time.A su-pervised Gaussian Process Regression(GPR)method was used to predict the optimal high-density pro-cess window.Notably,a rarely utilized combination of high-power and low-speed(HPLS)parameters was identified and experimentally verified.The microstructures,mechanical properties,degradation perfor-mance,biological properties,and antibacterial properties of Zn-2Cu specimens fabricated using three representative SLM parameter sets were systematically compared.The SLM Zn-2Cu alloy exhibited re-fined Zn grains and randomly distributedε-CuZn5 phases.Among the parameter sets,the HPLS group demonstrated the best mechanical properties,with an ultimate tensile strength of 119.00±1.73 MPa,a tensile elongation of 3%,and an ultimate compressive strength of 681.39±7.41 MPa.The degrada-tion rate of the SLM Zn-2Cu alloy remained moderate at approximately 0.16 mm/year,with no significant differences between parameter sets.Additionally,10%and 20%diluted extracts of SLM Zn-2Cu speci-mens exhibited favorable biocompatibility and alkaline phosphatase(ALP)activity in vitro using MC-3T3 cells.Furthermore,the SLM Zn-2Cu demonstrated superior antibacterial properties compared to SLM Zn.This study highlights the potential of additively manufactured Zn-2Cu alloys as promising bone implant materials and illustrates how machine learning can enhance the process optimization of SLM Zn-based alloys.
基金This work was financially supported by National Natural Science Foundation of China(No.51903197)Wuhu and Xidian University special fund for industry-universityresearch cooperation(No.XWYCXY-012020012)+3 种基金Open Fund of Zhijiang Lab(2021MC0AB02)China Postdoctoral Science Foundation(2019TQ02422019M660061XB)the Fundamental Research Funds for the Central Universities(JC2110,JB211305).
文摘A good method of synthesizing Ti_(3)C_(2)T_(x)(MXene)is critical for ensuring its success in practical applications,e.g.,electromagnetic interference shielding,electrochemical energy storage,catalysis,sensors,and biomedicine.The main concerns focus on the moderation of the approach,yield,and product quality.Herein,a modified approach,organic solvent-assisted intercalation and collection,was developed to prepare Ti_(3)C_(2)T_(x) flakes.The new approach simultaneously solves all the concerns,featuring a low requirement for facility(centrifugation speed<4000 rpm in whole process),gram-level preparation with remarkable yield(46.3%),a good electrical conductivity(8672 S cm^(−1)),an outstanding capacitive performance(352 F g^(−1)),and easy control over the dimension of Ti_(3)C_(2)T_(x) flakes(0.47–4.60μm^(2)).This approach not only gives a superb example for the synthesis of other MXene materials in laboratory,but sheds new light for the future mass production of Ti_(3)C_(2)T_(x) MXene.
基金the National Natural Science Foundation of China(81774162)。
文摘Objective:The present study aimed to investigate the effect of seasonal variation on neurotransmitter release in the hippocampus of normal rats and rats with pineal excision.Methods:Two time points,the summer and winter solstice,which are the longest and shortest days of the year,respectively,were selected.Male Spraguee Dawley rats that underwent a sham operation without pineal excision were included as a control group.The concentrations of 5-hydroxytryptamine(5-HT)andγ-aminobutyric acid(GABA)were determined by radioimmunoassays and enzyme-linked immunosorbent assays,respectively.Results:In the winter,the 5-HT and GABA levels in normal rats exhibited a significant difference compared with those in the operation group(P<.01).A difference was also noted in GABA levels between the normal group and the sham operation group(P<.05).The concentrations of 5-HT and GABA in the hippocampal tissues of the normal group exhibited a seasonal rhythm consisting of elevation during the summer and reduction during the winter(P<.01),while the GABA levels in the sham operation group exhibited a significant difference,with elevation during the summer and reduction during the winter(P<.01).In the operation group,GABA showed the same trend(P<.01).Conclusion:The seasonal rhythm of neurotransmitter secretion by the hippocampus(5-HT and GABA)consisted of elevation during the summer and reduction during the winter.During the winter,the pineal gland exhibited a reverse regulatory effect on the secretion of 5-HT and GABA in the hippocampus,and it exhibited seasonal selectivity with regard to the regulation of 5-HT.
基金supported by the China Postdoctoral Science Foundation(2022M712892)the Joint project Henan Province Medical Science and Technology Project(LHGJ20210297).
文摘Macrophages are essential components of the innate immune system and constitute a non-specific first line of host defense against pathogens and inflammation.Mitochondria regulate macrophage activation and innate immune responses in various inflammatory diseases,including cochlear inflammation.The distribution,number,and morphological characteristics of cochlear macrophages change significantly across different inner ear regions under various pathological conditions,including noise exposure,ototoxicity,and age-related degeneration.However,the exact mechanism underlying the role of mitochondria in macrophages in auditory function remains unclear.Here,we summarize the major factors and mitochondrial signaling pathways(e.g.,metabolism,mitochondrial reactive oxygen species,mitochondrial DNA,and the inflammasome)that influence macrophage activation in the innate immune response.In particular,we focus on the properties of cochlear macrophages,activated signaling pathways,and the secretion of inflammatory cytokines after acoustic injury.We hope this review will provide new perspectives and a basis for future research on cochlear inflammation.
基金supported by the Excellent Youth Science Fund of Henan Province,China(No.242300421147)the National Key Research and Development Program of China(No.2022YFD1500203)+1 种基金the National Natural Science Foundation of China(Nos.42377334 and 42007005)the Joint Fund Project of Henan Province,China(No.232103810009)。
文摘Cropland expansion has caused the loss of soil organic carbon(SOC)and the degradation of microbial communities.Fallowing is an important strategy for soil restoration,and fungi are critical in soil fertilization.This study compared the soil properties and fungal assemblage in two adjacent environments(farmland vs.fallowing)using a 30-year field experiment composed of five treatments:fallowing and agricultural management under no fertilization,chemical fertilization,and chemical fertilization plus cow manure or crop straw.The fallowed soil had more diverse fungi and maintained higher SOC than the artificially managed treatments.Importantly,the relative abundance of Chaetomiaceae was positively correlated with all the carbon components(SOC,dissolved organic carbon,and microbial biomass carbon)simultaneously.An RNA-Seq of Trichocladium uniseriatum,the key fungus affiliated with Chaetomiaceae,showed that straw addition significantly upregulated the genes for T.uniseriatum melanogenesis,resulting in recalcitrant necromass formation.A remarkable carbon dioxide(CO_(2))assimilation capacity of T.uniseriatum was revealed using^(13)C-labelling assay.Therefore,T.uniseriatum improved SOC storage directly by CO_(2)fixation and indirectly by melanogenesis.Fertilization of agricultural systems can stimulate the growth of T.uniseriatum.Inoculation of T.uniseriatum promoted crop growth,facilitating carbon absorption from the roots.This study highlights that the valuable microbial species resources preserved in fallowed soils can improve farmland ecosystems.
基金supported by the National Natural Science Foundation of China grant number 81530037 to Yuming Xu,82401556 to Shen Li and 82301320 to Peipei Li.
文摘The bifurcation regions of intracranial and extracranial arteries are common sites for atherosclerosis,predisposing to ischaemic stroke.1 Previous studies have shown that the unique haemodynamics at the bifurca-tion may lead to alterations in genes and proteins in this region.2 Elastin is closely associated with the progression of athero-sclerosis.3 However,under physiological conditions,the expression and distribu-tion of elastin in bifurcation regions have not yet been elucidated.Mice are the most frequently used animal model for studying atherosclerosis.This study focuses on carotid bifurcation,optimising the iDISCO(immunolabeling-enabled three-dimensional imaging of solvent-cleared organs)technique for whole tissue clearing and staining of the carotid artery in mice.4 These techniques,along with fluorescence micro-optical sectioning tomography(FMOST)technology,have also been used in studies on ischaemic stroke and kidney diseases,4 highlighting their potential for broader applications due to their high precision and three-dimensional imaging capabilities.5 Using FMOST technology in vitro,we have made a detailed visualisation of a U-shaped expression pattern of elastin at bifurcation regions for the first time.Specifically,elastin expression is found to be lowest at the bifurcation itself compared with the regions adjacent to or proximal to the bifurcation(figures 1A,B).Further-more,we observed disorganised arrange-ment of elastic fibres within the bifurcation zone(figures 1C,D).These findings provide important evidence linking elastic fibres to the pathogenesis of atherosclerosis at bifurcations and suggest the potential for more precise local therapies for athero-sclerosis,which could significantly advance precision medicine and reduce the poten-tial side effects on normal tissues.
基金supported by the National Natural Science Foundation of China(22207105,22277118,T2241028)the STI2030-Major Projects(2021ZD0203000(2021ZD0203003),China)+6 种基金Talent Introduction Project of Shandong First Medical University funds under Grant YS23-0000349the Science and Technology Innovation Program of the Chinese Academy of Agricultural Sciences(No.CAAS-ASTIP-2021-ISAPS,China)the Key Science and Technology Project of Jilin Province(20200504001YY,China)Science and Technology Development Plan Project of Jilin Province(20220204045GH,China)International Partnership Program of the Chinese Academy of Sciences(029GJHZ2024057GC,China)Open Research Fund of the State Key Laboratory of Brain Machine Intelligence,Zhejiang University(BMI2400014,China)National Natural Science Foundation of Hunan Province(2025JJ70246,China).
文摘Cannabidiol(CBD),a non-psychoactive cannabinoid,shows great promise in treating methamphetamine(METH)addiction.Nonetheless,the molecular target and the mechanism through which CBD treats METH addiction remain unexplored.Herein,CBD was shown to counteract METH-induced locomotor sensitization and conditioned place preference.Additionally,CBD mitigated the adverse effects of METH,such as cristae loss,a decline in ATP content,and a reduction in membrane potential.Employing an activity-based protein profiling approach,a target fishing strategy was used to uncover CBD's direct target.ATP5A1,a subunit of ATP synthase,was identified and validated as a CBD target.Moreover,CBD demonstrated the ability to ameliorate METH-induced ubiquitination of ATP5A1 via the D376 residue,thereby reversing the METH-induced reduction of ATP5A1 and promoting the assembly of ATP synthase.Pharmacological inhibition of the ATP efflux channel pannexin 1,blockade of ATP hydrolysis by a CD39 inhibitor,and blocking the adenosine A1 receptor(A1R)all attenuated the therapeutic benefits of CBD in mitigating METH-induced behavioral sensitization and CPP.Moreover,the RNA interference of ATP5A1 in the ventral tegmental area resulted in the reversal of CBD's therapeutic efficacy against METH addiction.Collectively,these data show that ATP5A1 is a target for CBD to inhibit METH-induced addiction behaviors through the ADO-A1R signaling pathway.
基金National Natural Science Foundation of China(82300717,82301320,82204385)China Postdoctoral Science Foundation(2022TQ0299,2023M733232)Henan Province Medical Sci-ence and Technology Key Project(Union construction)[LHGJ20220285].
文摘The liver serves as a crucial regulatory center in the human body,orchestrating various essential physiological processes and maintaining homeostasis.This organ is heterogeneous,consisting of hepatocytes,liver sinusoidal endothelial cells,hepatic stellate cells,and Kupffer cells.These cells are intricately linked in structure and communicate via autocrine and paracrine signaling,playing key roles in the regulation of liver regeneration and fibrosis following injury.In this review,we provide a brief overview of the different cell types within the vascular niche.Moreover,we discuss some of the molecular mechanisms within this niche that guide liver regeneration and fibrosis,as well as hepatocellular carcinoma.It is important to highlight that developing new treatments for liver diseases necessitates a comprehensive understanding of these cellular and molecular mechanisms.
基金supported by the National Science and Technology Innovation 2030 Major Project of China(2022ZD0205700)Natural Science Foundation of China(NSFC,81972701)+2 种基金CAMS Innovation Fund for Medical Sciences(CIFMS,2021-I2M-1-074,2022-I2M-2-004)National Special Support Program for High-level Talents,China Ministry of Science and Technology(National Key Research and Development Program,Grant 2017YFA0506200)Innovative and Entrepreneurial Team Program(Jiangsu Province).
文摘Boosting tumor immunosurveillance with vaccines has been proven to be a feasible and cost-effective strategy to fight cancer. Although major breakthroughs have been achieved in preventative tumor vaccines targeting oncogenic viruses, limited advances have been made in curative vaccines for virus-irrelevant malignancies. Accumulating evidence suggests that preconditioning tumor cells with certain cytotoxic drugs can generate whole-cell tumor vaccines with strong prophylactic activities. However, the immunogenicity of these vaccines is not sufficient to restrain the outgrowth of existing tumors. In this study, we identified arsenic trioxide (ATO) as a wide-spectrum cytotoxic and highly immunogenic drug through multiparameter screening. ATO preconditioning could generate whole-cell tumor vaccines with potent antineoplastic effects in both prophylactic and therapeutic settings. The tumor-preventive or tumor-suppressive benefits of these vaccines relied on CD8^(+) T cells and type I and II interferon signaling and could be linked to the release of immunostimulatory danger molecules. Unexpectedly, following ATO-induced oxidative stress, multiple cell death pathways were activated, including autophagy, apoptosis, necroptosis, and ferroptosis. CRISPR‒Cas9-mediated knockout of cell death executors revealed that the absence of Rip3, Mlkl, or Acsl4 largely abolished the efficacy of ATO-based prophylactic and therapeutic cancer vaccines. This therapeutic failure could be rescued by coadministration of danger molecule analogs. In addition, PD-1 blockade synergistically improved the therapeutic efficacy of ATO-based cancer vaccines by augmenting local IFN-γ production.
基金the National Natural Science Foundation of China(Nos.92161112 and 21932006)the National Key Research and Development Program of China(Nos.2018YFA0208504 and 2018YFA0703503)+1 种基金the Youth Innovation Promotion Association of CAS(No.2017049)the National Science Basic Program of Shaanxi(No.S2020-JC-WT-0001).
文摘Single-atom catalysts(SACs)with the advantages of homogeneous and heterogeneous catalysts have become a hot-spot in catalysis field.However,for lack of metal–metal bond in SACs,H_(2)has to go through heterolytic dissociation pathway,which has higher barrier than homolytic dissociation pathway,and thus limits the hydrogenation activity of SACs.Herein,we propose and demonstrate through constructing synergistic iridium single atoms and nanoparticles co-existed catalyst(denoted as Ir_(1+NPs)/CMK)to boost the catalytic activity of quinoline hydrogenation.Both experimental and density functional theory calculation results confirm that Ir_(1)single sites activate quinoline,while Ir nanoparticles boost hydrogen dissociation.H atoms generated at Ir nanoparticles migrate to the quinoline bounded Ir_(1)single sites to complete hydrogenation.The Ir_(1+NPs)/CMK catalyst exhibits much higher reactivity with turnover frequency of 7,800 h^(−1)than those counterpart Ir_(1)/CMK and IrNPs/CMK catalysts,and is 20,000 times higher activity of commercial Ir/C benchmark catalyst for hydrogenation of quinoline under the same reaction conditions.This synergistic catalysis strategy between single atoms and nanoparticles provides a solution to further improve the performance of SACs for hydrogenation.
基金the financial support from the National Key R&D Program of China(2018YFA0208504 and 2018YFA0703503)the National Natural Science Foundation of China(21932006)the Youth Innovation Promotion Association of CAS(2017049).
文摘Ionic liquids(ILs)have the advantages of low cost,eco-friendliness,abundant heteroatoms,excellent solubility,and coordinated ability with metal ions.These features make ILs a suitable precursor for fabricating metal singleatom catalysts(SACs).Herein,we prepared various metal single atoms anchored on ultrathin N-doped nanosheets(denoted as Cu_(1)/NC,Fe_(1)/NC,Co_(1)/NC,Ni_(1)/NC,and Pd_(1)/NC)by direct pyrolysis using ILs and g-C_(3)N_(4)nanosheets as templates.Taking benzene oxidation to phenol with H_(2)O_(2)as a model reaction to evaluate their catalytic performance and potential applications,Cu_(1)/NC calcined at 1000℃(denoted as Cu1/NC-1000)exhibits the highest activity with a turnover frequency of about 200 h^(-1)in the first 1 h at 60℃,which is better than that of most metal SACs reported in the literature.High benzene conversion of 82% with high phenol selectivity of 96% and excellent recyclability were achieved using the Cu_(1)/NC-1000 catalyst.This study provides an efficient general strategy for fabricating SACs using ILs for catalytic applications.
基金This work was supported in part by the National Key Research and Development Program of China （2016YFB 1000901）, the Program for Changjiang Scholars and Innovative Research Team in University （PCSIRT） of the Ministry of Education, China （IRT13059）, the National Basic Research Program （973 Program） of China （2013CB329604）, the Specialized Research Fund for the Doctoral Program of Higher Education （20130111110011）, and the National Natural Science Foundation of China （Grant Nos. 61273292, 61229301, 61503112, 61673152）.
文摘In the era of big data, the dimensionality of data is increasing dramatically in many domains. To deal with high dimensionality, online feature selection becomes critical in big data mining. Recently, online selection of dynamic features has received much attention. In situations where features arrive sequentially over time, we need to perform online feature selection upon feature arrivals. Meanwhile, considering grouped features, it is necessary to deal with features arriving by groups. To handle these challenges, some state-of- the-art methods for online feature selection have been proposed. In this paper, we first give a brief review of traditional feature selection approaches. Then we discuss specific problems of online feature selection with feature streams in detail. A comprehensive review of existing online feature selection methods is presented by comparing with each other. Finally, we discuss several open issues in online feature selection.
基金the National Natural Science Foundation of China(Grant No.51709103)Natural Science Foundation of Hunan Province,China(Grant Nos.2018JJ3242 and 2021JJ30362)+1 种基金Science and Technology Innovation Leading Plan of High Tech Industry in Hunan Province(Grant No.2021GK4055)Training Program for Excellent Young Innovators of Changsha(Grant No.kq1802020).
文摘Direct chemical oxidation and pure adsorption could not effectively remove p-Arsanilic acid(p-ASA)and the released inor-ganic arsenic.Herein,one novel biochar supported MnFe_(2)O_(4)(MFB)was synthesized and adopted for p-ASA degradation and synchronous adsorption of the generated inorganic arsenic.The MFB/persulfate(PS)system could remain effective under a wide pH range(3.0-9.0),and the released arsenic could be removed simultaneously by MFB.Mechanism investiga-tion revealed that the functional groups of MFB(i.e.O-C=O and C=O),Fe and Mn oxides on MFB all contributed to PS activation.O_(2)^(·−)and^(1)O_(2)were the main reactive oxygen species(ROS)responsible for p-ASA degradation,and^(1)O_(2)was the predominant ROS.Besides,the MFB possessed superior reusability.Therefore,it is expected to develop a potential method for organic arsenic contaminants removal via an oxidation-adsorption process,and the results could also shed light on the better understanding of the PS activation mechanisms.
