This study investigates the effects of Fe on the oxygen-evolution reaction(OER)in the presence of Au.Two distinct areas of OER were identified:the first associated with Fe sites at low overpotential(~330 mV),and the s...This study investigates the effects of Fe on the oxygen-evolution reaction(OER)in the presence of Au.Two distinct areas of OER were identified:the first associated with Fe sites at low overpotential(~330 mV),and the second with Au sites at high overpotential(~870 mV).Various factors such as surface Fe concentration,electrochemical method,scan rate,potential range,concentration,method of adding K_(2)Fe O_(4),nature of Fe,and temperature were varied to observe diverse behaviors during OER for Fe O_(x)H_(y)/Au.Trace amounts of Fe ions had a significant impact on OER,reaching a saturation point where the activity did not increase further.Strong electronic interaction between Fe and Au ions was indicated by X-ray photoelectron spectroscopy(XPS)and electron paramagnetic resonance(EPR)analyses.In situ visible spectroscopy confirmed the formation of Fe O_(4)^(2-)during OER.In situ Mossbauer and surfaceenhanced Raman spectroscopy(SERS)analyses suggest the involvement of Fe-based species as intermediates during the rate-determining step of OER.A lattice OER mechanism based on Fe O_(x)H_(y)was proposed for operation at low overpotentials.Density functional theory(DFT)calculations revealed that Fe oxide,Fe-oxide clusters,and Fe doping on the Au foil exhibited different activities and stabilities during OER.The study provides insights into the interplay between Fe and Au in OER,advancing the understanding of OER mechanisms and offering implications for the design of efficient electrocatalytic systems.展开更多
The prompt emission mechanism of gamma-ray bursts(GRBs)is still unclear,and the time-resolved spectral analysis of GRBs is a powerful tool for studying their underlying physical processes.We performed a detailed time-...The prompt emission mechanism of gamma-ray bursts(GRBs)is still unclear,and the time-resolved spectral analysis of GRBs is a powerful tool for studying their underlying physical processes.We performed a detailed time-resolved spectral analysis of 78 bright long GRB samples detected by Fermi/Gamma-ray Burst Monitor.A total of 1490 spectra were obtained and their properties were studied using a typical Band-shape model.First,the parameter distributions of the time-resolved spectrum are given as follows:the low-energy spectral indexα~-0.72,high-energy spectral indexβ~2.42,the peak energy E_(p)~221.69 keV,and the energy flux F~7.49×10^(-6)erg cm^(-2)s^(-1).More than 80%of the bursts exhibit the hardest low-energy spectral indexα_(max),exceeding the synchrotron limit(-2/3).Second,the evolution patterns of a and E_(p)were statistically analyzed.The results show that for multi-pulse GRBs the intensity-tracking pattern is more common than the hard-to-soft pattern in the evolution of both E_(p)andα.The hard-to-soft pattern is generally shown in single-pulse GRBs or in the initial pulse of multi-pulse GRBs.Finally,we found a significant positive correlation between F and E_(p),with half of the samples exhibiting a positive correlation between F andα.We discussed the spectral evolution of different radiation models.The diversity of spectral evolution patterns indicates that there may be more than one radiation mechanism occurring in the GRB radiation process,including photo spheric radiation and synchrotron radiation.However,it may also involve only one radiation mechanism,but more complicated physical details need to be considered.展开更多
Accurate measurement of the average plasma parameters in the edge region,including the temperature and density of electrons and ions,is critical for understanding the characteristics of the scrape-off layer(SOL) and d...Accurate measurement of the average plasma parameters in the edge region,including the temperature and density of electrons and ions,is critical for understanding the characteristics of the scrape-off layer(SOL) and divertor plasma transport in magnetically confined fusion research.On the J-TEXT tokamak,a multi-channel retarding field analyzer(RFA) probe has been developed to study average plasma parameters in the edge region under various poloidal divertor and island divertor configurations.The edge radial profile of the ion-to-electron temperature ratio,τ_(i/e),has been determined,which gradually decreases as the SOL ion self-collisionality,v_(SOL)*,increases.This is broadly consistent with what has been observed previously from various tokamak experiments.However,the comparison of experimental results under different configurations shows that in the poloidal divertor configuration,even under the same v_(SOL)*,τ_(i/e) in the SOL region becomes smaller as the distance from the X-point to the target plate increases.In the island divertor configuration,τ_(i/e) near the O-point is higher than that near the X-point at the same v_(SOL)*,and both are higher than those in the limiter configuration.These results suggest that the magnetic configuration plays a critical role in the energy distributions between electrons and ions at the plasma boundary.展开更多
The microstructure evolution and precipitation behavior of Al-Mg-Si alloy during initial aging were studied using hardness testing, conductivity testing, differential scanning calorimetry(DSC), and high resolution tra...The microstructure evolution and precipitation behavior of Al-Mg-Si alloy during initial aging were studied using hardness testing, conductivity testing, differential scanning calorimetry(DSC), and high resolution transmission electron microscopy(HRTEM). The results show that the precipitation sequence of the Al-Mg-Si alloy during initial aging can be represented as: supersaturated solid solution → spherical Mg/Si clusters → needle-like Guinier Preston(GP) zone → β″. Clusters are completely coherent with the Al matrix. The GP zone with relatively complete independent lattice parameters that differ slightly from the Al matrix parameters, is oriented along the direction of <111>Aland lying on {111}Alplane. The strength of the Al-Mg-Si alloy is greatly enhanced by the threedimensional strain field that exists between the β″ phase and the two {200}Alplanes. After aging at 170 ℃ for 6 h, the hardness reaches the peak of 127 HV and remains for a long time. At this stage, the electrical conductivity keeps relatively stable due to the formation of coherent precipitates(Mg/Si clusters/GP zones) and the reduction in solute atom concentration in the Al matrix. The severe coarsening and decreased number density of the β″ phase during the over-aging stage result in a significant decrease in the hardness.展开更多
Tanzania is located in eastern Africa with a predominantly agricultural ecomomy,the potential for developing and utilizing cultivated land are promising,but scientific guidance is required.B,Zn and Se are essential mi...Tanzania is located in eastern Africa with a predominantly agricultural ecomomy,the potential for developing and utilizing cultivated land are promising,but scientific guidance is required.B,Zn and Se are essential micronutrients for plants and human body with crucial biological functions,in particular,Se is significant for human health and considered as“the king of anti-cancer”.As these elements required by human or plants are mainly absorbed from soil directly or indirectly,therefore,it is important to understand the contents and distributions of them in the soil of cultivated land for guiding agricultural production.In this work,low-density geochemical survey at the scale of 1∶1000000 was carried out in Tanzania,and the results show that the concentrations of B,Zn and Se in stream sediments are low and their distributions are heterogeneous.According to the distributions of geological units,the existing cultivated land resources can be divided into five regions in Tanzania.Compared with the national background values,the concentrations of B,Zn and Se are insufficient overall but enriched locally in these regions.In general,element concentrations in stream sediments and soil have a positive correlation because of their similar sources,which is essential in agriculture application.Based on the information provided by low-density geochemical data and maps,the Se-sufficient and Se-rich regions were delineated in Tanzania,where can be used to develop Se-rich industries.Finally,this paper believes that geochemical survey is a powerful tool for cultivated land evaluation,agriculture management and land development.展开更多
Oxidative stress induced by factors such as ammonia nitrogen has become a major issue in shrimp farming.The effects of carotenoids on the growth and antioxidant capability of Litopenaeus vannamei juveniles were invest...Oxidative stress induced by factors such as ammonia nitrogen has become a major issue in shrimp farming.The effects of carotenoids on the growth and antioxidant capability of Litopenaeus vannamei juveniles were investigated in this study using dietary archaeal carotenoids supplementation.For four weeks,shrimp were given diets containing 0 mg/kg(Ctrl)and 55.98 mg/kg(Car)archaeal carotenoids.Dietary archaeal carotenoids significantly enhanced the astaxanthin content in shrimp muscles and carapaces,as well as the superoxide dismutase(SOD)and glutathione peroxidase(GSH-Px)activity(P<0.05).The malonaldehyde(MDA)content in Car group significantly decreased(P<0.05).The transcriptome analysis was conducted to determine the molecular processes in response to archaeal carotenoids supplementation.A total of 1536 differentially expressed genes(DEGs)were detected,including 538 upregulated DEGs and 998 downregulated DEGs.GO functional enrichment analysis between Ctrl and Car indicated that 26 GO terms including extracellular region,metabolic process,and proteolysis were enriched.The KEGG pathway enrichment analysis revealed that the amino sugar and nucleotide sugar metabolism,cysteine and methionine metabolism,glycine serine and threonine metabolism,and amino acid biosynthesis were enriched.Archaeal carotenoids influenced the expression of several important genes involved in reactive oxygen species(ROS)generation,Nrf2 signaling,and antioxidant enzymes.Seven DEGs were chosen to confirm the RNA-Seq data using qRT-PCR.The genes and pathways discovered in this work assist to elucidate the molecular processes through which archaeal carotenoid enhances L.vannamei antioxidative system.展开更多
Objective Diminished ovarian reserve(DOR)can lead to early menopause,poor fecundity,and an increased risk of disorders such as osteoporosis,cardiovascular disease,and cognitive impairment,seriously affecting the physi...Objective Diminished ovarian reserve(DOR)can lead to early menopause,poor fecundity,and an increased risk of disorders such as osteoporosis,cardiovascular disease,and cognitive impairment,seriously affecting the physical and mental health of women.There is still no safe and effective strategy or method to combat DOR.We have developed a novel Chinese herbal formula,Tongji anti-ovarian aging 101(TJAOA101),to treat DOR.However,its safety and efficacy need to be further validated.Methods In this prospective and pre-post clinical trial,100 eligible patients aged 18–45 diagnosed with DOR will be recruited.All participants receive TJAOA101 twice a day for 3 months.Then,comparisons before and after treatment will be analyzed,and the outcomes,including anti-mullerian hormone(AMH)and follicle-stimulating hormone(FSH)levels and the antral follicle count(AFC),the recovery rate of menopause,and the Kupperman index(KMI),will be assessed at baseline,every month during medication(the intervention period),and 1,3 months after medication(the follow-up period).Assessments for adverse events will be performed during the intervention and follow-up periods.Conclusion A multicenter,prospective study will be conducted to further confirm the safety and efficacy of TJAOA101 in treating DOR and to provide new therapeutic strategies for improving the quality of life in DOR patients.展开更多
Objective This study analyzed the role of G1 to S phase transition 1 protein(GSPT1)in promoting progression of liver cancer cells.Methods A bioinformatics database was used to analyze the expression levels of GSPT1 in...Objective This study analyzed the role of G1 to S phase transition 1 protein(GSPT1)in promoting progression of liver cancer cells.Methods A bioinformatics database was used to analyze the expression levels of GSPT1 in liver cancer tissues and the prognosis of patients.Subsequently,Western blotting and quantitative PCR were used to verify the expression levels of GSPT1 between normal hepatocytes and hepatoma cells.We used a CRISPR/Cas9 system to construct knockouts of GSPT1 in HepG2 and HCCLM9 liver cancer cells.The effect of GSPT1 on liver cancer cell migration and invasion was analyzed using flow cytometry,migration,and tumor formation assays.Results The Cancer Genome Atlas Liver Hepatocellular Carcinoma dataset indicated that GSPT1 expression was upregulated in liver cancer cell lines,and patients with liver cancer had poor prognosis.Knockout of GSPT1 in cells significantly inhibited tumor proliferation,cell migration,and growth in vivo.Conclusion In this study,we found that GSPT1 promotes the migration and invasion of liver cancer cells.展开更多
Cyclophilin(CYP)plays an important role in plant response to stress,and OsCYP2,one gene of cyclophlilin family,is involved in auxin signal transduction and stress signaling in rice.However,the mechanism that OsCYP2 is...Cyclophilin(CYP)plays an important role in plant response to stress,and OsCYP2,one gene of cyclophlilin family,is involved in auxin signal transduction and stress signaling in rice.However,the mechanism that OsCYP2 is involved in rice response to low temperature is still unclear.We identified a new OsCYP2 allelic mutant,lrl3,with fewer lateral roots,and the differences in shoot height,primary root length and adventitious root length increased with the growth process compared to the wild-type plant.Auxin signaling pathway was also affected and became insensitive to gravity.The transgenic rice plants with over-expression of OsCYP2 were more tolerant to low temperature than the wild-type plants,suggesting that OsCYP2 was involved in the low temperature response in rice.In addition,OsCYP2 negatively regulated the expression of OsTPS38,a terpene synthase gene,and was dependent on the OsCDPK7-mediated pathway in response to low temperature stress.OsTPS38-overexpressed transgenic line ox-2 was more sensitive to low temperature.Therefore,OsCYP2 may negatively regulate OsTPS38 through an OsCDPK7-dependent pathway to mediate the response to low temperature in rice.These results provide a new basis for auxin signaling genes to regulate rice response to low temperature stress.展开更多
BACKGROUND Gait is influenced by race,age,and diseases type.Reference values for gait are closely related to numerous health outcomes.To gain a comprehensive understanding of gait patterns,particularly in relation to ...BACKGROUND Gait is influenced by race,age,and diseases type.Reference values for gait are closely related to numerous health outcomes.To gain a comprehensive understanding of gait patterns,particularly in relation to race-related pathologies and disorders,it is crucial to establish reference values for gait in daily life considering sex and age.Therefore,our objective was to present sex and age-based reference values for gait in daily life,providing a valuable foundation for further research and clinical applications.AIM To establish reference values for lower extremity joint kinematics and kinetics during gait in asymptomatic adult women and men.METHODS Spatiotemporal,kinematics and kinetics parameters were measured in 171 healthy adults(70 males and 101 females)using the computer-aided soft tissue foot model.Full curve statistical parametric mapping was performed using independent and paired-samples t-tests.RESULTS Compared with females,males required more time(cycle time,double-limb support time,stance time,swing time,and stride time),and the differences were statistically significant.In addition,the step and stride lengths of males were longer.Compared to males,female cadence was faster,and statures-per-second and stride-per-minute were higher.There were no statistical differences in speed and stride width between the two groups.After adjusting for height,it was observed that women walked significantly faster than men,and they also had a higher cadence.However,in terms of step length,stride length,and stride width,both genders exhibited similarities.CONCLUSION We established reference values for gait speed and spatiotemporal gait parameters in Chinese university students.This contributes to a valuable database for gait assessment and evaluation of preventive or rehabilitative programs.展开更多
BACKGROUND Rotationplasty is often performed for malignant tumors,but type BIIIb rotationplasty is rarely reported,and there needs to be more evidence of the procedure and treatment.The purpose of this case study was ...BACKGROUND Rotationplasty is often performed for malignant tumors,but type BIIIb rotationplasty is rarely reported,and there needs to be more evidence of the procedure and treatment.The purpose of this case study was to report a new direction in the use of type BIIIb rotationplasty in treating patients with limb salvage and longterm non-healing infections.CASE SUMMARY Case 1:A 47-year-old man underwent radiotherapy for hemangioendothelioma in his left thigh,resulting in a femoral fracture.Despite the use of plates,intramedullary nailing,and external fixators,the femoral bone failed to unite due to infectious nonunion.Multiple operations were unable to control the infection,leaving the patient immobile.We performed a modified tibia-pelvic-constrained hip rotationplasty,utilizing a constrained prosthetic hip between the tibia and pelvis following a femur resection.Two years post-surgery,the patient was able to walk with the prosthetic device without any signs of recurring infection.The corresponding functional scores were 72 points for the Musculoskeletal Tumor Society(MSTS),53 for the Functional Mobility Assessment(FMA),93 for the Toronto Extremity Salvage Score(TESS),and 56 for the MOS 36-item short form health survey(SF-36).Case 2:A 59-year-old woman presented with liposarcoma in her left thigh.Magnetic resonance imaging revealed tumors in the medial,anterior,and posterior femur muscles,encircling the femoral vessels and nerves.Fortunately,there were no symptoms of sciatic dysfunction,and the tumor had not invaded the sciatic nucleus.After one year of follow-up,the patient expressed satisfaction with limb preservation post-type BIIIb rotationplasty.The corresponding functional scores were 63 points for the MSTS,47 for the FMA,88 for the TESS,and 52 for the SF-36.CONCLUSION Our study suggests that type BIIIb rotationplasty may be an alternative to amputation in patients with incurable infections.For malignant tumors of the lower extremities without invasion of the sciatic nerve,type BIIIb rotationplasty remains an excellent alternative to amputation.This surgical method may prevent amputation,improve functional outcomes,and facilitate biological reconstruction.展开更多
Towards virtual keyboard design and realization, the work in this paper presents a robust key input method for deployment in virtual keyboard systems. The proposed scheme harnesses the information contained within sha...Towards virtual keyboard design and realization, the work in this paper presents a robust key input method for deployment in virtual keyboard systems. The proposed scheme harnesses the information contained within shadows towards robustifying virtual key input. This scheme allows for input efficiency to be guaranteed in situations of relatively lower illumination, a core challenge associated with virtual keyboards. Contributions of the paper are two-fold. Firstly the paper pre-sents an approach towards effectively applying shadow information towards robustifying virtual key input systems;Secondly, through morphological operations, the performance of this input method is boosted by means of effectively alleviating noise and its impacts on overall algorithm performance, while highlighting the necessary features towards an efficient performance. While previous contributions have followed a similar trend, the contribution of this paper stresses on the intensification and improvement of both shadow and finger-tip feature highlighting schemes towards overall performance improvement. Experimental results presented in the paper demon-strate the efficiency and robustness of the approach. The attained results suggest that the scheme is capable of attaining high performances in terms of accuracy while being capable of addressing false touch situations.展开更多
Hypoxic preconditioning has been shown to improve hypoxic tolerance in mice,accompanied by the downregulation of DNA methyltransferases(DNMTs)in the brain.However,the roles played by DNMTs in the multiple neuroprotect...Hypoxic preconditioning has been shown to improve hypoxic tolerance in mice,accompanied by the downregulation of DNA methyltransferases(DNMTs)in the brain.However,the roles played by DNMTs in the multiple neuroprotective mechanisms associated with hypoxic preconditioning remain poorly understood.This study aimed to establish an in vitro model of hypoxic preconditioning,using a cultured mouse hippocampal neuronal cell line(HT22 cells),to examine the effects of DNMTs on the endogenous neuroprotective mechanisms that occur during hypoxic preconditioning.HT22 cells were divided into a control group,which received no exposure to hypoxia,a hypoxia group,which was exposed to hypoxia once,and a hypoxic preconditioning group,which was exposed to four cycles of hypoxia.To test the ability of hypoxic preadaptation to induce hypoxic tolerance,cell viability was measured using the 3-(4,5-dimethylthiazol-2-yl)-5(3-carboxymethonyphenol)-2-(4-sulfophenyl)-2H-tetrazolium assay.Cell viability improved in the hypoxic preconditioning group compared with that in the hypoxia group.The effects of hypoxic preconditioning on the cell cycle and apoptosis in HT22 cells were examined by western blot assay and flow cytometry.Compared with the hypoxia group,the expression levels of caspase-3 and spectrin,which are markers of early apoptosis and S-phase arrest,respectively,noticeably reduced in the hypoxic preconditioning group.Finally,enzyme-linked immunosorbent assay,real-time polymerase chain reaction,and western blot assay were used to investigate the changes in DNMT expression and activity during hypoxic preconditioning.The results showed that compared with the control group,hypoxic preconditioning downregulated the expression levels of DNMT3A and DNMT3B mRNA and protein in HT22 cells and decreased the activities of total DNMTs and DNMT3B.In conclusion,hypoxic preconditioning may exert anti-hypoxic neuroprotective effects,maintaining HT22 cell viability and inhibiting cell apoptosis.These neuroprotective mechanisms may be associated with the inhibition of DNMT3A and DNMT3B.展开更多
In order to study the mechanism of selective catalytic reduction of activated coke to remove NO in low-temperature flue gas and provide some theoretical basis for the development of related technologies.The pore sized...In order to study the mechanism of selective catalytic reduction of activated coke to remove NO in low-temperature flue gas and provide some theoretical basis for the development of related technologies.The pore sizedistribution and BET specific surface area of AC were obtain by data analyzing of N2 adsorption/desorption isotherm at -196 ℃ and carbon matrix and surface chemistry of virgin activated coke samples were characterized by acid-base titration and XPS.The process of selective catalytic reduction of activated coke (AC) samples with NH3 as reducing agent was studied in a fixed bed reactor at 150 ℃.The result shows that pore size distribution or BET specific surface of activated cokes have not correlation with denitrification activity for SCR.The NO reduction activities of the activated cokes are apparent to increase with their surface oxygen element content and total amount of acidic sites.Obviously there is good linear relationship between the NH3 adsorption capacity and activity for SCR with linear correlation coefficient 0.943.It has been presented that adsorption of NH3 on acidic functional groups in the edge of large polycyclic aromatic ring of activated coke is key rate controlling step in the SCR heterogeneous catalytic reaction.展开更多
文摘背景胃肠神经内分泌肿瘤(gastrointestinal neuroendocrine neoplasms,GI-NENs)临床表现多样,部分具有高侵袭性及转移性,预后差.收集我院诊治的GI-NENs患者的临床病理资料,免疫组化检测CD155、T细胞免疫球蛋白和ITIM结构域蛋白(T cell immunoreceptor with Ig and ITIM domains,TIGIT)的表达量,探讨其与临床病理和预后的关系,为患者的治疗提供一个新的方向.目的探讨CD155、TIGIT在GI-NENs中的表达量与临床病理特征的关系.方法收集2016-11/2020-08经我院诊治的168例GI-NENs患者的临床病理资料.免疫组化检测CD155、TIGIT的表达量,探讨其与临床病理和预后的关系.结果CD155和TIGIT在病理分级高的GI-NENs组织中,表达量也较高,差异有统计学意义(P<0.05);CD155表达量与年龄、肿瘤位置、肿瘤最大直径、病理分级、T分期、淋巴结转移、远处转移、TNM分期、Ki-67指数有关(P<0.05);TIGIT表达量与肿瘤最大直径、病理分级、T分期、淋巴结转移、TNM分期、Ki-67指数有关(P<0.05);CD155和TIGIT表达量高的患者预后较表达量低者差,差异有统计学意义(P<0.05).结论CD155和TIGIT表达量在不同分级、分期的GI-NENs患者存在差异,可能参与了GI-NENs的发生及进展的调控过程,高表达可能提示预后不佳.
基金the National Elite Foundationthe Institute for Advanced Studies in Basic Sciences for their financial supportfinancially supported by the National Natural Science Foundation of China(22173026,22350410386,22375200,U22A202175,21961142006)。
文摘This study investigates the effects of Fe on the oxygen-evolution reaction(OER)in the presence of Au.Two distinct areas of OER were identified:the first associated with Fe sites at low overpotential(~330 mV),and the second with Au sites at high overpotential(~870 mV).Various factors such as surface Fe concentration,electrochemical method,scan rate,potential range,concentration,method of adding K_(2)Fe O_(4),nature of Fe,and temperature were varied to observe diverse behaviors during OER for Fe O_(x)H_(y)/Au.Trace amounts of Fe ions had a significant impact on OER,reaching a saturation point where the activity did not increase further.Strong electronic interaction between Fe and Au ions was indicated by X-ray photoelectron spectroscopy(XPS)and electron paramagnetic resonance(EPR)analyses.In situ visible spectroscopy confirmed the formation of Fe O_(4)^(2-)during OER.In situ Mossbauer and surfaceenhanced Raman spectroscopy(SERS)analyses suggest the involvement of Fe-based species as intermediates during the rate-determining step of OER.A lattice OER mechanism based on Fe O_(x)H_(y)was proposed for operation at low overpotentials.Density functional theory(DFT)calculations revealed that Fe oxide,Fe-oxide clusters,and Fe doping on the Au foil exhibited different activities and stabilities during OER.The study provides insights into the interplay between Fe and Au in OER,advancing the understanding of OER mechanisms and offering implications for the design of efficient electrocatalytic systems.
基金performed under the auspices of the Science and Technology Foundation of Guizhou Province(grant No.Qian Ke He Ji Chu ZK[2021]027)Major Science and Technology Program of Xinjiang Uygur Autonomous Region through No.2022A03013-1+1 种基金the National Key Research and Development Program of China(No.2022YFC2205202)the National Natural Science Foundation of China grants 12288102,12041304 and 11847102。
文摘The prompt emission mechanism of gamma-ray bursts(GRBs)is still unclear,and the time-resolved spectral analysis of GRBs is a powerful tool for studying their underlying physical processes.We performed a detailed time-resolved spectral analysis of 78 bright long GRB samples detected by Fermi/Gamma-ray Burst Monitor.A total of 1490 spectra were obtained and their properties were studied using a typical Band-shape model.First,the parameter distributions of the time-resolved spectrum are given as follows:the low-energy spectral indexα~-0.72,high-energy spectral indexβ~2.42,the peak energy E_(p)~221.69 keV,and the energy flux F~7.49×10^(-6)erg cm^(-2)s^(-1).More than 80%of the bursts exhibit the hardest low-energy spectral indexα_(max),exceeding the synchrotron limit(-2/3).Second,the evolution patterns of a and E_(p)were statistically analyzed.The results show that for multi-pulse GRBs the intensity-tracking pattern is more common than the hard-to-soft pattern in the evolution of both E_(p)andα.The hard-to-soft pattern is generally shown in single-pulse GRBs or in the initial pulse of multi-pulse GRBs.Finally,we found a significant positive correlation between F and E_(p),with half of the samples exhibiting a positive correlation between F andα.We discussed the spectral evolution of different radiation models.The diversity of spectral evolution patterns indicates that there may be more than one radiation mechanism occurring in the GRB radiation process,including photo spheric radiation and synchrotron radiation.However,it may also involve only one radiation mechanism,but more complicated physical details need to be considered.
基金supported by the National Magnetic Confinement Fusion Energy R&D Program of China (No.2018YFE0309100)National Natural Science Foundation of China (No.51821005)。
文摘Accurate measurement of the average plasma parameters in the edge region,including the temperature and density of electrons and ions,is critical for understanding the characteristics of the scrape-off layer(SOL) and divertor plasma transport in magnetically confined fusion research.On the J-TEXT tokamak,a multi-channel retarding field analyzer(RFA) probe has been developed to study average plasma parameters in the edge region under various poloidal divertor and island divertor configurations.The edge radial profile of the ion-to-electron temperature ratio,τ_(i/e),has been determined,which gradually decreases as the SOL ion self-collisionality,v_(SOL)*,increases.This is broadly consistent with what has been observed previously from various tokamak experiments.However,the comparison of experimental results under different configurations shows that in the poloidal divertor configuration,even under the same v_(SOL)*,τ_(i/e) in the SOL region becomes smaller as the distance from the X-point to the target plate increases.In the island divertor configuration,τ_(i/e) near the O-point is higher than that near the X-point at the same v_(SOL)*,and both are higher than those in the limiter configuration.These results suggest that the magnetic configuration plays a critical role in the energy distributions between electrons and ions at the plasma boundary.
基金financially supported by the Research Foundation of Education Bureau Hunan Province,China (Grant No. 22C0598)。
文摘The microstructure evolution and precipitation behavior of Al-Mg-Si alloy during initial aging were studied using hardness testing, conductivity testing, differential scanning calorimetry(DSC), and high resolution transmission electron microscopy(HRTEM). The results show that the precipitation sequence of the Al-Mg-Si alloy during initial aging can be represented as: supersaturated solid solution → spherical Mg/Si clusters → needle-like Guinier Preston(GP) zone → β″. Clusters are completely coherent with the Al matrix. The GP zone with relatively complete independent lattice parameters that differ slightly from the Al matrix parameters, is oriented along the direction of <111>Aland lying on {111}Alplane. The strength of the Al-Mg-Si alloy is greatly enhanced by the threedimensional strain field that exists between the β″ phase and the two {200}Alplanes. After aging at 170 ℃ for 6 h, the hardness reaches the peak of 127 HV and remains for a long time. At this stage, the electrical conductivity keeps relatively stable due to the formation of coherent precipitates(Mg/Si clusters/GP zones) and the reduction in solute atom concentration in the Al matrix. The severe coarsening and decreased number density of the β″ phase during the over-aging stage result in a significant decrease in the hardness.
基金the cooperation projects between China Geological Survey and geological survey institutions of Africa(DD20190439,DD20160108,DD20221801)。
文摘Tanzania is located in eastern Africa with a predominantly agricultural ecomomy,the potential for developing and utilizing cultivated land are promising,but scientific guidance is required.B,Zn and Se are essential micronutrients for plants and human body with crucial biological functions,in particular,Se is significant for human health and considered as“the king of anti-cancer”.As these elements required by human or plants are mainly absorbed from soil directly or indirectly,therefore,it is important to understand the contents and distributions of them in the soil of cultivated land for guiding agricultural production.In this work,low-density geochemical survey at the scale of 1∶1000000 was carried out in Tanzania,and the results show that the concentrations of B,Zn and Se in stream sediments are low and their distributions are heterogeneous.According to the distributions of geological units,the existing cultivated land resources can be divided into five regions in Tanzania.Compared with the national background values,the concentrations of B,Zn and Se are insufficient overall but enriched locally in these regions.In general,element concentrations in stream sediments and soil have a positive correlation because of their similar sources,which is essential in agriculture application.Based on the information provided by low-density geochemical data and maps,the Se-sufficient and Se-rich regions were delineated in Tanzania,where can be used to develop Se-rich industries.Finally,this paper believes that geochemical survey is a powerful tool for cultivated land evaluation,agriculture management and land development.
基金Supported by the Project of China One-Belt-One-Road Foreign Expert Research Collaboration,Ministry of Science and Technology,China (No.DL2021002001L)the Open Project Program of State Key Laboratory of Food Nutrition and Safety,Tianjin University of Science&Technology (No.SKLFNS-KF-202205)。
文摘Oxidative stress induced by factors such as ammonia nitrogen has become a major issue in shrimp farming.The effects of carotenoids on the growth and antioxidant capability of Litopenaeus vannamei juveniles were investigated in this study using dietary archaeal carotenoids supplementation.For four weeks,shrimp were given diets containing 0 mg/kg(Ctrl)and 55.98 mg/kg(Car)archaeal carotenoids.Dietary archaeal carotenoids significantly enhanced the astaxanthin content in shrimp muscles and carapaces,as well as the superoxide dismutase(SOD)and glutathione peroxidase(GSH-Px)activity(P<0.05).The malonaldehyde(MDA)content in Car group significantly decreased(P<0.05).The transcriptome analysis was conducted to determine the molecular processes in response to archaeal carotenoids supplementation.A total of 1536 differentially expressed genes(DEGs)were detected,including 538 upregulated DEGs and 998 downregulated DEGs.GO functional enrichment analysis between Ctrl and Car indicated that 26 GO terms including extracellular region,metabolic process,and proteolysis were enriched.The KEGG pathway enrichment analysis revealed that the amino sugar and nucleotide sugar metabolism,cysteine and methionine metabolism,glycine serine and threonine metabolism,and amino acid biosynthesis were enriched.Archaeal carotenoids influenced the expression of several important genes involved in reactive oxygen species(ROS)generation,Nrf2 signaling,and antioxidant enzymes.Seven DEGs were chosen to confirm the RNA-Seq data using qRT-PCR.The genes and pathways discovered in this work assist to elucidate the molecular processes through which archaeal carotenoid enhances L.vannamei antioxidative system.
基金supported by grants from the National Natural Science Foundation of China(No.82001498 and No.82002768)the Natural Science Foundation of Hubei Province(No.2020CFB544)The Clinical Research Pilot Project of Tongji Hospital,Huazhong University of Science and Technology(No.2019CR205).
文摘Objective Diminished ovarian reserve(DOR)can lead to early menopause,poor fecundity,and an increased risk of disorders such as osteoporosis,cardiovascular disease,and cognitive impairment,seriously affecting the physical and mental health of women.There is still no safe and effective strategy or method to combat DOR.We have developed a novel Chinese herbal formula,Tongji anti-ovarian aging 101(TJAOA101),to treat DOR.However,its safety and efficacy need to be further validated.Methods In this prospective and pre-post clinical trial,100 eligible patients aged 18–45 diagnosed with DOR will be recruited.All participants receive TJAOA101 twice a day for 3 months.Then,comparisons before and after treatment will be analyzed,and the outcomes,including anti-mullerian hormone(AMH)and follicle-stimulating hormone(FSH)levels and the antral follicle count(AFC),the recovery rate of menopause,and the Kupperman index(KMI),will be assessed at baseline,every month during medication(the intervention period),and 1,3 months after medication(the follow-up period).Assessments for adverse events will be performed during the intervention and follow-up periods.Conclusion A multicenter,prospective study will be conducted to further confirm the safety and efficacy of TJAOA101 in treating DOR and to provide new therapeutic strategies for improving the quality of life in DOR patients.
基金supported by grants from the National Natural Science Foundation of China(No.81770283,No.82070302 and No.81902018)Clinical Medical Research Center of Peritoneal Cancer of Wuhan(No.2015060911020462)+1 种基金Natural Science Foundation of Hubei Province(No.2019CFB109)Technology and Innovation Seed Found,Zhongnan Hospital of Wuhan University(No.znpy2018004).
文摘Objective This study analyzed the role of G1 to S phase transition 1 protein(GSPT1)in promoting progression of liver cancer cells.Methods A bioinformatics database was used to analyze the expression levels of GSPT1 in liver cancer tissues and the prognosis of patients.Subsequently,Western blotting and quantitative PCR were used to verify the expression levels of GSPT1 between normal hepatocytes and hepatoma cells.We used a CRISPR/Cas9 system to construct knockouts of GSPT1 in HepG2 and HCCLM9 liver cancer cells.The effect of GSPT1 on liver cancer cell migration and invasion was analyzed using flow cytometry,migration,and tumor formation assays.Results The Cancer Genome Atlas Liver Hepatocellular Carcinoma dataset indicated that GSPT1 expression was upregulated in liver cancer cell lines,and patients with liver cancer had poor prognosis.Knockout of GSPT1 in cells significantly inhibited tumor proliferation,cell migration,and growth in vivo.Conclusion In this study,we found that GSPT1 promotes the migration and invasion of liver cancer cells.
基金The datasets presented in this study can be found in online repositories.The names of the repository/repositories and accession number(s)can be found below:NCBI-SRA database under the BioProject no.PRJNA732107 and accession nos.SRR14629497,SRR14629496,SRR14629495,and SRR14629494 for the RNA-seq data.
文摘Cyclophilin(CYP)plays an important role in plant response to stress,and OsCYP2,one gene of cyclophlilin family,is involved in auxin signal transduction and stress signaling in rice.However,the mechanism that OsCYP2 is involved in rice response to low temperature is still unclear.We identified a new OsCYP2 allelic mutant,lrl3,with fewer lateral roots,and the differences in shoot height,primary root length and adventitious root length increased with the growth process compared to the wild-type plant.Auxin signaling pathway was also affected and became insensitive to gravity.The transgenic rice plants with over-expression of OsCYP2 were more tolerant to low temperature than the wild-type plants,suggesting that OsCYP2 was involved in the low temperature response in rice.In addition,OsCYP2 negatively regulated the expression of OsTPS38,a terpene synthase gene,and was dependent on the OsCDPK7-mediated pathway in response to low temperature stress.OsTPS38-overexpressed transgenic line ox-2 was more sensitive to low temperature.Therefore,OsCYP2 may negatively regulate OsTPS38 through an OsCDPK7-dependent pathway to mediate the response to low temperature in rice.These results provide a new basis for auxin signaling genes to regulate rice response to low temperature stress.
基金Supported by Major Project of the Co-construction Science and Technology Program between the Science and Technology Department of the National Administration of Traditional Chinese Medicine and the Zhejiang Administration of Traditional Chinese Medicine,No.GZY-ZJ-KJ-23040Zhejiang Medical and Health Science and Technology Project,No.2022497035+2 种基金Quzhou City Science and Technology Project,No.2022K75Zhejiang Chinese Medical University Scientific Research Fund Project,No.2021FSYYZZ09,No.2021FSYYZZ14The study was reviewed and approved by the Department of Orthopedics,The First Affiliated Hospital of Zhejiang Chinese Medical University(Zhejiang Provincial Hospital of Traditional Chinese Medicine)Institutional Review Board[Approval No.2023-K-162-01].
文摘BACKGROUND Gait is influenced by race,age,and diseases type.Reference values for gait are closely related to numerous health outcomes.To gain a comprehensive understanding of gait patterns,particularly in relation to race-related pathologies and disorders,it is crucial to establish reference values for gait in daily life considering sex and age.Therefore,our objective was to present sex and age-based reference values for gait in daily life,providing a valuable foundation for further research and clinical applications.AIM To establish reference values for lower extremity joint kinematics and kinetics during gait in asymptomatic adult women and men.METHODS Spatiotemporal,kinematics and kinetics parameters were measured in 171 healthy adults(70 males and 101 females)using the computer-aided soft tissue foot model.Full curve statistical parametric mapping was performed using independent and paired-samples t-tests.RESULTS Compared with females,males required more time(cycle time,double-limb support time,stance time,swing time,and stride time),and the differences were statistically significant.In addition,the step and stride lengths of males were longer.Compared to males,female cadence was faster,and statures-per-second and stride-per-minute were higher.There were no statistical differences in speed and stride width between the two groups.After adjusting for height,it was observed that women walked significantly faster than men,and they also had a higher cadence.However,in terms of step length,stride length,and stride width,both genders exhibited similarities.CONCLUSION We established reference values for gait speed and spatiotemporal gait parameters in Chinese university students.This contributes to a valuable database for gait assessment and evaluation of preventive or rehabilitative programs.
基金Supported by the Army Logistics Scientific Research Projects,No.CNJ16C013.
文摘BACKGROUND Rotationplasty is often performed for malignant tumors,but type BIIIb rotationplasty is rarely reported,and there needs to be more evidence of the procedure and treatment.The purpose of this case study was to report a new direction in the use of type BIIIb rotationplasty in treating patients with limb salvage and longterm non-healing infections.CASE SUMMARY Case 1:A 47-year-old man underwent radiotherapy for hemangioendothelioma in his left thigh,resulting in a femoral fracture.Despite the use of plates,intramedullary nailing,and external fixators,the femoral bone failed to unite due to infectious nonunion.Multiple operations were unable to control the infection,leaving the patient immobile.We performed a modified tibia-pelvic-constrained hip rotationplasty,utilizing a constrained prosthetic hip between the tibia and pelvis following a femur resection.Two years post-surgery,the patient was able to walk with the prosthetic device without any signs of recurring infection.The corresponding functional scores were 72 points for the Musculoskeletal Tumor Society(MSTS),53 for the Functional Mobility Assessment(FMA),93 for the Toronto Extremity Salvage Score(TESS),and 56 for the MOS 36-item short form health survey(SF-36).Case 2:A 59-year-old woman presented with liposarcoma in her left thigh.Magnetic resonance imaging revealed tumors in the medial,anterior,and posterior femur muscles,encircling the femoral vessels and nerves.Fortunately,there were no symptoms of sciatic dysfunction,and the tumor had not invaded the sciatic nucleus.After one year of follow-up,the patient expressed satisfaction with limb preservation post-type BIIIb rotationplasty.The corresponding functional scores were 63 points for the MSTS,47 for the FMA,88 for the TESS,and 52 for the SF-36.CONCLUSION Our study suggests that type BIIIb rotationplasty may be an alternative to amputation in patients with incurable infections.For malignant tumors of the lower extremities without invasion of the sciatic nerve,type BIIIb rotationplasty remains an excellent alternative to amputation.This surgical method may prevent amputation,improve functional outcomes,and facilitate biological reconstruction.
文摘Towards virtual keyboard design and realization, the work in this paper presents a robust key input method for deployment in virtual keyboard systems. The proposed scheme harnesses the information contained within shadows towards robustifying virtual key input. This scheme allows for input efficiency to be guaranteed in situations of relatively lower illumination, a core challenge associated with virtual keyboards. Contributions of the paper are two-fold. Firstly the paper pre-sents an approach towards effectively applying shadow information towards robustifying virtual key input systems;Secondly, through morphological operations, the performance of this input method is boosted by means of effectively alleviating noise and its impacts on overall algorithm performance, while highlighting the necessary features towards an efficient performance. While previous contributions have followed a similar trend, the contribution of this paper stresses on the intensification and improvement of both shadow and finger-tip feature highlighting schemes towards overall performance improvement. Experimental results presented in the paper demon-strate the efficiency and robustness of the approach. The attained results suggest that the scheme is capable of attaining high performances in terms of accuracy while being capable of addressing false touch situations.
基金supported by the National Natural Science Foundation of China,Nos.81460283(to GS),81660307(to GS),31860307(to WX)the Science Foundation of Inner Mongolia Autonomous Region of China,Nos.2018LH08078(to GS),2018LH03029(to JHS)+2 种基金the Young Talents of Science and Technology in Universities of Inner Mongolia Autonomous Region of China,No.NJYT-18-B26(to WX)the Scientific Research Foundation of Baotou Medical College of China,Nos.BYJJ-YF 201717(to SCY),BYJJ-YF 201606(to WX)the National Key Research and Development Program of China,No.2017YFC1308405(to GS)。
文摘Hypoxic preconditioning has been shown to improve hypoxic tolerance in mice,accompanied by the downregulation of DNA methyltransferases(DNMTs)in the brain.However,the roles played by DNMTs in the multiple neuroprotective mechanisms associated with hypoxic preconditioning remain poorly understood.This study aimed to establish an in vitro model of hypoxic preconditioning,using a cultured mouse hippocampal neuronal cell line(HT22 cells),to examine the effects of DNMTs on the endogenous neuroprotective mechanisms that occur during hypoxic preconditioning.HT22 cells were divided into a control group,which received no exposure to hypoxia,a hypoxia group,which was exposed to hypoxia once,and a hypoxic preconditioning group,which was exposed to four cycles of hypoxia.To test the ability of hypoxic preadaptation to induce hypoxic tolerance,cell viability was measured using the 3-(4,5-dimethylthiazol-2-yl)-5(3-carboxymethonyphenol)-2-(4-sulfophenyl)-2H-tetrazolium assay.Cell viability improved in the hypoxic preconditioning group compared with that in the hypoxia group.The effects of hypoxic preconditioning on the cell cycle and apoptosis in HT22 cells were examined by western blot assay and flow cytometry.Compared with the hypoxia group,the expression levels of caspase-3 and spectrin,which are markers of early apoptosis and S-phase arrest,respectively,noticeably reduced in the hypoxic preconditioning group.Finally,enzyme-linked immunosorbent assay,real-time polymerase chain reaction,and western blot assay were used to investigate the changes in DNMT expression and activity during hypoxic preconditioning.The results showed that compared with the control group,hypoxic preconditioning downregulated the expression levels of DNMT3A and DNMT3B mRNA and protein in HT22 cells and decreased the activities of total DNMTs and DNMT3B.In conclusion,hypoxic preconditioning may exert anti-hypoxic neuroprotective effects,maintaining HT22 cell viability and inhibiting cell apoptosis.These neuroprotective mechanisms may be associated with the inhibition of DNMT3A and DNMT3B.
基金The authors are grateful to the National Key Research and Development Program of China(NO.2016YFC0204100).
文摘In order to study the mechanism of selective catalytic reduction of activated coke to remove NO in low-temperature flue gas and provide some theoretical basis for the development of related technologies.The pore sizedistribution and BET specific surface area of AC were obtain by data analyzing of N2 adsorption/desorption isotherm at -196 ℃ and carbon matrix and surface chemistry of virgin activated coke samples were characterized by acid-base titration and XPS.The process of selective catalytic reduction of activated coke (AC) samples with NH3 as reducing agent was studied in a fixed bed reactor at 150 ℃.The result shows that pore size distribution or BET specific surface of activated cokes have not correlation with denitrification activity for SCR.The NO reduction activities of the activated cokes are apparent to increase with their surface oxygen element content and total amount of acidic sites.Obviously there is good linear relationship between the NH3 adsorption capacity and activity for SCR with linear correlation coefficient 0.943.It has been presented that adsorption of NH3 on acidic functional groups in the edge of large polycyclic aromatic ring of activated coke is key rate controlling step in the SCR heterogeneous catalytic reaction.