Fe/N-based biomass porous carbon composite(Fe/N-p Carbon) was prepared by a facile high-temperature carbonization method from biomass,and the effect of Fe/N-p Carbon on the thermal decomposition of energetic molecular...Fe/N-based biomass porous carbon composite(Fe/N-p Carbon) was prepared by a facile high-temperature carbonization method from biomass,and the effect of Fe/N-p Carbon on the thermal decomposition of energetic molecular perovskite-based material DAP-4 was studied.Biomass porous carbonaceous materials was considered as the micro/nano support layers for in situ deposition of Fe/N precursors.Fe/Np Carbon was prepared simply by the high-temperature carbonization method.It was found that it showed the inherent catalysis properties for thermal decomposition of DAP-4.The heat release of DAP-4/Fe/N-p Carbon by DSC curves tested had increased slightly,compared from DAP-4/Fe/N-p Carbon-0.The decomposition temperature peak of DAP-4 at the presence of Fe/N-p Carbon had reduced by 79°C from384.4°C(pure DAP-4) to 305.4°C(DAP-4/Fe/N-p Carbon-3).The apparent activation energy of DAP-4thermal decomposition also had decreased by 29.1 J/mol.The possible catalytic decomposition mechanism of DAP-4 with Fe/N-p Carbon was proposed.展开更多
In the reversed field pinch(RFP),plasmas exhibit various self-organized states.Among these,the three-dimensional(3D)helical state known as the“quasi-single-helical”(QSH)state enhances RFP confinement.However,accurat...In the reversed field pinch(RFP),plasmas exhibit various self-organized states.Among these,the three-dimensional(3D)helical state known as the“quasi-single-helical”(QSH)state enhances RFP confinement.However,accurately describing the equilibrium is challenging due to the presence of 3D structures,magnetic islands,and chaotic regions.It is difficult to obtain a balance between the available diagnostic and the real equilibrium structure.To address this issue,we introduce KTX3DFit,a new 3D equilibrium reconstruction code specifically designed for the Keda Torus eXperiment(KTX)RFP.KTX3DFit utilizes the stepped-pressure equilibrium code(SPEC)to compute 3D equilibria and uses polarimetric interferometer signals from experiments.KTX3DFit is able to reconstruct equilibria in various states,including axisymmetric,doubleaxis helical(DAx),and single-helical-axis(SHAx)states.Notably,this study marks the first integration of the SPEC code with internal magnetic field data for equilibrium reconstruction and could be used for other 3D configurations.展开更多
The trajectory of the compact torus(CT)within a tokamak discharge is crucial to fueling.In this study,we developed a penetration model with a vacuum magnetic field region to accurately determine CT trajectories in tok...The trajectory of the compact torus(CT)within a tokamak discharge is crucial to fueling.In this study,we developed a penetration model with a vacuum magnetic field region to accurately determine CT trajectories in tokamak discharges.This model was used to calculate the trajectory and penetration parameters of CT injections by applying both perpendicular and tangential injection schemes in both HL-2A and ITER tokamaks.For perpendicular injection along the tokamak's major radius direction from the outboard,CTs with the same injection parameters exhibited a 0.08 reduction in relative penetration depth when injected into HL-2A and a 0.13reduction when injected into ITER geometry when considering the vacuum magnetic field region compared with cases where this region was not considered.In addition,we proposed an optimization method for determining the CT's initial injection velocity to accurately calculate the initial injection velocity of CTs for central fueling in tokamaks.Furthermore,this paper discusses schemes for the tangential injection of CT into tokamak discharges.The optimal injection angle and CT magnetic moment direction for injection into both HL-2A and ITER were determined through numerical simulations.Finally,the kinetic energy loss occurring when the CT penetrated the vacuum magnetic field region in ITER was reduced byΔEk=975.08 J by optimizing the injection angle for the CT injected into ITER.These results provide valuable insights for optimizing injection angles in fusion experiments.Our model closely represents actual experimental scenarios and can assist the design of CT parameters.展开更多
A multi-channel polarimeter-interferometer has been developed on the Keda Torus eXperiment(KTX)for the study of equilibrium dynamics and internal magnetic fluctuations.A three-wave technique based on terahertz solid-s...A multi-channel polarimeter-interferometer has been developed on the Keda Torus eXperiment(KTX)for the study of equilibrium dynamics and internal magnetic fluctuations.A three-wave technique based on terahertz solid-state sources(-650 GHz)is applied for simultaneous measurements of electron density and Faraday rotation angle.The output power of the microwave source is 2 mW.Faraday rotation effect using a rotating wave plate is tested with phase noise less than 0.8°,and the density phase noise is less than 0.9°.Measurement of Faraday rotation angle and density for discharges on KTX have demonstrated high sensitivity to internal MHD activities.展开更多
Density limit has long been a widely studied issue influencing the operating range of tokamaks.The rapid growth of the m/n=2/1(where m and n are poloidal and toroidal mode numbers,respectively)tearing mode is generall...Density limit has long been a widely studied issue influencing the operating range of tokamaks.The rapid growth of the m/n=2/1(where m and n are poloidal and toroidal mode numbers,respectively)tearing mode is generally regarded as a primary precursor to the density limit disruption.In this experiment,the coupling of the m/n=1/1 mode and the m/n=2/1 mode in highdensity plasma was observed.During a sawtooth cycle,the frequencies of the two modes gradually converge until they become equal.After that,toroidal coupling occurs between the 1/1 and 2/1 modes,resulting in a mutually fixed phase relationship.With the occurrence of toroidal coupling,the 2/1 mode is stabilized.Prior to the disruption,the cessation of the 1/1 and 2/1 mode coupling,along with the rapid growth in the amplitude of the 2/1 mode,can be observed.Additionally,under the same parameters,comparing discharges with or without the 1/1 mode,it is found that the presence of the 1/1 mode leads to higher plasma density and temperature parameters.展开更多
This paper analyzes the progress of handwritten Chinese character recognition technology,from two perspectives:traditional recognition methods and deep learning-based recognition methods.Firstly,the complexity of Chin...This paper analyzes the progress of handwritten Chinese character recognition technology,from two perspectives:traditional recognition methods and deep learning-based recognition methods.Firstly,the complexity of Chinese character recognition is pointed out,including its numerous categories,complex structure,and the problem of similar characters,especially the variability of handwritten Chinese characters.Subsequently,recognition methods based on feature optimization,model optimization,and fusion techniques are highlighted.The fusion studies between feature optimization and model improvement are further explored,and these studies further enhance the recognition effect through complementary advantages.Finally,the article summarizes the current challenges of Chinese character recognition technology,including accuracy improvement,model complexity,and real-time problems,and looks forward to future research directions.展开更多
Energetic molecular perovskites have attracted widespread attention in the fields of energy materials due to their high detonation performance.In this work,we reported the effect of MgCo_(2)O_(4) nanosheets on the the...Energetic molecular perovskites have attracted widespread attention in the fields of energy materials due to their high detonation performance.In this work,we reported the effect of MgCo_(2)O_(4) nanosheets on the thermal decomposition of ammonium perchlorate(NH_(4)ClO_(4),AP)-based energetic molecular perovskites(AP-based energetic molecular perovskites).The morphology and structure of the MgCo_(2)O_(4) nanosheets were characterized.And their catalytic effect on the thermal decomposition of AP-based energetic molecular perovskites(H_2pz)[NH_(4)(ClO_(4))_(3)](PAP-4),(H_2dabco)[NH_(4)(ClO_(4))_(3)](DAP-4),(H_2mpz)[NH_(4)(ClO_(4))_(3)](PAP-M_(4)),and (H_2hpz)[NH_(4)(ClO_(4))_(3)](PAP-H_(4)) was analyzed.The results showed that MgCo_(2)O_(4) nanosheets had excellent intrinsically catalytic performance towards enhancing the thermal decomposition of AP-based energetic molecular perovskites.After adding MgCo_(2)O_(4) nanosheets,the thermal decomposition peak temperatures of PAP-4,DAP-4,PAP-M_(4),and PAP-H_(4) had been reduced by35.7℃,48.4℃,37.9℃,and 43.6℃,respectively.And the activation energy(Ea)of the thermal decomposition of AP-based energetic molecular perovskites had been reduced,the Eaof PAP-H_(4) decreased by 46.4 kJ/mol at most among them.The catalytic mechanism of MgCo_(2)O_(4) nanosheets for AP-based energetic molecular perovskites is analyzed.This work provides a reference for the future application of AP-based energetic molecular perovskites.展开更多
Combined with the oxidizer anions and fuel cations,molecular perovskite energetic materials show a good potential.In this work,the combustion behavior and mechanism of metal fuel aluminium(Al)with molecular perovskite...Combined with the oxidizer anions and fuel cations,molecular perovskite energetic materials show a good potential.In this work,the combustion behavior and mechanism of metal fuel aluminium(Al)with molecular perovskite energetic material(H_(2)dabco)[NH4(ClO_(4))_(3)](DAP-4)as a high-energy oxidant was investigated.The DAP-4 based composites with metal fuel Al were designed and fabricated by the different mass ratios.Results showed that DAP-4 exhibits a good oxygen-supplied capacity for enhancing the combustion performance of Al.The maximum combustion heat of DAP-4/Al-3 at the Al/O mass ratio of 38:62 is up to 10,412 J/g in the inert gas,which is higher than those of other ratios and the mixtures of other energetic materials and Al.The evolution of pressure output,pressurization rate,and flame temperature was monitored for DAP-4/Al with different mass ratios.Composites DAP-4/Al/F were characterized by burning rates.The combustion reaction mechanism of metal fuel Al with DAP-4 as a high-energy oxidant was provided.DAP-4 was ignited firstly and released acid and oxidizing gases,which corroded Al_(2)O_(3)shells on Al particle surfaces and accelerated the combustion reaction with Al to release a lot of energy.This work offered a new idea that molecular perovskite energetic materials have great potential in the high-energy Al-based solid rocket propellants.展开更多
BACKGROUND Gastric cancer(GC)is a prevalent malignancy,leading to a high incidence of cancer-associated death.Cisplatin(DDP)-based chemotherapy is the principal therapy for clinical GC treatment,but DDP resistance is ...BACKGROUND Gastric cancer(GC)is a prevalent malignancy,leading to a high incidence of cancer-associated death.Cisplatin(DDP)-based chemotherapy is the principal therapy for clinical GC treatment,but DDP resistance is a severe clinical challenge and the mechanism remains poorly understood.Circular RNAs(circRNAs)have been identified to play crucial roles in modulating the chemoresistance of gastric cancer cells.AIM To explore the effect of circVAPA on chemotherapy resistance during GC progression.METHODS The effect of circVAPA on GC progression and chemotherapy resistance was analyzed by MTT assay,colony formation assay,Transwell assay,wound healing assay,and flow cytometry analysis in GC cells and DDP resistant GC cell lines,and tumorigenicity analysis in nude mice in vivo.The mechanism was investigated by luciferase reporter assay,quantitative real-time PCR,and Western blot analysis.RESULTS CircVAPA expression was up-regulated in clinical GC tissues compared with normal samples.CircVAPA depletion inhibited proliferation,migration,and invasion and increased apoptosis of GC cells.The expression of circVAPA,STAT3,and STAT3 downstream genes was elevated in DDP resistant SGC7901/DDP cell lines.CircVAPA knockdown attenuated the DDP resistance of GC cells.Mechanically,circVAPA was able to sponge miR-125b-5p,and miR-125b-5p could target STAT3 in the GC cells.MiR-125b-5p inhibitor reversed circVAPA depletion-enhanced inhibitory effect of DDP on GC cells,and STAT3 knockdown blocked circVAPA overexpression-induced proliferation of DDPtreated SGC7901/DDP cells.The depletion of STAT3 and miR-125b-5p inhibitor reversed circVAPA depletion-induced GC cell apoptosis.Functionally,circVAPA contributed to the tumor growth of SGC7901/DDP cells in vivo.CONCLUSION CircVAPA promotes chemotherapy resistance and malignant progression in GC by miR-125b-5p/STAT3 signaling.Our findings present novel insights into the mechanism by which circVAPA regulates chemotherapy resistance of GC cells.CircVAPA and miR-125b-5p may be considered as the potential targets for GC therapy.展开更多
Mesenchymal stem cells (MSCs) are characterized by their self-renewing capacity and differentiation potential into multiple tissues. Thus, management of the differentiation capacities of MSCs is important for MSC-ba...Mesenchymal stem cells (MSCs) are characterized by their self-renewing capacity and differentiation potential into multiple tissues. Thus, management of the differentiation capacities of MSCs is important for MSC-based regenerative medicine, such as craniofacial bone regeneration, and in new treatments for metabolic bone diseases, such as osteoporosis. In recent years, histone modification has been a growing topic in the field of MSC lineage specification, in which the Su(var)3-9, enhancer-of-zeste, trithorax (SET) domain-containing family and the Jumonji C (JmjC) domain-containing family represent the major histone lysine methyltransferases (KMTs) and histone lysine demethylases (KDMs), respectively. In this review, we summarize the current understanding of the epigenetic mechanisms by which SET domain-containine KMTs and JmiC domain-containinlz KDMs balance the osteogenic and adipogenic differentiation of MSCs.展开更多
BACKGROUND The Borrmann classification system is used to describe the macroscopic appearance of advanced gastric cancer,and Borrmann typeⅣdisease is independently associated with a poor prognosis.AIM To evaluate the ...BACKGROUND The Borrmann classification system is used to describe the macroscopic appearance of advanced gastric cancer,and Borrmann typeⅣdisease is independently associated with a poor prognosis.AIM To evaluate the prognostic significance of lymphatic and/or blood vessel invasion(LBVI)combined with the Borrmann type in advanced proximal gastric cancer(APGC).METHODS The clinicopathological and survival data of 440 patients with APGC who underwent curative surgery between 2005 and 2012 were retrospectively analyzed.RESULTS In these 440 patients,LBVI+status was associated with Borrmann typeⅣ,low histological grade,large tumor size,and advanced pT and pN status.The 5-year survival rate of LBVI+patients was significantly lower than that of LBVI– patients,although LBVI was not an independent prognostic factor in the multivariate analysis.No significant difference in the prognosis of patients with Borrmann typeⅢ/LBVI+disease and patients with Borrmann typeⅣdisease was observed.Therefore,we proposed a revised Borrmann typeⅣ(r-BorⅣ)as Borrmann typeⅢplus LBVI+,and found that r-BorⅣwas associated with poor prognosis in patients with APGC,which outweighed the prognostic significance of pT status.CONCLUSION LBVI is related to the prognosis of APGC,but is not an independent prognostic factor.LBVI status can be used to differentiate Borrmann typesⅢandⅣ,and the same approach can be used to treat r-BorⅣand Borrmann typeⅣ.展开更多
The lineage specification of mesenchymal stem/stromal cells(MSCs) is tightly regulated by a wide range of factors. Recently, the versatile functions of ZBP1(also known as DAI or DLM-1) have been reported in the blood ...The lineage specification of mesenchymal stem/stromal cells(MSCs) is tightly regulated by a wide range of factors. Recently, the versatile functions of ZBP1(also known as DAI or DLM-1) have been reported in the blood circulation and immune systems.However, the biological function of ZBP1 during the lineage specification of MSCs is still unknown. In the present study, we found that ZBP1 was upregulated during osteogenesis but downregulated during adipogenesis in mouse bone marrow-derived MSCs(m BMSCs). ZBP1 was highly expressed in osteoblasts but expressed at a relatively low level in marrow adipocytes. Knockdown of ZBP1 inhibited alkaline phosphataseactivity, extracellular matrix mineralization, and osteogenesis-related gene expression in vitro and reduced ectopic bone formation in vivo. Knockdown of ZBP1 also promoted adipogenesis in MSCs in vitro. Conversely, the overexpression of ZBP1 increased the osteogenesis but suppressed the adipogenesis of MSCs. When the expression of ZBP1 was rescued, the osteogenic capacity of ZBP1-depleted m BMSCs was restored at both the molecular and phenotypic levels.Furthermore, we demonstrated that ZBP1, a newly identified target of Wnt/β-catenin signaling, was required for β-catenin translocation into nuclei. Collectively, our results indicate that ZBP1 is a novel regulator of bone and fat transdifferentiation via Wnt/β-catenin signaling.展开更多
AFF1 and AFF4 belong to the AFF (AF4/FMR2) family of proteins, which function as scaffolding proteins linking two different transcription elongation factors, positive elongation factor b (P-TEFb) and ELL1/2, in su...AFF1 and AFF4 belong to the AFF (AF4/FMR2) family of proteins, which function as scaffolding proteins linking two different transcription elongation factors, positive elongation factor b (P-TEFb) and ELL1/2, in super elongation complexes (SECs). Both AFF1 and AFF4 regulate gene transcription through elongation and chromatln remodeling. However, their function in the osteogenic differentiation of mesenchymal stem cells (MSCs) is unknown. In this study, we show that small interfering RNA (siRNA)-mediated depletion of AFF1 in human MSCs leads to increased alkaline phosphatase (ALP) activity, enhanced mineralization and upregulated expression of osteogenic-related genes. On the contrary, depletion of AFF4 significantly inhibits the osteogenic potential of MSCs. In addition, we confirm that overexpression of AFF1 and AFF4 differentially affects osteogenic differentiation in vitro and MSC-mediated bone formation in vivo. Mechanistically, we find that AFFI regulates the expression of DKK1 via binding to its promoter region. Depletion of DKK1 in HA-AFFl-overexpressing MSCs abrogates the impairment of osteogenic differentiation. Moreover, we detect that AFF4 is enriched in the promoter region of ID1. AFF4 knockdown blunts the BRE luciferase activity, SP7 expression and ALP activity induced by BMP2 treatment. In conclusion, our data indicate that AFF1 and AFF4 differentially regulate the osteogenic differentiation of human MSCs.AFF1 and AFF4 belong to the AFF (AF4/FMR2) family of proteins, which function as scaffolding proteins linking two different transcription elongation factors, positive elongation factor b (P-TEFb) and ELL1/2, in super elongation complexes (SECs). Both AFFI and AFF4 regulate gene transcription through elongation and chromatln remodeling. However, their function in the osteogenic differentiation of mesenchymal stem cells (MSCs) is unknown. In this study, we show that small interfering RNA (siRNA)-mediated depletion of AFF1 in human MSCs leads to increased alkaline phosphatase (ALP) activity, enhanced mineralization and upregulated expression of osteogenic-related genes. On the contrary, depletion of AFF4 significantly inhibits the osteogenic potential of MSCs. In addition, we confirm that overexpression of AFF1 and AFF4 differentially affects osteogenic differentiation in vitro and MSC-mediated bone formation in vivo. Mechanistically, we find that AFFI regulates the expression of DKK1 via binding to its promoter region. Depletion of DKK1 in HA-AFFl-overexpressing MSCs abrogates the impairment of osteogenic differentiation. Moreover, we detect that AFF4 is enriched in the promoter region of ID1. AFF4 knockdown blunts the BRE luciferase activity, SP7 expression and ALP activity induced by BMP2 treatment. In conclusion, our data indicate that AFF1 and AFF4 differentially regulate the osteogenic differentiation of human MSCs.展开更多
BACKGROUND Endometriosis (EMs) is a chronic and recurrent,but benign,disease in women of reproductive age,and EMs patients have a high risk of developing gynecological tumors and autoimmune disorders.The etiology of E...BACKGROUND Endometriosis (EMs) is a chronic and recurrent,but benign,disease in women of reproductive age,and EMs patients have a high risk of developing gynecological tumors and autoimmune disorders.The etiology of EMs is not clear.Certain genetic markers in the eutopic endometrium are key in the pathogenesis of EMs.MicroRNAs (miRNAs) are implicated in several biological processes,such as cell proliferation,differentiation,and apoptosis.MiR-451 is interesting,as it acts as a tumor suppressor and is relevant to the poor prognosis of cancers.AIM To evaluate the expression levels and role of miR-451 in the eutopic endometrium and predict possible targets of miR-451 and related signaling pathways.METHODS Quantitative real-time polymerase chain reaction was used to evaluate miR-451 expression in cultured cell lines as well as in pathologic tissues from 40 patients with EMs and 20 donors with no history of the disease (controls).Cell Counting Kit-8 and flow cytometric assays were performed to determine cell proliferation and survival rates after transfection with miR-451 mimics and siRNAs.MiR-451 targets were predicted using miRDB and miRcode target-predicting databases.RESULTS We observed lower miR-451 levels in eutopic endometrial tissues from patients with EMs than in control tissues,and this difference was not related to the American Society for Reproductive Medicine stage.Ectopic overexpression of miR-451 in eutopic cells induced apoptosis and inhibited cell proliferation.SiRNA-mediated miR-451 knockdown reversed these effects.Using miRDB and miRcode,we identified 12 potential miR-451 target genes.We hypothesize that the expression of YWHAZ,OSR1,TTN,and CDKN2D may be regulated by miR- 451 and be involved in disease pathogenesis.CONCLUSION Reduced miR-451 expression in the eutopic endometrium contributes to the pathogenesis of EMs by promoting cell proliferation and reducing apoptosis.Thus,miR-451 is a novel biomarker for EMs.YWHAZ,OSR1,TTN,and CDKN2D are potential target genes of miR-451 and may have key roles in this disease.展开更多
Osteoporosis is a highly prevalent public health burden associated with an increased risk of bone fracture, particularly in aging women. Estrogen, an important medicinal component for the preventative and therapeutic ...Osteoporosis is a highly prevalent public health burden associated with an increased risk of bone fracture, particularly in aging women. Estrogen, an important medicinal component for the preventative and therapeutic treatment of postmenopausal osteoporosis, induces osteogenesis by activating the estrogen receptor signaling pathway and upregulating the expression of osteogenic genes, such as bone morphogenetic proteins(BMPs). The epigenetic regulation of estrogen-mediated osteogenesis,however, is still unclear. In this report, we found that estrogen significantly induced the expression of lysine-specific demethylase 6B(KDM6B) and that KDM6B depletion by shRNAs led to a significant reduction in the osteogenic potential of DMSCs.Mechanistically, upon estrogen stimulation, estrogen receptor-α(ERα) was recruited to the KDM6B promoter, directly enhancing KDM6B expression. Subsequently, KDM6B was recruited to the BMP2 and HOXC6 promoters, resulting in the removal of H3K27me3 marks and activating the transcription of BMP2 and HOXC6, the master genes of osteogenic differentiation. Furthermore, we found that estrogen enhanced DMSC osteogenesis during calvarial bone regeneration and that estrogen’s pro-osteogenic effect was dependent on KDM6B in vivo. Taken together, our results demonstrate the vital role of the ERα/KDM6B regulatory axis in the epigenetic regulation of the estrogen-dependent osteogenic response.展开更多
The discreteness is a common deficiency which impedes damage indices' practical application. It is caused by the arbitrary linear combination and some missing necessary variables. In order to deal with this proble...The discreteness is a common deficiency which impedes damage indices' practical application. It is caused by the arbitrary linear combination and some missing necessary variables. In order to deal with this problem,the correction term was added to the widely cited Park-Ang damage index. The unknown parameters in the correction term were obtained by the maximum likelihood estimation of these parameters' posterior distributions updated through Bayesian methodology. And the specimens for Bayesian updating were selected from PEER column database and Kawashima Earthquake Engineering Laboratory. Through model simplification process,a simplified modification was adopted,which has improved its goodness of fit to the experimental data. It has been found that the concrete core area and cross sectional area ratio,the longitudinal reinforcement ratio and the damage concentration factor are the critical variables affecting the error of the original damage index.展开更多
基金National Natural Science Foundation of China(Grant No.21975227)the Found of National defence Science and Technology Key Laboratory (Grant No.6142602210306)。
文摘Fe/N-based biomass porous carbon composite(Fe/N-p Carbon) was prepared by a facile high-temperature carbonization method from biomass,and the effect of Fe/N-p Carbon on the thermal decomposition of energetic molecular perovskite-based material DAP-4 was studied.Biomass porous carbonaceous materials was considered as the micro/nano support layers for in situ deposition of Fe/N precursors.Fe/Np Carbon was prepared simply by the high-temperature carbonization method.It was found that it showed the inherent catalysis properties for thermal decomposition of DAP-4.The heat release of DAP-4/Fe/N-p Carbon by DSC curves tested had increased slightly,compared from DAP-4/Fe/N-p Carbon-0.The decomposition temperature peak of DAP-4 at the presence of Fe/N-p Carbon had reduced by 79°C from384.4°C(pure DAP-4) to 305.4°C(DAP-4/Fe/N-p Carbon-3).The apparent activation energy of DAP-4thermal decomposition also had decreased by 29.1 J/mol.The possible catalytic decomposition mechanism of DAP-4 with Fe/N-p Carbon was proposed.
基金supported by National Natural Science Foundation of China(Nos.12175227 and 12375226)the National Magnetic Confinement Fusion Program of China(No.2022YFE03100004)+1 种基金the Fundamental Research Funds for the Central Universities(No.USTC 20210079)the Collaborative Innovation Program of Hefei Science Center,CAS(No.2022HSC-CIP022)。
文摘In the reversed field pinch(RFP),plasmas exhibit various self-organized states.Among these,the three-dimensional(3D)helical state known as the“quasi-single-helical”(QSH)state enhances RFP confinement.However,accurately describing the equilibrium is challenging due to the presence of 3D structures,magnetic islands,and chaotic regions.It is difficult to obtain a balance between the available diagnostic and the real equilibrium structure.To address this issue,we introduce KTX3DFit,a new 3D equilibrium reconstruction code specifically designed for the Keda Torus eXperiment(KTX)RFP.KTX3DFit utilizes the stepped-pressure equilibrium code(SPEC)to compute 3D equilibria and uses polarimetric interferometer signals from experiments.KTX3DFit is able to reconstruct equilibria in various states,including axisymmetric,doubleaxis helical(DAx),and single-helical-axis(SHAx)states.Notably,this study marks the first integration of the SPEC code with internal magnetic field data for equilibrium reconstruction and could be used for other 3D configurations.
基金supported by the National Magnetic Confinement Fusion Science Program of China(Nos.2022YFE03100004 and 2022YFE03060003)National Natural Science Foundation of China(Nos.12375226,12175227 and 11875255)the China Postdoctoral Science Foundation(No.2022M723066).
文摘The trajectory of the compact torus(CT)within a tokamak discharge is crucial to fueling.In this study,we developed a penetration model with a vacuum magnetic field region to accurately determine CT trajectories in tokamak discharges.This model was used to calculate the trajectory and penetration parameters of CT injections by applying both perpendicular and tangential injection schemes in both HL-2A and ITER tokamaks.For perpendicular injection along the tokamak's major radius direction from the outboard,CTs with the same injection parameters exhibited a 0.08 reduction in relative penetration depth when injected into HL-2A and a 0.13reduction when injected into ITER geometry when considering the vacuum magnetic field region compared with cases where this region was not considered.In addition,we proposed an optimization method for determining the CT's initial injection velocity to accurately calculate the initial injection velocity of CTs for central fueling in tokamaks.Furthermore,this paper discusses schemes for the tangential injection of CT into tokamak discharges.The optimal injection angle and CT magnetic moment direction for injection into both HL-2A and ITER were determined through numerical simulations.Finally,the kinetic energy loss occurring when the CT penetrated the vacuum magnetic field region in ITER was reduced byΔEk=975.08 J by optimizing the injection angle for the CT injected into ITER.These results provide valuable insights for optimizing injection angles in fusion experiments.Our model closely represents actual experimental scenarios and can assist the design of CT parameters.
基金supported by National Natural Science Foundation of China(No.12175227)the Fundamental Research Funds for the Central Universities(No.USTC 20210079)the Collaborative Innovation Program of Hefei Science Center,CAS(No.2022HSC-CIP022)。
文摘A multi-channel polarimeter-interferometer has been developed on the Keda Torus eXperiment(KTX)for the study of equilibrium dynamics and internal magnetic fluctuations.A three-wave technique based on terahertz solid-state sources(-650 GHz)is applied for simultaneous measurements of electron density and Faraday rotation angle.The output power of the microwave source is 2 mW.Faraday rotation effect using a rotating wave plate is tested with phase noise less than 0.8°,and the density phase noise is less than 0.9°.Measurement of Faraday rotation angle and density for discharges on KTX have demonstrated high sensitivity to internal MHD activities.
基金supported by National Natural Science Foundation of China(Nos.12175227 and 51821005)the Fundamental Research Funds for the Central Universities(No.USTC 20210079)the Collaborative Innovation Program of Hefei Science Center,CAS(No.2022HSC-CIP022)。
文摘Density limit has long been a widely studied issue influencing the operating range of tokamaks.The rapid growth of the m/n=2/1(where m and n are poloidal and toroidal mode numbers,respectively)tearing mode is generally regarded as a primary precursor to the density limit disruption.In this experiment,the coupling of the m/n=1/1 mode and the m/n=2/1 mode in highdensity plasma was observed.During a sawtooth cycle,the frequencies of the two modes gradually converge until they become equal.After that,toroidal coupling occurs between the 1/1 and 2/1 modes,resulting in a mutually fixed phase relationship.With the occurrence of toroidal coupling,the 2/1 mode is stabilized.Prior to the disruption,the cessation of the 1/1 and 2/1 mode coupling,along with the rapid growth in the amplitude of the 2/1 mode,can be observed.Additionally,under the same parameters,comparing discharges with or without the 1/1 mode,it is found that the presence of the 1/1 mode leads to higher plasma density and temperature parameters.
文摘This paper analyzes the progress of handwritten Chinese character recognition technology,from two perspectives:traditional recognition methods and deep learning-based recognition methods.Firstly,the complexity of Chinese character recognition is pointed out,including its numerous categories,complex structure,and the problem of similar characters,especially the variability of handwritten Chinese characters.Subsequently,recognition methods based on feature optimization,model optimization,and fusion techniques are highlighted.The fusion studies between feature optimization and model improvement are further explored,and these studies further enhance the recognition effect through complementary advantages.Finally,the article summarizes the current challenges of Chinese character recognition technology,including accuracy improvement,model complexity,and real-time problems,and looks forward to future research directions.
基金the National Natural Science Foundation of China(Grant No.21975227)the Found of National defence Sci&Tech Laboratory(Grant No.6142602210306)。
文摘Energetic molecular perovskites have attracted widespread attention in the fields of energy materials due to their high detonation performance.In this work,we reported the effect of MgCo_(2)O_(4) nanosheets on the thermal decomposition of ammonium perchlorate(NH_(4)ClO_(4),AP)-based energetic molecular perovskites(AP-based energetic molecular perovskites).The morphology and structure of the MgCo_(2)O_(4) nanosheets were characterized.And their catalytic effect on the thermal decomposition of AP-based energetic molecular perovskites(H_2pz)[NH_(4)(ClO_(4))_(3)](PAP-4),(H_2dabco)[NH_(4)(ClO_(4))_(3)](DAP-4),(H_2mpz)[NH_(4)(ClO_(4))_(3)](PAP-M_(4)),and (H_2hpz)[NH_(4)(ClO_(4))_(3)](PAP-H_(4)) was analyzed.The results showed that MgCo_(2)O_(4) nanosheets had excellent intrinsically catalytic performance towards enhancing the thermal decomposition of AP-based energetic molecular perovskites.After adding MgCo_(2)O_(4) nanosheets,the thermal decomposition peak temperatures of PAP-4,DAP-4,PAP-M_(4),and PAP-H_(4) had been reduced by35.7℃,48.4℃,37.9℃,and 43.6℃,respectively.And the activation energy(Ea)of the thermal decomposition of AP-based energetic molecular perovskites had been reduced,the Eaof PAP-H_(4) decreased by 46.4 kJ/mol at most among them.The catalytic mechanism of MgCo_(2)O_(4) nanosheets for AP-based energetic molecular perovskites is analyzed.This work provides a reference for the future application of AP-based energetic molecular perovskites.
基金National Natural Science Foundation of China(Grant No.22175026,21975227,11902300)the Foundation of National Key Laboratory of Defense Science and Technology(Grant No.6142602210306)State Key Laboratory of Explosion Science and Technology(No.QNKT20-07)for the support。
文摘Combined with the oxidizer anions and fuel cations,molecular perovskite energetic materials show a good potential.In this work,the combustion behavior and mechanism of metal fuel aluminium(Al)with molecular perovskite energetic material(H_(2)dabco)[NH4(ClO_(4))_(3)](DAP-4)as a high-energy oxidant was investigated.The DAP-4 based composites with metal fuel Al were designed and fabricated by the different mass ratios.Results showed that DAP-4 exhibits a good oxygen-supplied capacity for enhancing the combustion performance of Al.The maximum combustion heat of DAP-4/Al-3 at the Al/O mass ratio of 38:62 is up to 10,412 J/g in the inert gas,which is higher than those of other ratios and the mixtures of other energetic materials and Al.The evolution of pressure output,pressurization rate,and flame temperature was monitored for DAP-4/Al with different mass ratios.Composites DAP-4/Al/F were characterized by burning rates.The combustion reaction mechanism of metal fuel Al with DAP-4 as a high-energy oxidant was provided.DAP-4 was ignited firstly and released acid and oxidizing gases,which corroded Al_(2)O_(3)shells on Al particle surfaces and accelerated the combustion reaction with Al to release a lot of energy.This work offered a new idea that molecular perovskite energetic materials have great potential in the high-energy Al-based solid rocket propellants.
基金Natural Science Foundation of Liaoning Province,No.2019-MS-385.
文摘BACKGROUND Gastric cancer(GC)is a prevalent malignancy,leading to a high incidence of cancer-associated death.Cisplatin(DDP)-based chemotherapy is the principal therapy for clinical GC treatment,but DDP resistance is a severe clinical challenge and the mechanism remains poorly understood.Circular RNAs(circRNAs)have been identified to play crucial roles in modulating the chemoresistance of gastric cancer cells.AIM To explore the effect of circVAPA on chemotherapy resistance during GC progression.METHODS The effect of circVAPA on GC progression and chemotherapy resistance was analyzed by MTT assay,colony formation assay,Transwell assay,wound healing assay,and flow cytometry analysis in GC cells and DDP resistant GC cell lines,and tumorigenicity analysis in nude mice in vivo.The mechanism was investigated by luciferase reporter assay,quantitative real-time PCR,and Western blot analysis.RESULTS CircVAPA expression was up-regulated in clinical GC tissues compared with normal samples.CircVAPA depletion inhibited proliferation,migration,and invasion and increased apoptosis of GC cells.The expression of circVAPA,STAT3,and STAT3 downstream genes was elevated in DDP resistant SGC7901/DDP cell lines.CircVAPA knockdown attenuated the DDP resistance of GC cells.Mechanically,circVAPA was able to sponge miR-125b-5p,and miR-125b-5p could target STAT3 in the GC cells.MiR-125b-5p inhibitor reversed circVAPA depletion-enhanced inhibitory effect of DDP on GC cells,and STAT3 knockdown blocked circVAPA overexpression-induced proliferation of DDPtreated SGC7901/DDP cells.The depletion of STAT3 and miR-125b-5p inhibitor reversed circVAPA depletion-induced GC cell apoptosis.Functionally,circVAPA contributed to the tumor growth of SGC7901/DDP cells in vivo.CONCLUSION CircVAPA promotes chemotherapy resistance and malignant progression in GC by miR-125b-5p/STAT3 signaling.Our findings present novel insights into the mechanism by which circVAPA regulates chemotherapy resistance of GC cells.CircVAPA and miR-125b-5p may be considered as the potential targets for GC therapy.
基金supported by the National Institute of Dental and Craniofacial Research grants, K08DE024603-02, DE019412, and DE01651a grant from 111 Project of MOE, Chinasupported by Open Fund of State Key Laboratory of Oral Diseases, Sichuan University
文摘Mesenchymal stem cells (MSCs) are characterized by their self-renewing capacity and differentiation potential into multiple tissues. Thus, management of the differentiation capacities of MSCs is important for MSC-based regenerative medicine, such as craniofacial bone regeneration, and in new treatments for metabolic bone diseases, such as osteoporosis. In recent years, histone modification has been a growing topic in the field of MSC lineage specification, in which the Su(var)3-9, enhancer-of-zeste, trithorax (SET) domain-containing family and the Jumonji C (JmjC) domain-containing family represent the major histone lysine methyltransferases (KMTs) and histone lysine demethylases (KDMs), respectively. In this review, we summarize the current understanding of the epigenetic mechanisms by which SET domain-containine KMTs and JmiC domain-containinlz KDMs balance the osteogenic and adipogenic differentiation of MSCs.
基金Supported by the Foundation of Innovative Talents in Higher Education of Liaoning Province,No.LR2016043
文摘BACKGROUND The Borrmann classification system is used to describe the macroscopic appearance of advanced gastric cancer,and Borrmann typeⅣdisease is independently associated with a poor prognosis.AIM To evaluate the prognostic significance of lymphatic and/or blood vessel invasion(LBVI)combined with the Borrmann type in advanced proximal gastric cancer(APGC).METHODS The clinicopathological and survival data of 440 patients with APGC who underwent curative surgery between 2005 and 2012 were retrospectively analyzed.RESULTS In these 440 patients,LBVI+status was associated with Borrmann typeⅣ,low histological grade,large tumor size,and advanced pT and pN status.The 5-year survival rate of LBVI+patients was significantly lower than that of LBVI– patients,although LBVI was not an independent prognostic factor in the multivariate analysis.No significant difference in the prognosis of patients with Borrmann typeⅢ/LBVI+disease and patients with Borrmann typeⅣdisease was observed.Therefore,we proposed a revised Borrmann typeⅣ(r-BorⅣ)as Borrmann typeⅢplus LBVI+,and found that r-BorⅣwas associated with poor prognosis in patients with APGC,which outweighed the prognostic significance of pT status.CONCLUSION LBVI is related to the prognosis of APGC,but is not an independent prognostic factor.LBVI status can be used to differentiate Borrmann typesⅢandⅣ,and the same approach can be used to treat r-BorⅣand Borrmann typeⅣ.
基金supported by the Foundation of the National Natural Science Foundation of China (No. 81671024, 81371171, 81571009, and 81600877)the China Postdoctoral Science Foundation (2016M600745)。
文摘The lineage specification of mesenchymal stem/stromal cells(MSCs) is tightly regulated by a wide range of factors. Recently, the versatile functions of ZBP1(also known as DAI or DLM-1) have been reported in the blood circulation and immune systems.However, the biological function of ZBP1 during the lineage specification of MSCs is still unknown. In the present study, we found that ZBP1 was upregulated during osteogenesis but downregulated during adipogenesis in mouse bone marrow-derived MSCs(m BMSCs). ZBP1 was highly expressed in osteoblasts but expressed at a relatively low level in marrow adipocytes. Knockdown of ZBP1 inhibited alkaline phosphataseactivity, extracellular matrix mineralization, and osteogenesis-related gene expression in vitro and reduced ectopic bone formation in vivo. Knockdown of ZBP1 also promoted adipogenesis in MSCs in vitro. Conversely, the overexpression of ZBP1 increased the osteogenesis but suppressed the adipogenesis of MSCs. When the expression of ZBP1 was rescued, the osteogenic capacity of ZBP1-depleted m BMSCs was restored at both the molecular and phenotypic levels.Furthermore, we demonstrated that ZBP1, a newly identified target of Wnt/β-catenin signaling, was required for β-catenin translocation into nuclei. Collectively, our results indicate that ZBP1 is a novel regulator of bone and fat transdifferentiation via Wnt/β-catenin signaling.
基金supported by grants from the National Natural Science Foundation of China(NSFC,81722014,81571001,81500354,and 81621062)Sichuan Province Science and Technology Innovation Team Program(2017TD0016)State Key Laboratory of Oral Diseases(SKLOD201704)
文摘AFF1 and AFF4 belong to the AFF (AF4/FMR2) family of proteins, which function as scaffolding proteins linking two different transcription elongation factors, positive elongation factor b (P-TEFb) and ELL1/2, in super elongation complexes (SECs). Both AFF1 and AFF4 regulate gene transcription through elongation and chromatln remodeling. However, their function in the osteogenic differentiation of mesenchymal stem cells (MSCs) is unknown. In this study, we show that small interfering RNA (siRNA)-mediated depletion of AFF1 in human MSCs leads to increased alkaline phosphatase (ALP) activity, enhanced mineralization and upregulated expression of osteogenic-related genes. On the contrary, depletion of AFF4 significantly inhibits the osteogenic potential of MSCs. In addition, we confirm that overexpression of AFF1 and AFF4 differentially affects osteogenic differentiation in vitro and MSC-mediated bone formation in vivo. Mechanistically, we find that AFFI regulates the expression of DKK1 via binding to its promoter region. Depletion of DKK1 in HA-AFFl-overexpressing MSCs abrogates the impairment of osteogenic differentiation. Moreover, we detect that AFF4 is enriched in the promoter region of ID1. AFF4 knockdown blunts the BRE luciferase activity, SP7 expression and ALP activity induced by BMP2 treatment. In conclusion, our data indicate that AFF1 and AFF4 differentially regulate the osteogenic differentiation of human MSCs.AFF1 and AFF4 belong to the AFF (AF4/FMR2) family of proteins, which function as scaffolding proteins linking two different transcription elongation factors, positive elongation factor b (P-TEFb) and ELL1/2, in super elongation complexes (SECs). Both AFFI and AFF4 regulate gene transcription through elongation and chromatln remodeling. However, their function in the osteogenic differentiation of mesenchymal stem cells (MSCs) is unknown. In this study, we show that small interfering RNA (siRNA)-mediated depletion of AFF1 in human MSCs leads to increased alkaline phosphatase (ALP) activity, enhanced mineralization and upregulated expression of osteogenic-related genes. On the contrary, depletion of AFF4 significantly inhibits the osteogenic potential of MSCs. In addition, we confirm that overexpression of AFF1 and AFF4 differentially affects osteogenic differentiation in vitro and MSC-mediated bone formation in vivo. Mechanistically, we find that AFFI regulates the expression of DKK1 via binding to its promoter region. Depletion of DKK1 in HA-AFFl-overexpressing MSCs abrogates the impairment of osteogenic differentiation. Moreover, we detect that AFF4 is enriched in the promoter region of ID1. AFF4 knockdown blunts the BRE luciferase activity, SP7 expression and ALP activity induced by BMP2 treatment. In conclusion, our data indicate that AFF1 and AFF4 differentially regulate the osteogenic differentiation of human MSCs.
文摘BACKGROUND Endometriosis (EMs) is a chronic and recurrent,but benign,disease in women of reproductive age,and EMs patients have a high risk of developing gynecological tumors and autoimmune disorders.The etiology of EMs is not clear.Certain genetic markers in the eutopic endometrium are key in the pathogenesis of EMs.MicroRNAs (miRNAs) are implicated in several biological processes,such as cell proliferation,differentiation,and apoptosis.MiR-451 is interesting,as it acts as a tumor suppressor and is relevant to the poor prognosis of cancers.AIM To evaluate the expression levels and role of miR-451 in the eutopic endometrium and predict possible targets of miR-451 and related signaling pathways.METHODS Quantitative real-time polymerase chain reaction was used to evaluate miR-451 expression in cultured cell lines as well as in pathologic tissues from 40 patients with EMs and 20 donors with no history of the disease (controls).Cell Counting Kit-8 and flow cytometric assays were performed to determine cell proliferation and survival rates after transfection with miR-451 mimics and siRNAs.MiR-451 targets were predicted using miRDB and miRcode target-predicting databases.RESULTS We observed lower miR-451 levels in eutopic endometrial tissues from patients with EMs than in control tissues,and this difference was not related to the American Society for Reproductive Medicine stage.Ectopic overexpression of miR-451 in eutopic cells induced apoptosis and inhibited cell proliferation.SiRNA-mediated miR-451 knockdown reversed these effects.Using miRDB and miRcode,we identified 12 potential miR-451 target genes.We hypothesize that the expression of YWHAZ,OSR1,TTN,and CDKN2D may be regulated by miR- 451 and be involved in disease pathogenesis.CONCLUSION Reduced miR-451 expression in the eutopic endometrium contributes to the pathogenesis of EMs by promoting cell proliferation and reducing apoptosis.Thus,miR-451 is a novel biomarker for EMs.YWHAZ,OSR1,TTN,and CDKN2D are potential target genes of miR-451 and may have key roles in this disease.
基金supported by NIH/NIDCR grants K08DE024603, R01DE16513, and R01DE024828
文摘Osteoporosis is a highly prevalent public health burden associated with an increased risk of bone fracture, particularly in aging women. Estrogen, an important medicinal component for the preventative and therapeutic treatment of postmenopausal osteoporosis, induces osteogenesis by activating the estrogen receptor signaling pathway and upregulating the expression of osteogenic genes, such as bone morphogenetic proteins(BMPs). The epigenetic regulation of estrogen-mediated osteogenesis,however, is still unclear. In this report, we found that estrogen significantly induced the expression of lysine-specific demethylase 6B(KDM6B) and that KDM6B depletion by shRNAs led to a significant reduction in the osteogenic potential of DMSCs.Mechanistically, upon estrogen stimulation, estrogen receptor-α(ERα) was recruited to the KDM6B promoter, directly enhancing KDM6B expression. Subsequently, KDM6B was recruited to the BMP2 and HOXC6 promoters, resulting in the removal of H3K27me3 marks and activating the transcription of BMP2 and HOXC6, the master genes of osteogenic differentiation. Furthermore, we found that estrogen enhanced DMSC osteogenesis during calvarial bone regeneration and that estrogen’s pro-osteogenic effect was dependent on KDM6B in vivo. Taken together, our results demonstrate the vital role of the ERα/KDM6B regulatory axis in the epigenetic regulation of the estrogen-dependent osteogenic response.
基金Sponsored by the National Science and Technology Support Project of China(Grant No.2012BAK15B02)
文摘The discreteness is a common deficiency which impedes damage indices' practical application. It is caused by the arbitrary linear combination and some missing necessary variables. In order to deal with this problem,the correction term was added to the widely cited Park-Ang damage index. The unknown parameters in the correction term were obtained by the maximum likelihood estimation of these parameters' posterior distributions updated through Bayesian methodology. And the specimens for Bayesian updating were selected from PEER column database and Kawashima Earthquake Engineering Laboratory. Through model simplification process,a simplified modification was adopted,which has improved its goodness of fit to the experimental data. It has been found that the concrete core area and cross sectional area ratio,the longitudinal reinforcement ratio and the damage concentration factor are the critical variables affecting the error of the original damage index.