Valleytronics materials are a kind of special semiconductors which can host multiple symmetry-connected and wellseparated electron or hole pockets in the Brillouin zone when the system is slightly n or p doped. Since ...Valleytronics materials are a kind of special semiconductors which can host multiple symmetry-connected and wellseparated electron or hole pockets in the Brillouin zone when the system is slightly n or p doped. Since the low-energy particles residing in these pockets generally are not easily scattered to each other by small perturbations, they are endowed with an additional valley degree of freedom. Analogous to spin, the valley freedom can be used to process information,leading to the concept of valleytronics. The prerequisite for valleytronics is the generation of valley polarization. Thus,a focus in this field is achieving the electric generation of valley polarization, especially the static generation by the gate electric field alone. In this work, we briefly review the latest progress in this research direction, focusing on the concepts of the couplings between valley and layer, i.e., the valley–layer coupling which permits the gate-field control of the valley polarization, the couplings between valley, layer, and spin in magnetic systems, the physical properties, the novel designing schemes for electronic devices, and the material realizations of the gate-controlled valleytronics materials.展开更多
The thermal-elastic martensitic transformation from high-temperature Ni_(2)In-type hexagonal structure to low-temperature TiNiSi-type orthorhombic structure has been widely studied in MnMX(M=Ni or Co,and X=Ge or Si)al...The thermal-elastic martensitic transformation from high-temperature Ni_(2)In-type hexagonal structure to low-temperature TiNiSi-type orthorhombic structure has been widely studied in MnMX(M=Ni or Co,and X=Ge or Si)alloys.However,the answer to how the orthorhombic martensite nucleates and grows within the hexagonal parent is still unclear.In this work,the hexagonal-orthorhombic martensitic transformation in a Co and Ge co-substituted MnNiSi is investigated.One can find some orthorhombic laths embedded in the hexagonal parent at a temperature above the martensitic transformation start temperature(M_(s)).With the the sample cooing to M_(s),the laths turn broader,indicating that the martensitic transformation starts from these pre-existing orthorhombic laths.Microstructure observation suggests that these pre-existing orthorhombic laths do not originate from the hexagonal-orthorhombic martensitic transformation because of the difference between atomic occupations of doping elements in the hexagonal parent and those in the preexisting orthorhombic laths.The phenomenological crystallographic theory and experimental investigations prove that the pre-existing orthorhombic lath and generated orthorhombic martensite have the same crystallography relationship to the hexagonal parent.Therefore,the orthorhombic martensite can take these pre-existing laths as embryos and grow up.This work implies that the martensitic transformation in MnNiSi_(1-x)(CoNiGe)_(x) alloy is initiated by orthorhombic embryos.展开更多
Background Acute Stanford Type A Aortic Dissection(ATAAD)is a critical medical emergency characterized by significant morbidity and mortality.This study aims to identify specific gene expression patterns and RNA modif...Background Acute Stanford Type A Aortic Dissection(ATAAD)is a critical medical emergency characterized by significant morbidity and mortality.This study aims to identify specific gene expression patterns and RNA modification associated with ATAAD.Methods The GSE153434 dataset was obtained from the Gene Expression Omnibus(GEO)database.Differential expression analysis was conducted to identify differential expression genes(DEGs)associated with ATAAD.To validate the involvement of RNA modification in ATAAD,RNA modification-related genes(M6A,M1A,M5C,APA,A-to-I)were acquired from GeneCards,following by Least Absolute Shrinkage and Selection Operator(LASSO)regression analysis.A gene prediction signature consisting of key genes was established,and Real-time PCR was used to validate the gene expression in clinical samples.The patients were then divided into high and low-risk groups,and subsequent enrichment analysis,including Gene Ontology(GO),Kyoto Encyclopedia of Genes and Genomes(KEGG),Gene Set Enrichment Analysis(GSEA),Gene Set Variation Analysis(GSVA),and assessments of immune infiltration.A co-expression network analysis(WGCNA)was performed to explore gene-phenotype relationships and identify key genes.Results A total of 45 RNA modification genes were acquired.Six gene signatures(YTHDC1,WTAP,CFI,ADARB1,ADARB2,TET3)were developed for ATAAD diagnosis and risk stratification.Enrichment analysis suggested the potential involvement of inflammation and extracellular matrix pathways in the progression of ATAAD.The incorporation of pertinent genes from the GSE147026 dataset into the six-gene signature further validated the model's effectiveness.A significant upregulation in WTAP,ADARB2,and TET3 expression,whereas YTHDC1 exhibited a noteworthy downregulation in the ATAAD group.Conclusion Six-gene signature could serve as an efficient model for predicting the diagnosis of ATAAD.展开更多
Background:Green tea,mulberry leaf and corn silk are traditional herbs used in the prevention and treatment of diabetes in China for a long time,but their synergistic hypoglycemic effects and mechanisms remain unclear...Background:Green tea,mulberry leaf and corn silk are traditional herbs used in the prevention and treatment of diabetes in China for a long time,but their synergistic hypoglycemic effects and mechanisms remain unclear.Methods:The effective components of green tea,mulberry leaf and corn silk were extracted and enriched.Mixture design of experiments was used to study the influences of different combinations on the cell viability and glucose uptake level of L6 myoblasts,so as to determine the optimal synergistic hypoglycemic combination.The possible hypoglycemic mechanism of the optimal synergistic combination was explored by cytotoxicity assay,glucose uptake assay,and western blot.Results:Three polyphenol enrichment fractions of the herbs,30%ethanol elution fraction of green tea(GT),50%ethanol elution fraction of mulberry leaf(ML)and 60%ethanol elution fraction of corn silk(CS)were obtained.The antioxidant activities of GT-30%,ML-50%and CS-60%were superior to those of crude extracts,and showed strong potential inα-amylase andα-glucosidase inhibition activities.The optimal synergistic combination of crude extracts G7(crude extract of green tea:crude extract of mulberry leaf:crude extract of corn silk=1:5:3),polyphenol enrichment fractions R3(GT-30%:ML-50%:CS-60%=1:7:1)and monomers X2(epigallocatechin gallate:morusin:formononetin=3:1:2)were selected,respectively.G7,R3,and X2 showed promoting effects on the cell viability and glucose uptake of L6 myoblasts within the detected concentration range.In addition,G7,R3,and X2 could increase the expression levels of p-PI3K/PI3K and p-Akt/Akt in L6 myoblasts,and promote the translocation of Glut4,but G7 and R3 showed more significant effects.Conclusion:The synergistic hypoglycemic effects of green tea,mulberry leaf and corn silk had the characteristics of multiple-components and multiple-targets with p-PI3K/PI3K,p-Akt/Akt and the translocation of Glut4 signal pathways involved.The three traditional herbs might have the potential to be combined used for the prevention and treatment of diabetes based on the synergistic hypoglycemic effects.展开更多
BACKGROUND Most patients with hepatocellular carcinoma(HCC)have lost the opportunity for direct surgery at the time of diagnosis.Transarterial chemoembolization(TACE)combined with immune checkpoint inhibitors or tyros...BACKGROUND Most patients with hepatocellular carcinoma(HCC)have lost the opportunity for direct surgery at the time of diagnosis.Transarterial chemoembolization(TACE)combined with immune checkpoint inhibitors or tyrosine kinase inhibitors(TKI)can partially transform some unresectable HCC and improve the prognosis ef-fectively.However,based on the promising prospects of combined targeted and immunotherapy for the effective treatment of HCC,the positive role of palliative surgery in the conversion treatment of advanced HCC urgently needs further in-tensive re-assessment.CASE SUMMARY In this study,we describe two successful cases of"conversion therapy for un-resectable HCC"achieved mainly by palliative surgery combined with TACE plus immunotherapy and TKIs.A 48-year-old patient with newly diagnosed HCC,presenting with a 6-cm mass in the segment VII/VIII of the right liver with mul-tiple intrahepatic metastases,could not undergo one-stage radical surgical resection.He underwent palliative surgery with radiofrequency of metastatic lesions and the palliative resection of the primary mass,and received subsequent TACE treatments twice in the early postoperative period(2 weeks and 6 weeks),in addition to targeted and immune combination therapy with sintilimab injection and oral lenvatinib.No evidence of recurrence was observed during the 11-month follow-up period after surgery.The other patient was a 47-year-old patient with massive HCC(18 cm×15 cm×4.5 cm)in the left liver with severe cirrhosis.The left portal branch was occluded and a tumor thrombus formed,and the tumor partly involved the middle hepatic vein.The patient underwent palliative surgery of left hemihepatectomy(including resection of the middle hepatic vein)for HCC,followed by three TACE procedures and oral TKIs 2 weeks after surgery.Six months later,the re-examination via computed tomography revealed no tumour activity in the remaining right liver,while magnetic resonance imaging revealed slight local tumor enhancement in the caudate lobe of the liver considered,TACE was performed once again,and during the next follow-up of 10 months did not reveal new intrahepatic lesions or distant metastases.CONCLUSION These cases demonstrate that the addition of palliative surgery to conversion therapy in a selected population with a high tumor burden could benefit patients with initially unresectable HCC.展开更多
Cirrhosis develops from liver fibrosis and is the severe pathological stage of all chronic liver injury. Cirrhosis caused by hepatitis B virus and hepatitis C virus infection is especially common. Liver fibrosis and c...Cirrhosis develops from liver fibrosis and is the severe pathological stage of all chronic liver injury. Cirrhosis caused by hepatitis B virus and hepatitis C virus infection is especially common. Liver fibrosis and cirrhosis involve excess production of extracellular matrix,which is closely related to liver sinusoidal endothelial cells(LSECs). Damaged LSECs can synthesize transforming growth factor-beta and platelet-derived growth factor,which activate hepatic stellate cells and facilitate the synthesis of extracellular matrix. Herein,we highlight the angiogenic cytokines of LSECs related to liver fibrosis and cirrhosis at different stages and focus on the formation and development of liver fibrosis and cirrhosis. Inhibition of LSEC angiogenesis and antiangiogenic therapy are described in detail. Targeting LSECs has high therapeutic potential for liver diseases. Further understanding of the mechanism of action will provide stronger evidence for the development of anti-LSEC drugs and new directions for diagnosis and treatment of liver diseases.展开更多
Gene flow patterns and the genetic structure of domesticated crops like cotton are not well understood.Furthermore,marker-assisted breeding of cotton has lagged far behind that of other major crops because the loci as...Gene flow patterns and the genetic structure of domesticated crops like cotton are not well understood.Furthermore,marker-assisted breeding of cotton has lagged far behind that of other major crops because the loci associated with cotton traits such as fiber yield and quality have scarcely been identified.In this study,we used 19 microsatellites to first determine the population genetic structure and patterns of gene flow of superior germplasm resources in upland cotton.We then used association analysis to identify which markers were associated with 15 agronomic traits(including ten yield and five fiber quality traits).The results showed that the upland cotton accessions have low levels of genetic diversity(polymorphism information content=0.427),although extensive gene flow occurred among different ecological and geographic regions.Bayesian clustering analysis indicated that the cotton resources used in this study did not belong to obvious geographic populations,which may be the consequence of a single source of domestication followed by frequent genetic introgression mediated by human transference.A total of 82 maker-trait associations were examined in association analysis and the related ratios for phenotypic variations ranged from 3.04% to 47.14%.Interestingly,nine SSR markers were detected in more than one environmental condition.In addition,14 SSR markers were co-associated with two or more different traits.It was noteworthy that NAU4860 and NAU5077 markers detected at least in two environments were simultaneously associated with three fiber quality traits(uniformity index,specific breaking strength and micronaire value).In conclusion,these findings provide new insights into the population structure and genetic exchange pattern of cultivated cotton accessions.The quantitative trait loci of domesticated cotton identified will also be very useful for improvement of yield and fiber quality of cotton in molecular breeding programs.展开更多
BACKGROUND MicroRNA-21(miR-21)is related to hypertension and cardiac remodelling.Left atrium(LA)dilation is highly sensitive to small haemodynamic changes in the left ventricle(LV)that are induced by hypertension.This...BACKGROUND MicroRNA-21(miR-21)is related to hypertension and cardiac remodelling.Left atrium(LA)dilation is highly sensitive to small haemodynamic changes in the left ventricle(LV)that are induced by hypertension.This study aimed to elucidate the relationship between miR-21 expression and LA dilation in elderly patients with essential hypertension(EH).METHODS In this cross-sectional study,one hundred elderly patients with EH were recruited for the study.According to their left atrium diameters(LADs),the patients were divided into the LA dilation group[42 patients(42%)]and the no-LA dilation group[58 patients(58%)].The serum levels of miR-21 and chemical biomarkers used in the clinic,such as creatinine,blood urea nitrogen,uric acid,fasting blood glucose,total cholesterol(TC),triglyceride(TG),high-density lipoprotein cholesterol(HDLC),low-density lipoprotein cholesterol(LDL-C),very-low-density lipoprotein cholesterol,Lp(a),apolipoprotein A1(apoA1),and apolipoprotein B,were measured.All the patients underwent echocardiographic examination,and the LAD,interventricular septum(IVS),right atrium diameter(RAD),right ventricle diameter(RVD),left ventricular end-systolic diameter(LVESD),left ventricular end-systolic diameter(LVEDD)and left ventricular ejection fraction(LVEF)were measured.RESULTS The levels of miR-21[8.02(5.21,14.39)vs.6.05(3.81,8.95),P=0.011]and LVEF(67.02±3.82 vs.64.14±4.43,P=0.001)were higher in the LA dilation group.The levels of creatinine[70.40(64.45,80.15)vs.63.9(60.1,73.43)],P=0.020]were higher in the no-LA dilation group.The levels of HDLC(r=-0.209,P=0.037),apoA1(r=-0.269,P=0.007)and RAD(r=0.203,P=0.043)were significantly correlated with miR-21 expression.The LAD was significantly correlated with the RAD(r=0.287,P=0.004),RVD(r=0.450,P<0.001),LVEDD(r=0.248,P=0.013)and LVEF(r=0.232,P=0.020).Multivariate logistic regression revealed that miR-21 significantly influenced LA dilation in elderly patients with EH(P<0.05).CONCLUSIONS Circulating serum levels of miR-21 are increased in elderly patients with EH with LA dilation.miR-21 levels are significantly correlated with LA dilation in elderly patients with EH,and miR-21 may be a factor related to the clinical pathophysiological occurrence of and treatment for the progression of hypertension-related early heart damage in EH patients.展开更多
The electronic transport properties of a molecular junction based on doping tailoring armchair-type graphene nanoribbons(AGNRs)with different widths are investigated by applying the non-equilibrium Green's function...The electronic transport properties of a molecular junction based on doping tailoring armchair-type graphene nanoribbons(AGNRs)with different widths are investigated by applying the non-equilibrium Green's function formalism combined with first-principles density functional theory.The calculated results show that the width and doping play significant roles in the electronic transport properties of the molecular junction.A higher current can be obtained for the molecular junctions with the tailoring AGNRs with W=11.Furthermore,the current of boron-doped tailoring AGNRs with widths W=7 is nearly four times larger than that of the undoped one,which can be potentially useful for the design of high performance electronic devices.展开更多
Based on the microscopic nonlocal optical response theory, the resonant radiation force exerted on a semiconductorcoupled quantum well nanostructure(CQWN), induced by the nonlocal interaction between lasers and electr...Based on the microscopic nonlocal optical response theory, the resonant radiation force exerted on a semiconductorcoupled quantum well nanostructure(CQWN), induced by the nonlocal interaction between lasers and electrons in conduction bands, is investigated for two different polarized states. The numerical results show that the spatial nonlocality of optical response can cause a radiation shift(blue-shift) for the spectrum of the resonant radiation force, which is dependent on the CQWN width ratio, the barrier height, and polarized states sensitively. It is also confirmed that the resonant radiation force is steerable by the incident and polarized directions of incident light. This work may provide an advantageous method for detecting internal quantum properties of nanostructures, and open novel and raising possibilities for optical manipulation of nano-objects using laser-induced radiation force.展开更多
Pr_(0.5)Sr_(0.5)FeO_(3)(PSFO)and La_(0.25)Pr_(0.25)Sr_(0.5)FeO_(3)(LPSFO)nanofibers are prepared by electrospinning followed by calcination,and their morphologies,microstructures,electronic transports,and magnetic pro...Pr_(0.5)Sr_(0.5)FeO_(3)(PSFO)and La_(0.25)Pr_(0.25)Sr_(0.5)FeO_(3)(LPSFO)nanofibers are prepared by electrospinning followed by calcination,and their morphologies,microstructures,electronic transports,and magnetic properties are studied systematically.The temperature-dependent resistance curves of PSFO and LPSFO nanofibers are measured in a temperature range from 300 K to 10 K.With the temperature lowering,the resistance increases gradually and then decreases sharply due to the occurrence of ferromagnetic metal phase.The metal-insulator transition temperatures are about 110 K and 180 K for PSFO and LPSFO nanofibers,respectively.The electronic conduction behavior above the transition temperature can be described by one-dimensional Mott’s variable-range hopping(VRH)model.The hysteresis loops and the field-cooled(FC)and zero-field-cooled(ZFC)curves show that both PSFO nanofiber and LPSFO nanofiber exhibit ferromagnetism.Although the doping of La reduces the overall magnetization intensity of the material,it increases the ferromagnetic ratio of the system,which may improve the performance of LPSFO in solid oxide fuel cell.展开更多
Ba_(2)IrO_(4) is a sister compound of the widely investigated Sr_(2)IrO_(4) and has no IrO_(6) octahedral rotation nor net canted antiferromagnetic moment,thus it acts as a system more similar to the high-T_(c) cuprat...Ba_(2)IrO_(4) is a sister compound of the widely investigated Sr_(2)IrO_(4) and has no IrO_(6) octahedral rotation nor net canted antiferromagnetic moment,thus it acts as a system more similar to the high-T_(c) cuprate.In this work,we synthesize the Ba_(2)IrO_(4) epitaxial films by reactive molecular beam epitaxy and study their crystalline structure and transport properties under biaxial compressive strain.High resolution scanning transmission electron microscopy and x-ray diffraction confirm the high quality of films with partial strain relaxation.Under compressive epitaxial strain,the Ba_(2)IrO_(4) exhibits the strain-driven enhancement of the conductivity,consistent with the band gap narrowing and the stronger hybridization of Ir-t_(2g) and O-2p orbitals predicted in the first-principles calculations.展开更多
Objective To study the drug effects of "Caulis Sargentodoxae Formula" which dears away heat and blood clot on experimental endometriosis in rat, and to compare this effect with Danazol's effects. Method The model o...Objective To study the drug effects of "Caulis Sargentodoxae Formula" which dears away heat and blood clot on experimental endometriosis in rat, and to compare this effect with Danazol's effects. Method The model of endometriosis rat was induced by transplanting with endometrium surgically The rats were divided into 6 groups randomly: the non-treatment group, the castrate group, Danazol group(80 mg/kg), "Caulis Sargentodoxae Formula" group (110 g/kg), the medium dose group(77.5 g/kg) and the low dose group(55 g/kg). After 3 weeks' treatment, the volume ofendometrium was detected by cutting the rats' belly open, drawing the materials from endometrium for tissue section, and doing the quantity analysis of endometrium by semiautomatic image analysis machine.Results There was no significant difference of the endometrium volumes between the low dose group and the non-treatment group(P〉O.05), other groups' endometrium volumes were significantly lower than those of the non-treatment group(P〈0. 05). And apart from the low dose group, all other groups' heights of the endometrium epithelia were significantly lower than that of the non-treatment group(p〈0.01). Conclusion "Caulis Sargentodoxae Formula" can refrain the growth of the endometrium, and the effects are better than that of Danazol's.展开更多
The rapid development of iron and steel metallurgy technology has promoted the continuous innovation and iteration of carbon-containing refractories for clean steel smelting.To meet the high-quality requirements for c...The rapid development of iron and steel metallurgy technology has promoted the continuous innovation and iteration of carbon-containing refractories for clean steel smelting.To meet the high-quality requirements for clean steel production and full exploit the performance advantages of carbon-containing refractories in dynamic smelting environment,it is necessary to explore the role of graphite and modified graphite in carbon-containing refractories.Based on this,graphite surface modification methods,including surfactants,surface oxidation,and surface coating,and their applications in carbon-containing refractories are reviewed.The advantages and disadvantages of each method are analyzed for practical use.Furthermore,combined with the existing problems,the application prospect of improved graphite in carbon-containing refractories is discussed.展开更多
Physical cross-linking by hydrogen-bonds (H-bonds), providing a good combination of application properties of thermosets and processability of thermoplastics, is a potential strategy to resolve the recycling problem o...Physical cross-linking by hydrogen-bonds (H-bonds), providing a good combination of application properties of thermosets and processability of thermoplastics, is a potential strategy to resolve the recycling problem of traditional chemically cross-linked polyethylene. However, ureidopyrimidone (UPy), the most widely used H-bonding motif, is unfavorable for large-scale industrial application due to its poor thermal stability. In this work, H-bonds cross-linked polyethylene was successfully prepared by reactive melt blending maleic anhydride grafted polyethylene (PE-g-MAH) with 3-amino-1,2,4-triazole (ATA) to form amide triazole ring-carboxylic acid units. Triazole ring can easily generate multiple H-bonds with carboxylic acid and amide. More importantly, these units are more thermal stable than UPy due to the absence of unstable urea group of UPy. The introduction of H-bonds cross-linking leads to an obvious improvement in mechanical properties and creep resistance and a good maintain in thermal properties and recyclability. Furthermore, the reinforcement effect monotonically improves with increasing the density of H-bonds. The obtained good properties are mainly attributed to largely enhanced interchain interactions induced by H-bonds cross-linking and intrinsic reversibility of H-bonds. This work develops a novel way for the simple fabrication of H-bonds cross-linked PE with high performance through reactive melt blending.展开更多
Itch is an unpleasant sensation that provokes the desire to scratch.While acute itch serves as a protec-tive system to warn the body of external irritating agents,chronic itch is a debilitating but poorly-treated clin...Itch is an unpleasant sensation that provokes the desire to scratch.While acute itch serves as a protec-tive system to warn the body of external irritating agents,chronic itch is a debilitating but poorly-treated clinical dis-ease leading to repetitive scratching and skin lesions.How-ever,the neural mechanisms underlying the pathophysiol-ogy of chronic itch remain mysterious.Here,we identified a cell type-dependent role of the anterior cingulate cortex(ACC)in controlling chronic itch-related excessive scratch-ing behaviors in mice.Moreover,we delineated a neural circuit originating from excitatory neurons of the ACC to the ventral tegmental area(VTA)that was critically involved in chronic itch.Furthermore,we demonstrate that the ACC→VTA circuit also selectively modulated histaminergic acute itch.Finally,the ACC neurons were shown to predomi-nantly innervate the non-dopaminergic neurons of the VTA.Taken together,our findings uncover a cortex-midbrain cir-cuit for chronic itch-evoked scratching behaviors and shed novel insights on therapeutic intervention.展开更多
To find a novel counter electrode(CE)material for quantum dot-sensitized solar cells(QDSSCs),pompon-like NiCo_(2)O_(4) nanospheres are synthesized by a facile solvothermal and post-calcination method and we attempt to...To find a novel counter electrode(CE)material for quantum dot-sensitized solar cells(QDSSCs),pompon-like NiCo_(2)O_(4) nanospheres are synthesized by a facile solvothermal and post-calcination method and we attempt to apply it as a CE material for QDS SC.The catalytic performance of NiCo_(2)O_(4) counter electrode is investigated in detail through electrochemical impedance spectroscopy,Tafel test and cyclic voltammetry.The catalytic activity of NiCo_(2)O_(4) CE is superior to that of nanoflower-like Cu2S CE and traditional Cu2S/brass CE,which is mainly attributed to the large specific surface area,outstanding electrical conductivity of bimetallic oxides and the synergistic promotion effect of metals with different valence states.Under standard sunlight(air mass AM 1.5G 100 mW·cm^(-2)),the CdS/CdSe/ZnS-sensitized solar cell assembled with NiCo_(2)O_(4) CE achieved a photoelectric conversion efficiency of 5.55%,with a short current density of 22.49 mA·cm^(-2),an open circuit voltage of 0.574 V,and a fill factor of 0.43,which is slightly higher than the QDSSCs with nanoflower-like Cu_(2)S CE(4.75%)and traditional Cu_(2)S/brass CE(4.69%).This research provides ideas for discovering innovative and efficient CE materials for QDSSCs.展开更多
In this study, 6061 aluminum alloy and AZ31 B magnesium alloy composite plate was fabricated through explosive welding. Molecular dynamics(MD) simulations were conducted to investigate atomic diffusion behavior at b...In this study, 6061 aluminum alloy and AZ31 B magnesium alloy composite plate was fabricated through explosive welding. Molecular dynamics(MD) simulations were conducted to investigate atomic diffusion behavior at bonding interface in the AI/Mg composite plate. Corresponding experiments were conducted to validate the simulation results. The results show that diffusion coefficient of Mg atom is larger than that of A1 atom and the difference between these two coefficients becomes smaller with increasing collision velocity. The diffusion coefficient was found to depend on collision velocity and angle. It increases linearly with collision velocity when the collision angle is maintained constant at 10° and decreases linearly with collision angle when the collision velocity is maintained constantly at 440 m/s. Based on our MD simulation results and Fick's second law, a mathematical formula to calculate the thickness of diffusion layer was proposed and its validity was verified by relevant experiments. Transmission electron microscopy and energy-dispersive system were also used to investigate the atomic diffusion behavior at the bonding interface in the explosively welded 6061/AZ31B composite plate. The results show that there were obvious Al and Mg atom diffusion at the bonding interface,and the diffusion of magnesium atoms from magnesium alloy plate to aluminum alloy plate occurs much faster than the diffusion of aluminum atoms to the magnesium alloy plate. These findings from the current study can help to optimize the explosive welding process.展开更多
Objective:To clarify altered whole brain functional connectivity of the anterior cingulate cortex(ACC)in functional dyspepsia(FD)patients,and then to explore cerebral influence of acupuncture with deqi treating for FD...Objective:To clarify altered whole brain functional connectivity of the anterior cingulate cortex(ACC)in functional dyspepsia(FD)patients,and then to explore cerebral influence of acupuncture with deqi treating for FD.Methods:Thirty-two FD patients and 35 healthy subjects(HS)were firstly scanned by the resting-state blood oxygenation level-dependent functional magnetic resonance imaging(BOLD-fMRI)to compare differences of ACC-based functional connectivity(FC).Then 32 FD patients were randomized to receive 20 sessions’acupuncture treatment with(n=16)and without deqi(n=16),as well as underwent functional magnetic resonance imaging(fMRI)scans after treatment.After group re-division according to deqi response,changes of ACC subregions-based resting-state FC(rsFC)were compared between the actual with and without deqi group.Two seeds with bilateral of each were selected as regions of interest(ROIs)of the ACC,including two from the dorsal ACC:S2(BA24)(x=±5,y=2,z=46,r=3.5 mm)and two from the pregenual ACC:17(BA24)(x=±5,y=38,z=6,r=3.5 mm).The clinical changes of the Nepean Dyspepsia Index(NDI)that measuring symptoms and quality of life(QOL)were also used to further assess the correlation with ACC subregions rsFC in FD patients.Results:Compared to HS,FD patients showed significantly increased ACC subregions rsFC with left fusiform gyrus,temporal cortex,hippocampus(HIPP)/amygdala,temporal pole,and right INS,superior occipital gyrus,and bilateral precuneus,superior parietal lobule(SPL),and decreased rsFC with left postcentral/precentral gyrus(PoG/PrG),supplementary motor area(SMA)and right cerebellum.32 FD patients which were then re-divided into the actual deqi group(n=16)and actual without deqi group(n=16).The decrease of the NDI symptom score(pre-pos)in the actual deqi group was significantly greater than that in the actual without deqi group(P<0.05).Among the two groups,the actual deqi group showed increased ACC subregions rsFC with right SMA and bilateral PrG/PoG,and decreased rsFC with right precuneus,middle occipital gyrus,bilateral posterior cingulate cortex(PCC),HIPP/paraHIPP,angular gyrus and SPL after treatment.In addition,the changed NDI QOL scores(pre-post)of the actual deqi group was significantly positively correlated with their Fisher’s transformed Z value of the altered ACC subregion(left I7)rsFC with right SPL(r=-0.597,P=0.04<0.05,FDR corrected P>0.05).Conclusion:The results tested the hypothesis that the advantage of deqi on efficacy is related to affecting the ACC subregions rsFC.It suggested that deqi might participate in the adaptive modulation of disrupted relationship between the ACC subregions and the default mode network(DMN).展开更多
基金Project supported by the National Natural Science Foundation of China (Grant No. 12004035)the National Natural Science Fund for Excellent Young Scientists Fund Program(Overseas)。
文摘Valleytronics materials are a kind of special semiconductors which can host multiple symmetry-connected and wellseparated electron or hole pockets in the Brillouin zone when the system is slightly n or p doped. Since the low-energy particles residing in these pockets generally are not easily scattered to each other by small perturbations, they are endowed with an additional valley degree of freedom. Analogous to spin, the valley freedom can be used to process information,leading to the concept of valleytronics. The prerequisite for valleytronics is the generation of valley polarization. Thus,a focus in this field is achieving the electric generation of valley polarization, especially the static generation by the gate electric field alone. In this work, we briefly review the latest progress in this research direction, focusing on the concepts of the couplings between valley and layer, i.e., the valley–layer coupling which permits the gate-field control of the valley polarization, the couplings between valley, layer, and spin in magnetic systems, the physical properties, the novel designing schemes for electronic devices, and the material realizations of the gate-controlled valleytronics materials.
基金Project supported by the National Natural Science Foundation of China (Grant No.11974184)。
文摘The thermal-elastic martensitic transformation from high-temperature Ni_(2)In-type hexagonal structure to low-temperature TiNiSi-type orthorhombic structure has been widely studied in MnMX(M=Ni or Co,and X=Ge or Si)alloys.However,the answer to how the orthorhombic martensite nucleates and grows within the hexagonal parent is still unclear.In this work,the hexagonal-orthorhombic martensitic transformation in a Co and Ge co-substituted MnNiSi is investigated.One can find some orthorhombic laths embedded in the hexagonal parent at a temperature above the martensitic transformation start temperature(M_(s)).With the the sample cooing to M_(s),the laths turn broader,indicating that the martensitic transformation starts from these pre-existing orthorhombic laths.Microstructure observation suggests that these pre-existing orthorhombic laths do not originate from the hexagonal-orthorhombic martensitic transformation because of the difference between atomic occupations of doping elements in the hexagonal parent and those in the preexisting orthorhombic laths.The phenomenological crystallographic theory and experimental investigations prove that the pre-existing orthorhombic lath and generated orthorhombic martensite have the same crystallography relationship to the hexagonal parent.Therefore,the orthorhombic martensite can take these pre-existing laths as embryos and grow up.This work implies that the martensitic transformation in MnNiSi_(1-x)(CoNiGe)_(x) alloy is initiated by orthorhombic embryos.
基金supported by the Funding for Wu Jieping Medical Foundation’s special funding fund for clinical research(No.320.6750.2022-11-26)Scientific Research Project of Heilongjiang Provincial Health Commission(No.20220404021089)Open Project Program of Key Laboratory of Preservation of Human Genetic Resources and Disease Control in China(Harbin Medical University)Ministry of Education(No.LPHGRD2022-002)。
文摘Background Acute Stanford Type A Aortic Dissection(ATAAD)is a critical medical emergency characterized by significant morbidity and mortality.This study aims to identify specific gene expression patterns and RNA modification associated with ATAAD.Methods The GSE153434 dataset was obtained from the Gene Expression Omnibus(GEO)database.Differential expression analysis was conducted to identify differential expression genes(DEGs)associated with ATAAD.To validate the involvement of RNA modification in ATAAD,RNA modification-related genes(M6A,M1A,M5C,APA,A-to-I)were acquired from GeneCards,following by Least Absolute Shrinkage and Selection Operator(LASSO)regression analysis.A gene prediction signature consisting of key genes was established,and Real-time PCR was used to validate the gene expression in clinical samples.The patients were then divided into high and low-risk groups,and subsequent enrichment analysis,including Gene Ontology(GO),Kyoto Encyclopedia of Genes and Genomes(KEGG),Gene Set Enrichment Analysis(GSEA),Gene Set Variation Analysis(GSVA),and assessments of immune infiltration.A co-expression network analysis(WGCNA)was performed to explore gene-phenotype relationships and identify key genes.Results A total of 45 RNA modification genes were acquired.Six gene signatures(YTHDC1,WTAP,CFI,ADARB1,ADARB2,TET3)were developed for ATAAD diagnosis and risk stratification.Enrichment analysis suggested the potential involvement of inflammation and extracellular matrix pathways in the progression of ATAAD.The incorporation of pertinent genes from the GSE147026 dataset into the six-gene signature further validated the model's effectiveness.A significant upregulation in WTAP,ADARB2,and TET3 expression,whereas YTHDC1 exhibited a noteworthy downregulation in the ATAAD group.Conclusion Six-gene signature could serve as an efficient model for predicting the diagnosis of ATAAD.
基金the grant from National Key Research and Development Program of China(Grant No.2021YFE0110000)the grant from Tianjin Municipal Science and Technology Foundation(Grant No.22JCYBJC00160).
文摘Background:Green tea,mulberry leaf and corn silk are traditional herbs used in the prevention and treatment of diabetes in China for a long time,but their synergistic hypoglycemic effects and mechanisms remain unclear.Methods:The effective components of green tea,mulberry leaf and corn silk were extracted and enriched.Mixture design of experiments was used to study the influences of different combinations on the cell viability and glucose uptake level of L6 myoblasts,so as to determine the optimal synergistic hypoglycemic combination.The possible hypoglycemic mechanism of the optimal synergistic combination was explored by cytotoxicity assay,glucose uptake assay,and western blot.Results:Three polyphenol enrichment fractions of the herbs,30%ethanol elution fraction of green tea(GT),50%ethanol elution fraction of mulberry leaf(ML)and 60%ethanol elution fraction of corn silk(CS)were obtained.The antioxidant activities of GT-30%,ML-50%and CS-60%were superior to those of crude extracts,and showed strong potential inα-amylase andα-glucosidase inhibition activities.The optimal synergistic combination of crude extracts G7(crude extract of green tea:crude extract of mulberry leaf:crude extract of corn silk=1:5:3),polyphenol enrichment fractions R3(GT-30%:ML-50%:CS-60%=1:7:1)and monomers X2(epigallocatechin gallate:morusin:formononetin=3:1:2)were selected,respectively.G7,R3,and X2 showed promoting effects on the cell viability and glucose uptake of L6 myoblasts within the detected concentration range.In addition,G7,R3,and X2 could increase the expression levels of p-PI3K/PI3K and p-Akt/Akt in L6 myoblasts,and promote the translocation of Glut4,but G7 and R3 showed more significant effects.Conclusion:The synergistic hypoglycemic effects of green tea,mulberry leaf and corn silk had the characteristics of multiple-components and multiple-targets with p-PI3K/PI3K,p-Akt/Akt and the translocation of Glut4 signal pathways involved.The three traditional herbs might have the potential to be combined used for the prevention and treatment of diabetes based on the synergistic hypoglycemic effects.
基金Supported by Zhejiang Medical Science and Technology Project,No.2023KY704Zhejiang Traditional Chinese Medicine Science and Technology Project,No.2023ZR107 and No.2024ZF094+1 种基金Special Research Fund for Hospital Pharmacy of Zhejiang Pharmaceutical Association,No.2021ZYY08Zhejiang Medical Association Clinical Research Fund,No.2021ZYC-A64 and No.2021ZYC-A67.
文摘BACKGROUND Most patients with hepatocellular carcinoma(HCC)have lost the opportunity for direct surgery at the time of diagnosis.Transarterial chemoembolization(TACE)combined with immune checkpoint inhibitors or tyrosine kinase inhibitors(TKI)can partially transform some unresectable HCC and improve the prognosis ef-fectively.However,based on the promising prospects of combined targeted and immunotherapy for the effective treatment of HCC,the positive role of palliative surgery in the conversion treatment of advanced HCC urgently needs further in-tensive re-assessment.CASE SUMMARY In this study,we describe two successful cases of"conversion therapy for un-resectable HCC"achieved mainly by palliative surgery combined with TACE plus immunotherapy and TKIs.A 48-year-old patient with newly diagnosed HCC,presenting with a 6-cm mass in the segment VII/VIII of the right liver with mul-tiple intrahepatic metastases,could not undergo one-stage radical surgical resection.He underwent palliative surgery with radiofrequency of metastatic lesions and the palliative resection of the primary mass,and received subsequent TACE treatments twice in the early postoperative period(2 weeks and 6 weeks),in addition to targeted and immune combination therapy with sintilimab injection and oral lenvatinib.No evidence of recurrence was observed during the 11-month follow-up period after surgery.The other patient was a 47-year-old patient with massive HCC(18 cm×15 cm×4.5 cm)in the left liver with severe cirrhosis.The left portal branch was occluded and a tumor thrombus formed,and the tumor partly involved the middle hepatic vein.The patient underwent palliative surgery of left hemihepatectomy(including resection of the middle hepatic vein)for HCC,followed by three TACE procedures and oral TKIs 2 weeks after surgery.Six months later,the re-examination via computed tomography revealed no tumour activity in the remaining right liver,while magnetic resonance imaging revealed slight local tumor enhancement in the caudate lobe of the liver considered,TACE was performed once again,and during the next follow-up of 10 months did not reveal new intrahepatic lesions or distant metastases.CONCLUSION These cases demonstrate that the addition of palliative surgery to conversion therapy in a selected population with a high tumor burden could benefit patients with initially unresectable HCC.
基金Supported by the Young Elite Scientists Sponsorship Program by CAST,No.2016QNRC001Beijing Natural Science Foundation,No.7172187
文摘Cirrhosis develops from liver fibrosis and is the severe pathological stage of all chronic liver injury. Cirrhosis caused by hepatitis B virus and hepatitis C virus infection is especially common. Liver fibrosis and cirrhosis involve excess production of extracellular matrix,which is closely related to liver sinusoidal endothelial cells(LSECs). Damaged LSECs can synthesize transforming growth factor-beta and platelet-derived growth factor,which activate hepatic stellate cells and facilitate the synthesis of extracellular matrix. Herein,we highlight the angiogenic cytokines of LSECs related to liver fibrosis and cirrhosis at different stages and focus on the formation and development of liver fibrosis and cirrhosis. Inhibition of LSEC angiogenesis and antiangiogenic therapy are described in detail. Targeting LSECs has high therapeutic potential for liver diseases. Further understanding of the mechanism of action will provide stronger evidence for the development of anti-LSEC drugs and new directions for diagnosis and treatment of liver diseases.
基金grants from National Key R and D Program for Crop Breeding(2016YFD0100306)National Natural Science Foundation of China(No.31401431)+2 种基金the Shaanxi Science and Technology Innovation Team(2019TD-012)the Public health specialty in the Department of Traditional Chinese Medicine(Grants no.2017-66 and 2018-43)the Open Foundation of the Key Laboratory of Resource Biology and Biotechnology in Western China(Ministry of Education)(Grants no.ZSK2017007 and ZSK2019008)。
文摘Gene flow patterns and the genetic structure of domesticated crops like cotton are not well understood.Furthermore,marker-assisted breeding of cotton has lagged far behind that of other major crops because the loci associated with cotton traits such as fiber yield and quality have scarcely been identified.In this study,we used 19 microsatellites to first determine the population genetic structure and patterns of gene flow of superior germplasm resources in upland cotton.We then used association analysis to identify which markers were associated with 15 agronomic traits(including ten yield and five fiber quality traits).The results showed that the upland cotton accessions have low levels of genetic diversity(polymorphism information content=0.427),although extensive gene flow occurred among different ecological and geographic regions.Bayesian clustering analysis indicated that the cotton resources used in this study did not belong to obvious geographic populations,which may be the consequence of a single source of domestication followed by frequent genetic introgression mediated by human transference.A total of 82 maker-trait associations were examined in association analysis and the related ratios for phenotypic variations ranged from 3.04% to 47.14%.Interestingly,nine SSR markers were detected in more than one environmental condition.In addition,14 SSR markers were co-associated with two or more different traits.It was noteworthy that NAU4860 and NAU5077 markers detected at least in two environments were simultaneously associated with three fiber quality traits(uniformity index,specific breaking strength and micronaire value).In conclusion,these findings provide new insights into the population structure and genetic exchange pattern of cultivated cotton accessions.The quantitative trait loci of domesticated cotton identified will also be very useful for improvement of yield and fiber quality of cotton in molecular breeding programs.
基金supported by the 2019 Hebei Science and Technology Project (grant number19 277787D)2019 Hebei Innovation Capability Promotion Project (grant number 199776249D)
文摘BACKGROUND MicroRNA-21(miR-21)is related to hypertension and cardiac remodelling.Left atrium(LA)dilation is highly sensitive to small haemodynamic changes in the left ventricle(LV)that are induced by hypertension.This study aimed to elucidate the relationship between miR-21 expression and LA dilation in elderly patients with essential hypertension(EH).METHODS In this cross-sectional study,one hundred elderly patients with EH were recruited for the study.According to their left atrium diameters(LADs),the patients were divided into the LA dilation group[42 patients(42%)]and the no-LA dilation group[58 patients(58%)].The serum levels of miR-21 and chemical biomarkers used in the clinic,such as creatinine,blood urea nitrogen,uric acid,fasting blood glucose,total cholesterol(TC),triglyceride(TG),high-density lipoprotein cholesterol(HDLC),low-density lipoprotein cholesterol(LDL-C),very-low-density lipoprotein cholesterol,Lp(a),apolipoprotein A1(apoA1),and apolipoprotein B,were measured.All the patients underwent echocardiographic examination,and the LAD,interventricular septum(IVS),right atrium diameter(RAD),right ventricle diameter(RVD),left ventricular end-systolic diameter(LVESD),left ventricular end-systolic diameter(LVEDD)and left ventricular ejection fraction(LVEF)were measured.RESULTS The levels of miR-21[8.02(5.21,14.39)vs.6.05(3.81,8.95),P=0.011]and LVEF(67.02±3.82 vs.64.14±4.43,P=0.001)were higher in the LA dilation group.The levels of creatinine[70.40(64.45,80.15)vs.63.9(60.1,73.43)],P=0.020]were higher in the no-LA dilation group.The levels of HDLC(r=-0.209,P=0.037),apoA1(r=-0.269,P=0.007)and RAD(r=0.203,P=0.043)were significantly correlated with miR-21 expression.The LAD was significantly correlated with the RAD(r=0.287,P=0.004),RVD(r=0.450,P<0.001),LVEDD(r=0.248,P=0.013)and LVEF(r=0.232,P=0.020).Multivariate logistic regression revealed that miR-21 significantly influenced LA dilation in elderly patients with EH(P<0.05).CONCLUSIONS Circulating serum levels of miR-21 are increased in elderly patients with EH with LA dilation.miR-21 levels are significantly correlated with LA dilation in elderly patients with EH,and miR-21 may be a factor related to the clinical pathophysiological occurrence of and treatment for the progression of hypertension-related early heart damage in EH patients.
基金Supported by the National Natural Science Foundation of China under Grant Nos 11004156 and 11547172the Science and Technology Star Project of Shaanxi Province under Grant No 2016KJXX-45
文摘The electronic transport properties of a molecular junction based on doping tailoring armchair-type graphene nanoribbons(AGNRs)with different widths are investigated by applying the non-equilibrium Green's function formalism combined with first-principles density functional theory.The calculated results show that the width and doping play significant roles in the electronic transport properties of the molecular junction.A higher current can be obtained for the molecular junctions with the tailoring AGNRs with W=11.Furthermore,the current of boron-doped tailoring AGNRs with widths W=7 is nearly four times larger than that of the undoped one,which can be potentially useful for the design of high performance electronic devices.
基金Project supported by the Natural Science Foundation of Guangdong Province,China(Grant Nos.2016A030313439 and 2018A030313480)GDUPS(2017)+1 种基金the Key Program of the Natural Science Foundation of Guangdong Province,China(Grant No.2017B030311003)the Science and Technology Program of Guangzhou City,China(Grant No.201707010403)
文摘Based on the microscopic nonlocal optical response theory, the resonant radiation force exerted on a semiconductorcoupled quantum well nanostructure(CQWN), induced by the nonlocal interaction between lasers and electrons in conduction bands, is investigated for two different polarized states. The numerical results show that the spatial nonlocality of optical response can cause a radiation shift(blue-shift) for the spectrum of the resonant radiation force, which is dependent on the CQWN width ratio, the barrier height, and polarized states sensitively. It is also confirmed that the resonant radiation force is steerable by the incident and polarized directions of incident light. This work may provide an advantageous method for detecting internal quantum properties of nanostructures, and open novel and raising possibilities for optical manipulation of nano-objects using laser-induced radiation force.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.51973100 and 11904193)the Fund from the State Key Laboratory of Bio-Fibers and Eco-Textiles,Qingdao University,China(Grant No.RZ2000003334)the National Key Research and Development Project,China(Grant No.2019YFC0121402)。
文摘Pr_(0.5)Sr_(0.5)FeO_(3)(PSFO)and La_(0.25)Pr_(0.25)Sr_(0.5)FeO_(3)(LPSFO)nanofibers are prepared by electrospinning followed by calcination,and their morphologies,microstructures,electronic transports,and magnetic properties are studied systematically.The temperature-dependent resistance curves of PSFO and LPSFO nanofibers are measured in a temperature range from 300 K to 10 K.With the temperature lowering,the resistance increases gradually and then decreases sharply due to the occurrence of ferromagnetic metal phase.The metal-insulator transition temperatures are about 110 K and 180 K for PSFO and LPSFO nanofibers,respectively.The electronic conduction behavior above the transition temperature can be described by one-dimensional Mott’s variable-range hopping(VRH)model.The hysteresis loops and the field-cooled(FC)and zero-field-cooled(ZFC)curves show that both PSFO nanofiber and LPSFO nanofiber exhibit ferromagnetism.Although the doping of La reduces the overall magnetization intensity of the material,it increases the ferromagnetic ratio of the system,which may improve the performance of LPSFO in solid oxide fuel cell.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11774153,11861161004,51772143,11974163,and 51672125)the National Key Research and Development Program of China(Grant No.2016YFA0201104)+1 种基金the Fundamental Research Funds for the Central Universities,China(Grant Nos.0213-14380167 and 0213-14380198)the Hong Kong Research Grants Council(RGC)through the NSFC–RGC Joint Research Scheme,China(Grant No.N PolyU531/18).
文摘Ba_(2)IrO_(4) is a sister compound of the widely investigated Sr_(2)IrO_(4) and has no IrO_(6) octahedral rotation nor net canted antiferromagnetic moment,thus it acts as a system more similar to the high-T_(c) cuprate.In this work,we synthesize the Ba_(2)IrO_(4) epitaxial films by reactive molecular beam epitaxy and study their crystalline structure and transport properties under biaxial compressive strain.High resolution scanning transmission electron microscopy and x-ray diffraction confirm the high quality of films with partial strain relaxation.Under compressive epitaxial strain,the Ba_(2)IrO_(4) exhibits the strain-driven enhancement of the conductivity,consistent with the band gap narrowing and the stronger hybridization of Ir-t_(2g) and O-2p orbitals predicted in the first-principles calculations.
文摘Objective To study the drug effects of "Caulis Sargentodoxae Formula" which dears away heat and blood clot on experimental endometriosis in rat, and to compare this effect with Danazol's effects. Method The model of endometriosis rat was induced by transplanting with endometrium surgically The rats were divided into 6 groups randomly: the non-treatment group, the castrate group, Danazol group(80 mg/kg), "Caulis Sargentodoxae Formula" group (110 g/kg), the medium dose group(77.5 g/kg) and the low dose group(55 g/kg). After 3 weeks' treatment, the volume ofendometrium was detected by cutting the rats' belly open, drawing the materials from endometrium for tissue section, and doing the quantity analysis of endometrium by semiautomatic image analysis machine.Results There was no significant difference of the endometrium volumes between the low dose group and the non-treatment group(P〉O.05), other groups' endometrium volumes were significantly lower than those of the non-treatment group(P〈0. 05). And apart from the low dose group, all other groups' heights of the endometrium epithelia were significantly lower than that of the non-treatment group(p〈0.01). Conclusion "Caulis Sargentodoxae Formula" can refrain the growth of the endometrium, and the effects are better than that of Danazol's.
基金the project supported by the Natural Science Foundation of Hubei Province(Grant No.2023BAB106)the National Natural Science Foundation of China(Grant No.U20A20239).
文摘The rapid development of iron and steel metallurgy technology has promoted the continuous innovation and iteration of carbon-containing refractories for clean steel smelting.To meet the high-quality requirements for clean steel production and full exploit the performance advantages of carbon-containing refractories in dynamic smelting environment,it is necessary to explore the role of graphite and modified graphite in carbon-containing refractories.Based on this,graphite surface modification methods,including surfactants,surface oxidation,and surface coating,and their applications in carbon-containing refractories are reviewed.The advantages and disadvantages of each method are analyzed for practical use.Furthermore,combined with the existing problems,the application prospect of improved graphite in carbon-containing refractories is discussed.
基金financially supported by the National Natural Science Foundation of China (No. 51803130)Fundamental Research Funds for Central UniversitiesChongqing University Key Laboratory of Micro/Nano Materials Engineering and Technology (No. KFJJ2005)
文摘Physical cross-linking by hydrogen-bonds (H-bonds), providing a good combination of application properties of thermosets and processability of thermoplastics, is a potential strategy to resolve the recycling problem of traditional chemically cross-linked polyethylene. However, ureidopyrimidone (UPy), the most widely used H-bonding motif, is unfavorable for large-scale industrial application due to its poor thermal stability. In this work, H-bonds cross-linked polyethylene was successfully prepared by reactive melt blending maleic anhydride grafted polyethylene (PE-g-MAH) with 3-amino-1,2,4-triazole (ATA) to form amide triazole ring-carboxylic acid units. Triazole ring can easily generate multiple H-bonds with carboxylic acid and amide. More importantly, these units are more thermal stable than UPy due to the absence of unstable urea group of UPy. The introduction of H-bonds cross-linking leads to an obvious improvement in mechanical properties and creep resistance and a good maintain in thermal properties and recyclability. Furthermore, the reinforcement effect monotonically improves with increasing the density of H-bonds. The obtained good properties are mainly attributed to largely enhanced interchain interactions induced by H-bonds cross-linking and intrinsic reversibility of H-bonds. This work develops a novel way for the simple fabrication of H-bonds cross-linked PE with high performance through reactive melt blending.
基金supported by grants from the National Natural Science Foundation of China(81873787,81961128024,32170994,and 82201362)Shanghai Natural Science Foundation(18ZR1424800 and 20ZR1430000)+1 种基金a Shanghai Municipal Science and Technology Major Project(2018SHZDZX05)the innovative research team of high-level local universities in Shanghai.
文摘Itch is an unpleasant sensation that provokes the desire to scratch.While acute itch serves as a protec-tive system to warn the body of external irritating agents,chronic itch is a debilitating but poorly-treated clinical dis-ease leading to repetitive scratching and skin lesions.How-ever,the neural mechanisms underlying the pathophysiol-ogy of chronic itch remain mysterious.Here,we identified a cell type-dependent role of the anterior cingulate cortex(ACC)in controlling chronic itch-related excessive scratch-ing behaviors in mice.Moreover,we delineated a neural circuit originating from excitatory neurons of the ACC to the ventral tegmental area(VTA)that was critically involved in chronic itch.Furthermore,we demonstrate that the ACC→VTA circuit also selectively modulated histaminergic acute itch.Finally,the ACC neurons were shown to predomi-nantly innervate the non-dopaminergic neurons of the VTA.Taken together,our findings uncover a cortex-midbrain cir-cuit for chronic itch-evoked scratching behaviors and shed novel insights on therapeutic intervention.
基金financially supported by the Natural Science Foundation of China(Grant Nos.22071018 and 21671035)。
文摘To find a novel counter electrode(CE)material for quantum dot-sensitized solar cells(QDSSCs),pompon-like NiCo_(2)O_(4) nanospheres are synthesized by a facile solvothermal and post-calcination method and we attempt to apply it as a CE material for QDS SC.The catalytic performance of NiCo_(2)O_(4) counter electrode is investigated in detail through electrochemical impedance spectroscopy,Tafel test and cyclic voltammetry.The catalytic activity of NiCo_(2)O_(4) CE is superior to that of nanoflower-like Cu2S CE and traditional Cu2S/brass CE,which is mainly attributed to the large specific surface area,outstanding electrical conductivity of bimetallic oxides and the synergistic promotion effect of metals with different valence states.Under standard sunlight(air mass AM 1.5G 100 mW·cm^(-2)),the CdS/CdSe/ZnS-sensitized solar cell assembled with NiCo_(2)O_(4) CE achieved a photoelectric conversion efficiency of 5.55%,with a short current density of 22.49 mA·cm^(-2),an open circuit voltage of 0.574 V,and a fill factor of 0.43,which is slightly higher than the QDSSCs with nanoflower-like Cu_(2)S CE(4.75%)and traditional Cu_(2)S/brass CE(4.69%).This research provides ideas for discovering innovative and efficient CE materials for QDSSCs.
基金financially supported by the National Natural Science Foundation of China (No.51375328)
文摘In this study, 6061 aluminum alloy and AZ31 B magnesium alloy composite plate was fabricated through explosive welding. Molecular dynamics(MD) simulations were conducted to investigate atomic diffusion behavior at bonding interface in the AI/Mg composite plate. Corresponding experiments were conducted to validate the simulation results. The results show that diffusion coefficient of Mg atom is larger than that of A1 atom and the difference between these two coefficients becomes smaller with increasing collision velocity. The diffusion coefficient was found to depend on collision velocity and angle. It increases linearly with collision velocity when the collision angle is maintained constant at 10° and decreases linearly with collision angle when the collision velocity is maintained constantly at 440 m/s. Based on our MD simulation results and Fick's second law, a mathematical formula to calculate the thickness of diffusion layer was proposed and its validity was verified by relevant experiments. Transmission electron microscopy and energy-dispersive system were also used to investigate the atomic diffusion behavior at the bonding interface in the explosively welded 6061/AZ31B composite plate. The results show that there were obvious Al and Mg atom diffusion at the bonding interface,and the diffusion of magnesium atoms from magnesium alloy plate to aluminum alloy plate occurs much faster than the diffusion of aluminum atoms to the magnesium alloy plate. These findings from the current study can help to optimize the explosive welding process.
基金grants from the National Natural Science Foundation of Outstanding Youth Fund in China:81622052National Natural Science Foundation of China:81473602+2 种基金the major program of the National Natural Science Foundation of China:81590950the Ten Thousand Talent Program:W02020595Youth Science and Technology Innovative Team of Sichuan Province:2019JDTD0011。
文摘Objective:To clarify altered whole brain functional connectivity of the anterior cingulate cortex(ACC)in functional dyspepsia(FD)patients,and then to explore cerebral influence of acupuncture with deqi treating for FD.Methods:Thirty-two FD patients and 35 healthy subjects(HS)were firstly scanned by the resting-state blood oxygenation level-dependent functional magnetic resonance imaging(BOLD-fMRI)to compare differences of ACC-based functional connectivity(FC).Then 32 FD patients were randomized to receive 20 sessions’acupuncture treatment with(n=16)and without deqi(n=16),as well as underwent functional magnetic resonance imaging(fMRI)scans after treatment.After group re-division according to deqi response,changes of ACC subregions-based resting-state FC(rsFC)were compared between the actual with and without deqi group.Two seeds with bilateral of each were selected as regions of interest(ROIs)of the ACC,including two from the dorsal ACC:S2(BA24)(x=±5,y=2,z=46,r=3.5 mm)and two from the pregenual ACC:17(BA24)(x=±5,y=38,z=6,r=3.5 mm).The clinical changes of the Nepean Dyspepsia Index(NDI)that measuring symptoms and quality of life(QOL)were also used to further assess the correlation with ACC subregions rsFC in FD patients.Results:Compared to HS,FD patients showed significantly increased ACC subregions rsFC with left fusiform gyrus,temporal cortex,hippocampus(HIPP)/amygdala,temporal pole,and right INS,superior occipital gyrus,and bilateral precuneus,superior parietal lobule(SPL),and decreased rsFC with left postcentral/precentral gyrus(PoG/PrG),supplementary motor area(SMA)and right cerebellum.32 FD patients which were then re-divided into the actual deqi group(n=16)and actual without deqi group(n=16).The decrease of the NDI symptom score(pre-pos)in the actual deqi group was significantly greater than that in the actual without deqi group(P<0.05).Among the two groups,the actual deqi group showed increased ACC subregions rsFC with right SMA and bilateral PrG/PoG,and decreased rsFC with right precuneus,middle occipital gyrus,bilateral posterior cingulate cortex(PCC),HIPP/paraHIPP,angular gyrus and SPL after treatment.In addition,the changed NDI QOL scores(pre-post)of the actual deqi group was significantly positively correlated with their Fisher’s transformed Z value of the altered ACC subregion(left I7)rsFC with right SPL(r=-0.597,P=0.04<0.05,FDR corrected P>0.05).Conclusion:The results tested the hypothesis that the advantage of deqi on efficacy is related to affecting the ACC subregions rsFC.It suggested that deqi might participate in the adaptive modulation of disrupted relationship between the ACC subregions and the default mode network(DMN).