Voltage source converter based high voltage direct current(VSC-HVDC)can participate in voltage regulation by flexible control to help maintain the voltage stability of the power grid.In order to quantitatively evaluat...Voltage source converter based high voltage direct current(VSC-HVDC)can participate in voltage regulation by flexible control to help maintain the voltage stability of the power grid.In order to quantitatively evaluate its influence on the voltage interaction between VSC-HVDC and line commutated converter based high voltage direct current(LCC-HVDC),this paper proposes a hybrid multi-infeed interaction factor(HMIIF)calculation method considering the voltage regulation control characteristics of VSC-HVDC.Firstly,for a hybrid multi-infeed high voltage direct current system,an additional equivalent operating admittance matrix is constructed to characterize HVDC equipment characteristics under small disturbance.Secondly,based on the characteristic curve between the reactive power and the voltage of a certain VSC-HVDC project,the additional equivalent operating admittance of VSC-HVDC is derived.The additional equivalent operating admittance matrix calculation method is proposed.Thirdly,the equivalent bus impedance matrix is obtained by modifying the alternating current(AC)system admittance matrix with the additional equivalent operating admittance matrix.On this basis,the HMIIF calculation method based on the equivalent bus impedance ratio is proposed.Finally,the effectiveness of the proposed method is verified in a hybrid dual-infeed high voltage direct current system constructed in Power Systems Computer Aided Design(PSCAD),and the influence of voltage regulation control on HMIIF is analyzed.展开更多
A rigorous analytical method is presented for calculating the interaction factor between two identical piles subjected to vertical loads. Following the technique proposed by Muki and Sternberg, the problem is decompos...A rigorous analytical method is presented for calculating the interaction factor between two identical piles subjected to vertical loads. Following the technique proposed by Muki and Sternberg, the problem is decomposed into an extended soil mass and two fictitious piles characterized respectively by Young＇s modulus of the soil and that of the difference between the pile and soil. The unknown axial forces along fictitious piles are determined by solving a Fredholm integral equation of the second kind, which imposes the compatibility condition that the axial strains of the fictitious piles are equal to those corresponding to the centroidal axes of the extended soil. The real pile forces and displacements can subequally be calculated based on the determined fictitious pile forces, and finally, the validity of the proposed approach and desired pile interaction factors may be obtained. Results confirm the portray the influence of the governing parameters on the pile interaction.展开更多
A rigorous analytical method is presented, which takes into account the pile stiffening effects, using the theory of the transfer matrix-bottom rigidity for calculating the interaction factor between two identical pil...A rigorous analytical method is presented, which takes into account the pile stiffening effects, using the theory of the transfer matrix-bottom rigidity for calculating the interaction factor between two identical piles in multi-layered soils subjected to vertical loads. Following the technique proposed by Muki and Sternberg, the problem is decomposed into extended soil layers and two fictitious piles characterized respectively by Young's moduli of the layered soils and those of the differences between the piles and the layered soils. The unknown axial forces along fictitious piles are determined by solving a Fredholm integral equation of the second kind, which imposes the compatibility condition that the axial strains of the fictitious piles are equal to those corresponding to the centroidal axes of the extended layered soils. The real pile displacements can be calculated based on the determined fictitious pile forces, and finally, the desired pile interaction factors may be obtained. Selected results from parametrical studies are presented to confirm the validity of the proposed approach and portray the influence of the governing parameters on the pile interaction.展开更多
Inflorescences are flower-bearing shoots that originate from pools of stem cells in shoot apical meristems (SAM).Inflorescence architecture is determined by a process of meristem maturation,during which stem cell fate...Inflorescences are flower-bearing shoots that originate from pools of stem cells in shoot apical meristems (SAM).Inflorescence architecture is determined by a process of meristem maturation,during which stem cell fate switches from a vegetative to a reproductive growth program.A major factor in plant reproductive success in nature and yield in agriculture is the number of branches and flowers on inflorescences (Kobayashi and Weigel,2007;展开更多
The cyclic plastic straining electrode technique has been used to investigate the transient electrochemical behaviour of Fe-26Cr1Mo stainless steel in 1M H2SO4 solution at a passive potential.The influence of plastic ...The cyclic plastic straining electrode technique has been used to investigate the transient electrochemical behaviour of Fe-26Cr1Mo stainless steel in 1M H2SO4 solution at a passive potential.The influence of plastic strain amplitude and plastic strain rate on the dissolution current response was analysed. The experimental results showed that the transient current was dependent on the competitive process of the surface film rupture and repassivation of the new surface. The high plastic strain amplitude and the high plastic strain rate caused a change of electrochemical activity of specimen surface. In the condition of low strain amplitude and strain rate, the characteristics of current response was mainly relative tp the process of new surface repassivation.The competition kinetics has been analysed through the comparison of plastic strain rate and repassivating rate展开更多
Tumor necrosis factor-α(TNF-α)is a key player in the pathogenesis of rheumatoid arthritis(RA)and considered a promising target for therapeutic drug development.Activation of the nuclear factor-kappa B(NF-κB)pathway...Tumor necrosis factor-α(TNF-α)is a key player in the pathogenesis of rheumatoid arthritis(RA)and considered a promising target for therapeutic drug development.Activation of the nuclear factor-kappa B(NF-κB)pathway upon TNF-αbinding to its receptor is crucial for progression of RA.Stephanine(SA),an isoquinoline aporphine-type alkaloid recently identified in Stephania plants,exhibits anti-inflammatory properties,but its underlying mechanisms of action are unknown at present.In this study,we explored whether SA could ameliorate RA through inhibition of the NF-κB signaling pathway in association with TNF-αactivity.Our experiments revealed a binding affinity(K_(D))of SA for TNF-αof 2.934×10^(-6)mol/L.Additionally,SA at a concentration of 10μmol/L effectively hindered the binding of TNF-αto its receptors tumor necrosis factor receptor 1(TNFR1)and TNFR2.In vitro,SA prevented TNF-α-induced death of L929 cells and blocked NF-κB activation triggered by TNF-αin 293-TNF-αresponsive,as well as human fibroblast-like synoviocytes(HFLS)and human RA fibroblast-like synoviocytes(MH7A)cell lines.Furthermore,in a collagen-induced arthritis(CIA)mouse model,SA alleviated the symptoms of RA through suppression of NF-κB signaling.Our collective findings support the therapeutic efficacy of SA,a natural compound targeting TNF-α,in the management of RA.展开更多
BACKGROUND Hepatic ischemia-reperfusion(I/R)injury related to liver transplantation and hepatic resection remains a challenge in clinical practice.Accumulating evidence indicates that mitochondrial dysfunction is a cr...BACKGROUND Hepatic ischemia-reperfusion(I/R)injury related to liver transplantation and hepatic resection remains a challenge in clinical practice.Accumulating evidence indicates that mitochondrial dysfunction is a critical cause of I/R injury.The protein 4-nitrophenylphosphatase domain and non-neuronal SNAP25-like protein homolog 1(NIPSNAP1)is involved in the regulation of mitophagy and the recruitment of autophagy receptor proteins independent of PTEN induced putative kinase 1.AIM To clarify the protective mechanism of NIPSNAP1 against hepatic I/R,with a focus on mitophagy and mitochondrial dynamics,as well as the potential mechanism by which n6-methyladenosine(m6A)modification regulates NIPSNAP1.METHODS Mice were administered an adeno-associated virus in vivo and a hepatic I/R model was established via portal vein interruption followed by reperfusion to explore the effect of NIPSNAP1 on hepatic I/R.HepG2 cells were subjected to hypoxia/reoxygenation treatment in vitro.RESULTS We observed a significant downregulation of both NIPSNAP1 and insulin-like growth factor 2 mRNA-binding protein 2(IGF2BP2)expression in vivo and in vitro.NIPSNAP1 knockdown impaired mitophagy and disrupted mitochondrial dynamics;in contrast,NIPSNAP1 overexpression resulted in the opposite effects.Further studies revealed that IGF2BP2 functions as an m6A reader that targets and binds NIPSNAP1,thereby regulating its mRNA stability.CONCLUSION NIPSNAP1 prevents hepatic I/R injury by promoting mitophagy and maintaining mitochondrial homeostasis,serving as a novel target of the m6A reader IGF2BP2.Therefore,targeting the IGF2BP2/NIPSNAP1 axis may facilitate the development of better therapeutics for hepatic I/R.展开更多
AIM:Transforming growth interacting factor (TGIF) is an inhibitor of both transforming growth factor β (TGF-β) and retinoid signaling pathways. Moreover, the activation of MAPK pathway can prolong its half-life. How...AIM:Transforming growth interacting factor (TGIF) is an inhibitor of both transforming growth factor β (TGF-β) and retinoid signaling pathways. Moreover, the activation of MAPK pathway can prolong its half-life. However, its role in carcinogenesis is still unknown. Thus we attempted to investigate the effect of TGIF on biologic behaviors of gastric carcinoma cells.METHODS: Gastric carcinoma cell line, SGC-7901, was stably transfected with plasmid PcDNA3.1-TGIF. Western blotting and cell immunohistochemistry screening for the highly expressing clone of TGIF were employed. The growth of transfected cells was investigated by MTT and colonyformation assays, and apoptosis was measured by flow cytometry (FCM) and transmission electron microscopy.Tumorigenicity of the transfectant cells was also analyzed.RESULTS: TGIF had no effect on the proliferation, cell cycle and apoptosis of SGC-7901 cells, but cellular organelles of cells transfected with TGIF were richer than those of vector control or parental cells. Its clones were smaller than the control ones in plate efficiency, and its tumor tissues also had no obvious necrosis compared with the vector control or parental cells. Moreover, TGIF could resist TGF-β mediated growth inhibition.CONCLUSION: TGIF may induce differentiation of stomach neoplastic cells. In addition, TGIF can counteract the growth inhibition induced by TGF-β.展开更多
Environmental control of the alcohol dehydrogenase(Adh)and other stress response genes in plants is in part brought about by transcriptional regulation involving the G-box cis-acting DNA element and bZIP G-box Binding...Environmental control of the alcohol dehydrogenase(Adh)and other stress response genes in plants is in part brought about by transcriptional regulation involving the G-box cis-acting DNA element and bZIP G-box Binding Factors(GBFs).The mechanisms of GBF regulation and requirements for additional factors in this control process are not well understood.In an effort to identify potential GBF binding and control partners,maize GBF1 was used as bait in a yeast two-hybrid screen of an A.thaliana cDNA library.GBF Interacting Protein 1(GIP1)arose from the screen as a 496 amino acid protein with a predicted molecular weight of 53,748 kDa that strongly interacts with GBFs.Northern analysis of A.thaliana tissue suggests a 1.8-1.9 kb GIP1 transcript,predominantly in roots.Immunolocalization studies indicate that GIP1 protein is mainly localized to the nucleus.In vitro electrophoretic mobility shift assays using an Adh G-box DNA probe and recombinant A.thaliana GBF3 or maize GBF1,showed that the presence of GIP1 resulted in a tenfold increase in GBF DNA binding activity without altering the migration,suggesting a transient association between GIP1 and GBF.Addition of GIP1 to intentionally aggregated GBF converted GBF to lower molecular weight macromolecular complexes and GIP1 also refolded denatured rhodanese in the absence of ATP.These data suggest GIP1 functions to enhance GBF DNA binding activity by acting as a potent nuclear chaperone or crowbar,and potentially regulates the multimeric state of GBFs,thereby contributing to bZIP-mediated gene regulation.展开更多
Influence of intramolecular π-π interaction on the luminescent properties of thermally activated delayed fluorescence（TADF） molecule（3, 5-bis（3,6-di-tert-butyl-9 H-carbazol-9-yl）-phenyl）（pyridin-4-yl） methan...Influence of intramolecular π-π interaction on the luminescent properties of thermally activated delayed fluorescence（TADF） molecule（3, 5-bis（3,6-di-tert-butyl-9 H-carbazol-9-yl）-phenyl）（pyridin-4-yl） methanone（DTCBPY） is theoretically studied by using the density functional theory（DFT） and time-dependent density functional theory（TD-DFT）.Four conformations（named as A, B, C, and D） of the DTCBPY can be found by relax scanning, and the configuration C corresponds to the luminescent molecule detected experimentally. Besides, we calculate the proportion of each conformation by Boltzmann distribution, high configuration ratios（44% and 52%） can be found for C and D. Moreover, C and D are found to exist with an intramolecular π-π interaction between one donor and the acceptor; the intramolecular interaction brings a smaller Huang-Rhys factor and reduced reorganization energy. Our work presents a rational explanation for the experimental results and demonstrates the importance of the intramolecular π-π interaction to the photophysical properties of TADF molecules.展开更多
Starting with the interactive factors of relationship, this paper analyzes the interactive feature of relationship marketing within the marketing framework. Based on the interactive model of relationship marketing, th...Starting with the interactive factors of relationship, this paper analyzes the interactive feature of relationship marketing within the marketing framework. Based on the interactive model of relationship marketing, this paper puts forward suggestions concerning effective interactive management of relationship marketing from the organization.展开更多
The ecological environment of the Yellow River Basin has become more fragile under the combined action of natural and manmade activities.However,the change mechanisms of ecological vulnerability in different sub-regio...The ecological environment of the Yellow River Basin has become more fragile under the combined action of natural and manmade activities.However,the change mechanisms of ecological vulnerability in different sub-regions and periods vary,and the reasons for this variability are yet to be explained.Thus,in this study,we proposed a new remote sensing ecological vulnerability index by considering moisture,heat,greenness,dryness,land degradation,and social economy indicators and then analyzed and disclosed the spatial and temporal change patterns of ecological vulnerability of the Yellow River Basin,China from 2000 to 2022 and its driving mechanisms.The results showed that the newly proposed remote sensing ecological vulnerability index had a high accuracy,at 86.36%,which indicated a higher applicability in the Yellow River Basin.From 2000 to 2022,the average remote sensing ecological vulnerability index of the Yellow River Basin was 1.03,denoting moderate vulnerability level.The intensive vulnerability area was the most widely distributed,which was mostly located in the northern part of Shaanxi Province and the eastern part of Shanxi Province.From 2000 to 2022,the ecological vulnerability in the Yellow showed an overall stable trend,while that of the central and eastern regions showed an obvious trend of improvement.The gravity center of ecological vulnerability migrated southwest,indicating that the aggravation of ecological vulnerability in the southwestern regions was more severe than in the northeastern regions of the basin.The dominant single factor of changes in ecological vulnerability shifted from normalized difference vegetation index(NDVI)to temperature from 2000 to 2022,and the interaction factors shifted from temperature∩NDVI to temperature∩precipitation,which indicated that the global climate change exerted a more significant impact on regional ecosystems.The above results could provide decision support for the ecological protection and restoration of the Yellow River Basin.展开更多
Smart urban development is an inevitable choice, and is essential to overall strength improvement. It is important to explore an urban smart development path which unites smart growth with driving shrinkage perfectly ...Smart urban development is an inevitable choice, and is essential to overall strength improvement. It is important to explore an urban smart development path which unites smart growth with driving shrinkage perfectly in forming scientific and sustainable development concept and responding to new normal strategic opportunities. Based on statistic data of 294 prefecture-level cities and above in China from 2000 to 2015, we analyzed spatial and temporal evolution of urban smart development in China by constructing a dynamic fitting model of urban land expansion, population growth, and economic development as well as the coefficient of variation of urban smart development(CVSD). Further efforts were then made to consider differential distribution regularity of urban smart development so as to understand the driving mechanisms of heterogeneous classification of urban smart development in China from different scales and scale variation. Our results indicate that: 1) the disordered growth tendency of urban cities in China is overall well controlled in the middle, and late research and it mainly presented a doublet coexistence of shrinkage disordered cities and smart developing cities. It is particularly obvious that Northeast China and East China have regarded shrinkage disordered cities and smart developing cities as main development tendency separately. 2) Areas with basic stability and relative variation were relatively dispersed across the time period, but the proportion was far beyond areas with significant variation. It demonstrates a relative equilibrium spatial and temporal differential evolution pattern of prefecture-level cities and above in China, except for Tongling, Lanzhou and Chaoyang. 3) prefecture-level cities and above in China are mostly characterized by shrinkage disordered and smart development classification under the background of different scale and scale variation from 2000–2015; however, the spatial resonance relation is not obvious. 4) There are many interaction factors forming an important driving mechanism in developing the spatial and temporal pattern of urban smart development in China, including natural geographical factors, industrial structure adjustment, human capital radiation, regional traffic accessibility, and government decision-making intervention.展开更多
The penny-shaped cracks periodically distributed in infinite elastic body are studied. The prob- lem is approximately simplified to that of a single crack embedded in finite length cylinder and the stress intensity fa...The penny-shaped cracks periodically distributed in infinite elastic body are studied. The prob- lem is approximately simplified to that of a single crack embedded in finite length cylinder and the stress intensity factor is obtained by solving a Fredholm integral equation. Numerical results are given and the effects of crack interaction on the stress intensity factor are discussed.展开更多
The 12 May 2008 Mw 7.9 Wenchuan, China earthquake triggered about 200,000 landslides, which were controlled by a number of factors. This study examines five factors： slope angle, slope aspect, lithology, peak ground ...The 12 May 2008 Mw 7.9 Wenchuan, China earthquake triggered about 200,000 landslides, which were controlled by a number of factors. This study examines five factors： slope angle, slope aspect, lithology, peak ground acceleration （PGA）, and fault side （relative position on the seismogenic fault, i.e., hanging wall or footwall）, to determine how these factors control the co-seismic land- slide occurrence and whether one or more factors, acting alone or in concert, are involved in promoting or suppressing landslides. We performed a multi-factor statistical analysis using data from the 2008 Wenchuan earthquake. The results show that in the areas characterized by steep topography or where strong ground shaking occurred during the earthquake, there is a closer relation- ship between slope aspect and landslide number density （LND） than other areas. The relationship between lithology and LND values depends on PGA. In turn, the relationship between LND values and PGA is also influenced by lithology. In addition, the controlling effect of lithology on co-seismic landslides on the hanging wall of the seismogenic fault is greater than that on the footwall. Examining interactions among these factors can improve understanding of the mechanisms of co-seismic landslide occurrence.展开更多
Enteroviruses(EVs)are human pathogens commonly observed in children aged 0–5 years and adults.EV infections usually cause the common cold and hand-foot-and-mouth disease;however,more severe infections can result in m...Enteroviruses(EVs)are human pathogens commonly observed in children aged 0–5 years and adults.EV infections usually cause the common cold and hand-foot-and-mouth disease;however,more severe infections can result in multiorgan complications,such as polio,aseptic meningitis,and myocarditis.The molecular mechanisms by which enteroviruses cause these diseases are still poorly understood,but accumulating evidence points to two enterovirus proteases,2Apro and 3Cpro,as the key players in pathogenesis.The 2Apro performs post-translational proteolytic processing of viral polyproteins and cleaves several host factors to evade antiviral immune responses and promote viral replication.It was also discovered that coxsackievirus-induced cardiomyopathy was caused by 2Apro-mediated cleavage of dystrophin in cardiomyocytes,indicating that cellular protein proteolysis may play a key role in enterovirus-associated diseases.Therefore,studies of 2Apro could reveal additional substrates that may be associated with specific diseases.Here,we discuss the genetic and structural properties of 2Apro and review how the protease antagonizes innate immune responses to promote viral replication,as well as novel substrates and mechanisms for 2Apro.We also summarize the current approaches for identifying the substrates of 2Apro to discover novel mechanisms relating to certain diseases.展开更多
In this review, we highlight some recent methodological and theoretical develop- ments in estimation and testing of large panel data models with cross-sectional dependence. The paper begins with a discussion of issues...In this review, we highlight some recent methodological and theoretical develop- ments in estimation and testing of large panel data models with cross-sectional dependence. The paper begins with a discussion of issues of cross-sectional dependence, and introduces the concepts of weak and strong cross-sectional dependence. Then, the main attention is primarily paid to spatial and factor approaches for modeling cross-sectional dependence for both linear and nonlinear （nonparametric and semiparametric） panel data models. Finally, we conclude with some speculations on future research directions.展开更多
To determine the effect of humoral factors and their interaction on the developement of acute hypoxic pulmonary pressor response (HPPR), we performed studies in 16 mongrel dogs. We measured plasma levels of noradreali...To determine the effect of humoral factors and their interaction on the developement of acute hypoxic pulmonary pressor response (HPPR), we performed studies in 16 mongrel dogs. We measured plasma levels of noradrealin (NE), angiotensin Ⅱ (AII), prostaglandin F2α (PGF2α), 6-keto-prostaglandin F1α (6KPGF1α), thromboxane B2 (TXB2), leukotriene B4 (LTB4) and 5-hydroxytryptamine (5-HT) before, during and after HPPR. Multiple regression analysis showed that the changes of pulmonary arterial systolic pressure (PASP) and pulmonary arterial diastolic pressure (PADP) correlated well with those of plasma concentration of NE, PGF2α and 6KPGF1α, respectively (r were equal to 0.633 and 0.668, respectively, P<0.01). The results of orthogonal experiment analysis with an injection of exogenous NE, PGF2α and PGIα into main pulmonary artery of dogs showed that NE and the interaction of PGF2α and PGI2α increased PASP (P<0.05) and PGI2 attenuated PASP (P<0.01). The interaction of PGF2α and PGI2 and of PGF2α and NE increased PADP(P<0.01) and PGI2 attenuated PADP (P<0.01).展开更多
Based on the completely parametric crystal-field model, the energy level parameters, including free-ion parameters and crystal-field parameters, obtained by fitting the experimental energy level data sets of Ln^（3＋...Based on the completely parametric crystal-field model, the energy level parameters, including free-ion parameters and crystal-field parameters, obtained by fitting the experimental energy level data sets of Ln^（3＋） in LiYF_4 were systematically analyzed. The results revealed that the regular variation trends of the major parameters at relatively low site symmetry still existed. The g factors of ground states were calculated using the parameters obtained from least-squares fitting. The results for Ce^（3＋）, Nd^（3＋）, Sm^（3＋）, Dy^（3＋） and Yb^（3＋） were in good agreement with experiment, while those of Er^（3＋） deviated from experiment dramatically. Further study showed that the g factors depended strongly on B_4~6, and a slightly different B_4~6 value of -580cm^（-1） led to g factors agreeing well with the experimental values.展开更多
基金supported by the Technology Project of the State Grid Corporation Headquarters Management(Contract No.5100-202158467A-0-0-00).
文摘Voltage source converter based high voltage direct current(VSC-HVDC)can participate in voltage regulation by flexible control to help maintain the voltage stability of the power grid.In order to quantitatively evaluate its influence on the voltage interaction between VSC-HVDC and line commutated converter based high voltage direct current(LCC-HVDC),this paper proposes a hybrid multi-infeed interaction factor(HMIIF)calculation method considering the voltage regulation control characteristics of VSC-HVDC.Firstly,for a hybrid multi-infeed high voltage direct current system,an additional equivalent operating admittance matrix is constructed to characterize HVDC equipment characteristics under small disturbance.Secondly,based on the characteristic curve between the reactive power and the voltage of a certain VSC-HVDC project,the additional equivalent operating admittance of VSC-HVDC is derived.The additional equivalent operating admittance matrix calculation method is proposed.Thirdly,the equivalent bus impedance matrix is obtained by modifying the alternating current(AC)system admittance matrix with the additional equivalent operating admittance matrix.On this basis,the HMIIF calculation method based on the equivalent bus impedance ratio is proposed.Finally,the effectiveness of the proposed method is verified in a hybrid dual-infeed high voltage direct current system constructed in Power Systems Computer Aided Design(PSCAD),and the influence of voltage regulation control on HMIIF is analyzed.
基金The National Natural Science Foundation of China(No.50478022)
文摘A rigorous analytical method is presented for calculating the interaction factor between two identical piles subjected to vertical loads. Following the technique proposed by Muki and Sternberg, the problem is decomposed into an extended soil mass and two fictitious piles characterized respectively by Young＇s modulus of the soil and that of the difference between the pile and soil. The unknown axial forces along fictitious piles are determined by solving a Fredholm integral equation of the second kind, which imposes the compatibility condition that the axial strains of the fictitious piles are equal to those corresponding to the centroidal axes of the extended soil. The real pile forces and displacements can subequally be calculated based on the determined fictitious pile forces, and finally, the validity of the proposed approach and desired pile interaction factors may be obtained. Results confirm the portray the influence of the governing parameters on the pile interaction.
基金National Natural Science Foundation of China(No.50478022)Research and Innovation Project of Shanghai Education Committee,China(No.10YZ208)Excellent Young Teacher Project of Shanghai Education Committee,China(No.dsd08005)
文摘A rigorous analytical method is presented, which takes into account the pile stiffening effects, using the theory of the transfer matrix-bottom rigidity for calculating the interaction factor between two identical piles in multi-layered soils subjected to vertical loads. Following the technique proposed by Muki and Sternberg, the problem is decomposed into extended soil layers and two fictitious piles characterized respectively by Young's moduli of the layered soils and those of the differences between the piles and the layered soils. The unknown axial forces along fictitious piles are determined by solving a Fredholm integral equation of the second kind, which imposes the compatibility condition that the axial strains of the fictitious piles are equal to those corresponding to the centroidal axes of the extended layered soils. The real pile displacements can be calculated based on the determined fictitious pile forces, and finally, the desired pile interaction factors may be obtained. Selected results from parametrical studies are presented to confirm the validity of the proposed approach and portray the influence of the governing parameters on the pile interaction.
基金supported by startup funding to C.X.from State Key Laboratory of Plant Genomics and Institute of Genetics and Developmental Biology,Chinese Academy of Sciences,and a National Science Foundation grant(IOS-1556171)to Z.B.L
文摘Inflorescences are flower-bearing shoots that originate from pools of stem cells in shoot apical meristems (SAM).Inflorescence architecture is determined by a process of meristem maturation,during which stem cell fate switches from a vegetative to a reproductive growth program.A major factor in plant reproductive success in nature and yield in agriculture is the number of branches and flowers on inflorescences (Kobayashi and Weigel,2007;
文摘The cyclic plastic straining electrode technique has been used to investigate the transient electrochemical behaviour of Fe-26Cr1Mo stainless steel in 1M H2SO4 solution at a passive potential.The influence of plastic strain amplitude and plastic strain rate on the dissolution current response was analysed. The experimental results showed that the transient current was dependent on the competitive process of the surface film rupture and repassivation of the new surface. The high plastic strain amplitude and the high plastic strain rate caused a change of electrochemical activity of specimen surface. In the condition of low strain amplitude and strain rate, the characteristics of current response was mainly relative tp the process of new surface repassivation.The competition kinetics has been analysed through the comparison of plastic strain rate and repassivating rate
基金supported by the grants from the National Natural Science Foundation of China(82404638)the Xingdian Talent Plan of Yunnan Province(XDYC-QNRC-2023-0427 and XDYC-YLXZ-2022-0025)the Natural Science Foundation of Yunnan Province(202101BD070001-034,202101BD070001-049,202201AT070267,and 202201AU070183).
文摘Tumor necrosis factor-α(TNF-α)is a key player in the pathogenesis of rheumatoid arthritis(RA)and considered a promising target for therapeutic drug development.Activation of the nuclear factor-kappa B(NF-κB)pathway upon TNF-αbinding to its receptor is crucial for progression of RA.Stephanine(SA),an isoquinoline aporphine-type alkaloid recently identified in Stephania plants,exhibits anti-inflammatory properties,but its underlying mechanisms of action are unknown at present.In this study,we explored whether SA could ameliorate RA through inhibition of the NF-κB signaling pathway in association with TNF-αactivity.Our experiments revealed a binding affinity(K_(D))of SA for TNF-αof 2.934×10^(-6)mol/L.Additionally,SA at a concentration of 10μmol/L effectively hindered the binding of TNF-αto its receptors tumor necrosis factor receptor 1(TNFR1)and TNFR2.In vitro,SA prevented TNF-α-induced death of L929 cells and blocked NF-κB activation triggered by TNF-αin 293-TNF-αresponsive,as well as human fibroblast-like synoviocytes(HFLS)and human RA fibroblast-like synoviocytes(MH7A)cell lines.Furthermore,in a collagen-induced arthritis(CIA)mouse model,SA alleviated the symptoms of RA through suppression of NF-κB signaling.Our collective findings support the therapeutic efficacy of SA,a natural compound targeting TNF-α,in the management of RA.
基金Supported by the National Natural Science Foundation of China,No.82200658.
文摘BACKGROUND Hepatic ischemia-reperfusion(I/R)injury related to liver transplantation and hepatic resection remains a challenge in clinical practice.Accumulating evidence indicates that mitochondrial dysfunction is a critical cause of I/R injury.The protein 4-nitrophenylphosphatase domain and non-neuronal SNAP25-like protein homolog 1(NIPSNAP1)is involved in the regulation of mitophagy and the recruitment of autophagy receptor proteins independent of PTEN induced putative kinase 1.AIM To clarify the protective mechanism of NIPSNAP1 against hepatic I/R,with a focus on mitophagy and mitochondrial dynamics,as well as the potential mechanism by which n6-methyladenosine(m6A)modification regulates NIPSNAP1.METHODS Mice were administered an adeno-associated virus in vivo and a hepatic I/R model was established via portal vein interruption followed by reperfusion to explore the effect of NIPSNAP1 on hepatic I/R.HepG2 cells were subjected to hypoxia/reoxygenation treatment in vitro.RESULTS We observed a significant downregulation of both NIPSNAP1 and insulin-like growth factor 2 mRNA-binding protein 2(IGF2BP2)expression in vivo and in vitro.NIPSNAP1 knockdown impaired mitophagy and disrupted mitochondrial dynamics;in contrast,NIPSNAP1 overexpression resulted in the opposite effects.Further studies revealed that IGF2BP2 functions as an m6A reader that targets and binds NIPSNAP1,thereby regulating its mRNA stability.CONCLUSION NIPSNAP1 prevents hepatic I/R injury by promoting mitophagy and maintaining mitochondrial homeostasis,serving as a novel target of the m6A reader IGF2BP2.Therefore,targeting the IGF2BP2/NIPSNAP1 axis may facilitate the development of better therapeutics for hepatic I/R.
文摘AIM:Transforming growth interacting factor (TGIF) is an inhibitor of both transforming growth factor β (TGF-β) and retinoid signaling pathways. Moreover, the activation of MAPK pathway can prolong its half-life. However, its role in carcinogenesis is still unknown. Thus we attempted to investigate the effect of TGIF on biologic behaviors of gastric carcinoma cells.METHODS: Gastric carcinoma cell line, SGC-7901, was stably transfected with plasmid PcDNA3.1-TGIF. Western blotting and cell immunohistochemistry screening for the highly expressing clone of TGIF were employed. The growth of transfected cells was investigated by MTT and colonyformation assays, and apoptosis was measured by flow cytometry (FCM) and transmission electron microscopy.Tumorigenicity of the transfectant cells was also analyzed.RESULTS: TGIF had no effect on the proliferation, cell cycle and apoptosis of SGC-7901 cells, but cellular organelles of cells transfected with TGIF were richer than those of vector control or parental cells. Its clones were smaller than the control ones in plate efficiency, and its tumor tissues also had no obvious necrosis compared with the vector control or parental cells. Moreover, TGIF could resist TGF-β mediated growth inhibition.CONCLUSION: TGIF may induce differentiation of stomach neoplastic cells. In addition, TGIF can counteract the growth inhibition induced by TGF-β.
基金This research was supported by the U S Department of Agriculture Grants 00-35304-96Ol and 98-35301-6083.
文摘Environmental control of the alcohol dehydrogenase(Adh)and other stress response genes in plants is in part brought about by transcriptional regulation involving the G-box cis-acting DNA element and bZIP G-box Binding Factors(GBFs).The mechanisms of GBF regulation and requirements for additional factors in this control process are not well understood.In an effort to identify potential GBF binding and control partners,maize GBF1 was used as bait in a yeast two-hybrid screen of an A.thaliana cDNA library.GBF Interacting Protein 1(GIP1)arose from the screen as a 496 amino acid protein with a predicted molecular weight of 53,748 kDa that strongly interacts with GBFs.Northern analysis of A.thaliana tissue suggests a 1.8-1.9 kb GIP1 transcript,predominantly in roots.Immunolocalization studies indicate that GIP1 protein is mainly localized to the nucleus.In vitro electrophoretic mobility shift assays using an Adh G-box DNA probe and recombinant A.thaliana GBF3 or maize GBF1,showed that the presence of GIP1 resulted in a tenfold increase in GBF DNA binding activity without altering the migration,suggesting a transient association between GIP1 and GBF.Addition of GIP1 to intentionally aggregated GBF converted GBF to lower molecular weight macromolecular complexes and GIP1 also refolded denatured rhodanese in the absence of ATP.These data suggest GIP1 functions to enhance GBF DNA binding activity by acting as a potent nuclear chaperone or crowbar,and potentially regulates the multimeric state of GBFs,thereby contributing to bZIP-mediated gene regulation.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11374195 and 21403133)Taishan Scholar Project of Shandong Normal University,China+1 种基金the Promotive Research Fund for Excellent Young and Middle-aged Scientists of Shandong Province,China(Grant No.BS2014cl001)the China Postdoctoral Science Foundation(Grant No.2014M560571)
文摘Influence of intramolecular π-π interaction on the luminescent properties of thermally activated delayed fluorescence（TADF） molecule（3, 5-bis（3,6-di-tert-butyl-9 H-carbazol-9-yl）-phenyl）（pyridin-4-yl） methanone（DTCBPY） is theoretically studied by using the density functional theory（DFT） and time-dependent density functional theory（TD-DFT）.Four conformations（named as A, B, C, and D） of the DTCBPY can be found by relax scanning, and the configuration C corresponds to the luminescent molecule detected experimentally. Besides, we calculate the proportion of each conformation by Boltzmann distribution, high configuration ratios（44% and 52%） can be found for C and D. Moreover, C and D are found to exist with an intramolecular π-π interaction between one donor and the acceptor; the intramolecular interaction brings a smaller Huang-Rhys factor and reduced reorganization energy. Our work presents a rational explanation for the experimental results and demonstrates the importance of the intramolecular π-π interaction to the photophysical properties of TADF molecules.
文摘Starting with the interactive factors of relationship, this paper analyzes the interactive feature of relationship marketing within the marketing framework. Based on the interactive model of relationship marketing, this paper puts forward suggestions concerning effective interactive management of relationship marketing from the organization.
基金funded by the National Natural Science Foundation of China(42471329,42101306,42301102)the Natural Science Foundation of Shandong Province(ZR2021MD047)+1 种基金the Scientific Innovation Project for Young Scientists in Shandong Provincial Universities(2022KJ224)the Gansu Youth Science and Technology Fund Program(24JRRA100).
文摘The ecological environment of the Yellow River Basin has become more fragile under the combined action of natural and manmade activities.However,the change mechanisms of ecological vulnerability in different sub-regions and periods vary,and the reasons for this variability are yet to be explained.Thus,in this study,we proposed a new remote sensing ecological vulnerability index by considering moisture,heat,greenness,dryness,land degradation,and social economy indicators and then analyzed and disclosed the spatial and temporal change patterns of ecological vulnerability of the Yellow River Basin,China from 2000 to 2022 and its driving mechanisms.The results showed that the newly proposed remote sensing ecological vulnerability index had a high accuracy,at 86.36%,which indicated a higher applicability in the Yellow River Basin.From 2000 to 2022,the average remote sensing ecological vulnerability index of the Yellow River Basin was 1.03,denoting moderate vulnerability level.The intensive vulnerability area was the most widely distributed,which was mostly located in the northern part of Shaanxi Province and the eastern part of Shanxi Province.From 2000 to 2022,the ecological vulnerability in the Yellow showed an overall stable trend,while that of the central and eastern regions showed an obvious trend of improvement.The gravity center of ecological vulnerability migrated southwest,indicating that the aggravation of ecological vulnerability in the southwestern regions was more severe than in the northeastern regions of the basin.The dominant single factor of changes in ecological vulnerability shifted from normalized difference vegetation index(NDVI)to temperature from 2000 to 2022,and the interaction factors shifted from temperature∩NDVI to temperature∩precipitation,which indicated that the global climate change exerted a more significant impact on regional ecosystems.The above results could provide decision support for the ecological protection and restoration of the Yellow River Basin.
基金Under the auspices of National Natural Science Foundation of China(No.41101548)Philosophy and Social Science Research Program of Heilongjiang Province in 2016(No.16JBL01)+1 种基金Key Research Projects of Economic and Social Development in Heilongjiang Province(No.JD2016014)Human Civilization and Social Science Supportive Program for Excellent Young Scholars of Harbin Normal University(No.SYQ2014-06)
文摘Smart urban development is an inevitable choice, and is essential to overall strength improvement. It is important to explore an urban smart development path which unites smart growth with driving shrinkage perfectly in forming scientific and sustainable development concept and responding to new normal strategic opportunities. Based on statistic data of 294 prefecture-level cities and above in China from 2000 to 2015, we analyzed spatial and temporal evolution of urban smart development in China by constructing a dynamic fitting model of urban land expansion, population growth, and economic development as well as the coefficient of variation of urban smart development(CVSD). Further efforts were then made to consider differential distribution regularity of urban smart development so as to understand the driving mechanisms of heterogeneous classification of urban smart development in China from different scales and scale variation. Our results indicate that: 1) the disordered growth tendency of urban cities in China is overall well controlled in the middle, and late research and it mainly presented a doublet coexistence of shrinkage disordered cities and smart developing cities. It is particularly obvious that Northeast China and East China have regarded shrinkage disordered cities and smart developing cities as main development tendency separately. 2) Areas with basic stability and relative variation were relatively dispersed across the time period, but the proportion was far beyond areas with significant variation. It demonstrates a relative equilibrium spatial and temporal differential evolution pattern of prefecture-level cities and above in China, except for Tongling, Lanzhou and Chaoyang. 3) prefecture-level cities and above in China are mostly characterized by shrinkage disordered and smart development classification under the background of different scale and scale variation from 2000–2015; however, the spatial resonance relation is not obvious. 4) There are many interaction factors forming an important driving mechanism in developing the spatial and temporal pattern of urban smart development in China, including natural geographical factors, industrial structure adjustment, human capital radiation, regional traffic accessibility, and government decision-making intervention.
基金The project suppoted by National Natural Science Foundation of China
文摘The penny-shaped cracks periodically distributed in infinite elastic body are studied. The prob- lem is approximately simplified to that of a single crack embedded in finite length cylinder and the stress intensity factor is obtained by solving a Fredholm integral equation. Numerical results are given and the effects of crack interaction on the stress intensity factor are discussed.
基金This research was supported by the National Natural Science Foundation of China （Grant Nos. 41472202 and 41202235） and the National Basic Research Program of China （No. 2012BAK10B03）. Comments from three anonymous reviewers significantly improved this manuscript.
文摘The 12 May 2008 Mw 7.9 Wenchuan, China earthquake triggered about 200,000 landslides, which were controlled by a number of factors. This study examines five factors： slope angle, slope aspect, lithology, peak ground acceleration （PGA）, and fault side （relative position on the seismogenic fault, i.e., hanging wall or footwall）, to determine how these factors control the co-seismic land- slide occurrence and whether one or more factors, acting alone or in concert, are involved in promoting or suppressing landslides. We performed a multi-factor statistical analysis using data from the 2008 Wenchuan earthquake. The results show that in the areas characterized by steep topography or where strong ground shaking occurred during the earthquake, there is a closer relation- ship between slope aspect and landslide number density （LND） than other areas. The relationship between lithology and LND values depends on PGA. In turn, the relationship between LND values and PGA is also influenced by lithology. In addition, the controlling effect of lithology on co-seismic landslides on the hanging wall of the seismogenic fault is greater than that on the footwall. Examining interactions among these factors can improve understanding of the mechanisms of co-seismic landslide occurrence.
基金supported by the National Key Research and Development Program of China (Project No.2021YFC2302003).
文摘Enteroviruses(EVs)are human pathogens commonly observed in children aged 0–5 years and adults.EV infections usually cause the common cold and hand-foot-and-mouth disease;however,more severe infections can result in multiorgan complications,such as polio,aseptic meningitis,and myocarditis.The molecular mechanisms by which enteroviruses cause these diseases are still poorly understood,but accumulating evidence points to two enterovirus proteases,2Apro and 3Cpro,as the key players in pathogenesis.The 2Apro performs post-translational proteolytic processing of viral polyproteins and cleaves several host factors to evade antiviral immune responses and promote viral replication.It was also discovered that coxsackievirus-induced cardiomyopathy was caused by 2Apro-mediated cleavage of dystrophin in cardiomyocytes,indicating that cellular protein proteolysis may play a key role in enterovirus-associated diseases.Therefore,studies of 2Apro could reveal additional substrates that may be associated with specific diseases.Here,we discuss the genetic and structural properties of 2Apro and review how the protease antagonizes innate immune responses to promote viral replication,as well as novel substrates and mechanisms for 2Apro.We also summarize the current approaches for identifying the substrates of 2Apro to discover novel mechanisms relating to certain diseases.
基金Supported by the National Natural Science Foundation of China(71131008(Key Project)and 71271179)
文摘In this review, we highlight some recent methodological and theoretical develop- ments in estimation and testing of large panel data models with cross-sectional dependence. The paper begins with a discussion of issues of cross-sectional dependence, and introduces the concepts of weak and strong cross-sectional dependence. Then, the main attention is primarily paid to spatial and factor approaches for modeling cross-sectional dependence for both linear and nonlinear （nonparametric and semiparametric） panel data models. Finally, we conclude with some speculations on future research directions.
文摘To determine the effect of humoral factors and their interaction on the developement of acute hypoxic pulmonary pressor response (HPPR), we performed studies in 16 mongrel dogs. We measured plasma levels of noradrealin (NE), angiotensin Ⅱ (AII), prostaglandin F2α (PGF2α), 6-keto-prostaglandin F1α (6KPGF1α), thromboxane B2 (TXB2), leukotriene B4 (LTB4) and 5-hydroxytryptamine (5-HT) before, during and after HPPR. Multiple regression analysis showed that the changes of pulmonary arterial systolic pressure (PASP) and pulmonary arterial diastolic pressure (PADP) correlated well with those of plasma concentration of NE, PGF2α and 6KPGF1α, respectively (r were equal to 0.633 and 0.668, respectively, P<0.01). The results of orthogonal experiment analysis with an injection of exogenous NE, PGF2α and PGIα into main pulmonary artery of dogs showed that NE and the interaction of PGF2α and PGI2α increased PASP (P<0.05) and PGI2 attenuated PASP (P<0.01). The interaction of PGF2α and PGI2 and of PGF2α and NE increased PADP(P<0.01) and PGI2 attenuated PADP (P<0.01).
基金Project supported by the National Key Basic Research Program of China(2013CB921800)the National Natural Science Foundation of China(11274299,11374291,11574298,11204292,11404321)the Anhui Provincial Natural Science Foundation(1308085QE75)
文摘Based on the completely parametric crystal-field model, the energy level parameters, including free-ion parameters and crystal-field parameters, obtained by fitting the experimental energy level data sets of Ln^（3＋） in LiYF_4 were systematically analyzed. The results revealed that the regular variation trends of the major parameters at relatively low site symmetry still existed. The g factors of ground states were calculated using the parameters obtained from least-squares fitting. The results for Ce^（3＋）, Nd^（3＋）, Sm^（3＋）, Dy^（3＋） and Yb^（3＋） were in good agreement with experiment, while those of Er^（3＋） deviated from experiment dramatically. Further study showed that the g factors depended strongly on B_4~6, and a slightly different B_4~6 value of -580cm^（-1） led to g factors agreeing well with the experimental values.
