Objective:Triple-negative breast cancer(TNBC)is highly metastatic,and there is an urgent unmet need to develop novel therapeutic strategies leading to the new drug discoveries against metastasis.The transforming growt...Objective:Triple-negative breast cancer(TNBC)is highly metastatic,and there is an urgent unmet need to develop novel therapeutic strategies leading to the new drug discoveries against metastasis.The transforming growth factor-β(TGF-β)is known to promote the invasive and migratory potential of breast cancer cells through induction of epithelial–mesenchymal transition(EMT)via the ERK/NF-κB/Snail signaling pathway,leading to breast cancer metastasis.Targeting this pathway to revert the EMT would be an attractive,novel therapeutic strategy to halt breast cancer metastasis.Methods:Effects of enterolactone(EL)on the cell cycle and apoptosis were investigated using flow cytometry and a cleaved caspase-3 enzyme-linked immunosorbent assay(ELISA),respectively.Effects of TGF-βinduction and EL treatment on the functional malignancy of MDA-MB-231 breast cancer cells were investigated using migration and chemo-invasion assays.The effects of EL on EMT markers and the ERK/NF-κB/Snail signaling pathway after TGF-βinduction were studied using confocal microscopy,quantitative reverse transcription polymerase chain reaction(q RT-PCR),Western blot,and flow cytometry.Results:Herein,we report that EL exhibits a significant antimetastatic effect on MDA-MB-231 cells by almost reverting the TGF-β-induced EMT in vitro.EL downregulates the mesenchymal markers N-cadherin and vimentin,and upregulates the epithelial markers E-cadherin and occludin.It represses actin stress fiber formation via inhibition of mitogen-activated protein kinase p-38(MAPK-p38)and cluster of differentiation 44(CD44).EL also suppresses ERK-1/2,NF-κB,and Snail at the m RNA and protein levels.Conclusions:Briefly,EL was found to inhibit TGF-β-induced EMT by blocking the ERK/NF-κB/Snail signaling pathway,which is a promising target for breast cancer metastasis therapy.展开更多
A tetrad mechanism for exciting long waves, for example edge waves, is described based on nonlinear resonant wave-wave interactions. In this mechanism, resonant interactions pass energy to an edge wave, from the three...A tetrad mechanism for exciting long waves, for example edge waves, is described based on nonlinear resonant wave-wave interactions. In this mechanism, resonant interactions pass energy to an edge wave, from the three participating gravity waves. The estimated action flux into the edge wave can be orders of magni- tude greater than the transfer fluxes derived from other competing mechanisms, such as triad interactions. More- over, the numerical results show that the actual transfer rates into the edge wave from the three participating gravity waves are two- to three- orders of magnitude greater than bottom friction.展开更多
The electromagnetic direct chill (EMDC) casting process is a welt-established production route for aluminum alloy ingot, however, the skin effect restricts the casting diameter. In order to avoid this problem, annul...The electromagnetic direct chill (EMDC) casting process is a welt-established production route for aluminum alloy ingot, however, the skin effect restricts the casting diameter. In order to avoid this problem, annulus electromagnetic direct chill (A-EMDC) casting process has been developed. A three-dimension finite element computational model of A-EMDC casting process was established by using ANSYS Magnetic-Nodal programs and FLOTRAN CFD programs. Microstruetures of A-EMDC casting semi-solid Al-6Si-3Cu-Mg alloy billets were investigated. Two pairs of vortexes occur within the crystallizer with opposite direction in A-EMDC. The annulus gap is advantageous to increasing circulate flow, reducing the temperature gradient as well as shallowing liquid sump depth. The microstructure obtained by A-EMDC is globular or rosette-like, and the microstructure is homogeneous in the billet.展开更多
Phase diagrams of two isothermal sections of the Ni-Ti-Ta ternary system at 1000 and 1200℃in a full composition range were determined by X-ray diffraction and electron probe microanalysis.The experimental results ind...Phase diagrams of two isothermal sections of the Ni-Ti-Ta ternary system at 1000 and 1200℃in a full composition range were determined by X-ray diffraction and electron probe microanalysis.The experimental results indicated a ternary compoundτphase with low solid solubility and composition ranges of(16.3-22.4)at.%Ta,(15.9-24.1)at.%Ti and(58.5-60.0)at.%Ni at 1000℃.The two terminal solid solutions(bcc-(Ta)andβ-Ti)formed a continuous solid solution at 1000 and 1200℃.A certain amount of Ti can dissolve into Ni-Ta intermetallic compounds near the Ni-Ta side,with the highest value of 21.9 at.%observed in the Ni;Ta compound at 1000℃.展开更多
Arc erosion morphologies of Ag/MeO(10) electrical contact materials after 50000 operations under direct current of 19 V and 20 A and resistive load conditions were investigated using scanning electron microscope(SE...Arc erosion morphologies of Ag/MeO(10) electrical contact materials after 50000 operations under direct current of 19 V and 20 A and resistive load conditions were investigated using scanning electron microscope(SEM) and a 3D optical profiler(3DOP). The results indicated that 3DOP could supply clearer and more detailed arc erosion morphology information. Arc erosion resistance of Ag/SnO_2(10) electrical contact material was the best and that of Ag/CuO(10) was the worst. Arc erosion morphology of Ag/MeO(10) electrical contact materials mainly included three different types. Arc erosion morphologies of Ag/ZnO(10) and Ag/SnO_2(10) electrical contact materials were mainly liquid splash and evaporation, and those of Ag/CuO(10) and Ag/CdO(10) were mainly material transfer from anode to cathode. Arc erosion morphology of Ag/SnO_2(6)In_2O_3(4) electrical contact materials included both liquid splash, evaporation and material transfer. In addition, the formation process and mechanism on arc erosion morphology of Ag/MeO(10) electrical contact materials were discussed.展开更多
The ionic liquid, 1-butyl-3-methylimidazolium dibutylphosphate ([BMIM][DBP]) was prepared and the vapor pressures of three set of binary solutions H2O(1)/CH3OH(1)/C2H5OH(1) + [BMIM][DBP](2) were measured at different ...The ionic liquid, 1-butyl-3-methylimidazolium dibutylphosphate ([BMIM][DBP]) was prepared and the vapor pressures of three set of binary solutions H2O(1)/CH3OH(1)/C2H5OH(1) + [BMIM][DBP](2) were measured at different temperature and in the ILs mole fraction range from 0.1 to 0.6 with a static equilibrium apparatus. The measured vapor pressures were correlated with Non-Random Two Liquid (NRTL) activity coefficient model and the average relative deviations (ARD) between experimental and correlated vapor pressures for these binary solutions were 3.19%, 2.42% and 2.95%, respectively. Then, the vapor pressures of two set of ternary solutions H2O(1) + CH3OH(2)/C2H5OH(2) + [BMIM][DBP](3) were measured with an inclined boiling apparatus and further predicted with NRTL activity coefficient model based on the binary interaction parameters coming from fitting the vapor pressures of the binary solutions. The results indicated that the ternary solutions containing [BMIM][DBP] were shown a strong negative deviation from Raoult's Law when the mole fraction of [BMIM][DBP] was larger than 0.2, which meant that ternary solutions could absorb the refrigerant vapors at the same or below solution temperature. Meanwhile, the average relative deviations between experimental and predicted vapor pressures for ternary solutions were 2.92% and 3.06%, respectively. Consequently, the NRTL active coefficient model used for non-electrolyte solutions was still valid for predicting vapor-liquid equilibrium of binary or ternary solutions containing ILs.展开更多
As expounded in some recent mathematical conferences, this research on that amazing source of algebraic ideas known as Fermat's equation is aimed to prove how Fermat triples can be limited until the impossible existe...As expounded in some recent mathematical conferences, this research on that amazing source of algebraic ideas known as Fermat's equation is aimed to prove how Fermat triples can be limited until the impossible existence through a criterion of incompatible parities related to unexplored properties of the binomial coefficients. In this paper, the authors use a technique based on the analysis of four numbers and their internal relations with three basic compulsory factors. It leads to the practical impossibility to find any triple of natural numbers candidate to satisfy Fermat's equation, because when the authors try to meet a condition between parity and range the authors are compelled to violate the other one, so that they are irreducibly alternative. In particular, there is a parity violation when the authors choose all the basic factors in the allowed range and the authors obtain exceeding values of one of the involved variables when the authors try to restore the parity. Since Fermat's last theorem would consequently be demonstrated, many readers could recall the never found elementary proof of FLT (Fermat's last theorem) claimed by Pierre de Fermat. The authors are not encouraging such an interpretation because this paper is intended as a journey into Fermat's equation and the reader's attitude should be towards the algebraic achievements here proposed, with their possible hidden flaws and future developments, rather than to legendary problems like Fermat's riddle.展开更多
In order to investigate the origin of catalytic power for serine proteases,the role of the hydrogen bond in the catalytic triad was studied in the proteolysis process of the peptides chymotrypsin inhibitor 2(CI2),MCTI...In order to investigate the origin of catalytic power for serine proteases,the role of the hydrogen bond in the catalytic triad was studied in the proteolysis process of the peptides chymotrypsin inhibitor 2(CI2),MCTI-A,and a hexapeptide(SUB),respectively.We first calculated the free energy profile of the proton transfer between His and Asp residues of the catalytic triad in the enzyme-substrate state and transition state by employing QM/MM molecular dynamics simulations.The results show that a low-barrier hydrogen bond(LBHB)only forms in the transition state of the acylation of CI2,while it is a normal hydrogen bond in the acylation of MCTI-A or SUB.In addition,the change of the hydrogen bond strength is much larger in CI2 and SUB systems than in MCTI-A system,which decreases the acylation energy barrier significantly for CI2 and SUB.Clearly,a LBHB formed in the transition state region helps accelerate the acylation reaction.But to our surprise,a normal hydrogen bond can also help to decrease the energy barrier.The key to reducing the reaction barrier is the increment of hydrogen bond strength in the transition state state,whether it is a LBHB or not.Our studies cast new light on the role of the hydrogen bond in the catalytic triad,and help to understand the catalytic triad of serine proteases.展开更多
Based on the trivariate reduction technique two different trivariate Bernoulli mixtures of univariate uniform distributions and their associated trivariate copulas with bivariate linear Spearman marginal copulas are c...Based on the trivariate reduction technique two different trivariate Bernoulli mixtures of univariate uniform distributions and their associated trivariate copulas with bivariate linear Spearman marginal copulas are considered. Mathematical characterizations of these Bernoulli mixture models are obtained. Since Bernoulli mixture trivariate reduction copulas are not compatible with all valid grade correlation coefficients, and there exist linear Spearman compatible non-Bernoulli mixture trivariate copulas, one can ask when there exists at all a trivariate copula with given linear Spearman marginal copulas. Based on a known concordance ordering compatibility criterion, a set of grade correlation inequalities, which must necessarily be satisfied for compatibility, is derived. The existence question for trivariate copulas with compatible linear Spearman marginal copulas is settled in the main result, which states that this set of inequalities is also sufficient for compatibility. The constructive proof makes use of two new classes of trivariate copulas that are obtained from the Bernoulli mixture trivariate copulas through a natural parametric extension. Finally, the obtained classes of trivariate copulas are compared with another class that contains as special case some trivariate copulas with linear Spearman marginal copulas. Since the latter class is incompatible with some type of linear Spearman copulas, the new classes of trivariate copulas build a richer class in this respect. Moreover, in contrast to the mentioned class, which requires in general 11 different elementary copulas in the defining convex linear combination, the new classes require at most five of them, which results in a more parsimonious parametric modelling.展开更多
This paper is composed of three elements: 3D modeling, web design and heritage visualization on the basis of the chronological restoration of Fort Frontenac in 1673, 1675, 1680, 1685 and 1688, changing from narrow an...This paper is composed of three elements: 3D modeling, web design and heritage visualization on the basis of the chronological restoration of Fort Frontenac in 1673, 1675, 1680, 1685 and 1688, changing from narrow and plain to broad, grand features. The aim is to use computer graphic design to inform and create an interest in historical visualization by rebuilding Fort Frontenac using 3D modeling and interactive design. The final model can be integrated into an interactive website to learn more about the fort's historic importance. It is apparent that using computer graphics can save time and money when it comes to historical visualization. Visitors do not have to travel to the actual archaeological buildings and can simply use the web in their own homes to learn about this information virtually. In order to create a sophisticated restoration of archaeological buildings, meticulously assessing historical records will draw viewers into the visualizations, such as the historical world of Fort Frontenac. As a result, the completed restoration allows the viewers to effectively understand the fort's social system, habits and historical events.展开更多
This work provides a method to explore the transport property of the electrolyte aqueous solutions with one or two ionic liquids, especially focus on their electrical conductivity. The conductivities were measured for...This work provides a method to explore the transport property of the electrolyte aqueous solutions with one or two ionic liquids, especially focus on their electrical conductivity. The conductivities were measured for the ternary systems Na Cl–[C6mim][Cl](1-hexyl-3-methylimidazolium chloride)–H2O, [C6mim][BF4]–[C6mim][Cl]–H2O,Na NO3–[C6mim][BF4](1-hexyl-3-methylimidazolium tetrafluoroborate)–H2O, and [C4mim][BF4](1-butyl-3-methylimidazolium tetrafluoroborate)–[C6mim][BF4]–H2O, and their binary subsystems NaN O3–H2O, NaC l–H2O,[C6mim][BF4]–H2O, [C6mim][Cl]–H2O, and [C4mim][BF4]–H2O, respectively. The conductivities of the ternary systems were also determined using generalized Young's rule and semi-ideal solution theory in terms of the data of their binary solutions. The comparison showed that the two simple equations provide good predictions for conductivity of mixed electrolyte solutions and the mixed ionic liquid solutions based on the conductivity of their binary subsystems.展开更多
Triple-negative breast cancer (TNBC), characterized by the lack of expression of the estrogen receptor, the progesterone receptor, and the human epidermal growth factor receptor 2, is an aggressive form of cancer th...Triple-negative breast cancer (TNBC), characterized by the lack of expression of the estrogen receptor, the progesterone receptor, and the human epidermal growth factor receptor 2, is an aggressive form of cancer that conveys unpredictable and poor prognosis due to limited treatment options and lack of effective targeted therapies. Wnt/β-catenin signaling is hyperactivated in TNBC, which promotes the progression of TNBC. However, the molecular mechanism of Wnt/β-catenin activation in TNBC remains unknown. Here, we report the drastic overexpression of miR-221/222 in all of four TNBC cell lines and TNBC primary tumor samples from patients. Furthermore, we demonstrate by both ex vivo and xenograft experiments that inhibiting miR-221/222 expression in a TNBC cell line (MDA-MB-231) suppresses its proliferation, viability, epithelial-to-mesenchymal transition, and migration; whereas expressing miR-221/222 in a non-TNBC line (MCF7) promotes all of the above cancer properties. miR-221/222 achieve so by directly repressing multiple negative regulators of the Wnt/β-catenin signaling pathway, including WIF1, SFRP2, DKK2, and AXIN2, to activate the pathway. Notably, the level of miR-221/222 expression is inversely correlated whereas that of WIF1, DKK2, SFRP2, and AXIN2 expression is positively correlated with the patient survival. Last, we show that anti-miR-221/222 significantly increases apoptotic cells with tamoxifen/Wnt3a treatment but not with cyclophosphamide/Wnt3a treatment. These results demonstrate that miR-221/222 activate the Wnt/β-catenin signaling to promote the aggressiveness and TNBC properties of breast cancers, and thus reveal a new prospect for TNBC treatment.展开更多
In this paper, we first show that there is a Hom-Lie algebra structure on the set of(σ, σ)-derivations of an associative algebra. Then we construct the dual representation of a representation of a Hom-Lie algebra.We...In this paper, we first show that there is a Hom-Lie algebra structure on the set of(σ, σ)-derivations of an associative algebra. Then we construct the dual representation of a representation of a Hom-Lie algebra.We introduce the notions of a Manin triple for Hom-Lie algebras and a purely Hom-Lie bialgebra. Using the coadjoint representation, we show that there is a one-to-one correspondence between Manin triples for Hom-Lie algebras and purely Hom-Lie bialgebras. Finally, we study coboundary purely Hom-Lie bialgebras and construct solutions of the classical Hom-Yang-Baxter equations in some special Hom-Lie algebras using Hom-O-operators.展开更多
Let A and K be positive integers and ε∈ {-2,-1,1,2}. The main contribution of the paper is a proof that each of the D(ε~2)-triples {K, A^2 K+2εA,(A +1)~2 K + 2ε(A+1)} has uniqui extension to a D(ε~2)-quadruple. ...Let A and K be positive integers and ε∈ {-2,-1,1,2}. The main contribution of the paper is a proof that each of the D(ε~2)-triples {K, A^2 K+2εA,(A +1)~2 K + 2ε(A+1)} has uniqui extension to a D(ε~2)-quadruple. This is used to slightly strengthen the conditions required for the existencc of a D(1)-quintuple whose smallest three elements form a regular triple.展开更多
In the past two decades, organic solar cells (OSCs) have at- tracted significant attention owing to their merits of achieving light-weight, flexible, low-cost devices [1,2]. Ternary OSC as an efficient way to improv...In the past two decades, organic solar cells (OSCs) have at- tracted significant attention owing to their merits of achieving light-weight, flexible, low-cost devices [1,2]. Ternary OSC as an efficient way to improve the power conversion efficiencies (PCEs) of OSCs has inspired great interest from researchers to investigate ternary OSCs and result in many efficient de- vices. Ternary OSCs allow collecting high- and low-energy photons by separated semiconductors in a single active layer to minimize the thermalization loss and broaden absorption range to improve the performance of OSCs. However, most reported ternary OSCs only have active layer of about 100 nm in thickness.展开更多
Prior studies using single and binary adsorbates indicate that nanografting impacts the reaction pathways and local structure of self-assembled monolayers (SAMs). This work explores the influence of nanografting in ...Prior studies using single and binary adsorbates indicate that nanografting impacts the reaction pathways and local structure of self-assembled monolayers (SAMs). This work explores the influence of nanografting in the case of ternary SAMs. Using atomic force microscopy (AFM) as both a nanografting and imaging tool, the local structures of two ternary SAMs, SC14:SSC10CHO:SC2COOH and SC18:SSC10CHO:SC2COOH, formed under natural growth and nanografting were imaged and compared. The results indicate that nanografting impacts the degree of phase segregation and the domain height in ternary SAMs. In addition to the previously known effect of altering self-assembly pathways, this study reveals an additional impact for these ternary systems: By shaving over the previous trajectory (grafted region), nanografting could start exchange reactions and lateral movement of surface-bound thiols, which leads to new and somewhat unanticipated local structures.展开更多
Based on the modification of the simplified coherent potential approximation (SCPA), a model is developed to calculate the composition dependence of the band gap energy of Ⅲ-V ternary alloys with the same anion. Th...Based on the modification of the simplified coherent potential approximation (SCPA), a model is developed to calculate the composition dependence of the band gap energy of Ⅲ-V ternary alloys with the same anion. The derived equation is used to fit the experimental band gap energy of InxAl1-xN, InxGa1-xN and A1xGal xN with x from 0 to 1. It is found that the fitting results are better than those done by using SCPA. The fitting results are also better than those obtained by using the formula with a small bowing coefficient, especially for InxAl1-xN. In addition, our model can also be used to describe the composition de- pendence of band gap energy of other Ⅲ-V ternary alloys.展开更多
Let A be a von Neumann algebra with no central abelian projections. It is proved that if an additive map δ :A → A satisfies δ([[a, b], c]) = [[δ(a), b], c] + [[a, δ(b)], c] +[[a, b], δ(c)] for any a, b, c∈ A wi...Let A be a von Neumann algebra with no central abelian projections. It is proved that if an additive map δ :A → A satisfies δ([[a, b], c]) = [[δ(a), b], c] + [[a, δ(b)], c] +[[a, b], δ(c)] for any a, b, c∈ A with ab = 0(resp. ab = P, where P is a fixed nontrivial projection in A), then there exist an additive derivation d from A into itself and an additive map f :A → ZA vanishing at every second commutator [[a, b], c] with ab = 0(resp.ab = P) such that δ(a) = d(a) + f(a) for any a∈ A.展开更多
文摘Objective:Triple-negative breast cancer(TNBC)is highly metastatic,and there is an urgent unmet need to develop novel therapeutic strategies leading to the new drug discoveries against metastasis.The transforming growth factor-β(TGF-β)is known to promote the invasive and migratory potential of breast cancer cells through induction of epithelial–mesenchymal transition(EMT)via the ERK/NF-κB/Snail signaling pathway,leading to breast cancer metastasis.Targeting this pathway to revert the EMT would be an attractive,novel therapeutic strategy to halt breast cancer metastasis.Methods:Effects of enterolactone(EL)on the cell cycle and apoptosis were investigated using flow cytometry and a cleaved caspase-3 enzyme-linked immunosorbent assay(ELISA),respectively.Effects of TGF-βinduction and EL treatment on the functional malignancy of MDA-MB-231 breast cancer cells were investigated using migration and chemo-invasion assays.The effects of EL on EMT markers and the ERK/NF-κB/Snail signaling pathway after TGF-βinduction were studied using confocal microscopy,quantitative reverse transcription polymerase chain reaction(q RT-PCR),Western blot,and flow cytometry.Results:Herein,we report that EL exhibits a significant antimetastatic effect on MDA-MB-231 cells by almost reverting the TGF-β-induced EMT in vitro.EL downregulates the mesenchymal markers N-cadherin and vimentin,and upregulates the epithelial markers E-cadherin and occludin.It represses actin stress fiber formation via inhibition of mitogen-activated protein kinase p-38(MAPK-p38)and cluster of differentiation 44(CD44).EL also suppresses ERK-1/2,NF-κB,and Snail at the m RNA and protein levels.Conclusions:Briefly,EL was found to inhibit TGF-β-induced EMT by blocking the ERK/NF-κB/Snail signaling pathway,which is a promising target for breast cancer metastasis therapy.
文摘A tetrad mechanism for exciting long waves, for example edge waves, is described based on nonlinear resonant wave-wave interactions. In this mechanism, resonant interactions pass energy to an edge wave, from the three participating gravity waves. The estimated action flux into the edge wave can be orders of magni- tude greater than the transfer fluxes derived from other competing mechanisms, such as triad interactions. More- over, the numerical results show that the actual transfer rates into the edge wave from the three participating gravity waves are two- to three- orders of magnitude greater than bottom friction.
基金Project(2009AA03Z534) supported by the National Hi-tech Research and Development Program of ChinaProject(2006CB605203) supported by the National Basic Research Program of China
文摘The electromagnetic direct chill (EMDC) casting process is a welt-established production route for aluminum alloy ingot, however, the skin effect restricts the casting diameter. In order to avoid this problem, annulus electromagnetic direct chill (A-EMDC) casting process has been developed. A three-dimension finite element computational model of A-EMDC casting process was established by using ANSYS Magnetic-Nodal programs and FLOTRAN CFD programs. Microstruetures of A-EMDC casting semi-solid Al-6Si-3Cu-Mg alloy billets were investigated. Two pairs of vortexes occur within the crystallizer with opposite direction in A-EMDC. The annulus gap is advantageous to increasing circulate flow, reducing the temperature gradient as well as shallowing liquid sump depth. The microstructure obtained by A-EMDC is globular or rosette-like, and the microstructure is homogeneous in the billet.
基金financially supported by the National Natural Science Foundation of China(No.51831007)National Key R&D Program of China(No.2017YFB0702901)。
文摘Phase diagrams of two isothermal sections of the Ni-Ti-Ta ternary system at 1000 and 1200℃in a full composition range were determined by X-ray diffraction and electron probe microanalysis.The experimental results indicated a ternary compoundτphase with low solid solubility and composition ranges of(16.3-22.4)at.%Ta,(15.9-24.1)at.%Ti and(58.5-60.0)at.%Ni at 1000℃.The two terminal solid solutions(bcc-(Ta)andβ-Ti)formed a continuous solid solution at 1000 and 1200℃.A certain amount of Ti can dissolve into Ni-Ta intermetallic compounds near the Ni-Ta side,with the highest value of 21.9 at.%observed in the Ni;Ta compound at 1000℃.
基金Project(2012QNZT003)supported by the Fundamental Research Funds for the Central Universities,ChinaProject(2012M521542)supported by the Postdoctoral Science Foundation of China+1 种基金Project(14JJ3014)supported by the Hunan Provincial Natural Science Foundation of ChinaProject(BSh1202)supported by the Zhejiang Provincial Postdoctoral Scientific Research Foundation of China
文摘Arc erosion morphologies of Ag/MeO(10) electrical contact materials after 50000 operations under direct current of 19 V and 20 A and resistive load conditions were investigated using scanning electron microscope(SEM) and a 3D optical profiler(3DOP). The results indicated that 3DOP could supply clearer and more detailed arc erosion morphology information. Arc erosion resistance of Ag/SnO_2(10) electrical contact material was the best and that of Ag/CuO(10) was the worst. Arc erosion morphology of Ag/MeO(10) electrical contact materials mainly included three different types. Arc erosion morphologies of Ag/ZnO(10) and Ag/SnO_2(10) electrical contact materials were mainly liquid splash and evaporation, and those of Ag/CuO(10) and Ag/CdO(10) were mainly material transfer from anode to cathode. Arc erosion morphology of Ag/SnO_2(6)In_2O_3(4) electrical contact materials included both liquid splash, evaporation and material transfer. In addition, the formation process and mechanism on arc erosion morphology of Ag/MeO(10) electrical contact materials were discussed.
基金Supported by the National Natural Science Foundation of China (51076021)
文摘The ionic liquid, 1-butyl-3-methylimidazolium dibutylphosphate ([BMIM][DBP]) was prepared and the vapor pressures of three set of binary solutions H2O(1)/CH3OH(1)/C2H5OH(1) + [BMIM][DBP](2) were measured at different temperature and in the ILs mole fraction range from 0.1 to 0.6 with a static equilibrium apparatus. The measured vapor pressures were correlated with Non-Random Two Liquid (NRTL) activity coefficient model and the average relative deviations (ARD) between experimental and correlated vapor pressures for these binary solutions were 3.19%, 2.42% and 2.95%, respectively. Then, the vapor pressures of two set of ternary solutions H2O(1) + CH3OH(2)/C2H5OH(2) + [BMIM][DBP](3) were measured with an inclined boiling apparatus and further predicted with NRTL activity coefficient model based on the binary interaction parameters coming from fitting the vapor pressures of the binary solutions. The results indicated that the ternary solutions containing [BMIM][DBP] were shown a strong negative deviation from Raoult's Law when the mole fraction of [BMIM][DBP] was larger than 0.2, which meant that ternary solutions could absorb the refrigerant vapors at the same or below solution temperature. Meanwhile, the average relative deviations between experimental and predicted vapor pressures for ternary solutions were 2.92% and 3.06%, respectively. Consequently, the NRTL active coefficient model used for non-electrolyte solutions was still valid for predicting vapor-liquid equilibrium of binary or ternary solutions containing ILs.
文摘As expounded in some recent mathematical conferences, this research on that amazing source of algebraic ideas known as Fermat's equation is aimed to prove how Fermat triples can be limited until the impossible existence through a criterion of incompatible parities related to unexplored properties of the binomial coefficients. In this paper, the authors use a technique based on the analysis of four numbers and their internal relations with three basic compulsory factors. It leads to the practical impossibility to find any triple of natural numbers candidate to satisfy Fermat's equation, because when the authors try to meet a condition between parity and range the authors are compelled to violate the other one, so that they are irreducibly alternative. In particular, there is a parity violation when the authors choose all the basic factors in the allowed range and the authors obtain exceeding values of one of the involved variables when the authors try to restore the parity. Since Fermat's last theorem would consequently be demonstrated, many readers could recall the never found elementary proof of FLT (Fermat's last theorem) claimed by Pierre de Fermat. The authors are not encouraging such an interpretation because this paper is intended as a journey into Fermat's equation and the reader's attitude should be towards the algebraic achievements here proposed, with their possible hidden flaws and future developments, rather than to legendary problems like Fermat's riddle.
基金supported by the National Key Research and Development Program of China(2017YFA0206500)the National Natural Science Foundation of China(No.22073040)。
文摘In order to investigate the origin of catalytic power for serine proteases,the role of the hydrogen bond in the catalytic triad was studied in the proteolysis process of the peptides chymotrypsin inhibitor 2(CI2),MCTI-A,and a hexapeptide(SUB),respectively.We first calculated the free energy profile of the proton transfer between His and Asp residues of the catalytic triad in the enzyme-substrate state and transition state by employing QM/MM molecular dynamics simulations.The results show that a low-barrier hydrogen bond(LBHB)only forms in the transition state of the acylation of CI2,while it is a normal hydrogen bond in the acylation of MCTI-A or SUB.In addition,the change of the hydrogen bond strength is much larger in CI2 and SUB systems than in MCTI-A system,which decreases the acylation energy barrier significantly for CI2 and SUB.Clearly,a LBHB formed in the transition state region helps accelerate the acylation reaction.But to our surprise,a normal hydrogen bond can also help to decrease the energy barrier.The key to reducing the reaction barrier is the increment of hydrogen bond strength in the transition state state,whether it is a LBHB or not.Our studies cast new light on the role of the hydrogen bond in the catalytic triad,and help to understand the catalytic triad of serine proteases.
文摘Based on the trivariate reduction technique two different trivariate Bernoulli mixtures of univariate uniform distributions and their associated trivariate copulas with bivariate linear Spearman marginal copulas are considered. Mathematical characterizations of these Bernoulli mixture models are obtained. Since Bernoulli mixture trivariate reduction copulas are not compatible with all valid grade correlation coefficients, and there exist linear Spearman compatible non-Bernoulli mixture trivariate copulas, one can ask when there exists at all a trivariate copula with given linear Spearman marginal copulas. Based on a known concordance ordering compatibility criterion, a set of grade correlation inequalities, which must necessarily be satisfied for compatibility, is derived. The existence question for trivariate copulas with compatible linear Spearman marginal copulas is settled in the main result, which states that this set of inequalities is also sufficient for compatibility. The constructive proof makes use of two new classes of trivariate copulas that are obtained from the Bernoulli mixture trivariate copulas through a natural parametric extension. Finally, the obtained classes of trivariate copulas are compared with another class that contains as special case some trivariate copulas with linear Spearman marginal copulas. Since the latter class is incompatible with some type of linear Spearman copulas, the new classes of trivariate copulas build a richer class in this respect. Moreover, in contrast to the mentioned class, which requires in general 11 different elementary copulas in the defining convex linear combination, the new classes require at most five of them, which results in a more parsimonious parametric modelling.
文摘This paper is composed of three elements: 3D modeling, web design and heritage visualization on the basis of the chronological restoration of Fort Frontenac in 1673, 1675, 1680, 1685 and 1688, changing from narrow and plain to broad, grand features. The aim is to use computer graphic design to inform and create an interest in historical visualization by rebuilding Fort Frontenac using 3D modeling and interactive design. The final model can be integrated into an interactive website to learn more about the fort's historic importance. It is apparent that using computer graphics can save time and money when it comes to historical visualization. Visitors do not have to travel to the actual archaeological buildings and can simply use the web in their own homes to learn about this information virtually. In order to create a sophisticated restoration of archaeological buildings, meticulously assessing historical records will draw viewers into the visualizations, such as the historical world of Fort Frontenac. As a result, the completed restoration allows the viewers to effectively understand the fort's social system, habits and historical events.
基金Supported by the National Natural Science Foundation of China(51066004)the Scientific Research Project of Higher Education Institutions of Inner Mongolia(NJZY14172)the Innovation Fund of Inner Mongolia Science and Technology(2011NCL060)
文摘This work provides a method to explore the transport property of the electrolyte aqueous solutions with one or two ionic liquids, especially focus on their electrical conductivity. The conductivities were measured for the ternary systems Na Cl–[C6mim][Cl](1-hexyl-3-methylimidazolium chloride)–H2O, [C6mim][BF4]–[C6mim][Cl]–H2O,Na NO3–[C6mim][BF4](1-hexyl-3-methylimidazolium tetrafluoroborate)–H2O, and [C4mim][BF4](1-butyl-3-methylimidazolium tetrafluoroborate)–[C6mim][BF4]–H2O, and their binary subsystems NaN O3–H2O, NaC l–H2O,[C6mim][BF4]–H2O, [C6mim][Cl]–H2O, and [C4mim][BF4]–H2O, respectively. The conductivities of the ternary systems were also determined using generalized Young's rule and semi-ideal solution theory in terms of the data of their binary solutions. The comparison showed that the two simple equations provide good predictions for conductivity of mixed electrolyte solutions and the mixed ionic liquid solutions based on the conductivity of their binary subsystems.
基金This research was funded by the Shanghai Institute for Advanced Immunochmical Studies at ShanghaiTech University to H.L.S.L. was supported by the National Natural Science Foundation of China (81772798). Z.L. was supported by the School of Life Science and Technology at ShanghaiTech University.
文摘Triple-negative breast cancer (TNBC), characterized by the lack of expression of the estrogen receptor, the progesterone receptor, and the human epidermal growth factor receptor 2, is an aggressive form of cancer that conveys unpredictable and poor prognosis due to limited treatment options and lack of effective targeted therapies. Wnt/β-catenin signaling is hyperactivated in TNBC, which promotes the progression of TNBC. However, the molecular mechanism of Wnt/β-catenin activation in TNBC remains unknown. Here, we report the drastic overexpression of miR-221/222 in all of four TNBC cell lines and TNBC primary tumor samples from patients. Furthermore, we demonstrate by both ex vivo and xenograft experiments that inhibiting miR-221/222 expression in a TNBC cell line (MDA-MB-231) suppresses its proliferation, viability, epithelial-to-mesenchymal transition, and migration; whereas expressing miR-221/222 in a non-TNBC line (MCF7) promotes all of the above cancer properties. miR-221/222 achieve so by directly repressing multiple negative regulators of the Wnt/β-catenin signaling pathway, including WIF1, SFRP2, DKK2, and AXIN2, to activate the pathway. Notably, the level of miR-221/222 expression is inversely correlated whereas that of WIF1, DKK2, SFRP2, and AXIN2 expression is positively correlated with the patient survival. Last, we show that anti-miR-221/222 significantly increases apoptotic cells with tamoxifen/Wnt3a treatment but not with cyclophosphamide/Wnt3a treatment. These results demonstrate that miR-221/222 activate the Wnt/β-catenin signaling to promote the aggressiveness and TNBC properties of breast cancers, and thus reveal a new prospect for TNBC treatment.
基金supported by National Natural Science Foundation of China (Grant No. 11471139)Natural Science Foundation of Jilin Province (Grant No. 20170101050JC)Nan Hu Scholar Development Program of Xin Yang Normal University
文摘In this paper, we first show that there is a Hom-Lie algebra structure on the set of(σ, σ)-derivations of an associative algebra. Then we construct the dual representation of a representation of a Hom-Lie algebra.We introduce the notions of a Manin triple for Hom-Lie algebras and a purely Hom-Lie bialgebra. Using the coadjoint representation, we show that there is a one-to-one correspondence between Manin triples for Hom-Lie algebras and purely Hom-Lie bialgebras. Finally, we study coboundary purely Hom-Lie bialgebras and construct solutions of the classical Hom-Yang-Baxter equations in some special Hom-Lie algebras using Hom-O-operators.
基金supported by Grants-in-Aid for Scientific Research(JSPS KAKENHI) (Grant No. 16K05079)
文摘Let A and K be positive integers and ε∈ {-2,-1,1,2}. The main contribution of the paper is a proof that each of the D(ε~2)-triples {K, A^2 K+2εA,(A +1)~2 K + 2ε(A+1)} has uniqui extension to a D(ε~2)-quadruple. This is used to slightly strengthen the conditions required for the existencc of a D(1)-quintuple whose smallest three elements form a regular triple.
文摘In the past two decades, organic solar cells (OSCs) have at- tracted significant attention owing to their merits of achieving light-weight, flexible, low-cost devices [1,2]. Ternary OSC as an efficient way to improve the power conversion efficiencies (PCEs) of OSCs has inspired great interest from researchers to investigate ternary OSCs and result in many efficient de- vices. Ternary OSCs allow collecting high- and low-energy photons by separated semiconductors in a single active layer to minimize the thermalization loss and broaden absorption range to improve the performance of OSCs. However, most reported ternary OSCs only have active layer of about 100 nm in thickness.
文摘Prior studies using single and binary adsorbates indicate that nanografting impacts the reaction pathways and local structure of self-assembled monolayers (SAMs). This work explores the influence of nanografting in the case of ternary SAMs. Using atomic force microscopy (AFM) as both a nanografting and imaging tool, the local structures of two ternary SAMs, SC14:SSC10CHO:SC2COOH and SC18:SSC10CHO:SC2COOH, formed under natural growth and nanografting were imaged and compared. The results indicate that nanografting impacts the degree of phase segregation and the domain height in ternary SAMs. In addition to the previously known effect of altering self-assembly pathways, this study reveals an additional impact for these ternary systems: By shaving over the previous trajectory (grafted region), nanografting could start exchange reactions and lateral movement of surface-bound thiols, which leads to new and somewhat unanticipated local structures.
基金supported by the Special Funds for Major State Basic Research Project (Grant No. 2011CB301900)the National Natural Science Foundation of China (Grant No. 60990311)
文摘Based on the modification of the simplified coherent potential approximation (SCPA), a model is developed to calculate the composition dependence of the band gap energy of Ⅲ-V ternary alloys with the same anion. The derived equation is used to fit the experimental band gap energy of InxAl1-xN, InxGa1-xN and A1xGal xN with x from 0 to 1. It is found that the fitting results are better than those done by using SCPA. The fitting results are also better than those obtained by using the formula with a small bowing coefficient, especially for InxAl1-xN. In addition, our model can also be used to describe the composition de- pendence of band gap energy of other Ⅲ-V ternary alloys.
基金supported by the National Natural Science Foundation of China(No.11401452)the China Postdoctoral Science Foundation(No.2015M581513)
文摘Let A be a von Neumann algebra with no central abelian projections. It is proved that if an additive map δ :A → A satisfies δ([[a, b], c]) = [[δ(a), b], c] + [[a, δ(b)], c] +[[a, b], δ(c)] for any a, b, c∈ A with ab = 0(resp. ab = P, where P is a fixed nontrivial projection in A), then there exist an additive derivation d from A into itself and an additive map f :A → ZA vanishing at every second commutator [[a, b], c] with ab = 0(resp.ab = P) such that δ(a) = d(a) + f(a) for any a∈ A.