Three new rare earth ternary complexes, RE(PB)_3bpy (RE=Sm^(3+) , Eu^(3+) , and Tb^(3+) ), were synthesized by the reaction of 1-(p-phenylethynyl- phenyl)-1,3-butanedione (HPB) and 2,2′-bipyridine (bpy) with rare ear...Three new rare earth ternary complexes, RE(PB)_3bpy (RE=Sm^(3+) , Eu^(3+) , and Tb^(3+) ), were synthesized by the reaction of 1-(p-phenylethynyl- phenyl)-1,3-butanedione (HPB) and 2,2′-bipyridine (bpy) with rare earth chloride RECl_3 , respectively, in alcohol solution. The compositions were characterized by means of infrared (IR) spectra, chemical analysis, elemental analysis, and thermodynamic analysis. Luminescent properties of the three complexes were studied. At room temperature, under UV light excitation, the Sm^(3+) , Eu^(3+) , and Tb^(3+) complexes exhibit characteristic emission of the central ions. The fluorescence spectra show that the fluorescence emission intensity of Eu^(3+) complex is the strongest. The narrow strongest emission band of Eu^(3+) complex is considered to be a valuable material with bright red fluorescence.展开更多
In order to study the luminescent properties of ternary rare earth complexes with fl-diketone ligand, three new β-diketone ligands, 1-phenyl-3-（p-phenylethynylphenyl）-1,3-propanedione（HPPP）, 1-（2-thienyl）-3-（p...In order to study the luminescent properties of ternary rare earth complexes with fl-diketone ligand, three new β-diketone ligands, 1-phenyl-3-（p-phenylethynylphenyl）-1,3-propanedione（HPPP）, 1-（2-thienyl）-3-（p-phenylethynylphenyl）-1,3-propanedione （HTPP） and 1-（2-furyl）-3-（p-phenylethynylphenyl）-1,3-propanedione （HFPP）, were synthesized by Sonogashira coupling reaction and Claisen condensation. Three new ternary rare earth complexes, TbL3phen （L = PPP, TPP, or FPP）, were synthesized by the reaction of rare earth chloride TbCl3,1,10-phenanthroline （phen） with HPPP, HTPP, or HFPP respectively, in alcohol solution. The compositions were characterized by means of elemental analysis, chemical analysis, and IR spectra. Luminescent properties of the three new complexes have been studied. The results show that the ternary Yb（Ⅲ） complexes only emit the weak fluorescence of the Tb（Ⅲ） ion, which reveals the triplet state energy of the ligands does not match well with the excited state vibrating energy of Tb^3＋ ion.展开更多
Let X and Y be Banach spaces.For A∈L(X),B∈L(Y),C∈L(Y,X),let MCbe the operator matrix defined on X⊕Y by M_(C)=(AC0B)∈L(X⊕Y).In this paper we investigate the decomposability for MC.We consider Bishop’s property(...Let X and Y be Banach spaces.For A∈L(X),B∈L(Y),C∈L(Y,X),let MCbe the operator matrix defined on X⊕Y by M_(C)=(AC0B)∈L(X⊕Y).In this paper we investigate the decomposability for MC.We consider Bishop’s property(β),decomposition property(δ)and Dunford’s property(C)and obtain the relationship of these properties between M_(C) and its entries.We explore how σ_(*)(M_(C))shrinks from σ_(*)(A)∪σ_(*)(B),where σ_(*)denotes σ_(β),σ_(δ),σ_(C),σ_(dec).In particular,we develop some sufficient conditions for equality σ_(*)(MC)=σ_(*)(A)∪σ_(*)(B).Besides,we consider the perturbation of these properties for MCand show that in perturbing with certain operators C the properties for MCkeeps with A,B.Some examples are given to illustrate our results.Furthermore,we study the decomposability for(0AB0).Finally,we give applications of decomposability for operator matrices.展开更多
A theoretical study of structural and electronic properties of β-HMX crystal is performed using density-functional theory(DFT). The total density of states(TDOS) is presented. The atomic orbit projected density of st...A theoretical study of structural and electronic properties of β-HMX crystal is performed using density-functional theory(DFT). The total density of states(TDOS) is presented. The atomic orbit projected density of state(PDOS) from the p-type orbit of C,N,O and the s-type orbit of H is discussed. The study by analyzing the PDOS shows that the structure of β-HMX crystal possesses C-H···O intra- and inter-molecular hydrogen-bonding. There exists a hydrogen bonding between H5 -1s and O12 -2p orbits,between H19 -1s and O28 -2p orbits of intra molecules,and between H19 -1s and O24 -2p orbits of inter molecules. The Mulliken population analysis is also made.展开更多
Taxol is a 'blockbuster' antitumor drug produced by Taxus species with extremely low amount, while its analogue 7-β-xylosyl-10-deacetyltaxol is generally much higher in the plants. Both the fungal enzymes LXY...Taxol is a 'blockbuster' antitumor drug produced by Taxus species with extremely low amount, while its analogue 7-β-xylosyl-10-deacetyltaxol is generally much higher in the plants. Both the fungal enzymes LXYL-P1à1 and LXYL-P1à2 can convert 7-β-xylosyl-10-deacetyltaxol into10-deacetyltaxol for Taxol semi-synthesis. Of them, LXYL-P1à2 is twice more active than LXYLP1à1, but there are only 11 significantly different amino acids in terms of the polarity and acidic-basic properties between them. In this study, single and multiple site-directed mutations at the 11 sites from LXYL-P1à1 to LXYL-P1à2 were performed to define the amino acids with upward bias in activities and to acquire variants with improved catalytic properties. Among all the 17 mutants, E12(A72 T/V91 S) was the most active and even displayed 2.8-and 3-fold higher than LXYL-P1à2 on β-xylosidase andβ-glucosidase activities. The possible mechanism for such improvement was proposed by homology modeling and molecular docking between E12 and 7-β-xylosyl-10-deacetyltaxol. The recombinant yeast GS115-P1 E12-7 was constructed by introducing variant E12, the molecular chaperone gene pdi and the bacterial hemoglobin gene vhb. This engineered yeast rendered 4 times higher biomass enzyme activity than GS115-3.5 K-P1à2 that had been used for demo-scale fermentation. Thus, GS115-P1 E12-7 becomes a promising candidate to replace GS115-3.5 K-P1à2 for industrial purpose.展开更多
A novel carbazole functionalized β-diketone, methyl 6-（9-ethylcarbazole-3-yl）-oxoacetyl-2-pyridinecarboxylate （MEP）, and its corresponding binary Eu（III） complexes Eu（MEP）y2H2O and ternary complex Eu（MEP）aP...A novel carbazole functionalized β-diketone, methyl 6-（9-ethylcarbazole-3-yl）-oxoacetyl-2-pyridinecarboxylate （MEP）, and its corresponding binary Eu（III） complexes Eu（MEP）y2H2O and ternary complex Eu（MEP）aPhen with 1,10-Phenanthroline （Phen） were prepared. The ligand was characterized based on elemental analysis, FT-IR, and ^1H NMR, and the complexes were characterized with elemental analysis, FT-IR and thermogravimetric and differential thermal analysis （TG-DTA）. The investigation of fluorescence properties of the complexes Eu（MEP）3·2H2O and Eu（MEP）3Phen showed that the Eu（III） ion could be sensitized efficiently by the ligand to some extent, in partitular, in the ternary system, the secondary ligand Phen acting as a light-harvesting center was involved in the highly efficient energy transfer process, and the emission was stronger than the binary complex. In addition, the introduction of the carbazole moiety enlarged the n-conjugated system of the ligand and enhanced the luminescent intensity of the complexes.展开更多
DICER1 is a key enzyme responsible for the maturation of microRNAs. Recent evidences suggested that DICER1 and microRNAs expressed in epididymis were involved in the control of male fertility. However, the exact mecha...DICER1 is a key enzyme responsible for the maturation of microRNAs. Recent evidences suggested that DICER1 and microRNAs expressed in epididymis were involved in the control of male fertility. However, the exact mechanism remains to be elucidated. Here, we created a mouse line by targeted disruption of Dicerl gene in the principal cells of distal caput epididymis. Our data indicated that a set of β-defensin genes were downregulated by DICER1 rather than by microRNAs. Moreover, DICER1 was significantly enriched in the promoter of β-defensin gene and controlled transcription. Besides, the antibacterial ability of the adult epididymis significantly declined upon Dicerl deletion both in vitro and in vivo. And a higher incidence of reproductive defect was observed in middle-aged Dicerl^-|- males. These results suggest that DICER1 plays an important role in transcription of β-defensin genes, which are associated with the natural antibacterial properties in a microRNA-independent manner, and further impacts the male fertility.展开更多
In recent years,certain foundry processes have made it possible to obtain products with very thin parts,below the4mmthreshold of the permanent mold casting technology.The safety margins of these castings have been red...In recent years,certain foundry processes have made it possible to obtain products with very thin parts,below the4mmthreshold of the permanent mold casting technology.The safety margins of these castings have been reduced,so the T6heattreatment conditions adopted for the Al?7Si?Mg alloys need to be investigated to identify the best combination of strength andductility.Furthermore,the cost and the production time associated with T6heat treatment have to be optimized.In the present work,an experimental study was carried out to optimize the solution treatment and artificial aging conditions in gravity cast thin bars ofB356aluminum alloy modified with Sr.Two solution temperatures were selected,530°C and550°C,respectively,with solutiontime ranging from2to8h,followed by water quenching and artificial aging at165°C with aging time from2to32h.The results ofhardness and tensile tests were correlated with differential scanning calorimetry(DSC)analysis.The best combination of mechanicalproperties and heat treatment duration was obtained with2h solutionizing at550°C and8h aging at165°C.DSC analysis showedthat the alloy’s mechanical properties reach the maximum value when theβ''phase is completely developed during the artificialaging.展开更多
In this paper, we introduce the class of Hamilton type operators and study various properties of this class. We show that every Hamilton type operator with property（β） or（δ） is decomposable. In addition,we prove...In this paper, we introduce the class of Hamilton type operators and study various properties of this class. We show that every Hamilton type operator with property（β） or（δ） is decomposable. In addition,we prove that a Hamilton type operator T satisfies property（β）, Dunford＇s property（C） and Weyl＇s theorem if and only if its adjoint does.展开更多
Three new rare earth ternary complexes, RE（PPP）3bpy （RE=Sm3＋, Eu3＋, Tb3＋）, were synthesized by the reaction of 1-phenyl-3- （p-phenylethynylphenyl）-1,3-propanedione （HPPP） and 2,2＇-bipyridine（bpy） with ra...Three new rare earth ternary complexes, RE（PPP）3bpy （RE=Sm3＋, Eu3＋, Tb3＋）, were synthesized by the reaction of 1-phenyl-3- （p-phenylethynylphenyl）-1,3-propanedione （HPPP） and 2,2＇-bipyridine（bpy） with rare earth chloride RECl13, respectively, in alcohol solution. The compositions were characterized by means of infrared （IR） spectra, chemical analysis, elemental analysis, and thermodynanaic analysis. Luminescent properties of the three complexes were studied. At room temperature, under UV light excitation, the Sm3＋, Eu3＋ and Tb3＋ complexes exhibited characteristic emission of the central ions. The fluorescence spectra showed that the fluorescence emission intensity of Eu3＋ complex was the strongest. The narrow strongest emission band of Eu3＋ complex was considered to be a valuable material with bright red fluorescence.展开更多
Three novel β-diketones （HPPP, HTPP, and HFPP） ligands were synthesized by Sonogashira coupling reaction and Claisen condensation. The structure of β-diketones was confirmed with elemental analysis, IR, NMR and MS...Three novel β-diketones （HPPP, HTPP, and HFPP） ligands were synthesized by Sonogashira coupling reaction and Claisen condensation. The structure of β-diketones was confirmed with elemental analysis, IR, NMR and MS spectra. Three new ternary complexes consisting of Eu（Ⅲ）, β-diketones, and 1,10-phenanthroline（phen） were synthesized and characterized as TbL3phen （L=PPP, TPP, FPP） with elemental analysis, chemical analysis, and IR spectra, and their luminescence properties were studied.展开更多
基金supported by the National Natural Science Foundation of China(No.21141008)the Natural Science Foundation of Inner Mongolia,China(No.2009MS0205)Baotou Science and Technology Bureau,China(No.2010J2004)
文摘Three new rare earth ternary complexes, RE(PB)_3bpy (RE=Sm^(3+) , Eu^(3+) , and Tb^(3+) ), were synthesized by the reaction of 1-(p-phenylethynyl- phenyl)-1,3-butanedione (HPB) and 2,2′-bipyridine (bpy) with rare earth chloride RECl_3 , respectively, in alcohol solution. The compositions were characterized by means of infrared (IR) spectra, chemical analysis, elemental analysis, and thermodynamic analysis. Luminescent properties of the three complexes were studied. At room temperature, under UV light excitation, the Sm^(3+) , Eu^(3+) , and Tb^(3+) complexes exhibit characteristic emission of the central ions. The fluorescence spectra show that the fluorescence emission intensity of Eu^(3+) complex is the strongest. The narrow strongest emission band of Eu^(3+) complex is considered to be a valuable material with bright red fluorescence.
文摘In order to study the luminescent properties of ternary rare earth complexes with fl-diketone ligand, three new β-diketone ligands, 1-phenyl-3-（p-phenylethynylphenyl）-1,3-propanedione（HPPP）, 1-（2-thienyl）-3-（p-phenylethynylphenyl）-1,3-propanedione （HTPP） and 1-（2-furyl）-3-（p-phenylethynylphenyl）-1,3-propanedione （HFPP）, were synthesized by Sonogashira coupling reaction and Claisen condensation. Three new ternary rare earth complexes, TbL3phen （L = PPP, TPP, or FPP）, were synthesized by the reaction of rare earth chloride TbCl3,1,10-phenanthroline （phen） with HPPP, HTPP, or HFPP respectively, in alcohol solution. The compositions were characterized by means of elemental analysis, chemical analysis, and IR spectra. Luminescent properties of the three new complexes have been studied. The results show that the ternary Yb（Ⅲ） complexes only emit the weak fluorescence of the Tb（Ⅲ） ion, which reveals the triplet state energy of the ligands does not match well with the excited state vibrating energy of Tb^3＋ ion.
基金Supported by National Natural Science Foundation of China(Grant No.11761029)Inner Mongolia Higher Education Science and Technology Research Project(Grant Nos.NJZY22323 and NJZY22324)Inner Mongolia Natural Science Foundation(Grant No.2018MS07020)。
文摘Let X and Y be Banach spaces.For A∈L(X),B∈L(Y),C∈L(Y,X),let MCbe the operator matrix defined on X⊕Y by M_(C)=(AC0B)∈L(X⊕Y).In this paper we investigate the decomposability for MC.We consider Bishop’s property(β),decomposition property(δ)and Dunford’s property(C)and obtain the relationship of these properties between M_(C) and its entries.We explore how σ_(*)(M_(C))shrinks from σ_(*)(A)∪σ_(*)(B),where σ_(*)denotes σ_(β),σ_(δ),σ_(C),σ_(dec).In particular,we develop some sufficient conditions for equality σ_(*)(MC)=σ_(*)(A)∪σ_(*)(B).Besides,we consider the perturbation of these properties for MCand show that in perturbing with certain operators C the properties for MCkeeps with A,B.Some examples are given to illustrate our results.Furthermore,we study the decomposability for(0AB0).Finally,we give applications of decomposability for operator matrices.
基金the support from the National Natural Science Foundation of China (Grant Nos. 10976019 and 10676025)
文摘A theoretical study of structural and electronic properties of β-HMX crystal is performed using density-functional theory(DFT). The total density of states(TDOS) is presented. The atomic orbit projected density of state(PDOS) from the p-type orbit of C,N,O and the s-type orbit of H is discussed. The study by analyzing the PDOS shows that the structure of β-HMX crystal possesses C-H···O intra- and inter-molecular hydrogen-bonding. There exists a hydrogen bonding between H5 -1s and O12 -2p orbits,between H19 -1s and O28 -2p orbits of intra molecules,and between H19 -1s and O24 -2p orbits of inter molecules. The Mulliken population analysis is also made.
基金supported by the National Natural Science Foundation of China (Grants nos. 81573325 and 31270796)the National Mega-project for Innovative Drugs (Grants nos. 2018ZX09711001-006-001 and 2012ZX09301002-001-005, China)+1 种基金the fundamental Research Funds for the Central Universities (Grant no. 2017PT35001, China)CAMS Innovation Fund for Medical Sciences (Grant no. CIFMS-2017-I2M-4-004, China)
文摘Taxol is a 'blockbuster' antitumor drug produced by Taxus species with extremely low amount, while its analogue 7-β-xylosyl-10-deacetyltaxol is generally much higher in the plants. Both the fungal enzymes LXYL-P1à1 and LXYL-P1à2 can convert 7-β-xylosyl-10-deacetyltaxol into10-deacetyltaxol for Taxol semi-synthesis. Of them, LXYL-P1à2 is twice more active than LXYLP1à1, but there are only 11 significantly different amino acids in terms of the polarity and acidic-basic properties between them. In this study, single and multiple site-directed mutations at the 11 sites from LXYL-P1à1 to LXYL-P1à2 were performed to define the amino acids with upward bias in activities and to acquire variants with improved catalytic properties. Among all the 17 mutants, E12(A72 T/V91 S) was the most active and even displayed 2.8-and 3-fold higher than LXYL-P1à2 on β-xylosidase andβ-glucosidase activities. The possible mechanism for such improvement was proposed by homology modeling and molecular docking between E12 and 7-β-xylosyl-10-deacetyltaxol. The recombinant yeast GS115-P1 E12-7 was constructed by introducing variant E12, the molecular chaperone gene pdi and the bacterial hemoglobin gene vhb. This engineered yeast rendered 4 times higher biomass enzyme activity than GS115-3.5 K-P1à2 that had been used for demo-scale fermentation. Thus, GS115-P1 E12-7 becomes a promising candidate to replace GS115-3.5 K-P1à2 for industrial purpose.
基金supported by China Postdoctoral Science Foundation (20080431027)the Postdoctoral Science Foundation of Central South University (50573019)
文摘A novel carbazole functionalized β-diketone, methyl 6-（9-ethylcarbazole-3-yl）-oxoacetyl-2-pyridinecarboxylate （MEP）, and its corresponding binary Eu（III） complexes Eu（MEP）y2H2O and ternary complex Eu（MEP）aPhen with 1,10-Phenanthroline （Phen） were prepared. The ligand was characterized based on elemental analysis, FT-IR, and ^1H NMR, and the complexes were characterized with elemental analysis, FT-IR and thermogravimetric and differential thermal analysis （TG-DTA）. The investigation of fluorescence properties of the complexes Eu（MEP）3·2H2O and Eu（MEP）3Phen showed that the Eu（III） ion could be sensitized efficiently by the ligand to some extent, in partitular, in the ternary system, the secondary ligand Phen acting as a light-harvesting center was involved in the highly efficient energy transfer process, and the emission was stronger than the binary complex. In addition, the introduction of the carbazole moiety enlarged the n-conjugated system of the ligand and enhanced the luminescent intensity of the complexes.
基金the National Basic Research Program of China(973 Program2014CB943103)the National Natural Science Foundation of China(31471104,31671203,and 31571192).
文摘DICER1 is a key enzyme responsible for the maturation of microRNAs. Recent evidences suggested that DICER1 and microRNAs expressed in epididymis were involved in the control of male fertility. However, the exact mechanism remains to be elucidated. Here, we created a mouse line by targeted disruption of Dicerl gene in the principal cells of distal caput epididymis. Our data indicated that a set of β-defensin genes were downregulated by DICER1 rather than by microRNAs. Moreover, DICER1 was significantly enriched in the promoter of β-defensin gene and controlled transcription. Besides, the antibacterial ability of the adult epididymis significantly declined upon Dicerl deletion both in vitro and in vivo. And a higher incidence of reproductive defect was observed in middle-aged Dicerl^-|- males. These results suggest that DICER1 plays an important role in transcription of β-defensin genes, which are associated with the natural antibacterial properties in a microRNA-independent manner, and further impacts the male fertility.
基金partly funded by Regione Lombardia–MIUR(research program “2 MILLIMETRI” ID 30152773)
文摘In recent years,certain foundry processes have made it possible to obtain products with very thin parts,below the4mmthreshold of the permanent mold casting technology.The safety margins of these castings have been reduced,so the T6heattreatment conditions adopted for the Al?7Si?Mg alloys need to be investigated to identify the best combination of strength andductility.Furthermore,the cost and the production time associated with T6heat treatment have to be optimized.In the present work,an experimental study was carried out to optimize the solution treatment and artificial aging conditions in gravity cast thin bars ofB356aluminum alloy modified with Sr.Two solution temperatures were selected,530°C and550°C,respectively,with solutiontime ranging from2to8h,followed by water quenching and artificial aging at165°C with aging time from2to32h.The results ofhardness and tensile tests were correlated with differential scanning calorimetry(DSC)analysis.The best combination of mechanicalproperties and heat treatment duration was obtained with2h solutionizing at550°C and8h aging at165°C.DSC analysis showedthat the alloy’s mechanical properties reach the maximum value when theβ''phase is completely developed during the artificialaging.
基金Supported by the National Natural Science Foundation of China under Grant No.11601130 and 11761029the Natural Science Foundation of the Department of Education of Henan Province under Grant No.16A110033and 17A110005Doctoral Foundation of Henan Normal University No.qd15133
文摘In this paper, we introduce the class of Hamilton type operators and study various properties of this class. We show that every Hamilton type operator with property（β） or（δ） is decomposable. In addition,we prove that a Hamilton type operator T satisfies property（β）, Dunford＇s property（C） and Weyl＇s theorem if and only if its adjoint does.
基金National Natural Science Foundation of China(21141008)Natural Science Foundation of Inner Mongolia(2009MS0205)Bao Tou Science and Technology Bureau(2010J2004)
文摘Three new rare earth ternary complexes, RE（PPP）3bpy （RE=Sm3＋, Eu3＋, Tb3＋）, were synthesized by the reaction of 1-phenyl-3- （p-phenylethynylphenyl）-1,3-propanedione （HPPP） and 2,2＇-bipyridine（bpy） with rare earth chloride RECl13, respectively, in alcohol solution. The compositions were characterized by means of infrared （IR） spectra, chemical analysis, elemental analysis, and thermodynanaic analysis. Luminescent properties of the three complexes were studied. At room temperature, under UV light excitation, the Sm3＋, Eu3＋ and Tb3＋ complexes exhibited characteristic emission of the central ions. The fluorescence spectra showed that the fluorescence emission intensity of Eu3＋ complex was the strongest. The narrow strongest emission band of Eu3＋ complex was considered to be a valuable material with bright red fluorescence.
基金supported by the Natural Science Foundation of Inner Mongolia (200508010210)the Education Department of Inner Mongolia (NJ06002, NJcxy08124)Science and Technology Bureau of Baotou (2007G1013)
文摘Three novel β-diketones （HPPP, HTPP, and HFPP） ligands were synthesized by Sonogashira coupling reaction and Claisen condensation. The structure of β-diketones was confirmed with elemental analysis, IR, NMR and MS spectra. Three new ternary complexes consisting of Eu（Ⅲ）, β-diketones, and 1,10-phenanthroline（phen） were synthesized and characterized as TbL3phen （L=PPP, TPP, FPP） with elemental analysis, chemical analysis, and IR spectra, and their luminescence properties were studied.
