AIM： To find and identify specific nuclear matrix proteins associated with proliferation and differentiation of carcinoma cells, which will be potential markers for cancer diagnosis and targets in cancer therapy. MET...AIM： To find and identify specific nuclear matrix proteins associated with proliferation and differentiation of carcinoma cells, which will be potential markers for cancer diagnosis and targets in cancer therapy. METHODS： Nuclear matrix proteins were selectively extracted from MGcS0-3 cells treated with or without hexamethylamine bisacetamide （HMBA）, and subjected to 2-D gel electrophoresis. The resulted protein patterns were analyzed by Melanie software. Spots of nuclear matrix proteins differentially expressed were excised and subjected to in situ digestion with trypsin. Peptide masses were obtained by matrix-assisted laser-desorption/ ionization time of flight mass spectrometry （MALDI-TOFMS） analysis and submitted for database searching using Mascot tool. RESULTS： The MGc80-3 cells were induced into differentiation by HMBA. There were 22 protein spots which changed remarkably in the nuclear matrix, from differentiation of MGcS0-3 cells compared to control. Eleven of which were identified. Seven proteinsactin, prohibitin, porin 31HL, heterogeneous nuclear dbonucleoprotein A2/B1, vimentin, ATP synthase, and heat shock protein 60 were downregulated, whereas three proteins - heat shock protein gp96, heat shock protein 90-beta, and valosin-containing protein were upregulated, and the oxygen-regulated protein was only found in the differentiated MGc80-3 cells. CONCLUSION： The induced differentiation of carcinoma cells is accompanied by the changes of nuclear matrix proteins. Further characterization of those proteins will show the mechanism of cellular proliferation and differentiation, as well as cancer differentiation.展开更多
The main objective of this paper is to provide the tool rather than the classical adjoint representation of Lie algebra;which is essential in the conception of the Chevalley Eilenberg Cohomology. We introduce the noti...The main objective of this paper is to provide the tool rather than the classical adjoint representation of Lie algebra;which is essential in the conception of the Chevalley Eilenberg Cohomology. We introduce the notion of representation induced by a 2 - 3 matrix. We construct the corresponding Chevalley Eilenberg differential and we compute all its cohomological groups.展开更多
Al2O3-ZrO2 with a high level of hardness and toughness is known as ceramic steel. Due to its unique properties it can be used as a reinforcement in fabrication of metal matrix composites. In this study, nanoparticles ...Al2O3-ZrO2 with a high level of hardness and toughness is known as ceramic steel. Due to its unique properties it can be used as a reinforcement in fabrication of metal matrix composites. In this study, nanoparticles of Al2O3-10% ZrO2 with an average size of 80 nm were used to fabricate Al matrix composites containing 0.5, 1, 1.5 and 2 wt.% of the reinforcement. The fabrication route was stir casting at 850?C. There is no report about usage of this reinforcement in fabrication of composites in the literature. The microstructures of the as-cast composites were studied by scanning electron microscope (SEM). Density measurement, hardness and tensile properties were carried out to identify the mechanical properties of the composites. The results revealed that with increasing the reinforcement content, density decreased while yield, ultimate tensile strength and compressive strength increased. Also, hardness increased by increasing the reinforcement content up to 1 wt.% Al2O3-10% ZrO2 but it decreased in the samples containing higher amounts of reinforcement.展开更多
In this investigation, the Gleeble 1500 test simulator was used for carrying out experiments of joining by the pressurized combustion synthesis (PCS). The intermetallic compound Ni3Al was bonded by us- ing the exothe...In this investigation, the Gleeble 1500 test simulator was used for carrying out experiments of joining by the pressurized combustion synthesis (PCS). The intermetallic compound Ni3Al was bonded by us- ing the exothermic synthesis reaction of a mixture of element Ni and Al poweders pre - compacted as the interlayer material.Effects of the key process parameters, such as the heating rate and joining tem- perature as well as the hold time, on the joint formation and microstructural homogeneity were studied. The feasibility of the addition of Al2O3 particles in the joint interlayer for producing intermetallic -ma- trix composite joints are also explored. Results show that the microstructrual homogeneity in the synthe- sized joint interlayer was significantly influenced by the joining process paramenters.The fully synthesized Ni2Al joints exhibited an average tensile strength of 486MPa at R. T. With the addition of Al2O3 ce- ramic particles in the reactants, joints with reighrced Ni3Al - matrix composite interlayer were ob- tained.展开更多
The modular multilevel matrix converter(M3C)is a potential frequency converter for low-frequency AC transmission.However,capacitor voltage control of high-voltage and largecapacity M3C is more difficult,especially for...The modular multilevel matrix converter(M3C)is a potential frequency converter for low-frequency AC transmission.However,capacitor voltage control of high-voltage and largecapacity M3C is more difficult,especially for voltage balancing between branches.To solve this problem,this paper defines sequence circulating components and theoretically analyzes the influence mechanism of different sequence circulating components on branch capacitor voltage.A fully decoupled branch energy balancing control method based on four groups of sequence circulating components is proposed.This method can control capacitor voltages of nine branches in horizontal,vertical and diagonal directions.Considering influences of both circulating current and voltage,a cross decoupled control is designed to improve control precision.Simulation results are taken from a low-frequency transmission system based on PSCAD/EMTDC,and effectiveness and precision of the proposed branch energy balancing control method are verified in the case of nonuniform parameters and an unbalanced power system.展开更多
Background It is known that ultraviolet irradiation can affect cellular function through a number of signaling pathways ( ) epigallocatechin 3 gallate (EGCG) is the major effective component in green tea and can offer...Background It is known that ultraviolet irradiation can affect cellular function through a number of signaling pathways ( ) epigallocatechin 3 gallate (EGCG) is the major effective component in green tea and can offer protection from ultraviolet induced damage In this study, we investigated the protective mechanism of EGCG on human dermal fibroblasts damaged by ultraviolet A (UVA) in vitro Methods Transcription factor Jun protein levels were measured by Western blot Matrix metalloproteinase 1 (MMP 1) and tissue inhibitor of metalloproteinase 1 (TIMP 1) mRNA were studied by reverse transcription polymerase chain reaction (RT PCR) analysis in conjunction with computer assisted image analysis MMP 1 and TIMP 1 proteins were quantified by enzyme linked immunosorbent assay (ELISA) Results EGCG decreased transcription activity of Jun protein after induction by UVA Both the mRNA and protein levels of MMP 1 were increased by UVA irradiation, while no significant changes were observed in TIMP 1 levels The ratio of MMP 1 to TIMP 1 showed statistically significant differences compared with the control EGCG decreased the ratio of MMP 1 to TIMP 1 by inhibiting UVA induced MMP 1 expression ( P <0 05) Conclusion EGCG can protect human fibroblasts against UVA damage by downregulating the transcription activity of Jun protein and the expression of MMP 1 The ratio of MMP 1 to TIMP 1, rather than the levels of MMP 1 or TIMP 1 alone, may play a significant role in human skin photodamage展开更多
目的研究活动期类风湿关节炎(rheum atoid arthritis,RA)患者血清基质金属蛋白酶-3(m atrix m etalloproteinase3,M M P-3)、金属蛋白酶组织抑制剂-1(tissue inhibitors ofm etalloproteinase1,TIM P-1)的水平及其相关影响因素,探讨M M ...目的研究活动期类风湿关节炎(rheum atoid arthritis,RA)患者血清基质金属蛋白酶-3(m atrix m etalloproteinase3,M M P-3)、金属蛋白酶组织抑制剂-1(tissue inhibitors ofm etalloproteinase1,TIM P-1)的水平及其相关影响因素,探讨M M P-3及TIM P-1在R A的作用机制。方法选择41例初诊活动期RA患者和30名正常健康志愿者,以酶联免疫吸附试验(ELISA)分别检测血清M M P-3及TIM P-1水平,计算M M P-3/TIM P-1,同时测定关节功能、X线、关节肿胀数(SJC)、血沉(ESR)、类风湿因子(R F)、C反应蛋白(CR P)等相关实验室指标。结果活动期R A患者血清M M P-3、TIM P-1明显增高(P<0.01),且以M M P-3增高更为显著,M M P-3/TIM P-1较正常组亦增高(P<0.05)。不同关节功能分级时,上述指标差异无统计学意义(P>0.05),而不同X线分期时,各指标差异有统计学意义(P<0.01或P<0.05)。M M P-3、M M P-3/TIM P-1与SJC(P<0.01)、CRP(P<0.01)、ESR(P<0.05)呈正相关,二者与年龄、病程、晨僵时间、RF无明显相关性(P>0.05)。结论M M P-3、TIM P-1在RA血清中高水平存在,二者比例失衡导致RA发生。M M P-3、M M P-3/TIM P-1的高低可作为反映病情活动及预后的指标,阻断M M P-3高水平有可能成为治疗RA的新途径之一。展开更多
基金Supported by the National Natural Science Foundation of China,No. 30470877the Natural Science Foundation of Fujian Province, No. C0310003
文摘AIM： To find and identify specific nuclear matrix proteins associated with proliferation and differentiation of carcinoma cells, which will be potential markers for cancer diagnosis and targets in cancer therapy. METHODS： Nuclear matrix proteins were selectively extracted from MGcS0-3 cells treated with or without hexamethylamine bisacetamide （HMBA）, and subjected to 2-D gel electrophoresis. The resulted protein patterns were analyzed by Melanie software. Spots of nuclear matrix proteins differentially expressed were excised and subjected to in situ digestion with trypsin. Peptide masses were obtained by matrix-assisted laser-desorption/ ionization time of flight mass spectrometry （MALDI-TOFMS） analysis and submitted for database searching using Mascot tool. RESULTS： The MGc80-3 cells were induced into differentiation by HMBA. There were 22 protein spots which changed remarkably in the nuclear matrix, from differentiation of MGcS0-3 cells compared to control. Eleven of which were identified. Seven proteinsactin, prohibitin, porin 31HL, heterogeneous nuclear dbonucleoprotein A2/B1, vimentin, ATP synthase, and heat shock protein 60 were downregulated, whereas three proteins - heat shock protein gp96, heat shock protein 90-beta, and valosin-containing protein were upregulated, and the oxygen-regulated protein was only found in the differentiated MGc80-3 cells. CONCLUSION： The induced differentiation of carcinoma cells is accompanied by the changes of nuclear matrix proteins. Further characterization of those proteins will show the mechanism of cellular proliferation and differentiation, as well as cancer differentiation.
文摘The main objective of this paper is to provide the tool rather than the classical adjoint representation of Lie algebra;which is essential in the conception of the Chevalley Eilenberg Cohomology. We introduce the notion of representation induced by a 2 - 3 matrix. We construct the corresponding Chevalley Eilenberg differential and we compute all its cohomological groups.
文摘Al2O3-ZrO2 with a high level of hardness and toughness is known as ceramic steel. Due to its unique properties it can be used as a reinforcement in fabrication of metal matrix composites. In this study, nanoparticles of Al2O3-10% ZrO2 with an average size of 80 nm were used to fabricate Al matrix composites containing 0.5, 1, 1.5 and 2 wt.% of the reinforcement. The fabrication route was stir casting at 850?C. There is no report about usage of this reinforcement in fabrication of composites in the literature. The microstructures of the as-cast composites were studied by scanning electron microscope (SEM). Density measurement, hardness and tensile properties were carried out to identify the mechanical properties of the composites. The results revealed that with increasing the reinforcement content, density decreased while yield, ultimate tensile strength and compressive strength increased. Also, hardness increased by increasing the reinforcement content up to 1 wt.% Al2O3-10% ZrO2 but it decreased in the samples containing higher amounts of reinforcement.
文摘In this investigation, the Gleeble 1500 test simulator was used for carrying out experiments of joining by the pressurized combustion synthesis (PCS). The intermetallic compound Ni3Al was bonded by us- ing the exothermic synthesis reaction of a mixture of element Ni and Al poweders pre - compacted as the interlayer material.Effects of the key process parameters, such as the heating rate and joining tem- perature as well as the hold time, on the joint formation and microstructural homogeneity were studied. The feasibility of the addition of Al2O3 particles in the joint interlayer for producing intermetallic -ma- trix composite joints are also explored. Results show that the microstructrual homogeneity in the synthe- sized joint interlayer was significantly influenced by the joining process paramenters.The fully synthesized Ni2Al joints exhibited an average tensile strength of 486MPa at R. T. With the addition of Al2O3 ce- ramic particles in the reactants, joints with reighrced Ni3Al - matrix composite interlayer were ob- tained.
基金supported by National Key R&D Program of China(No.2021YFB2401100).
文摘The modular multilevel matrix converter(M3C)is a potential frequency converter for low-frequency AC transmission.However,capacitor voltage control of high-voltage and largecapacity M3C is more difficult,especially for voltage balancing between branches.To solve this problem,this paper defines sequence circulating components and theoretically analyzes the influence mechanism of different sequence circulating components on branch capacitor voltage.A fully decoupled branch energy balancing control method based on four groups of sequence circulating components is proposed.This method can control capacitor voltages of nine branches in horizontal,vertical and diagonal directions.Considering influences of both circulating current and voltage,a cross decoupled control is designed to improve control precision.Simulation results are taken from a low-frequency transmission system based on PSCAD/EMTDC,and effectiveness and precision of the proposed branch energy balancing control method are verified in the case of nonuniform parameters and an unbalanced power system.
文摘Background It is known that ultraviolet irradiation can affect cellular function through a number of signaling pathways ( ) epigallocatechin 3 gallate (EGCG) is the major effective component in green tea and can offer protection from ultraviolet induced damage In this study, we investigated the protective mechanism of EGCG on human dermal fibroblasts damaged by ultraviolet A (UVA) in vitro Methods Transcription factor Jun protein levels were measured by Western blot Matrix metalloproteinase 1 (MMP 1) and tissue inhibitor of metalloproteinase 1 (TIMP 1) mRNA were studied by reverse transcription polymerase chain reaction (RT PCR) analysis in conjunction with computer assisted image analysis MMP 1 and TIMP 1 proteins were quantified by enzyme linked immunosorbent assay (ELISA) Results EGCG decreased transcription activity of Jun protein after induction by UVA Both the mRNA and protein levels of MMP 1 were increased by UVA irradiation, while no significant changes were observed in TIMP 1 levels The ratio of MMP 1 to TIMP 1 showed statistically significant differences compared with the control EGCG decreased the ratio of MMP 1 to TIMP 1 by inhibiting UVA induced MMP 1 expression ( P <0 05) Conclusion EGCG can protect human fibroblasts against UVA damage by downregulating the transcription activity of Jun protein and the expression of MMP 1 The ratio of MMP 1 to TIMP 1, rather than the levels of MMP 1 or TIMP 1 alone, may play a significant role in human skin photodamage
文摘目的研究活动期类风湿关节炎(rheum atoid arthritis,RA)患者血清基质金属蛋白酶-3(m atrix m etalloproteinase3,M M P-3)、金属蛋白酶组织抑制剂-1(tissue inhibitors ofm etalloproteinase1,TIM P-1)的水平及其相关影响因素,探讨M M P-3及TIM P-1在R A的作用机制。方法选择41例初诊活动期RA患者和30名正常健康志愿者,以酶联免疫吸附试验(ELISA)分别检测血清M M P-3及TIM P-1水平,计算M M P-3/TIM P-1,同时测定关节功能、X线、关节肿胀数(SJC)、血沉(ESR)、类风湿因子(R F)、C反应蛋白(CR P)等相关实验室指标。结果活动期R A患者血清M M P-3、TIM P-1明显增高(P<0.01),且以M M P-3增高更为显著,M M P-3/TIM P-1较正常组亦增高(P<0.05)。不同关节功能分级时,上述指标差异无统计学意义(P>0.05),而不同X线分期时,各指标差异有统计学意义(P<0.01或P<0.05)。M M P-3、M M P-3/TIM P-1与SJC(P<0.01)、CRP(P<0.01)、ESR(P<0.05)呈正相关,二者与年龄、病程、晨僵时间、RF无明显相关性(P>0.05)。结论M M P-3、TIM P-1在RA血清中高水平存在,二者比例失衡导致RA发生。M M P-3、M M P-3/TIM P-1的高低可作为反映病情活动及预后的指标,阻断M M P-3高水平有可能成为治疗RA的新途径之一。
