B2-CuZr phase reinforced amorphous alloy matrix composites has become one of the research hotspots in the field of materials science due to the“transformation-induced plasticity”phenomenon,which makes the composites...B2-CuZr phase reinforced amorphous alloy matrix composites has become one of the research hotspots in the field of materials science due to the“transformation-induced plasticity”phenomenon,which makes the composites show better macroscopic plastic deformability and obvious work-hardening behavior compared to the conventional amorphous alloy matrix composites reinforced with ductile phases.However,the in-situ metastable B2-CuZr phase tends to undergo eutectoid decomposition during solidification,and the volume fraction,size,and distribution of B2-CuZr phase are difficult to control,which limits the development and application of these materials.To date,much efforts have been made to solve the above problems through composition optimization,casting parameter tailoring,and post-processing technique.In this study,a review was given based on relevant studies,focusing on the predictive approach,reinforcing mechanism,and microstructure tailoring methods of B2-CuZr phase reinforced amorphous alloy matrix composites.The research focus and future prospects were also given for the future development of the present composite system.展开更多
The crisis of excessive increase in CO_(2)emissions has quickly become a serious issue and requires low-cost and bio-compatible solutions.The employee of membrane technology for CO_(2)gas separation has garnered signi...The crisis of excessive increase in CO_(2)emissions has quickly become a serious issue and requires low-cost and bio-compatible solutions.The employee of membrane technology for CO_(2)gas separation has garnered significant interest among researchers.However,this method encounters challenges related to selectivity and permeability.Therefore,modifying and reinforcing the polymer membranes to improve gas separation performance seems essential.Among the various methods for polymer membrane modification,modification with magnesium-based fillers to prepare a mixed matrix membrane(MMM)is considered an efficient method.Owing to magnesium metal's low weight,low density,high strength,and good selectivity,magnesium-based materials(Mg-based materials)have more porosity,higher available surface area,more adsorption sites,lighter weight,and more gas absorption tendency than other fillers,which makes them an attractive choice for the preparation of gas separation MMMs.This research deals with the introduction of Mg-based materials,various methods of synthesis of Mg-based materials,different methods of introducing Mg-based materials into the membrane matrix,and their effect on the performance of MMMs in CO_(2)gas separation applications.Therefore,this review can provide researchers with light horizons in using the high potential of Mg-based materials as efficient fillers in MMMs to achieve excellent permeability and selectivity and generally improve their performance in CO_(2)gas separation applications.展开更多
In this study,Pebax■2533 polymer was used as the continuous phase and UiO-67 was employed as the filler to prepare mixed matrix membranes.UiO-67 is usually synthesized using two ligands:biphenyl-4,4'-dicarboxylat...In this study,Pebax■2533 polymer was used as the continuous phase and UiO-67 was employed as the filler to prepare mixed matrix membranes.UiO-67 is usually synthesized using two ligands:biphenyl-4,4'-dicarboxylate(bpdc)and 2,2'-bipyridine-5,5'-dicarboxylic acid(bpy).In this research,UiO-67 was synthesized not only with these two ligands but also using a mixed ligand approach(50% bpdc and 50% bpy).The synthesized UiOs were incorporated into the polymer matrix at mass percentages ranging from 0% to 2% to form the mixed matrix membranes(MMMs).Membranes containing UiO-67 with mixed ligands exhibited a greater affinity for CO_(2) compared to other membranes.Various analytical techniques,including X-ray diffraction,thermogravimetric analyzer,Fourier transform infrared spectroscope(FTIR),field emission scanning electron micro scope(FESEM),and differential scanning calorimetry,were used to analyze the properties of the prepared membranes.The FTIR spectrum confirmed all desired bands of Pebax?2533 and UiO-67 in the MMMs.The FESEM images showed that the pure Pebax membrane has a uniform structure,and the developed membranes are uniformly incorporated with the synthesized UiO-67 nanoparticles.Gas permeation measurements indicated that CO_(2) permeability and CO_(2)/CH_4 selectivity increased from 402.7 Barrer(1 Barrer=1.33×10^(-14)m^(3)(STP)·m·m^(-2)·s^(-1)·kPa^(-1))and 9.32 for the pure Pebax membrane at 1.0 MPa to 770.1 Barrer and 16.96 in the modified membrane.Additionally,the gas permeation test results demonstrated that adding functionalized porous nanofillers increases the CO_(2)separation performance.Permeability tests at different temperatures revealed that as temperature was raised,at constant pressure,CO_(2) permeability for the membrane containing the mixed ligand increased from 682.2 Barrer to 733.5 Barrer,While CO_(2)/CH_(4) selectivity decreased from 15.46 to 13.43.展开更多
Covalent organic skeletons(COFs)have been widely used in gas separation due to their excellent pore structure,high crystallinity,and high specific surface area.In this work,Dha Tab-COF was synthesized by solvothermal ...Covalent organic skeletons(COFs)have been widely used in gas separation due to their excellent pore structure,high crystallinity,and high specific surface area.In this work,Dha Tab-COF was synthesized by solvothermal method and filled in polyether block polyamide(PEBAX)to form mixed matrix membranes(MMMs).Various characterization methods such as Fourier transform infrared spectroscopy(FT-IR),Xray photoelectron spectroscopy(XPS),scanning electron microscopy(SEM)and X-ray diffractometry(XRD)were used to characterize the structure of Dha Tab-COF as well as the MMMs.The effects of operating pressure,operating temperature and the content of Dha Tab-COF particles on the CO_(2)/CH_(4)separation performance of the membranes were investigated.The best separation performance with a CO_(2)permeability of 295.8 barrer(1 barrer=7.52×10^(-18)m^(3)·(STP)·m^(-2)·m·s^(-1)·Pa^(-1))and a CO_(2)/CH_(4)selectivity of 21.6 was achieved when the Dha Tab-COF content is 2%(mass),which were 45.7%and 108.1%higher than that of the pure PEBAX membrane,respectively.展开更多
目的探讨幽门螺杆菌(Hp)阳性早期胃癌患者肿瘤组织中转化生长因子-β_(1)(TGF-β_(1))mRNA、金属基质蛋白酶-2(MMP-2)mRNA、青霉素结合蛋白1A(PBP1A)m RNA表达水平与复发的关系,并分析其对复发的预测价值。方法选取2018年3月至2023年7...目的探讨幽门螺杆菌(Hp)阳性早期胃癌患者肿瘤组织中转化生长因子-β_(1)(TGF-β_(1))mRNA、金属基质蛋白酶-2(MMP-2)mRNA、青霉素结合蛋白1A(PBP1A)m RNA表达水平与复发的关系,并分析其对复发的预测价值。方法选取2018年3月至2023年7月南阳市中心医院收治的214例Hp阳性早期胃癌患者进行前瞻性研究,所有患者均行内镜黏膜下剥离术(ESD),采用实时荧光定量聚合酶链反应(qRT-PCR)法检测肿瘤组织、癌旁组织中TGF-β_(1)m RNA、MMP-2 m RNA、PBP1A m RNA表达水平,并分析其与临床病理特征相关性。依据ESD术后是否复发分为复发组、未复发组,采用q RT-PCR法检测两组患者的TGF-β_(1)m RNA、MMP-2 m RNA、PBP1A m RNA表达水平。采用偏相关性分析肿瘤组织中TGF-β_(1)m RNA、MMP-2 m RNA、PBP1A m RNA表达水平与复发的关系。采用受试者工作特征(ROC)曲线分析TGF-β_(1)m RNA、MMP-2 mRNA、PBP1A m RNA表达水平对复发的预测价值。结果肿瘤组织中TGF-β_(1)mRNA、MMP-2 m RNA表达水平分别为1.04±0.26、1.45±0.31,明显高于癌旁组织的0.85±0.14、1.18±0.25,PBP1A m RNA表达水平为0.31±0.10,明显低于癌旁组织的0.43±0.12,差异均有统计学意义(P<0.05);列联相关系数C分析显示,肿瘤组织中TGF-β_(1)mRNA、MMP-2 m RNA表达水平与临床分期、浸润深度、淋巴结转移呈正相关(P<0.05),与分化程度呈负相关(P<0.05),而PBP1A m RNA表达水平与临床分期、浸润深度、淋巴结转移呈负相关(P<0.05),与分化程度呈正相关(P<0.05);复发组患者的TGF-β_(1)mRNA、MMP-2 m RNA表达水平分别为1.31±0.25、1.74±0.31,明显高于未复发组的1.01±0.20、1.42±0.25,PBP1A mRNA表达水平为0.18±0.05,明显低于未复发组的0.32±0.10,差异均有统计学意义(P<0.05);偏相关性分析显示,肿瘤组织中TGF-β_(1)mRNA、MMP-2m RNA、PBP1A m RNA表达水平与复发显著相关(P<0.05);TGF-β_(1)mRNA、MMP-2 mRNA、PBP1A mRNA单项及联合预测复发的曲线下面积(AUC)分别为0.755、0.742、0.795、0.915,敏感度为75.00%、70.00%、75.00%、80.00%,特异度为72.25%、67.54%、76.95%、95.81%,且预测效能显著高于各指标单独预测价值(Z=2.376、2.413、1.997,P=0.018、0.016、0.046)。结论Hp阳性早期胃癌患者肿瘤组织中TGF-β_(1)m RNA、MMP-2 m RNA表达水平升高,PBP1A m RNA表达水平降低,且与临床病理特征、复发密切相关,联合检测其水平对复发具有较高的预测价值。展开更多
OBJECTIVE:To study the effect of Lichong decoction(LD) on expression of matrix metalloproteinase-2(MMP-2) and metalloproteinase-2(TIMP-2) in a rat model of uterine leiomyoma(UL).METHODS:UL was induced in rats using ex...OBJECTIVE:To study the effect of Lichong decoction(LD) on expression of matrix metalloproteinase-2(MMP-2) and metalloproteinase-2(TIMP-2) in a rat model of uterine leiomyoma(UL).METHODS:UL was induced in rats using exogenous estrogen and progesterone.LD was administered(p.o.) for 4 weeks,and mifepristone(RU-486)used as a control.To observe the effect of LD on the uterine coefficient and uterine transverse diameter,a radioimmunoassay method was used to detect serum levels of sex hormones.Light microscopic analyses of pathologic changes in the tissues of UL rats were evaluated.Expression of the proteins of matrix metalloproteinases(MMPs) and tissue inhibitors of metalloproteinases(TIMPs) in uterine tissues was assessed by immunohistochemical staining and western blotting.RESULTS:A UL model in rats was established successfully.LD reduced uterine weight,uterine coefficient,and uterine transverse diameter compared with untreated controls.LD reduced levels of estradiol,progesterone,follicle-stimulating hormone,and luteinizing hormone in our UL models.LD improved the pathologic condition of uterine muscle.Expression of MMP-2 protein decreased to varying extents in LD-treated groups,but TIMP-2 levels were enhanced.LD appears to reduce MMP-2 expression and increase TIMP-2 expression in UL tissue.CONCLUSION:These data suggest that the mechanism of action of LD on ULs may involve reduction of MMP-2 expression and increase in TIMP-2 expression in rats.展开更多
To study the role of the reversion-inducing-cysteine-rich protein with Kazal motifs （RECK） gene and matrix metalloproteinase-2 （MMP-2） in the regulation of trophoblast invasion of early pregnancy. Immunohistochemi...To study the role of the reversion-inducing-cysteine-rich protein with Kazal motifs （RECK） gene and matrix metalloproteinase-2 （MMP-2） in the regulation of trophoblast invasion of early pregnancy. Immunohistochemistry, Western blot and gelatin zymography were used to detect the RECK protein expression localization, expression level and MMP-2 activation level in the placental tissues harvested from 52 normal pregnant women （27 in the early pregnancy, 25 in the term pregnancy）. Immunohistochemistry showed that RECK expression was found both in villous tissues of early pregnancy group and term pregnancy group and was mainly observed in cell membrane and cytoplasm of cytotrophoblasts and syneytiotrophoblasts. RECK expression increased with gestational time. RECK expression of early pregnancy group was significantly lower than that of term pregnancy group （P〈0.05）. RECK expression was significantly lower in cellular column （CC） with invasion ability. Western blot showed that the RECK protein expression in early pregnancy group was significantly lower than that in term pregnancy （P〈0.05）. The optical density values of RECK protein expression in early pregnancy group and term pregnancy group were 1.35±0.14 and 2.68±0.26, respectively, while MMP-2 activation ratio was contrary to RECK protein expression and decreased with the gestation time （P〈0.01）. The MMP-2 activation ratios of early pregnancy group and term pregnancy group were 0.46±0.05 and 0.10±0.02, respectively. The expression of the tumor inhibitory gene RECK was positively related with the invasion ability of trophoblasts, while the invasion gene MMP-2 was negatively related with the ability. The interaction between RECK and MMP-2 may play an important role in the regulation of the trophoblast invasion in early pregnancy.展开更多
Background Excessive deposition of extraceUular matrix(ECM)in the kidney is the hallmark of diabetic nephropathy.Increased matrix synthesis has been well documented but the effects of diabetes on degradative pathways,...Background Excessive deposition of extraceUular matrix(ECM)in the kidney is the hallmark of diabetic nephropathy.Increased matrix synthesis has been well documented but the effects of diabetes on degradative pathways,particularly in the in vivo setting.The renal protective effect of these pathways on matrix accumulation has not been fully elucidated.The present study was understaken to investigate the activity of matrix metalloproteinase-2(MMP-2),the expression of MMP-2 and tissue inhibitor of metalloproteinase-2(TIMP-2)in kidney tissues of diabetic rats,and to explore the degradative pathway of typeⅣcollagen(Ⅳ-C)and the renal protective effects of ACE inhibition-benazepril.展开更多
基金supported by the National Natural Science Foundation of China(No.52101138,No.52201075)the Natural Science Foundation of Hubei Province(No.2023AFB798,No.2022CFB614)+3 种基金the Shenzhen Science and Technology Program(No.JCYJ20220530160813032)the State Key Laboratory of Solidification Processing in NWPU(No.SKLSP202309,No.SKLSP202308)the Guangdong Basic and Applied Basic Research Foundation(No.2022A1515011227)the State Key Laboratory of Powder Metallurgy of Central South University(No.SklpmKF-05)。
文摘B2-CuZr phase reinforced amorphous alloy matrix composites has become one of the research hotspots in the field of materials science due to the“transformation-induced plasticity”phenomenon,which makes the composites show better macroscopic plastic deformability and obvious work-hardening behavior compared to the conventional amorphous alloy matrix composites reinforced with ductile phases.However,the in-situ metastable B2-CuZr phase tends to undergo eutectoid decomposition during solidification,and the volume fraction,size,and distribution of B2-CuZr phase are difficult to control,which limits the development and application of these materials.To date,much efforts have been made to solve the above problems through composition optimization,casting parameter tailoring,and post-processing technique.In this study,a review was given based on relevant studies,focusing on the predictive approach,reinforcing mechanism,and microstructure tailoring methods of B2-CuZr phase reinforced amorphous alloy matrix composites.The research focus and future prospects were also given for the future development of the present composite system.
文摘The crisis of excessive increase in CO_(2)emissions has quickly become a serious issue and requires low-cost and bio-compatible solutions.The employee of membrane technology for CO_(2)gas separation has garnered significant interest among researchers.However,this method encounters challenges related to selectivity and permeability.Therefore,modifying and reinforcing the polymer membranes to improve gas separation performance seems essential.Among the various methods for polymer membrane modification,modification with magnesium-based fillers to prepare a mixed matrix membrane(MMM)is considered an efficient method.Owing to magnesium metal's low weight,low density,high strength,and good selectivity,magnesium-based materials(Mg-based materials)have more porosity,higher available surface area,more adsorption sites,lighter weight,and more gas absorption tendency than other fillers,which makes them an attractive choice for the preparation of gas separation MMMs.This research deals with the introduction of Mg-based materials,various methods of synthesis of Mg-based materials,different methods of introducing Mg-based materials into the membrane matrix,and their effect on the performance of MMMs in CO_(2)gas separation applications.Therefore,this review can provide researchers with light horizons in using the high potential of Mg-based materials as efficient fillers in MMMs to achieve excellent permeability and selectivity and generally improve their performance in CO_(2)gas separation applications.
基金Babol Noshirvani University of Technology for financially support of this project(BNUT/393054/2023)。
文摘In this study,Pebax■2533 polymer was used as the continuous phase and UiO-67 was employed as the filler to prepare mixed matrix membranes.UiO-67 is usually synthesized using two ligands:biphenyl-4,4'-dicarboxylate(bpdc)and 2,2'-bipyridine-5,5'-dicarboxylic acid(bpy).In this research,UiO-67 was synthesized not only with these two ligands but also using a mixed ligand approach(50% bpdc and 50% bpy).The synthesized UiOs were incorporated into the polymer matrix at mass percentages ranging from 0% to 2% to form the mixed matrix membranes(MMMs).Membranes containing UiO-67 with mixed ligands exhibited a greater affinity for CO_(2) compared to other membranes.Various analytical techniques,including X-ray diffraction,thermogravimetric analyzer,Fourier transform infrared spectroscope(FTIR),field emission scanning electron micro scope(FESEM),and differential scanning calorimetry,were used to analyze the properties of the prepared membranes.The FTIR spectrum confirmed all desired bands of Pebax?2533 and UiO-67 in the MMMs.The FESEM images showed that the pure Pebax membrane has a uniform structure,and the developed membranes are uniformly incorporated with the synthesized UiO-67 nanoparticles.Gas permeation measurements indicated that CO_(2) permeability and CO_(2)/CH_4 selectivity increased from 402.7 Barrer(1 Barrer=1.33×10^(-14)m^(3)(STP)·m·m^(-2)·s^(-1)·kPa^(-1))and 9.32 for the pure Pebax membrane at 1.0 MPa to 770.1 Barrer and 16.96 in the modified membrane.Additionally,the gas permeation test results demonstrated that adding functionalized porous nanofillers increases the CO_(2)separation performance.Permeability tests at different temperatures revealed that as temperature was raised,at constant pressure,CO_(2) permeability for the membrane containing the mixed ligand increased from 682.2 Barrer to 733.5 Barrer,While CO_(2)/CH_(4) selectivity decreased from 15.46 to 13.43.
基金supported by the National Natural Science Foundation of China(No.22271022,No 22378327).
文摘Covalent organic skeletons(COFs)have been widely used in gas separation due to their excellent pore structure,high crystallinity,and high specific surface area.In this work,Dha Tab-COF was synthesized by solvothermal method and filled in polyether block polyamide(PEBAX)to form mixed matrix membranes(MMMs).Various characterization methods such as Fourier transform infrared spectroscopy(FT-IR),Xray photoelectron spectroscopy(XPS),scanning electron microscopy(SEM)and X-ray diffractometry(XRD)were used to characterize the structure of Dha Tab-COF as well as the MMMs.The effects of operating pressure,operating temperature and the content of Dha Tab-COF particles on the CO_(2)/CH_(4)separation performance of the membranes were investigated.The best separation performance with a CO_(2)permeability of 295.8 barrer(1 barrer=7.52×10^(-18)m^(3)·(STP)·m^(-2)·m·s^(-1)·Pa^(-1))and a CO_(2)/CH_(4)selectivity of 21.6 was achieved when the Dha Tab-COF content is 2%(mass),which were 45.7%and 108.1%higher than that of the pure PEBAX membrane,respectively.
文摘目的探讨幽门螺杆菌(Hp)阳性早期胃癌患者肿瘤组织中转化生长因子-β_(1)(TGF-β_(1))mRNA、金属基质蛋白酶-2(MMP-2)mRNA、青霉素结合蛋白1A(PBP1A)m RNA表达水平与复发的关系,并分析其对复发的预测价值。方法选取2018年3月至2023年7月南阳市中心医院收治的214例Hp阳性早期胃癌患者进行前瞻性研究,所有患者均行内镜黏膜下剥离术(ESD),采用实时荧光定量聚合酶链反应(qRT-PCR)法检测肿瘤组织、癌旁组织中TGF-β_(1)m RNA、MMP-2 m RNA、PBP1A m RNA表达水平,并分析其与临床病理特征相关性。依据ESD术后是否复发分为复发组、未复发组,采用q RT-PCR法检测两组患者的TGF-β_(1)m RNA、MMP-2 m RNA、PBP1A m RNA表达水平。采用偏相关性分析肿瘤组织中TGF-β_(1)m RNA、MMP-2 m RNA、PBP1A m RNA表达水平与复发的关系。采用受试者工作特征(ROC)曲线分析TGF-β_(1)m RNA、MMP-2 mRNA、PBP1A m RNA表达水平对复发的预测价值。结果肿瘤组织中TGF-β_(1)mRNA、MMP-2 m RNA表达水平分别为1.04±0.26、1.45±0.31,明显高于癌旁组织的0.85±0.14、1.18±0.25,PBP1A m RNA表达水平为0.31±0.10,明显低于癌旁组织的0.43±0.12,差异均有统计学意义(P<0.05);列联相关系数C分析显示,肿瘤组织中TGF-β_(1)mRNA、MMP-2 m RNA表达水平与临床分期、浸润深度、淋巴结转移呈正相关(P<0.05),与分化程度呈负相关(P<0.05),而PBP1A m RNA表达水平与临床分期、浸润深度、淋巴结转移呈负相关(P<0.05),与分化程度呈正相关(P<0.05);复发组患者的TGF-β_(1)mRNA、MMP-2 m RNA表达水平分别为1.31±0.25、1.74±0.31,明显高于未复发组的1.01±0.20、1.42±0.25,PBP1A mRNA表达水平为0.18±0.05,明显低于未复发组的0.32±0.10,差异均有统计学意义(P<0.05);偏相关性分析显示,肿瘤组织中TGF-β_(1)mRNA、MMP-2m RNA、PBP1A m RNA表达水平与复发显著相关(P<0.05);TGF-β_(1)mRNA、MMP-2 mRNA、PBP1A mRNA单项及联合预测复发的曲线下面积(AUC)分别为0.755、0.742、0.795、0.915,敏感度为75.00%、70.00%、75.00%、80.00%,特异度为72.25%、67.54%、76.95%、95.81%,且预测效能显著高于各指标单独预测价值(Z=2.376、2.413、1.997,P=0.018、0.016、0.046)。结论Hp阳性早期胃癌患者肿瘤组织中TGF-β_(1)m RNA、MMP-2 m RNA表达水平升高,PBP1A m RNA表达水平降低,且与临床病理特征、复发密切相关,联合检测其水平对复发具有较高的预测价值。
基金Supported by National Natural Science Fund(Study on the Action Mechanism of Inhibition of Uterine Leiomyoma of Regulation of Lichong Decoction for Ang-Tie-2 Transduction Pathway,No.81373812Research on the Regulating Mechanism of the Inhibitory Effect of Nourishing Healthy Qi and Eliminating Blood Stasis Chinese Medicine on Extracellular Matrix Metabolize in Uterine Leiomyoma,No.81073096)
文摘OBJECTIVE:To study the effect of Lichong decoction(LD) on expression of matrix metalloproteinase-2(MMP-2) and metalloproteinase-2(TIMP-2) in a rat model of uterine leiomyoma(UL).METHODS:UL was induced in rats using exogenous estrogen and progesterone.LD was administered(p.o.) for 4 weeks,and mifepristone(RU-486)used as a control.To observe the effect of LD on the uterine coefficient and uterine transverse diameter,a radioimmunoassay method was used to detect serum levels of sex hormones.Light microscopic analyses of pathologic changes in the tissues of UL rats were evaluated.Expression of the proteins of matrix metalloproteinases(MMPs) and tissue inhibitors of metalloproteinases(TIMPs) in uterine tissues was assessed by immunohistochemical staining and western blotting.RESULTS:A UL model in rats was established successfully.LD reduced uterine weight,uterine coefficient,and uterine transverse diameter compared with untreated controls.LD reduced levels of estradiol,progesterone,follicle-stimulating hormone,and luteinizing hormone in our UL models.LD improved the pathologic condition of uterine muscle.Expression of MMP-2 protein decreased to varying extents in LD-treated groups,but TIMP-2 levels were enhanced.LD appears to reduce MMP-2 expression and increase TIMP-2 expression in UL tissue.CONCLUSION:These data suggest that the mechanism of action of LD on ULs may involve reduction of MMP-2 expression and increase in TIMP-2 expression in rats.
文摘To study the role of the reversion-inducing-cysteine-rich protein with Kazal motifs （RECK） gene and matrix metalloproteinase-2 （MMP-2） in the regulation of trophoblast invasion of early pregnancy. Immunohistochemistry, Western blot and gelatin zymography were used to detect the RECK protein expression localization, expression level and MMP-2 activation level in the placental tissues harvested from 52 normal pregnant women （27 in the early pregnancy, 25 in the term pregnancy）. Immunohistochemistry showed that RECK expression was found both in villous tissues of early pregnancy group and term pregnancy group and was mainly observed in cell membrane and cytoplasm of cytotrophoblasts and syneytiotrophoblasts. RECK expression increased with gestational time. RECK expression of early pregnancy group was significantly lower than that of term pregnancy group （P〈0.05）. RECK expression was significantly lower in cellular column （CC） with invasion ability. Western blot showed that the RECK protein expression in early pregnancy group was significantly lower than that in term pregnancy （P〈0.05）. The optical density values of RECK protein expression in early pregnancy group and term pregnancy group were 1.35±0.14 and 2.68±0.26, respectively, while MMP-2 activation ratio was contrary to RECK protein expression and decreased with the gestation time （P〈0.01）. The MMP-2 activation ratios of early pregnancy group and term pregnancy group were 0.46±0.05 and 0.10±0.02, respectively. The expression of the tumor inhibitory gene RECK was positively related with the invasion ability of trophoblasts, while the invasion gene MMP-2 was negatively related with the ability. The interaction between RECK and MMP-2 may play an important role in the regulation of the trophoblast invasion in early pregnancy.
基金This study was supported by a grant from the Natural Science Foundation of Shandong Province(No.Y2002C35).
文摘Background Excessive deposition of extraceUular matrix(ECM)in the kidney is the hallmark of diabetic nephropathy.Increased matrix synthesis has been well documented but the effects of diabetes on degradative pathways,particularly in the in vivo setting.The renal protective effect of these pathways on matrix accumulation has not been fully elucidated.The present study was understaken to investigate the activity of matrix metalloproteinase-2(MMP-2),the expression of MMP-2 and tissue inhibitor of metalloproteinase-2(TIMP-2)in kidney tissues of diabetic rats,and to explore the degradative pathway of typeⅣcollagen(Ⅳ-C)and the renal protective effects of ACE inhibition-benazepril.
