Compared with the conventional Charpy impact test method,the oscillographic impact test can help in the behavioral analysis of materials during the fracture process.In this study,the trade-off relationship between the...Compared with the conventional Charpy impact test method,the oscillographic impact test can help in the behavioral analysis of materials during the fracture process.In this study,the trade-off relationship between the strength and toughness of a DZ2 axle steel at various tempering temperatures and the cause of the improvement in impact toughness was evaluated.The tempering process dramatically influenced carbide precipitation behavior,which resulted in different aspect ratios of carbides.Impact toughness improved along with the rise in tempering temperature mainly due to the increase in energy required in impact crack propagation.The characteristics of the impact crack propagation process were studied through a comprehensive analysis of stress distribution,oscilloscopic impact statistics,fracture morphology,and carbide morphology.The poor impact toughness of low-tempering-temperature specimens was attributed to the increased number of stress concentration points caused by carbide morphology in the small plastic zone during the propagation process,which resulted in a mixed distribution of brittle and ductile fractures on the fracture surface.展开更多
AimTo study effects of PVP K30 on the aque ou s solubility and dissolution properties of daidzein. Methods To measure the aqueous solubility and dissolution rates of daidzein in three diffe rent states (within solid d...AimTo study effects of PVP K30 on the aque ou s solubility and dissolution properties of daidzein. Methods To measure the aqueous solubility and dissolution rates of daidzein in three diffe rent states (within solid dispersions, physical mixtures and as a pure drug) and investigate drug-polymer interactions in the solid state using X-ray powder d iffraction and fourier-transform infrared spectroscopy. Results The negative values of the Gibbs free energy and enthalpy of transfer explaine d the spontaneous transfer of daidzein from phosphate buffer solution (PBS) to a solution of PVP in PBS. X-ray powder diffraction patterns showed that the drug was in the amorphous state (ratio of the drug ∶ PVP<1∶5) when dispers ed i n PVP K30. The infrared spectra indicated there exist interactions between the O H of daidzein and the C=O of PVP K30. Conclusionthe dispersion of daidzein in PVP K30 considerably enhances the solubility and dissolution rat e.展开更多
Microwave-assisted extraction was optimized with response surface methodology for HPLC-fluorescence determination of puerarin and daidzein in Radix Puerariae thomsonii.The optimized extraction procedure was achieved b...Microwave-assisted extraction was optimized with response surface methodology for HPLC-fluorescence determination of puerarin and daidzein in Radix Puerariae thomsonii.The optimized extraction procedure was achieved by soaking the sample with 70% methanol（1∶15,v/v）for 30 min,and then microwave irradiation for 11 min at a power of 600 W.Coupling the extraction process with HPLC-fluorescence presented good recovery,satisfactory precision,and good linear relation.Compared with a method from the Chinese Pharmacopoeia,the proposed method enables higher extraction efficiency and more accurate analytical results.It can be of potential value in quality assessment of Radix Puerariae thomsonii medicinal materials.展开更多
Daidzein, a plant extract, has antioxidant activity. It is hypothesized, in this study, that daidzein exhibits neuroprotective effects on cerebral ischemia. Rat models of middle cerebral artery oc- clusion were intrap...Daidzein, a plant extract, has antioxidant activity. It is hypothesized, in this study, that daidzein exhibits neuroprotective effects on cerebral ischemia. Rat models of middle cerebral artery oc- clusion were intraperitoneally administered daidzein. Biochemical and immunohistochemical tests showed that superoxide dismutase and nuclear respiratory factor 1 expression levels in the brain tissue decreased after ischemia and they increased obviously after daidzein administra- tion; malondialdehyde level and apoptosis-related cysteine peptidase caspase-3 and caspase-9 immunoreactivity in the brain tissue increased after ischemia and they decreased obviously after daidzein administration. Hematoxylin-eosin staining and luxol fast blue staining results showed that intraperitoneal administration of daidzein markedly alleviated neuronal damage in the ischemic brain tissue. These findings suggest that daidzein exhibits neuroprotective effects on ischemic brain tissue by decreasing oxygen free radical production, which validates the afore- mentioned hypothesis.展开更多
Background： Although isoflavones are natural dietary antioxidants, they may have toxicological effects. This study aimed to evaluate the redox system in tissues of finishing pigs by supplementation with high dose of ...Background： Although isoflavones are natural dietary antioxidants, they may have toxicological effects. This study aimed to evaluate the redox system in tissues of finishing pigs by supplementation with high dose of daidzein（640 mg/kg）.Results： The supplementation of high dose of daidzein for 64 d increased the activity of superoxide dismutase and total antioxidant capacity in longissimus muscle but down-regulated the expression of reactive oxygen species（ROS）-producing enzyme NADPH oxidase-2 and cyclooxygenase-2. In contrast, high-level supplementation with daidzein exerted pro-oxidant changes in back fat, abdominal fat, liver, and plasma, as reflected by increased contents of malondialdehyde, a lipid peroxidation product, in these tissues. Furthermore, daidzein supplementation resulted in higher expression of ROS-producing enzymes, including NADPH oxidase-1 and cyclooxygenase-1in liver, 5-lipoxygenase（5-LOX） in backfat and NADPH oxidase-2 both in abdominal fat and backfat. The supplementation of daidzein did not affect meat quality parameters in longissimus muscle, including marbling score,eye muscle areas, intramuscular fat, shear force, drip loss, p H and meat color.Conclusions： This experiment suggests that dietary supplementation of finishing pigs with daidzein at a high dose level improves redox status in muscle but exerts pro-oxidant effect in liver and fat tissues.展开更多
Objective： To investigate whether dietary daidzein interact with endogenous 17β-Estradiol （E2） to give rise to additive or inhibitory effects on proliferation and apoptosis in breast cancer cells. Methods： Cell ...Objective： To investigate whether dietary daidzein interact with endogenous 17β-Estradiol （E2） to give rise to additive or inhibitory effects on proliferation and apoptosis in breast cancer cells. Methods： Cell cycle distribution and apoptosis induction were analyzed by using flow cytometry when breast cancer cell lines MCF-7 were cotreated with daidzein （1, 5 μmol/L） and E2 （0.1-10 nmol/L） for 5 days. Whether daidzein could alter E2-modulated mRNA expression of estrogen receptor alpha （ERα）, estrogen receptor beta （ERI3） and ERβ-estrogen response element （ERE） dependent transcription was investigated by RT-PCR and luciferase induction assays. The effects of daidzein on E2-modulated expression of proapoptotic p53, bax and antiapoptotic bcl-2 at both mRNA and protein levels were also investigated by RT-PCR and Western blot. Results： Daidzein enhanced the antiapoptotic effect in an Ea dose-dependent manner, but had no effect on E2-induced proliferation. Daidzein antagonized E2-induced ERβ mRNA expression and ERβ-ERE dependent transcription. In addition, daidzein only antagonized E2-upregulated expression of p53 and bax, but had no effect on E2-upregulated expression of bcl-2. Conclusion： Daidzein enhances the antiapoptotic effect of E2 on breast cancer cells by inhibiting E2-mediated p53-bax proapoptotic pathway. These results suggest that dietary daidzein may enhance deleterious effect of endogenous E2 in hormone-dependent breast cancer.展开更多
A rapid method for the simultaneous determination of daidzein,genistein and formonetin in solanum Lyratum Thunb by high performance liquid chromatography(HPLC)was developed.Separation was achieved on a Diamonsil C18 c...A rapid method for the simultaneous determination of daidzein,genistein and formonetin in solanum Lyratum Thunb by high performance liquid chromatography(HPLC)was developed.Separation was achieved on a Diamonsil C18 column(250 mm×4.6 mm,5 μm)with isocratic elution,using a mobile phase of methanol-tetrahydrofuran-water(44∶3∶53,v/v).The wavelength was set at 260 nm and column was maintained at 35 ℃.The linear ranges of daidzein,genistein and formonetin were 1.0-40.0,0.1-4.0 and 0.1-4.0 μg/mL,respectively.The average recoveries were between 98.4% and 101.3%.This method could be used for the quality control of Solanum lyratum Thunb due to its simplification,reliability,rapidity and excellent precision.展开更多
Four Holstein dairy cows in the 7th month of late lactation were sampled, and self-control method was used. Daidzein was added to the concentrated feed at the dose of 10mg/kg during the treatment stage. Results showed...Four Holstein dairy cows in the 7th month of late lactation were sampled, and self-control method was used. Daidzein was added to the concentrated feed at the dose of 10mg/kg during the treatment stage. Results showed that daidzein lessened the declining tendency of milk yield in late lactation and increased the milk yield to some extents. Lactoprotein was evidently increased (P<0.01), while milkfat was not affected evidently. The level of T4 in serum was evidently increased (P<0.05); the levels of GH, PRL, E2 and TSH in serum were prone to rising while T3 was prone to decreasing . It was concluded that daidzein could indirectly affect milk yield and components of milk by regulating the levels of intrinsic hormones.展开更多
The attenuating effect of daidzein (DAI) on oxidative toxicity induced by Aroclor 1254 (A1254) was investigated in mouse testicular cells. Cells were exposed to A1254 alone or with DAI. The oxidative damage was estima...The attenuating effect of daidzein (DAI) on oxidative toxicity induced by Aroclor 1254 (A1254) was investigated in mouse testicular cells. Cells were exposed to A1254 alone or with DAI. The oxidative damage was estimated by measuring malondialdehyde (MDA) formation, superoxide dismutase (SOD) activity and glutathione (GSH) content. Results show that A1254 induced a decrease of germ cell number, an elevation in thiobarbituric acid reactive substances (TBARS) but a decrease in SOD activity and GSH content. However, simultaneous supplementation with DAI decreased TBARS level and increased SOD activity and GSH content. Consequently, dietary DAI may restore the intracellular antioxidant system to attenuate the oxidative toxicity of A1254 in testicular cells.展开更多
The present study preliminarily evaluated neurotoxicity injuries induced by chlorpyrifos in PC12 cell,which were used as a model for nervous cell system.In cultured PC12 cell,application of soy isoflavones(genistein,d...The present study preliminarily evaluated neurotoxicity injuries induced by chlorpyrifos in PC12 cell,which were used as a model for nervous cell system.In cultured PC12 cell,application of soy isoflavones(genistein,daidzein,monomer and mixture)significantly reduced chlorpyrifos induced toxicity,a widely used pesticide,and resulted in a better cell survival rate.Treatments with isoflavones reduced malondialdehyde content,reactive oxygengeneration and acetylcholine level in medium,and maintained mitochondrial membrane potential integrity.Daidzein enhanced endogenous antioxidant system in PC12 cell with an increasing in superoxide dismutase perunit activity.Genistein reduced acetylcholine content in the medium.Daidzein and genistein showed different effects,and their combined effect were greater than individual.In conclusion,soy isoflavones as an antioxidant and neuroprotectant,enhanced choline metabolism,which effectively mitigated disadvantageous influence of PC12 cell caused by chlorpyrifos.展开更多
Daidzein (DA) was microinjected into mediobasal hypothalamus (MBH) and nucleus ventrome-dialis thalami (VM) of the castrated male Goettingen Mini pigs (n = 9, 10 μl·animal-1, 8 pgDA·μl-1 and plasma luteini...Daidzein (DA) was microinjected into mediobasal hypothalamus (MBH) and nucleus ventrome-dialis thalami (VM) of the castrated male Goettingen Mini pigs (n = 9, 10 μl·animal-1, 8 pgDA·μl-1 and plasma luteinizing hormone (LH) levels were compared between the prior and the posterior treatment. The result showed that LH levels after the cerebral administration (ad) tended to increase compared to the levels before ad. In MBH, LH levels in 4 cases (4/5), rose and were not changed in 1 case at 0.5 - 2 hours after ad compared to those before ad. There were no significant changes at 2.5 hours after ad. When it was injected in VM, LH levels in 3 cases (3/4) rose, and were not changed in 1 case after ad compared to those before ad. In the control, there were no changes in plasma LH levels between the pre-and post-treatment except 1 case in MBH. This study suggested that DA could up-regulate LH secretion through hypothalamus level in the castrated boars.展开更多
基金the National Natural Science Foundation of China(Nos.52001310 and 52130002)the National Science and Technology Major Project(No.J2019-VI-0019-0134)+1 种基金KC Wong Education Foundation(No.GJTD-2020-09)Institute of Metal Res earch Innovation Fund(No.2023-ZD01)。
文摘Compared with the conventional Charpy impact test method,the oscillographic impact test can help in the behavioral analysis of materials during the fracture process.In this study,the trade-off relationship between the strength and toughness of a DZ2 axle steel at various tempering temperatures and the cause of the improvement in impact toughness was evaluated.The tempering process dramatically influenced carbide precipitation behavior,which resulted in different aspect ratios of carbides.Impact toughness improved along with the rise in tempering temperature mainly due to the increase in energy required in impact crack propagation.The characteristics of the impact crack propagation process were studied through a comprehensive analysis of stress distribution,oscilloscopic impact statistics,fracture morphology,and carbide morphology.The poor impact toughness of low-tempering-temperature specimens was attributed to the increased number of stress concentration points caused by carbide morphology in the small plastic zone during the propagation process,which resulted in a mixed distribution of brittle and ductile fractures on the fracture surface.
文摘AimTo study effects of PVP K30 on the aque ou s solubility and dissolution properties of daidzein. Methods To measure the aqueous solubility and dissolution rates of daidzein in three diffe rent states (within solid dispersions, physical mixtures and as a pure drug) and investigate drug-polymer interactions in the solid state using X-ray powder d iffraction and fourier-transform infrared spectroscopy. Results The negative values of the Gibbs free energy and enthalpy of transfer explaine d the spontaneous transfer of daidzein from phosphate buffer solution (PBS) to a solution of PVP in PBS. X-ray powder diffraction patterns showed that the drug was in the amorphous state (ratio of the drug ∶ PVP<1∶5) when dispers ed i n PVP K30. The infrared spectra indicated there exist interactions between the O H of daidzein and the C=O of PVP K30. Conclusionthe dispersion of daidzein in PVP K30 considerably enhances the solubility and dissolution rat e.
基金the National Natural Science foundationof China(No.20875060) for financial support
文摘Microwave-assisted extraction was optimized with response surface methodology for HPLC-fluorescence determination of puerarin and daidzein in Radix Puerariae thomsonii.The optimized extraction procedure was achieved by soaking the sample with 70% methanol（1∶15,v/v）for 30 min,and then microwave irradiation for 11 min at a power of 600 W.Coupling the extraction process with HPLC-fluorescence presented good recovery,satisfactory precision,and good linear relation.Compared with a method from the Chinese Pharmacopoeia,the proposed method enables higher extraction efficiency and more accurate analytical results.It can be of potential value in quality assessment of Radix Puerariae thomsonii medicinal materials.
文摘Daidzein, a plant extract, has antioxidant activity. It is hypothesized, in this study, that daidzein exhibits neuroprotective effects on cerebral ischemia. Rat models of middle cerebral artery oc- clusion were intraperitoneally administered daidzein. Biochemical and immunohistochemical tests showed that superoxide dismutase and nuclear respiratory factor 1 expression levels in the brain tissue decreased after ischemia and they increased obviously after daidzein administra- tion; malondialdehyde level and apoptosis-related cysteine peptidase caspase-3 and caspase-9 immunoreactivity in the brain tissue increased after ischemia and they decreased obviously after daidzein administration. Hematoxylin-eosin staining and luxol fast blue staining results showed that intraperitoneal administration of daidzein markedly alleviated neuronal damage in the ischemic brain tissue. These findings suggest that daidzein exhibits neuroprotective effects on ischemic brain tissue by decreasing oxygen free radical production, which validates the afore- mentioned hypothesis.
基金supported by the“National Natural Science Foundation of China”(Grant No.31072041)“National Basic Research Program of China(973 Program)”(Grant No.2012CB124706-4,2012CB124706-5)+1 种基金Science and Technology Planning Project of Guangdong Province(Grant No.2013A061401020)Science and Technology Program of Guangzhou(Grant NO.2014Y2-00121)
文摘Background： Although isoflavones are natural dietary antioxidants, they may have toxicological effects. This study aimed to evaluate the redox system in tissues of finishing pigs by supplementation with high dose of daidzein（640 mg/kg）.Results： The supplementation of high dose of daidzein for 64 d increased the activity of superoxide dismutase and total antioxidant capacity in longissimus muscle but down-regulated the expression of reactive oxygen species（ROS）-producing enzyme NADPH oxidase-2 and cyclooxygenase-2. In contrast, high-level supplementation with daidzein exerted pro-oxidant changes in back fat, abdominal fat, liver, and plasma, as reflected by increased contents of malondialdehyde, a lipid peroxidation product, in these tissues. Furthermore, daidzein supplementation resulted in higher expression of ROS-producing enzymes, including NADPH oxidase-1 and cyclooxygenase-1in liver, 5-lipoxygenase（5-LOX） in backfat and NADPH oxidase-2 both in abdominal fat and backfat. The supplementation of daidzein did not affect meat quality parameters in longissimus muscle, including marbling score,eye muscle areas, intramuscular fat, shear force, drip loss, p H and meat color.Conclusions： This experiment suggests that dietary supplementation of finishing pigs with daidzein at a high dose level improves redox status in muscle but exerts pro-oxidant effect in liver and fat tissues.
基金supported by the National Natural Science Foundation of China (No.30671508)by State Key Laboratory for Agrobiotechnology of China (No.2009SKLAB07-5)
文摘Objective： To investigate whether dietary daidzein interact with endogenous 17β-Estradiol （E2） to give rise to additive or inhibitory effects on proliferation and apoptosis in breast cancer cells. Methods： Cell cycle distribution and apoptosis induction were analyzed by using flow cytometry when breast cancer cell lines MCF-7 were cotreated with daidzein （1, 5 μmol/L） and E2 （0.1-10 nmol/L） for 5 days. Whether daidzein could alter E2-modulated mRNA expression of estrogen receptor alpha （ERα）, estrogen receptor beta （ERI3） and ERβ-estrogen response element （ERE） dependent transcription was investigated by RT-PCR and luciferase induction assays. The effects of daidzein on E2-modulated expression of proapoptotic p53, bax and antiapoptotic bcl-2 at both mRNA and protein levels were also investigated by RT-PCR and Western blot. Results： Daidzein enhanced the antiapoptotic effect in an Ea dose-dependent manner, but had no effect on E2-induced proliferation. Daidzein antagonized E2-induced ERβ mRNA expression and ERβ-ERE dependent transcription. In addition, daidzein only antagonized E2-upregulated expression of p53 and bax, but had no effect on E2-upregulated expression of bcl-2. Conclusion： Daidzein enhances the antiapoptotic effect of E2 on breast cancer cells by inhibiting E2-mediated p53-bax proapoptotic pathway. These results suggest that dietary daidzein may enhance deleterious effect of endogenous E2 in hormone-dependent breast cancer.
基金supported by Liaoning Technology Gallery(2007226011)Shenyang Technology Division(1071164-9-00)
文摘A rapid method for the simultaneous determination of daidzein,genistein and formonetin in solanum Lyratum Thunb by high performance liquid chromatography(HPLC)was developed.Separation was achieved on a Diamonsil C18 column(250 mm×4.6 mm,5 μm)with isocratic elution,using a mobile phase of methanol-tetrahydrofuran-water(44∶3∶53,v/v).The wavelength was set at 260 nm and column was maintained at 35 ℃.The linear ranges of daidzein,genistein and formonetin were 1.0-40.0,0.1-4.0 and 0.1-4.0 μg/mL,respectively.The average recoveries were between 98.4% and 101.3%.This method could be used for the quality control of Solanum lyratum Thunb due to its simplification,reliability,rapidity and excellent precision.
基金Elitist Innovation Fund of Henan Province (12100030)
文摘Four Holstein dairy cows in the 7th month of late lactation were sampled, and self-control method was used. Daidzein was added to the concentrated feed at the dose of 10mg/kg during the treatment stage. Results showed that daidzein lessened the declining tendency of milk yield in late lactation and increased the milk yield to some extents. Lactoprotein was evidently increased (P<0.01), while milkfat was not affected evidently. The level of T4 in serum was evidently increased (P<0.05); the levels of GH, PRL, E2 and TSH in serum were prone to rising while T3 was prone to decreasing . It was concluded that daidzein could indirectly affect milk yield and components of milk by regulating the levels of intrinsic hormones.
基金the Program for New Century Excellent Talentsin University of the Ministry of Education of China (No. NCET-05-0514)the Postdoctoral Science Foundation of China (No. 20060400325)
文摘The attenuating effect of daidzein (DAI) on oxidative toxicity induced by Aroclor 1254 (A1254) was investigated in mouse testicular cells. Cells were exposed to A1254 alone or with DAI. The oxidative damage was estimated by measuring malondialdehyde (MDA) formation, superoxide dismutase (SOD) activity and glutathione (GSH) content. Results show that A1254 induced a decrease of germ cell number, an elevation in thiobarbituric acid reactive substances (TBARS) but a decrease in SOD activity and GSH content. However, simultaneous supplementation with DAI decreased TBARS level and increased SOD activity and GSH content. Consequently, dietary DAI may restore the intracellular antioxidant system to attenuate the oxidative toxicity of A1254 in testicular cells.
基金supported by the National Key Technology R&D Program of the Ministry of Science and Technology(2012BAD33B03)China Agriculture Research System(CARS-04)+1 种基金the China Postdoctoral Science Foundation(2018M631876)Open Research Fund of National Research Center of Engineering and Technology of Tea Quality and Safety(2017NTQS0201)。
文摘The present study preliminarily evaluated neurotoxicity injuries induced by chlorpyrifos in PC12 cell,which were used as a model for nervous cell system.In cultured PC12 cell,application of soy isoflavones(genistein,daidzein,monomer and mixture)significantly reduced chlorpyrifos induced toxicity,a widely used pesticide,and resulted in a better cell survival rate.Treatments with isoflavones reduced malondialdehyde content,reactive oxygengeneration and acetylcholine level in medium,and maintained mitochondrial membrane potential integrity.Daidzein enhanced endogenous antioxidant system in PC12 cell with an increasing in superoxide dismutase perunit activity.Genistein reduced acetylcholine content in the medium.Daidzein and genistein showed different effects,and their combined effect were greater than individual.In conclusion,soy isoflavones as an antioxidant and neuroprotectant,enhanced choline metabolism,which effectively mitigated disadvantageous influence of PC12 cell caused by chlorpyrifos.
文摘Daidzein (DA) was microinjected into mediobasal hypothalamus (MBH) and nucleus ventrome-dialis thalami (VM) of the castrated male Goettingen Mini pigs (n = 9, 10 μl·animal-1, 8 pgDA·μl-1 and plasma luteinizing hormone (LH) levels were compared between the prior and the posterior treatment. The result showed that LH levels after the cerebral administration (ad) tended to increase compared to the levels before ad. In MBH, LH levels in 4 cases (4/5), rose and were not changed in 1 case at 0.5 - 2 hours after ad compared to those before ad. There were no significant changes at 2.5 hours after ad. When it was injected in VM, LH levels in 3 cases (3/4) rose, and were not changed in 1 case after ad compared to those before ad. In the control, there were no changes in plasma LH levels between the pre-and post-treatment except 1 case in MBH. This study suggested that DA could up-regulate LH secretion through hypothalamus level in the castrated boars.
