A strain saccharomycete STSM-1 with high flocculanting activity was isolated from activated sludge with conventional methods. The high production rate and the low cost STSM-1 medium was obtained by selecting different...A strain saccharomycete STSM-1 with high flocculanting activity was isolated from activated sludge with conventional methods. The high production rate and the low cost STSM-1 medium was obtained by selecting different kinds of media, carbon source, nitrogen source and inorganic salt ion. The best flocculant-producing conditions were found by changing medium initial pH, culture temperature and ventilation flow. The best flocculating effect was obtained by changing positive ion types, density and concentration of flocculant.展开更多
A compound bioflocculant CBF,produced by mixed culture of Rhizobium radiobacter F2 and Bacillus sphaeicus F6, was investigated with regard to its production and flocculating properties. The optimization of the culture...A compound bioflocculant CBF,produced by mixed culture of Rhizobium radiobacter F2 and Bacillus sphaeicus F6, was investigated with regard to its production and flocculating properties. The optimization of the culture medium constituents including carbon source,nitrogen source and C / N ratio,metal ions and ionic strength on CBF production were studied. Flocculating properties of CBF were examined by a series of experiments and CBF had good flocculating activities in kaolin suspension with divalent cations and stable over wide range of p H. Studies of the flocculating properties revealed that the flocculation could be stimulated by cations Ca2+,Mg2+,Fe2+,Al3+and Fe3+. In addition,it was stable at 4-30 ℃ in the presence of Ca Cl2. It was found to be effective for flocculation of a kaolin suspension under neutral and weak alkaline conditions( p H 7. 0- 9. 0),and flocculating activities of higher than 95% were obtained when the CBF concentrations among 6- 14 mg / L at p H 8. 0. The results of this study indicate that CBF is a potential replacement of conventional synthetic flocculants and is widely applied in water treatment and downstream processing of food and fermentation industries.展开更多
目的阐明胃脂酶(LIPF)在胃癌细胞增殖、迁移和侵袭中的作用及其对丝裂原活化蛋白激酶(MAPK)信号通路的影响。方法采用GEPIA和Human Protein Altas评估胃癌组织中LIPF的表达。实时定量PCR(qPCR)和蛋白印迹(Western blot)检测LIPF在胃癌细...目的阐明胃脂酶(LIPF)在胃癌细胞增殖、迁移和侵袭中的作用及其对丝裂原活化蛋白激酶(MAPK)信号通路的影响。方法采用GEPIA和Human Protein Altas评估胃癌组织中LIPF的表达。实时定量PCR(qPCR)和蛋白印迹(Western blot)检测LIPF在胃癌细胞SGC-7901中的表达。SGC-7901细胞分为阴性对照组、LIPF过表达组和LIPF过表达+MAPK激活剂组。通过MTT、划痕实验和Transwell实验分析SGC-7901细胞中的细胞活力、迁移和侵袭能力。qPCR和Western blot用于检测细胞周期蛋白依赖性激酶4(CDK4)、基质金属蛋白酶9(MMP9)、磷酸化p38(p-p38)和磷酸化c-Jun氨基末端激酶(p-JNK)的表达。结果LIPF在胃癌组织和SGC-7901细胞中表达降低(P<0.05)。与阴性对照组相比,LIPF过表达组的细胞增殖活力、划痕愈合率和侵袭细胞数均减少且CDK4、MMP9、p-p38和-JNK水平降低(P<0.05)。此外,与LIPF过表达组相比,LIPF过表达+MAPK激活剂组的细胞增殖活力、划痕愈合率和侵袭细胞数增加,且CDK4、MMP9、p-p38和-JNK水平升高(P<0.05)。结论LIPF可通过体外调控p38 MAPK信号通路抑制胃癌的增殖、迁移和侵袭,可能为胃癌患者提供新的治疗干预措施。展开更多
This study aimed to investigate the influence of pH,heat and enzymatic treatments on the activity of antibacterial substance in MRS,skim soy milk and bovine milk media fermented by a potential probiotic Lactobacillus ...This study aimed to investigate the influence of pH,heat and enzymatic treatments on the activity of antibacterial substance in MRS,skim soy milk and bovine milk media fermented by a potential probiotic Lactobacillus fermentum F6.The antibacterial activity of the culture supernatant of L.fermentum F6 was tested against a wide range of Gram-positive and Gram-negative pathogenic bacteria including Staphylococcus aureus,Escherichia coli,Listeria monocytogenes,Salmonella typhimurium,and Shigella flexneri.Different antibacterial activities were detected in MRS and milk but not in soy milk.We presumed that three kinds of probable components including organic acids,heat-stable and heat-labile proteinaceous compounds were involved in antibacterial activity of fermented MRS and milk.The influence of acids on antibacterial activity was pH-dependent and this effect multiplied with thermal treatments seemed complex.Data analyses showed various significant differences of antibacterial activity among five pathogens were observed in pH and heat treatments.The untreated fermented milk showed higher inhibitory activity to Gram-positive pathogenic bacteria than Gram-negative bacteria （P 〈 0.05）,indicating antibacterial substances of fermented milk are greatly different from fermented MRS.An accurate stimulated gastrointestinal transit showed antibacterial substances would have no influence on intestinal flora.Acidic range of antibacterial substances from pH 2.0 to 6.0 can be potentially used as food biopreservatives and alternative therapeutics.展开更多
A derivative of Brevianamide F,(3 S,8 a R)-3-((1-allyl-1 H-3-indolyl)methyl)-hexahy-dropyrrolo[1,2-a]pyrazine-1,4-dione, was synthesized and characterized by 1 H NMR, 13 C NMR and confirmed by X-ray crystal structure ...A derivative of Brevianamide F,(3 S,8 a R)-3-((1-allyl-1 H-3-indolyl)methyl)-hexahy-dropyrrolo[1,2-a]pyrazine-1,4-dione, was synthesized and characterized by 1 H NMR, 13 C NMR and confirmed by X-ray crystal structure analysis. This compound crystallizes in orthorhombic system, space group P212121 with a = 9.59590(10), b = 12.70430(10), c = 14.5425(2)A, V = 1772.86(3)A^3, Z = 4, μ(CuK α) = 0.712 mm^-1, Dc = 1.279 g/cm^3, 16019 reflections measured(9.24°≤2θ≤147.28°), 3524 unique(Rint = 0.0309, Rsigma = 0.0175) which were used in all calculations. The final R = 0.0567(I > 2σ(I)) and wR = 0.1411(all data). The structure exhibits intermolecular hydrogen bonds typed O–H…O, leading to the formation of one-dimensional chains. The title compound was tested for inhibitory activity toward B-16, C6, RM-1 and BV-2 cancer cell lines.展开更多
Bacillus subtilis HJX1, a biocontrol strain of Fusarium oxysporum f. sp. cubense, could inhibit growth of several plant pathogenic fungi in vitro. To un- derstand its mechanism of fungistasis, we extracted crude prote...Bacillus subtilis HJX1, a biocontrol strain of Fusarium oxysporum f. sp. cubense, could inhibit growth of several plant pathogenic fungi in vitro. To un- derstand its mechanism of fungistasis, we extracted crude protein from fermentation broth of the strain HJX1 through ammonium sulfate precipitation, and prelimina- rily studied fungistatic activities at different conditions. The results showed that the crude protein was insensitive to protease K, trypsin or ultraviolet radiation. The fungistatic activity was unchanged when treated in water batch at 40 ℃, 60 ℃, 80 ℃ or 100 ℃ for 30 min, and the fungistatic activity maintained 60% when trea- ted at 121℃ for 30 min.展开更多
Effects of Tripterypium Wilfordii Hook f (TWH) on sperm atozoa in the epi- didym is and splenic NK cells activity in m ale m ice w ere observed using MTT assay and silver impregnation m ethods. The results show ed t...Effects of Tripterypium Wilfordii Hook f (TWH) on sperm atozoa in the epi- didym is and splenic NK cells activity in m ale m ice w ere observed using MTT assay and silver impregnation m ethods. The results show ed that the density, viability and m otility of the epididym alsperm atozoa in the experim entalgroupstreated w ith TWH w ere m ore significantly reduced than those in the controlgroup (P< 0.01). The head sw elling, head separation from tailin the groups treated w ith TWH w ere observed. The inhibition of splenicNK cellsactivity in m iceby TWH w asdose-dependent. Inhi- bition by TⅡand TWH athigh dose on the NK cells activity w as significant (P< 0.01 and P< 0.05), w hileinhibitory effectsof TWH atinterm ediateand low doseson the NK cells activity w ere notobserved (P> 0.05). Itw as concluded thatTWH at low er antifertility dose did not significantly inhibit the splenic NK cells activity. It m ightbe usefulforevaluating thetherapeuticeffectsof TWH in futureclinicalprac- tice.展开更多
The coronal mass ejections (CMEs) produce by Sun poloidal magnetic fields contribute to geomagnetic storms. The geomagnetic storm effects produced by one-day-shock, two-days-shock and three-days-shock activities on Ou...The coronal mass ejections (CMEs) produce by Sun poloidal magnetic fields contribute to geomagnetic storms. The geomagnetic storm effects produced by one-day-shock, two-days-shock and three-days-shock activities on Ouagadougou station F2 layer critical frequency time variation are analyzed. It is found that during the solar minimum and the increasing phases, the shock activity produces both positive and negative storms. The positive storm is observed during daytime. At the solar maximum and the decreasing phases only the positive storm is produced. At the solar minimum there is no three-days-shock activity. During the solar increasing phase the highest amplitude of the storm effect is due to the one-day-shock activity and the lowest is produced by the two-days-shock activity. At the solar maximum phase the ionosphere electric current system is not affected by the shock activity. Nevertheless, the highest amplitude of the storm effect is caused by the two-days-shock activity and the lowest by the one-day-shock activity. During the solar decreasing phase, the highest amplitude provoked by the storm is due to the three-days-shock activity and the lowest by the one-day-shock activity.展开更多
The potential energy surface and reaction mechanism corresponding to the reaction of ytterbium monocation with fluoromethane, which represents a prototype of the activation of C-F bond in fluorohydrocarbons by bare la...The potential energy surface and reaction mechanism corresponding to the reaction of ytterbium monocation with fluoromethane, which represents a prototype of the activation of C-F bond in fluorohydrocarbons by bare lanthanide cations, have been investigated for the first time by using density functional theory. A direct fluorine abstraction mechanism was revealed, and the related thermochemistry data were determined. The electron-transfer reactivity of the reaction was analyzed using the two-state model, and a strongly avoided crossing behavior on the transition state region was shown. The present results support the reaction mechanism inferred from early experimental data and the related thermochemistry data can provide a guide for further experimental researches.展开更多
文摘A strain saccharomycete STSM-1 with high flocculanting activity was isolated from activated sludge with conventional methods. The high production rate and the low cost STSM-1 medium was obtained by selecting different kinds of media, carbon source, nitrogen source and inorganic salt ion. The best flocculant-producing conditions were found by changing medium initial pH, culture temperature and ventilation flow. The best flocculating effect was obtained by changing positive ion types, density and concentration of flocculant.
基金Sponsored by the National High Technology Research and Development Program of China(Grant No.2009AA062906)the"Twelfth Five-Year Plan"National Key Technology R&D Program of China(Grant No.2012BAD14B06-04)+2 种基金the National Natural Science Foundation of China(Grant No.51478140&51408200)State Key Laboratory of Urban Water Resource and Environment(Harbin Institute of Technology)(Grant No.2015DX06)Promising Youngsters Training Program of Heilongjiang University of Science and Technology(Grant No.Q20120201)
文摘A compound bioflocculant CBF,produced by mixed culture of Rhizobium radiobacter F2 and Bacillus sphaeicus F6, was investigated with regard to its production and flocculating properties. The optimization of the culture medium constituents including carbon source,nitrogen source and C / N ratio,metal ions and ionic strength on CBF production were studied. Flocculating properties of CBF were examined by a series of experiments and CBF had good flocculating activities in kaolin suspension with divalent cations and stable over wide range of p H. Studies of the flocculating properties revealed that the flocculation could be stimulated by cations Ca2+,Mg2+,Fe2+,Al3+and Fe3+. In addition,it was stable at 4-30 ℃ in the presence of Ca Cl2. It was found to be effective for flocculation of a kaolin suspension under neutral and weak alkaline conditions( p H 7. 0- 9. 0),and flocculating activities of higher than 95% were obtained when the CBF concentrations among 6- 14 mg / L at p H 8. 0. The results of this study indicate that CBF is a potential replacement of conventional synthetic flocculants and is widely applied in water treatment and downstream processing of food and fermentation industries.
基金the National Nature Science Foundation of China (30660135, 30800861)the National High-Tech R&D Program of China (863 Program, 2006AA10Z345, 2007AA10Z353)the Ear Marked Fund for Modern Agro-Industry Technology Research System, China (NCET-06-0269)
文摘This study aimed to investigate the influence of pH,heat and enzymatic treatments on the activity of antibacterial substance in MRS,skim soy milk and bovine milk media fermented by a potential probiotic Lactobacillus fermentum F6.The antibacterial activity of the culture supernatant of L.fermentum F6 was tested against a wide range of Gram-positive and Gram-negative pathogenic bacteria including Staphylococcus aureus,Escherichia coli,Listeria monocytogenes,Salmonella typhimurium,and Shigella flexneri.Different antibacterial activities were detected in MRS and milk but not in soy milk.We presumed that three kinds of probable components including organic acids,heat-stable and heat-labile proteinaceous compounds were involved in antibacterial activity of fermented MRS and milk.The influence of acids on antibacterial activity was pH-dependent and this effect multiplied with thermal treatments seemed complex.Data analyses showed various significant differences of antibacterial activity among five pathogens were observed in pH and heat treatments.The untreated fermented milk showed higher inhibitory activity to Gram-positive pathogenic bacteria than Gram-negative bacteria （P 〈 0.05）,indicating antibacterial substances of fermented milk are greatly different from fermented MRS.An accurate stimulated gastrointestinal transit showed antibacterial substances would have no influence on intestinal flora.Acidic range of antibacterial substances from pH 2.0 to 6.0 can be potentially used as food biopreservatives and alternative therapeutics.
基金financially sponsored by the Natural Science Foundation of Hebei Province(No.B2015208134)
文摘A derivative of Brevianamide F,(3 S,8 a R)-3-((1-allyl-1 H-3-indolyl)methyl)-hexahy-dropyrrolo[1,2-a]pyrazine-1,4-dione, was synthesized and characterized by 1 H NMR, 13 C NMR and confirmed by X-ray crystal structure analysis. This compound crystallizes in orthorhombic system, space group P212121 with a = 9.59590(10), b = 12.70430(10), c = 14.5425(2)A, V = 1772.86(3)A^3, Z = 4, μ(CuK α) = 0.712 mm^-1, Dc = 1.279 g/cm^3, 16019 reflections measured(9.24°≤2θ≤147.28°), 3524 unique(Rint = 0.0309, Rsigma = 0.0175) which were used in all calculations. The final R = 0.0567(I > 2σ(I)) and wR = 0.1411(all data). The structure exhibits intermolecular hydrogen bonds typed O–H…O, leading to the formation of one-dimensional chains. The title compound was tested for inhibitory activity toward B-16, C6, RM-1 and BV-2 cancer cell lines.
基金Supported by the natural science foundation of Hainan Province in 2015(20158304)
文摘Bacillus subtilis HJX1, a biocontrol strain of Fusarium oxysporum f. sp. cubense, could inhibit growth of several plant pathogenic fungi in vitro. To un- derstand its mechanism of fungistasis, we extracted crude protein from fermentation broth of the strain HJX1 through ammonium sulfate precipitation, and prelimina- rily studied fungistatic activities at different conditions. The results showed that the crude protein was insensitive to protease K, trypsin or ultraviolet radiation. The fungistatic activity was unchanged when treated in water batch at 40 ℃, 60 ℃, 80 ℃ or 100 ℃ for 30 min, and the fungistatic activity maintained 60% when trea- ted at 121℃ for 30 min.
文摘Effects of Tripterypium Wilfordii Hook f (TWH) on sperm atozoa in the epi- didym is and splenic NK cells activity in m ale m ice w ere observed using MTT assay and silver impregnation m ethods. The results show ed that the density, viability and m otility of the epididym alsperm atozoa in the experim entalgroupstreated w ith TWH w ere m ore significantly reduced than those in the controlgroup (P< 0.01). The head sw elling, head separation from tailin the groups treated w ith TWH w ere observed. The inhibition of splenicNK cellsactivity in m iceby TWH w asdose-dependent. Inhi- bition by TⅡand TWH athigh dose on the NK cells activity w as significant (P< 0.01 and P< 0.05), w hileinhibitory effectsof TWH atinterm ediateand low doseson the NK cells activity w ere notobserved (P> 0.05). Itw as concluded thatTWH at low er antifertility dose did not significantly inhibit the splenic NK cells activity. It m ightbe usefulforevaluating thetherapeuticeffectsof TWH in futureclinicalprac- tice.
文摘The coronal mass ejections (CMEs) produce by Sun poloidal magnetic fields contribute to geomagnetic storms. The geomagnetic storm effects produced by one-day-shock, two-days-shock and three-days-shock activities on Ouagadougou station F2 layer critical frequency time variation are analyzed. It is found that during the solar minimum and the increasing phases, the shock activity produces both positive and negative storms. The positive storm is observed during daytime. At the solar maximum and the decreasing phases only the positive storm is produced. At the solar minimum there is no three-days-shock activity. During the solar increasing phase the highest amplitude of the storm effect is due to the one-day-shock activity and the lowest is produced by the two-days-shock activity. At the solar maximum phase the ionosphere electric current system is not affected by the shock activity. Nevertheless, the highest amplitude of the storm effect is caused by the two-days-shock activity and the lowest by the one-day-shock activity. During the solar decreasing phase, the highest amplitude provoked by the storm is due to the three-days-shock activity and the lowest by the one-day-shock activity.
基金supported by the National Science Foundation of Shandong Province(No.Z2000B02).
文摘The potential energy surface and reaction mechanism corresponding to the reaction of ytterbium monocation with fluoromethane, which represents a prototype of the activation of C-F bond in fluorohydrocarbons by bare lanthanide cations, have been investigated for the first time by using density functional theory. A direct fluorine abstraction mechanism was revealed, and the related thermochemistry data were determined. The electron-transfer reactivity of the reaction was analyzed using the two-state model, and a strongly avoided crossing behavior on the transition state region was shown. The present results support the reaction mechanism inferred from early experimental data and the related thermochemistry data can provide a guide for further experimental researches.
