设群G为一个有限群.如果群G中素数幂、双素幂阶元的共轭类长的集合为{1,p^a,m,p^bm},那么群G是可解的,其中a>b为正整数,p为素数且与m互素.进一步,给出了群G/Z(G)的结构,这是对文"Chen R F,Zhao X H.A criterion for a group to ...设群G为一个有限群.如果群G中素数幂、双素幂阶元的共轭类长的集合为{1,p^a,m,p^bm},那么群G是可解的,其中a>b为正整数,p为素数且与m互素.进一步,给出了群G/Z(G)的结构,这是对文"Chen R F,Zhao X H.A criterion for a group to have nilpotent p-complements[J].Monatsh Math,2016,179(2):221-225"中定理A主要结论的一个推广.展开更多
Objectives To identify the 5'untranslated region of Zika virus(ZIKV 5'UTR)RNA-binding proteins and to investigate the impact of the binding protein on the activity of internal ribosomal entry site(IRES)located...Objectives To identify the 5'untranslated region of Zika virus(ZIKV 5'UTR)RNA-binding proteins and to investigate the impact of the binding protein on the activity of internal ribosomal entry site(IRES)located in ZIKV 5'UTR and virus production.Methods Interacting proteins in U251 cells were captured using tRSA-tagged ZIKV 5'UTR RNA and tRSA-ZIKV 5'UTR RNA-binding proteins were visualized by SDS-PAGE silver staining,Subsequently,liquid chromatographytandem mass spectrometry(LC-MS/MS),bioinformatics analysis,and Western blot were used to identify the candidate proteins binding to ZIKV 5'UTR.Dicistronic expression assay and plaque forming assay were performed to analyze the effect of the binding protein on ZIKV IRES activity and ZIKV production,respecitvely.Results tRSA RNA pull-down assay,LC-MS/MS,and Western blot analysis showed that polypyrimidine tractbinding protein(PTB)bound to the ZIKV 5'UTR.Furthermore,dual luciferase reporter assay revealed that overexpression of PTB significantly enhanced the IRES activity of ZIKV(t=10.220,P<0.001),while PTB knockdown had the opposite effect(t=4.897,P<0.01).Additionally,virus plaque forming assay demonstrated that up-regulation of PTB expression significantly enhanced viral titer(t=6.400,P<0.01),whereas reducing PTB expression level weakened virus infectivity(t=5.055,P<0.01).Conclusion PTB positively interacts with the ZIKV 5'UTR and enhances IRES activity and virus production.展开更多
In recent years,growth hormone and insulin-like growth factors have become key regulators of bone metabolism and remodeling,crucial for maintaining healthy bone mass throughout life.Studies have shown that adult growt...In recent years,growth hormone and insulin-like growth factors have become key regulators of bone metabolism and remodeling,crucial for maintaining healthy bone mass throughout life.Studies have shown that adult growth hormone deficiency leads to alterations in bone remodeling,significantly affecting bone microarchitecture and increasing fracture risk.Although recombinant human growth hormone replacement therapy can mitigate these adverse effects,improving bone density,and reduce fracture risk,its effectiveness in treating osteoporosis,especially in adults with established growth hormone deficiency,seems limited.Bisphosphonates inhibit bone resorption by targeting farnesyl pyrophosphate synthase in osteoclasts,and clinical trials have confirmed their efficacy in improving osteoporosis.Therefore,for adult growth hormone deficiency patients with osteoporosis,the use of bisphosphonates alongside growth hormone replacement therapy is recommended.展开更多
[Objective] China is the world's largest fertilizer consumer. Fertilizer plays an important role in maintaining China's food security. Along with population and economic growth, overuse of fertilizers has caused ser...[Objective] China is the world's largest fertilizer consumer. Fertilizer plays an important role in maintaining China's food security. Along with population and economic growth, overuse of fertilizers has caused serious environmental problems, such as soil acidification, decline in soil organic carbon, and agricultural non-point source pollution. This study aimed to analyze the factors influencing farmers" decision making on fertilizer use, and provide policy recommendations on ways to affect fertilization. [Method] An econometric model reflecting fertilization of rural households was estimated from a survey distributed to 1 043 households randomly selected from 19 provinces in China. [Result] Results of the study showed that education years of fertilizer decision maker, fertilizer quality, organic fertilizer application, fertilizer price, and agricultural product price had significant effects on the fertilizer application rate at 1% level. Soil nutrient affected the fertilizer application rate at 10% level. [Conclusion] Policies aimed at improving the reasonable use of fertilizer should focus on the regulation of chemical fertilizer price, foundation of the organic-inorganic fertilizer system, soil testing, formulated fertilization, and agricultural extension service.展开更多
[Objective] The paper aimed at researching lectins in muscles of Varicorhinus macrolepis and providing scientific basis for researching the adaptation mechanism and immune response of V.macrolepis to environment,which...[Objective] The paper aimed at researching lectins in muscles of Varicorhinus macrolepis and providing scientific basis for researching the adaptation mechanism and immune response of V.macrolepis to environment,which were advantageous for the protection and reproduction of V.macrolepis.[Method] V.macrolepis was used as test materials for the hemagglutination test by dialdehyde fixation to prove the existence of lectins in muscle crude homogenate of Varicorhinus macrolepis and study the physical and chemical characters.[Result] Lectins in muscle crude homogenate of V.macrolepis had shown hemagglutination effects on erythrocytes of six types of animals and had the maximum hemagglutination activity against rabbit erythrocytes,which belonged to the S-type lectins with optimal pH ranged from 4 to 8 and optimal temperature at 60 ℃.Results from the saccharide inhibition test had indicated that the sucrose was the only kind of saccharide which had inhibited the hemagglutination,suggesting that sucrose had played an important role in the process of recognition and aggregation of lectins.[Conclusion] It had been speculated that the optimal pH ranges for thermal sensitivity and hemagglutination activity of lectins in different types of aquatic organisms were similar.展开更多
The metal-acid bifunctional catalysts have been used for bio-oil upgrading and pyrolytic lignin hydrocracking. In this work, the effects of the metal-acid bifunctional catalyst prop- erties, including acidity, pore si...The metal-acid bifunctional catalysts have been used for bio-oil upgrading and pyrolytic lignin hydrocracking. In this work, the effects of the metal-acid bifunctional catalyst prop- erties, including acidity, pore size and supported metal on hydrocracking of pyrolytic lignin in supercritical ethanol and hydrogen were investigated at 260 ℃. A series of catalysts were prepared and characterized by BET, XRD, and NHa-TPD techniques. The results showed that enhancing the acidity of the catalyst without metal can promote pyrolytic lignin poly- merization to form more solid and condensation to produce more water. The pore size of microporous catalyst was smaller than mesoporous catalyst. Together with strong acid- ity, it caused pyrolytic lignin further hydrocrack to numerous gas. Introducing Ru into acidic catalysts promoted pyrolytic lignin hydrocracking and inhibited the polymerization and condensation, which caused the yield of pyrolytic lignin liquefaction product to increase significantly. Therefore, bifunctional catalyst with high hydrocracking activity metal Ru supported on materials with acidic sites and mesopores was imperative to get satisfactory results for the conversion of pyrolytic lignin to liquid products under supercritical conditions and hydrogen atmosphere.展开更多
Micro-arc oxidation (MAO) process was carried out in a dual electrolyte system of NaAlO 2 and Na 3 PO 4 to develop compact, smooth and corrosion-resistant coatings on ZK60 Mg alloy by single factor experiments. The ...Micro-arc oxidation (MAO) process was carried out in a dual electrolyte system of NaAlO 2 and Na 3 PO 4 to develop compact, smooth and corrosion-resistant coatings on ZK60 Mg alloy by single factor experiments. The microstructural characteristics of coatings were investigated by X-ray diffractometry (XRD) and scanning electron microscopy (SEM) coupled with energy dispersive X-ray spectroscopy (EDS). Test of mass loss was conducted at a 3.5% NaCl solution to assess the resistance to corrosion. The effect of every element in the dual electrolyte system on voltage—time responses during MAO process and the coating characteristic were also analyzed and discussed systematically via single factor experiments. The results reveal that the main components of NaAlO 2 and Na 3 PO 4 as well as additives of NaOH, NaB4O7 and C6H5Na3O7 demonstrate different effects on MAO process and coating characteristics. By means of single factor experiments, an optimized dual electrolyte system was developed, containing 17.5 g/L NaAlO 2, 5.0 g/LNa3 PO4, 5.0 g/L NaOH, 3.0 g/L NaB4O7 and 4.2g/LC6H5Na3O7 .展开更多
Pot experiments were conducted to investigate the influence of Si fertilizer on yield and N-uptake and use efficiency of double-season rice under the conditions of equal nitrogen, phosphorus and potassium nutrients. T...Pot experiments were conducted to investigate the influence of Si fertilizer on yield and N-uptake and use efficiency of double-season rice under the conditions of equal nitrogen, phosphorus and potassium nutrients. The results showed that along with the increase of Si fertilizer application, the yield of early and late rice increased firstly and then decreased within the range of SiO2 application rate of 0-0.8 g/kg soil. There was a significant parabolic correlation between the amounts of Si fertilizer application and rice grain yield (r= 0.931 2 and r= 0.973 3 in early-and late-rice season, respectively). Results showed that efficient Si fertilizer application enchanced N contents in different plant components of early rice at maturity stages with increased nitrogen uptake of double cropping rice and nitrogen harvest index of late rice.展开更多
A new flavanone was isolated from the roots of Desmos cochinchinensis Lour Its chemical structure was elucidated by spectral analysis as 7 hydroxy 5 methoxy 8 formyl 6 methylflavanone, named desmosflavanone Ⅱ
A novel closed-loop control strategy of a silicon microgyroscope (SMG) is proposed. The SMG is sealed in metal can package in drive and sense modes and works under the air pressure of 10 Pa. Its quality factor reach...A novel closed-loop control strategy of a silicon microgyroscope (SMG) is proposed. The SMG is sealed in metal can package in drive and sense modes and works under the air pressure of 10 Pa. Its quality factor reaches greater than l0 000. Self-oscillating and closed-loop methods based on electrostatic force feedback are adopted in both measure and control circuits. Both single side driving and sensing methods are used to simplify the drive circuit. These dual channel decomposition and reconstruction closed loops are applied in sense modes. The testing results demonstrate that useful signals and guadrature signals do not interact with each other because of the decoupling of their phases. Under the condition of a scale factor of 9. 6 mV/((°) .s), in a full measurement range of±300 (°)/s, the zero bias stability reaches 28 (°)/h with a nonlinear coefficient of 400 × 10^-6 and a simulated bandwidth of more than 100 Hz. The overall performance is improved by two orders of magnitude in comparison to that at atmospheric pressure.展开更多
Ferritic steel with a nominal composition of Fe-14Cr-3W-0.42Ti-0.32Y was prepared by mixing gas-atomized prealloyed powder and mechanically alloyed powder. The microstructure is much different fxom other ferritic stee...Ferritic steel with a nominal composition of Fe-14Cr-3W-0.42Ti-0.32Y was prepared by mixing gas-atomized prealloyed powder and mechanically alloyed powder. The microstructure is much different fxom other ferritic steels with the same composition and prepared via only mechanically alloyed powder. A bi-modal structure, which consists of pure ferritic grains and martensitic grains, was obtained after hot forging and air cooling. A phase transformation of αbcc→γfcc→α'bcc was also discovered in microstructural observation. The bi-modal microstructure shows a good combination of high strength and high ductility.展开更多
To investigate the metabolites of baicalein 6,7-diacetate in rats. HPLC-DAD and LC/MS^n methods were used to analyze the metabolites in intestinal tract and plasma after oral administration of baicalein 6,7-diacetate ...To investigate the metabolites of baicalein 6,7-diacetate in rats. HPLC-DAD and LC/MS^n methods were used to analyze the metabolites in intestinal tract and plasma after oral administration of baicalein 6,7-diacetate to rats. Baicalein 6,7-diacetate was degraded into baicalein 6-monoacetate and baicalein in rat intestinal tract, and four baicalein glucuronides, baicalein 6-0- glucuronide, baicalein 6-methoxyl-7-O-glucuronide, baicalein 6,7-di-O-glucuronide, and baicalein 6-O-glucose-7-O-glucuronide were detected and tentatively identified in rat plasma. This is the first time to report the metabolites of baicalein 6,7-diacetate in rats. Six metabolites were identified in rat intestinal tract and plasma.展开更多
AIM: To determine the anti-inflammatory activity of probiotic Bifidobacteria in Bifidobacteria-fermented milk (BFM) which is effective against active ulcerative colitis (UC) and exacerbations of UC, and to explore the...AIM: To determine the anti-inflammatory activity of probiotic Bifidobacteria in Bifidobacteria-fermented milk (BFM) which is effective against active ulcerative colitis (UC) and exacerbations of UC, and to explore the immunoregulatory mechanisms. METHODS: Peripheral blood mononuclear cells (PBMNC) from UC patients or HT-29 cells were co-cultured with heat-killed probiotic bacteria or culture supernatant of Bifidobacterium breve strain Yakult (BbrY) or Bifidobacterium bifidum strain Yakult (BbiY) to estimate the amount of IL-10 or IL-8 secreted. RESULTS: Both strains of probiotic Bifidobacteria contained in the BFM induced IL-10 production in PBMNC from UC patients, though BbrY was more effective than BbiY. Conditioned medium (CM) and DNA of both strains inhibited IL-8 secretion in HT-29 cells stimulated with TNF-α, whereas no such effect was observed with heat- killed bacteria. The inhibitory effect of CM derived from BbiY was greater than that of CM derived from BbrY. DNAs of the two strains had a comparable inhibitory activity against the secretion of IL-8. CM of BbiY induced a repression of IL-8 gene expression with a higher expression of IκB-ζ mRNA 4 h after culture of HT-29 cells compared to that in the absence of CM.CONCLUSION: Probiotic Bifidobacterium strains in BFM enhance IL-10 production in PBMNC and inhibit IL-8 secretion in intestinal epithelial cells, suggesting that BFM has anti-inflammatory effects against ulcerative colitis.展开更多
To compare meiofaunal community in the two mangrove wetlands in Tong'an Bay, Xiamen, China, and probe the response of meiofauna to high organic matter, sampling was carried out in Fenglin and Xiang'an mangrove wetla...To compare meiofaunal community in the two mangrove wetlands in Tong'an Bay, Xiamen, China, and probe the response of meiofauna to high organic matter, sampling was carried out in Fenglin and Xiang'an mangrove wetlands in the bay. The results showed that the Ne/Co ratio (nematode to benthic copepod) and organic matter in Fenglin mangrove wetland were higher than those in Xiang'an mangrove wetland. The meiofaunal abundance in Fenglin mangrove was all lower than that in Xiang'an mangrove wetland in summer, autumn and spring, while the meiofaunal abundance in Fenglin mangrove was higher than that in Xiang'an mangrove wetland in winter. Two-way ANOVA results showed that the meiofaunal abundance and nematode abundance were significantly different between regions, seasons and regionxseason. With all the results in the present study, we confirmed that the positive response of meiofaunal and nematode abundance were only detected for medium organic matter contents according to the Xiang'an wetland's level, and that the distribution of meiofaunal abundance would be influenced by sand content. Higher copepod abundance and lower N/C value usually suggest better environmental quality.展开更多
[Objective] This study was conducted to investigate the effects of different gibberellic acid and hydrogen peroxide concentrations and different soaking time on the germination potential and germination rate of Scutel...[Objective] This study was conducted to investigate the effects of different gibberellic acid and hydrogen peroxide concentrations and different soaking time on the germination potential and germination rate of Scutellaria baicalensis, so as to improve the breeding efficiency of S. baicalensis. [Method] Dry seeds were divided into 3 groups, each containing 50 grains, which were weighed and put in a culture dish and soaked with distilled water covering the surface of seeds at room temperature. The seed weight was measured by gravimetric method once every 30 min from 30 rain after soaking, until the weight of the seeds no longer changed. [Result] With the increase of the concentration of hydrogen peroxide, the germination rate of S. baicalensis was improved gradually, and reached 32.0% under the concentration of 1.0% at the soaking time of 24 h; and with the increase of the concentration of gibberellic acid, the germination rate of S. baicalensis was improved gradually, and reached 64.0% under the concentration of 600 mg/L at the soaking time of 24 h. [Conclusion] The constant temperature at 25 ℃ in the incubator could also improve the seed germination rate; and the germination rate achieved by treating the seeds with gibbereUic acid was remarkably higher than that achieved by treating the seeds with hydrogen peroxide.展开更多
Quantitative trait loci (QTLs) for chlorophyll content of a rice leaf weremapped on to the molecular marker linkage map of a double-haploid (DH) population derived from across between two rice varieties 'IR64'...Quantitative trait loci (QTLs) for chlorophyll content of a rice leaf weremapped on to the molecular marker linkage map of a double-haploid (DH) population derived from across between two rice varieties 'IR64' and 'Azucena' in both nutrient solutionand soil cultureexperiments to detect rice nitrogen nutrition status under low N stress A chlorophyll meter was usedto measure the soil plant analysis development (SPAD) value of the topmost fully expanded leaf asthe index of chlorophyll content thatexpressed nitrogen status in rice plants. Totally 3 QTLs forSPAD values, two on chromosome 3 located at interval RG179-CDO337 and RG348-RZ329, respectively, andone on chromosome 10 at interval RZ500-RG134, were detected under stressed conditions of low N inthe soil and/or nutrient solution culture experiments. One QTL located at interval RG179-GDO337 onchromosome 3 associated with a relative change in SPAD value from a high N level to a low N level inthe soil culture experiment was also detected.Based on the different responses to low N stressbetween the two parents, it was supposed that the QTLs identified in this study associated withnitrogen efficiency in rice at low N levels might be useful in applying marker technology to ricebreeding programs.展开更多
A method for determination of astaxanthin and astaxanthin eaters in shrimp shell by high performance liquid chromatography is established.Shrimp shell are addressed with 5%hydrochloric acid to remove calcium ions.Afte...A method for determination of astaxanthin and astaxanthin eaters in shrimp shell by high performance liquid chromatography is established.Shrimp shell are addressed with 5%hydrochloric acid to remove calcium ions.After shell is dried,organics from shrimp shell are extracted with anhydrous ethanol.The alcohol extrative of the shrimp shell is mixed with the ammonium sulfate to extract astaxanthin by aqueous two-phase extraction.The crude astaxanthin is collected,which is distributed in the middle layer of the aqueous two-phase layer.After distilled water is added to the crude astaxanthin,the aqueous solution is centrifuged,and the previous step is repeated for several times.The precipitation in centrifuge tube is collected and dried.The crude astaxanthin dried is dissolved with acetone,and the sample solution is separated by TLC.Every pigment on the TLC plate is collected and dissolved with acetone.The pigments are determined by high performance liquid chromatograph.The results show that aqueous two-phase system,3 mL alcohol extractive of astaxanthin and 4.5 mL 20%ammonium sulfate,can be used to acquire crude astaxanthin.The wavelength of the maximum peak of astaxanthin in ethanol solution is 472 nm.A variety of pigments can be separated from the crude astaxanthin by thin-layer chromatography,including free astaxanthin,astaxanthin monoester,astaxanthin diester,echinenone and other substances.It can be seen from high performance liquid chromatography that the appearance time of free astaxanthin is from 4 min to 5.5 min,and the appearance time of astaxanthin monoester is from 10.5 min to 27.8 min.The method is simple about the sample pretreatment and feasible about the determination of astaxanthin and astaxanthin esters in shrimp shell.展开更多
AIM: To assess the safety of Bifidobacterium/ongum (B. longum) JDM301 based on complete genome sequences. METHODS: The complete genome sequences of JDM301 were determined using the GS 20 system. Putative virulence...AIM: To assess the safety of Bifidobacterium/ongum (B. longum) JDM301 based on complete genome sequences. METHODS: The complete genome sequences of JDM301 were determined using the GS 20 system. Putative virulence factors, putative antibiotic resis- tance genes and genes encoding enzymes respon- sible for harmful metabolites were identified by blast with virulence factors database, antibiotic resistance genes database and genes associated with harmful metabolites in previous reports. Minimum inhibitory concentration of 16 common antimicrobial agents was evaluated by E-test RESULTS: JDM301 was shown to contain 36 genes as- sociated with antibiotic resistance, 5 enzymes related to harmful metabolites and 162 nonspecific virulence fac- tors mainly associated with transcriptional regulation, adhesion, sugar and amino acid transport. B. longum JDM301 was intrinsically resistant to ciprofloxacin, ami- kacin, gentamicin and streptomycin and susceptible to vancomycin, amoxicillin, cephalothin, chloramphenicol, erythromycin, ampicillin, cefotaxime, rifampicin, imi- penem and trimethoprim-sulphamethoxazol. JDM301 was moderately resistant to bacitracin, while an earlier study showed that bifidobacteria were susceptible to this antibiotic. A tetracycline resistance gene with the risk of transfer was found in JDM301, which needs to be experimentally validated. CONCLUSION: The safety assessment of JDM301 using information derived from complete bacterial ge- nome will contribute to a wider and deeper insight into the safety of probiotic bacteria.展开更多
文摘设群G为一个有限群.如果群G中素数幂、双素幂阶元的共轭类长的集合为{1,p^a,m,p^bm},那么群G是可解的,其中a>b为正整数,p为素数且与m互素.进一步,给出了群G/Z(G)的结构,这是对文"Chen R F,Zhao X H.A criterion for a group to have nilpotent p-complements[J].Monatsh Math,2016,179(2):221-225"中定理A主要结论的一个推广.
文摘Objectives To identify the 5'untranslated region of Zika virus(ZIKV 5'UTR)RNA-binding proteins and to investigate the impact of the binding protein on the activity of internal ribosomal entry site(IRES)located in ZIKV 5'UTR and virus production.Methods Interacting proteins in U251 cells were captured using tRSA-tagged ZIKV 5'UTR RNA and tRSA-ZIKV 5'UTR RNA-binding proteins were visualized by SDS-PAGE silver staining,Subsequently,liquid chromatographytandem mass spectrometry(LC-MS/MS),bioinformatics analysis,and Western blot were used to identify the candidate proteins binding to ZIKV 5'UTR.Dicistronic expression assay and plaque forming assay were performed to analyze the effect of the binding protein on ZIKV IRES activity and ZIKV production,respecitvely.Results tRSA RNA pull-down assay,LC-MS/MS,and Western blot analysis showed that polypyrimidine tractbinding protein(PTB)bound to the ZIKV 5'UTR.Furthermore,dual luciferase reporter assay revealed that overexpression of PTB significantly enhanced the IRES activity of ZIKV(t=10.220,P<0.001),while PTB knockdown had the opposite effect(t=4.897,P<0.01).Additionally,virus plaque forming assay demonstrated that up-regulation of PTB expression significantly enhanced viral titer(t=6.400,P<0.01),whereas reducing PTB expression level weakened virus infectivity(t=5.055,P<0.01).Conclusion PTB positively interacts with the ZIKV 5'UTR and enhances IRES activity and virus production.
基金This work was supported by the Special Project of Performance Incentive and Guidance for Scientific Research Institutions of Chongqing,China (jxyn2022-5)。
文摘In recent years,growth hormone and insulin-like growth factors have become key regulators of bone metabolism and remodeling,crucial for maintaining healthy bone mass throughout life.Studies have shown that adult growth hormone deficiency leads to alterations in bone remodeling,significantly affecting bone microarchitecture and increasing fracture risk.Although recombinant human growth hormone replacement therapy can mitigate these adverse effects,improving bone density,and reduce fracture risk,its effectiveness in treating osteoporosis,especially in adults with established growth hormone deficiency,seems limited.Bisphosphonates inhibit bone resorption by targeting farnesyl pyrophosphate synthase in osteoclasts,and clinical trials have confirmed their efficacy in improving osteoporosis.Therefore,for adult growth hormone deficiency patients with osteoporosis,the use of bisphosphonates alongside growth hormone replacement therapy is recommended.
基金Supported by International Plant Nutrition Institute,China Program~~
文摘[Objective] China is the world's largest fertilizer consumer. Fertilizer plays an important role in maintaining China's food security. Along with population and economic growth, overuse of fertilizers has caused serious environmental problems, such as soil acidification, decline in soil organic carbon, and agricultural non-point source pollution. This study aimed to analyze the factors influencing farmers" decision making on fertilizer use, and provide policy recommendations on ways to affect fertilization. [Method] An econometric model reflecting fertilization of rural households was estimated from a survey distributed to 1 043 households randomly selected from 19 provinces in China. [Result] Results of the study showed that education years of fertilizer decision maker, fertilizer quality, organic fertilizer application, fertilizer price, and agricultural product price had significant effects on the fertilizer application rate at 1% level. Soil nutrient affected the fertilizer application rate at 10% level. [Conclusion] Policies aimed at improving the reasonable use of fertilizer should focus on the regulation of chemical fertilizer price, foundation of the organic-inorganic fertilizer system, soil testing, formulated fertilization, and agricultural extension service.
基金Supported by National Natural Science Foundation of China(3070007131172074)National Natural Science Foundation of Shandong Province(ZR2010CL002)~~
文摘[Objective] The paper aimed at researching lectins in muscles of Varicorhinus macrolepis and providing scientific basis for researching the adaptation mechanism and immune response of V.macrolepis to environment,which were advantageous for the protection and reproduction of V.macrolepis.[Method] V.macrolepis was used as test materials for the hemagglutination test by dialdehyde fixation to prove the existence of lectins in muscle crude homogenate of Varicorhinus macrolepis and study the physical and chemical characters.[Result] Lectins in muscle crude homogenate of V.macrolepis had shown hemagglutination effects on erythrocytes of six types of animals and had the maximum hemagglutination activity against rabbit erythrocytes,which belonged to the S-type lectins with optimal pH ranged from 4 to 8 and optimal temperature at 60 ℃.Results from the saccharide inhibition test had indicated that the sucrose was the only kind of saccharide which had inhibited the hemagglutination,suggesting that sucrose had played an important role in the process of recognition and aggregation of lectins.[Conclusion] It had been speculated that the optimal pH ranges for thermal sensitivity and hemagglutination activity of lectins in different types of aquatic organisms were similar.
文摘The metal-acid bifunctional catalysts have been used for bio-oil upgrading and pyrolytic lignin hydrocracking. In this work, the effects of the metal-acid bifunctional catalyst prop- erties, including acidity, pore size and supported metal on hydrocracking of pyrolytic lignin in supercritical ethanol and hydrogen were investigated at 260 ℃. A series of catalysts were prepared and characterized by BET, XRD, and NHa-TPD techniques. The results showed that enhancing the acidity of the catalyst without metal can promote pyrolytic lignin poly- merization to form more solid and condensation to produce more water. The pore size of microporous catalyst was smaller than mesoporous catalyst. Together with strong acid- ity, it caused pyrolytic lignin further hydrocrack to numerous gas. Introducing Ru into acidic catalysts promoted pyrolytic lignin hydrocracking and inhibited the polymerization and condensation, which caused the yield of pyrolytic lignin liquefaction product to increase significantly. Therefore, bifunctional catalyst with high hydrocracking activity metal Ru supported on materials with acidic sites and mesopores was imperative to get satisfactory results for the conversion of pyrolytic lignin to liquid products under supercritical conditions and hydrogen atmosphere.
基金Project(JSAWT-09-02)supported by the Key Laboratory of Advanced Welding Technology of Jiangsu Province,ChinaProject supported by the Priority Academic Program Development of Jiangsu Higher Education Institutions,China
文摘Micro-arc oxidation (MAO) process was carried out in a dual electrolyte system of NaAlO 2 and Na 3 PO 4 to develop compact, smooth and corrosion-resistant coatings on ZK60 Mg alloy by single factor experiments. The microstructural characteristics of coatings were investigated by X-ray diffractometry (XRD) and scanning electron microscopy (SEM) coupled with energy dispersive X-ray spectroscopy (EDS). Test of mass loss was conducted at a 3.5% NaCl solution to assess the resistance to corrosion. The effect of every element in the dual electrolyte system on voltage—time responses during MAO process and the coating characteristic were also analyzed and discussed systematically via single factor experiments. The results reveal that the main components of NaAlO 2 and Na 3 PO 4 as well as additives of NaOH, NaB4O7 and C6H5Na3O7 demonstrate different effects on MAO process and coating characteristics. By means of single factor experiments, an optimized dual electrolyte system was developed, containing 17.5 g/L NaAlO 2, 5.0 g/LNa3 PO4, 5.0 g/L NaOH, 3.0 g/L NaB4O7 and 4.2g/LC6H5Na3O7 .
文摘Pot experiments were conducted to investigate the influence of Si fertilizer on yield and N-uptake and use efficiency of double-season rice under the conditions of equal nitrogen, phosphorus and potassium nutrients. The results showed that along with the increase of Si fertilizer application, the yield of early and late rice increased firstly and then decreased within the range of SiO2 application rate of 0-0.8 g/kg soil. There was a significant parabolic correlation between the amounts of Si fertilizer application and rice grain yield (r= 0.931 2 and r= 0.973 3 in early-and late-rice season, respectively). Results showed that efficient Si fertilizer application enchanced N contents in different plant components of early rice at maturity stages with increased nitrogen uptake of double cropping rice and nitrogen harvest index of late rice.
文摘A new flavanone was isolated from the roots of Desmos cochinchinensis Lour Its chemical structure was elucidated by spectral analysis as 7 hydroxy 5 methoxy 8 formyl 6 methylflavanone, named desmosflavanone Ⅱ
基金The National High Technology Research and Development Program of China (863Program)(No.2002AA812038)the National Defense Pre-Research Support Program (No.41308050109)
文摘A novel closed-loop control strategy of a silicon microgyroscope (SMG) is proposed. The SMG is sealed in metal can package in drive and sense modes and works under the air pressure of 10 Pa. Its quality factor reaches greater than l0 000. Self-oscillating and closed-loop methods based on electrostatic force feedback are adopted in both measure and control circuits. Both single side driving and sensing methods are used to simplify the drive circuit. These dual channel decomposition and reconstruction closed loops are applied in sense modes. The testing results demonstrate that useful signals and guadrature signals do not interact with each other because of the decoupling of their phases. Under the condition of a scale factor of 9. 6 mV/((°) .s), in a full measurement range of±300 (°)/s, the zero bias stability reaches 28 (°)/h with a nonlinear coefficient of 400 × 10^-6 and a simulated bandwidth of more than 100 Hz. The overall performance is improved by two orders of magnitude in comparison to that at atmospheric pressure.
基金Projects (50634060,50721003) supported by the National Natural Science Foundation of ChinaProject (2009AA03Z526) supported by the High-tech Research and Development Program of ChinaProject supported by the Open-End Fund for Valuable and Precision Instruments of Central South University
文摘Ferritic steel with a nominal composition of Fe-14Cr-3W-0.42Ti-0.32Y was prepared by mixing gas-atomized prealloyed powder and mechanically alloyed powder. The microstructure is much different fxom other ferritic steels with the same composition and prepared via only mechanically alloyed powder. A bi-modal structure, which consists of pure ferritic grains and martensitic grains, was obtained after hot forging and air cooling. A phase transformation of αbcc→γfcc→α'bcc was also discovered in microstructural observation. The bi-modal microstructure shows a good combination of high strength and high ductility.
文摘To investigate the metabolites of baicalein 6,7-diacetate in rats. HPLC-DAD and LC/MS^n methods were used to analyze the metabolites in intestinal tract and plasma after oral administration of baicalein 6,7-diacetate to rats. Baicalein 6,7-diacetate was degraded into baicalein 6-monoacetate and baicalein in rat intestinal tract, and four baicalein glucuronides, baicalein 6-0- glucuronide, baicalein 6-methoxyl-7-O-glucuronide, baicalein 6,7-di-O-glucuronide, and baicalein 6-O-glucose-7-O-glucuronide were detected and tentatively identified in rat plasma. This is the first time to report the metabolites of baicalein 6,7-diacetate in rats. Six metabolites were identified in rat intestinal tract and plasma.
文摘AIM: To determine the anti-inflammatory activity of probiotic Bifidobacteria in Bifidobacteria-fermented milk (BFM) which is effective against active ulcerative colitis (UC) and exacerbations of UC, and to explore the immunoregulatory mechanisms. METHODS: Peripheral blood mononuclear cells (PBMNC) from UC patients or HT-29 cells were co-cultured with heat-killed probiotic bacteria or culture supernatant of Bifidobacterium breve strain Yakult (BbrY) or Bifidobacterium bifidum strain Yakult (BbiY) to estimate the amount of IL-10 or IL-8 secreted. RESULTS: Both strains of probiotic Bifidobacteria contained in the BFM induced IL-10 production in PBMNC from UC patients, though BbrY was more effective than BbiY. Conditioned medium (CM) and DNA of both strains inhibited IL-8 secretion in HT-29 cells stimulated with TNF-α, whereas no such effect was observed with heat- killed bacteria. The inhibitory effect of CM derived from BbiY was greater than that of CM derived from BbrY. DNAs of the two strains had a comparable inhibitory activity against the secretion of IL-8. CM of BbiY induced a repression of IL-8 gene expression with a higher expression of IκB-ζ mRNA 4 h after culture of HT-29 cells compared to that in the absence of CM.CONCLUSION: Probiotic Bifidobacterium strains in BFM enhance IL-10 production in PBMNC and inhibit IL-8 secretion in intestinal epithelial cells, suggesting that BFM has anti-inflammatory effects against ulcerative colitis.
基金supported by the National Natural Science Foundation of China(Grant No.41176089)supported by WEL(abbreviation of Key Laboratory of the Coastal and Wetland Ecosystems,Ministry of Education)Visiting Fellowship Program from Xiamen University
文摘To compare meiofaunal community in the two mangrove wetlands in Tong'an Bay, Xiamen, China, and probe the response of meiofauna to high organic matter, sampling was carried out in Fenglin and Xiang'an mangrove wetlands in the bay. The results showed that the Ne/Co ratio (nematode to benthic copepod) and organic matter in Fenglin mangrove wetland were higher than those in Xiang'an mangrove wetland. The meiofaunal abundance in Fenglin mangrove was all lower than that in Xiang'an mangrove wetland in summer, autumn and spring, while the meiofaunal abundance in Fenglin mangrove was higher than that in Xiang'an mangrove wetland in winter. Two-way ANOVA results showed that the meiofaunal abundance and nematode abundance were significantly different between regions, seasons and regionxseason. With all the results in the present study, we confirmed that the positive response of meiofaunal and nematode abundance were only detected for medium organic matter contents according to the Xiang'an wetland's level, and that the distribution of meiofaunal abundance would be influenced by sand content. Higher copepod abundance and lower N/C value usually suggest better environmental quality.
文摘[Objective] This study was conducted to investigate the effects of different gibberellic acid and hydrogen peroxide concentrations and different soaking time on the germination potential and germination rate of Scutellaria baicalensis, so as to improve the breeding efficiency of S. baicalensis. [Method] Dry seeds were divided into 3 groups, each containing 50 grains, which were weighed and put in a culture dish and soaked with distilled water covering the surface of seeds at room temperature. The seed weight was measured by gravimetric method once every 30 min from 30 rain after soaking, until the weight of the seeds no longer changed. [Result] With the increase of the concentration of hydrogen peroxide, the germination rate of S. baicalensis was improved gradually, and reached 32.0% under the concentration of 1.0% at the soaking time of 24 h; and with the increase of the concentration of gibberellic acid, the germination rate of S. baicalensis was improved gradually, and reached 64.0% under the concentration of 600 mg/L at the soaking time of 24 h. [Conclusion] The constant temperature at 25 ℃ in the incubator could also improve the seed germination rate; and the germination rate achieved by treating the seeds with gibbereUic acid was remarkably higher than that achieved by treating the seeds with hydrogen peroxide.
基金Project supported by the National Natural Science Foundation of China (No. 30070443).
文摘Quantitative trait loci (QTLs) for chlorophyll content of a rice leaf weremapped on to the molecular marker linkage map of a double-haploid (DH) population derived from across between two rice varieties 'IR64' and 'Azucena' in both nutrient solutionand soil cultureexperiments to detect rice nitrogen nutrition status under low N stress A chlorophyll meter was usedto measure the soil plant analysis development (SPAD) value of the topmost fully expanded leaf asthe index of chlorophyll content thatexpressed nitrogen status in rice plants. Totally 3 QTLs forSPAD values, two on chromosome 3 located at interval RG179-CDO337 and RG348-RZ329, respectively, andone on chromosome 10 at interval RZ500-RG134, were detected under stressed conditions of low N inthe soil and/or nutrient solution culture experiments. One QTL located at interval RG179-GDO337 onchromosome 3 associated with a relative change in SPAD value from a high N level to a low N level inthe soil culture experiment was also detected.Based on the different responses to low N stressbetween the two parents, it was supposed that the QTLs identified in this study associated withnitrogen efficiency in rice at low N levels might be useful in applying marker technology to ricebreeding programs.
基金supported by Liao Ning Revitalization Talents Program No. XLYC1807161Dalian High-level Talents Innovation Support Plan No. 2017RQ063+4 种基金Dalian Ocean University Zhanlan scholar ProgramThe National Natural Science Foundation of China under contract Nos. 41206013, 41430963the Public Science and Technology Research Funds Projects of Ocean under contract No. 201205018the National Science and Technology Support Program under contract No. 2014BAB12B02Projects of Institute of Marine Industry Technology of Liaoning Universities
文摘A method for determination of astaxanthin and astaxanthin eaters in shrimp shell by high performance liquid chromatography is established.Shrimp shell are addressed with 5%hydrochloric acid to remove calcium ions.After shell is dried,organics from shrimp shell are extracted with anhydrous ethanol.The alcohol extrative of the shrimp shell is mixed with the ammonium sulfate to extract astaxanthin by aqueous two-phase extraction.The crude astaxanthin is collected,which is distributed in the middle layer of the aqueous two-phase layer.After distilled water is added to the crude astaxanthin,the aqueous solution is centrifuged,and the previous step is repeated for several times.The precipitation in centrifuge tube is collected and dried.The crude astaxanthin dried is dissolved with acetone,and the sample solution is separated by TLC.Every pigment on the TLC plate is collected and dissolved with acetone.The pigments are determined by high performance liquid chromatograph.The results show that aqueous two-phase system,3 mL alcohol extractive of astaxanthin and 4.5 mL 20%ammonium sulfate,can be used to acquire crude astaxanthin.The wavelength of the maximum peak of astaxanthin in ethanol solution is 472 nm.A variety of pigments can be separated from the crude astaxanthin by thin-layer chromatography,including free astaxanthin,astaxanthin monoester,astaxanthin diester,echinenone and other substances.It can be seen from high performance liquid chromatography that the appearance time of free astaxanthin is from 4 min to 5.5 min,and the appearance time of astaxanthin monoester is from 10.5 min to 27.8 min.The method is simple about the sample pretreatment and feasible about the determination of astaxanthin and astaxanthin esters in shrimp shell.
基金Supported by The National Key Program for Infectious Diseases of China,No. 2008ZX10004 and 2009ZX10004the Program of Shanghai Subject Chief Scientist,No. 09XD1402700+1 种基金the Program of Shanghai Research and Development,No. 10JC1408200a China Partnering Award from the Biotechnology and Biological Sciences Research Council,United Kingdom
文摘AIM: To assess the safety of Bifidobacterium/ongum (B. longum) JDM301 based on complete genome sequences. METHODS: The complete genome sequences of JDM301 were determined using the GS 20 system. Putative virulence factors, putative antibiotic resis- tance genes and genes encoding enzymes respon- sible for harmful metabolites were identified by blast with virulence factors database, antibiotic resistance genes database and genes associated with harmful metabolites in previous reports. Minimum inhibitory concentration of 16 common antimicrobial agents was evaluated by E-test RESULTS: JDM301 was shown to contain 36 genes as- sociated with antibiotic resistance, 5 enzymes related to harmful metabolites and 162 nonspecific virulence fac- tors mainly associated with transcriptional regulation, adhesion, sugar and amino acid transport. B. longum JDM301 was intrinsically resistant to ciprofloxacin, ami- kacin, gentamicin and streptomycin and susceptible to vancomycin, amoxicillin, cephalothin, chloramphenicol, erythromycin, ampicillin, cefotaxime, rifampicin, imi- penem and trimethoprim-sulphamethoxazol. JDM301 was moderately resistant to bacitracin, while an earlier study showed that bifidobacteria were susceptible to this antibiotic. A tetracycline resistance gene with the risk of transfer was found in JDM301, which needs to be experimentally validated. CONCLUSION: The safety assessment of JDM301 using information derived from complete bacterial ge- nome will contribute to a wider and deeper insight into the safety of probiotic bacteria.