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991.
992.
响应面分析法优化当归粗多糖提取工艺 总被引:1,自引:0,他引:1
选取岷县当归药材为原料,采用水提醇沉法进行多糖提取,以当归粗多糖得率为指标,探讨加水量、回流提取时间、水提液的浓缩比、醇沉后所达含醇比例对当归多糖得率的影响。在单因素分析的基础上,采用响应面分析法(RSM)确定了当归粗多糖最佳提取条件为:加水量837.6 mL/100 g,浓缩后溶液体积为228.12 mL,最终含乙醇浓度为65.80%,回流提取时间2 h,在此条件下预测当归粗多糖得率理论的最佳值为10.44%,实际验证值为10.40%,两者相符,说明RSM法分析的可靠性。 相似文献
993.
目的采用液相悬浮芯片系统同时测定实验兔圆小囊中IL-1β、IL-1R1、IL=8、IL-8RA和IL=15各基因的表达情况,并对该方法进行评价。方法利用Affymetrix的Panomics QuantiGene Plex2.0Assay中bDNA信号放大和多磁珠分析技术,来同时检测两种实验兔圆小囊中多重mRNA并定量。建立实验兔免疫相关白介素基因的液相悬浮芯片检测方法。结果可同时检测IL-1β、IL=1R1、IL-8、IL=8RA和IL-15各基因的含量,并发现WHBE兔IL-15基因的相对表达量显著高于JW兔(P〈0.05),IL-1R1基因的相对表达量显著高于JW兔(P〈0.01),IL-8RA基因在WHBE兔中的相对表达量也高于JW兔(P〈0.05)。结论建立了实验兔白介素基因的液相悬浮芯片检测方法,WHBE兔的IL-15、IL-1R1和IL-8RA基因表达量较高,可能与WHBE兔独特的免疫学特性有关。 相似文献
994.
目的筛选试验鱼适宜急性毒性试验的发育期。方法将诸氏鲻虾虎鱼早期仔鱼、中期仔鱼、晚期仔鱼、稚鱼、幼鱼及成鱼暴露于一定浓度的钻井液中,比较钻井液对不同发育期诸氏鲻虾虎鱼的急性毒性。结果早期仔鱼48 h LC50为157 mg/L,中期仔鱼48 h LC50大于500 mg/L;中期仔鱼96 h LC50为79 mg/L,晚期仔鱼96h LC50为625 mg/L,稚鱼、幼鱼、成鱼96 h LC50显著大于500 mg/L;卤虫无节幼体96 h LC50为105 mg/L;不同发育期诸氏鲻虾虎鱼对钻井液的敏感性顺序为:早期仔鱼〉中期仔鱼〉晚期仔鱼〉稚、幼、成鱼。结论诸氏鲻虾虎鱼的早期仔鱼适用于海洋污染物急性毒性评价。 相似文献
995.
Chun-Qiao Liu Li Deng Peng Zhang Shu-Rong Zhang Luo Liu Tao Xu Fang Wang Tian-Wei Tan 《World journal of microbiology & biotechnology》2013,29(8):1391-1398
A mutant Xanthomonas maltophilia BT-112 with high α-anomer-selective glycosylation activity was screened by a series of mutation methods including UV light, N-methyl-N-nitro-N-nitroso-guanidine treatment and quick neutron mutation. The α-arbutin titer increased 15-folds compared with the parent strain. The optimal conditions for culture medium and the operational conditions for lab-scale fermenter were investigated. Under optimized conditions, the maximal hydroquinone (HQ) tolerance of cells and yield of α-arbutin were 120 mM and 30.6 g/l, respectively. The molar conversion yield of α-arbutin based on the amount of HQ supplied reached 93.6 %. The product was identified as α-arbutin by 13C NMR and 1H NMR analysis. In conclusion, the results in this work provide a one-step and cost-effective method for the large-scale production of α-arbutin. 相似文献
996.
Peng Xing Jiuwen Zheng Huabing Li Qing Liu 《World journal of microbiology & biotechnology》2013,29(2):373-377
The main goal of this work was to determine which methanogens were present during the anaerobic degradation of Microcystis biomass in the water columns of freshwater lakes. Simulation experiments were performed in which 30 ml Microcystis slurries were anaerobically incubated in 60 ml airtight bottles at three temperatures (15, 25, and 35 °C) for over 90 days. The production of CH4 was monitored, and the methanogenic community was analyzed by cloning and sequencing the mcrA genes in samples incubated at the three different temperatures. In total, four clusters were detected at different temperatures by phylogenetic analysis of mcrA genes; these included members of Methanomicrobiales, Methanobacteriaceae, and Methanosarcina. An apparent linkage between temperature and phylogeny of the methanogenic community was observed: Methanomicrobiales and Methanobacteriaceae dominated the incubation system at the lower temperatures of 15 and 25 °C, whereas Methanosarcina prevailed at 35 °C. The dominance of these hydrogenotrophic methanogens suggested that, at least at lower temperatures, H2 and CO2 might be the primary substrates for CH4 production during Microcystis anaerobic decomposition. 相似文献
997.
998.
Yan Zheng Xiao-quan Shan Peng Sun Long-zhu Jin 《Chemical Speciation and Bioavailability》2013,25(1):30-36
AbstractThe feasibility of using reversed-phase high performance liquid chromatography (RP-HPLC) for the separation of metallothioneins (MTs) and subsequent determination of cadmium in MTs by graphite furnace atomic absorption spectrometry (GFAAS) in rabbit kidney and liver has been studied. RP-HPLC was used to isolate, characterise and quantitate liver and kidney MT isoforms. The MTs were eluted from a radially compressed C18 column with a neutral sodium phosphate buffer and detected by UV absorbance at 254 nm. Rabbit liver MTs was found to be comprised of seven distinct isoforms with five of which were found to be subspecies of the MT-I isoform. Rabbit kidney MTs exhibited only two predominant isoforms. A standard calibration curve was constructed using purified rabbit kidney MT-I and MT-II which demonstrated excellent linear correlation between peak height and the quantity of MT injected into the column. Recovery of MT from RP-HPLC was found to exceed 90%. Kidney and liver tissues from rabbit by feeding low levels of cadmium in diets was assayed using the RP-HPLC analysis of cytosol samples. Feeding stable cadmium in the diet resulted in the deposition of MT in the kidney rather than in the liver. The cadmium content in MT isoforms was determined by GFAAS. Less than 10% of the total cadmium in kidney was associated with MTs. 相似文献
999.
Zhao Peng Nao Shibata Hideaki Tada 《Bioscience, biotechnology, and biochemistry》2013,77(12):2094-2097
ABSTRACTCCR5-mediated cytotoxicity of staphylococcal bi-component toxins was investigated using human CCR5-expressing CHO cells. Cytotoxicity of rim domain loop-exchange mutants between LukE and Hlg2 indicated that loop-4 of LukE is essential for cytotoxicity in combination with LukD. Interestingly, Hlg2 showed LukF-dependent CCR5-mediated cytotoxicity, suggesting that the F-components of toxins also play a role in the cell-specific cytotoxicity. 相似文献
1000.
目的 对重庆医科大学附属第二医院2001年1月1日至2009年12月31日10年临床标本中分离的主要革兰阴性杆菌耐药性变化进行分析,为临床合理用药提供依据.方法 采用回顾性方法对十年间大肠埃希菌、肺炎克雷伯菌、铜绿假单胞菌和不动杆菌的药敏结果用WHONET 5.4软件进行统计分析.结果 大肠埃希菌、肺炎克雷伯菌对亚胺培南耐药率小于5%;对阿米卡星、哌拉西林/他唑巴坦、头孢吡肟耐药率小于30%;对三代头孢、头孢西丁和氨曲南耐药率为40%左右;对青霉素类、喹诺酮类和磺胺类耐药率大于50%.铜绿假单胞菌对头孢他啶、头孢吡肟和亚胺培南耐药率小于40%;对其余监测抗生素耐药率大于50%.不动杆菌属对亚胺培南耐药率小于25%(2009年除外),对其余监测抗生素耐药率很高,维持在50% ~ 96%.铜绿假单胞菌、鲍曼不动杆菌泛耐药菌检出率分别为0~14%和0~48%.结论 革兰阴性杆菌对常用抗菌药物的耐药已非常普遍,且有逐年升高的趋势;肠杆菌科对碳青霉烯类、阿米卡星、哌拉西林/他唑巴坦、头孢吡肟耐药率相对较低;非发酵菌耐药性增加明显,铜绿假单胞菌、不动杆菌泛耐菌增加明显;严格控制抗菌药物的应用及耐药菌和泛耐药菌的传播和爆发流行已迫在眉睫. 相似文献