谈关于流感嗜血杆菌的分离培养实验分析

目的:探讨耐氨苄西林的流感嗜血杆菌产生β-内酰胺酶的机制.方法:对临床分离的112株流感嗜血杆菌耐药菌用纸片法作β-内酰胺酶测定,用PCR法检测产酶流感嗜血杆菌中的β-内酰胺酶基因的存在.结果:纸片法测得产酶菌株32株,产酶率28.6%(32/112):32株产酶菌中PCR法测β-内酰胺酶基因阳性菌株29株,阳性率为90.6%(29/32),其中质粒DNA模板组阳性为25株,基因组DNA模板组阳性为4例.结论:(1)流感嗜血杆菌耐氨苄西林主要由质粒介导产生β-内酰胺酶所造成.(2)PCR法是研究流感嗜血杆菌是否携带β-内酰胺酶基因及该基因所在位置的简便而有效的方法.     

好氧反硝化菌AD-1处理大豆乳清废水厌氧出水的性能评价

为了提高污水中氮素的去除效率,本研究自某大学微生物实验室开发的处理大豆乳清废水厌氧出水的CAAC(Continuous Aerobic-anaerobic Coupled)反应器污泥中筛选出1株高效好氧反硝化菌AD-1,经16S rDNA序列同源性比较和系统发育分析初步鉴定为恶臭假单胞菌(pseudomonas putida)。通过摇瓶批次培养考察菌株AD-1对以硝酸盐为唯一氮源的DM反硝化培养基的脱氮性能。48h时AD-1的TN和NO3-N去除率分别达到63.31%和63.35%,NO2-N浓度虽始终处于较低水平却呈高低波动状态,培养后期CODcr/TN下降是限制AD-1反硝化效率的主要因素之一。AD-1处理大豆乳清废水厌氧出水时NO3-N去除率接近100%,具有较高效的反硝化特性。结果表明,该菌株可作为处理大豆乳清废水厌氧出水及其它含氮废水的生物强化剂。     

浅析一株石油降解菌去除石油污染土壤中的油

从某石油厂区附近土样中分离出石油降解菌,经筛选得到13株石油降解较好的真菌。对这13株进行石油降解试验,其中石油降解效果最好的S92对模拟石油降解的降解率为87.0%。以S92菌株为原菌株通过紫外诱变得到一株石油降解能力显著提高的菌株S-3-15。用此菌株对石油污染土样进行石油降解试验,固液质量比为2∶5,接种量为20%,温度为37℃,摇床转速为150r/min,好氧培养了15d,其降解率达到了98.3%。     

深凹杯伞(Wtshyp2011001)的采集分离及液体优化培养

通过山西五台山特殊菌株的采集分离与鉴定,得到一种具有重要研究价值的特殊菌株深凹杯伞,代号:Wtshyp2011001。利用液体发酵培养及培养基优化筛选,得到一套深凹杯伞(Wtshyp2011001)菌株培养的最佳培养基配方及工艺条件,对该菌丝进行粗多糖提取,为今后开展中试放大培养及药效学研究提供了可靠数据。     

一株秋茄内生真菌(MF59)对植物病原真菌拮抗活性的研究

从红树林植物秋茄茎部中分离到一株内生真菌MF59,经鉴定为曲霉属。平板对峙实验结果表明,它对茄丝核菌、尖孢镰刀菌、蜡叶枝霉等多种植物病原真菌表现出良好的拮抗活性,它有可能成为对由这些病原真菌引起的植物病害进行生物防治的良好的微生物菌株。     

降解石油复合微生物菌剂的筛选研究

从30个土样中筛选出3株高效原油降解菌株,它们为DCH-16,DCH-19和DCH-20,7天后降油率分别为75.6%,80.3%和73.2%。经鉴定,分别是脂肪酸芽孢杆菌属Alicycolobacillus,芽孢肠状杆菌属Sporomaculum和盐芽孢杆菌属Halobacillus。将此3株高效原油降解菌在原油培养基中进行复合实验,结果表明,在相同条件下复合菌降油效果优于单菌;菌株DCH-19与DCH-20复合的最佳原油降解条件为:接种量比1:1(总接种量为10%),pH值为7.5,底物浓度20mg.mL-1,温度35℃,原油降解时间为7天。将实验复筛所得部分降油菌用于胜华炼厂废水处理,效果最好的是菌DCH-19和DCH-20的复合,处理两天后降油率达到80.2%。表明复合菌株DCH-19和DCH-20有很强的适应能力。     

生鲜牛乳中产Nisin菌株的筛选

食品防腐剂分为合成防腐剂和天然防腐剂。天然防腐剂具有抗菌性强、安全无毒等合成防腐剂无法比拟的优点。现被广泛应用的天然防腐剂就是乳酸链球菌素(nisin)。本实验采用一种简单、高效的定向筛选乳酸链球菌素产生菌的方法,从生鲜牛乳中分离选育出三株产"Nisin"的乳酸菌,通过抑菌试验对其作了初步鉴定。     

邯郸市主城区主要行道树的多样性调查分析

本项研究采用抽样调查方法对邯郸市主城区20条主要道路的行道树进行的详细调查,分析邯郸市主城区行道树的物种组成、胸径,探讨多样性指数和行道树绿化发展趋势。结果表明:①邯郸市主城区行道树共有18科25属28种,其中乔木20种,隶属19属14科;行道树种类最多的科是蔷薇科,悬铃木(Platanus hispanica)、国槐(Sophora japonica linn)、紫薇(Lagerstroemia indica)、毛白杨(Populus tomentosa Carr)、栾树(Koelreuteria paniclata Laxm)、银杏(Ginkgo biloba)、臭椿(Ailanthus altissima)、美国白蜡(Fraxinus americana)是邯郸市主城区行道树的骨干树种。②针对邯郸市行道树多样性的不足,提出了邯郸市行道树绿化的发展趋势。     

2006年度国家自然科学基金资助项目及项目负责人专栏介绍 新疆大学生命科学与技术学院——马合木提·哈力克教授

<正>"新疆塔里木马鹿栖息地破碎化对种群遗传多态性的影响"荣获2006年度国家自然科学基金面上项目资助塔里木马鹿(Cervus elaphus yarkandensis)为马鹿亚种之一,属国家II级重点保护动物,又是重要经济动物。在中国濒危动物红皮书     

低温肉制品中腐败微生物的生理生化分析

以低温肉质品为研究对象,研究其在储藏过程中微生物的变化,并从中分离出引起食品腐败的微生物。通过研究,共分离出11个菌株。通过形态鉴定和革兰氏染色分析,结果表明,11株菌有7株菌即产酸又产气,4株菌只产酸不产气;有3株菌M.R.试验呈阳性,8株菌呈阴性;有3株菌V.P.试验呈阳性反应;有10株菌H2O2酶试验呈阳性反应;11株菌都不产H2S;硝酸盐还原试验说明分离出的11株菌都呈阳性反应;通过革兰氏染色试验说明,有3株菌为革兰氏阳性菌,8株菌为革兰氏阴性菌。     

Loss from the chasing of MAX stocks: Evidence from China

We evaluate the implications of the MAX effect in the Chinese financial market. First, the MAX effect prevails in China: A zero-cost MAX strategy, which goes long (short) stocks with the highest (lowest) maximum daily return in the prior month, generates significant losses over the full sample period. Second, further analysis on firm characteristics confirms that the MAX stocks exhibit lottery-like features, and the (negative) performance of the MAX strategy varies over time and is related to investor sentiment. Third, the MAX effect gets weaker after the introduction of short-selling in 2010. Finally, we document that there exists a reversed MAX effect among mutual funds, because a similarly implemented MAX strategy generates significant positive risk-adjusted returns among equity funds in China.     

中国进口贸易利益规模及其分解 ——基于产品多样性视角的研究

本文从产品多样性视角考察中国进口贸易利益规模。基于现有文献的研究模型和中国海关2002年至2012年进口数据,本文发现在一系列对称性假设下中国进口贸易带来产品多样性增加的贸易利益总体规模较小。分产品类别看,中间产品、工业品及初级产品贡献了绝大部分贸易利益。分产业类别看,金属矿的开采、化学品及化学制品的制造及与资源、初级产品相关的行业贡献较大。     

Spillovers from universities: Evidence from the land-grant program

This paper estimates the short- and long-run effects of universities on geographic clustering of economic activity, labor market composition and local productivity and presents evidence of local spillovers from universities. I treat the designation of land-grant universities in the 1860s as a natural experiment after controlling for the confounding factors with a combination of synthetic control methods and event-study analyses. Three key results are obtained. First, the designation increased local population density by 6 percent within 10 years and 45 percent in 80 years. Second, the designation did not change the relative size of local manufacturing sector. Third, the designation enhanced local manufacturing output per worker by $2136 (1840 dollars; 57 percent) in 80 years while the short-run effects were negligible. This positive effect on the productivity in non-education sectors suggests the existence of local spillovers from universities. Over an 80-year horizon, my results indicate that the increase in manufacturing productivity reflects both the impact of direct spillovers from universities and general agglomeration economies that arise from the increase in population.     

Empirical evidence on the sign of the slope of the hazard rate from unemployment from a fixed effects model

Empirical evidence on the sign of the slope of the hazard rate from unemployment is obtained from a fixed effects model based on the gamma distribution for unemployment duration. The data used are pairs of unemployment spells for adult males in the control and experimental groups of the Denver Income Maintenance Experiment. The sample selection issue involved in selecting the pair of spells used in the empirical work is discussed. The empirical results suggest that for these samples the hazard function is monotone decreasing and support the assumptions that the first two spells of unemployment are identically distributed and can be modelled using the gamma distribution.     

Flight from the Ghetto

A bstract . The movement of middle-class Blacks from the Black ghettos is a phenomenon which greatly intensified in the 1970s. Using 1980 data for ten Florida Standard Metropolitan Statistical Areas with large populations, it was determined that the intensity of the migration varied greatly among the cities , for a variety of different reasons. All ten cities, however, experienced clustering among the middle-class Blacks who moved from the ghettos. This clustering was usually around large public service institutions , principal employers of the group. Tracts selected by the Black middle class generally have homes more expensive and newer than the tract average, and the period of occupancy of the residents was shorter than the tract average. Usually Black households in White tracts within the Florida cities do not have socioeconomic parity with their White cohorts.