噬菌体鸡尾酒制剂对牛奶中产志贺毒素大肠杆菌O157:H7的抑制作用

目的:研究噬菌体鸡尾酒混合制剂对牛奶中产志贺毒素大肠杆菌O157:H7的抑制作用研究.方法:采用双层平板法,以产志贺毒素大肠杆菌O157:H7 ATCC 43895为宿主菌,从污水中分离裂解性噬菌体.通过体外抑菌试验研究其在牛奶样品中的抑菌效果.结果:噬菌体C13.6、C13.9和C34.6的噬菌斑透亮清晰;能裂解宿主菌ATCC 43895及其他O157:H7大肠杆菌,为宽宿主谱;噬菌体鸡尾酒混合制剂对牛奶中O157:H7大肠杆菌的抑菌效果为:在25℃条件下,MOI=10,处理2 h及以上抑菌效果极其显著,在10 h时宿主菌数量下降4.30(lg(CFU/mL)).结论:该噬菌体混合制剂对牛奶中O157:H7大肠杆菌有良好的抑制作用,具有作为食品防腐剂的潜能.     

日本血吸虫压电免疫传感器的研究

在压电石英晶体金电极表面形成MPA（疏基丙酸）单分子膜,经NHS和EDC活化后固定血吸虫抗原（SjAg）,研制成血吸虫抗体（SjAb）压电免疫传感器．研究了包被抗原浓度、抗原抗体结合时间,TSM声波免疫传感的响应特性、重现性等实验条件的影响．压电晶体的频移值与IRS浓度在0－36μg／ml范围内有良好的线性关系．将此传感器用于兔抗血吸虫抗体血清样品的测定,结果令人满意．     

日本血吸虫免疫反应中抗原价数及平衡常数Kass的测定

在压电石英晶体金电极表面形成巯基丙酸(MPA)单分子膜、经NHS和EDC活化后固定血吸虫抗原(SjAg),研制成血吸虫抗体(SjAb)压电免疫传感器．研究测定了抗原价数及免疫反应平衡常数Kass,结果令人满意。     

日本血吸虫压电免疫传感器的研究

在压电石英晶体金电极表面形成MPA(疏基丙酸)单分子膜,经NHS和EDC活化后固定血吸虫抗原(SiAg),研制成血吸虫抗体(SjAb)压电免疫传感器。研究了包被抗原浓度、抗原抗体结合时间,TSM声波免疫传感的响应特性、重现性等实验条件的影响。压电晶体的频移值与IRS浓度在0～36μg/ml范围内有良好的线性关系,将此传感器用于兔抗血吸虫抗体血清样品的测定,结果令人满意。     

一种新型酶免疫传感器的制备及其性能

本文研究的酶免疫传感器是采用再生丝素将待测抗原(兔IgG)固定在石墨电极表面,选用抗体(山羊抗兔IgG-HRP)与其识别结合.利用H2O2将抗原体结合的电位响应信号放大,采用直接电位法检测IgG的浓度.该传感器测定IgG的最低检测浓度可达1.2×10-10mol/L,标准曲线的线性范围在4.1×10-7～1.2×10-10mol/L,响应时间为15s.通过电泳的方法加速抗原抗体的识别结合,反应时间由原来的90min缩短到30min,这在国内外鲜有报道.这种以固定化抗原结合酶标抗体量的多少作为检测抗原标准的新型酶免疫传感器,不仅在临床检测、生物医学研究领域中,而且在动植物疾病检测、环境监测等领域都有着广阔的应用前景.     

血红蛋白在二氧化钛球腔阵列上的直接电化学研究

采用Langmuir—Blodgett术和溶胶-凝胶（sol—gel）法在氧化铟锡（ITO）表面制备了TiO2球腔阵列．研究了TiO2球腔阵列的电化学性质,结果表明：所制备的TiO2球腔阵列具有微电极阵列特性．将血红蛋白（Hb）直接吸附在TiO2球腔阵列内部,制备过氧化氢（H2O2）生物传感器．修饰电极对过氧化氢（H2O2）的电流响应快速稳定、重现性和选择性较好,在9．00×10^-7～4．44×10^-4mol／L范围内H2O2浓度与响应电流呈现良好的线性关系,其检出限为3．12×10^-7mol／L,米氏常数为0．138mmol／L．     

碳纳米管组装电极上计时电流法测定辣根过氧化物酶的研究

以多壁碳纳米管修饰玻碳电极为工作电极,研究了辣根过氧化物酶（HRP）一对苯二酚（HQ）-H2O2体系的电化学催化行为。比较碳纳米管修饰玻碳电极和玻碳电极,峰电位从64mV（vs．SCE）前移至116mV,催化电流提高了10倍。对工作电位、介质pH、H2O2和HQ浓度进行了选择。在优化的实验条件下,采用计时电流法测定HRP的线性范围为5．0×10-10～1．0×10-10g／mL。检出限为2．5x1×10-10g／mL。该法具有电极制作简单和灵敏度高等优点。     

日本血吸虫免疫反应中抗原价数及平衡常数Kass的测定

在压电石英晶体金电极表面形成流基丙酸（MPA）单分子膜,经NHS和EDC活化后固定血吸虫抗原（SjAg）,研制成血吸虫抗体（SjAb）压电免疫传感器．研究测定了抗原价数及免疫反应平衡常数Kass,结果令人满意．     

聚靛蓝胭脂红固定过氧化物酶生物传感器的研究

采用电化学聚合法制备聚靛蓝胭脂红膜,并通过静电吸附固定辣根过氧化物酶,形成聚靛蓝胭脂红修饰的辣根过氧化物酶电极。聚靛蓝胭脂红在电极与酶分子之间传递电荷,因此,在没有额外的电子媒介体的条件下,通过循环伏安法考察电极的电化学特性。探讨了pH值、温度、工作电位和抗坏血酸等对此生物传感器电催化还原H2O2的影响。此生物传感器制作简单、响应时间短(5 s)、选择性好、灵敏度高,对H2O2线性响应范围为5×10-7~1×10-2mol.l-1检出限为5×10-8mol.l-1     

基于Nafion固定天青I和纳米CdS共修饰玻碳电极的H2O2生物传感器

利用滴涂于玻碳电极（GCE）表面的以Nnfion膜中负电性的磺酸基与天青I（AI）阳离子之间的静电作用,实现天青I在电极上的固定化,再通过静电吸附和自组装技术将纳米CdS吸附的辣根过氧化物酶（HRP）修饰到电极表面,制备出性能良好的H2O2生物传感器。采用循环伏安法（CV）和计时电流法考察了该传感器的电化学性质。实验表明,该传感器具有良好的生物催化活性,较高的灵敏度,良好的选择性和稳定性,且易于制作等特点。响应电流与H2O2浓度在8．0×10^-6～1．6×10^-3 moL／L范围呈现良好的线性关系,检出限为2．72×10^-6 moL／L。     

卡思卡特城堡

It is worthy of noting that, whilst Crookston Castle witnessed the earlier and happier portion of Mary's variegated life,     

不同的吃喝玩乐

一、吃和喝吃苹果 eat an apple, 吃药 take medicine,吃糖 have some sweets,吃饭 have one's meals,吃馆子 dine out,吃惊 be surprised/     

漏洞百出的教育

Many college freshmen arrive woefully unprepared to do college work, and as disadvantaged populations continue to grow, the share of the American work force that has made it through college is expected to plummet. Many experts blame that educational failure not just on high schools but also on colleges. School & College, a special report by The Chronicle, looks at efforts to fix the system. What reforms would better prepare students for college? What should schools and colleges be doing differently? How should state and federal officials help?     

只要努力,不要后悔

There are numbers of crossroads on our long and unpredictable life journey where we totally have no idea about which direction to choose. No matter what our decision is, we should not turn back, but face the music and go ahead instead. I am this kind of girl who always does try without regretting, one example is how I dealt with my love.     

浅谈移民问题

Migration occurs behind a variety of reasons and has a great effect on the whole world. People may migrate in order to improve their economic situation, or in order to escape civil strife, persecution, and environmental disasters. The impact of migration is complex, bringing both benefits anddisadvantages. This paper briefly talks about the causes of migration, the allocation of benefits, and the ways in which individual countries and the international community deal with this important subject.     

Sister Carrie, an Adherent of Desires

Sister Carrie is one of the most controversial characters in American literature.Thought as a "fallen woman" firstly,she was defined as a "new woman" by some critics later. However, by digging into the motivaton behind the whole process of Carrie's "success", the relationship between Carrie and her creator (the author), the social conditions of then American, it can be found that Carrie has never been free-standing on her thought and she has never found her real-sdf even after becoming a famous actress. In a society dominated by mass consumerism Carrie is only an adherent of her own desires. She also is a representative of all those country girls flooded into cities, a symbol and a sacrifice of the urbanization of America in a time countryside was overcome by cities.     

Improvement of one-cycle controller by use of proportional integral differential controller

1.IntroductionOne-cyclecontrolmethod,whichwasproposedaboutonedecadeago[1],hasbecomeanattractivemethodinspecialfieldssuchaspowerfactorcorrection[2-6],switchingamplifiers[7,8],etc.Themainideaofthiscontrollerisbasedonintegrationofdiodevoltageinone-cycleandforcesittobeexactlyequaltothereferencevalue.Themainadvantageofthiscontrollerisitsrealtimeabilitytorejectthevariationofinputvoltage[1].Despitethisgreatability,ithasnogoodperformancesinrejectingofloaddisturbanceandfollowingreferencecommands.Espec…     

库克斯顿城堡

城堡, 是欧洲典型的建筑之一, 每个城堡都有一个美丽的传说或是一段历史。从本期开始, 我们将推出“城堡之旅”, 带各位读者去浏览、观赏欧洲各地的城堡, 开始一段文化与历史的旅途!     

The Reader Response Approach to Teaching of English Literature

During interview with English majors, it was found that a majority of students expressed disappointment with their experience of English literature classes. Students' dislike of learning English literature appears to be the major problem of teaching English literature in China. Reader response approach is a good way to solve this problem. In this paper, I explain the rationale behind the reader response approach, such as its origin, definition, features, assumptions, and strategies. Then I illustrate how reader response approach works as a teaching strategy by presenting several teaching models. At last I evaluate its usefuiness for teachers and present the advantages of reader response approach in Chinese context.