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1.
在检测细菌、真菌和大肠菌群时,抗防腐剂型微生物培养基可消除样品中浓度为 2.0g/L(Kg)的山梨酸、山梨酸钾、苯甲酸及苯甲酸钠的干扰;抗消毒剂型微生物培养基可分别消除150mg/ L二氧化氯、400mp/ L过氧乙酸、700mg/ L次氯酸钠及180mp/ L过氧化氢的干扰;抗臭氧型微生物培养基可以消除10.0mg/L的臭氧和余氯的干扰。大样倾注平板法可以取5mL的样品,适用所有样品的检测;液体大样法可以取100mL的样品,适用于所有样品的检测及增菌,特别适用于无色液体样品;最小近似数法可以检出次大样中  相似文献   

2.
抗消毒剂型微生物培养基研究   总被引:2,自引:1,他引:1  
二氧化氯、过氧乙酸、次氯酸钠及过氧化氢等消毒剂高浓度可以杀灭微生物,低浓度可以抑制微生物生长。在微生物检测中,要消除消毒剂的干扰,培养基的抗消毒剂指数必须控制在12.0—24.5之间。消毒剂解抑剂Ⅰ的抗消毒剂指数为 12.0,对细菌和真菌生长无明显抑制作用,加入经改良和优化的普通培养基后,制得5种抗消毒剂型培养基,在灭菌前后和一年的保存期内,其抗消毒剂指数基本保持不变。当采用大样倾注平板法和液体大样法检测残留消毒剂的样品时,使用抗消毒剂型培养基检出细菌和真菌能力大大高于普通培养基。  相似文献   

3.
二氧化氯、过氧乙酸、次氯酸钠及过氧化氢等消毒剂高浓度可以杀灭微生物,低浓度可以抑制微生物生长。在微生物检测中,要消除消毒剂的干扰,培养基的抗消毒剂指数必须控制在12.0—24.5之间。消毒剂解抑剂Ⅰ的抗消毒剂指数为 12.0,对细菌和真菌生长无明显抑制作用,加入经改良和优化的普通培养基后,制得5种抗消毒剂型培养基,在灭菌前后和一年的保存期内,其抗消毒剂指数基本保持不变。当采用大样倾注平板法和液体大样法检测残留消毒剂的样品时,使用抗消毒剂型培养基检出细菌和真菌能力大大高于普通培养基。  相似文献   

4.
食品饮料中残留防腐剂、消毒剂和臭氧会对其中的细菌和真菌的检出造成严重干扰,当采用大样倾注平板法和液体大样法测定细菌和真菌总数及采用国标大肠菌群测定法测定大肠菌群MPN值时,使用抗防腐剂型、抗消毒剂型及抗臭氧型微生物培养基分别检测含有防腐剂山梨酸钾及苯甲酸钠、消毒剂二氧化氧和臭氧的样品,其检出细菌、真菌和大肠菌群的能力大大高于普通微生物培养基,与采用普通微生物培养基检测不合防腐剂、消毒剂及臭氧的样品中的细菌、真菌和大肠菌群的检出能力基本一致。  相似文献   

5.
抗干扰微生物培养基的抗干扰性能研究   总被引:3,自引:3,他引:0  
食品饮料中残留防腐剂、消毒剂和臭氧会对其中的细菌和真菌的检出造成严重干扰,当采用大样倾注平板法和液体大样法测定细菌和真菌总数及采用国标大肠菌群测定法测定大肠菌群MPN值时,使用抗防腐剂型、抗消毒剂型及抗臭氧型微生物培养基分别检测含有防腐剂山梨酸钾及苯甲酸钠、消毒剂二氧化氧和臭氧的样品,其检出细菌、真菌和大肠菌群的能力大大高于普通微生物培养基,与采用普通微生物培养基检测不合防腐剂、消毒剂及臭氧的样品中的细菌、真菌和大肠菌群的检出能力基本一致。  相似文献   

6.
食品饮料中含有山梨酸、山梨酸钾、苯甲酸及苯甲酸钠等防腐剂会对其中的细菌和真菌的检出造成严重干扰,把测定体系的抗防腐剂指数控制在81.1~94.5之间,可较好地消除防腐剂对微生物生长的抑制。防腐剂解抑剂Ⅲ的抗防腐剂指数为92.34,对细菌和真菌的生长无抑制作用,加入经改良和优化的普通培养基后,制得5种抗防腐剂型培养基,在灭菌前后和一年保存期内,它们的抗防腐剂指数基本保持不变。与普通培养基比较,当采用大样倾注平板法和液体大样法检测含有防腐剂的样品时,抗防腐剂型培养基可极大地提高样品中的细菌和真菌的检出率。  相似文献   

7.
食品饮料中含有山梨酸、山梨酸钾、苯甲酸及苯甲酸钠等防腐剂会对其中的细菌和真菌的检出造成严重干扰,把测定体系的抗防腐剂指数控制在81.1~94.5之间,可较好地消除防腐剂对微生物生长的抑制。防腐剂解抑剂Ⅲ的抗防腐剂指数为92.34,对细菌和真菌的生长无抑制作用,加入经改良和优化的普通培养基后,制得5种抗防腐剂型培养基,在灭菌前后和一年保存期内,它们的抗防腐剂指数基本保持不变。与普通培养基比较,当采用大样倾注平板法和液体大样法检测含有防腐剂的样品时,抗防腐剂型培养基可极大地提高样品中的细菌和真菌的检出率。  相似文献   

8.
向日葵籽苗下胚轴原生质体,培养在含有BA0.5mg/L,2,4-D0.5mg/L,NAA0.1mg/L和葡萄糖0.55mg/L的改良Kao培养基中,24~28h后,原生质体开始分裂。包埋在琼脂糖0.6%中的原生质体,培养5d后,分裂频率达95%以上。生长旺盛的小愈伤组织转移到含有2ip0.1mg/L,IAA0.01mg/L,腺嘌呤40mg/L和GA30.01mg/L的Thompson液体培养基上13d后,原生质体诱导的少数愈伤组织发生根分化。  相似文献   

9.
培养因子对艾西南瓜芽增殖及不定根形成的影响   总被引:2,自引:0,他引:2  
以艾西丝南瓜带芽茎段为外植体,研究了基本培养基、激素、糖、光照、培养基支持物等因子对芽增殖及不定要根形成的影响。结果表明:艾西丝南瓜芽增殖的最佳培养条件为:MS+BA0.5 ̄1.0mg/L+IAA0.1 ̄0.5mg/L+食用白糖30g/L,芽的月增殖系数稳定在10左右;不定根诱导的适宜条件是:1/2MS+食用白糖20g/L生根率达86%;且自然散射光条件(1000 ̄5000Lx)优于灯光(1000  相似文献   

10.
体外培养大鼠星形细胞的缺糖缺氧性损伤及药物的保护   总被引:4,自引:1,他引:3  
本实验用大鼠星形细胞体外培养模型,观察了细胞在不同条件下乳酸脱氨酶(LDH)的漏出。发现当去掉葡萄糖后,细胞缺氧5和7h后LDH漏出明显增加,5b为59.7±25.3U/mg蛋白(对照组24.7±16.3,P<0.05),7h为68.3±89U/mg蛋白(对照组39.9±212,P<0.01)。用3-氧-甲基-[1- ̄3H]-D-葡萄糖摄取法测量细胞体积,结果显示缺糖缺氧5h后细胞明显肿胀,从对照组的4.1±1.2增加到8.1±3.2μl/mg蛋白(P<0.01)。丹参有效成分764-3在0.5至50μmol/L时能减少缺糖缺氧细胞LDH漏出;在50μmol/L时能减小缺糖缺氧细胞的体积。谷氨酸受体拮抗剂DNQX(6,7-dinitroquinoxaline-2,3dione)50μmol/L能减轻星形细胞肿胀和LDH漏出。  相似文献   

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It has now been over twenty years since a novel herpesviral genome was identified in Kaposi's sarcoma biopsies. Since then, the cumulative research effort by molecular biologists, virologists, clinicians, and epidemiologists alike has led to the extensive characterization of this tumor virus, Kaposi's sarcoma-associated herpesvirus(KSHV; also known as human herpesvirus 8(HHV-8)), and its associated diseases. Here we review the current knowledge of KSHV biology and pathogenesis, with a particular emphasis on new and exciting advances in the field of epigenetics. We also discuss the development and practicality of various cell culture and animal model systems to study KSHV replication and pathogenesis.  相似文献   

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Comprises species occurring mostly in subtidal habitats in tropical, subtropical and warm-temperate areas of the world. An analysis of the type species, V. spiralis (Sonder) Lamouroux ex J. Agardh, a species from Australia, establishes basic characters for distinguishing species in the genus. These characters are (1) branching patterns of thalli, (2) flat blades that may be spiralled on their axis, (3) width of the blade, (4) primary or secondary derivation of sterile and fertile branchlets and (5) position of sterile and fertile branchlets on the thalli. Application of the latter two characters provides an important basic method for separation of species into three major groups. Osmundaria , a genus known only in southern Australia, was studied in relation to Vidalia , and its separation from the Vidalia assemblage is not accepted. Species of Vidalia therefore are transferred to the older genus name, Osmundaria. Two new species, Osmundaria papenfussii and Osmundaria oliveae are described from Natal. Confusion in the usage of the epithet, Vidalia fimbriala Brown ex Turner has been clarified, and Vidalia gregaria Falkenberg, described as an epiphyte on Osmundaria pro/ifera Lamouroux, is revealed to be young branches of the host, Osmundaria prolifera.  相似文献   

18.
Fifteen chromosome counts of six Artemisia taxa and one species of each of the genera Brachanthemum, Hippolytia, Kaschgaria, Lepidolopsis and Turaniphytum are reported from Kazakhstan. Three of them are new reports, two are not consistent with previous counts and the remainder are confirmations of very scarce (one to four) earlier records. All the populations studied have the same basic chromosome number, x = 9, with ploidy levels ranging from 2x to 6x. Some correlations between ploidy level, morphological characters and distribution are noted.  相似文献   

19.
肝癌中HBV和HCV基因和抗原的分布及意义   总被引:1,自引:0,他引:1  
采用原位分子杂交方法检测HCV RNA及HBV X基因;采用免疫组织化学方法研究HCV核心抗原,非结构区C33c抗原及HBxAg在肝细胞肝癌中的定位及分布.结果表明(1)HCV RNA、HBV X基因在肝细胞肝癌组织检出率分别为40%(55/136)和82%(112/136).HCV RNA定位于癌细胞的胞浆内,阳性细胞呈散在、灶状及弥漫分布三种形式;HBV X基因在肝癌细胞中的分布呈胞浆型、核型及核浆型,阳性细胞也呈上述三种分布形式;(2)HCV C33c抗原、核心抗原在肝细胞肝癌中的阳性率为81%(133/164)及86%(141/164).C33c抗原定位于癌细胞及肝细胞的胞浆内;核心抗原既定位于癌细胞核中,又可定位于胞浆中.C33c抗原阳性细胞以灶状分布为主;而核心抗原阳性细  相似文献   

20.
For a plant selection model with frequency-independent viabilities, fertilities and selfing rates, it is shown that apart from global fixation, for certain parameter combinations a protected polymorphism and facultative fixation (either allele may become fixed according to initial frequencies) may both occur. Facultative fixation requires different selling rates for the dominant and recessive type. Protection of the polymorphism requires resource allocation for male and female function. In this connection the problem of purely genetically caused population extinction is discussed.
For general frequency dependence and regular segregation, the chances for establishment of a completely recessive gene are compared to those of a completely dominant gene. It is proven that the process of establishment of the recessive gene, despite a fitness advantage, may be considerably endangered by drift effects if random mating prevails. The recessive gene may reach the same effectivity in establishment as a dominant gene, only if the recessive homozygote mates exclusively with its own type during the period of establishment.  相似文献   

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