990 resultados para O-2 ((1)DELTA(G))


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Sono e imunidade parecem apresentar uma relação de reciprocidade. A ativação do sistema imune altera o padrão de sono e distúrbios do sono podem afetar a função imune. Além disso, é bem descrito que a privação de sono paradoxal (PSP) leva à hiperalgesia e o tratamento com fármacos clássicos, como opióides ou antidepressivos tricíclicos, não é capaz de reverter este quadro. Neste trabalho, avaliamos se a PSP afetaria a resposta inflamatória e a sobrevida em ratos e se o tratamento com um análogo sintético de lipoxinas (ATL-1) seria capaz de reverter a hiperalgesia induzida pela PSP. Todos os protocolos experimentais foram previamente aprovados pelo Comitê de Ética para o Uso de Animais, da UERJ (CEUA/032/2010). Ratos Wistar machos foram submetidos a 96 h de PSP, induzidas pelo método de plataforma única (PU) ou de múltiplas plataformas modificado (MPM). Após 96 h de PSP os animais foram submetidos ao modelo da bolha de ar ou pleurisia utilizando-se a carragenina como agente flogístico, ou ainda a PSP foi aplicada antes ou após a indução de um modelo de ligação e perfuração do ceco (CLP). Quatro horas após a injeção de carragenina os animais apresentaram um aumento no recrutamento de leucócitos para a cavidade da bolha, porém não houve diferença entre animais PSP e controles. O número total de leucócitos no plasma não se alterou após a injeção de carragenina. Na pleurisia, os animais PSP apresentaram um aumento nos níveis de IL-6, IL-1β e TNF-α no plasma, enquanto apenas IL-1β e IL-6 estavam aumentados no exsudato pleural dos animais que receberam carragenina. O padrão de recrutamento de leucócitos para o local da injúria foi bastante semelhante entre os animais controle e PSP 2 h, 4 h e 24 h após a injeção de carragenina. Houve um aumento progressivo com o tempo, apresentando um pico em 24 h, no entanto, não foi observada diferença significativa na resposta dos grupos PSP. A PSP aplicada antes ou após a indução do CLP reduziu a sobrevida dos animais, mas não alterou o acúmulo de neutrófilos, nos dois protocolos. Quando a PSP foi aplicada antes do CLP, os níveis séricos de IL-6 estavam aumentados nos grupos PSP e PSPCLP, porém quando a PSP foi aplicada após o CLP, ambas IL-6 e IL-1β estavam aumentadas nos grupo PSPCLP. O efeito do tratamento com ATL-1 (10 g/kg, i.v.) na hiperalgesia induzida pela PSP foi determinado através do teste da formalina. O análogo reduziu o número de comportamentos relacionados à dor em animais PSP e controles na fase inflamatória do teste. Nossos resultados demonstraram que a PSP por 96 h aumentou os níveis plasmáticos de citocinas, reduziu a sobrevida dos animais, contudo não foi capaz de alterar o recrutamento de leucócitos frente a um estímulo inflamatório ou infeccioso. O aumento de mediadores inflamatórios observado nesses animais pode estar relacionado à hiperalgesia em animais PSP, uma vez que o tratamento com o ATL-1 reverteu esse efeito, possivelmente através de mecanismos envolvendo sua ação anti-inflamatória.

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Studies were conducted to evaluate the quality of hilsa fish during icing and freezing storage at -20°C by determining organoleptic and bacteriological aspects. The fishes stored in ice were organoleptically in acceptable condition 2 for 20 days. The bacterial load in muscles of 4 days ice stored fish was 2.5x10² CFU/g which gradually increased up to 1.8x10⁵ CFU/g after 20 days when the fishes were organoleptically in acceptable condition. The keeping qualities of different days of ice stored fishes were also evaluated during their subsequent frozen storage at -20°C. Both 4 and 7 days of ice stored fishes were organoleptically in acceptable condition up to 48 weeks but the highest degree of freshness was found for fish stored in ice for 4 days before freezing at -20°C. The result indicates that the longer is the duration of ice storage before freezing, the shorter is the shelf life of the fish. The initial bacterial load prior to freezing of the 4 and 7 days of ice stored samples were 2.5x10³ CFU/g and 3.8x10⁴ CFU/g, respectively which reduced to 2.21x10² CFU/g and 2.38x10² CFU/g, respectively at the end of the 24 weeks of frozen storage. However, after 40 weeks the bacterial load in the frozen stored sample fell below the detection level.

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近缘动物染色体同源区内的脆性部位在进化上是保守的,可作为染色体具有共同起源的标志, 结合G-带的比较,可用以阐明近缘动物染色体的同源性和染色体进化。图版2图2表1参24

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银额果蝇昆明群体有丝分裂中期核型中存在B染色体, 出现频率为69.1%在已 研究过的来自各个地区的银额果蝇中, 昆明群体的B染色体频率最高。B染色体 数目为1—6条。该群体内单雌系间的B染色体数目不同, 个体间和细胞间的B染色 体数目也不同。在核型中, B染色体最小, 形态稳定, 点状, C-带和G-带呈阳性 。 图版1图2表1参12

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The oxygen vacancy has been inferred to be the critical defect in HfO 2, responsible for charge trapping, gate threshold voltage instability, and Fermi level pinning for high work function gates, but it has never been conclusively identified. Here, the electron spin resonance g tensor parameters of the oxygen vacancy are calculated, using methods that do not over-estimate the delocalization of the defect wave function, to be g xx = 1.918, g yy = 1.926, g zz = 1.944, and are consistent with an observed spectrum. The defect undergoes a symmetry lowering polaron distortion to be localized mainly on a single adjacent Hf ion. © 2012 American Institute of Physics.

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2甲-基-3-甲氧基-4-苯基丁酸(MMPB)法是检测微囊藻毒素(Microcystins,MC)的重要方法之一。本文研究了温度、pH值、反应时间和氧化剂浓度等实验参数的影响,并在优化条件下采用气相色谱法对水中的微囊藻毒素进行检测。实验得到的最佳反应条件为:pH=9,初始反应温度2℃反应1 h,再升温至25℃反应2 h;KMnO4的初始浓度为0.0156 mol/L。本法对水溶液中的微囊藻的检出限为0.0225μg,回收率为93.5%。

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本文在实验室批量培养,室外小池大量培养和塑料大棚大面积培养的基础上,研究了植物激素2,4-D刺激鱼腥藻增殖的效应。浓度在0.01—2.00μg/mL范围内都具有刺激鱼腥藻增殖的效果,随着浓度增加,这种效果降低。品质分析结果表明,0.01μg/mL2.4-D可提高蛋白质和叶绿素a的含量;浓度为0.05μg/mL时,二者的含量与对照相差不大;浓度达到0.1μg/mL时,二者的含量降低。本文提出,2,4-D刺激鱼腥藻增殖的应用浓度应在0.05μg/mL以下,以0.01μg/mL效果最佳。

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本工作通过较系统地研究Ziegler-Natta型钼催化体系对丁二烯聚合的催化作用,发现一类活性很高的钼催化剂。此类催化剂以无毒,资源丰富的加氢汽油为溶剂,活性已接近工业化的Ni、Co、Ti等体系。同时,本工作又找到了大幅度调节聚合物分子量和链结构的方法,发现了具有活性聚合特点的钼催化体系,初步考察了钼体系催化丁二烯聚合的动力学行为;并利用红外光谱,~(13)C-NRM、X-射线衍射和热分析等方法研究了所得聚合物的链结构和聚集态结构,对聚合物的基本性能也进行了初步考察,发现所得聚合物的一些基本性能超过天然橡胶。此类高活性钼催化剂由MoCl_4OR和(i-Bu)_2AlOAr组成,R为C_(8-18)烷基,Ar为芳基。本催化体系在70 ℃下催化丁二烯聚合时,催化剂用量为Mo/J摩尔比等于4 * 10~(-5)时,转化率可达78%。本体系聚合物分子量可用烯丙基卤等调节,其中烯丙基碘的效果最好。在Mo/J = 8 * 10~(-5)时,烯丙基碘/Mo摩尔比为0.1时即可使聚合物分子量下降约50万;烯丙基碘/Mo摩尔比为10时,聚合物重均分子量即小于20万(不加烯丙基碘为270万)。本体系聚合物分子量分布很窄,聚合温度为30 - 70 ℃时,_W/_n为1.5-2.0;_W/_n与聚合温度呈直线关系,利用外推法估计和动力学考察,本体系在-18 ℃左右有可能引发活性聚合。本体系聚丁二烯含有85%以上1,2-链节,其1,2-链节含量也可以用某些极性添加剂来调节。利用烯丙基碘做调节剂,可制得1,2-链节含量高达98%的聚丁二烯。烯丙基碘还可以调节聚合物链节的立体构型和序列分布;随着烯丙基碘用量的增加,间同1,2-链节增多,全同和无规1,2-链节减少,序列分布的有规性增加,链结构趋于规整。根据动力学初步研究结果,本体系催化丁二烯聚合的速度对单体浓度呈一级关系,表现活化能为17.07千卡/摩卡,催化剂利用率为4%,链增长速度常数为: k_(p30℃) = 40 (升/摩尔·分,下同), k_(p40℃) = 97, k_(p50℃) = 267, k_(p60℃) = 508, k_(p70℃) = 12077。本体系聚合物在烯丙基碘/Mo摩尔比小于2时,无论静态或拉伸下均为无定型;烯丙基碘/Mo摩尔比大于2而小于8时,静态下为无定型,而拉伸时产生结晶,与天然橡胶类似;烯丙基碘/Mo摩尔比大于8时,静态下亦有一定程度的结果。

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聚合物的结构决定了它的分子链的运动,分子链的运动又可表征聚合物的结构,而且聚合物的宏观性质又受到它的微观运动的影响。因此有目的地开发各种聚合物材料,充分利用其独特的性质,都离不开研究它的微观运动。这就是结构-性能-运动的关系。1,2-聚丁二烯作为一种弹性体,近十几年研究得较多,主要局限在它的链节结构(1,2-链节)与其物理机械性能的关系方面,其目的是为了弥补顺丁橡胶的不足。对于1,2-链节与其分子链的微观运动则研究得较少。然而这方面的研究对于1,2-聚丁二烯弹性体的开发和应用无疑是有益的。研究1,2-聚丁二烯的链节结构与其分子链的相互作用,首先需要选择适当的表征分子链的各种相互作用的参数。聚合物分子链的长程运动,可分为分子链内旋转运动和分子链间相互作用。其中分子链间相互作用通常用聚合物的内聚能密度表示,分子链内旋转运动决定分子链的柔顺性,而它们二者共同影响聚合物的玻璃化温度。因此实验中首先测定1,2-聚丁二烯的玻璃化温度和内聚能密度,从研究1,2-链节与1,2-聚丁二烯分子链的忌的相互作用和分子链间的相互作用着手。实验需要的1,2-聚丁二烯样品部分是用丁基锂制备的,也有别人提供的钼体系和铁体系的样品。样品的1,2-链节含量从8%至90%。主要用线膨胀法(还有DSC法及扭摆法)测定了1,2-聚丁二烯的玻璃化温度。不仅发现了1,2-聚丁二烯的玻璃化温度随1,2-链节增多而提高,而且得到了它们在玻璃化转变时的体积膨胀系数。这个系数对于后面研究分子链柔顺性是有用的。聚合物的内聚能密度是其溶解度参数的平方。实验选用特性粘数法测定1,2-聚丁二烯的溶解度参数,其中关键在于选择适当的溶剂。这方面失败的教训是由于所用的溶剂在化学结构和极性上与聚合物的相差甚大。由于这种限制,测定1,2-聚丁二烯的溶解度参数时,难以找到化学结构和极性合适且溶解度参数又相当的纯溶剂。因此按照溶解度参数理论,配制了不同溶解度参数的环已焓一甲苯混合溶剂,代替部分纯溶剂。测定结果表明,1,2-链节含量为16%的样品,其溶解度参数为8.6([卡/立方厘米]~(1/2)),其余含量较高的样品,都是8.5([卡/立方厘米]~(1/2))。用混合溶剂测定聚合物的溶解度参数还是第一资,其可靠性取决于混合溶剂的溶解度参数的准确性。根据溶解度参数理论,我们提出克分子体积相近,且无特殊的相互作用的二元混合溶剂的溶解度参数,等于它们各自的溶解度参数按体积分数的加合。环已烷和甲苯的克分子体积分别为108.7和106.8立方厘米,它们的溶解度参数的极性分量S_极 → 0,再假定混合时没有吸热效应,它们二者按体积分数加合的溶解度参数可以定量使用。用时还从三个方面进行了验证,(1)用克分子体积相差较大(分别为147.4和89.4立方厘米)的正庚焓-苯混合溶剂作为反证;(2)根据特性粘数理论,用Matsuo方程;(3)由三元(溶剂1-溶剂2-聚合物)体系的Flory-Huggins相互作用参数等,它们都证实了上面提出的混合溶剂测定1,2-聚丁二烯溶解度参数的条件。根据前面的实验结果发现,1,2-链节与1,2-聚丁二烯的玻璃化温度有关,与其内聚能密度基本无关。建么1,2-链节必定与其分子链柔顺性有关。为了更准确地说明1,2-链节对1,2-聚丁二烯分子链柔顺性的影响,需要选择表征分子链柔顺性的参数。聚合物的分子链中相互作用的直观表现是它的分子链柔顺性,而分子链的柔顺性起因于它的链状分子和分子链的内旋转运动。因此我们选用分子链内旋转的参数(内旋转势垒和内旋转异构化能)表征1,2-聚丁二烯分子链的柔顺性。目前文献报道的计算分子链内旋转异构化能的方法,大多数是根据Gibbs-DiMarzio的玻璃化转变理论。这些方法一般都比较复杂。我们提出从聚合物发生玻璃化转变时的温度和体积膨胀系数,计算分子链内旋转异构化能的简便方法。这个方法的基本出发点是认为聚合物发生玻璃化转变时的自由体积,对不同结构的聚合物并非常数,其原因在于玻璃化转变时的聚合物体积膨胀系数部分地来自于分子链构象变化的贡献。分子链内旋转引起构象变化时,分子链的内旋转异构化能也相应地变化。因此玻璃化转变时,分子链的构象变化既对聚合物的体积膨胀系数有影响,又与分子链内旋转异构化能有联系,那么此时的聚合物的体积膨胀系数,与单个分子链的内旋转异构化能必然有某种联系。若用Δα·Tg(Δα是随态和玻璃态的体积膨胀系数)表示玻璃化温度Tg下,单个分子链处于能量状态∈的几率,Ng表示相同温度下,分子链中处于相同能量状态中的柔顺链分数,按照统计力学原理得到∈=-K·TgLn((Δα·Tg)/(1-Δα·Tg))。(1)

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一、根据凝胶色谱柱的单分散校准关系和试样的实效关系在概念和实质上的区别以及两者在理论上的定量速率,建议了一个从一组重均和数均分子量已确知的多分散试样的实验谱图同时订定凝胶色谱柱的分子量校准关系和扩展因子的计算觅数方法。用聚苯乙烯和聚丁二烯订定的扩展因子—算出体积依赖关系相互重合,与试样的结构无关。如将扩展因子视作常数时,其具体数值可从实验谱图的方差与实效关系和单分散校准关系的斜率比值之间的定量连系得到选定。二、对高1,2聚丁二烯的级份和原试样作了凝胶色谱、光散射和粘度的测量。建议了从一组分布宽度不等的试样的凝胶色谱数据和光散射及粘度测定结果求得单分散[3]-M方程的三种不同方法。用三种方法所得高1,2聚丁二烯的单分散[3]-M方程相互重合。三、导得了从凝胶色谱图所得乙均分子量的扩展改正因子。由光散射得到了乙均迥转半径与乙均分子量的实验数据,订定了单分散1,2聚丁二烯在溶液中的分子尺寸与分子量间的关系。对实验数据作进一步的分析,获得了高1,2聚丁二烯的特性比和空间住阻因子的具体数值,并讨论了1,2结构含量对形态结构的影响。

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1、喜树碱类衍生物抗HIV构效关系与作用机制研究 喜树碱为传统的抗肿瘤药物。本研究对经过化学结构修饰的喜树碱类衍生物进行抗HIV活性及作用机制的研究,并初步探讨了其抗HIV构效关系。 我们对喜树碱类衍生物A系列化合物A1(喜树碱)、A2(10-羟基喜树碱)及A3(7-羟基喜树碱)进行了抗HIV活性检测。化合物A1和A3有较好的抗HIV-1和抗HIV-2活性,化合物A2没有显示抗HIV活性。表明化合物A1的C-10位上-OH基团修饰可能会降低抗HIV活性,化合物A1的C-7位上-CH2OH基团修饰和C-20位-CH3缺失可能会提高其抗HIV活性。对化合物A3和A1的抗HIV机制研究发现:二者对整合酶有一定的结合活性,对慢性感染H9/HIV-1ⅢB 和Jurkat/HIV-1ⅢB细胞中病毒复制没有抑制活性、不能阻断H9/HIV-1ⅢB与正常细胞间的融合,对重组的HIV-1蛋白酶和逆转录酶没有抑制活性。化合物A1和A3不具有选择性杀伤HIV-1ⅢB慢性感染的H9和Jurkat细胞系的作用。进一步进行化合物A3诱导 H9和H9/HIV-1ⅢB、Jurkat和Jurkat/HIV-1ⅢB的凋亡实验显示,化合物A3诱导感染HIV-1ⅢB和未感染病毒细胞的凋亡没有选择性。据此我们初步认为化合物A3和A1的抗HIV作用可能与抑制整合酶活性有关,该化合物可能还作用于其它靶点。 喜树碱类衍生物B系列中化合物B1为20(S)-O - [-O-( 1'-氧基-2',2',6',6'-四甲基哌啶-4'-丁二酸)]-20-喜树碱酯,化合物B2为20(S)-O - [-N-( 1'-氧基-2',2',6',6'-四甲基-1',2',5',6'-四氢吡啶酰胺)-4'-丙氨酸)]-20-喜树碱酯)。我们对化合物B1和B2进行了抗HIV活性检测。结果显示:化合物B2有较好的抗HIV-1和抗HIV-21、喜树碱类衍生物抗HIV构效关系与作用机制研究 喜树碱为传统的抗肿瘤药物。本研究对经过化学结构修饰的喜树碱类衍生物进行抗HIV活性及作用机制的研究,并初步探讨了其抗HIV构效关系。 我们对喜树碱类衍生物A系列化合物A1(喜树碱)、A2(10-羟基喜树碱)及A3(7-羟基喜树碱)进行了抗HIV活性检测。化合物A1和A3有较好的抗HIV-1和抗HIV-2活性,化合物A2没有显示抗HIV活性。表明化合物A1的C-10位上-OH基团修饰可能会降低抗HIV活性,化合物A1的C-7位上-CH2OH基团修饰和C-20位-CH3缺失可能会提高其抗HIV活性。对化合物A3和A1的抗HIV机制研究发现:二者对整合酶有一定的结合活性,对慢性感染H9/HIV-1ⅢB 和Jurkat/HIV-1ⅢB细胞中病毒复制没有抑制活性、不能阻断H9/HIV-1ⅢB与正常细胞间的融合,对重组的HIV-1蛋白酶和逆转录酶没有抑制活性。化合物A1和A3不具有选择性杀伤HIV-1ⅢB慢性感染的H9和Jurkat细胞系的作用。进一步进行化合物A3诱导 H9和H9/HIV-1ⅢB、Jurkat和Jurkat/HIV-1ⅢB的凋亡实验显示,化合物A3诱导感染HIV-1ⅢB和未感染病毒细胞的凋亡没有选择性。据此我们初步认为化合物A3和A1的抗HIV作用可能与抑制整合酶活性有关,该化合物可能还作用于其它靶点。 喜树碱类衍生物B系列中化合物B1为20(S)-O - [-O-( 1'-氧基-2',2',6',6'-四甲基哌啶-4'-丁二酸)]-20-喜树碱酯,化合物B2为20(S)-O - [-N-( 1'-氧基-2',2',6',6'-四甲基-1',2',5',6'-四氢吡啶酰胺)-4'-丙氨酸)]-20-喜树碱酯)。我们对化合物B1和B2进行了抗HIV活性检测。结果显示:化合物B2有较好的抗HIV-1和抗HIV-2活性,而化合物B1的抗HIV活性差。表明化合物B1的C-4’位-CH2被-NH取代,同时C-3’位-CH3修饰可能会提高其抗HIV活性。对化合物B2的抗HIV机制研究发现,化合物B2对慢性感染H9/HIV-1ⅢB细胞中病毒复制没有抑制活性、不能阻断H9/HIV-1ⅢB与正常细胞间的融合,对HIV-1蛋白酶、重组的HIV-1逆转录酶及整合酶没有抑制活性。化合物B2不具有选择性杀伤HIV-1ⅢB慢性感染的H9细胞系的作用。化合物B2抗HIV的作用机制还需进一步研究。 2、HIV/AIDS患者疱疹病毒感染状况及性病患者的HIV感染状况分析 疱疹病毒是AIDS患者合并感染的常见病原体。引起人类疾病的8种疱疹病毒与HIV感染及AIDS进展、机会性感染、恶性肿瘤密切相关。为了解HIV/AIDS患者人类8型疱疹病毒感染状况,我们检测了30例AIDS患者、40例HIV携带者及70例正常对照的液标本中8型疱疹病毒感染状况。采用ELISA法检测单纯疱疹病毒1型(HSV-1)、单纯疱疹病毒2型(HSV-2)、水痘-带状疱疹病毒(VZV)和巨细胞病毒(CMV);采用PCR法检测EB病毒(EBV)、疱疹病毒6型(HHV-6)、疱疹病毒7型(HHV-7)及疱疹病毒8型(HHV-8)。结果显示,HIV/AIDS患者中HSV-1、HSV-2、VZV、CMV、HHV-6、HHV-8 阳性率均高于健康体检者,其中AIDS患者VZV感染率与HIV携带者有显著性差异;在AIDS患者中多种疱疹病毒共感染普遍存在,必须重视HIV/AIDS患者合并疱疹病毒感染的防治。 性病可促进HIV的传播,了解性病患者的HIV感染状况及临床特征具有重要的意义。在自愿接受HIV咨询检测的基础上,对临床确诊的412例性病患者进行HIV-1/2抗体检测,并对其临床特征进行分析研究。结果显示412例性病患者的HIV检出率为2.9%。性病患者中检出HIV阳性率依次为:尖锐湿疣(6.2%)、生殖器疱疹(4.2%)、梅毒(3.4%)、淋病(1.5%)及非淋菌性尿道炎(1.0%)。83.3%合并感染HIV的性病患者存在多性伴,商业性行为普遍存在,安全套使用率极低现象。感染HIV的尖锐湿疣及生殖器疱疹患者以频繁复发为突出表现,1例合并感染HIV的梅毒患者半年即进展为神经梅毒。性病患者是HIV感染的重要高危人群,危险性行为是其感染HIV和其它性病的主要原因,应该加强性病患者的HIV检测。对临床上频繁复发的尖锐湿疣及生殖器疱疹患者、快速进展的梅毒患者应高度怀疑合并HIV感染的可能。

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本文筛选一株苏芸金杆菌与氧化葡萄糖酸杆菌组成的新组合菌G. B529,并对其生物学性质进行研究,结果表明:新组合菌的摇瓶发酵转化率较原菌系提高4.83个百分点,发酵速度快,且具有耐受高浓度(10%)山梨糖的特性。为使G. B529的潜能得到最大程度的发挥,对其影响因素进行研究。首先应用均匀设计方法确立了G. B529的发酵培养基优化配比,在所实验的范围内,发酵转化率与玉米浆浓度成正相关性,尿素浓度 1.45%佩W/V)时,转化率达最大。其次种液各参数对发酵影响实验确立了判断种子质量高低的方法。结果显示种液中的大菌OD值一1.6 X小菌OD值可以作为种液的质量指数。最后对种子质量的影响实验显示适当提高玉米浆、葡萄糖等成分的浓度与降低尿素的浓度及调高pH值均有利于种液质量的改善。同时低接种量、大通气量和选择种龄为14小时均有助于种液质量指数的提高。 新组合菌系在选定的条件下枷3罐中4批发酵显示出很强的发酵能力,平均醇酸转化率较对照提高8.16个百分点,周期缩短10.6小时。其在300M3罐中生产试用行,连续26批次的平均醇酸转化率达87.40%,较生产用菌提高3.32个百分点。平均周期也缩短1.3小时。

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1-甲基-2-甲氧羰基-3, 6, 8-三羟基-7-甲氧基蒽醌是从唐菖蒲干球茎中分离到的具有环氧化酶-2选择性抑制活性的多取代蒽醌类化合物。本文试图合成该化合物,实现了其类似物的合成,同时发现了几个未见报道的反应。 1.通过Diels-Alder 反应合成了关键中间体——3-甲基-5-羟基-1, 2, 4-苯三甲酸三甲酯,1-COOMe选择性水解产物与1, 2, 3-三甲氧基苯进行分子间Friedel-Crafts反应的产物再进行分子内Friedel-Crafts反应得到了目标产物的类似物1-甲基-2-甲氧羰基-3-羟基-6,7,8-三甲氧基蒽醌(路线1)。目标产物及其它类似物的合成正在进行中。 2.以乙酰乙酸甲酯和巴豆醛为原料,经过Michael加成、分子内的Aldol反应、芳香化、选择性甲酰化和还原反应,得到关键中间体2-甲基-3-羟甲基-6-甲氧基苯甲酸甲酯及其衍生物。通过该化合物与3,4,5-三甲氧基苯甲酸甲酯进行Friedel-Crafts烷基化反应得到了多取代的二苯基甲烷衍生物,拟进一步关环合成目标化合物(路线2)。 3.发现邻甲氧基苯甲酸甲酯中酯甲基可以被正丁基锂和仲丁基锂中烷基交换生成相应的酯,反应的机理不明确。当使用叔丁基锂时,得到的是邻甲氧基苯基叔丁酮,这个方法可以用来合成芳基叔丁酮类化合物。 4.以2-苄氧基-6-甲基苯甲酸甲酯为原料进行氯甲基化反应时,以苯和二氯乙烷作溶剂,发生了苄基的迁移和芳环的偶联,分别得到2,2'-二甲基-3,3'-二甲氧羰基-4,4'-二羟基联苯和2,2'-二甲基-3,3'-二甲氧羰基-4,4'-二羟基-5,5'-二苄基联苯。这是对称联苯合成的新方法。 5.水杨酸羟基邻对位的选择性甲酰化可以分别通过水杨酸和水杨酸甲酯用HMTA/CF3COOH来实现。 6.Lewis酸催化3,4,5-三甲氧基苄醇环化成1, 2, 3, 6, 7, 8, 11, 12, 13-nonamethoxyl-10,15-dihydro-5H-trbibenzo [a, d, g] cyclononene (NDTC),产率(54%)高于已有方法(12%)。 Methyl 3,6,8-trihydroxy-7-methoxy-1-methylanthraquinone-2-carboxylate is a new COX-2 selective inhibitor isolated from Gladiolus gandavensis. Two strategies were investigated to synthesis this compound, in which some important reactions were discovered. 1. The key intermediate 5-hydroxy-3-methylbenzene-1,2,4-tricarboxylic acid 2,4-dimethyl ester was prepared via Diels-Alder reaction followed by selective hydrolysis of 1-COOMe. This compound was coupled with 1,2,3-trimethoxybenzene and the product undergo intramolecular Friedel-Crafts reaction to give methyl 3-hydroxy-5,6,7-trimethoxy-1-methylanthraquinone-2-carboxylate (1st route). The target compound and other analogues are being prepared with the same procedure. 2. The key intermediates methyl 3-hydroxymethyl-6-methoxy-2-methylbenzoate and its derivatives were prepared starting from crotonaldehyde and methyl acetoacetate via Michael addition, intramolecular aldol reaction, aromatization, formylation and reduction. The intermediates were coupled respectively with derivatives of gallic acid to give polysubstituted diphenylmethane. However, attempts to cyclize these compounds to the target compounds and analogues were not successful (2nd route). 3. In the process for ortho-lithiation of methyl 2-methoxybenzoate, the substrate converted respectively to n-butyl 2-methoxybenzoate and sec-butyl 2-methoxybenzoate when n-BuLi and sec-BuLi were used. However, tert-BuLi reacted with methyl 2-methoxybenzoate afford 2-methoxyphenyl tert-butyl ketone, which could be used to synthesize aryl tert-butyl ketones. 4. The transformtion of methyl 2-benzoxy-6-methylbenzoate to dimethyl 4,4'-dihydroxy-2,2'-dimethylbiphenyl-3,3'-dicarboxylate in benzene, and dimethyl 5,5'-dibenzyl-4,4'-dihydroxy-2,2'-dimethylbiphenyl-3,3'-dicarboxylate in 1,2-dichloroethane in the presence of ZnCl2 provides a new method for the synthesis of symmetric biphenyl. 5. The formylation of salicylic acid at C-5 and methyl 2-hydroxybenzoate at C-3 could be regioselectively realized by using HMTA/CF3COOH. 6. Racemic 1, 2, 3, 6, 7, 8, 11, 12, 13-nonamethoxyl-10, 15-dihydro-5H-trbibenzo [a, d, g] cyclononene was prepared via Lewis acids catalyzed trimerization of 3, 4, 5-trimethoxylbenzyl alcohol with yield (54%) higher than the reported procesure (12%).

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在糖化学合成中,1,6-脱水吡喃糖不仅是合成具有生物活性低聚糖、糖共体、抗原、抗体以及天然产物等化合物重要原料,而且还是许多具有生物活性的天然产物的结构单元。同时,它还具有[3,2,1]的双环缩醛结构,使其在糖化学合成中具有高的立体选择性和区域选择性,同时减少了C-1 和C-6 位的保护和去保护的优点。此外,环内的缩醛开环后,又可以相应地在C-1 和C-6 位进行官能团转化以及糖苷化反应。 本文报道了一种新的1,6-脱水吡喃糖的合成方法,并设计合成了2-C-支链-1,6-脱水吡喃葡萄糖1-195、1-197、1-198 以及2-C-支链-6-硫代1,6-脱水吡喃葡萄糖1-225。到目前为止,1,6-脱水糖开环并进行糖苷化反应,存在选择性较差、产率低的缺点。我们发现,在乙腈做溶剂的条件下,NiCl5 能高立体选择性高产率地催化化合物1-195、1-197、1-198 开环并与ROH、RSH 发生糖苷化反应。在NiCl5-乙腈条件下,合成了一系列2-C-支链-α-糖苷和2-C-支链-β-硫代糖苷,并对2-C-支链1,6-脱水吡喃葡萄糖的生成机理以及开环机理进行了探讨。 烯糖在糖化学合成中是重要的起始原料,从Fischer 首次合成烯糖至今,一直不断地有新的合成方法出现。但目前文献报道的方法存在所用试剂有毒、价格贵和操作繁琐等缺点。我们对Fischer-Zach 方法进行了改进, 发现Zn-NaH2PO4-H2O 和Zn-PEG600-H2O 体系都能很好地合成烯糖。该方法具有条件温和、绿色环保、操作简单的优点。在Zn-NaH2PO4 溶液或Zn-PEG600 条件下,以溴代糖为原料,高产率地合成一系列的烯糖。 The 1,6-anhydrohexopyranoses are crucial subunits of myriad bioactive nature products, as well as important syntons of carbohydrate chemistry which have been extensively used to prepare the biologically potential oligosaccharides, glycoconjugates, antibiotics, and structurally varied nature products. Their particular [3.2.1] bicyclic skeleton makes them have high regio- and stereo-control in a variety of reactions, and such structure avoids protecting hydroxyl groups at C1 and C6.Additionally, the cleavage of the internal acetal under acidic conditions could be beneficial for further transformations of functional group and glycosylation of the corresponding pyranosyl sugar at the C6 or C1 site. Herein we developed a novel approach to prepare the 1,6-anhydrohexopyranose, and synthesized the 2-C-branched-1,6-anhydrohexopyranose 1-195, 1-197, 1-198 and 2-C-branched-6-thio-1,6-anhydrohexopyranose 1-225. Until now, glycosylation of 1,6-anhydrohexopyranoses has been limited because of the low yields and low stereoselectivity. In this paper, we found that NiCl5-MeCN system could selectively cleave the ring of 1,6-anhydrohexopyranoses with alcohols and thiols at room temperature in high yields. A series of 2-C-branched-α-glycosides and 2-C-branched-β-thioglycosides have been synthesized via NiCl5-catalyzed. Furthermore, we investigated the formation and ring-opening mechanism of 2-C-acetylmethyl-1,6-anhydrohexopyranose. Glycals are significant starting material in carbohydrate chemistry. After the Fischer-Zach method for forming glucal was reported for the first time, the numerous synthetic methods for glycals have been explored. However, there are several drawbacks in the existing methods, such as the usage of very expensive and toxic reagents, intricate operation, and the influence of acid-sensitive and base-sensitive functional group. We improved the Fischer-Zach method and developed a facile, mild and environmentally benign methodology towards the synthesis of the glycals in Zn-NaH2PO4-H2O or Zn-PEG600-H2O system. Our method involves the treatment of glycosyl bromides with Zn in NaH2PO4 aqueous solution or PEG600-H2O at room temperature, affording various glycals in excellent yields.

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In this paper, we explored the characteristics of the interference effects between perturbative states in hyperfine induced 2s2p P-3(0), P-3(2) -> 2s(2) S-1(0) transitions of Be-like ions. It was found that the interference effects non-monotonically change with increasing atomic number Z in these two transitions. The strongest interference effect is near Z = 9 for 2s2p P-3(0), -> 2s(2) (1)S(0)transition and near Z = 7 for the other.