霉化对天然橡胶组分及其热降解过程的影响

采用红外光谱仪分析了微波干燥未霉化天然橡胶(NR)和霉化天然橡胶(NR—m)的组分。图谱显示,NR在1541.20cm-1处有酰胺Ⅱ吸收峰,而NR—m没有。采用热重分析法分别在氮气和空气气氛中测试了微波干燥的NR和NR—m热降解和热氧降解。TG和DTG曲线显示,NR和NR—m的热降解均为1步反应,热氧降解均为2步反应。在等速升温条件下,NR的热降解温度和热氧降解温度均高于NR—m,NR降解时的活化能明显低于NR—m;2试样的反应级数为:在热降解中n>2,在热氧降解中n<2;在热降解中NR的相关系数r均大于NR—m;随升温速率的增大,2试样的A值和A1值均增大。

茶扦插苗根腐性苗枯病菌茄镰孢霉专化型研究及相关问题的商榷

茶扦插苗根腐性苗枯病是广西一些茶圃的常见病害,严重影响茶苗出圃。明确该病病原菌分类地位可以为病害防治提供理论依据。为此,作者从桂北茶扦插苗圃中随机采得18株病株标本,分离出镰孢霉纯菌株16株,单孢菌纯系培养18株(GF01～GF18号)。参照BOOTH镰刀菌分类鉴定标准,对代表性单孢菌株GF08号的培养菌进行了形态鉴定;以蘸根法和土壤伤根法测试其致病性,同时在12科22种植物上进行接种试验。结果表明,该菌与茄镰孢霉[Fusarium solani(Mart.)Sacc.]形态特征一致,经柯赫氏法则验证确定其为茶扦插苗根腐性苗枯病的病原菌。该菌除侵染山茶科的福云六号大叶种和白毛茶外,对其余11科20种植物均不致病。因此鉴定该菌为茄镰孢霉一新专化型:Fusarium solani(Mart.)Sacc.f.sp.theae Chuan-Ya Lai etChuan-Bi Lai。

博来霉素性肺纤维化大鼠NADPH氧化酶介导的细胞外基质重构机制研究

目的探讨博来霉素性肺纤维化大鼠NADPH氧化酶介导的细胞外基质重构机制。方法 40只SD大鼠随机分为4组:对照组、模型组、乙酰香草素低剂量和高剂量组。一次性气管注入博来霉素复制大鼠肺纤维化模型,乙酰香草低剂量组灌胃乙酰香草素1μmol/L,高剂量组灌胃乙酰香草素10μmol/L治疗,对照组大鼠给予等剂量的生理盐水。分析各组大鼠肺组织羟脯氨酸及丙二醛(MDA)及超氧化物歧化酶(SOD)含量,Western Blotting法分析各组大鼠肺组织NADPH氧化酶亚基及细胞外基质重构相关酶系的表达。结果模型组大鼠肺组织羟脯氨酸及MDA水平明显增高,SOD水平明显降低;模型组大鼠肺组织NADPH氧化酶亚基p22phox及p47phox表达明显增强,且MMP2/9及TIMP1/2的表达也明显增强。低剂量和高剂量的乙酰香草素均可以明显改善上述指标的异常(P<0.05,P<0.01),且具有剂量依从性效果。结论乙酰香草素通过抑制NADPH氧化酶的过度激活及细胞外基质重构改善博来霉素性肺纤维化损伤。

“化环霉”治疗奶牛脓性子宫内膜炎的试验

用氯化钠、四环素、青霉素治疗奶牛脓性子宫内膜炎 ,治疗组 2 5头治愈 92 % ,对照组为 33.33%。 1998年 ,对患脓性子宫内膜炎奶牛共 40头 ,用“化环霉”治疗 2 5头 ,同时采用青、链霉素治疗 15头 ,试验结果表明“化环霉”治疗脓性子宫内膜炎治愈率 92 % ,有效率 10 0 % ,而青、链霉素的治愈率 33.3 % ,有效率 86 .6 6 % ,无效率 13 .33%。

苦参液雾化吸入辅佐治疗小儿哮喘44例疗效观察

目的:选择一种安全、快捷且副作用少的治疗小儿哮喘急性发作的方法。方法:88例小儿哮喘随机分成中西药治疗组及西药对照组,每组44例,对照组常规给予抗生素、激素及口服美喘清,治疗组在常规治疗基础上辅佐苦参液雾化吸入。结果:治疗组显效、有效、无效的例数分别为36、4、4例,对照组则为12、24、8例,两组比较差异显著(Hc=21.335,P<0.01)。疗程结束时,治疗组咳嗽、喘息、哮鸣音、湿罗音消失的例数分别为12、36、32、32例,对照组则分别为4、20、16,8例,两组比较差异显著(P<0.05～0.01)。结论:苦参液雾化吸入可作为小儿哮喘重要的辅助治疗方法之一。

Minocycline attenuates cognitive impairment and restrains oxidative stress in the hippocampus of rats with chronic cerebral hypoperfusion

Objective Nitric oxide （NO） was speculated to play an Minocycline, a tetracycline derivative, reduced inflammation important role in the pathophysiology of cerebral ischemia. and protected against cerebral ischemia. To study the neuroprotection mechanism of minocycline for vascular dementia, the influences of minocycline on expressions of inducible nitric oxide synthase （iNOS） and endothelial nitric oxide synthase （eNOS） were observed in the brains of Wistar rats. Methods The vascular dementia rat model was established by permanent bilateral common carotid arteries occlusion （BCCAO）. Wistar rats were divideded into 3 groups randomly： sham-operation group （S group）, vascular dementia model group （M group）, and minocycline treatment group （MT group）. The behaviour was tested with Morris water maze and open-field task. Expressions of iNOS and eNOS were measured by immunohistochemistry and reverse transcriptase-polymerase chain reaction （RT-PCR）. The optical density value was measured by imaging analysis. Percentage of positive ceils with iNOS and eNOS expression was analyzed with optical microscope. Results Minocycline attenuated cognitive impairment. Inducible NOS was significantly down-regulated in MT group, compared with that in M group （P 〈 0.01）, while eNOS was significantly up-regulated, compared with that in M group （P 〈 0.01）. The expressions of iNOS and eNOS in M and MT groups were higher than those in S group （P 〈 0.01）. Conclusion Minocycline can down-regulate the expression of iNOS and up-regulate the expression of eNOS in vascular dementia, which restrains apoptosis and oxidative stress to protect neural function.

Research on Correlation between Synthesis of Stilbenes and Aflatoxin Accumulation Caused by Aspergillus flavus in Peanut Seeds

In peanuts, a mechanism of resistance to fungal infection is reported on the synthesis of stilbene phytoalexins, which are antibiotic, low molecular weight metabolites. The phytoalexin-associated response of different peanut varieties to the inoculation with A. flavus has not been investigated and might be useful for breed- ing resistant peanut cultivars. In this study, peanut varieties resistant or susceptible to aflatoxin accumulation caused by A. flavus were selected to compare the synthe- sis differences of the four main stilbenes （resveratrol, ε-viniferin, 6-viniferin and pterostilbene） and the activities of their resistant enzymes （PAL, POD, PPO）, and explore the relationship between stilbene synthesis and resistance to aflatoxin accu- mulation. The results indicated that the synthesis speed of stilbenes was related to the resistance to aflatoxin accumulation in peanuts seeds. The total content of the four stilbenes reached the highest value of 47.37 μg/g in the resistant cultivars （Qian huasheng 3） after inoculation by A. flavus （54 times of the control） on the 3nd day, while the total content of stilbenes in susceptible cultivars （Huayu 22） was 5.5 μg/g. The content of stilbenes and the activities of their resistant enzymes from the resistant cultivars were both higher than from the susceptible one. The four peanut varieties with relative higher stilbene contents and lower disease index and aflatoxin content were selected by using the stilbene content. Very significant negative corre- lation, with correlation coefficients （r） of -0.789, -0.851 and -0.850, was observed between the stilbene content with disease index, the content of aflatoxin B1 and the total content of aflatoxins, respectively. Therefore, the study suggested that the total content of stilbene compounds might serve as an important chemical index in peanut seeds after inoculation with A. flavus on the 3nd day, during screening and breeding of peanut varieties resistant to aflatoxin accumulation.

Construction of Exogenous Expression Vector of Trichoderma reesei

[Objective] The study was to construct a exogenous expression vector for Trichoderma reesei.[Method] Using CBHI promoter and terminator of T.reesei strain 40359,we constructed an expression vector of T.reesei strain 40359 for expressing Hpt gene and got six strains capable of growing on basic medium containing 175 mg/L of hygromycin B,further conducted hygromycin resistance test.[Results] In comparison with the original strain（wild type）,hygromycin resistance the six engineered strains was increased by 75%;the hygromycin resistance could inherit stably.[Conclusion] Our results laid basis for biological study on T.reesei at molecular and genetically engineering levels.

Effects of Chitosan and Organosilicon on Antioxidant Enzyme Activity of Tomato Seedlings Diseased with Botrytis cinerea

[Objective] The aim was to explore effects of chitosan and organosilicon on tomato resistance against Botrytis cinerea. [Method] With leaf spraying method adopted, four groups were set in the test, including control group, groups treated with Botrytis cinerea, with chitosan and Botrytis cinerea, and with chitosan, organosilicon, and Botrytis cinerea, in order to study on effects of chitosan and organosilicon on antioxidant enzyme activities of tomato. [Result] Antioxidant enzyme activities of tomato seedlings were improved in groups with chitosan, organosilicon, and Botrytis cinerea and with chitosan and Botrytis cinerea compared with the group treated with Botrytis cinerea. On the 6th d, activities of PAL, SOD, POD, PPO and CAT in groups with chitosan and Botrytis cinerea, and with chitosan, organosilicon, and Botrytis cinerea increased by 27.36%, 52.07%, 43.55%, 82.02% and 71.82%, and 18.91%, 30.22%, 57.14%, 38.09% and 53.64%, respectively. [Conclusion] Antioxidant enzyme activities of tomato seedlings could be improved by chitosan and organosilicon.

Study on Purification and Properties of Antibacterial Substance from Antagonistic Bacteria P72 against Wheat Scab

[Objective] The study aimed to explore the antibacterial activity and stability of antagonistic bacteria P72 against wheat scab.[Method] The Bacillus subtilis P72 was inoculated into fermentation media with the inoculation amount 5%,then cultured on shaking table at 28 ℃ for 48 h and centrifuged at 8 000 r/min for 10 min.The supernatant of fermentation broth was purified and then the genetic stability,thermal stability and pH stability were detected.[Result] By DEAE-52 ion exchange chromatography,the protein eluted by 0.5 mol/L NaCl solution possessed the strongest antagonistic ability against wheat scab pathogen.The SDS-PAGE electrophoresis showed that the molecular weight of the purified protein with antibacterial effect was 40 kD.By stability test,the antibacterial substance produced by P72 strain showed heritable antagonistic activity,high stability below 60 ℃,stability to acid and unstability to alkali.[Conclusion] The antagonistic bacteria P72 had strong antagonistic ability to wheat scab pathogen,stable antibacterial activity and thermal stability,so it would possess a wide development prospect.

Triterpenoid Saponins from Eclipta prostrata L.

Five triterpenoid saponins were isolated from the Chinese traditional medicine Eclipta prostrata L.. On the basis of their chemical properties and spectral data, they were identified as eclalbasaponins II(1), I(2), III(3), 3-O-[b-D-glucopyranosyl(12)-b-D-glucopyranosyl]-16a-ethoxy-olean-12-ene-28-oic acid-28-O-b-D-glu-copyranoside(4) and 3-O-[(2-O-sulfuryl-b-D-glucopyranosyl)(12)-b-D-glucopyranosyl]-echinocystic acid-28-O-b-D-glucopyranoside(5). Compounds 4 and 5 are new compounds and named eclalbasaponins XI and XII, respectively. Compounds 1 and 5 induced morphological deformation of Pyricularia oryzae mycelia.

Biotransformation of Gastrodin by Mucor spinosus

Microbial transformation of gastrodin by Mucor spinosus strain 3.3450, resulted in a product with a transformation rate close to 100 per cent. This product was identified as p-hydroxy benzyl alcohol on the basis of its 1H, 13C NMR and EI-MS spectral data. It could be inferred that the enzyme responsible for the biotransforma-tion reaction was a kind of extracellular and constitutive enzyme since the transformation reaction of the substrate could be carried out in cell free extracts of the fermentation broth of the Mucor spinosus.

IMMOBILIZED ASPERGILLUS ORYZAE CELLS AND THEIR ACTIVITIES

Aminoacylase was immobilized on the mycelium cells of Aspergillus oryzae by using ethylenediamine, gelatin and glutylalhyde. The proper immobilized condition was studied by orthogonal experimental design. The immobilized cells with excellent activity and stability for optically resoluting N acetyl DL alanine were obtained. The effects of pH, temperature, ion concentration and substrate concentration on the reactive activity of immobilized cells were studied. The continuous optical resolution of N acetyl DL alanine was investigated respectively in an immobilized cells column (ICC) and in a novel couple immobilized cells bed & membrane reactor(CICBMR). The results indicate that the immobilized cells are suitable for industrial applications.

草垛自燃原因的新见解

文章借助于以往草垛自燃火灾现场的勘查信息和研究成果,通过对全国各地公布的多个草垛着火现象进行归纳总结,分析认为草垛受潮霉化产生沼气是草垛着火的内因条件,动物活动毛皮摩擦生电并在运动中放电打火是引起草垛燃烧的外因条件,由此建立了一套"草垛受潮霉化产生沼气,通过动物活动使毛皮生电放电引燃沼气与草垛燃烧"的新观点,为草垛维护、管理和避免类似情况的着火提出了建设性的意见。

SA-gal在肿瘤放免治疗中清除作用的实验研究

研究半乳糖化链霉亲和素 (Streptavidin -gal,SA -gal)和亲和素 (Avidin ,Av)在大肠癌预定位放免显像中对血中标记生物素化单抗的“清除”作用。从荷瘤鼠的尾静脉内注射131I标记的生物素化单抗 ( 131I-bt-McAb)预定位于肿瘤靶位 ,2 4h后 2组实验组分别给予SA -gal和Av ,再过 6h分别行体内分布测定和显像。对照组未给予清除剂。结果表明 ,SA -gal、Av使用后 6h ,血中131I -bt-McAb水平都明显降低 ,肿瘤 血比值明显提高 (对照组、Av清除组、SA -gal清除组的肿瘤 血比值分别为 0 .4 2、2 .0 9、5.2 3,3组之间P <0 .0 5) ;与Av相比 ,SA -gal清除作用更强 ,而且在体内脏器分布上 ,其非特异性摄取也明显地较Av少。实验结果提示 ,SA -gal和Av作为清除剂在肿瘤预定位放免治疗中能有效地加快血中标记单抗的清除 ,使肿瘤靶 非靶比值得以明显地提高 ;两者相比 ,SA -gal优于Av。

A MONOCLONAL ANTIBODY RECOGNIZING NON DERIVATIVE 13 HYDROXY GIBBERELLINS AND THEIR GLUCOSIDES *

The production and characterization of a monoclonal antibody (MAb AB10) against GA 3 glucoside as well as GA 3 is described. MAb AB10 was derived from an immunogen in which human serum albumin (HSA) was linked to GA 3 at carbon 3. This antibody showed high affinity for GA 3 glucoside as well as for 13 hydroxy gibberellins (GA 1, GA 3, GA 5, etc). The affinity of MAb AB10 for 13 hydroxy GAs was significantly reduced by methylation of the 7 oic acid but not by glycosylation of 3 hydroxyl group. Based on this antibody, both of competitive enzyme linked immunosorbent assays (ELISAs) for GA 3 glucoside and for GA 3 were developed. These two ELISAs displayed linear detection ranges from 0 2 pmol to 20 pmol. Using these assays, the fluctuation of GA 3 like and GA 3 glucoside like substances in the leaves of Rumex japonicus was investigated. The results indicated that the glycosylation of free GAs was connected with leaf senescence and that the function of 6 benzyl amino purine in retarding the leaf senescence was probably related to delaying the process of glycosylation of free GAs.

Content Variation of Active Components in Mulberry Fruit During Ripening Process

Ten mulberry species were taken as materials to detect contents of DNJ,polysaccharide and flavonoid.The results indicated that the three active components differed significantly upon species.Hongguo 2 and Shushen 1,which are of high contents of active components,were selected as materials to measure contents change of active components in fresh fruits during ripening process after full-bloom stage.The research suggested that DNJ mass fractions of Hongguo 2 and Shushen 1 on the 3rd d in full-bloom stage were 0.074 1% and 0.072 5%;DNJ declined gradually with growth of the fruit and DNJ contents in the two cultivars decreased by 49.80% and 58.90% on the 31st d in full-bloom stage,compared with the 3rd d.As mulberry grew,polysaccharide contents in Hongguo 2 and Shushen 1 were increasing and achieved peaks on the 27th d in full-bloom stage at 9.570% and 10.276%,respectively.For total flavonoids,the contents in Hongguo 2 and Shushen 1 were both of two peaks on 11th d and 27th d.The mass fractions were 0.313%,0.444%,and 0.264%,0.326%,accordingly.In addition,DNJ contents in ripe seeds of Hongguo 2 and Shushen 1 were significantly higher than those in fruit,but total flavonoid contents were lower.Polysaccharide was not detected.It can be concluded that mulberry fruits growing for 27 d can be either as excellent food or for medicine.