浙江中部地区野榧的调查

简述了浙江中部地区被称为"野榧"的植物,并非指一种植物,而是三尖杉、南方红豆杉、粗榧和野生榧树等几种植物.同时介绍了它们的叶与果实的主要区别;指出这些重要野生植物资源应加以保护.     

1株植物乳杆菌生物学特性的研究

研究1株植物乳杆菌(N3)的生物学特性,实验结果表明该菌能耐受80~85℃的高温和0.20kg/cm2蒸汽压力;直接分解玉米淀粉的乳酸产率为7.05%(36 h)和8.19%(48 h);能耐受pH为4.5的酸性环境;在人工胃液中的活菌数为4.1×106CFU/g;对金霉素、土霉素、痢特灵和氟哌酸等抗生素的敏感性强,而对防霉剂和脱霉素不敏感。植物乳杆菌(N3)是1株优良的益生素生产菌。     

光学相干层析成像技术用于裸鼠皮肤霉菌感染研究

利用中心波长为850 nm的宽带光源SLD实现了纵向分辨率为8μm的光学相干层析成像系统。系统采用傅里叶域光学延迟线实现了深度扫描速度为160 mm/s,成像深度为3 mm。获得了裸鼠皮肤霉菌感染部位和健康皮肤的光学相干层析(optical coherence tom ography,OCT)图像,皮肤病变前后的内部结构信息清晰可见。     

组织工程皮肤生物反应器的研究与设计

目的设计一套生物反应器,能针对不同支架材料———细胞复合物进行构建组织工程皮肤。方法根据皮肤的自身生长特点和不同支架材料-细胞复合物的特性,模拟皮肤的生长环境和力学环境,通过生物反应器解决组织工程皮肤构建中支架的装夹和气液界面问题。结果生物反应器由控制系统和生物反应器主体两部分构成,能提供对多种皮肤细胞复合物的动态培养。结论皮肤生物反应器能够满足不同组织工程皮肤产品的需要。能够形成气液界面和模拟生物力学的刺激。     

Whole blood glutathione peroxidase and erythrocyte superoxide dismutase activities, serum trace elements (Se, Cu, Zn) and cardiovascular risk factors in subjects from the city of Ponta Delgada, Island of San Miguel, The Azores Archipelago, Portugal

Activities of whole blood glutathione peroxidase (GSH-Px) and erythrocyte superoxide dismutase (SOD) and serum levels of selenium (Se), copper (Cu) and zinc (Zn) were measured in 118 apparently healthy subjects aged 20-60 years from the city of Ponta Delgada, Island of San Miguel, The Azores Archipelago, Portugal. Data were analysed by age/gender, lipid profile and blood pressure as cardiovascular risk factors searching for their relevance when assessing reference values for antioxidant biomarkers. GSH-Px was in the same range, but SOD was significantly lower than in other Portuguese populations. Neither activity differed with gender. GSH-Px activity increased with age, namely in normolipidemic men versus the hyperlipidemic group in which a decrease was observed. This suggests a progressive impairment of GSH-Px with age caused by an enhanced production of oxidant species in hyperlipidemia. GSH-Px was 30% lower in male hypertensives versus normotensives. SOD activity did not relate to age or blood pressure but was 17% higher in the hyperlipidemic men versus the normolipidemic group, suggesting a better antioxidant protection by SOD than by GSH-Px in hyperlipidemia and hypertension. Se was higher in men versus women, particularly in the older subjects, and partly related to hyperlipidemia. Zn levels showed a similar dependency on gender, not related to age or lipid profile. Cu levels were much higher in women than in men in all age or lipid profile classes and decreased in hyperlipidemia. They were lowered with age in both genders, particularly in normolipidemic women. The present research therefore suggests that hyperlipidemia and hypertension do affect antioxidant status and should be considered when assessing antioxidant biomarkers in blood.     

A new fast algorithm for solving the minimum spanning tree problem based on DNA molecules computation

The minimum spanning tree (MST) problem is to find minimum edge connected subsets containing all the vertex of a given undirected graph. It is a vitally important NP-complete problem in graph theory and applied mathematics, having numerous real life applications. Moreover in previous studies, DNA molecular operations usually were used to solve NP-complete head-to-tail path search problems, rarely for NP-hard problems with multi-lateral path solutions result, such as the minimum spanning tree problem. In this paper, we present a new fast DNA algorithm for solving the MST problem using DNA molecular operations. For an undirected graph with n vertex and m edges, we reasonably design flexible length DNA strands representing the vertex and edges, take appropriate steps and get the solutions of the MST problem in proper length range and O(3m + n) time complexity. We extend the application of DNA molecular operations and simultaneity simplify the complexity of the computation. Results of computer simulative experiments show that the proposed method updates some of the best known values with very short time and that the proposed method provides a better performance with solution accuracy over existing algorithms.     

一株紫罗兰蓝色素产生菌的分离、鉴定及其活性产物的特性分析

[目的]调查秦巴山地区微生物物种的多样性,建立用于活性产物筛选的微生物代谢产物库和菌种资源库,通过数据库平台进行资源共享.[方法]采用不同的分离方法,分离存在于不同生境的微生物类群,通过形态、生理生化及分子生物手段鉴定菌种,发酵并通过甲醇提取代谢产物.[结果]从本地区土壤样本中分离获得一株产水溶性紫罗兰蓝色素的放线菌Str-4331,在高氏培养基上其气生菌丝为白色,产生水溶性紫罗兰色素,镜检观察孢子丝螺旋形,孢子椭圆形至长圆形,通过形态、生理生化特征初步确定为链霉菌.利用ClustalX对其16S rRNA进行序列比对,用Neighbor-Joining (NJ)构建系统发育树,并用Bootstraping法对其评价.实验结果表明,该菌基因序列与砖红链霉菌(Streptomyces lateritius) LMG 19372基因序列有99％的最高相似性.抑菌试验表明,活性产物具有较强的抗革兰氏阳性细菌活性.色素在水溶液中颜色随着pH的变化而变化.质谱分析显示3个主要化合物,分子量分别为557.68、588.43、485.18 kD,其中分子量为557.68 kD化合物与榴菌素B分子量一致.[结论]根据菌株的16S rRNA序列分析结果,结合菌株的培养特性和生理生化特性,将菌株Str-4331归属为砖红链霉菌(S.lateritius).该菌种首次在本地区分离到,具有进一步研究开发的价值.     

Arginine vasopressin does not mediate heat loss in the tail of the rat

It has been reported that hypothermia induced by arginine vasopressin (AVP) is brought about by a coordinated response of reduced thermogenesis in brown adipose tissue (BAT) and increased heat loss through the tail of rats. However, it is well known that AVP is one of the strongest peripheral vasoconstrictors. Whether the AVP-induced hypothermia is associated with an increase in heat loss through the tail is questionable. Therefore, the present study assessed the relationship between the effects of AVP on tail skin temperature and the induced hypothermic response, and to determine if peripheral AVP administration increases heat loss from the tail. Core, BAT and tail skin temperature were monitored by telemetry in male Sprague–Dawley rats before and after intraperitoneal administration of AVP or vasopressin receptor antagonist. We also analyzed simultaneously of the time-course of AVP-induced hypothermic response and its relationship with changes in BAT temperature, and effect of AVP on grooming behavior. The key observations in this study were: (1) rats dosed with AVP induced a decrease in heat production (i.e., a reduction of BAT thermogenesis) and an increase of saliva spreading for evaporative heat loss (i.e., grooming behavior); (2) AVP caused a marked decrease in tail skin temperature and this effect was prevented by the peripheral administration of the vasopressin V1a receptor antagonist, suggesting that exogenous AVP does not increase heat loss in the tail of rats; (3) the vasopressin V1a receptor antagonist could elevate core temperature without affecting tail skin temperature, suggesting that endogenous AVP is involved in suppression of thermogenesis, but not mediates heat loss in the tail of rats. Overall, the present study does not support the conclusion of previous reports that AVP increased tail heat loss in rats, because AVP-induced hypothermia in the rat is accompanied by a decrease in tail skin temperature. The data indicate that exogenous AVP-induced hypothermia attributed to the suppression of thermoregulatory heat production and the increase of saliva spreading for evaporative heat loss.     

Seasonal acclimatization to the hot summer over 60 days in the Republic of Korea suppresses sweating sensitivity during passive heating

The main objective of this study was to determine the central mechanisms involved in suppression of thermal sweating after seasonal acclimatization (SA) during passive heating (immersing the legs in 43 °C hot water for 30 min). Testing was performed in July (before-SA) and August (after-SA) [25.2±2.2 °C, 73.9±10.3% relative humidity (RH), Cheonan (Chungnam,126° 52′N, 33.38′E), in the Republic of Korea. All experiments were carried out in an automated climatic chamber (25.0±0.5 °C and RH 60.0±3.00%). Twelve healthy men (height, 174.6±5.40 cm; weight, 65.4±5.71 kg; age, 22.7±2.90 yr) participated. The local sweat onset time was delayed in the after-SA compared to that in the before-SA (p<0.001). The local sweat rate and whole body sweat loss volume decreased in the after-SA compared to those in the before-SA (p<0.001). In addition, evaporative loss volume decreased significantly in the after-SA compared to that in the before-SA [chest, upper-back, thigh and forearm (p<0.001)]. Changes in tympanic temperature and mean body temperature were significantly lower (p<0.05) and the basal metabolic rate decreased significantly in the after-SA compared to those in the before-SA (p<0.001). These results suggest that maintenance of a lower body temperature and basal metabolic rate can occur and blunt the central sudomotor mechanisms following seasonal acclimatization, which suppresses sweating sensitivity.