TiO2光催化氧化法的提高效率方法及其环保应用

本文阐述了利用金属掺杂、表面敏化、表面螯合、表面衍生、表面沉积贵金属、掺杂稀土元素、复合半导体及电子捕获剂扩大了TiO2半导体的光吸收波长范围或降低其载流子的复合率,从而提高TiO2半导体光催化氧化法的效率,并介绍了其在空气净化、污水处理等环境保护方面的应用。     

双壳纲动物核糖体RNA 185-ITS1序列及其在分子系统发育研究中的应用

测定了双壳纲不同科、属、种及种内共11个个体的核糖体RNA 18S-ITS1序列。结果表明,该序列在种间存在很高的多态性,长度从558bp到784bp不等,碱基差异百分比在10.7％～61.7％之间,ITS1序列同源性很低,有片段的插入与缺失。种间18S部分序列碱基差异百分比在0.9％～23.7％之间,变化主要是碱基的转换。用邻接法(NJ)构建了8个种的18S部分序列(约240bp)的系统发育树,与传统形态学分类结果相符。马氏珠母贝(Pinctada martensi)4个不同地域个体间的序列差异百分比在0.6％～1.9％之间。分析指出:18S基因可以作为双壳纲动物高阶元系统发育的分子标记;ITS1序列种间变化很大,可以应用于该纲物种的分类及鉴别,在亲缘关系相近种及种内变异相对较小,但核苷酸变异位点信息量丰富,可用于属内种间、亚种和群体间的遗传多样性研究。     

Synthesis of 2-substituted-pyrrolidinethiourea derivatives and their antagonist effect on vanilloid receptor

Four pyrrolidine derivatives were prepared by the formation of a 5-membered ring based on capsazepine. Among them, the two carbon extended derivatives, 4a (IC(50)=55 microM) and 4b (IC(50)=3 microM), both showed different levels of antagonist activity against the vanilloid receptor in a (45)Ca(2+)-influx assay.     

Telomere erosion-induced mitotic catastrophe in continuously grown chinese hamster don cells

We have previously reported that telomere erosion is the earliest chromatin modification in cells entering the apoptotic pathway. The purpose of this investigation was to determine whether loss of telomeric DNA was involved in inducing mitotic catastrophe and death in Chinese hamster Don cells. Don, a male Chinese hamster-derived cell line which requires daily subculturing to remain diploid, was grown without subculturing for 1-4 days at 37 degrees C and analyzed cytologically. Our results indicated that (1) the frequency of metaphase chromosomes with structural anomalies was significantly higher in 3-day continuously grown cells than in 1-day control cells (8.2% vs 5.7%; P < 0.01), (2) the mitotic index was considerably lower in 3-day continuously grown cells (0.13%) than in control cells (3.64%), (3) cells grown for 3 days continuously showed a higher incidence (7.6%) of endoreduplicated metaphase chromosomes than did control cells (4.9%), (4) 4-day continuously grown Don cells showed significantly smaller amounts of telomeric DNA in interphase nuclei than did control cells, and (5) apoptotic cells were more frequent in 4-day cell cultures (40.6%) than in control cells (4.3%). These results support our earlier observations and contribute additional support for our hypothesis that telomere reduction is the cause of mitotic catastrophe and that cell death in continuously grown Don cells occurs because of the loss of telomeric DNA.     

Weight cycling-induced alteration in fatty acid metabolism

Epidemiological studies have suggested that repeated weight cycling over time may increase the risk of coronary heart disease. The mechanism involved remains poorly understood, but the change in lipid metabolism during weight cycling has been offered as a possible explanation. The present study investigated the effect of weight cycling on the size and fatty acid composition of rat fat pads as well as serum cholesterol, triglyceride, glucose, insulin, and glucagon in rats. Two consecutive weight cycles were induced by 40% energy restriction followed by ad libitum refeeding of either a moderate-fat (MF; 22% energy) or a high-fat (HF; 45% energy) diet. The lipogenic enzymes, including fatty acid synthase, acetyl-CoA carboxylase, malic enzyme, pyruvate kinase, and lipoprotein lipase in the weight-cycled (WC) rats fed only the HF diet, yielded an overshoot of activities at the end of two weight cycles. These changes were accompanied by an 80% increase in the size of the adipocyte and a 40-50% increase in the size of perirenal and epididymal fat tissues in HF-WC rats. Regardless of whether the rats were fed the HF or MF diet, all WC rats showed a gradual reduction in linoleic and alpha-linolenic acid and an increase in palmitic, palmitoleic, and stearic acid in total body lipid. It is concluded that weight cycling in rats may promote body fatness if an HF diet is consumed and can significantly alter whole body fatty acid balance irrespective of whether they consumed an MF or HF diet. Most importantly, the weight cycling led to an overshoot or fluctuation of serum cholesterol, triglyceride, glucose, insulin, and glucagon. If weight cycling is associated with an increased risk of cardiovascular disease, then, part of the mechanism may involve the changes in these risk factors.     

Local assessments of marine mammals in cross-cultural environments

Biodiversity assessments by research scientists are often logistically difficult and expensive to implement in remote areas. Locally-based approaches have the potential to overcome some of these challenges by capitalising on the knowledge and capacity of local people. Many Indigenous people in northern Australia are custodians of coastal areas that support globally significant populations of tropical marine mammals, including coastal dolphins and dugongs. The objective of our study was to design and implement a locally-based approach in a cross-cultural environment to assess the distribution of marine mammals in the remote waters of the Gulf of Carpentaria, Northern Territory. The study was conducted as a partnership between Yanyuwa Aboriginal families, research scientists, government officers and the li-Anthawirriyarra Sea Rangers. We conducted a series of participatory mapping workshops to share and record local observations of dolphins and dugongs. These observations provided the longitudinal information required to inform the design of the first dedicated marine mammal vessel survey in the Gulf of Carpentaria. The vessel surveys found three species of dolphins present in the area (Australian snubfin, humpback and bottlenose dolphins), even though sightings were low; dugongs being much more common. We found that the integrative and locally-based approach built the capacity of both the li-Anthawirriyarra Sea Rangers and research scientists to assess the distribution of marine mammals. If replicated over longer time-frames and coordinated over broader spatial scales, information on distribution and abundance derived from locally-based approaches has the potential to inform the status of marine mammals.