Disinfection of surfaces by photocatalytic oxidation with titanium dioxide and UVA light

Particularly in microbiological laboratories and areas in intensive medical use, regular and thorough disinfection of surfaces is required in order to reduce the numbers of bacteria and to prevent bacterial transmission. The conventional methods of disinfection with wiping are not effective in the longer term, cannot be standardized, are time- and staff-intensive and use aggressive chemicals. Disinfection with hard ultraviolet C (UVC) light is usually not satisfactory, as the depth of penetration is inadequate and there are occupational medicine risks. Photocatalytic oxidation on surfaces coated with titanium dioxide (TiO2) might offer a possible alternative. In the presence of water and oxygen, highly reactive OH-radicals are generated by TiO2 and mild ultraviolet A (UVA). These radicals are able to destroy bacteria, and may therefore be effective in reducing bacterial contamination. Direct irradiation with UVC however can produce areas of shadow in which bacteria are not inactivated. Using targeted light guidance and a light-guiding sheet (out of a UVA-transmittant, Plexiglas, for example), as in the method described in the present study, bacterial inactivation over the entire area is possible. The effectiveness of the method was demonstrated using bacteria relevant to hygiene such as Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus and Enterococcus faecium. For these bacteria, a reduction efficiency (RE) more than 6log10 steps in 60 min was observed. Using Candida albicans, a RE of 2log10 steps in 60 min was seen. Light and scanning electron microscopic examinations suggest that the germ destruction achieved takes place through direct damage to cell walls caused by OH-radicals.     

Levels of dioxins in fish and fishery products on the German market

In 1995-1998 the contents of polychlorinated dibenzodioxins and dibenzofurans of 184 pooled fish samples were analysed. Sampling focused on fish and fishery products with a market share of more than 1% and covered all fishing grounds important for the supply of the German market. Investigation included 15 different fish species, shrimp, mussel and squid samples and various fishery products, typically on the German market. Generally lean fish species like cod, saithe or Alaska pollock were less contaminated on fresh weight basis than fat fish species like herring, Greenland halibut and sardine. In herring the dioxin content is related to the fishing ground. Low concentrations were found in North Sea herring, high concentrations measured in samples from the Baltic Sea. Dioxin contents in fishery products did not differ significantly from the raw fish samples. Results allow an estimation of the daily intake of dioxins and furans via fish consumption in Germany. Based on a daily fish consumption of 20 g the average intake of dioxins via fish is 6.2 pg WHO-PCDD/F-TEQs per person and day.     

软移动性：使欧洲旅游业更可持续

旅游者们越来越意识到交通的负面影响（包括噪音和其他类型的污染）.繁重的交通会影响旅游目的地的娱乐或其他价值.对于旅游胜地以赢利为目的的管理者来说，交通方式和参观者的满意程度及再访愿望之间的关系正越来越重要.     

Interdisciplinary conflict analysis and conflict mitigation in local resource management

Within the Swedish research program SUCOZOMA (Sustainable Coastal Zone Management) several conflict studies have been carried out. Whereas the detailed results of these studies are published separately, this paper reviews important results from conflict research in combination with a summarizing and generalizing discussion of approaches and main results of SUCOZOMA's resource and conflicts studies. After an analysis of interdisciplinary and theoretical research about environmental and resource use conflicts, the methodology used in SUCOZOMA is presented, a combined stakeholder and conflict analysis. It can be summarized in four main points: i) to map the stakeholders and their interests; i) to analyse the conflicts; iii) to develop methods for conflict mitigation and cooperation with stakeholders; iv) to integrate these components in a system for the management of natural resources. Exemplary case studies of resource use conflicts have been carried out at the Swedish west and east coast including coastal fishery, mussel culture, coastal planning and specific conflicts such as between species protection (seals) and coastal fishery. Researchers are involved as experts and as conflicting parties, and the role of scientists as stakeholders deserves special attention in conflict research. Conflict management is not only for the solution of present conflicts, but part of integrated resource management systems where knowledge transfer, institutional development, collective learning of scientific, political and administrative actors, and cooperation between scientists and resource users can occur.     

Die Trennung von Zuckern,Aminozuckern und Aminosäuren. Anwendung auf die Blutgruppensubstanz

The Science of Nature -