实验动物建筑设施节能技术探讨

实验动物建筑设施的节能方案设计是制约设施建立与正常运行管理的关键因素。良好的节能措施包括优化屏障环境与IVC笼具工艺布局设计,有利于保证实验区空气质量、节省综合投资及提高设施3-5倍的利用率;采用变风量空调控制系统,可大大降低新风的热能耗,并使空调负荷减少约10%-50%新风量能耗;采用先进的中央空调智能节电系统（简称GL-CAC）,可实现中央空调辅机节电30%-60%、主机节电5%-20%的目标;优化卫生热水与消毒蒸汽设备工程可节约50%的投资及其运行费用;对设施系统运行实施科学管理,也可以节省人力资源与年度运行管理费用。     

The challenges of implementing pathogen control strategies for fishes used in biomedical research

Over the past several decades, a number of fish species, including the zebrafish, medaka, and platyfish/swordtail, have become important models for human health and disease. Despite the increasing prevalence of these and other fish species in research, methods for health maintenance and the management of diseases in laboratory populations of these animals are underdeveloped. There is a growing realization that this trend must change, especially as the use of these species expands beyond developmental biology and more towards experimental applications where the presence of underlying disease may affect the physiology animals used in experiments and potentially compromise research results. Therefore, there is a critical need to develop, improve, and implement strategies for managing health and disease in aquatic research facilities. The purpose of this review is to report the proceedings of a workshop entitled "Animal Health and Disease Management in Research Animals" that was recently held at the 5th Aquatic Animal Models for Human Disease in September 2010 at Corvallis, Oregon to discuss the challenges involved with moving the field forward on this front.     

海洋生境修复和生物资源养护原理与技术研究进展及展望

由于人类活动导致的海洋生境、生态系统以及生物资源的衰退已经引起了全球的高度重视。以生态修复的原理为基础,综述了海洋生境修复和生物资源养护的关键设施、关键技术、监测与效果评价以及综合管理的国内外研究进展,并对海洋生境修复与生物资源养护的研究热点和重点进行了展望,以期为我国海洋生境修复和生物资源养护提供参考。     

Composting of poultry manure and wheat straw in a closed reactor: optimum mixture ratio and evolution of parameters

The main objectives of this work were to investigate the evolution of some principal physico-chemical properties (temperature, carbon dioxide, oxygen, ammonia, pH, electrical conductivity, organic matter) and microbial population (mesophilic and thermophilic bacteria and fungi) during composting poultry manure with wheat straw in a reactor system, and to evaluate the optimum mixture ratio for organic substrate production. The experiments were carried out in four small laboratory reactors (1 l) and one large reactor (32 l) under adiabatic conditions over 14 days. During the process the highest temperature was 64.6°C, pH varied between 7.40 and 8.85, electrical conductivity varied between 3.50 and 4.31 dS m⁻¹ and the highest value of organic matter (dry weight) degradation was 47.6%. Mesophilic bacteria and fungi predominated in the beginning, and started the degradation with generation of metabolic heat. By increasing the temperature in reactors, the number of thermophilic microorganisms also increased, which resulted in faster degradation of substrate. The application of a closed reactor showed a rapid degradation of manure/straw mixture as well as a good control of the emissions of air polluting gases into atmosphere. The results showed that the ratio of manure to straw 5.25:1 (dry weight) was better for composting process than the other mixture ratios.     

Nitrogen loss in chicken litter compost as affected by carbon to nitrogen ratio and turning frequency

The study was undertaken to investigate the effects of carbon to nitrogen (C:N) ratio and turning frequency (TF) on the loss of total nitrogen (TN) during composting of chicken litter (a mixture of chicken manure, waste feed, feathers and sawdust) with a view to producing good quality compost. Carbon to nitrogen ratios of 20:1, 25:1 and 30:1 and TF of 2, 4 and 6 days were experimented. The initial physico-chemical properties of the litter were determined. During the composting process, moisture level in the piles was periodically replenished to 55% and the temperature, pH and TN of the chicken litter were periodically monitored. Also, the dry matter (DM), total carbon (TC), total phosphorus (P) and total potassium (K) were examined at the end of composting. The results showed that both C:N ratio and TF had significant (p < or = 0.05) effect on pile temperature, pH changes, TN, TC, P and K losses while DM was only affected (p < or = 0.05) by C:N ratio. All treatments reached maturation at about 87 days as indicated by the decline of pile temperatures to near ambient temperature. Losses of TN, which were largely attributed to volatilization of ammonia (NH3), were highest within the first 28 days when the pile temperatures and pH values were above 33 degrees C and 7.7, respectively. Moisture loss increased as C:N ratio and TF increased. In conclusion, the treatment with a combination of 4 days TF and C:N ratio 25:1 (T4R25) had the minimum TN loss (70.73% of the initial TN) and this indicated the most efficient combination.     

Ochratoxin A Analysen im Blut von Arbeitnehmern in der Abfallwirtschaft

Tasks such as manual sorting of domestic wastes for recyclable goods and the deposition of various materials may result in inhalation of mycotoxin-containing aerosols. Ochratoxin A (OTA) was analyzed in blood samples from workers employed at waste handling facilities in Southern Germany to assess the potential impact of this mycotoxin, and explore its use as a biomarker of exposure to bioaerosols. Results from this analysis are reported: OTA serum levels (median values) in subgroups of workers involved in waste deposition (n=76 ‘Deponierer’) or in waste sorting (n=60 ‘Wertstoffsortierer’) were 0.36 and 0.53 ng/ml, respectively. Both groups are natives of countries within the European Community (EU). In waste sorters who were born in other European (non-EU) countries (n=72) or elsewhere (n=12 from Asia, Africa), the OTA serum levels were 0.50 and 0.37 ng/ml, respectively. In controls (n=84 office clerks at the facilities; EU citizens) the median OTA value was 0.39 ng/ml. Comparing the different groups, and previously published data on median OTA levels in the general population (0.21 ng/ml) which result from dietary (background) exposure to OTA in Germany, our data point to an additional uptake of this mycotoxin by inhalation in workers with exposure to bioaerosols. The results support the view that apart from the pathogenic and allergological relevance of microbial emissions from garbage, secondary fungal metabolites, and thus toxicological aspects, deserve further attention.

Presented at the 25^th Mykotoxin Workshop in Giessen, Germany, May 19–21, 2003     

Anaerobic/Aerobic Composting of Soil Contaminated with 2,4,6-Trinitrotoluene

A loam soil from Pennsylvania without a history of exposure to explosives was incubated with 5 g kg^-1 of ¹⁵N-labeled 2,4,6-trinitrotoluene (TNT) and 200 μCi kg^-1 of ¹⁴C-TNT for 3 days and then amended with compost at a 1:2 soil to compost ratio. The compost was prepared by mixing 40% alfalfa hay, 40% grass hay, 10% spent mushroom compost, and 10% municipal biosolids. The mixture of soil and compost was inoculated with methanogens from cattle manure, amended with glucose and starch, and incubated for 37 days under anaerobic conditions. The anaerobic incubation was followed by 26 days of forced aerobic incubation. At the end of the aerobic phase, most of the radioactivity was associated with organic matter; only 8.7% could be extracted with water and methanol, but no TNT was present in the extracts as determined by high-performance liquid chromatography. The unextractable radioactivity was associated with humic acid (40.0±1.0%), fulvic acid (14.3±1.4%), and humin (28.2±0.5%). Radioactive materials associated with humic acid and humin were analyzed by solid-state ¹⁵N-nuclear magnetic resonance (NMR) spectrometry. The NMR spectra indicated that nitro groups of TNT had been reduced to amino groups thatwere subsequently involved in the formation of covalent bonds with soil organic matter.     

Denitrifying population dynamic and evolution of nitrogen gas during a composting process

Abstract Little information exists about nitrogen losses through microbial activity during treatment of solid urban waste (SUW) by processes such as composting. In the present study, in addition to evaluating the pattern of nitrogen losses by denitrification at different stages of the process, a comparison between the method of Pochon and Tardieux, and an improved gas chromatographic method for estimating denitrifying populations was undertaken, Though the MPN (Most Probable Number) enumerations were higher using the colorimetric method than the gas chromatographic one, the patterns of the two graphs showing numbers of denitrifiers during composing were the same. The highest numbers were revealed immediately after loading the reactor (10⁷–10⁸/g d.w.), lower numbers of denitrifiers were found in the second sampling corresponding to the thermophilic phase (10³–10⁴/g d.w.). These numbers increased gradually as the waste material stabilized (10th to 123rd day of composting) to again reach values of 10⁷–10⁸/g d.w.     

Biological conversion of olive pomace into compost by using Trichoderma harzianum and Phanerochaete chrysosporium

Olive pomace was composted by using a reactor for a period of 50 days in four bioreactors. Urea was added to adjust C/N ration between 25–30. At the end of 50 days of composting using Trichoderma harzianum and Phanerochaete chrysosporium, cellulose and lignin were highly degraded. It was found that after 30 days, P. chrysosporium and T. harzianum degraded approximately 71.9% of the lignin and 59.25% of the cellulose, respectively. The percent of ash content in the raw waste mixture was 13%. This percentage increased from 13% to 18.55% in treatment bioreactors and from 13% to 13.55% in control reactors during 50 day of composting process. The amount of CO₂ produced by the treated sample was 3 mg of CO₂/g organic carbon which is indicated that the treated sample was considered as stable compost. The results proved that the use of accelerating agents was found to be efficient in producing mature stable with nearly non-phytotoxicity compared to control sample in less than 50 days.