Protective effects of seaweeds against liver injury caused by carbon tetrachloride in rats

Three species of seaweeds collected from Tung Ping Chau, Hong Kong, were screened for their hepatoprotective activity using carbon tetrachloride (CCl4)-induced liver injury in the rat as a model of chemical hepatitis. A single oral dose of 1.25 ml/kg of CCl4 was able to produce significantly elevated levels of serum glutamic pyruvic transaminase (GPT) and glutamic oxaloacetic transminase (GOT). Administration of 150, 300 and 600 mg/kg of aqueous extracts from Myagropsis myagroides, Sargassum henslowianum and S. siliquastrum, respectively, significantly reduced the CCl4-induced acute elevation in the levels of GPT and GOT in rats. The same result was also seen in the histopathological study of liver tissue. The seaweed crude extracts probably acted to protect against CCl4-induced liver injury through their antioxidant properties.     

Formation and mitigation of PCDD/Fs in iron ore sintering

The sintering of iron ore is presently a significant industrial source of polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDD/Fs) worldwide owing to the fundamental requirement of the operation of a high temperature process to pre-treat fines and to recycle plant by-products arising from the integrated iron and steelworks. The process is a noteworthy contributor of PCDD/F indirectly due to decreasing PCDD/F releases from municipal solid waste incineration. Commonly PCDD/F formation from the process is associated with the addition of oily mill scales although raw material containing a combination of C, Cl and specific metal catalyst has been shown to drastically increase PCDD/F formation in the process. The degenerate graphitic structure of carbon present in coke fuel and soot formed and the chemistry of catalytic metals and Cl are important factors. A review on PCDD/F emission in this process has been carried out, including examination of its formation mechanism, congener distribution, contributing factors and mitigation strategies, with emphasis on the use of inhibiting compound to achieve suppression. A detailed analysis of the de novo and precursor theories of formation and the contributing factor is given since the subject of PCDD/F formation is still controversial. The de novo formation pathway identified in sinter plants and controlled studies performed in the laboratory as well as at pilot-scale are discussed; where appropriate, a comparison is drawn between sintering and other thermal processes emitting PCDD/Fs. Summary of the latest developments in PCDD/F downstream abatement strategies presently employed in full scale industrial plants is provided. Potential inhibiting compounds are discussed in terms of their mode of action and merits under sintering conditions.     

中国露天生物质燃烧的温室气体排放及秸秆禁燃政策的协同减排效应

露天生物质燃烧是温室气体（CO₂、CH₄、N₂O）的重要排放源之一,这些排放可影响本地、区域和全球的大气化学和气候变化,并带来一系列生态环境问题,进而对人类及其他生物的生存环境产生影响.本研究采用卫星火点排放清单（FINN）,对2010—2019年中国露天生物质燃烧温室气体排放进行研究,并分析秸秆禁燃政策对温室气体排放的影响,对后续秸秆禁燃政策的制定具有重要参考价值.结果表明,我国2010—2019年平均年温室气体排放量为1.53×10⁸ t（将CH₄和N₂O的温室效应换算为同等效应的CO₂当量单位）,总体呈波动性下降趋势.温室气体排放量最大的植被类型是森林（7.43×10⁷ t）和农作物（3.19×10⁷ t）,分别占总排放量的48.7%和20.9%.从月分布来看,露天生物质燃烧排放的温室气体集中在2—6月,3月是高峰值.从空间分布上看,排放主要集中在华南、西南和华东地区,占总排放量的72.9%.从2013年以来,秸秆禁燃政策的加强在一定程度上降低了露天农作物秸秆燃烧排放的温室气体和PM_2.5.从变化量看,28个省份实现了秸秆燃烧排放的温室气体与PM_2.5同步下降.     

个体防护装备国家标准制修订工作流程

个体防护装备国家标准作为国家标准的一个重要组成部分．其制修订工作除了要符合国家的各项规定外，还有其特殊性。现就其具体的工作流程，进行详细的介绍，供个体防护装备科研单位和企业参考。     

Studies on thallium toxicity, its tissue distribution and histopathological effects in rats

The distribution of thallium (Tl) in the body and its toxic effect on the histology and function of the liver and kidney of rats after Tl administration were investigated using biochemical and histopathological assays. Male albino rats exhibited a markedly dose-dependent increase in the serum levels of aspartate aminotransferase (AST) and alanine aminotransferase (ALT) at 16 h after an intraperitoneal injection of 30, 60 or 120 mg/kg Tl. The serum level of creatinine in the rats injected with 30 mg/kg Tl, elevated significantly after 4 days of administration. The distribution of Tl in the tissues of intoxicated rats was uneven. The content of Tl was found to be highest in the kidney, followed by ileum, stomach and liver. Histological examination demonstrated frequent occurrence of hepatocyte necrosis and vacuolation in the liver and pathological changes of renal tubules in the treated rats.     

The geomorphology and ecosystem service economic value baselines of tributary watersheds in Malaysia

Environment, Development and Sustainability - This study presents how a cluster of tributary watersheds was evaluated for geomorphology and ecosystem service economic value baselines. Tributary...     

Relationship of firm attributes,ownership structure and business network on climate change efforts: evidence from Malaysia

This paper presents a case study of land-use/land-cover (LULC) changes from 1975 to 2014 in the central highlands of Ethiopia and traces out its impact on socioeconomic conditions of the local community in the study area. We used four time series Landsat satellite images, that is, Landsat MSS (1975), Landsat Thematic Mapper (1986), Enhanced Thematic Mapper (2000), and Landsat 8 OLI scenes (2014), to investigate the changes in LULC. In addition, individual interviews with 51 randomly selected households, discussions with focus group and key informants, and field observations were also incorporated for the study. The image classification indicated four categories of LULC classes: Natural forest, eucalyptus plantations, cropland/settlements, and grasslands. Between 1975 and 2014, cropland/settlements and eucalyptus plantations considerably increased, whereas grassland cover drastically decreased. According to the results, the area under cropland/settlements and eucalyptus plantations increased by 62 and 335%, respectively, with 74% concomitant decrease in the area of grasslands in the same period. Survey results showed that deterioration of soil fertility (41.2%) followed by shortage of land (35.3%) is the major constraint for crop production for poor farmers in the study area. However, better-off farmers ranked deterioration of soil fertility (64.7%) followed by lack of credit (17.6%) as priority constraints for crop production. Interviews mainly focused on selected women group revealed that the expansion of eucalyptus in the area greatly curbed the burdens of collecting fuel woods from long distances in the past. The availability of too many religious holidays (on average 16 days/month) directly or indirectly contributes to the current seasonal food shortages of the community. Generally, our results show that the community in the study area is beset with a host of social, economic, and institutional challenges. As a result, majority of the farming households are destitute, unable to make a livelihood from their small plot of land and live in absolute poverty. Therefore, in light of these finding, it is imperative that timely interventions by government and other development stakeholders are needed to come to grips with problems of soil fertility, land-use change, and food insecurity in the study area.