Investigation of the Organic Solvent Resistance Mechanisms in Rhodococcus and Lysinibacillus Using Several Molecular Forensic Tools

Rhodococcus erythropolis IBB_Po5 (KM405337) and Lysinibacillus xylanilyticus IBB_Po7 (KM405338) showed good tolerance to 5% (v/v) organic solvents (alkanes, aromatics). However, 5% (v/v) alkanes (i.e., cyclohexane, n-hexane, n-decane) were less toxic for R. erythropolis IBB_Po5 and L. xylanilyticus IBB_Po7 cells, compared with 5% (v/v) aromatics (i.e., toluene, o-xylene, ethylbenzene). The high organic solvent tolerance of these two Gram-positive bacteria could be due to the presence in their genome of some catabolic (alkB1, todM, xylM) and trehalose-6-phosphate synthase (otsA1) genes. R. erythropolis IBB_Po5 possesses three catabolic genes (i.e., alkB1, todM, xylM), while L. xylanilyticus IBB_Po7 possesses only one catabolic gene (i.e., alkB1). Numerous adaptations involved in organic solvents tolerance were depicted in R. erythropolis IBB_Po5 and L. xylanilyticus IBB_Po7 cells exposed to 5% (v/v) alkanes and aromatics (i.e., changes in the cell growth rate, membrane permeability, cell morphology, biosurfactant emulsification index, carotenoids profile, DNA fingerprinting). Therefore, microbiological, biochemical, and DNA fingerprinting studies of the bacteria isolated from polluted environments could provide valuable information that may complement or supplement other forensic investigations.     

灭草松在腐殖酸上的吸附及其机理

通过吸附动力学、吸附等温线和IR，ESR技术，研究了腐殖酸对灭草松的吸附及吸附机理，并且对pH、离子强度对吸附过程的影响进行了探讨。结果表明灭草松在腐殖酸上经过大约4h的初始快速阶段，此后进入慢速吸附过程。溶液pH可能会影响腐殖酸的构型。高pH时，吸附量随溶液离子强度增加稍有增加。灭草松在腐殖酸上的吸附过程中存在氢键、电荷转移作用，疏水分配也是可能存在的机理。     

Behavior of the herbicide dimepiperate with homoionic clays in aqueous solution

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Predicting particle deposition on HVAC heat exchangers

Particles in indoor environments may deposit on the surfaces of heat exchangers that are used in heating, ventilation and air conditioning (HVAC) systems. Such deposits can lead to performance degradation and indoor air quality problems. We present a model of fin-and-tube heat-exchanger fouling that deterministically simulates particle impaction, gravitational settling, and Brownian diffusion and uses a Monte Carlo simulation to account for impaction due to air turbulence. The model predicts that <2% of submicron particles will deposit on heat exchangers with air flows and fin spacings that are typical of HVAC systems. For supermicron particles, deposition increases with particle size. The dominant deposition mechanism for 1–10 μm particles is impaction on fin edges. Gravitational settling, impaction, and air turbulence contribute to deposition for particles larger than 10 μm. Gravitational settling is the dominant deposition mechanism for lower air velocities, and impaction on refrigerant tubes is dominant for higher velocities. We measured deposition fractions for 1–16 μm particles at three characteristic air velocities. On average, the measured results show more deposition than the model predicts for an air speed of 1.5 m s⁻¹. The amount that the model underpredicts the measured data increases at higher velocities and especially for larger particles, although the model shows good qualitative agreement with the measured deposition fractions. Discontinuities in the heat-exchanger fins are hypothesized to be responsible for the increase in measured deposition. The model and experiments reported here are for isothermal conditions and do not address the potentially important effects of heat transfer and water phase change on deposition.     

污水土地处理系统的应用分析

污水土地处理与人民生活息息相关，这就使得污水土地处理作为一项环境治理的实用技术越来越多地引起人们的重视。本文阐述了该处理技术的优缺点，论述了其消除污染物危害的机理，特别讨论了污水土地处埋系统设计中需要考虑的因素。     

Detoxification and repair process of ozone injury: from O3 uptake to gene expression adjustment

Plants react to O₃ threat by setting up a variety of defensive strategies involving the co-ordinated modulation of stress perception, signalling and metabolic responses. Although stomata largely controls O₃ uptake, differences in O₃ tolerance cannot always be ascribed to changes in stomatal conductance but cell protective and repair processes should be taken into account. O₃-driven ROS production in the apoplast induces a secondary, active, self-propagating generation of ROS, whose levels must be finely tuned, by many enzymatic and non-enzymatic antioxidant systems, to induce gene activation without determining uncontrolled cell death. Additional signalling molecules, as ethylene, jasmonic and salicylic acid are also crucial to determine the spreading and the containment of leaf lesions. The main recent results obtained on O₃ sensing, signal transduction, ROS formation and detoxification mechanisms are here discussed.     

Banging heads onboard buses: Assessment scheme to improve injury mitigation for bus passengers

Abstract

Objective: Although bus travel is one of the safest modes of transport, a substantial number of bus passengers in London are still injured in collision and harsh maneuver incidents, in particular emergency braking. It is not well understood how these passengers are injured. The objective was to better understand the injury mechanisms and develop countermeasures with a test and assessment procedure to prevent or mitigate these injuries.

Methods: The UK national STATS19 data were used to determine the size of the problem. Data, including CCTV footage, in combination with inspection of current buses, were used to determine injury mechanisms and identify features and areas in buses associated with more injuries.

An assessment system based on visual inspection was developed to encourage a reduction in the number of features associated with injury.

Results: The STATS19 analysis showed that three quarters of all injured casualties occurred in incidents where there was no impact, with this proportion rising for seriously injured casualties. Overrepresentation of older females was also seen.

The CCTV analysis and bus examinations highlighted issues with poorly positioned handrails, lack of compartmentalization (restraint), and objects with sharp edges and corners. It also showed that a much higher proportion of passengers seated in the area close to the middle doors and wheelchair area were injured compared to other areas of the bus. Factors contributing to this result were that this area contained more features associated with injury and that persons with reduced mobility have greater exposure in this area; that is, more vulnerable passengers currently sit in the less safe areas of the bus.

Conclusions: A novel analysis of CCTV footage has enabled a better understanding of injury mechanisms for bus passengers to be developed. In combination with inspection of current buses, this has been used to develop an assessment system to improve the safety of buses in London.     

Inactivation and risk control of pathogenic microorganisms in municipal sludge treatment: A review

• Diversity and detection methods of pathogenic microorganisms in sludge. • Control performance of sludge treatment processes on pathogenic microorganisms. • Risk of pathogen exposure in sludge treatment and land application. The rapid global spread of coronavirus disease 2019 (COVID-19) has promoted concern over human pathogens and their significant threats to public health security. The monitoring and control of human pathogens in public sanitation and health facilities are of great importance. Excessive sludge is an inevitable byproduct of sewage that contains human and animal feces in wastewater treatment plants (WWTPs). It is an important sink of different pollutants and pathogens, and the proper treatment and disposal of sludge are important to minimize potential risks to the environment and public health. However, there is a lack of comprehensive analysis of the diversity, exposure risks, assessment methods and inactivation techniques of pathogenic microorganisms in sludge. Based on this consideration, this review summarizes the control performance of pathogenic microorganisms such as enterovirus, Salmonella spp., and Escherichia coli by different sludge treatment technologies, including composting, anaerobic digestion, aerobic digestion, and microwave irradiation, and the mechanisms of pathogenic microorganism inactivation in sludge treatment processes are discussed. Additionally, this study reviews the diversity, detection methods, and exposure risks of pathogenic microorganisms in sludge. This review advances the quantitative assessment of pathogenic microorganism risks involved in sludge reuse and is practically valuable to optimize the treatment and disposal of sludge for pathogenic microorganism control.     

自然灾害经济管理机制研究

近50年来,国内外学者对灾害经济问题进行了较为深入的研究,各国政府在灾害管理实践方面也积累了大量的经验,借鉴这些研究成果和管理经验,结合"汶川地震"灾害经济管理的实际,就完善我国以人为本的自然灾害管理机制和确保地震重灾区的可持续重建,提出了7点建议.     

山东省农业多功能的时空演化特征与驱动机制分析

农业供给侧改革与乡村振兴背景下,深入挖掘各地区农业多种功能,统筹不同农业功能特征地域的协调发展,成为促进农业增收、实现农业可持续发展、保障食物安全的关键。农业多功能的演变受到区域农业资源禀赋与社会经济发展水平和阶段的复杂影响。以山东省为例,选取2004年、2011年、2017年三个时间截面,构建农业多功能评价指标体系,运用空间错位指数、回归分析等方法对县域农业多功能的时空演变规律与驱动机制进行分析。研究发现：（1）2004—2017年,山东省农业的农产品供给功能和经济发展功能分别呈先升后降和先降后升的增长态势,社会保障功能和生态服务功能分别呈持续下降和先降后升的下降趋势。（2）研究期内,农产品供给功能与生态服务功能对农业资源禀赋依赖较强,分别呈现出沿平原—丘陵—山地递减与递增的空间格局;经济发展功能与社会保障功能受社会经济发展水平和阶段影响较大,时空差异明显。（3）各驱动因子对于同一功能中不同要素的作用方向与强度存在差异,引发农业各功能结构的变化。基于功能视角提出山东省农业转型发展的路径选择与分区优化策略。