Molecular Mechanisms of RSV and Air Pollution Interaction: A Scoping Review

RSV is one of the major infectious agents in paediatrics, and its relationship with air pollution is frequently observed. However, the molecular basis of this interaction is sparsely reported. We sought to systematically review the existing body of literature and identify the knowledge gaps to answer the question: which molecular mechanisms are implied in the air pollutants–RSV interaction? Online databases were searched for original studies published before August 2022 focusing on molecular mechanisms of the interaction. The studies were charted and a narrative synthesis was based upon three expected directions of influence: a facilitated viral entry, an altered viral replication, and an inappropriate host reaction. We identified 25 studies published between 1993 and 2020 (without a noticeable increase in the number of studies) that were performed in human (n = 12), animal (n = 10) or mixed (n = 3) models, and analysed mainly cigarette smoke (n = 11), particulate matter (n = 4), nanoparticles (n = 3), and carbon black (n = 2). The data on a damage to the epithelial barrier supports the hypothesis of facilitated viral entry; one study also reported accelerated viral entry upon an RSV conjugation to particulate matter. Air pollution may result in the predominance of necrosis over apoptosis, and, as an effect, an increased viral load was reported. Similarly, air pollution mitigates epithelium function with decreased IFN-γ and Clara cell secretory protein levels and decreased immune response. Immune response might also be diminished due to a decreased viral uptake by alveolar macrophages and a suppressed function of dendritic cells. On the other hand, an exuberant inflammatory response might be triggered by air pollution and provoke airway hyperresponsiveness (AHR), prolonged lung infiltration, and tissue remodeling, including a formation of emphysema. AHR is mediated mostly by increased IFN-γ and RANTES concentrations, while the risk of emphysema was related to the activation of the IL-17 → MCP-1 → MMP-9 → MMP-12 axis. There is a significant lack of evidence on the molecular basics of the RSV–air pollution interaction, which may present a serious problem with regards to future actions against air pollution effects. The major knowledge gaps concern air pollutants (mostly the influence of cigarette smoke was investigated), the mechanisms facilitating an acute infection or a worse disease course (since it might help plan short-term, especially non-pharmacological, interventions), and the mechanisms of an inadequate response to the infection (which may lead to a prolonged course of an acute infection and long-term sequelae). Thus far, the evidence is insufficient regarding the broadness and complexity of the interaction, and future studies should focus on common mechanisms stimulated by various air pollutants and a comparison of influence of the different contaminants at various concentrations.     

Biological Solubilisation of Leather Industry Waste in Anaerobic Conditions: Effect of Chromium (III) Presence,Pre-Treatments and Temperature Strategies

Collagen-based polymers and their blends have attracted considerable interest for new materials development due to their unique combination of biocompatibility, physical and mechanical properties and durability. Leather, a modified natural biopolymer made from animal rawhide and the first synthetic collagen-based polymer known since the dawn of civilization, combines all these features. Rawhide is transformed into leather by tanning, a process in which the collagen is cross-linked with different agents to make it stronger and more durable and to prevent its decay. Research on the development of environmentally friendly procedures and sustainable materials with higher efficiency and lower costs is a rapidly growing field, and leather industry is not an exemption. Chrome-tanned and vegetable-tanned (chromium-free) shavings from the leather industry present a high content of organic matter, yet they are considered recalcitrant waste to be degraded by microbiological processes like anaerobic digestion (AD), a solid technology to treat organic waste in a circular economy framework. In this technology however, the solubilisation of organic solid substrates is a significant challenge to improving the efficiency of the process. In this context, we have investigated the process of microbial decomposition of leather wastes from the tannery industry to search for the conditions that produce optimal solubilisation of organic matter. Chrome-tanned and chromium-free leather shavings were pre-treated and anaerobically digested under different temperature ranges (thermophilic–55 °C-, intermediate–42 °C- and mesophilic–35 °C) to evaluate the effect on the solubilisation of the organic matter of the wastes. The results showed that the presence of chromium significantly inhibited the solubilization (up to 60%) in the mesophilic and intermediate ranges; this is the fastest and most efficient solubilization reached under thermophilic conditions using the chromium-free leather shaving as substrates. The most suitable temperature for the solubilization was the thermophilic regime (55 °C) for both chromium-free and chrome-tanned shavings. No significant differences were observed in the thermophilic anaerobic digestion of chromium-free shavings when a pre-treatment was applied, since the solubilisation was already high without pre-treatment. However, the pre-treatments significantly improved the solubilisation in the mesophilic and intermediate configurations; the former pre-treatment was better suited in terms of performance and cost-effectiveness compared to the thermophilic range. Thus, the solubilisation of chromium-free tannery solid wastes can be significantly improved by applying appropriate pre-treatments at lower temperature ranges; this is of utter importance when optimizing anaerobic processes of recalcitrant organic wastes, with the added benefit of substantial energy savings in the scaling up of the process in an optimised circular economy scenario.     

生物粉末活性炭/超滤组合工艺处理微污染原水

针对微污染原水中存在的有机物和氨氮等污染物,采用生物粉末活性炭/超滤(BPAC/UF)组合工艺进行处理。结果表明,当进水氨氮浓度较低时,硝化细菌活性较差,无法充分发挥生物降解作用,氨氮去除率较低,同时有机物去除率也较低;当进水氨氮浓度在0. 6 mg/L左右时,可以形成稳定的生物活性炭,组合工艺对氨氮的去除率较高,且对有机物的去除率较为稳定。进水中主要以分子质量<5 ku的有机物为主,组合工艺对这部分有机物的去除率也最高。组合工艺对疏水性物质的去除,主要依靠生物粉末活性炭的吸附降解和膜面滤饼层的截留作用。NaClO强化反冲洗可以很好地降低跨膜压差的增长速度,当NaClO浓度为400 mg/L、反冲洗时间为10min时可达到最佳清洗效果。     

臭氧/氯消毒中藻类有机物生成消毒副产物的特征

饮用水源地藻华会释放大量藻类有机物(AOM),AOM与氯消毒剂反应生成的消毒副产物(DBPs)会给饮用水用户带来不容忽视的健康风险。为此,探究了臭氧/氯消毒对AOM结构和DBPs生成的影响。结果表明,臭氧氧化能有效去除AOM中芳香蛋白和酚类、叶绿素a、藻蓝蛋白结构物质,但是对腐殖酸类结构的去除效果相对较差。DBPs生成总量随臭氧投加浓度的升高而增加,其中主要是三氯甲烷(TCM);卤代乙腈和卤代酮的生成总量随臭氧投加浓度的变化趋势不明显。延长臭氧接触时间会明显增加1 h氯化中TCM的生成量,氯化24 h时DBPs生成总量与臭氧接触时间无关。在臭氧/氯消毒过程中,AOM的DBPs生成潜能低于天然有机物(NOM)。AOM有利于一溴一氯乙腈的生成,而NOM会生成更多的二氯乙腈。     

SWATH型科考船柴油发电机组气囊隔振设计方案

小水线面双体船(small waterplane area twin-hull ship,SWATH)型科考船作为承担远洋深海科考任务的特种船舶,对船舶的水下辐射噪声和自噪声控制十分严格.为了控制SWATH型科考船自噪声,针对科考船上主要振动噪声源1100 kW柴油发电机组采用气囊隔振技术,进行机组气囊隔振系统的设计和...     

理想费米气体狄塞尔循环效率的研究

在分析了研究狄塞尔循环时需要考虑其量子效应的必要性以及该循环在实际社会生产中的广泛应用前景后,首先给出以理想气体为工作物质的狄塞尔循环的效率表达式,然后以理想费米气体为例,根据其状态方程及其热力学性质获得以理想量子气体为工作物质的狄塞尔循环的效率表达式,通过比较得出提高实际热机效率的主要途径.     

PVC-U塑料异型材的原辅材料分析

塑料异型材的物理化学性能,不但对型材的外观如表面光亮度等有影响,而且对型材的焊接强度和低温冲击强度等有重要的影响。文章从型材原辅材料的结构及特点等方面来研究原辅材料的选用对PVC型材的性能和外观的影响,重点对PVC、微粒子填充和抗冲击改性剂进行研究,提出合理的原辅材料要求,且设计高效的型材配方。     

强化混凝技术去除水中有机物的研究进展

强化混凝技术是指通过增加混凝剂投加量、投加助凝剂、使用新型高效混凝剂、调整pH值及进行氧化预处理从而提高常规混凝处理中有机物的去除效果,最大限度地去除消毒副产物的前驱物,是一种经济有效的深度处理技术,无需投入大量的资金.系统介绍了强化混凝技术在有机物去除方面研究与实践所取得的最新成果,指出了进一步研究中亟需解决的问题,以期为我国强化混凝技术的研究与应用提供有益的借鉴.     

二级处理出水中有机物的分级特性

为研究二级出水中有机物的化学特性,以哈尔滨市W污水处理厂为研究对象,利用XAD树脂将二级处理出水中的有机物分级为5个组分:疏水性有机酸(HPO-A)、疏水性中性有机物(HPO-N)、过渡亲水性有机酸(TPI-A)、过渡亲水性中性有机物(TPI-N)和亲水性有机物(HPI).采用氯化反应实验、可生物降解溶解性有机碳和尺寸分布测定,以及紫外和红外光谱分析考察二级处理出水中不同有机组分的特性.结果表明:HPO-A是加氯消毒时产生三卤甲烷的主要有机组分.各有机组分中,溶解性有机碳(DOC)(<0.025μm)均是主要的有机碳形式和主要的三卤甲烷前体物.各组分的可生化性为:HPI>TPI-A>HPO-A>TPI-N>HPO-N.各组分的芳香性为:HPO-N>HPO-A>TPI-N>TPI-A>HPI.HPO-N和TPI-N中碳氢化合物的含量较高.在二级处理出水中,HPO-A和HPI的含量相对较高,是主要的有机组分.此外,不同有机组分的化学特性不同.     

高温除尘用金属纤维滤料的性能研究

为了解高温除尘用金属纤维滤料的过滤性能,采用对比试验的方式,对金属纤维滤料、普通针刺毡滤料和聚四氟乙烯(poly tetra fluoro ethylene, PTFE)覆膜滤料进行过滤性能试验,结果发现：老化试验前,金属纤维滤料排放浓度较高,老化试验后,排放浓度低于0.1 mg/m³;清灰周期长,清灰周期约为普通针刺毡的2倍,与针刺毡覆膜滤料基本一致;残余阻力约在350 Pa左右,与普通针刺毡、PTFE覆膜滤料基本一致。金属纤维滤料作为新型滤材,过滤性能良好,完全能满足高温除尘的性能需求。