COMETABOLIC BIODEGRADATION OF GROUNDWATER CONTAMINANTS BY ACIDOPHILIC METHANOTROPHS

Chlorinated solvents have been widely used in various industrial process. The wide applications and improperly disposed has resulted in groundwater and soil contaminated with these compounds. In contaminated groundwater, trichloroethylene (TCE) and dichloroethylene (DCE) are two commonly detected volatile organic compounds (VOCs) and 1,2,3-trichloropropane (TCP) is a common co-contaminant. These three contaminants are known or suspended carcinogens. Maximum contaminant levels for TCE and DCE in drinking water has been set by EPA. In 2009, the U.S. EPA listed TCP in the Drinking Water Contaminant Candidate List 3(CCL3) (EPA 2009). To protect public health, these compounds need to be removed from contaminated aquifers and soils. While bioremediation technologies for chlorinated solvents have been successfully demonstrated in neutral pH aquifers, these technologies are often ineffective for remediating chlorinated solvents contamination in acidic aquifers (i.e., pH <5.5). Acidophilic methanotrophs have been detected in several low pH environments, but their presence and potential role in chlorinated solvents degradation in acidic aquifers is unknown. This study used stable isotope probing-based techniques to identify the presence and diversity of acidophilic methanotrophs in chlorinated solvent-contaminated acidic aquifers. By using TCE as a model groundwater contaminant, application of stable isotope probing-based technique has successfully identified active methanotrophs that were capable of degrading TCE in microcosms prepared from two low pH aquifer materials. A total of thirty-five clones of methanotrophs were derived from low pH microcosms in which methane and TCE degradation had been observed, with 29 clustered in γ-Proteobacteria and 6 clustered in α-Proteobacteria. None of the clones has a high similarity to known acidophilic methanotrophs from other environments. The presence and diversity of particulate MMO and soluble MMO were also investigated. The pmoA gene was detected predominantly at one site, and the presence of a specific form of mmoX in numerous samples suggested that Methylocella spp. may be common in acidic aquifers. Finally, a methane-grown culture at pH 4 was enriched from an acidic aquifer and its ability to biodegrade various chlorinated ethenes was tested. Interestingly, the mixed culture rapidly degraded TCE and vinyl chloride, but not cis-1,2-DCE after growth on methane. Research efforts also extended to examine the degradative ability of pure acidophilic methanotrophs to chlorinated solvents, with respect to degradation kinetics and transformation capacity(Tc), and effects of carbon substrates on the degradative enzyme expression. Two acidophilic methanotrophic strains were used as model microorganisms. Both strains were able to grow on multi-carbon sources, while only methane-grown cells showed non-specific enzyme activity based on naphthalene oxidation tests. Positive PCR results confirmed that Methylocella tundrae carried the cluster gene of propane monooxygenase and probably could use propane as the carbon source. While the strain grew well on isopropanol (an immediate product of propane oxidation), the strain grew poorly with propane. Interestingly, the isopropanol-grown cells showed negative results in naphthalene oxidation assay, suggesting that isopropanol might not be an inducer for propane monooxygenase. Methane-grown Methylocella tundrae and Methylocystis bryophila were able to degrade TCE and cis-1,2-DCE. Only Methylocella tundrae could degrade TCP. The results of this study suggest that aerobic biodegradation of TCE and other chlorinated solvents in low pH groundwater may be facilitated by methanotrophic bacteria, and that there are potentially a wide variety of different strains that inhabit acidic aquifers

Structure and mechanical properties of multicomponent AlNiCoFeCrTiMo alloy obtained by mechanical alloying and sintering

The purpose of the work is to study the structure and mechanical properties of AlNiCoFeCrTiMo HEA obtained by mechanical alloying and sintering. In order to achieve this purpose, the following tasks are solved: 1) The selection and justifying alloy powder compositions applying the phase formation empirical rules to obtain solid solutions in high-entropy alloys (determination of the mixing entropy; mixing enthalpy; the difference of atomic radii δ; the valence electron concentration (VEC), and calculate the necessary batches. 2) Fabrication of the high-entropy alloy powders by mechanical alloying and study its structure and phase composition as well as thermal stability. 3) Selection the sintering method for conservation of nanostructure and phase composition in HEA after mechanical alloying; production compact samples. 4) Analyse the structure, phase and chemical composition, as well as mechanical properties. 5) Analyse the results of the experiment and draw conclusions. Research methods and equipment: The mechanical alloying was carried out in a planetary ball mill; Spraying was performed on a DYMET 405 setup. The structure and phase composition were studied using a scanning electron microscope, REMMA—106I and X-ray diffractometer, Ultima IV. The NETZSCH differential scanning calorimeter is used to measure the differential scanning calorimetry signal (DSC) curve of the HEA. Microhardness was determined by indentation on a PMT-3 and Micron Gamma machine. Scientific novelty of the results: Comparing the microstructure and mechanical properties of pressure sintering and SPS sintered HEA, it can be concluded that, the high-entropy alloy prepared by pressure sintering has better microstructure and high mechanical properties. Tests have proved that the AlNiCoFeCrTiMo high-entropy alloy prepared by MA-SPS has higher strength and hardnes

Role of Notch signaling pathway in bone marrow mesenchymal stem cell therapy for phosgene inhalationinduced lung injury in rats

Purpose: To determining the expression and role of the Notch signaling pathway (NSP) in phosgene inhalation-induced lung injury in rats, and the therapeutic effect of bone marrow mesenchymal stem cell (MSC) on the lung lesions.Methods: Wistar rats (220 - 280 g) were randomly assigned to air inhalation group, phosgene inhalation group, and mesenchymal stem cell (MSC) intervention group. Each group had 8 rats. Directional flow phosgene inhalation device was used to produce phosgene inhalation-induced lung injury in the rats. Serum inflammatory cytokines (TNF-α, IL-8 and IL-6) were determined using ELISA assay kits. The expressions of proteins related to the NSP (Notch1, Notch2, Hes1, Hes5) were quantified using Western blot.Results: Phosgene inhalation brought about significant increase in TNF-α, IL-8 and IL-6 levels (p &lt; 0.01), but MSC intervention significantly reduced the expressions of these inflammatory factors to varying degrees (p &lt; 0.05), although their levels were still significantly high, relative to the air inhalation group. Results from western blot showed that the Notch1, Notch2, Hes1 and Hes5 were upregulated in the phosgene inhalation group, when relative to the air inhalation group (p &lt; 0.01). Protein expressions in the MSC intervention group were lower than those in the non-intervention groups (p &lt; 0.05).Conclusion: Phosgene inhalation activates Notch signaling pathway, while MSC intervention inhibits this signaling pathway. Thus, inhibition of NSP may be implicated in the protective effect of MSC therapy against phosgene-induced lung injury.Keywords: Phosgene, Lung injury, Notch signalling pathway, Mesenchymal stem cell

Advancing Treatment Strategies: A Comprehensive Review of Drug Delivery Innovations for Chronic Inflammatory Respiratory Diseases

Chronic inflammatory respiratory diseases, such as asthma, chronic obstructive pulmonary disease (COPD), and cystic fibrosis, present ongoing challenges in terms of effective treatment and management. These diseases are characterized by persistent inflammation in the airways, leading to structural changes and compromised lung function. There are several treatments available for them, such as bronchodilators, immunomodulators, and oxygen therapy. However, there are still some shortcomings in the effectiveness and side effects of drugs. To achieve optimal therapeutic outcomes while minimizing systemic side effects, targeted therapies and precise drug delivery systems are crucial to the management of these diseases. This comprehensive review focuses on the role of drug delivery systems in chronic inflammatory respiratory diseases, particularly nanoparticle-based drug delivery systems, inhaled corticosteroids (ICSs), novel biologicals, gene therapy, and personalized medicine. By examining the latest advancements and strategies in these areas, we aim to provide a thorough understanding of the current landscape and future prospects for improving treatment outcomes in these challenging conditions

Comprehensive Analysis of the Profiles of Differentially Expressed mRNAs, lncRNAs, and circRNAs in Phosgene-Induced Acute Lung Injury

Phosgene exposure can cause acute lung injury (ALI), for which there is no currently available effective treatment. Mesenchymal stem cells (MSCs) which have been proven to have therapeutic potential and be helpful in the treatment of various diseases, but the mechanisms underlying the function of MSCs against phosgene-induced ALI are still poorly explored. In this study, we compared the expression profiles of mRNAs, lncRNAs, and circRNAs in the lung tissues from rats of three groups—air control (group A), phosgene-exposed (group B), and phosgene + MSCs (group C). The results showed that 389 mRNAs, 198 lncRNAs, and 56 circRNAs were differently expressed between groups A and B; 130 mRNAs, 107 lncRNAs, and 35 circRNAs between groups A and C; and 41 mRNAs, 88 lncRNAs, and 18 circRNAs between groups B and C. GO and KEGG analyses indicated that the differentially expressed RNAs were mainly involved in signal transduction, immune system processes, and cancers. In addition, we used a database to predict target microRNAs (miRNAs) interacting with circRNAs and the R network software package to construct a circRNA-targeted miRNA gene network map. Our study showed new insights into changes in the RNA expression in ALI, contributing to explore the mechanisms underlying the therapeutic potential of MSCs in phosgene-induced ALI

再生水无计划间接补充饮用水的雌激素健康风险 Health risk induced by estrogens during unplanned indirect potable reuse of reclaimed water from domestic wastewater

以城市污水为水源的再生水中含有一定量的雌激素类内分泌干扰物，其在无计划间接补充饮用水过程中存在潜在健康风险。针对再生水经河流补给湖库型水源地的典型场景，研究了再生水中雌酮、雌二醇、17α-乙炔基雌二醇、双酚A、壬基酚和辛基酚在水体中的变化规律，评价了雌激素的健康风险。结果表明，再生水(二级出水)中雌激素类物质的质量浓度多分布在0.1~100 ng·L-1水平；双酚A和壬基酚的浓度较高，可达到1~10μg·L-1水平。再生水间接补充饮用水过程中，雌激素的浓度受到上游来水稀释、河道湖库自然降解和饮用水处理工艺去除等作用的影响。雌酮、雌二醇、双酚A、壬基酚和辛基酚的非致癌风险较小，都低于规定值1。当湖库型水源地的水力停留时间大于30 d时，再生水中17α-乙炔基雌二醇对人体的非致癌风险值大多小于1；当停留时间小于10 d且再生水占饮用水比例达50%以上时，16%~47%样品的17α-乙炔基雌二醇的非致癌风险值大于1，其健康风险需优先关注。 The estrogenic endocrine disruptors in reclaimed water from domestic wastewater may induce health risks to human being, when reclaimed water is used for augmentation of drinking water unplannedly and indirectly. This study investigated changes in concentrations of estrone, estradiol, 17alpha-ethinyl estradiol, bisphenol A, nonylphenol and octylphenol in reclaimed water during the reuse of reclaimed water for augmentation to water source such as lakes and reservoir via river. Thereafter, health risk induced by estrogens during the resue of reclaimed water was evaluated. The concentration of estrogen in secondary effluent ranged 0.1-100 ng x L(-1). The highest concentrations of bisphenol A and nonylphenol reached up to 1-10 microg x L(-1). During the indirect reuse of reclaimed water as potable water, the dilution and degradation in river and lake, and the removal by drinking water treatment process could change the concentrations of estrogen. The non-carcinogenic risks of estrone, estradiol, bisphenol A, nonylphenol and octylphenol were lower than 1. When the hydraulic retention time of 17alpha-ethinyl estradiol (EE2) in lakes and reservoir was higher than 30 days, the non-carcinogenic risk of EE2 was lower than 1 in most cases. When the hydraulic retention time of EE2 in lakes and reservoir was less than 30 days and the percentages of reclaimed water in drinking water were higher than 50%, the non-carcinogenic risk induced by EE2 was higher than 1 in 20%-50% samples. This indicated that the risks of EE2 should be concerned

Low-protein diets with balanced amino acids reduce nitrogen excretion and foot pad dermatitis without affecting the growth performance and meat quality of free-range yellow broilers

An experiment was conducted to evaluate the effects of crude protein (CP) levels on growth performance, carcase quality, meat quality, immune indices, litter and faeces quality, as well as welfare quality, in free-range yellow broilers using balanced amino acid technology. In total, 600 one-d-old Suqin yellow broilers were raised for 21 d. On d 22, 540 birds with similar BW (390 ± 7 g SD) were randomly selected and placed into 9 pens (3 groups with 3 replicates per group and 60 birds each replicate) and then reared to 56 d of age. The birds were fed a diet containing CP 19% (control), 18% or 17% (measured value: 18.878%, 17.881%, 17.052%, respectively), in three groups for 35 d. The results revealed that decreasing dietary CP levels from 19% to 17% had no impact on broiler growth performance, carcase quality and meat quality (p > .05). The relative immune organ weights also showed no change to the lowering of dietary CP levels (p > .05), whereas serum albumin was significantly influenced by decreasing dietary CP levels (p = .042). Furthermore, nitrogen content in litter and faeces, as well as the footpad dermatitis score for welfare indices, were decreased with decreased dietary CP levels (p = .009, p = .014, p = .045, respectively). The results of this study suggest that low-protein diets with balanced amino acids reduce nitrogen excretion and footpad dermatitis without effecting the performance, carcase quality, and meat quality of free-range yellow broilers

A self-weakening mechanism for tropical cyclones

A mechanism leading to the self-weakening of tropical cyclones is proposed using the Weather and Research and Forecasting model. A comparison between an experiment with variable Coriolis parameter f and one on an f-plane shows that after the initial intensification the former is characterized by a smaller intensity. As opposed to the tropical cyclone on the f-plane, the one with variable f weakens significantly after reaching maturity. Analyses of the 3-D circulation show that the main reason for the weakening is dry intrusion in the mid-upper troposphere from the west. Once the dry intrusion reaches the inner vortex, strong downdrafts reduce the high equivalent potential temperature in the boundary layer inflow. The subsequent updrafts in the eyewall, characterized by lower equivalent potential temperature, are considerably reduced and, consequently, the secondary circulation weakens. Back-trajectories are used to determine the origin of the dry intrusion. It is found that the air parcels expelled from the storm deep convection into the outflow layer recirculate anticyclonically back into the vortex, causing a self-weakening of the tropical cyclone. A time span for the recirculation of at least 48 h allows the air parcels to sink substantially before reaching the vortex circulation. Some implications of the intrinsic nature of this process are briefly discussed

Single-Cell RNA-Sequencing Reveals Epithelial Cell Signature of Multiple Subtypes in Chemically Induced Acute Lung Injury

Alveolar epithelial cells (AECs) play a role in chemically induced acute lung injury (CALI). However, the mechanisms that induce alveolar epithelial type 2 cells (AEC2s) to proliferate, exit the cell cycle, and transdifferentiate into alveolar epithelial type 1 cells (AEC1s) are unclear. Here, we investigated the epithelial cell types and states in a phosgene-induced CALI rat model. Single-cell RNA-sequencing of bronchoalveolar lavage fluid (BALF) samples from phosgene-induced CALI rat models (Gas) and normal controls (NC) was performed. From the NC and Gas BALF samples, 37,245 and 29,853 high-quality cells were extracted, respectively. All cell types and states were identified and divided into 23 clusters; three cell types were identified: macrophages, epithelial cells, and macrophage proliferating cells. From NC and Gas samples, 1315 and 1756 epithelial cells were extracted, respectively, and divided into 11 clusters. The number of AEC1s decreased considerably following phosgene inhalation. A unique SOX9-positive AEC2 cell type that expanded considerably in the CALI state was identified. This progenitor cell type may develop into alveolar cells, indicating its stem cell differentiation potential. We present a single-cell genome-scale transcription map that can help uncover disease-associated cytologic signatures for understanding biological changes and regeneration of lung tissues during CALI