Heavy metal pollution is a global issue that poses significant risks to ecosystems and human health. Microorganisms offer a promising bioremediation approach due to their ability to mitigate metal-induced metabolic damage in an eco-friendly, efficient, and cost-effective manner. Among them, Gram-positive Bacillus species exhibit a high heavy metal adsorption capacity and secrete metabolites with diverse functional properties. Under heavy metal stress, these metabolites play a crucial role in alleviating metal-induced damage. However, the application of Bacillus metabolites in heavy metal remediation faces challenges, including prolonged treatment durations, the necessity for stable environmental conditions, and specific nutrient requirements.This review summarizes recent research on the effects of heavy metal exposure on the metabolic pathways and metabolites of Bacillus spp., elucidates their role in influencing metal bioavailability and chemical transformations, and explores innovative strategies to enhance the stability of Bacillus-mediated heavy metal remediation. The review aims to provide valuable insights for optimizing bioremediation strategies, facilitating the selection of efficient degrading strains, and advancing the sustainable management of heavy metal contamination.

Aristolochic acid I (AAI), the predominant compound in Aristolochiaceae plants and Asarum species, is a widespread environmental contaminant capable of accumulating in soil, contaminating water and crops, ultimately entering the human body. Its nephrotoxic, carcinogenic, and reproductive toxic effects pose significant health concerns. This study investigates the impact of maternal AAI exposure on meiotic prophase I (MPI) during early fetal oogenesis. Pregnant mice were orally administered AAI at doses of 0.03125, 0.125, and 1 mg/kg from 14.5 to 16.5 dpc, with fetal ovaries collected at 17.5 dpc. AAI exposure induced meiotic defects in fetal oocytes, including delayed progression of MPI, increased DNA damage, and impaired homologous recombination. Furthermore, AAI induced oxidative stress, reduced mitochondrial membrane potential and triggered apoptosis, leading to a diminished ovarian reserve in neonatal ovaries. Mechanistically, these defects were mediated by heat shock proteins which altered protein-protein interactions crucial for DNA repair. Given the pivotal role of early oogenesis in determining female fertility and ensuring the health of offspring, these findings underscore the potential reproductive risks of AAI exposure during pregnancy. This study highlights the urgent need for greater awareness of foodborne contaminants and the implementation of preventative measures to mitigate maternal AAI exposure, thereby safeguarding offspring fertility and health.

We report an innovative method of extracting water distribution network (WDN) historical repair location data from images of paper repair data maps, to provide usable geo-referenced digitally formatted data. For most water utilities, repair location data typically fall into two eras: pre- and post-GIS, approximately corresponding to pre- and post-2000. Automated conversion of pre-2000 paper maps to a geo-referenced digital format provides additional data to clarify trends in pipe repair causative factors, such as material defects, corrosive or creeping soils, and traffic. We applied the methodology to more than 3,000 maps of the Los Angeles Department of Water and Power WDN, thereby extending the record of repairs backward from 2000 to 1975, almost doubling the number of repair records. The methodology's value, when using the resulting data for analysis, lies in the following: (a) large volumes of hard copy data can now be acquired in an automated manner, saving significant time and effort, (b) specific repair locations are accurately captured, resulting in (c) more reliable, confident, analyses, and results, (d) ongoing problem areas, due to corrosive or creeping soils for example, can be more specifically understood.

A new scour countermeasure using solidified slurry for offshore foundation has been proposed recently. Fluidized solidified slurry is pumped to seabed area around foundation for scour protection or pumped into the developed scour holes for scour repair as the fluidized material solidifies gradually. In the pumping operation and solidification, the engineering behaviors of solidified slurry require to be considered synthetically for the reliable application in scour repair and protection of ocean engineering such as the pumpability related flow value, flow diffusion behavior related rheological property, anti-scour performance related retention rate in solidification and bearing capacity related strength property after solidification. In this study, a series of laboratory tests are conducted to investigate the effects of mix proportion (initial water content and binder content) on the flow value, rheological properties, density, retention rate of solidified slurry and unconfined compressive strength (UCS). The results reveal that the flow value increases with the water content and decreases with the binder amount. All the solidified slurry exhibits Bingham plastic behavior when the shear rate is larger than 5 s-1. The Bingham model has been employed to fit the rheology test results, and empirical formulas for obtaining the density, yield stress and viscosity are established, providing scientific support for the numerical assessment of flow and diffusion of solidified slurry. Retention rate of solidified slurry decreases with the water flow velocity and flow value, which means the pumpability of solidified slurry is contrary to anti-scour performance. The unconfined compressive strength after solidification reduces as the water content increases and binder content decreases. A design and application procedure of solidified soil for scour repair and protection is also proposed for engineering reference.

In recent years, heavy metal pollution has become increasingly prominent, severely damaging ecosystems and biodiversity, and posing a serious threat to human health. However, the results of current methods for heavy metal restoration are not satisfactory, so it is urgent to find a new and effective method. Peptides are the units that make up proteins, with small molecular weights and strong biological activities. They can effectively repair proteins by forming complexes, reducing heavy metal ions, activating the plant's antioxidant defense system, and promoting the growth and metabolism of microorganisms. Peptides show great potential for the remediation of heavy metal contamination due to their special structure and properties. This paper reviews the research progress in recent years on the use of peptides to remediate heavy metal pollution, describes the mechanisms and applications of remediation, and provides references for the remediation of heavy metal pollution.

The properties of a large number of concrete infrastructures in China are deteriorating year by year, raising the need for repairing and strengthening these infrastructures. By introducing waterborne polymers into a cement concrete system, brittle cracks and easy bonding performance defects of concrete can be compensated for to form a long-life, semi rigid, waterborne polymer-modified cementitious repair material with a promising development prospect. This paper investigates the modification effect of polymer emulsions on ordinary cement mortar. Our research mainly focused on the physical and mechanical properties, durability, microstructure and application status of waterborne polymer-modified cementitious composites. Literature studies show that with the increase in waterborne polymer content (0 wt%similar to 20 wt%), the performance of cement mortar significantly improves, which in turn expands its application range. Compared with ordinary cement mortar, the introduction of waterborne polymers blocks some of the pores in the cement to a certain extent, thus improving its permeability, freeze-thaw resistance and durability. Finally, this paper describes the application of waterborne polymer-cementitious composites in western saline soil environments, as well as discusses the prospects of their development.

This research aims to estimate the expected economic losses associated with the repair cost of a set of codecompliant moment-resisting reinforced concrete buildings located on different soil conditions in Mexico City. The loss assessment methodology is based on the second generation of the Performance-Based Earthquake Engineering (PBEE) framework, which quantifies the seismic performance of buildings in terms of metrics such as economic losses, downtime, and casualties, which are more meaningful to owners and stakeholders for the decision-making process. The methodology uses a probabilistic approach that takes into account uncertainties in seismic intensity, structural response, component damage, and consequence prediction. The seismic response of structures was calculated in terms of inter-story drifts and floor accelerations to assess the damage to their structural and non-structural components. In addition, taking into account the seismic hazard of the site, the expected annual losses (EAL) are calculated to provide insight into the seismic performance evaluation of structures with different characteristics in terms of the financial impact in seismic-prone regions like Mexico City.

The mechanism of perchlorate resistance of the desert cyanobacterium Chroococcidiopsis sp. CCMEE 029 was investigated by assessing whether the pathways associated with its desiccation tolerance might play a role against the destabilizing effects of this chaotropic agent. During 3 weeks of growth in the presence of 2.4 mM perchlorate, an upregulation of trehalose and sucrose biosynthetic pathways was detected. This suggested that in response to the water stress triggered by perchlorate salts, these two compatible solutes play a role in the stabilization of macromolecules and membranes as they do in response to dehydration. During the perchlorate exposure, the production of oxidizing species was observed by using an oxidant-sensing fluorochrome and determining the expression of the antioxidant defense genes, namely superoxide dismutases and catalases, while the presence of oxidative DNA damage was highlighted by the over-expression of genes of the base excision repair. The involvement of desiccation-tolerance mechanisms in the perchlorate resistance of this desert cyanobacterium is interesting since, so far, chaotropic-tolerant bacteria have been identified among halophiles. Hence, it is anticipated that desert microorganisms might possess an unrevealed capability of adapting to perchlorate concentrations exceeding those naturally occurring in dry environments. Furthermore, in the endeavor of supporting future human outposts on Mars, the identified mechanisms might contribute to enhance the perchlorate resistance of microorganisms relevant for biologically driven utilization of the perchlorate-rich soil of the red planet.

The primary objective of current seismic design codes is to ensure the life safety of building occupants under extreme seismic events. These codes normally permit structural and nonstructural damage during a design-level earthquake, leading to the possibility of significant economic losses and recovery time for the building. Recovery time is a significant factor in the seismic performance of buildings because it affects not only the owner and users of a building, but also the overall recovery of the community. In designing low-rise buildings, current design requirements in different jurisdictions can produce footings with vastly different sizes, which can significantly affect building performance. Therefore, there is a need to investigate the effects of footing size on the expected recovery time of low-rise buildings. In this study, 2-storey concentrically braced frame buildings at a site class D are selected to evaluate the impact of the size of the footings on the repair time of low-rise buildings. These buildings are in Vancouver, Canada, and have X-bracing systems. The buildings are modelled in OpenSees using an advanced numerical model. Nonlinear response history analysis is performed employing a set of ground motions that match the soil condition of the site. The recovery time is estimated, including the delay time to start repairs and the time required to repair the damaged members. The findings of this study suggest that not capacity-protected (NCP) footings (i.e., rocking foundations) could be the preferred choice for short-period CBF buildings on soft soil.

Mount Everest provides natural advantages to finding radiation-resistant extremophiles that are functionally mechanistic and possess commercial significance. (1) Background: Two bacterial strains, designated S5-59T and S8-45T, were isolated from moraine samples collected from the north slope of Mount Everest at altitudes of 5700m and 5100m above sea level. (2) Methods: The present study investigated the polyphasic features and genomic characteristics of S5-59(T) and S8-45(T). (3) Results: The major fatty acids and the predominant respiratory menaquinone of S5-59(T) and S8-45(T) were summed as feature 3 (comprising C16:1 omega 6c and/or C16:1 omega 7c) and ubiquinone-10 (Q-10). Phylogenetic analyses based on 16S rRNA sequences and average nucleotide identity values among these two strains and their reference type strains were below the species demarcation thresholds of 98.65% and 95%. Strains S5-59(T) and S8-45(T) harbored great radiation resistance. The genomic analyses showed that DNA damage repair genes, such as mutL, mutS, radA, radC, recF, recN, etc., were present in the S5-59(T) and S8-45(T) strains. Additionally, strain S5-59(T) possessed more genes related to DNA protection proteins. The pan-genome analysis and horizontal gene transfers revealed that strains of Sphingomonas had a consistently homologous genetic evolutionary radiation resistance. Moreover, enzymatic antioxidative proteins also served critical roles in converting ROS into harmless molecules that resulted in resistance to radiation. Further, pigments and carotenoids such as zeaxanthin and alkylresorcinols of the non-enzymatic antioxidative system were also predicted to protect them from radiation. (4) Conclusions: Type strains S5-59(T) (=JCM 35564T =GDMCC 1.3193T) and S8-45(T) (=JCM 34749T =GDMCC 1.2715T) represent two novel species of the genus Sphingomonas with the proposed name Sphingomonas qomolangmaensis sp. nov. and Sphingomonas glaciei sp. nov. The type strains, S5-59(T) and S8-45(T), were assessed in a deeply genomic study of their radiation-resistant mechanisms and this thus resulted in a further understanding of their greater potential application for the development of anti-radiation protective drugs.