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Phosphorus (P) is a vital element in biological molecules, and one of the main limiting elements for biomass production as plant-available P represents only a small fraction of total soil P. Increasing global food demand and modern agricultural consumption of P fertilizers could lead to excessive inputs of inorganic P in intensively managed croplands, consequently rising P losses and ongoing eutrophication of surface waters. Despite phosphate solubilizing microorganisms (PSMs) are widely accepted as eco-friendly P fertilizers for increasing agricultural productivity, a comprehensive and deeper understanding of the role of PSMs in P geochemical processes for managing P deficiency has received inadequate attention. In this review, we summarize the basic P forms and their geochemical and biological cycles in soil systems, how PSMs mediate soil P biogeochemical cycles, and the metabolic and enzymatic mechanisms behind these processes. We also highlight the important roles of PSMs in the biogeochemical P cycle and provide perspectives on several environmental issues to prioritize in future PSM applications.

Crude oil contamination occurs frequently in soil; thus, on-site measurement of oil content is critical for controlling petroleum contamination, but it is challenging. Conventional chemical analysis requires complicated sample pretreatment and high-cost facilities, requiring on-site and cost-effective approaches. This study innovated a whole-cell bioreporter assay by combining Acinetobacter-hosted n-alkane and genotoxicity bioreporters to directly and simultaneously evaluate the contamination level and genotoxicities of crude oil in contaminated soils. Ultrasound pretreatment was employed to accelerate the measurement process, and the first-order release kinetic model was used to calculate crude oil content in an easy operation. The detection limit of the bioreporters was satisfactory at 0.1 mg/L, and the quantification range was 0.1–10 mg/L. The developed bioreporter assay effectively assessed the bioavailability and toxicity of crude oil in real contaminated soils and recognized distinct toxicities after soil weathering. Our findings highlight the feasibility of using the whole-cell bioreporter assay to evaluate the bioavailability and toxicity of crude oil, offering supporting data for the selection of remediation strategies.

In this work we describe a theoretical model that predicts the interfacial contact stiffness of fractal rough surfaces by considering the effects of elastic and plastic deformations of the fractal asperities. We also develop an original test rig that simulates dovetail joints for turbo machinery blades, which can fine tune the normal contact load existing between the contacting surfaces of the blade root. The interfacial contact stiffness is obtained through an inverse identification method in which finite element simulations are fitted to the experimental results. Excellent agreement is observed between the contact stiffness predicted by the theoretical model and by the analogous experimental results. We demonstrate that the contact stiffness is a power law function of the normal contact load with an exponent α within the whole range of fractal dimension D (1 <  D  < 2). We also show that for 1 <  D  < 1.5 the Pohrt-Popov behavior ( α  = 1/(3 −  D )) is valid, however for 1.5 <  D  < 2, the exponent α is different and equal to 2( D  − 1)/ D . The diversity between the model developed in the work and the Pohrt-Popov one is explained in detail.

Cd is one of the potential toxic elements (PTEs) exerting great threats on the environment and living organisms and arising extensive attentions worldwide. Sedum alfredii Hance, a Cd hyperaccumulator, is of great importance in studying the mechanisms of Cd hyperaccumulation and has potentials for phytoremediation. ATP-binding cassette sub-family C (ABCC) belongs to the ABC transporter family, which is deemed to closely associate with multiple physiological processes including cellular homeostasis, metal detoxification, and transport of metabolites. In the present work, ten ABCC proteins were identified in S. alfredii Hance, exhibiting uniform domain structure and divergently clustering with those from Arabidopsis . Tissue-specific expression analysis indicated that some SaABCC genes had significantly higher expression in roots ( Sa23221 and Sa88F144 ), stems ( Sa13F200 and Sa14F98 ) and leaves ( Sa13F200 ). Co-expression network analysis using these five SaABCC genes as hub genes produced two clades harboring different edge genes. Transcriptional expression profiles responsive to Cd illustrated a dramatic elevation of Sa14F190 and Sa18F186 genes. Heterologous expression in a Cd-sensitive yeast cell line, we confirmed the functions of Sa14F190 gene encoding ABCC in Cd accumulation. Our study performed a comprehensive analysis of ABCCs in S. alfredii Hance, firstly mapped their tissue-specific expression patterns responsive to Cd stress, and characterized the roles of Sa14F190 genes in Cd accumulation.

Spectroscopic techniques such as Fourier-transform infrared (FTIR) spectroscopy are used to study interactions of light with biological materials. This interaction forms the basis of many analytical assays used in disease screening/diagnosis, microbiological studies, and forensic/environmental investigations. Advantages of spectrochemical analysis are its low cost, minimal sample preparation, non-destructive nature and substantially accurate results. However, an urgent need exists for repetition and validation of these methods in large-scale studies and across different research groups, which would bring the method closer to clinical and/or industrial implementation. For this to succeed, it is important to understand and reduce the effect of random spectral alterations caused by inter-individual, inter-instrument and/or inter-laboratory variations, such as variations in air humidity and CO2 levels, and aging of instrument parts. Thus, it is evident that spectral standardization is critical to the widespread adoption of these spectrochemical technologies. By using calibration transfer procedures, in which the spectral response of a secondary instrument is standardized to resemble the spectral response of a primary instrument, different sources of variation can be normalized into a single model using computational-based methods, such as direct standardization (DS) and piecewise direct standardization (PDS); therefore, measurements performed under different conditions can generate the same result, eliminating the need for a full recalibration. Here, we have constructed a protocol for model standardization using different transfer technologies described for FTIR spectrochemical applications. This is a critical step toward the construction of a practical spectrochemical analysis model for daily routine analysis, where uncertain and random variations are present.The aim of this spectral standardization model is to expedite multicenter studies with large numbers of samples. The protocol covers sample preparation, acquisition of FTIR spectra, data preprocessing and model standardization.

Microorganisms responsible for the degradation of phenanthrene in a clean forest soil sample were identified by DNA-based stable isotope probing (SIP). The soil was artificially amended with either 12C- or 13C-labeled phenanthrene, and soil DNA was extracted on days 3, 6 and 9. Terminal restriction fragment length polymorphism (TRFLP) results revealed that the fragments of 219- and 241-bp in HaeIII digests were distributed throughout the gradient profile at three different sampling time points, and both fragments were more dominant in the heavy fractions of the samples exposed to the 13C-labeled contaminant. 16S rRNA sequencing of the 13C-enriched fraction suggested that Acidobacterium spp. within the class Acidobacteria, and Collimonas spp. within the class Betaproteobacteria, were directly involved in the uptake and degradation of phenanthrene at different times. To our knowledge, this is the first report that the genus Collimonas has the ability to degrade PAHs. Two PAH-RHDα genes were identified in 13C-labeled DNA. However, isolation of pure cultures indicated that strains of Staphylococcus sp. PHE-3, Pseudomonas sp. PHE-1, and Pseudomonas sp. PHE-2 in the soil had high phenanthrene-degrading ability. This emphasizes the role of a culture-independent method in the functional understanding of microbial communities in situ.

Guided wave Electro Magnetic Acoustic Transducers (EMATs) offer an elegant method for structural inspection and localisation relative to geometric features, such as welds. This paper presents a Lorentz force EMAT construction framework, where a numerical model has been developed for optimising Printed Circuit Board (PCB) coil parameters as well as a methodology for optimising magnet array parameters to a user’s needs. This framework was validated experimentally to show its effectiveness through comparison to an industry built EMAT. The framework was then used to design and manufacture a Side-Shifted Unidirectional Periodic Permanent Magnet (PPM) EMAT for use on a mobile robotic system, which uses guided waves for ranging to build internal maps of a given subject, identifying welded sections, defects and other structural elements. The unidirectional transducer setup was shown to operate in simulation and was then manufactured to compare to the bidirectional transmitter and two-receiver configurations on a localisation system. The unidirectional setup was shown to have clear benefits over the bidirectional setup for mapping an unknown environment using guided waves as there were no dead spots of mapping where signal direction could not be interpreted. Additionally, overall package size was significantly reduced, which in turn allows more measurements to be taken within confined spaces and increases robotic crawler mobility.

With the advent of a new era for health and medical treatment, characterized by the integration of mobile technology, a significant digital divide has surfaced, particularly in the engagement of older individuals with mobile health (mHealth). The health of a family is intricately connected to the well-being of its members, and the use of media plays a crucial role in facilitating mHealth care. Therefore, it is important to examine the mediating role of media use behavior in the connection between the family health of older individuals and their inclination to use mHealth devices. This study aims to investigate the impact of family health and media use behavior on the intention of older individuals to use mHealth devices in China. The study aims to delve into the intricate dynamics to determine whether media use behavior serves as a mediator in the relationship between family health and the intention to use mHealth devices among older adults. The ultimate goal is to offer well-founded and practical recommendations to assist older individuals in overcoming the digital divide. The study used data from 3712 individuals aged 60 and above, sourced from the 2022 Psychology and Behavior Investigation of Chinese Residents study. Linear regression models were used to assess the relationships between family health, media use behavior, and the intention to use mHealth devices. To investigate the mediating role of media use behavior, we used the Sobel-Goodman Mediation Test. This analysis focused on the connection between 4 dimensions of family health and the intention to use mHealth devices. A positive correlation was observed among family health, media use behavior, and the intention to use mHealth devices (r=0.077-0.178, P<.001). Notably, media use behavior was identified as a partial mediator in the relationship between the overall score of family health and the intention to use mHealth devices, as indicated by the Sobel test (z=5.451, P<.001). Subgroup analysis further indicated that a complete mediating effect was observed specifically between family health resources and the intention to use mHealth devices in older individuals with varying education levels. The study revealed the significance of family health and media use behavior in motivating older adults to adopt mHealth devices. Media use behavior was identified as a mediator in the connection between family health and the intention to use mHealth devices, with more intricate dynamics observed among older adults with lower education levels. Going forward, the critical role of home health resources must be maximized, such as initiatives to develop digital education tailored for older adults and the creation of media products specifically designed for them. These measures aim to alleviate technological challenges associated with using media devices among older adults, ultimately bolstering their inclination to adopt mHealth devices.

Background Bacteria from the genus Polaromonas are dominant phylotypes found in a variety of low-temperature environments in polar regions. The diversity and biogeographic distribution of Polaromonas have been largely expanded on the basis of 16 S rRNA gene amplicon sequencing. However, the evolution and cold adaptation mechanisms of Polaromonas from polar regions are poorly understood at the genomic level. Results A total of 202 genomes of the genus Polaromonas were analyzed, and 121 different species were delineated on the basis of average nucleotide identity (ANI) and phylogenomic placements. Remarkably, 8 genomes recovered from polar environments clustered into a separate clade (‘polar group’ hereafter). The genome size, coding density and coding sequences (CDSs) of the polar group were significantly different from those of other nonpolar Polaromonas . Furthermore, the enrichment of genes involved in carbohydrate and peptide metabolism was evident in the polar group. In addition, genes encoding proteins related to betaine synthesis and transport were increased in the genomes from the polar group. Phylogenomic analysis revealed that two different evolutionary scenarios may explain the adaptation of Polaromonas to cold environments in polar regions. Conclusions The global distribution of the genus Polaromonas highlights its strong adaptability in both polar and nonpolar environments. Species delineation significantly expands our understanding of the diversity of the Polaromonas genus on a global scale. In this study, a polar-specific clade was found, which may represent a specific ecotype well adapted to polar environments. Collectively, genomic insight into the metabolic diversity, evolution and adaptation of the genus Polaromonas at the genome level provides a genetic basis for understanding the potential response mechanisms of Polaromonas to global warming in polar regions.

Rotor systems installed in a transportation system or under seismic excitations are considered to have a moving base. Although extensive research has been conducted on the dynamic behavior of the single-rotor system under base motions, few studies have dealt with the dynamics of dual-rotor systems, especially the counter-rotating dual-rotor systems used in airplane engines. Moreover, mass unbalance and gravity are unavoidable excitations for most rotor systems. Therefore, the vibration properties of a counter-rotating dual-rotor system with the coupled effects of base motions, mass unbalance and gravity are investigated in this paper for the first time. Using the Lagrange principle associated with the finite element method, a general model for dual-rotor systems under base motions was established by using Timoshenko beam elements, leading to a detailed analysis of the natural properties and harmonic responses of the system. The results revealed that different whirling modes (backward, forward or both) may be mutually excited. This research can be helpful for the design and vibration analysis of dual-rotor systems concerned with base motion.