Genetic distribution, characterization, and function of Escherichia coli type III secretion system 2 (ETT2).

Many Gram-negative bacteria use type Ⅲ secretion system (T3SS) to inject effector proteins and subvert host signaling pathways, facilitating the growth, survival, and virulence. Notably, some bacteria harbor multiple distinct T3SSs with different functions. An extraordinary T3SS, the Escherichia coli Type III Secretion System 2 (ETT2), is widespread among Escherichia coli (E. coli) strains. Since many ETT2 carry genetic mutations or deletions, it is thought to be nonfunctional. However, increasing studies highlight ETT2 contributes to E. coli pathogenesis. Here, we present a comprehensive overview of genetic distribution and characterization of ETT2. Subsequently, we outline its functional potential, contending that an intact ETT2 may retain the capacity to translocate effector proteins and manipulate the host's innate immune response. Given the potential zoonotic implications associated with ETT2-carrying bacteria, further investigations into the structure, function and regulation of ETT2 are imperative for comprehensive understanding of E. coli pathogenicity and the development of effective control strategies.

Photothermal Properties and Solar Water Evaporation Performance of Lignin-Based Polyurethane Foam Composites.

Solar interfacial evaporation is the most promising route for desalination because it is highly efficient, affordable and offers green energy. Polyurethane foam (PUF) is an ideal substrate material for efficient solar water evaporation because of its low thermal conductivity, affordability, and high efficiency for continuous water transport. However, PUF exhibits poor mechanical properties after water absorption and expansion, and lacks the photothermal conversion effect. In this study, biorefinery lignin with efficient photothermal properties was introduced to prepare functional lignin-based PUF (LPUF), and the relationship between the molecular structure of fractioned lignin and the solar water evaporation performance was systematically investigated. The addition of lignin effectively enhanced the mechanical properties of LPUF after water absorption and swelling, and imparted the foam with a photothermal conversion effect. The water evaporation rate of LPUF was as high as 2.58 kg m-2 h-1 and could be further improved to more than 3.0 kg m-2 h-1 after loading polyaniline (PANI) on the surface of LPUF. LPUF-PANI exerted an excellent purification effect on dye wastewater with outstanding long-term stability, providing a potential solution for ecofriendly and sustainable economic production of fresh water. This study broadens the effective utilization of LPUF bulk materials in the fields of energy and environment.

Impact of altitude on the dosage of indoor particulates entering an individual's small airways.

The complexity of indoor particulate exposure intensifies at higher altitudes owing to the increased lung capacity that residents develop to meet the higher oxygen demands. Altitude variations impact atmospheric pressure and alter particulate dynamics in ambient air and the human respiratory tract, complicating particulate inhalation. This study assessed the fraction of PM2.5 and PM10 entering small airways. This assessment covered an altitude range from 400 m above sea level to 3650 m, and an in vitro respiratory tract model was used. The experimental results confirmed that with increasing altitude, the penetration fractions of PM2.5 and PM10 significantly increased from 0.133 ± 0.031 and 0.141 ± 0.045 to 0.404 ± 0.159 and 0.353 ± 0.132, respectively. Additionally, the computational fluid dynamics simulation results revealed that among particles with sizes of 0.1 to 10 µm, the 7.5-µm particles exhibited the most substantial reduction in deposition in the upper airway, displaying a decrease of 6.27%. Our findings underscore the health risks faced by low-altitude residents during acclimatization to higher altitudes, as they experience heightened exposure to particulate matter sources.

Analysis of mandibular asymmetry in adolescent and adult patients with unilateral posterior crossbite on cone-beam computed tomography.

INTRODUCTION: This study aimed to evaluate mandibular asymmetry in unilateral posterior crossbite (UPXB) patients and compare the asymmetry between adolescents and adults with UPXB. METHODS: This study included and analyzed cone-beam computed tomography scans of 125 subjects. The subjects were divided into a UPXB group and a control group according to the presence or absence of UPXB, and each group included adolescent patients (aged 10-15 years) and adult patients (aged 20-40 years). Linear, angular, and volumetric measurements were obtained to evaluate the asymmetries of the mandibles. RESULTS: Both adolescent and adult patients in the UPXB group presented asymmetries in condylar unit length, ramal height, body length, and mediolateral ramal inclination (P <0.05). Adult patients with UPXB showed greater asymmetries than adolescents. Differences with condylar unit length, condylar unit width, ramal height, condylar unit volume, and hemimandibular volume were significantly greater in adult UPXB patients than adolescent UPXB patients (P <0.05). CONCLUSIONS: The worsening of mandibular asymmetries in UPXB adults suggests that asymmetry in UPXB patients may progress over time; therefore, early treatment should be considered for UPXB adolescent patients. Further studies are still needed to evaluate the effectiveness of early treatment.

A lytic phage to control multidrug-resistant avian pathogenic Escherichia coli (APEC) infection.

The inappropriate use of antibiotics has led to the emergence of multidrug-resistant strains. Bacteriophages (phages) have gained renewed attention as promising alternatives or supplements to antibiotics. In this study, a lytic avian pathogenic Escherichia coli (APEC) phage designated as PEC9 was isolated and purified from chicken farm feces samples. The morphology, genomic information, optimal multiplicity of infection (MOI), one-step growth curve, thermal stability, pH stability, in vitro antibacterial ability and biofilm formation inhibition ability of the phage were determined. Subsequently, the therapeutic effects of the phages were investigated in the mice model. The results showed that PEC9 was a member of the siphovirus-like by electron microscopy observation. Biological characterization revealed that it could lyse two serotypes of E. coli, including O1 (9/20) and O2 (6/20). The optimal multiplicity of infection (MOI) of phage PEC9 was 0.1. Phage PEC9 had a latent period of 20 min and a burst period of 40 min, with an average burst size of 68 plaque-forming units (PFUs)/cell. It maintained good lytic activity at pH 3-11 and 4-50°C and could efficiently inhibit the bacterial planktonic cell growth and biofilm formation, and reduce bacterial counts within the biofilm, when the MOI was 0.01, 0.1, and 1, respectively. Whole-genome sequencing showed that PEC9 was a dsDNA virus with a genome of 44379 bp and GC content of 54.39%. The genome contains 56 putative ORFs and no toxin, virulence, or resistance-related genes were detected. Phylogenetic tree analysis showed that PEC9 is closely related to E. coli phages vB_EcoS_Zar3M, vB_EcoS_PTXU06, SECphi18, ZCEC10, and ZCEC11, but most of these phages exhibit different gene arrangement. The phage PEC9 could successfully protect mice against APEC infection, including improved survival rate, reduced bacterial loads, and organ lesions. To conclude, our results suggest that phage PEC9 may be a promising candidate that can be used as an alternative to antibiotics in the control of APEC infection.

Fluid-structure interaction analysis of airflow, structural mechanics and aerosol dynamics in a four-generation acinar model.

Elucidating the aerosol dynamics in the pulmonary acinar region is imperative for both health risk assessment and inhalation therapy, especially nowadays with the occurrence of the global COVID-19 pandemic. During respiration, the chest's outward elastic recoil and the lungs' inward elastic recoil lead to a change of transmural pressure, which drives the lungs to expand and contract to inhale and expel airflow and aerosol. In contrast to research using predefined wall motion, we developed a four-generation acinar model and applied an oscillatory pressure on the model outface to generate structure deformation and airflow. With such tools at hand, we performed a computational simulation that addressed both the airflow characteristic, structural mechanics, and aerosol dynamics in the human pulmonary acinar region. Our results showed that there is no recirculating flow in the sac. The structural displacement and stress were found to be positively related to the change of model volume and peaked at the end of inspiration. It was noteworthy that the stress distribution on the acinar wall was significantly heterogeneous, and obvious concentrations of stress were found at the junction of the alveoli and the ducts or the junction of the alveoli and alveoli in the sac. Our result demonstrated the effect of breathing cycles and aerosol diameter on deposition fraction and location of aerosols in the size range of 0.1-5 µm. Multiple respiratory cycles were found necessary for adequate deposition or escape of submicron particles while having a negligible influence on the transport of large particles, which were dominated by gravity. Our study can provide new insights into the further investigation of airflow, structural mechanics, and aerosol dynamics in the acinar depth.

Experimental Investigation on the Low-Velocity Impact Response of Tandem Nomex Honeycomb Sandwich Panels.

Sandwich panels are often subjected to unpredictable impacts and crashes in applications. The core type and impactor shape affect their impact response. This paper investigates the responses of five tandem Nomex honeycomb sandwich panels with different core-types under low-velocity-impact conditions with flat and hemispherical impactors. From the force response and impact displacement, gradient-tandem and foam-filled structures can improve the impact resistance of sandwich panels. Compared with the single-layer sandwich panel, the first peak of contact force of the foam-gradient-filled tandem honeycomb sandwich panels increased by 34.84%, and maximum impact displacement reduced by 50.98%. The resistance of gradient-tandem Nomex honeycomb sandwich panels under low-velocity impact outperformed uniform-tandem structures. Foam-filled structures change the impact responses of the tandem sandwich panels. Impact damage with a flat impactor was more severe than the hemispherical impactor. The experimental results are helpful in the design of tandem Nomex honeycomb sandwich panels.

Characteristics, pathogenic mechanism, zoonotic potential, drug resistance, and prevention of avian pathogenic Escherichia coli (APEC).

Although most Escherichia coli (E. coli) strains are commensal and abundant, certain pathogenic strains cause severe diseases from gastroenteritis to extraintestinal infections. Extraintestinal pathogenic E. coli (ExPEC) contains newborn meningitis E. coli (NMEC), uropathogenic E. coli (UPEC), avian pathogenic E. coli (APEC), and septicemic E. coli (SEPEC) based on their original host and clinical symptom. APEC is a heterogeneous group derived from human ExPEC. APEC causes severe respiratory and systemic diseases in a variety of avians, threatening the poultry industries, food security, and avian welfare worldwide. APEC has many serotypes, and it is a widespread pathogenic bacterium in poultry. In addition, ExPEC strains share significant genetic similarities and similar pathogenic mechanisms, indicating that APEC potentially serves as a reservoir of virulence and resistance genes for human ExPEC, and the virulence and resistance genes can be transferred to humans through food animals. Due to economic losses, drug resistance, and zoonotic potential, APEC has attracted heightened awareness. Various virulence factors and resistance genes involved in APEC pathogenesis and drug resistance have been identified. Here, we review the characteristics, epidemiology, pathogenic mechanism zoonotic potential, and drug resistance of APEC, and summarize the current status of diagnosis, alternative control measures, and vaccine development, which may help to have a better understanding of the pathogenesis and resistance of APEC, thereby reducing economic losses and preventing the spread of multidrug-resistant APEC to humans.

An evaluation method for product design solutions for healthy aging companionship.

Background: With the development trend of healthy aging and intelligent integration, escort products have become a new means of healthy aging. Healthy old-age care pays attention to the convenience and informatization of life. To meet the needs, designers often design multiple accompanying product solutions, and it is very important to use reasonable evaluation methods to decide on the optimal solution. Purposes: A new comprehensive evaluation method is proposed to reduce the subjectivity and one-sidedness of the selection process of intelligent escort product design solutions, and to make the decision more objective and reasonable. Such decisions can enhance the experience and naturalness of the elderly using intelligent products. Methods: First, a large number of user interviews were analyzed using the grounded theory, gradually refine through theoretical coding, and abstracted with the design scheme evaluation index. Second, the idea of game-theoretic weighting is used to optimize a linear combination of subjective and objective weights to determine the final weights of each evaluation indicator. Finally, the evaluation and selection are completed based on the solution ranking determined by the approximate ideal solution ranking method (TOPSIS). It is applied for the selection of the elderly escort robot design, and the usability test is conducted using the PSSUQ to verify the selection results. Results: A new comprehensive evaluation method can better complete the preferential selection of product design solutions for healthy aging escorts, and reduce the subjectivity and one-sidedness of the evaluation. Conclusion: This method compensates for the reliance on personal experience in the selection of options, and improve the subjectivity of the evaluation index determination process and the deviation of index weighting. Improving the objectivity and scientificity of decision-making reduces the blindness of design and production. It also provides a theoretical reference for the research scholars of healthy aging companion products.

Successive organic solvent fractionation and homogenization of technical lignin for polyurethane foam with high mechanical performance.

This work demonstrates an organic solvent fractionation method for lignin homogenization, which can effectively reduce the lignin heterogeneity and use each lignin fraction to prepare polyurethane foams (PUFs) with excellent mechanical properties. Such fractions were fully characterized by GPC, NMR (31P, 2D-HSQC), FTIR, and TG to obtain a detailed description of the structures and properties. The properties of PUFs from each lignin fraction showed higher compatibility than that from unfractionated industrial lignin, as studied by morphology and DSC analysis. The improvement of compatibility between the fractionated lignin fractions and polyethylene glycol can effectively enhance the mechanical properties of the prepared PUFs. The hysteresis loss (43.10%-51.85%) and resilience (95.81%-98.81%) of the fractionated lignin polyurethane foams (LPUFs) were better than that from the unfractionated LPUFs (hysteresis loss 41.64%, resilience 94.67%) at the lignin content of 5%. Subsequently, the strong relationships between lignin structures and PUF properties were demonstrated in detail. The suggested approach provides greater possibilities to prepare LPUFs with tunable properties based on real industrial lignin fractions, rather than modified lignin.

Adolescents' Algorithmic Resistance to Short Video APP's Recommendation: The Dual Mediating Role of Resistance Willingness and Resistance Intention.

Adolescents have gradually become a vital group of interacting with social media recommendation algorithms. Although numerous studies have been conducted to investigate negative reactions (both psychological and behavioral reactance) that the dark side of recommendation algorithms brings to social media users, little is known about the resistance intention and behavior based on their agency in the daily process of encountering algorithms. Focusing on the concept of algorithm resistance, this study used a two-path model (distinguishing resistance willingness and resistance intention) to investigate the algorithmic resistance of rural Chinese adolescents (N = 905) in their daily use of short video apps. The findings revealed that the perceived threat to freedom, algorithmic literacy, and peer influence were positively associated with the resistance willingness and intention; while the independent psychology on algorithmic recommendations significantly weakened resistance willingness and intention. Furthermore, this study verified the mediating role of resistance willingness and intention between the above independent variables and resistance behavior. Additionally, the positive impact of resistance willingness on resistance intention was confirmed. In conclusion, this study offers a comprehensive approach to further understanding adolescents' algorithmic resistance awareness and behavior by combining psychological factors, personal competency, and interpersonal influences, as well as two types of resistance reactions (rational and irrational).

Visualization of the infection risk assessment of SARS-CoV-2 through aerosol and surface transmission in a negative-pressure ward.

Since December 2019, coronavirus disease (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has become a great challenge to the world's public health system. Nosocomial infections have occurred frequently in medical institutions worldwide during this pandemic. Thus, there is an urgent need to construct an effective surveillance and early warning system for pathogen exposure and infection to prevent nosocomial infections in negative-pressure wards. In this study, visualization and construction of an infection risk assessment of SARS-CoV-2 through aerosol and surface transmission in a negative-pressure ward were performed to describe the distribution regularity and infection risk of SARS-CoV-2, the critical factors of infection, the air changes per hour (ACHs) and the viral variation that affect infection risk. The SARS-CoV-2 distribution data from this model were verified by field test data from the Wuhan Huoshenshan Hospital ICU ward. ACHs have a great impact on the infection risk from airborne exposure, while they have little effect on the infection risk from surface exposure. The variant strains demonstrated significantly increased viral loads and risks of infection. The level of protection for nurses and surgeons should be increased when treating patients infected with variant strains, and new disinfection methods, electrostatic adsorption and other air purification methods should be used in all human environments. The results of this study may provide a theoretical reference and technical support for reducing the occurrence of nosocomial infections.