Controlled Synthesis of MOF-Derived Nano-Microstructure toward Lightweight and Wideband Microwave Absorption.

Correlating metal-organic framework (MOF) synthesis processes and microwave absorption (MA) enhancement mechanisms is a pioneer project. Nevertheless, the correlation process still relies mainly on empirical doctrine, which hardly corresponds to the specific mechanism of the effect on the dielectric properties. Hereby, after the strategy of modulation of protonation engineering and solvothermal temperature in the synthesis route, the obtained sheet-like self-assembled nanoflowers were constructed. Porous structures with multiple heterointerfaces, abundant defects, and vacancies are obtained by controlled design of the synthesis procedure. The rearrangement of charges and enhanced polarization can be promoted. The designed electromagnetic properties and special nano-microstructures of functional materials have significant impact on their electromagnetic wave energy conversion effects. As a consequence, the MA performance of the samples has been enhanced toward broadband absorption (6.07 GHz), low thickness (2.0 mm), low filling (20%), and efficient loss (-25 dB), as well as being suitable for practical environmental applications. This work establishes the connection between the MOF-derived materials synthesis process and the MA enhancement mechanism, which provides insight into various microscopic microwave loss mechanisms.

Printable two-dimensional superconducting monolayers.

Two-dimensional superconductor (2DSC) monolayers with non-centrosymmetry exhibit unconventional Ising pair superconductivity and an enhanced upper critical field beyond the Pauli paramagnetic limit, driving intense research interest. However, they are often susceptible to structural disorder and environmental oxidation, which destroy electronic coherence and provide technical challenges in the creation of artificial van der Waals heterostructures (vdWHs) for devices. Herein, we report a general and scalable synthesis of highly crystalline 2DSC monolayers via a mild electrochemical exfoliation method using flexible organic ammonium cations solvated with neutral solvent molecules as co-intercalants. Using NbSe2 as a model system, we achieved a high yield (>75%) of large-sized single-crystal monolayers up to 300 µm. The as-fabricated, twisted NbSe2 vdWHs demonstrate high stability, good interfacial properties and a critical current that is modulated by magnetic field when one flux quantum fits to an integer number of moiré cells. Additionally, formulated 2DSC inks can be exploited to fabricate wafer-scale 2D superconducting wire arrays and three-dimensional superconducting composites with desirable morphologies.

OxyR-regulated T6SS functions in coordination with siderophore to resist oxidative stress.

The formation of reactive oxygen species is harmful and can destroy intracellular macromolecules such as lipids, proteins, and DNA, even leading to bacterial death. To cope with this situation, microbes have evolved a variety of sophisticated mechanisms, including antioxidant enzymes, siderophores, and the type VI secretion system (T6SS). However, the mechanism of oxidative stress resistance in Cupriavidus pinatubonensis is unclear. In this study, we identified Reut_A2805 as an OxyR ortholog in C. pinatubonensis, which positively regulated the expression of T6SS1 by directly binding to its operon promoter region. The study revealed that OxyR-regulated T6SS1 combats oxidative stress by importing iron into bacterial cells. Moreover, the T6SS1-mediated outer membrane vesicles-dependent iron acquisition pathway played a crucial role in the oxidative stress resistance process. Finally, our study demonstrated that the T6SS1 and siderophore systems in C. pinatubonensis exhibit different responses in combating oxidative stress under low-iron conditions, providing a comprehensive understanding of how bacterial iron acquisition systems function in diverse conditions.IMPORTANCEThe ability to eliminate reactive oxygen species is crucial for bacterial survival. Continuous formation of hydroperoxides can damage metalloenzymes, disrupt DNA integrity, and even result in cell death. While various mechanisms have been identified in other bacterial species to combat oxidative stress, the specific mechanism of oxidative stress resistance in C. pinatubonensis remains unclear. The importance of this study is that we elucidate the mechanism that OxyR-regulated T6SS1 combats oxidative stress by importing iron with the help of bacterial outer membrane vesicle. Moreover, the study highlights the contrasting responses of T6SS1- and siderophore-mediated iron acquisition systems to oxidative stress. This study provides a comprehensive understanding of bacterial iron acquisition and its role in oxidative stress resistance in C. pinatubonensis under low-iron conditions.

Corrigendum to "Function of N6-Methyladenosine Modification in Tumors".

[This corrects the article DOI: 10.1155/2021/6461552.].

Impact of exercise training on gut microbiome imbalance in obese individuals: a study based on Mendelian randomization analysis.

Objective: The aim of this study was to investigate the relationship between exercise and gut Microbiome and to assess its possible causality. Methods: Using Mendelian randomization (MR) research methods, we collected genetic data from different populations, including genetic variants associated with relative abundance or presence of microbial taxa as instrumental variables. At the same time, we extracted results related to obesity and gut Microbiome from existing relevant studies and used inverse variance weighting (IVW), weighted median, and MR-Egger regression to assess the causal relationship between obesity and gut Microbiome. We plotted forest plots and scatter plots of the association between obesity and gut Microbiome. Results: Gut Microbiome was positively associated with obesity, and four bacterial genera (Akkermansia, RuminococcaceaeUCG011, Holdemania, and Intestinimonas) were associated with obesity according to inverse variance-weighted estimation in at least one MR method. Inverse variance weighted estimation showed that obesity was associated with obesity in Akkermansia (OR = 0.810, 95% CI 0.608-1.079, p = 0.04), RuminococcaceaeUCG011 (OR = 1.238, 95% CI 0. 511-2.999, p = 0.04), Holdemania Intestinimonas (OR = 1.214, 95% CI 1.002-1.470, p = 0.03), and Intestinimonas (OR = 0.747, 95% CI 0.514-1.086, p = 0.01) had a relevant effect. Obesity decreased the abundance of Akkermansia, Intestinimonas microbiome and increased the abundance of RuminococcaceaeUCG011, Holdemania microbiome. Conclusion: The results of this study, conducted using a two-sample Mendelian randomization method, suggest a causal relationship between obesity and intestinal microbiome. Obesity decreased the abundance of Akkermansia, Intestinimonas microbiome and increased the abundance of RuminococcaceaeUCG011, Holdemania microbiome. More randomized controlled trials are necessary to elucidate the protective effects of exercise on gut Microbiome and its unique protective mechanisms.

Giant flexoelectric response of uniformly dispersed BT-PVDF composite films induced by SDS-assisted treatment.

Polymer-ceramic composites are commonly used as flexoelectric films. In existing studies, the flexoelectric effect of composites are generally improved by adjusting the material structures or adding ferroelectric materials. Further improvement of flexoelectric response has encountered a bottleneck. Considering from a new perspective, this study innovatively proposes to prepare the uniformly dispersed BT-PVDF composite films with giant flexoelectric response by surfactant SDS-assisted treatment. According to the engineering applications, tilt sensors have been fabricated with the SDS/BT-PVDF composite films. The prepared tilt sensors can accurately sense the tilt change in a small-angle range (0-10°) between the coaxial connecting parts, the response signal changes significantly (49.25-72.35 mV/°), and the response speed can reach 0.166 s. The research provides a new idea for improving the flexoelectric response and also paves a way for developing tilt sensors through a low-cost, facile, and reliable method, showing potential applications including bending sensing and structural health monitoring.

A Fur-regulated type VI secretion system contributes to oxidative stress resistance and virulence in Yersinia pseudotuberculosis.

The type VI secretion system (T6SS) is a widespread protein secretion apparatus deployed by many Gram-negative bacterial species to interact with competitor bacteria, host organisms, and the environment. Yersinia pseudotuberculosis T6SS4 was recently reported to be involved in manganese acquisition; however, the underlying regulatory mechanism still remains unclear. In this study, we discovered that T6SS4 is regulated by ferric uptake regulator (Fur) in response to manganese ions (Mn2+), and this negative regulation of Fur was proceeded by specifically recognizing the promoter region of T6SS4 in Y. pseudotuberculosis. Furthermore, T6SS4 is induced by low Mn2+ and oxidative stress conditions via Fur, acting as a Mn2+-responsive transcriptional regulator to maintain intracellular manganese homeostasis, which plays important role in the transport of Mn2+ for survival under oxidative stress. Our results provide evidence that T6SS4 can enhance the oxidative stress resistance and virulence for Y. pseudotuberculosis. This study provides new insights into the regulation of T6SS4 via the Mn2+-dependent transcriptional regulator Fur, and expands our knowledge of the regulatory mechanisms and functions of T6SS from Y. pseudotuberculosis.

Ultrathin Al-air batteries by reducing the thickness of solid electrolyte using aerosol jet printing.

Flexible Al-air batteries have great potential in the field of wearable electronic devices. However, how to reduce the thickness of the battery and improve their applicability in wearable applications is still an unresolved thorny problem. Therefore, this article focuses on the strategies to minimize the thickness of the solid electrolyte for flexible Al-air batteries. In this paper, an innovative aerosol jet printing method is used to prepare the ultrathin neutral electrolyte with a thickness of 18.3-74.5 µm. This study discusses the influence of the thickness and ion concentration on the conductance of the electrolyte in detail. The ultrathin electrolyte has been applied to the flexible Al-air battery, and the battery performance has been explored. The cell pack composed of single cells is light and thin, and can successfully drive small electrical equipment. This study provided new ideas for the preparation of ultrathin electrolyte for flexible energy products.

N6-methyladenosine and Neurological Diseases.

N6-methyladenosine (m6A) is a dynamic reversible methylation modification of the adenosine N6 position and is the most common chemical epigenetic modification among mRNA post-transcriptional modifications, including methylation, demethylation, and recognition. Post-transcriptional modification involves multiple protein molecules, including METTL3, METTL14, WTAP, KIAA1429, ALKBH5, YTHDF1/2/3, and YTHDC1/2. m6A-related proteins are expressed in almost all cells. However, the abnormal expression of m6A-related proteins may occur in the nervous system, thereby affecting neuritogenesis, brain volume, learning and memory, memory formation and consolidation, etc., and is implicated in the development of diseases, such as Parkinson's disease, Alzheimer's disease, multiple sclerosis, depression, epilepsy, and brain tumors. This review focuses on the functions of m6A in the development of central nervous system diseases, thus contributing to a deeper understanding of disease pathogenesis and providing potential clinical therapeutic targets for neurological diseases.

Inhibition of Hydrogen Evolution by a Bifunctional Membrane between Anode and Electrolyte of Aluminum-Air Battery.

The hydrogen evolution reaction of the anode is a severe barrier that limits the further commercial application of Al-air batteries. Therefore, this study introduces a bifunctional membrane for the inhibition of hydrogen evolution in Al-air batteries. The reference to Al2O3@PAN as "bifunctional" means that it has both hydrophobic and anti-corrosion functions. Al2O3 can effectively inhibit the migration of hydroxide ions, and PAN is an excellent hydrophobic material. The bifunctional membrane is placed between the aluminum anode and the electrolyte, which can prevent the invasion of excess water and hydroxide ions, thereby inhibiting the hydrogen evolution corrosion of the anode. Electrochemical tests have confirmed that the corrosion inhibition rate of a bifunctional membrane containing 1.82 wt. % Al2O3@PAN is as high as 89.24%. The specific capacity of Al-air batteries containing this membrane can reach 1950 mAh/g, and the utilization rate of the aluminum anode has reached 61.2%, which is helpful in reducing the waste of aluminum resources. The results prove that the bifunctional membrane has excellent anti-corrosion properties. Bifunctional membranes can also be used to prevent the corrosion of metals in other fields.

Function of N6-Methyladenosine Modification in Tumors.

N6-Methyladenosine (m6A) modification is a dynamic and reversible methylation modification at the N6-position of adenosine. As one of the most prevalent posttranscriptional methylation modifications of RNA, m6A modification participates in several mRNA processes, including nuclear export, splicing, translation, and degradation. Some proteins, such as METTL3, METTL14, WTAP, ALKBH5, FTO, and YTHDF1/2/3, are involved in methylation. These proteins are subdivided into writers (METTL3, METTL14, WTAP), erasers (ALKBH5, FTO), and readers (YTHDF1/2/3) according to their functions in m6A modification. Several studies have shown that abnormal m6A modification occurs in tumors, including colorectal cancer, liver cancer, breast cancer, nasopharyngeal carcinoma, and gastric cancer. The proteins for m6A modification are involved in tumor proliferation, angiogenesis, metastasis, immunity, and other processes. Herein, the roles of m6A modification in cancer are discussed, which will improve the understanding of tumorigenesis, as well as the diagnosis, treatment, and prognosis of tumors.

Epstein-Barr Virus and Neurological Diseases.

Epstein-Barr virus (EBV), also known as human herpesvirus 4, is a double-stranded DNA virus that is ubiquitous in 90-95% of the population as a gamma herpesvirus. It exists in two main states, latent infection and lytic replication, each encoding viral proteins with different functions. Human B-lymphocytes and epithelial cells are EBV-susceptible host cells. EBV latently infects B cells and nasopharyngeal epithelial cells throughout life in most immunologically active individuals. EBV-infected cells, free viruses, their gene products, and abnormally elevated EBV titers are observed in the cerebrospinal fluid. Studies have shown that EBV can infect neurons directly or indirectly via infected B-lymphocytes, induce neuroinflammation and demyelination, promote the proliferation, degeneration, and necrosis of glial cells, promote proliferative disorders of B- and T-lymphocytes, and contribute to the occurrence and development of nervous system diseases, such as Alzheimer's disease, Parkinson's disease, multiple sclerosis, acute cerebellar ataxia, meningitis, acute disseminated encephalomyelitis, and brain tumors. However, the specific underlying molecular mechanisms are unclear. In this paper, we review the mechanisms underlying the role of EBV in the development of central nervous system diseases, which could bebeneficial in providing new research ideas and potential clinical therapeutic targets for neurological diseases.

Aerobactin-Mediated Iron Acquisition Enhances Biofilm Formation, Oxidative Stress Resistance, and Virulence of Yersinia pseudotuberculosis.

Aerobactin is a citrate-hydroxamate siderophore that is critical for the virulence of pathogenic enteric bacteria. However, although the aerobactin-producing iucABCD-iutA operon is distributed widely in the genomes of Yersinia species, none of the pathogenic Yersinia spp. was found to produce aerobactin. Here, we showed that the iucABCD-iutA operon in the food-borne enteric pathogen Yersinia pseudotuberculosis YPIII is a functional siderophore system involved in iron acquisition. The expression of the operon was found to be directly repressed by the ferric uptake regulator (Fur) in an iron concentration-dependent manner. In addition, we demonstrated that the aerobactin-mediated iron acquisition contributes to bacterial growth under iron-limited conditions. Moreover, we provided evidence that aerobactin plays important roles in biofilm formation, resistance to oxidative stress, ROS removal, and virulence of Y. pseudotuberculosis. Overall, our study not only uncovered a novel strategy of iron acquisition in Y. pseudotuberculosis but also highlighted the importance of aerobactin in the pathogenesis of Y. pseudotuberculosis.

Directly Electrospun Carbon Nanofibers Incorporated with Mn3O4 Nanoparticles as Bending-Resistant Cathode for Flexible Al-Air Batteries.

Al-air batteries are regarded as potential power source for flexible and wearable devices. However, the traditional cathodes of Al-air batteries are easy to be broken after continuous bending. This is why few Al-air batteries have been tested under the state of dynamic bending so far. Herein, carbon nanofibers incorporated with Mn3O4 catalyst have been prepared as bending-resistant cathodes through direct electrospinning. The cathode assembled in Al-air battery showed excellent electrochemical and mechanical stability. A high specific capacity of 1021 mAh/cm2 was achieved after bending 1000 times, which is 81.7% of that in platform state. This work will facilitate the progress of using Al-air battery in flexible electronics.

Environmentally persistent free radicals in PM2.5: a review.

Environmentally persistent free radicals (EPFRs) are a new class of pollutants that are long-lived in fine particles (PM2.5), i.e., their 1/e lifetime ranges from days to months (or even infinite). They are capable of producing harmful reactive oxygen species such as hydroxyl radicals. The redox cycling of EPFRs is considered as an important pathway for PM2.5 to induce oxidative stress inside the humans, causing adverse health effects such as respiratory and cardiovascular diseases. Consequently, research regarding their toxicity, formation and environmental occurrences in PM2.5 has attracted increasing attentions globally during the past two decades. However, literature data in this field remain quite limited and discrete. Hence, an extensive review is urgently needed to summarize the current understanding of this topic. In this work, we systematically reviewed the analytical methods and environmental occurrences, e.g., types, concentrations, and decay behaviors, as well as possible sources of EPFRs in PM2.5. The types of pretreatment methods, g-values of common EPFRs and categories of decay processes were discussed in detail. Moreover, great efforts were made to revisit the original data of the published works of EPFRs in airborne particulate matter and provided additional useful information for comparison where possible, e.g., their mean and standard deviation of g-values, line widths (ΔH p-p), and concentrations. Finally, possible research opportunities were highlighted to further advance our knowledge of this emerging issue.