Search

Respiratory disease caused by the presence of bacteria in the atmosphere seriously threatens human health. Air pollution as harmful suspended particles, like haze, is conducive to bacterial spread and growth; it must be prevented to avoid harming the respiratory tract. Herein, filtration membranes possessing superior antibacterial activity are considered as an effective means to protect humans from atmospheres contaminated with bacteria. The aim of this study is to prepare an environmentally friendly and biodegradable multifunctional biopolymer composite nanofibrous membrane, which can be used as a candidate material for air filtration applications. Since traditional air filtration materials do not degrade in the natural environment, we synthesized a nanofibrous membrane composed of gelatin (GT) and silk fibroin (SF), in which antibacterial agent can anchor via electrostatic spinning. Also, both GT and SF can break down in the natural environment, which avoids secondary pollution of the atmosphere. Preliminary experiments show that GS nanofibrous membranes are excellent carriers of antibacterial agent for antibacterial applications. Several characterizations and testing measurements indicate that resultant nanofibrous membranes are effective against Gram-positive and Gram-negative bacteria. Moreover, a water vapor transmission rate test shows the excellent filtration performance of the materials. The Ag nanoparticle-embedded filtration membrane with antibacterial properties was synthesized by electrospinning method to combat respiratory diseases caused by bacteria suspended in air pollution. The nanofibrous membrane was made up of gelatin and silk fibroin and was biodegradable. As an antibacterial agent, silver could avoid drug resistance and subsequent testing showed that these membranes had excellent antibacterial properties against both S. aureus and E. coli, as well as good air permeability and were suitable for filtration applications. [ABSTRACT FROM AUTHOR]

A recent single-cell survey of the small-intestinal epithelium suggests that mucosal pentraxin 2 (Mptx2) is a new Paneth cell marker, but its function and involved mechanism in the Paneth cell are still unknown. Therefore, we create Mptx2 knockout (Mptx2−/−) mice to investigate its precise effects on intestinal homeostasis using models of lipopolysaccharide (LPS), methicillin-resistant Staphylococcus aureus (MRSA) peritoneal infection, and dextran sulfate sodium (DSS)–induced intestinal injury and inflammation. We here find that Mptx2 is selectively expressed in Paneth cells in the small intestines of mice. Mptx2−/− mice have increased susceptibility to intestinal inflammation and injured. Mptx2 deficiency reduces Paneth cell count and expression of antimicrobial factors, leading to altered intestinal bacteria composition. Loss of Mptx2 aggravates MRSA infection–induced damage in the intestine while decreasing autophagy in Paneth cells. Mptx2−/− mice are more vulnerable to LPS-induced intestinal possibly due to inhibition of the autophagy/endoplasmic reticulum (ER) stress pathway. Mptx2−/− mice are susceptible to DSS-induced colitis that could be ameliorated by treatment with gentamicin or vancomycin antibiotics. In conclusion, Mptx2 is essential to maintain intestinal homeostasis potentially via regulation of autophagy in Paneth cells. Mucosal pentraxin 2 (Mptx2) is identified as a marker of Paneth cells, and its deficiency is shown to trigger microbiota dysbiosis and increased epithelial invasion by bacteria while also reducing secretory autophagy. [ABSTRACT FROM AUTHOR]

A silver (Ag)‐loaded biostructured carbon/cadmium sulfide (CdS) lamellar composite photocatalyst was synthesized using a hydrothermal and photodeposition method. Camellia petals functioned both as a biological layered template and as a source of carbon. The prepared composite photocatalyst demonstrated good absorption under visible light and exhibited excellent photocatalytic degradation performance. The photocatalytic degradation efficiency of the obtained composites substantially improved compared with pure CdS. The 5 wt.‐% Ag‐loaded C/CdS sample exhibited the highest photocatalytic activity, reaching 96.5 % after 180 min, which was 8.7 times that of pure CdS. Specifically, the biocarbon sheet enhanced the absorption of visible light. Furthermore, the high electrical conductivity of Ag can effectively transfer and separate photogenerated electrons and holes, thus enhancing both photocatalytic performance and stability. [ABSTRACT FROM AUTHOR]

Background: Megacystis microcolon intestinal hypoperistalsis syndrome (MMIHS) is a rare and serious congenital disorder with poor outcomes, where a heterozygous missense mutation is present in the ACTG2 gene. Here, we aimed to investigate the pathogenesis of ACTG2 in MMIHS. Methods: A cohort with 20 patients with MMIHS was screened. Actg2R257C heterozygous mutant mice were generated using the CRISPR/Cas9 system. Gastrointestinal (GI) motility, voluntary urination, collagen gel contraction, and G‐actin/F‐actin analysis were performed. Key Results: The R257C variant of ACTG2 most frequently occurred in patients with MMIHS and demonstrated the typical symptoms of MMIHS. Actg2R257C heterozygous mutant mice had dilated intestines and bladders. The functional assay showed a prolonged total time of GI transit and decreased urine spot area. Collagen gel contraction assay and G‐actin/F‐actin analysis indicated that mutant mice showed reduced area of contraction of smooth muscle cells (SMCs) and impaired actin polymerization. Conclusions & Inferences: A mouse model demonstrating MMIHS‐like symptoms was generated. The Actg2R257C heterozygous variant impairs SMCs contraction by interfering with actin polymerization, leading to GI motility disorders. [ABSTRACT FROM AUTHOR]