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Zn/MnO2systems using non-alkaline aqueous electrolytes have attracted tremendous interest as rechargeable aqueous Zn ion batteries due to their safety and high specific capacities. Despite their promising electrochemical performance, however, their reaction mechanism has remained elusive. Here, we examined the structural evolution of cryptomelane α-MnO2cathode by ex situ transmission electron microscopy after electrochemical testing using two different non-alkaline aqueous Zn electrolytes with acetate and triflate salts of different pH values. We have discovered that the systems tested in both electrolytes exhibit a dissolution–deposition reaction mechanism through dissolution–deposition of Mn2+ions from/on the cathodes with a display of similar discharge/charge product formation. We have also found that the cell tested using the acetate electrolyte shows evidence of structural irreversibility that might contribute to its rapid capacity degradation. This finding offers an important insight into optimizing the cathode design for enhanced electrochemical function of aqueous Zn/MnO2batteries.

Potato common scab is a soil-borne bacterial disease caused by Streptomyces scabies, which is ubiquitous and difficult to control. In this study, the issue of developing antimicrobial agents derived from plant extracts against S. scabieswas addressed. Three bioactive phenolic compounds, named gallic acid, 1-O-galloyl-β-d-glucose, and corilagin, were isolated and identified from Phyllanthus emblicapomace through bioassay-guided fractionation. The antibacterial effects of these compounds on S. scabieswere evaluated with MIC values of 0.63, 0.31, and 1.25 mg/mL, respectively. Furthermore, Structure-activity relationship analyses of 17 gallic acid and its structural analogs revealed that the R6position of the benzene ring was a key factor to their antibacterial activity against S. scabies, among which pyrogallol had the best antibacterial effect. Scanning electron microscopy showed that when S. scabieswas exposed to this gallic acid and its structural analogs, the cell membranes of which was damaged. The results will help promote the development and structural modification of plant-derived bacteriostatic agents.

The traditional Chinese herb Anoectochilus roxburghii (A. roxburghii)is well-known for its medicinal value, but few studies have reported its ability to combat metabolic syndrome activities in vitro. In this study, the extraction of seven compounds from A. roxburghiiusing 70% ethanol, RP-C18, thin layer chromatography (TLC), Sephadex LH-20, high performance liquid chromatography (HPLC) and subsequent identification of their structures through nuclear magnetic resonance (NMR). Among these compounds, kaempferol-3-O-rutinoside and isorhamnetin-3-O-α-l-rhamnopyranoside-7-O-β-d-glucopyranoside were obtained from A. roxburghiifor the first time. Results showed that those compounds inhibited key enzymes involved in metabolic syndrome in vitro. Molecular docking and binding free energy calculations were employed to elucidate the inhibition mechanism of these compounds, while SwissADME was used to assess their drug-like characteristics. Notably, 9-hydroxy-megastigma-4,7-dien-3-one-9-O-β-d-glucopyranoside has the potential as an α-amylase inhibitor for the first time. This research enriches the compound library of A. roxburghiiand provides new ideas for medication research and the development of metabolic syndrome.

Primitive mammalian heart transforms from a single tube to a four-chambered muscular organ during a short developmental window. We found that knocking out global microRNA by deleting Dgcr8microprocessor in Mesp1cardiovascular progenitor cells lead to the formation of extremely dilated and enlarged heart due to defective cardiomyocyte (CM) differentiation. Transcriptome analysis revealed unusual upregulation of vascular gene expression in Dgcr8cKO hearts. Single cell RNA sequencing study further confirmed the increase of angiogenesis genes in single Dgcr8cKO CM. We also performed global microRNA profiling of E9.5 heart for the first time, and identified that miR-541 was transiently highly expressed in E9.5 hearts. Interestingly, introducing miR-541 back into microRNA-free CMs partially rescued their defects, downregulated angiogenesis genes and significantly upregulated cardiac genes. Moreover, miR-541 can target Ctgfand inhibit endothelial function. Our results suggest that microRNAs are required to suppress abnormal angiogenesis gene program to maintain CM differentiation.

The reduction and subsequent oxidation of silver hollandite nanorods, Ag1.5Mn8O16, were explored in aqueous ZnSO4 electrolyte for the first time. The impact of reduction on the electrodes was probed where images of recovered cathodes were collected to evaluate the changes in morphology, structural, and electrochemical properties as a function of varying potential. Ag metal particle formation upon reduction was observed on reduction through a reduction-displacement reaction as confirmed by SEM/EDS, XRD, and XAS results accompanied by a decrease in charge transfer impedance, as determined by electrochemical impedance spectroscopy. On charge, in contrast to the reduction/oxidation electrochemistry in non-aqueous media where irreversible formation of silver metal was observed, disappearance of the silver metal is observed indicating oxidation of the silver centers is facilitated in aqueous electrolyte.

ABSTRACTIn November 2011, The Rockefeller University Center for Clinical and Translational Science (CCTS), the Laboratory of Microbiology and Infectious Diseases, and Clinical Directors Network (CDN) launched a research and learning collaborative project with six community health centers in the New York City metropolitan area to determine the nature (clonal type) of community-acquired Staphylococcus aureusstrains causing skin and soft tissue infections (SSTIs). Between November 2011 and March 2013, wound and nasal samples from 129 patients with active SSTIs suspicious for S. aureuswere collected and characterized by molecular typing techniques. In 63 of 129 patients, the skin wounds were infected by S. aureus: methicillin-resistant S. aureus(MRSA) was recovered from 39 wounds and methicillin-sensitive S. aureus(MSSA) was recovered from 24. Most—46 of the 63–wound isolates belonged to the CC8/Panton-Valentine leukocidin-positive (PVL+) group of S. aureusclone USA300: 34 of these strains were MRSA and 12 were MSSA. Of the 63 patients with S. aureusinfections, 30 were also colonized by S. aureusin the nares: 16 of the colonizing isolates were MRSA, and 14 were MSSA, and the majority of the colonizing isolates belonged to the USA300 clonal group. In most cases (70%), the colonizing isolate belonged to the same clonal type as the strain involved with the infection. In three of the patients, the identity of invasive and colonizing MRSA isolates was further documented by whole-genome sequencing.

Aqueous Zn/MnO2batteries (AZMOB) with mildly acidic electrolytes hold promise as potential green grid-level energy storage solutions for clean power generation. Mechanistic understanding is critical to advance capacity retention needed by the application but is complex due to the evolution of the cathode solid phases and the presence of dissolved manganese in the electrolyte due to a dissolution–deposition redox process. This work introduces operandomultiphase extended X-ray absorption fine structure (EXAFS) analysis enabling simultaneous characterization of both aqueous and solid phases involved in the Mn redox reactions. The methodology was successfully conducted in multiple electrolytes (ZnSO4, Zn(CF3SO3)2, and Zn(CH3COO)2) revealing similar manganese coordination environments but quantitative differences in distribution of Mnn+species in the solid and solution phases. Complementary Raman spectroscopy was utilized to identify the less crystalline Mn-containing products formed under charge at the cathodes. This was further augmented by transmission electron microscopy (TEM) to reveal the morphology and surface condition of the deposited solids. The results demonstrate an effective approach for bulk-level characterization of poorly crystalline multiphase solids while simultaneously gaining insight into the dissolved transition-metal species in solution. This work provides demonstration of a useful approach toward gaining insight into complex electrochemical mechanisms where both solid state and dissolved active materials are important contributors to redox activity.

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