Surface Coating of ZIF-8 Nanoparticles with Polyacrylic Acid: A Facile Approach to Enhance Chemical Stability for Biomedical Applications.

Nanoparticles of zeolitic imidazole framework-8 (ZIF-8 NPs), which are the subclass of metal-organic frameworks consisting of Zn ion and 2-methylimidazole, have been identified as promising drug carriers since their large microporous structure is suited for encapsulating hydrophobic drug molecules. However, one of the limitations of ZIF-8 NPs is their low stability in physiological solutions, especially in the presence of water and phosphate anions. These molecules can interact with the coordinatively unsaturated Zn sites at the external surface to induce the degradation of ZIF-8 NPs.

Manganese Porphyrin-Containing Polymeric Micelles: A Novel Approach for Intracellular Catalytic Formation of Per/Polysulfide Species from a Hydrogen Sulfide Donor.

Per/polysulfide species that are generated from endogenously produced hydrogen sulfide have critical regulatory roles in a wide range of cellular processes. However, the lack of delivery systems that enable controlled and sustained release of these unstable species in biological systems hinders the advancement of sulfide biology research, as well as the translation of knowledge to therapeutic applications. Here, a novel approach is developed to generate per/polysulfide species in cells by combining an H S donor and manganese porphyrin-containing polymeric micelles (MnPMCs) that catalyze oxidization of H S to per/polysulfide species.

Recent advance in self-assembled polymeric nanomedicines for gaseous signaling molecule delivery.

Gaseous signaling molecules such as nitric oxide (NO), carbon monoxide (CO), and hydrogen sulfide (H S) have recently been recognized as essential signal mediators that regulate diverse physiological and pathological processes in the human body. With the evolution of gaseous signaling molecule biology, their therapeutic applications have attracted growing attention. One of the challenges in translational research of gaseous signaling molecules is the lack of efficient and safe delivery systems.

Catalytic Behavior of K-doped Fe/MgO Catalysts for Ammonia Synthesis Under Mild Reaction Conditions.

An important part of realizing a carbon-neutral society using ammonia will be the development of an inexpensive yet efficient catalyst for ammonia synthesis under mild reaction conditions (<400 °C, <10 MPa). Here, we report Fe/K(3)/MgO, fabricated via an impregnation method, as a highly active catalyst for ammonia synthesis under mild reaction conditions (350 °C, 1.0 MPa).

Thin Layer Chromatography-Freeze Surface-Enhanced Raman Spectroscopy: A Powerful Tool for Monitoring Synthetic Reactions.

Thin layer chromatography (TLC) is widely used to confirm the formation of the target compound in chemical synthesis. The key issue in TLC is spot identification as it primarily relies on retention factors. Coupling of TLC with surface-enhanced Raman spectroscopy (SERS), which gives direct molecular information, is an appropriate choice, to overcome this challenge.

Freeze Surface-Enhanced Raman Scattering Coupled with Thin-Layer Chromatography: Pesticide Detection and Quantification Case.

Thin-layer chromatography (TLC) is widely used in various branches of chemical science to separate components in complex mixtures because of its simplicity. In most cases, analyte spots are visually detected by fluorescence, and the retention factor () is determined from the distance traveled by the analyte. Further characterizations are often necessary to identify separated chemicals because molecular information other than is not available.

TEMPERATURE-DEPENDENT DEGRADATION OF SOIL ORGANIC MATTER IN FARMLANDS AND PASTURES.

To determine the rates of soil organic matter degradation in farmlands and pastures and their temperature dependency, soil samples collected in Aomori, Japan, were sieved and incubated at different temperatures (10, 20 and 30°C) for 700 d, with amounts of respired CO2 being measured during the incubation period. Results were analysed using a three-compartment model (active, intermediate and resistant compartment), and the decomposition rates of the two labile compartments were approximated using an exponential decay function. The Arrhenius equation was applied to the decay function rate constant to obtain rate constants at the examined temperatures.

Tunable Thermal Switch via Order-Order Transition in Liquid Crystalline Block Copolymer.

Organic material-based thermal switch is drawing much attention as one of the key thermal management devices in organic electronic devices. This study aims at tuning the switching temperature () of thermal conductivity by using liquid crystalline block copolymers (BCs) with different order-order transition temperature () related to the types of mesogens in the side chain. The BC films with low of 363 K and high of 395 K exhibit reversible thermal conductivity switching behaviors at of ∼360 K and ∼390 K, respectively.

Co Nanoparticle Catalysts Encapsulated by BaO-LaO Nanofractions for Efficient Ammonia Synthesis Under Mild Reaction Conditions.

Ruthenium catalysts may allow for realization of renewable energy-based ammonia synthesis processes using mild reaction conditions (<400 °C, <10 MPa). However, ruthenium is relatively rare and therefore expensive. Here, we report a Co nanoparticle catalyst loaded on a basic Ba/LaO support and prereduced at 700 °C (Co/Ba/LaO_700red) that showed higher ammonia synthesis activity at 350 °C and 1.

Effects of changes in polycyclic aromatic hydrocarbons (PAHs) emissions and degradation on their concentrations in Tokyo from 2007 and 2016.

The concentrations of polycyclic aromatic hydrocarbons (PAHs) in aerosol were measured in Shinjuku, which is central Tokyo, Japan, for 10 years from 2007 to 2016. The effects of changes in emission sources and their degradation by reaction with ozone were assessed in this study. There was no significant increasing or decreasing trend of the PAH concentrations during 10 years (P > 0.

Characterization of 3-isopropylmalate dehydrogenase from extremely halophilic archaeon Haloarcula japonica.

3-Isopropylmalate dehydrogenase (IPMDH) catalyzes oxidative decarboxylation of (2R, 3S)-3-isopropylmalate to 2-oxoisocaproate in leucine biosynthesis. In this study, recombinant IPMDH (HjIPMDH) from an extremely halophilic archaeon, Haloarcula japonica TR-1, was characterized. Activity of HjIPMDH increased as KCl concentration increased, and the maximum activity was observed at 3.

The mutation of Thr315 to Asn of GH10 xylanase XynR increases the alkaliphily but decreases the alkaline resistance.

XynR is a thermophilic and alkaline GH10 xylanase, identified in the culture broth of alkaliphilic and thermophilic Bacillus sp. strain TAR-1. We previously selected S92E as a thermostable variant from a site saturation mutagenesis library.

Feasible conditions for Japanese woody biomass utilization.

There is an abundance of woody biomass in Japan. However, its economic feasibility is limited. There have been several discussions on whether generation of heat or electrical power is more suitable for woody biomass.

Functional expression of the reverse transcriptase αβ heterodimer from avian myeloblastosis virus in Escherichia coli.

The α subunit of avian myeloblastosis virus reverse transcriptase (AMV-RT) is generated from the β-subunit by proteolysis, and the αβ heterodimer represents the active form. The codon-optimized gene was expressed in Escherichia coli, and an active αβ heterodimer was generated. The RNA amplification activity of the purified recombinant AMV-RT αβ heterodimer was similar to that of the native one.

Characterization of a GlgC homolog from extremely halophilic archaeon Haloarcula japonica.

Glycogen synthesis in bacteria is mainly organized by the products of glgB, glgC, and glgA genes comprising the widely known glg operon. On the genome of extremely halophilic archaeon Haloarcula japonica, there was a gene cluster analogous to the bacterial glg operon. In this study, we focused on a GlgC homolog of Ha.

Insight into the mechanism of thermostabilization of GH10 xylanase from Bacillus sp. strain TAR-1 by the mutation of S92 to E.

The mechanism of thermostabilization of GH10 xylanase, XynR, from Bacillus sp. strain TAR-1 by the mutation of S92 to E was investigated. Thermodynamic analysis revealed that thermostabilization was driven by the decrease in entropy change of activation for thermal inactivation.

The novel potent TEAD inhibitor, K-975, inhibits YAP1/TAZ-TEAD protein-protein interactions and exerts an anti-tumor effect on malignant pleural mesothelioma.

The Hippo signaling pathway regulates cell fate and organ development. In the Hippo pathway, transcriptional enhanced associate domain (TEAD) which is a transcription factor is activated by forming a complex with yes-associated protein 1 (YAP1) or transcriptional coactivator with PDZ-binding motif (TAZ, also called WWTR1). Hyper-activation of YAP1/TAZ, leading to the activation of TEAD, has been reported in many cancers, including malignant pleural mesothelioma (MPM).

Development and Reorganization of Orientation Representation in the Cat Visual Cortex: Experience-Dependent Synaptic Rewiring in Early Life.

To date, numerous mathematical models have been proposed on the basis of some types of Hebbian synaptic learning to account for the activity-dependent development of orientation maps as well as neuronal orientation selectivity. These models successfully reproduced orientation map-like spatial patterns. Nevertheless, we still have questions: (1) How does synaptic rewiring occur in the visual cortex during the formation of orderly orientation maps in early life? (2) How does visual experience contribute to the maturation of orientation selectivity of visual cortical neurons and reorganize orientation maps? (3) How does the sensitive period for orientation plasticity end? In this study, we performed animal experiments and mathematical modeling to understand the mechanisms underlying synaptic rewiring for experience-dependent formation and reorganization of orientation maps.

Pretreatment and posttreatment in the biolistic transformation of tea plant () somatic embryos.

The tea plant () contains various metabolic substances, including catechins and caffeine, for which genetic transformation techniques are essential for investigating the associated metabolic pathways. In this study, we sought to optimize the conditions and culture process for particle bombardment-mediated transformation of tea plant somatic embryos. We describe somatic embryo pretreatment for effective transient transformation in biolistic bombardment and the posttreatment conditions of somatic embryos for accelerating differentiation after bombardment.

Multifunctional Catalytic Surface Design for Concerted Acceleration of One-Pot Hydrosilylation-CO Cycloaddition.

Silica-supported Rh-ammonium iodide catalyst showed high performance for hydrosilylation-CO cycloaddition reaction sequences. The catalyst was prepared by surface grafting of Rh and the silane-coupling reaction of the ammonium iodide moiety. The acceleration of each catalytic reaction was realized due to the concerted catalysis between Rh species, immobilized organic functions, and surface Si-OH groups.

Metabolic and chemical regulation of tRNA modification associated with taurine deficiency and human disease.

Modified uridine containing taurine, 5-taurinomethyluridine (τm5U), is found at the anticodon first position of mitochondrial (mt-)transfer RNAs (tRNAs). Previously, we reported that τm5U is absent in mt-tRNAs with pathogenic mutations associated with mitochondrial diseases. However, biogenesis and physiological role of τm5U remained elusive.

Surface Protonics Promotes Catalysis.

Catalytic steam reforming of methane for hydrogen production proceeds even at 473 K over 1 wt% Pd/CeO catalyst in an electric field, thanks to the surface protonics. Kinetic analyses demonstrated the synergetic effect between catalytic reaction and electric field, revealing strengthened water pressure dependence of the reaction rate when applying an electric field, with one-third the apparent activation energy at the lower reaction temperature range. Operando-IR measurements revealed that proton conduction via adsorbed water on the catalyst surface occurred during electric field application.

[Antioxidant Activity of Salacia Plant (Salacia reticulata)].

Antioxidant activities of aqueous extracts prepared from powdered leaves and stems of Salacia reticulata, a Salacia plant that grows in Sri Lanka, were investigated. Lipid peroxide levels and some hepatic injury markers in plasma, liver and/or kidney of mice treated with ferric nitrilotriacetate (Fe-NTA) were increased as compared to those of control mice. Oral preadministration of extracts of Salacia leaves and stems at doses of 100, 200 and 400 mg/kg body weight prevented the elevations of lipid peroxides and injury markers in a dose-dependent manner.