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Comparative Genomic Analysis and BTEX Degradation Pathways of a Thermotolerant Cupriavidus cauae PHS1
No full textVolatile organic compounds such as benzene, toluene, ethylbenzene, and isomers of xylenes (BTEX) constitute a group of monoaromatic compounds that are found in petroleum and have been classified as priority pollutants. In this study, based on its newly sequenced genome, we reclassified the previously identified BTEX-degra ding thermotolerant strain Ralstonia sp. PHS1 as Cupriavidus cauae PHS1. Also presented are the complete genome sequence of C. cauae PHS1, its annotation, species delineation, and a comparative analysis of the BTEX-degrading gene cluster. Moreover, we cloned and characterized the BTEX-degrading pathway genes in C. cauae PHS1, the BTEX-degrading gene cluster of which consists of two monooxygenases and meta-cleavage genes. A genome-wide investigation of the PHS1 coding sequence and the experimentally confirmed regioselectivity of the toluene monooxygenases and catechol 2,3-dioxygenase allowed us to reconstruct the BTEX degradation pathway. The degradation of BTEX begins with aromatic ring hydroxylation, followed by ring cleavage, and eventually enters the core carbon metabolism. The information provided here on the genome and BTEX-degrading pathway of the thermotolerant strain C. cauae PHS1 could be useful in constructing an efficient production host
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Roles of context in L2 learners??? self-regulatory actions: The case of videoconference-based EFL writing course.
No full textTo date, studies of English as a foreign language (EFL) learners??? motivational regulation have centered on the traditional offline classroom setting with little consideration of the contingency of learning context. The aims of this study were to reveal the dynamics of EFL learners??? self-regulatory responses to and their instructors??? perspectives of videoconference-based writing class. Specifically, this study focused on several factors embedded in the context, including native English-speaking instructors, videoconference platform, and English-medium instruction (EMI). A mixed method was used to analyze the questionnaire responses of 264 students from two science and engineering universities and subsequent interviews with seven students and ten native English-speaking instructors. The analyses revealed that learners??? three proficiency levels affected their engagement with instructor feedback and text processing, the most prevalent motivational regulation strategies. In the two lower proficiency groups, these regulatory actions did not correlate with the EMI factor. The beginner group in particular struggled to regulate motivation, disfavoring the videoconference platform. In the analysis of instructor interviews, the discrepancy in the students??? self-regulatory actions among proficiency levels was rarely acknowledged or addressed by the instructors. The findings are discussed to give insight into EFL writing instruction in the emerging higher education context
Versatile, Stable, and Scalable Gel-Like Aerophobic Surface System (GLASS) for Hydrogen Production
No full textFacile removal of adsorbed gas bubbles from electrode surfaces is crucial to realize efficient and stable energy conversion devices based on electrochemical gas evolution reactions. Conventional studies on bubble removal have limited applicability and scalability due to their reliance on complex and energy/time-intensive processes. In this study, a simple and versatile method is reported to fabricate large-area superaerophobic electrodes (up to 100 cm2) for diverse gas evolution reactions using the gel-like aerophobic surface system (GLASS). GLASS electrodes are readily and uniformly fabricated by simple spin-coating and cross-linking of polyallylamine on virtually any kinds of electrodes within 5 min under ambient conditions. Intrinsically hydrophilic gel overlayers with interconnected open pores allow the physical separation of bubble adhesion and catalytic active sites, reducing bubble adhesion strength, and promoting the removal of gas bubbles. As a result, GLASS electrodes exhibit greatly enhanced efficiency and stability for diverse gas evolution reactions, such as hydrogen evolution, hydrazine oxidation, and oxygen evolution reactions. This study provides deeper insights into understanding the effect of the hydrophilic microenvironment on gas evolution reactions and designing practical electrochemical devices
TET family proteins are dispensable for dopamine neurons in health and Parkinson???s disease pathology
No full textDNA undergoes demethylation via the oxidation of 5-methylcytosine (5mC), which is mediated by the Ten ElevenTranslocation (TET) family of proteins. Notably, 5hmC is highly enriched in the brain than other tissues, the levelof which is dynamically regulated during development, aging, and in brain disorders. In addition, accumulatingevidence has recently revealed that 5-hmC and TETs play a significant role in synaptic functions, anxiety,addiction, and cognition in several brain regions. Furthermore, TET enzymes have turned out to be essential fordiverse types of neurons in health and brain disorders. In this study, by generating triple knockout (TKO) mice ofTET family proteins (TET1, 2, and 3) selectively in dopamine (DA) neurons, we investigated the functional rolesof TET proteins in the structure and the function of DA neurons, which are pivotal for voluntary movement,reward-related behaviors, and motivation. Here we unexpectedly show that triple knockout (TKO) of all three TETproteins in dopamine (DA) neurons did not lead to significant alterations of neuronal structure and function innormal and pathological conditions. Thus, contrary to the previous reports, TET family enzymes may bedispensable for the structure and function of dopamine neurons in health and Parkinson???s disease
Enhancing the durability performance of thermally damaged concrete with ground-granulated blast furnace slag and fly ash
No full textThis study investigates the effectiveness of ground-granulated blast furnace slag (GGBFS) and fly ash in improving the durability of concrete specimens subjected to thermal damage. Multiple techniques, including nonlinear impact resonance acoustic spectroscopy (NIRAS), compressive strength, X-ray diffraction, and thermogravimetry, are employed to capture the physical and chemical phenomena resulting from a temperature elevation of 200, 400, 600, and 800 ???C. The experimental results demonstrated that replacing cement with fly ash (20 wt%) and GGBFS (40 wt%) yields significant mitigation of microcracking development, highlighting their potential as agents for enhancing concrete durability under high-temperature exposure. Notably, the hysteresis nonlinearity parameter (??) measured using NIRAS exhibits a high sensitivity for detecting the transition from micro to macroscale defects, and the trend of ?? sufficiently coincides with the results of the mineralogical analyses, confirming the evaporation of free water, dehydration of calcium silicate hydrate (C-S-H), and decomposition of calcium hydroxide (CH)
Indefinite and Bidirectional Near-infrared Nanocrystal Photoswitching
No full textMaterials whose luminescence can be switched by optical stimulation drive technologies ranging from superresolution imaging1,2,3,4, nanophotonics5, and optical data storage6,7, to targeted pharmacology, optogenetics, and chemical reactivity8. These photoswitchable probes, including organic fluorophores and proteins, can be prone to photodegradation and often operate in the ultraviolet or visible spectral regions. Colloidal inorganic nanoparticles6,9 can offer improved stability, but the ability to switch emission bidirectionally, particularly with near-infrared (NIR) light, has not, to our knowledge, been reported in such systems. Here, we present two-way, NIR photoswitching of avalanching nanoparticles (ANPs), showing full optical control of upconverted emission using phototriggers in the NIR-I and NIR-II spectral regions useful for subsurface imaging. Employing single-step photodarkening10,11,12,13 and photobrightening12,14,15,16, we demonstrate indefinite photoswitching of individual nanoparticles (more than 1,000 cycles over 7???h) in ambient or aqueous conditions without measurable photodegradation. Critical steps of the photoswitching mechanism are elucidated by modelling and by measuring the photon avalanche properties of single ANPs in both bright and dark states. Unlimited, reversible photoswitching of ANPs enables indefinitely rewritable two-dimensional and three-dimensional multilevel optical patterning of ANPs, as well as optical nanoscopy with sub-?? localization superresolution that allows us to distinguish individual ANPs within tightly packed clusters