Preparation and properties of two-dimensional Ti2CTxMXene based on electroetching method.

The continuous advancements in wearable electronics have drawn significant attention toward 2D MXenes materials for energy storage owing to their abundant availability, adaptability, and distinctive physicochemical properties. Two unresolved concerns currently revolve around environmental pollution by F-containing etching and finite kinetics caused because of re-stacking of nanosheets. In this study, Al was electrochemically etched from porous Ti2AlC electrodes without the use of fluorine, through a selective electrochemical etching process in dilute hydrochloric acid. Subsequently, Ti2CTxMXene was vertically grown on carbon fiber (CF) substrates. The resulting Ti2CTx@CF electrodes are lightweight, thin, and flexible, exhibiting a surface capacitance of 330 mF cm-2at a constant current density of 1 mA cm-2after 2000 cycles. They display a surface capacitance retention of 96.16% and a high energy density of 45.3µWh cm-2at a power density of 0.497 mW cm-2. These metrics underscore the Ti2CTx@CF electrode's commendable multifunctionality, electrochemical performance, ion transport efficiency, and charge storage capacity. Moreover, a flexible energy storage electrode material with a high area capacity was developed by combining Ti2CTxMXene nanosheets, possessing a large specific surface area, with a flexible carbon fabric substrate.

Efficient production of R-2-(4-hydroxyphenoxy) propionic acid by Beauveria bassiana using biofilm-based two-stage fermentation.

In this work, a novel biofilm-based fermentation of Beauveria bassiana was employed to convert R-2- phenoxypropionic acid (R-PPA) to R-2-(4-hydroxyphenoxy) propionic acid (R-HPPA). The biofilm culture model of Beauveria bassiana produced a significantly higher R-HPPA titer than the traditional submerged fermentation method. Mannitol dosage, tryptone dosage, and initial pH were the factors that played a significant role in biofilm formation and R-HPPA synthesis. Under the optimal conditions, the maximum R-HPPA titer and productivity approached 22.2 g/L and 3.2 g/(L·d), respectively. A two-stage bioreactor combining agitation and static incubation was developed to further increase R-HPPA production. The process was optimized to achieve 100 % conversion of R-PPA, with a maximum R-HPPA titer of 50 g/L and productivity of 3.8 g/(L·d). This newly developed biofilm-based two-stage fermentation process provides a promising strategy for the industrial production of R-HPPA and related hydroxylated aromatic compounds.

[3H]Dopamine Uptake through the Dopamine and Norepinephrine Transporters is Decreased in the Prefrontal Cortex of Transgenic Mice Expressing HIV-1 Transactivator of Transcription Protein.

Dysregulation of dopamine neurotransmission has been linked to the development of human immunodeficiency virus (HIV)-associated neurocognitive disorder (HAND). To investigate the mechanisms underlying this phenomenon, this study used an inducible HIV-1 transactivator of transcription (Tat) transgenic (iTat-tg) mouse model, which demonstrates brain-specific Tat expression induced by administration of doxycycline. We found that induction of Tat expression in the iTat-tg mice for either 7 or 14 days resulted in a decrease (∼30%) in the V max of [3H]dopamine uptake via both the dopamine transporter (DAT) and norepinephrine transporter (NET) in the prefrontal cortex (PFC), which was comparable to the magnitude (∼35%) of the decrease in B max for [3H]WIN 35,428 and [3H]nisoxetine binding to DAT and NET, respectively. The decreased V max was not accompanied by a reduction of total or plasma membrane expression of DAT and NET. Consistent with the decreased V max for DAT and NET in the PFC, the current study also found an increase in the tissue content of DA and dihydroxyphenylacetic acid in the PFC of iTat-tg mice after 7 days' administration of doxycycline. Electrophysiological recordings in layer V pyramidal neurons of the prelimbic cortex from iTat-tg mice found a significant reduction in action potential firing, which was not sensitive to selective inhibitors for DAT and NET, respectively. These findings provide a molecular basis for using the iTat-tg mouse model in the studies of NeuroHIV. Determining the mechanistic basis underlying the interaction between Tat and DAT/NET may reveal novel therapeutic possibilities for preventing the increase in comorbid conditions as well as HAND. SIGNIFICANCE STATEMENT: Human immunodeficiency virus (HIV)-1 infection disrupts dopaminergic neurotransmission, leading to HIV-associated neurocognitive disorders (HANDs). Based on our in vitro and in vivo studies, dopamine uptake via both dopamine and norepinephrine transporters is decreased in the prefrontal cortex of HIV-1 Tat transgenic mice, which is consistent with the increased dopamine and dihydroxyphenylacetic acid contents in this brain region. Thus, these plasma membrane transporters are an important potential target for therapeutic intervention for patients with HAND.