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HIV is a lentivirus characterized by the formation of its mature core. Visualization and structural examination of HIV requires purification of virions to high concentrations. The yield and integrity of these virions are crucial for ensuring a uniform representation of all viral particles in subsequent analyses. In this study, we present a method for purification of HIV virions which minimizes forces applied to virions while maximizing the efficiency of collection. This method allows us to capture between 1,000 and 5,000 HIV virions released from individual HEK293 cells after transfection with the NL4.3 HIV backbone, a 10 fold advantage over other methods. We utilized this approach to investigate HIV core formation from several constructs: pNL4-3(RT:D 185 A&D 186 A) with an inactive reverse transcriptase, NL4.3(IN: V 165 A&R 166 A) with a type-II integrase mutation, and NL4.3(Ѱ: Δ(105-278)&Δ(301-332)) featuring an edited Ѱ packaging signal. Notably, virions from NL4.3(Ѱ: Δ(105-278)&Δ(301-332)) displayed a mixed population, comprising immature virions, empty cores, and cores with detectable internal density. Conversely, virions derived from NL4.3(IN: V 165 A&R 166 A) exhibited a type II integrase mutant phenotype characterized by empty cores and RNP density localized around the cores, consistent with previous studies. In contrast, virions released from pNL4-3(RT:D 185 A&D 186 A) displayed mature cores containing detectable RNP density. We suggest that the purification methods developed in this study can significantly facilitate the characterization of enveloped viruses.

Electrochemical water oxidation is believed to be an effective pathway to produce clean, carbon-free, and environmentally sustainable green energy. In this work, we report a simple, easy-to-construct, facile, low-cost, and single-step galvanic technique to synthesize a Pd-supported temperature-assisted MoO x thin film nanocomposite for effective water oxidation. The most suitable nanocomposite exhibits very low overpotential at 10 mA/cm 2 with smaller Tafel slope values for both hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) processes in an alkaline medium. The formation of a metal oxide-metal junction accelerates the growth of more active sites, promoting induced electronic synergism at the MoO x -Pd interface. This endows higher electrical conductivity and faster electron transfer kinetics, thus accelerating the faster water dissociation reaction following the Tafel-Volmer mechanism to boost the HER process in an alkaline medium. The excellent electrochemical HER and OER performances of our electrocatalyst even supersede the accomplishments of the benchmark catalysts Pt/C and RuO 2 . Moreover, neither of these two catalysts demonstrates both catalytic reactions, i.e., HER and OER at the same time, which have been observed for our synthesized catalyst. Our findings illustrate the potential of a thin-film MoO x -Pd nanocomposite to be an exceedingly effective electrocatalyst developed by interface engineering strategies. This also provides insight into designing several other semiconductor composite catalysts using simple synthesis techniques for highly efficient HER/OER processes that could be alternatives to benchmark electrocatalysts for water electrolysis.

Hexavalent chromium exposure via inhalation, ingestion, or both has been proven to adversely affect internal organs, induce toxic effects, cause allergies, and contribute to the development of cancer. It requires a substantial and challenging effort to detect several heavy metal ions conveniently, sensitively, and reliably by using materials that are easy to synthesize and have a high yield. The impact of light on the electrocatalytic oxidation/reduction process proves an environmentally friendly methodology with numerous applications in pollution control. The extensive use of photoactive materials in photoelectrochemical (PEC) sensors necessitates the development of stable and highly effective photoactive materials. Hence, the solvothermal synthesis of the organic-inorganic hybrid nanocomposite β-Bi 2 O 3 -Bi 2 WO 6 /H 2 TPP with varying weight percentages of meso -tetraphenylporphyrin (H 2 TPP) resulted in a selective electrode for electrocatalytic and photoelectrocatalytic reduction of Cr 6+ on fluorine-doped tin oxide (FTO) by an adsorption-reduction mechanism. H 2 TPP increases the active site density and provides an effective surface area for efficient adsorption by providing both pyridinic- and pyrrolic-N atoms to β-Bi 2 O 3 -Bi 2 WO 6 /H 2 TPP. H 2 TPP could effectively adsorb Cr 6+ in the β-Bi 2 O 3 -Bi 2 WO 6 /H 2 TPP composite system through electrostatic interaction, and the adsorbed Cr 6+ ions were reduced to trivalent chromium Cr 3+ , resulting in promising Cr 6+ sensing. The projected density of states and Bader charge calculations result in the electrostatic attraction among the N-2p orbital of H 2 TPP and the 3d and 4s orbitals of the Cr atom, resulting in the adsorption of the hexavalent Cr atom onto the active center of H 2 TPP. Moreover, the addition of H 2 TPP results in the development of a mesoporous surface that offers strong electrical conductivity, a substantial surface area, improved charge-mass transport, intimate contact between the electrolyte and catalyst, an extended fluorescence lifetime, and increased stability. The role of pH values was thoroughly investigated. All electrochemical and photoelectrochemical studies were carried out on 5 wt % H 2 TPP-ornated β-Bi 2 O 3 -Bi 2 WO 6 . Nanocomposite β-Bi 2 O 3 -Bi 2 WO 6 /5 wt % H 2 TPP demonstrated reliable cyclic stability, reproducibility, good sensitivity (8.005 μA mM cm -2 ), and a low limit of detection (LOD) (8.0 nM) toward photoelectrocatalytic reduction of Cr 6+ . The interference study in the presence of a few inorganic entities exhibited excellent selectivity. This tale amplification approach for developing a β-Bi 2 O 3 -Bi 2 WO 6 /5 wt % H 2 TPP nanocomposite system suggests a deeper understanding of the application of photoelectrocatalytic reduction of Cr 6+ in environmental remediation with real samples under light irradiation.

In this research, highly efficient heterogeneous bifunctional (BF) electrocatalysts (ECs) have been strategically designed by Fe coordination (C R ) complexes, [Fe 2 L 2 (H 2 O) 2 Cl 2 ] (C1) and [Fe 2 L 2 (H 2 O) 2 (SO 4 )].2(CH 4 O) (C2) where the high seven C R number synergistically modifies the electronic environment of the Fe centre for facilitation of H 2 O electrolysis. The electronic status of Fe and its adjacent atomic sites have been further modified by the replacement of -Cl - in C1 by -SO 4 2- in C2. Interestingly, compared to C1, the O-S-O bridged C2 reveals superior BF activity with extremely low overpotential (η) at 10 mA cm -2 (140 mV OER , 62 mV HER ) and small Tafel slope (120.9 mV dec -1 OER , 45.8 mV dec -1 HER ). Additionally, C2 also facilitates a high-performance alkaline H 2 O electrolyzer with cell voltage of 1.54 V at 10 mA cm -2 and exhibits remarkable long-term stability. Thus, exploration of the intrinsic properties of metal-organic framework (MOF)-based ECs opens up a new approach to the rational design of a wide range of molecular catalysts., (© 2023 Wiley-VCH GmbH.)

A luminescent nanoprobe (N P ), MnO 2 -modified Er 3+ /Yb 3+ -codoped Ag 2 MoO 4 upconversion nanoparticles (UCNPs; cod-AMO-3/MnO 2 ), was constructed for rapid, sensitive, and selective "turn-on" detection of trace As 3+ . Herein, two kinds of luminescent N P s were developed based on luminescence resonance energy transfer (LRET) between cod-AMO-3 as the energy donor and MnO 2 as the energy acceptor. By using MnO 2 as the matrix in cod-AMO-3/MnO 2 fluorometric assay, the upconversion luminescence (UCL) intensity ( I UCL ) of the cod-AMO-3 probe was quenched significantly through LRET, illustrating MnO 2 as an efficient quencher for UCL. With the addition of As 3+ , a stable bidentate binuclear (BB) corner-sharing bridged complex (As 5+ -MnO 2 ) was probably formed, which alters the surface of the upconversion N P , leading to gradual separation between UCNPs and MnO 2 and subsequent recovery of I UCL . Interestingly, it possessed superior sensitivity, reaction kinetics, and also high selectivity toward As 3+ in aqueous solution. Our optimized cod-AMO-3/MnO 2 nanocomposite (NComp) demonstrated a linear range of 0-150 ppb and an ultrasensitive detection limit of 0.028 ppb for As 3+ , which is extremely below the regulatory level, signifying the promising practical usage of this system. To the best of our knowledge, such a surface-modified Ln 3+ -codoped Ag-based nanosensor being applied for As 3+ detection probably has not been reported yet, and it is rather unexplored. In a nutshell, the ability to monitor the As 3+ concentration may enable the rational design of a convenient platform for a diverse range of environmental monitoring applications.

Background: There is a dearth of high-quality evidence from digital health interventions in routine program settings in low- and middle-income countries. We previously conducted a randomized controlled trial (RCT) in Zimbabwe, demonstrating that 2-way texting (2wT) was safe and effective for follow-up after adult voluntary medical male circumcision (VMMC)., Objective: To demonstrate the replicability of 2wT, we conducted a larger RCT in both urban and rural VMMC settings in South Africa to determine whether 2wT improves adverse event (AE) ascertainment and, therefore, the quality of follow-up after VMMC while reducing health care workers' workload., Methods: A prospective, unblinded, noninferiority RCT was conducted among adult participants who underwent VMMC with cell phones randomized in a 1:1 ratio between 2wT and control (routine care) in North West and Gauteng provinces. The 2wT participants responded to a daily SMS text message with in-person follow-up only if desired or an AE was suspected. The control group was requested to make in-person visits on postoperative days 2 and 7 as per national VMMC guidelines. All participants were asked to return on postoperative day 14 for study-specific review. Safety (cumulative AEs ≤day 14 visit) and workload (number of in-person follow-up visits) were compared. Differences in cumulative AEs were calculated between groups. Noninferiority was prespecified with a margin of -0.25%. The Manning score method was used to calculate 95% CIs., Results: The study was conducted between June 7, 2021, and February 21, 2022. In total, 1084 men were enrolled (2wT: n=547, 50.5%, control: n=537, 49.5%), with near-equal proportions of rural and urban participants. Cumulative AEs were identified in 2.3% (95% CI 1.3-4.1) of 2wT participants and 1.0% (95% CI 0.4-2.3) of control participants, demonstrating noninferiority (1-sided 95% CI -0.09 to ∞). Among the 2wT participants, 11 AEs (9 moderate and 2 severe) were identified, compared with 5 AEs (all moderate) among the control participants-a nonsignificant difference in AE rates (P=.13). The 2wT participants attended 0.22 visits, and the control participants attended 1.34 visits-a significant reduction in follow-up visit workload (P<.001). The 2wT approach reduced unnecessary postoperative visits by 84.8%. Daily response rates ranged from 86% on day 3 to 74% on day 13. Among the 2wT participants, 94% (514/547) responded to ≥1 daily SMS text messages over 13 days., Conclusions: Across rural and urban contexts in South Africa, 2wT was noninferior to routine in-person visits for AE ascertainment, demonstrating 2wT safety. The 2wT approach also significantly reduced the follow-up visit workload, improving efficiency. These results strongly suggest that 2wT provides quality VMMC follow-up and should be adopted at scale. Adaptation of the 2wT telehealth approach to other acute follow-up care contexts could extend these gains beyond VMMC., Trial Registration: ClinicalTrials.gov NCT04327271; https://www.clinicaltrials.gov/ct2/show/NCT04327271., (©Caryl Feldacker, Jacqueline Pienaar, Beatrice Wasunna, Felex Ndebele, Calsile Khumalo, Sarah Day, Hannock Tweya, Femi Oni, Maria Sardini, Binod Adhikary, Evelyn Waweru, Mourice Barasa Wafula, Anna Dixon, Krishna Jafa, Yanfang Su, Kenneth Sherr, Geoffrey Setswe. Originally published in the Journal of Medical Internet Research (https://www.jmir.org), 09.05.2023.)

During 2015-2018, eight black carbon (BC) monitoring sites were established in Nepal and Bhutan to fill a significant data gap regarding BC measurement in Central Himalaya. This manuscript analyzes and presents data from these eight stations and one additional station on the Tibetan plateau (TP). Complex topography, varied emission sources, and atmospheric transport pathways significantly impacted the BC concentrations across these stations, with annual mean concentrations varying from 36 ng m -3 to 45,737 ng m -3 . Higher annual mean concentrations (5609 ± 4515 ng m -3 ) were recorded at low-altitude sites than in other locations, with seasonal concentrations highest in the winter (7316 ± 2541 ng m -3 ). In contrast, the annual mean concentrations were lowest at high-altitude sites (376 ± 448 ng m -3 ); the BC concentrations at these sites peaked during the pre-monsoon season (930 ± 685 ng m -3 ). Potential source contributions to the total observed BC were analyzed using the absorption angstrom exponent (AAE). AAE analysis showed the dominance of biomass burning sources (>50 %), except in Kathmandu. By combining our data with previously published literature, we put our measurements in perspective by presenting a comprehensive assessment of BC concentrations and their variability over the Hindu Kush Himalayan (HKH) region. The BC levels in all three geographic regions, high, mid, and low altitude significantly influenced by the persistent seasonal meteorology. However, the mid-altitude stations were substantially affected by valley dynamics and urbanization. The low-altitude stations experienced high BC concentrations during the winter and post-monsoon seasons. Concentration weighted trajectory (CWT) and frequency analyses revealed the dominance of long-range transported pollution during winter over HKH, from west to east. South Asian sources remained significant during the monsoon season. During pre- and post-monsoon, the local, regional, and long-distance pollution varied depending on the location of the receptor site., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 Elsevier B.V. All rights reserved.)

A selective electrode for oxygen reduction reaction (ORR) and electrocatalytic reduction of 4-nitrophenol ( p -NP) was fabricated on a glassy carbon electrode using organic-inorganic Bi 2 MoO 6 /H 2 TPP nanocomposites with different weight percentages of tetraphenylporphyrin, synthesized by the solvothermal process. Materials thus synthesized were characterized through UV-Vis diffuse reflectance spectroscopy, X-ray photoelectron spectroscopy (XPS), field emission scanning electron microscopy (FE-SEM), energy-dispersive X-ray spectroscopy (EDX), high-resolution transmission electron microscopy (HR-TEM), Fourier transform infrared spectroscopy (FT-IR), and X-ray diffraction (XRD) analysis. The electrocatalytic performance of the modified electrode toward ORR in the 0.1 M KOH solution, the onset potential E onset (0.942 V), E 1/2 (0.704 V) vs RHE, J d (-5.545 mA cm -2 ), and n = 4 physicochemical parameters were well appreciable. It exhibits good catalytic activity toward ORR through a four-electron pathway with excellent stability and high active site density, and thus, the in situ Porphy-decorated metal oxide system facilitates the electron transport process. High selectivity and efficacy for the oxygen reduction reaction (ORR) are a significant measure for several energy-converting applications. The decorated electrode, glassy carbon electrode (GCE)/Bi 2 MoO 6 /3 wt % Porphy, serves as an electrochemical sensor that exhibited good sensitivity (0.4683 μAμM -1 cm -2 ), good reproducibility, a low detection limit (0.0940 μM), and long-term stability in the aqueous phase without any appreciable effect in the presence of some common organic and inorganic interferences for the detection of p -NP in a linear concentration range of 0.5-350 μM. Therefore, the material performs as an effective electrode for both the ORR and the electrocatalytic reduction of p -NP with real matrix samples at room conditions.