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This work explores a new application of titanium nitride nanoparticles (TiN NPs) as efficient photothermal materials in enhancing the greenhouse effect. We demonstrate that a simple greenhouse using TiN NPs-embedded black paint boasts several advantages in solar drying technology, which are indicated by the drying of red chilli. In particular, the greenhouse using TiN NPs significantly improves the drying efficiency, which reduces the mass of red chilli by approximately four times and results in dried chilli with a moisture content of 10% within two days. In addition, by conducting long experiments in various environments, we found that the relative humidity can have a predominant role over the temperature in the solar drying of red chilli and observed that the re-adsorption of moisture can take place during the drying process, which prolongs the drying time and reduces the quality of the dried products.

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Background: Data on Neisseria gonorrhoeae (NG) and Chlamydia trachomatis (CT) infections within HIV pre-exposure prophylaxis (PrEP) programs in low- and middle-income countries (LMICs) are limited. Our study reports the prevalence, anatomical distribution, and correlates of NG and CT infections within an HIV PrEP program in Hanoi, Vietnam. Methods: From January-December 2022, HIV PrEP program clients who were male at birth, ≥16 years old, reported ≥1 male sex partner in the prior 12 months, were enrolled. A questionnaire collected sociodemographics, sexual behaviors, and clinical data. CT/NG testing was performed on self-collected urine, rectal, and pharyngeal specimens. Multivariate logistic regression was used to identify factors associated with CT and NG infections. Results: There were 529 participants enrolled, the median age was 25.1 years. The overall prevalence of CT or NG was 28.9% (153/529). The prevalence of NG was 14.3% and highest for pharyngeal infections (11.7%), while for CT, the prevalence was 20.4% and highest for rectal infections (14.0%). Symptoms in the prior week were reported by 45.8% (70/153) of those with CT or NG infections. Condomless anal sex (aOR= 1.98; 95% CI: 1.27, 3.08) and sexualized drug use in the prior 6 months (aOR= 1.68; 95% CI: 1.07, 2.65) were associated with CT/NG infections. Conclusions: Our study found a high prevalence of NG and CT infections, including pharyngeal and rectal infections, within an HIV PrEP program in Hanoi, Vietnam. The findings underscore the need for further research on CT/NG prevention and the development of evidence-based guidelines for CT/NG screening in HIV PrEP programs in LMIC settings.

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BACKGROUND: In Vietnam and other global settings, men who have sex with men (MSM) have become the population at greatest risk of HIV infection. Although HIV pre-exposure prophylaxis (PrEP) has been implemented as a prevention strategy, PrEP outcomes may be affected by low persistence and adherence among MSM with unhealthy alcohol use. MSM have a high prevalence of unhealthy alcohol use in Vietnam, which may affect PrEP outcomes. METHODS: Design: We will conduct a two-arm hybrid type 1 effectiveness-implementation randomized controlled trial of a brief alcohol intervention (BAI) compared to the standard of care (SOC) at the Sexual Health Promotion (SHP) clinic Hanoi, Vietnam. PARTICIPANTS: Sexually active MSM (n=564) who are newly initiating PrEP or re-initiating PrEP and have unhealthy alcohol use will be recruited and randomized 1:1 to the SOC or BAI arm. A subgroup of participants (n=20) in each arm will be selected for longitudinal qualitative interviews; an additional subset (n=48) in the BAI arm will complete brief quantitative and qualitative interviews after completion of the BAI to assess the acceptability of the intervention. Additional implementation outcomes will be assessed through interviews with clinic staff and stakeholders (n=35). INTERVENTION: Study participants in both arms will receive standard care for PrEP clients. In the BAI arm, each participant will receive two face-to-face intervention sessions and two brief booster phone sessions, based on cognitive behavioral therapy and delivered in motivational interviewing informed style, to address their unhealthy alcohol use. OUTCOMES: Effectiveness (PrEP and alcohol use) and cost-effectiveness outcomes will be compared between the two arms. Intervention implementation outcomes (acceptability, feasibility, adoption) will be assessed among MSM participants, clinic staff, and stakeholders. DISCUSSION: This proposed trial will assess an alcohol intervention for MSM with unhealthy alcohol use who initiate or re-initiate PrEP, while simultaneously preparing for subsequent implementation. The study will measure the effectiveness of the BAI for increasing PrEP persistence through reducing unhealthy alcohol use in a setting where excessive alcohol consumption is a normative behavior. If effective, implementation-focused results will inform future scale-up of the BAI in similar settings. TRIAL REGISTRATION: NCT06094634 on clinicaltrials.gov. Registered 16 October 2023.

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BACKGROUND: Mycoplasma genitalium causes a sexually transmitted infection and is also emerging as an important antimicrobial resistant pathogen. Data on M. genitalium infections among men who have sex with men (MSM) in low-resource settings are sparse. METHODS: From January to December 2022, participants in an HIV pre-exposure prophylaxis (PrEP) program in Hanoi, Vietnam were enrolled into the study. Demographic, behavioral, and clinical characteristics were collected. Self-collected urine, rectal, and pharyngeal specimens were tested for M. genitalium using the Alinity m STI Assay (Abbott Molecular, USA). Univariate and multivariate logistic regression were performed to assess for factors associated with infections. RESULTS: Among 477 participants, the median age was 25.3 years (21.7-29.6) and 92.2% (n = 440) identified as MSM; 48.6% had ≥2 sex partners and 38.1% reported condomless anal sex in the prior month. The overall prevalence of M. genitalium infection was 10.9% (52/477); 7.3% (34/464) rectal, 3.2% (15/476) urethral, and 1.9% (9/476) pharyngeal. Infections were asymptomatic in 71.2% (37/52). Among those with M. genitalium, 30.7% (16/52) were co-infected with either N. gonorrhoeae or C. trachomatis. Among those reporting rectal (n = 51) or urethral (n = 35) symptoms, but without C. trachomatis or N. gonorrhoeae co-infections, five (9.8%) had rectal infections and one (2.9%) had urethral infection. Participants with M. genitalium were more likely to be asymptomatic than participants without M. genitalium (aOR 1.93; 95% CI 1.01-3.71). CONCLUSIONS: M. genitalium infections were common among primarily MSM engaged in an HIV PrEP program in Vietnam. The prevalence was highest in rectal specimens and nearly three quarters of M. genitalium infections were asymptomatic. Testing for M. genitalium infections among those with symptoms is important to enable pathogen-directed therapy. Additional research on antimicrobial resistance and treatment strategies for M. genitalium in low-resource settings is needed.

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BACKGROUND: Evidence-based interventions (EBIs) often address normative behaviors. If a behavior is also common among clinicians, they may be skeptical about the necessity or effectiveness of an EBI. Alternatively, clinicians' attitudes and behaviors may be misaligned, or they may lack the knowledge and self-efficacy to deliver the EBI. Several EBIs address unhealthy alcohol use, a common and often culturally acceptable behavior. But unhealthy alcohol use may be particularly harmful to people with HIV (PWH). Here, we present an implementation trial using an experiential implementation strategy to address clinicians' knowledge, attitudes, and behaviors. Clinicians receive the experiential intervention before they begin delivering an evidence-based brief alcohol intervention (BAI) to PWH with unhealthy alcohol use. METHODS: Design: In this hybrid type 3 implementation-effectiveness cluster randomized controlled trial, ART clinics (n = 30) will be randomized 1:1 to facilitation, a flexible strategy to address implementation barriers, or facilitation plus the experiential brief alcohol intervention (EBAI). In the EBAI arm, clinicians, irrespective of their alcohol use, will be offered the BAI as experiential learning. EBAI will address clinicians' alcohol-related attitudes and behaviors and increase their knowledge and confidence to deliver the BAI. PARTICIPANTS: ART clinic staff will be enrolled and assessed at pre-BAI training, post-BAI training, 3, 12, and 24 months. All PWH at the ART clinics who screen positive for unhealthy alcohol use will be offered the BAI. A subset of PWH (n = 810) will be enrolled and assessed at baseline, 3, and 12 months. OUTCOMES: We will compare implementation outcomes (acceptability, fidelity, penetration, costs, and sustainability) and effectiveness outcomes (viral suppression and alcohol use) between the two arms. We will assess the impact of site-level characteristics on scaling-up the BAI. We will also evaluate how experiencing the BAI affected clinical staff's alcohol use and clinic-level alcohol expectations in the EBAI arm. DISCUSSION: This trial contributes to implementation science by testing a novel strategy to implement a behavior change intervention in a setting in which clinicians themselves may engage in the behavior. Experiential learning may be useful to address normative and difficult to change lifestyle behaviors that contribute to chronic diseases. TRIAL REGISTRATION: NCT06358885 (04/10/2024), https://clinicaltrials.gov/study/NCT06358885 .

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Etching technology - one of the representative modern semiconductor device makers - serves as a broad descriptor for the process of removing material from the surfaces of various materials, whether partially or entirely. Meanwhile, thinning technology represents a novel and highly specialized approach within the realm of etching technology. It indicates the importance of achieving an exceptionally sophisticated and precise removal of material, layer-by-layer, at the nanoscale. Notably, thinning technology has gained substantial momentum, particularly in top-down strategies aimed at pushing the frontiers of nano-worlds. This rapid development in thinning technology has generated substantial interest among researchers from diverse backgrounds, including those in the fields of chemistry, physics, and engineering. Precisely and expertly controlling the layer numbers of 2D materials through the thinning procedure has been considered as a crucial step. This is because the thinning processes lead to variations in the electrical and optical characteristics. In this comprehensive review, the strategies for top-down thinning of representative 2D materials (e.g., graphene, black phosphorus, MoS2, h-BN, WS2, MoSe2, and WSe2) based on conventional plasma-assisted thinning, integrated cyclic plasma-assisted thinning, laser-assisted thinning, metal-assisted splitting, and layer-resolved splitting are covered in detail, along with their mechanisms and benefits. Additionally, this review further explores the latest advancements in terms of the potential advantages of semiconductor devices achieved by top-down 2D material thinning procedures.

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In recent years, spatial atomic layer deposition (SALD) has gained significant attention for its remarkable capability to accelerate ALD growth by several orders of magnitude compared to conventional ALD, all while operating at atmospheric pressure. Nevertheless, the persistent challenge of inadvertent contributions from chemical vapor deposition (CVD) in SALD processes continues to impede control over film homogeneity, and properties. This research underscores the often-overlooked influence of diffusion coefficients and important geometric parameters on the close-proximity SALD growth patterns. We introduce comprehensive physical models complemented by finite element method simulations for fluid dynamics to elucidate SALD growth kinetics across diverse scenarios. Our experimental findings, in alignment with theoretical models, reveal distinctive growth rate trends in ZnO and SnO2films as a function of the deposition gap. These trends are ascribed to precursor diffusion effects within the SALD system. Notably, a reduced deposition gap proves advantageous for both diffusive and low-volatility bulky precursors, minimizing CVD contributions while enhancing precursor chemisorption kinetics. However, in cases involving highly diffusive precursors, a deposition gap of less than 100µm becomes imperative, posing technical challenges for large-scale applications. This can be ameliorated by strategically adjusting the separation distance between reactive gas outlets to mitigate CVD contributions, which in turn leads to a longer deposition time. Furthermore, we discuss the consequential impact on material properties and propose a strategy to optimize the injection head to control the ALD/CVD growth mode.

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The promotional effects on photocatalytic hydrogen production of Cu x O clusters deposited using atomic layer deposition (ALD) on P25 TiO2 are presented. The structural and surface chemistry study of Cu x O/TiO2 samples, along with first principles density functional theory simulations, reveal the strong interaction of ALD deposited Cu x O with TiO2, leading to the stabilization of Cu x O clusters on the surface; it also demonstrated substantial reduction of Ti4+ to Ti3+ on the surface of Cu x O/TiO2 samples after Cu x O ALD. The Cu x O/TiO2 photocatalysts showed remarkable improvement in hydrogen productivity, with 11 times greater hydrogen production for the optimum sample compared to unmodified P25. With the combination of the hydrogen production data and characterization of Cu x O/TiO2 photocatalysts, we inferred that ALD deposited Cu x O clusters have a dual promotional effect: increased charge carrier separation and improved light absorption, consistent with known copper promoted TiO2 photocatalysts and generation of a substantial amount of surface Ti3+ which results in self-doping of TiO2 and improves its photo-activity for hydrogen production. The obtained data were also employed to modify the previously proposed expanding photocatalytic area and overlap model to describe the effect of cocatalyst size and weight loading on photocatalyst activity. Comparing the trend of surface Ti3+ content increase and the photocatalytically promoted area, calculated with our model, suggests that the depletion zone formed around the heterojunction of Cu x O-TiO2 is the main active area for hydrogen production, and the hydrogen productivity of the photocatalyst depends on the surface coverage by this active area. However, the overlap of these areas suppresses the activity of the photocatalyst.

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BACKGROUND: Neisseria gonorrhoeae (NG) and Chlamydia trachomatis (CT) disproportionately affect men who have sex with men (MSM). Data on the prevalence, anatomical distribution, and correlates of NG and CT infections among MSM in Vietnam are limited. METHODS: Between July 2017 and April 2019, MSM 16 years or older without HIV were enrolled into an observational cohort study. Baseline data, including sociodemographics, sexual behavior, and HIV status, were collected. Testing for NG and CT were performed on urine, rectal, and pharyngeal specimens. Multivariate logistic regression models identified factors associated with NG and CT infections at baseline. RESULTS: In total, 1489 participants underwent NG/CT testing. The median age was 22 years (interquartile range, 20-26 years). There were 424 (28.5%) NG or CT infections: 322 (21.6%) with CT and 173 (11.6%) with NG. Rectal infections were most common for CT (73.9%), whereas pharyngeal infections were most common for NG (70.5%). Independent risk factors for CT or NG infection included ≥2 sex partners in the prior month (adjusted odds ratio [aOR], 2.04; 95% confidence interval [CI], 1.44-2.91), condomless anal sex (aOR, 1.44; 95% CI, 1.12-1.86), and meeting sex partners online (aOR, 1.35; 95% CI, 1.03-1.76). Recent genitourinary or rectal symptoms were not associated with infections. CONCLUSIONS: The overall and extragenital prevalences of NG and CT infections were high within this sample of young MSM without HIV in Hanoi. Testing limited to urethral specimens would have missed nearly three-quarters of CT and NG infections, supporting the need for routine testing at multiple anatomic sites.

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Highly responsive methanol sensors working at low temperatures are developed using hierarchical ZnO nanorods decorated by Pt nanoparticles. The sensing materials are fabricated following a 3-step process: electrospinning of ZnO nanofibers, hydrothermal growth of hierarchical ZnO nanorods on the nanofibers and UV-assisted deposition of Pt nanoparticles. The morphology, structure and properties of the materials are examined by field-effect scanning electron microscopy, transmission electron microscope, x-ray diffraction, x-ray photoelectron spectroscopy, UV-Vis absorption spectroscopy, and electrical measurements. The methanol sensing performance is investigated at different working temperatures in the range of 110 °C-260 °C. It is observed that the surface modification of the ZnO hierarchical nanorods by Pt nanoparticles results in a remarkable enhancement of the sensing response toward methanol, which can reach approximately 19 500 times higher than that of the unmodified ZnO nanorods-based sensor. In addition, this modification enables lower working temperatures with an optimum range of 140 °C-200 °C. Based on the achieved results, a methanol sensing mechanism of the Pt/ZnO structure is proposed.

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This work presents a gas-phase approach for the synthesis of Cu2O/TiO2powder-based photocatalysts using atomic layer deposition (ALD). The process is carried out in a fluidized bed reactor working at atmospheric pressure using (trimethylvinylsilyl)-hexafluoroacetulacetonate copper(I) as the Cu-precursor and H2O vapor as the oxidizer. The saturating regime of the chemical reactions and the linear growth of ALD are achieved. In combination with the unsaturated regime, the ALD approach enables the deposition of ultrasmall Cu2O clusters with average diameters in the range of 1.3-2.0 nm, narrow particle size distributions and tunable Cu2O loadings on P25 TiO2nanoparticles. The photocatalytic performance of Cu2O/TiO2photocatalysts is investigated by the degradation of organic dyes, including Rhodamine B (RhB), methyl orange, and methylene blue; the results demonstrate that the surface modification of TiO2nanoparticles by Cu2O nanoclusters significantly enhances the photocatalytic activity of TiO2. This is attributed to the efficient charge transfer between Cu2O and TiO2that reduces the charge recombination. The photocatalytic reaction mechanism is further investigated for the degradation of RhB, revealing the dominating role of holes, which contribute to both direct hole oxidation and indirect oxidation (i.e. via the formation of hydroxyl radicals). Our approach provides a fast, scalable and efficient process to deposit ultrasmall Cu2O clusters in a controllable fashion for surface engineering and modification.

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ABSTRACT: We used data from the Health in Men-Hanoi cohort to determine the proportion of HIV-negative men who have sex with men with PrEP indications in Hanoi. Among 717 men who have sex with men, 537 (72.2% [66.6%-77.3%]) had ≥1 PrEP indication, signaling a substantial need for PrEP scale-up. Condomless anal intercourse was the most frequent indication (68.7% [60.3%-76.1%]), followed by previous/current sexually transmitted infection (59.4% [51.0%-67.2%]).

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Photocatalysts for water purification typically lack efficiency for practical applications. Here we present a multi-component (Pt:SiO2:TiO2(P25)) material that was designed using knowledge of reaction mechanisms of mono-modified catalysts (SiO2:TiO2, and Pt:TiO2) combined with the potential of atomic layer deposition (ALD). The deposition of ultrathin SiO2 layers on TiO2 nanoparticles, applying ALD in a fluidized bed reactor, demonstrated in earlier studies their beneficial effects for the photocatalytic degradation of organic pollutants due to more acidic surface Si-OH groups which benefit the generation of hydroxyl radicals. Furthermore, our investigation on the role of Pt on TiO2(P25), as an improved photocatalyst, demonstrated that suppression of charge recombination by oxygen adsorbed on the Pt particles, reacting with the separated electrons to superoxide radicals, acts as an important factor for the catalytic improvement. Combining both materials into the resulting Pt:SiO2:TiO2(P25) nanopowder exceeded the dye degradation performance of both the individual SiO2:TiO2(P25) (1.5 fold) and Pt:TiO2(P25) (4-fold) catalysts by 6-fold as compared to TiO2(P25). This approach thus shows that by understanding the individual materials' behavior and using ALD as an appropriate deposition technique enabling control on the nano-scale, new materials can be designed and developed, further improving the photocatalytic activity. Our research demonstrates that ALD is an attractive technology to synthesize multicomponent catalysts in a precise and scalable way.

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Nanostructures of titanium nitride (TiN) have recently been considered as a new class of plasmonic materials that have been utilized in many solar energy applications. This work presents the synthesis of a novel nanostructure of TiN that has a nanodonut shape from natural ilmenite ore using a low-cost and bulk method. The TiN nanodonuts exhibit strong and spectrally broad localized surface plasmon resonance absorption in the visible region centered at 560 nm, which is well suited for thermoplasmonic applications as a nanoscale heat source. The heat generation is investigated by water evaporation experiments under simulated solar light, demonstrating excellent solar light harvesting performance of the nanodonut structure.

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A fundamental understanding of the interplay between ligand-removal kinetics and metal aggregation during the formation of platinum nanoparticles (NPs) in atomic layer deposition of Pt on TiO2 nanopowder using trimethyl(methylcyclo-pentadienyl)platinum(IV) as the precursor and O2 as the coreactant is presented. The growth follows a pathway from single atoms to NPs as a function of the oxygen exposure (PO2 × time). The growth kinetics is modeled by accounting for the autocatalytic combustion of the precursor ligands via a variant of the Finke-Watzky two-step model. Even at relatively high oxygen exposures (<120 mbar s) little to no Pt is deposited after the first cycle and most of the Pt is atomically dispersed. Increasing the oxygen exposure above 120 mbar s results in a rapid increase in the Pt loading, which saturates at exposures >> 120 mbar s. The deposition of more Pt leads to the formation of NPs that can be as large as 6 nm. Crucially, high PO2 (≥5 mbar) hinders metal aggregation, thus leading to narrow particle size distributions. The results show that ALD of Pt NPs is reproducible across small and large surface areas if the precursor ligands are removed at high PO2 .

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This work investigated the suppression of photocatalytic activity of titanium dioxide (TiO2) pigment powders by extremely thin aluminum oxide (Al2O3) films deposited via an atomic-layer-deposition-type process using trimethylaluminum (TMA) and H2O as precursors. The deposition was performed on multiple grams of TiO2 powder at room temperature and atmospheric pressure in a fluidized bed reactor, resulting in the growth of uniform and conformal Al2O3 films with thickness control at sub-nanometer level. The as-deposited Al2O3 films exhibited excellent photocatalytic suppression ability. Accordingly, an Al2O3 layer with a thickness of 1 nm could efficiently suppress the photocatalytic activities of rutile, anatase, and P25 TiO2 nanoparticles without affecting their bulk optical properties. In addition, the influence of high-temperature annealing on the properties of the Al2O3 layers was investigated, revealing the possibility of achieving porous Al2O3 layers. Our approach demonstrated a fast, efficient, and simple route to coating Al2O3 films on TiO2 pigment powders at the multigram scale, and showed great potential for large-scale production development.

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We tailored the size distribution of Pt nanoparticles (NPs) on graphene nanoplatelets at a given metal loading by using low-temperature atomic layer deposition carried out in a fluidized bed reactor operated at atmospheric pressure. The Pt NPs deposited at low temperature (100 °C) after 10 cycles were more active and stable towards the propene oxidation reaction than their high-temperature counterparts. Crucially, the gap in the catalytic performance was retained even after prolonged periods of time (>24 hours) at reaction temperatures as high as 450 °C. After exposure to such harsh conditions the Pt NPs deposited at 100 °C still retained a size distribution that is narrower than the one of the as-synthesized NPs obtained at 250 °C. The difference in performance correlated with the difference in the number of facet sites as estimated after the catalytic test. Our approach provides not only a viable route for the scalable synthesis of stable supported Pt NPs with tailored size distributions but also a tool for studying the structure-function relationship.