NMR proton relaxation for measuring the relative concentration of nanoparticles in liquids.

The measurement of relative concentration of nanoparticles in liquids has been investigated using NMR proton relaxation, addressing a gap in analytical capabilities for highly concentrated dispersions. This technique has a limited footprint, short measurement time and ease of operation making it a promising quality control method to support the development and manufacture of nanomaterials.

Engineering a DNA origami mediated multicolour quantum dot platform for sub-diffraction spectral separation imaging.

The validation of super-resolution optical imaging techniques requires well-defined reference samples that can be used repeatedly and reliably as model standards. Here, we engineer a DNA origami scaffold-mediated multicolour quantum dot hybrid nanostructure and test it using a recently proposed Quantum Dot-based spectral separation technique. We show that multivalent DNA structures offer a robust and precise nanoscale quantum dot placement scaffold, while the spectral resolution method provides relatively simple and fast image acquisition capabilities using any standard confocal or fluorescence microscope capable of spectral signal separation and a single excitation laser wavelength.

Use of Antimicrobials among Suspected COVID-19 Patients at Selected Hospitals, Bangladesh: Findings from the First Wave of COVID-19 Pandemic.

Antimicrobials are empirically used in COVID-19 patients resulting in increased antimicrobial resistance. Our objective was to assess antimicrobial use among suspected COVID-19 in-patients. From March to August 2020, we collected data from in-patients of 12 tertiary-level hospitals across Bangladesh. We identified suspected COVID-19 patients; collected information on antimicrobial received within 24 h before and on hospitalization; tested nasopharyngeal swab for SARS-CoV-2 using rRT-PCR. We used descriptive statistics and a regression model for data analysis. Among 1188 suspected COVID-19 patients, 69% were male, 40% had comorbidities, and 53% required oxygen. Antibiotics were used in 92% of patients, 47% within 24 h before, and 89% on admission. Patients also received antiviral (1%) and antiparasitic drugs (3%). Third-generation cephalosporin use was the highest (708; 60%), followed by macrolide (481; 40%), and the majority (853; 78%) who took antibiotics were SARS-CoV-2 negative. On admission, 77% mild and 94% moderately ill patients received antibiotics. Antibiotic use on admission was higher among severely ill patients (AOR = 11.7; 95% CI: 4.5-30.1) and those who received antibiotics within 24 h before hospital admission (AOR = 1.6; 95% CI: 1.0-2.5). Antimicrobial use was highly prevalent among suspected COVID-19 in-patients in Bangladesh. Initiating treatment with third-generation cephalosporin among mild to moderately ill patients was common. Promoting antimicrobial stewardship with monitoring is essential to prevent blanket antibiotic use, thereby mitigating antimicrobial resistance.

Single visit versus multiple visit root canal.

Single visit endodontics offers many advantages over multi visit treatment. Therefore, it is of interest to assess the preference of single visit over multiple visit root canals. We used 86,000 patient records and selected 9017 records matching the inclusion criteria for the analysis using statistical tools (Chi square test at p value <0.05). Data shows that people between 26 to 45 years are often affected with dental caries. Available data is biased towards multi visits rather than single visit regardless number of canals.

Edge-oriented and steerable hyperbolic polaritons in anisotropic van der Waals nanocavities.

Highly confined and low-loss polaritons are known to propagate isotropically over graphene and hexagonal boron nitride in the plane, leaving limited degrees of freedom in manipulating light at the nanoscale. The emerging family of biaxial van der Waals materials, such as α-MoO3 and V2O5, support exotic polariton propagation, as their auxiliary optical axis is in the plane. Here, exploiting this strong in-plane anisotropy, we report edge-tailored hyperbolic polaritons in patterned α-MoO3 nanocavities via real-space nanoimaging. We find that the angle between the edge orientation and the crystallographic direction significantly affects the optical response, and can serve as a key tuning parameter in tailoring the polaritonic patterns. By shaping α-MoO3 nanocavities with different geometries, we observe edge-oriented and steerable hyperbolic polaritons as well as forbidden zones where the polaritons detour. The lifetime and figure of merit of the hyperbolic polaritons can be regulated by the edge aspect ratio of nanocavity.

Electrically Activated UV-A Filters Based on Electrochromic MoO3-x.

Chromism-based optical filters is a niche field of research, due to there being only a handful of electrochromic materials. Typically, electrochromic transition metal oxides such as MoO3 and WO3 are utilized in applications such as smart windows and electrochromic devices (ECD). Herein, we report MoO3-x-based electrically activated ultraviolet (UV) filters. The MoO3-x grown on indium tin oxide (ITO) substrate is mechanically assembled onto an electrically activated proton exchange membrane. Reversible H+ injection/extraction in MoO3-x is employed to switch the optical transmittance, enabling an electrically activated optical filter. The devices exhibit broadband transmission modulation (325-800 nm), with a peak of ∼60% in the UV-A range (350-392 nm). Comparable switching times of 8 s and a coloration efficiency of up to 116 cm2 C-1 are achieved.

Dual Selective Gas Sensing Characteristics of 2D α-MoO3-x via a Facile Transfer Process.

Metal oxide-based gas sensor technology is promising due to their practical applications in toxic and hazardous gas detection. Orthorhombic α-MoO3 is a planar metal oxide with a unique layered structure, which can be obtained in a two-dimensional (2D) form. In the 2D form, the larger surface area-to-volume ratio of the material facilitates significantly higher interaction with gas molecules while exhibiting exceptional transport properties. The presence of oxygen vacancies results in nonstoichiometric MoO3 (MoO3-x), which further enhances the charge carrier mobility. Here, we study dual gas sensing characteristics and mechanism of 2D α-MoO3-x. Herein, conductometric dual gas sensors based on chemical vapor deposited 2D α-MoO3-x are developed and demonstrated. A facile transfer process is established to integrate the material into any arbitrary substrate. The sensors show high selectivity toward NO2 and H2S gases with response and recovery rates of 295.0 and 276.0 kΩ/s toward NO2 and 28.5 and 48.0 kΩ/s toward H2S, respectively. These gas sensors also show excellent cyclic endurance with a variation in ΔR ∼ 112 ± 1.64 and 19.5 ± 1.13 MΩ for NO2 and H2S, respectively. As such, this work presents the viability of planar 2D α-MoO3-x as a dual selective gas sensor.

Community pharmacist perceptions of their role and the use of social media and mobile health applications as tools in public health.

BACKGROUND: A number of barriers prevent community pharmacists (CPs) from impacting public health (PH) outcomes. Social media (SM) and mobile health apps (MH apps) may offer ways to help the public make positive health decisions. OBJECTIVES: To evaluate CP perceptions of their role in PH and the use of SM and MH apps in this regard. METHODS: This was a mixed method study using a cross-sectional survey and follow-up interviews. The survey covered: CPs role in PH; CP use of SM; CP use of MH apps; non-identifiable demographic information. Following ethical approval and piloting, responses were collected on paper and online. The study population was CPs in Greater London, UK (n = 2931). A minimum sample size of 340 was calculated (95% confidence interval/5% margin of error). To achieve this, 596 surveys were distributed. Responses (n = 257) were analysed using descriptive statistics. Twenty-five respondents were willing to take part in follow-up one-to-one interviews. Twenty interviews were completed as data saturation was achieved after the 14th. Interviews were transcribed and analysed using framework methodology as described by Ritchie and Spencer in 1994. RESULTS: Survey response rate was 43%. Respondents represented English CPs in terms of age but males and non-whites were over-represented. The majority of CPs accessed SM and MH apps for personal use but did not recommend these in a professional capacity due to lack of awareness and confidentiality/liability concerns. Most would promote an SM health page (78.6%) or MH app (83.7%) if maintained by healthcare professionals (HCPs). Under 35s were more positive about these tools in PH. Two interview themes emerged: The role of CPs in PH; Concerns and opportunities for the use of technology in PH. CONCLUSIONS: Most CPs, particularly those under 30, were positive about the use of SM and MH apps in PH. Training on the use of such tools among the pharmacy team, and an awareness of the availability of evidence-based apps will ensure their wider adoption.

Reversible resistive switching behaviour in CVD grown, large area MoOx.

Non-volatile resistive memory devices are theorized to be the most promising pathway towards analog memory and neuromorphic computing. Two-dimensional MoO3 is a versatile planar transition metal oxide, whose properties can be readily tuned, making it anywhere from a wide bandgap semiconductor to a semi-metal. Successful integration of such a planar metal oxide into resistive memory can enable adaptive and low power memory applications. Here, we investigate the non-volatile and reversible resistive switching behaviour of oxygen deficient MoOx in a cross-point metal/insulator/metal (MIM) architecture. Layered MoOx films are synthesised using chemical vapour deposition (CVD) and reveal excellent resistive switching performance with relatively low electroforming and operating voltages. Switching ratios of ∼103 and stable data retention of >104 s are achieved. As such, this work demonstrates the viability of MoOx as a resistive memory element and paves the way for future two-dimensional resistive memory technologies.

Ambient Protection of Few-Layer Black Phosphorus via Sequestration of Reactive Oxygen Species.

Few-layer black phosphorous (BP) has emerged as a promising candidate for next-generation nanophotonic and nanoelectronic devices. However, rapid ambient degradation of mechanically exfoliated BP poses challenges in its practical deployment in scalable devices. To date, the strategies employed to protect BP have relied upon preventing its exposure to atmospheric conditions. Here, an approach that allows this sensitive material to remain stable without requiring its isolation from the ambient environment is reported. The method draws inspiration from the unique ability of biological systems to avoid photo-oxidative damage caused by reactive oxygen species. Since BP undergoes similar photo-oxidative degradation, imidazolium-based ionic liquids are employed as quenchers of these damaging species on the BP surface. This chemical sequestration strategy allows BP to remain stable for over 13 weeks, while retaining its key electronic characteristics. This study opens opportunities to practically implement BP and other environmentally sensitive 2D materials for electronic applications.