Accuracy and Performance of Triage Blood Pressure Measurements in A Real-World Clinic Setting.

OBJECTIVES: To investigate the agreement and accuracy of triage blood pressure (BP) in a real-world clinic setting, compared with the reference standard. STUDY DESIGN: Paired triage and standardized BP measurements from patients 4 through 21 years old evaluated in an obesity-related hypertension clinic were obtained via chart-review. Triage BPs were measured by a medical assistant or nurse, often by automated device. Triplicate manual BPs were obtained by the clinic physician. Bland-Altman analyses determined mean differences between paired triage and mean standardized BPs. GEE-based multivariable relative risk (RR) regression determined the RR of triage BP overestimation by ≥ 5 mmHg. Overall agreement, sensitivity, specificity, positive predictive value, and negative predictive value of triage BP measurements identifying hypertensive BP were determined. RESULTS: One hundred thirty participants with 347 clinic encounters were included. Mean age was 13.3 years (SD 3.94), 76% were Black, and 58% were male. Overall mean systolic and diastolic BP difference was 8.7 mmHg (95% limits on agreement: -16.66, 34.07) and 4.1 mmHg (95% limits on agreement: -18.56, 26.68), respectively. Triage systolic BP was more likely overestimated by ≥ 5 mmHg when a large adult (RR = 1.49; 95% CI: 1.00, 2.21) or thigh cuff (RR = 1.94; 95% CI: 1.08, 3.51) was required compared with when a child/adult cuff was required. Overall agreement in identifying hypertensive BP was 57.6%. Sensitivity (52.6%), specificity (63.4%), positive predictive value (60.8%), and negative predictive value (55.3%) were low across all cuffs. CONCLUSIONS: There was poor agreement between usual triage and standardized BP measurements, with potential for significant clinical implications. CLINICAL TRIAL REGISTRATION: ReNEW Clinic Cohort Study (ReNEW), NCT03816462, https://clinicaltrials.gov/ct2/show/NCT03816462.

Assessment of Neurology Residency Program Websites across North America during COVID-19.

With virtual interviews for residency applications, residency program websites have become increasingly important resources for applicants. We evaluated the comprehensiveness of US and Canadian neurology residency program website, comparing this to published rankings of the best neurology and neurosurgery hospitals (for US programs) and number of residency positions (for US and Canadian programs). US program websites were found to be largely more comprehensive than Canadian websites, more extensive websites were associated with better program rankings and fewer residency seats in the US, and US regional differences in comprehensiveness were present. We recommend standardized guidelines to increase website comprehensiveness across programs.

Analysis of MCQ and distractor use in a large first year Health Faculty Foundation Program: assessing the effects of changing from five to four options.

BACKGROUND: Multiple choice questions are commonly used in summative assessment. It is still common practice for tertiary institutions and accrediting bodies to use five-option single best answer multiple choice questions, despite a substantial body of evidence showing that multiple choice questions with only three or four options provide effective and discriminatory assessment. METHODS: In this study we investigated the distribution of distractor efficacy in exams from four large first-year undergraduate courses in chemistry and in anatomy and physiology in a Health Faculty; assessed the impact on overall student score after changing from five-option to four-option single best answer multiple choice questions; and assessed the impact of changing from five options to four options on item difficulty and discrimination. RESULTS: For the five-option questions analysed, 19% had four effective distractors, which is higher than previous studies, but still a minority of questions. After changing from five to four options, the overall student performance on all multiple choice questions was slightly lower in the second offering of one course, slightly higher in the second offering of another course, and similar in the second offering for two courses. For a subset of questions that were used in both offerings, there were negligible differences in item difficulty and item discrimination between offerings. CONCLUSIONS: These results provide further evidence that five-option questions are not superior to four-option questions, with reduction to four options making little if any difference to overall performance, particularly when MCQ is used in conjunction with other assessment types (including short answer questions, and practical or laboratory assessment). Further areas of study that arise from these findings are: to investigate the reasons for resistance to changing established assessment practice within institutions and by accrediting bodies; and to analyse student perceptions of the impact of a reduced number of options in MCQ-based assessment.

Vacancy impacts on electronic and mechanical properties of MX2 (M = Mo, W and X = S, Se) monolayers.

Monolayers of transition metal dichalcogenides (TMD) exhibit excellent mechanical and electrical characteristics. Previous studies have shown that vacancies are frequently created during the synthesis, which can alter the physicochemical characteristics of TMDs. Even though the properties of pristine TMD structures are well studied, the effects of vacancies on the electrical and mechanical properties have received far less attention. In this paper, we applied first-principles density functional theory (DFT) to comparatively investigate the properties of defective TMD monolayers including molybdenum disulfide (MoS2), molybdenum diselenide (MoSe2), tungsten disulfide (WS2), and tungsten diselenide (WSe2). The impacts of six types of anion or metal complex vacancies were studied. According to our findings, the electronic and mechanical properties are slightly impacted by anion vacancy defects. In contrast, vacancies in metal complexes considerably affect their electronic and mechanical properties. Additionally, the mechanical properties of TMDs are significantly influenced by both their structural phases and anions. Specifically, defective diselenides become more mechanically unstable due to the comparatively poor bonding strength between Se and metal based on the analysis of the crystal orbital Hamilton population (COHP). The outcomes of this study may provide the theoretical knowledge base to boost more applications of the TMD systems through defect engineering.

Theoretical understanding of electronic and mechanical properties of 1T' transition metal dichalcogenide crystals.

Transition metal dichalcogenides (TMDs) with a 1T' layer structure have recently received intense interest due to their outstanding physical and chemical properties. While the physicochemical behaviors of 1T' TMD monolayers have been widely investigated, the corresponding properties of layered 1T' TMD crystals have rarely been studied. As TMD monolayers do not have interlayer interactions, their physicochemical properties will differ from those of layered TMD materials. In this study, the electronic and mechanical characteristics of a range of 1T' TMDs are systematically examined by means of density functional theory (DFT) calculations. Our results reveal that the properties of 1T' TMDs are mainly affected by their anions. The disulfides are stiffer and more rigid, diselenides are more brittle. In addition, the 1T' polytype is softer than 2H TMDs. Comparison with the properties of the monolayers shows that the interlayer van der Waals forces can slightly weaken the TM-X covalent bonding strength, which can further influence the mechanical properties. These insights revealed by our theoretical studies may boost more applications of 1T' TMD materials.

Multiscale numerical simulation of in-plane mechanical properties of two-dimensional monolayers.

Many applications of two dimensional (2D) materials are often achieved through strain engineering, which is directly dependent on their in-plane mechanical characteristics. Therefore, understanding the in-plane mechanical characteristics of the 2D monolayers becomes imperative. Nevertheless, direct experimental measurements of in-plane mechanical properties of 2D monolayers face great difficulties due to the issues related to the availability of high-quality 2D materials and sophisticated facilities. As an alternative, numerical simulation has the potential to theoretically predict such properties. This review presents some recent progress in numerically exploring the in-plane mechanical properties of 2D materials, including first-principles density functional theory, force-field based classical molecular dynamics, and the finite-element method. The relevant case studies are provided to describe the applications of these methods along with their pros and cons. We hope that the multiscale simulation methods discussed in this review will inspire new ideas and boost further advances of the computational study on the in-plane mechanical properties of 2D materials.

Photoelectrochemical characterization of a robust TiO2/BDD heterojunction electrode for sensing application in aqueous solutions.

Titanium dioxide (TiO(2)) and boron-doped diamond (BDD) are two of the most popular functional materials in recent years. In this work, TiO(2) nanoparticles were immobilized onto the BDD electrodes by a dip-coating technique. Continuous and uniform mixed-phase (anatase and rutile) and pure-anatase TiO(2)/BDD electrodes were obtained after calcination processes at 700 and 450 degrees C, respectively. The particle sizes of both types of TiO(2) film range from 20 to 30 nm. In comparison with a TiO(2)/indium tin oxide (ITO) electrode, the TiO(2)/BDD electrode demonstrates a higher photoelectrocatalytic activity toward the oxidation of organic compounds, such as glucose and potassium hydrogen phthalate. Among all the tested TiO(2) electrodes, the mixed-phase TiO(2)/BDD electrode demonstrated the highest photoelectrocatalytic activity, which can be attributed to the formation of the p-n heterojunction between TiO(2) and BDD. The electrode was subsequently used to detect a wide spectrum of organic compounds in aqueous solution using a steady-state current method. An excellent linear relationship between the steady-state photocurrents and equivalent organic concentrations was attained. The steady-state oxidation photocurrents of the mixed-phase TiO(2)/BDD electrode were insensitive to pH in the range of pH 2-10. Furthermore, the electrodes exhibited excellent robustness under strong acidic conditions that the TiO(2)/ITO electrodes cannot stand. These characteristics bestow the mixed-phase TiO(2)/BDD electrode to be a versatile material for the sensing of organic compounds.

The fabrication of CNTs/TiO(2) photoanodes for sensitive determination of organic compounds.

Titanium dioxide (TiO(2)) and carbon nanotubes (CNTs) are the two most popular functional materials in recent years. In this study, CNTs/TiO(2) composite and TiO(2) photoanodes were fabricated by a dip-coating technique, followed by subsequent calcination. The resultant photoanodes were characterized by scanning electron microscopy (SEM), x-ray diffraction (XRD), and UV-visible spectroscopy (UV-vis). The results suggest that the carbon nanotubes were successfully incorporated with the TiO(2) nanoparticulates without damage and that the resultant TiO(2) nanoparticles consisted of anatase and rutile. The CNTs/TiO(2) photoanodes were capable of oxidizing various types of organic compounds (e.g. glucose, potassium hydrogen phthalate, and phenol) in aqueous solutions in a photoelectrochemical bulk cell. In comparison with the pure TiO(2) photoanode, the sensitivity of the photoanode for the detection of organic compounds has been improved by 64%, while the background current was reduced by 80% due to the introduction of the CNTs. These advantages can be ascribed to the improved adsorptivity to organic compounds, increased absorption of UV light and enhanced electron transport at the CNTs/TiO(2) photoanode due to the introduction of the CNTs.

DFT-Guided Design and Fabrication of Carbon-Nitride-Based Materials for Energy Storage Devices: A Review.

Carbon nitrides (including CN, C2N, C3N, C3N4, C4N, and C5N) are a unique family of nitrogen-rich carbon materials with multiple beneficial properties in crystalline structures, morphologies, and electronic configurations. In this review, we provide a comprehensive review on these materials properties, theoretical advantages, the synthesis and modification strategies of different carbon nitride-based materials (CNBMs) and their application in existing and emerging rechargeable battery systems, such as lithium-ion batteries, sodium and potassium-ion batteries, lithium sulfur batteries, lithium oxygen batteries, lithium metal batteries, zinc-ion batteries, and solid-state batteries. The central theme of this review is to apply the theoretical and computational design to guide the experimental synthesis of CNBMs for energy storage, i.e., facilitate the application of first-principle studies and density functional theory for electrode material design, synthesis, and characterization of different CNBMs for the aforementioned rechargeable batteries. At last, we conclude with the challenges, and prospects of CNBMs, and propose future perspectives and strategies for further advancement of CNBMs for rechargeable batteries.

Effect of Structural Phases on Mechanical Properties of Molybdenum Disulfide.

Molybdenum disulfide (MoS2) is a promising layer-structured material for use in many applications due to its tunable structural and electronic properties in terms of its structural phases. Its performance including efficiency and durability is often dependent on its mechanical properties. To understand the effects of the structural phase on its mechanical properties, a comparative study on the mechanical properties of bulk 2H, 3R, 1T, and 1T' MoS2 was conducted using the first-principles density functional theory. Since considerable applications of MoS2 are developed through strain engineering, the impact of the external pressure on its mechanical properties was also considered. Our results suggest a strong relationship between the mechanical properties of MoS2 and the structural symmetry of its crystal. Accordingly, the impacts of the external pressure on the mechanical properties of MoS2 also greatly vary with respect to the structural phases. Among all of the considered phases, the 2H and 3R MoS2 have a larger bulk modulus, Young's modulus, shear modulus, and microhardness due to their higher stability. Conversely, 1T and 1T' MoS2 are less strong. As such, 1T and 1T' MoS2 can be a better candidate for strain engineering.

Degradation of ronidazole by electrochemically simultaneously generated persulfate and ferrous ions.

Nitroimidazoles are found in pharmaceuticals and personal care products (PPCPs) and, when discharged into the environment, have adverse effects on human health and survival. Advanced oxidation technologies (AOTs) based on persulfate (PS) can rapidly and efficiently degrade organic pollutants via strong oxidizing radicals under activation conditions. This study investigated the degradation of ronidazole (RNZ) by indirect electrolytic generation of PS and its activator, ferrous ion (Fe2+). An electrochemical system was developed, with a high concentration of PS generated at the anode while the activator Fe2+ was produced at the cathode. It showed that ammonium polyphosphate (APP) could effectively promote the electrolysis of PS. A high current efficiency (88%) at the anode could be obtained after 180 min at a high current density (300 mA cm-2). However, Fe2+ was inhibited at the cathode due to material control. The degradation of RNZ in the Fe2+/PS system generated from the electrochemical system was also explored. Increasing PS concentration and Fe2+/PS ratio were beneficial to the RNZ degradation. In homogeneous reactions, the degradation efficiency of RNZ could be improved by decreasing the Fe2+ addition rate through a peristaltic pump. Five intermediates were also detected and the degradation pathways were proposed. These findings provide a new method and mechanism for rapid and efficient degradation of RNZ.

Effect of pyrite on enhancement of zero-valent iron corrosion for arsenic removal in water: A mechanistic study.

In this study, the enhanced effect of pyrite (FeS2) on zero-valent iron (Fe0) corrosion for arsenic (As) removal was investigated in a combined-Fe0/FeS2 system. The effects of different Fe0/FeS2 composition, dosage and initial pH were evaluated by batch experiments. Results showed that the best combination ratio of Fe0:FeS2 (w/w) was 1:1 and the optimal dosage of mixture was 2.0 g/L. The combination of Fe0 and FeS2 in a system significantly enhanced the reactivity of Fe0 for effective As removal within a broad pH range (3.0-9.0). The effective As removal in the combined-Fe0/FeS2 system was primarily ascribed to being enhanced corrosion of Fe0 by addition of FeS2. SEM and XRD characterizations strongly verified this point. Specifically, the mechanism study (the releases of Fe2+ and total Fe ion, variations of pH values as well as XPS characterization) suggested that FeS2 in the combined-Fe0/FeS2 system could alleviate the passivation of Fe0 (pHini 3.0-5.0) and accelerate the dissolution of pristine oxide film that coated on Fe0 surface (pHini 6.8-9.0). Besides, FeS2 in combined-Fe0/FeS2 system could also accelerate the reactions between Fe0 to O2 at pHini 3.0-9.0. These phenomena were well explained by a galvanic couple between Fe0 and FeS2, where FeS2 was a cathode and Fe0 was an anode. Consequently, electrons released from Fe0 that mediated by FeS2 to oxide film, passivation layer and O2 were accelerated in combined-Fe0/FeS2 system and thereby enhanced the corrosion of Fe0 for efficient As removal. Our findings suggest that utilizing FeS2 to enhance the corrosion of Fe0 would be a promising technology for remediation of As-contaminated water.

High-performance nanoporous TiO2/La2O3 hybrid photoanode for dye-sensitized solar cells.

An organic lanthanum solution was prepared and used for modifying the nanoporous TiO(2) photoanode for dye-sensitized solar cells (DSSCs). The preliminary characterization results demonstrate that La(2)O(3) was formed on the surface of the TiO(2) photoanodes. The X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) analyses suggest that La(3+) was introduced into the TiO(2) nanocrystalline, while, the scanning electron microscopy (SEM) and tunnelling electron microscopy (TEM) characterizations suggest that a thin La(2)O(3) layer forms on surface of the TiO(2) nanostructure. The La(2)O(3) layer is able to alleviate the electron recombination as a passivation layer. Though the slight decrease in surface areas were induced by the surface modification, the dye loading were maintained, which can be attributed to the formation of strong co-ordination bonding between the dye molecules and the lanthanide. The bonding can also facilitate the electron transfer between the dye molecules and TiO(2) conduction band. Consequently, the open circuit potential and short circuit current were boosted significantly and the overall energy conversion efficiency of the DSSCs was remarkably improved from 6.84% for the control film to 9.67% for the La(3+)-modified film.