Enhancing the Sensitivity of NDIR Spectroscopy Using Plasmonic Crystal Structures

Monitoring the concentration of methane is of crucial importance for health, safety, and maintenance. NDIR spectroscopy is a widely used commercially available method of monitoring the concentration of Gases. Enhancing the sensitivity of the IR detector enhances the limit of detection of NDIR sensors. Plasmonic crystal structures have been shown to enhance the absorption of EM radiation at certain wavelengths depending on their dimensions. In this thesis, a 13 fold enhancement in the LOD of a methane NDIR gas sensor was achieved by designing a plasmonic crystal structure. The structure is a layer of gold with a two dimensional array of micro sized holes. The dimensions of the structure were optimized by COMSOL simulations to get maximum absorption at λ=7.7 µm. The structure was fabricated and the NDIR sensor was developed to experimentally show the enhancement. The experimental results showed good agreement with the simulations and achieved the expected enhancement

Enhancing the Responsivity of Uncooled Infrared Detectors Using Plasmonics for High-Performance Infrared Spectroscopy

A lead zirconate titanate (PZT;Pb(Zr0.52Ti0.48)O3) layer embedded infrared (IR) detector decorated with wavelength-selective plasmonic crystals has been investigated for high-performance non-dispersive infrared (NDIR) spectroscopy. A plasmonic IR detector with an enhanced IR absorption band has been designed based on numerical simulations, fabricated by conventional microfabrication techniques, and characterized with a broadly tunable quantum cascade laser. The enhanced responsivity of the plasmonic IR detector at specific wavelength band has improved the performance of NDIR spectroscopy and pushed the limit of detection (LOD) by an order of magnitude. In this paper, a 13-fold enhancement in the LOD of a methane gas sensing using NDIR spectroscopy is demonstrated with the plasmonic IR detector

Adherence to antihypertensives in the United States: A comparative meta‐analysis of 23 million patients

Abstract Adherence to antihypertensives is crucial for control of blood pressure. This study analyzed factors and interventions that could affect adherence to antihypertensives in the US. PubMed, Scopus, Web of Science, and Embase were searched on January 21, 2022 and December 25, 2023 for studies on the adherence to antihypertensives in the US. Nineteen studies and 23 545 747 patients were included in the analysis, which showed that adherence to antihypertensives was the highest among Whites (OR: 1.47, 95% CI 1.34–1.61 compared to African Americans). Employment status and sex were associated with insignificant differences in adherence rates. In contrast, marital status yielded a significant difference where unmarried patients demonstrated low adherence rates compared to married ones (OR: 0.8, 95% CI 0.67–0.95). On analysis of comorbidities, diabetic patients reported lower adherence to antihypertensives (OR: 0.95, 95% CI 0.92–0.97); furthermore, patients who did not have Alzheimer showed higher adherence rates. Different BMIs did not significantly affect the adherence rates. Patients without insurance reported significantly lower adherence rates than insured patients (OR: 3.93, 95% CI 3.43–4.51). Polypill users had higher adherence rates compared with the free‐dose combination (OR: 1.21, 95% CI 1.2–1.21), while telepharmacy did not prove to be as effective. Lower adherence rates were seen among African Americans, uninsured, or younger patients. Accordingly, interventions such as fixed‐dose combinations should be targeted at susceptible groups. Obesity and overweight did not affect the adherence to antihypertensives

Roles of Exogenous α-Lipoic Acid and Cysteine in Mitigation of Drought Stress and Restoration of Grain Quality in Wheat

Cysteine (Cys) and α-lipoic acid (ALA) are naturally occurring antioxidants (sulfur-containing compounds) that can protect plants against a wide spectrum of environmental stresses. However, up to now, there are no conclusive data on their integrative roles in mitigation of drought stress in wheat plants. Here, we studied the influence of ALA at 0.02 mM (grain dipping pre-cultivation treatment) and Cys (25 and 50 ppm as a foliar application) under well watered and deficit irrigation (100% and 70% of recommended dose). The results showed that deficit irrigation markedly caused obvious cellular oxidative damage as indicated by elevating the malondialdehyde (MDA) and hydrogen peroxide content (H2O2). Moreover, water stressed plants exhibited multiple changes in physiological metabolism, which affected the quantitative and qualitative variables of grain yield. The enzymatic antioxidants, including superoxide dismutase (SOD), ascorbate peroxidase (APX), catalase (CAT) and peroxidase (POX) were improved by Cys application. SOD and APX had the same response when treated with ALA, but CAT and POX did not. Moreover, both studied molecules stimulated chlorophyll (Chl) and osmolytes’ biosynthesis. In contrast, the Chl a/b ratio was decreased, while flavonoids were not affected by either of the examined molecules. Interestingly, all above-mentioned changes were associated with an improvement in the scavenging capacity of reactive oxygen species (ROS), leaf relative water content (RWC), grain number, total grain yield, weight of 1000 kernels, gluten index, falling number, and alveographic parameters (P, W, and P/L values). Furthermore, heatmap plot analysis revealed several significant correlations between different studied parameters, which may explore the importance of applied Cys and ALA as effective compounds in wheat cultivation under water deficit conditions

Roles of Exogenous α-Lipoic Acid and Cysteine in Mitigation of Drought Stress and Restoration of Grain Quality in Wheat

Cysteine (Cys) and α-lipoic acid (ALA) are naturally occurring antioxidants (sulfur-containing compounds) that can protect plants against a wide spectrum of environmental stresses. However, up to now, there are no conclusive data on their integrative roles in mitigation of drought stress in wheat plants. Here, we studied the influence of ALA at 0.02 mM (grain dipping pre-cultivation treatment) and Cys (25 and 50 ppm as a foliar application) under well watered and deficit irrigation (100% and 70% of recommended dose). The results showed that deficit irrigation markedly caused obvious cellular oxidative damage as indicated by elevating the malondialdehyde (MDA) and hydrogen peroxide content (H2O2). Moreover, water stressed plants exhibited multiple changes in physiological metabolism, which affected the quantitative and qualitative variables of grain yield. The enzymatic antioxidants, including superoxide dismutase (SOD), ascorbate peroxidase (APX), catalase (CAT) and peroxidase (POX) were improved by Cys application. SOD and APX had the same response when treated with ALA, but CAT and POX did not. Moreover, both studied molecules stimulated chlorophyll (Chl) and osmolytes’ biosynthesis. In contrast, the Chl a/b ratio was decreased, while flavonoids were not affected by either of the examined molecules. Interestingly, all above-mentioned changes were associated with an improvement in the scavenging capacity of reactive oxygen species (ROS), leaf relative water content (RWC), grain number, total grain yield, weight of 1000 kernels, gluten index, falling number, and alveographic parameters (P, W, and P/L values). Furthermore, heatmap plot analysis revealed several significant correlations between different studied parameters, which may explore the importance of applied Cys and ALA as effective compounds in wheat cultivation under water deficit conditions