Multiplexed Detection of Pathogens Using Solid-Phase Loop-Mediated Isothermal Amplification on a Supercritical Angle Fluorescence Array for Point-of-Care Applications.

Adaptations of new generation molecular techniques for multiplexed detection of pathogens are gaining interest in the field of point-of-care (POC) industry and onsite testing. Loop-mediated isothermal amplification (LAMP), an advanced molecular amplification technique, has proven promising due to its unique features that suits ideal for POC applications. However, application of LAMP for multiplexed detection of pathogens remains challenging because of the difficulty in the identification of specific LAMP amplicons that does not have a well-definite molecular size. In this study, we developed a solid-phase loop-mediated isothermal amplification (SP-LAMP) technique to address the challenge. Integration of LAMP with the supercritical angle fluorescence (SAF) micro-optic structures as a solid support (SS) in an array format enabled spatial separation of LAMP amplicons in a multiplexed configuration. Important parameters such as length of the SS primers, length of the primer-binding region, the effect of surface density of immobilized SS primers, and cross-reactivity among the primers of different targets were iteratively tested and optimized. With the combination of SP-LAMP and SAF techniques, it was possible to detect multiple pathogens that include Salmonella spp, Campylobater spp., Campylobacter coli, Campylobacter jejuni, avian influenza virus (AIV), and pan avian internal control (IC) under singleplex conditions. The multiplexing capacity of the SP-LAMP was demonstrated using AIV and IC with promising results. The success of SP-LAMP has opened a promising direction toward the development of a multiplex POC system for rapid detection of multiple pathogens.

Elimination of Carryover Contamination in Real-Time Reverse Transcriptase Loop-Mediated Isothermal Amplification for Rapid Detection of the SARS-CoV-2 Virus in Point-of-Care Testing.

Loop-mediated isothermal amplification (LAMP) is being used as a robust rapid diagnostic tool to prevent the transmission of infectious diseases. However, carryover contamination of LAMP-amplified products originating from previous tests has been a problem in LAMP-based bio-analytical assays. In this study, we developed a Cod-uracil-DNA-glycosylase real-time reverse transcriptase LAMP assay (Cod-UNG-rRT-LAMP) for the elimination of carryover contamination and the rapid detection of SARS-CoV-2 in point-of-care (POC) testing. Using the Cod-UNG-rRT-LAMP assay, the SARS-CoV-2 virus could be detected as low as 2 copies/µl (8 copies/reaction) within 45 min of amplification and 2.63 ± 0.17 pg (equivalent to 2.296 × 109 copies) of contaminants per reaction could be eliminated. Analysis of clinical SARS-CoV-2 samples using the Cod-UNG-rRT-LAMP assay showed an excellent agreement with a relative accuracy of 98.2%, sensitivity of 97.1%, and specificity of 95.2% in comparison to rRT-PCR. The results obtained in this study clearly demonstrate the feasibility of the use of the Cod-UNG-rRT-LAMP assay for applications toward the POC diagnosis of SARS-CoV-2 and on-site testing of other pathogens.

Factors associated with anxiety and depression among chronic obstructive pulmonary disease outpatients in Ho Chi Minh City, Vietnam.

This study investigates the prevalence of and associated factors with depression and anxiety among chronic obstructive pulmonary disease (COPD) outpatients at Pham Ngoc Thach Hospital, Ho Chi Minh City, Vietnam. A cross-sectional study was conducted between March and May 2020 at the hospital's outpatient department. Those aged ≥18 years, diagnosed with COPD and undergoing COPD treatment, were eligible. The Hospital Anxiety and Depression Scale was used to measure depression and anxiety. Dyspnea was assessed using the modified Medical Research Council (mMRC) dyspnea scale. Among 392 patients, 381 (97%) participated in the study. The number of patients with depression and anxiety was 33.1% and 21.3%, respectively. Compared to men, women were more likely to experience depression (adjusted odds ratio [aOR] = 2.12, 95% confidence interval [CI] = 1.06-4.24) and anxiety (aOR = 4.11, 95% CI = 1.90-8.87). Those not having caregivers were more likely to experience depression (aOR = 3.03, 95% CI = 1.27-7.20) and anxiety (aOR = 3.47, 95% CI = 1.26-9.60). Having mMRC dyspnea scale ≥2 was associated with higher odds of experiencing depression (aOR = 5.94, 95% CI = 3.63-9.72) and anxiety (aOR = 6.78, 95% CI = 3.48-13.18). Those not adhering to medication treatment (aOR = 2.32, 95% CI = 1.15-4.70) and having comorbidity (aOR = 2.02, 95% CI = 1.10-3.73) were more likely to experience anxiety. Routine screening of COPD patients for depression and anxiety is necessary so that early interventions could be provided.

Enhanced Power Output of a Triboelectric Nanogenerator using Poly(dimethylsiloxane) Modified with Graphene Oxide and Sodium Dodecyl Sulfate.

In this work, a new approach to modifying poly(dimethylsiloxane) (PDMS) as a negative triboelectric material using graphene oxide (GO) and a sodium dodecyl sulfate (SDS) surfactant was reported. A porous PDMS@GO@SDS composite triboelectric nanogenerator (TENG) could deliver an output voltage and current of up to 438 V and 11 µA/cm2, respectively. These values were 3-fold higher than those of the flat PDMS. The superior performance is attributed to the intensified negative charges on PDMS from the oxygen functional groups of GO and anionic head groups of the SDS molecules. The outstanding performance and straightforward, low-cost fabrication process of the PDMS@GO@SDS TENG would be beneficial for the further development of powerful NGs integrated into wearable electronics and self-charging power cells.

A comparative study of supercapacitive performances of nickel cobalt layered double hydroxides coated on ZnO nanostructured arrays on textile fibre as electrodes for wearable energy storage devices.

We demonstrated an efficient method for the fabrication of novel, flexible electrodes based on ZnO nanoflakes and nickel-cobalt layered double hydroxides (denoted as ZnONF/NiCoLDH) as a core-shell nanostructure on textile substrates for wearable energy storage devices. NiCoLDH coated ZnO nanowire (denoted as ZnONW/NiCoLDH) flexible electrodes are also prepared for comparison. As an electrode for supercapacitors, ZnONF/NiCoLDH exhibits a high specific capacitance of 1624 F g(-1), which is nearly 1.6 times greater than ZnONW/NiCoLDH counterparts. It also shows a maximum energy density of 48.32 W h kg(-1) at a power density of 27.53 kW kg(-1), and an excellent cycling stability with capacitance retention of 94% and a Coulombic efficiency of 93% over 2000 cycles. We believe that the superior performance of the ZnONF/NiCoLDH hybrids is due primarily to the large surface area of the nanoflake structure and the open spaces between nanoflakes, both of which provide a large space for the deposition of NiCoLDH, resulting in reduced internal resistance and improved capacitance performance. Our results are significant for the development of electrode materials for high-performance wearable energy storage devices.