This work presents a low-cost transcription loop-mediated isothermal amplification (RT-LAMP) instrument for nucleic acid detection, employing an Arduino Nano microcontroller. The cooling system includes customized printed circuit boards (PCBs) that serve as electrical resistors and incorporate fans. An aluminum block is designed to accommodate eight vials. The system also includes two PCB heaters—one for sample heating and the other for vial lid heating to prevent condensation. The color detection system comprises a TCS3200 color 8-sensor array coupled to one side of the aluminum heater body and a white 8-LED array coupled to the other side, controlled by two Multiplexer/Demultiplexer devices. LED light passes through the sample, reaching the color sensor and conveying color information crucial for detection. The top board is maintained at 110 ± 2 °C, while the bottom board is held at 65 ± 0.5 °C throughout the RT-LAMP assay. Validation tests successfully demonstrated the efficacy of the colorimetric RT-LAMP reactions using SARS-CoV-2 RNA amplification as a sample viability test, achieving 100% sensitivity and 97.3% specificity with 66 clinical samples. Our instrument offers a cost-effective (USD 100) solution with automated result interpretation and superior sensitivity compared to visual inspection. While the prototype was tested with SARS-CoV-2 RNA samples, its versatility extends to detecting other pathogens using alternative primers, showcasing its potential for broader applications in biosensing.

Gelatine is the external standard matrix of choice for quantitative biomaging of elements and metal tags in tissue. Its ablation characteristics closely match that of tissue when using 193 and 213 nm lasers, but this has not been demonstrated at 266 nm. With the interest in 266 nm laser ablation systems growing due to the selective ablation of tissue over glass substrates, this gap needed to be investigated. Optical profilometry was used to map the line crater volumes of gelatine and murine brain and quadriceps tissues ablated with a 266 nm laser. Raw gelatine did not ablate in a similar manner to either tissue type and ultra-violet absorbent chemical additives were required to match ablation volumes. Addition of either 4 g L^-1l-tryptophan or 3 g L^-1 gallic acid was used to match the ablation volume of murine quadriceps. Murine brain tissue had an increased ablation volume over the quadriceps tissue (1400 ± 130 versus 1100 ± 160 μm³ at 1.5 J cm^-2), and the addition of 5 g L^-1 gallic acid and the use of low laser energy (≤1.5 J cm^-2) was required to match the ablation of brain tissue. The modified standards were tested on a 213 nm laser, and the addition of either additive to gelatine did not affect ablation volume. The effect of additives on fractionation and two-phase sample transport was investigated, no fractionation was observed, and a decrease in two-phase sample transport of up to 60 % was obtained with the modified gelatine. This decrease was caused by the reduced laser energy required for ablation. Finally, the potential uses of optical profilometry as a standardisation tool are discussed.

Purpose: Convalescent plasma (CP), obtained from individuals who have recovered from COVID-19, has been widely explored as a potential therapeutic option, particularly in the absence of vaccines and monoclonal antibody treatments. This study aimed to evaluate the effectiveness of CP therapy in improving survival among non-immunized COVID-19 patients hospitalized in Brazil. Methods: This retrospective unicentric cohort study was conducted at a private hospital in Campo Largo, Paraná, Brazil, from July 2020 to February 2021. A total of 245 hospitalized COVID-19 patients were included, confirmed by RT-qPCR or antigen testing. Patients were divided into two groups: those receiving CP alongside standard treatment (n=100) and those receiving standard treatment alone (n=145). Survival outcomes were assessed using Kaplan-Meier analysis and Cox regression, while inflammatory responses were evaluated through C-reactive protein (CRP) measurements. Results: Patients treated with CP had a significantly higher survival rate (91%) compared to the control group (82.8%) (P=0.0363). The survival benefit persisted throughout the follow-up period, with a 2.25-fold lower risk of death in the CP group after adjusting for age (P=0.0480). However, no significant differences in CRP levels were observed between groups at discharge, suggesting that CP's benefits may be mediated through immune modulation rather than direct anti-inflammatory effects. Conclusions: Our findings indicate that CP therapy significantly improves survival in non-immunized COVID-19 patients, reinforcing its potential role in settings with limited access to advanced treatments. Future studies should explore CP’s mechanisms of action and its integration into broader therapeutic strategies.

Quantitative elemental bioimaging workflows are well established and typically rely on matrix-matched standards for comparable and repeatable calibration. However, variations in tissue thickness, microtome cutting artefacts, and cell density are usually assumed to have negligible impact on method uncertainties. Common mitigation strategies include endogenous signal normalization with ¹²C or ³¹P, complete ablation of thin sections, or analysis of thicker specimens under stable laser fluences. While effective for homogeneous specimens, these approaches may fail in heterogeneous tissues with disparate anatomical structures, variable cell populations, or inconsistencies in sectioning, leading to uncontrolled anomalies and potentially misleading interpretation of elemental distributions. To overcome these limitations, here we incorporate optical profilometry into quantitative bioimaging workflows to directly measure tissue surface topographies and correct for thickness variations. Topographic maps were acquired for gelatin standards and representative tissues, including murine kidney, multi-organ arrays, human meningioma, and emphysematous lung, revealing substantial deviations from nominal thicknesses and heterogeneous surface roughness. These data were registered against LA-ICP-MS elemental images and applied for volume normalization. Volume correction significantly altered elemental quantification. In kidney, Cu, Fe, and Zn increased 4-5 fold, whereas in meningioma, Cu and Fe increased 8-10 fold, with Zn similarly elevated. Correlations of endogenous signals with thickness were tissue-dependent: in the kidney, ¹²C strongly correlated (R = 0.66) and ³¹P moderately (R = 0.44), while in the meningioma, both were weak (¹²C R = 0.21; ³¹P R = 0.09), though ³¹P moderately tracked cell density (R = 0.51). These results demonstrate that profilometry-based volume correction improves accuracy, reproducibility, and interpretability of elemental bioimaging, particularly in heterogeneous tissues.