15 research outputs found
Prioritizing Health Care Strategies to Reduce Childhood Mortality
IMPORTANCE: Although child mortality trends have decreased worldwide, deaths among children younger than 5 years of age remain high and disproportionately circumscribed to sub-Saharan Africa and Southern Asia. Tailored and innovative approaches are needed to increase access, coverage, and quality of child health care services to reduce mortality, but an understanding of health system deficiencies that may have the greatest impact on mortality among children younger than 5 years is lacking. OBJECTIVE: To investigate which health care and public health improvements could have prevented the most stillbirths and deaths in children younger than 5 years using data from the Child Health and Mortality Prevention Surveillance (CHAMPS) network. DESIGN, SETTING, AND PARTICIPANTS: This cross-sectional study used longitudinal, population-based, and mortality surveillance data collected by CHAMPS to understand preventable causes of death. Overall, 3390 eligible deaths across all 7 CHAMPS sites (Bangladesh, Ethiopia, Kenya, Mali, Mozambique, Sierra Leone, and South Africa) between December 9, 2016, and December 31, 2021 (1190 stillbirths, 1340 neonatal deaths, 860 infant and child deaths), were included. Deaths were investigated using minimally invasive tissue sampling (MITS), a postmortem approach using biopsy needles for sampling key organs and fluids. MAIN OUTCOMES AND MEASURES: For each death, an expert multidisciplinary panel reviewed case data to determine the plausible pathway and causes of death. If the death was deemed preventable, the panel identified which of 10 predetermined health system gaps could have prevented the death. The health system improvements that could have prevented the most deaths were evaluated for each age group: stillbirths, neonatal deaths (aged <28 days), and infant and child deaths (aged 1 month to <5 years). RESULTS: Of 3390 deaths, 1505 (44.4%) were female and 1880 (55.5%) were male; sex was not recorded for 5 deaths. Of all deaths, 3045 (89.8%) occurred in a healthcare facility and 344 (11.9%) in the community. Overall, 2607 (76.9%) were deemed potentially preventable: 883 of 1190 stillbirths (74.2%), 1010 of 1340 neonatal deaths (75.4%), and 714 of 860 infant and child deaths (83.0%). Recommended measures to prevent deaths were improvements in antenatal and obstetric care (recommended for 588 of 1190 stillbirths [49.4%], 496 of 1340 neonatal deaths [37.0%]), clinical management and quality of care (stillbirths, 280 [23.5%]; neonates, 498 [37.2%]; infants and children, 393 of 860 [45.7%]), health-seeking behavior (infants and children, 237 [27.6%]), and health education (infants and children, 262 [30.5%]). CONCLUSIONS AND RELEVANCE: In this cross-sectional study, interventions prioritizing antenatal, intrapartum, and postnatal care could have prevented the most deaths among children younger than 5 years because 75% of deaths among children younger than 5 were stillbirths and neonatal deaths. Measures to reduce mortality in this population should prioritize improving existing systems, such as better access to antenatal care, implementation of standardized clinical protocols, and public education campaigns
Towards microbioprocess control:an inexpensive 3D printed microbioreactor with integrated online real-time glucose monitoring
Abstract
Bioprocessing is of crucial importance in pharmaceutical, biofuel, food and other industries. Miniaturization of bioprocesses into microbioreactors allows multiplexing of experiments as well as reduction of reagent consumption and labour-intensity. A crucial part of the research within microbioreactors is biochemical analysis of product, byproduct and substrate concentrations that currently heavily relies on large analytical equipment. Biosensors are a promising analytical tool, however, integration into a microbioreactor is associated with challenges in ensuring sterility, appropriate sensing range, control of matrix effects and stability. In this work we present a novel biosensor integrated analytical chip that features an internal, actuated buffer flow in contact with a biosensor downstream and a diffusion limiting membrane exposed to the sample upstream. The technology was developed and tested using an electrochemical glucose oxidase biosensor and was found to successfully surmount the aforementioned challenges including the extension of the linear range of sensitivity to more than 20 g L⁻¹ for online, real time monitoring of glucose. The biosensor integration chip with the glucose biosensor was then mounted onto a 3D printed microbioreactor with 1 mL of internal volume. The system successfully monitored the consumption of glucose of Saccharomyces cerevisiae in real time for more than 8 h. The developed technology and measurement methodologies are transferrable to other biosensors and microbioreactors as well as large scale applications
Erratum to: A disposable biosensor for the determination of alpha-amylase in human saliva
Desarrollo de un polímero de impronta molecular selectivo a ácido fólico para su determinación en extractos de alimentos utilizando extracción en fase sólida dispersiva y LC-MS
El ácido fólico (FA) es un compuesto que pertenece al grupo de las vitaminas B (vitamina B9) de gran importancia nutricional. Existen diferentes metodologías para llevar a cabo su determinación de manera precisa en diferentes matrices y, en todas ellas, se hace necesario incluir una etapa de extracción previa a su determinación, lo que mejora la sensibilidad de las mediciones y reduce los posibles efectos matriz. Tanto la extracción en fase sólida (SPE) como técnicas relacionadas que utilizan polímeros de impronta molecular (MIP) permiten una purificación simple y efectiva, así como una preconcentración del FA presente en alimentos y muestras biológicas. En este trabajo se ha desarrollado un nuevo MIP para la extracción selectiva de FA en matrices alimentarias. Para ello, se han estudiado diversas combinaciones de monómeros (ácido metacrílico (MAA), 4-vinilpiridina (4VPy) y cloruro de vinilbencil trimetilamonio (VBTMAC)) y entrecruzadores (etilenglicoldimetacrilato (EGDMA) y divinilbenceno (DVB)) en diversos porógenos. Las isotermas de absorción muestran que la mayor afinidad se consigue usando VBTMAC como monómero funcional y EGDMA como entrecruzador. Posteriormente, se optimizó la relación FA:VBTMAC:EGDMA (1:25:250) y se determinaron sus propiedades de unión, tanto cinéticas como de equilibrio, determinando una alta afinidad (2.5 mmol g-1) y una elevada relación MIP/NIP (superior a 37).Posteriormente, se usó este MIP para la extracción de FA en lechuga y galletas enriquecidas mediante extracción en fase sólida dispersiva (DSPE) y su ulterior análisis por LC-MS, obteniendo una recuperación y repetibilidad apropiadas (≥ 79,50% y ≤ 13,15 (% RDS), respectivamente).Fil: Panjan, Peter. University Of Oulu; FinlandiaFil: Monasterio, Romina Paula. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto de Biología Agrícola de Mendoza. Universidad Nacional de Cuyo. Facultad de Ciencias Agrarias. Instituto de Biología Agrícola de Mendoza; ArgentinaFil: Fernández Gutiérrez, Alberto. Universidad de Granada. Facultad de Ciencias; EspañaFil: Sesay, Adama M.. University Of Oulu; FinlandiaFil: Carrasco-Pancorbo, Alegría. Universidad de Granada. Facultad de Ciencias; EspañaFil: Fernandez Sanchez, Jorge F.. Universidad de Granada. Facultad de Ciencias; EspañaXXII Reunión de la Sociedad Española de Química AnalíticaValladolidEspañaSociedad Española de Química Analític
Characterization of an enzymatic packed-bed microreactor:experiments and modeling
Abstract A micro packed-bed reactor (µPBR) based on two-parallel-plates configuration with immobilized Candida antarctica lipase B in the form of porous particles (Novozym® 435) was theoretically and experimentally characterized. A residence time distribution (RTD) within µPBRs comprising various random distributions of particles placed in one layer was computationally predicted by a mesoscopic lattice Boltzmann (LB) method. Numerical simulations were compared with measurements of RTD, obtained by stimulus-response experiment with a pulse input using glucose as a tracer, monitored by an electrochemical glucose oxidase microbiosensor integrated with the reactor. The model was validated by a good agreement between the experimental data and predictions of LB model at different conditions. The developed µPBR was scaled-up in length and width comprising either a single or two layers of Novozym® 435 particles and compared regarding the selected enzyme-catalyzed transesterification. A linear increase in the productivity with the increase in all dimensions of the µPBR between two-plates demonstrated very efficient and simple approach for the capacity rise. Further characterization of µPBRs of various sizes using the piezoresistive pressure sensor revealed very low pressure drops as compared to their conventional counterparts and thereby great applicability for production systems based on numbering-up approach
Microfluidic flow injection immunoassay system for algal toxins determination:a case of study
Abstract
A novel flow injection microfluidic immunoassay system for continuous monitoring of saxitoxin, a lethal biotoxin, in seawater samples is presented in this article. The system consists of a preimmobilized G protein immunoaffinity column connected in line with a lab-on-chip setup. The detection of saxitoxin in seawater was carried out in two steps: an offline incubation step (competition reaction) performed between the analyte of interest (saxitoxin or Ag, as standard or seawater sample) and a tracer (an enzyme-conjugated antigen or Ag*) toward a specific polyclonal antibody. Then, the mixture was injected through a “loop” of a few μL using a six-way injection valve into a bioreactor, in line with the valve. The bioreactor consisted of a small glass column, manually filled with resin upon which G protein has been immobilized. When the mixture flowed through the bioreactor, all the antibody-antigen complex, formed during the competition step, is retained by the G protein. The tracer molecules that do not interact with the capture antibody and protein G are eluted out of the column, collected, and mixed with an enzymatic substrate directly within the microfluidic chip, via the use of two peristaltic pumps. When Ag* was present, a color change (absorbance variation, ΔAbs) of the solution is detected at a fixed wavelength (655 nm) by an optical chip docking system and registered by a computer. The amount of saxitoxin, present in the sample (or standard), that generates the variation of the intensity of the color, will be directly proportional to the concentration of the analyte in the analyzed solution. Indeed, the absorbance response increased proportionally to the enzymatic product and to the concentration of saxitoxin in the range of 3.5 × 10⁻⁷–2 × 10⁻⁵ ng ml⁻¹ with a detection limit of 1 × 10⁻⁷ ng ml⁻¹ (RSD% 15, S N⁻¹ equal to 3). The immunoanalytical system has been characterized, optimized, and tested with seawater samples. This analytical approach, combined with the transportable and small-sized instrumentation, allows for easy in situ monitoring of marine water contaminations
A fully online sensor-equipped, disposable multiphase microbioreactor as a screening platform for biotechnological applications
Abstract
A new disposable, multiphase, microbioreactor (MBR; with a working volume of 550 μl) equipped with online sensors is presented for biotechnological screening research purposes owing to its high‐throughput potential. Its design and fabrication, online sensor integration, and operation are described. During aerobic cultivation, sufficient oxygen supply is the most important factor that influences growth and product formation. The MBR is a microbubble column bioreactor (μBC), and the oxygen supply was realized by active pneumatic bubble aeration, ensuring sufficient volumetric liquid‐phase mass transfer (kLa) and proper homogenization of the cultivation broth. The μBC was equipped with miniaturized sensors for the pH, dissolved oxygen, optical density and glucose concentration that allowed real‐time online monitoring of these process variables during cultivation. The challenge addressed here was the integration of sensors in the limited available space. The MBR was shown to be a suitable screening platform for the cultivation of biological systems. Batch cultivations of Saccharomyces cerevisiae were performed to observe the variation in the process variables over time and to show the robustness and operability of all the online sensors in the MBR
Electrochemical impedance spectroscopy for monitoring of alkaline phosphatase reaction with substrate
Abstract
Electrochemical impedance spectroscopy was compared to square wave voltammetry for monitoring the reaction between alkaline phosphatase and its substrates