Biological soil amendments (BSAs) are essential agricultural inputs that provide critical nutrients in organic leafy green production. Heat-treated poultry pellets (HTPP) and seabird guano (SBG), which have been treated to reduce microbial pathogen loads, are gaining popularity among growers. Using these BSAs in the process of side-dressing, providing nutrients to crops while growing, may provide opportunities for externally introduced bacterial pathogens to survive in soil.
View Article and Find Full Text PDFBackground: Bullying is a pervasive issue that can occur in any setting, including among nursing students and within the nursing profession. Faculty members have a vital role in resolving bullying.
Objectives: To examine the nursing faculty members' responses to incidents of bullying within two nursing institutions in Pangasinan.
Rural environments lack basic sanitation services. Facilities for obtaining water and disposing sewage are often under the initiative of each resident, who may not be able to build and maintain them properly. Thus, water for human consumption is subject to fecal contamination and, consequently, the presence of waterborne pathogens, such as enteric viruses.
View Article and Find Full Text PDFThe quality of the water consumed by a given community is related to its quality of life. In this sense, this study aimed to evaluate, from the perspective of health risk, the physical, chemical, and microbiological quality of drinking water, in a quilombola community, and the qualitative aspects intrinsic to its use and storage. For this, water samples, collected at the exits of the collective water supply system and from eight cisterns that store rainwater, used for human consumption, were analyzed.
View Article and Find Full Text PDFThis paper describes for the first time the use of paper-based analytical devices at crime scenes to estimate the post-mortem interval (PMI), based on the colorimetric determination of Fe in vitreous humour (VH) samples. Experimental parameters such as the paper substrate, the microzone diameter, the sample volume and the 1,10-phenanthroline (o-phen) concentration were optimised in order to ensure the best analytical performance. Grade 1 CHR paper, microzone with diameter of 5 mm, a sample volume of 4 μL and an o-phen concentration of 0.
View Article and Find Full Text PDFThis chapter describes two different methodologies used to improve the analytical performance of colorimetric paper-based biosensors. Microfluidic paper-based analytical devices (μPADs) have been produced by a stamping process and CO laser ablation and modified, respectively, through an oxidation step and incorporation of silica nanoparticles on the paper structure. Both methods are employed in order to overcome the largest problem associated with colorimetric detection, the heterogeneity of the color distribution in the detection zones.
View Article and Find Full Text PDFHere we report for the first time the use of an electronic micropipette as hydrodynamic (HD) injector for microchip electrophoresis (ME) devices. The micropipette was directly coupled to a PDMS device, which had been fabricated in a simple cross format with two auxiliary channels for sample volume splitting. Sample flow during the injection procedure was controlled in automatic dispenser mode using a volume of 0.
View Article and Find Full Text PDFThis study describes a simple, rapid, and cost-effective fabrication of PDMS electrophoresis microchips using poly(vinyl acetate) (PVAc) emulsion as photoresist master. High-relief microfluidic structures were defined on poly(vinyl acetate) previously deposited on printed circuit boards surfaces without cleanroom facilities and sophisticated instrumentation. After a UV exposure, channels with heights ranging from 30 to 140 μm were obtained by controlling the emulsion mass deposited on the master surface.
View Article and Find Full Text PDFThis paper describes the modification of microfluidic paper-based analytical devices (μPADs) with chitosan to improve the analytical performance of colorimetric measurements associated with enzymatic bioassays. Chitosan is a natural biopolymer extensively used to modify biosensing surfaces due to its capability of providing a suitable microenvironment for the direct electron transfer between an enzyme and a reactive surface. This hypothesis was investigated using glucose and uric acid (UA) colorimetric assays as model systems.
View Article and Find Full Text PDFThis paper describes a silica nanoparticle-modified microfluidic paper-based analytical device (μPAD) with improved color intensity and uniformity for three different enzymatic reactions with clinical relevance (lactate, glucose, and glutamate). The μPADs were produced on a Whatman grade 1 filter paper and using a CO2 laser engraver. Silica nanoparticles modified with 3-aminopropyltriethoxysilane were then added to the paper devices to facilitate the adsorption of selected enzymes and prevent the washing away effect that creates color gradients in the colorimetric measurements.
View Article and Find Full Text PDFA systematic investigation was conducted to study the effect of paper type on the analytical performance of a series of microfluidic paper-based analytical devices (μPADs) fabricated using a CO2 laser engraver. Samples included three different grades of Whatman chromatography paper, and three grades of Whatman filter paper. According to the data collected and the characterization performed, different papers offer a wide range of flow rate, thickness, and pore size.
View Article and Find Full Text PDFThis paper reports for the first time the use of colored toner to produce polyester toner (PT) ME devices. Colored PT devices were designed in drawing software and printed on a polyester film using a color laser printer with 3600 dpi resolution. The colored toner is composed of a copolymer mixture (styrene and acrylate), wax, silicon dioxide, and pigments.
View Article and Find Full Text PDFThis paper reports the fabrication of polyester-toner (PT) electrophoresis microchips with improved analytical performance and extended lifetime. This has been achieved with a better understanding about the EOF generation and the influence of some parameters including the channel dimensions (width and depth), the injection mode, and the addition of organic solvent to the running buffer. The analytical performance of the PT devices was investigated using a capacitively coupled contactless conductivity detector and inorganic cations as model analytes.
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