Radionuclide Determination In Surface Water Samples By Inductively Coupled Plasma With Sector Field Mass Spectrometry (ICP-SFMS)

The determination of naturally occurring radionuclides in the environment by inductively coupled plasma mass spectrometry of high resolution (ICP-SFMS) has gained recognition over the last fifteen years, relative to the radiometric techniques, as the result of improvement in instrumental performance, sample introduction equipment and sample preparation. With the increase in instrumental sensitivity, it is now possible to measure ultratrace levels of many radioisotopes.The aim of this work was to determined the natural radionuclides (232Th, 234U, 235U and 238U) in surface water using Inductively Coupled Plasma-Sector Field Mass Spectrometry (ICP-SFMS). The samples were sampling from Lerma river, State of Mexico at february to april 2015. The process of treatment of sample consisted in perform an acid digestion according to the 3015A USEPA method followed of the direct measurement in ICP-SFMS. Results obtained were: a) identify the presence of 232Th, 234U, 235U and 238U isotopes in water, b) isotopic ratios were for 234U/238U=1.133 ± 0.016. ICP-SFMS has gained popularity in the field of radiochemistry, particularly as a method of detection for long lived-actinides

Applied Radiation and Isotopes Monte Carlo Verification of Output Correction Factors for a TrueBeam STx linac

The recent publication of the new code of practice IEAA/AAPM TRS-483 introduces the use of output correction factors to correct the changes in detector response in relative dosimetry of small photon beams. In TRS-483, average correction factors are reported for several detectors at 6 and 10 MV with and without attening. These correction factors were determined by Monte Carlo simulation or experimental measurements using several linacs of di erent brands and vendors. The goal of this work was to validate the output correction factors reported in TRS-483 for a 6 MV (with and without attening lter) of a TrueBeam STx® linac with Monte Carlo simulation for four radiation detectors employed in the dosimetry of small photon beams and whose output correction factors were determined using di erent radiation source than TrueBeam STx®: PTW®31010, PTW®31016, IBA®CC-01, and IBA®SFD. The results show that Monte Carlo calculated output factors, and those reported in the code of practice TRS-483 fully agree within 1%. The use of generic correction factors for a TrueBeam STx® and the detectors studied in this work is adequate for small dosimetry static beams within the uncertainties of Monte Carlo calculations and output correction factors reported in TRS-483. Key words: TRS-483, Monte Carlo simulation, output correction factors, detector model, Phase Space File, Latent Varianc

Exploiting residual cocoa biomass to extract advanced materials as building blocks for manufacturing nanoparticles aimed at alleviating formation-induced oxidative stress on human dermal fibroblasts

\ua9 2024 RSC. The global adoption of by-product valorisation processes aligns with the circular economy framework, ensuring sustainability in the agricultural sector. In cocoa production, residual biomass can offer the opportunity to extract advanced materials, contributing to nanotherapeutic solutions for biomedical applications. This study explores extraction processes for valorising cocoa pod husks (CPHs) and optimising valuable cocoa-derived biocompounds for enhanced health benefits. Various extraction processes are compared, revealing the significant influence of CPH powder amount and extraction time. Furthermore, metabolic analysis identifies 124 compounds in the metabolite mix, including tartaric acid, gluconic acid and bioactive agents with antioxidant properties, resulting in a high total phenolic content of 3.88 \ub1 0.06 mg g−1. Moreover, the extracted pectin, obtained through alkaline and enzymatic routes, shows comparable yields but exhibits superior antioxidant capacity compared to commercial pectin. The study progresses to using these extracted biocompounds to develop Layer-by-Layer multifunctionalised nanoparticles (LbL-MNPs). Physico-chemical characterisation via ζ-potential, FTIR-ATR, and XPS confirms the successful multilayer coating on mesoporous silica nanoparticles (MNPs). TEM analysis demonstrates a uniform and spherical nanoparticle morphology, with a size increase after coating. In vitro biological characterisation with neo-dermal human fibroblast cells reveals enhanced metabolic activity and biocompatibility of LbL-MNPs compared to bare MNPs. Also, the engineered nanoparticles demonstrate a protective effect against H2O2-induced intracellular oxidative stress on human dermal fibroblast cell lines, showcasing their potential as antioxidant carriers for biomedical applications

Implementación de una red Modbus con Labview

En la siguiente monografía se presenta una de las soluciones para la comunicación de un PC con tres APs (Autómatas Programables) o PC`s esclavos, para el monitoreo de esta red se utilizara el protocolo de comunicaciones Modbus. En el primer capítulo se describen las características generales del protocolo Modbus, como, modos de transmisión (RTU, ASCII), funciones más comunes del protocolo que van a ser implementadas en el programa, etc. En el capitulo dos se hace una descripción de la implementación del protocolo Modbus en Labview, se hace también un análisis de las tramas que se envían y se reciben. En el capítulo tres se describe las redes seriales que se van a utilizar (RS 232 y RS 485), una comparación entre estas y también se describe un conversor de estándar RS232 a RS 485 necesario para implementar el bus. En el cuarto capítulo se describen las Tramas que envía el PC maestro como aplicación a los tres PCs esclavos o APs, este capítulo también habla acerca de la aplicación en Labview y los Drivers de comunicación, aquí se presenta un análisis de las librerías de Modbus. Por ultimo en el capítulo quinto se dan análisis de resultados y conclusiones de acuerdo a los resultados obtenidos

DeepToF: Off-the-shelf real-time correction of multipath interference in time-of-flight imaging

Time-of-flight (ToF) imaging has become a widespread technique for depth estimation, allowing affordable off-the-shelf cameras to provide depth maps in real time. However, multipath interference (MPI) resulting from indirect illumination significantly degrades the captured depth. Most previous works have tried to solve this problem by means of complex hardware modifications or costly computations. In this work, we avoid these approaches and propose a new technique to correct errors in depth caused by MPI, which requires no camera modifications and takes just 10 milliseconds per frame. Our observations about the nature of MPI suggest that most of its information is available in image space; this allows us to formulate the depth imaging process as a spatially-varying convolution and use a convolutional neural network to correct MPI errors. Since the input and output data present similar structure, we base our network on an autoencoder, which we train in two stages. First, we use the encoder (convolution filters) to learn a suitable basis to represent MPI-corrupted depth images; then, we train the decoder (deconvolution filters) to correct depth from synthetic scenes, generated by using a physically-based, time-resolved renderer. This approach allows us to tackle a key problem in ToF, the lack of ground-truth data, by using a large-scale captured training set with MPI-corrupted depth to train the encoder, and a smaller synthetic training set with ground truth depth to train the decoder stage of the network. We demonstrate and validate our method on both synthetic and real complex scenarios, using an off-the-shelf ToF camera, and with only the captured, incorrect depth as input

Эффективность и результативность дистанционного обучения

В докладе обсуждаются вопросы эффективности и результативности дистанционного обучения в Беларуси

Impact of a Costello Syndrome-Causing Mutation on Learning and Myelin-Producing Cells

Background:Costello Syndrome (CS) is a rare genetic disorder caused by hyperactivating mutations in the HRAS gene, which controls the RAS/MAPK intracellular pathway. Symptoms of CS typically include neurocognitive developmental delays, increased risk of autism spectrum disorder, intellectual disabilities, and other neurological issues. Additionally, most CS patients present with white matter (WM) abnormalities. WM has been proposed to regulate learning due to its roles in increasing/synchronizing action potentials and protecting neuronal axons. Females of a myelin-focused mouse model of CS (PlpCre;HRasG12V; pHRas) show learning deficits in a myelin-regulated test (the complex running wheel; CW) that resolve with time. To shed light onto the mechanisms of these learning deficits, the goal of our study is to describe changes in oligodendrocyte (OL; myelin-producing cells) lineage cells in pHRas mice. Methods: To correlate the cellular and functional impact of HRas mutation on OL lineage (OLL) cells, HRas mutation was induced in mature OLs (mOL) using a tamoxifen-inducible system. Four months after recombination, mice were subjected to the voluntary CW test (a wheel with unevenly spaced rungs), and learning curves were analyzed. An acquisition phase of 14 days was followed by a break from CWs of 3 weeks and a second CW phase of 7 days (memory of skills acquired). After the second exposure to the CW, mice were euthanized, and brain sections were collected for staining with DAPI (nucleated cells), GFP (recombinant cells), PDGFRα (oligodendrocyte precursor cells; OPCs), and Sox10 (OLL cells). Then, cell quantification was performed after conducting confocal imaging. Seven regions of the corpus callosum, across 4 coronal sections, were analyzed for regional differences in the numbers of PDGFR+ OPCs and Sox10+ OLL cells. Results: Our antecedents show that at 2 weeks and 2 months post-mutation, there were significant decreases in distance, average speed, and max speed ran, as well as activity in mutant mice compared to WTs (defective learning curves). However, at 4 months post-mutation, there were no significant differences in learning curves between mutant and WT mice. We then wondered how OPC populations remained at 4 months post-tamoxifen when differences in behavioral phenotypes were no longer detected. We observed that the number of PDGFR+ OPCs decreased in the lateral region of the most anterior coronal section of the corpus callosum, suggesting non-cell-autonomous effects of pHRas on proliferation and/or differentiation of OPCs. Conclusion: Taken together, our results shed light on the role of the HRas mutation on CS mouse models that show transient learning deficits on the CW after the induction of the mutation. Our working hypothesis is that decreased number of OPCs may be a result of an increase in their differentiation into mOLs (to form myelin that restores learning) but lead to a proliferative exhaustion state. We propose an immediate impact (weeks) of HRas mutation on learning that is ameliorated by OPC differentiation \u3c 4 months post-injection. Finding the mechanism of these events can aid in the understanding of this disease and in designing therapeutic treatments based on restoration of myelin function