258 research outputs found

    Dynamic Atomic Contributions To Infrared Intensities Of Fundamental Bands.

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    Dynamic atomic intensity contributions to fundamental infrared intensities are defined as the scalar products of dipole moment derivative vectors for atomic displacements and the total dipole derivative vector of the normal mode. Intensities of functional group vibrations of the fluorochloromethanes can be estimated within 6.5 km mol(-1) by displacing only the functional group atoms rather than all the atoms in the molecules. The asymmetric CF2 stretching intensity, calculated to be 126.5 km mol(-1) higher than the symmetric one, is accounted for by an 81.7 km mol(-1) difference owing to the carbon atom displacement and 40.6 km mol(-1) for both fluorine displacements. Within the Quantum Theory of Atoms in Molecules (QTAIM) model differences in atomic polarizations are found to be the most important for explaining the difference in these carbon dynamic intensity contributions. Carbon atom displacements almost completely account for the differences in the symmetric and asymmetric CCl2 stretching intensities of dichloromethane, 103.9 of the total calculated value of 105.2 km mol(-1). Contrary to that found for the CF2 vibrations intramolecular charge transfer provoked by the carbon atom displacement almost exclusively explains this difference. The very similar intensity values of the symmetric and asymmetric CH2 stretching intensities in CH2F2 arise from nearly equal carbon and hydrogen atom contributions for these vibrations. All atomic contributions to the intensities for these vibrations in CH2Cl2 are very small. Sums of dynamic contributions of the individual intensities for all vibrational modes of the molecule are shown to be equal to mass weighted atomic effective charges that can be determined from atomic polar tensors evaluated from experimental infrared intensities and frequencies. Dynamic contributions for individual intensities can also be determined solely from experimental data.1730378-3038

    Presence of stratospheric humidity in the ozone column depletion on the west coast of South America

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    The ozone column depletion over the western coast of South America has been previously explained, based on the existence of winds in the area of the depletion, which cause compression and thinning of the ozone layer. However, the presence of humidity and methane transported by these winds to the stratosphere where the ozone depletion is present gives evidence that these compounds also participate in the depletion of the ozone layer. These two compounds, humidity and methane, are analysed during the ozone depletion of January, 1998. It is observed that when humidity presents fluctuations, ozone has fluctuations too. A maximum of humidity corresponds to a minimum of ozone, but there is a shift in altitude between them. This shift is observed in the stratosphere and upper troposphere and corresponds to approximately 500 m. It is important to point out that during this event El Ni˜no was present and the sources of methane are the Amazon forest and the Pacific Ocean. The data for this study was obtained from NASA and HALOE

    Influence of physical exercise and sodium intake on arterial pressure and cardiac hypertrophy in rats

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    Há evidências de que a hipertrofia cardíaca (HC) seja um fator de risco para várias doenças cardiovasculares. Uma variedade de estímulos pode levar à HC, entre os quais estão condições que gerem sobrecarga de volume ou pressão, como o exercício físico e a dieta rica em cloreto de sódio (NaCl). Com o objetivo de verificar a possibilidade de o exercício físico e a ingestão de dieta rica em NaCl influenciarem na pressão arterial e trofismo miocárdico, realizou-se o presente estudo. Foram utilizados 36 ratos Holtzman, do sexo feminino, pesando entre 200 e 300 gramas, e divididos nos seguintes grupos (n=6): Grupo I (dieta com água sem NaCl), Grupo II (dieta com água sem NaCl), Grupo III (dieta com solução de NaCl a 2,5%), Grupo IV (dieta com solução de NaCl a 5%), Grupo V (dieta com solução de NaCl a 2,5%), Grupo VI (dieta com solução de NaCl a 5%). Os animais dos grupos II, III e IV praticaram natação durante 100 minutos ao dia, por cinco semanas, após as quais foram mortos e seus corações pesados. As medidas de pressão arterial (PA) e de peso durante o experimento foram comparadas. Houve diminuição do peso dos grupos submetidos a exercício físico e / ou dieta salina: Grupo I (229,0 g), Grupo II (201,17 g), Grupo III (207,0 g), Grupo IV (149,17 g) e Grupo V (156,17 g). Ao final do experimento, o grupo que foi submetido à dieta mais rica em sódio juntamente com exercício mostrou uma PA significativamente maior (102,67 mmHg) que o Grupo I (88,83 mmHg), sem fatores de risco. Houve uma maior relação peso do coração/peso corporal nos grupos III (0,452 %) e IV (0,417 %), em comparação com o Grupo I (0,337%). Concluindo, houve indícios de hipertrofia cardíaca e aumento da pressão arterial nos animais que ingeriram solução salina e realizaram exercício físico.Evidence shows that cardiac hypertrophy (CH) is a risk factor for many cardiovascular diseases. Several stimuli may cause CH-like manifestations and promote volume or pressure overload. Exercise-induced cardiac hypertrophy is an expected adaptation to regular exercise training. Salt intake has been shown to be the most important determinant of blood pressure in different populations. The purpose of the present work was to verify the influence of physical exercise and sodium intake on the blood pressure and myocardium. The study was performed on 36 rats divided into six groups: Group I (diet without salt overload), Group II (diet without salt overload and swimming), Group III (diet with 2.5% NaCl solution and swimming), Group IV (diet with 5% NaCl solution and swimming), Group V (diet with 2.5% NaCl solution without exercise), Group VI (diet with 5% NaCl solution without exercise). The arterial pressure was significantly lower in Group I when compared with Group IV. The ratio of cardiac mass/body mass was increased in Groups III and IV. In conclusion, there was evidence that exercise training and NaCl intake promotes arterial hypertension and cardiac hypertrophy

    Nanostructured Polypyrrole Powder: A Structural and Morphological Characterization

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    Polypyrrole (PPY) powder was chemically synthesized using ferric chloride (FeCl3) and characterized by X-ray diffraction (XRD), Le Bail Method, Fourier Transform Infrared Spectrometry (FTIR), and Scanning Electron Microscopy (SEM). XRD pattern showed a broad scattering of a semicrystalline structure composed of main broad peaks centered at 2θ = 11.4°, 22.1°, and 43.3°. Crystallinity percentage was estimated by the ratio between the sums of the peak areas to the area of amorphous broad halo due to the amorphous phase and showed that PPY has around 20 (1)%. FTIR analysis allowed assigning characteristic absorption bands in the structure of PPY. SEM showed micrometric particles of varying sizes with morphologies similar to cauliflower. Crystal data (monoclinic, space group P 21/c, a=7.1499 (2) Å, b=13.9470 (2) Å, c=17.3316 (2) Å, α=90 Å, β=61.5640 (2) Å and γ=90 Å) were obtained using the FullProf package program under the conditions of the method proposed by Le Bail. Molecular relaxation was performed using the density functional theory (DFT) and suggests that tetramer polymer chains are arranged along the “c” direction. Average crystallite size was found in the range of 20 (1) Å. A value of 9.33 × 10−9 S/cm was found for PPY conductivity

    Simultaneous removal of o-and p-nitrophenol from contaminated water by wet peroxide oxidation using carbon-coated magnetic ferrite as catalyst

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    Groundwater is the most common source of drinking water worldwide and is currently facing contamination problems with the discharge of pollutants into aquatic systems through different means, namely through municipal, industrial and agricultural activities. Contaminants, such as herbicides, pharmaceuticals, phenolic compounds and personal care products are not removed by conventional treatments from wastewater treatment plants, leading to their accumulation in the environment. In this regard, o-nitrophenol (o-NP) and p-nitrophenol (p-NP), commonly used as raw materials in chemical and pharmaceutical engineering, represent a severe risk to humans and aquatic life, leading to the necessity to properly treat wastewaters containing these contaminants before discharge into the aquatic environment. Catalytic wet peroxide oxidation (CWPO) showed promising results for removing nitrophenols from wastewater in previous works. In this technology, H2O2 is used as an oxidant, and its interaction with a suitable catalyst leads to the formation of hydroxyl radicals under determined conditions already established in literature (pH and temperature have a strong influence) [1]. Typical catalysts employed have a transition metal in its structure. Carbon-based catalysts also have activity in this technology, mostly ascribed to the electronic properties of the carbonaceous surface. Furthermore, carbon-coated metal oxide materials (hybrid) have also demonstrated potential applications in CWPO. Those structures combine carbon and metal activities with the advantage of protecting the metal core from leaching, increasing the efficiency and stability of the catalysts.Adriano S. Silva thanks his doctoral Grant with reference SFRH/BD/151346/2021 financed by the Portuguese Foundation for Science and Technology (FCT), with funds from NORTE2020, under MIT Portugal Program. This work was financially supported by UIDB/00690/2020 (CIMO), LA/P/0045/2020 (ALiCE), UIDB/50020/2020, UI-DP/50020/2020 (LSRE-LCM) and the project RTChip4Theranostics, with the reference NORTE-01-0145-FEDER-029394. Fernanda F. Roman acknowledges the national funding by FCT through the individual research grant SFRH/BD/143224/2019info:eu-repo/semantics/publishedVersio

    Assessment of honey bee cells using deep learning

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    Temporal assessment of honey bee colony strength is required for different applications in many research projects. This task often requires counting the number of cells with brood and food reserves multiple times a year from images taken in the apiary. There are thousands of cells in each frame, which makes manual counting a time-consuming and tedious activity. Thus, the assessment of frames has been frequently been performed in the apiary in an approximate way by using methods such as the Liebefeld. The automation of this process using modern imaging processing techniques represents a major advance. The objective of this work was to develop a software capable of extracting each cell from frame images, classify its content and display the results to the researcher in a simple way. The cells’ contents display a high variation of patterns which added to light variation make their classification by software a challenging endeavor. To address this challenge, we used Deep Neural Networks (DNNs) for image processing. DNNs are known by achieving the state-of-art in many fields of study including image classification, because they can learn features that best describe the content being classified, such as the interior of frame cells. Our DNN model was trained with over 60,000 manually labeled images whose cells were classified into seven classes: egg, larvae, capped larvae, honey, nectar, pollen, and empty. Our contribution is an end-to-end software capable of doing automatic background removal, cell detection, and classification of its content based on an input image. With this software the researcher is able to achieve an average accuracy of 94% over all classes and get better results compared with approximation methods and previous techniques that used handmade features like color and texture.This research was funded through the 2013-2014 BiodivERsA/FACCE-JPJ joint call for research proposals,witht he national funders FCT (Portugal), CNRS (France), and MEC (Spain).info:eu-repo/semantics/publishedVersio

    Hybrid multi-core shell magnetic nanoparticles for wet peroxide oxidation of paracetamol: application in synthetic and real matrices

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    Clean water availability is becoming a matter of global concern in the last decades. The responsible entities for wastewater treatment do not have the proper facilities to deal with a wide range of pollutants. Special attention should be given to emerging contaminants, whose presence in water bodies may cause adverse effects on the aquatic ecosystem and human health. Most studies in the literature do not consider the development of their solution in real matrices, which can hinder the applicability of the explored alternative in the real scenario. Therefore, in this work, we demonstrate the applicability of hybrid magnetic nanoparticles for removing paracetamol (PCM) from simulated and real matrices by catalytic wet peroxide oxidation (CWPO). To achieve carbon coating, the nanoparticles were prepared via the traditional route (resorcinol/formaldehyde, CoFe@CRF). A new methodology was also considered for synthesizing thin-layered carbon-coated magnetic nanoparticles (phloroglucinol/ glyoxalic acid, CoFe@CPG). TEM images revealed a multi-core shell structure formation, with an average carbon layer size of 7.8 ± 0.5 and 3.2 ± 0.3 nm for resorcinol/formaldehyde and phloroglucinol/ glyoxalic acid methodology, respectively. Screening the materials’ activity for PCM oxidation by CWPO revealed that the nanoparticle prepared by phloroglucinol/glyoxalic acid methodology has higher performance for the degradation of PCM, achieving 63.5% mineralization after 24 h of reaction, with similar results for more complex matrices. Iron leaching measured at the end of all reactions has proven that the carbon layer protects the core against leaching.This work was financially supported by project RTChip4Theranostics (NORTE-01–0145-FEDER-029394), by CIMO (UIDB/00690/2020) through FEDER under Program PT2020. Fernanda F. Roman acknowledges the Foundation for Science and Technology (FCT) and the European Social Fund (FSE) for the individual research grant with reference SFRH/BD/143224/2019. Adriano Silva and Ana Paula F. da Silva were supported by the doctoral Grant SFRH/BD/151346/2021 and PRT/BD/ 153090/2021 financed by the Portuguese Foundation for Science and Technology (FCT) with funds from NORTE2020, under MIT Portugal Program. Jose L. Diaz De Tuesta acknowledges the financial support through the program of Atracción al Talento of Comunidad de Madrid (Spain) for the individual research grant 2022-T1/AMB-23946.info:eu-repo/semantics/publishedVersio

    Evaluation of efficacy and safety of itraconazole oral solution for the treatment of oropharyngeal candidiasis in AIDS patients

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    This study was a non-comparative multicenter clinical trial to evaluate the efficacy and tolerability of itraconazole oral solution 200 mg/day (100 mg twice a day in the fasting state) for the treatment of oropharyngeal candidiasis in AIDS patients. We included 50 patients who were treated and followed for up to 3 weeks after ending therapy in the analysis. Mycological cures at the end of therapy occurred in 20/50 patients (40%), but colonization by Candida sp. was recorded in 42/50 (84%) by the end of follow-up. A high rate of clinical response was observed in 46/50 (92%), and the response was sustained for up to 21 days after stopping therapy in 24/46 patients (52%). Clinical relapses were documented among 22 patients, but all causative fungal organisms associated with a relapse were susceptible to itraconazole. There were many patients with persistence or recurrence of Candida, but without mucositis. Relapse of Candida mucositis was significantly related to low levels of CD4 lymphocytes exhibited by symptomatic patients. The drug was well tolerated by all but 1 patient. We conclude that itraconazole oral solution (100 mg bid for 7-14 days) is a well tolerated and effective treatment for suppressing the symptoms of oropharyngeal candidiasis in AIDS patients. Patients with severe immunosuppression may relapse and require frequent cycles of treatment or longterm suppressive therapy.Federal University of Paraná Clinical HospitalAliança HospitalFederal University of São Paulo DIPA Special Mycology LaboratoryJanssen-Cilag Farmacêutica do BrasilUNIFESP, DIPA Special Mycology LaboratorySciEL

    Automatic detection and classification of honey bee comb cells using deep learning

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    In a scenario of worldwide honey bee decline, assessing colony strength is becoming increasingly important for sustainable beekeeping. Temporal counts of number of comb cells with brood and food reserves offers researchers data for multiple applications, such as modelling colony dynamics, and beekeepers information on colony strength, an indicator of colony health and honey yield. Counting cells manually in comb images is labour intensive, tedious, and prone to error. Herein, we developed a free software, named DeepBee©, capable of automatically detecting cells in comb images and classifying their contents into seven classes. By distinguishing cells occupied by eggs, larvae, capped brood, pollen, nectar, honey, and other, DeepBee© allows an unprecedented level of accuracy in cell classification. Using Circle Hough Transform and the semantic segmentation technique, we obtained a cell detection rate of 98.7%, which is 16.2% higher than the best result found in the literature. For classification of comb cells, we trained and evaluated thirteen different convolutional neural network (CNN) architectures, including: DenseNet (121, 169 and 201); InceptionResNetV2; InceptionV3; MobileNet; MobileNetV2; NasNet; NasNetMobile; ResNet50; VGG (16 and 19) and Xception. MobileNet revealed to be the best compromise between training cost, with ~9 s for processing all cells in a comb image, and accuracy, with an F1-Score of 94.3%. We show the technical details to build a complete pipeline for classifying and counting comb cells and we made the CNN models, source code, and datasets publicly available. With this effort, we hope to have expanded the frontier of apicultural precision analysis by providing a tool with high performance and source codes to foster improvement by third parties (https://github.com/AvsThiago/DeepBeesource).This research was developed in the framework of the project “BeeHope - Honeybee conservation centers in Western Europe: an innovative strategy using sustainable beekeeping to reduce honeybee decline”, funded through the 2013-2014 BiodivERsA/FACCE-JPI Joint call for research proposals, with the national funders FCT (Portugal), CNRS (France), and MEC (Spain).info:eu-repo/semantics/publishedVersio
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