269 research outputs found

    Electrosynthesis of 2,3-butanediol and methyl ethyl ketone from acetoin in flow cells

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    Acetoin could shortly become a platform molecule due to current progress in fermentation technology, the megatrend for shifting from an oil-based economy to one based on biomass, the quest for green manufacturing processes and its two highly reactive carbonyl and hydroxyl moieties. In this paper, the successful electro-conversion of acetoin into two valuable chemicals, 2,3-butandiol (2,3-BD) and methyl ethyl ketone (MEK), at constant electrical current in aqueous phase at room temperature using both divided and undivided 20 cm2 filter-press flow cells under experimental conditions suitable for industrial production is reported. Cathode material is the key parameter to drive the electroreduction towards one or another chemical. 2,3-BD is the major chemical produced by electrohydrogenation when low hydrogen overvoltage cathodes, such as Pt and Ni, of high surface area obtained by PVD coating on a carbon gas diffusion layer are used, while MEK is the principal product produced by electrohydrogenolysis when high hydrogen overvoltage cathodes, such as graphite, Pb and Cd foils, are employed. 2,3-BD and MEK can be obtained, respectively, in 92.8% and 85.7% selectivities, 71.7% and 80.4% current efficiencies, with 1.21 and 1.08 kg.h-1.m-2 productivities and power consumptions of 2.94 and 4.1 kWh.kg-1 using undivided cells and aqueous K2HPO4 electrolysis media at pHs of 3.6 and 5.5. The reported electroconversion of acetoin is highly flexible because 2,3-BD and MEK can be produced by changing just the cathode but using the same cell, with the same electrolyte at the same current density

    Influence of La3+ on the microestructure of bismuth titanate solid solutions

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    [ES] En este trabajo se reporta la síntesis de la serie de soluciones sólidas de titanato de bismuto, Bi4Ti3O12 con La3+ por coprecipitación de los respectivos hidróxidos. Las soluciones sólidas se caracterizaron por difracción de rayos-X y medidas de densidad. Por técnicas de SEM se determinó la influencia del La3+ en la microestructura del titanato de bismuto puro. En este estudio se prepararon diversas composiciones de la solución sólida a y se sinterizaron a 850ºC. Los resultados se presentan en función de la concentración del dopante.[EN] In this work a solid solution of bismuth titanate Bi4Ti3O12 with La3+ is synthesised by coprecipitation of their hydroxides. The solid solutions were characterised by X-ray powder diffraction and density measurements. By SEM the influence of La3+ in bismuth titanate was analised. In this study several compositions of the solid solution were prepared and sintered at 850ºC. The results are presented as a function of the dopant concentration.Los autores agradecen el apoyo de los proyectos PAPIIT, DGAPA, UNAM No. IN102700 y CONACYT No. 33361-U.Peer reviewe

    Vibrational characterictics of asymmetric metal-ceramic piezocomposites

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    [ES] Se han estudiado las características mecánico-vibracionales de piezocomposites metal-cerámica asimétricos. Kovar-PZT. Para esta caracterización se utilizó la técnica de vibrometría láser mediante la cual se obtienen perfiles de amplitud a diferentes frecuencias para el piezocomposite. Se muestran los modos diferenciados de vibración en el intervalo de 2 Hz a 20 kHz y se discuten los resultados en la perspectiva de optimizar el diseño de los dispositivos.[EN] The mechanical and vibrational characteristics of asymmetric metal-ceramic piezocomposites, Kovar-PZT, have heen studied. For this characterization a laser vibrometry technique was used to obtain amplitude profiles of vibration at different frequencies for the piezocomposite. The vibration spectra showed modes in the range 2 Hz to 20 kHz. The results were discussed in the framework of design optimization.Los autores agradecen el apoyo financiero para la realización de esta investigación a la Universidad Nacional Autónoma de México, Consejo Nacional de Ciencia y Tecnología de México, Comisión Internacional de Ciencia y Tecnología de España y Programa para la Cooperación y el Desarrollo a través de los proyectos PAPIIT-IN106998, CONACYT-27624U, CICYT MAT97-694-C02-01 y CYTED Red VIII.F.Peer reviewe

    Metabolite Profiling of Colvillea racemosa via UPLC-ESI-QTOF-MS Analysis in Correlation to the In Vitro Antioxidant and Cytotoxic Potential against A549 Non-Small Cell Lung Cancer Cell Line

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    In this study, flower and leaf extracts of Colvillea racemosa were considered a source of bioactive compounds. In this context, the objective of the study focused on investigating the anticancer potential as well as the phytochemical composition of both extracts. The extracts were analyzed by UPLC-ESI-QTOF-MS, and the bioactivity was tested using in vitro antioxidant assays (FRAP, DPPH, and ABTS) in addition to cytotoxic assays on non-small cell lung cancer cell line (A549). Our results clearly indicated the potent radical scavenging capacity of both extracts. Importantly, the flower extract exhibited a greater antioxidant capacity than the leaf extract. In terms of cytotoxic activity, leaf and flower extracts significantly inhibited cell viability with IC50 values of 17.0 and 17.2 μg/mL, respectively. The phytochemical characterization enabled the putative annotation of 42 metabolites, such as saccharides, phenolic acids, flavonoids, amino acids, and fatty acids. Among them, the flavonoid C-glycosides stand out due to their high relative abundance and previous reports on their anticancer bioactivity. For a better understanding of the bioactive mechanisms, four flavonoids (vitexin, kaempferol-3-O-rutinoside, luteolin, and isoorientin) were selected for molecular docking on hallmark protein targets in lung cancer as represented by γ-PI3K, EGFR, and CDK2 through in-silico studies. In these models, kaempferol-3-O-rutinoside and vitexin had the highest binding scores on γ-PI3K and CDK2, followed by isoorientin, so they could be highly responsible for the bioactive properties of C. racemosa extracts.Contract RYC2021-032119-I, founded by MCIN/AEI/10.13039/501100011033 and NextGenerationEU/PRTRSpanish Ministry of Science and Innovation for the postdoctoral contract Juan de la Cierva-Formación (FJC2020-044298-I

    Estudo piloto em cuidadores de pacientes com enfermidades neurológicas, sobre o significado e conhecimento de cuidados paliativos

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    Aim. To describe the meaning attributed to palliative care (PC) by caregivers, as well as their preference with respect to informing the patient and their satisfaction in their caring role. Methodology: Study descriptive transversal, sample intended of 40 caregivers of neurologic patients needing PC. A questionnaire about knowledge of the topic and their burnout status was applied. A descriptive-comparative analysis was carried out with 95% (pObjetivo. Describir el significado que atribuyen cuidadores a los cuidados paliativos (CPS), así como su preferencia respecto a informar al paciente y su satisfacción con el papel de cuidador. Metodología. Estudio descriptivo transversal, muestra intencional de 40 cuidadores de enfermos neurológicos con necesidad de CPS. Se aplicó un cuestionario de conocimientos sobre el tema y sobrecarga. Se realizó análisis descriptivo-comparativo con un intervalo de confianza de 95% (pObjetivo. Descrever o significado que atribuem cuidadores aos cuidados paliativos (CPS), assim como sua preferência com respeito a informar ao paciente e sua satisfação com o papel de cuidador. Metodologia. Estudo descritivo transversal, amostra intencional de 40 cuidadores de enfermos neurológicos com necessidade de CPS. Aplicou-se um questionário de conhecimentos sobre o tema e sobrecarga. Realizou-se análise descritivo-comparativa com um intervalo de confiança de 95% (

    Analysis of the Relationship between Lifestyle and Coffee Consumption Habits, from the Myth Approach, in the Municipalities of Orizaba, Tehuipango, and Zongolica Veracruz.

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    Coffee consumption habits have evolved along with society for more than 300 years around the world. Social changes imply different lifestyles in each culture. Lifestyles influence the myths used by people in their consumption decisions. The objective of this research is to determine the relationship between lifestyle and coffee consumption habits, from the perspective of myth, in the inhabitants of the Mexican municipalities of Orizaba, Tehuipango, and Zongolica. A survey was conducted with a sample of inhabitants of the three municipalities studied. The statistical analyzes applied were the central limit theorem, Pearson, and Chi-square. The results show that the variables Consumption habits-Lifestyle-Myth, are highly dependent on the level of perception of people. It is concluded that the coffee myth corresponds to the "family union" in the study municipalities. This myth is not characterized in the evolutionary stages contemplated in the "waves of coffee"

    Shoot iron status and auxin are involved in iron deficiency-induced phytosiderophores release in wheat

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    Background: The release of phytosiderephores (PS) to the rhizosphere is the main root response to iron (Fe) deficiency in graminaceous plants. We have investigated the role of the Fe status in the shoot as well as of the signaling pathways controlled by three relevant phytoregulators-indolacetic acid (IAA), ethylene and nitric oxide (NO) - in the regulation of this root response in Fe-starved wheat plants. To this end, the PS accumulation in the nutrient solution and the root expression of the genes encoding the nicotianamine aminotransferase (TaNAAT) and ferritin (TaFER) have been evaluated in plants subjected to different treatments. Results: The application of Fe to leaves of Fe-deficient plants prevented the increase in both PS root release and TaNAAT gene expression thus showing the relevant role of the shoot to root communication in the regulation of PS root release and some steps of PS biosynthesis. Experiments with specific hormone inhibitors showed that while ethylene and NO did not positively regulate Fe deficiency induced PS root release, auxin plays an essential role in the regulation of this process. Moreover, the application of IM to Fe-sufficient plants promoted both PS root release and TaNAAT gene expression thus indicating that auxin might be involved in the shoot to root signaling network regulating Fe-deficiency root responses in wheat Conclusions: These results therefore indicate that PS root release in Fe-deficient wheat plants is directly modulated by the shoot Fe status through signaling pathways involving, among other possible effectors, auxin

    Resolution of complex fluorescence spectra of lipids and nicotinic acetylcholine receptor by multivariate analysis reveals protein-mediated effects on the receptor's immediate lipid microenvironment

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    Analysis of fluorescent spectra from complex biological systems containing various fluorescent probes with overlapping emission bands is a challenging task. Valuable information can be extracted from the full spectra, however, by using multivariate analysis (MA) of measurements at different wavelengths. We applied MA to spectral data of purified Torpedo nicotinic acetylcholine receptor (AChR) protein reconstituted into liposomes made up of dioleoylphosphatidic acid (DOPA) and dioleoylphosphatidylcholine (DOPC) doped with two extrinsic fluorescent probes (NBD-cholesterol/pyrene-PC). Förster resonance energy transfer (FRET) was observed between the protein and pyrene-PC and between pyrene-PC and NBD-cholesterol, leading to overlapping emission bands. Partial least squares analysis was applied to fluorescence spectra of pyrene-PC in liposomes with different DOPC/DOPA ratios, generating a model that was tested by an internal validation (leave-one-out cross-validation) and was further used to predict the apparent lipid molar ratio in AChR-containing samples. The values predicted for DOPA, the lipid with the highest Tm, indicate that the protein exerts a rigidifying effect on its lipid microenvironment. A similar conclusion was reached from excimer formation of pyrene-PC, a collisional-dependent phenomenon. The excimer/monomer ratio (E/M) at different DOPC/DOPA molar ratios revealed the restricted diffusion of the probe in AChR-containing samples in comparison to pure lipid samples devoid of protein. FRET from the AChR (donor) to pyrene-PC (acceptor) as a function of temperature was found to increase with increasing temperature, suggesting a shorter distance between AChR and pyrene PC. Taken together, the results obtained by MA on complex spectra indicate that the AChR rigidifies its surrounding lipid and prefers DOPA rather than DOPC in its immediate microenvironment

    Evolution of vaccination rates after the implementation of a free systematic pneumococcal vaccination in Catalonian older adults: 4-years follow-up

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    BACKGROUND: The systematic vaccination with 23-valent polysaccharide pneumococcal vaccine (PPV) was introduced as a strategic objective of health for all the people over 65 in Catalonia in 1999. We analysed the evolution of the pneumococcal vaccination rates from 2000 to 2003. METHODS: We conducted a retrospective population-based study including all the individuals 65 years or older assigned to 8 Primary Care Centres (PCCs) in Tarragona (Catalonia, Spain), who figured in the administrative population databases on 31 December 2003 (n = 10,410 persons). We assessed whether every person had received PPV during the last four years (2000 to 2003) or whether they had received it before January 2000. Data sources were the computerised clinical records of the 8 participating PCCs, which included adult vaccination registries and diagnoses coded of International Classification of Diseases 9(th )Review RESULTS: The overall vaccination uptake increased to 38.6% at the end of 2000. Global accumulated coverages increased more slowly the following years: 44.4% in 2001, 50.9% in 2002, and 53.1% at the end of 2003. Vaccine uptake varied significantly according to age (46.7% in people 65–74 years-old, 60.9% in people 75 years or more; p < 0.001) and number of diseases or risk factors (DRFs) for pneumonia (47.1% vaccinated in people without DRFs, 56.8% in patients with one DRF, and 62.2% in patients with two or more DRFs; p < 0.001). The highest coverages were observed among those patients with: diabetes (65.9%), active neoplasia (64.8%), history of stroke (63.7%), and chronic lung disease (63.5%). The lowest uptake was observed among smokers (48.7%). DISCUSSION: The pneumococcal vaccination coverage increased quickly after the introduction of the recommendation for free vaccination in all the elderly people (with and without risk factors), but two years after the improvement the coverage became stable and increased slowly

    Genomic, Pathway Network, and Immunologic Features Distinguishing Squamous Carcinomas

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    This integrated, multiplatform PanCancer Atlas study co-mapped and identified distinguishing molecular features of squamous cell carcinomas (SCCs) from five sites associated with smokin
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