552 research outputs found

    Termodinamičko ispitivanje prijelaza acetanilida i fenacetina iz vode u organska otapala

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    The molar (KCo/w) and rational (KXo/w) partition coefficients in the octanol/buffer, i-propyl myristate/buffer, chloroform/buffer, and cyclohexane/buffer systems were determined for acetanilide and phenacetin at 25.0, 30.0, 35.0, and 40.0 °C. In all cases except for cyclohexane, the KCo/w and KXo/w values were greater than unity. This demonstrates that these two drugs have predominantly lipophilic behavior. Gibbs and van\u27t Hoff thermodynamic analyses have revealed that the transfer of these drugs from water to organic solvents is spontaneous and that it is mainly driven enthalpically for i-propyl myristate and chloroform, and entropy-driven for octanol and cyclohexane.U radu su određeni molarni (KCo/w) i razdjelni (Kxo/w) particijski koeficijenti acetanilida i fenacetina u sustavima oktanol/pufer, i-propil-miristat/pufer, kloroform/pufer i cikloheksan/pufer na 25,0, 30,0, 35,0 i 40 C. U svim slučajevima osim za cikloheksan, vrijednosti KCo/w i Kxo/w bile su veće od jedan. To ukazuje da su ova dva lijeka pretežno lipofilna. Gibbsova i van’t Hoffova termodinamička analiza su otkrile da je prijelaz tih lijekova iz vode u organska otapala spontan i da su uglavnom pokrenuti entalpijski za i-propil-miristat i kloroform te entropijski za oktanol i cikloheksan

    Does the Integration of Lean Production and Industry 4.0 in Green Supply Chains Generate a Better Operational Performance?

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    Purpose – The tightening of environmental measures and policies in various countries around the world is forcing manufacturing companies, particularly those that make up the automotive industry, to improve their production processes, through the implementation of approaches such as lean production and industry 4.0 technologies, to reduce industrial waste. However, the literature indicates that the implementation of lean production and Industry 4.0 does not always lead to an improvement in the level of operational performance. Therefore, this study analyzes the effects of the implementation of lean production practices and Industry 4.0 on a green supply chain and the operational performance of manufacturing companies in the Mexican automotive industry. Methodology/design/approach - A theoretical research framework consisting of six hypotheses was developed and validated by applying PLS-SEM and using a sample of 460 companies from the Mexican automotive industry. Findings - The results show that the level of operational performance of manufacturing companies increases substantially with the implementation of lean production and industry 4.0 practices, as well as a green supply chain. Originality/value - This study contributes to the literature on lean production and Industry 4.0 by providing robust empirical evidence of the positive effects of implementing these approaches on the green supply chain and operational performance of manufacturing companies. Practical implications - Managers of manufacturing companies will be able to use the results of this study to improve their production systems and to demonstrate the effects of these practices on operational performance

    Nanoparticle-and liposome-carried drugs: New strategies for active targeting and drug delivery across blood-brain barrier

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    The blood-brain barrier (BBB), the unusual microvascular endothelial interface between the central nervous system (CNS) and the circulatory system, is a major hindrance to drug delivery in the brain parenchyma. Besides the absence of fenestrations and the abundance of tight junctions, ATP-binding cassette (ABC) transporters critically reduce drug entry within the CNS, as they carry many drugs back into the bloodstream. Nanoparticle-and liposome-carried drugs, because of their increased cellular uptake and reduced efflux through ABC transporters, have been developed in recent times to circumvent the low drug permeability of the BBB. This review discusses the role of ABC transporters in controlling drug penetration into the brain parenchyma, the rationale for using nanoparticle-and liposome-based strategies to increase drug delivery across the BBB and new therapeutic strategies for using nanoparticle-and liposome-carried drugs in different conditions, ranging from CNS tumors and neurodegenerative diseases to viral infections and epilepsy. © 2013 Bentham Science Publishers

    Understanding the performance of an AnMBR treating urban wastewater and food waste via model simulation and characterization of the microbial population dynamics

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    [EN] An anaerobic membrane bioreactor (AnMBR) pilot plant treating kitchen food waste (FW) jointly with urban wastewater was run for 536 days. Different operational conditions were tested varying the sludge retention time (SRT), the hydraulic retention time (HRT) and the penetration factor (PF) of food waste disposers. COD removal efficiency exceeded 90% in all tested conditions. The joint treatment resulted in an almost 3-fold increase in methane production (at 70 days of SRT, 24 h HRT and 80% PF) in comparison with the treatment of urban wastewater only. Mathematical model simulations and Illumina technology were used to obtain in-depth information of this outstanding process performance. Both the PF and SRT factors increased influent biodegradability. The experimental results were accurately reproduced via model simulations modifying only the influent biodegradability. The high SRT and the presence of ground FW in the influent resulted in higher hydrolytic activity. Not only did the Archaea population increase 3-fold but Levilinea genera was also significantly raised. Three new genera characterised by anaerobic fermentation of amino acids (Leptolinea, Aminomonas and Aminobacterium) were among the ten most abundant of the total sequences identified during the joint treatment, indicating an improvement in the hydrolysis step of anaerobic degradation. Influent biodegradability remained at high values when FW addition stopped.This research work has been financially supported by the Generalitat Valenciana (PROMETEO/2012/029 PROJECT), which is gratefully acknowledged.Durán Pinzón, F.; Zamorano -López, N.; Barat, R.; Ferrer, J.; Aguado García, D. (2018). Understanding the performance of an AnMBR treating urban wastewater and food waste via model simulation and characterization of the microbial population dynamics. Process Biochemistry. 67:139-146. https://doi.org/10.1016/j.procbio.2018.02.010S1391466

    Utilidad de la relación aclaramiento de creatinina - índice de resistencia de la ecografía Doppler renal como predictor de rechazo agudo en riñones trasplantados

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    ResumenObjetivoAnalizar la utilidad de la asociación del índice de resistencia (IR) en las arterias arcuatas renales con el aclaramiento de creatinina (Cl Cr) para predecir el rechazo agudo del riñón trasplantado.Materiales y métodosSe realizó un estudio prospectivo de una cohorte de 87 pacientes que fueron sometidos a una biopsia renal por alteraciones clínicas de la función renal. Se les midió el IR junto con el Cl Cr mediante el método de modificación de la dieta en la enfermedad renal.ResultadosLa sensibilidad de la asociación IR mayor de 0,7 y Cl Cr 0-30 fue del 53,3% (intervalo de confianza [IC] de 95%: 34,3-71,7%) y la especificidad del 98,2% (95% IC: 90,4-100%). El área bajo la curva fue de 0,758 (95% IC: 0,665-0,85), el likelihood ratio positivo de 22,9 (95% IC: 4,16-214), el likelihood ratio negativo de 0,475 (95% IC: 0,324- 0,685), el odds ratio de 62,9, el valor predictivo positivo de 94,1% (95% IC: 71,3- 99,9%) y el valor predictivo negativo de 79,1% (95% IC: 68,3-88,4%).ConclusiónLa asociación IR mayor de 0,7 y Cl Cr 0-30 demostró ser útil para confirmar la posibilidad de rechazo renal agudo, al tener una buena especificidad (98,2%) a pesar de su baja sensibilidad (53%).AbstractObjectiveTo determine the usefulness of the association between the resistance index (RI) values in renal arcuate arteries and creatinine clearance (Cr Cl) levels in order to predict or detect acute rejection in a kidney transplant patient.Materials and methodsA prospective study was conducted on a cohort of 87 patients who were subjected to a kidney biopsy due to clinical changes in renal function. The RI was measured, and Cr Cl levels determined using the modification of diet in renal disease formula.ResultsThe sensitivity of an RI association higher than 0.7 and a Cr Cl 0-30 was 53.3% (95% confidence interval [CI]: 34.3-71.7%), with a specificity of 98.2% (95% CI: 90.4-100%). The area under the curve was 0.758 (95% CI: 0.665-0.85), the positive and negative likelihood ratio was 22.9 (95% CI: 4.16-214) and 0.475 (95% CI: 0.324-0.685), respectively. The odds ratio was 62.9, and the positive and negative predicted value was 94.1% (95% CI: 71.3-99.9%) and 79.1% (95% CI: 68.3-88.4%), respectively.ConclusionThe RI association higher than 0.7- Cr Cl 0-30 showed to be useful to detect the possibility of acute renal rejection, with its good specificity (98.2%), although with a low sensitivity (53%)

    Well-defined regions of the Plasmodium falciparum reticulocyte binding protein homologue 4 mediate interaction with red blood cell membrane

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    Two widely studied parasite protein families are considered attractive targets for developing a fully effective antimalarial vaccine: the erythrocyte binding antigen (EBA) family defining a sialic acid-dependent invasion pathway, and reticulocyte-binding homologue (RH) proteins associated with sialic acid-independent red blood cell (RBC) invasion. In this study, the micronemal invasive PfRH4 protein was finely mapped using 20-mer-long synthetic peptides spanning the entire protein length to identify protein regions that establish high affinity interactions with human RBCs. Twenty conserved, mainly ?-helical high-activity binding peptides (HABPs) with nanomolar dissociation constants and recognizing 32, 25, 22, and 20 kDaRBCmembrane molecules in a chymotrypsin and/or trypsin-sensitive manner were identified in this protein. Anti-PfRH4 rabbit sera and PfRH4 HABPs inhibited merozoite invasion in vitro, therefore suggesting the implication of these HABPs in Plasmodium falciparum invasion and supporting their inclusion in further structural and immunological studies to design potential components of a minimal subunit-based, multiantigenic, chemically synthesized antimalarial vaccine. ©2009 American Chemical Society

    Infección por SARS-CoV-2 y obesidad

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    La pandemia por coronavirus 2019 (COVID-19) ha tenido diferentes efectos. Uno de ellos fue concentrar la atención de múltiples investigadores y clínicos para dedicarse a estudiar y tratar de entender los retos de esta infección en diferentes poblaciones, que se han determinado en riesgo de presentar una manifestación más grave de la infección. La obesidad ha sido recientemente identificada como una de las comorbilidades de mayor riesgo junto con la insuficiencia cardíaca, con una probabilidad siete veces mayor para el requerimiento de ventilación mecánica invasiva. La obesidad es un factor en la gravedad de la enfermedad del SARS-CoV-2, que tiene un mayor impacto en pacientes con un índice de masa corporal (IMC) ?35 kg/m2 . Los pacientes con obesidad, especialmente aquellos con grado severo, deben tomar medidas adicionales para evitar el contagio con SARS-CoV-2, mediante el cumplimiento de las medidas de prevención durante la pandemia actual, si se quiere, de forma más rigurosa

    Alpha-taxonomy in the cricetid rodent Neomicroxus, a first assessment

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    Neomicroxus, a recently named genus, comprises small-bodied cricetid rodents patchily distributed in high-Andean ranges from Ecuador to Venezuela. Currently, two species of Neomicroxus are recognized, N. bogotensis, endemic to the Cordillera Oriental in Colombia and Cordillera de Mérida and Páramo de Tamá in Venezuela, and N. latebricola that occurs northern Andes of Ecuador. The genus is among the most poorly understood Neotropical rodents and to date no formal assessment about its alpha taxonomy was conducted. Based on DNA evidence of the first portion of the mitochondrial cytochrome b gene (cytb) and the first exon of the interphotoreceptor retinoid binding protein (IRBP), as well as craniodental measurements,we explored the divergence degree, genetic structure and phyletic relationships of the two species currently allocated under Neomicroxus. Our analyses support the monophyly of the genus as well as its uncertain tribal affiliation. Neomicroxus was retrieved as structured in two main branches, in agreement with the traditional recognition of two species. The populations referred to N. bogotensis exhibit deep divergence values (> 6 %) pointing to the existence of undescribed species under its concept. In contrast, populations of N. latebricola show a shallow genetic structure although implying recognizable geographical breaks. A moderate degree of genetic and morphological differentiation supports a new subspecies for the western populations of N. latebricola. Our contribution is the first attempt to better understanding the alpha taxonomy of Neomicroxus, highlighting the importance of the geographic complexity as a barrier to the genetic flow in N. bogotensis and the significance of the subspecies concept to formalize the geographic variation recovered in N. latebricola.Neomicroxus, un género recientemente nominado, agrupa roedores cricétidos de pequeño tamaño distribuidos en zonas altas de los Andes, desde Ecuador hasta Venezuela. Actualmente, se reconocen dos especies, N. bogotensis endémica de la Cordillera Oriental de Colombia, Cordillera de Mérida y Páramo de Tamá en Venezuela, y N. latebricola, que ocupa el norte de los Andes en Ecuador. Este género se encuentra entre los roedores neotropicales menos conocidos y, hasta la fecha, no se ha realizado ninguna evaluación formal sobre su taxonomía alfa. Basados en secuencias de ADN de la primera porción del gen mitocondrial del citocromo b (cytb) y el primer exón de la proteína de unión del interfotoreceptor del retinoide (IRBP) e información métrica cráneo-dentaria, exploramos el grado de divergencia, estructura genética y relaciones filogenéticas de las dos especies actualmente asignadas bajo Neomicroxus. Nuestros análisis apoyan la monofilia del género como así también su afiliación tribal incierta. Se recuperaron dos clados principales en concordancia con las especies reconocidas dentro del género. Las poblaciones referidas a N. bogotensis muestran valores de divergencia profunda (> 6 %) que sugieren la existencia de una especie no descrita. En contraste, las poblaciones de N. latebricola muestran una estructura genética somera pero que implica quiebres geográficos reconocibles. La diferenciación genética y morfológica moderada apoyan la existencia de una nueva subespecie para las poblaciones occidentales de N. latebricola. Nuestra contribución es el primer intento de comprender la taxonomía alfa de Neomicroxus, destacando la importancia de la complejidad geográfica como barrera para el flujo genético en N. bogotensis y la importancia del concepto de subespecie para formalizar la variación geográfica observada en N. latebricola.Fil: Cañón Valenzuela, Carola Patricia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico. Instituto de Diversidad y Evolución Austral; ArgentinaFil: Curay, Jenny. Instituto Nacional de Biodiversidad; EcuadorFil: Brito, Jorge. Instituto Nacional de Biodiversidad; EcuadorFil: Colmenares-Pinzón, Javier E.. Universidad Industrial Santander; ColombiaFil: Pardiñas, Ulises Francisco J.. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico. Instituto de Diversidad y Evolución Austral; Argentina. Instituto Nacional de Biodiversidad; Ecuado
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