1,576 research outputs found
Role of Rho-kinase in mediating contraction of chicken embryo femoral arteries
Rho-kinase-dependent Ca(2+) sensitization is an essential process for contraction of mammalian vascular smooth muscle but the information about its effects in non-mammalian vessels is scarce. We aimed to investigate, using the Rho-kinase inhibitor hydroxyfasudil, the potential role of the Rho-kinase pathway of Ca(2+) sensitization in depolarization- and agonist-mediated contraction of chicken embryo (at day 19 of the 21 days of incubation) femoral arteries. Contraction elicited by KCl (125 mM) comprised two phases (phasic and tonic contraction), both of which were abolished in the absence of extracellular Ca(2+). Hydroxyfasudil (10 μM) left the initial phasic component nearly intact but abolished the tonic component. Hydroxyfasudil also induced a marked impairment of the contractions elicited by phenylephrine (PE), the thromboxane A(2) mimetic U46619, and endothelin-1. In contrast, inhibition of protein kinase C (PKC) by chelerythrine did not affect KCl- or PE-induced contractions, indicating lack of participation of PKC-mediated Ca(2+) sensitization. Incubation under chronic hypoxia (15% O(2) from day 0) impaired embryonic growth but did not significantly affect hydroxyfasudil-mediated relaxation. In summary, our findings are indicative of a role for Rho-kinase activity in depolarization- and agonist-induced force generation in chicken embryo femoral arteries
Fuzzy inference system for the identification of over-the-counter (otc) drugs.
This document shows the details of the implementation of a fuzzy inference system, for the identification of four over-the-counter drugs (Naproxen, Calcium Carbonate, Muvett and Winadol), by using a Raman Spectroscopy, which output is the characterization of the substance. Data obtained from Raman Spectroscopy are modeled with Matlab®- Fuzzy Logic Toolbox
Crystalline Structure and Vacancy Ordering across a Surface Phase Transition in Sn/Cu(001)
We report a surface X-ray diffraction study of the crystalline structure changes and critical behavior across the (3√2 × √2)R45° → (√2 × √2)R45° surface phase transition at 360 K for 0.5 monolayers of Sn on Cu(100). The phase transition is of the order-disorder type and is due to the disordering of the Cu atomic vacancies present in the low temperature phase. Two different atomic sites for Sn atoms, characterized by two different heights, are maintained across the surface phase transition.This work was funded by the Spanish MINECO under Grants FIS2011-23230 and MAT2014-52477-C5-5-P. E.G.M. and P.S. acknowledge financial support from MINECO through the “Maria de Maeztu” Programme for Units of Excellence in R&D (MDM-2014-0377).Peer Reviewe
Drug delivery systems for potential treatment of intracellular bacterial infections.
Despite the advent of a considerable number of new antibiotics, treatment of intracellular pathogens still represents a major pharmaceutical challenge. The antibiotic concentration in those specialized niches are often subtherapeutic, for which high doses of antibiotics must often be used. This is not only costly but may also increase localized or systemic side effects. There is therefore an urgent need for materials and methods to enable clinicians to achieve therapeutically effective intracellular concentration of those antibiotics which show good efficiency in vitro. In this setting, the possible use of drug delivery systems (DDS) loaded with antibiotics that exhibit a high in vitro bactericidal activity deserves to be considered. Entrapping or encapsulating the drug within a delivery system provides a greater control of the pharmacokinetic behavior of the active molecule. This more efficient use of antibiotics may diminish their drawbacks and provide the basis for shortening the current time required by classical treatments. This review will focus on the role of DDS as a potential tool against intracellular bacteria
Response of epilithic diatom communities to environmental gradients in subtropical temperate Brazilian rivers
This work aims to analyse the response of epilithic diatom communities to enviranmental gradients in subtropical temperate southern Brazilian rivers to contribute to the development of a widely applicable methodology for water-quality monitoring. Samples for physical, chemical and biological determination were collected monthly, fram December 2001 to November 2002 and fram March 2003 to February 2004, at 9 stations along the rivers Pardo and Pardinho in the hydrographical basin of Rio Pardo, State of Rio Grande do Sul (RS), Brazil. Physical and chemical variables (water temperature, pH, dissolved oxygen, biochemical oxygen demand, chemical oxygen demand, nitrates, nitrites, phosphates and total dissolved solids) and biological variables (epilithic diatom communities) were used as parameters for water-quality assessment. The data matrix was examined by means of a multivariate ordination using Detrended Correspondence Analysis (DCA). In total, 270 taxa were identified to specific or infra-specific levels. The results showed that of all the physical and chemical variables used, the main gradient along the DCA first axis was eutraphication, which was indicated by its significant correlation with phosphates (p < 0.00l). Hence, the species' scores on the DCA axis were used as an operational criterion for indicating their tolerance to eutrophication. From this analysis, the 10 taxa that were the most tolerant to eutrophication were: Cyclotella meneghiniana, Fallacia monoculata, Nitzschia acicularis, N. clausii, N. nana, N. palea, Nitzschia sp., Pinnularia sp., Sellaphora pupula sensu lato and Ulnaria acuso The present study showed that epilithic diatom assemblages reflect anthropogenic changes in hydrographic basins in subtropical temperate streams, especially pollution by organic enrichment and eutraphication. Key words: Diatoms, eutrophication, biomonitoring, southern Brazilian rivers.Este trabajo pretende analizar la respuesta de la comunidad de diatomeas epilíticas a gradientes ambientales en ríos brasileños templados subtropicales, con el objetivo de contribuir al desarrollo de una metodología ampliamente aplicable para la monitorización de la calidad del agua. Diversas muestras para determinaciones físicas, químicas y biológicas fueron recogidas mensualmente, de diciembre de 2001 a noviembre de 2002, y de marzo de 2003 afebrero de 2004, en nueve estaciones de muestre o distribuidas a lo largo de los ríos Pardo y Pardinho, localizados en la Cuenca Hidrográfica del Río Pardo, Estado del Río Grande del Sur; Brasil. Variables físicas y químicas (temperatura del agua, pH, oxígeno disuelto, demanda bioquímica de oxígeno, demanda química de oxígeno, nitratos, nitritos, fosfato y sólidos totales disueltos) y biológicas (comunidad de diatomeas epilíticas) fueron usadas como parámetros para evaluar la calidad del agua. El conjunto de datos fue analizado por medio de una ordenación multivariante usando el Análisis de Correspondencias sin Tendencias (DCA). En total, 270 taxones fueron identificados a nivel especifico o infra-especifico. Los resultados indicaron que, entre todas las variables físicas y químicas usadas, el principal gradiente establecido a lo largo del primer eje DCA fue la eutrojización, señalada por su correlación significativa con la concentración de fosfatos (p < 0.001). De esta forma, los valores alcanzados por las especies en el primer eje DCA fueron usados como un criterio operativo para indicar su tolerancia a la eutrojización. Los 10 taxones más tolerantes a la eutrojizaciónfueron: Cyc10tella meneghiniana, Fallacia monoculata, Nitzschia acicularis, N. c1ausii, N. nana, N. palea, Nitzschia sp., Pinnularia sp., Sellaphora pupula sensu lato y Ulnaria acuso El presente estudio muestra que la comunidad de diatomeas epilíticas refleja cambios antropogénicos en ríos templados subtropicales de cuencas hidrográjicas, especialmente la contaminación por enriquecimiento orgánico y eutrofización
Role of economic instruments in water allocation reform: lessons from Europe
A growing number of countries are reforming their water allocation regimes through the use of economic instruments. This article analyzes the performance of economic instruments in water allocation reforms compared against their original design objectives in five European countries: England, France, Italy, Spain and the Netherlands. We identify the strengths of, barriers to and unintended consequences of economic instruments in the varying socio-economic, legal, institutional and biophysical context in each case study area, and use this evidence to draw out underlying common guidelines and recommendations. These lessons will help improve the effectiveness of future reforms while supporting more efficient water resources allocation
Amplificação sísmica de maciços estratificados com areias liquidificáveis: Agravamento dos assentamentos e deslocamentos laterais à superfície
Fisiopatología del paciente quemado
RESUMEN Las quemaduras extensas son uno de los traumas más severos al cual puede verse expuesto un individuo, este tipo de trauma tiene efectos locales y sistémicos bien establecidos pero no muy bien comprendidos por la mayoría del personal de salud. Pueden comprometer directa o indirectamente a casi todos los sistemas del organismo. El objetivo de éste artículo es ofrecer una explicación sencilla y sistemática, que permita al lector entender mejor como responde el cuerpo humano ante un trauma extenso por quemadura, se espera que esta lectura mejore la comprensión de la fsiopatología de este tipo de trauma y por lo tanto se manifeste en el actuar diario del personal de salud. Palabras clave: Quemaduras, fsiopatología, cirugía plástica ABSTRACT An extensive burn wound is among the most severe trauma a patient can be exposed to, it has well defned local and systemic effects; however, these effects are little understood by most of the health care personal. This injury can compromise directly or indirectly every system in the body. The objective of this article is to offer a simple and systematic review that allows the reader a better understanding of the response of the human body after an extensive burn injury, it is expected that this paper contributes to the better understanding of the physiology of this type of trauma and therefore be expressed in the daily work of the health care personal. Keywords: Burns, physiopathology, plastic surger
Fisiopatología del paciente quemado
RESUMEN Las quemaduras extensas son uno de los traumas más severos al cual puede verse expuesto un individuo, este tipo de trauma tiene efectos locales y sistémicos bien establecidos pero no muy bien comprendidos por la mayoría del personal de salud. Pueden comprometer directa o indirectamente a casi todos los sistemas del organismo. El objetivo de éste artículo es ofrecer una explicación sencilla y sistemática, que permita al lector entender mejor como responde el cuerpo humano ante un trauma extenso por quemadura, se espera que esta lectura mejore la comprensión de la fsiopatología de este tipo de trauma y por lo tanto se manifeste en el actuar diario del personal de salud. Palabras clave: Quemaduras, fsiopatología, cirugía plástica ABSTRACT An extensive burn wound is among the most severe trauma a patient can be exposed to, it has well defned local and systemic effects; however, these effects are little understood by most of the health care personal. This injury can compromise directly or indirectly every system in the body. The objective of this article is to offer a simple and systematic review that allows the reader a better understanding of the response of the human body after an extensive burn injury, it is expected that this paper contributes to the better understanding of the physiology of this type of trauma and therefore be expressed in the daily work of the health care personal. Keywords: Burns, physiopathology, plastic surger
Novel bioactive hydrophobic gentamicin carriers for the treatment of intracellular bacterial infections.
Gentamicin (GEN) is an aminoglycoside antibiotic with a potent antibacterial activity against a wide variety of bacteria. However, its poor cellular penetration limits its use in the treatment of infections caused by intracellular pathogens. One potential strategy to overcome this problem is the use of particulate carriers that can target the intracellular sites of infection. In this study GEN was ion paired with the anionic AOT surfactant to obtain a hydrophobic complex (GEN-AOT) that was formulated as a particulated material either by the Precipitation with a Compressed Antisolvent (PCA) method, or by encapsulation into poly(D,L-lactide-co-glycolide) (PLGA) nanoparticles (NPs). The micronization of GEN-AOT by PCA yielded a particulated material with a higher surface area than the non-precipitated complex, while PLGA NPs within a size range of 250-330 nm and a sustained release of the drug over 70 days were obtained by preparing the NPs using the emulsion solvent evaporation method. For the first time, GEN encapsulation efficiency values around 100% were achieved for the different NP formulations with no signs of interaction between the drug and the polymer. Finally, in vitro studies against the intracellular bacteria Brucella melitensis, used as a model of intracellular pathogen, demonstrated that the bactericidal activity of GEN was unmodified after ion-pairing, precipitation or encapsulation into NPs. These results, encourage their use for treatment for infections caused by GEN sensitive intracellular bacteria
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