2,942 research outputs found
Determination of biosorption mechanism in biomass of agave, using spectroscopic and microscopic techniques for the purification of contaminated water
[Abstract] Lead (Pb2+) and copper (Cu2+) are polluting metals due to their toxicity; however, the extraction of these metals is essential for economic development, so it is important to look for efficient and low-cost alternatives that can remove heavy metals from the various bodies of water. One of the alternatives used in this work is biosorption, for which an agroindustrial waste (epidermis from Agave atrovirens) was used to evaluate the affinity of removal of lead and copper in aqueous solutions; in addition, spectroscopy and microscopy techniques were used to elucidate and corroborate the removal and affinity capacity of the agave epidermis for both metals studied. The optimal pH value for the removal of both metals was 3. The adsorption isotherms yielded a qmax of 25.7 and 8.6 mg/g for lead and copper, respectively. Adjusting to the Langmuir-Freundlich model, the adsorption kinetics were pseudo-second order, and it was found that the equilibrium time was at 140 min. The spectroscopy and microscopy analyses corroborated the affinity between metals and functional groups of the agave, as well as with the elemental analysis, which reported 17.38% of lead and 4.25% of copper.[Resumen] El plomo (Pb2+) y el cobre (Cu2+) son metales contaminantes debido a su toxicidad; sin embargo, la extracción de estos metales es indispensable para el desarrollo económico, por lo que es importante buscar alternativas eficientes y de bajo costo que puedan remover metales pesados de los diversos cuerpos de agua. Una de las alternativas utilizadas en este trabajo es la biosorción, para la cual se utilizó un residuo agroindustrial (epidermis de Agave atrovirens), para evaluar la afinidad de remoción del plomo y cobre en soluciones acuosas; adicionalmente, se emplearon técnicas de espesctroscopía y microscopía que permitieron elucidar y corroborar la capacidad de remoción y afinidad que tuvo la epidermis de A. atrovirens para ambos metales estudiados. El valor óptimo de pH para la remoción de ambos metales fue 3. Las isotermas de adsorción arrojaron una qmax de 25.7 y 8.6 mg/g para el plomo y cobre, respectivamente. Ajustando al modelo de Langmuir-Freundlich, las cinéticas de adsorción resultaron de pseudo-segundo orden, se encontró que el tiempo de equilibrio es a los 140 min. El análisis espectroscópico y microscópico, corroboró la afinidad entre metales y grupos funcionales del agave, así como con el análisis elemental, el cual reportó 17.38% de plomo y 4.25% de cobre
Identification of Key Molecules Involved in the Protection of Vultures Against Pathogens and Toxins
This is an open access article distributed under the terms of
the Creative Commons Attribution License.This work was supported by the Junta de Comunidades de Castilla-La Mancha (JCCM),
project PII1I09-0243-4350.Peer Reviewe
Culture of Gracilaria gracilis and Chondracanthus teedei from Vegetative Fragments in the Field and Carpospores in Laboratory
Gracilarioids and Gigartinales are of great economic importance due to the phycocolloids they contain in their cell wall and are used in different industries worldwide. Field and laboratory cultures of two species of red seaweeds (Gracilaria gracilis and Chondracanthus teedei), confirmed after DNA analysis, were carried out to foster the increasing use of this species in Spain as a food source. Vegetative cultures carried out in an open-lock gate within a traditional salina in the ay of Cadiz (Southern Spain) rendered maximum growth rates in April (3.64% day(-1)) for G. gracilis and in November (4.68% day(-1)) for C. teedei, the latter showing significant differences between the months of the year. For laboratory cultures, samples of the two species used for sporulation were obtained from tidal creeks in several nearby locations of the Bay. In order to grow fertile carposporophytes from spores, Provasoli enriched seawater medium (ES medium), Miquel A + B and f/2 were used as culture medium at a temperature of 18 degrees C and irradiance of 30 mu mol m(-2) s(-1) in 12:12 h photoperiod. Both species developed a basal disc after 12-15 days in ES medium and Miquel A + B, and new microscopic seedlings were observed at 20-25 days in ES medium. With f/2 medium, no growth was observed after sporulation. The life cycle of G. gracilis was completed in ES medium over a period of 11 months with a mean growth rate of 3.28% day(-1). The present study is an important step towards the development of seaweed cultivation in the Bay of Cadiz, especially in integrated multi-trophic cultivation in salinas as part of the more sustainable use of the marine resources in coastal communities
Suckling, male effect and kisspeptin in the reproductive management of ewes in postpartum anestrus
Objective: To describe the management strategies of controlled suckling and the male effect to reduce postpartum anestrus, and to show the participation of kisspeptin to regulate the effect of both factors.
Design/Methodology/Approach: A review of scientific publications was conducted, in order to show the importance of suckling and the male effect as strategies to reduce postpartum anestrus in the ewe, as well as the relation of kisspeptin with both factors.
Results: Seasonal anestrus can be avoided with the use of breeds adapted to the local environment, such as Pelibuey. Postpartum anestrus occurs mainly as a result of suckling, since the latter inhibits the pulsating secretion of the gonadotropin-releasing hormone (GnRH) and the luteinizing hormone (LH). The exact path of this inhibition is unknown, although it seems that endogenous opioid peptides and kisspeptin are intermediaries. Controlled suckling and the male effect are management strategies that improve the reproductive behavior of postpartum ewes. Kisspeptin regulates the influence of the male effect through the secretion of GnRH/LH.
Study Limitations/Implications: To understand the impacts of suckling and the male effect on the duration of postpartum anestrus, as well as the participation of kisspeptin in the regulation of both effects, will allow designing management strategies to improve the reproductive efficiency of the ewes.
Findings/Conclusions: Controlled suckling and the male effect reduce postpartum anestrus and improve the reproductive behavior of the ewes; advancing knowledge of the kisspeptin effect could improve the effectiveness of both techniques
Efecto terapéutico del afecto positivo
Resumen. La capacidad para regular las emociones de manera eficaz facilita la adaptación de las personas alámbito social y es uno de los elementos fundamentales para entender cómo las personas más resilientes son capacesde afrontar las situaciones adversas y salir reforzadas. El análisis de estas variables permitiría comprendermejor la relación que la literatura científica establece entre el estado afectivo positivo y una mejor salud física ymental. Uno de los aspectos más relevantes en esta relación son las habilidades para reconocer y expresar lasemociones, que permiten su fácil integración en programas de prevención y rehabilitación. Además, estas habilidadespodrían potenciarse en el contexto clínico a través de la mejora en la interacción emocional entre el personalsanitario y los pacientes, con un enfoque prioritario hacia la regulación de las emociones positivas.Summary. The ability to regulate emotions effectively makes it easier for individuals to adapt to their socialcontext, and it is one of the keys to understanding how the most resilient people are better able to cope with adversesituations and emerge from them stronger than before. An analysis of these variables would allow for a betterunderstanding of the relationship that previous scientific literature has established between positive emotionalstates and improved physical and mental health. Among the most important aspects of this relationship is anability to recognize and express emotions, which would indicate that these skills would be suitable for inclusionin prevention and rehabilitation programs. In addition, these abilities can be enhanced in the clinical contextthrough improved emotional interaction between health professionals and patients, aimed at fostering positiveemotion regulation
Ameloblastoma mandibular: revisión de la literatura y presentación de seis casos
El ameloblastoma es un tumor odontogénico benigno de origen
epitelial sin inducción en el tejido conectivo. En el tratamiento
del mismo se debe valorar el tipo clínico (sólido y multiquístico,
uniquístico, periférico), la localización y el tamaño del tumor,
así como la edad del paciente. Recientemente se han publicado
algunos artículos con el fin de actualizar los conocimientos y
actitudes terapéuticas frente al ameloblastoma.
Se presentan seis casos de pacientes afectos de ameloblastomas
localizados en la mandíbula, tratados en los últimos siete años.
Se aportan datos acerca de su aparición clínica, sus características
histológicas, el manejo terapéutico realizado que consistió
en la extirpación de la lesión, fresado perilesional del hueso o
resección en bloque, según el tipo de ameloblastoma. Finalmente
analizamos el seguimiento y la aparición de recidivas en los
pacientes presentados.
El objetivo de este artículo es revisar los conceptos respecto al
ameloblastoma que se han publicado recientemente y valorar
su influencia en la actitud del clínico a la hora de actuar frente
a esta patología, tomando como punto de partida para ilustrar
está discusión la presentación de nuestra experiencia respecto
al ameloblastoma.Ameloblastoma is a benign odontogenic tumour of epithelial
origin without induction in the connective tissue. In treating this
type of tumour, it is important to assess the clinical type (solid,
multicystic, unicystic, peripheral), localisation, and size of the
tumour as well as age of the patient. Articles have recently been
published with the purpose of providing updated knowledge
and therapeutic approaches to ameloblastoma. We present six
cases of patients with localised mandibular ameloblastoma who
were treated during the last seven years. We present data on
clinical appearance, histological characteristics, and therapeutic
approach that was used, which included excision of the lesion,
perilesional drilling of the bone, or block resection, according
to the type of ameloblastoma. Lastly, we analysed follow-up
measures and the rate of recurrence in these patients. The aim of
this paper is to review the concepts relating to ameloblastoma
that have been published recently and to assess their influence on
the clinical attitude taken when facing this pathology, using our
experience with ameloblastoma as a starting point to illustrate
this discussion
Examination of the Feynman-Hibbs Approach in the Study of Ne-Coronene Clusters at Low Temperatures
Feynman-Hibbs (FH) effective potentials constitute an appealing approach for
investigations of many-body systems at thermal equilibrium since they allow us
to easily include quantum corrections within standard classical simulations. In
this work we apply the FH formulation to the study of Ne-coronene clusters
( 1-4, 14) in the 2-14 K temperature range. Quadratic (FH2) and quartic
(FH4) contributions to the effective potentials are built upon Ne-Ne and
Ne-coronene analytical potentials. In particular, a new corrected expression
for the FH4 effective potential is reported. FH2 and FH4 cluster energies and
structures -obtained from energy optimization through a basin-hoping algorithm
as well as classical Monte Carlo simulations- are reported and compared with
reference path integral Monte Carlo calculations. For temperatures K,
both FH2 and FH4 potentials are able to correct the purely classical
calculations in a consistent way. However, the FH approach fails at lower
temperatures, especially the quartic correction. It is thus crucial to assess
the range of applicability of this formulation and, in particular, to apply the
FH4 potentials with great caution. A simple model of isotropic harmonic
oscillators allows us to propose a means of estimating the cut-off temperature
for the validity of the method, which is found to increase with the number of
atoms adsorbed on the coronene molecule
Relación entre las pruebas de funcionalidad de la marcha en personas con daño cerebral adquirido en fase subaguda
Objetivo: Analizar el grado de relación entre cuatro pruebas que valoran la funcionalidad de la marcha en sujetos jóvenes con daño cerebral adquirido (DCA) en fase subaguda y conocer el grado de relación entre estas pruebas y la percepción subjetiva de seguridad en actividades de la vida diaria.
Metodología: 67 participantes jóvenes con DCA en fase subaguda (43 hombres y 24 mujeres) con una edad media 35,09 años. Se realizó estadística descriptiva de todas las variables demográficas: género, edad, IMC, meses desde que se produjo la lesión y etiología lesional. Para analizar si existe correlación entre las variables se utilizó el coeficiente de Pearson.
Resultados: El Timed 10-Meter Walk presenta una correlación muy alta con Timed Up and Go (TUG) (r=093), alta con el 6-Minute Walk Test (r=0,77) y moderada con el Step Test (r=0,56). El 6-Minute Walk Test presenta una correlación alta con el TUG (r=0,82) y una correlación moderada con el Step Test (r=0,69). El Step Test presenta una correlación moderada con el TUG (r= -0,68). The Activities-specific Balance Confidence Scale (ABC) presenta una correlación moderada con el Timed 10-Meter Walk (r=0,42), TUG (R=0,40), 6-Minute Walk Test (r=0,40) y Step Test (r=0,44).
Conclusiones: Las pruebas de funcionalidad de la marcha presentan una correlación significativa entre moderada y muy alta en personas jóvenes con DCA. El ABC presenta una correlación significativa moderada con las cuatro variables de funcionalidad de la marcha analizadas en esta població
Assessment of quality of life in oral cancer
Quality of life (QL) in oral cancer patients has become one of the most important parameters to consider in the diagnosis and post-treatment follow-up. The purpose of this article has been to review the papers published that study the QL in oral cancer patients, the different QL questionnaires used, the clinical results obtained, and the systematic revisions available in the indexed literature for the last 10 years. The term QL appears as a keyword in an increasing number of articles throughout the past 10 years; however, few studies focus on oral cancer. Most of them assess all head and neck cancers, which conform to a heterogeneous group with several different features depending on location (oral cavity, oropharynx, larynx, hypopharynx, nasopharynx and salivary glands). Most studies evaluate QL in short periods of time, normally within the first year after the diagnosis. Series do not discern between different therapeutic options, and they generally center on Northern European or Northern American populations. There are few instruments translated and validated into Spanish that measure QL, a fundamental characteristic to link QL to own patients? socio-cultural parameters. Data related with QL are mostly related to patient (age, sex, co-morbidity), tumour (location, size), and treatment (surgical treatment, radiotherapy association, reconstruction, cervical dissection, and/or feeding tube). Nowadays QL?s assessment is considered an essential component of an oral cancer patient as well as the survival, morbidity and years free of disease. Although many aspects related to QL in oral cancer patients have been published throughout the past 10 years, more systematic research is needed to be able to apply it on a daily basis
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