1,703 research outputs found
Booster or additional vaccination doses in patients vaccinated against COVID-19.
Several health organizations, mainly in Western countries, have recently authorized the use of a booster dose of the COVID-19 vaccine for patients previously vaccinated with mRNA vaccines, with criteria that do not always coincide.
The COVID Scientific Committee of the Illustrious College of Physicians of Madrid (ICOMEM) has received and asked several questions about this situation, to which the group has tried to give answers, after deliberation and consensus.
The efficacy of the vaccines administered so far is beyond doubt and they have managed to reduce, fundamentally, the severe forms of the disease. The duration of this protection is not well known, is different in different individuals and for different variants of the virus and is not easily predictable with laboratory tests.
Data on the real impact of a supplementary or “booster” dose in the scientific literature are scarce for the moment and its application in large populations such as those in the state of Israel may be associated with a decrease in the risk of new and severe episodes in the short observation period available.
We also lack sufficient data on the safety and potential adverse effects of these supplementary doses and we do not know the ideal time to administer them in different situations.
In this state of affairs, it seems prudent to administer supplemental doses to those exposed to a higher risk, such as immunocompromised individuals and the elderly. On the other hand, we consider that this is not the time to accelerate, on the spur of the moment, a massive administration of a third dose to other population groups that are less exposed and at lower risk, without waiting for adequate scientific information, which will undoubtedly arrive gradually. We do not believe that this position is incompatible with the practical and ethical warnings made by the World Health Organization in this respect.post-print162 K
Evaluación de elastómeros vulcanizados
En el desarrollo de elastómeros se utilizan varios tipos de compuestos con finalidades diferentes para mejorar las propiedades mecánicas que brinda el caucho base. La mejora de las propiedades va estar dada por los diferentes efectos de las interacciones entre dichos compuestos, por esta razón existe una gran variedad de elastómeros que abren cada día más su campo de aplicación. En este trabajo se estudió la influencia de tres elementos, en un caucho acrilonitrilo, a traves de ensayos normalizados a temperatura ambiente. Se concluyó que existe marcada influencia de las variables independientes estudiadas: Disulfuro de Tetrametil tiuram (TMTD, ultraacelerante), Dures Resin (resina reforzante) y ZnO-Al (Oxido de zinccon 4% de trazas de Aluminio, activador de la reaccion devulcanización), sobre las propiedades fisico-mecanica. Se corroboró la dependencia entre la dureza, resistencia a la tracción y módulo de elasticidad reportada en la literatura
Christiansen grammar evolution for the modelling of psychological processes
This is an electronic version of the paper presented at the International Industrial Simulation Conference (ISC 2007), held in Delft (The Netherlands)Psychologists have developed models of associative learning
for more than 30 years. Despite the strong efforts made, they
still suffer many shortcomings. We have tried to build an
integral model of habituation, the simplest type of learning
within the area of associative learning and the basic support
for other types. To overcome the deficiencies of traditional
models, we have made used of Christiansen Grammar Evolution.
This evolutionary technique is capable of automatically
search for a target expression (the model) in a given formal
language (the formalism of the model). Under this perspective,
that we call Automatic Modelling, we have found models
of habituation with interesting characteristics.This work has been partially sponsored by the Spanish Ministry
of Education and Science (MEC), project number TSI2005-08225-
C07-06
Análisis de la resiliencia ante inundaciones en los municipios de Ixtlahuaca y Atlacomulco, Estado de México.
Para conocer la conformación de la resiliencia en la población ante las inundaciones ocurridas en los municipios de Ixtlahuaca y Atlacomulco, se diseñó una metodología que fue adaptada y estructurada de acuerdo con las necesidades de la investigación. Por tal motivo, se aplicó el método histórico para la identificación de las zonas inundables, mismas que fueron representadas de manera cartográfica para cada uno de los municipios. Posteriormente se consultó información referente a los índices de marginación de las personas que habitan en las áreas de estudio. Por otro lado se utilizó la encuesta como técnica para recolectar información de la población que habita en zonas inundables; los datos obtenidos fueron analizados por medio de gráficas que sintetizan los elementos esenciales que han conformado la resiliencia por parte de la población. Adicionalmente se muestran las matrices AVC para relacionar las condiciones de vulnerabilidad socioeconómica y los elementos de la resiliencia. Derivado de lo anterior, se presentan de manera general algunas propuestas que fueron formuladas para integrar este concepto a las autoridades encargadas del tema
Evaluación de elastómero vulcanizado (Parte II)
Toda mezcla elastómerica se desarrolla en base a unaformulación para obtener diferentes propiedades físicomecánicas y químicas que la diferencian del resto. En lapresente investigación se continuó el estudio de caracterizaciónde las formulaciones, (continuación de la parte I),evaluando en este caso tres nuevas propiedades comovariables respuesta, resistencia al desgaste, el coeficientede Poisson, y el envejecimiento, utilizando como variablesindependientes el contenido de Disulfuro de Tetrametil tiuram(TMTD, ultraacelerante), Dures Resin (resina reforzante) y ZnO-Al (Óxido de cinc con 4% de trazas de Aluminio, activador de la reacción de vulcanización), de esta forma quedan definidas las principales propiedades de las formulaciones estudiadas que permiten dar respuesta a las diferentes solicitaciones mecánicas. Los datos obtenidos son imprescindibles para la modelación de la pieza que se quiera fabricar con dicha formulación
Expresión proteica de p53 y proliferación celular en leucoplasias orales
Objetivos: Conocer la expresión proteica de las alteraciones
genéticas que se producen en las etapas precoces de la cancerización
del campo de cavidad oral en nuestro medio. Estudiar
la proliferación celular mediante Ki-67 y la expresión de la
proteína p53 para valorar si las alteraciones en la expresión
proteica de estos marcadores suceden de forma secuencial a
través de las distintas etapas en la cancerización del campo de
la cavidad oral.
Material y métodos: Se realizó un estudio mediante técnicas de
inmunohistoquímica sobre 53 pacientes que presentaron lesiones
de leucoplasia oral, atendidos por el Servicio de O.R.L del
Hospital Universitario de Salamanca, desde 1.990 hasta 2000.
Se incluyen en el estudio 11 muestras de epitelio normal, 15
displasias leves y moderadas, 15 carcinomas in situ, y 12 carcinomas
microinvasores. Resultados: Encontramos la proliferación
celular aumentada y sobreexpresión de p53 a medida que avanzamos
en el grado de severidad histopatológica de las lesiones.
Las alteraciones más precoces son el aumento significativo de
la proliferación celular en displasias leves y moderadas y el
aumento de expresión de p53.
Conclusión: La leucoplasia oral es un estado precanceroso que
constituye una lesión cancerizable debido a las alteraciones genéticas
que intervienen en la evolución de la lesión. El estudio
inmunohistoquímico y molecular de las lesiones es un medio rutinario
que permite conocer la expresión proteica de las alteraciones
genéticas, que puede ayudar en el diagnóstico precoz y tratamiento
de esta patología, teniendo especial relevancia el estudio de Ki-67
en etapas iniciales y p53 en lesiones más avanzadas.OBJECTIVES: We intend to know the protein expression of
genetic alterations that take place in the early stages in the field
cancerization of oral cavity in our means as well as to study the
cellular proliferation by means of Ki-67 and the protein product
expression of p53 to value if the alterations in the protein
products expression of these markers happen in a sequential
pathway through the different stages in the field cancerization
of oral cavity.
MATERIALS AND METHODS: A study was made by immunohistochemistry
on 53 patients that presented lesions of oral
leukoplaquia, assisted by the ENT service at University Hospital
of Salamanca, from 1.990 up to 2000. 11 samples of normal epithelium,
15 mild to moderate dysplasias, 15 in situ carcinomas
and 12 microinvasive carcinomas are included in the study.
RESULTS: we find an increased cellular proliferation and p53
over-expression as we advance in the grade of severity histopathologic
of these lesions. The most early alterations are a
significant increase of cell proliferation in mild and moderate
dysplasias and an increased p53 over-expression.
CONCLUSIONS: Oral leukoplaquia is a precancerous stage that constitutes a canzerisable lesion due to the genetic alterations
that mediate in the evolution of lesion. Routine Immunohistochemical
and molecular study of these lesions allow us to
know the protein expression of genetic alterations that can help
in the early diagnosis and treatment of this pathology, having
special relevance the study of Ki-67 in early stages and p53 in
advanced lesions
Toxicity of a dental adhesive compared with ionizing radiation and zoledronic acid
Background: To determine the toxicity of aqueous dilutions of a universal self-priming dental adhesive (DA) and
comparing these with those elicited by exposure to ionizing radiation (IR), Zoledronic acid (Z) treatment and the
synergic effects of the combined treatment with IR+Z.
Material and Methods: The genotoxic effect of DA was determined by the increase in the frequency of micronuclei
in cytokinesis-blocked in cultured human lymphocytes before and after exposure to 2Gy of X-rays. The cytotoxic effect was studied by using the MTT cell viability test in normal prostate cell lines (PNT2) after exposure
to different X-ray doses (0Gy-20Gy). The cell lines divided into different groups and treated with different test
substances: DA in presence of O
2
, DA in absence of O
2
, Z-treated and control.
Results: An in vitro dose-dependent and time-dependent cytotoxic effect of DA, Z and IR on PNT2 cells (
p
>0.001)
was demonstrated. DA without-O
2
, following the recommendations of manufacturers, had a more pronounced
effect of increasing cell death than DA with-O
2
(
p
<0.001). In the genotoxicity assay, DA at 25% of its original
concentration significantly increased chromosome damage (
p
<0.001). The samples studied were found to be toxic,
and the samples photo-polymerized in absence of O
2
showed a bigger cytotoxic effect comparable to the additive
toxic effect showed by the combined treatment of IR+Z.
Conclusions: Additional effort should be carried out to develop adhesives, which would reduce the release of hazardus substances; since toxic effects are similar to that reported by other agents whose clinical use is controlled by the
health authorities
Assessment of integrated solutions for the combined energy efficiency improvement and seismic strengthening of existing URM buildings
The European building stock is an aging infrastructure, mainly built prior to building codes. Furthermore, 65% of these buildings are located in seismic regions, which need to be both energetic and seismically retrofitted to comply with performance targets. Given this, this manuscript presents integrated constructive solutions that combine both energy efficiency improvement and seismic strengthening. The goal and novelty is to design and to evaluate one-shot, compatible, noninvasive, and complementary solutions applied to the façades of buildings with a minimum cost. To do so, different constraints have been borne in mind: the urban environment, achievable seismic and energy performance targets, and reduced construction costs. The method was applied to an old Spanish neighbourhood constructed in the 1960s. Different retrofitting packages were proposed for an unreinforced masonry case study building. A sensitivity analysis was performed to assess the effects of each configuration. A benefit/cost ratio was proposed to comparatively assess and to rank the solutions. The results of the seismoenergetic performance assessment showed that improving the behaviour of walls leads to higher benefit ratios than improving the openings. However, this latter strategy generates much lower construction costs. Integrating seismic into energetic retrofitting solutions supposes negligible additional costs but can improve the seismic behaviour of buildings by up to 240%. The optimal solution was the addition of higher ratios of steel grids and intermediate profiles in openings while adding thermal insulation in walls and renovating the window frames with PVC and standard 4/6/4 double glazing
Comparative analysis between the Spanish and Portuguese seismic codes. Application to a border RC primary school
The Iberian Peninsula is close to the Eurasia-Africa plate boundary resulting in a considerable seismic hazard. In fact, the southwestern Iberian Peninsula is affected by far away earthquakes of long-return period with large-very large magnitude. A project named PERSISTAH (Projetos de Escolas Resilientes aos SISmos no Território do Algarve e de Huelva, in Portuguese) aims to cooperatively assess the seismic vulnerability of primary schools located in the Algarve (Portugal) and Huelva (Spain). Primary schools have been selected due to the considerable amount of similar buildings and their seismic vulnerability. In Portugal, the Decreto Lei 235/83 (RSAEEP) is mandatory while in Spain, the mandatory code is the Seismic Building Code (NCSE-02). In both countries, the Eurocode-8 (EC-8) is recommended. Despite the fact that both regions would be equally affected by an earthquake, both seismic codes are significantly different. This research compares the seismic action of Ayamonte (Huelva) and Vila Real de Santo António (Portugal). Both towns are very close and located at both sides of the border. Moreover, they share the same geology. This analysis has been applied considering a RC primary school building located in Huelva. To do so, the performance-based method has been used. The seismic action and the damage levels are compared and analysed. The results have shown considerable differences in the seismic actions designation, in the performance point values and in the damage levels. The values considered in the Portuguese code are significantly more unfavourable. An agreement between codes should be made for border regions.This work has been supported by the INTERREG-POCTEP Spain-Portugal programme
and the European Regional Development Fund through the 0313_PERSISTAH_5_P project
and the VI-PPI of the University of Seville by the granting of a scholarship. The grant provided by the Instituto Universitario de Arquitectura y Ciencias de la Construcción is acknowledged.info:eu-repo/semantics/publishedVersio
E-cadherin, laminin and collagen IV expression in the evolution from dysplasia to oral squamous cell carcinoma
Objetivos: Estudiar la pérdida o reducción de la adhesión celular mediada por E-cadherina en leucoplasias, carcinomas epidermoides y metástasis ganglionares. Estudiar la pérdida de continuidad de la expresión de laminina y colágeno IV en la membrana basal epitelial en el desarrollo biológico de las leucoplasias y carcinomas orales. Material y metodo: Hemos estudiado 124 muestras de pacientes portadores de leucoplasias y carcinomas orales con diversos diagnósticos que abarcan desde epitelio normal (13 muestras), displasias leves (2), displasias moderadas (12), carcinomas in situ (13) carcinomas microinvasores (11) Carcinoma epidermoide oral (64 muestras) y metástasis ganglionar (9). Se construyeron 7 bloques de tissue microarrays con aguja de 2mm y se realizó un estudio mediante técnica inmunohistoquímica para E-cadherina (clona 36, T.D. ABD Company), Laminina (078P, Biogenex) y Colágeno IV (PHM12, Biogenex). Resultados: En Displasias Leves y Moderadas presentan pérdida de expresión de E-cadherina, Laminina, y Colágeno IV (20%). En Carcinomas in situ y Microinvasores, presentaron pérdida de expresión de E-cadherina (73%), y en Laminina y Colágeno IV (57%). En los carcinomas epidermoides, encontramos pérdida de expresión de E-cadherina (90%) y discontinuidad en la M. basal (70%). Todas las metástasis ganglionares presentaron pérdida de E-cadherina y discontinuidad en Laminina y Colágeno IV. Conclusiones: La pérdida de expresión de E-cadherina se incrementa al aumentar el grado de displasia de las lesiones. La perdida de continuidad en la expresión de laminina y Colágeno IV sigue una evolución paralela desde displasias a metástasis ganglionares. La disminución en la expresión de los tres marcadores ha sido significativa en la evolución de las lesiones orales
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