Search results for "reserva"
showing 10 items of 630 documents
Nuevos métodos de detección de metástasis en corteza ovárica criopreservada de pacientes con cáncer de mama
2015
En la actualidad, se está produciendo un aumento de las tasas de supervivencia en determinadas formas de cáncer que se considera que afectan principalmente a niños y personas jóvenes, como las neoplasias hematológicas y ciertos tipos de tumores sólidos. El cáncer de mama es la neoplasia maligna más frecuente en mujeres en edad reproductiva y en muchos casos no han cumplido con su proyecto reproductivo. El tratamiento con dosis altas de quimioterapia y/o radioterapia en pacientes de sexo femenino puede generar efectos deletéreos sobre el ovario. La dotación folicular puede ser destruida, lo que se asocia a un fallo ovárico precoz y la pérdida de la fertilidad. El grado de gonadotoxicidad var…
Fronteras entre el DCL y personas mayores sanas
2016
Los cambios demográficos de los últimos años han generado grandes cambios poblacionales, con un gran número de personas mayores. Dentro de este marco de cambio demográfico, se plantea un nuevo reto para la sanidad y el estudio del desarrollo humano, ya que esta etapa está altamente asociada con aspectos relacionados con el deterioro y la enfermedad, concretamente, uno de los aspectos que más destaca por su incidencia y preocupación tiene que ver con el área cognitiva. De entre estas patologías, el deterioro cognitivo leve (DCL) se plantea como uno de los síndromes que mayores inquietudes están creando en la neurociencia debido a la evidencia sobre su posible evolución a demencia, así como a…
Reventilation Episodes During the Sapropel S1 Deposition in the Eastern Mediterranean Based on Holococcolith Preservation
2019
Organic-rich layers (sapropels), preserved in eastern Mediterranean marine sediment records, represent pronounced perturbations to thermohaline circulation and environmental conditions in the basin, in response to enhanced African monsoon activity and subsequent massive freshwater discharge. During the most recent event, Sapropel S1 formed between 10.8 and 6.1 ka, when freshwater-driven stratification caused seafloor anoxia below ~1,800-m depth, as a result of both failure of deep water formation and enhanced productivity. Here we analyze coccolith assemblages from the open eastern Mediterranean that form a west-east transect across the basin and provide insights on past environmental chang…
DNA integrity, growth pattern, spindle formation, chromosomal constitution and imprinting patterns of mouse oocytes from vitrified pre-antral follicl…
2010
Cryopreservation of follicles for culture and oocyte growth and maturation in vitro provides an option to increase the number of fertilizable oocytes and restore fertility in cases where transplantation of ovarian tissue poses a risk for malignant cell contamination. Vitrification for cryopreservation is fast and avoids ice crystal formation. However, the influences of exposure to high concentrations of cryoprotectants on follicle development, oocyte growth and maturation, and particularly, on the DNA integrity and methylation imprinting has not been studied systematically. Follicle survival and development, DNA damage, oocyte growth patterns, maturation, spindle formation and chromosomal c…
Investigating a simplified method for noninvasive genetic sampling in East African mammals using silica dried scat swabs
2020
Abstract Swabbing scat has proved to be an effective noninvasive method to collect DNA from mammals in the field. Previously, this method has relied on preservative liquids or freezing to preserve the DNA collected on swabs. In this study, we determine the effectiveness of using silica to simply dry the swab in field as an alternative way to prevent DNA degredation. Four species were included in the study; reticulated giraffe, impala, fringe‐eared oryx, and lion. Swabs were taken at multiple time points for giraffe and impala scat samples, with the lion and oryx sampled opportunistically. Mitochondrial DNA was successfully amplified and sequenced from scat swabs from all species; however, e…
Lactic acid bacteria associated with vacuum-packed cooked meat product spoilage: population analysis by rDNA-based methods.
2007
Aim: To determine the lactic acid bacteria (LAB) implicated in bloating spoilage of vacuum-packed and refrigerated meat products. Methods and Results: A total of 18 samples corresponding to four types of meat products, with and without spoilage symptoms, were studied. In all, 387 colonies growing on de Man, Rogosa and Sharpe, yeast glucose lactose peptone and trypticase soy yeast extract plates were identified by internal spacer region (ISR), ISR-restriction fragment length polymorphism and rapid amplified ribosomal DNA restriction analysis profiles as Lactobacillus (37%), Leuconostoc (43%), Carnobacterium (11%), Enterococcus (4%) and Lactococcus (2%). Leuconostoc mesenteroides dominated …
Salt drying: a low-cost, simple and efficient method for storing plants in the field and preserving biological repositories for DNA diversity researc…
2013
Although a variety of methods have been optimized for the collection and storage of plant specimens, most of these are not suited for field expeditions for a variety of logistic reasons. Drying specimens with silica gel in polyethylene bags is currently the standard for field-sampling methods that are suitable for subsequent DNA extraction. However, silica-gel repositories are not readily available in remote areas, and its use is not very cost-effective for the long-term storage of collections or in developing countries with limited research budgets. Salting is an ancient and traditional drying process that preserves food samples by dehydrating tissues and inhibiting water-dependent cellula…
The influence of platform switching in dental implants. A literature review.
2010
Introduction: The platform switching concept involves the reduction of the restoration abutment diameter with respect to the diameter of the dental implant. In 1991, dental implants of 5 and 6 mm diameter platforms were introduced. However, matching-diameter prosthetic abutments were not available. These implants were restored with “standard”-diameter prosthetic components (4,1 mm). Long-term follow up around these wide-platforms showed higher levels of bone preservation. In time, it has been called platform switching. The first case report applying this concept was indexed in MedLine in 2005. Materials and Methods: The aim of this article is to carry out a literature review of articles whi…
Determination of alternative preservatives in cosmetic products by chromophoric derivatization followed by vortex-assisted liquid-liquid semimicroext…
2016
An analytical method for the simultaneous determination of phenethyl alcohol, methylpropanediol, phenylpropanol, caprylyl glycol, and ethylhexylglycerin, which are used as alternative preservatives in cosmetic products, has been developed. The method is based on liquid chromatography with UV spectrophotometric detection after chromophoric derivatization with benzoyl chloride and vortex-assisted liquid-liquid semimicroextraction. Different chromatographic parameters, derivatization conditions, and sample preparation variables were studied. Under optimized conditions, the limits of detection values for the analytes ranged from 0.02 to 0.06µgmL(-1). The method was validated with good recovery …
Green, rapid and simultaneous determination of ‘alternative preservatives’ in cosmetic formulations by gas chromatography-mass spectrometry
2022
Abstract Some hydroxylated compounds commonly used in cosmetic formulations including short chain glycols, benzylic alcohols, and organic acids show antimicrobial activity, although they are not considered as preservatives according to the existing European legislation. These ‘alternative preservatives’ are not exempt of potential side-effects for cosmetics users. The aim of this work is to develop a simple and affordable analytical method useful for the simultaneous and green determination of fourteen compounds used as ‘alternative preservatives’ in cosmetic samples with different matrices. The proposed method allows a rapid sample preparation by simple dissolution or dispersion of the sam…