Search results for " Skin"
showing 10 items of 1220 documents
A comparison of various calibration techniques applied to the ninhydrin-cefoxitin determination
1996
Abstract This report deals with spectrophotometric determination of cefoxitin from intact antibiotics or from its acid induced degradation product by means of their reaction with ninhydrin in a strong sulphuric acid medium. To obtain the calibration graphs four methods were used: absorbance of reacted cefoxitin against a reagent blank as an analytical signal, first-derivative signal of absorbance against a water blank as an analytical signal, first-derivative signal of absorbance against a reagent blank as an analytical signal and the H-Point Standard Additions Method (HPSAM) by using absorbance increment values as analytical signals. The HPSAM is applied to the determination of cefoxitin i…
Carboxylated-xyloglucan and peptide amphiphile co-assembly in wound healing.
2021
Abstract Hydrogel wound dressings can play critical roles in wound healing protecting the wound from trauma or contamination and providing an ideal environment to support the growth of endogenous cells and promote wound closure. This work presents a self-assembling hydrogel dressing that can assist the wound repair process mimicking the hierarchical structure of skin extracellular matrix. To this aim, the co-assembly behaviour of a carboxylated variant of xyloglucan (CXG) with a peptide amphiphile (PA-H3) has been investigated to generate hierarchical constructs with tuneable molecular composition, structure, and properties. Transmission electron microscopy and circular dichroism at a low c…
Energy regulatory signals and food reward.
2009
The hormones insulin, leptin, and ghrelin have been demonstrated to act in the central nervous system (CNS) as regulators of energy homeostasis, acting at medial hypothalamic sites. Here, we summarize research demonstrating that, in addition to direct homeostatic actions at the hypothalamus, CNS circuitry that subserves reward and is also a direct and indirect target for the action of these endocrine regulators of energy homeostasis. Specifically, insulin and leptin can decrease food reward behaviors and modulate the function of neurotransmitter systems and neural circuitry that mediate food reward, the midbrain dopamine (DA) and opioidergic pathways. Ghrelin can increase food reward behavi…
Comparison of several methods used for the determination of cephalosporins. Analysis of cephalexin in pharmaceutical samples
2002
The precision of UV absorbance of intact and acid degraded cephalosporins, ninhydrin, high performance liquid chromatography and iodometric methods used for analysis of cefoxitin, cefotaxime, cephazolin and cephalexin were compared. To obtain the calibration graphs the analytical signal used were: absorbance, first derivative absorbance, second derivative absorbance and H-point Standard Additions Method by using absorbance values at two selected wavelengths as analytical signal. These methods and calibration graphs were also used for the determination of cephalexin in pharmaceutical samples.
An empirical test of Sokolov's entropy model of the orienting response.
1974
Several hypotheses, most of them deduced from Sokolov's entropy model of the Orienting Response (OR), were tested. The Galvanic Skin Response (GSR) served as the indicator of the OR. Printed language, analyzed with regard to the information content in bits, was used as stimulus material. Forty-eight female students served as subjects. The results indicate: (1) that the uncertainty of a situation does not determine the strength of the OR, (2) that the strength of the OR depends on the information carried by an event, and (3) that the processing of this information, as indicated by the OR, may be delayed by one or more events in a serial application. For tonic level over a series of events no…
Chemical Routes Toward Multicompartment Colloids
2012
The search for mimicking natural living and non-living systems with synthetic products leads to the fabrication of advanced colloidal morphologies with hierarchical micro- and nanostructures. Different chemical routes toward the synthesis of colloids with complex morphologies are presented and a tentative analogy between these routes and the four basic arithmetic operations is proposed.
Increasing the levels of 2-phenylethyl acetate in wine through the use of a mixed culture of Hanseniaspora osmophila and Saccharomyces cerevisiae
2009
The impact of mixed cultures of Hanseniaspora osmophila and Saccharomyces cerevisiae with different initial yeast ratios on wine composition has been examined. The mixed culture significantly affected sugar consumption, the main enological parameters and ester concentrations, with the exception of glycerol, isoamyl acetate and diethyl succinate levels. Remarkably, in wines obtained with mixed cultures the concentration of 2-phenylethyl acetate was approximately 3- to 9-fold greater than that produced by S. cerevisiae pure culture. Moreover sensory evaluation revealed a stronger fruity character in wines fermented with mixed cultures than in control wines. Independently of the mixed culture …
Consequences of food-attraction conditioning in Helix: a behavioral and electrophysiological study
1996
Food-attraction conditioning is a learning phenomenon by which adult Helix pomatia acquire the ability to locate food through exposure to that particular food. Food-conditioned snails can be distinguished from ‘naive’ snails during their approach to food. ‘Naive’ snails keep their tentacles upright — whereas ‘food-conditioned’ animals bend the tentacles down-ward, in a horizontal orientation, pointed in the direction of the food.
Prevalence and risk factors of actinic keratosis in patients attending Italian dermatology clinics
2017
Background: Actinic keratosis (AK) is a common keratinocyte intraepidermal neoplasia. Objective: To assess AK prevalence and potential risk factors in patients attending Italian general dermatology clinics. Materials & methods: This retrospective study was conducted on clinical data from consecutive white outpatients aged ≥30 years, attending 24 general dermatology clinics between December 2014 and February 2015. AK prevalence (entire population) and multivariate risk factor analysis (patients with current/previous AK and complete data) are presented. Results: AK prevalence in 7,284 patients was 27.4% (95% CI: 26.4-28.4%); 34.3% in men and 20.0% in women (p<0.001). Independent AK ris…
MULTISPECTRAL VENOUS IMAGES ANALYSIS FOR OPTIMUM ILLUMINATION SELECTION
2013
International audience; Intravenous (IV) catheterization is the most important phase in medical practices of daily life. It is hard to localize veins in patients who have deep veins, minor age or dark skin; hence multiple attempts become indispensable for proper catheterization in such cases. Near Infrared (NIR) Imaging allow to visualize the veins underneath the skin of persons having non-visibility of veins problem. This paper reports the pre-selection of illuminants that ensure best veins/tissues contrast for patients having different skin tone. The sample subjects have been divided in four different classes based on the Luminance value of their skin tone in order to extract the best ill…