993 resultados para Erwin, Gary


Relevância:

10.00% 10.00%

Publicador:

Resumo:

Objective: Waveform analysis has been used to assess vascular resistance and predict cardiovascular events. We aimed to identify microvascular abnormalities in patients with impaired glucose tolerance (IGT) using ocular waveform analysis. The effects of pioglitazone were also assessed. Methods: Forty patients with IGT and twenty-four controls were studied. Doppler velocity recordings were obtained from the central retinal, ophthalmic and common carotid arteries, and sampled at 200 Hz. A discrete wavelet-based analysis method was employed to quantify waveforms. The resistive index (RI),was also determined. Patients with IGT were randomised to pioglitazone or placebo and measurements repeated after 12 weeks treatment. Results: In the ocular waveforms, significant differences in power spectra were observed in frequency band four (corresponding to frequencies between 6.25 and 12.50 Hz) between groups (p

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Nanocomposites of poly(ethylene terephthalate) PET with a partially synthetic fluoromica were prepared by melt mixing and extruded into sheet and subjected to large-scale biaxial stretching. Transmission electron microscopy (TEM) analysis of the mica tactoids showed that biaxial stretching had caused the tactoids to be more orientated and with improved exfoliation. The moduli of the nanocomposites were enhanced with increasing mica loading and the reinforcement effect was higher when the stretch ratio was 2 or 2.5, accommodated by having more aligned tactoids and reduced agglomeration. Enhancement in modulus was less pronounced for a stretch ratio of 3. Storage modulus was enhanced more significantly above the glass transition temperature. The barrier properties were enhanced by addition of mica before and after stretching. The Halpin-Tsai theory underpredicted the relative modulus of the PET nanocomposites, whereas the Nielsen model over-predicted the relative permeability. POLYM. ENG. SCI., 2012. (c) 2011 Society of Plastics Engineers

Relevância:

10.00% 10.00%

Publicador:

Resumo:

OBJECTIVE:
Patients with type 2 diabetes mellitus (T2DM) are at increased risk of developing cardiovascular disease, largely as a result of defective production of cardioprotective nitric oxide and a concomitant rise in oxidative stress. Dietary interventions that could reverse this trend would be extremely beneficial. Here we investigated whether dietary n-3 polyunsaturated fatty acid (n-3 PUFA) supplementation positively affected platelet nitroso-redox imbalance.
RESEARCH DESIGN AND METHODS:
We randomized hypertensive T2DM patients (T2DM HT; n = 22) and age-and-sex matched hypertensive study participants without diabetes (HT alone; n = 23) in a double-blind, crossover fashion to receive 8 weeks of n-3 PUFAs (1.8 g eicosapentaenoic acid and 1.5 g docosahexaenoic acid) or identical olive oil capsules (placebo), with an intervening 8-week washout period. Platelet nitrite and superoxide were measured and compared before and after treatment; 8-isoprostane was determined by ELISA and subcellular compartmentalization of the NAD(P)H oxidase subunit p47-phox examined by Western blotting.
RESULTS:
The n-3 PUFA supplementation reduced 8-isoprostane and superoxide levels in platelets from T2DM HT, but not HT alone, participants, without effect on nitrite production. This coincided with a significant decrease in p47-phox membrane localization and a similar reduction in superoxide to that achieved with apocynin. At baseline, a subcohort of T2DM HT and HT alone participants showed evidence of nitric oxide synthase (NOS)-derived superoxide production, indicating defective enzymatic activity. This was reversed significantly in T2DM HT participants after treatment, demonstrating improved NOS function.
CONCLUSIONS:
Our finding that n-3 PUFAs diminish platelet superoxide production in T2DM HT patients in vivo suggests a therapeutic role for these agents in reducing the vascular-derived oxidative stress associated with diabetes.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

An efficient chemical synthesis of 5a-carba-alpha-D-mannose and its enzymatic elaboration to 5a-carba-alpha-D-mannose-6-phosphate, using yeast hexokinase, is described.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Background: Studies of cross-cultural variations in the perception of emotion have typically compared rates of recognition of static posed stimulus photographs. That research has provided evidence for universality in the recognition of a range of emotions but also for some systematic cross-cultural variation in the interpretation of emotional expression. However, questions remain about how widely such findings can be generalised to real life emotional situations. The present study provides the first evidence that the previously reported interplay between universal and cultural influences extends to ratings of natural, dynamic emotional stimuli.

Methodology/Principal Findings: Participants from Northern Ireland, Serbia, Guatemala and Peru used a computer based tool to continuously rate the strength of positive and negative emotion being displayed in twelve short video sequences by people from the United Kingdom engaged in emotional conversations. Generalized additive mixed models were developed to assess the differences in perception of emotion between countries and sexes. Our results indicate that the temporal pattern of ratings is similar across cultures for a range of emotions and social contexts. However, there are systematic differences in intensity ratings between the countries, with participants from Northern Ireland making the most extreme ratings in the majority of the clips.

Conclusions/Significance: The results indicate that there is strong agreement across cultures in the valence and patterns of ratings of natural emotional situations but that participants from different cultures show systematic variation in the intensity with which they rate emotion. Results are discussed in terms of both ‘in-group advantage’ and ‘display rules’ approaches. This study indicates that examples of natural spontaneous emotional behaviour can be used to study cross-cultural variations in the perception of emotion.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

For many years psychological research on facial expression of emotion has relied heavily on a recognition paradigm based on posed static photographs. There is growing evidence that there may be fundamental differences between the expressions depicted in such stimuli and the emotional expressions present in everyday life. Affective computing, with its pragmatic emphasis on realism, needs examples of natural emotion. This paper describes a unique database containing recordings of mild to moderate emotionally coloured responses to a series of laboratory based emotion induction tasks. The recordings are accompanied by information on self-report of emotion and intensity, continuous trace-style ratings of valence and intensity, the sex of the participant, the sex of the experimenter, the active or passive nature of the induction task and it gives researchers the opportunity to compare expressions from people from more than one culture.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

In spite of intensive research, computational modeling of the injection stretch blow molding (ISBM) still cannot match the accuracy of other polymer processes such as injection molding. There is a lack of understanding of the interdependence among the machine parameters set up by the operators, process parameters, material behavior, and the resulting final thickness distribution and performance of the molded product. The work presented in this paper describes a set of instrumentation tools developed for investigation of the ISBM process in an industrial setting. Results are presented showing the pressure and air temperature evolution inside the mold, the stretch rod force and displacement history, and the moment of contact of the polymer with seven discrete locations on the mold.