379 research outputs found
Early impairment of endothelial structure and function in young normal-weight women with polycystic ovary syndrome
The aim of this study was to evaluate the presence of early vascular damage in young normal-weight women with polycystic ovary syndrome (PCOS).Thirty young normal-weight women with PCOS, who had no additional metabolic or cardiovascular diseases, and 30 healthy women (controls) matched for age and body mass index were studied. A complete hormonal assay was performed in each subject. Serum insulin and glucose levels were measured at baseline and after the oral glucose tolerance test. Plasma endothelin-1 levels and serum lipid profile were also assessed. The endothelial function was studied by flow-mediated dilation on the brachial artery, and arterial structure was evaluated by intima-media thickness measurement using Doppler ultrasound of both common carotid arteries.A significant (P < 0.05) difference in flow-mediated dilation (14.3 +/- 1.9% vs. 18.1 +/- 2.0% for PCOS patients and controls, respectively) and in intima-media thickness (0.53 +/- 0.09 mm vs. 0.39 +/- 0.08 mm for PCOS patients and controls, respectively) was found between PCOS and control subjects. Serum endothelin-1 levels were also significantly (P < 0.05) higher in PCOS patients compared with controls (1.1 +/- 0.4 pmol/liter vs. 0.5 +/- 0.2 pmol/liter for PCOS patients and controls, respectively).In conclusion, our data show that young, normal-weight, nondyslipidemic, nonhypertensive women with PCOS have an early impairment of endothelial structure and function
TeO bolometers with Cherenkov signal tagging: towards next-generation neutrinoless double beta decay experiments
CUORE, an array of 988 TeO bolometers, is about to be one of the most
sensitive experiments searching for neutrinoless double-beta decay. Its
sensitivity could be further improved by removing the background from
radioactivity. A few years ago it has been pointed out that the signal from
s can be tagged by detecting the emitted Cherenkov light, which is not
produced by s. In this paper we confirm this possibility. For the first
time we measured the Cherenkov light emitted by a CUORE crystal, and found it
to be 100 eV at the -value of the decay. To completely reject the
background, we compute that one needs light detectors with baseline noise below
20 eV RMS, a value which is 3-4 times smaller than the average noise of the
bolometric light detectors we are using. We point out that an improved light
detector technology must be developed to obtain TeO bolometric experiments
able to probe the inverted hierarchy of neutrino masses.Comment: 5 pages, 4 figures. Added referee correction
Abdominal fat quantity and distribution in women with polycystic ovary syndrome and extent of its relation to insulin resistance.
CONTEXT: Increased abdominal fat has been linked to insulin resistance and increased cardiovascular risk. Because many patients with polycystic ovary syndrome (PCOS) present abdominal obesity, it may be the cause of insulin resistance in this disorder.
SETTING: Fat quantity and distribution were evaluated by dual x-ray absorptiometry at the Departments of Clinical Medicine at the University of Palermo and the University of Naples, Italy.
PATIENTS: A total of 110 patients with PCOS and 112 weight-matched controls were studied. Anthropometric data, blood glucose, serum insulin, and testosterone were evaluated. Total, trunk, and central abdominal fat quantity were measured by total-body dual x-ray absorptiometry.
RESULTS: Compared with weight-matched controls, patients with PCOS had similar quantity of total and trunk fat but higher quantity of central abdominal fat. This difference was not observed when comparing obese PCOS and obese controls but depended on differences between overweight and normoweight patients and controls. All obese subjects, independently of having PCOS or not, had increased central abdominal fat. The same parameter was increased in 71% of overweight PCOS, 50% of overweight controls, and 30% of normoweight PCOS patients. PCOS patients with increased central abdominal fat had significantly higher (P < 0.01) insulin levels and significantly reduced (P < 0.01) insulin sensitivity than controls with similar quantities of central abdominal fat. Overweight PCOS patients with normal abdominal fat had significantly higher (P < 0.05) insulin levels and significantly reduced (P < 0.05) insulin sensitivity than overweight controls with normal abdominal fat.
CONCLUSIONS: Most obese subjects, independent of being affected by PCOS, have an abdominal form of obesity. However, abdominal fat excess may not be the only determinant of insulin resistance in PCOS
Patient empowerment and the Mediterranean diet as a possible tool to tackle prediabetes associated with overweight or obesity: a pilot study
AIM:
The objective of this study was to investigate the effect of implementation of short-term patient empowerment as applied to Mediterranean diet (MD) adherence on metabolic and anthropometric parameters in prediabetic overweight or obese subjects.
METHODS:
The sample included 42 subjects with prediabetes, aged 18-75 years and with body mass index (BMI) > 25 kg/m2, who received dietary advice on MD by nutritionists during session groups every 2 weeks for 4 months. Data on energy caloric intake and macronutrient consumption were collected using a 7-day food diary record. Adherence to MD was investigated through the PREvención con DIeta MEDiterránea (PREDIMED) questionnaire. No advice was given regarding caloric restriction and physical activity. At baseline and at the end of the study, each subject underwent anthropometric, metabolic, and nutritional assessments.
RESULTS:
Approximately 40.5% of subjects had achieved restoration of normal glucose tolerance by the end of the study. Fasting plasma glucose, glycated hemoglobin (HbA1C), BMI, waist circumference, blood pressure, visceral adiposity index, triglycerides, and total and LDL cholesterol levels were significantly decreased, while HDL cholesterol had significantly increased by the end of the study. The subjects significantly increased adherence to MD, as assessed by the PREDIMED questionnaire at follow-up. A reduction of prevalence of the metabolic syndrome was also reported. Interestingly, the PREDIMED score correlated with HbA1C values at follow-up, after adjusting for BMI and total caloric intake.
CONCLUSIONS:
Implementation of short-term patient empowerment as applied to MD adherence was shown to improve anthropometric and metabolic parameters in prediabetic overweight or obese subjects. This is of considerable importance, given that diet must be the cornerstone of treatment in patients at high risk of developing type 2 diabetes
Development of a Li2MoO4 scintillating bolometer for low background physics
We present the performance of a 33 g Li2MoO4 crystal working as a
scintillating bolometer. The crystal was tested for more than 400 h in a
dilution refrigerator installed in the underground laboratory of Laboratori
Nazionali del Gran Sasso (Italy). This compound shows promising features in the
frame of neutron detection, dark matter search (solar axions) and neutrinoless
double-beta decay physics. Low temperature scintillating properties were
investigated by means of different alpha, beta/gamma and neutron sources, and
for the first time the Light Yield for different types of interacting particle
is estimated. The detector shows great ability of tagging fast neutron
interactions and high intrinsic radiopurity levels (< 90 \muBq/kg for 238-U and
< 110 \muBq/kg for 232-Th).Comment: revised versio
New experimental limits on the alpha decays of lead isotopes
For the first time a PbWO4 crystal was grown using ancient Roman lead and it
was run as a cryogenic detector. Thanks to the simultaneous and independent
read-out of heat and scintillation light, the detector was able to discriminate
beta/gamma interactions with respect to alpha particles down to low energies.
New more stringent limits on the alpha decays of the lead isotopes are
presented. In particular a limit of T_{1/2} > 1.4*10^20 y at a 90% C.L. was
evaluated for the alpha decay of 204Pb to 200Hg
First bolometric measurement of the two neutrino double beta decay of Mo with a ZnMoO crystals array
The large statistics collected during the operation of a ZnMoO array, for
a total exposure of 1.3 kg day of Mo, allowed the first
bolometric observation of the two neutrino double beta decay of Mo. The
observed spectrum of each crystal was reconstructed taking into account the
different background contributions due to environmental radioactivity and
internal contamination. The analysis of coincidences between the crystals
allowed the assignment of constraints to the intensity of the different
background sources, resulting in a reconstruction of the measured spectrum down
to an energy of 300 keV. The half-life extracted from the data is
T= [7.15 0.37 (stat) 0.66 (syst)] 10
y.Comment: 6 pages, 2 figure, Accepted for publication in Journal of Physics G:
Nuclear and Particle Physic
Discrimination of alpha and beta/gamma interactions in a TeO bolometer
TeO crystals have proven to be superb bolometers for the search of
neutrinoless double beta decay in many respects. However, if used alone, they
do not exhibit any feature that allows to discriminate an alpha energy deposit
from a beta/gamma one. This fact limits their ability to reject the background
due to natural radioactivity and eventually affects the sensitivity of the
search. In this paper we show the results of a TeO crystal where, in
coincidence with its bolometric heat signal, also the luminescence light
escaping the crystal is recorded. The results show that we are able to measure
the light produced by beta/gamma particles, which can be explained as due to
Cerenkov emission. No light is detected from alpha particles, allowing the
rejection of this background source.Comment: 5 pages, 6 figure
Particle discrimination in TeO2 bolometers
TeO2 crystals are used as bolometric detectors in experiments searching for the neutrinoless double beta decay. The extreme rarity of the studied signal requires an ultra low background level. The natural radioactivity of the materials represents for these experiments the main background source, in particular the component due to α particles. In this work, we present a possibility for particle discrimination in TeO2 bolometers using the ˇCerenkov radiation. The results show that we are able to measure the light produced by β/γ particles, which can be explained as due to ˇCerenkov emission. No light is detected from α particles, allowing the rejection of this background source
Particle discrimination in TeO2 bolometers
TeO2 crystals are used as bolometric detectors in experiments searching for the neutrinoless double beta decay. The extreme rarity of the studied signal requires an ultra low background level. The natural radioactivity of the materials represents for these experiments the main background source, in particular the component due to α particles. In this work, we present a possibility for particle discrimination in TeO2 bolometers using the ˇCerenkov radiation. The results show that we are able to measure the light produced by β/γ particles, which can be explained as due to ˇCerenkov emission. No light is detected from α particles, allowing the rejection of this background source
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