3,288 research outputs found
Impaired Insulin sensitivity and Insulin secretion in Haemodialysis patients with and without Secondary Hyperparathyroidism
The aim of our study was to investigate insulin sensitivity and beta cell function in hemodialysis (HD) patients without diabetes. We hypothesized that parathyroid gland function was a determinant of insulin sensitivity and/or beta cell function. The study was a randomized, cross-sectional one and patients were divided into two groups (total 27 patients), Gp.1 being those with relative hypoparathyroidism (iPTH<200 pg/ml)  9 (33.3%), Gp.2 those with hyperparathyroidism (iPTH200 pg/ml)  18 (66.6%) with Gp.3 (consisting of 43 healthy subjects acting as controls). Insulin resistance and insulin secretion were calculated from fasting serum insulin and glucose concentrations by the Homeostatic Model Assessment score (HOMA IR and HOMA BETA). The value of HOMA IR (3.28±1.3 for Gp.1, 4.80±2.4 for Gp.2, 1.70±0.8 for Gp.3) as well as the glucose level (5.0±1.0mmol/l in Gp.1, 5.2±0.8mmol/ l in Gp.2, 4.6±0.4mmol/l in Gp.3) was significantly higher in HD patients than in control subjects. Excessive insulin secretion was present in HD patients (as assessed by HOMA BETA) significantly higher only in Gp.1 (p=0.02).peer-reviewe
Social cognition in individuals with 22q11.2 deletion syndrome and its link with psychopathology and social outcomes: a review
Background: The 22q11.2 deletion syndrome (22q11DS) is a genetic syndrome that results in a highly variable profile
of affected individuals of which impairments in the social domain and increased psychopathology are the most
prominent. Notably, 25â30% of affected individuals eventually develop schizophrenia/psychosis, predisposing persons
with the syndrome to increased risk for this disorder. Because social cognition is considered to underlie social behavior
and to be related to psychopathology, this systematic review investigated social cognition in individuals with 22q11DS
and examined reported links across its domains with psychopathology and social outcomes. This can provide the basis
for a closer understanding of the path from risk to disorder and will inform on the specific domains that can be
targeted with preventive intervention strategies.
Method: Systematic literature review of studies that reported the links between social cognitive domains and
psychopathology and/or social outcomes in individuals with 22q11DS. Electronic databases searched were
PubMed and PsycINFO.
Results: Defined eligibility criteria identified a total of ten studies to be included in the present review. Selected
studies investigated links between two domains of social cognition (emotion processing and theory of mind (ToM))
and psychopathology and/or social outcomes. With respect to the links to psychopathology, two aspects of social
cognition were related primarily to negative symptoms. Results regarding the associations to positive and emotional
symptoms (anxiety/depression) are limited and require further investigation. Even though both aspects of social
cognition were associated with social outcomes, several studies also found no links between these two domains. Both
reports invite for an additional examination of reported results and specific considerations regarding chosen constructs.
Conclusion: Although equivocal, results of the present review provide sufficient evidence that social cognition is a
useful domain for the closer elucidation of clinical outcomes and social difficulties in this population. At the same time,
longitudinal studies and consideration of other variables are also necessary for a timely understanding of affected
persons in this respect
Shielding Considerations for CubeSat Structures During Solar Maximum
The purpose of this lessons learned paper is to communicate the utility of shielding in small spacecraft planning for the support of mission assurance and reliability. Numerous SmallSats have been flying in polar low Earth orbit for science, communications, technology demonstrations, and imaging with academic, commercial, and government interests. Shielding has been part of mission assurance and reliability from the advent of long duration spacecraft missions. The Shields-1 CubeSat has been operating in polar low Earth orbit since 16 December 2018 with atomic number (Z)-grade radiation shielding and demonstrates shielding effectiveness. Shields-1 has collected a representative example of solar minimum data in 2019 with 8 Teledyne uDosimeters over varying shielding effectivenesses. It serves as current experimental data and has been compared with NOVICE Shielding estimates using the AP8 â AE8 trapped radiation model with the Shields-1 CAD and generic CubeSat 3 unit (U) models. Using NOVICE model radiation analysis coding, the shielding effectivenesses, based on a generic CubeSat 3U structure with 4 electronic boards, were estimated for aluminum wall thicknesses ranging from 0.204-cm to 4.44-cm (0.550-g/cm2 â 12.0-g/cm2) thick aluminum. For modeled polar orbiting spacecraft, solar maximum total ionizing dose (TID) increases by nearly a magnitude for thin-walled aluminum 0.550-g/cm2 - 0.686-g/cm2 (0.204-cm â 0.254-cm) typical CubeSat structures. The shielding effectiveness by NOVICE Sigma estimates, which is a shielding sphere approximation around a detector, showed a linear relationship with wall thickness, which increased over the wall thickness by a ratio of 1.43 determined by linear regression analysis. Using NOVICE Adjoint Monte-Carlo Modeling of solar minimum and solar maximum with the inclusion of a worst-case solar particle event over a 1-year mission without geomagnetic shielding, the TID for minimum and maximum conditions for a generic 3U with a wall thickness of 0.254 cm is 158 RAD and 1540 RAD, respectively. The modeled total solar maximum TID is over estimated, because at low orbital latitudes a spacecraft will have shielding from the Earthâs magnetic field. However, TID will still be significant at high latitudes over the poles, where a spacecraft is exposed in a solar particle event. In contrast, to a thin-walled generic 3U CubeSat, the Shields-1 electronics enclosure has a shielding effectiveness of 21.3 g/cm2 from NOVICE Sigma modeling and is expected to show reduced total ionizing dose increases during the present active Solar Cycle 25 period. Because solar particle events during solar maximum increase TID on electronic parts with thin-walled shielding in short periods of time, it is a mission assurance and reliability consideration on the spacecraftâs mission value versus adding shielding for risk reduction of premature spacecraft or instrument payload loss. Since the volumes of many instruments and system electronics have reduced with small spacecraft, shielding material costs and weight penalties have diminished. A small spacecraft project budget and schedule may limit traditional radiation-hardened part use and radiation testing requirements, where shielding can contribute to mission assurance and reliability with reduced costs
A bright metastable atom source at 80 K
We describe a high flux source of cold (80 K) metastable helium atoms. The source employs a direct current nozzle discharge which produces in excess of 10Âčâ” atoms/steradian/s. Liquid nitrogen cooling of the discharge source yields atomic velocities below 900 msâ»Âč. Such a source has practical applications for experiments concerned with laser cooling and trapping of metastable helium atoms
Removal of organically bound sulfur from oil shale by iron(III)-ion generated-regenerated from pyrite by the action of Acidithiobacillus ferrooxidans
Oil shales are one of the alternative sources of hydrocarbon fuels ("synthetic petroleum"), characterized by the increased sulfur and nitrogen content which represent even greater ecological problem in use, compared to classical fuels. Acidithiobacillus ferrooxidans is capable of oxidizing pyrite to iron (III)-ion, providing a strong oxidation agent at low pH. We have used this oxidizing agent for oxidation of sulfur present in DBT as a substrate model to demonstrate its potential to oxidize organically bound sulfur in oil shales. An HCl-concentrate was used as the hydrocarbon matrix. Acidithiobacillus ferrooxidans is already recognized to oxidize the pyritic sulfur component, thereby potentially providing a complete sulfur removal system. By applying GC-MS we established that DBT transformation occurred by oxidation or elimination of sulfur. The products obtained are more soluble in water than parent compounds and this reduces concentration of organic sulfur.BIOHYDROMETALLURY: FROM THE SINGLE CELL TO THE ENVIRONMEN
Effects of mechanical ventilation at low lung volume on respiratory mechanics and nitric oxide exhalation in normal rabbits
Lung mechanics, exhaled NO (NOe), and TNF-(alpha) in serum and bronchoalveolar lavage fluid were assessed in eight closed and eight open chest, normal anesthetized rabbits undergoing prolonged (3-4 h) mechanical ventilation (MV) at low volume with physiological tidal volumes (10 ml/kg). Relative to initial MV on positive end-expiratory pressure (PEEP), MV at low volume increased lung quasi-static elastance (+267 and +281%), airway (+471 and +382%) and viscolelastic resistance (+480 and +294%), and decreased NOe (-42 and -25%) in closed and open chest rabbits, respectively. After restoration of PEEP, viscoelastic resistance returned to control, whereas airway resistance remained elevated (+120 and +31%) and NOe low (-25 and -20%) in both groups of rabbits. Elastance remained elevated (+23%) only in closed-chest animals, being associated with interstitial pulmonary edema, as reflected by increased lung wet-to-dry weight ratio with normal albumin concentration in bronchoalveolar lavage fluid. In contrast, in 16 additional closed- and open-chest rabbits, there were no changes of lung mechanics or NOe after prolonged MV on PEEP only. At the end of prolonged MV, TNF-(alpha) was practically undetectable in serum, whereas its concentration in bronchoalveolar lavage fluid was low and similar in animals subjected or not subjected to ventilation at low volume (62 vs. 43 pg/ml). These results indicate that mechanical injury of peripheral airways due to their cyclic opening and closing during ventilation at low volume results in changes in lung mechanics and reduction in NOe and that these alterations are not mediated by a proinflammatory process, since this is expressed by TNF-(alpha) levels
Polyphenols and non-alcoholic fatty liver disease: impact and mechanisms:impact and mechanisms
Non-alcoholic fatty liver disease (NAFLD) is considered to be the hepatic component of the metabolic syndrome and its prevalence is rapidly increasing due to its strong association with insulin resistance and obesity. At present, given that NAFLD is highly prevalent and therapies are limited, much attention is focused on identifying effective dietary strategies for the prevention and treatment of the disease. Polyphenols are a group of plant bioactive compounds whose regular consumption have been associated with a reduction in the risk of a number of metabolic disorders associated with NAFLD. Here we review the emerging and relatively consistent evidence from cell culture and rodent studies showing that select polyphenols positively modulate a variety of contributors to the NAFLD phenotype, through diverse and complementary mechanisms of action. In particular, the reduction of de novo lipogenesis (via sterol regulatory element-binding protein 1c) and increased fatty acid ÎČ-oxidation, presumably involving AMP-activated protein kinase activation, will be discussed. The indirect antioxidant and anti-inflammatory properties of polyphenols which have been reported to contribute to the amelioration of NAFLD will also be addressed. In addition to a direct study of the liver, rodent studies have provided insight into the impact of polyphenols on adipose tissue function and whole body insulin sensitivity, which are likely to in part modulate their impact on NAFLD development. Finally an overview of the limited data from clinical trials will be given along with a discussion of the dose extrapolation from animal studies to human subjects
Anthropometric and physical characteristics allow differentiation of young female volleyball players according to playing position and level of expertise
The aim of our study was to determine the differences in some anthropometric and physical performance variables of young Croatian female volleyball players (aged 13 to 15) in relation to playing position (i.e., independent variable) and performance level within each position (i.e., independent variable). Players were categorized according to playing position (i.e., role) as middle blockers (n=28), opposite hitters (n=41), passer-hitters (n=54), setters (n=30), and liberos (n=28). Within each position, players were divided into a more successful group and a less successful group according to team ranking in the latest regional championship and player quality within the team. Height and body mass, somatotype by the Heath-Carter method, and four tests of lower body power, speed, agility and upper body power (i.e., dependent variables) were assessed. Players in different positions differed significantly in height and all three somatotype components, but no significant differences were found in body mass, body mass index or measured physical performance variables. Players of different performance level differed significantly in both anthropometric and physical performance variables. Generally, middle blockers were taller, more ectomorphic, less mesomorphic and endomorphic, whereas liberos were shorter, less ectomorphic, more mesomorphic and endomorphic than players in other positions. More successful players in all positions had a lower body mass index, were less mesomorphic and endomorphic, and more ectomorphic than less successful players. Furthermore, more successful players showed better lower body power, speed, agility and upper body power. The results of this study can potentially provide coaches with useful indications about the use of somatotype selection and physical performance assessment for talent identification and development
Uphill walking at iso-efficiency speeds
Uphill walking gait has been extensively studied, but the optimal uphill speed able to enhance the metabolic demand without increasing fatigability has so far received little attention. Therefore, the aim of this study was to assess the metabolic/kinematic demand at constant speed (6 km\ub7h 121 G0 level, G2 2% uphill, G7 7% uphill) and at iso-efficiency speeds (G2IES 5.2 km\ub7h 121 2% uphill and G7IES 3.9 km\ub7h 121 7% uphill). For this aim, physically active women (n:24, Age 33.40 \ub1 4.97 years, BMI 21.62 \ub1 2.06 kg/m-2) after an 8-min warm-up were studied on a treadmill for 10\u2b9 for every walking condition with a 5\u2b9 rest in between. Average
heart rate (AVG-HR), rating of perceived exertion (RPE) and kinematic variables (stance time, swing time, stride length, stride cycle, stride-length variability, stride-cycle variability and internal work) were studied. Modif\ufeffications in stance time, stride length and stride cycle (p<0.005), and lower internal-work values (p<0.001) occurred in G7IES in comparison to the other conditions. Swing time was significantly modified only in G7IES compared to G0 and G7 (p<0.001 and p<0.005, respectively). Stride-length variability and stride-cycle variability were higher in G7IES compared to the other conditions (p<0.001). G7 induced the highest AVG-HR (p<0.005) and RPE (p<0.001) compared to the other conditions. This study demonstrates that by applying the equation for
uphill walking gait, it is possible to maintain a similar metabolic demand and RPE at iso-efficiency speeds during
uphill compared to level walking, inducing at the same time a modification of the kinematic parameters of walking gait performed at the same slope condition
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