517 research outputs found
Recommended from our members
Food, Acid Supplementation and Drug Absorption - a Complicated Gastric Mix: a Randomized Control Trial.
PURPOSE:The purpose of this study was to determine the impact of food on gastric pH and the ability of over the counter betaine hydrochloride (BHCl) acid to reacidify gastric pH after food-induced elevations in gastric pH. METHODS:This open-label cross over clinical study (NCT02758015) included 9 subjects who were randomly assigned to one of 16 possible, 4-period cross-over sequences to determine the impact and relationship of food and gastric pH with acid supplementation. Subjects were administered various doses (1500 mg, 3000 mg and 4500 mg) of betaine hydrochloride (BHCl) to determine the ability of acid supplementation to reacidify gastric pH after the elevation of gastric pH caused by the ingestion of food. RESULTS:Following the administration of food and the resulting elevation in gastric pH, time to return to baseline gastric pH levels without acid supplementation was 49.7 ± 14.0 min. Administering 4500 mg of BHCl acid in capsules was able to reacidify gastric pH levels back to baseline following the administration of food in approximately 17.3 ± 5.9 min. AUCpH of each treatment were similar and not statistically different. Mean max pH following the administration of food was 3.20 ± 0.55. CONCLUSION:The ability of food to elevate and maintain gastric pH levels in the presence of acid supplementation was made evident throughout the study. A 4500 mg dose of BHCl was required to reacidify gastric pH after the administration of food. This study details the difficulty faced by clinicians in dosing a poorly soluble, weakly basic drug to patients receiving acid reducing agents where administration with food is recommended to avoid gastric side effects. TRIAL REGISTRATION:https://clinicaltrials.gov/ct2/show/NCT02758015
Possible observation of parametrically amplified coherent phasons in K0.3MoO3 using time-resolved extreme-ultraviolet ARPES
We use time- and angle-resolved photoemission spectroscopy (tr-ARPES) in the
Extreme Ultraviolet (EUV) to measure the time- and momentum-dependent
electronic structure of photo-excited K0.3MoO3. Prompt depletion of the Charge
Density Wave (CDW) condensate launches coherent oscillations of the amplitude
mode, observed as a 1.7-THz-frequency modulation of the bonding band position.
In contrast, the anti-bonding band oscillates at about half this frequency. We
attribute these oscillations to coherent excitation of phasons via parametric
amplification of phase fluctuations.Comment: 4 figure
Comparing extrapolations of the coronal magnetic field structure at 2.5 solar radii with multi-viewpoint coronagraphic observations
The magnetic field shapes the structure of the solar corona but we still know
little about the interrelationships between the coronal magnetic field
configurations and the resulting quasi-stationary structures observed in
coronagraphic images (as streamers, plumes, coronal holes). One way to obtain
information on the large-scale structure of the coronal magnetic field is to
extrapolate it from photospheric data and compare the results with
coronagraphic images. Our aim is to verify if this comparison can be a fast
method to check systematically the reliability of the many methods available to
reconstruct the coronal magnetic field. Coronal fields are usually extrapolated
from photospheric measurements typically in a region close to the central
meridian on the solar disk and then compared with coronagraphic images at the
limbs, acquired at least 7 days before or after to account for solar rotation,
implicitly assuming that no significant changes occurred in the corona during
that period. In this work, we combine images from three coronagraphs
(SOHO/LASCO-C2 and the two STEREO/SECCHI-COR1) observing the Sun from different
viewing angles to build Carrington maps covering the entire corona to reduce
the effect of temporal evolution to ~ 5 days. We then compare the position of
the observed streamers in these Carrington maps with that of the neutral lines
obtained from four different magnetic field extrapolations, to evaluate the
performances of the latter in the solar corona. Our results show that the
location of coronal streamers can provide important indications to discriminate
between different magnetic field extrapolations.Comment: Accepted by A&A the 20th of May, 201
Effect of a supplement rich in alkaline minerals on acid-base balance in humans
This is an Open Access article distributed under the terms of the Creative Commons Attribution Licens
Chemical stabilization of dentin extracellular matrix detected by FEISEM and EDS
Dentin collagen degradation represents an important limit to the stability of the resin-dentin interface in conservative dentistry. In vitro application of 1-ethyl-3-(3- dimethylaminopropyl)-carbodiimide hydrochloride (EDC), an imide-based zerolength cross-linking agent, showed [1] the capability to inactivate the endogenous dentin matrix metalloproteinases and to increase the mechanical properties of the organic dentin extracellular matrix. In the present study, a correlative high resolution SEM (FEISEM) with an Energy Dispersive Spectroscopy (EDS) analysis was performed to characterize the fine structure and the chemical modifications of EDCstabilized human dentin, after compressive mechanical stress (Chewing Simulation - CS). Demineralized human dentin disks were assigned to four groups: (1) artificial saliva at 37°C for 30 days; (2) pre-treatment with 0.5M EDC for 60 s, then as in Group 1; (3) CS challenge for 30 days; (4) 0.5M EDC as in Group 2 and CS challenge as in Group 3. The FEISEM analysis revealed that the EDC-pretreatment made the collagen fibrillar network more compact, in comparison to controls and this effect was particularly evident on the surface of not stressed samples. Along with the increased compactness of the collagen complex, the EDS analysis showed a significant semi-quantitative increase of sulfur. The presence of chlorine in EDC treated samples was also detectable. The increase of sulfur, not present in EDC composition, suggests a possible implication of sulfate glycosaminoglycans containing proteoglycans during the extracellular matrix stabilization, as also suggested by the concurrent increase of the amorphous matrix. The presence of chlorine in EDC treated samples induces to conclude that the activity of the cross-linking agent is stable even after the experimental time intervals
Metabolic and physiologic improvements from consuming a paleolithic, hunter-gatherer type diet
Background: The contemporary American diet figures centrally in the pathogenesis of numerous chronic diseases-'diseases of civilization'. We investigated in humans whether a diet similar to that consumed by our preagricultural hunter-gatherer ancestors (that is, a paleolithic type diet) confers health benefits. Methods: We performed an outpatient, metabolically controlled study, in nine nonobese sedentary healthy volunteers, ensuring no weight loss by daily weight. We compared the findings when the participants consumed their usual diet with those when they consumed a paleolithic type diet. The participants consumed their usual diet for 3 days, three ramp-up diets of increasing potassium and fiber for 7 days, then a paleolithic type diet comprising lean meat, fruits, vegetables and nuts, and excluding nonpaleolithic type foods, such as cereal grains, dairy or legumes, for 10 days. Outcomes included arterial blood pressure (BP); 24-h urine sodium and potassium excretion; plasma glucose and insulin areas under the curve (AUC) during a 2 h oral glucose tolerance test (OGTT); insulin sensitivity; plasma lipid concentrations; and brachial artery reactivity in response to ischemia. Results: Compared with the baseline (usual) diet, we observed (a) significant reductions in BP associated with improved arterial distensibility (À3.1±2.9, P ¼ 0.01 and þ 0.19±0.23, P ¼ 0.05);(b) significant reduction in plasma insulin vs time AUC, during the OGTT (P ¼ 0.006); and (c) large significant reductions in total cholesterol, low-density lipoproteins (LDL) and triglycerides (À0.8±0.6 (P ¼ 0.007), À0.7±0.5 (P ¼ 0.003) and À0.3±0.3 (P ¼ 0.01) mmol/l respectively). In all these measured variables, either eight or all nine participants had identical directional responses when switched to paleolithic type diet, that is, near consistently improved status of circulatory, carbohydrate and lipid metabolism/physiology. Conclusions: Even short-term consumption of a paleolithic type diet improves BP and glucose tolerance, decreases insulin secretion, increases insulin sensitivity and improves lipid profiles without weight loss in healthy sedentary humans
- …