195 research outputs found

    Frequency-dependent anti arrhythmic effects of crataegus monogyna on the extracellular field potential recordings in the rabbit atrioventricular node, an experimental model of AF

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    Introduction: Despite extensive studies that have been performed on the effects of Crataegus monogyna in cardiovascular diseases, only few investigations have addressed the antiarrhythmic properties of this plant. Aims of the present study were: 1) To determine the protective role of methanolic extract of C. monogyna on the rate-dependent model and the concealed conduction of the AV node. 2) To explore the role of Na+-K+ ATPase in the protective role of C. monogyna Methods: Male New Zealand rabbits (1.5-2kg) were used in all experiments. Stimulation protocols were used to measure basic and rate-dependent AV nodal properties (recovery, atrial fibrilation and zone of concealment) in two groups (N=14). In the first group, all the stimulation protocols were performed before and after the administration of different concentrations of C. monogyna extract (n=7), while in the second group (n=7), all stimulation protocols were carried out in the presence of ouabaine (0.05 μM) and the plant extract. Results: Basic and rate-dependent properties of the AV node were inhibited after the addition of the extract of C. monogyna to Kerebs Henselite solution. At the maximum concentration of C. monogyna (30 mg/l), WBCL cycle length was significantly increased from 156.5±3.4 to 173±5.8 ms and the nodal functional refractory period was prolonged from 164.4±4.1 to 182.7±3.8 ms (P<0.05). Significant decreases of ventricular rhythm were recorded in both selective concentrations of the plant extract. The depressant electrophysiological effect of C. monogyna on the AV node was not abolished by ouabaine, a selective inhibitor of Na+-K+ ATPase enzyme. Conclusion: The results showed a potential anti-arrhythmic and protective effect for C. monogyna. The effect of the plant extract in increasing nodal refractory period and widening of the concealment zone might be the major mechanisms involved. The protective role of C. monogyna was not related to the Na+-K+ ATPase activity

    The Effect of Different Types of Coating and Packaging on the Physical Properties of Persimmon Fruit under Load

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    Since persimmon is a pressure-sensitive fruit and it is difficult to store this fruit in warehouses, in this research, an attempt has been made to examine the parameters affecting the reduction of changes in its physical properties. The samples were loaded at 150 and 250 N, three types of foam container packaging with polyolefin film, polyethylene-terephthalate, and ordinary box, and four types of polyamine putrescine coating with concentrations of 1 and 2 mM, distilled water and uncoated. Properties such as Physiological Weight Loss, volume, and the density of persimmon fruit, as well as the firmness of this fruit in the prepost-storage stage were examined. The results showed, the highest firmness was obtained in the treatment of putrescine at a concentration of 1 mM and a foam container with polyethylene film with a value of 6.5 N, which was almost three times the firmness of uncoated fruits. The lowest Physiological Weight Loss, volume, and density were obtained in the same type of coating and packaging. The values of these parameters were 2.458%, 1.82, and 0.833%, respectively, compared to the first day of storage. Overall, the use of polyamine treatment showed a significant effect on changes in the physical properties of persimmon fruit, and foam containers with polyolefin film emerged as the optimal packaging option, resulting in the least amount of change among the different types of packaging used

    Histopathology and cholinergic assessment of Pterocarya fraxinifolia on chicken embryo

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    There are no reports of toxicological studies of Pterocarya fraxinifolia. The leaves are used for fishing, which also an anesthetic agent. Currently, many drugs utilized in anesthesia practice are modified cholinergic transmission and acetylcholine esterase inhibitors; these are parts of anaesthetic pharmacy. Therefore, cholinergic assessment was surveyed in chicken embryo, which Pterocarya fraxinifolia extractes were injected in 0.1, 1 and 10 mg concentration at day 4 of incubation. Serum and brain cholinesterase were analyzed on day 20 of incubation. The signs were not due to the changes of cholinesterase activity. In histopathology examination, massive necrosis was observed in the spinal cord. Other tissues such as heart, kidneys, skeletal bones and muscles, trachea and lungs, digestive system and endocrine glands were completely developed. This data suggests that the spinal cord is a target organ of the bioactive component of this plant

    Dietary Protein and Blood Pressure: A Systematic Review

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    Background - Elevated blood pressure (BP), which is a major risk factor for cardiovascular disease, is highly prevalent worldwide. Recently, interest has grown in the role of dietary protein in human BP. We performed a systematic review of all published scientific literature on dietary protein, including protein from various sources, in relation to human BP. Methodology/Principal Findings - We performed a MEDLINE search and a manual search to identify English language studies on the association between protein and blood pressure, published before June 2010. A total of 46 papers met the inclusion criteria. Most observational studies showed no association or an inverse association between total dietary protein and BP or incident hypertension. Results of biomarker studies and randomized controlled trials indicated a beneficial effect of protein on BP. This beneficial effect may be mainly driven by plant protein, according to results in observational studies. Data on protein from specific sources (e.g. from fish, dairy, grain, soy, and nut) were scarce. There was some evidence that BP in people with elevated BP and/or older age could be more sensitive to dietary protein. Conclusions/Significance - In conclusion, evidence suggests a small beneficial effect of protein on BP, especially for plant protein. A blood pressure lowering effect of protein may have important public health implications. However, this warrants further investigation in randomized controlled trials. Furthermore, more data are needed on protein from specific sources in relation to BP, and on the protein-BP relation in population subgroup

    Search for low-mass dark matter via bremsstrahlung radiation and the Migdal effect in SuperCDMS

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    We present a new analysis of previously published SuperCDMS data using a profile likelihood framework to search for sub-GeV dark matter (DM) particles through two inelastic scattering channels: bremsstrahlung radiation and the Migdal effect. By considering these possible inelastic scattering channels, experimental sensitivity can be extended to DM masses that are undetectable through the DM-nucleon elastic scattering channel, given the energy threshold of current experiments. We exclude DM masses down to 220 MeV/c2 at 2.7Ă—10-30 cm2 via the bremsstrahlung channel. The Migdal channel search provides overall considerably more stringent limits and excludes DM masses down to 30 MeV/c2 at 5.0Ă—10-30 cm2

    Dietary differences between elderly Iranians living in Sweden and Iran a cross-sectional comparative study

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    <p>Abstract</p> <p>Background</p> <p>During the last decades, global migration has increased and many immigrant groups have a higher prevalence than the native born population of several cardiovascular disease risk factors, including poor dietary habits. However, it is uncertain if dietary habits in immigrant populations reflect dietary habits in their country of origin or if the current diet is a consequence of the migration and possible change of dietary habits. The aim of this study was to examine possible dietary differences between elderly Iranians living in Stockholm, Sweden with elderly Iranians living in Tehran, Iran, taking into account sex, age, marital status, and education.</p> <p>Methods</p> <p>Dietary intakes were assessed by semi - quantitative food frequency questionnaire in a cross-sectional study of 121 Iranians living in Stockholm and 52 Iranians living in Tehran, aged 60-80. Differences in dietary habits between the two groups was analysed by bootstrapped regression analyses with 1000 replications.</p> <p>Results</p> <p>Iranians living in Sweden had significantly higher intake of protein, total fat, fiber than Iranians living in Iran, but lower consumption of carbohydrates. The observed differences in intake of macronutrients were reflected in consumed amount of all food items, which were higher among Iranians living in Iran with the exception of bread and grain consumption which was lower.</p> <p>Conclusions</p> <p>There are general differences in dietary habits between Iranians living in Iran and Iranians living in Sweden. Parts of observed differences in dietary habits may reflect a favourable adoption process to the Swedish dietary habits after migration. Meanwhile other differences are point of concern in light of the high prevalence of overweight, among Iranians living in Sweden and can have unfavourable impact in particular in the context of cardiovascular health.</p

    Cardiovascular risk assessment - From individual risk prediction to estimation of global risk and change in risk in the population

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    Cardiovascular disease is the most common cause of death and risk prediction formulae such as the Framingham Risk Score have been developed to easily identify patients at high risk that may require therapeutic interventions. Using cardiovascular risk formulae at a population level to estimate and compare average cardiovascular risk among groups has been recently proposed as a way to facilitate surveillance of net cardiovascular risk and target public health interventions. Risk prediction formulas may help to compare interventions that cause effects of different magnitudes and directions in several cardiovascular risk factors, because these formulas assess the net change in risk using easily obtainable clinical variables. Because of conflicting data estimates of the incidence and prevalence of cardiovascular disease, risk prediction formulae may be a useful tool to estimate such risk at a population level

    G4CMP: Condensed Matter Physics Simulation Using the Geant4 Toolkit

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    G4CMP simulates phonon and charge transport in cryogenic semiconductor crystals using the Geant4 toolkit. The transport code is capable of simulating the propagation of acoustic phonons as well as electron and hole charge carriers. Processes for anisotropic phonon propagation, oblique charge-carrier propagation, and phonon emission by accelerated charge carriers are included. The simulation reproduces theoretical predictions and experimental observations such as phonon caustics, heat-pulse propagation times, and mean charge-carrier drift velocities. In addition to presenting the physics and features supported by G4CMP, this report outlines example applications from the dark matter and quantum information science communities. These communities are applying G4CMP to model and design devices for which the energy transported by phonons and charge carriers is germane to the performance of superconducting instruments and circuits placed on silicon and germanium substrates. The G4CMP package is available to download from GitHub: github.com/kelseymh/G4CMP.Comment: 21 pages, 11 figures, 10 table
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