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Search Results: 1 - 10 of 327 matches for " hydration "
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The Quantum-Mechanical Sensitivity of Cell Hydration in Mammals  [PDF]
Anna Nikoghosyan, Lilia Narinyan, Armenuhi Heqimyan, Sinerik Ayrapetyan
Open Journal of Biophysics (OJBIPHY) , 2018, DOI: 10.4236/ojbiphy.2018.83009
Abstract: The elucidation of the mechanism on the biological effects of weak chemical and physical factors on cells and organism is one of the modern problems in life sciences. According to the Receptor Theory of Prof. Bernard Katz the impact of the biological substances on cells is realized through the activation of ligand-gated ion channels in the membrane. However, this theory doesn’t provide a satisfactory explanation on the similar biological effects of extremely low concentrations of different chemical substances, which are unable to activate the ionic channels in the membrane and have non-linear dose-dependent effect on cells. Previously we have suggested that the metabolic control of cell hydration serves as a universal quantum-mechanical sensor for different weak physical and chemical signals. For supporting this hypothesis, in this article the comparative study of the effects of low concentrations of both cold (non-radioactive) and [3H]-ouabain (specific inhibitor for Na+/K+-ATPase) on the hydration in different tissues of rats has been performed. The obtained data have shown that cold and [3H]-ouabain have different effects on cell hydration and such a difference depends on the initial metabolic state of tissues. On the basis of our previous and present results it is suggested that such a quantum-mechanical sensitivity of cell hydration is realized through the cyclic-nucleotides-dependent Na+/Ca2+ exchange, having a crucial role in the metabolic regulation of cell hydration.
Preparation and Characterization of Homogeneous Hydroxyapatite/Chitosan Composite Scaffolds via In-Situ Hydration  [PDF]
Hong Li, Chang-Ren Zhou, Min-Ying Zhu, Jin-Huan Tian, Jian-Hua Rong
Journal of Biomaterials and Nanobiotechnology (JBNB) , 2010, DOI: 10.4236/jbnb.2010.11006
Abstract: Hydroxyapatite(HAP)/Chitosan(CS) composite is a biocompatible and bioactive material for tissue engineering. A novel homogeneous HAP/CS composite scaffold was developed via lyophilization and in situ hydration. A model CS solution with a Ca/P atom ratio of 1.67 was prepared through titration and stirring so as to attain a homogeneous dispersion of HAP particles. After lyophilization and in situ hydration, rod-shaped HAP particles (5 μm in diameter) within the CS matrix homogeneously scattered at the pore wall of the CS scaffold. X-ray diffraction (XRD) and Fouri-er-Transformed Infrared spectroscopy (FTIR) confirmed the formation of HAP crystals. The compressive strength in the composite scaffold indicated a significant increment over a CS-only scaffold. Bioactivity in vitro was completed by immersing the scaffold in simulated body fluid (SBF), and the result suggested that there was an increase in apatite formation on the HAP/CS scaffolds. Biological in vivo cell culture with MC 3T3-E1 cells for up to 7 days demonstrated that a homogeneous incorporation of HAP particles into CS scaffold led to higher cell viability compared to that of the pure CS scaffold or the HAP/CS scaffold blended. The results suggest that the homogeneous composite scaffold with better strength, bioactivity and biocompatibility can be prepared via in vitro hydration, which may serve as a good scaffold for bone tissue engineering.
Study the Critical Role of Admixtures in Cement Production: The Optimum State of Cassiterite (SnO2) Addition as a Natural Mineralizer-Oxide Influencing the Cement Properties  [PDF]
Ioannis Baziotis, Andreas Chandrinos
Advances in Chemical Engineering and Science (ACES) , 2011, DOI: 10.4236/aces.2011.14031
Abstract: In this work we evaluate the role of a natural mineralizer-oxide like cassiterite (SnO2) on the cement properties. In particular, we study the effect of different quantities of SnO2 with 0.5, 1.0, 1.5 and 2.0 wt% on burnability of industrial raw mix by free lime evaluation. We obtain four datasets, with successive increase of temperature at 1250℃, 1350℃, 1400℃ and 1450℃. We study the produced cassiterite-added clinker with X-ray diffraction (XRD), thermal analysis (DTA) and scanning electron microscopy (SEM). Though, we characterize the new phases formed and whether, adding excess SnO2 is promote forms of C3S, C2S influencing the final quality of cement.
Do Patients Drink Enough Water? Actual Pure Water Intake Compared to the Theoretical Daily Rules of Drinking Eight 8-Ounce Glasses and Drinking Half Your Body Weight in Ounces  [PDF]
Paul A. Oakley, Melissa L. Baird
Journal of Water Resource and Protection (JWARP) , 2015, DOI: 10.4236/jwarp.2015.711072
Abstract: Water is vital for virtually every bodily process, but many people don’t drink enough water. We assessed how much actual water, on average, was drank by 100 consecutive patients from a well-ness clinic. The average water intake was about five 8-ounce glasses of water a day. When compared to the “drink eight glasses of water a day” rule, our sample was 3 glasses short. When compared to the “drink half your body weight in ounces” rule, our sample was 6 glasses short. Chronic, unintentional dehydration is so common that it may be better to consider many “dehydration diseases” such as asthma and allergies as well as non-infectious conditions and chronic pains to be identified as “indicators of body thirst” and not the conditions that today are considered “diseases of unknown etiology”. Physiologically there are parameters of dehydration that can be measured prior to one feeling “thirsty”, and therefore, simply drinking “ad libitum” or by natural instinct may not be adequate. Patients need to be told to drink more water and to keep a mental daily tally to be sure to optimize their hydration status to better their health.
The Influence of Personality and Health Beliefs on Maintaining Proper Hydration  [PDF]
Stephen M. Patterson, Deborah E. Spinks
Psychology (PSYCH) , 2011, DOI: 10.4236/psych.2011.28123
Abstract: The present study was designed to examine factors that could facilitate or impede adherence to proper hydration. Forty volunteers (20 male, 20 female) were randomly assigned to one of two groups: Informed Group (n = 20) and Uninformed Group (n = 20). Bioelectrical impedance was used to measure intracellular (ICW) and extracellular (ECW) body water at Time 1 and 2. Personality, health beliefs, and health behaviors inventories were administered at Time 1. A health information brochure on proper hydration and consequences of poor hydration was given to the Informed Group. All participants were given six 1-liter bottles of water and drank two bottles per day. Both ICW, F(1,38) = 4.79, p < .05, and ECW, F(1,38) = 10.12, p < .005, significantly increased for both groups, and females had significantly greater changes than males in ECW, F(1,38) = 4.43, p < .05, and ICW, F(1,38) = 4.48, p < .05. Health information had no significant effect on female adherence but was a significant predictor of male adherence, β = .266, p < .05. Agreeableness, r = .36, p < .05, and social desirability, r = .33, p < .05, were the only personality factors related to change in ECW for the group as a whole. Health beliefs were unrelated to adherence, but general health concern, β = –.053, p < .05, was a significant predictor of change in ECW for males, although it was an inverse relationship.
Is increased water consumption among older adults associated with improvements in glucose homeostasis?  [PDF]
Adrienne G. Clark, Elizabeth A. Dennis Parker, Jyoti S. Savla, Kevin P. Davy, Brenda M. Davy
Open Journal of Preventive Medicine (OJPM) , 2013, DOI: 10.4236/ojpm.2013.35049
Abstract: Obesity and impaired glucose homeostasis in older adults place these individuals at risk for diabetes. Dehydration, glucose homeostasis, and insulin resistance are related; while aging and dehydration are associated with decreased glucose tolerance, weight loss can improve glycemia. For older adults following hypocaloric diets, additional water consumption may lead to greater weight loss. Further more, research suggests an association between insulin resistance and the body water retention hormone, arginine vasopressin (AVP). Analysis of the association between plasma copeptin (an AVP derivative) and fasting glucose, insulin, and homeostasis model assessment of insulin resistance (HOMA-IR) may provide further insight into the relationship between dehydration and diabetes risk. Our objective was to investigate the possibility that increased water consumption among older adults (n = 29, BMI = 31 ± 1 kg/m2, age = 62 ± 1 years) could improve glucose homeostasis beyond that observed with weight loss, as well as associations between plasma copeptin and diabetes risk. This retrospective analysis utilized data from a previous investigation, in which obese/overweight older adults were assigned to one of two groups: 1) Water: consume 500 ml of water prior to three daily meals over a 12-week hypocaloric diet intervention, or 2) Non-water: hypocaloric diet alone. In the present analysis, fasting plasma glucose and insulin, HOMA-IR, and plasma copeptin were evaluated, and compared to urinary specific gravity (USG), drinking water consumption, and body weight. Analyses performed using group assignment, volume of drinking water consumed or among a subgroup pair-matched for weight loss and sex did not reveal significant differences between groups. However in the full sample, plasma insulin concentration was associated with USG (r = 0.512, P < 0.01) and copeptin (r = 0.389, P < 0.05), and HOMA-IR was associated with USG (r = 0.530, P < 0.01) at week 12. Improvements in fasting insulin for water group participants (-8.5 +/-4 pmol/L) were also detected. Associations between hydration and insulin resistance support the need for future investigations addressing hydration status and diabetes risk.

Dielectric Permittivity of Various Cement-Based Materials during the First 24 Hours Hydration  [PDF]
Natt Makul
Open Journal of Inorganic Non-metallic Materials (OJINM) , 2013, DOI: 10.4236/ojinm.2013.34009
Abstract:

The dielectric permittivity of cementitious materials during 24 hours hydration period at a frequency of 2.45 GHz using a network analyzer with open-ended probe technique was measured. Influences of water-to-cementitious ratios, cement types, pozzolans and aggregate types are taken into consideration. The results show that dielectric permittivity is strongly affected by initial water-to-cementitious ratio and the rate of hydration reaction which can be changed by fineness of cement (Types 1 and 3), pozzolan materials and aggregates (river sand with/without crushed limestone rock). Dielectric permittivity is relatively high and remains constant during the dormant period, after that it decreases rapidly when the hydration reaction resumes and continues to decrease during the acceleratory period.

Peculiar Set-Retarding Effect of Miserly Amounts of Pyrocatechol on Calcium Aluminate Cement Hydration  [PDF]
Alexey Brykov, Mikhail Voronkov, Olga Nekrasova, Maxim Mokeev
Materials Sciences and Applications (MSA) , 2018, DOI: 10.4236/msa.2018.95031
Abstract: Pyrocatechol (benzene-1,2-diol) acts upon a calcium aluminate cement (CAC) as a very strong set and hardening retardant and a potent plasticizing agent at the same time. By studying CAC-pyrocatechol compositions using different analytical methods it was shown that pyrocatechol indeed slows CAC hydration and decreases strength of hardening stone. What makes this behavior a peculiar one is that pyrocatechol is known to accelerate Portland cement (PC) setting drastically.
Hipodermoclisis en pacientes con cáncer terminal
Hernández Perera,Abel; Hall Smith,Charles; Hernández Perera,Aliana;
Revista Cubana de Medicina , 2011,
Abstract: introduction: the subcutaneous route is an alternative frequently used in patients with advanced stage cancer to administer medication, however, its hydration is exceptional in our country, thus, present study was conducted to know if it is feasible to administer subcutaneous hydration in patients with terminal oncologic diseases, the technique's characteristics and potential difficulties during its implementation. methods: ten patients presenting with advanced stage cancer and dehydration or its risk underwent subcutaneous hydration with infusion volume and rhythm fitted to each patient. results: eighteen punctures were carried out in 10 patients for a total of 55 days of infusion. the mean volume administered was of 1 000 ml/d with an infusion rhythm fluctuating between 20and 80 ml/h. the infusion point was changed each 2-4 d, as average, with a variable length between 1 and 10 d, mainly due to accumulation in the puncture zone. conclusion: the subcutaneous route for hydration of patients with oncologic diseases in terminal stage is simple and seems free from significant complications.
About the Hydration of Mg++: A Quantum DFT Study
Martine Adrian-Scotto,Diana Vasileva,Georges Mallet,Dan Vasilescu
Internet Electronic Journal of Molecular Design , 2004,
Abstract: The hydration of magnesium dication is studied using the DFT method BPW91/6-31G(d,p), which gives remarkable results for the reproduction of the infra-red spectrum of liquid water. The enthalpies and the Gibbs free energies of Mg++ hydration are computed using the standard and the cluster procedures, up to eight added molecules of water. The entropic contribution to the hydration phenomenon is discussed using frequency analyses.
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