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Sample records for chronic osmotic minipump

  1. Olanzapine-induced weight gain: chronic infusion using osmotic minipumps does not result in stable plasma levels due to degradation of olanzapine in solution

    NARCIS (Netherlands)

    van der Zwaal, Esther M.; Luijendijk, Mieneke C. M.; Adan, Roger A. H.; la Fleur, Susanne E.

    2008-01-01

    The mechanisms underlying olanzapine-induced weight gain have not yet been fully elucidated. To examine the effects of long-term treatment with olanzapine on different aspects of energy balance, we administered olanzapine to male rats. Osmotic minipumps were chosen as preferred mode of

  2. Increased osmotic sensitivity for antidiuretic response in chronic chagas' disease

    Directory of Open Access Journals (Sweden)

    Joel Paulo Russomano Veiga

    1985-06-01

    Full Text Available The osmotic threshold for attaining the antidiuretic response to hypertonic saline infusion and Progressive dehydration was studied in 31 patients with the chronic form of Chagas' disease and 16 control patients. The chagasic patients exhibited enhanced osmoticsensitivity to the antidiuretic response. This was demonstrated by lower values of the increments in plasma osmolarity sufficient to induce a significant fall in water clearance, without alterations in the osmolar clearance or creatinine excretion. The time needed to attain the antidiuretic response was shorterfor chagasics in relation to normal subjects. The results suggest the existence of a disturbance in the fine control of osmoregulation in the chagasic patients. They are interpreted to be a consequence of the denervation in hypothalamic or extrahypothalamic areas that regulate the secretion of vasopressin in chronic Chagas' disease.O limiar de sensibilidade osmótíca para obtenção de resposta antídiurética foi avaliado em 31 pacientes com a forma crônica da moléstia de Chagas, através de infusão de salina hipertônica ou desidratação. Os resultados, quando comparados com os obtidos em 16 pacientes-controle, mostram uma sensibilidade osmótíca aumentada para os chagásicos, dados os menores valores do incremento na osmolaridade plasmática, suficiente para induzir uma queda significativa na depuração de água livre, sem alterações na depuração osmolar ou na excreção de creatínina. Também, o tempo necessário para atingir a antídiurese foi mais curto para os chagásicos do que para os controles. Os resultados sugerem a existência de um distúrbio na osmorregulação, nos pacientes chagásicos, caracterizado por uma sensibilidade osmótíca aumentada dos osmorreceptores para liberação da vasopressina. Estes dados interpretam-se como conseqüente à desnervação em áreas hipotalâmicas ou extra-hipotalâmicas, relacionadas com a secreção do horm

  3. RBC deformability and amino acid concentrations after hypo-osmotic challenge may reflect chronic cell hydration status in healthy young men

    OpenAIRE

    Stookey, Jodi D; Klein, Alexis; Hamer, Janice; Chi, Christine; Higa, Annie; Ng, Vivian; Arieff, Allen; Kuypers, Frans A; Larkin, Sandra; Perrier, Erica; Lang, Florian

    2013-01-01

    Biomarkers of chronic cell hydration status are needed to determine whether chronic hyperosmotic stress increases chronic disease risk in population-representative samples. In vitro, cells adapt to chronic hyperosmotic stress by upregulating protein breakdown to counter the osmotic gradient with higher intracellular amino acid concentrations. If cells are subsequently exposed to hypo-osmotic conditions, the adaptation results in excess cell swelling and/or efflux of free amino acids. This stu...

  4. Development of nonfibrotic left ventricular hypertrophy in an ANG II-induced chronic ovine hypertension model

    DEFF Research Database (Denmark)

    Klatt, Niklas; Scherschel, Katharina; Schad, Claudia

    2016-01-01

    setting. Therefore, the aim of this study was to establish a minimally invasive ovine hypertension model using chronic angiotensin II (ANG II) treatment and to characterize its effects on cardiac remodeling after 8 weeks. Sheep were implanted with osmotic minipumps filled with either vehicle control (n...... = 7) or ANG II (n = 9) for 8 weeks. Mean arterial blood pressure in the ANG II-treated group increased from 87.4 ± 5.3 to 111.8 ± 6.9 mmHg (P = 0.00013). Cardiovascular magnetic resonance imaging showed an increase in left ventricular mass from 112 ± 12.6 g to 131 ± 18.7 g after 7 weeks (P = 0...... any differences in epicardial conduction velocity and heterogeneity. These data demonstrate that chronic ANG II treatment using osmotic minipumps presents a reliable, minimally invasive approach to establish hypertension and nonfibrotic LVH in sheep....

  5. Application of a two-phase thermosyphon loop with minichannels and a minipump in computer cooling

    Directory of Open Access Journals (Sweden)

    Bieliński Henryk

    2016-03-01

    Full Text Available This paper focuses on the computer cooling capacity using the thermosyphon loop with minichannels and minipump. The one-dimensional separate model of two-phase flow and heat transfer in a closed thermosyphon loop with minichannels and minipump has been used in calculations. The latest correlations for minichannels available in literature have been applied. This model is based on mass, momentum, and energy balances in the evaporator, rising tube, condenser and the falling tube. A numerical analysis of the mass flux and heat transfer coefficient in the steady state has been presented.

  6. RBC deformability and amino acid concentrations after hypo-osmotic challenge may reflect chronic cell hydration status in healthy young men

    Science.gov (United States)

    Stookey, Jodi D; Klein, Alexis; Hamer, Janice; Chi, Christine; Higa, Annie; Ng, Vivian; Arieff, Allen; Kuypers, Frans A; Larkin, Sandra; Perrier, Erica; Lang, Florian

    2013-01-01

    Biomarkers of chronic cell hydration status are needed to determine whether chronic hyperosmotic stress increases chronic disease risk in population-representative samples. In vitro, cells adapt to chronic hyperosmotic stress by upregulating protein breakdown to counter the osmotic gradient with higher intracellular amino acid concentrations. If cells are subsequently exposed to hypo-osmotic conditions, the adaptation results in excess cell swelling and/or efflux of free amino acids. This study explored whether increased red blood cell (RBC) swelling and/or plasma or urine amino acid concentrations after hypo-osmotic challenge might be informative about relative chronic hyperosmotic stress in free-living men. Five healthy men (20–25 years) with baseline total water intake below 2 L/day participated in an 8-week clinical study: four 2-week periods in a U-shaped A-B-C-A design. Intake of drinking water was increased by +0.8 ± 0.3 L/day in period 2, and +1.5 ± 0.3 L/day in period 3, and returned to baseline intake (0.4 ± 0.2 L/day) in period 4. Each week, fasting blood and urine were collected after a 750 mL bolus of drinking water, following overnight water restriction. The periods of higher water intake were associated with significant decreases in RBC deformability (index of cell swelling), plasma histidine, urine arginine, and urine glutamic acid. After 4 weeks of higher water intake, four out of five participants had ½ maximal RBC deformability below 400 mmol/kg; plasma histidine below 100 μmol/L; and/or undetectable urine arginine and urine glutamic acid concentrations. Work is warranted to pursue RBC deformability and amino acid concentrations after hypo-osmotic challenge as possible biomarkers of chronic cell hydration. PMID:24303184

  7. Long-term morphine delivery via slow release morphine pellets or osmotic pumps: Plasma concentration, analgesia, and naloxone-precipitated withdrawal.

    Science.gov (United States)

    McLane, Virginia D; Bergquist, Ivy; Cormier, James; Barlow, Deborah J; Houseknecht, Karen L; Bilsky, Edward J; Cao, Ling

    2017-09-15

    Slow-release morphine sulfate pellets and osmotic pumps are common routes of chronic morphine delivery in mouse models, but direct comparisons of these drug delivery systems are lacking. In this study, we assessed the efficacy of slow-release pellets versus osmotic pumps in delivering morphine to adult mice. Male C57BL/6NCr mice (8weeksold) were implanted subcutaneously with slow-release pellets (25mg morphine sulfate) or osmotic pumps (64mg/mL, 1.0μL/h). Plasma morphine concentrations were quantified via LC-MS/MS, analgesic efficacy was determined by tail flick assay, and dependence was assessed with naloxone-precipitated withdrawal behaviors (jumping) and physiological effects (excretion, weight loss). Morphine pellets delivered significantly higher plasma drug concentrations compared to osmotic pumps, which were limited by the solubility of the morphine sulfate and pump volume/flow rate. Within 96h post-implantation, plasma morphine concentrations were indistinguishable in pellet vs. pump-treated samples. While osmotic pump did not have an antinociceptive effect in the tail flick assay, pumps and pellets induced comparable dependence symptoms (naloxone-precipitated jumping behavior) from 24-72h post-implantation. In this study, we compared slow-release morphine pellets to osmotic minipumps for morphine delivery in mice. We found that osmotic pumps and subcutaneous morphine sulfate pellets yielded significantly different pharmacokinetics over a 7-day period, and as a result significantly different antinociceptive efficacy. Nonetheless, both delivery methods induced dependence as measured by naloxone-precipitated withdrawal. Copyright © 2017 Elsevier Inc. All rights reserved.

  8. Chronic sympathetic activation promotes downregulation of ß-adrenoceptor-mediated effects in the guinea pig heart independently of structural remodeling and systolic dysfunction

    DEFF Research Database (Denmark)

    Soltysinska, Ewa; Thiele, Stefanie; Osadchiy, Oleg

    2011-01-01

    pathway upon chronic infusion of isoproterenol, a ß-adrenoceptor agonist, at a dose producing no structural left ventricular (LV) remodeling and systolic dysfunction. Subcutaneous isoproterenol infusion (400 µg kg(-1) h(-1) over 16 days) to guinea pigs using osmotic minipumps produced no change in cardiac...... weights, LV internal dimensions, myocyte cross-sectional area, extent of interstitial fibrosis, and basal contractile function. Isolated, perfused heart preparations from isoproterenol-treated guinea pigs exhibited attenuated responsiveness to acute ß-adrenoceptor stimulation, as evidenced by reduced LV...

  9. Erythrocyte osmotic fragility and lipid peroxidation following chronic co-exposure of rats to chlorpyrifos and deltamethrin, and the beneficial effect of alpha-lipoic acid

    Directory of Open Access Journals (Sweden)

    Chidiebere Uchendu

    2014-01-01

    Full Text Available The present study aimed to evaluate the effect of chronic co-exposure to chlorpyrifos (CPF and deltamethrin (DLT on erythrocyte osmotic fragility, lipid peroxidation and the ameliorative effect of alpha-lipoic acid (ALA on erythrocyte fragility. Thirty-six male Wistar rats divided into six groups of six rats each were used for the study. Groups I (S/oil and II (ALA were given soya oil (2 ml/kg and ALA (60 mg/kg, respectively. Rats in group III (DLT and IV (CPF were exposed to DLT (6.25 mg/kg and CPF (4.75 mg/kg (1/20th of the previously determined LD50 of 125 mg/kg and 95 mg/kg, respectively, over a period of 48 h. Rats in group V (CPF + DLT were co-exposed to CPF (4.75 mg/kg and DLT (6.25 mg/kg, while those in group VI (ALA + CPF + DLT were pretreated with ALA (60 mg/kg and then co-exposed to CPF and DLT, 45 min later. The treatments were administered by gavage once daily for a period of 16 weeks. Blood collected at the end of the experimental period were analyzed for erythrocyte osmotic fragility and malondialdehyde (MDA concentration. The study showed that chronic co-exposure to CPF and DLT resulted in an increase in erythrocyte fragility and MDA concentration which were ameliorated by supplementation with alpha-lipoic acid. The study concluded that repeated co-exposure to CPF and DLT elevated erythrocyte fragility probably due to increased lipid peroxidation, and pretreatment with alpha-lipoic acid ameliorated these alterations.

  10. Saltstone Osmotic Pressure

    Energy Technology Data Exchange (ETDEWEB)

    Nichols, Ralph L. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Dixon, Kenneth L. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRN

    2013-09-23

    Recent research into the moisture retention properties of saltstone suggest that osmotic pressure may play a potentially significant role in contaminant transport (Dixon et al., 2009 and Dixon, 2011). The Savannah River Remediation Closure and Disposal Assessments Group requested the Savannah River National Laboratory (SRNL) to conduct a literature search on osmotic potential as it relates to contaminant transport and to develop a conceptual model of saltstone that incorporates osmotic potential. This report presents the findings of the literature review and presents a conceptual model for saltstone that incorporates osmotic potential. The task was requested through Task Technical Request HLW-SSF-TTR- 2013-0004.

  11. Saltstone Osmotic Pressure

    International Nuclear Information System (INIS)

    Nichols, Ralph L.; Dixon, Kenneth L.

    2013-01-01

    Recent research into the moisture retention properties of saltstone suggest that osmotic pressure may play a potentially significant role in contaminant transport (Dixon et al., 2009 and Dixon, 2011). The Savannah River Remediation Closure and Disposal Assessments Group requested the Savannah River National Laboratory (SRNL) to conduct a literature search on osmotic potential as it relates to contaminant transport and to develop a conceptual model of saltstone that incorporates osmotic potential. This report presents the findings of the literature review and presents a conceptual model for saltstone that incorporates osmotic potential. The task was requested through Task Technical Request HLW-SSF-TTR-2013-0004. Simulated saltstone typically has very low permeability (Dixon et al. 2008) and pore water that contains a large concentration of dissolved salts (Flach and Smith 2013). Pore water in simulated saltstone has a high salt concentration relative to pore water in concrete and groundwater. This contrast in salt concentration can generate high osmotic pressures if simulated saltstone has the properties of a semipermeable membrane. Estimates of osmotic pressure using results from the analysis of pore water collected from simulated saltstone show that an osmotic pressure up to 2790 psig could be generated within the saltstone. Most semi-permeable materials are non-ideal and have an osmotic efficiency 3 , KNO 3 , Na 3 PO 4 x12H 2 O, and K 3 PO 4 when exposed to a dilute solution. Typically hydraulic head is considered the only driving force for groundwater in groundwater models. If a low permeability material containing a concentrated salt solution is present in the hydrogeologic sequence large osmotic pressures may develop and lead to misinterpretation of groundwater flow and solute transport. The osmotic pressure in the semi-permeable material can significantly impact groundwater flow in the vicinity of the semi-permeable material. One possible outcome is that

  12. Chronic intraventricular administration of lysergic acid diethylamide (LSD) affects the sensitivity of cortical cells to monocular deprivation.

    Science.gov (United States)

    McCall, M A; Tieman, D G; Hirsch, H V

    1982-11-04

    In kittens, but not in adult cats, depriving one eye of pattern vision by suturing the lids shut (monocular deprivation or MD) for one week reduces the proportion of binocular units in the visual cortex. A sensitivity of cortical units in adult cats to MD can be produced by infusing exogenous monoamines into the visual cortex. Since LSD interacts with monoamines, we have examined the effects of chronic administration of LSD on the sensitivity to MD for cortical cells in adult cats. Cats were assigned randomly to one of four conditions: MD/LSD, MD/No-LSD, No-MD/LSD, No-MD/No-LSD. An osmotic minipump delivered either LSD or the vehicle solution alone during a one-week period of MD. The animals showed no obvious anomalies during the administration of the drug. After one week the response properties of single units in area 17 of the visual cortex were studied without knowledge of the contents of the individual minipumps. With the exception of ocular dominance, the response properties of units recorded in all animals did not differ from normal. In the control animals (MD/No-LSD, No-MD/LSD, No-MD/No-LSD) the average proportion of binocular cells was 78%; similar to that observed for normal adult cats. However, in the experimental animals, which received LSD during the period of MD, only 52% of the cells were binocular. Our results suggest that chronic intraventricular administration of LSD affects either directly or indirectly the sensitivity of cortical neurons to MD.

  13. [Extrapontine osmotic myelinolysis].

    Science.gov (United States)

    Silva, Federico A; Rueda-Clausen, Christian F; Ramírez, Fabián

    2005-06-01

    Extrapontine osmotic myelinolysis is a rare nervous system complication. Symptoms of this malady were presented during the clinical examination of a 49-year-old alcoholic male, who arrived at the hospital emergency room in a state of cardiorespiratory arrest. After resuscitation methods were applied, the patient was found in metabolic acidosis (pH 7.014) and was treated with sodium bicarbonate. Forty-eight hours later, sodium levels in the patient had risen from 142 to 174 mEq/l. During the period of clinical observation, the patient showed signs of cognitive impairment, disartria, bilateral amaurosis, hyporeflexia and right-half body hemiparesias. After 72 hours, computer tomography was applied; this showed a bilateral lenticular hypodensity with internal and external capsule compromise. One month later, when the patient was referred to another institution for rehabilitation, the patient showed cognitive impairment, bilateral optic atrophy, residual disartria, bradikynesia and double hemiparesia.

  14. Osmotic water transport in aquaporins

    DEFF Research Database (Denmark)

    Zeuthen, Thomas; Alsterfjord, Magnus; Beitz, Eric

    2013-01-01

    Abstract  We test a novel, stochastic model of osmotic water transport in aquaporins. A solute molecule present at the pore mouth can either be reflected or permeate the pore. We assume that only reflected solute molecules induce osmotic transport of water through the pore, while permeating solute...... molecules give rise to no water transport. Accordingly, the rate of water transport is proportional to the reflection coefficient σ, while the solute permeability, P(S), is proportional to 1 - σ. The model was tested in aquaporins heterologously expressed in Xenopus oocytes. A variety of aquaporin channel...... sizes and geometries were obtained with the two aquaporins AQP1 and AQP9 and mutant versions of these. Osmotic water transport was generated by adding 20 mM of a range of different-sized osmolytes to the outer solution. The osmotic water permeability and the reflection coefficient were measured...

  15. Role of Osmotic Adjustment in Plant Productivity

    Energy Technology Data Exchange (ETDEWEB)

    Gebre, G.M.

    2001-01-11

    Successful implementation of short rotation woody crops requires that the selected species and clones be productive, drought tolerant, and pest resistant. Since water is one of the major limiting factors in poplar (Populus sp.) growth, there is little debate for the need of drought tolerant clones, except on the wettest of sites (e.g., lower Columbia River delta). Whether drought tolerance is compatible with productivity remains a debatable issue. Among the many mechanisms of drought tolerance, dehydration postponement involves the maintenance of high leaf water potential due to, for example, an adequate root system. This trait is compatible with productivity, but requires available soil moisture. When the plant leaf water potential and soil water content decline, the plant must be able to survive drought through dehydration tolerance mechanisms, such as low osmotic potential or osmotic adjustment. Osmotic adjustment and low osmotic potential are considered compatible with growth and yield because they aid in the maintenance of leaf turgor. However, it has been shown that turgor alone does not regulate cell expansion or stomatal conductance and, therefore, the role of osmotic adjustment is debated. Despite this finding, osmotic adjustment has been correlated with grain yield in agronomic crop species, and gene markers responsible for osmotic adjustment are being investigated to improve drought tolerance in productive progenies. Although osmotic adjustment and low osmotic potentials have been investigated in several forest tree species, few studies have investigated the relationship between osmotic adjustment and growth. Most of these studies have been limited to greenhouse or container-grown plants. Osmotic adjustment and rapid growth have been specifically associated in Populus and black spruce (Picea mariuna (Mill.) B.S.P.) progenies. We tested whether these relationships held under field conditions using several poplar clones. In a study of two hybrid poplar

  16. Osmotic effects of polyethylene glycol.

    Science.gov (United States)

    Schiller, L R; Emmett, M; Santa Ana, C A; Fordtran, J S

    1988-04-01

    Polyethylene glycol (PEG) has been used to increase the osmotic pressure of fluids used to cleanse the gastrointestinal tract. However, little is known about its osmotic activity. To investigate this activity systematically, solutions of PEG of differing molecular weights were made and subjected to measurement of osmolality by both freezing point depression and vapor pressure osmometry. Measured osmolality was increasingly greater than predicted from average molecular weight as PEG concentration increased. Measurement of sodium activity in NaCl/PEG solutions by means of an ion-selective electrode suggested that the higher than expected osmolality could be due in part to interactions that, in effect, sequestered water from the solution. Osmolality was consistently greater by freezing point osmometry than by vapor pressure osmometry. To determine which osmometry method reflected biologically relevant osmolality, normal subjects underwent steady-state total gut perfusion with an electrolyte solution containing 105 g/L of PEG 3350. This produced rectal effluent that was hypertonic by freezing point osmometry but isotonic by vapor pressure osmometry. Assuming that luminal fluid reaches osmotic equilibrium with plasma during total gut perfusion, this result suggests that the vapor pressure osmometer accurately reflects the biologically relevant osmolality of intestinal contents. We conclude that PEG exerts more of an osmotic effect than would be predicted from its molecular weight. This phenomenon may reflect interactions between PEG and water molecules that alter the physical chemistry of the solution and sequester water from the solution.

  17. Osmotic Effects in Sludge Dewatering

    DEFF Research Database (Denmark)

    Keiding, Kristian; Rasmussen, Michael R.

    2003-01-01

    A model of filtration dewatering is presented. The model is based on the d’Arcy flow equation in which the resistance to filtration is described by the Corzeny–Carman equation and the driving force is the difference between the external pressure and the osmotic pressure of the filter cake. It has...

  18. Chronic CNS oxytocin signaling preferentially induces fat loss in high-fat diet-fed rats by enhancing satiety responses and increasing lipid utilization.

    Science.gov (United States)

    Blevins, James E; Thompson, Benjamin W; Anekonda, Vishwanath T; Ho, Jacqueline M; Graham, James L; Roberts, Zachary S; Hwang, Bang H; Ogimoto, Kayoko; Wolden-Hanson, Tami; Nelson, Jarrell; Kaiyala, Karl J; Havel, Peter J; Bales, Karen L; Morton, Gregory J; Schwartz, Michael W; Baskin, Denis G

    2016-04-01

    Based largely on a number of short-term administration studies, growing evidence suggests that central oxytocin is important in the regulation of energy balance. The goal of the current work is to determine whether long-term third ventricular (3V) infusion of oxytocin into the central nervous system (CNS) is effective for obesity prevention and/or treatment in rat models. We found that chronic 3V oxytocin infusion between 21 and 26 days by osmotic minipumps both reduced weight gain associated with the progression of high-fat diet (HFD)-induced obesity and elicited a sustained reduction of fat mass with no decrease of lean mass in rats with established diet-induced obesity. We further demonstrated that these chronic oxytocin effects result from 1) maintenance of energy expenditure at preintervention levels despite ongoing weight loss, 2) a reduction in respiratory quotient, consistent with increased fat oxidation, and 3) an enhanced satiety response to cholecystokinin-8 and associated decrease of meal size. These weight-reducing effects persisted for approximately 10 days after termination of 3V oxytocin administration and occurred independently of whether sucrose was added to the HFD. We conclude that long-term 3V administration of oxytocin to rats can both prevent and treat diet-induced obesity.

  19. Controlled porosity solubility modulated osmotic pump tablets of gliclazide.

    Science.gov (United States)

    Banerjee, Arti; Verma, P R P; Gore, Subhash

    2015-06-01

    A system that can deliver drug at a controlled rate is very important for the treatment of various chronic diseases such as diabetes, asthma, and heart disease. Poorly water-soluble drug with pH-dependent solubility such as gliclazide (GLZ) offers challenges in the controlled-release formulation because of low dissolution rate and poor bioavailability. Solid dispersion (SD) of GLZ consisted of hydroxypropyl cellulose (HPC-SSL) as a polymeric solubilizer was manufactured by hot melt extrusion (HME) technology. Then, controlled porosity osmotic pump (CPOP) tablet of gliclazide was designed to deliver drug in a controlled manner up to 16 h. The developed formulation was optimized for type and level of pore former and coating weight gain. The optimized formulation was found to exhibit zero order kinetics independent of pH and agitation speed but depends on osmotic pressure of dissolution media indicated that mechanism of drug release was osmotic pressure. The in vivo performance prediction of developed formulation using convolution approach revealed that the developed formulation was superior to the existing marketed extended-release formulation in terms of attaining steady state plasma levels and indicated adequate exposure in translating hypoglycemic response. The prototype solubilization method combined with controlled porosity osmotic pump based technique could provide a unique way to increase dissolution rate and bioavailability of many poorly water-soluble, narrow therapeutic index drugs used in diabetes, cardiovascular diseases, etc.

  20. Fouling in Membrane Distillation, Osmotic Distillation and Osmotic Membrane Distillation

    Directory of Open Access Journals (Sweden)

    Mourad Laqbaqbi

    2017-03-01

    Full Text Available Various membrane separation processes are being used for seawater desalination and treatment of wastewaters in order to deal with the worldwide water shortage problem. Different types of membranes of distinct morphologies, structures and physico-chemical characteristics are employed. Among the considered membrane technologies, membrane distillation (MD, osmotic distillation (OD and osmotic membrane distillation (OMD use porous and hydrophobic membranes for production of distilled water and/or concentration of wastewaters for recovery and recycling of valuable compounds. However, the efficiency of these technologies is hampered by fouling phenomena. This refers to the accumulation of organic/inorganic deposits including biological matter on the membrane surface and/or in the membrane pores. Fouling in MD, OD and OMD differs from that observed in electric and pressure-driven membrane processes such electrodialysis (ED, membrane capacitive deionization (MCD, reverse osmosis (RO, nanofiltration (NF, ultrafiltration (UF, microfiltration (MF, etc. Other than pore blockage, fouling in MD, OD and OMD increases the risk of membrane pores wetting and reduces therefore the quantity and quality of the produced water or the concentration efficiency of the process. This review deals with the observed fouling phenomena in MD, OD and OMD. It highlights different detected fouling types (organic fouling, inorganic fouling and biofouling, fouling characterization techniques as well as various methods of fouling reduction including pretreatment, membrane modification, membrane cleaning and antiscalants application.

  1. The physics of osmotic pressure

    Science.gov (United States)

    Bowler, M. G.

    2017-09-01

    Osmosis drives the development of a pressure difference of many atmospheres between a dilute solution and pure solvent with which it is in contact through a semi-permeable membrane. The educational importance of this paper is that it presents a novel treatment in terms of fluid mechanics that is quantitative and exact. It is also simple and intuitive, showing vividly how osmotic pressures are generated and maintained in equilibrium, driven by differential solvent pressures. The present rigorous analysis using the virial theorem seems unknown and can be easily understood—and taught—at various different levels. It should be valuable to undergraduates, graduate students and indeed to the general physicist.

  2. Efficiency of osmotic pipe flows

    DEFF Research Database (Denmark)

    Haaning, Louise Sejling; Jensen, Kaare Hartvig; Helix Nielsen, Claus

    2013-01-01

    efficiency of these flows is limited by the presence of “unstirred” concentration boundary layers near the tube walls, and our primary aim is to understand and quantify these layers and their effect on the flow. We measure the outlet flow rate Qout while varying the inlet flow rate Q*, concentration c......We present experiments and theory for flows of sugar or salt solutions in cylindrical tubes with semipermeable walls (hollow fiber membranes) immersed in water, quantifying the strength of the osmotic driving force in relation to the dimensionless parameters that specify the system. The pumping...

  3. Osmotic homeostasis and NKLy lymphoma cells radiosensitivity

    International Nuclear Information System (INIS)

    Tishchenko, V.V.; Magda, I.N.

    1992-01-01

    In experiments with cells of ascites NKLy lymphoma differing in ploidy and position in the cell cycle, a study was made of the radiosensitivity, osmotic homeostasis peculiarities and thermoradiation changes in potassium content. It was shown that the resistance of osmotic homeostasis of NKLy cells to thermoradiation correlated with their radioresistance

  4. The Influence of the Osmotic Dehydration Process on Physicochemical Properties of Osmotic Solution.

    Science.gov (United States)

    Lech, Krzysztof; Michalska, Anna; Wojdyło, Aneta; Nowicka, Paulina; Figiel, Adam

    2017-12-16

    The osmotic dehydration (OD) process consists of the removal of water from a material during which the solids from the osmotic solution are transported to the material by osmosis. This process is commonly performed in sucrose and salt solutions. Taking into account that a relatively high consumption of those substances might have a negative effect on human health, attempts have been made to search for alternatives that can be used for osmotic dehydration. One of these is an application of chokeberry juice with proven beneficial properties to human health. This study aimed to evaluate the physicochemical properties of the OD solution (chokeberry juice concentrate) before and after the osmotic dehydration of carrot and zucchini. The total polyphenolics content, antioxidant capacity (ABTS, FRAP), dynamic viscosity, density, and water activity were examined in relation to the juice concentration used for the osmotic solution before and after the OD process. During the osmotic dehydration process, the concentration of the chokeberry juice decreased. Compounds with lower molecular weight and lower antioxidant capacity present in concentrated chokeberry juice had a stronger influence on the exchange of compounds during the OD process in carrot and zucchini. The water activity of the osmotic solution increased after the osmotic dehydration process. It was concluded that the osmotic solution after the OD process might be successfully re-used as a product with high quality for i.e. juice production.

  5. Osmocapsules for direct measurement of osmotic strength.

    Science.gov (United States)

    Kim, Shin-Hyun; Lee, Tae Yong; Lee, Sang Seok

    2014-03-26

    Monodisperse microcapsules with ultra-thin membranes are microfluidically designed to be highly sensitive to osmotic pressure, thereby providing a tool for the direct measurement of the osmotic strength. To make such osmocapsules, water-in-oil-in-water double-emulsion drops with ultra-thin shells are prepared as templates through emulsification of core-sheath biphasic flow in a capillary microfluidic device. When photocurable monomers are used as the oil phase, the osmocapsules are prepared by in-situ photopolymerization of the monomers, resulting in semipermeable membranes with a relatively large ratio of membrane thickness to capsule radius, approximately 0.02. These osmocapsules are buckled by the outward flux of water when they are subjected to a positive osmotic pressure difference above 125 kPa. By contrast, evaporation-induced consolidation of middle-phase containing polymers enables the production of osmocapsules with a small ratio of membrane thickness to capsule radius of approximately 0.002. Such an ultra-thin membrane with semi-permeability makes the osmocapsules highly sensitive to osmotic pressure; a positive pressure as small as 12.5 kPa induces buckling of the capsules. By employing a set of distinct osmocapsules confining aqueous solutions with different osmotic strengths, the osmotic strength of unknown solutions can be estimated through observation of the capsules that are selectively buckled. This approach provides the efficient measurement of the osmotic strength using only a very small volume of liquid, thereby providing a useful alternative to other measurement methods which use complex setups. In addition, in-vivo measurement of the osmotic strength can be potentially accomplished by implanting these biocompatible osmocapsules into tissue, which is difficult to achieve using conventional methods. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  6. Extra pontine osmotic demyelination syndrome.

    Science.gov (United States)

    Zunga, Pervaiz M; Farooq, Omar; Dar, Mohd I; Dar, Ishrat H; Rashid, Samia; Rather, Abdul Q; Basu, Javid A; Ashraf, Mohammed; Bhat, Jahangeer A

    2015-01-01

    The osmotic demyelination syndrome (ODS) has been identified as a complication of the rapid correction of hyponatremia for decades. However, in recent years, a variety of other medical conditions have been associated with the development of ODS, independent of changes in serum sodium which cause a rapid changes in osmolality of the interstitial (extracellular) compartment of the brain leading to dehydration of energy-depleted cells with subsequent axonal damage that occurs in characteristic areas. Slow correction of the serum sodium concentration and additional administration of corticosteroids seems to be a major prevention step in ODS patients. In the current report we aimed to share a rare case which we observed in our hospital. A 65 year old female admitted as altered sensorium with history of vomiting, diarrhea was managed with intravenous fluids for 2 days at a peripheral health centre. Patient was referred to our centre with encephalopathy, evaluated and found to have hyponatremia and hypokalemia rest of biochemical parameters and septic profile were normal. Patient's electrolyte disturbances were managed as per guidelines but encephalopathy persisted. Supportive treatment was continued and patient was discharged after 2 wks of stay in hospital after gaining full sensorium and neurological functions.

  7. Studies on osmotic concentration of radioactive effluents

    International Nuclear Information System (INIS)

    Thomas, K.C.; Ramachandhran, V.; Misra, B.M.

    1986-01-01

    The potential of direct osmosis for concentrating radioactive effluents is examined on the laboratory scale. Studies were carried out using asymmetric cellulose acetate membranes of a range of porosities under varying salinity gradients. A suitable bench scale osmotic concentrator employing tubular membrane systems has been fabricated and tested. An attempt to understand the mechanism of water permeation under osmotic and hydrostatic gradients has been made based on the irreversible thermodynamic approach. The solute separation of sodium chloride and radionuclides under osmosis is in the range of 85 to 95% for various osmotic sink solutions. The osmotic water flux is observed to be lower than the hydraulic water flux under reverse osmosis conditions. While the solute separation increases with an increase in annealing temperature, water flux decreases for both osmosis and reverse osmosis systems for various feed salinities. The effect of concentration polarization is analysed, and the effect of feed and osmotic sink velocity on the performance of the osmotic concentrator has also been studied. (orig.)

  8. Chronic infusion of lisinopril into hypothalamic paraventricular nucleus modulates cytokines and attenuates oxidative stress in rostral ventrolateral medulla in hypertension

    Energy Technology Data Exchange (ETDEWEB)

    Li, Hong-Bao [Department of Physiology and Pathophysiology, Xi' an Jiaotong University Cardiovascular Research Center, Xi' an Jiaotong University School of Medicine, Xi' an 710061 (China); Qin, Da-Nian, E-mail: dnqin@stu.edu.cn [Department of Physiology, Shantou University Medical College, Shantou 515041 (China); Ma, Le [Department of Public Health, Xi' an Jiaotong University School of Medicine, Xi' an 710061 (China); Miao, Yu-Wang [Department of Physiology and Pathophysiology, Xi' an Jiaotong University Cardiovascular Research Center, Xi' an Jiaotong University School of Medicine, Xi' an 710061 (China); Zhang, Dong-Mei [Department of Physiology, Dalian Medical University, Dalian 116044 (China); Lu, Yan [Department of Clinical Laboratory, Sanaitang Hospital, Lanzhou 730030 (China); Song, Xin-Ai [Department of Physiology and Pathophysiology, Xi' an Jiaotong University Cardiovascular Research Center, Xi' an Jiaotong University School of Medicine, Xi' an 710061 (China); Zhu, Guo-Qing [Key Laboratory of Cardiovascular Disease and Molecular Intervention, Department of Physiology, Nanjing Medical University, Nanjing 210029 (China); Kang, Yu-Ming, E-mail: ykang@mail.xjtu.edu.cn [Department of Physiology and Pathophysiology, Xi' an Jiaotong University Cardiovascular Research Center, Xi' an Jiaotong University School of Medicine, Xi' an 710061 (China)

    2014-09-01

    The hypothalamic paraventricular nucleus (PVN) and rostral ventrolateral medulla (RVLM) play a critical role in the generation and maintenance of sympathetic nerve activity. The renin–angiotensin system (RAS) in the brain is involved in the pathogenesis of hypertension. This study was designed to determine whether inhibition of the angiotensin-converting enzyme (ACE) in the PVN modulates cytokines and attenuates oxidative stress (ROS) in the RVLM, and decreases the blood pressure and sympathetic activity in renovascular hypertensive rats. Renovascular hypertension was induced in male Sprague–Dawley rats by the two-kidney one-clip (2K1C) method. Renovascular hypertensive rats received bilateral PVN infusion with ACE inhibitor lisinopril (LSP, 10 μg/h) or vehicle via osmotic minipump for 4 weeks. Mean arterial pressure (MAP), renal sympathetic nerve activity (RSNA), and plasma proinflammatory cytokines (PICs) were significantly increased in renovascular hypertensive rats. The renovascular hypertensive rats also had higher levels of ACE in the PVN, and lower level of interleukin-10 (IL-10) in the RVLM. In addition, the levels of PICs, the chemokine MCP-1, the subunit of NAD(P)H oxidase (gp91{sup phox}) and ROS in the RVLM were increased in hypertensive rats. PVN treatment with LSP attenuated those changes occurring in renovascular hypertensive rats. Our findings suggest that the beneficial effects of ACE inhibition in the PVN in renovascular hypertension are partly due to modulation cytokines and attenuation oxidative stress in the RVLM. - Highlights: • Chronic ACE inhibition in PVN on renovascular hypertension was investigated. • 2K1C resulted in sympathoexcitation, increased plasma PICs and hypertension. • 2K1C rats had higher levels of cytokines and reactive oxygen species (ROS) in RVLM. • Chronic inhibiting PVN ACE attenuates cytokines and ROS in RVLM in hypertension.

  9. Chronic infusion of lisinopril into hypothalamic paraventricular nucleus modulates cytokines and attenuates oxidative stress in rostral ventrolateral medulla in hypertension

    International Nuclear Information System (INIS)

    Li, Hong-Bao; Qin, Da-Nian; Ma, Le; Miao, Yu-Wang; Zhang, Dong-Mei; Lu, Yan; Song, Xin-Ai; Zhu, Guo-Qing; Kang, Yu-Ming

    2014-01-01

    The hypothalamic paraventricular nucleus (PVN) and rostral ventrolateral medulla (RVLM) play a critical role in the generation and maintenance of sympathetic nerve activity. The renin–angiotensin system (RAS) in the brain is involved in the pathogenesis of hypertension. This study was designed to determine whether inhibition of the angiotensin-converting enzyme (ACE) in the PVN modulates cytokines and attenuates oxidative stress (ROS) in the RVLM, and decreases the blood pressure and sympathetic activity in renovascular hypertensive rats. Renovascular hypertension was induced in male Sprague–Dawley rats by the two-kidney one-clip (2K1C) method. Renovascular hypertensive rats received bilateral PVN infusion with ACE inhibitor lisinopril (LSP, 10 μg/h) or vehicle via osmotic minipump for 4 weeks. Mean arterial pressure (MAP), renal sympathetic nerve activity (RSNA), and plasma proinflammatory cytokines (PICs) were significantly increased in renovascular hypertensive rats. The renovascular hypertensive rats also had higher levels of ACE in the PVN, and lower level of interleukin-10 (IL-10) in the RVLM. In addition, the levels of PICs, the chemokine MCP-1, the subunit of NAD(P)H oxidase (gp91 phox ) and ROS in the RVLM were increased in hypertensive rats. PVN treatment with LSP attenuated those changes occurring in renovascular hypertensive rats. Our findings suggest that the beneficial effects of ACE inhibition in the PVN in renovascular hypertension are partly due to modulation cytokines and attenuation oxidative stress in the RVLM. - Highlights: • Chronic ACE inhibition in PVN on renovascular hypertension was investigated. • 2K1C resulted in sympathoexcitation, increased plasma PICs and hypertension. • 2K1C rats had higher levels of cytokines and reactive oxygen species (ROS) in RVLM. • Chronic inhibiting PVN ACE attenuates cytokines and ROS in RVLM in hypertension

  10. Casein Micelle Dispersions under Osmotic Stress

    Science.gov (United States)

    Bouchoux, Antoine; Cayemitte, Pierre-Emerson; Jardin, Julien; Gésan-Guiziou, Geneviève; Cabane, Bernard

    2009-01-01

    Abstract Casein micelles dispersions have been concentrated and equilibrated at different osmotic pressures using equilibrium dialysis. This technique measured an equation of state of the dispersions over a wide range of pressures and concentrations and at different ionic strengths. Three regimes were found. i), A dilute regime in which the osmotic pressure is proportional to the casein concentration. In this regime, the casein micelles are well separated and rarely interact, whereas the osmotic pressure is dominated by the contribution from small residual peptides that are dissolved in the aqueous phase. ii), A transition range that starts when the casein micelles begin to interact through their κ-casein brushes and ends when the micelles are forced to get into contact with each other. At the end of this regime, the dispersions behave as coherent solids that do not fully redisperse when osmotic stress is released. iii), A concentrated regime in which compression removes water from within the micelles, and increases the fraction of micelles that are irreversibly linked to each other. In this regime the osmotic pressure profile is a power law of the residual free volume. It is well described by a simple model that considers the micelle to be made of dense regions separated by a continuous phase. The amount of water in the dense regions matches the usual hydration of proteins. PMID:19167314

  11. Inverse osmotic process for radioactive laundry waste

    Energy Technology Data Exchange (ETDEWEB)

    Ebara, K; Takahashi, S; Sugimoto, Y; Yusa, H; Hyakutake, H

    1977-01-07

    Purpose: To effectively recover the processing amount reduced in a continuous treatment. Method: Laundry waste containing radioactive substances discharged from a nuclear power plant is processed in an inverse osmotic process while adding starch digesting enzymes such as amylase and takadiastase, as well as soft spherical bodies such as sponge balls of a particle diameter capable of flowing in the flow of the liquid wastes along the inverse osmotic membrane pipe and having such a softness and roundness as not to damage the inverse osmotic membrane. This process can remove the floating materials such as thread dusts or hairs deposited on the membrane surface by the action of the soft elastic balls and remove paste or the like through decomposition by the digesting enzymes. Consequently, effective recovery can be attained for the reduced processing amount.

  12. Inverse osmotic process for radioactive laundry waste

    International Nuclear Information System (INIS)

    Ebara, Katsuya; Takahashi, Sankichi; Sugimoto, Yoshikazu; Yusa, Hideo; Hyakutake, Hiroshi.

    1977-01-01

    Purpose: To effectively recover the processing amount reduced in a continuous treatment. Method: Laundry waste containing radioactive substances discharged from a nuclear power plant is processed in an inverse osmotic process while adding starch digesting enzymes such as amylase and takadiastase, as well as soft spherical bodies such as sponge balls of a particle diameter capable of flowing in the flow of the liquid wastes along the inverse osmotic membrane pipe and having such a softness and roundness as not to damage the inverse osmotic membrane. This process can remove the floating materials such as thread dusts or hairs deposited on the membrane surface by the action of the soft elastic balls and remove paste or the like through decomposition by the digesting enzymes. Consequently, effective recovery can be attained for the reduced processing amount. (Furukawa, Y.)

  13. New Osmosis Law and Theory: the New Formula that Replaces van't Hoff Osmotic Pressure Equation

    OpenAIRE

    Huang, Hung-Chung; Xie, Rongqing

    2012-01-01

    This article derived a new abstract concept from the osmotic process and concluded it via "osmotic force" with a new law -- "osmotic law". The "osmotic law" describes that, in an osmotic system, osmolyte moves osmotically from the side with higher "osmotic force" to the side with lower "osmotic force". In addition, it was proved mathematically that the osmotic process could be explained perfectly via "osmotic force" and "osmotic laws", which can prevent the difficulties in using current "osmo...

  14. Osmotic dehydration of fish: principal component analysis

    Directory of Open Access Journals (Sweden)

    Lončar Biljana Lj.

    2014-01-01

    Full Text Available Osmotic treatment of the fish Carassius gibelio was studied in two osmotic solutions: ternary aqueous solution - S1, and sugar beet molasses - S2, at three solution temperatures of 10, 20 and 30oC, at atmospheric pressure. The aim was to examine the influence of type and concentration of the used hypertonic agent, temperature and immersion time on the water loss, solid gain, dry mater content, aw and content of minerals (Na, K, Ca and Mg. S2 solution has proven to be the best option according to all output variables.[ Projekat Ministarstva nauke Republike Srbije, br. TR 31055

  15. Dependence of osmotic pressure on solution properties

    International Nuclear Information System (INIS)

    Fritz, S.J.

    1978-01-01

    Hydrostatic pressure, temperature, salt concentration, and the chemical composition of the salt are parameters affecting solution properties. Pressure and temperature have little effect on osmosis, but osmotic pressure variations due to type of dissolved salt may be significant, especially at high concentrations. For a given salt solution, concentration variations cause large differences in osmotic pressure. A representative difference in concentration across a clay layer in a relatively shallow groundwater system might be 100 to 1,000 ppm. When expressed as ppm NaCl, this difference could cause a head difference of 0.8 to 8 meters of water if one of the rock bodies were closed to fluid escape

  16. Chronic infusion of epigallocatechin-3-O-gallate into the hypothalamic paraventricular nucleus attenuates hypertension and sympathoexcitation by restoring neurotransmitters and cytokines.

    Science.gov (United States)

    Yi, Qiu-Yue; Li, Hong-Bao; Qi, Jie; Yu, Xiao-Jing; Huo, Chan-Juan; Li, Xiang; Bai, Juan; Gao, Hong-Li; Kou, Bo; Liu, Kai-Li; Zhang, Dong-Dong; Chen, Wen-Sheng; Cui, Wei; Zhu, Guo-Qing; Shi, Xiao-Lian; Kang, Yu-Ming

    2016-11-16

    Reactive oxygen species (ROS) in the brain are involved in the pathogenesis of hypertension. Epigallocatechin-3-O-gallate (EGCG), one of the active compounds in green tea, has anti-oxidant, anti-inflammatory and vascular protective properties. This study was designed to determine whether chronic infusion of EGCG into the hypothalamic paraventricular nucleus (PVN) attenuates ROS and sympathetic activity and delays the progression of hypertension by up-regulating anti-inflammatory cytokines, reducing pro-inflammatory cytokines (PICs) and decreasing nuclear factor-kappa B (NF-κB) activity, as well as restoring the neurotransmitters balance in the PVN of spontaneously hypertensive rats (SHR). Adult normotensive Wistar-Kyoto (WKY) rats and SHR received bilateral PVN infusion of EGCG (20μg/h) or vehicle via osmotic minipumps for 4 weeks. SHR showed higher mean arterial pressure, plasma proinflammatory cytokines and circulating norepinephrine (NE) levels compared with WKY rats. SHR also had higher PVN levels of the subunit of NAD(P)H oxidase (gp91 phox ), ROS, tyrosine hydroxylase, and PICs; increased NF-κB activity; and lower PVN levels of interleukin-10 (IL-10) and 67kDa isoform of glutamate decarboxylase (GAD67) than WKY rats. PVN infusion of EGCG attenuated all these changes in SHR. These findings suggest that SHR have an imbalance between excitatory and inhibitory neurotransmitters, as well as an imbalance between pro- and anti-inflammatory cytokines in the PVN. Chronic inhibition of ROS in the PVN restores the balance of neurotransmitters and cytokines in the PVN, thereby attenuating hypertensive response and sympathetic activity. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  17. Dietary-induced binge eating increases prefrontal cortex neural activation to restraint stress and increases binge food consumption following chronic guanfacine.

    Science.gov (United States)

    Bello, Nicholas T; Walters, Amy L; Verpeut, Jessica L; Caverly, Jonathan

    2014-10-01

    Binge eating is a prominent feature of bulimia nervosa and binge eating disorder. Stress or perceived stress is an often-cited reason for binge eating. One notion is that the neural pathways that overlap with stress reactivity and feeding behavior are altered by recurrent binge eating. Using young adult female rats in a dietary-induced binge eating model (30 min access to binge food with or without 24-h calorie restriction, twice a week, for 6 weeks) we measured the neural activation by c-Fos immunoreactivity to the binge food (vegetable shortening mixed with 10% sucrose) in bingeing and non-bingeing animals under acute stress (immobilization; 1 h) or no stress conditions. There was an increase in the number of immunopositive cells in the dorsal medial prefrontal cortex (mPFC) in stressed animals previously exposed to the binge eating feeding schedules. Because attention deficit hyperactive disorder (ADHD) medications target the mPFC and have some efficacy at reducing binge eating in clinical populations, we examined whether chronic (2 weeks; via IP osmotic mini-pumps) treatment with a selective alpha-2A adrenergic agonist (0.5 mg/kg/day), guanfacine, would reduce binge-like eating. In the binge group with only scheduled access to binge food (30 min; twice a week; 8 weeks), guanfacine increased total calories consumed during the 30-min access period from the 2-week pre-treatment baseline and increased binge food consumption compared with saline-treated animals. These experiments suggest that mPFC is differentially activated in response to an immobilization stress in animals under different dietary conditions and chronic guanfacine, at the dose tested, was ineffective at reducing binge-like eating. Copyright © 2014 Elsevier Inc. All rights reserved.

  18. Chronic treatment with prazosin or duloxetine lessens concurrent anxiety-like behavior and alcohol intake: evidence of disrupted noradrenergic signaling in anxiety-related alcohol use.

    Science.gov (United States)

    Skelly, Mary J; Weiner, Jeff L

    2014-07-01

    Alcohol use disorders have been linked to increased anxiety, and enhanced central noradrenergic signaling may partly explain this relationship. Pharmacological interventions believed to reduce the excitatory effects of norepinephrine have proven effective in attenuating ethanol intake in alcoholics as well as in rodent models of ethanol dependence. However, most preclinical investigations into the effectiveness of these drugs in decreasing ethanol intake have been limited to acute observations, and none have concurrently assessed their anxiolytic effects. The purpose of these studies was to examine the long-term effectiveness of pharmacological interventions presumed to decrease norepinephrine signaling on concomitant ethanol self-administration and anxiety-like behavior in adult rats with relatively high levels of antecedent anxiety-like behavior. Adult male Long-Evans rats self-administered ethanol on an intermittent access schedule for eight to ten weeks prior to being implanted with osmotic minipumps containing either an a1-adrenoreceptor antagonist (prazosin, 1.5 mg/kg/day), a β1/2-adrenoreceptor antagonist (propranolol, 2.5 mg/kg/day), a serotonin/norepinephrine reuptake inhibitor (duloxetine, 1.5 mg/kg/day) or vehicle (10% dimethyl sulfoxide). These drugs were continuously delivered across four weeks, during which animals continued to have intermittent access to ethanol. Anxiety-like behavior was assessed on the elevated plus maze before treatment and again near the end of the drug delivery period. Our results indicate that chronic treatment with a low dose of prazosin or duloxetine significantly decreases ethanol self-administration (P chronic treatment with putative inhibitors of central noradrenergic signaling may attenuate ethanol intake via a reduction in anxiety-like behavior.

  19. Quantified Effects of Late Pregnancy and Lactation on the Osmotic ...

    African Journals Online (AJOL)

    Quantified Effects of Late Pregnancy and Lactation on the Osmotic Stability of ... in the composition of erythrocyte membranes associated with the physiologic states. Keywords: Erythrocyteosmotic stability, osmotic fragility, late pregnancy, ...

  20. Increased Resistance to osmotic lysis of sickled erythrocytes ...

    African Journals Online (AJOL)

    treated with CNw had significantly reduced osmotic lysis when compared with the untreated set (P<0.05, respectively) at various hypotonic NaCl concentrations. Various Hb genotypes exhibited a graded increase in osmotic pressure lysis in ...

  1. Osmotic stress upregulates the transcription of thiamine (vitamin B1 ...

    African Journals Online (AJOL)

    Osmotic stress upregulates the transcription of thiamine (vitamin B1) ... Oil palm's responses in terms of the expression profiles of these two thiamine biosynthesis genes to an osmotic stress inducer, polyethylene glycol ... from 32 Countries:.

  2. Comparative Erythrocytes Osmotic Fragility Test and some ...

    African Journals Online (AJOL)

    Erythrocytes osmotic fragility and haematological parameters of subjects with HbAS (sickle cell trait) and HbSS (sickle cell anaemia) were determined and compared with subjects with HbAA (normal adult haemoglobin), which acted as control. They were divided into three groups of 40 subjects for HbAA, 35 subjects for ...

  3. The plant cuticle is required for osmotic stress regulation of abscisic acid biosynthesis and osmotic stress tolerance in Arabidopsis

    KAUST Repository

    Wang, Zhenyu; Xiong, Liming; Li, Wenbo; Zhu, Jian-Kang; Zhu, Jianhua

    2011-01-01

    Osmotic stress activates the biosynthesis of abscisic acid (ABA). One major step in ABA biosynthesis is the carotenoid cleavage catalyzed by a 9-cis epoxycarotenoid dioxygenase (NCED). To understand the mechanism for osmotic stress activation of ABA

  4. [Chronic diarrhea].

    Science.gov (United States)

    Stelzer, Teresa; Heuss, Ludwig Theodor

    2014-09-01

    Defined by lasting more than four weeks - is a common but often challenging clinical scenario. It is important to be aware that diarrhoea means different things to different patients. The evaluation of chronic diarrhoea depends on taking an excellent history and careful physical examination as well as planning investigations thoughtfully. Functional diarrhea ist the most common cause of chronic diarrhea in the developed countries and motility disorders are more common than inflammatory, osmotic or secretory causes. In some cases categorizing patients by their stool characteristics can be helpful in directing further evaluation.

  5. Osmotic consolidation of suspensions and gels

    International Nuclear Information System (INIS)

    Miller, K.T.; Zukoski, C.F.

    1994-01-01

    An osmotic method for the consolidation of suspensions of ceramic particles is demonstrated. Concentrated solutions of poly(ethylene oxide) are separated from a suspension of ceramic particles by a semipermeable membrane, creating a gradient in solvent chemical potential. Solvent passes from the suspension into the polymer solution, lowering its free energy and consolidating the suspension. Dispersions of stable 8-nm hydrous zirconia particles were consolidated to over 47% by volume. Suspensions of α-alumina in three states of aggregation (dispersed, weakly flocculated, and strongly flocculated) were consolidated to densities greater than or equal to those produced in conventional pressure filtration. Moreover, the as-consolidated alumina bodies were partially drained of fluid during the osmotic consolidation process, producing cohesive partially dried bodies with improved handling characteristics

  6. Plasma osmotic changes during major abdominal surgery.

    Science.gov (United States)

    Malone, R A; McLeavey, C A; Arens, J F

    1977-12-01

    Fluid balance across the capillary membrane is maintained normally by a balance of hydrostatic and colloid osmotic pressures (COP). In 12 patients having major intra-abdominal procedures, the COP was followed during the operative and immediate postoperative periods. The patients' intraoperative fluid management consisted of replacing shed blood with blood and following Shires' concept of crystalloid replacement. Significant decreases in COP to approximately two thirds of the initial value occurred in patients having intra-abdominal procedures versus only a 10 percent decrease in those having peripheral procedures (greater than .001). As a result of this decrease in COP, the balance between hydrostatic and colloid osmotic pressures is lost and risk of pulmonary intersitial edema is increased.

  7. A REVIEW ON OSMOTIC DRUG DELIVERY SYSTEM

    OpenAIRE

    Harnish Patel; Upendra Patel; Hiren Kadikar; Bhavin Bhimani; Dhiren Daslaniya; Ghanshyam Patel

    2012-01-01

    Conventional oral drug delivery systems supply an instantaneous release of drug, which cannot control the release of the drug and effective concentration at the target site. This kind of dosing pattern may result in constantly changing, unpredictable plasma concentrations. Drugs can be delivered in a controlled pattern over a long period of time by the process of osmosis. Osmotic devices are the most promising strategy based systems for controlled drug delivery. They are the most reliable con...

  8. Hydrothermal Carbonization of Spent Osmotic Solution (SOS Generated from Osmotic Dehydration of Blueberries

    Directory of Open Access Journals (Sweden)

    Kaushlendra Singh

    2014-09-01

    Full Text Available Hydrothermal carbonization of spent osmotic solution (SOS, a waste generated from osmotic dehydration of fruits, has the potential of transformation into hydrochars, a value-added product, while reducing cost and overall greenhouse gas emissions associated with waste disposal. Osmotic solution (OS and spent osmotic solution (SOS generated from the osmotic dehydration of blueberries were compared for their thermo-chemical decomposition behavior and hydrothermal carbonization. OS and SOS samples were characterized for total solids, elemental composition, and thermo-gravimetric analysis (TGA. In addition, hydrothermal carbonization was performed at 250 °C and for 30 min to produce hydrochars. The hydrochars were characterized for elemental composition, Brunauer-Emmett-Teller (BET surface area, particle shape and surface morphology. TGA results show that the SOS sample loses more weight in the lower temperature range than the OS sample. Both samples produced, approximately, 40%–42% (wet-feed basis hydrochar during hydrothermal carbonization but with different properties. The OS sample produced hydrochar, which had spherical particles of 1.79 ± 1.30 μm diameter with a very smooth surface. In contrast, the SOS sample produced hydrochar with no definite particle shape but with a raspberry-like surface.

  9. Osmotic and Heat Stress Effects on Segmentation.

    Directory of Open Access Journals (Sweden)

    Julian Weiss

    Full Text Available During vertebrate embryonic development, early skin, muscle, and bone progenitor populations organize into segments known as somites. Defects in this conserved process of segmentation lead to skeletal and muscular deformities, such as congenital scoliosis, a curvature of the spine caused by vertebral defects. Environmental stresses such as hypoxia or heat shock produce segmentation defects, and significantly increase the penetrance and severity of vertebral defects in genetically susceptible individuals. Here we show that a brief exposure to a high osmolarity solution causes reproducible segmentation defects in developing zebrafish (Danio rerio embryos. Both osmotic shock and heat shock produce border defects in a dose-dependent manner, with an increase in both frequency and severity of defects. We also show that osmotic treatment has a delayed effect on somite development, similar to that observed in heat shocked embryos. Our results establish osmotic shock as an alternate experimental model for stress, affecting segmentation in a manner comparable to other known environmental stressors. The similar effects of these two distinct environmental stressors support a model in which a variety of cellular stresses act through a related response pathway that leads to disturbances in the segmentation process.

  10. Electro-osmotic flows inside triangular microchannels

    International Nuclear Information System (INIS)

    Vocale, P; Spiga, M; Geri, M; Morini, G L

    2014-01-01

    This work presents a numerical investigation of both pure electro-osmotic and combined electro-osmotic/pressure-driven flows inside triangular microchannels. A finite element analysis has been adopted to solve the governing equations for the electric potential and the velocity field, accounting for a finite thickness of the electric double layer. The influence of non-dimensional parameters such as the aspect ratio of the cross-section, the electrokinetic diameter and the ratio of the pressure force to the electric force on the flow behavior has been investigated. Numerical results point out that the velocity field is significantly influenced by the aspect ratio of the cross section and the electrokinetic diameter. More specifically, the aspect ratio plays an important role in determining the maximum volumetric flow rate, while the electrokinetic diameter is crucial to establishing the range of pressures that may be sustained by the electro-osmotic flow. Numerical results are also compared with two correlations available in the literature which enable to assess the volumetric flow rate and the pressure head for microchannels featuring a rectangular, a trapezoidal or an elliptical cross-section.

  11. Enhanced monoclonal antibody production by gradual increase of osmotic pressure

    OpenAIRE

    Lin, Jianqiang; Takagi, Mutsumi; Qu, Yinbo; Gao, Peiji; Yoshida, Toshiomi

    1999-01-01

    The time length required for the adaptation of AFP-27 hybridoma cells to high osmotic pressure and the effect of a gradual increase of osmotic pressure on monoclonal antibody production were investigated. When the cells were subjected to an increase of osmotic pressure from 300 mOsmol kg-1 to 366 mOsmol kg- 1, the intracellular content of osmoprotective free amino acids reached a maximum level 6 h after the osmotic pressure was increased to 366 mOsmol kg-1. The same time period of 6 h incubat...

  12. Chronic escitalopram treatment attenuated the accelerated rapid eye movement sleep transitions after selective rapid eye movement sleep deprivation: a model-based analysis using Markov chains.

    Science.gov (United States)

    Kostyalik, Diána; Vas, Szilvia; Kátai, Zita; Kitka, Tamás; Gyertyán, István; Bagdy, Gyorgy; Tóthfalusi, László

    2014-11-19

    Shortened rapid eye movement (REM) sleep latency and increased REM sleep amount are presumed biological markers of depression. These sleep alterations are also observable in several animal models of depression as well as during the rebound sleep after selective REM sleep deprivation (RD). Furthermore, REM sleep fragmentation is typically associated with stress procedures and anxiety. The selective serotonin reuptake inhibitor (SSRI) antidepressants reduce REM sleep time and increase REM latency after acute dosing in normal condition and even during REM rebound following RD. However, their therapeutic outcome evolves only after weeks of treatment, and the effects of chronic treatment in REM-deprived animals have not been studied yet. Chronic escitalopram- (10 mg/kg/day, osmotic minipump for 24 days) or vehicle-treated rats were subjected to a 3-day-long RD on day 21 using the flower pot procedure or kept in home cage. On day 24, fronto-parietal electroencephalogram, electromyogram and motility were recorded in the first 2 h of the passive phase. The observed sleep patterns were characterized applying standard sleep metrics, by modelling the transitions between sleep phases using Markov chains and by spectral analysis. Based on Markov chain analysis, chronic escitalopram treatment attenuated the REM sleep fragmentation [accelerated transition rates between REM and non-REM (NREM) stages, decreased REM sleep residence time between two transitions] during the rebound sleep. Additionally, the antidepressant avoided the frequent awakenings during the first 30 min of recovery period. The spectral analysis showed that the SSRI prevented the RD-caused elevation in theta (5-9 Hz) power during slow-wave sleep. Conversely, based on the aggregate sleep metrics, escitalopram had only moderate effects and it did not significantly attenuate the REM rebound after RD. In conclusion, chronic SSRI treatment is capable of reducing several effects on sleep which might be the consequence

  13. A Simple Student Laboratory on Osmotic Flow, Osmotic Pressure, and the Reflection Coefficient.

    Science.gov (United States)

    Feher, Joseph J.; Ford, George D.

    1995-01-01

    Describes a laboratory exercise containing a practical series of experiments that novice students can perform within two hours. The exercise provides a confirmation of van't Hoff's law while placing more emphasis on osmotic flow than pressure. Students can determine parameters such as the reflection coefficient which stress the interaction of both…

  14. The plant cuticle is required for osmotic stress regulation of abscisic acid biosynthesis and osmotic stress tolerance in Arabidopsis

    KAUST Repository

    Wang, Zhenyu

    2011-05-01

    Osmotic stress activates the biosynthesis of abscisic acid (ABA). One major step in ABA biosynthesis is the carotenoid cleavage catalyzed by a 9-cis epoxycarotenoid dioxygenase (NCED). To understand the mechanism for osmotic stress activation of ABA biosynthesis, we screened for Arabidopsis thaliana mutants that failed to induce the NCED3 genee xpression in response to osmotic stress treatments. The ced1 (for 9-cis epoxycarotenoid dioxy genase defective 1) mutant isolated in this study showed markedly reduced expression of NCED3 in response to osmotic stress (polyethylene glycol)treatments compared with the wild type. Other ABA biosynthesis genes are also greatly reduced in ced1 under osmotic stress. ced1 mutant plants are very sensitive to even mild osmotic stress. Map-based cloning revealed unexpectedly thatCED1 encodes a putative a/b hydrolase domain-containing protein and is allelic to the BODYGUARD gene that was recently shown to be essential for cuticle biogenesis. Further studies discovered that other cut in biosynthesis mutants are also impaired in osmotic stress induction of ABA biosynthesis genes and are sensitive to osmotic stress. Our work demonstrates that the cuticle functions not merely as a physical barrier to minimize water loss but also mediates osmotic stress signaling and tolerance by regulating ABA biosynthesis and signaling. © 2011 American Society of Plant Biologists. All rights reserved.

  15. Osmotic stress on nitrification in an airlift bioreactor

    International Nuclear Information System (INIS)

    Jin Rencun; Zheng Ping; Mahmood, Qaisar; Hu Baolan

    2007-01-01

    The effect of osmotic pressure on nitrification was studied in a lab-scale internal-loop airlift-nitrifying reactor. The reactor slowly adapted to the escalating osmotic pressure during 270 days operation. The conditions were reversed to the initial stage upon full inhibition of the process. Keeping influent ammonium concentration constant at 420 mg N L -1 and hydraulic retention time at 20.7 h, with gradual increase in osmotic pressure from 4.3 to 18.8 x 10 5 Pa by adding sodium sulphate, the ammonium removal efficiencies of the nitrifying bioreactor were maintained at 93-100%. Further increase in osmotic pressure up to 19.2 x 10 5 Pa resulted in drop of the ammonium conversion to 69.2%. The osmotic pressure caused abrupt inhibition of nitrification without any alarm and the critical osmotic pressure value causing inhibition remained between 18.8 and 19.2 x 10 5 Pa. Nitrite oxidizers were found more sensitive to osmotic stress as compared with ammonia oxidizers, leading to nitrite accumulation up to 61.7% in the reactor. The performance of bioreactor recovered gradually upon lowering the osmotic pressure. Scanning and transmission electron microscopy indicated that osmotic stress resulted in simplification of the nitrifying bacterial populations in the activated sludge as the cellular size reduced; the inner membrane became thinner and some unknown inclusions appeared within the cells. The microbial morphology and cellular structure restored upon relieving the osmotic pressure. Addition of potassium relieved the effect of osmotic pressure upon nitrification. Results demonstrate that the nitrifying reactor possesses the potential to treat ammonium-rich brines after acclimatization

  16. Osmotic stress alters chromatin condensation and nucleocytoplasmic transport

    Energy Technology Data Exchange (ETDEWEB)

    Finan, John D.; Leddy, Holly A. [Department of Orthopaedic Surgery, Duke University Medical Center, Durham, NC (United States); Department of Biomedical Engineering, Duke University, Durham, NC (United States); Guilak, Farshid, E-mail: guilak@duke.edu [Department of Orthopaedic Surgery, Duke University Medical Center, Durham, NC (United States); Department of Biomedical Engineering, Duke University, Durham, NC (United States)

    2011-05-06

    Highlights: {yields} The rate of nucleocytoplasmic transport increases under hyper-osmotic stress. {yields} The mechanism is a change in nuclear geometry, not a change in permeability of the nuclear envelope. {yields} Intracytoplasmic but not intranuclear diffusion is sensitive to osmotic stress. {yields} Pores in the chromatin of the nucleus enlarge under hyper-osmotic stress. -- Abstract: Osmotic stress is a potent regulator of biological function in many cell types, but its mechanism of action is only partially understood. In this study, we examined whether changes in extracellular osmolality can alter chromatin condensation and the rate of nucleocytoplasmic transport, as potential mechanisms by which osmotic stress can act. Transport of 10 kDa dextran was measured both within and between the nucleus and the cytoplasm using two different photobleaching methods. A mathematical model was developed to describe fluorescence recovery via nucleocytoplasmic transport. As osmolality increased, the diffusion coefficient of dextran decreased in the cytoplasm, but not the nucleus. Hyper-osmotic stress decreased nuclear size and increased nuclear lacunarity, indicating that while the nucleus was getting smaller, the pores and channels interdigitating the chromatin had expanded. The rate of nucleocytoplasmic transport was increased under hyper-osmotic stress but was insensitive to hypo-osmotic stress, consistent with the nonlinear osmotic properties of the nucleus. The mechanism of this osmotic sensitivity appears to be a change in the size and geometry of the nucleus, resulting in a shorter effective diffusion distance for the nucleus. These results may explain physical mechanisms by which osmotic stress can influence intracellular signaling pathways that rely on nucleocytoplasmic transport.

  17. Novel regulation of aquaporins during osmotic stress.

    Science.gov (United States)

    Vera-Estrella, Rosario; Barkla, Bronwyn J; Bohnert, Hans J; Pantoja, Omar

    2004-08-01

    Aquaporin protein regulation and redistribution in response to osmotic stress was investigated. Ice plant (Mesembryanthemum crystallinum) McTIP1;2 (McMIPF) mediated water flux when expressed in Xenopus leavis oocytes. Mannitol-induced water imbalance resulted in increased protein amounts in tonoplast fractions and a shift in protein distribution to other membrane fractions, suggesting aquaporin relocalization. Indirect immunofluorescence labeling also supports a change in membrane distribution for McTIP1;2 and the appearance of a unique compartment where McTIP1;2 is expressed. Mannitol-induced redistribution of McTIP1;2 was arrested by pretreatment with brefeldin A, wortmannin, and cytochalasin D, inhibitors of vesicle trafficking-related processes. Evidence suggests a role for glycosylation and involvement of a cAMP-dependent signaling pathway in McTIP1;2 redistribution. McTIP1;2 redistribution to endosomal compartments may be part of a homeostatic process to restore and maintain cellular osmolarity under osmotic-stress conditions.

  18. Osmotic properties of sulfobutylether and hydroxypropyl cyclodextrins.

    Science.gov (United States)

    Zannou, E A; Streng, W H; Stella, V J

    2001-08-01

    The purpose of this study was to determine the osmolality of sulfobutylether (SBE) and hydroxypropyl (HP) derivatives of cyclodextrins (CDs) via vapor pressure osmometry (VPO) and freezing point depression (FPD). (SBE) and HP-CDs are efficient excipients capable of solubilizing and stabilizing poorly water-soluble drugs in parenteral formulations. (SBE)-CDs have also been used as solubility enhancers and osmotic agents for the sustained release of poorly water-soluble drugs from osmotic pump tablets. The knowledge of the CD's osmolality in solution or inside such tablets would allow one to further characterize the release mechanisms. Experiments were conducted at 37 degrees C with eight types of HP and (SBE)-CDs. The aqueous solutions ranged from 0.005-0.350 mol(-1). Methods were developed to allow the measurement of high osmolalities using a vapor pressure osmometer or a differential scanning calorimeter. The osmolality calculations from the VPO and FPD measurements correlated well. The osmolality of (SBE)-CDs was significantly higher than the osmolality of HP-CDs and increased with the total degree of substitution (TDS). All CDs showed deviations from ideality at high concentrations. Empirical correlations of osmolality with concentration and TDS allowed the prediction of osmolality over a wide concentration range. This study also gave some useful insights into the behavior of CD derivatives in solution.

  19. Chronic administration of the dopamine D2/3 agonist ropinirole invigorates performance of a rodent slot machine task, potentially indicative of less distractible or compulsive-like gambling behaviour.

    Science.gov (United States)

    Cocker, Paul J; Tremblay, M; Kaur, S; Winstanley, Catharine A

    2017-01-01

    Whilst dopamine agonist therapies can successfully manage the symptoms of diseases such as Parkinson's disease (PD), fibromyalgia and restless leg syndrome, they can also cause impulse control and addiction disorders such as gambling disorder (GD). These compulsive behaviours seriously undermine the utility of such treatments. The objective of the study was to model this phenomenon using a rodent slot machine task (rSMT) in order to investigate the neurobiological basis underlying such behavioural changes. Male Long Evans rats were trained to perform the rSMT. The D 2 -like agonist ropinirole, or saline, was then delivered continuously for 28 days via osmotic mini-pump. The effects of ropinirole on baseline rSMT performance, as well as extinction and reinstatement sessions, were determined during this time. Brain samples from key frontostriatal regions implicated in GD and PD were then harvested immediately or after a 4-week washout period during which behaviour returned to pre-drug baseline. Ropinirole invigorated task performance, in that drug treatment resulted in a robust and sustained increase in the number of trials completed. Ex vivo analyses revealed that chronic ropinirole treatment led to a pattern of changes indicative of upregulation within the β-arrestin-AKT-GSK3β intracellular cascade, recently theorised to dominate D 2 -mediated signalling under hyperdopaminergic conditions, in the dorsal striatum, rather than the canonical PKA-dependent signalling pathway associated with D 2 receptor activation. Such findings provide novel insight into the role of dopamine signalling in mediating compulsive-like gambling behaviour and may inform more directed pharmacotherapies for the treatment of both idiopathic and iatrogenic GD.

  20. The effects of exogenous proline and osmotic stress on morpho ...

    African Journals Online (AJOL)

    USER

    2010-06-21

    Jun 21, 2010 ... For evaluation of growth parameters of strawberry callus under osmotic stress and exogenous proline, embryonic calli were transferred to Murashige and Skoog (MS) medium containing four sucrose. (osmotic stress) treatments including 3, 6, 9 and 12% and various concentrations of exogenous L- proline ...

  1. The effects of exogenous proline and osmotic stress on morpho ...

    African Journals Online (AJOL)

    For evaluation of growth parameters of strawberry callus under osmotic stress and exogenous proline, embryonic calli were transferred to Murashige and Skoog (MS) medium containing four sucrose (osmotic stress) treatments including 3, 6, 9 and 12% and various concentrations of exogenous Lproline (0, 2.5, 5 and 10 ...

  2. Osmotic Power: A Fresh Look at an Old Experiment

    Science.gov (United States)

    Dugdale, Pam

    2014-01-01

    Electricity from osmotic pressure might seem a far-fetched idea but this article describes a prototype in Norway where the osmotic pressure generated between salt and fresh water drives a turbine. This idea was applied in a student investigation, where they were tasked with researching which alternative materials could be used for the…

  3. 21 CFR 864.6600 - Osmotic fragility test.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Osmotic fragility test. 864.6600 Section 864.6600 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES HEMATOLOGY AND PATHOLOGY DEVICES Manual Hematology Devices § 864.6600 Osmotic fragility...

  4. Improved Erythrocyte Osmotic Fragility and Packed Cell Volume ...

    African Journals Online (AJOL)

    Improved Erythrocyte Osmotic Fragility and Packed Cell Volume following administration of Aloe barbadensis Juice Extract in Rats. ... Abstract. Aloe barbadensis is a popular house plant that has a long history of a multipurpose folk remedy. ... Keywords: osmotic fragility, packed cell volume, haemoglobin, Aloe vera ...

  5. Osmotic mechanism of the loop extrusion process

    Science.gov (United States)

    Yamamoto, Tetsuya; Schiessel, Helmut

    2017-09-01

    The loop extrusion theory assumes that protein factors, such as cohesin rings, act as molecular motors that extrude chromatin loops. However, recent single molecule experiments have shown that cohesin does not show motor activity. To predict the physical mechanism involved in loop extrusion, we here theoretically analyze the dynamics of cohesin rings on a loop, where a cohesin loader is in the middle and unloaders at the ends. Cohesin monomers bind to the loader rather frequently and cohesin dimers bind to this site only occasionally. Our theory predicts that a cohesin dimer extrudes loops by the osmotic pressure of cohesin monomers on the chromatin fiber between the two connected rings. With this mechanism, the frequency of the interactions between chromatin segments depends on the loading and unloading rates of dimers at the corresponding sites.

  6. Isolated Extrapontine Myelinolysis of Osmotic Demyelination Syndrome

    Directory of Open Access Journals (Sweden)

    Ömer Yılmaz

    2013-01-01

    Full Text Available The osmotic demyelination syndrome (ODS has been identified as a complication of the rapid correction of hyponatremia for decades (King and Rosner, 2010. However, in recent years, a variety of other medical conditions have been associated with the development of ODS, independent of changes in serum sodium which cause a rapid changes in osmolality of the interstitial (extracellular compartment of the brain leading to dehydration of energy-depleted cells with subsequent axonal damage that occurs in characteristic areas (King and Rosner, 2010. Slow correction of the serum sodium concentration and additional administration of corticosteroids seems to be a major prevention step in ODS patients. In the current report we aimed to share a rare case which we observed in our clinic.

  7. Toward an injectable continuous osmotic glucose sensor.

    Science.gov (United States)

    Johannessen, Erik; Krushinitskaya, Olga; Sokolov, Andrey; Philipp, Häfliger; Hoogerwerf, Arno; Hinderling, Christian; Kautio, Kari; Lenkkeri, Jaakko; Strömmer, Esko; Kondratyev, Vasily; Tønnessen, Tor Inge; Mollnes, Tom Eirik; Jakobsen, Henrik; Zimmer, Even; Akselsen, Bengt

    2010-07-01

    The growing pandemic of diabetes mellitus places a stringent social and economic burden on the society. A tight glycemic control circumvents the detrimental effects, but the prerogative is the development of new more effective tools capable of longterm tracking of blood glucose (BG) in vivo. Such discontinuous sensor technologies will benefit from an unprecedented marked potential as well as reducing the current life expectancy gap of eight years as part of a therapeutic regime. A sensor technology based on osmotic pressure incorporates a reversible competitive affinity assay performing glucose-specific recognition. An absolute change in particles generates a pressure that is proportional to the glucose concentration. An integrated pressure transducer and components developed from the silicon micro- and nanofabrication industry translate this pressure into BG data. An in vitro model based on a 3.6 x 8.7 mm large pill-shaped implant is equipped with a nanoporous membrane holding 4-6 nm large pores. The affinity assay offers a dynamic range of 36-720 mg/dl with a resolution of +/-16 mg/dl. An integrated 1 x 1 mm(2) large control chip samples the sensor signals for data processing and transmission back to the reader at a total power consumption of 76 microW. Current studies have demonstrated the design, layout, and performance of a prototype osmotic sensor in vitro using an affinity assay solution for up to four weeks. The small physical size conforms to an injectable device, forming the basis of a conceptual monitor that offers a tight glycemic control of BG. 2010 Diabetes Technology Society.

  8. Salt Effect on Osmotic Pressure of Polyelectrolyte Solutions: Simulation Study

    Directory of Open Access Journals (Sweden)

    Jan-Michael Y. Carrillo

    2014-07-01

    Full Text Available Abstract: We present results of the hybrid Monte Carlo/molecular dynamics simulations of the osmotic pressure of salt solutions of polyelectrolytes. In our simulations, we used a coarse-grained representation of polyelectrolyte chains, counterions and salt ions. During simulation runs, we alternate Monte Carlo and molecular dynamics simulation steps. Monte Carlo steps were used to perform small ion exchange between simulation box containing salt ions (salt reservoir and simulation box with polyelectrolyte chains, counterions and salt ions (polyelectrolyte solution. This allowed us to model Donnan equilibrium and partitioning of salt and counterions across membrane impermeable to polyelectrolyte chains. Our simulations have shown that the main contribution to the system osmotic pressure is due to salt ions and osmotically active counterions. The fraction of the condensed (osmotically inactive counterions first increases with decreases in the solution ionic strength then it saturates. The reduced value of the system osmotic coefficient is a universal function of the ratio of the concentration of osmotically active counterions and salt concentration in salt reservoir. Simulation results are in a very good agreement with osmotic pressure measurements in sodium polystyrene sulfonate, DNA, polyacrylic acid, sodium polyanetholesulfonic acid, polyvinylbenzoic acid, and polydiallyldimethylammonium chloride solutions.

  9. Self-assembly of silk fibroin under osmotic stress

    Science.gov (United States)

    Sohn, Sungkyun

    The supramolecular self-assembly behavior of silk fibroin was investigated using osmotic stress technique. In Chapter 2, a ternary phase diagram of water-silk-LiBr was constructed based on X-ray results on the osmotically stressed regenerated silk fibroin of Bombyx mori silkworm. Microscopic data indicated that silk I is a hydrated structure and a rough estimate of the number of water molecules lost by the structure upon converting from silk I to silk II has been made, and found to be about 2.2 per [GAGAGS] hexapeptide. In Chapter 3, wet-spinning of osmotically stressed, regenerated silk fibroin was performed, based on the prediction that the enhanced control over structure and phase behavior using osmotic stress method helps improve the physical properties of wet-spun regenerated silk fibroin fibers. The osmotic stress was applied in order to pre-structure the regenerated silk fibroin molecule from its original random coil state to more oriented state, manipulating the phase of the silk solution in the phase diagram before the start of spinning. Monofilament fiber with a diameter of 20 microm was produced. In Chapter 4, we investigated if there is a noticeable synergistic osmotic pressure increase between co-existing polymeric osmolyte and salt when extremely highly concentrated salt molecules are present both at sample subphase and stressing subphase, as is the case of silk fibroin self-assembly. The equilibration method that measures osmotic pressure relative to a reference with known osmotic pressure was introduced. Osmotic pressure of aqueous LiBr solution up to 2.75M was measured and it was found that the synergistic effect was insignificant up to this salt concentration. Solution parameters of stressing solutions and Arrhenius kinetics based on time-temperature relationship for the equilibration process were derived as well. In Chapter 5, self-assembly behavior of natural silk fibroin within the gland of Bombyx mori silkworm was investigated using osmotic

  10. Mechanism of actuation in conducting polymers: Osmotic expansion

    DEFF Research Database (Denmark)

    Bay, Lasse; Jacobsen, Torben; West, Keld

    2001-01-01

    Conducting polymers expand or contract when their redox state is changed. This expansion/contraction effect can be separated in an intrinsic part because of changes of the polymer backbone on reduction/oxidation and a part depending on the surrounding electrolyte phase, because of osmotic expansion...... is compared with measurements on PPy(DBS) films. The experiments show that the expansion decreases as the electrolyte concentration is increased. This means that a considerable part of the total expansion is due to the osmotic effect. The osmotic effect should be taken into account when interpreting...

  11. Differential behavioral effects of the antidepressants reboxetine, fluoxetine, and moclobemide in a modified forced swim test following chronic treatment.

    Science.gov (United States)

    Cryan, John F; Page, Michelle E; Lucki, Irwin

    2005-11-01

    The forced swim test (FST) is the most widely used model for assessing potential antidepressant activity in rodents following acute or short-term treatment. However, few studies have compared the effects of short- and long-term antidepressant treatment on behaviors in the test, despite the need to treat patients chronically to produce clinical effects. The current studies examined whether antidepressants from different classes produce different behavioral effects following short-term treatment and whether such effects change following administration for a longer duration. The effects of administering short-term (3 days) and long-term (14 days) treatments of antidepressants from three different chemical classes with distinct mechanisms of action via osmotic minipump were examined: the selective norepinephrine reuptake inhibitor reboxetine (10 and 60 mg kg(-1) day(-1)), the selective serotonin reuptake inhibitor fluoxetine (2.5 and 15 mg kg(-1) day(-1)), and the reversible inhibitor of monoamine oxidase moclobemide (2.5 and 15 mg kg(-1) day(-1)). All testing was carried out in a 15-min test with no preswim session in order to negate any confounding aspect of an induction procedure. The majority of antidepressant-sensitive behavioral changes were observed in the first 5 min of the test. The low dose of reboxetine failed to alter behavior in the test after 3 days but significantly decreased immobility and increased climbing behavior following administration for 14 days, whereas the high dose of reboxetine was equally effective following 3 and 14 days of treatment. In a similar fashion, the low dose of fluoxetine failed to alter behavior in the test following 3 days, but showed an augmented response on immobility and increased swimming following administration for 14 days. The high dose of fluoxetine was slightly more effective at reducing immobility following administration for 14 days than 3 days. The low dose of moclobemide decreased immobility and increased climbing

  12. Chronic intracerebroventricular morphine and lactation in rats: dependence and tolerance in relation to oxytocin neurones.

    Science.gov (United States)

    Rayner, V C; Robinson, I C; Russell, J A

    1988-02-01

    1. Acutely, opioids inhibit oxytocin secretion. To study the responses of oxytocin neurones during chronic opioid exposure, forty-five lactating rats were infused continuously from a subcutaneous osmotically driven mini-pump via a lateral cerebral ventricle with morphine sulphate solution from day 2 post-partum for 5-7 days; the infusion rate was increased 2- or 2.5-fold each 40 h from 10 micrograms/h initially up to 50 micrograms/h; controls were infused with vehicle (1 microliter/h, twenty-eight rats) or were untreated (eight rats). 2. Maternal behaviour was disrupted in 27% of the morphine-treated rats; in rats that remained maternal morphine did not affect body weight or water intake but increased rectal temperature by 0.82 +/- 0.14 degrees C (mean +/- S.E.M.) across the first 4 days. 3. Weight gain of the litters of maternal morphine-treated rats was reduced by 32% during 7 days, predominantly in the first day of treatment when milk transfer was also reduced. Observation of pup behaviour during suckling showed decreased frequency of milk ejections on only the second day of morphine treatment. Plasma concentration of prolactin after 6 days was similar in maternal morphine-treated and control rats, but reduced by 90% in non-maternal morphine-treated rats, indicating normal control of prolactin secretion by suckling in morphine-treated rats. 4. Oxytocin and vasopressin contents, measured by radioimmunoassay, in the supraoptic and paraventricular nuclei and in the neurohypophysis were similar between fourteen maternal morphine-treated, twelve vehicle-treated and eight untreated lactating rats; thus exposure to morphine did not involve increased production and storage of oxytocin. 5. Distribution of [3H]morphine infused intracerebroventricularly into six virgin female rats for 6 days was measured by scintillation counting of tissue extracts. Morphine concentration in the hypothalamus and neurohypophysis was 2.7 and 12.8 micrograms/g, respectively, and in blood

  13. Efficiency of Osmotic Dehydration of Apples in Polyols Solutions

    Directory of Open Access Journals (Sweden)

    Joanna Cichowska

    2018-02-01

    Full Text Available The present study aimed to evaluate the influence of selected compounds from the polyol group, as well as other saccharides, on the osmotic dehydration process of apples. The following alternative solutions were examined: erythritol, xylitol, maltitol, inulin and oligofructose. Efficiency of the osmotic dehydration process was evaluated based on the kinetics of the process, and through comparison of the results obtained during the application of a sucrose solution. This innovative research utilizes alternative solutions in osmotic pretreatment, which until now, have not been commonly used in fruit processing by researchers worldwide. Results indicate that erythritol and xylitol show stronger or similar efficiency to sucrose; however, the use of inulin, as well as oligofructose, was not satisfactory due to the insufficient, small osmotic driving forces of the process, and the low values of mass transfer parameters.

  14. Efficiency of Osmotic Dehydration of Apples in Polyols Solutions.

    Science.gov (United States)

    Cichowska, Joanna; Żubernik, Joanna; Czyżewski, Jakub; Kowalska, Hanna; Witrowa-Rajchert, Dorota

    2018-02-17

    The present study aimed to evaluate the influence of selected compounds from the polyol group, as well as other saccharides, on the osmotic dehydration process of apples. The following alternative solutions were examined: erythritol, xylitol, maltitol, inulin and oligofructose. Efficiency of the osmotic dehydration process was evaluated based on the kinetics of the process, and through comparison of the results obtained during the application of a sucrose solution. This innovative research utilizes alternative solutions in osmotic pretreatment, which until now, have not been commonly used in fruit processing by researchers worldwide. Results indicate that erythritol and xylitol show stronger or similar efficiency to sucrose; however, the use of inulin, as well as oligofructose, was not satisfactory due to the insufficient, small osmotic driving forces of the process, and the low values of mass transfer parameters.

  15. Method of osmotic energy harvesting using responsive compounds and molecules

    KAUST Repository

    Hu, Xiao; Cai, Yufeng; Lai, Zhiping; Zhong, Yujiang

    2017-01-01

    The present invention discloses and claims a more efficient and economical method and system for osmotic energy production and capture using responsive compounds and molecules. The present invention is an energy harvest system enabled by stimuli

  16. Plant response to sunflower seeds to osmotic conditioning

    Directory of Open Access Journals (Sweden)

    Camila Santos Barros de Morais

    2014-10-01

    Full Text Available The aim of this study was to evaluate the effect of seeds osmotic conditioning in seedlings emergence and plants performance of sunflower. Three lots of seeds sunflower (Catissol, was submited to osmotic conditioning with polyethylene glycol solution, –2,0 MPa in aerated system, under 15 ºC for 8 hour and then was evaluated for germination tests and vigour. Under filed conditions was conducted emergency evaluations of seedling, plants development as well as the productivity and seeds quality, and the accumulation of nutrients in the seeds. The osmotic conditioning improve the survival of seedling, the dry matter mass to aerial part of plants from 60 days after sowing and oil content, in lots with low seeds physiological quality. The osmotic conditioning not increase the seeds yield but promotes the vigour of seeds produced, regardless of the lot used for sowing seeds.

  17. A physiological evaluation of the enhanced osmotic stress tolerance ...

    African Journals Online (AJOL)

    ELO

    2012-01-05

    Jan 5, 2012 ... SR3 and Jinan 177 were hydroponically subjected to osmotic stress, the accumulation of proline .... hydroponically in half strength Hoagland's solution for three weeks ..... ascrobate specific peroxidase in spinach chloroplasts.

  18. Method of osmotic energy harvesting using responsive compounds and molecules

    KAUST Repository

    Hu, Xiao

    2017-07-27

    The present invention discloses and claims a more efficient and economical method and system for osmotic energy production and capture using responsive compounds and molecules. The present invention is an energy harvest system enabled by stimuli responsive draw solutions that are competent in terms of energy production, geographic location flexibility, and the affordable, efficient and economical production and delivery of osmotic power. Specifically, the present invention is a novel osmotic power system that uses stimuli responsive draw solutions, economically feasible larger permeable membranes, and low grade heat sources to deliver osmotic power more efficiently and economically with less negative environmental impact, greater power output, and located in more geographically diverse areas of the world than previously thought possible for supporting such a power source.

  19. Experimental Support for a Predictive Osmotic Model of Clay Membranes

    International Nuclear Information System (INIS)

    Fritz, S.J.

    2001-01-01

    Osmosis has been cited as a mechanism for explaining anomalously high fluid pressures in the subsurface. Clays and shales act as membranes, and osmotic flux across these units may result in pressures sufficiently high to explain these anomalies. The theoretical osmotic pressures as calculated solely from solution properties can be quite large; however, it is not yet resolved whether these geologic membranes are sufficiently ideal to generate such pressures

  20. Osmotic and stimulant laxatives for the management of childhood constipation

    OpenAIRE

    Gordon, Morris; Macdonald, John; Parker, Claire; Akobeng, Anthony; Thomas, Adrian

    2016-01-01

    Background\\ud \\ud Constipation within childhood is an extremely common problem. Despite the widespread use of osmotic and stimulant laxatives by health professionals to manage constipation in children, there has been a long standing paucity of high quality evidence to support this practice.\\ud \\ud \\ud Objectives\\ud \\ud We set out to evaluate the efficacy and safety of osmotic and stimulant laxatives used to treat functional childhood constipation.\\ud \\ud \\ud Search methods\\ud \\ud We searched ...

  1. Osmotic pressure in a bacterial swarm.

    Science.gov (United States)

    Ping, Liyan; Wu, Yilin; Hosu, Basarab G; Tang, Jay X; Berg, Howard C

    2014-08-19

    Using Escherichia coli as a model organism, we studied how water is recruited by a bacterial swarm. A previous analysis of trajectories of small air bubbles revealed a stream of fluid flowing in a clockwise direction ahead of the swarm. A companion study suggested that water moves out of the agar into the swarm in a narrow region centered ∼ 30 μm from the leading edge of the swarm and then back into the agar (at a smaller rate) in a region centered ∼ 120 μm back from the leading edge. Presumably, these flows are driven by changes in osmolarity. Here, we utilized green/red fluorescent liposomes as reporters of osmolarity to verify this hypothesis. The stream of fluid that flows in front of the swarm contains osmolytes. Two distinct regions are observed inside the swarm near its leading edge: an outer high-osmolarity band (∼ 30 mOsm higher than the agar baseline) and an inner low-osmolarity band (isotonic or slightly hypotonic to the agar baseline). This profile supports the fluid-flow model derived from the drift of air bubbles and provides new (to our knowledge) insights into water maintenance in bacterial swarms. High osmotic pressure at the leading edge of the swarm extracts water from the underlying agar and promotes motility. The osmolyte is of high molecular weight and probably is lipopolysaccharide. Copyright © 2014 Biophysical Society. Published by Elsevier Inc. All rights reserved.

  2. Osmotic dehydration of fruits and vegetables: a review.

    Science.gov (United States)

    Yadav, Ashok Kumar; Singh, Satya Vir

    2014-09-01

    The main cause of perishability of fruits and vegetables are their high water content. To increase the shelf life of these fruits and vegetables many methods or combination of methods had been tried. Osmotic dehydration is one of the best and suitable method to increase the shelf life of fruits and vegetables. This process is preferred over others due to their vitamin and minerals, color, flavor and taste retention property. In this review different methods, treatments, optimization and effects of osmotic dehydration have been reviewed. Studied showed that combination of different osmotic agents were more effective than sucrose alone due to combination of properties of solutes. During the experiments it was found that optimum osmosis was found at approximately 40 °C, 40 °B of osmotic agent and in near about 132 min. Pretreatments also leads to increase the osmotic process in fruits and vegetables. Mass transfer kinetics study is an important parameter to study osmosis. Solids diffusivity were found in wide range (5.09-32.77 kl/mol) studied by Fick's laws of diffusion. These values vary depending upon types of fruits and vegetables and osmotic agents.

  3. Mass transfer kinetics during osmotic dehydration of pomegranate arils.

    Science.gov (United States)

    Mundada, Manoj; Hathan, Bahadur Singh; Maske, Swati

    2011-01-01

    The mass transfer kinetics during osmotic dehydration of pomegranate arils in osmotic solution of sucrose was studied to increase palatability and shelf life of arils. The freezing of the whole pomegranate at -18 °C was carried out prior to osmotic dehydration to increase the permeability of the outer cellular layer of the arils. The osmotic solution concentrations used were 40, 50, 60°Bx, osmotic solution temperatures were 35, 45, 55 °C. The fruit to solution ratio was kept 1:4 (w/w) during all the experiments and the process duration varied from 0 to 240 min. Azuara model and Peleg model were the best fitted as compared to other models for water loss and solute gain of pomegranate arils, respectively. Generalized Exponential Model had an excellent fit for water loss ratio and solute gain ratio of pomegranate arils. Effective moisture diffusivity of water as well as solute was estimated using the analytical solution of Fick's law of diffusion. For above conditions of osmotic dehydration, average effective diffusivity of water loss and solute gain varied from 2.718 × 10(-10) to 5.124 × 10(-10) m(2)/s and 1.471 × 10(-10) to 5.147 × 10(-10) m(2)/s, respectively. The final product was successfully utilized in some nutritional formulations such as ice cream and bakery products.

  4. PHOTOMETRIC EVIDENCE FOR THE OSMOTIC BEHAVIOR OF RAT LIVER MICROSOMES

    Science.gov (United States)

    Tedeschi, Henry; James, Joseph M.; Anthony, William

    1963-01-01

    Electron microscope observations are consistent with the interpretation that the elements of the endoplasmic reticulum are osmotically active in situ as well as after isolation. More recently, it has been reported that microsomal suspensions equilibrate almost completely with added C14-sucrose and that no osmotic behavior is evident from photometric data. These findings were considered at variance with the electron microscope data. However, equilibration with added label simply attests to a relatively high permeability, and, in addition, the photometric data need not be critical. Osmotic volume changes, measured photometrically, may be masked by concomitant events (e.g., changes in the refractive index of the test solutions at varying osmotic pressures, breakdown of the particles, and agglutination). For these reasons the photometric experiments were repeated. In this work, the reciprocal of optical density of microsomal suspensions was found to vary linearly with the reciprocal of concentration of the medium at constant refractive index. These changes probably correspond to osmotic volume changes, since the effect was found to be (a) independent of substance used and (b) osmotically reversible. The transmission of the suspension was found to vary with the refractive index of the medium, the concentration of particles, and the wavelength of incident light, according to relationships that are similar to or identical with those obtained for mitochondrial suspensions. PMID:14064105

  5. [Chronic diarrhea with uncommon etiology].

    Science.gov (United States)

    Gil Borrás, R; Juan Vidal, O; Talavera Encinas, M I; Bixquert Jiménez, M

    2005-03-01

    Chronic diarrhea is a common syndrome. An etiological diagnosis is often reached through clinical history, physical examination and simple tests. In some cases, when the etiology is not found, the syndrome is called functional diarrhea, even though established criteria are often not fulfilled. We present the case of a patient with diarrhea for several months. The most common causes were ruled out through clinical history, physical examination, radiographic studies and laboratory tests, and the patient was diagnosed with functional diarrhea. Three months later, the patient presented a neck mass, and biopsy revealed medullary carcinoma of the thyroid. A review of recommendations for the systematic evaluation of chronic diarrhea is presented. A general approach should include careful history taking characteristics of diarrhea (onset, associated symptoms, epidemiological factors, iatrogenic causes such as laxative ingestion), a thorough physical examination with special attention to the anorectal region, and routine laboratory tests (complete blood count and serum chemistry). In addition, stool analysis including electrolytes (fecal osmotic gap), leukocytes, fecal occult blood, excess stool fat and laxative screening can yield important objective information to classify the diarrhea as: osmotic (osmotic gaps > 125 mOsm/Kg), secretory (osmotic gaps diarrhea described above. A systematic approach to the evaluation of chronic diarrhea is warranted. Medullary thyroid carcinoma and other endocrine syndromes causing chronic diarrhea are very rare. Measurement of serum peptide concentrations should only be performed when clinical presentation and findings in stool or radiographic studies suggest this etiology.

  6. Osmotic Compounds Enhance Antibiotic Efficacy against Acinetobacter baumannii Biofilm Communities.

    Science.gov (United States)

    Falghoush, Azeza; Beyenal, Haluk; Besser, Thomas E; Omsland, Anders; Call, Douglas R

    2017-10-01

    Biofilm-associated infections are a clinical challenge, in part because a hydrated matrix protects the bacterial community from antibiotics. Herein, we evaluated how different osmotic compounds (maltodextrin, sucrose, and polyethylene glycol [PEG]) enhance antibiotic efficacy against Acinetobacter baumannii biofilm communities. Established (24-h) test tube biofilms (strain ATCC 17978) were treated with osmotic compounds in the presence or absence of 10× the MIC of different antibiotics (50 μg/ml tobramycin, 20 μg/ml ciprofloxacin, 300 μg/ml chloramphenicol, 30 μg/ml nalidixic acid, or 100 μg/ml erythromycin). Combining antibiotics with hypertonic concentrations of the osmotic compounds for 24 h reduced the number of biofilm bacteria by 5 to 7 log ( P baumannii strains were similarly treated with 400-Da PEG and tobramycin, resulting in a mean 2.7-log reduction in recoverable bacteria compared with tobramycin treatment alone. Multivariate regression models with data from different osmotic compounds and nine antibiotics demonstrated that the benefit from combining hypertonic treatments with antibiotics is a function of antibiotic mass and lipophilicity ( r 2 > 0.82; P baumannii and Escherichia coli K-12. Augmenting topical antibiotic therapies with a low-mass hypertonic treatment may enhance the efficacy of antibiotics against wound biofilms, particularly when using low-mass hydrophilic antibiotics. IMPORTANCE Biofilms form a barrier that protects bacteria from environmental insults, including exposure to antibiotics. We demonstrated that multiple osmotic compounds can enhance antibiotic efficacy against Acinetobacter baumannii biofilm communities, but viscosity is a limiting factor, and the most effective compounds have lower molecular mass. The synergism between osmotic compounds and antibiotics is also dependent on the hydrophobicity and mass of the antibiotics. The statistical models presented herein provide a basis for predicting the optimal combination of

  7. Transcriptional evidence for the role of chronic venlafaxine treatment in neurotrophic signaling and neuroplasticity including also Glutamatergic [corrected] - and insulin-mediated neuronal processes.

    Directory of Open Access Journals (Sweden)

    Viola Tamási

    Full Text Available Venlafaxine (VLX, a serotonine-noradrenaline reuptake inhibitor, is one of the most commonly used antidepressant drugs in clinical practice for the treatment of major depressive disorder (MDD. Despite being more potent than its predecessors, similarly to them, the therapeutical effect of VLX is visible only 3-4 weeks after the beginning of treatment. Furthermore, recent papers show that antidepressants, including also VLX, enhance the motor recovery after stroke even in non depressed persons. In the present, transcriptomic-based study we looked for changes in gene expressions after a long-term VLX administration.Osmotic minipumps were implanted subcutaneously into Dark Agouti rats providing a continuous (40 mg/kg/day VLX delivery for three weeks. Frontal regions of the cerebral cortex were isolated and analyzed using Illumina bead arrays to detect genes showing significant chances in expression. Gene set enrichment analysis was performed to identify specific regulatory networks significantly affected by long term VLX treatment.Chronic VLX administration may have an effect on neurotransmitter release via the regulation of genes involved in vesicular exocytosis and receptor endocytosis (such as Kif proteins, Myo5a, Sv2b, Syn2 or Synj2. Simultaneously, VLX activated the expression of genes involved in neurotrophic signaling (Ntrk2, Ntrk3, glutamatergic transmission (Gria3, Grin2b and Grin2a, neuroplasticity (Camk2g/b, Cd47, synaptogenesis (Epha5a, Gad2 and cognitive processes (Clstn2. Interestingly, VLX increased the expression of genes involved in mitochondrial antioxidant activity (Bcl2 and Prdx1. Additionally, VLX administration also modulated genes related to insulin signaling pathway (Negr1, Ppp3r1, Slc2a4 and Enpp1, a mechanism that has recently been linked to neuroprotection, learning and memory.Our results strongly suggest that chronic VLX treatment improves functional reorganization and brain plasticity by influencing gene expression in

  8. Structure and osmotic pressure of ionic microgel dispersions

    Energy Technology Data Exchange (ETDEWEB)

    Hedrick, Mary M. [Department of Physics, North Dakota State University, Fargo, North Dakota 58108-6050 (United States); Department of Chemistry and Biochemistry, North Dakota State University, Fargo, North Dakota 58108-6050 (United States); Chung, Jun Kyung; Denton, Alan R., E-mail: alan.denton@ndsu.edu [Department of Physics, North Dakota State University, Fargo, North Dakota 58108-6050 (United States)

    2015-01-21

    We investigate structural and thermodynamic properties of aqueous dispersions of ionic microgels—soft colloidal gel particles that exhibit unusual phase behavior. Starting from a coarse-grained model of microgel macroions as charged spheres that are permeable to microions, we perform simulations and theoretical calculations using two complementary implementations of Poisson-Boltzmann (PB) theory. Within a one-component model, based on a linear-screening approximation for effective electrostatic pair interactions, we perform molecular dynamics simulations to compute macroion-macroion radial distribution functions, static structure factors, and macroion contributions to the osmotic pressure. For the same model, using a variational approximation for the free energy, we compute both macroion and microion contributions to the osmotic pressure. Within a spherical cell model, which neglects macroion correlations, we solve the nonlinear PB equation to compute microion distributions and osmotic pressures. By comparing the one-component and cell model implementations of PB theory, we demonstrate that the linear-screening approximation is valid for moderately charged microgels. By further comparing cell model predictions with simulation data for osmotic pressure, we chart the cell model’s limits in predicting osmotic pressures of salty dispersions.

  9. Drying characteristics of osmotically pretreated cranberries : Energy and quality aspects

    Energy Technology Data Exchange (ETDEWEB)

    Grabowski, S.; Marcotte, M. [Agriculture and Agri-Food Canada, St. Hyacinthe, PQ (Canada). Food Research and Development Centre; Poirier, M.; Kudra, T. [Natural Resources Canada, Varennes, PQ (Canada). CANMET Energy Technology Centre

    2002-06-01

    This paper presents the results of a study in which osmotically pretreated cranberries were dried. The osmotic treatment included dehydration and sugar infusion. The process involved pretreating halved cranberries in a standard osmotic solution followed by freeze-drying, vacuum-drying and air-drying in various dryers, such as cabinet-air-through, fluid bed, pulsed fluid bed, and vibrated fluid bed dryers. The intent was to identify the best drying technology. The comparison criteria selected were energy consumption and product quality. Product quality for freeze-dried berries was quantified based on anthocyanins content, rehydration ratio, color, and taste. Unit heat consumption could be used for selecting the drying method, as all other drying methods yielded similar but slightly lower quality products. The highest energy efficiency was obtained with the vibrated fluid bed and the pulsed fluid bed. It was noted that drying rates were reduced during the second drying period when sugar was infused into the cranberries during osmotic pretreatment, but the total energy consumption was reduced by osmotic dehydration. 22 refs., 1 tab., 5 figs.

  10. Drying and osmotic conditioning in Hancornia speciosa Gomes seeds

    Directory of Open Access Journals (Sweden)

    Tathiana Elisa Masetto

    Full Text Available Hancornia speciosa is a native tree species of the Brazilian Cerrado whose seeds are desiccation sensitive. In this study, we aimed to evaluate drying and osmotic conditioning in H. speciosa seeds. We used fresh seeds with 48% moisture content, which were slowly dried until they attained contents of 20%, 15%, 10% and 5%. To evaluate osmotic conditioning, the seeds were imbibed in 12 mL osmotic solutions at 0.0; -0.2; -0.4 and -0.6 MPa for two days. After that, they were dehydrated until their original moisture content. The experiments were carried out in a completely randomized design with four repetitions with 50 seeds each. Reduction in moisture content from 20% to 5% decreased the physiological potential of seeds. H. speciosa seeds do not require osmotic priming with PEG solutions, because imbibition of seeds in osmotic solutions of up to -0.6 MPa results in reduction of germination rate and seedling length.

  11. Quantification of osmotic water transport in vivo using fluorescent albumin.

    Science.gov (United States)

    Morelle, Johann; Sow, Amadou; Vertommen, Didier; Jamar, François; Rippe, Bengt; Devuyst, Olivier

    2014-10-15

    Osmotic water transport across the peritoneal membrane is applied during peritoneal dialysis to remove the excess water accumulated in patients with end-stage renal disease. The discovery of aquaporin water channels and the generation of transgenic animals have stressed the need for novel and accurate methods to unravel molecular mechanisms of water permeability in vivo. Here, we describe the use of fluorescently labeled albumin as a reliable indicator of osmotic water transport across the peritoneal membrane in a well-established mouse model of peritoneal dialysis. After detailed evaluation of intraperitoneal tracer mass kinetics, the technique was validated against direct volumetry, considered as the gold standard. The pH-insensitive dye Alexa Fluor 555-albumin was applied to quantify osmotic water transport across the mouse peritoneal membrane resulting from modulating dialysate osmolality and genetic silencing of the water channel aquaporin-1 (AQP1). Quantification of osmotic water transport using Alexa Fluor 555-albumin closely correlated with direct volumetry and with estimations based on radioiodinated ((125)I) serum albumin (RISA). The low intraperitoneal pressure probably accounts for the negligible disappearance of the tracer from the peritoneal cavity in this model. Taken together, these data demonstrate the appropriateness of pH-insensitive Alexa Fluor 555-albumin as a practical and reliable intraperitoneal volume tracer to quantify osmotic water transport in vivo. Copyright © 2014 the American Physiological Society.

  12. Structure and osmotic pressure of ionic microgel dispersions

    International Nuclear Information System (INIS)

    Hedrick, Mary M.; Chung, Jun Kyung; Denton, Alan R.

    2015-01-01

    We investigate structural and thermodynamic properties of aqueous dispersions of ionic microgels—soft colloidal gel particles that exhibit unusual phase behavior. Starting from a coarse-grained model of microgel macroions as charged spheres that are permeable to microions, we perform simulations and theoretical calculations using two complementary implementations of Poisson-Boltzmann (PB) theory. Within a one-component model, based on a linear-screening approximation for effective electrostatic pair interactions, we perform molecular dynamics simulations to compute macroion-macroion radial distribution functions, static structure factors, and macroion contributions to the osmotic pressure. For the same model, using a variational approximation for the free energy, we compute both macroion and microion contributions to the osmotic pressure. Within a spherical cell model, which neglects macroion correlations, we solve the nonlinear PB equation to compute microion distributions and osmotic pressures. By comparing the one-component and cell model implementations of PB theory, we demonstrate that the linear-screening approximation is valid for moderately charged microgels. By further comparing cell model predictions with simulation data for osmotic pressure, we chart the cell model’s limits in predicting osmotic pressures of salty dispersions

  13. Magnetic resonance studies on the brain edema by the administration of the osmotic agents

    International Nuclear Information System (INIS)

    Niino, Masaki; Asakura, Tetsuhiko; Nakamura, Katsumi; Yatsushiro, Kazutaka; Kadota, Koki; Sasahira, Masahiro; Fujimoto, Toshiro; Shimooki, Susumu.

    1990-01-01

    Changes of proton relaxation times (T 1 and T 2 ) and MR imaging of the brain edema by the administration of the osmotic agents (mannitol or glycerol) were studied. Subjects were 11 patients who were composed of 4 gliomas, 2 metastatic brain tumors, 2 meningiomas, 2 hypertensive intracerebral hematomas, and a C-P angle tumor. 20% mannitol or 10% glycerol 550 ml was rapidly injected intravenously. Scanning was done before injection, just after injection, and post injection until 2 hours with passing times. We regarded the peritumoral or perihemorrahgical low density area on the CT scan as the edema, and then, relaxation times of the edema was obtained from the ROI of the calculated images corresponding to the surrounding low density area on the CT scan. The results were as follows. 1) In general, relaxation times of the edema showed a tendency to decrease after injection of the osmotic agents. Normal white matter, in the same way, showed the decreasing tendency, but the degree of the decreasing was more clearly in the edematous areas than in the white matter. 2) The changes of relaxation times did not show a uniform pattern. In most cases, relaxation times decreased just after injection. But in a few cases, relaxation times increased just after injection, transiently. In some cases, decreased relaxation times continued more than 2 hours, in the other cases, relaxation times increased at 2 hours. 3) The changes of relaxation times thought to be varied by some factors, that is --kinds of the lesions causing edema, degree of malignancy of the lesions, or phase of edema (acute or chronic) etc. 4) Osmotic agents were supposed to dehydrate the edematous lesions. In the current MR systems, there are considerably large standard deviations and inequality in the magnetic field, therefore, further investigations should be done moreover. (author)

  14. Detection of osmotic damages in GRP boat hulls

    Science.gov (United States)

    Krstulović-Opara, L.; Domazet, Ž.; Garafulić, E.

    2013-09-01

    Infrared thermography as a tool of non-destructive testing is method enabling visualization and estimation of structural anomalies and differences in structure's topography. In presented paper problem of osmotic damage in submerged glass reinforced polymer structures is addressed. The osmotic damage can be detected by a simple humidity gauging, but for proper evaluation and estimation testing methods are restricted and hardly applicable. In this paper it is demonstrated that infrared thermography, based on estimation of heat wave propagation, can be used. Three methods are addressed; Pulsed thermography, Fast Fourier Transform and Continuous Morlet Wavelet. An additional image processing based on gradient approach is applied on all addressed methods. It is shown that the Continuous Morlet Wavelet is the most appropriate method for detection of osmotic damage.

  15. Osmotic stress tolerance in semi-terrestrial tardigrades

    DEFF Research Database (Denmark)

    Heidemann, Nanna W T; Smith, Daniel K.; Hygum, Thomas L.

    2016-01-01

    Little is known about ionic and osmotic stress tolerance in tardigrades. Here, we examine salt stress tolerance in Ramazzottius oberhaeuseri and Echiniscus testudo from Nivå (Denmark) and address whether limno-terrestrial tardigrades can enter a state of quiescence (osmobiosis) in the face of high......-ionic osmolytes as compared to NaCl. Ramazzottius oberhaeuseri furthermore readily regained activity following gradual increases in non-ionic osmolytes and NaCl of up to 2434 ± 28 and 1905 ± 3 mOsm kg−1, respectively, showing that short-term acclimation promoted salt stress tolerance. Our results suggest...... that the limno-terrestrial R. oberhaeuseri enters a state of quiescence in the face of high external osmotic pressure and that it, in this state, is highly tolerant of ionic and osmotic stress....

  16. Solute Transfer in Osmotic Dehydration of Vegetable Foods: A Review.

    Science.gov (United States)

    Muñiz-Becerá, Sahylin; Méndez-Lagunas, Lilia L; Rodríguez-Ramírez, Juan

    2017-10-01

    While various mechanisms have been proposed for the water transfer during osmotic dehydration (OD), little progress has been made to understand the mechanisms of solute transfer during osmotic dehydration. The transfer of solutes has been often described only by the diffusion mechanism; however, numerous evidences suggest the participation of a variety of mechanisms. This review deals with the main issues of solute transfer in the OD of vegetables. In this context, several studies suggest that during OD of fruits and vegetables, the migration of solutes is not influenced by diffusion. Thus, new theories that may explain the solute transport are analyzed, considering the influence of the plant microstructure and its interaction with the physicochemical properties of osmotic liquid media. In particular, the surface adhesion phenomenon is analyzed and discussed, as a possible mechanism present during the transfer of solutes in OD. © 2017 Institute of Food Technologists®.

  17. Studies of Protein Solution Properties Using Osmotic Pressure Measurements

    Science.gov (United States)

    Agena, S.; Bogle, David; Pusey, Marc; Agena, S.

    1998-01-01

    Examination of the protein crystallization process involves investigation of the liquid and solid state and a protein's properties in these states. Liquid state studies such as protein self association in solution by light scattering methods or other methods have been used to examine a protein Is properties and therefore its crystallization process and conditions. Likewise can osmotic pressure data be used to examine protein properties and various published osmotic pressure studies were examined by us to correlate osmotic pressure to protein solution properties. The solution behavior of serum albumin, alpha - chymotrypsin, beta - lactoglobulin and ovalbumin was examined over a range of temperatures, pH values and different salt types and concentrations. Using virial expansion and a local composition model the non ideal solution behavior in form of the activity coefficients (thermodynamic) was described for the systems. This protein activity coefficient data was related to a protein's solubility behavior and this process and the results will be presented.

  18. Folding propensity of intrinsically disordered proteins by osmotic stress

    International Nuclear Information System (INIS)

    Mansouri, Amanda L.; Grese, Laura N.; Rowe, Erica L.

    2016-01-01

    Proteins imparted with intrinsic disorder conduct a range of essential cellular functions. To better understand the folding and hydration properties of intrinsically disordered proteins (IDPs), we used osmotic stress to induce conformational changes in nuclear co-activator binding domain (NCBD) and activator for thyroid hormone and retinoid receptor (ACTR). Osmotic stress was applied by the addition of small and polymeric osmolytes, where we discovered that water contributions to NCBD folding always exceeded those for ACTR. Both NCBD and ACTR were found to gain a-helical structure with increasing osmotic stress, consistent with their folding upon NCBD/ACTR complex formation. Using small-angle neutron scattering (SANS), we further characterized NCBD structural changes with the osmolyte ethylene glycol. Here a large reduction in overall size initially occurred before substantial secondary structural change. In conclusion, by focusing on folding propensity, and linked hydration changes, we uncover new insights that may be important for how IDP folding contributes to binding.

  19. Recycling of osmotic solutions in microwave-osmotic dehydration: product quality and potential for creation of a novel product.

    Science.gov (United States)

    Wray, Derek; Ramaswamy, Hosahalli S

    2016-08-01

    Despite osmotic dehydration being a cost effective process for moisture removal, the cost implications of making, regenerating, and properly disposing of the spent osmotic solutions contributes greatly to the economic feasibility of the drying operation. The potential for recycling of osmotic solutions and their use for creation of a novel product was explored using microwave-osmotic dehydration under continuous flow spray (MWODS) conditions. Identical runs were repeated 10 times to determine the progressive physical and compositional effects of the thermal treatment and leaching from the cranberry samples. The microbiological stability and constant drying performance indicated that MWODS would be well suited for employing recycled solutions. While the anthocyanin content of the solution never approached that of cranberry juice concentrate, it is demonstrated that the spent syrup can infuse these health positive components into another product (apple). This study found that re-using osmotic solutions is a viable option to reduce cost in future MWODS applications, with no detriment to product quality and potential to use the spent solution for novel products. © 2015 Society of Chemical Industry. © 2015 Society of Chemical Industry.

  20. Testing for Chronic Diarrhea.

    Science.gov (United States)

    Raman, M

    Chronic diarrhea is a frequently encountered symptom in clinical practice. The etiologies for chronic diarrhea are diverse and broad with varying clinical implications. A useful method of categorizing chronic diarrhea to guide a diagnostic work-up is a pathophysiology-based framework. Chronic diarrhea may be categorized as malabsorptive, secretory, osmotic, and inflammatory or motility related. Frequently, overlap between categories may exist for any given diarrhea etiology and diagnostic testing must occur with an understanding of the differential diagnosis. Investigations to achieve a diagnosis for chronic diarrhea range from screening blood and stool tests to more directed testing such as diagnostic imaging, and endoscopic and histological evaluation. The pathophysiology-based framework proposed in this chapter will allow the clinician to select screening tests followed by targeted tests to minimize cost and complications to the patient, while providing a highly effective method to achieve an accurate diagnosis. © 2017 Elsevier Inc. All rights reserved.

  1. The safety of osmotically acting cathartics in colonic cleansing

    DEFF Research Database (Denmark)

    Nyberg, Caroline; Hendel, J.; Nielsen, O.H.

    2010-01-01

    Efficient cleansing of the colon before a colonoscopy or a radiological examination is essential. The osmotically acting cathartics (those given the Anatomical Therapeutic Chemical code A06AD) currently used for this purpose comprise products based on three main substances: sodium phosphate...... hyperphosphatemia and irreversible kidney damage owing to acute phosphate nephropathy, have been reported after use of sodium-phosphate-based products. The aim of this Review is to provide an update on the potential safety issues related to the use of osmotically acting cathartics, especially disturbances of renal...

  2. Relation between lowered colloid osmotic pressure, respiratory failure, and death.

    Science.gov (United States)

    Tonnesen, A S; Gabel, J C; McLeavey, C A

    1977-01-01

    Plasma colloid osmotic pressure was measured each day in 84 intensive care unit patients. Probit analysis demonstrated a direct relationship between colloid osmotic pressure (COP) and survival. The COP associated with a 50% survival rate was 15.0 torr. COP was higher in survivors than in nonsurvivors without respiratory failure and in patients who recovered from respiratory failure. We conclude that lowered COP is associated with an elevated mortality rate. However, the relationship to death is not explained by the relationship to respiratory failure.

  3. Myocardial structural, contractile and electrophysiological changes in the guinea-pig heart failure model induced by chronic sympathetic activation

    DEFF Research Database (Denmark)

    Soltysinska, Ewa; Osadchiy, Oleg; Olesen, Søren-Peter

    2011-01-01

    Widely used murine models of adrenergic-induced cardiomyopathy offer little insight into electrical derangements seen in human heart failure owing to profound differences in the characteristics of ventricular repolarization in mice and rats compared with humans. We therefore sought to determine...... whether sustained adrenergic activation may produce a clinically relevant heart failure phenotype in the guinea-pig, an animal species whose ventricular action potential shape and restitution properties resemble those determined in humans. Isoprenaline (ISO), a ß-adrenoceptor agonist, was infused...... at variable dosage and duration using either subcutaneously implanted osmotic minipumps or daily injections, in an attempt to establish the relevant treatment protocol. We found that 3 months of daily ISO injections (final dose of 1 mg kg(-1), i.p.) promote heart failure evidenced by cardiac hypertrophy...

  4. A cellulose synthase-like protein is required for osmotic stress tolerance in Arabidopsis

    KAUST Repository

    Zhu, Jianhua; Lee, Byeongha; Dellinger, Michael T.; Cui, Xinping; Zhang, Changqing; Wu, Shang; Nothnagel, Eugene A.; Zhu, Jian-Kang

    2010-01-01

    Osmotic stress imposed by soil salinity and drought stress significantly affects plant growth and development, but osmotic stress sensing and tolerance mechanisms are not well understood. Forward genetic screens using a root-bending assay have

  5. Osmotically driven membrane process for the management of urban runoff in coastal regions

    KAUST Repository

    Li, Zhenyu; Valladares Linares, Rodrigo; Abu-Ghdaib, Muhannad; Zhan, Tong; Yangali-Quintanilla, Victor; Amy, Gary L.

    2014-01-01

    An osmotic detention pond was proposed for the management of urban runoff in coastal regions. Forward osmosis was employed as a bridge to utilize natural osmotic energy from seawater for concentrating and reusing urban runoff water, and as a barrier

  6. [Pathophysiology of chronic diarrhea].

    Science.gov (United States)

    Gerok, W

    2000-10-12

    The symptom of diarrhoea is defined as an abnormally frequent discharge from the bowel (more than 3 times a day) and a semisolid or fluid consistency of the faecal matter. Diarrhoea is termed chronic when it lasts more than four weeks. Diarrhoea is the result of disturbances in enteral water and electrolyte balance. Increased intestinal motility is usually not the cause but the result of diarrhoea. Transport of water through the gut is dependent on the osmotic gradient between interstitium and gut lumen. The secretion of chloride ions by the cells of the intestinal glands plays a major role in water secretion into the gut lumen, while sodium and potassium absorption in the villous zone of the enterocytes is crucial for enteral water absorption. Enteral water and electrolyte balance is regulated by the autonomic and enteral nervous system, by gastrointestinal hormones and signal messengers of mesenchymal cells. Pathogenetically, one distinguishes between secretory and osmotic diarrhoea. Furthermore, mixed forms of both pathogenic types can occur. The various types can be differentiated clinically and by the "osmotic gap". Diarrhoea can be a symptom of various diseases. Its pathogenesis is illustrated using examples of diarrhoea in pathological bile acid absorption, bacterial infections, carbohydrate malabsorption or disaccharidase insufficiency and in chronic inflammatory bowel disease.

  7. Alterations in the colonic microbiota in response to osmotic diarrhea.

    Science.gov (United States)

    Gorkiewicz, Gregor; Thallinger, Gerhard G; Trajanoski, Slave; Lackner, Stefan; Stocker, Gernot; Hinterleitner, Thomas; Gülly, Christian; Högenauer, Christoph

    2013-01-01

    Diseases of the human gastrointestinal (GI) tract are often accompanied by diarrhea with profound alterations in the GI microbiota termed dysbiosis. Whether dysbiosis is due to the disease itself or to the accompanying diarrhea remains elusive. With this study we characterized the net effects of osmotic diarrhea on the composition of the GI microbiota in the absence of disease. We induced osmotic diarrhea in four healthy adults by oral administration of polyethylene glycol 4000 (PEG). Stool as well as mucosa specimens were collected before, during and after diarrhea and 16S rDNA-based microbial community profiling was used to assess the microbial community structure. Stool and mucosal microbiotas were strikingly different, with Firmicutes dominating the mucosa and Bacteroidetes the stools. Osmotic diarrhea decreased phylotype richness and showed a strong tendency to equalize the otherwise individualized microbiotas on the mucosa. Moreover, diarrhea led to significant relative shifts in the phyla Bacteroidetes and Firmicutes and to a relative increase in the abundance of Proteobacteria on the mucosa, a phenomenon also noted in several inflammatory and diarrheal GI diseases. Changes in microbial community structure induced by osmotic diarrhea are profound and show similarities to changes observed in other GI diseases including IBD. These effects so must be considered when specimens from diarrheal diseases (i.e. obtained by stratification of samples according to diarrheal status) or conditions wherein bowel preparations like PEG (i.e. specimens obtained during endoscopy) are used.

  8. Alterations in the colonic microbiota in response to osmotic diarrhea.

    Directory of Open Access Journals (Sweden)

    Gregor Gorkiewicz

    Full Text Available BACKGROUND & AIMS: Diseases of the human gastrointestinal (GI tract are often accompanied by diarrhea with profound alterations in the GI microbiota termed dysbiosis. Whether dysbiosis is due to the disease itself or to the accompanying diarrhea remains elusive. With this study we characterized the net effects of osmotic diarrhea on the composition of the GI microbiota in the absence of disease. METHODS: We induced osmotic diarrhea in four healthy adults by oral administration of polyethylene glycol 4000 (PEG. Stool as well as mucosa specimens were collected before, during and after diarrhea and 16S rDNA-based microbial community profiling was used to assess the microbial community structure. RESULTS: Stool and mucosal microbiotas were strikingly different, with Firmicutes dominating the mucosa and Bacteroidetes the stools. Osmotic diarrhea decreased phylotype richness and showed a strong tendency to equalize the otherwise individualized microbiotas on the mucosa. Moreover, diarrhea led to significant relative shifts in the phyla Bacteroidetes and Firmicutes and to a relative increase in the abundance of Proteobacteria on the mucosa, a phenomenon also noted in several inflammatory and diarrheal GI diseases. CONCLUSIONS: Changes in microbial community structure induced by osmotic diarrhea are profound and show similarities to changes observed in other GI diseases including IBD. These effects so must be considered when specimens from diarrheal diseases (i.e. obtained by stratification of samples according to diarrheal status or conditions wherein bowel preparations like PEG (i.e. specimens obtained during endoscopy are used.

  9. Self-consistent unstirred layers in osmotically driven flows

    DEFF Research Database (Denmark)

    Jensen, Kåre Hartvig; Bohr, Tomas; Bruus, Henrik

    2010-01-01

    It has long been recognized that the osmotic transport characteristics of membranes may be strongly influenced by the presence of unstirred concentration boundary layers adjacent to the membrane. Previous experimental as well as theoretical works have mainly focused on the case where the solutions...

  10. Effect of road transport stress on Erthrocyte Osmotic Fragility (EOF ...

    African Journals Online (AJOL)

    After an overnight fast, venous blood was collected from each subject for the determination of serum cortisol, glucose concentration and erythrocyte osmotic fragility. The subjects were then transported at a speed of 65 – 75Km/h covering a distance of 180km. Thereafter venous blood was again collected (within 10 minutes) ...

  11. Compression and reswelling of microgel particles after an osmotic shock

    NARCIS (Netherlands)

    Sleeboom, J.F.; Voudouris, P.; Punter, M.T.J.J.M.; Aangenendt, F.J.; Florea, D.; van der Schoot, P.P.A.M.; Wyss, H.M.

    2016-01-01

    We use dedicated microfluidic devices to expose soft hydrogel particles to a rapid change in the externally applied osmotic pressure and observe a non-monotonic response: After an initial rapid compression the particle slowly reswells to approximately its original size. Using a simple

  12. Drying of carrots in slices with osmotic dehydration

    African Journals Online (AJOL)

    SAM

    2014-07-23

    Jul 23, 2014 ... extend the shelf-life by a few weeks, one year or more. The methods .... drated carrots, this work studied the drying of carrot with pre-osmotic ... e) Weight Loss - obtained directly using balance semi-analytical model BEL ...

  13. Modeling and computational simulation of the osmotic evaporation process

    Directory of Open Access Journals (Sweden)

    Freddy Forero Longas

    2016-09-01

    Conclusions: It was found that for the conditions studied the Knudsen diffusion model is most suitable to describe the transfer of water vapor through the hydrophobic membrane. Simulations developed adequately describe the process of osmotic evaporation, becoming a tool for faster economic development of this technology.

  14. Root water extraction under combined water and osmotic stress

    NARCIS (Netherlands)

    Jong van Lier, de Q.; Dam, van J.C.; Metselaar, K.

    2009-01-01

    Using a numerical implicit model for root water extraction by a single root in a symmetric radial flow problem, based on the Richards equation and the combined convection-dispersion equation, we investigated some aspects of the response of root water uptake to combined water and osmotic stress. The

  15. Osmotic pressure of ring polymer solutions : A Monte Carlo study

    NARCIS (Netherlands)

    Flikkema, Edwin; Brinke, Gerrit ten

    2000-01-01

    Using the wall theorem, the osmotic pressure of ring polymers in solution has been determined using an off-lattice topology conserving Monte Carlo algorithm. The ring polymers are modeled as freely-jointed chains with point-like beads, i.e., under conditions corresponding to θ-conditions for the

  16. Osmotic generation of 'anomalous' fluid pressures in geological environments

    Science.gov (United States)

    Neuzii, C.E.

    2000-01-01

    Osmotic pressures are generated by differences in chemical potential of a solution across a membrane. But whether osmosis can have a significant effect on the pressure of fluids in geological environments has been controversial, because the membrane properties of geological media are poorly understood. 'Anomalous' pressures - large departures from hydrostatic pressure that are not explicable in terms of topographic or fluid-density effects are widely found in geological settings, and are commonly considered to result from processes that alter the pore or fluid volume, which in turn implies crustal changes happening at a rate too slow to observe directly. Yet if osmosis can explain some anomalies, there is no need to invoke such dynamic geological processes in those cases. Here I report results of a nine- year in situ measurement of fluid pressures and solute concentrations in shale that are consistent with the generation of large (up to 20 MPa) osmotic-pressure anomalies which could persist for tens of millions of years. Osmotic pressures of this magnitude and duration can explain many of the pressure anomalies observed in geological settings. The require, however, small shale porosity and large contrasts in the amount of dissolved solids in the pore waters - criteria that may help to distinguish between osmotic and crystal-dynamic origins of anomalous pressures.

  17. An analysis of electro-osmotic and magnetohydrodynamic heat pipes

    International Nuclear Information System (INIS)

    Harrison, M.A.

    1988-01-01

    Mechanically simple methods of improving heat transport in heat pipes are investigated. These methods are electro-osmotic and magnetohydrodynamic augmentation. For the electro-osmotic case, a detailed electrokinetic model is used. The electrokinetic model used includes the effects of pore surface curvature and multiple ion diffusivities. The electrokinetic model is extended to approximate the effects of elevated temperature. When the electro-osmotic model is combined with a suitable heat-pipe model, it is found that the electro-osmotic pump should be a thin membrane. Arguments are provided that support the use of a volatile electrolyte. For the magnetohydrodynamic case, a brief investigation is provided. A quasi-one-dimensional hydromagnetic duct flow model is used. This hydromagnetic model is extended to approximate flow effects unique to heat pipes. When combined with a suitable heat pipe model, it is found that there is no performance gain for the case considered. In fact, there are serious pressure-distribution problems that have not been previously recognized. Potential solutions to these pressure-distribution problems are suggested

  18. Vocal Fold Epithelial Response to Luminal Osmotic Perturbation

    Science.gov (United States)

    Sivasankar, Mahalakshmi; Fisher, Kimberly V.

    2007-01-01

    Purpose: Dry-air challenges increase the osmolarity of fluid lining the luminal surface of the proximal airway. The homeostasis of surface fluid is thought to be essential for voice production and laryngeal defense. Therefore, the authors hypothesized that viable vocal fold epithelium would generate a water flux to reduce an osmotic challenge (150…

  19. Development of an electro-osmotic heat pump

    NARCIS (Netherlands)

    Stoel, J.P. van der; Oostendorp, P.A.

    1999-01-01

    The majority of heat pumps and refrigerators is driven by a mechanical compressor. Although they usually function very well, the search for new and in some cases better heat pumping concepts continues. One of the topics in this field is the development of an electro-osmotic heat pump. As each

  20. A Simple Membrane Osmometer System & Experiments that Quantitatively Measure Osmotic Pressure

    Science.gov (United States)

    Marvel, Stephen C.; Kepler, Megan V.

    2009-01-01

    It is important for students to be exposed to the concept of osmotic pressure. Understanding this concept lays the foundation for deeper discussions that lead to more theoretical aspects of water movement associated with the concepts of free energy, water potential, osmotic potential, pressure potential, and osmotic adjustment. The concept of…

  1. Modeling osmotic salinity effects on yield characteristics of substrate-grown greenhouse crops

    NARCIS (Netherlands)

    Sonneveld, C.; Bos, van den A.L.; Voogt, W.

    2004-01-01

    In a series of experiments with different osmotic potentials in the root environment, various vegetables, and ornamentals were grown in a substrate system. The osmotic potential was varied by addition of nutrients. Yield characteristics of the crop were related to the osmotic potential of the

  2. Osmotic demyelination syndrome with recent chemotherapy in normonatremic patient: A case report

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Sungjae; Baek, Hye Jin; Jung, Hyun Kyung; Kim, Seon Jeong; Lee, Yedaun; Lee, Kwaghwi; Ryu, Ji Hwa; Kim, Hong Dae [Dept. of Radiology, Haeundae Paik Hospital, Inje University College of Medicine, Busan (Korea, Republic of)

    2014-11-15

    Osmotic demyelination syndrome (ODS), an acquired demyelinating condition of the central pons and/or other regions of the brain, is frequently associated with rapid correction of hyponatremia. There are several reports of ODS in other clinical setting such as malnutrition, alcoholism, transplantation, malignancy, and chronic debilitating illness. However, cases of ODS associated with chemotherapy have not been frequently reported. Here, we describe a case of ODS in a normonatremic patient recently underwent chemotherapy for colon cancer. The diagnosis was confirmed by MRI showing a typical T2 hyperintensity in the central pons. This case suggests that ODS is not always associated with hyponatremia and that ODS can have a favorable clinical and radiologic prognosis.

  3. The combined effects of pyridostigmine and chronic stress on brain cortical and blood acetylcholinesterase, corticosterone, prolactin and alternation performance in rats.

    Science.gov (United States)

    Kant, G J; Bauman, R A; Feaster, S R; Anderson, S M; Saviolakis, G A; Garcia, G E

    2001-01-01

    Thousands of soldiers who served in the Gulf War have symptoms that have been collectively termed Gulf War Illness (GWI). It has been suggested that a combination of operational stress and pyridostigmine, a drug given as a pretreatment to protect soldiers against the effects of exposure to nerve agents, might have had unexpected adverse health effects causing these symptoms. Our laboratory has previously modeled operational stress in rats using a paradigm of around-the-clock intermittent signalled footshock. In the present studies, this model was used to investigate the potential synergistic effects of chronic stress and pyridostigmine on physiology and behavior. Seventy-two rats were trained to perform an alternation lever pressing task to earn their entire daily food intake. The rats were then implanted with osmotic minipumps containing vehicle, pyridostigmine (25 mg/ml pyridostigmine bromide) or physostigmine (20 mg/ml eserine hemisulfate). The pumps delivered 1 microl/h, which resulted in a cumulative dosing of approximately 1.5 mg/kg/day of pyridostigmine or 1.2 mg/kg/day of physostigmine, equimolar doses of the two drugs. The rats were then returned to their home cages where performance continued to be measured 24 h/day. After 4 days, 24 of the 72 rats were trained to escape signalled footshock (avoidance-escape group) and 24 other rats (yoked-stressed group) were each paired to a rat in the avoidance-escape group. The remaining 24 rats were not subjected to footshock (unstressed group). Shock trials were intermittently presented in the home cage 24 h/day for 3 days, while alternation performance continued to be measured. Since only 12 test cages were available, each condition was repeated to achieve a final n of six rats per group. Pyridostigmine and physostigmine each decreased blood acetylcholinesterase levels by approximately 50%. Physostigmine also decreased brain cortical acetylcholinesterase levels by approximately 50%, while pyridostigmine had no

  4. In vitro screening of potato genotypes for osmotic stress tolerance

    Directory of Open Access Journals (Sweden)

    Gelmesa Dandena

    2017-02-01

    Full Text Available Potato (Solanum tuberosum L. is a cool season crop which is susceptible to both drought and heat stresses. Lack of suitable varieties of the crop adapted to drought-prone areas of the lowland tropics deprives farmers living in such areas the opportunity to produce and use the crop as a source of food and income. As a step towards developing such varieties, the present research was conducted to evaluate different potato genotypes for osmotic stress tolerance under in vitro conditions and identify drought tolerant genotypes for future field evaluation. The experiment was carried out at the Leibniz University of Hannover, Germany, by inducing osmotic stress using sorbitol at two concentrations (0.1 and 0.2 M in the culture medium. A total of 43 genotypes collected from different sources (27 advanced clones from CIP, nine improved varieties, and seven farmers’ cultivars were used in a completely randomized design with four replications in two rounds. Data were collected on root and shoot growth. The results revealed that the main effects of genotype, sorbitol treatment, and their interactions significantly (P < 0.01 influenced root and shoot growthrelated traits. Under osmotic stress, all the measured root and shoot growth traits were significantly correlated. The dendrogram obtained from the unweighted pair group method with arithmetic mean allowed grouping of the genotypes into tolerant, moderately tolerant, and susceptible ones to a sorbitol concentration of 0.2 M in the culture medium. Five advanced clones (CIP304350.100, CIP304405.47, CIP392745.7, CIP388676.1, and CIP388615.22 produced shoots and rooted earlier than all other genotypes, with higher root numbers, root length, shoot and root mass under osmotic stress conditions induced by sorbitol. Some of these genotypes had been previously identified as drought-tolerant under field conditions, suggesting the capacity of the in vitro evaluation method to predict drought stress tolerant

  5. Analytical Expressions for Thermo-Osmotic Permeability of Clays

    Science.gov (United States)

    Gonçalvès, J.; Ji Yu, C.; Matray, J.-M.; Tremosa, J.

    2018-01-01

    In this study, a new formulation for the thermo-osmotic permeability of natural pore solutions containing monovalent and divalent cations is proposed. The mathematical formulation proposed here is based on the theoretical framework supporting thermo-osmosis which relies on water structure alteration in the pore space of surface-charged materials caused by solid-fluid electrochemical interactions. The ionic content balancing the surface charge of clay minerals causes a disruption in the hydrogen bond network when more structured water is present at the clay surface. Analytical expressions based on our heuristic model are proposed and compared to the available data for NaCl solutions. It is shown that the introduction of divalent cations reduces the thermo-osmotic permeability by one third compared to the monovalent case. The analytical expressions provided here can be used to advantage for safety calculations in deep underground nuclear waste repositories.

  6. Osmotic pressure of the cutaneous surface fluid of Rana esculenta

    DEFF Research Database (Denmark)

    Hviid Larsen, Erik; Ramløv, Hans

    2012-01-01

    The osmotic pressure of the cutaneous surface fluid (CSF) in vivo was measured for investigating whether evaporative water loss (EWL) derives from water diffusing through the skin or fluid secreted by exocrine subepidermal mucous glands. EWL was stimulated by subjecting R. esculenta to 30–34 °C....../Kg, n = 16. Osmolality of lymph was, 239 ± 4 mosmol/Kg, n = 8. Thus the flow of water across the epidermis would be in the direction from CSF to the interstitial fluid driven by the above osmotic gradients and/or coupled to the inward active Na+ flux via the slightly hyperosmotic paracellular...... compartment [EH Larsen et al. (2009) Acta Physiologica 195: 171–186]. It is concluded that the source of EWL of the frog on land is the fluid secreted by the mucous glands and not water diffusing through the skin. The study supports the hypothesis [EH Larsen (2011) Acta Physiologica 202: 435–464] that volume...

  7. Optimization of the Energy Output of Osmotic Power Plants

    Directory of Open Access Journals (Sweden)

    Florian Dinger

    2013-01-01

    Full Text Available On the way to a completely renewable energy supply, additional alternatives to hydroelectric, wind, and solar power have to be investigated. Osmotic power is such an alternative with a theoretical global annual potential of up to 14400 TWh (70% of the global electricity consumption of 2008 per year. It utilizes the phenomenon that upon the mixing of fresh water and oceanic salt water (e.g., at a river mouth, around 2.88 MJ of energy per 1 m3 of fresh water is released. Here, we describe a new approach to derive operational parameter settings for osmotic power plants using a pressure exchanger for optimal performance, either with respect to maximum generated power or maximum extracted energy. Up to now, only power optimization is discussed in the literature, but when considering the fresh water supply as a limiting factor, the energy optimization appears as the challenging task.

  8. Glucose Monitoring System Based on Osmotic Pressure Measurements

    Directory of Open Access Journals (Sweden)

    Alexandra LEAL

    2011-02-01

    Full Text Available This paper presents the design and development of a prototype sensor unit for implementation in a long-term glucose monitoring system suitable for estimating glucose levels in people suffering from diabetes mellitus. The system utilizes osmotic pressure as the sensing mechanism and consists of a sensor prototype that is integrated together with a pre-amplifier and data acquisition unit for both data recording and processing. The sensor prototype is based on an embedded silicon absolute pressure transducer and a semipermeable nanoporous membrane that is enclosed in the sensor housing. The glucose monitoring system facilitates the integration of a low power microcontroller that is combined with a wireless inductive powered communication link. Experimental verification have proven that the system is capable of tracking osmotic pressure changes using albumin as a model compound, and thereby show a proof of concept for novel long term tracking of blood glucose from remote sensor nodes.

  9. Hydro-osmotic Instabilities in Active Membrane Tubes

    Science.gov (United States)

    Al-Izzi, Sami C.; Rowlands, George; Sens, Pierre; Turner, Matthew S.

    2018-03-01

    We study a membrane tube with unidirectional ion pumps driving an osmotic pressure difference. A pressure-driven peristaltic instability is identified, qualitatively distinct from similar tension-driven Rayleigh-type instabilities on membrane tubes. We discuss how this instability could be related to the function and biogenesis of membrane bound organelles, in particular, the contractile vacuole complex. The unusually long natural wavelength of this instability is in agreement with that observed in cells.

  10. Osmotic dehydration of fruits and vegetables: a review

    OpenAIRE

    Yadav, Ashok Kumar; Singh, Satya Vir

    2012-01-01

    The main cause of perishability of fruits and vegetables are their high water content. To increase the shelf life of these fruits and vegetables many methods or combination of methods had been tried. Osmotic dehydration is one of the best and suitable method to increase the shelf life of fruits and vegetables. This process is preferred over others due to their vitamin and minerals, color, flavor and taste retention property. In this review different methods, treatments, optimization and effec...

  11. Does Osmotic Stress Affect Natural Product Expression in Fungi?

    Science.gov (United States)

    Overy, David; Correa, Hebelin; Roullier, Catherine; Chi, Wei-Chiung; Pang, Ka-Lai; Rateb, Mostafa; Ebel, Rainer; Shang, Zhuo; Capon, Rob; Bills, Gerald; Kerr, Russell

    2017-08-13

    The discovery of new natural products from fungi isolated from the marine environment has increased dramatically over the last few decades, leading to the identification of over 1000 new metabolites. However, most of the reported marine-derived species appear to be terrestrial in origin yet at the same time, facultatively halo- or osmotolerant. An unanswered question regarding the apparent chemical productivity of marine-derived fungi is whether the common practice of fermenting strains in seawater contributes to enhanced secondary metabolism? To answer this question, a terrestrial isolate of Aspergillus aculeatus was fermented in osmotic and saline stress conditions in parallel across multiple sites. The ex-type strain of A. aculeatus was obtained from three different culture collections. Site-to-site variations in metabolite expression were observed, suggesting that subculturing of the same strain and subtle variations in experimental protocols can have pronounced effects upon metabolite expression. Replicated experiments at individual sites indicated that secondary metabolite production was divergent between osmotic and saline treatments. Titers of some metabolites increased or decreased in response to increasing osmolite (salt or glycerol) concentrations. Furthermore, in some cases, the expression of some secondary metabolites in relation to osmotic and saline stress was attributed to specific sources of the ex-type strains.

  12. Development and evaluation of microporous osmotic tablets of diltiazem hydrochloride

    Directory of Open Access Journals (Sweden)

    Afifa Bathool

    2012-01-01

    Full Text Available Microporous osmotic tablet of diltiazem hydrochloride was developed for colon targeting. These prepared microporous osmotic pump tablet did not require laser drilling to deliver the drug to the specific site of action. The tablets were prepared by wet granulation method. The prepared tablets were coated with microporous semipermeable membrane and enteric polymer using conventional pan coating process. The incorporation of sodium lauryl sulfate (SLS, a leachable pore-forming agent, could form in situ delivery pores while coming in contact with gastrointestinal medium. The effect of formulation variables was studied by changing the amounts of sodium alginate and NaCMC in the tablet core, osmogen, and that of pore-forming agent (SLS used in the semipermeable coating. As the amount of hydrophilic polymers increased, drug release rate prolonged. It was found that drug release was increased as the concentration of osmogen and pore-former was increased. Fourier transform infrared spectroscopy and Differential scanning calorimetry results showed that there was no interaction between drug and polymers. Scanning electron microscopic studies showed the formation of pores after predetermined time of coming in contact with dissolution medium. The formation of pores was dependent on the amount of pore former used in the semipermeable membrane. in vitro results showed acid-resistant, timed release at an almost zero order up to 24 hours. The developed osmotic tablets could be effectively used for prolonged delivery of Diltiazem HCl.

  13. Active osmotic exchanger for advanced filtration at the nano scale

    Science.gov (United States)

    Marbach, Sophie; Bocquet, Lyderic

    2015-11-01

    One of the main functions of the kidney is to remove the waste products of an organism, mostly by excreting concentrated urea while reabsorbing water and other molecules. The human kidney is capable of recycling about 200 liters of water per day, at the relatively low cost of 0.5 kJ/L (standard dialysis requiring at least 150 kJ/L). Kidneys are constituted of millions of parallel filtration networks called nephrons. The nephrons of all mammalian kidneys present a specific loop geometry, the Loop of Henle, that is believed to play a key role in the urinary concentrating mechanism. One limb of the loop is permeable to water and the other contains sodium pumps that exchange with a common interstitium. In this work, we take inspiration from this osmotic exchanger design to propose new nanofiltration principles. We first establish simple analytical results to derive general operating principles, based on coupled water permeable pores and osmotic pumps. The best filtration geometry, in terms of power required for a given water recycling ratio, is comparable in many ways to the mammalian nephron. It is not only more efficient than traditional reverse osmosis systems, but can also work at much smaller pressures (of the order of the blood pressure, 0.13 bar, as compared to more than 30 bars for pressure-retarded osmosis systems). We anticipate that our proof of principle will be a starting point for the development of new filtration systems relying on the active osmotic exchanger principle.

  14. Osmotic heat engine using thermally responsive ionic liquids

    KAUST Repository

    Zhong, Yujiang

    2017-07-11

    The osmotic heat engine (OHE) is a promising technology for converting low grade heat to electricity. Most of the existing studies have focused on thermolytic salt systems. Herein, for the first time, we proposed to use thermally responsive ionic liquids (TRIL) that have either an upper critical solution temperature (UCST) or lower critical solution temperature (LCST) type of phase behavior as novel thermolytic osmotic agents. Closed-loop TRIL-OHEs were designed based on these unique phase behaviors to convert low grade heat to work or electricity. Experimental studies using two UCST-type TRILs, protonated betaine bis(trifluoromethyl sulfonyl)imide ([Hbet][Tf2N]) and choline bis(trifluoromethylsulfonyl)imide ([Choline][Tf2N]) showed that (1) the specific energy of the TRIL-OHE system could reach as high as 4.0 times that of the seawater and river water system, (2) the power density measured from a commercial FO membrane reached up to 2.3 W/m2, and (3) the overall energy efficiency reached up to 2.6% or 18% of the Carnot efficiency at no heat recovery and up to 10.5% or 71% of the Carnet efficiency at 70% heat recovery. All of these results clearly demonstrated the great potential of using TRILs as novel osmotic agents to design high efficient OHEs for recovery of low grade thermal energy to work or electricity.

  15. Physiologically Based Pharmacokinetic and Absorption Modeling for Osmotic Pump Products.

    Science.gov (United States)

    Ni, Zhanglin; Talattof, Arjang; Fan, Jianghong; Tsakalozou, Eleftheria; Sharan, Satish; Sun, Dajun; Wen, Hong; Zhao, Liang; Zhang, Xinyuan

    2017-07-01

    Physiologically based pharmacokinetic (PBPK) and absorption modeling approaches were employed for oral extended-release (ER) drug products based on an osmotic drug delivery system (osmotic pumps). The purpose was to systemically evaluate the in vivo relevance of in vitro dissolution for this type of formulation. As expected, in vitro dissolution appeared to be generally predictive of in vivo PK profiles, because of the unique feature of this delivery system that the in vitro and in vivo release of osmotic pump drug products is less susceptible to surrounding environment in the gastrointestinal (GI) tract such as pH, hydrodynamic, and food effects. The present study considered BCS (Biopharmaceutics Classification System) class 1, 2, and 3 drug products with half-lives ranging from 2 to greater than 24 h. In some cases, the colonic absorption models needed to be adjusted to account for absorption in the colon. C max (maximum plasma concentration) and AUCt (area under the concentration curve) of the studied drug products were sensitive to changes in colon permeability and segmental GI transit times in a drug product-dependent manner. While improvement of the methodology is still warranted for more precise prediction (e.g., colonic absorption and dynamic movement in the GI tract), the results from the present study further emphasized the advantage of using PBPK modeling in addressing product-specific questions arising from regulatory review and drug development.

  16. Osmotic stress response in the wine yeast Dekkera bruxellensis.

    Science.gov (United States)

    Galafassi, Silvia; Toscano, Marco; Vigentini, Ileana; Piškur, Jure; Compagno, Concetta

    2013-12-01

    Dekkera bruxellensis is mainly associated with lambic beer fermentation and wine production and may contribute in a positive or negative manner to the flavor development. This yeast is able to produce phenolic compounds, such as 4-ethylguaiacol and 4-ethylphenol which could spoil the wine, depending on their concentration. In this work we have investigated how this yeast responds when exposed to conditions causing osmotic stress, as high sorbitol or salt concentrations. We observed that osmotic stress determined the production and accumulation of intracellular glycerol, and the expression of NADH-dependent glycerol-3-phosphate dehydrogenase (GPD) activity was elevated. The involvement of the HOG MAPK pathway in response to this stress condition was also investigated. We show that in D. bruxellensis Hog1 protein is activated by phosphorylation under hyperosmotic conditions, highlighting the conserved role of HOG MAP kinase signaling pathway in the osmotic stress response. Gene Accession numbers in GenBank: DbHOG1: JX65361, DbSTL1: JX965362. Copyright © 2013 Elsevier Ltd. All rights reserved.

  17. Design of an osmotic pressure sensor for sensing an osmotically active substance

    International Nuclear Information System (INIS)

    Ch, Nagesh; Paily, Roy P

    2015-01-01

    A pressure sensor based on the osmosis principle has been designed and demonstrated successfully for the sensing of the concentration levels of an osmotically active substance. The device is fabricated using the bulk micro-machining technique on a silicon on insulator (SOI) substrate. The substrate has a square cavity on the bottom side to fill with the reference glucose solution and a silicon (Si) membrane on the top side for the actuation. Two sets of devices, having membrane thicknesses of 10 µm and 25 µm, but the same area of 3 mm ×3 mm, are fabricated. The cavity is filled with a glucose solution of 100 mg dL −1 and it is sealed with a semi-permeable membrane made up of cellulose acetate material. The glucose solution is employed to prove the functionality of the device and it is tested for different glucose concentration levels, ranging from 50 mg dL −1 to 450 mg dL −1 . The output voltage obtained for the corresponding glucose concentration levels ranges from −6.7 mV to 22.7 mV for the 10 µm device and from −1.7 mV to 4 mV for the 25 µm device. The device operation was simulated using the finite element method (FEM) and the finite volume method (FVM), and the simulation and experimental results match closely. A response time of 40 min is obtained in the case of the 10 µm device compared to one of 30 min for the 25 µm device. The response times obtained for these devices are found to be small compared to those in similar works based on the osmosis principle. This pressure sensor has the potential to provide controlled drug delivery if it can be integrated with other microfluidic devices. (paper)

  18. Recent experimental data may point to a greater role for osmotic pressures in the subsurface

    Science.gov (United States)

    Neuzil, C.E.; Provost, A.M.

    2009-01-01

    Uncertainty about the origin of anomalous fluid pressures in certain geologic settings has caused researchers to take a second look at osmosis, or flow driven by chemical potential differences, as a pressure‐generating process in the subsurface. Interest in geological osmosis has also increased because of an in situ experiment by Neuzil (2000) suggesting that Pierre Shale could generate large osmotic pressures when highly compacted. In the last few years, additional laboratory and in situ experiments have greatly increased the number of data on osmotic properties of argillaceous formations, but they have not been systematically examined. In this paper we compile these data and explore their implications for osmotic pressure generation in subsurface systems. Rather than base our analysis on osmotic efficiencies, which depend strongly on concentration, we calculated values of a quantity we term osmotic specific surface area (Aso) that, in principle, is a property of the porous medium only. The Aso values are consistent with a surprisingly broad spectrum of osmotic behavior in argillaceous formations, and all the formations tested exhibited at least a modest ability to generate osmotic pressure. It appears possible that under appropriate conditions some formations can be highly effective osmotic membranes able to generate osmotic pressures exceeding 30 MPa (3 km of head) at porosities as high as ∼0.1 and pressures exceeding 10 MPa at porosities as high as ∼0.2. These findings are difficult to reconcile with the lack of compelling field evidence for osmotic pressures, and we propose three explanations for the disparity: (1) Our analysis is flawed and argillaceous formations are less effective osmotic membranes than it suggests; (2) the necessary subsurface conditions, significant salinity differences within intact argillaceous formations, are rare; or (3) osmotic pressures are unlikely to be detected and are not recognized when encountered. The last possibility

  19. SAXS investigations on lipid membranes under osmotic stress

    Energy Technology Data Exchange (ETDEWEB)

    Rubim, R.L.; Vieira, V.; Gerbelli, B.B.; Teixeira da Silva, E.R.; Oliveira, C.L.P.; Oliveira, E.A. [Universidade de Sao Paulo (USP), Sao Paulo, SP (Brazil)

    2012-07-01

    Full text: In this work we, experimentally, investigate the interactions between lipid bilayers. A structural characterization is performed by small angle x-ray scattering (SAXS) on multilamellar systems under known osmotic pressure. Changes in the composition of membranes can modify their mechanical properties and structural parameters, like the flexibility of these membranes, which plays a key role on the determination of the tridimensional organization of bilayers. The membranes are composed of soya lecithin, where the major component is DPPC (Dipalmitoylphosphatidylcholine), and fatty acids are incorporated to the membrane in different concentrations, in order to turn the membrane more fluid. The membranes are inserted in a solution of PVP [poly(vinyl-pyrrolidone) - 40000] and the polymer will apply an osmotic pressure on them. The osmotic pressure is controlled by preparing PVP solutions of desired composition and, as we know the concentration of polymer in solution, we can obtain the intensity of the osmotic pressure. SAXS experiments were done in order to determine the distance between the bilayer. From the position of the Bragg peaks, the lamellar periodicity (the thickness of the membranes plus their distance of separation) was determined. Using theoretical model for the form and structure factors we fitted those experimental data and determined the thickness of the membranes. The distance between the membranes was controlled by the osmotic pressure (P) applied to the membranes and, for a given pressure, we determine the distance between the bilayers (a) on equilibrium. The experimental curve P(a) is theoretically described by the different contributions from van der Waals, hydration and fluctuation forces. From the fitting of experimental curves, relevant parameters characterizing the strength of the different interactions are obtained, such as Hamaker and rigidity constant [2, 3]. We observe that the separation between the bilayers on equilibrium is

  20. Osmotic phenomena in application for hyperbaric oxygen treatment.

    Science.gov (United States)

    Babchin, A; Levich, E; Melamed M D, Y; Sivashinsky, G

    2011-03-01

    Hyperbaric oxygen (HBO) treatment defines the medical procedure when the patient inhales pure oxygen at elevated pressure conditions. Many diseases and all injuries are associated with a lack of oxygen in tissues, known as hypoxia. HBO provides an effective method for fast oxygen delivery in medical practice. The exact mechanism of the oxygen transport under HBO conditions is not fully identified. The objective of this article is to extend the colloid and surface science basis for the oxygen transport in HBO conditions beyond the molecular diffusion transport mechanism. At a pressure in the hyperbaric chamber of two atmospheres, the partial pressure of oxygen in the blood plasma increases 10 times. The sharp increase of oxygen concentration in the blood plasma creates a considerable concentration gradient between the oxygen dissolved in the plasma and in the tissue. The concentration gradient of oxygen as a non-electrolyte solute causes an osmotic flow of blood plasma with dissolved oxygen. In other words, the molecular diffusion transport of oxygen is supplemented by the convective diffusion raised due to the osmotic flow, accelerating the oxygen delivery from blood to tissue. A non steady state equation for non-electrolyte osmosis is solved asymptotically. The solution clearly demonstrates two modes of osmotic flow: normal osmosis, directed from lower to higher solute concentrations, and anomalous osmosis, directed from higher to lower solute concentrations. The fast delivery of oxygen from blood to tissue is explained on the basis of the strong molecular interaction between the oxygen and the tissue, causing an influx of oxygen into the tissue by convective diffusion in the anomalous osmosis process. The transport of the second gas, nitrogen, dissolved in the blood plasma, is also taken into the consideration. As the patient does not inhale nitrogen during HBO treatment, but exhales it along with oxygen and carbon dioxide, the concentration of nitrogen in blood

  1. Osmotic therapies added to antibiotics for acute bacterial meningitis

    Science.gov (United States)

    Wall, Emma Cb; Ajdukiewicz, Katherine Mb; Bergman, Hanna; Heyderman, Robert S; Garner, Paul

    2018-01-01

    Background Every day children and adults die from acute community-acquired bacterial meningitis, particularly in low-income countries, and survivors risk deafness, epilepsy and neurological disabilities. Osmotic therapies may attract extra-vascular fluid and reduce cerebral oedema, and thus reduce death and improve neurological outcomes. This is an update of a Cochrane Review first published in 2013. Objectives To evaluate the effects of osmotic therapies added to antibiotics for acute bacterial meningitis in children and adults on mortality, deafness and neurological disability. Search methods We searched CENTRAL (2017, Issue 1), MEDLINE (1950 to 17 February 2017), Embase (1974 to 17 February 2017), CINAHL (1981 to 17 February 2017), LILACS (1982 to 17 February 2017) and registers of ongoing clinical trials (ClinicalTrials.com, WHO ICTRP) (21 February 2017). We also searched conference abstracts and contacted researchers in the field (up to 12 December 2015). Selection criteria Randomised controlled trials testing any osmotic therapy in adults or children with acute bacterial meningitis. Data collection and analysis Two review authors independently screened the search results and selected trials for inclusion. Results are presented using risk ratios (RR) and 95% confidence intervals (CI) and grouped according to whether the participants received steroids or not. We used the GRADE approach to assess the certainty of the evidence. Main results We included five trials with 1451 participants. Four trials evaluated glycerol against placebo, and one evaluated glycerol against 50% dextrose; in addition three trials evaluated dexamethasone and one trial evaluated acetaminophen (paracetamol) in a factorial design. Stratified analysis shows no effect modification with steroids; we present aggregate effect estimates. Compared to placebo, glycerol probably has little or no effect on death in people with bacterial meningitis (RR 1.08, 95% CI 0.90 to 1.30; 5 studies, 1272

  2. Effect of plasma colloid osmotic pressure on intraocular pressure during haemodialysis

    OpenAIRE

    Tokuyama, T.; Ikeda, T.; Sato, K.

    1998-01-01

    BACKGROUND—In a previous case report, it was shown that an increase in plasma colloid osmotic pressure induced by the removal of fluid during haemodialysis was instrumental in decreasing intraocular pressure. The relation between changes in intraocular pressure, plasma osmolarity, plasma colloid osmotic pressure, and body weight before and after haemodialysis is evaluated.
METHODS—Intraocular pressure, plasma osmolarity, plasma colloid osmotic pressure, and body weight were evaluated before a...

  3. Gene expression analysis in response to osmotic stimuli in the intervertebral disc with DNA microarray.

    Science.gov (United States)

    Zhang, Wenzhi; Li, Xu; Shang, Xifu; Zhao, Qichun; Hu, Yefeng; Xu, Xiang; He, Rui; Duan, Liqun; Zhang, Feng

    2013-12-27

    Intervertebral disc (IVD) cells experience a broad range of physicochemical stimuli under physiologic conditions, including alterations in their osmotic environment. At present, the molecular mechanisms underlying osmotic regulation in IVD cells are poorly understood. This study aims to screen genes affected by changes in osmotic pressure in cells of subjects aged 29 to 63 years old, with top-scoring pair (TSP) method. Gene expression data set GSE1648 was downloaded from Gene Expression Omnibus database, including four hyper-osmotic stimuli samples, four iso-osmotic stimuli samples, and three hypo-osmotic stimuli samples. A novel, simple method, referred to as the TSP, was used in this study. Through this method, there was no need to perform data normalization and transformation before data analysis. A total of five pairs of genes ((CYP2A6, FNTB), (PRPF8, TARDBP), (RPS5, OAZ1), (SLC25A3, NPM1) and (CBX3, SRSF9)) were selected based on the TSP method. We inferred that all these genes might play important roles in response to osmotic stimuli and age in IVD cells. Additionally, hyper-osmotic and iso-osmotic stimuli conditions were adverse factors for IVD cells. We anticipate that our results will provide new thoughts and methods for the study of IVD disease.

  4. Swelling, mechanical and friction properties of PVA/PVP hydrogels after swelling in osmotic pressure solution.

    Science.gov (United States)

    Shi, Yan; Xiong, Dangsheng; Liu, Yuntong; Wang, Nan; Zhao, Xiaoduo

    2016-08-01

    The potential of polyvinyl alcohol/polyvinylpyrrolidone (PVA/PVP) hydrogels as articular cartilage replacements was in vitro evaluated by using a macromolecule-based solution to mimic the osmotic environment of cartilage tissue. The effects of osmotic pressure solution on the morphology, crystallinity, swelling, mechanical and friction properties of PVA/PVP hydrogels were investigated by swelling them in non-osmotic and osmotic pressure solutions. The results demonstrated that swelling ratio and equilibrium water content were greatly reduced by swelling in osmotic solution, and the swelling process was found to present pseudo-Fickian diffusion character. The crystallization degree of hydrogels after swelling in osmotic solution increased more significantly when it compared with that in non-osmotic solution. After swelling in osmotic solution for 28days, the compressive tangent modulus and storage modulus of hydrogels were significantly increased, and the low friction coefficient was reduced. However, after swelling in the non-osmotic solution, the compressive tangent modulus and friction coefficient of hydrogels were comparable with those of as-prepared hydrogels. The better material properties of hydrogels in vivo than in vitro evaluation demonstrated their potential application in cartilage replacement. Copyright © 2016 Elsevier B.V. All rights reserved.

  5. Transcriptome Profiling of Watermelon Root in Response to Short-Term Osmotic Stress.

    Science.gov (United States)

    Yang, Yongchao; Mo, Yanling; Yang, Xiaozheng; Zhang, Haifei; Wang, Yongqi; Li, Hao; Wei, Chunhua; Zhang, Xian

    2016-01-01

    Osmotic stress adversely affects the growth, fruit quality and yield of watermelon (Citrullus lanatus (Thunb.) Matsum. & Nakai). Increasing the tolerance of watermelon to osmotic stress caused by factors such as high salt and water deficit is an effective way to improve crop survival in osmotic stress environments. Roots are important organs in water absorption and are involved in the initial response to osmosis stress; however, few studies have examined the underlying mechanism of tolerance to osmotic stress in watermelon roots. For better understanding of this mechanism, the inbred watermelon accession M08, which exhibits relatively high tolerance to water deficits, was treated with 20% polyethylene glycol (PEG) 6000. The root samples were harvested at 6 h after PEG treatment and untreated samples were used as controls. Transcriptome analyses were carried out by Illumina RNA sequencing. A total of 5246 differentially expressed genes were identified. Gene ontology enrichment and biochemical pathway analyses of these 5246 genes showed that short-term osmotic stress affected osmotic adjustment, signal transduction, hormone responses, cell division, cell cycle and ribosome, and M08 may repress root growth to adapt osmotic stress. The results of this study describe the watermelon root transcriptome under osmotic stress and propose new insight into watermelon root responses to osmotic stress at the transcriptome level. Accordingly, these results allow us to better understand the molecular mechanisms of watermelon in response to drought stress and will facilitate watermelon breeding projects to improve drought tolerance.

  6. An osmotic model of the growing pollen tube.

    Directory of Open Access Journals (Sweden)

    Adrian E Hill

    Full Text Available Pollen tube growth is central to the sexual reproduction of plants and is a longstanding model for cellular tip growth. For rapid tip growth, cell wall deposition and hardening must balance the rate of osmotic water uptake, and this involves the control of turgor pressure. Pressure contributes directly to both the driving force for water entry and tip expansion causing thinning of wall material. Understanding tip growth requires an analysis of the coordination of these processes and their regulation. Here we develop a quantitative physiological model which includes water entry by osmosis, the incorporation of cell wall material and the spreading of that material as a film at the tip. Parameters of the model have been determined from the literature and from measurements, by light, confocal and electron microscopy, together with results from experiments made on dye entry and plasmolysis in Lilium longiflorum. The model yields values of variables such as osmotic and turgor pressure, growth rates and wall thickness. The model and its predictive capacity were tested by comparing programmed simulations with experimental observations following perturbations of the growth medium. The model explains the role of turgor pressure and its observed constancy during oscillations; the stability of wall thickness under different conditions, without which the cell would burst; and some surprising properties such as the need for restricting osmotic permeability to a constant area near the tip, which was experimentally confirmed. To achieve both constancy of pressure and wall thickness under the range of conditions observed in steady-state growth the model reveals the need for a sensor that detects the driving potential for water entry and controls the deposition rate of wall material at the tip.

  7. Osmotic membrane bioreactor for phenol biodegradation under continuous operation

    Energy Technology Data Exchange (ETDEWEB)

    Praveen, Prashant; Loh, Kai-Chee, E-mail: chelohkc@nus.edu.sg

    2016-03-15

    Highlights: • Osmotic membrane bioreactor was used for phenol biodegradation in continuous mode. • Extractant impregnated membranes were used to alleviate substrate inhibition. • Phenol removal was achieved through both biodegradation and membrane rejection. • Phenol concentrations up to 2500 mg/L were treated at HRT varying in 2.8–14 h. • A biofilm removal strategy was formulated to improve bioreactor sustainability. - Abstract: Continuous phenol biodegradation was accomplished in a two-phase partitioning osmotic membrane bioreactor (TPPOMBR) system, using extractant impregnated membranes (EIM) as the partitioning phase. The EIMs alleviated substrate inhibition during prolonged operation at influent phenol concentrations of 600–2000 mg/L, and also at spiked concentrations of 2500 mg/L phenol restricted to 2 days. Filtration of the effluent through forward osmosis maintained high biomass concentration in the bioreactor and improved effluent quality. Steady state was reached in 5–6 days at removal rates varying between 2000 and 5500 mg/L-day under various conditions. Due to biofouling and salt accumulation, the permeate flux varied from 1.2–7.2 LMH during 54 days of operation, while maintaining an average hydraulic retention time of 7.4 h. A washing cycle, comprising 1 h osmotic backwashing using 0.5 M NaCl and 2 h washing with water, facilitated biofilm removal from the membranes. Characterization of the extracellular polymeric substances (EPS) through FTIR showed peaks between 1700 and 1500 cm{sup −1}, 1450–1450 cm{sup −1} and 1200–1000 cm{sup −1}, indicating the presence of proteins, phenols and polysaccharides, respectively. The carbohydrate to protein ratio in the EPS was estimated to be 0.3. These results indicate that TPPOMBR can be promising in continuous treatment of phenolic wastewater.

  8. Tirilazad mesylate protects stored erythrocytes against osmotic fragility.

    Science.gov (United States)

    Epps, D E; Knechtel, T J; Bacznskyj, O; Decker, D; Guido, D M; Buxser, S E; Mathews, W R; Buffenbarger, S L; Lutzke, B S; McCall, J M

    1994-12-01

    The hypoosmotic lysis curve of freshly collected human erythrocytes is consistent with a single Gaussian error function with a mean of 46.5 +/- 0.25 mM NaCl and a standard deviation of 5.0 +/- 0.4 mM NaCl. After extended storage of RBCs under standard blood bank conditions the lysis curve conforms to the sum of two error functions instead of a possible shift in the mean and a broadening of a single error function. Thus, two distinct sub-populations with different fragilities are present instead of a single, broadly distributed population. One population is identical to the freshly collected erythrocytes, whereas the other population consists of osmotically fragile cells. The rate of generation of the new, osmotically fragile, population of cells was used to probe the hypothesis that lipid peroxidation is responsible for the induction of membrane fragility. If it is so, then the antioxidant, tirilazad mesylate (U-74,006f), should protect against this degradation of stored erythrocytes. We found that tirilazad mesylate, at 17 microM (1.5 mol% with respect to membrane lecithin), retards significantly the formation of the osmotically fragile RBCs. Concomitantly, the concentration of free hemoglobin which accumulates during storage is markedly reduced by the drug. Since the presence of the drug also decreases the amount of F2-isoprostanes formed during the storage period, an antioxidant mechanism must be operative. These results demonstrate that tirilazad mesylate significantly decreases the number of fragile erythrocytes formed during storage in the blood bank.

  9. An Osmotic Model of the Growing Pollen Tube

    Science.gov (United States)

    Hill, Adrian E.; Shachar-Hill, Bruria; Skepper, Jeremy N.; Powell, Janet; Shachar-Hill, Yair

    2012-01-01

    Pollen tube growth is central to the sexual reproduction of plants and is a longstanding model for cellular tip growth. For rapid tip growth, cell wall deposition and hardening must balance the rate of osmotic water uptake, and this involves the control of turgor pressure. Pressure contributes directly to both the driving force for water entry and tip expansion causing thinning of wall material. Understanding tip growth requires an analysis of the coordination of these processes and their regulation. Here we develop a quantitative physiological model which includes water entry by osmosis, the incorporation of cell wall material and the spreading of that material as a film at the tip. Parameters of the model have been determined from the literature and from measurements, by light, confocal and electron microscopy, together with results from experiments made on dye entry and plasmolysis in Lilium longiflorum. The model yields values of variables such as osmotic and turgor pressure, growth rates and wall thickness. The model and its predictive capacity were tested by comparing programmed simulations with experimental observations following perturbations of the growth medium. The model explains the role of turgor pressure and its observed constancy during oscillations; the stability of wall thickness under different conditions, without which the cell would burst; and some surprising properties such as the need for restricting osmotic permeability to a constant area near the tip, which was experimentally confirmed. To achieve both constancy of pressure and wall thickness under the range of conditions observed in steady-state growth the model reveals the need for a sensor that detects the driving potential for water entry and controls the deposition rate of wall material at the tip. PMID:22615784

  10. Artificial neural network model of pork meat cubes osmotic dehydration

    OpenAIRE

    Pezo, Lato L.; Ćurčić, Biljana Lj.; Filipović, Vladimir S.; Nićetin, Milica R.; Koprivica, Gordana B.; Mišljenović, Nevena M.; Lević, Ljubinko B.

    2013-01-01

    Mass transfer of pork meat cubes (M. triceps brachii), shaped as 1x1x1 cm, during osmotic dehydration (OD) and under atmospheric pressure was investigated in this paper. The effects of different parameters, such as concentration of sugar beet molasses (60-80%, w/w), temperature (20-50ºC), and immersion time (1-5 h) in terms of water loss (WL), solid gain (SG), final dry matter content (DM), and water activity (aw), were investigated using experimental results. Five artificial neural net...

  11. Compression and Reswelling of Microgel Particles after an Osmotic Shock

    Science.gov (United States)

    Sleeboom, Jelle J. F.; Voudouris, Panayiotis; Punter, Melle T. J. J. M.; Aangenendt, Frank J.; Florea, Daniel; van der Schoot, Paul; Wyss, Hans M.

    2017-09-01

    We use dedicated microfluidic devices to expose soft hydrogel particles to a rapid change in the externally applied osmotic pressure and observe a surprising, nonmonotonic response: After an initial rapid compression, the particle slowly reswells to approximately its original size. We theoretically account for this behavior, enabling us to extract important material properties from a single microfluidic experiment, including the compressive modulus, the gel permeability, and the diffusivity of the osmolyte inside the gel. We expect our approach to be relevant to applications such as controlled release, chromatography, and responsive materials.

  12. Magnetic resonance studies on the brain edema by the administration of the osmotic agents; Special references to the relaxation times

    Energy Technology Data Exchange (ETDEWEB)

    Niino, Masaki; Asakura, Tetsuhiko; Nakamura, Katsumi; Yatsushiro, Kazutaka; Kadota, Koki (Kagoshima Univ. (Japan). Faculty of Medicine); Sasahira, Masahiro; Fujimoto, Toshiro; Shimooki, Susumu

    1990-03-01

    Changes of proton relaxation times (T{sub 1} and T{sub 2}) and MR imaging of the brain edema by the administration of the osmotic agents (mannitol or glycerol) were studied. Subjects were 11 patients who were composed of 4 gliomas, 2 metastatic brain tumors, 2 meningiomas, 2 hypertensive intracerebral hematomas, and a C-P angle tumor. 20% mannitol or 10% glycerol 550 ml was rapidly injected intravenously. Scanning was done before injection, just after injection, and post injection until 2 hours with passing times. We regarded the peritumoral or perihemorrahgical low density area on the CT scan as the edema, and then, relaxation times of the edema was obtained from the ROI of the calculated images corresponding to the surrounding low density area on the CT scan. The results were as follows. (1) In general, relaxation times of the edema showed a tendency to decrease after injection of the osmotic agents. Normal white matter, in the same way, showed the decreasing tendency, but the degree of the decreasing was more clearly in the edematous areas than in the white matter. (2) The changes of relaxation times did not show a uniform pattern. In most cases, relaxation times decreased just after injection. But in a few cases, relaxation times increased just after injection, transiently. In some cases, decreased relaxation times continued more than 2 hours, in the other cases, relaxation times increased at 2 hours. (3) The changes of relaxation times thought to be varied by some factors, that is --kinds of the lesions causing edema, degree of malignancy of the lesions, or phase of edema (acute or chronic) etc. (4) Osmotic agents were supposed to dehydrate the edematous lesions. In the current MR systems, there are considerably large standard deviations and inequality in the magnetic field, therefore, further investigations should be done moreover. (author).

  13. Evaluation of chronic diarrhea.

    Science.gov (United States)

    Juckett, Gregory; Trivedi, Rupal

    2011-11-15

    Chronic diarrhea, defined as a decrease in stool consistency for more than four weeks, is a common but challenging clinical scenario. It can be divided into three basic categories: watery, fatty (malabsorption), and inflammatory. Watery diarrhea may be subdivided into osmotic, secretory, and functional types. Watery diarrhea includes irritable bowel syndrome, which is the most common cause of functional diarrhea. Another example of watery diarrhea is microscopic colitis, which is a secretory diarrhea affecting older persons. Laxative-induced diarrhea is often osmotic. Malabsorptive diarrhea is characterized by excess gas, steatorrhea, or weight loss; giardiasis is a classic infectious example. Celiac disease (gluten-sensitive enteropathy) is also malabsorptive, and typically results in weight loss and iron deficiency anemia. Inflammatory diarrhea, such as ulcerative colitis or Crohn disease, is characterized by blood and pus in the stool and an elevated fecal calprotectin level. Invasive bacteria and parasites also produce inflammation. Infections caused by Clostridium difficile subsequent to antibiotic use have become increasingly common and virulent. Not all chronic diarrhea is strictly watery, malabsorptive, or inflammatory, because some categories overlap. Still, the most practical diagnostic approach is to attempt to categorize the diarrhea by type before testing and treating. This narrows the list of diagnostic possibilities and reduces unnecessary testing. Empiric therapy is justified when a specific diagnosis is strongly suspected and follow-up is available.

  14. Nano-funnels as electro-osmotic ``tweezers and pistons''

    Science.gov (United States)

    Wang, Yanqian; Panyukov, Sergey; Zhou, Jinsheng; Menard, Laurent D.; Ramsey, J. Michael; Rubinstien, Michael

    2014-03-01

    An electric field is used to force a DNA molecule into a nano-channel by compensating the free energy penalty that results from the reduced conformational entropy of the confined macromolecule. Narrow nano-channels require high critical electric fields to achieve DNA translocation, leading to short dwell times of DNA in these channels. We demonstrate that nano-funnels integrated with nano-channels reduce the free energy barrier and lower the critical electric field required for DNA translocation. A focused electric field within the funnel increases the electric force on the DNA, compresses the molecule, and increases the osmotic pressure at the nano-channel entrance. This ``electro-osmotic piston'' forces the molecule into the nano-channel at lower electric fields than those observed without the funnel. Appropirately designed nano-funnels can also function as tweezers that allow manipulation of the position of the DNA molecule. The predictions of our theory describing double-stranded DNA behavior in nano-funnel - nano-channel devices are consistent with experimental results. Thanks for the financial support from NSF (DMR-1309892, DMR-1121107, DMR-1122483), NIH (1-P50-HL107168, 1-P01-HL108808-01A1, R01HG02647), NHGRI and CF Foundation.

  15. Novel Regulation of Aquaporins during Osmotic Stress1

    Science.gov (United States)

    Vera-Estrella, Rosario; Barkla, Bronwyn J.; Bohnert, Hans J.; Pantoja, Omar

    2004-01-01

    Aquaporin protein regulation and redistribution in response to osmotic stress was investigated. Ice plant (Mesembryanthemum crystallinum) McTIP1;2 (McMIPF) mediated water flux when expressed in Xenopus leavis oocytes. Mannitol-induced water imbalance resulted in increased protein amounts in tonoplast fractions and a shift in protein distribution to other membrane fractions, suggesting aquaporin relocalization. Indirect immunofluorescence labeling also supports a change in membrane distribution for McTIP1;2 and the appearance of a unique compartment where McTIP1;2 is expressed. Mannitol-induced redistribution of McTIP1;2 was arrested by pretreatment with brefeldin A, wortmannin, and cytochalasin D, inhibitors of vesicle trafficking-related processes. Evidence suggests a role for glycosylation and involvement of a cAMP-dependent signaling pathway in McTIP1;2 redistribution. McTIP1;2 redistribution to endosomal compartments may be part of a homeostatic process to restore and maintain cellular osmolarity under osmotic-stress conditions. PMID:15299122

  16. Protozoa inhibition by different salts: Osmotic stress or ionic stress?

    Science.gov (United States)

    Li, Changhao; Li, Jingya; Lan, Christopher Q; Liao, Dankui

    2017-09-01

    Cell density and morphology changes were tested to examine the effects of salts including NaHCO 3 , NaCl, KHCO 3 , and KCl at 160 mM on protozoa. It was demonstrated that ionic stress rather than osmotic stress led to protozoa cell death and NaHCO 3 was shown to be the most effective inhibitor. Deformation of cells and cell shrinkage were observed when protozoan cells were exposed to polyethylene glycol (PEG) or any of the salts. However, while PEG treated cells could fully recover in both number and size, only a small portion of the salt-treated cells survive and cell size was 36-58% smaller than the regular. The disappearance of salt-treated protozoa cells was hypothetically attributed to disruption of the cytoplasmic membrane of these cells. It is further hypothesized that the PEG-treated protozoan cells carried out regulatory volume increase (RVI) after the osmotic shock but the RVI of salt-treated protozoa was hurdled to varied extents. © 2017 American Institute of Chemical Engineers Biotechnol. Prog., 33:1418-1424, 2017. © 2017 American Institute of Chemical Engineers.

  17. Augmentation of peristaltic microflows through electro-osmotic mechanisms

    International Nuclear Information System (INIS)

    Chakraborty, Suman

    2006-01-01

    The present work aims to theoretically establish that the employment of an axial electric field can substantially augment the rate of microfluidic transport occurring in peristaltic microtubes. For theoretical analysis, shape evolution of the tube is taken to be arbitrary, except for the fact that the characteristic wavelength is assumed to be significantly greater than the average radius of cross section. First, expressions for the velocity profile within the tube are derived and are subsequently utilized to obtain variations in the net flow rate across the same, as a function of the pertinent system parameters. Subsequently, the modes of interaction between the electro-osmotic and peristaltic mechanisms are established through the variations in the time-averaged flow rates for zero pressure rise and the pressure rise for zero time-averaged flow rates, as expressed in terms of the occlusion number, characteristic electro-osmotic velocity and the peristaltic wave speed. From the simulation predictions, it is suggested that a judicious combination of peristalsis and an axial electrokinetic body force can drastically enhance the time-averaged flow rate, provided that the occlusion number is relatively small

  18. Does osmotic distillation change the isotopic relation of wines?

    Directory of Open Access Journals (Sweden)

    Schmitt Matthias

    2014-01-01

    Full Text Available Currently partial alcohol reduction of wine is in the focus of research worldwide. There are several technologies available to achieve this target. These techniques are either based on distilling or membrane processes. Osmotic distillation, one of the possibilities, is a quite modern membrane process that can be used. During that process, wine is pumped in counter flow to water along a micro porous, hydrophobic membrane. The volatile components of the wine can permeate that membrane and are dissolved in water. The driving force of that process is the vapor pressure difference between the volatiles on the wine and water side of the membrane. The aim of this work was to determine if the alcohol reduction by osmotic distillation can change the isotopic relation in a wine. Can this enological practice change the composition of a wine in a way that an illegal water addition is simulated? Different wines were reduced by 2% alcohol v/v with varying process parameters. The isotopic analysis of the O 16/18 ratio in the wine were performed according to the OIV methods (353/2009 These analyses showed that the isotopic ratio is modified by an alcohol reduction of 2% v/v in a way that corresponds to an addition of 4–5% of external water.

  19. Quorum sensing regulates the osmotic stress response in Vibrio harveyi.

    Science.gov (United States)

    van Kessel, Julia C; Rutherford, Steven T; Cong, Jian-Ping; Quinodoz, Sofia; Healy, James; Bassler, Bonnie L

    2015-01-01

    Bacteria use a chemical communication process called quorum sensing to monitor cell density and to alter behavior in response to fluctuations in population numbers. Previous studies with Vibrio harveyi have shown that LuxR, the master quorum-sensing regulator, activates and represses >600 genes. These include six genes that encode homologs of the Escherichia coli Bet and ProU systems for synthesis and transport, respectively, of glycine betaine, an osmoprotectant used during osmotic stress. Here we show that LuxR activates expression of the glycine betaine operon betIBA-proXWV, which enhances growth recovery under osmotic stress conditions. BetI, an autorepressor of the V. harveyi betIBA-proXWV operon, activates the expression of genes encoding regulatory small RNAs that control quorum-sensing transitions. Connecting quorum-sensing and glycine betaine pathways presumably enables V. harveyi to tune its execution of collective behaviors to its tolerance to stress. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

  20. Osmotic and activity coefficients of triorganophosphates in n-octane

    International Nuclear Information System (INIS)

    Sagert, N.H.; Lau, D.W.P.

    1982-01-01

    Vapour pressure osmometry was used to measure osmotic coefficients for tributylphosphate (TBP), tricresylphosphate (TCP), and triethylhexylphosphate (THEP) in n-octane at 30, 40, 50, and 60 0 C and at molalities up to 0.3 mol/kg. Activity coefficients and excess thermodynamic properties (unsymmetrical definition) were calculated from these osmotic coefficients. At 30 0 C, the excess Gibbs free energies for 0.1 mol of solute in 1.0 kg n-octane were -42 J, -66 J, and -20 J for TBP, TCP, and TEHP, respectively. The more ideal behavior of the TEHP-octane system is attributed to the increasing importance of hydrocarbon-hydrocarbon interactions as the chain length is increased. The excess enthalpies for 0.1 mol of solute in 1.0 kg of solvent were -100 J, and -300 J, and -150 J for TBP, TCP, and TEHP, respectively. Thus, association of these solutes arises primarily from entropic effects. Our data could generally be accommodated adequately by postulating association of monomers into dimmers. The exception was TCP at lower temperatures, where more complex models were required

  1. Thermal and Osmotic Tolerance of 'Irukandji' Polyps: Cubozoa; Carukia barnesi.

    Directory of Open Access Journals (Sweden)

    Robert Courtney

    Full Text Available This research explores the thermal and osmotic tolerance of the polyp stage of the Irukandji jellyfish Carukia barnesi, which provides new insights into potential polyp habitat suitability. The research also targets temperature, salinity, feeding frequency, and combinations thereof, as cues for synchronous medusae production. Primary findings revealed 100% survivorship in osmotic treatments between 19 and 46‰, with the highest proliferation at 26‰. As salinity levels of 26‰ do not occur within the waters of the Great Barrier Reef or Coral Sea, we conclude that the polyp stage of C. barnesi is probably found in estuarine environments, where these lower salinity conditions commonly occur, in comparison to the medusa stage, which is oceanic. Population stability was achieved at temperatures between 18 and 31°C, with an optimum temperature of 22.9°C. We surmise that C. barnesi polyps may be restricted to warmer estuarine areas where water temperatures do not drop below 18°C. Asexual reproduction was also positively correlated with feeding frequency. Temperature, salinity, feeding frequency, and combinations thereof did not induce medusae production, suggesting that this species may use a different cue, possibly photoperiod, to initiate medusae production.

  2. The osmotic pressure of 3He-4He mixtures along the phase separation curve

    NARCIS (Netherlands)

    van de Klundert, L.J.M.; Bos, M.R.E.; van der Meij, J.A.M.; Steffens, H.A.

    1977-01-01

    The osmotic pressure of 3He-4He mixtures was measured along the phase separation curve at temperatures up to 500 mK by balancing it with the fountain pressure of pure 4He. The usefullness of the secondary osmotic pressure thermometer was reinvestigated.

  3. The osmotic pressure of 3He-4He mixtures along the phase separation curve

    International Nuclear Information System (INIS)

    Klundert, L.J.M. van de; Bos, M.R.E.; Meij, J.A.M. van der; Steffens, H.A.

    1977-01-01

    The osmotic pressure of 3 He- 4 He mixtures was measured along the phase separation curve at temperatures up to 500 mK by balancing it with the fountain pressure of pure 4 He. The usefullness of the secondary osmotic pressure thermometer was reinvestigated. (Auth.)

  4. Effect of osmotic stress on in vitro propagation of Musa sp. (Malbhog ...

    African Journals Online (AJOL)

    This study demonstrates up to 36% reduced microbial contamination in aseptic culture establishment and subsequent micropropagation due to osmotic stress induction in the banana suckers. Osmotic stress was induced by keeping the freshly collected suckers in shade and measuring fresh weight at 0, 7, 14, 21, and 28 ...

  5. Influence of osmotic pressure changes on the opening of existing cracks in 2 intervertebral disc models

    NARCIS (Netherlands)

    Wognum, Silvia; Huyghe, Jacques M.; Baaijens, Frank P. T.

    2006-01-01

    An experimental hydrogel model and a numerical mixture model were used to investigate why the disc herniates while osmotic pressure is decreasing. To investigate the influence of decreasing osmotic pressure on the opening of cracks in the disc. In the degeneration process, the disc changes structure

  6. The dependence of molecular transmembrane electrotransfer efficiency on medium conductivity and osmotic pressure

    OpenAIRE

    Jakutavičiūtė, Milda; Ruzgys, Paulius; Šatkauskas, Saulius

    2014-01-01

    The electrotransfer efficiency was evaluated for different external medium conductivities, osmotic pressures and electric pulse voltages. It was found that increase in conductivity or decrease in electric pulse strength decreases electrotransfer efficiency. Decrease in osmotic pressure tends to decrease electrotransfer efficiency.

  7. Mechanical properties of the collagen network in human articular cartilage as measured by osmotic stress technique

    NARCIS (Netherlands)

    Basser, P.J.; Schneiderman, R.; Bank, R.A.; Wachtel, E.; Maroudas, A.

    1998-01-01

    We have used an isotropic osmotic stress technique to assess the swelling pressures of human articular cartilage over a wide range of hydrations in order to determine from these measurements, for the first time, the tensile stress in the collagen network, P(c), as a function of hydration. Osmotic

  8. Hybrid Pressure Retarded Osmosis−Membrane Distillation (PRO−MD) Process for Osmotic Power and Clean Water Generation

    KAUST Repository

    Han, Gang; Zuo, Jian; Wan, Chunfeng; Chung, Neal Tai-Shung

    2015-01-01

    unique advantages of high water recovery rate, huge osmotic power generation, well controlled membrane fouling, and minimal environmental impacts. Experimental results show that the PRO−MD hybrid process is promising that not only can harvest osmotic

  9. [Chronic diarrhea: etiologies and diagnostic evaluation].

    Science.gov (United States)

    Schoepfer, A

    2008-04-30

    Chronic diarrhea is defined as a decrease in fecal consistency lasting for four or more weeks. A myriad of disorders are associated with chronic diarrhea. In developed countries, chronic diarrhea is mostly caused by non-infectious diseases. There are four pathogenic mechanisms leading to chronic diarrhea: osmotic diarrhea, secretory diarrhea, inflammatory diarrhea, and dysmotility. Overlaps between these mechanisms are possible. A 72-hour fecal collection as well as the fasting test are important diagnostic tools to identify the underlying pathomechanism. The identification of the pathomechanism narrows down the possible etiologies of chronic diarrhea and allows therefore a cost-saving diagnostic workup. The endoscopy is well established in the workup of chronic diarrhea. This article gives an overview about the main causes and mechanisms leading to chronic diarrhea and proposes an algorithm for the diagnostic evalution.

  10. Optimum condition of producing crisp osmotic banana using superheated steam puffing.

    Science.gov (United States)

    Tabtiang, Surapit; Prachayawarakorn, Somkiat; Soponronnarit, Somchart

    2017-03-01

    Puffing can improve textural property of snacks. Nevertheless, high temperature puffing accelerates non-enzymatic browning reactions. The osmotic treatment using sucrose solution potentially retards the browning, but the high amount of sucrose gain causes hard texture. The objective of this work was therefore to study the effects of osmotic time, puffing time and puffing temperature on banana qualities such as colour, shrinkage and textural property. The experimental results showed that puffing temperature, puffing time and osmotic time significantly affected colour, shrinkage and textual properties. The optimisation using response surface methodology was used for a trade-off between colour and textural properties. To obtain a good quality product, the puffed osmotic banana should be operated at the osmotic time of 43 min and puffing temperature of 220 °C and puffing time of 2 min. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

  11. Fecal osmotic gap and pH in experimental diarrhea of various causes.

    Science.gov (United States)

    Eherer, A J; Fordtran, J S

    1992-08-01

    Although the osmotic gap of fecal fluid is often used to distinguish osmotic diarrhea from secretory diarrhea, there has never been a scientific evaluation of the validity of this concept. Similarly, although a low fecal fluid pH value is used to indicate that diarrhea is mediated by carbohydrate malabsorption, the validity of this method is unproven. Therefore, in the present study, diarrhea was induced in normal subjects by different mechanisms and fecal fluid osmotic gap (using an assumed fecal fluid osmolality of 290 mOsm/kg) and pH were measured. In secretory diarrhea caused by phenolphthalein, the osmotic gap was always less than 50 mOsm/kg, whereas in osmotic diarrhea caused by polyethylene glycol, magnesium hydroxide, lactulose, and sorbitol, the osmotic gap always exceeded 50 mOsm/kg. In osmotic diarrhea caused by sodium sulfate, the fecal fluid osmotic gap was less than 50 mOsm/kg, but phenolphthalein-induced secretory diarrhea could be distinguished from sodium sulfate-induced osmotic diarrhea by the fecal chloride concentration. When diarrhea was caused by carbohydrate malabsorption (lactulose or sorbitol), the fecal fluid pH was always less than 5.6 and usually less than 5.3; by contrast, other causes of diarrhea rarely caused a fecal pH as low as 5.6 and never caused a pH less than 5.3. It is concluded that measurement of fecal fluid osmotic gap and pH can distinguish various mechanisms of experimental diarrhea in normal subjects. The concepts on which these tests are based are therefore verified experimentally.

  12. Osmotic dehydration of fruit and berry raw materials in the food industry

    Directory of Open Access Journals (Sweden)

    N. A. Gribova

    2017-01-01

    Full Text Available Osmotic dehydration has recently received more attention as an effective method of preserving fruits and berries. Osmosis is a simple process that facilitates the processing of fruits and berries in order to preserve the original characteristics, namely nutritional value and organoleptic properties: color, aroma and texture. Osmotic dehydration has found wide application in the preservation of food products, as the activity of water in fruits and berries decreases, in some of them up to 90% of water is contained. The process of osmotic dehydration with the help of various agents is less energy-intensive than the process of drying or freezing, since it can be processed at ambient temperature. Osmotic dehydration has potential advantages in preserving the quality of food and in maintaining healthy food for the food industry. Treatment includes dehydration of fruits and berries by an osmotic agent followed by dehydration in dry or frozen apparatus where the moisture content decreases and the product becomes more stable. This process is a partial dewatering process to provide improved product quality compared to conventional drying processes or freezing. The purpose of studying osmotic dehydration is to identify the advantages and disadvantages in the treatment of osmotic agents. Various aspects of osmotic dehydration technology are considered, namely the solutions used, the characteristics of solutions, the effect of variable processes and the qualitative characteristics of osmo-dehydrated products. Factors of osmotic dehydration that depend on the osmotic agent, concentration of solute, temperature, time, size, shape and compactness of the material, mixing and the ratio of the solution to the samples.

  13. Zinc absorption in experimental osmotic diarrhea: effect of long-chain fatty acids.

    Science.gov (United States)

    Lee, S Y; Wapnir, R A

    1993-03-01

    The effect of free fatty acids on zinc absorption was studied in a rat model of chronic osmotic diarrhea induced with magnesium citrate and phenolphthalein. In vivo rates of zinc removal from the lumen and analysis of tissue for zinc uptake and metallothionein alterations were monitored. One mmol/L stearate enhanced zinc absorption in rats with or without diarrhea, from 207 +/- 22 and 353 +/- 13 pmol/min x cm to 676 +/- 34 and 610 +/- 26 pmol/min x cm, respectively. Palmitate was only effective in normal rats. Zinc absorption inversely correlated with mucosal zinc content in the perfused intestinal segments, in both type of rats. Hepatic metallothionein was enhanced by zinc and even more by oleate plus zinc in both groups; kidney metallothionein in animals with diarrhea was normalized by either oleate or zinc. The data support previous reports on the effect of long-chain fatty acids on the enhancement of zinc absorption: saturation and a longer chain appear to be positive factors. A membrane modification role of long-chain fatty acids could have nutritional implications in the formulation of special diets.

  14. Osmotically driven flows in microchannels separated by a semipermeable membrane

    DEFF Research Database (Denmark)

    Jensen, Kåre Hartvig; Lee, J.; Bohr, Tomas

    2009-01-01

    We have fabricated lab-on-a-chip systems with microchannels separated by integrated membranes allowing for osmotically driven microflows. We have investigated these flows experimentally by studying the dynamics and structure of the front of a sugar solution travelling in 200 mu m wide and 50-200 mu...... m deep microchannels. We find that the sugar front travels at a constant speed, and that this speed is proportional to the concentration of the sugar solution and inversely proportional to the depth of the channel. We propose a theoretical model, which, in the limit of low axial flow resistance......, predicts that the sugar front should indeed travel with a constant velocity. The model also predicts an inverse relationship between the depth of the channel and the speed, and a linear relation between the sugar concentration and the speed. We thus find good qualitative agreement between the experimental...

  15. Osmotic de-swelling and swelling of latex dispersions

    International Nuclear Information System (INIS)

    Bonnet-Gonnet, Cecile

    1993-01-01

    This research thesis reports the comparison of, on the one hand, direct measurements of de-swelling resistance of latex dispersions obtained by osmotic pressure with, on the other hand, predictions made by models of electrostatic interactions. This resistance is explained in the case of sulphate-stabilised polystyrene particles (direct repulsion between charged particles), and in the case of copolymer (ps-pba) particles covered by an amphiphilic polymer (interactions between surface macromolecules and polymers). The study of de-swelling and swelling cycles highlights the existence of thresholds beyond which the concentrated dispersion has some cohesion. This irreversibility can be modelled by a Van der Waals attraction. The role of hydrophobic forces in latex destabilisation is studied [fr

  16. Environmental impacts by running an osmotic power plan

    Energy Technology Data Exchange (ETDEWEB)

    Staalstroem, A.; Gitmark, J.

    2012-07-01

    The possible environmental impact by running an osmotic power plant is assessed by using results from monitoring of the prototype plant at Tofte in the Oslofjord, where a water flow of approximately 13 L/s of freshwater is mixed with 20 L/s of saltwater and discharged at 2 m depth. The results from the biological investigations show no impact of the discharge water on the benthic communities in the area. Eutrophication effects near the discharge point are identified as the main environmental concern in an up-scaled power plant. Water samples from the saltwater intake indicate that the phosphorous concentration often is higher at 35 m depth than in the euphotic layer, and there will be a net supply of phosphorous to this layer. By diving the outlet plume below the euphotic zone, eutrophication effects as well as possible effects from use of chemicals and possible changed temperature and salinity in the surface layer is avoided. (Author)

  17. Solute coupled diffusion in osmotically driven membrane processes.

    Science.gov (United States)

    Hancock, Nathan T; Cath, Tzahi Y

    2009-09-01

    Forward osmosis (FO) is an emerging water treatment technology with potential applications in desalination and wastewater reclamation. In FO, water is extracted from a feed solution using the high osmotic pressure of a hypertonic solution that flows on the opposite side of a semipermeable membrane; however, solutes diffuse simultaneously through the membrane in both directions and may jeopardize the process. In this study, we have comprehensively explored the effects of different operating conditions on the forward diffusion of solutes commonly found in brackish water and seawater, and reverse diffusion of common draw solution solutes. Results show that reverse transport of solutes through commercially available FO membranes range between 80 mg to nearly 3,000 mg per liter of water produced. Divalent feed solutes have low permeation rates (less than 1 mmol/m2-hr) while monovalent ions and uncharged solutes exhibit higher permeation. Findings have significant implications on the performance and sustainability of the FO process.

  18. Osmotic pressure induced tensile forces in tendon collagen.

    Science.gov (United States)

    Masic, Admir; Bertinetti, Luca; Schuetz, Roman; Chang, Shu-Wei; Metzger, Till Hartmut; Buehler, Markus J; Fratzl, Peter

    2015-01-22

    Water is an important component of collagen in tendons, but its role for the function of this load-carrying protein structure is poorly understood. Here we use a combination of multi-scale experimentation and computation to show that water is an integral part of the collagen molecule, which changes conformation upon water removal. The consequence is a shortening of the molecule that translates into tensile stresses in the range of several to almost 100 MPa, largely surpassing those of about 0.3 MPa generated by contractile muscles. Although a complete drying of collagen would be relevant for technical applications, such as the fabrication of leather or parchment, stresses comparable to muscle contraction already occur at small osmotic pressures common in biological environments. We suggest, therefore, that water-generated tensile stresses may play a role in living collagen-based materials such as tendon or bone.

  19. GABA not only a neurotransmitter: osmotic regulation by GABAAR signalling

    Directory of Open Access Journals (Sweden)

    Tiziana eCesetti

    2012-01-01

    Full Text Available In neurons the anionic channel γ-aminobutyric (GABA A receptor (GABAAR plays a central role in mediating both the neurotrophic and neurotransmitter role of GABA. Activation of this receptor by GABA also affects the function of non-neuronal cells in the central nervous system (CNS, as GABAARs are expressed in mature macroglia and in almost all progenitor types, including neural stem cells. The relevance of GABA signalling in non-neuronal cells has been comparatively less investigated than in neurons. However, it is becoming increasingly evident that these cells are direct targets of GABA regulation. In non-neuronal cells GABAAR activation leads to influx or efflux of chloride (Cl- depending on the electrochemical gradient. Ion transport is indissolubly associated to water fluxes across the plasma membrane and plays a key role in brain physiology. Therefore, GABAAR could affect osmotic tension in the brain by modulating ion gradients. In addition, since water movements also occur through specialized water channels and transporters, GABAAR signalling could affect the movement of water also by regulating the function of the channels and transporters involved, thereby affecting not only the direction of the water fluxes but also their dynamics. This regulation has consequences at the cellular level as it modulates cell volume and activates multiple intracellular signalling mechanisms important for cell proliferation, maturation and survival. It may also have consequences at the systemic level. For example, it may indirectly control neuronal excitability, by regulating the extracellular space and interstitial concentration of Cl-, and contribute to brain water homeostasis. Therefore, GABAergic osmotic regulation should be taken into account during the treatment of pathologies requiring the administration of GABAAR modulators and for the development of therapies for diseases causing water unbalance in the brain.

  20. Assessment of Chronic Administration of Aloe Vera Gel On ...

    African Journals Online (AJOL)

    The study was designed to investigate the effects of chronic administration of Aloe vera gel extract on markers of hepatic damage, lipid profiles and erythrocyte osmotic fragility using the Wistar rats. Forty male Wistar rats divided into four groups of ten rats per group were used in the study. Group I which served as the control ...

  1. Use of osmotic dehydration to improve fruits and vegetables quality during processing.

    Science.gov (United States)

    Maftoonazad, Neda

    2010-11-01

    Osmotic treatment describes a preparation step to further processing of foods involving simultaneous transient moisture loss and solids gain when immersing in osmotic solutions, resulting in partial drying and improving the overall quality of food products. The different aspects of the osmotic dehydration (OD) technology namely the solutes employed, solutions characteristics used, process variables influence, as well as, the quality characteristics of the osmodehydrated products will be discussed in this review. As the process is carried out at mild temperatures and the moisture is removed by a liquid diffusion process, phase change that would be present in the other drying processes will be avoided, resulting in high quality products and may also lead to substantial energy savings. To optimize this process, modeling of the mass transfer phenomenon can improve high product quality. Several techniques such as microwave heating, vacuum, high pressure, pulsed electric field, etc. may be employed during or after osmotic treatment to enhance performance of the osmotic dehydration. Moreover new technologies used in osmotic dehydration will be discussed. Patents on osmotic dehydration of fruits and vegetables are also discussed in this article.

  2. The Arabidopsis Vacuolar Sorting Receptor1 Is Required for Osmotic Stress-Induced Abscisic Acid Biosynthesis

    KAUST Repository

    Wang, Zhen-Yu

    2014-11-21

    Osmotic stress activates the biosynthesis of the phytohormone abscisic acid (ABA) through a pathway that is rate limited by the carotenoid cleavage enzyme 9-cis-epoxycarotenoid dioxygenase (NCED). To understand the signal transduction mechanism underlying the activation of ABA biosynthesis, we performed a forward genetic screen to isolate mutants defective in osmotic stress regulation of the NCED3 gene. Here, we identified the Arabidopsis (Arabidopsis thaliana) Vacuolar Sorting Receptor1 (VSR1) as a unique regulator of ABA biosynthesis. The vsr1 mutant not only shows increased sensitivity to osmotic stress, but also is defective in the feedback regulation of ABA biosynthesis by ABA. Further analysis revealed that vacuolar trafficking mediated by VSR1 is required for osmotic stress-responsive ABA biosynthesis and osmotic stress tolerance. Moreover, under osmotic stress conditions, the membrane potential, calcium flux, and vacuolar pH changes in the vsr1 mutant differ from those in the wild type. Given that manipulation of the intracellular pH is sufficient to modulate the expression of ABA biosynthesis genes, including NCED3, and ABA accumulation, we propose that intracellular pH changes caused by osmotic stress may play a signaling role in regulating ABA biosynthesis and that this regulation is dependent on functional VSR1.

  3. The Arabidopsis Vacuolar Sorting Receptor1 Is Required for Osmotic Stress-Induced Abscisic Acid Biosynthesis

    KAUST Repository

    Wang, Zhen-Yu; Gehring, Christoph A; Zhu, Jianhua; Li, Feng-Min; Zhu, Jian-Kang; Xiong, Liming

    2014-01-01

    Osmotic stress activates the biosynthesis of the phytohormone abscisic acid (ABA) through a pathway that is rate limited by the carotenoid cleavage enzyme 9-cis-epoxycarotenoid dioxygenase (NCED). To understand the signal transduction mechanism underlying the activation of ABA biosynthesis, we performed a forward genetic screen to isolate mutants defective in osmotic stress regulation of the NCED3 gene. Here, we identified the Arabidopsis (Arabidopsis thaliana) Vacuolar Sorting Receptor1 (VSR1) as a unique regulator of ABA biosynthesis. The vsr1 mutant not only shows increased sensitivity to osmotic stress, but also is defective in the feedback regulation of ABA biosynthesis by ABA. Further analysis revealed that vacuolar trafficking mediated by VSR1 is required for osmotic stress-responsive ABA biosynthesis and osmotic stress tolerance. Moreover, under osmotic stress conditions, the membrane potential, calcium flux, and vacuolar pH changes in the vsr1 mutant differ from those in the wild type. Given that manipulation of the intracellular pH is sufficient to modulate the expression of ABA biosynthesis genes, including NCED3, and ABA accumulation, we propose that intracellular pH changes caused by osmotic stress may play a signaling role in regulating ABA biosynthesis and that this regulation is dependent on functional VSR1.

  4. A cellulose synthase-like protein is required for osmotic stress tolerance in Arabidopsis

    KAUST Repository

    Zhu, Jianhua

    2010-04-16

    Osmotic stress imposed by soil salinity and drought stress significantly affects plant growth and development, but osmotic stress sensing and tolerance mechanisms are not well understood. Forward genetic screens using a root-bending assay have previously identified salt overly sensitive (sos) mutants of Arabidopsis that fall into five loci, SOS1 to SOS5. These loci are required for the regulation of ion homeostasis or cell expansion under salt stress, but do not play a major role in plant tolerance to the osmotic stress component of soil salinity or drought. Here we report an additional sos mutant, sos6-1, which defines a locus essential for osmotic stress tolerance. sos6-1 plants are hypersensitive to salt stress and osmotic stress imposed by mannitol or polyethylene glycol in culture media or by water deficit in the soil. SOS6 encodes a cellulose synthase-like protein, AtCSLD5. Only modest differences in cell wall chemical composition could be detected, but we found that sos6-1 mutant plants accumulate high levels of reactive oxygen species (ROS) under osmotic stress and are hypersensitive to the oxidative stress reagent methyl viologen. The results suggest that SOS6/AtCSLD5 is not required for normal plant growth and development but has a critical role in osmotic stress tolerance and this function likely involves its regulation of ROS under stress. © 2010 Blackwell Publishing Ltd.

  5. The Role of Superoxide Dismutase in Inducing of Wheat Seedlings Tolerance to Osmotic Shock

    Directory of Open Access Journals (Sweden)

    Oboznyi A.I.

    2013-08-01

    Full Text Available Influence of short-term hardening osmotic exposure (immersion in 1 M sucrose solution with subsequent transferring to distilled water for 20 min on the hydrogen peroxide generation and superoxide dismutase activity in wheat (Triticum aestivum L., cv. Elegiya seedlings and their tolerance to osmotic shock were investigated. During the initial 30 min after osmotic exposure, the increasing of hydrogen peroxide amount in roots and shoots (to a lesser extent was observed, but the resistance of the seedlings and superoxide dismutase (SOD activity decreased. Sometime later the decrease in hydrogen peroxide amount and the increase of seedlings tolerance to osmotic shock took place. SOD activity increased in 10 min after hardening osmotic exposure. Transient accumulation of hydrogen peroxide induced in this way was suppressed by the treatment of seedlings with sodium diethyldithiocarbamate (DDC, SOD inhibitor. DDC and hydrogen peroxide scavenger dimethylthiourea decreased positive hardening effect of osmotic exposure on the development of seedlings tolerance. It was concluded that SOD providing the generation of signal hydrogen peroxide pool took part in the induction of seedlings tolerance to osmotic shock development caused by preliminary hardening effect.

  6. Development of hyper osmotic resistant CHO host cells for enhanced antibody production.

    Science.gov (United States)

    Kamachi, Yasuharu; Omasa, Takeshi

    2018-04-01

    Cell culture platform processes are generally employed to shorten the duration of new product development. A fed-batch process with continuous feeding is a conventional platform process for monoclonal antibody production using Chinese hamster ovary (CHO) cells. To establish a simplified platform process, the feeding method can be changed from continuous feed to bolus feed. However, this change induces a rapid increase of osmolality by the bolus addition of nutrients. The increased osmolality suppresses cell culture growth, and the final product concentration is decreased. In this study, osmotic resistant CHO host cells were developed to attain a high product concentration. To establish hyper osmotic resistant CHO host cells, CHO-S host cells were passaged long-term in a hyper osmotic basal medium. There were marked differences in cell growth of the original and established host cells under iso- (328 mOsm/kg) or hyper-osmolality (over 450 mOsm/kg) conditions. Cell growth of the original CHO host cells was markedly decreased by the induction of osmotic stress, whereas cell growth of the hyper osmotic resistant CHO host cells was not affected. The maximum viable cell concentration of hyper osmotic resistant CHO host cells was 132% of CHO-S host cells after the induction of osmotic stress. Moreover, the hyper osmotic resistant characteristic of established CHO host cells was maintained even after seven passages in iso-osmolality basal medium. The use of hyper osmotic resistance CHO host cells to create a monoclonal antibody production cell line might be a new approach to increase final antibody concentrations with a fed-batch process. Copyright © 2017 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

  7. Osmotic coefficients of water for thorium nitrate solutions at 25, 37, and 50oC

    International Nuclear Information System (INIS)

    Lemire, R.J.; Sagert, N.H.; Lau, D.W.P.

    1983-01-01

    Vapor pressure osmometry was used to measure osmotic coefficients of water for thorium nitrate solutions at 25, 37, and 50 o C and at molalities up to 0.2 mol·kg -1 . The data were fitted to three- and four-parameter equations containing limiting-law terms for a 4:1 electrolyte. The variation of the osmotic coefficients as a function of temperature was found to be small. The results are compared to published values for the osmotic coefficients. (author)

  8. Physicochemical characteristics of guava “Paluma” submitted to osmotic dehydration

    OpenAIRE

    Roselene Ferreira Oliveira; Lia Mara Moterlle; Edmar Clemente

    2014-01-01

    The aim of this work was to evaluate the conservation post process osmotic of guava stored temperature at 5oC. Guava (Psidium guajava L.), red variety “Paluma” minimally processed by mild osmotic dehydration, were packaged in polyethylene terephthalate (PET) and stored temperature at 5ºC. Non-treated guava, packed in PET trays, was used as control. The treatment used was osmotic dehydration in sucrose syrup at 60ºBrix and physicochemical determinations were pH, total soluble solids (TSS), tot...

  9. A micropuncture study of proximal tubular transport of lithium during osmotic diuresis

    DEFF Research Database (Denmark)

    Leyssac, P P; Holstein-Rathlou, N H; Skøtt, P

    1990-01-01

    Lithium and sodium are normally reabsorbed in parallel with water by the renal proximal tubule whereby their tubular fluid-to-plasma concentration ratios (TF/P) remain close to unity throughout the proximal convoluted segment. During osmotic diuresis, the late proximal (TF/P)Na is known to decrease....... The present experiments were undertaken to study whether the late proximal TF/P for Li decreases like that of Na during osmotic diuresis. Data were obtained in a control period (C) and in two successive periods during mannitol diuresis (P1, P2). Glomerular filtration rate decreased gradually during osmotic...

  10. Neutral lipid production in Dunaliella salina during osmotic stress and adaptation

    DEFF Research Database (Denmark)

    Yao, Shuo; Lu, Jingquan; Sárossy, Zsuzsa

    2016-01-01

    The salt-tolerant green microalga Dunaliella salina can survive both hyper- and hypo-osmotic shock. Upon osmotic shock, the cells transiently and rapidly decreased or increased in size within minutes and slowly over hours acquired their original cell size and volume. Cell size distribution differs...... significantly in the cultures grown in the salinity range from 1.5 to 15 % NaCl. By using Nile Red fluorescence to detect neutral lipids, it became clear that only hyper-osmotic shock on cells induced transient neutral lipid appearance in D. salina, while those transferred from 9 to 15 % NaCl stimulated...

  11. The rate of hypo-osmotic challenge influences regulatory volume decrease (RVD) and mechanical properties of articular chondrocytes.

    Science.gov (United States)

    Wang, Z; Irianto, J; Kazun, S; Wang, W; Knight, M M

    2015-02-01

    Osteoarthritis (OA) is associated with a gradual reduction in the interstitial osmotic pressure within articular cartilage. The aim of this study was to compare the effects of sudden and gradual hypo-osmotic challenge on chondrocyte morphology and biomechanics. Bovine articular chondrocytes were exposed to a reduction in extracellular osmolality from 327 to 153 mOsmol/kg applied either suddenly (osmotic stress, 66% of chondrocytes exhibited an increase in diameter followed by RVD, whilst 25% showed no RVD. By contrast, cells exposed to gradual hypo-osmotic stress exhibited reduced cell swelling without subsequent RVD. There was an increase in the equilibrium modulus for cells exposed to sudden hypo-osmotic stress. However, gradual hypo-osmotic challenge had no effect on cell mechanical properties. This cell stiffening response to sudden hypo-osmotic challenge was abolished when actin organization was disrupted with cytochalasin D or RVD inhibited with REV5901. Both sudden and gradual hypo-osmotic challenge reduced cortical F-actin distribution and caused chromatin decondensation. Sudden hypo-osmotic challenge increases chondrocyte mechanics by activation of RVD and interaction with the actin cytoskeleton. Moreover, the rate of hypo-osmotic challenge is shown to have a profound effect on chondrocyte morphology and biomechanics. This important phenomenon needs to be considered when studying the response of chondrocytes to pathological hypo-osmotic stress. Copyright © 2014 Osteoarthritis Research Society International. Published by Elsevier Ltd. All rights reserved.

  12. Chronic pancreatitis

    Science.gov (United States)

    Chronic pancreatitis - chronic; Pancreatitis - chronic - discharge; Pancreatic insufficiency - chronic; Acute pancreatitis - chronic ... abuse over many years. Repeated episodes of acute pancreatitis can lead to chronic pancreatitis. Genetics may be ...

  13. Oral supplementation of vitamin E reduces osmotic fragility of RBC in hemolytic anemic patients with G6PD deficiency

    International Nuclear Information System (INIS)

    Sultana, N.; Begum, S.; Begum, N.; Ali, T.

    2009-01-01

    Vitamin E has role in maintaining the integrity of red cell member by preventing oxidation of polyunsaturated fatty acids, thus protects cells from oxidative stress-induced lysis in G6PD deficiency. Changes in osmotic fragility of RBC and some absolute values like MCV, MCH and MCHC may occur in haemolytic anaemic patients with G6PD deficiency. To observe the effects of vitamin E supplementation on these changes in order to evaluate the role of this anti-oxidant vitamin in reducing chronic haemolysis in G6PD deficient patients. A total number of 102 subjects with age ranged of 5 to 40 years of both sexes were included in the study. Among them 68 were G6PD enzyme deficient patients, of whom 34 were in supplemented group (experimental group) and 34 were in non-supplemented group (control group). The supplemented group received vitamin E supplementation for 60 consecutive days at a dose of 800 IU/day for adult and 400 IU/day for children ?12 years (in a divided dose, i.e., 4 times daily). Age and sex matched 34 apparently healthy subjects with normal blood G6PD level were taken to observe the base line data (healthy control) and also for comparison. All the G6PD deficient patients were selected from Out Patient Department (OPD) of Haematology, Banglabandhu Sheikh Mujib Medical University (BSMMU), Dhaka, Bangladesh from July 2005 to June 2006 and all healthy subjects were selected from personal contact. Blood G6PD level, osmotic fragility of RBC were measured by standard techniques and MCV, MCH, and MCHC were obtained by calculation. All the parameters were measured on day 1 of their first visit and also were on day 60 in deficient group. Data were compared among the deficient groups, also in supplemented group just before and after supplementation. Analysis of data was done by appropriate statistical method. Mean starting and completing points of osmotic fragility of RBC were significantly higher but MCV. MCH, MCHC were significantly lower in patients suffering from

  14. Red blood cell phosphate concentration and osmotic resistance during dietary phosphate depletion in dairy cows

    NARCIS (Netherlands)

    Grünberg, W; Mol, J A; Teske, E

    BACKGROUND: Hypophosphatemia in early lactating dairy cows has been implicated as primary cause for postparturient hemoglobinuria in cattle. Decreased availability of phosphorus has been proposed to reduce adenosine triphosphate synthesis of erythrocytes and thereby reduce osmotic resistance of

  15. The osmotic second virial coefficient and the Gibbs-McMillan-Mayer framework

    DEFF Research Database (Denmark)

    Mollerup, J.M.; Breil, Martin Peter

    2009-01-01

    The osmotic second virial coefficient is a key parameter in light scattering, protein crystallisation. self-interaction chromatography, and osmometry. The interpretation of the osmotic second virial coefficient depends on the set of independent variables. This commonly includes the independent...... variables associated with the Kirkwood-Buff, the McMillan-Mayer, and the Lewis-Randall solution theories. In this paper we analyse the osmotic second virial coefficient using a Gibbs-McMillan-Mayer framework which is similar to the McMillan-Mayer framework with the exception that pressure rather than volume...... is an independent variable. A Taylor expansion is applied to the osmotic pressure of a solution where one of the solutes is a small molecule, a salt for instance, that equilibrates between the two phases. Other solutes are retained. Solvents are small molecules that equilibrate between the two phases...

  16. Osmotic actuation for microfluidic components in point-of-care applications

    KAUST Repository

    Chen, Yu-Chih; Ingram, Patrick; Lou, Xia; Yoon, Euisik

    2013-01-01

    at low cost. In this work, we report two key active components actuated by osmotic mechanism for total integrated microfluidic system. For the proof of concept, we have demonstrated valve actuation, which can maintain stable ON/OFF switching operations

  17. On equations for the total suction and its matric and osmotic components

    International Nuclear Information System (INIS)

    Dao, Vinh N.T.; Morris, Peter H.; Dux, Peter F.

    2008-01-01

    A clear fundamental understanding of suctions is crucial for the study of the behaviour of plastic cement mortar and concrete, including plastic shrinkage cracking. In this paper, the expression relating the change in free energy of the pore water with an isothermal change in pressure is first derived. Based upon definitions of suctions, it is then shown that total, matric, and osmotic suctions can all be expressed in the same thermodynamic form. The widely accepted, but not yet satisfactorily validated, assumption that the total suction comprises matric and osmotic components is then confirmed theoretically. The well-known Kelvin equation for matric suction, and Morse and van't Hoff equations for osmotic suction are subsequently derived from the corresponding thermodynamic equations. The applicability of latter two equations in evaluating the osmotic suctions of cement mortar and concrete is highlighted

  18. Cross tolerance of osmotically and ionically adapted cell lines of rice ...

    African Journals Online (AJOL)

    saad

    2012-01-10

    Jan 10, 2012 ... The phenomenon of cross tolerance in osmotically and ionically adapted rice .... the mean values of 5 replicates ± standard error. variance showed .... Education Commission of Pakistan and Pakistan Science. Foundation.

  19. Alleviation of osmotic stress of water and salt in germination and ...

    African Journals Online (AJOL)

    STORAGESEVER

    2008-07-04

    Jul 4, 2008 ... ening, osmoconditioning, osmohardening, and hormonal priming have ... germination, emergence and plant growth of wheat (Das and Choudhury .... In the present study, a significant three way interaction. (osmotic agents ...

  20. Ebselen exhibits glycation-inhibiting properties and protects against osmotic fragility of human erythrocytes in vitro.

    Science.gov (United States)

    Soares, Julio C M; Folmer, Vanderlei; Da Rocha, João B T; Nogueira, Cristina W

    2014-05-01

    Diabetic status is associated with an increase on oxidative stress markers in humans and animal models. We have investigated the in vitro effects of high concentrations of glucose on the profile of oxidative stress and osmotic fragility of blood from control and diabetic patients; we considered whether its antioxidant properties could afford some protection against glucose-induced osmotic fragility, and whether ebselen could act as an inhibitor of hemoglobin glycation. Raising blood glucose to 5-100 mmol/L resulted in a concentration-dependent increase of glycated hemoglobin (HbA1c; P Ebselen significantly reduced the glucose-induced increase in osmotic fragility and inhibited HbA1c formation (P < 0.0001). These results indicate that blood from patients with uncontrolled diabetes are more sensitive to osmotic shock than from patients with controlled diabetes and control subjects in relation to increased production of free radicals in vivo. © 2014 International Federation for Cell Biology.

  1. Studies of osmotic diarrhea induced in normal subjects by ingestion of polyethylene glycol and lactulose.

    OpenAIRE

    Hammer, H F; Santa Ana, C A; Schiller, L R; Fordtran, J S

    1989-01-01

    The purpose of these studies was to gain insight into the pathophysiology of pure osmotic diarrhea and the osmotic diarrhea caused by carbohydrate malabsorption. Diarrhea was induced in normal volunteers by ingestion of polyethylene glycol (PEG), which is nonabsorbable, not metabolized by colonic bacteria, and carries no electrical charge. In PEG-induced diarrhea, (a) stool weight was directly correlated with the total mass of PEG ingested; (b) PEG contributed 40-60% of the osmolality of the ...

  2. A model of strategic marketing alliances for hospices: vertical, internal, osmotic alliances and the complete model.

    Science.gov (United States)

    Starnes, B J; Self, D R

    1999-01-01

    This article develops two previous research efforts. William J. Winston (1994, 1995) has proposed a set of strategies by which health care organizations can benefit from forging strategic alliances. Raadt and Self (1997) have proposed a classification model of alliances including horizontal, vertical, internal, and osmotic. In the second of two articles, this paper presents a model of vertical, internal, and osmotic alliances. Advantages and disadvantages of each are discussed. Finally, the complete alliance system model is presented.

  3. The effects of osmotic stress on the structure and function of the cell nucleus.

    Science.gov (United States)

    Finan, John D; Guilak, Farshid

    2010-02-15

    Osmotic stress is a potent regulator of the normal function of cells that are exposed to osmotically active environments under physiologic or pathologic conditions. The ability of cells to alter gene expression and metabolic activity in response to changes in the osmotic environment provides an additional regulatory mechanism for a diverse array of tissues and organs in the human body. In addition to the activation of various osmotically- or volume-activated ion channels, osmotic stress may also act on the genome via a direct biophysical pathway. Changes in extracellular osmolality alter cell volume, and therefore, the concentration of intracellular macromolecules. In turn, intracellular macromolecule concentration is a key physical parameter affecting the spatial organization and pressurization of the nucleus. Hyper-osmotic stress shrinks the nucleus and causes it to assume a convoluted shape, whereas hypo-osmotic stress swells the nucleus to a size that is limited by stretch of the nuclear lamina and induces a smooth, round shape of the nucleus. These behaviors are consistent with a model of the nucleus as a charged core/shell structure pressurized by uneven partition of macromolecules between the nucleoplasm and the cytoplasm. These osmotically-induced alterations in the internal structure and arrangement of chromatin, as well as potential changes in the nuclear membrane and pores are hypothesized to influence gene transcription and/or nucleocytoplasmic transport. A further understanding of the biophysical and biochemical mechanisms involved in these processes would have important ramifications for a range of fields including differentiation, migration, mechanotransduction, DNA repair, and tumorigenesis. (c) 2009 Wiley-Liss, Inc.

  4. Screening for Osmotic Stress Responses in Rice Varieties under Drought Condition

    OpenAIRE

    Simon Swapna; Korukkanvilakath Samban Shylaraj

    2017-01-01

    Drought is the major abiotic stress factor that limits rice production worldwide. To evaluate the osmotic stress responses in rice varieties under drought condition, a total of 42 high-yielding rice varieties were collected from various research stations of Kerala Agricultural University in India. The experimental setup comprises of initial hydroponic treatments at different osmotic potentials, artificially induced by desired strengths of polyethylene glycol (PEG6000), and followed by the pot...

  5. Extracellular-matrix-mediated osmotic pressure drives Vibrio cholerae biofilm expansion and cheater exclusion

    OpenAIRE

    Yan, Jing; Nadell, Carey D.; Stone, Howard A.; Wingreen, Ned S.; Bassler, Bonnie L.

    2017-01-01

    Biofilms, surface-attached communities of bacteria encased in an extracellular matrix, are a major mode of bacterial life. How the material properties of the matrix contribute to biofilm growth and robustness is largely unexplored, in particular in response to environmental perturbations such as changes in osmotic pressure. Here, using Vibrio cholerae as our model organism, we show that during active cell growth, matrix production enables biofilm-dwelling bacterial cells to establish an osmot...

  6. Release and Decay Kinetics of Copeptin vs AVP in Response to Osmotic Alterations in Healthy Volunteers.

    Science.gov (United States)

    Fenske, Wiebke K; Schnyder, Ingeborg; Koch, Gilbert; Walti, Carla; Pfister, Marc; Kopp, Peter; Fassnacht, Martin; Strauss, Konrad; Christ-Crain, Mirjam

    2018-02-01

    Copeptin is the C-terminal fragment of the arginine vasopressin (AVP) prohormone whose measurement is more robust than that of AVP. Similar release and clearance characteristics have been suggested promoting copeptin as a surrogate marker. To characterize the physiology of osmotically regulated copeptin release and its half-life in direct comparison with plasma AVP. Ninety-one healthy volunteers underwent a standardized three-phase test protocol including (1) osmotic stimulation into the hypertonic range by hypertonic-saline infusion followed by osmotic suppression via (2) oral water load and (3) subsequent glucose infusion. Plasma copeptin, AVP, serum sodium, and osmolality levels were measured in regular intervals. In phase 1, an increase in median osmotic pressure [289 (286; 291) to 311 (309; 314) mOsm/kg H2O] caused similar release kinetics of plasma copeptin [4 (3.1; 6) to 29.3 (18.6; 48.2) pmol/L] and AVP [1 (0.7; 1.6) to 10.3 (6.8; 18.8) pg/mL]. Subsequent osmotic suppression to 298 (295; 301) mOsm/kg at the end of phase 3 revealed markedly different decay kinetics between both peptides-an estimated initial half-life of copeptin being approximately 2 times longer than that of AVP (26 vs 12 minutes). Copeptin is released in equimolar amounts with AVP in response to osmotic stimulation, suggesting its high potential as an AVP surrogate for differentiation of osmotic disorders. Furthermore, we here describe the decay kinetics of copeptin in response to osmotic depression enabling to identify a half-life for copeptin in direct comparison with AVP. Copyright © 2017 Endocrine Society

  7. Direct measurement of osmotic pressure of glycosaminoglycan solutions by membrane osmometry at room temperature.

    Science.gov (United States)

    Chahine, Nadeen O; Chen, Faye H; Hung, Clark T; Ateshian, Gerard A

    2005-09-01

    Articular cartilage is a hydrated soft tissue composed of negatively charged proteoglycans fixed within a collagen matrix. This charge gradient causes the tissue to imbibe water and swell, creating a net osmotic pressure that enhances the tissue's ability to bear load. In this study we designed and utilized an apparatus for directly measuring the osmotic pressure of chondroitin sulfate, the primary glycosaminoglycan found in articular cartilage, in solution with varying bathing ionic strength (0.015 M, 0.15 M, 0.5 M, 1 M, and 2 M NaCl) at room temperature. The osmotic pressure (pi) was found to increase nonlinearly with increasing chondroitin sulfate concentration and decreasing NaCl ionic bath environment. Above 1 M NaCl, pi changes negligibly with further increases in salt concentration, suggesting that Donnan osmotic pressure is negligible above this threshold, and the resulting pressure is attributed to configurational entropy. Results of the current study were also used to estimate the contribution of osmotic pressure to the stiffness of cartilage based on theoretical and experimental considerations. Our findings indicate that the osmotic pressure resulting from configurational entropy is much smaller in cartilage (based on an earlier study on bovine articular cartilage) than in free solution. The rate of change of osmotic pressure with compressive strain is found to contribute approximately one-third of the compressive modulus (H(A)(eff)) of cartilage (Pi approximately H(A)(eff)/3), with the balance contributed by the intrinsic structural modulus of the solid matrix (i.e., H(A) approximately 2H(A)(eff)/3). A strong dependence of this intrinsic modulus on salt concentration was found; therefore, it appears that proteoglycans contribute structurally to the magnitude of H(A), in a manner independent of osmotic pressure.

  8. Osmotic dehydration of fruit and berry raw materials in the food industry

    OpenAIRE

    N. A. Gribova; L. G. Eliseeva

    2017-01-01

    Osmotic dehydration has recently received more attention as an effective method of preserving fruits and berries. Osmosis is a simple process that facilitates the processing of fruits and berries in order to preserve the original characteristics, namely nutritional value and organoleptic properties: color, aroma and texture. Osmotic dehydration has found wide application in the preservation of food products, as the activity of water in fruits and berries decreases, in some of them up to 90% o...

  9. Using miniature osmotic infusion pumps to maintain tritiated thymidine exposure to cells in culture

    International Nuclear Information System (INIS)

    Neely, J.E.; Hake, D.A.

    1982-01-01

    To provide a constant level of tracer doses of tritiated thymidine to cultured cells during continuous infusion, miniature osmotic infusion pumps were used to provide replacement thymidine. By determining the loss of isotope from the media during nonreplacement, the rate of constant infusion replacement to maintain thymidine levels was calculated. The replacement rates were similar for the three cell lines examined and allowed a standard osmotic pump infusion

  10. Sandwich-structured hollow fiber membranes for osmotic power generation

    KAUST Repository

    Fu, Feng Jiang; Zhang, Sui; Chung, Neal Tai-Shung

    2015-01-01

    In this work, a novel sandwich-structured hollow fiber membrane has been developed via a specially designed spinneret and optimized spinning conditions. With this specially designed spinneret, the outer layer, which is the most crucial part of the sandwich-structured membrane, is maintained the same as the traditional dual-layer membrane. The inner substrate layer is separated into two layers: (1) an ultra-thin middle layer comprising a high molecular weight polyvinylpyrrolidone (PVP) additive to enhance integration with the outer polybenzimidazole (PBI) selective layer, and (2) an inner-layer to provide strong mechanical strength for the membrane. Experimental results show that a high water permeability and good mechanical strength could be achieved without the expensive post treatment process to remove PVP which was necessary for the dual-layer pressure retarded osmosis (PRO) membranes. By optimizing the composition, the membrane shows a maximum power density of 6.23W/m2 at a hydraulic pressure of 22.0bar when 1M NaCl and 10mM NaCl are used as the draw and feed solutions, respectively. To our best knowledge, this is the best phase inversion hollow fiber membrane with an outer selective PBI layer for osmotic power generation. In addition, this is the first work that shows how to fabricate sandwich-structured hollow fiber membranes for various applications. © 2015 Elsevier B.V.

  11. Artificial neural network model of pork meat cubes osmotic dehydratation

    Directory of Open Access Journals (Sweden)

    Pezo Lato L.

    2013-01-01

    Full Text Available Mass transfer of pork meat cubes (M. triceps brachii, shaped as 1x1x1 cm, during osmotic dehydration (OD and under atmospheric pressure was investigated in this paper. The effects of different parameters, such as concentration of sugar beet molasses (60-80%, w/w, temperature (20-50ºC, and immersion time (1-5 h in terms of water loss (WL, solid gain (SG, final dry matter content (DM, and water activity (aw, were investigated using experimental results. Five artificial neural network (ANN models were developed for the prediction of WL, SG, DM, and aw in OD of pork meat cubes. These models were able to predict process outputs with coefficient of determination, r2, of 0.990 for SG, 0.985 for WL, 0.986 for aw, and 0.992 for DM compared to experimental measurements. The wide range of processing variables considered for the formulation of these models, and their easy implementation in a spreadsheet calculus make it very useful and practical for process design and control.

  12. OSMOTIC PRESSURE INFLUENCE ON THE VEGETABLE CHIPS DEHYDRATION PROCESS

    Directory of Open Access Journals (Sweden)

    LILIANA I. MIHALCEA

    2017-03-01

    Full Text Available The low fruit and vegetable consumption identified by the World Health Organization is a significant factor for adverse health consequences, like obesity and noncommunicable diseases. In the worldwide effort of boosting fruit and vegetable consumption to at least five servings of fruits and vegetables per day (5-A-Day, healthy, mildly sweet and salty dried crunchy vegetable snacks can add up increasing attractiveness of vegetables among youngsters. The objectives of this research were to obtain sweet and salty dried parsnip snacks, pretreated with concentrated whey (CW and concentrated hydrolyzed whey (HW, to study the influence of osmotic pressure and temperature (45, 55 and 65 °C on the convective drying process and to estimate the kinetic parameters (diffusion coefficients, activation energy of parsnip drying. Nonlinear regression models were applied to estimate the drying parameters based on Henderson - Pabis equations. Results have shown that the activation energy required during drying by the chips treated with HW (23.89 kJ·mol-1 and CW (20.06 kJ·mol-1 is lower than in the reference sample (31.02 kJ·mol-1. Moreover, these represents a smart valorization of a by product from dairy industry rich in valuable minerals, proteins and sugars in the veggie industry.

  13. [Physiological analysis of various types of osmotic diuresis].

    Science.gov (United States)

    Marina, A S; Kutina, A V; Natochin, Iu V

    2011-12-01

    Efficacy of drugs reduced proximal reabsorption was compared in experiments with female Wistar rats. Urine flow rate for the 1st h of experiment was enhanced after polyethylene glycol-400 (PEG) and 6% Na2SO4 infusion by over 30-fold, exenatide--40-fold, glycerol--11-fold as compared with the control. The maximal values of Na+ excretion were observed during Na2SO4 and exenatide administration (280 +/- 31 micromol/h vs. 3.2 +/- 0.6 Imol/h/100 g bw). The highest K+ excretion was revealed in experiments with glycerol administration (41 +/- 5 micromol/h vs. 7 +/- 2 micromol/h/100 g bw), Mg2+ --after exenatide injection (5.3 +/- 1.3 micromol/h vs. 0.16 +/- 0.03 micromol/ h/100 g bw). Diuretic effects were additive after combined administration of maximal doses of exenatide and PEG which suggests a different mechanism of action of solutes filtrated (PEG) to the proximal nephron segment and generated due to Na+/HW-exchange inhibition (exenatide). Osmotic diuretics differ by potency, mechanism of diuretic action and selectivity of ion excretion).

  14. Hydrodynamic bifurcation in electro-osmotically driven periodic flows

    Science.gov (United States)

    Morozov, Alexander; Marenduzzo, Davide; Larson, Ronald G.

    2018-06-01

    In this paper, we report an inertial instability that occurs in electro-osmotically driven channel flows. We assume that the charge motion under the influence of an externally applied electric field is confined to a small vicinity of the channel walls that, effectively, drives a bulk flow through a prescribed slip velocity at the boundaries. Here, we study spatially periodic wall velocity modulations in a two-dimensional straight channel numerically. At low slip velocities, the bulk flow consists of a set of vortices along each wall that are left-right symmetric, while at sufficiently high slip velocities, this flow loses its stability through a supercritical bifurcation. Surprisingly, the flow state that bifurcates from a left-right symmetric base flow has a rather strong mean component along the channel, which is similar to pressure-driven velocity profiles. The instability sets in at rather small Reynolds numbers of about 20-30, and we discuss its potential applications in microfluidic devices.

  15. Sandwich-structured hollow fiber membranes for osmotic power generation

    KAUST Repository

    Fu, Feng Jiang

    2015-11-01

    In this work, a novel sandwich-structured hollow fiber membrane has been developed via a specially designed spinneret and optimized spinning conditions. With this specially designed spinneret, the outer layer, which is the most crucial part of the sandwich-structured membrane, is maintained the same as the traditional dual-layer membrane. The inner substrate layer is separated into two layers: (1) an ultra-thin middle layer comprising a high molecular weight polyvinylpyrrolidone (PVP) additive to enhance integration with the outer polybenzimidazole (PBI) selective layer, and (2) an inner-layer to provide strong mechanical strength for the membrane. Experimental results show that a high water permeability and good mechanical strength could be achieved without the expensive post treatment process to remove PVP which was necessary for the dual-layer pressure retarded osmosis (PRO) membranes. By optimizing the composition, the membrane shows a maximum power density of 6.23W/m2 at a hydraulic pressure of 22.0bar when 1M NaCl and 10mM NaCl are used as the draw and feed solutions, respectively. To our best knowledge, this is the best phase inversion hollow fiber membrane with an outer selective PBI layer for osmotic power generation. In addition, this is the first work that shows how to fabricate sandwich-structured hollow fiber membranes for various applications. © 2015 Elsevier B.V.

  16. Suppressive effect of cellulose on osmotic diarrhea caused by maltitol in healthy female subjects.

    Science.gov (United States)

    Oku, Tsuneyuki; Hongo, Ryoko; Nakamura, Sadako

    2008-08-01

    Using a single-group time-series design, we determined that osmotic diarrhea caused by maltitol ingestion was suppressed by the addition of not only soluble but also insoluble dietary fiber in healthy humans. We then clarified that cellulose delayed gastric emptying in rats. Twenty-seven healthy volunteers ingested maltitol step-wise at doses of 15, 20, 25, 30, 35, 40 and 45 g from small to large amounts. Within that range of ingested amounts, 22 out of 27 subjects experienced osmotic diarrhea from maltitol ingestion, and the minimal dose level of maltitol that induced osmotic diarrhea (MMD) was established for each subject. When 5 g of cellulose was added to the MMD, osmotic diarrhea was suppressed in 13 out of 19 subjects (68.4%), while partially hydrolyzed alginate-Na (PHA-Na), a soluble dietary fiber, suppressed osmotic diarrhea in 10 out of 20 subjects (50.0%). When a mixed solution of cellulose and maltitol was administered to rats, the gastric emptying of maltitol was significantly delayed at 30 and 60 min after administration (p=0.019, p=0.013), respectively. PHA-Na also significantly delayed gastric emptying at 30 min (p=0.013). In conclusion, cellulose can suppress the osmotic diarrhea caused by maltitol ingestion in humans and delay the gastric emptying of maltitol in rats. A new physiological property of cellulose was clarified in this study.

  17. Lower critical solution temperature (LCST) phase separation of glycol ethers for forward osmotic control.

    Science.gov (United States)

    Nakayama, Daichi; Mok, Yeongbong; Noh, Minwoo; Park, Jeongseon; Kang, Sunyoung; Lee, Yan

    2014-03-21

    Lower critical solution temperature (LCST) phase transition of glycol ether (GE)-water mixtures induces an abrupt change in osmotic pressure driven by a mild temperature change. The temperature-controlled osmotic change was applied for the forward osmosis (FO) desalination. Among three GEs evaluated, di(ethylene glycol) n-hexyl ether (DEH) was selected as a potential FO draw solute. A DEH-water mixture with a high osmotic pressure could draw fresh water from a high-salt feed solution such as seawater through a semipermeable membrane at around 10 °C. The water-drawn DEH-water mixture was phase-separated into a water-rich phase and a DEH-rich phase at around 30 °C. The water-rich phase with a much reduced osmotic pressure released water into a low-salt solution, and the DEH-rich phase was recovered into the initial DEH-water mixture. The phase separation behaviour, the residual GE concentration in the water-rich phase, the osmotic pressure of the DEH-water mixture, and the osmotic flux between the DEH-water mixture and salt solutions were carefully analysed for FO desalination. The liquid-liquid phase separation of the GE-water mixture driven by the mild temperature change between 10 °C and 30 °C is very attractive for the development of an ideal draw solute for future practical FO desalination.

  18. A view on thermodynamics of concentrated electrolytes: Modification necessity for electrostatic contribution of osmotic coefficient

    Science.gov (United States)

    Sahu, Jyoti; Juvekar, Vinay A.

    2018-05-01

    Prediction of the osmotic coefficient of concentrated electrolytes is needed in a wide variety of industrial applications. There is a need to correctly segregate the electrostatic contribution to osmotic coefficient from nonelectrostatic contribution. This is achieved in a rational way in this work. Using the Robinson-Stokes-Glueckauf hydrated ion model to predict non-electrostatic contribution to the osmotic coefficient, it is shown that hydration number should be independent of concentration so that the observed linear dependence of osmotic coefficient on electrolyte concentration in high concentration range could be predicted. The hydration number of several electrolytes (LiCl, NaCl, KCl, MgCl2, and MgSO4) has been estimated by this method. The hydration number predicted by this model shows correct dependence on temperature. It is also shown that the electrostatic contribution to osmotic coefficient is underpredicted by the Debye-Hückel theory at concentration beyond 0.1 m. The Debye-Hückel theory is modified by introducing a concentration dependent hydrated ionic size. Using the present analysis, it is possible to correctly estimate the electrostatic contribution to the osmotic coefficient, beyond the range of validation of the D-H theory. This would allow development of a more fundamental model for electrostatic interaction at high electrolyte concentrations.

  19. The osmotic stress response of split influenza vaccine particles in an acidic environment.

    Science.gov (United States)

    Choi, Hyo-Jick; Kim, Min-Chul; Kang, Sang-Moo; Montemagno, Carlo D

    2014-12-01

    Oral influenza vaccine provides an efficient means of preventing seasonal and pandemic disease. In this work, the stability of envelope-type split influenza vaccine particles in acidic environments has been investigated. Owing to the fact that hyper-osmotic stress can significantly affect lipid assembly of vaccine, osmotic stress-induced morphological change of split vaccine particles, in conjunction with structural change of antigenic proteins, was investigated by the use of stopped-flow light scattering (SFLS), intrinsic fluorescence, transmission electron microscopy (TEM), and hemagglutination assay. Split vaccine particles were found to exhibit a step-wise morphological change in response to osmotic stress due to double-layered wall structure. The presence of hyper-osmotic stress in acidic medium (0.3 osmolarity, pH 2.0) induced a significant level of membrane perturbation as measured by SFLS and TEM, imposing more damage to antigenic proteins on vaccine envelope than can be caused by pH-induced conformational change at acidic iso-osmotic condition. Further supports were provided by the intrinsic fluorescence and hemagglutinin activity measurements. Thus, hyper-osmotic stress becomes an important factor for determining stability of split vaccine particles in acidic medium. These results are useful in better understanding the destabilizing mechanism of split influenza vaccine particles in gastric environment and in designing oral influenza vaccine formulations.

  20. Osmotic dehydration of Braeburn variety apples in the production of sustainable food products

    Science.gov (United States)

    Ciurzyńska, Agnieszka; Cichowska, Joanna; Kowalska, Hanna; Czajkowska, Kinga; Lenart, Andrzej

    2018-01-01

    The aim of this work was to investigate the effects of osmotic dehydration conditions on the properties of osmotically pre-treated dried apples. The scope of research included analysing the most important mass exchange coefficients, i.e. water loss, solid gain, reduced water content and water activity, as well as colour changes of the obtained dried product. In the study, apples were osmotically dehydrated in one of two 60% solutions: sucrose or sucrose with an addition of chokeberry juice concentrate, for 30 and 120 min, in temperatures of 40 and 60°C. Ultrasound was also used during the first 30 min of the dehydration process. After osmotic pre-treatment, apples were subjected to innovative convective drying with the puffing effect, and to freeze-drying. Temperature and dehydration time increased the effectiveness of mass exchange during osmotic dehydration. The addition of chokeberry juice concentrate to standard sucrose solution and the use of ultrasound did not change the value of solid gain and reduced water content. Water activity of the dried apple tissue was not significantly changed after osmotic dehydration, while changes in colour were significant.

  1. Controlled release of glaucocalyxin - a self-nanoemulsifying system from osmotic pump tablets with enhanced bioavailability.

    Science.gov (United States)

    Yanfei, Miao; Guoguang, Chen; Lili, Ren; Pingkai, Ouyang

    2017-03-01

    The purpose of this study was to develop a new formulation to enhance the bioavailability simultaneously with controlled release of glaucocalyxin A (GLA). In this study, controlled release of GLA was achieved by the osmotic release strategy taking advantage of the bioavailability enhancing capacity of self-nanoemulsifying drug delivery systems (SNEDDS). The formulation of GLA-SNEDDS was selected by the solubility and pseudoternary-phase diagrams studies. The prepared GLA-SNEDDS formulations were characterized for self-emulsification time, effect of pH and robustness to dilution, droplet size analysis and zeta potential. The optimized GLA-SNEDDS were used to prepare GLA-SNEDDS osmotic pump tablet via direct powder compression method. The effect of formulation variables on the release characteristic was investigated. GLA-SNEDDS osmotic pump tablets were administered to beagle dogs and their pharmacokinetics were compared to GLA and GLA-SNEDDS as a control. In vitro drug release studies indicated that the GLA-SNEDDS osmotic pump tablet showed sustained release profiles with 90% released within 12 h. Pharmacokinetic study showed steady blood GLA with prolonged T max and mean residence time (MRT), and enhanced bioavailability for GLA-SNEDDS osmotic pump tablet. It was concluded that simultaneous controlling on GLA release and enhanced bioavailability had been achieved by a combination of osmotic pump tablet and SNEDDS.

  2. Chronic intrastriatal dopamine infusions in rats with unilateral lesions of the substantia nigra

    International Nuclear Information System (INIS)

    Hargraves, R.; Freed, W.J.

    1987-01-01

    This study examined the effects of continuously supplied dopamine delivered directly into the dopamine-deficient striatum. Rats received unilateral lesions of the substantia nigra by stereotaxic administration of 6-hydroxydopamine and were tested for apomorphine-induced rotational behavior and general activity. Osmotic mini-pumps were filled with dopamine in various concentrations, implanted subcutaneously and connected to a cannula implanted directly into the striatum. The system delivered solution at a rate of .5 μl/hr for two weeks. Dopamine in a dosage of 0.5 μg/per hour reduced apomorphine-induced rotational behavior by a mean of 52 +/- 5.8% (mean +/- SEM n=20) with a maximal individual decrease of 99%. There was no change in general activity or increase in stereotype behavior. Infusions of vehicle solutions did not decrease rotational behavior. Spread of the infused dopamine and its metabolites was estimated by adding 3 H-dopamine to the pumps in tracer quantities. Radioactivity was highly concentrated at the infusion site and decreased rapidly within a few mm from the infusion site. Continuous infusion methods may eventually prove to be effective in the treatment of nigro-striatal degenerative disease. 12 references, 4 figures

  3. Erythrocyte Osmotic Fragility and Excitability Score in Rabbit fed Hibiscus Sabdariffa in Graded Level.

    Science.gov (United States)

    Adenkola, A Y; Oluremi, O I A

    2014-12-29

    This study was conducted for 10 weeks with the aim of investigating the erythrocyte membrane integrity as measured by erythrocyte osmotic fragility and excitability scores of rabbits fed graded level of Hibiscus sabdariffa calyx (HSC). Twenty weaners' rabbit of both sexes were used for the study and were placed on four experimental diets which contain the following percentages of HSC 0 %, 25 %, 50 %, 75 %, as feed additive and were added at 0 g, 62.5 g, 125 g, 187.5 g designated as T1, T2, T3 and T4 experimental diets. Excitability scores were measured weekly as described by Voisnet et al. (1997). At the end of the experiment, the rabbits were slaughtered by severing the jugular vein. A Blood sample (2 ml) was collected from each rabbit into sampled bottles, containing the Na EDTA as anticoagulant for hematological analysis. Packed cell volume (PCV) Haemoglobin concentration (Hb), Total red blood cell (RBC) count, Total leukocyte count as well as differential leukocyte was determined using standard method. The percentage haemolysis recorded at 0.3 % to 0.8 % was significantly (P < 0.05) higher in rabbits in T1 compared to the remaining 3 diets. The result of excitability score shows that rabbit on diet 1 and 2 had a lower value which was significantly (P < 0.05) lower than rabbits on diets 3 and 4 with a value of 65.5 ± 5.0 and 70.00 ± 5.50 % respectively. In conclusion this study demonstrated for the first time that chronic administration of HSC improves haematological parameters, brain mood and function as well as maintaining erythrocyte membrane integrity.

  4. Cryohemolysis, erythrocyte osmotic fragility, and supplementary hematimetric indices in the diagnosis of hereditary spherocytosis.

    Science.gov (United States)

    Emilse, Ledesma Achem Miryam; Cecilia, Haro; María, Terán Magdalena; Eugenia, Mónaco María; Alicia, Issé Blanca; Lazarte, Sandra Stella

    2018-03-01

    Hereditary spherocytosis (HS) is a chronic hemolytic anemia characterized by microspherocytes in the peripheral blood and increased erythrocyte osmotic fragility (EOF). This study evaluated the cryohemolysis test (CHT); initial hemolysis (IH); immediate and incubated hemolysis percentage in 5.5 g/L NaCl (H5.5); mean corpuscular hemoglobin concentration (MCHC); red blood cell distribution width (RDW); and Hb/MCHC, Hb/RDW, and MCHC/RDW ratios for the diagnosis of HS. Data from 13 patients with HS were evaluated at the Instituto de Bioquímica Aplicada and compared with data from 14 unaffected individuals and 11 patients with anemia due to another etiology. Total blood and reticulocyte counts, CHT, and immediate and incubated EOF were performed in all subjects; sensitivity, specificity, efficiency, and Youden index (YI) were calculated. Eight patients with HS had MCHC ≥345 g/L, 10 had RDW ≥14.5%, 12 had IH >5.0 g/L, 11 had immediate H5.5 ≥5%, and 13 had incubated H5.5 ≥50% (the cut-off value to consider HS). The efficiency and YI were: immediate H5.5 (0.94-0.85), incubated H5.5 (0.89-0.82), IH (0.89-0.78), MCHC (0.87-0.62), CHT (0.84-0.54), and Hb/MCHC (0.71-0.56), respectively. The calculated ratios could distinguish subjects with HS from unaffected individuals ( P 0.05). Although the CHT and supplementary hematimetric indexes were useful to differentiate individuals with SH from healthy controls, they cannot distinguish from anemias of other etiology. CHT and MCHC, in addition to EOF, are recommended for diagnosing HS patients because of their low cost and efficiency.

  5. Expression profiling on soybean leaves reveals integration of ER- and osmotic-stress pathways

    Directory of Open Access Journals (Sweden)

    Dewey Ralph E

    2007-11-01

    Full Text Available Abstract Background Despite the potential of the endoplasmic reticulum (ER stress response to accommodate adaptive pathways, its integration with other environmental-induced responses is poorly understood in plants. We have previously demonstrated that the ER-stress sensor binding protein (BiP from soybean exhibits an unusual response to drought. The members of the soybean BiP gene family are differentially regulated by osmotic stress and soybean BiP confers tolerance to drought. While these results may reflect crosstalk between the osmotic and ER-stress signaling pathways, the lack of mutants, transcriptional response profiles to stresses and genome sequence information of this relevant crop has limited our attempts to identify integrated networks between osmotic and ER stress-induced adaptive responses. As a fundamental step towards this goal, we performed global expression profiling on soybean leaves exposed to polyethylene glycol treatment (osmotic stress or to ER stress inducers. Results The up-regulated stress-specific changes unmasked the major branches of the ER-stress response, which include enhancing protein folding and degradation in the ER, as well as specific osmotically regulated changes linked to cellular responses induced by dehydration. However, a small proportion (5.5% of total up-regulated genes represented a shared response that seemed to integrate the two signaling pathways. These co-regulated genes were considered downstream targets based on similar induction kinetics and a synergistic response to the combination of osmotic- and ER-stress-inducing treatments. Genes in this integrated pathway with the strongest synergistic induction encoded proteins with diverse roles, such as plant-specific development and cell death (DCD domain-containing proteins, an ubiquitin-associated (UBA protein homolog and NAC domain-containing proteins. This integrated pathway diverged further from characterized specific branches of ER-stress as

  6. Sixteen-Day Bedrest Significantly Increases Plasma Colloid Osmotic Pressure

    Science.gov (United States)

    Hargens, Alan R.; Hsieh, S. T.; Murthy, G.; Ballard, R. E.; Convertino, V. A.; Wade, Charles E. (Technical Monitor)

    1994-01-01

    Upon exposure to microgravity, astronauts lose up to 10% of their total plasma volume, which may contribute to orthostatic intolerance after space flight. Because plasma colloid osmotic pressure (COP) is a primary factor maintaining plasma volume, our objective was to measure time course changes in COP during microgravity simulated by 6 deg. head-down tilt (HDT). Seven healthy male subjects (30-55 years of age) were placed in HDT for 16 days. For the purpose of another study, three of the seven subjects were chosen to exercise on a cycle ergometer on day 16. Blood samples were drawn immediately before bedrest on day 14 of bedrest, 18-24 hours following exercise while all subjects were still in HDT and 1 hour following bedrest termination. Plasma COP was measured in all 20 microliter EDTA-treated samples using an osmometer fitted with a PM 30 membrane. Data were analyzed with paired and unpaired t-tests. Plasma COP on day 14 of bedrest (29.9 +/- 0.69 mmHg) was significantly higher (p less than 0.005) than the control, pre-bedrest value (23.1 +/- 0.76 mmHg). At one hour of upright recovery after HDT, plasma COP remained significantly elevated (exercise: 26.9 +/- 0.87 mmHg; no exercise: 26.3 +/- 0.85 mmHg). Additionally, exercise had no significant effect on plasma COP 18-24 hours following exercise (exercise: 27.8 +/- 1.09 mmHg; no exercise: 27.1 +/- 0.78 mmHg). Our results demonstrate that plasma COP increases significantly with microgravity simulated by HDT. However, preliminary results indicate exercise during HDT does not significantly affect plasma COP.

  7. Response of Escherichia coli growth rate to osmotic shock.

    Science.gov (United States)

    Rojas, Enrique; Theriot, Julie A; Huang, Kerwyn Casey

    2014-05-27

    It has long been proposed that turgor pressure plays an essential role during bacterial growth by driving mechanical expansion of the cell wall. This hypothesis is based on analogy to plant cells, for which this mechanism has been established, and on experiments in which the growth rate of bacterial cultures was observed to decrease as the osmolarity of the growth medium was increased. To distinguish the effect of turgor pressure from pressure-independent effects that osmolarity might have on cell growth, we monitored the elongation of single Escherichia coli cells while rapidly changing the osmolarity of their media. By plasmolyzing cells, we found that cell-wall elastic strain did not scale with growth rate, suggesting that pressure does not drive cell-wall expansion. Furthermore, in response to hyper- and hypoosmotic shock, E. coli cells resumed their preshock growth rate and relaxed to their steady-state rate after several minutes, demonstrating that osmolarity modulates growth rate slowly, independently of pressure. Oscillatory hyperosmotic shock revealed that although plasmolysis slowed cell elongation, the cells nevertheless "stored" growth such that once turgor was reestablished the cells elongated to the length that they would have attained had they never been plasmolyzed. Finally, MreB dynamics were unaffected by osmotic shock. These results reveal the simple nature of E. coli cell-wall expansion: that the rate of expansion is determined by the rate of peptidoglycan insertion and insertion is not directly dependent on turgor pressure, but that pressure does play a basic role whereby it enables full extension of recently inserted peptidoglycan.

  8. Osmotic and stimulant laxatives for the management of childhood constipation.

    Science.gov (United States)

    Gordon, Morris; MacDonald, John K; Parker, Claire E; Akobeng, Anthony K; Thomas, Adrian G

    2016-08-17

    Constipation within childhood is an extremely common problem. Despite the widespread use of osmotic and stimulant laxatives by health professionals to manage constipation in children, there has been a long standing paucity of high quality evidence to support this practice. We set out to evaluate the efficacy and safety of osmotic and stimulant laxatives used to treat functional childhood constipation. We searched MEDLINE, EMBASE, the Cochrane Central Register of Controlled Trials, and the Cochrane IBD Group Specialized Trials Register from inception to 10 March 2016. There were no language restrictions. We also searched the references of all included studies, personal contacts and drug companies to identify studies. Randomised controlled trials (RCTs) which compared osmotic or stimulant laxatives to placebo or another intervention, with participants aged 0 to 18 years old were considered for inclusion. The primary outcome was frequency of defecation. Secondary endpoints included faecal incontinence, disimpaction, need for additional therapies and adverse events. Relevant papers were identified and two authors independently assessed the eligibility of trials, extracted data and assessed methodological quality using the Cochrane risk of bias tool. The primary outcome was frequency of defecation. Secondary endpoints included faecal incontinence, disimpaction, need for additional therapies and adverse events. For continuous outcomes we calculated the mean difference (MD) and 95% confidence interval (CI) using a fixed-effect model. For dichotomous outcomes we calculated the risk ratio (RR) and 95% CI using a fixed-effect model. The Chi(2) and I(2) statistics were used to assess statistical heterogeneity. A random-effects model was used in situations of unexplained heterogeneity. We assessed the overall quality of the evidence supporting the primary and secondary outcomes using the GRADE criteria. Twenty-five RCTs (2310 participants) were included in the review. Fourteen

  9. Effect of Osmotic Pressure on the Stability of Whole Inactivated Influenza Vaccine for Coating on Microneedles.

    Directory of Open Access Journals (Sweden)

    Hyo-Jick Choi

    Full Text Available Enveloped virus vaccines can be damaged by high osmotic strength solutions, such as those used to protect the vaccine antigen during drying, which contain high concentrations of sugars. We therefore studied shrinkage and activity loss of whole inactivated influenza virus in hyperosmotic solutions and used those findings to improve vaccine coating of microneedle patches for influenza vaccination. Using stopped-flow light scattering analysis, we found that the virus underwent an initial shrinkage on the order of 10% by volume within 5 s upon exposure to a hyperosmotic stress difference of 217 milliosmolarity. During this shrinkage, the virus envelope had very low osmotic water permeability (1 - 6×10-4 cm s-1 and high Arrhenius activation energy (Ea = 15.0 kcal mol-1, indicating that the water molecules diffused through the viral lipid membranes. After a quasi-stable state of approximately 20 s to 2 min, depending on the species and hypertonic osmotic strength difference of disaccharides, there was a second phase of viral shrinkage. At the highest osmotic strengths, this led to an undulating light scattering profile that appeared to be related to perturbation of the viral envelope resulting in loss of virus activity, as determined by in vitro hemagglutination measurements and in vivo immunogenicity studies in mice. Addition of carboxymethyl cellulose effectively prevented vaccine activity loss in vitro and in vivo, believed to be due to increasing the viscosity of concentrated sugar solution and thereby reducing osmotic stress during coating of microneedles. These results suggest that hyperosmotic solutions can cause biphasic shrinkage of whole inactivated influenza virus which can damage vaccine activity at high osmotic strength and that addition of a viscosity enhancer to the vaccine coating solution can prevent osmotically driven damage and thereby enable preparation of stable microneedle coating formulations for vaccination.

  10. A review on controlled porosity osmotic pump tablets and its evaluation

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    Chinmaya Keshari Sahoo

    2015-12-01

    Full Text Available Conventional drug delivery system provides an immediate release of drug which does not control the release of the drug and does not maintain effective concentration at target site for a longer period of time. Hence to avoid the shortcomings there is development of various controlled drug delivery systems. Among these osmotic drug delivery system (ODDS utilizes the principle of osmotic pressure and delivers drug dose in an optimized manner to maintain drug concentration within the therapeutic window and minimizes toxic effects. ODDS releases drug at a controlled rate that is independent of the pH and thermodynamics of dissolution medium. The release of drug from ODDS follows zero order kinetics. The release of drug from osmotic system depends upon various formulation factors such as solubility, osmotic pressure of the core components, size of the delivery orifice and nature of the rate controlling membrane. Controlled porosity osmotic pump (CPOP contains drug, osmogens, excipients in core and a coating of semipermeable membrane with water soluble additives. In CPOP water soluble additives dissolve after coming in contact with water, resulting in an in situ formation of a microporous membrane. The present study gives an idea about osmosis, CPOP, components of CPOP and its evaluation.

  11. Osmotic stress, endogenous abscisic acid and the control of leaf morphology in Hippuris vulgaris L

    Science.gov (United States)

    Goliber, T. E.; Feldman, L. J.

    1989-01-01

    Previous reports indicate that heterophyllous aquatic plants can be induced to form aerial-type leaves on submerged shoots when they are grown in exogenous abscisic acid (ABA). This study reports on the relationship between osmotic stress (e.g. the situation encountered by a shoot tip when it grows above the water surface), endogenous ABA (as measured by gas chromatography-electron capture detector) and leaf morphology in the heterophyllous aquatic plant, Hippuris vulgaris. Free ABA could not be detected in submerged shoots of H. vulgaris but in aerial shoots ABA occurred at ca. 40 ng (g fr wt)-1. When submerged shoots were osmotically stressed ABA appeared at levels of 26 to 40 ng (g fr wt)-1. These and other data support two main conclusions: (1) Osmotically stressing a submerged shoot causes the appearance of detectable levels of ABA. (2) The rise of ABA in osmotically stressed submerged shoots in turn induces a change in leaf morphology from the submerged to the aerial form. This corroborates the hypothesis that, in the natural environment, ABA levels rise in response to the osmotic stress encountered when a submerged shoot grows up through the water/air interface and that the increased ABA leads to the production of aerial-type leaves.

  12. Flow cytometric determination of osmotic behaviour of animal erythrocytes toward their engineering for drug delivery

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    Kostić Ivana T.

    2015-01-01

    Full Text Available Despite the fact that the methods based on the osmotic properties of the cells are the most widely used for loading of drugs in human and animal erythrocytes, data related to the osmotic properties of erythrocytes derived from animal blood are scarce. This work was performed with an aim to investigate the possibility of use the flow cytometry as a tool for determination the osmotic behaviour of porcine and bovine erythrocytes, and thus facilitate the engineering of erythrocytes from animal blood to be drug carriers. The method of flow cytometry successfully provided the information about bovine and porcine erythrocyte osmotic fragility, and made the initial steps in assessment of erythrocyte shape in a large number of erythrocytes. Although this method is not able to confirm the swelling of pig erythrocytes, it indicated to the differences in pig erythrocytes that had basic hematological parameters inside and outside the reference values. In order to apply/use the porcine and bovine erythrocytes as drug carriers, the method of flow cytometry, confirming the presence of osmotically different fractions of red blood cells, indicated that various amounts of the encapsulated drug in porcine and bovine erythrocytes can be expected.

  13. THE IMPORTANCE OF THE ERYTHROCYTES OSMOTIC FRAGILITY TEST PERFORMED IN CHILDREN WITH INDIRECT HYPERBILIRUB1NEMIA

    Directory of Open Access Journals (Sweden)

    Ivana Stojanović

    2005-07-01

    Full Text Available The osmotic fragility test of erythrocytes is useful in the diagnosis of different types of hereditary hemolytic anemias followed with hyperbilirubinemia. Hemolytic anemias, characterized by accelerated destruction of red blood cells, are usually the consequence of many metabolic abnormalities like cellular membrane defect, erythrocyte enzymes defect or hemoglobin abnormalities – hemoglobinopathies. The object of our study was to assess the relationship between osmotic fragility test of erythrocytes and severity of indirect hyperbilirubinemia in some inherited erythrocytes’ disorders. We did the osmotic fragility test of erythrocytes by using Dacie, s method with normal values of erythrocytes hemolysis between 0,48 to 0,34% NaCl (minimal to maximal hemolysis. In hereditary spherocytosis, fragility of erythrocytes was increased (min. at 0,50 % NaCl to max. 0,44 % NaCl . In the child with β- thalassemia and cycle cell anemia erythrocytes fragility was decreased (min . at 0,42 to max. 0,32 % NaCl, that is 0,40% min. of hemolysis and 0,34% max. hemolysis in the second case. In newborn infants with high levels of indirect bilirubin in serum as a cause of physiological jaundice, the osmotic fragility test was within a normal range. Our findings point out the diagnostic value of osmotic fragility test in assessing patients with the indirect hyperbilirubinemia. This simple and important diagnostic test can be performed in small laboratories.

  14. Cystic fibrosis airway secretions exhibit mucin hyperconcentration and increased osmotic pressure

    Science.gov (United States)

    Henderson, Ashley G.; Ehre, Camille; Button, Brian; Abdullah, Lubna H.; Cai, Li-Heng; Leigh, Margaret W.; DeMaria, Genevieve C.; Matsui, Hiro; Donaldson, Scott H.; Davis, C. William; Sheehan, John K.; Boucher, Richard C.; Kesimer, Mehmet

    2014-01-01

    The pathogenesis of mucoinfective lung disease in cystic fibrosis (CF) patients likely involves poor mucus clearance. A recent model of mucus clearance predicts that mucus flow depends on the relative mucin concentration of the mucus layer compared with that of the periciliary layer; however, mucin concentrations have been difficult to measure in CF secretions. Here, we have shown that the concentration of mucin in CF sputum is low when measured by immunologically based techniques, and mass spectrometric analyses of CF mucins revealed mucin cleavage at antibody recognition sites. Using physical size exclusion chromatography/differential refractometry (SEC/dRI) techniques, we determined that mucin concentrations in CF secretions were higher than those in normal secretions. Measurements of partial osmotic pressures revealed that the partial osmotic pressure of CF sputum and the retained mucus in excised CF lungs were substantially greater than the partial osmotic pressure of normal secretions. Our data reveal that mucin concentration cannot be accurately measured immunologically in proteolytically active CF secretions; mucins are hyperconcentrated in CF secretions; and CF secretion osmotic pressures predict mucus layer–dependent osmotic compression of the periciliary liquid layer in CF lungs. Consequently, mucin hypersecretion likely produces mucus stasis, which contributes to key infectious and inflammatory components of CF lung disease. PMID:24892808

  15. Interaction of prechilling, temperature, osmotic stress, and light in Picea abies seed germination

    International Nuclear Information System (INIS)

    Leinonen, K.; Rita, H.

    1995-01-01

    A multi-factor experimental approach and proportional odds model was used to study interactions between five environmental factors significant to Norway spruce seed germination: prechilling (at +4.5 °C), suboptimal temperatures (+12 and +16 °C), osmotically induced water stress (–0.3 Mpa and 0 Mpa), prolonged white light, and short-period far-red light. Temperature and osmotic stress interacted with one another in the germination of seeds: the effect of osmotic stress being stronger at +16 °C than at +12 °C. In natural conditions, this interaction may prevent germination early in the summer when soil dries and temperature increases. Prolonged white light prevented germination at low temperature and low osmotic potential. Inhibitory effect was less at higher temperatures and higher osmotic potential, as well as after prechilling. Short-period far-red light did not prevent germination of unchilled seeds in darkness. Prechilling tended to make seeds sensitive to short pulses of far-red light, an effect which depended on temperature: at +12 °C the effect on germination was promotive, but at +16 °C, inhibitory and partly reversible by white light. It seems that Norway spruce seeds may have adapted to germinate in canopy shade light rich in far-red. The seeds may also have evolved mechanisms to inhibit germination in prolonged light

  16. Effect of Osmotic Stress on Seed Germination Indices of Nigella sativa and Silybum marianum

    Directory of Open Access Journals (Sweden)

    H Balouchi

    2012-04-01

    Full Text Available Evaluation of medicinal plants to drought and salt stress tolerance, in an attempt to plant them under drought and saline regions, is of utmost importance. Environmental stresses, especially drought and salt, reduce the global crop yields more than other factors. Selection of drought tolerant crops at germination stage, usually is, the fast and low cost method. In order to study the effect of osmotic stress on germination indices of black cumin and milk thistle, an experiment carried out in a completely randomized design with four replications at the Seed Technology Laboratoary of Yasouj University in 2008. Treatments were 0 (as control, -2.4, -4.8, -7.2 and -9.4 bar osmotic potentials created by using PEG 6000. Results showed that, decreasing of osmotic potential reduced speed of germination and its percentage, root and shoot lengths and dry matter in these two plants. Black cumin showed higher tolerance, to -4.8 bar osmotic potential, as compared to milk thistle. However, milk thistle showed higher tolerance to drought stress, up to this osmotic potential (-4.8 bar, compared to black cumin. Milk thistle had lower germination speed and percentage at higher drought stress as compared to black cumin. Generally, milk thistle showed better growth and survival than black cumin due to its higher root and shoot length and dry matter.

  17. Osmotic coefficients and apparent molar volumes of 1-hexyl-3-methylimidazolium trifluoromethanesulfonate ionic liquid in alcohols

    International Nuclear Information System (INIS)

    González, Emilio J.; Calvar, Noelia; Macedo, Eugénia A.

    2014-01-01

    Highlights: • Physical and osmotic properties of [HMim][TfO] in alcohols are reported. • Apparent molar properties and osmotic coefficients were obtained. • Apparent molar volumes were fitted using a Redlich–Meyer type equation. • The osmotic coefficients were modeled with the Extended Pitzer and the MNRTL models. -- Abstract: In this work, density for the binary mixtures of 1-hexyl-3-methylimidazolium trifluoromethanesulfonate in alcohols (1-propanol, or 2-propanol, or 1-butanol, or 2-butanol, or 1-pentanol) was measured at T = 323.15 K and atmospheric pressure. From this property, the corresponding apparent molar volumes were calculated and fitted to a Redlich–Meyer type equation. For these mixtures, the osmotic and activity coefficients, and vapor pressures of these binary systems were also determined at the same temperature using the vapor pressure osmometry technique. The experimental osmotic coefficients were modeled by the Extended Pitzer model of Archer. The parameters obtained in this correlation were used to calculate the mean molal activity coefficients and the excess Gibbs free energy for the studied mixtures

  18. Understanding Fast and Robust Thermo-osmotic Flows through Carbon Nanotube Membranes: Thermodynamics Meets Hydrodynamics.

    Science.gov (United States)

    Fu, Li; Merabia, Samy; Joly, Laurent

    2018-04-19

    Following our recent theoretical prediction of the giant thermo-osmotic response of the water-graphene interface, we explore the practical implementation of waste heat harvesting with carbon-based membranes, focusing on model membranes of carbon nanotubes (CNT). To that aim, we combine molecular dynamics simulations and an analytical model considering the details of hydrodynamics in the membrane and at the tube entrances. The analytical model and the simulation results match quantitatively, highlighting the need to take into account both thermodynamics and hydrodynamics to predict thermo-osmotic flows through membranes. We show that, despite viscous entrance effects and a thermal short-circuit mechanism, CNT membranes can generate very fast thermo-osmotic flows, which can overcome the osmotic pressure of seawater. We then show that in small tubes confinement has a complex effect on the flow and can even reverse the flow direction. Beyond CNT membranes, our analytical model can guide the search for other membranes to generate fast and robust thermo-osmotic flows.

  19. Sorbitol treatment extends lifespan and induces the osmotic stress response in Caenorhabditis elegans

    Directory of Open Access Journals (Sweden)

    Devon eChandler-Brown

    2015-10-01

    Full Text Available The response to osmotic stress is a highly conserved process for adapting to changing environmental conditions. Prior studies have shown that hyperosmolarity by addition of sorbitol to the growth medium is sufficient to increase both chronological and replicative lifespan in the budding yeast, Saccharomyces cerevisiae. Here we report a similar phenomenon in the nematode Caenorhabditis elegans. Addition of sorbitol to the nematode growth medium induces an adaptive osmotic response and increases C. elegans lifespan by about 35%. Lifespan extension from 5% sorbitol behaves similarly to dietary restriction in a variety of genetic backgrounds, increasing lifespan additively with mutation of daf-2(e1370 and independently of daf-16(mu86, sir-2.1(ok434, aak-2(ok524, and hif-1(ia04. Dietary restriction by bacterial deprivation or mutation of eat-2(ad1113 fails to further extend lifespan in the presence of 5% sorbitol. Two mutants with constitutive activation of the osmotic response, osm-5(p813 and osm-7(n1515, were found to be long-lived, and lifespan extension from sorbitol required the glycerol biosynthetic enzymes GPDH-1 and GPDH-2. Taken together, these observations demonstrate that exposure to sorbitol at levels sufficient to induce an adaptive osmotic response extends lifespan in worms and define the osmotic stress response pathway as a longevity pathway conserved between yeast and nematodes.

  20. Extracellular-matrix-mediated osmotic pressure drives Vibrio cholerae biofilm expansion and cheater exclusion.

    Science.gov (United States)

    Yan, Jing; Nadell, Carey D; Stone, Howard A; Wingreen, Ned S; Bassler, Bonnie L

    2017-08-23

    Biofilms, surface-attached communities of bacteria encased in an extracellular matrix, are a major mode of bacterial life. How the material properties of the matrix contribute to biofilm growth and robustness is largely unexplored, in particular in response to environmental perturbations such as changes in osmotic pressure. Here, using Vibrio cholerae as our model organism, we show that during active cell growth, matrix production enables biofilm-dwelling bacterial cells to establish an osmotic pressure difference between the biofilm and the external environment. This pressure difference promotes biofilm expansion on nutritious surfaces by physically swelling the colony, which enhances nutrient uptake, and enables matrix-producing cells to outcompete non-matrix-producing cheaters via physical exclusion. Osmotic pressure together with crosslinking of the matrix also controls the growth of submerged biofilms and their susceptibility to invasion by planktonic cells. As the basic physicochemical principles of matrix crosslinking and osmotic swelling are universal, our findings may have implications for other biofilm-forming bacterial species.Most bacteria live in biofilms, surface-attached communities encased in an extracellular matrix. Here, Yan et al. show that matrix production in Vibrio cholerae increases the osmotic pressure within the biofilm, promoting biofilm expansion and physical exclusion of non-matrix producing cheaters.

  1. An analysis of the effects of osmotic backwashing on the seawater reverse osmosis process.

    Science.gov (United States)

    Park, JunYoung; Jeong, WooWon; Nam, JongWoo; Kim, JaeHun; Kim, JiHoon; Chon, Kangmin; Lee, Euijong; Kim, HyungSoo; Jang, Am

    2014-01-01

    Fouling control is an important consideration in the design and operation of membrane-based water treatment processes. It has been generally known that chemical cleaning is still the most common method to remove foultants and maintain the performance of reverse osmosis (RO) desalination. Regardless of the chemical membrane cleaning methods applied effectively, however, frequent chemical cleaning can shorten the membrane life. In addition, it also increases operating and maintenance costs due to the waste chemical disposal. As an alternative, osmotic backwashing can be applied to RO membranes by diluting the concentration polarization (CP) layer. In this study, the effects of osmotic backwashing were analysed under different total dissolved salts (TDSs) and backwashing conditions, and the parameters of the osmotic backwashing were evaluated. The results of the analysis based on the properties of the organic matters found in raw water showed that the cleaning efficiency in respect to the fouling by hydrophilic organic matters was the greatest. Osmotic backwashing was carried out by changing the TDS of the permeate. As a result, the backwashing volume decreased with time due to the CP of the permeate and the backwashing volume. The difference in the osmotic pressure between the raw water and the permeate (Delta pi) also decreased as time passed. It was confirmed that when the temperature of the effluent was high, both the cleaning efficiency and the backwashing volume, which inpours at the same time, increased. When the circulation flow of the effluent was high, both the cleaning efficiency and the backwashing volume increased.

  2. Osmotic and apparent molar properties of binary mixtures alcohol + 1-butyl-3-methylimidazolium trifluoromethanesulfonate ionic liquid

    International Nuclear Information System (INIS)

    González, Emilio J.; Calvar, Noelia; Domínguez, Ángeles; Macedo, Eugénia A.

    2013-01-01

    Highlights: ► Osmotic and physical properties of binary mixtures {alcohol + [BMim][TfO]} were measured. ► From experimental data, apparent molar properties and osmotic coefficients were calculated. ► The apparent properties were fitted using a Redlich–Meyer type equation. ► The osmotic coefficients were correlated using the Extended Pitzer model. -- Abstract: In this work, physical properties (densities and speeds of sound) for the binary systems {1-propanol, or 2-propanol, or 1-butanol, or 2-butanol, or 1-pentanol + 1-butyl-3-methylimidazolium trifluoromethanesulfonate} were experimentally measured from T = (293.15 to 323.15) K and at atmospheric pressure. These data were used to calculate the apparent molar volume and apparent molar isentropic compression which were fitted to a Redlich–Meyer type equation. This fit was used to obtain the corresponding apparent molar properties at infinite dilution. On the other hand, the osmotic and activity coefficients and vapor pressures of these binary mixtures were also determined at T = 323.15 K using the vapor pressure osmometry technique. The Extended Pitzer model of Archer was employed to correlate the experimental osmotic coefficients. From the parameters obtained in the correlation, the mean molal activity coefficients and the excess Gibbs free energy for the studied mixtures were calculated

  3. Physicochemical characteristics of guava “Paluma” submitted to osmotic dehydration

    Directory of Open Access Journals (Sweden)

    Roselene Ferreira Oliveira

    2014-09-01

    Full Text Available The aim of this work was to evaluate the conservation post process osmotic of guava stored temperature at 5oC. Guava (Psidium guajava L., red variety “Paluma” minimally processed by mild osmotic dehydration, were packaged in polyethylene terephthalate (PET and stored temperature at 5ºC. Non-treated guava, packed in PET trays, was used as control. The treatment used was osmotic dehydration in sucrose syrup at 60ºBrix and physicochemical determinations were pH, total soluble solids (TSS, total titratable acidity (TTA, reducing sugars (RS, total sugars (TS and parameters related to colour read (a*, chroma (c*, yellow (b*, luminosity (L* of the fresh and osmotically dehydrated guava slices. The dehydrated fruits lost about 34.45% of water, concentrating contents of soluble solids, total and reducing sugars, when compared to control samples. The pH value remained around 3.76 for the OD fruits and 3.87 for the fresh fruits. The colour of the dehydrated fruits was more intense than the control samples’. The guava slices osmotic dehydration had 21 days of shelf life, showed physicochemical characteristics significantly superior to the control samples’, having a stable and high quality product as a result.

  4. Lithium clearance in chronic nephropathy

    DEFF Research Database (Denmark)

    Kamper, A L; Holstein-Rathlou, N H; Leyssac, P P

    1989-01-01

    1. Lithium clearance measurements were made in 72 patients with chronic nephropathy of different aetiology and moderate to severely reduced renal function. 2. Lithium clearance was strictly correlated with glomerular filtration rate, and there was no suggestion of distal tubular reabsorption...... of lithium or influence of osmotic diuresis. 3. Fractional reabsorption of lithium was reduced in most patients with glomerular filtration rates below 25 ml/min. 4. Calculated fractional distal reabsorption of sodium was reduced in most patients with glomerular filtration rates below 50 ml/min. 5. Lithium...... that lithium clearance may be a measure of the delivery of sodium and water from the renal proximal tubule. With this assumption it was found that adjustment of the sodium excretion in chronic nephropathy initially takes place in the distal parts of the nephron (loop of Henle, distal tubule and collecting duct...

  5. Methods to increase the rate of mass transfer during osmotic dehydration of foods.

    Science.gov (United States)

    Chwastek, Anna

    2014-01-01

    Traditional methods of food preservation such as freezing, freeze drying (lyophilization), vacuum drying, convection drying are often supplemented by new technologies that enable obtaining of high quality products. Osmotic dehydration is more and more often used during processing of fruits and vegetables. This method allows maintaining good organoleptic and functional properties in the finished product. Obtaining the desired degree of dehydration or saturation of the material with an osmoactive substance often requires  elongation of time or use of high temperatures. In recent years much attention was devoted to techniques aimed at increasing the mass transfer between the dehydrated material and the hypertonic solution. The work reviews the literature focused on methods of streamlining the process of osmotic dehydration which include the use of: ultrasound, high hydrostatic pressure, vacuum osmotic dehydration and pulsed electric field.

  6. Recommendation to use iso-osmotic contrast medium in interventional treatment

    International Nuclear Information System (INIS)

    Zhou Bing; Cheng Yongde

    2012-01-01

    With the rapid development of imaging diagnostic and interventional therapeutic techniques, the contrast medium (CM) has been used more and more common in clinical practice, and meanwhile more and more attention has been paid to the CM-related adverse events. Contrast induced nephropathy (CN) is the most common CM-related adverse event, and CM-related neurotoxicity has already attracted the physicians' attention. The osmotic pressure of the iso-osmotic contrast medium (IOCM) is quite the same as that of the plasma, and therefore its safety is higher than that of low-osmotic contrast medium (LOCM), the patient's tolerance to IOCM is better than that to LOCM. For this reason, the use of IOCM should be strongly recommended in interventional procedures, which is of great significance to the reduction of the occurrence of CM-related adverse events. (authors)

  7. Temperature and pressure dependent osmotic pressure in liquid sodium-cesium alloys

    International Nuclear Information System (INIS)

    Rashid, R.I.M.A.

    1987-01-01

    The evaluation of the osmotic pressure in terms of the concentration fluctuations of mixtures and the equations of state of the pure liquids is considered. The temperature and pressure dependent experimentally measured concentration-concentration correlations in the long wavelength limit of liquid sodium-cesium alloys are used to demonstrate the appreciable dependence of the temperature and pressure on the osmotic pressure as a function of concentration. Introducing interchange energies as functions of temperature and pressure, our analysis is consistent with the Flory model. Thus, a formalism for evaluating the state dependent osmotic pressure is developed and our numerical work is considered to be an extension of the calculations of Rashid and March in the sense that a temperature and pressure dependent interchange energy parameter that more closely parameterizes the state dependent concentration fluctuations in the liquid alloys, is used. (author)

  8. Shelf-life extension of gilthead seabream fillets by osmotic treatment and antimicrobial agents.

    Science.gov (United States)

    Tsironi, T N; Taoukis, P S

    2012-02-01

    The objectives of the study were to evaluate the effect of selected antimicrobial agents on the shelf life of osmotically pretreated gilthead seabream and to establish reliable kinetic equations for shelf-life determination validated in dynamic conditions. Fresh gilthead seabream (Sparus aurata) fillets were osmotically treated with 50% high dextrose equivalent maltodextrin (HDM, DE 47) plus 5% NaCl and 0·5% carvacrol, 0·5% glucono-δ-lactone or 1% Citrox (commercial antimicrobial mix). Untreated and treated slices were aerobically packed and stored isothermally (0-15°C). Microbial growth and quality-related chemical indices were modelled as functions of temperature. Models were validated at dynamic storage conditions. Osmotic pretreatment with the use of antimicrobials led to significant shelf-life extension of fillets, in terms of microbial growth and organoleptic deterioration. The shelf life was 7 days for control samples at 5°C. The osmotic pretreatment with carvacrol, glucono-δ-lactone and Citrox allowed for shelf-life extension by 8, 10 and 5 days at 5°C, respectively. The results of the study show the potential of adding carvacrol, glucono-δ-lactone or Citrox in the osmotic solution to extend the shelf life and improve commercial value of chilled osmotically pretreated fish products. The developed models can be a reliable tool for predicting the shelf life of fresh or minimally processed gilthead seabream fillets in the real chill chain. © 2012 The Authors. Journal of Applied Microbiology © 2012 The Society for Applied Microbiology.

  9. OSMOTIC DEHYDRATION KINETICS OF GUAVAS IN MALTOSE SOLUTIONS WITH CALCIUM SALT*

    Directory of Open Access Journals (Sweden)

    S. DI S. MASTRANTONIO

    2009-03-01

    Full Text Available

    The osmotic dehydration kinetics of guavas in maltose solutions at 40 and 60ºBrix, with addition of 0, 0.6 and 1.2% of calcium lactate was studied in this paper and the final product quality was evaluated. The experiments were carried out up to 60 hours and samples were taken for analysis at different times to evaluate guavas weight reduction, water loss and sugar gain and to characterize the product according to its texture and color. After 24 hours of process the mass transfer of water and sugar between the osmotic solution and the fruit was negligible, showing that process equilibrium was reached. The increase of sugar concentration in the osmotic solution showed strong influence on the dehydration process, increasing the water loss and reducing sugar gain. The presence of calcium ions in the osmotic solution also influenced the kinetics of mass transfer and showed a strong influence on fruit texture. Higher values of stress and strain at failure were obtained when calcium lactate was employed. The effect of the different osmotic treatments on the color parameters was also investigated and significant changes were observed in the values of chroma C* and hue H* due to sugar concentration and calcium addition.

    KEYWORDS: Osmotic dehydration; kinetics; guava; maltose; calcium lactate.

  10. Use of macrogol 4000 in chronic constipation.

    Science.gov (United States)

    De Giorgio, R; Cestari, R; Corinaldesi, R; Stanghellini, V; Barbara, G; Felicani, C; Di Nardo, G; Cucchiara, S

    2011-08-01

    Chronic constipation is a common functional disorder of the gastrointestinal tract, affecting up to 35% of the general population, and especially the elderly. However, its definition as perceived by the patient can vary, making it difficult to understand the problem and find appropriate therapeutic measures. The approach to chronic constipation, thus, needs a thorough understanding of the patient's complaint and the main pathophysiological mechanism requiring treatment. Lifestyle changes do not usually meet with complete patient satisfaction. Other treatments include different types of laxatives. Of these, osmotic laxatives appear one of the most effective and are, therefore, frequently prescribed. This review will cover the topic of osmotic laxatives, specifically focusing on polyethylene glycol (PEG/macrogol 4000) in chronic constipation and as a key agent for bowel cleansing prior to colonoscopy. PEG formulations, including macrogol 4000, are safe, effective treatments for constipation, even in children and elderly patients. Macrogol 4000 may well be more palatable than combined formulations (macrogol 3350 with electrolytes), which could help improve adherence to the long-term treatment required for chronic constipation. PEG/macrogol is also recommended as an effective option for bowel cleansing prior to colonoscopy. The improved cost-effectiveness of macrogol over other commonly prescribed laxatives, such as lactulose, should be taken into consideration.

  11. Mathematical modelling of the osmotic dehydration of cherry tomato (Lycopersicon esculentum var. cerasiforme

    Directory of Open Access Journals (Sweden)

    AZOUBEL Patricia Moreira

    2000-01-01

    Full Text Available Osmotic dehydration of cherry tomato as influenced by osmotic agent (sodium chloride and a mixed sodium chloride and sucrose solutions and solution concentration (10 and 25% w/w at room temperature (25°C was studied. Kinetics of water loss and solids uptake were determined by a two parameter model, based on Fick's second law and applied to spherical geometry. The water apparent diffusivity coefficients obtained ranged from 2.17x10-10 to 11.69x10-10 m²/s.

  12. The osmotic fragility of human erythrocytes is inhibited by laser irradiation

    International Nuclear Information System (INIS)

    Habodaszova, D.; Sikurova, L.; Waczulikova, I.

    2004-01-01

    In this study we investigated the influence of green laser irradiation (532 nm, 30 mW, 31,7 J/cm 2 ) on the membrane integrity of human erythrocytes and compared the results with the effect of infrared laser irradiation (810 nm, 50 mW, 31,3 J/cm 2 ). To evaluate the membrane integrity of erythrocytes, one clinical parameter, the osmotic fragility, was investigated. We observed a decrease in osmotic fragility of the erythrocytes after irradiation by the green laser light as well as by the infrared laser compared to non-irradiated controls (Authors)

  13. Chronic intracerebroventricular infusion of nociceptin/orphanin FQ increases food and ethanol intake in alcohol-preferring rats.

    Science.gov (United States)

    Cifani, Carlo; Guerrini, Remo; Massi, Maurizio; Polidori, Carlo

    2006-11-01

    Central administration of low doses of nociceptin/orphanin FQ (N/OFQ), the endogenous ligand of the opioid-like orphan receptor NOP, have been shown to reduce ethanol consumption, ethanol-induced conditioned place preference and stress-induced reinstatement of alcohol-seeking behavior in alcohol preferring rats. The present study evaluated the effect of continuous (7 days) lateral brain ventricle infusions of N/OFQ (0, 0.25, 1, 4, and 8 microg/h), by means of osmotic mini-pumps, on 10% ethanol intake in Marchigian-Sardinian alcohol-preferring (msP) rats provided 2h or 24h access to it. N/OFQ dose-dependently increased food intake in msP rats. On the other hand, in contrast to previous studies with acute injections, continuous lateral brain ventricle infusion of high doses of N/OFQ increased ethanol consumption when the ethanol solution was available for 24h/day or 2h/day. The present study demonstrates that continuous activation of the opioidergic N/OFQ receptor does not blunt the reinforcing effects of ethanol. Moreover, the data suggest that continuous activation of the opioidergic N/OFQ receptor is not a suitable way to reduce alcohol abuse.

  14. Arabidopsis decuple mutant reveals the importance of SnRK2 kinases in osmotic stress responses in vivo

    KAUST Repository

    Fujii, Hiroaki; Verslues, Paul E.; Zhu, Jian-Kang

    2011-01-01

    Osmotic stress associated with drought or salinity is a major factor that limits plant productivity. Protein kinases in the SNF1-related protein kinase 2 (SnRK2) family are activated by osmotic stress, suggesting that the kinases are involved

  15. Arabidopsis decuple mutant reveals the importance of SnRK2 kinases in osmotic stress responses in vivo

    KAUST Repository

    Fujii, Hiroaki

    2011-01-10

    Osmotic stress associated with drought or salinity is a major factor that limits plant productivity. Protein kinases in the SNF1-related protein kinase 2 (SnRK2) family are activated by osmotic stress, suggesting that the kinases are involved in osmotic stress signaling. However, due to functional redundancy, their contribution to osmotic stress responses remained unclear. In this report, we constructed an Arabidopsis line carrying mutations in all 10 members of the SnRK2 family. The decuple mutant snrk2.1/2/3/4/5/6/7/8/9/10 grew poorly under hyperosmotic stress conditions but was similar to the wild type in culture media in the absence of osmotic stress. The mutant was also defective in gene regulation and the accumulation of abscisic acid (ABA), proline, and inositol 1,4,5-trisphosphate under osmotic stress. In addition, analysis of mutants defective in the ABA-activated SnRK2s (snrk2.2/3/6) and mutants defective in the rest of the SnRK2s (snrk2.1/4/5/7/8/9/10) revealed that SnRK2s are a merging point of ABA-dependent and -independent pathways for osmotic stress responses. These results demonstrate critical functions of the SnRK2s in mediating osmotic stress signaling and tolerance.

  16. Biochemical degradation and physical migration of polyphenolic compounds in osmotic dehydrated blueberries with pulsed electric field and thermal pretreatments.

    Science.gov (United States)

    Yu, Yuanshan; Jin, Tony Z; Fan, Xuetong; Wu, Jijun

    2018-01-15

    Fresh blueberries were pretreated by pulsed electric fields (PEF) or thermal pretreatment and then were subject to osmotic dehydration. The changes in contents of anthocyanins, predominantly phenolic acids and flavonols, total phenolics, polyphenol oxidase (PPO) activity and antioxidant activity in the blueberry samples during pretreatment and osmotic dehydration were investigated. Biochemical degradation and physical migration of these nutritive compounds from fruits to osmotic solutions were observed during the pretreatments and osmotic dehydration. PEF pretreated samples had the least degradation loss but the most migration loss of these compounds compared to thermally pretreated and control samples. Higher rates of water loss and solid gain during osmotic dehydration were also obtained by PEF pretreatment, reducing the dehydration time from 130 to 48h. PEF pretreated and dehydrated fruits showed superior appearance to thermally pretreated and control samples. Therefore, PEF pretreatment is a preferred technology that balances nutritive quality, appearance, and dehydration rate. Published by Elsevier Ltd.

  17. A numerical method for osmotic water flow and solute diffusion with deformable membrane boundaries in two spatial dimension

    Science.gov (United States)

    Yao, Lingxing; Mori, Yoichiro

    2017-12-01

    Osmotic forces and solute diffusion are increasingly seen as playing a fundamental role in cell movement. Here, we present a numerical method that allows for studying the interplay between diffusive, osmotic and mechanical effects. An osmotically active solute obeys a advection-diffusion equation in a region demarcated by a deformable membrane. The interfacial membrane allows transmembrane water flow which is determined by osmotic and mechanical pressure differences across the membrane. The numerical method is based on an immersed boundary method for fluid-structure interaction and a Cartesian grid embedded boundary method for the solute. We demonstrate our numerical algorithm with the test case of an osmotic engine, a recently proposed mechanism for cell propulsion.

  18. A new insight into membrane fouling mechanism in submerged membrane bioreactor: osmotic pressure during cake layer filtration.

    Science.gov (United States)

    Zhang, Meijia; Peng, Wei; Chen, Jianrong; He, Yiming; Ding, Linxian; Wang, Aijun; Lin, Hongjun; Hong, Huachang; Zhang, Ye; Yu, Haiying

    2013-05-15

    Big gap between experimental filtration resistance of cake layer formed on membrane surface and the hydraulic resistance calculated through the Carman-Kozeny equation, suggested the existence of a new membrane fouling mechanism: osmotic pressure during cake layer filtration in SMBR system. An osmotic pressure model based on chemical potential difference was then proposed. Simulation of the model showed that osmotic pressure accounted for the major fraction of total operation pressure, and pH, applied pressure and ionic strength were the key determining factors for osmosis effect. It was found that, variations of osmotic pressure with pH, applied pressure and added ionic strength were well coincident with perditions of model's simulation, providing the first direct evidences of the real occurrence of osmosis mechanism and the feasibility of the proposed model. These findings illustrate the essential role of osmotic pressure in filtration resistance, and improve fundamental understanding on membrane fouling in SMBR systems. Copyright © 2013 Elsevier Ltd. All rights reserved.

  19. Correlation and prediction of osmotic coefficient and water activity of aqueous electrolyte solutions by a two-ionic parameter model

    International Nuclear Information System (INIS)

    Pazuki, G.R.

    2005-01-01

    In this study, osmotic coefficients and water activities in aqueous solutions have been modeled using a new approach based on the Pitzer model. This model contains two physically significant ionic parameters regarding ionic solvation and the closest distance of approach between ions in a solution. The proposed model was evaluated by estimating the osmotic coefficients of nine electrolytes in aqueous solutions. The obtained results showed that the model is suitable for predicting the osmotic coefficients in aqueous electrolyte solutions. Using adjustable parameters, which have been calculated from regression between the experimental osmotic coefficient and the results of this model, the water activity coefficients of aqueous solutions were calculated. The average absolute relative deviations of the osmotic coefficients between the experimental data and the calculated results were in agreement

  20. Study on enhanced lymphatic tracing of isosulfan blue injection by influence of osmotic pressure on lymphatic exposure.

    Science.gov (United States)

    Ye, Tiantian; He, Rui; Wu, Yue; Shang, Lei; Wang, Shujun

    2018-04-01

    Isosulfan blue (IB) is being used as a lymphatic tracer has been approved by the FDA in 1981. This study aimed at improving lymphatic exposure of IB injection by osmotic pressure regulation to achieve step-by step lymphatic tracing. First, IB injection with appropriate osmotic pressure, stability, and suitable pH was prepared. Next, the lymphatic tracing ability of different osmotic pressure was studied to determine the blue-stained state of IB in three-level lymph nodes after subcutaneous administration. Furthermore, pharmacokinetics of lymphatic drainage, lymph node uptake, and plasma concentration was investigate to explore the improving law of the lymphatic tracing by osmotic pressure, and combined with tissue irritation to determine the optimal osmotic pressure. At last, the tissue distribution in mice of IB injection which had the property of optimal osmotic pressure was investigated. The results showed that increasing osmotic pressure could significantly reduce injection site retention and increase IB concentration of lymph node. The lymph nodes could be obviously blue-stained by IB injection which had 938 mmol/kg osmotic pressure and would not cause inflammatory reaction and blood exposure. The tissue distribution study suggested that IB injection which had 938 mmol/kg osmotic pressure was mainly distributed into gallbladder and duodenum that verified the reports that 90% IB was excreted through the feces through biliary excretion. In conclusion, this study provides the basic study to improve lymphatic exposure of IB injection by regulate the osmotic pressure and have the potential to be the helpful guidance for the elective lymph node dissection.

  1. Osmotic actuation for microfluidic components in point-of-care applications

    KAUST Repository

    Chen, Yu-Chih

    2013-01-01

    We present a novel design of micropumps and valves driven by osmotic force for point-of-care applications. Although there have been significant progresses in microfluidic components and control devices such as fluidic diodes, switches, resonators and digital-to-analog converters, the ultimate power source still depends on bulky off-chip components, which are expensive and cannot be easily miniaturized. For point-of-care applications, it is critical to integrate all the components in a compact size at low cost. In this work, we report two key active components actuated by osmotic mechanism for total integrated microfluidic system. For the proof of concept, we have demonstrated valve actuation, which can maintain stable ON/OFF switching operations under 125 kPa back pressure. We have also implemented an osmotic pump, which can pump a high flow rate over 30 μL/min for longer than 30 minutes. The experimental data demonstrates the possibility and potential of applying osmotic actuation in point-of-care disposable microfluidics. © 2013 IEEE.

  2. Osmotic Pressure Simulations of Amino Acids and Peptides Highlight Potential Routes to Protein Force Field Parameterization

    Science.gov (United States)

    Miller, Mark S.; Lay, Wesley K.

    2016-01-01

    Recent molecular dynamics (MD) simulations of proteins have suggested that common force fields overestimate the strength of amino acid interactions in aqueous solution. In an attempt to determine the causes of these effects, we have measured the osmotic coefficients of a number of amino acids using the AMBER ff99SB-ILDN force field with two popular water models, and compared the results with available experimental data. With TIP4P-Ew water, interactions between aliphatic residues agree well with experiment, but interactions of the polar residues serine and threonine are found to be excessively attractive. For all tested amino acids, the osmotic coefficients are lower when the TIP3P water model is used. Additional simulations performed on charged amino acids indicate that the osmotic coefficients are strongly dependent on the parameters assigned to the salt ions, with a reparameterization of the sodium:carboxylate interaction reported by the Aksimentiev group significantly improving description of the osmotic coefficient for glutamate. For five neutral amino acids, we also demonstrate a decrease in solute-solute attractions using the recently reported TIP4P-D water model and using the KBFF force field. Finally, we show that for four two-residue peptides improved agreement with experiment can be achieved by re-deriving the partial charges for each peptide. PMID:27052117

  3. Effects of osmotic stress on predation behaviour of Asterias rubens L.

    NARCIS (Netherlands)

    Aguera Garcia, Antonio; Schellekens, Tim; Jansen, J.M.; Smaal, A.C.

    2015-01-01

    Environmental stress plays an important role in determining ecosystem functioning and structure. In estuarine areas both tidal and seasonal salinity changes may cause osmotic stress on predators, affecting their behaviour and survival. The interaction between these predators and their prey may

  4. Simulating Osmotic Equilibria: A New Tool for Calculating Activity Coefficients in Concentrated Aqueous Salt Solutions.

    Science.gov (United States)

    Bley, Michael; Duvail, Magali; Guilbaud, Philippe; Dufrêche, Jean-François

    2017-10-19

    Herein, a new theoretical method is presented for predicting osmotic equilibria and activities, where a bulk liquid and its corresponding vapor phase are simulated by means of molecular dynamics using explicit polarization. Calculated time-averaged number density profiles provide the amount of evaporated molecules present in the vapor phase and consequently the vapor-phase density. The activity of the solvent and the corresponding osmotic coefficient are determined by the vapor density at different solute concentrations with respect to the reference vapor density of the pure solvent. With the extended Debye-Hückel equation for the activity coefficient along with the corresponding Gibbs-Duhem relation, the activity coefficients of the solutes are calculated by fitting the osmotic coefficients. A simple model based on the combination of Poisson processes and Maxwell-Boltzmann velocity distributions is introduced to interpret statistical phenomena observed during the simulations, which are related to evaporation and recondensation. This method is applied to aqueous dysprosium nitrate [Dy(NO 3 ) 3 ] solutions at different concentrations. The obtained densities of the liquid bulk and the osmotic and activity coefficients are in good agreement with the experimental results for concentrated and saturated solutions. Density profiles of the liquid-vapor interface at different concentrations provide detailed insight into the spatial distributions of all compounds.

  5. Quercitol and osmotic adaptation of field-grown Eucalyptus under seasonal drought stress.

    Science.gov (United States)

    Arndt, Stefan K; Livesley, Stephen J; Merchant, Andrew; Bleby, Timothy M; Grierson, Pauline F

    2008-07-01

    This study investigated the role of quercitol in osmotic adjustment in field-grown Eucalyptus astringens Maiden subject to seasonal drought stress over the course of 1 year. The trees grew in a native woodland and a farm plantation in the semi-arid wheatbelt region of south Western Australia. Plantation trees allocated relatively more biomass to leaves than woodland trees, but they suffered greater drought stress over summer, as indicated by lower water potentials, CO(2)assimilation rates and stomatal conductances. In contrast, woodland trees had relatively fewer leaves and suffered less drought stress. Plantation trees under drought stress engaged in osmotic adjustment, but woodland trees did not. Quercitol made a significant contribution to osmotic adjustment in drought-stressed trees (25% of total solutes), and substantially more quercitol was measured in the leaves of plantation trees (5% dry matter) than in the leaves of woodland trees (2% dry matter). We found no evidence that quercitol was used as a carbon storage compound while starch reserves were depleted under drought stress. Differences in stomatal conductance, biomass allocation and quercitol production clearly indicate that E. astringens is both morphologically and physiologically 'plastic' in response to growth environment, and that osmotic adjustment is only one part of a complex strategy employed by this species to tolerate drought.

  6. Feasibility of electro-osmotic belt filter dewatering technology at pilot scale

    CSIR Research Space (South Africa)

    Snyman, HG

    2000-01-01

    Full Text Available -air. The technology was found as sensitive to polyelectrolyte dosages as belt presses. The performance of the electro-osmotic belt filter was sensitive to feed rate, but performed well with non-thickened waste activated sludge (0.61% solids), resulting in cake solids...

  7. Field effect control of electro-osmotic flow in microfluidic networks

    NARCIS (Netherlands)

    van der Wouden, E.J.

    2006-01-01

    This thesis describes the development of a Field Effect Flow Control (FEFC) system for the control of Electro Osmotic Flow (EOF) in microfluidic networks. For this several aspects of FEFC have been reviewed and a process to fabricate microfluidic channels with integrated electrodes has been

  8. Osmotic Gradients Induce Bio-reminiscent Morphological Transformations in Giant Unilamellar Vesicles

    Directory of Open Access Journals (Sweden)

    Kamila eOglecka

    2012-05-01

    Full Text Available We report observations of large-scale, in-plane and out-of-plane membrane deformations in giant uni- and multilamellar vesicles composed of binary and ternary lipid mixtures in the presence of net transvesicular osmotic gradients. The lipid mixtures we examined consisted of binary mixtures of DOPC and DPPC lipids and ternary mixtures comprising POPC, sphingomyelin, and cholesterol over a range of compositions – both of which produce co-existing phases for selected ranges of compositions at room temperature under thermodynamic equilibrium. In the presence of net osmotic gradient, we find that the in-plane phase separation potential of these mixtures is non-trivially altered and a variety of out-of-plane morphological remodeling occurs. The repertoire of membrane deformations we observe display striking resemblance to their biological counterparts in live cells encompassing vesiculation, membrane fission and fusion, tubulation and pearling, as well as expulsion of entrapped vesicles from multicompartmental GUV architectures through large, self-healing transient pores. These observations suggest that the forces introduced by simple osmotic gradients across membrane boundaries could act as a trigger for shape-dependent membrane and vesicle trafficking activities. We speculate that such coupling of osmotic gradients with membrane properties might have provided lipid-mediated mechanisms during the early evolution of membrane compartmentalization in the absence of osmoregulatory protein machinery.

  9. A simple relation for the concentration dependence of osmotic pressure and depletion thickness in polymer solutions

    NARCIS (Netherlands)

    Fleer, G.J.; Skvortsov, A.M.; Tuinier, R.

    2007-01-01

    We propose simple expressions II/IIo = 1 + and (omega/omega(ex))(3 alpha-1) and (delta(0)/delta)(2) = 1 + (omega/omega(ex))(2 alpha) for the osmotic pressure II and the depletion thickness 6 as a function of the polymer concentration omega. Here, IIo and delta 0 correspond to the dilute limit, and

  10. Microwave assisted air drying of osmotically treated pineapple with variable power programmes

    CSIR Research Space (South Africa)

    Botha, GE

    2012-01-01

    Full Text Available Variable power programmes for microwave assisted air drying of pineapple were studied. The pineapple pieces were pre-treated by osmotic dehydration in a 55º Brix sucrose solution at 40ºC for 90 minutes. Variable power output programmes were designed...

  11. Recent development in osmotic dehydration of fruit and vegetables: a review.

    Science.gov (United States)

    Chandra, Suresh; Kumari, Durvesh

    2015-01-01

    Osmotic dehydration of fruits and vegetables is achieved by placing the solid/semi solid, whole or in pieces, in a hypertonic solution (sugar and/or salt) with a simultaneous counter diffusion of solutes from the osmotic solution into the tissues. Osmotic dehydration is recommended as a processing method to obtain better quality of food products. Partial dehydration allows structural, nutritional, sensory, and other functional properties of the raw material to be modified. However, the food industry uptake of osmotic dehydration of foods has not been extensive as expected due to the poor understanding of the counter current flow phenomena associated with it. However, these flows are in a dynamic equilibrium with each other and significantly influence the final product in terms of preservation, nutrition, and organoleptic properties. The demand of healthy, natural, nutritious, and tasty processed food products continuously increases, not only for finished products, but also for ingredient to be included in complex foods such as ice cream, cereals, dairy, confectionaries, and bakery products.

  12. Nonlinear Effects in Osmotic Volume Flows of Electrolyte Solutions through Double-Membrane System

    NARCIS (Netherlands)

    Slezak, A.; Jasik-Slezak, J.; Grzegorczyn, S.; Slezak-Prochazka, I.

    The results of experimental study of volume osmotic flows in a double-membrane system are presented in this article. The double-membrane system consists of two membranes (M-u, M-d) oriented in horizontal planes and three identical compartments (u, m, d), containing unstirred binary or ternary ionic

  13. Flux limitation in ultrafiltration: Osmotic pressure model and gel layer model

    NARCIS (Netherlands)

    Wijmans, J.G.; Nakao, S.; Smolders, C.A.

    1984-01-01

    The characteristic permeate flux behaviour in ultrafiltration, i.e., the existence of a limiting flux which is independent of applied pressure and membrane resistance and a linear plot of the limiting flux versus the logarithm of the feed concentration, is explained by the osmotic pressure model. In

  14. Fabrication of a novel cascade high-pressure electro-osmotic pump.

    Science.gov (United States)

    Zhang, Feifang; Wang, Rong; Han, Tingting; Yang, Bingcheng; Liang, Xinmiao

    2011-07-07

    A novel cascade electro-osmotic pump (EOP) has been fabricated by alternately connecting a cation monolithic column and anion monolithic column in series. In this manner, the change of electric polarity between each stage of the cascade EOP is easily achieved and the pressure output of the EOP could be greatly enhanced without increase of the applied voltage.

  15. Osmotic Pressure in the Physics Course for Students of the Life Sciences

    Science.gov (United States)

    Hobbie, Russell K.

    1974-01-01

    Discusses the use of an ideal gas model to explain osmotic equilibrium and nonequilibrium flows through an ideal semipermeable membrane. Included are a justification of the relationship between an ideal gas and a dilute solution, a review of the irreversible thermodynamic flow, and some sample applications to physiology. (CC)

  16. Ultrafiltration of protein solutions; the role of protein association in rejection and osmotic pressure

    NARCIS (Netherlands)

    van den Berg, G.B.; Hanemaaijer, J.H.; Smolders, C.A.

    1987-01-01

    The monomer-dimer equilibrium of the protein β-lactoglobulin under neutral conditions appears to influence the rejection and the osmotic pressure build-up, both phenomena closely related to ultrafiltration. Rejection measurements indicate different rejections for the β-lactoglobulin monomers and

  17. Relationship between osmotic pressure of the blood and secretion of sweat

    Science.gov (United States)

    Montuori, A.

    1978-01-01

    Experiments with cats show that the thermic secretion of sweat represents a specific case of a general law: The central nervous apparatus that controls the secretion of sweat begins to function when the osmotic pressure of the blood drops below normal.

  18. Equilibrium and Dynamic Osmotic Behaviour of Aqueous Solutions with Varied Concentration at Constant and Variable Volume

    Science.gov (United States)

    Minkov, Ivan L.; Manev, Emil D.; Sazdanova, Svetla V.; Kolikov, Kiril H.

    2013-01-01

    Osmosis is essential for the living organisms. In biological systems the process usually occurs in confined volumes and may express specific features. The osmotic pressure in aqueous solutions was studied here experimentally as a function of solute concentration (0.05–0.5 M) in two different regimes: of constant and variable solution volume. Sucrose, a biologically active substance, was chosen as a reference solute for the complex tests. A custom made osmotic cell was used. A novel operative experimental approach, employing limited variation of the solution volume, was developed and applied for the purpose. The established equilibrium values of the osmotic pressure are in agreement with the theoretical expectations and do not exhibit any evident differences for both regimes. In contrast, the obtained kinetic dependences reveal striking divergence in the rates of the process at constant and varied solution volume for the respective solute concentrations. The rise of pressure is much faster at constant solution volume, while the solvent influx is many times greater in the regime of variable volume. The results obtained suggest a feasible mechanism for the way in which the living cells rapidly achieve osmotic equilibrium upon changes in the environment. PMID:24459448

  19. Optimisation of ultrasound-assisted osmotic dehydration of sweet potato (Ipomea batatas) using response surface methodology.

    Science.gov (United States)

    Oladejo, Ayobami Olayemi; Ma, Haile

    2016-08-01

    Sweet potato is a highly nutritious tuber crop that is rich in β-carotene. Osmotic dehydration is a pretreatment method for drying of fruit and vegetables. Recently, ultrasound technology has been applied in food processing because of its numerous advantages which include time saving, little damage to the quality of the food. Thus, there is need to investigate and optimise the process parameters [frequency (20-50 kHz), time (10-30 min) and sucrose concentration (20-60% w/v)] for ultrasound-assisted osmotic dehydration of sweet potato using response surface methodology. The optimised values obtained were frequency of 33.93 kHz, time of 30 min and sucrose concentration of 35.69% (w/v) to give predicted values of 21.62, 4.40 and 17.23% for water loss, solid gain and weight reduction, respectively. The water loss and weight reduction increased when the ultrasound frequency increased from 20 to 35 kHz and then decreased as the frequency increased from 35 to 50 kHz. The results from this work show that low ultrasound frequency favours the osmotic dehydration of sweet potato and also reduces the use of raw material (sucrose) needed for the osmotic dehydration of sweet potato. © 2015 Society of Chemical Industry. © 2015 Society of Chemical Industry.

  20. Water and sucrose diffusion coefficients during osmotic dehydration of sapodilla (Achras zapota L.

    Directory of Open Access Journals (Sweden)

    Lívia Muritiba Pereira de Lima Coimbra

    Full Text Available ABSTRACT: Sapodilla is an original fruit from Central America that is well adapted in all regions of the Brazilian territory. Despite its wide adaptation and acceptance in fruit markets, it is rare to find it outside tropical regions, partially because of its high perishability. The development of alternative, simple, and inexpensive methods to extend the conservation and marketing of these fruits is important, and osmotic dehydration is one of these methods. The main objective of this study was to determine the water and sucrose diffusion coefficients during the osmotic dehydration of sapodilla. This process was performed in short duration (up to 6h to evaluate detailed information on water loss and solids gain kinetics at the beginning of the process and in long duration (up to 60h to determine the equilibrium concentrations in sapodilla. The immersion time had greater influence on the water and sucrose diffusion coefficients (P<0.05; the maximum water loss (WL and solute gain (SG occurred in the osmotic solution at the highest concentration. Water and sucrose diffusion coefficients ranged from 0.00 x 10-10 m2/s to 1.858 x 10-10 m2/s, and from 0.00 x 10-10to 2.304 x 10-10 m2/s, respectively. Thus, understanding the WL and SG kinetics during the process of sapodilla osmotic dehydration could significantly contribute to new alternatives of preservation and commercialization of this fruit.

  1. Osmotic stress adaptation of Paracoccidioides lutzii, Pb01, monitored by proteomics.

    Science.gov (United States)

    Rodrigues, Leandro Nascimento da Silva; Brito, Wesley de Almeida; Parente, Ana Flávia Alves; Weber, Simone Schneider; Bailão, Alexandre Melo; Casaletti, Luciana; Borges, Clayton Luiz; Soares, Célia Maria de Almeida

    2016-10-01

    The ability to respond to stressful conditions is essential for most living organisms. In pathogenic organisms, this response is required for effective transition from a saprophytic lifestyle to the establishment of pathogenic interactions within a susceptible host. Hyperosmotic stress has been used as a model to study signal transduction and seems to cause many cellular adaptations, including the alteration of protein expression and cellular volume as well as size regulation. In this work, we evaluated the proteomic profile of Paracoccidioides lutzii Pb01 yeast cells during osmotic stress induced by potassium chloride. We performed a high accuracy proteomic technique (NanoUPLC-MS(E)) to identify differentially expressed proteins during osmotic shock. The data describe an osmoadaptative response of this fungus when subjected to this treatment. Proteins involved in the synthesis of cell wall components were modulated, which suggested cell wall remodeling. In addition, alterations in the energy metabolism were observed. Furthermore, proteins involved in amino acid metabolism and hydrogen peroxide detoxification were modulated during osmotic stress. Our study suggests that P. lutzii Pb01. presents a vast osmoadaptative response that is composed of different proteins that act together to minimize the effects caused by osmotic stress. Copyright © 2016 Elsevier Inc. All rights reserved.

  2. Characterization of Macrophomina phaseolina isolates by their response to different osmotic potentials and AFLP

    Directory of Open Access Journals (Sweden)

    Bárbara J. Gutiérrez Cedeño

    2014-01-01

    Full Text Available Charcoal rot of Phaseolus vulgaris is caused by the fungus Macrophomina phaseolina, the disease is associated with high temperature and water stress. The objective of this study was to characterize isolates of M. phaseolina by their response to different osmotic potentials and AFLP. The growth of 11 isolates was determined on potato dextrose agar at 48 and 72 h in a gradient of osmotic potential induced using NaCl as well as their effects on germination of sclerotia. Three water groups were statistically different indicating differential response to osmotic potential and all sclerotia grown under these conditions, germinated between 24 and 48h. There were groups of isolates that were tolerant to water stress induced. The AFLP genotyping allowed the formation of five genetic groups, showing a wide genetic variability. Of the nine starters CTA-AT showed a high degree of confidence in the identification of genotypes of M. phaseolina and CAA-AC had the lowest discriminatory power. These results show that M. phaseolina isolates responded differently to osmotic potential and are genetically different between them. Although there was a clear correspondence of genetic groups to water groups; these responses are important features in the search for alternative management in black bean pathosystem. Keywords: molecular marker, M. phaseolina, water deficit

  3. Development and Optimization of Osmotically Controlled Asymmetric Membrane Capsules for Delivery of Solid Dispersion of Lycopene

    Directory of Open Access Journals (Sweden)

    Nitin Jain

    2014-01-01

    Full Text Available The aim of the present investigation is to develop and statistically optimize the osmotically controlled asymmetric membrane capsules of solid dispersion of lycopene. Solid dispersions of lycopene with β-cyclodextrin in different ratios were prepared using solvent evaporation method. Solubility studies showed that the solid dispersion with 1 : 5 (lycopene : β-cyclodextrin exhibited optimum solubility (56.25 mg/mL for osmotic controlled delivery. Asymmetric membrane capsules (AMCs were prepared on glass mold pins via dip coating method. Membrane characterization by scanning electron microscopy showed inner porous region and outer dense region. Central composite design response surface methodology was applied for the optimization of AMCs. The independent variables were ethyl cellulose (X1, glycerol (X2, and NaCl (X3 which were varied at different levels to analyze the effect on dependent variables (percentage of cumulative drug release (Y1 and correlation coefficient of drug release (Y2. The effect of independent variables on the response was significantly influential. The F18 was selected as optimized formulation based on percentage of CDR (cumulative drug release of 85.63% and correlation coefficient of 0.9994. The optimized formulation was subjected to analyze the effect of osmotic pressure and agitational intensity on percentage of CDR. The drug release was independent of agitational intensity but was dependent on osmotic pressure of dissolution medium.

  4. Effect of process variables on the osmotic dehydration of star-fruit slices

    Directory of Open Access Journals (Sweden)

    Camila Dalben Madeira Campos

    2012-06-01

    Full Text Available The objective of this work was to study the effect of blanching and the influence of temperature, solution concentration, and the initial fruit:solution ratio on the osmotic dehydration of star-fruit slices. For blanching, different concentrations of citric and ascorbic acids were studied. The samples immersed in 0.75% citric acid presented little variation in color in relation to the fresh star-fruit. Osmotic dehydration was carried out in an incubator with orbital shaking, controlled temperature, and constant shaking at 120 rpm. The influence of process variables was studied in trials defined by a complete 23 central composite design. In general, water loss and solids gain were positively influenced by temperature and by solution concentration. Nevertheless, lower temperatures reduced water loss throughout the osmotic dehydration process. An increase in the amount of dehydrating solution (initial fruit:solution ratio slightly influenced the evaluated responses. The process carried out at 50 ºC with a solution concentration of 50% resulted in a product with lower solids gain and greater water loss. Under these conditions, blanching minimized the effect of the osmotic treatment on star-fruit browning, and therefore the blanched fruits showed little variation in color in relation to the fresh fruit.

  5. Free water transport, small pore transport and the osmotic pressure gradient

    NARCIS (Netherlands)

    Parikova, Alena; Smit, Watske; Zweers, Machteld M.; Struijk, Dirk G.; Krediet, Raymond T.

    2008-01-01

    BACKGROUND: Water transport in peritoneal dialysis (PD) patients occurs through the small pores and water channels, the latter allowing free water transport (FWT). The osmotic gradient is known to be one of the major determinants of water transport. The objective of the study was to analyse the

  6. Comparison of the compressive yield response of aggregated suspensions: Pressure filtration, centrifugation, and osmotic consolidation

    International Nuclear Information System (INIS)

    Miller, K.T.; Melant, R.M.; Zukoski, C.F.

    1996-01-01

    The compressive rheological responses of suspensions containing flocculated kaolin, alumina (average particle sizes of 0.2 and 0.5 microm), and hydrous zirconia (average particle sizes of 8, 57, and 139 nm) particles have been measured using three different techniques: pressure filtration, volume fraction profile during centrifugation, and sediment height during centrifugation at multiple spinning speeds. While the volume fraction profile technique appears to be experimentally most robust, equivalent responses are found using the different techniques, indicating that the compressive yield stress is a material property of a given suspension. The compressive yield stress of each suspension increases rapidly with volume fraction but cannot be generally described using simple power-law or exponential fits. The compressive yield stress also increases with the inverse square of particle size. The packing behavior of the suspensions undergoing osmotic consolidation is compared with the mechanical compressive yield response. Some suspensions exhibited the same packing behavior as in the mechanical techniques, while others consistently packed to higher densities during osmotic consolidation. Although equivalent osmotic and mechanical loads do not always result in the same volume fractions, the similar increases in volume fraction with applied driving force suggest that both the osmotic and mechanical techniques are controlled by the force needed to rearrange the particle network

  7. Sugar beet molasses: Properties and applications in osmotic dehydration of fruits and vegetables

    Directory of Open Access Journals (Sweden)

    Šarić Ljubiša Ć.

    2016-01-01

    Full Text Available Molasses is an important by-product of sugar beet or sugar cane refining industry and it was one of the first sweeteners used in human nutrition. Sugar cane molasses has unique characteristics that can make it suitable for application in food industry, especially in confectionery and bakery products. On the other hand, sugar beet molasses has not had greater application in the human diet, primarily because of its strong smell and taste of the beet, which makes it unattractive for consumption. Since recent investigations showed that sugar beet molasses can be used as a hypertonic solution in osmotic dehydration of different materials of plant and animal origin, the objective of this work was to review recently studied sugar beet molasses in terms of its applications in osmotic dehydrations of fruits and vegetables. Previous studies showed that sugar beet molasses is an excellent medium for osmotic dehydration of fruits and vegetables (apple, carrot, plum, etc. primarily due to a high content of dry matter (80%, w/w and specific nutrient content. An important advantage of using sugar beet molasses as a hypertonic solution is an enrichment of the dehydrated material in minerals and vitamins, which penetrate from molasses into the plant tissue. Concentration of sugar beet molasses solution and immersion time had the biggest influence on the process of osmotic dehydration of fruit and vegetables, while the temperature of the solution was the least influential parameter. The effect of immersion time on the kinetics of osmotic dehydration in sugar beet molasses increases with an increase in concentration of hypertonic solution. Fruit and vegetables dehydrated in sugar beet molasses had a higher dry matter content compared to samples treated in sucrose solutions. Besides, application of sugar beet molasses in osmotic dehydration of fruits and vegetables had some other advantages such as lower cost of molasses compared to sugar and its liquid aggregate

  8. Osmotic potential calculations of inorganic and organic aqueous solutions over wide solute concentration levels and temperatures

    Energy Technology Data Exchange (ETDEWEB)

    Cochrane, T. T., E-mail: agteca@hotmail.com [AGTECA S.A., 230 Oceanbeach Road, Mount Maunganui, Tauranga 3116 (New Zealand); Cochrane, T. A., E-mail: tom.cochrane@canterbury.ac.nz [Department of Civil and Natural Resources Engineering, University of Canterbury, Private Bag 4800, Christchurch 8140 (New Zealand)

    2016-01-15

    Purpose: To demonstrate that the authors’ new “aqueous solution vs pure water” equation to calculate osmotic potential may be used to calculate the osmotic potentials of inorganic and organic aqueous solutions over wide ranges of solute concentrations and temperatures. Currently, the osmotic potentials of solutions used for medical purposes are calculated from equations based on the thermodynamics of the gas laws which are only accurate at low temperature and solute concentration levels. Some solutions used in medicine may need their osmotic potentials calculated more accurately to take into account solute concentrations and temperatures. Methods: The authors experimented with their new equation for calculating the osmotic potentials of inorganic and organic aqueous solutions up to and beyond body temperatures by adjusting three of its factors; (a) the volume property of pure water, (b) the number of “free” water molecules per unit volume of solution, “N{sub f},” and (c) the “t” factor expressing the cooperative structural relaxation time of pure water at given temperatures. Adequate information on the volume property of pure water at different temperatures is available in the literature. However, as little information on the relative densities of inorganic and organic solutions, respectively, at varying temperatures needed to calculate N{sub f} was available, provisional equations were formulated to approximate values. Those values together with tentative t values for different temperatures chosen from values calculated by different workers were substituted into the authors’ equation to demonstrate how osmotic potentials could be estimated over temperatures up to and beyond bodily temperatures. Results: The provisional equations formulated to calculate N{sub f}, the number of free water molecules per unit volume of inorganic and organic solute solutions, respectively, over wide concentration ranges compared well with the calculations of N{sub f

  9. Osmotic potential calculations of inorganic and organic aqueous solutions over wide solute concentration levels and temperatures

    International Nuclear Information System (INIS)

    Cochrane, T. T.; Cochrane, T. A.

    2016-01-01

    Purpose: To demonstrate that the authors’ new “aqueous solution vs pure water” equation to calculate osmotic potential may be used to calculate the osmotic potentials of inorganic and organic aqueous solutions over wide ranges of solute concentrations and temperatures. Currently, the osmotic potentials of solutions used for medical purposes are calculated from equations based on the thermodynamics of the gas laws which are only accurate at low temperature and solute concentration levels. Some solutions used in medicine may need their osmotic potentials calculated more accurately to take into account solute concentrations and temperatures. Methods: The authors experimented with their new equation for calculating the osmotic potentials of inorganic and organic aqueous solutions up to and beyond body temperatures by adjusting three of its factors; (a) the volume property of pure water, (b) the number of “free” water molecules per unit volume of solution, “N f ,” and (c) the “t” factor expressing the cooperative structural relaxation time of pure water at given temperatures. Adequate information on the volume property of pure water at different temperatures is available in the literature. However, as little information on the relative densities of inorganic and organic solutions, respectively, at varying temperatures needed to calculate N f was available, provisional equations were formulated to approximate values. Those values together with tentative t values for different temperatures chosen from values calculated by different workers were substituted into the authors’ equation to demonstrate how osmotic potentials could be estimated over temperatures up to and beyond bodily temperatures. Results: The provisional equations formulated to calculate N f , the number of free water molecules per unit volume of inorganic and organic solute solutions, respectively, over wide concentration ranges compared well with the calculations of N f using recorded

  10. Studies of osmotic diarrhea induced in normal subjects by ingestion of polyethylene glycol and lactulose.

    Science.gov (United States)

    Hammer, H F; Santa Ana, C A; Schiller, L R; Fordtran, J S

    1989-10-01

    The purpose of these studies was to gain insight into the pathophysiology of pure osmotic diarrhea and the osmotic diarrhea caused by carbohydrate malabsorption. Diarrhea was induced in normal volunteers by ingestion of polyethylene glycol (PEG), which is nonabsorbable, not metabolized by colonic bacteria, and carries no electrical charge. In PEG-induced diarrhea, (a) stool weight was directly correlated with the total mass of PEG ingested; (b) PEG contributed 40-60% of the osmolality of the fecal fluid, the remainder being contributed by other solutes either of dietary, endogenous, or bacterial origin; and (c) fecal sodium, potassium, and chloride were avidly conserved by the intestine, in spite of stool water losses exceeding 1,200 g/d. Diarrhea was also induced in normal subjects by ingestion of lactulose, a disaccharide that is not absorbed by the small intestine but is metabolized by colonic bacteria. In lactulose-induced diarrhea, (a) a maximum of approximate 80 g/d of lactulose was metabolized by colonic bacteria to noncarbohydrate moieties such as organic acids; (b) the organic acids were partially absorbed in the colon; (c) unabsorbed organic acids obligated the accumulation of inorganic cations (Na greater than Ca greater than K greater than Mg) in the diarrheal fluid; (d) diarrhea associated with low doses of lactulose was mainly due to unabsorbed organic acids and associated cations, whereas with larger doses of lactulose unmetabolized carbohydrates also played a major role; and (e) the net effect of bacterial metabolism of lactulose and partial absorption of organic acids on stool water output was done dependent. With low or moderate doses of lactulose, stool water losses were reduced by as much as 600 g/d (compared with equimolar osmotic loads of PEG); with large dose, the increment in osmotically active solutes within the lumen exceeded the increment of the ingested osmotic load, and the severity of diarrhea was augmented.

  11. PEG-induced osmotic stress in Mentha x piperita L.: Structural features and metabolic responses.

    Science.gov (United States)

    Búfalo, Jennifer; Rodrigues, Tatiane Maria; de Almeida, Luiz Fernando Rolim; Tozin, Luiz Ricardo Dos Santos; Marques, Marcia Ortiz Mayo; Boaro, Carmen Silvia Fernandes

    2016-08-01

    The present study investigated whether osmotic stress induced by the exposure of peppermint (Mentha x piperita L.) to moderate and severe stress for short periods of time changes the plant's physiological parameters, leaf anatomy and ultrastructure and essential oil. Plants were exposed to two levels of polyethyleneglycol (50 g L(-1) and 100 g L(-1) of PEG) in a hydroponic experiment. The plants exposed to 50 g L(-1) maintained metabolic functions similar to those of the control group (0 g L(-1)) without changes in gas exchange or structural characteristics. The increase in antioxidant enzyme activity reduced the presence of free radicals and protected membranes, including chloroplasts and mitochondria. In contrast, the osmotic stress caused by 100 g L(-1) of PEG inhibited leaf gas exchange, reduced the essential oil content and changed the oil composition, including a decrease in menthone and an increase in menthofuran. These plants also showed an increase in peroxidase activity, but this increase was not sufficient to decrease the lipid peroxidation level responsible for damaging the membranes of organelles. Morphological changes were correlated with the evaluated physiological features: plants exposed to 100 g L(-1) of PEG showed areas with collapsed cells, increases in mesophyll thickness and the area of the intercellular space, cuticle shrinkage, morphological changes in plastids, and lysis of mitochondria. In summary, our results revealed that PEG-induced osmotic stress in M. x piperita depends on the intensity level of the osmotic stress applied; severe osmotic stress changed the structural characteristics, caused damage at the cellular level, and reduced the essential oil content and quality. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

  12. Estimating contribution of anthocyanin pigments to osmotic adjustment during winter leaf reddening.

    Science.gov (United States)

    Hughes, Nicole M; Carpenter, Kaylyn L; Cannon, Jonathan G

    2013-01-15

    The association between plant water stress and synthesis of red, anthocyanin pigments in leaves has led some plant biologists to propose an osmotic function of leaf reddening. According to this hypothesis, anthocyanins function as a solute in osmotic adjustment (OA), contributing to depression of osmotic potential (Ψ(π)) and maintenance of turgor pressure during drought-stressed conditions. Here we calculate the percent contribution of anthocyanin to leaf Ψ(π) during OA in two angiosperm evergreen species, Galax urceolata and Gaultheria procumbens. Both species exhibit dramatic leaf reddening under high light during winter, concomitant with declines in leaf water potential and accumulation of solutes. Data previously published by the authors on osmotic potential at full turgor (Ψ(π,100)) of G. urceolata and G. procumbens leaves before and after leaf reddening were used to estimate OA. In vivo molar concentrations of anthocyanin, glucose, fructose, and sucrose measured from the same individuals were converted to pressure equivalents using the Ideal Gas Law, and percent contribution to OA was estimated. Estimated mean OA during winter was -0.7MPa for G. urceolata and -0.8MPa for G. procumbens. In vivo concentrations of anthocyanin (3-10mM) were estimated to account for ∼2% of OA during winter, and comprised <0.7% of Ψ(π,100) in both species. Glucose, fructose, and sucrose combined accounted for roughly 50 and 80% of OA for G. urceolata and G. procumbens, respectively, and comprised ∼20% of Ψ(π,100). We observed that a co-occurring, acyanic species (Vinca minor) achieved similar OA without synthesizing anthocyanin. We conclude that anthocyanins represent a measurable, albeit meager, component of OA in red-leafed evergreen species during winter. However, due to their low concentrations, metabolic costliness relative to other osmolytes, and striking red color (unnecessary for an osmotic function), it is unlikely that they are synthesized solely for an

  13. Investigation of the Effects of Extracellular Osmotic Pressure on Morphology and Mechanical Properties of Individual Chondrocyte.

    Science.gov (United States)

    Nguyen, Trung Dung; Oloyede, Adekunle; Singh, Sanjleena; Gu, YuanTong

    2016-06-01

    It has been demonstrated that most cells of the body respond to osmotic pressure in a systematic manner. The disruption of the collagen network in the early stages of osteoarthritis causes an increase in water content of cartilage which leads to a reduction of pericellular osmolality in chondrocytes distributed within the extracellular environment. It is therefore arguable that an insight into the mechanical properties of chondrocytes under varying osmotic pressure would provide a better understanding of chondrocyte mechanotransduction and potentially contribute to knowledge on cartilage degeneration. In this present study, the chondrocyte cells were exposed to solutions with different osmolality. Changes in their dimensions and mechanical properties were measured over time. Atomic force microscopy (AFM) was used to apply load at various strain-rates and the force-time curves were logged. The thin-layer elastic model was used to extract the elastic stiffness of chondrocytes at different strain-rates and at different solution osmolality. In addition, the porohyperelastic (PHE) model was used to investigate the strain-rate-dependent responses under the loading and osmotic pressure conditions. The results revealed that the hypo-osmotic external environment increased chondrocyte dimensions and reduced Young's modulus of the cells at all strain-rates tested. In contrast, the hyper-osmotic external environment reduced dimensions and increased Young's modulus. Moreover, using the PHE model coupled with inverse FEA simulation, we established that the hydraulic permeability of chondrocytes increased with decreasing extracellular osmolality which is consistent with previous work in the literature. This could be due to a higher intracellular fluid volume fraction with lower osmolality.

  14. MORPHOMETRIC PARAMETERS AND MICRORELIEF OF THE LUMBRICUS CELOMOCYTES IN THE CONDITIONS OF THE OSMOTIC PRESSURE

    Directory of Open Access Journals (Sweden)

    Andrey Andreevich Prisnyi

    2017-10-01

    Full Text Available Background: Study the morphometric parameters and microrelief of the coelomocytes membrane of the Lumbricus representatives in normal and under osmotic pressure. Materials and methods: In the experiments, representatives of three species belonging to the genus Lumbricus were used. To conduct each series of experiments a coelomic liquid of 15 representatives of each species was used. From the circulation system of each individual examined, at least 250 cells were processed. The study of morphometric parameters of coelomocytes was carried out in isotonic conditions, and also with the use of osmotic tests in vitro. The features of the surface topography of coelomocytes were study using the “Integra Vita Probe Nanaboratorium” (NT-MDT, Russia. The analysis of amplitude and functional average statistical parameters of membrane roughness is carried out. The results of the research were processed using statistics methods using the Microsoft Excel 7.0 analysis package. Results: The Lumbricus representatives of revealed differences in the responses of amoebocytes and eleocytes to the effect of osmotic stress. Under the conditions of osmotic pressure, several morphologically different forms were found among the cells of each type. This indicates the potential ability of coelomocytes to spread out on the substrate for any type of osmotic pressure. The change in the topography of the cell membrane of coelomocytes under the hypoosmotic pressure is characterized by a smoothing of the microrelief structures with a decrease in the size of the microvysings and microinvaginations. Conclusion: The microrelief of the coelomocytes membrane reflects the features of their functional status changing under the influence of environmental factors.

  15. Carbamazepine solubility enhancement in tandem with swellable polymer osmotic pump tablet: A promising approach for extended delivery of poorly water-soluble drugs

    Directory of Open Access Journals (Sweden)

    Hadjira Rabti

    2014-06-01

    Full Text Available Elementary osmotic pump (EOP is a unique extended release (ER drug delivery system based on the principle of osmosis. It has the ability to minimize the amount of the drug, accumulation and fluctuation in drug level during chronic uses. Carbamazepine (CBZ, a poorly water-soluble antiepileptic drug, has serious side effects on overdoses and chronic uses. The aim of the present study was to design a new EOP tablet of CBZ containing a solubility enhancers and swellable polymer to reduce its side effects and enhance the patient compliance. Firstly, a combination of solubilizing carriers was selected to improve the dissolution of the slightly soluble drug. Then, designing the new EOP tablet and investigating the effect of different variables of core and coat formulations on drug release behavior by single parameter optimization and by Taguchi orthogonal design with analysis of variance (ANOVA, respectively. The results showed that CBZ solubility was successfully enhanced by a minimum amount of combined polyvinyl pyrrolidone (PVP K30 and sodium lauryl sulfate (SLS. The plasticizer amount and molecular weight (MW together with the osmotic agent amount directly affect the release rate whereas the swellable polymer amount and viscosity together with the semi-permeable membrane (SPM thickness inversely influence the release rate. In addition, the tendency of following zero order kinetics was mainly affected by the coat components rather than those of the core. Further, orifice size does not have any significant effect on the release behavior within the range of 0.1 mm to 0.8 mm. In this study we report the successful formulation of CBZ-EOP tablets, which were similar to the marketed product Tegretol CR 200 and able to satisfy the USP criterion limits and to deliver about 80% of CBZ at a rate of approximately zero order for up to 12 h.

  16. Comparison of a low dose polyethylene glycol electrolyte solution with lactulose for treatment of chronic constipation

    OpenAIRE

    Attar, A; Lemann, M; Ferguson, A; Halphen, M; Boutron, M; Flourie, B; Alix, E; Salmeron, M; Guillemot, F; Chaussade, S; Menard, A; Moreau, J; Naudin, G; Barthet, M

    1999-01-01

    Background—Polyethylene glycol (PEG) 3350 is a non-absorbable, non-metabolised osmotic agent used in lavage solutions for gut cleansing. 
Aims—To compare the efficacy of PEG and lactulose in chronic constipation. 
Methods—A total of 115 patients with chronic constipation entered a multicentre, randomised, comparative trial. They initially received two sachets containing either PEG (13 g/sachet) or lactulose (10 g/sachet) and were given an option to change the dose to one ...

  17. Osmotic concentration in three races of honey bee, Apis mellifera L. under environmental conditions of arid zone.

    Science.gov (United States)

    Ali, Hussain; Alqarni, Abdulaziz S; Owayss, Ayman A; Hassan, Awad M; Smith, Brian H

    2017-07-01

    Hemolymph osmolarity has great effect on honey bee health, especially in arid and semi-arid zones. It regulates water and nutrients in stressed tissues. Osmotic concentration in three races ( Apis mellifera ligustica , A. m. carnica and A. m. jemenitica ) of Apis mellifera was tested in central Saudi Arabia during spring and summer seasons in 2015. Newly emerged bee workers were first marked and later their hemolymph was extracted after intervals of 1, 5, 10, 15, 20 and 25 days. A significant positive correlation between age and osmolarity was found in all three races during spring and summer seasons. The lowest combined osmotic concentration for all three races was found after 1 day interval, while the highest osmotic concentration was recorded after 25 days. Among all races, A. m. ligustica showed significantly high osmotic concentration after 25 days in spring and summer seasons as compared to the other two races. Only A. m. jemenitica showed similar osmotic concentration after 10 and 15 days in both spring and summer seasons compared to other two races. Mean osmotic concentration of all three races was significantly different after 20 and 25 days in spring and summer seasons. Overall mean recorded during summer was significantly higher than the mean of spring season. Combined osmotic concentration in young drones of all races was significantly lower than that of old drones during spring and summer seasons.

  18. Optimization of Vacuum Frying Parameters in Combination with Osmotic Dehydration of Kiwi Slices to Produce Healthy Product

    Directory of Open Access Journals (Sweden)

    Fatemeh Aghabozorg Afjeh Aghabozorg Afjeh

    2014-05-01

    Full Text Available Osmotic dehydration under discontinuous reduced pressure is one of the new methods of preparation fruits and vegetable processing with in view of good health. Processing of foods at high temperatures used to cook them can cause the formation of carcinogenic substances like acrylamide, and this risk remains even if the trans-fat is removed. The low temperatures employed in this method resulted in the products with the desired texture, nutritional, and colour. The purpose of this research was evaluation of the variable effects of osmotic dehydration process (ambient pressure, contact time of product and solution, concentration and temperature of osmotic solution on the quality factors of product (colour changes, texture, moisture, oil uptake, and water loss to solid gain ratio and achieving the optimum process conditions. Studying the quality parameters of the product, the temperature range of osmotic solution, pressure, concentration of the osmotic solution and contact time of product and solution were assumed as 30 to 50°C, 500 to 700 mbar, 30 to 50% and 60 to 180 min, respectively. The test plans involving 31 tests were obtained by using response surface statistical models and central composite design. They were fried at the condition of 108ºC, 8 min and 320 mbar by using statistical correlations, 48.71ºC for the osmotic solution temperature, 592.07 mbar for the pressure, 62.92 min for the time and 34.87% for the osmotic solution. Concentrations were obtained as optimum conditions of osmotic dehydration of kiwi slices under reduced pressure. In summary combination of osmotic dehydration and vacuum frying improved the quality of the final fried kiwi, so this method is recommended for production of healthy products.

  19. Flow cytometric osmotic fragility test and eosin-5'-maleimide dye-binding tests are better than conventional osmotic fragility tests for the diagnosis of hereditary spherocytosis.

    Science.gov (United States)

    Arora, R D; Dass, J; Maydeo, S; Arya, V; Radhakrishnan, N; Sachdeva, A; Kotwal, J; Bhargava, M

    2018-03-24

    Hereditary spherocytosis (HS) is the most common inherited hemolytic anemia with heterogeneous clinico-laboratory manifestations. We evaluated the flow-cytometric tests: eosin-5'-maleimide (EMA) and flow-cytometric osmotic fragility test (FOFT) and the conventional osmotic fragility tests (OFT) for the diagnosis of hereditary spherocytosis (HS). One hundred two suspected HS patients underwent EMA, FOFT, incubated OFT (IOFT), and room temperature OFT (RT-OFT). In addition, 10 cases of immune hemolytic anemia (IHA) were included, and performance of the above 4 tests was evaluated. For EMA and FOFT, 5 normal controls were assessed together with the patients and cutoffs were calculated using receiver-operator-characteristics curve (ROC) analysis. The best cutoff for %EMA decrease was 12.5%, and for FOFT, %residual red cells (%RRC) was 25.6%. The sensitivity and specificity of RT-OFT was 62.06% and 86.3%, respectively, while that of IOFT was 79.31% and 87.67%, respectively. Both flow cytometric tests performed better. Sensitivity and specificity of EMA was 86.2% and 93.9% respectively, and that of FOFT was 96.6% and 98.63%, respectively. The combination of the FOFT with IOFT or EMA dye-binding test yields a sensitivity of 100%, but with EMA, it had a higher specificity. Hb/MCHC was a predictor of the severity of the disease while %EMA decrease and %RRC did not correlate with severity of the disease. Flow-cytometric osmotic fragility test is the best possible single test followed by EMA for diagnosis of HS. A combination of FOFT and EMA can correctly diagnose 100% patients. These tests are likely to replace conventional OFTs in future. © 2018 John Wiley & Sons Ltd.

  20. Cochrane Review: Osmotic and stimulant laxatives for the management of childhood constipation (Review).

    Science.gov (United States)

    Gordon, Morris; Naidoo, Khimara; Akobeng, Anthony K; Thomas, Adrian G

    2013-01-01

    Constipation within childhood is an extremely common problem. Despite the widespread use of osmotic and stimulant laxatives by health professionals to manage constipation in children, there has been a long standing paucity of high quality evidence to support this practice. We set out to evaluate the efficacy and safety of osmotic and stimulant laxatives used to treat functional childhood constipation. The search (inception to May 7, 2012) was standardised and not limited by language and included electronic searching (MEDLINE, EMBASE, Cochrane Central Register of Controlled Trials, Cochrane Inflammatory Bowel Disease and Functional Bowel Disorders Group Specialized Trials Register), reference searching of all included studies, personal contacts and drug companies. Randomised controlled trials (RCTs) which compared osmotic or stimulant laxatives with either placebo or another intervention, with patients aged 0 to 18 years old were considered for inclusion. The primary outcome was frequency of defecation. Secondary endpoints included faecal incontinence, disimpaction, need for additional therapies and adverse events. Relevant papers were identified and the authors independently assessed the eligibility of trials. Methodological quality was assessed using the Cochrane risk of bias tool.The Cochrane RevMan software was used for analyses. Patients with final missing outcomes were assumed to have relapsed. For continuous outcomes we calculated a mean difference (MD) and 95% confidence interval (CI) using a fixed-effect model. For dichotomous outcomes we calculated an odds ratio (OR) and 95% confidence intervals (95% CI) using a fixed-effect model. The chi square and I(2) statistics were used to assess statistical heterogeneity. A random-effects model was used in situations of unexplained heterogeneity Eighteen RCTs (1643 patients) were included in the review. Nine studies were judged to be at high risk of bias due to lack of blinding, incomplete outcome data and selective

  1. Alleviation of Osmotic Stress Effects by Exogenous Application of Salicylic or Abscisic Acid on Wheat Seedlings

    Science.gov (United States)

    Marcińska, Izabela; Czyczyło-Mysza, Ilona; Skrzypek, Edyta; Grzesiak, Maciej T.; Janowiak, Franciszek; Filek, Maria; Dziurka, Michał; Dziurka, Kinga; Waligórski, Piotr; Juzoń, Katarzyna; Cyganek, Katarzyna; Grzesiak, Stanisław

    2013-01-01

    The aim of the study was to assess the role of salicylic acid (SA) and abscisic acid (ABA) in osmotic stress tolerance of wheat seedlings. This was accomplished by determining the impact of the acids applied exogenously on seedlings grown under osmotic stress in hydroponics. The investigation was unique in its comprehensiveness, examining changes under osmotic stress and other conditions, and testing a number of parameters simultaneously. In both drought susceptible (SQ1) and drought resistant (CS) wheat cultivars, significant physiological and biochemical changes were observed upon the addition of SA (0.05 mM) or ABA (0.1 μM) to solutions containing half-strength Hoagland medium and PEG 6000 (−0.75 MPa). The most noticeable result of supplementing SA or ABA to the medium (PEG + SA and PEG + ABA) was a decrease in the length of leaves and roots in both cultivars. While PEG treatment reduced gas exchange parameters, chlorophyll content in CS, and osmotic potential, and conversely, increased lipid peroxidation, soluble carbohydrates in SQ1, proline content in both cultivars and total antioxidants activity in SQ1, PEG + SA or PEG + ABA did not change the values of these parameters. Furthermore, PEG caused a two-fold increase of endogenous ABA content in SQ1 and a four-fold increase in CS. PEG + ABA increased endogenous ABA only in SQ1, whereas PEG + SA caused a greater increase of ABA content in both cultivars compared to PEG. In PEG-treated plants growing until the harvest, a greater decrease of yield components was observed in SQ1 than in CS. PEG + SA, and particularly PEG + ABA, caused a greater increase of these yield parameters in CS compared to SQ1. In conclusion, SA and ABA ameliorate, particularly in the tolerant wheat cultivar, the harmful effects and after effects of osmotic stress induced by PEG in hydroponics through better osmotic adjustment achieved by an increase in proline and carbohydrate content as well as by an increase in antioxidant activity

  2. Alleviation of Osmotic Stress Effects by Exogenous Application of Salicylic or Abscisic Acid on Wheat Seedlings

    Directory of Open Access Journals (Sweden)

    Katarzyna Cyganek

    2013-06-01

    Full Text Available The aim of the study was to assess the role of salicylic acid (SA and abscisic acid (ABA in osmotic stress tolerance of wheat seedlings. This was accomplished by determining the impact of the acids applied exogenously on seedlings grown under osmotic stress in hydroponics. The investigation was unique in its comprehensiveness, examining changes under osmotic stress and other conditions, and testing a number of parameters simultaneously. In both drought susceptible (SQ1 and drought resistant (CS wheat cultivars, significant physiological and biochemical changes were observed upon the addition of SA (0.05 mM or ABA (0.1 μM to solutions containing half-strength Hoagland medium and PEG 6000 (−0.75 MPa. The most noticeable result of supplementing SA or ABA to the medium (PEG + SA and PEG + ABA was a decrease in the length of leaves and roots in both cultivars. While PEG treatment reduced gas exchange parameters, chlorophyll content in CS, and osmotic potential, and conversely, increased lipid peroxidation, soluble carbohydrates in SQ1, proline content in both cultivars and total antioxidants activity in SQ1, PEG + SA or PEG + ABA did not change the values of these parameters. Furthermore, PEG caused a two-fold increase of endogenous ABA content in SQ1 and a four-fold increase in CS. PEG + ABA increased endogenous ABA only in SQ1, whereas PEG + SA caused a greater increase of ABA content in both cultivars compared to PEG. In PEG-treated plants growing until the harvest, a greater decrease of yield components was observed in SQ1 than in CS. PEG + SA, and particularly PEG + ABA, caused a greater increase of these yield parameters in CS compared to SQ1. In conclusion, SA and ABA ameliorate, particularly in the tolerant wheat cultivar, the harmful effects and after effects of osmotic stress induced by PEG in hydroponics through better osmotic adjustment achieved by an increase in proline and carbohydrate content as well as by an increase in antioxidant

  3. Inefficacy of osmotic backwash induced by sodium chloride salt solution in controlling SWRO membrane fouling

    Science.gov (United States)

    Farooque, A. Mohammed; Al-Jeshi, Subhi; Saeed, Mohamed O.; Alreweli, Ali

    2014-12-01

    A study was conducted to evaluate the efficacy of osmotic backwash induced by high salt (NaCl) concentration solution on feed side of seawater reverse osmosis (SWRO) membranes, online and offline, in controlling membrane fouling and therefore minimizing/eliminating the need for chemical cleaning. SWRO membranes were deliberately fouled by feeding seawater from an open intake located on the Arabian Gulf Coast without dosing chemicals. The fouled membranes were subjected to offline cleaning with the salt solution of up to 25 % concentration. Despite the partial removal of foulants from the membrane surface, SWRO membrane performance could not be restored, indicating the ineffectiveness of osmotic backwash in aiding offline salt cleaning. Similarly, online osmotic backwash was found to be not only ineffective in removing foulants from membrane surfaces but actually increased the fouling rate, as indicated by faster fouling rates compared to other cases. Although the driving force required for the osmotic backwash existed, the generated back flow proved to be insufficient to detach foulants from membrane surfaces. During the study period, the average SWRO membrane flux was maintained between 19 and 23 LMH, whereas the average generated back flow flux by high salt concentration solution was only 11 LMH, which was not adequate to remove foulants from membrane surfaces. Moreover, it seems that the membrane configuration as well as inherent microstructure of SWRO membrane places certain constraints on the osmotic backwash process and renders osmotic backwash ineffective in tackling SWRO membrane fouling. Hence, chemical cleaning is essential to restore SWRO membrane performance whenever fouling occurs, and the use of highly concentrated salt solution does not have any significant benefit. Membrane autopsy revealed only an insignificant accumulation of biofouling layer despite the absence of disinfection. However, it was shown that culturable biofilm bacteria species

  4. Osmotically-driven membrane processes for water reuse and energy recovery

    Science.gov (United States)

    Achilli, Andrea

    Osmotically-driven membrane processes are an emerging class of membrane separation processes that utilize concentrated brines to separate liquid streams. Their versatility of application make them an attractive alternative for water reuse and energy production/recovery. This work focused on innovative applications of osmotically-driven membrane processes. The novel osmotic membrane bioreactor (OMBR) system for water reuse was presented. Experimental results demonstrated high sustainable flux and relatively low reverse diffusion of solutes from the draw solution into the mixed liquor. Membrane fouling was minimal and controlled with osmotic backwashing. The OMBR system was found to remove greater than 99% of organic carbon and ammonium-nitrogen. Forward osmosis (FO) can employ different draw solution in its process. More than 500 inorganic compounds were screened as draw solution candidates, the desktop screening process resulted in 14 draw solutions suitable for FO applications. The 14 draw solutions were then tested in the laboratory to evaluate water flux and reverse salt diffusion through the membrane. Results indicated a wide range of water flux and reverse salt diffusion depending on the draw solution utilized. Internal concentration polarization was found to lower both water flux and reverse salt diffusion by reducing the draw solution concentration at the interface between the support and dense layer of the membrane. A small group of draw solutions was found to be most suitable for FO processes with currently available FO membranes. Another application of osmotically-driven membrane processes is pressure retarded osmosis (PRO). PRO was investigated as a viable source of renewable energy. A PRO model was developed to predict water flux and power density under specific experimental conditions. The predictive model was tested using experimental results from a bench-scale PRO system. Previous investigations of PRO were unable to verify model predictions due to

  5. Ionic and osmotic relations in quinoa (Chenopodium quinoa Willd.) plants grown at various salinity levels.

    Science.gov (United States)

    Hariadi, Yuda; Marandon, Karl; Tian, Yu; Jacobsen, Sven-Erik; Shabala, Sergey

    2011-01-01

    Ionic and osmotic relations in quinoa (Chenopodium quinoa Willd.) were studied by exposing plants to six salinity levels (0-500 mM NaCl range) for 70 d. Salt stress was administered either by pre-mixing of the calculated amount of NaCl with the potting mix before seeds were planted or by the gradual increase of NaCl levels in the irrigation water. For both methods, the optimal plant growth and biomass was achieved between 100 mM and 200 mM NaCl, suggesting that quinoa possess a very efficient system to adjust osmotically for abrupt increases in NaCl stress. Up to 95% of osmotic adjustment in old leaves and between 80% and 85% of osmotic adjustment in young leaves was achieved by means of accumulation of inorganic ions (Na(+), K(+), and Cl(-)) at these NaCl levels, whilst the contribution of organic osmolytes was very limited. Consistently higher K(+) and lower Na(+) levels were found in young, as compared with old leaves, for all salinity treatments. The shoot sap K(+) progressively increased with increased salinity in old leaves; this is interpreted as evidence for the important role of free K(+) in leaf osmotic adjustment under saline conditions. A 5-fold increase in salinity level (from 100 mM to 500 mM) resulted in only a 50% increase in the sap Na(+) content, suggesting either a very strict control of xylem Na(+) loading or an efficient Na(+) removal from leaves. A very strong correlation between NaCl-induced K(+) and H(+) fluxes was observed in quinoa root, suggesting that a rapid NaCl-induced activation of H(+)-ATPase is needed to restore otherwise depolarized membrane potential and prevent further K(+) leak from the cytosol. Taken together, this work emphasizes the role of inorganic ions for osmotic adjustment in halophytes and calls for more in-depth studies of the mechanisms of vacuolar Na(+) sequestration, control of Na(+) and K(+) xylem loading, and their transport to the shoot.

  6. Recovery of leaf elongation during short term osmotic stress correlates with osmotic adjustment and cell turgor restoration in different durum wheat cultivars

    International Nuclear Information System (INIS)

    Mahdid, M.

    2014-01-01

    In order to investigate the responses of leaf elongation rate (LER), turgor and osmotic adjustment (OA) during a short-term stress (7 hours) imposed by PEG6000 and a recovery phase, three durum wheat (Triticum durum L.) varieties (Inrat; MBB; and OZ ) were grown in aerated nutrient solutions. Leaf elongation kinetics of leaf 3 was estimated using LVDT. Turgor was estimated using a cell pressure probe; osmotic potential as well as total sugars and potassium (K+) concentrations were estimated from expressed sap of elongation zone. Growth recovered rapidly and then stabilised at a lower value. A significant difference was found in % recovery of LER between the varieties. The cessation of growth after stress coincided with a decrease in turgor followed by a recovery period reaching control values in MBB and Inrat. A strong correlation (R2 = 0.83) between the reduction in turgor (turgor) and % recovery of LER was found at 7 hours after stress. The difference in the partial recovery of LER between varieties was thus related to the capacity of partial turgor recovery. Partial turgor recovery is associated with sugar or K+ based OA which indicates its importance in maintaining high LER values under water deficit. (author)

  7. Analytical Solution of Electro-Osmotic Peristalsis of Fractional Jeffreys Fluid in a Micro-Channel

    Directory of Open Access Journals (Sweden)

    Xiaoyi Guo

    2017-11-01

    Full Text Available The electro-osmotic peristaltic flow of a viscoelastic fluid through a cylindrical micro-channel is studied in this paper. The fractional Jeffreys constitutive model, including the relaxation time and retardation time, is utilized to describe the viscoelasticity of the fluid. Under the assumptions of long wavelength, low Reynolds number, and Debye-Hückel linearization, the analytical solutions of pressure gradient, stream function and axial velocity are explored in terms of Mittag-Leffler function by Laplace transform method. The corresponding solutions of fractional Maxwell fluid and generalized second grade fluid are also obtained as special cases. The numerical analysis of the results are depicted graphically, and the effects of electro-osmotic parameter, external electric field, fractional parameters and viscoelastic parameters on the peristaltic flow are discussed.

  8. Laboratory Characterization of Chemico-osmotic, Hydraulic and Diffusion Properties of Rocks: Apparatus Development

    International Nuclear Information System (INIS)

    Takeda, M.; Hiratsuka, T.; Ito, K.

    2009-01-01

    Excess fluid pressures induced by chemical osmosis in natural formations may have a significant influence on groundwater systems in a geological time scale. Examinations of the possibility and duration times require characterization of the chemico-osmotic, hydraulic and diffusion properties of representative formation media under field conditions. To develop a laboratory apparatus for chemical osmosis experiments that simulates in-situ conditions, typical litho-static and background pore pressures, a fundamental concept of the chemical osmosis experiment using a closed fluid circuit system (referred to as a closed system hereafter) was revisited. Coupled processes in the experiment were examined numerically. In preliminary experiments at atmospheric pressure a chemical osmosis experiment using the closed system was demonstrated. An approximation method for determining the chemico-osmotic property was attempted. Based on preliminary examinations, an experimental system capable of loading the confining and pore pressures on the sample was thus developed. (authors)

  9. Numerical simulation of electro-osmotic consolidation coupling non-linear variation of soil parameters

    Science.gov (United States)

    Wu, Hui; Hu, Liming; Wen, Qingbo

    2017-06-01

    Electro-osmotic consolidation is an effective method for soft ground improvement. A main limitation of previous numerical models on this technique is the ignorance of the non-linear variation of soil parameters. In the present study, a multi-field numerical model is developed with the consideration of the non-linear variation of soil parameters during electro-osmotic consolidation process. The numerical simulations on an axisymmetric model indicated that the non-linear variation of soil parameters showed remarkable impact on the development of the excess pore water pressure and degree of consolidation. A field experiment with complex geometry, boundary conditions, electrode configuration and voltage application was further simulated with the developed numerical model. The comparison between field and numerical data indicated that the numerical model coupling of the non-linear variation of soil parameters gave more reasonable results. The developed numerical model is capable to analyze engineering cases with complex operating conditions.

  10. Second sound, osmotic pressure, and Fermi-liquid parameters in 3He-4He solutions

    International Nuclear Information System (INIS)

    Corruccini, L.R.

    1984-01-01

    Second-sound velocities and osmotic pressures are analyzed to obtain the first experimental values for the Landau compressibility parameter F 0 /sup s/ in 3 He- 4 He solutions. Data are presented as a function of pressure and 3 He concentration, and are compared to theoretical predictions. The square of the second-sound velocity at finite temperature is found to be accurately proportional to the internal energy of a perfect Fermi gas. Using inertial effective masses given by the Landau-Pomeranchuk theory, the square of the velocity is found to separate into two parts: a temperature-dependent part characterized completely by ideal Fermi-gas behavior and a temperature-independent part containing all the Fermi-liquid corrections. This is related to a similar separation found in the osmotic pressure

  11. Hydrodynamic instabilities and concentration polarization coupled by osmotic pressure in a Taylor-Couette cell

    Science.gov (United States)

    Martinand, Denis; Tilton, Nils

    2016-11-01

    This study addresses analytically and numerically the coupling between hydrodynamic instabilities and osmotic pressure driven by concentration polarization. The configuration consists of a Taylor-Couette cell filled with a Newtonian fluid carrying a passive scalar. Whereas the concentric inner and outer cylinders are membranes permeable to the solvent, they totally reject the scalar. As a radial in- or outflow of solvent is imposed through both cylinders, a concentration boundary layer develops on the cylinder where the solvent exits, until an equilibrium steady state is reached. In addition, the rotation of the inner cylinder is used to drive centrifugal instabilities in the form of toroidal vortices, which interact with the concentration boundary layer. By means of the osmotic pressure, concentration polarization is found to promote or hinder the hydrodynamic instabilities, depending on capacity of the vortices and diffusion to increase the concentration field at the membrane. The results obtained by analytical stability analysis agree with dedicated Direct Numerical Simulations.

  12. Ion and solvent Transport in Polypyrrole: Experimental Test of Osmotic Model

    DEFF Research Database (Denmark)

    Velmurugu, Yogambigai; Skaarup, Steen

    2005-01-01

    Ion and solvent transport in the conjugated polymer actuator material, polypyrrole, doped with the immobile anion dodecyl benzene sulphonate, has been investigated by simultaneous cyclic voltammetry and Electrochemical Quartz Crystal Microbalance measurements. The purpose was to elucidate the pre...... from almost pure cation transport to ca. equal amount of anion transport; exchanging Br- for Cl- ions has only negligible effect at lower concentrations at equal osmotic pressures. Ca. 4 H2O molecules are tightly bound to each Na+ ion at concentrations ... the precise nature of the mobile species during redox cycling, and to seek confirmation for the osmotic mechanism of actuation. Three testable aspects of the model were confirmed: The number of inserted H2O molecules decreases with electrolyte concentration; at the same time the mechanism gradually changes...

  13. Sedimentation equilibria of ferrofluids: II. Experimental osmotic equations of state of magnetite colloids

    International Nuclear Information System (INIS)

    Luigjes, Bob; Thies-Weesie, Dominique M E; Erné, Ben H; Philipse, Albert P

    2012-01-01

    The first experimental osmotic equation of state is reported for well-defined magnetic colloids that interact via a dipolar hard-sphere potential. The osmotic pressures are determined from the sedimentation equilibrium concentration profiles in ultrathin capillaries using a low-velocity analytical centrifuge, which is the subject of the accompanying paper I. The pressures of the magnetic colloids, measured accurately to values as low as a few pascals, obey Van ’t Hoff’s law at low concentrations, whereas at increasing colloid densities non-ideality appears in the form of a negative second virial coefficient. This virial coefficient corresponds to a dipolar coupling constant that agrees with the coupling constant obtained via independent magnetization measurements. The coupling constant manifests an attractive potential of mean force that is significant but yet not quite strong enough to induce dipolar chain formation. Our results disprove van der Waals-like phase behavior of dipolar particles for reasons that are explained. (paper)

  14. Improvement of lipid yield from microalgae Spirulina platensis using ultrasound assisted osmotic shock extraction method

    Science.gov (United States)

    Adetya, NP; Hadiyanto, H.

    2018-01-01

    Microalgae Spirulina sp. has been identified as potential source of natural food supplement and food colorant. The high water content of microalgae (70-90%) causes an obstacle in biomass dehydration which requires large amounts of energy, eventually damaging the lipid in the microalgae. Therefore, the lipid must be extracted by using a suitable method which complies to wet biomass conditions. One of the methods is applying osmotic shock. This study was aimed to investigate the influence of osmotic agent (NaCl) concentration (10-30%) and extraction time (20-50 min) on yield of lipid and also to determine the optimal conditions in the extraction process through response surface methodology. The extraction was conducted at a temperature of 40°C under ultrasound frequency of 40 kHz. The result showed that the optimum yield lipid obtained was 6.39% in 16.98% NaCl concentration for 36 minutes 10 seconds.

  15. Approximate Mathematical Modeling of Osmotic Dehydration of Cone-Shaped Fruits and Vegetables in Hypertonic Solutions

    Directory of Open Access Journals (Sweden)

    Mohammad Sirousazar

    2017-07-01

    Full Text Available Water loss kinetics in osmotic dehydration of cone-shaped fruits and vegetables was modeled on the basis of diffusion mechanism, using the Fick’s second law. The model was developed by taking into account the influences of the fruit geometrical characteristics, initial water content of fruit, water diffusion coefficient in fruit, and the water concentration in hypertonic solution. Based on the obtained model, it was shown that the water diffusion coefficient and the initial water concentration of fruit have direct effects on the dehydration rate and also inverse influence on the dehydration duration. The geometrical parameters of fruit and water concentration in hypertonic solution showed direct effect on the dehydration duration as well as inverse effect on the dehydration rate. The presented model seems to be useful tool to predict the dehydration kinetics of cone-shaped fruit during osmotic dehydration process and to optimize the process prior to perform the experiments.

  16. Topology and shape optimization of induced-charge electro-osmotic micropumps

    DEFF Research Database (Denmark)

    Gregersen, Misha Marie; Okkels, Fridolin; Bazant, M. Z.

    2009-01-01

    For a dielectric solid surrounded by an electrolyte and positioned inside an externally biased parallel-plate capacitor, we study numerically how the resulting induced-charge electro-osmotic (ICEO) flow depends on the topology and shape of the dielectric solid. In particular, we extend existing...... conventional electrokinetic models with an artificial design field to describe the transition from the liquid electrolyte to the solid dielectric. Using this design field, we have succeeded in applying the method of topology optimization to find system geometries with non-trivial topologies that maximize...... the net induced electro-osmotic flow rate through the electrolytic capacitor in the direction parallel to the capacitor plates. Once found, the performance of the topology-optimized geometries has been validated by transferring them to conventional electrokinetic models not relying on the artificial...

  17. A novel zinc-finger-like gene from Tamarix hispida is involved in salt and osmotic tolerance.

    Science.gov (United States)

    An, Yan; Wang, Yucheng; Lou, Lingling; Zheng, Tangchun; Qu, Guan-Zheng

    2011-11-01

    In the present study, a zinc-finger-like cDNA (ThZFL) was cloned from the Tamarix hispida. Northern blot analysis showed that the expression of ThZFL can be induced by salt, osmotic stress and ABA treatment. Overexpression of the ThZFL confers salt and osmotic stress tolerance in both yeast Saccharomyces cerevisiae and tobacco. Furthermore, MDA levels in ThZFL transformed tobacco were significantly decreased compared with control plants under salt and osmotic stress, suggesting ThZFL may confer stress tolerance by decreasing membrane lipid peroxidation. Subcellular localization analysis showed the ThZFL protein is localized in the cell wall. Our results indicated the ThZFL gene is an excellent candidate for genetic engineering to improve salt and osmotic tolerance in agricultural plants.

  18. Osmotic Power Generation by Inner Selective Hollow Fiber Membranes: An investigation of thermodynamics, mass transfer, and module scale modelling

    KAUST Repository

    Xiong, Jun Ying; Cai, Dong Jun; Chong, Qing Yu; Lee, Swin Hui; Chung, Neal Tai-Shung

    2016-01-01

    A comprehensive analysis of fluid motion, mass transport, thermodynamics and power generation during pressure retarded osmotic (PRO) processes was conducted. This work aims to (1) elucidate the fundamental relationship among various membrane

  19. Methods to increase the rate of mass transfer during osmotic dehydration of foods

    OpenAIRE

    Anna Chwastek

    2014-01-01

    Traditional methods of food preservation such as freezing, freeze drying (lyophilization), vacuum drying, convection drying are often supplemented by new technologies that enable obtaining of high quality products. Osmotic dehydration is more and more often used during processing of fruits and vegetables. This method allows maintaining good organoleptic and functional properties in the finished product. Obtaining the desired degree of dehydration or saturation of the material with an osmoacti...

  20. A microfluidic chip for blood plasma separation using electro-osmotic flow control

    International Nuclear Information System (INIS)

    Jiang, Hai; Weng, Xuan; Chon, Chan Hee; Wu, Xudong; Li, Dongqing

    2011-01-01

    In this paper, a microfluidic-based chip with two straight microchannels and five branch microchannels was designed and tested to separate blood plasma from a small sample of fresh human blood. The electro-osmotic flow method was used to control the separation of blood plasma. Blood cell removal and blood plasma extraction were realized in experiments. The efficiency of extracting blood plasma can be as high as 26%

  1. Assessment of Osmotic Pre-Drying Treatment on Drying Rates of Fresh Tomato Fruits

    Directory of Open Access Journals (Sweden)

    P. A. Idah

    2014-06-01

    Full Text Available The aim of this work is to investigate the influence of osmotic pre-drying treatments on drying rates of tomato (Lycopersiconesculentum at various drying temperatures. Fresh Roma tomato fruit samples were sliced to a thickness of 5 mm and the seeds were removed. Weight of 300 g was measured for each of the three replicates and immersed in a hypertonic solution of sucrose of different concentrations 40 and 60 oBrix each held for osmotic duration of 1 and 2 hours, drained for 10 min and then dried at 50, 60, and 70 oC in a mechanical dryer. Control samples were also weighed 300 g per replicate and dried at 50, 60, and 70 oC without pre-drying treatment. The initial moisture content of fresh tomato used was 94.5% (wb. Moisture loss of each sample was monitored and recorded hourly until the product has reached the desired final moisture content (≤ 7%.The data collected were subjected to statistical analysis of variance (ANOVA and Duncan New Multiple range tests (DNMRT to ascertain the level of significance differences between the individual treatments and their interaction at p ≤ 0.05.The results show that at all the drying temperatures used, the control tomato samples exhibited the fastest drying rate with an average of 35.2 g/hr, samples pre-treated at 40 oBrix has an average drying rate of 26.6 g/hr, while samples pre-treated at 60 oBrix has the slowest drying rate of 25.2 g/hr. It was also revealed that samples subjected to 1 hour osmotic time have faster drying rates than those treated for 2 hours osmotic time.

  2. Transformation of oats and its application to improving osmotic stress tolerance.

    Science.gov (United States)

    Maqbool, Shahina B; Zhong, Heng; Oraby, Hesham F; Sticklen, Mariam B

    2009-01-01

    Oat (Avena sativa L.), a worldwide temperate cereal crop, is deficient in tolerance to osmotic stress due to drought and/or salinity. To genetically transform the available commercial oat cultivars, a genotype-independent and efficient regeneration system from shoot apical meristems was developed using four oat cultivars: Prairie, Porter, Ogle, and Pacer. All these oat cultivars generated a genotype-independent in vitro differentiated multiple shoots from shoot apical meristems at a high frequency. Using this system, three oat cultivars were genetically co-transformed with pBY520 (containing hva1 and bar) and pAct1-D (containing gus) using biolistic trade mark bombardment. Transgenic plants were selected and regenerated using herbicide resistance and GUS as a marker. Molecular and biochemical analyses of putative transgenic plants confirmed the co-integration of hva1 and bar genes with a frequency of 100%, and 61.6% of the transgenic plants carried all three genes (hva1, bar and gus). Further analyses of R0, R1, and R2 progenies confirmed stable integration, expression, and Mendalian inheritance for all transgenes. Histochemical analysis of GUS protein in transgenic plants showed a high level of GUS expression in vascular tissues and in the pollen grains of mature flowers. Immunochemical analysis of transgenic plants indicated a constitutive expression of hva1 at all developmental stages. However, the level of HVA1 was higher during the early seedling stages. The characteristic of HVA1 expression for osmotic tolerance in transgenic oat progeny was analyzed in vitro as well as in vivo. Transgenic plants exhibited significantly (Pplants. The symptoms of wilting or death of leaves as observed in 80% of non-transgenic plants due to osmotic stress was delayed and detected only in less than 10% of trans-genic plants. These observations confirmed the characteristic of HVA1 protein as providing or enhancing the osmotic tolerance in transgenic plants against salinity and

  3. Hydration induced material transfer in membranes of osmotic pump tablets measured by synchrotron radiation based FTIR.

    Science.gov (United States)

    Wu, Li; Yin, Xianzhen; Guo, Zhen; Tong, Yajun; Feng, Jing; York, Peter; Xiao, Tiqiao; Chen, Min; Gu, Jingkai; Zhang, Jiwen

    2016-03-10

    Osmotic pump tablets are reliable oral controlled drug delivery systems based on their semipermeable membrane coating. This research used synchrotron radiation-based Fourier transform infrared (SR-FTIR) microspectroscopy and imaging to investigate the hydration induced material transfer in the membranes of osmotic pump tablets. SR-FTIR was applied to record and map the chemical information of a micro-region of the membranes, composed of cellulose acetate (CA, as the water insoluble matrix) and polyethylene glycol (PEG, as the soluble pore forming agent and plasticizing agent). The microstructure and chemical change of membranes hydrated for 0, 5, 10 and 30min were measured using SR-FTIR, combined with scanning electronic microscopy and atom force microscopy. The SR-FTIR microspectroscopy results indicated that there was a major change at the absorption range of 2700-3100cm(-1) in the membranes after different periods of hydration time. The absorption bands at 2870-2880cm(-1) and 2950-2960cm(-1) were assigned to represent CA and PEG, respectively. The chemical group signal distribution illustrated by the ratio of PEG to CA demonstrated that the trigger of drug release in the preliminary stage was due to the rapid transfer of PEG into liquid medium with a sharp decrease of PEG in the membranes. The SR-FTIR mapping results have demonstrated the hydration induced material transfer in the membranes of osmotic pump tablets and enabled reassessment of the drug release mechanism of membrane controlled osmotic pump systems. Copyright © 2016 Elsevier B.V. All rights reserved.

  4. Effect of Osmotic Stress on Seed Germination Indices of Nigella sativa and Silybum marianum

    OpenAIRE

    H Balouchi; A. Yadavi; M. Movahedi Dehnavi

    2012-01-01

    Evaluation of medicinal plants to drought and salt stress tolerance, in an attempt to plant them under drought and saline regions, is of utmost importance. Environmental stresses, especially drought and salt, reduce the global crop yields more than other factors. Selection of drought tolerant crops at germination stage, usually is, the fast and low cost method. In order to study the effect of osmotic stress on germination indices of black cumin and milk thistle, an experiment carried out in a...

  5. RESOURCE RECOVERY BY OSMOTIC BIOELECTROCHEMICAL SYSTEMS  TOWARDS SUSTAINABLE WASTEWATER TREATMENT

    OpenAIRE

    Qin, Mohan

    2017-01-01

    Recovering valuable resources from wastewater will transform wastewater management from a treatment focused to sustainability focused strategy, and creates the need for new technology development. An innovative treatment concept - osmotic bioelectrochemical system (OsBES), which is based on cooperation between bioelectrochemical systems (BES) and forward osmosis (FO), has been introduced and studied in the past few years. An OsBES can accomplish simultaneous treatment of wastewater and recove...

  6. Stress responses of the industrial workhorse Bacillus licheniformis to osmotic challenges.

    Directory of Open Access Journals (Sweden)

    Rebecca Schroeter

    Full Text Available The Gram-positive endospore-forming bacterium Bacillus licheniformis can be found widely in nature and it is exploited in industrial processes for the manufacturing of antibiotics, specialty chemicals, and enzymes. Both in its varied natural habitats and in industrial settings, B. licheniformis cells will be exposed to increases in the external osmolarity, conditions that trigger water efflux, impair turgor, cause the cessation of growth, and negatively affect the productivity of cell factories in biotechnological processes. We have taken here both systems-wide and targeted physiological approaches to unravel the core of the osmostress responses of B. licheniformis. Cells were suddenly subjected to an osmotic upshift of considerable magnitude (with 1 M NaCl, and their transcriptional profile was then recorded in a time-resolved fashion on a genome-wide scale. A bioinformatics cluster analysis was used to group the osmotically up-regulated genes into categories that are functionally associated with the synthesis and import of osmostress-relieving compounds (compatible solutes, the SigB-controlled general stress response, and genes whose functional annotation suggests that salt stress triggers secondary oxidative stress responses in B. licheniformis. The data set focusing on the transcriptional profile of B. licheniformis was enriched by proteomics aimed at identifying those proteins that were accumulated by the cells through increased biosynthesis in response to osmotic stress. Furthermore, these global approaches were augmented by a set of experiments that addressed the synthesis of the compatible solutes proline and glycine betaine and assessed the growth-enhancing effects of various osmoprotectants. Combined, our data provide a blueprint of the cellular adjustment processes of B. licheniformis to both sudden and sustained osmotic stress.

  7. Stress responses of the industrial workhorse Bacillus licheniformis to osmotic challenges.

    Science.gov (United States)

    Schroeter, Rebecca; Hoffmann, Tamara; Voigt, Birgit; Meyer, Hanna; Bleisteiner, Monika; Muntel, Jan; Jürgen, Britta; Albrecht, Dirk; Becher, Dörte; Lalk, Michael; Evers, Stefan; Bongaerts, Johannes; Maurer, Karl-Heinz; Putzer, Harald; Hecker, Michael; Schweder, Thomas; Bremer, Erhard

    2013-01-01

    The Gram-positive endospore-forming bacterium Bacillus licheniformis can be found widely in nature and it is exploited in industrial processes for the manufacturing of antibiotics, specialty chemicals, and enzymes. Both in its varied natural habitats and in industrial settings, B. licheniformis cells will be exposed to increases in the external osmolarity, conditions that trigger water efflux, impair turgor, cause the cessation of growth, and negatively affect the productivity of cell factories in biotechnological processes. We have taken here both systems-wide and targeted physiological approaches to unravel the core of the osmostress responses of B. licheniformis. Cells were suddenly subjected to an osmotic upshift of considerable magnitude (with 1 M NaCl), and their transcriptional profile was then recorded in a time-resolved fashion on a genome-wide scale. A bioinformatics cluster analysis was used to group the osmotically up-regulated genes into categories that are functionally associated with the synthesis and import of osmostress-relieving compounds (compatible solutes), the SigB-controlled general stress response, and genes whose functional annotation suggests that salt stress triggers secondary oxidative stress responses in B. licheniformis. The data set focusing on the transcriptional profile of B. licheniformis was enriched by proteomics aimed at identifying those proteins that were accumulated by the cells through increased biosynthesis in response to osmotic stress. Furthermore, these global approaches were augmented by a set of experiments that addressed the synthesis of the compatible solutes proline and glycine betaine and assessed the growth-enhancing effects of various osmoprotectants. Combined, our data provide a blueprint of the cellular adjustment processes of B. licheniformis to both sudden and sustained osmotic stress.

  8. Translocation of DNA Molecules through Nanopores with Salt Gradients: The Role of Osmotic Flow

    Science.gov (United States)

    Hatlo, Marius M.; Panja, Debabrata; van Roij, René

    2011-08-01

    Recent experiments of translocation of double-stranded DNA through nanopores [M. Wanunu , Nature Nanotech. 5, 160 (2009)NNAABX1748-338710.1038/nnano.2009.379] reveal that the DNA capture rate can be significantly influenced by a salt gradient across the pore. We show that osmotic flow combined with electrophoretic effects can quantitatively explain the experimental data on the salt-gradient dependence of the capture rate.

  9. Influence of osmotic pressure on the growth of three species of the genus Zoophthora

    Directory of Open Access Journals (Sweden)

    Jerzy Piątkowski

    2013-12-01

    Full Text Available Strains accomodated in the genus Zoophthora are very sensitive to osmotic value of their habitat. Hipertonical molarity of buffers and NaCl decreases the growth, but this effect strongly depends on the species tested and on the kind of buffer. In 0.66% phtalan buffer the growth of Z. lanceolata is completely stopped whereas Z. psyllae and Z. aphrophora is inhibited only in 50% comparing to the control.

  10. Approximate Mathematical Modeling of Osmotic Dehydration of Cone-Shaped Fruits and Vegetables in Hypertonic Solutions

    OpenAIRE

    Mohammad Sirousazar

    2017-01-01

    Water loss kinetics in osmotic dehydration of cone-shaped fruits and vegetables was modeled on the basis of diffusion mechanism, using the Fick’s second law. The model was developed by taking into account the influences of the fruit geometrical characteristics, initial water content of fruit, water diffusion coefficient in fruit, and the water concentration in hypertonic solution. Based on the obtained model, it was shown that the water diffusion coefficient and the initial water concentratio...

  11. Phenotypic variations in osmotic lysis of Sahel goat erythrocytes in non-ionic glucose media.

    Science.gov (United States)

    Igbokwe, Nanacha Afifi; Igbokwe, Ikechukwu Onyebuchi

    2016-03-01

    Erythrocyte osmotic lysis in deionised glucose media is regulated by glucose influx, cation efflux, and changes in cell volume after water diffusion. Transmembrane fluxes may be affected by varied expression of glucose transporter protein and susceptibility of membrane proteins to glucose-induced glycosylation and oxidation in various physiologic states. Variations in haemolysis of Sahel goat erythrocytes after incubation in hyposmotic non-ionic glucose media, associated with sex, age, late pregnancy, and lactation, were investigated. The osmotic fragility curve in glucose media was sigmoidal with erythrocytes from goats in late pregnancy (PRE) or lactation (LAC) or from kid (KGT) or middle-aged (MGT) goats. Non-sigmoidal phenotype occurred in yearlings (YGT) and old (OGT) goats. The composite fragility phenotype for males and non-pregnant dry (NPD) females was non-sigmoidal. Erythrocytes with non-sigmoidal curves were more stable than those with sigmoidal curves because of inflectional shift of the curve to the left. Erythrocytes tended to be more fragile with male than female sex, KGT and MGT than YGT and OGT, and LAC and PRE than NPD. Thus, sex, age, pregnancy, and lactation affected the haemolytic pattern of goat erythrocytes in glucose media. The physiologic state of the goat affected the in vitro interaction of glucose with erythrocytes, causing variations in osmotic stability with variants of fragility phenotype. Variations in the effect of high extracellular glucose concentrations on the functions of membrane-associated glucose transporter, aquaporins, and the cation cotransporter were presumed to be relevant in regulating the physical properties of goat erythrocytes under osmotic stress.

  12. Refinement of elastic, poroelastic, and osmotic tissue properties of intervertebral disks to analyze behavior in compression.

    Science.gov (United States)

    Stokes, Ian A F; Laible, Jeffrey P; Gardner-Morse, Mack G; Costi, John J; Iatridis, James C

    2011-01-01

    Intervertebral disks support compressive forces because of their elastic stiffness as well as the fluid pressures resulting from poroelasticity and the osmotic (swelling) effects. Analytical methods can quantify the relative contributions, but only if correct material properties are used. To identify appropriate tissue properties, an experimental study and finite element analytical simulation of poroelastic and osmotic behavior of intervertebral disks were combined to refine published values of disk and endplate properties to optimize model fit to experimental data. Experimentally, nine human intervertebral disks with adjacent hemi-vertebrae were immersed sequentially in saline baths having concentrations of 0.015, 0.15, and 1.5 M and the loss of compressive force at constant height (force relaxation) was recorded over several hours after equilibration to a 300-N compressive force. Amplitude and time constant terms in exponential force-time curve-fits for experimental and finite element analytical simulations were compared. These experiments and finite element analyses provided data dependent on poroelastic and osmotic properties of the disk tissues. The sensitivities of the model to alterations in tissue material properties were used to obtain refined values of five key material parameters. The relaxation of the force in the three bath concentrations was exponential in form, expressed as mean compressive force loss of 48.7, 55.0, and 140 N, respectively, with time constants of 1.73, 2.78, and 3.40 h. This behavior was analytically well represented by a model having poroelastic and osmotic tissue properties with published tissue properties adjusted by multiplying factors between 0.55 and 2.6. Force relaxation and time constants from the analytical simulations were most sensitive to values of fixed charge density and endplate porosity.

  13. Relationship between solute permeability and osmotic remediability in a galactose-negative strain of Saccharomyces cerevisiae.

    Science.gov (United States)

    Bassel, J; Douglas, H C

    1970-11-01

    An osmotic remedial allele, gal 7-1, in the galactose pathway of Saccharomyces cerevisiae responds to either penetrating (ethylene glycol and diethylene glycol) or nonpenetrating (KCl, NaCl, and sorbitol) solutes in the growth medium. Extracts from cells grown under restrictive conditions gave no increase in enzyme activity (gal-1-phosphate, uridylyl transferase) when exposed to the penetrating solutes; thus protein synthesis or possibly polymer assembly is proposed as the critical step remedied by the addition of the solutes.

  14. GERMINATION AND INITIAL GROWTH OF COWPEA CULTIVARS UNDER OSMOTIC STRESS AND SALICYLIC ACID

    OpenAIRE

    ARAÚJO, EDILENE DANIEL DE; MELO, ALBERTO SOARES DE; ROCHA, MARIA DO SOCORRO; CARNEIRO, REBECA FERREIRA; ROCHA, MAURISRAEL DE MOURA

    2018-01-01

    ABSTRACT Cowpea is one of the major food crops in Northeast Brazil, where it is commonly cultivated in the semi-arid regions with limited water availability. It is important to study the elicitors associated with cowpea to mitigate any deleterious effects of abiotic stress on the initial establishment of this crop. In this study, we aimed to evaluate the morphophysiological changes in cowpea cultivars under osmotic stress with seeds soaked in salicylic acid. The germination test was conducted...

  15. Colloid osmotic pressure during and after surgical interventions in adult and geriatric dogs

    Directory of Open Access Journals (Sweden)

    Mario A.F. Rego

    Full Text Available ABSTRACT: The objective this study is to evaluate colloid osmotic pressure (COP fluctuations in adult and senile dogs during surgical interventions. Thirty-six healthy dogs to surgical interventions, distributed in two groups, A and B, according to their age, and were all subjected to the same anesthetic protocol. Values of albumin, total plasmatic protein and COP were evaluated from samples collected before pre-anesthetic medication, fifteen minutes after pre-anesthetic medication, and shortly after the end of the intervention. Results were tested using t-test to compare among groups and ANOVA for repeated measures followed by Tukey’s test to compare different moments within the same group. Statistical significance was set at p<0.05. In both groups, significant decreases were observed in colloid osmotic pressure, as well as albumin and total proteins (p<0.001. Despite slightly lower COP values for the group of adult animals, this difference was not significant as there was a high individual variation within groups. The results therefore indicate no difference in colloid osmotic pressure values or fluctuation patterns among adult and senile dogs (p=0.124. The observed results indicate that colloid osmotic pressure decreases significantly during surgical procedures, due to hypotension caused by the anesthetic drugs and to hemodilution caused by the fluid administration but there is no difference between groups. However, in both adult and senile dogs, these variables recover gradually after the animals awaken, through increased urine production and recovery of vascular tonus, indicating the successful reestablishment of homeostasis.

  16. Optimizing Solute-Solute Interactions in the GLYCAM06 and CHARMM36 Carbohydrate Force Fields Using Osmotic Pressure Measurements.

    Science.gov (United States)

    Lay, Wesley K; Miller, Mark S; Elcock, Adrian H

    2016-04-12

    GLYCAM06 and CHARMM36 are successful force fields for modeling carbohydrates. To correct recently identified deficiencies with both force fields, we adjusted intersolute nonbonded parameters to reproduce the experimental osmotic coefficient of glucose at 1 M. The modified parameters improve behavior of glucose and sucrose up to 4 M and improve modeling of a dextran 55-mer. While the modified parameters may not be applicable to all carbohydrates, they highlight the use of osmotic simulations to optimize force fields.

  17. Neuroendocrine and cardiovascular parameters during simulation of stress-induced rise in circulating oxytocin in the rat.

    Science.gov (United States)

    Ondrejcakova, M; Bakos, J; Garafova, A; Kovacs, L; Kvetnansky, R; Jezova, D

    2010-07-01

    Physiological functions of oxytocin released during stress are not well understood. We have (1) investigated the release of oxytocin during chronic stress using two long-term stress models and (2) simulated stress-induced oxytocin secretion by chronic treatment with oxytocin via osmotic minipumps. Plasma oxytocin levels were significantly elevated in rats subjected to acute immobilization stress for 120 min, to repeated immobilization for 7 days and to combined chronic cold stress exposure for 28 days with 7 days immobilization. To simulate elevation of oxytocin during chronic stress, rats were implanted with osmotic minipumps subcutaneously and treated with oxytocin (3.6 microg/100 g body weight/day) or vehicle for 2 weeks. Chronic subcutaneous oxytocin infusion led to an increase in plasma oxytocin, adrenocorticotropic hormone, corticosterone, adrenal weights and heart/body weight ratio. Oxytocin treatment had no effect on the incorporation of 5-bromo-2-deoxyuridine into DNA in the heart ventricle. Mean arterial pressure response to intravenous phenylephrine was reduced in oxytocin-treated animals. Decrease in adrenal tyrosin hydroxylase mRNA following oxytocin treatment was not statistically significant. Oxytocin treatment failed to modify food intake and slightly increased water consumption. These data provide evidence on increased concentrations of oxytocin during chronic stress. It is possible that the role of oxytocin released during stress is in modulating hypothalamic-pituitary-adrenocortical axis and selected sympathetic functions.

  18. Effect of drought and abscisic acid application on the osmotic adjustment of four wheat cultivars

    International Nuclear Information System (INIS)

    Iqbal, S.; Bano, A.

    2010-01-01

    The accumulation of osmolytes in leaf tissues and the abscisic acid-induced stomatal closure are well-recognized mechanisms associated with drought tolerance in crop plants. We determine the response in terms of osmotic potential and the contents of leaf proline, glycine betaine and soluble sugar at booting and grain filling stages of four wheat (Triticum aestivum L.) cultivars to drought and exogenously applied abscisic acid (ABA) in a pot study. Leaf sample were collected 3, 6 and 9 days after drought induction and at 48 and 72 h of re-watering (recovery). Marked decreases in osmotic potential associated with the accumulation of proline, glycine betaine and soluble sugars occurred under conditions of drought stress Accession 011320 was most sensitive to drought and showed the largest decrease in osmotic potential and least accumulation of proline, sugar and glycine betaine The inhibitory effects of drought stress were ameliorated by exogenous application of ABA. This ameliorating effect was more pronounced at the booting than at grain filling stage particularly in the sensitive accession 011320. Upon rewatering the recovery from drought stress was found to be greater in case of abscisic acid application. The leaf praline content is seen to be a suitable indicator for selecting drought-tolerant genotypes. (author)

  19. Regulation of Aquaporin Z osmotic permeability in ABA tri-block copolymer

    Directory of Open Access Journals (Sweden)

    Wenyuan Xie

    2015-08-01

    Full Text Available Aquaporins are transmembrane water channel proteins present in biological plasma membranes that aid in biological water filtration processes by transporting water molecules through at high speeds, while selectively blocking out other kinds of solutes. Aquaporin Z incorporated biomimetic membranes are envisaged to overcome the problem of high pressure needed, and holds great potential for use in water purification processes, giving high flux while keeping energy consumption low. The functionality of aquaporin Z in terms of osmotic permeability might be regulated by factors such as pH, temperature, crosslinking and hydrophobic thickness of the reconstituted bilayers. Hence, we reconstituted aquaporin Z into vesicles that are made from a series of amphiphilic block copolymers PMOXA-PDMS-PMOXAs with various hydrophobic molecular weights. The osmotic permeability of aquaporin Z in these vesicles was determined through a stopped-flow spectroscopy. In addition, the temperature and pH value of the vesicle solutions were adjusted within wide ranges to investigate the regulation of osmotic permeability of aquaporin Z through external conditions. Our results show that aquaporin Z permeability was enhanced by hydrophobic mismatch. In addition, the water filtration mechanism of aquaporin Z is significantly affected by the concentration of H+ and OH- ions.

  20. Soybean mother plant exposure to temperature stress and its effect on germination under osmotic stress

    International Nuclear Information System (INIS)

    Khalil, S.K.; Rehman, A.; Khan, A.Z.; Mexal, J.G.; Zubair, M.; Wahab, S.; Khalil, I.H.; Mohammad, F.

    2010-01-01

    High temperature reduces quality of soybean seed developed at different positions on the plant. The objective of this research was to study the quality of seed produced under different temperature regimes located at different position in the canopy. Soybean plants grown in pots were transferred at first pod stage to three growth chambers fixed at 18/10, 25/15 and 32/20 deg. C day/night temperature having 13/11 hrs day/night length. The plants remained in growth chambers until physiological maturity. Seeds harvested from each growth chamber were exposed to osmotic stress having osmotic potential of -0.5 MPa and unstressed control. Both stressed and control treatments were germinated in three growth chambers fixed at 18, 25 and 35 deg. C. Seed developed at lowest temperature (18/10 deg. C day/night) had maximum germination. Germination decreased linearly with increased day/night temperature and lowest germination was recorded at highest temperature of 32/20 deg. C (day/night). Seed developed at bottom position was heaviest and had better germination compared with seed developed at middle and top position. Seed germination was highest at 25 deg. C and took fewer days to 50% germination than 18 and 25 deg. C. Osmotic stress decreased germination and delayed days to 50% germination than control. It can be concluded that optimum temperature for seed development was 18/10 deg. C (day/night) whereas best germination temperature was 25 deg. C. (author)

  1. Osmotic pressure and virial coefficients of star and comb polymer solutions: dissipative particle dynamics.

    Science.gov (United States)

    Wang, Tzu-Yu; Fang, Che-Ming; Sheng, Yu-Jane; Tsao, Heng-Kwong

    2009-03-28

    The effects of macromolecular architecture on the osmotic pressure pi and virial coefficients (B(2) and B(3)) of star and comb polymers in good solvents are studied by dissipative particle dynamics simulations for both dilute and semiconcentrated regimes. The dependence of the osmotic pressure on polymer concentration is directly calculated by considering two reservoirs separated by a semipermeable, fictitious membrane. Our simulation results show that the ratios A(n+1) identical with B(n+1)/R(g)(3n) are essentially constant and A(2) and A(3) are arm number (f) dependent, where R(g) is zero-density radius of gyration. The value of dimensionless virial ratio g = A(3)/A(2)(2) increases with arm number of stars whereas it is essentially arm number independent for comb polymers. In semiconcentrated regime the scaling relation between osmotic pressure and volume fraction, pi proportional to phi(lambda), still holds for both star and comb polymers. For comb polymers, the exponent lambda is close to lambda(*) (approximately = 2.73 for linear chains) and is independent of the arm number. However, for star polymers, the exponent lambda deviates from lambda(*) and actually grows with increasing the arm number. This may be attributed to the significant ternary interactions near the star core in the many-arm systems.

  2. Osmotic stress alters the balance between organic and inorganic solutes in flax (Linum usitatissimum).

    Science.gov (United States)

    Quéro, Anthony; Molinié, Roland; Elboutachfaiti, Redouan; Petit, Emmanuel; Pau-Roblot, Corinne; Guillot, Xavier; Mesnard, François; Courtois, Josiane

    2014-01-01

    Flax (Linum usitatissimum) is grown for its oil and its fiber. This crop, cultivated in temperate regions, has seen a renewed interest due to the presence of abundant molecules of interest for many applications. Little information is available about the behavior of flax during osmotic stress; yet this is considered a major stress that causes significant yield losses in most crops. To control the presence of this stress better, flax behavior was investigated following the application of osmotic stress and the response was examined by applying increasing concentrations of PEG 8000. This resulted in the reorganization of 32 metabolites and 6 mineral ions in the leaves. The analysis of these two types of solute highlighted the contrasting behavior between a higher metabolite content (particularly fructose, glucose and proline) and a decrease in mineral ions (especially nitrate and potassium) following PEG treatment. However, this reorganization did not lead to a greater accumulation of solutes, with the total amount remaining unchanged in leaves during osmotic stress. Copyright © 2013 Elsevier GmbH. All rights reserved.

  3. Osmotic stress regulates the strength and kinetics of sugar binding to the maltoporin channel

    International Nuclear Information System (INIS)

    Gurnev, Philip A; Bezrukov, Sergey M; Harries, Daniel; Adrian Parsegian, V

    2010-01-01

    We study the effect of osmotic stress, exerted by salts, on carbohydrate binding to the sugar-specific bacterial channel maltoporin. When the channel is reconstituted into planar lipid bilayers, single events of its occlusion by sugar are seen as transient interruptions in the flow of small ions. We find that, for most salts, changes in the free energy of maltoporin-sugar binding vary linearly with solution osmotic pressure. Such a change in binding with solution osmolarity indicates that for each salt a constant number of salt-excluding water molecules is released upon sugar-maltoporin association at all salt concentrations. We find that larger numbers of water molecules are released upon binding of the cyclic carbohydrate β-cyclodextrin (CD) than upon binding of the corresponding linear homologue maltoheptaose (m7). Remarkably, the extent to which salts affect the binding constants and rates depends sensitively on the type of salt; dehydration in solutions of different anions corresponds to the Hofmeister series. In sodium sulfate solutions, CD and m7 respectively release about 120 and 35 salt-excluding water molecules; in sodium chloride solutions, 35 and 15 waters. No water release is observed with sodium bromide. Finally, by adding adamantane, known to form an inclusion complex with CD, we can infer that CD not only dehydrates but also undergoes a conformational change upon binding to the channel. As a practical outcome, our results also demonstrate how osmotic stress can improve single-molecule detection of different solutes using protein-based nanopores.

  4. Effect of calcium/sodium ion exchange on the osmotic properties and structure of polyelectrolyte gels.

    Science.gov (United States)

    Horkay, Ferenc; Basser, Peter J; Hecht, Anne-Marie; Geissler, Erik

    2015-12-01

    We discuss the main findings of a long-term research program exploring the consequences of sodium/calcium ion exchange on the macroscopic osmotic and elastic properties, and the microscopic structure of representative synthetic polyelectrolyte (sodium polyacrylate, (polyacrylic acid)) and biopolymer gels (DNA). A common feature of these gels is that above a threshold calcium ion concentration, they exhibit a reversible volume phase transition. At the macroscopic level, the concentration dependence of the osmotic pressure shows that calcium ions influence primarily the third-order interaction term in the Flory-Huggins model of polymer solutions. Mechanical tests reveal that the elastic modulus is practically unaffected by the presence of calcium ions, indicating that ion bridging does not create permanent cross-links. At the microscopic level, small-angle neutron scattering shows that polyacrylic acid and DNA gels exhibit qualitatively similar structural features in spite of important differences (e.g. chain flexibility and chemical composition) between the two polymers. The main effect of calcium ions is that the neutron scattering intensity increases due to the decrease in the osmotic modulus. At the level of the counterion cloud around dissolved macroions, anomalous small-angle X-ray scattering measurements made on DNA indicate that divalent ions form a cylindrical sheath enveloping the chain, but they are not localized. Small-angle neutron scattering and small-angle X-ray scattering provide complementary information on the structure and interactions in polymer solutions and gels. © IMechE 2015.

  5. In silico identification of known osmotic stress responsive genes from Arabidopsis in soybean and Medicago

    Directory of Open Access Journals (Sweden)

    Nina M. Soares-Cavalcanti

    2012-01-01

    Full Text Available Plants experience various environmental stresses, but tolerance to these adverse conditions is a very complex phenomenon. The present research aimed to evaluate a set of genes involved in osmotic response, comparing soybean and medicago with the well-described Arabidopsis thaliana model plant. Based on 103 Arabidopsis proteins from 27 categories of osmotic stress response, comparative analyses against Genosoja and Medicago truncatula databases allowed the identification of 1,088 soybean and 1,210 Medicago sequences. The analysis showed a high number of sequences and high diversity, comprising genes from all categories in both organisms. Genes with unknown function were among the most representative, followed by transcription factors, ion transport proteins, water channel, plant defense, protein degradation, cellular structure, organization & biogenesis and senescence. An analysis of sequences with unknown function allowed the annotation of 174 soybean and 217 Medicago sequences, most of them concerning transcription factors. However, for about 30% of the sequences no function could be attributed using in silico procedures. The establishment of a gene set involved in osmotic stress responses in soybean and barrel medic will help to better understand the survival mechanisms for this type of stress condition in legumes.

  6. Influence of power ultrasound on the main quality properties and cell viability of osmotic dehydrated cranberries.

    Science.gov (United States)

    Nowacka, Malgorzata; Fijalkowska, Aleksandra; Wiktor, Artur; Dadan, Magdalena; Tylewicz, Urszula; Dalla Rosa, Marco; Witrowa-Rajchert, Dorota

    2018-02-01

    The aim of the study was to investigate the effect of ultrasound treatment in two osmotic solutions, carried out at different time, on some physical properties, antioxidant activity and cell survival of cranberries. Ultrasound treatment was conducted at 21kHz for 30 and 60min in liquid medium: 61.5% sucrose solution and 30% sucrose solution with 0.1% steviol glycosides addition. Some samples before the ultrasound treatment were subjected to cutting or blanching. The results showed that dry matter content and concentration of the dissolved substances increased during ultrasound treatment in osmotic solution, however higher value was observed for treatment in 61.5% sucrose solution and for longer time. Water activity and volume of cranberries did not change after the ultrasonic treatment. Combined treatment led to colour and antioxidant activity alterations as well. A cell viability of whole and cut samples decreased after 60min of osmotic treatment and completely lost in the blanched samples. Copyright © 2017 Elsevier B.V. All rights reserved.

  7. Osmotic coefficients of alcoholic mixtures containing BMpyrDCA: Experimental determination and correlation

    International Nuclear Information System (INIS)

    Calvar, N.; Domínguez, Á.; Macedo, E.A.

    2014-01-01

    Graphical abstract: - Highlights: • Osmotic coefficients of alcohols with BMpyrDCA ionic liquid are determined. • Experimental data were correlated with Extended Pitzer model of Archer and MNRTL. • Mean molal activity coefficients and excess Gibbs free energies were calculated. • The results have been interpreted in terms of interactions. - Abstract: The vapour pressure osmometry technique (VPO) has been used to obtain the osmotic coefficients of the binary mixtures of the primary and secondary alcohols 1-propanol, 2-propanol, 1-butanol, 2-butanol and 1-pentanol with the ionic liquid 1-butyl-1-methylpyrrolidinium dicyanamide, BMpyrDCA. From these coefficients, the corresponding activity coefficients and vapour pressures of the mixtures have been also determined. The results have been discussed in terms of solute–solvent and ion–ion interactions and have been compared with those taken from literature in order to analyse the influence of the anion or cation constituting the ionic liquid. For the treatment of the experimental data, the Extended Pitzer model of Archer and the MNRTL model have been applied, obtaining standard deviations from the experimental osmotic coefficients lower than 0.015 and 0.065, respectively. From the parameters obtained with the Extended Pitzer model or Archer, the mean molal activity coefficients and the excess Gibbs free energy for the studied mixtures have been calculated

  8. Vapour pressures and osmotic coefficients of binary mixtures containing alcohol and pyrrolidinium-based ionic liquids

    International Nuclear Information System (INIS)

    Calvar, N.; Domínguez, Á.; Macedo, E.A.

    2013-01-01

    Highlights: • Osmotic coefficients of alcohols with pyrrolidinium ILs are determined. • Experimental data were correlated with extended Pitzer model of Archer and MNRTL. • Mean molal activity coefficients and excess Gibbs free energies were calculated. • The results have been interpreted in terms of interactions. -- Abstract: The osmotic and activity coefficients and vapour pressures of mixtures containing primary (1-propanol, 1-butanol and 1-pentanol) and secondary (2-propanol and 2-butanol) alcohols with pyrrolidinium-based ionic liquids (1-butyl-1-methyl pyrrolidinium bis(trifluoromethylsulfonyl)imide, C 4 MpyrNTf 2 , and 1-butyl-1-methyl pyrrolidinium trifluoromethanesulfonate, C 4 MpyrTFO) have been experimentally determined at T = 323.15 K. For the experimental measurements, the vapour pressure osmometry technique has been used. The results on the influence of the structure of the alcohol and of the anion of the ionic liquid on the determined properties have been discussed and compared with literature data. For the correlation of the osmotic coefficients obtained, the Extended Pitzer model of Archer and the Modified Non-Random Two Liquids model were applied. The mean molal activity coefficients and the excess Gibbs energy for the studied mixtures were calculated from the parameters obtained in the correlation

  9. Separation of ions in nanofluidic channels with combined pressure-driven and electro-osmotic flow.

    Science.gov (United States)

    Gillespie, Dirk; Pennathur, Sumita

    2013-03-05

    Separation of ionic species with the same electrophoretic mobility but different valence in electrolyte systems can occur within nanometer-scale channels with finite electrical double layers (EDLs). This is because EDL thicknesses are a significant fraction of slit height in such channels and can create transverse analyte concentration profiles that allow for unique separation modalities when combined with axial fluid flow. Previous work has shown such separation to occur using either pressure-driven flow or electro-osmotic flow separately. Here, we develop a Poisson-Boltzmann model to compare the separation of such ions using the combination of both pressure-driven and electro-osmotic flow. Applying a pressure gradient in the opposite direction of electro-osmotic flow can allow for zero or infinite retention of analyte species, which we investigate using three different wall boundary conditions. Furthermore, we determine conditions in fused silica nanochannels with which to generate optimal separation between two analytes of different charge but the same mobility. We also give simple rules of thumb to achieve the best separation efficacy in nanochannel systems.

  10. Theoretical and experimental investigations of the potential of osmotic energy for power production.

    Science.gov (United States)

    Sharif, Adel O; Merdaw, Ali A; Aryafar, Maryam; Nicoll, Peter

    2014-08-08

    This paper presents a study on the potential of osmotic energy for power production. The study includes both pilot plant testing and theoretical modelling as well as cost estimation. A projected cost of £30/MWh of clean electricity could be achieved by using a Hydro-Osmotic Power (HOP) plant if a suitable membrane is used and the osmotic potential difference between the two solutions is greater than 25 bar; a condition that can be readily found in many sites around the world. Results have shown that the membrane system accounts for 50%-80% of the HOP plant cost depending on the salinity difference level. Thus, further development in membrane technology and identifying suitable membranes would have a significant impact on the feasibility of the process and the route to market. As the membrane permeability determines the HOP process feasibility, this paper also describes the effect of the interaction between the fluid and the membrane on the system permeability. It has been shown that both the fluid physical properties as well as the membrane micro-structural parameters need to be considered if further development of the HOP process is to be achieved.

  11. Theoretical and Experimental Investigations of the Potential of Osmotic Energy for Power Production †

    Science.gov (United States)

    Sharif, Adel O.; Merdaw, Ali A.; Aryafar, Maryam; Nicoll, Peter

    2014-01-01

    This paper presents a study on the potential of osmotic energy for power production. The study includes both pilot plant testing and theoretical modelling as well as cost estimation. A projected cost of £30/MWh of clean electricity could be achieved by using a Hydro-Osmotic Power (HOP) plant if a suitable membrane is used and the osmotic potential difference between the two solutions is greater than 25 bar; a condition that can be readily found in many sites around the world. Results have shown that the membrane system accounts for 50%–80% of the HOP plant cost depending on the salinity difference level. Thus, further development in membrane technology and identifying suitable membranes would have a significant impact on the feasibility of the process and the route to market. As the membrane permeability determines the HOP process feasibility, this paper also describes the effect of the interaction between the fluid and the membrane on the system permeability. It has been shown that both the fluid physical properties as well as the membrane micro-structural parameters need to be considered if further development of the HOP process is to be achieved. PMID:25110959

  12. Molecular sieving action of the cell membrane during gradual osmotic hemolysis

    Energy Technology Data Exchange (ETDEWEB)

    MacGregor, R.D. II

    1977-05-01

    Rat erythrocytes were hemolyzed by controlled gradual osmotic hemolysis to study cell morphology and hemoglobin loss from individual cells. Results suggest that each increase in the rate of loss of a protein from the cells during the initial phases of controlled gradual osmotic hemolysis is caused by the passage of a previously impermeable species across the stressed membrane. Similarly, during the final stages of controlled gradual osmotic hemolysis, each sharp decrease in the rate of loss of a protein corresponds to the termination of a molecular flow. A theoretical model is described that predicts the molecular sieving of soluble globular proteins across the stressed red cell membrane. Hydrophobic interactions occur between the soluble proteins and the lipid bilayer portion of the cell membrane. A spectrin network subdivides the bilayer into domains that restrict the insertion of large molecules into the membrane. Other membrane proteins affect soluble protein access to the membrane. Changes in the loss curves caused by incubation of red cells are discussed in terms of the model.

  13. Design and development of controlled porosity osmotic tablet of diltiazem hydrochloride

    Directory of Open Access Journals (Sweden)

    Sadhana R Shahi

    2012-01-01

    Full Text Available The present work aims towards the design and development of extended release formulation of freely water-soluble drug diltiazem hydrochloride (DLTZ based on osmotic technology by using controlled porosity approach. DLTZ is an ideal candidate for a zero-order drug delivery system because it is freely water-soluble and has a short half-life (2-3 h. Sodium chloride (Osmogen was added to the core tablet to alter the solubility of DLTZ in an aqueous medium. Cellulose acetate (CA and sorbitol were used as semipermeable membrane and pore former, respectively. The effect of different formulation variables namely concentration of osmogen in the core tablet, % pore former, % weight gain, pH of the dissolution medium and agitation intensity on the in vitro release was studied. DLTZ release was directly proportional to % pore former and inversely proportional to % weight gain. The optimized formulation (F8 delivered DLTZ independent of pH and agitation intensity for 12 h at the upper level concentration of % pore former (25% w/w and middle level concentration of % weight gain (6% w/w. The comparative study of elementary osmotic pump (EOP and controlled porosity osmotic pump revealed that it superior than conventional EOP and also easier and cost effective to formulate.

  14. Theoretical and Experimental Investigations of the Potential of Osmotic Energy for Power Production

    Directory of Open Access Journals (Sweden)

    Adel O. Sharif

    2014-08-01

    Full Text Available This paper presents a study on the potential of osmotic energy for power production. The study includes both pilot plant testing and theoretical modelling as well as cost estimation. A projected cost of £30/MWh of clean electricity could be achieved by using a Hydro-Osmotic Power (HOP plant if a suitable membrane is used and the osmotic potential difference between the two solutions is greater than 25 bar; a condition that can be readily found in many sites around the world. Results have shown that the membrane system accounts for 50%–80% of the HOP plant cost depending on the salinity difference level. Thus, further development in membrane technology and identifying suitable membranes would have a significant impact on the feasibility of the process and the route to market. As the membrane permeability determines the HOP process feasibility, this paper also describes the effect of the interaction between the fluid and the membrane on the system permeability. It has been shown that both the fluid physical properties as well as the membrane micro-structural parameters need to be considered if further development of the HOP process is to be achieved.

  15. Controlling Release of Integral Lipid Nanoparticles Based on Osmotic Pump Technology.

    Science.gov (United States)

    Tian, Zhiqiang; Yu, Qin; Xie, Yunchang; Li, Fengqian; Lu, Yi; Dong, Xiaochun; Zhao, Weili; Qi, Jianping; Wu, Wei

    2016-08-01

    To achieve controlled release of integral nanoparticles by the osmotic pump strategy using nanostructured lipid carriers (NLCs) as model nanoparticles. NLCs was prepared by a hot-homogenization method, transformed into powder by lyophilization, and formulated into osmotic pump tablets (OPTs). Release of integral NLCs was visualized by live imaging after labeling with a water-quenching fluorescent probe. Effects of formulation variables on in vitro release characteristics were evaluated by measuring the model drug fenofibrate. Pharmacokinetics were studied in beagle dogs using the core tablet and a micronized fenofibrate formulation as references. NLCs are released through the release orifices of the OPTs as integral nanoparticles. Near zero-order kinetics can be achieved by optimizing the influencing variables. After oral administration, decreased C max and steady drug levels for as long as over 24 h are observed. NLC-OPTs show an oral bioavailability of the model drug fenofibrate similar to that of the core tablets, which is about 1.75 folds that of a fast-release formulation. Controlled release of integral NLCs is achieved by the osmotic pump strategy.

  16. Abscisic acid regulates root growth under osmotic stress conditions via an interacting hormonal network with cytokinin, ethylene and auxin.

    Science.gov (United States)

    Rowe, James H; Topping, Jennifer F; Liu, Junli; Lindsey, Keith

    2016-07-01

    Understanding the mechanisms regulating root development under drought conditions is an important question for plant biology and world agriculture. We examine the effect of osmotic stress on abscisic acid (ABA), cytokinin and ethylene responses and how they mediate auxin transport, distribution and root growth through effects on PIN proteins. We integrate experimental data to construct hormonal crosstalk networks to formulate a systems view of root growth regulation by multiple hormones. Experimental analysis shows: that ABA-dependent and ABA-independent stress responses increase under osmotic stress, but cytokinin responses are only slightly reduced; inhibition of root growth under osmotic stress does not require ethylene signalling, but auxin can rescue root growth and meristem size; osmotic stress modulates auxin transporter levels and localization, reducing root auxin concentrations; PIN1 levels are reduced under stress in an ABA-dependent manner, overriding ethylene effects; and the interplay among ABA, ethylene, cytokinin and auxin is tissue-specific, as evidenced by differential responses of PIN1 and PIN2 to osmotic stress. Combining experimental analysis with network construction reveals that ABA regulates root growth under osmotic stress conditions via an interacting hormonal network with cytokinin, ethylene and auxin. © 2016 The Authors. New Phytologist © 2016 New Phytologist Trust.

  17. Salinity- and population-dependent genome regulatory response during osmotic acclimation in the killifish (Fundulus heteroclitus) gill.

    Science.gov (United States)

    Whitehead, Andrew; Roach, Jennifer L; Zhang, Shujun; Galvez, Fernando

    2012-04-15

    The killifish Fundulus heteroclitus is abundant in osmotically dynamic estuaries and it can quickly adjust to extremes in environmental salinity. We performed a comparative osmotic challenge experiment to track the transcriptomic and physiological responses to two salinities throughout a time course of acclimation, and to explore the genome regulatory mechanisms that enable extreme osmotic acclimation. One southern and one northern coastal population, known to differ in their tolerance to hypo-osmotic exposure, were used as our comparative model. Both populations could maintain osmotic homeostasis when transferred from 32 to 0.4 p.p.t., but diverged in their compensatory abilities when challenged down to 0.1 p.p.t., in parallel with divergent transformation of gill morphology. Genes involved in cell volume regulation, nucleosome maintenance, ion transport, energetics, mitochondrion function, transcriptional regulation and apoptosis showed population- and salinity-dependent patterns of expression during acclimation. Network analysis confirmed the role of cytokine and kinase signaling pathways in coordinating the genome regulatory response to osmotic challenge, and also posited the importance of signaling coordinated through the transcription factor HNF-4α. These genome responses support hypotheses of which regulatory mechanisms are particularly relevant for enabling extreme physiological flexibility.

  18. The roles of different salts and a novel osmotic pressure control strategy for improvement of DHA production by Schizochytrium sp.

    Science.gov (United States)

    Hu, Xue-Chao; Ren, Lu-Jing; Chen, Sheng-Lan; Zhang, Li; Ji, Xiao-Jun; Huang, He

    2015-11-01

    The effects of different osmotic pressure, changed by six salts (NaCl, Na2SO4, (NH4)2SO4, KH2PO4 and MSG), on cell growth and DHA synthesis by Schizochytrium sp. were investigated. Six optimal mediums were obtained to study different osmotic pressure combinations at cell growth stage and DHA synthesis stage. Results showed that cultivated cell in higher osmotic pressure condition and fermented in lower osmotic pressure condition was benefit to enhance DHA synthesis. Combination 17-6 could get the maximum cell dry weight of 56.95 g/L and the highest DHA percentage in total fatty acids of 55.21%, while combination 17-B could get the highest lipid yield of 33.47 g/L with 42.10% DHA in total fatty acids. This was the first report about the enhancement of DHA production by osmotic regulation and this work provided two novel osmotic control processes for high lipid yield and high DHA percentage in total fatty acids.

  19. Endothelial surface layer degradation by chronic hyaluronidase infusion induces proteinuria in apolipoprotein E-deficient mice.

    Directory of Open Access Journals (Sweden)

    Marijn C Meuwese

    Full Text Available OBJECTIVE: Functional studies show that disruption of endothelial surface layer (ESL is accompanied by enhanced sensitivity of the vasculature towards atherogenic stimuli. However, relevance of ESL disruption as causal mechanism for vascular dysfunction remains to be demonstrated. We examined if loss of ESL through enzymatic degradation would affect vascular barrier properties in an atherogenic model. METHODS: Eight week old male apolipoprotein E deficient mice on Western-type diet for 10 weeks received continuous active or heat-inactivated hyaluronidase (10 U/hr, i.v. through an osmotic minipump during 4 weeks. Blood chemistry and anatomic changes in both macrovasculature and kidneys were examined. RESULTS: Infusion with active hyaluronidase resulted in decreased ESL (0.32±0.22 mL and plasma volume (1.03±0.18 mL compared to inactivated hyaluronidase (0.52±0.29 mL and 1.28±0.08 mL, p<0.05 respectively.Active hyaluronidase increased proteinuria compared to inactive hyaluronidase (0.27±0.02 vs. 0.15±0.01 µg/µg protein/creatinin, p<0.05 without changes in glomerular morphology or development of tubulo-interstitial inflammation. Atherosclerotic lesions in the aortic branches showed increased matrix production (collagen, 32±5 vs. 18±3%; glycosaminoglycans, 11±5 vs. 0.1±0.01%, active vs. inactive hyaluronidase, p<0.05. CONCLUSION: ESL degradation in apoE deficient mice contributes to reduced increased urinary protein excretion without significant changes in renal morphology. Second, the induction of compositional changes in atherogenic plaques by hyaluronidase point towards increased plaque vulnerability. These findings support further efforts to evaluate whether ESL restoration is a valuable target to prevent (micro vascular disease progression.

  20. Cell Wall Remodeling Enzymes Modulate Fungal Cell Wall Elasticity and Osmotic Stress Resistance.

    Science.gov (United States)

    Ene, Iuliana V; Walker, Louise A; Schiavone, Marion; Lee, Keunsook K; Martin-Yken, Hélène; Dague, Etienne; Gow, Neil A R; Munro, Carol A; Brown, Alistair J P

    2015-07-28

    The fungal cell wall confers cell morphology and protection against environmental insults. For fungal pathogens, the cell wall is a key immunological modulator and an ideal therapeutic target. Yeast cell walls possess an inner matrix of interlinked β-glucan and chitin that is thought to provide tensile strength and rigidity. Yeast cells remodel their walls over time in response to environmental change, a process controlled by evolutionarily conserved stress (Hog1) and cell integrity (Mkc1, Cek1) signaling pathways. These mitogen-activated protein kinase (MAPK) pathways modulate cell wall gene expression, leading to the construction of a new, modified cell wall. We show that the cell wall is not rigid but elastic, displaying rapid structural realignments that impact survival following osmotic shock. Lactate-grown Candida albicans cells are more resistant to hyperosmotic shock than glucose-grown cells. We show that this elevated resistance is not dependent on Hog1 or Mkc1 signaling and that most cell death occurs within 10 min of osmotic shock. Sudden decreases in cell volume drive rapid increases in cell wall thickness. The elevated stress resistance of lactate-grown cells correlates with reduced cell wall elasticity, reflected in slower changes in cell volume following hyperosmotic shock. The cell wall elasticity of lactate-grown cells is increased by a triple mutation that inactivates the Crh family of cell wall cross-linking enzymes, leading to increased sensitivity to hyperosmotic shock. Overexpressing Crh family members in glucose-grown cells reduces cell wall elasticity, providing partial protection against hyperosmotic shock. These changes correlate with structural realignment of the cell wall and with the ability of cells to withstand osmotic shock. The C. albicans cell wall is the first line of defense against external insults, the site of immune recognition by the host, and an attractive target for antifungal therapy. Its tensile strength is conferred by

  1. From microgravity to osmotic conditions: mechanical integration of plant cells in response to stress

    Science.gov (United States)

    Wojtaszek, Przemyslaw; Kasprowicz, Anna; Michalak, Michal; Janczara, Renata; Volkmann, Dieter; Baluska, Frantisek

    Chemical reactions and interactions between molecules are commonly thought of as being at the basis of Life. Research of recent years, however, is more and more evidently indicating that physical forces are profoundly affecting the functioning of life at all levels of its organiza-tion. To detect and to respond to such forces, plant cells need to be integrated mechanically. Cell walls are the outermost functional zone of plant cells. They surround the individual cells, and also form a part of the apoplast. In cell suspensions, cell walls are embedded in the cul-ture medium which can be considered as a superapoplast. Through physical and chemical interactions they provide a basis for the structural and functional cell wall-plasma membrane-cytoskeleton (WMC) continuum spanning the whole cell. Here, the working of WMC contin-uum, and the participation of signalling molecules, like NO, would be presented in the context of plant responses to stress. In addition, the effects of the changing composition of WMC continuum will be considered, with particular attention paid to the modifications of the WMC components. Plant cells are normally adapted to changing osmotic conditions, resulting from variable wa-ter availability. The appearance of the osmotic stress activates adaptory mechanisms. If the strength of osmotic stress grows relatively slowly over longer period of time, the cells are able to adapt to conditions that are lethal to non-adapted cells. During stepwise adaptation of tobacco BY-2 suspension cells to the presence of various osmotically active agents, cells diverged into independent, osmoticum type-specific lines. In response to ionic agents (NaCl, KCl), the adhe-sive properties were increased and randomly dividing cells formed clumps, while cells adapted to nonionic osmotica (mannitol, sorbitol, PEG) revealed ordered pattern of precisely positioned cell divisions, resulting in the formation of long cell files. Changes in the growth patterns were accompanied by

  2. Chronic Pancreatitis.

    Science.gov (United States)

    Stram, Michelle; Liu, Shu; Singhi, Aatur D

    2016-12-01

    Chronic pancreatitis is a debilitating condition often associated with severe abdominal pain and exocrine and endocrine dysfunction. The underlying cause is multifactorial and involves complex interaction of environmental, genetic, and/or other risk factors. The pathology is dependent on the underlying pathogenesis of the disease. This review describes the clinical, gross, and microscopic findings of the main subtypes of chronic pancreatitis: alcoholic chronic pancreatitis, obstructive chronic pancreatitis, paraduodenal ("groove") pancreatitis, pancreatic divisum, autoimmune pancreatitis, and genetic factors associated with chronic pancreatitis. As pancreatic ductal adenocarcinoma may be confused with chronic pancreatitis, the main distinguishing features between these 2 diseases are discussed. Copyright © 2016 Elsevier Inc. All rights reserved.

  3. Effect of pore structure on chemico-osmotic, diffusion and hydraulic properties of mud-stones

    International Nuclear Information System (INIS)

    Takeda, M.; Manaka, M.; Ito, K.; Miyoshi, S.; Tokunaga, T.

    2012-01-01

    Document available in extended abstract form only. An in-situ experiment by Neuzil (2000) has obtained the substantial proof of chemical osmosis in natural clayey formation. Chemical osmosis in clayey formations has thus received attention in recent years in the context of geological disposal of radioactive waste. Chemical osmosis is the diffusion of water through a semi-permeable membrane driven by the difference of chemical potentials between solutions to compensate the difference of water potentials, increasing the other potential differences, such as the pressure difference. Accordingly, the chemical osmosis could generate localized, abnormal fluid pressures in geological formations where formation media act as semi-permeable membranes and groundwater salinity is not uniform. Without taking account of the chemical osmosis, groundwater flow modeling may mislead the prediction of the groundwater flow direction. Therefore the possibility of chemical osmosis needs to be identified for potential host formations for radioactive waste repositories. The chemico-osmotic property of formation media is an essential parameter to identify the possibility of chemical osmosis in the formation; however, the diffusion and hydraulic properties are also fundamental parameters to estimate the duration of chemical osmosis since they control the spatial variation of salinity and the dissipation of osmotically induced pressures. In order to obtain the chemico-osmotic, diffusion and hydraulic parameters from a rock sample, this study developed a laboratory experimental system capable of performing chemical osmosis and permeability experiments. A series of experiments were performed on mud-stones. The chemico-osmotic parameter of each rock sample was further interpreted by the osmotic efficiency model proposed by Bresler (1973) to examine the pore structure inherent in rocks. Diatomaceous and siliceous mud-stone samples were obtained from drill cores taken from the Koetoi and Wakkanai

  4. Chronic Pericarditis

    Science.gov (United States)

    ... surgery) and is considered subacute. Causes Usually, the cause of chronic effusive pericarditis is unknown. However, it may be caused by cancer, tuberculosis , or an underactive thyroid gland ( hypothyroidism ), and it occasionally occurs in people with chronic ...

  5. Chronic Pain

    Science.gov (United States)

    ... pain. Psychotherapy, relaxation and medication therapies, biofeedback, and behavior modification may also be employed to treat chronic pain. × ... pain. Psychotherapy, relaxation and medication therapies, biofeedback, and behavior modification may also be employed to treat chronic pain. ...

  6. Negatively Charged Hyperbranched Polyglycerol Grafted Membranes for Osmotic Power Generation from Municipal Wastewater

    KAUST Repository

    Li, Xue; Cai, Tao; Chen, Chunyan; Chung, Neal Tai-Shung

    2015-01-01

    Osmotic power holds great promise as a clean, sustainable and largely unexploited energy resource. Recent membrane development for pressure-retarded osmosis (PRO) is making the osmotic power generation more and more realistic. However, severe performance declines have been observed because the porous layer of PRO membranes is fouled by the feed stream. To overcome it, a negatively charged antifouling PRO hollow fiber membrane has been designed and studied in this work. An antifouling polymer, derived from hyperbranched polyglycerol and functionalized by α-lipoic acid and succinic anhydride, was synthesized and grafted onto the polydopamine (PDA) modified poly(ether sulfone) (PES) hollow fiber membranes. In comparison to unmodified membranes, the charged hyperbranched polyglycerol (CHPG) grafted membrane is much less affected by organic deposition, such as bovine serum albumin (BSA) adsorption, and highly resistant to microbial growths, demonstrated by E. coli adhesion and S. aureus attachment. CHPG-g-TFC was also examined in PRO tests using a concentrated wastewater as the feed. Comparing to the plain PES-TFC and non-charged HPG-g-TFC, the newly developed membrane exhibits not only the smallest decline in water flux but also the highest recovery rate. When using 0.81 M NaCl and wastewater as the feed pair in PRO tests at 15 bar, the average power density remains at 5.6 W/m2 in comparison to an average value of 3.6 W/m2 for unmodified membranes after four PRO runs. In summary, osmotic power generation may be sustained by properly designing and anchoring the functional polymers to PRO membranes.

  7. [Effects of secretory and osmotic diarrhea on rats intestinal function and morphology].

    Science.gov (United States)

    de Lima de Mon, Margarita; Cioccia, Anna M; González, Eduardo; Hevia, Patricio

    2002-03-01

    In order to compare intestinal morphology and function, diarrhea was produced in rats using laxatives in the diet. The 14 day study included two groups of rats with diarrhea (osmotic or secretory), two groups without diarrhea but with a degree of malnutrition which was similar to that seen in the rats with diarrhea (malnourished without diarrhea) and a well-nourished group (control). The inclusion of laxatives(lactose or bisoxatin acetate) cause a reduction in food intake, diarrhea an malnutrition. It also caused a reduction in dietary protein and fat digestibility which was proportional to the severity of diarrhea and more pronounced in secretory diarrhea. In the malnourished rats without diarrhea, malnutrition did not affect their absorptive function. Both in the rats with secretory and osmotic diarrhea an intestinal hypertrophy was observed. This hypertrophy was proportional to the severity of diarrhea and independent of its aetiology. In the intestines of the rats with both types of diarrhea there was inflammation, a greater number of mitotic figures but the flattening of the villi seen in the malnourished rats without diarrhea was not seen. In osmotic diarrhea there was, in addition, a patchy damage of the surface of the jejunal mucosa and an increment in the number of goblet cells, indicating a more severe intestinal deterioration. Since despite this greater deterioration, these rats absorbed more protein and fat we concluded that the alterations in intestinal morphology seen in this study was not predictive of intestinal function. The study also showed that diarrhea had a trophic effect on the intestine which did not occur in malnourished rats without diarrhea.

  8. Negatively charged hyperbranched polyglycerol grafted membranes for osmotic power generation from municipal wastewater.

    Science.gov (United States)

    Li, Xue; Cai, Tao; Chen, Chunyan; Chung, Tai-Shung

    2016-02-01

    Osmotic power holds great promise as a clean, sustainable and largely unexploited energy resource. Recent membrane development for pressure-retarded osmosis (PRO) is making the osmotic power generation more and more realistic. However, severe performance declines have been observed because the porous layer of PRO membranes is fouled by the feed stream. To overcome it, a negatively charged antifouling PRO hollow fiber membrane has been designed and studied in this work. An antifouling polymer, derived from hyperbranched polyglycerol and functionalized by α-lipoic acid and succinic anhydride, was synthesized and grafted onto the polydopamine (PDA) modified poly(ether sulfone) (PES) hollow fiber membranes. In comparison to unmodified membranes, the charged hyperbranched polyglycerol (CHPG) grafted membrane is much less affected by organic deposition, such as bovine serum albumin (BSA) adsorption, and highly resistant to microbial growths, demonstrated by Escherichia coli adhesion and Staphylococcus aureus attachment. CHPG-g-TFC was also examined in PRO tests using a concentrated wastewater as the feed. Comparing to the plain PES-TFC and non-charged HPG-g-TFC, the newly developed membrane exhibits not only the smallest decline in water flux but also the highest recovery rate. When using 0.81 M NaCl and wastewater as the feed pair in PRO tests at 15 bar, the average power density remains at 5.6 W/m(2) in comparison to an average value of 3.6 W/m(2) for unmodified membranes after four PRO runs. In summary, osmotic power generation may be sustained by properly designing and anchoring the functional polymers to PRO membranes. Copyright © 2015 Elsevier Ltd. All rights reserved.

  9. Prediction of Osmotic Pressure of Ionic Liquids Inside a Nanoslit by MD Simulation and Continuum Approach

    Science.gov (United States)

    Moon, Gi Jong; Yang, Yu Dong; Oh, Jung Min; Kang, In Seok

    2017-11-01

    Osmotic pressure plays an important role in the processes of charging and discharging of lithium batteries. In this work, osmotic pressure of the ionic liquids confined inside a nanoslit is calculated by using both MD simulation and continuum approach. In the case of MD simulation, an ionic liquid is modeled as singly charged spheres with a short-ranged repulsive Lennard-Jones potential. The radii of the spheres are 0.5nm, reflecting the symmetry of ion sizes for simplicity. The simulation box size is 11nm×11nm×7.5nm with 1050 ion pairs. The concentration of ionic liquid is about 1.922mol/L, and the total charge on an individual wall varies from +/-60e(7.944 μm/cm2) to +/-600e(79.44 μm/cm2) . In the case of continuum approach, we classify the problems according to the correlation length and steric factor, and considered the four separate cases: 1) zero correlation length and zero steric factor, 2) zero correlation length and non-zero steric factor, 3) non-zero correlation length and zero steric factor, and 4) non-zero correlation and non-zero steric factor. Better understanding of the osmotic pressure of ionic liquids confined inside a nanoslit can be achieved by comparing the results of MD simulation and continuum approach. This research was supported by the National Research Foundation of Korea (NRF) Grant funded by the Korea government (MSIP: Ministry of Science, ICT & Future Planning) (No. 2017R1D1A1B05035211).

  10. Negatively Charged Hyperbranched Polyglycerol Grafted Membranes for Osmotic Power Generation from Municipal Wastewater

    KAUST Repository

    Li, Xue

    2015-11-18

    Osmotic power holds great promise as a clean, sustainable and largely unexploited energy resource. Recent membrane development for pressure-retarded osmosis (PRO) is making the osmotic power generation more and more realistic. However, severe performance declines have been observed because the porous layer of PRO membranes is fouled by the feed stream. To overcome it, a negatively charged antifouling PRO hollow fiber membrane has been designed and studied in this work. An antifouling polymer, derived from hyperbranched polyglycerol and functionalized by α-lipoic acid and succinic anhydride, was synthesized and grafted onto the polydopamine (PDA) modified poly(ether sulfone) (PES) hollow fiber membranes. In comparison to unmodified membranes, the charged hyperbranched polyglycerol (CHPG) grafted membrane is much less affected by organic deposition, such as bovine serum albumin (BSA) adsorption, and highly resistant to microbial growths, demonstrated by E. coli adhesion and S. aureus attachment. CHPG-g-TFC was also examined in PRO tests using a concentrated wastewater as the feed. Comparing to the plain PES-TFC and non-charged HPG-g-TFC, the newly developed membrane exhibits not only the smallest decline in water flux but also the highest recovery rate. When using 0.81 M NaCl and wastewater as the feed pair in PRO tests at 15 bar, the average power density remains at 5.6 W/m2 in comparison to an average value of 3.6 W/m2 for unmodified membranes after four PRO runs. In summary, osmotic power generation may be sustained by properly designing and anchoring the functional polymers to PRO membranes.

  11. Combined osmotic dehydration and drying process of pirarucu (Arapaima gigas) fillets.

    Science.gov (United States)

    Martins, Mayara Galvão; da Silva Pena, Rosinelson

    2017-09-01

    The osmotic dehydration (OD) and complementary drying of pirarucu ( Arapaima gigas ) fillets were studied. Pieces of the dorsal portion of pirarucu (60 mm × 20 mm × 10 mm) underwent OD in a binary solution (NaCl-water) with the application of vacuum pulse following a central rotatable composite design. The effect of the following process variables was assessed: temperature (20-40 °C), osmotic solution concentration (15-25% NaCl), and vacuum pulse pressure (7-101 kPa) on water loss (WL), solid gain (SG), and water activity (a w ). OD kinetics was obtained and the Peleg model was fitted to WL and SG data. The osmotically dehydrated pirarucu was dried (40-70 °C) in a fixed-bed dryer and mathematical models were fitted to the drying data. The optimal operational condition for the OD process was 35 °C, solution with 25% NaCl, and atmospheric pressure, which yielded WL of 14.87 ± 1.46%, SG of 8.56 ± 0.45%, and a w of 0.87 ± 0.02. The Peleg model efficiently predicted the WL and SG kinetics. The increase in the water loss in drying was more evident at low temperatures (40-50 °C) with effective diffusivity ranging from 10.85 × 10 -9 to 12.30 × 10 -9 m 2 /s. The Midilli and Page models efficiently predicted the drying kinetics.

  12. Biophysical characterization of the Lactobacillus delbrueckii subsp. bulgaricus membrane during cold and osmotic stress and its relevance for cryopreservation.

    Science.gov (United States)

    Meneghel, Julie; Passot, Stéphanie; Dupont, Sébastien; Fonseca, Fernanda

    2017-02-01

    Freezing lactic acid bacteria often leads to cell death and loss of technological properties. Our objective was to provide an in-depth characterization of the biophysical properties of the Lactobacillus delbrueckii subsp. bulgaricus membrane in relation to its freeze resistance. Freezing was represented as a combination of cold and osmotic stress. This work investigated the relative incidence of increasing sucrose concentrations coupled or not with subzero temperatures without ice nucleation on the biological and biophysical responses of two strains with different membrane fatty acid compositions and freeze resistances. Following exposure of bacterial cells to the highest sucrose concentration, the sensitive strain exhibited a survival rate of less than 10 % and 5 h of acidifying activity loss. Similar biological activity losses were observed upon freeze-thawing and after osmotic treatment for each strain thus highlighting osmotic stress as the main source of cryoinjury. The direct measurement of membrane fluidity by fluorescence anisotropy was linked to membrane lipid organization characterized by FTIR spectroscopy. Both approaches made it possible to investigate the specific contributions of the membrane core and the bilayer external surface to cell degradation caused by cold and osmotic stress. Cold-induced membrane rigidification had no significant implication on bacterial freeze-thaw resistance. Interactions between extracellular sucrose and membrane phospholipid headgroups under osmotic stress were also observed. Such interactions were more evident in the sensitive strain and when increasing sucrose concentration, thus suggesting membrane permeabilization. The relevance of biophysical properties for elucidating mechanisms of cryoinjury and cryoprotection is discussed.

  13. The use of laminarias for osmotic dilation of the cervix in gynecological brachytherapy applications

    International Nuclear Information System (INIS)

    Mayr, Nina A.; Sorosky, Joel I.; Zhen Weining; Weidner, Geoffrey J.; Hussey, David H.; Anderson, Barrie; Buller, Richard E.

    1998-01-01

    Purpose: Osmotic dilators (laminarias) have been used for gradual nontraumatic dilation of the cervical canal for various intrauterine procedures; however, this technique has not been well accepted in gynecological brachytherapy. The purpose of this study was to evaluate the efficacy of osmotic cervical dilation for brachytherapy in gynecologic cancer patients, without the use of general/regional anesthesia, and to assess patient tolerance, complications, and outcome. Methods and Materials: Thirteen brachytherapy procedures were performed in 6 patients with clinical Stages I and II endometrial (5) and Stage IB cervical cancer (1), who were unable to tolerate general/regional anesthesia because of severe medical problems. An osmotic dilator (synthetic laminaria) was inserted into the cervical os 10-12 h before each brachytherapy procedure and removed just before the procedure. Standard Fletcher-Suit-Delclos tandem insertions with vaginal colpostats or cylinders were then performed. Degree of cervical dilation, patient discomfort, procedure time, intra- and postoperative complications were recorded, and local control and survival were assessed. Median follow-up was 31 months (range: 8-35 months). Results: The diameter of the dilated cervical os after laminaria removal was adequate (≥ 5 mm) for tandem insertion, and no additional mechanical dilation was required in all but one procedure (1 of 13). All procedures were performed without general/regional anesthesia. The mean duration of the procedures was 44 min (range, 20-60 min). Discomfort was minimal in all cases. There were no intra- or postoperative complications. All patients maintained local control until death (1 of metastatic disease, 2 of intercurrent disease) or last follow-up (2 with no evidence of disease, 1 alive with metastatic disease). Conclusion: This preliminary study suggests that osmotic cervical dilation with a synthetic laminaria is a useful technique to facilitate intrauterine tandem insertion

  14. Colloid osmotic pressure in decompensated cirrhosis. A 'mirror image' of portal venous hypertension

    DEFF Research Database (Denmark)

    Henriksen, J H

    1985-01-01

    Colloid osmotic pressure in plasma (IIP) and ascitic fluid (IIA) and hydrostatic pressures in the hepatoportal system were measured simultaneously in 20 patients with decompensated cirrhosis. IIP was significantly decreased (mean, 21 mm Hg, versus normal, 30 mm Hg; P less than 0.01), and IIA...... was significantly below that of plasma (average, 25% of IIP; P less than 0.01). Portal pressure (transmural), determined as wedged hepatic venous minus inferior vena caval pressure (WHV--IVCP), was significantly increased (mean, 18 mm Hg, versus normal, 3 mm Hg; P less than 0.01) and inversely correlated to IIA...

  15. Analysis of unsaturated clayey materials hydration incorporating the effect of thermo-osmotic flow

    International Nuclear Information System (INIS)

    Sanchez, M.; Arson, C.

    2012-01-01

    Document available in extended abstract form only. The hydraulic gradient is the main physical phenomenon influencing the movement of water in permeable porous media. It is, however, not the only one. Figure 1 presents the main kinds of flow that can occur in a porous media alongside with the corresponding gradient responsible for the movements. The word 'law' is generally used for the diagonal terms associated with the direct flow phenomena, and the name 'effect' is reserved to the non-diagonal ones, called also 'coupled processes'. Lippmann (1907) discovered and named the phenomenon of thermo-osmosis. He discovered it experimentally by separating a volume of water into two parts by means of a membrane. Different temperatures were held in the two regions of the system. The thermal gradient caused a flow of water through the membrane from the cold to the hot side. In permeable reservoirs, the non-diagonal coefficients are relatively small and negligible compared to the diagonal terms. That is the reason why the coupled processes are generally ignored when analyzing problems in aquifers. However, in non-isothermal problems involving low permeability media and/or low hydraulic gradients thermo-osmosis may play a more influential role. Srivastava and Avasthi (1975) and Horseman and McEwen (1996) showed that water flux due to thermo-osmosis can easily exceed Darcy flux in low permeability clays. The 'phenomenological coefficient' that links each flow with the corresponding driving gradient must be measured experimentally. Accounting for thermo-osmosis is assuming that the transport of heat may modify the transport of fluids. The counterpart phenomenon of thermo-osmosis is thermo-filtration, which reflects the influence of a pressure gradient on heat flow. Thermo-osmosis and thermo-filtration are generally formulated as reciprocal relations, so that the coupled conductivity terms related to each phenomenon are set equal. Thermo-osmotic effects have been studied in the

  16. The response of foodborne pathogens to osmotic and desiccation stresses in the food chain

    DEFF Research Database (Denmark)

    Burgess, Catherine M.; Gianotti, Andrea; Gruzdev, Nadia

    2016-01-01

    In combination with other strategies, hyperosmolarity and desiccation are frequently used by the food processing industry as a means to prevent bacterial proliferation, and particularly that of foodborne pathogens, in food products. However, it is increasingly observed that bacteria, including...... human pathogens, encode mechanisms to survive and withstand these stresses. This review provides an overview of the mechanisms employed by Salmonella spp., Shiga toxin producing E. coli, Cronobacter spp., Listeria monocytogenes and Campylobacter spp. to tolerate osmotic and desiccation stresses...... and identifies gaps in knowledge which need to be addressed to ensure the safety of low water activity and desiccated food products....

  17. Slow and steady cell shrinkage reduces osmotic stress in bovine and murine oocyte and zygote vitrification.

    Science.gov (United States)

    Lai, D; Ding, J; Smith, G W; Smith, G D; Takayama, S

    2015-01-01

    Does the use of a new cryoprotectant agent (CPA) exchange protocol designed to minimize osmotic stress improve oocyte or zygote vitrification by reducing sublethal cryodamage? The use of a new CPA exchange protocol made possible by automated microfluidics improved oocyte and zygote vitrification with superior morphology as indicated by a smoother cell surface, higher sphericity, higher cytoplasmic lipid retention, less cytoplasmic leakage and higher developmental competence compared with conventional methods. The use of more 'steps' of CPA exposure during the vitrification protocol increases cryosurvival and development in the bovine model. However, such an attempt to eliminate osmotic stress is limited by the practicality of performing numerous precise pipetting steps in a short amount of time. Murine meiotically competent germinal vesicle intact oocytes and zygotes were harvested from the antral follicles in ovaries and ampulla, respectively. Bovine ovaries were obtained from a local abattoir at random stages of the estrous cycle. A total of 110 murine oocytes, 802 murine zygotes and 52 bovine oocytes were used in this study. Microfluidic devices were fabricated using conventional photo- and soft-lithography. CPAs used were 7.5% ethylene glycol (EG) and 7.5% dimethyl sulfoxide (DMSO) for equilibration solution and 15% EG, 15% DMSO and 0.5 M sucrose for vitrification solution. End-point analyses include mathematical modeling using Kedem-Katchalsky equations, morphometrics assessed by conventional and confocal microscopy, cytoplasmic lipid quantification by nile red staining, cytoplasmic leakage quantification by fluorescent dextran intercalation and developmental competence analysis by 96 h embryo culture and blastomere quantification. The automated microfluidics protocol decreased the shrinkage rate of the oocyte and zygote by 13.8 times over its manual pipetting alternative. Oocytes and zygotes with a lower shrinkage rate during CPA exposure experienced less

  18. Xylem diameter changes during osmotic stress, desiccation and freezing in Pinus sylvestris and Populus tremula.

    Science.gov (United States)

    Lintunen, Anna; Lindfors, Lauri; Nikinmaa, Eero; Hölttä, Teemu

    2017-04-01

    Trees experience low apoplastic water potential frequently in most environments. Low apoplastic water potential increases the risk of embolism formation in xylem conduits and creates dehydration stress for the living cells. We studied the magnitude and rate of xylem diameter change in response to decreasing apoplastic water potential and the role of living parenchyma cells in it to better understand xylem diameter changes in different environmental conditions. We compared responses of control and heat-injured xylem of Pinus sylvestris (L.) and Populus tremula (L.) branches to decreasing apoplastic water potential created by osmotic stress, desiccation and freezing. It was shown that xylem in control branches shrank more in response to decreasing apoplastic water potential in comparison with the samples that were preheated to damage living xylem parenchyma. By manipulating the osmotic pressure of the xylem sap, we observed xylem shrinkage due to decreasing apoplastic water potential even in the absence of water tension within the conduits. These results indicate that decreasing apoplastic water potential led to withdrawal of intracellular water from the xylem parenchyma, causing tissue shrinkage. The amount of xylem shrinkage per decrease in apoplastic water potential was higher during osmotic stress or desiccation compared with freezing. During desiccation, xylem diameter shrinkage involved both dehydration-related shrinkage of xylem parenchyma and water tension-induced shrinkage of conduits, whereas dehydration-related shrinkage of xylem parenchyma was accompanied by swelling of apoplastic ice during freezing. It was also shown that the exchange of water between symplast and apoplast within xylem is clearly faster than previously reported between the phloem and the xylem. Time constant of xylem shrinkage was 40 and 2 times higher during osmotic stress than during freezing stress in P. sylvestris and P. tremula, respectively. Finally, it was concluded that the

  19. Polyamines and plant stress - Activation of putrescine biosynthesis by osmotic shock

    Science.gov (United States)

    Flores, H. E.; Galston, A. W.

    1982-01-01

    The putrescine content of oat leaf cells and protoplasts increases up to 60-fold within 6 hours of exposure to osmotic stress (0.4 to 0.6 molar sorbitol). Barley, corn, wheat, and wild oat leaves show a similar response. Increased arginine decarboxylase activity parallels the rise in putrescine, whereas ornithine decarboxylase remains unchanged. DL-alpha-Difluoromethylarginine, a specific irreversible inhibitor of arginine decarboxylase, prevents the stress-induced rise in increase in arginine decarboxylase activity and putrescine synthesis, indicating the preferential activation of this pathway.

  20. Assessment of chronic diarrhea in early infancy in Tehran Tertiary Care Center; Tehran-Iran

    Directory of Open Access Journals (Sweden)

    Farzaneh Motamed

    2015-03-01

    Full Text Available Introduction Chronic diarrhea of infancy is a heterogeneous syndrome that includes several diseases with different etiologies. The aim of this study was investigating chronic diarrhea, its etiologies, clinical features and outcomes in infancy.Materials and Methods Retrospective study investigating infants hospitalized in the gastroenterology department of Tehran tertiary care center.The main demographic data, etiology, characteristics of diarrhea, and outcome were evaluated. Data were analyzed by SPSS software,version 16.Results In this study, 63/9% of cases were female and 36/1% were male. 24 cases (66/7% had osmotic diarrhea and 11 (30/6% had secretory diarrhea. In this study there was no significant statistical correlation between type of diarrhea and sex, gestational Age, severity of dehydration, birth weight and nutrition. The majority of patients with osmotic (58/3% and secretory diarrhea (63/6%, had weight percentile below 3%, which showed a significant statistical difference (p value

  1. Ionic and osmotic relations in quinoa (Chenopodium quinoa Willd.) plants grown at various salinity level

    DEFF Research Database (Denmark)

    Hariadi, Yuda; Marandon, Karl; Tian, Yu

    2011-01-01

    or by the gradual increase of NaCl levels in the irrigation water. For both methods, the optimal plant growth and biomass was achieved between 100 mM and 200 mM NaCl, suggesting that quinoa possess a very efficient system to adjust osmotically for abrupt increases in NaCl stress. Up to 95% of osmotic adjustment......Cl-induced activation of H+-ATPase is needed to restore otherwise depolarized membrane potential and prevent further K+ leak from the cytosol. Taken together, this work emphasizes the role of inorganic ions for osmotic adjustment in halophytes and calls for more in-depth studies of the mechanisms of vacuolar Na...

  2. Artificial neural network and response surface methodology modeling in mass transfer parameters predictions during osmotic dehydration of Carica papaya L.

    Directory of Open Access Journals (Sweden)

    J. Prakash Maran

    2013-09-01

    Full Text Available In this study, a comparative approach was made between artificial neural network (ANN and response surface methodology (RSM to predict the mass transfer parameters of osmotic dehydration of papaya. The effects of process variables such as temperature, osmotic solution concentration and agitation speed on water loss, weight reduction, and solid gain during osmotic dehydration were investigated using a three-level three-factor Box-Behnken experimental design. Same design was utilized to train a feed-forward multilayered perceptron (MLP ANN with back-propagation algorithm. The predictive capabilities of the two methodologies were compared in terms of root mean square error (RMSE, mean absolute error (MAE, standard error of prediction (SEP, model predictive error (MPE, chi square statistic (χ2, and coefficient of determination (R2 based on the validation data set. The results showed that properly trained ANN model is found to be more accurate in prediction as compared to RSM model.

  3. Benchtop-magnetic resonance imaging (BT-MRI) characterization of push-pull osmotic controlled release systems.

    Science.gov (United States)

    Malaterre, Vincent; Metz, Hendrik; Ogorka, Joerg; Gurny, Robert; Loggia, Nicoletta; Mäder, Karsten

    2009-01-05

    The mechanism of drug release from push-pull osmotic systems (PPOS) has been investigated by Magnetic Resonance Imaging (MRI) using a new benchtop apparatus. The signal intensity profiles of both PPOS layers were monitored non-invasively over time to characterize the hydration and swelling kinetics. The drug release performance was well-correlated to the hydration kinetics. The results show that (i) hydration and swelling critically depend on the tablet core composition, (ii) high osmotic pressure developed by the push layer may lead to bypassing the drug layer and incomplete drug release and (iii) the hydration of both the drug and the push layers needs to be properly balanced to efficiently deliver the drug. MRI is therefore a powerful tool to get insights on the drug delivery mechanism of push-pull osmotic systems, which enable a more efficient optimization of such formulations.

  4. Chronic stress accelerates the development of endometriosis in mouse through adrenergic receptor β2.

    Science.gov (United States)

    Long, Qiqi; Liu, Xishi; Qi, Qiuming; Guo, Sun-Wei

    2016-11-01

    Does chronic stress in mice accelerate the development of endometriosis, and, if so, through what mechanism? Exposure to chronic stress accelerates the development of endometriosis and exacerbates the endometriosis-associated generalized hyperalgesia, most likely through activation of the adrenoceptor β2 (ADRB2) and cAMP responsive element-binding protein (CREB). Women with endometriosis tend to have higher levels of psychological stress, which is known to impact negatively on health in general and to promote tumor growth and metastasis in particular. Exposure to chronic stress before and after the induction of endometriosis is reported to increase lesion sizes in rodents, but it is unclear whether adrenoceptors are involved or not in the stress-promoted development of endometriosis. Three independent, prospective, randomized mouse experimentations. A total of 184 virgin female Balb/C mice were used. In Experiment 1, the mice were randomly divided into four groups: the control group, which received no stress; the before, after and both groups, which received immobilization stress before, after and both before and after the induction of endometriosis, respectively. In Experiment 2, mice were randomly divided into four groups one day after the induction of endometriosis: phosphate buffer saline (PBS) and propranolol (PROP) groups, which received the mini-pump containing, respectively, PBS only and propranolol (a non-selective ADRB antagonist) but no stress, STR+PROP and STR+PBS groups, which received stress and the mini-pump containing, respectively, propranolol and PBS. The immobilization stress started after the insertion of mini-pumps. In Experiment 3, mice were induced with endometriosis. Three days after the induction, they were randomly divided into four groups: control, ADRAa, ADRB2a, and ADRBa, which received the mini-pump containing solution only, metaraminol (a non-specific α adrenoceptor agonist), tebutaline (a specific ADRB2 agonist), or isoproterenol

  5. Design of robust hollow fiber membranes with high power density for osmotic energy production

    KAUST Repository

    Zhang, Sui; Sukitpaneenit, Panu; Chung, Neal Tai-Shung

    2014-01-01

    This study highlights the design strategy of highly asymmetric hollow fiber membranes that possess both characteristics of high flux and high mechanical strength to effectively reap the osmotic energy from seawater brine with an ultrahigh power density. An advanced co-extrusion technology was employed to fabricate the polyethersulfone (PES) hollow fiber supports with diversified structures from macrovoid to sponge-like. The microstructure of the supports is found critical for the stability and water permeability of the thin film composite (TFC) membranes. A high porosity in the porous layer is needed to reduce internal concentration polarization, while a thick and relatively dense skin layer underneath the TFC layer is required to maintain good mechanical stability and stress dissipation. The pore size of the supporting layer underneath the TFC layer must be small with a narrow pore size distribution to ensure the formation of a less-defective, highly permeable and mechanically stable TFC layer. The newly developed hollow fiber comprising high asymmetry, high porosity, and a thick skin layer with a small and narrow pore size distribution underneath the TFC layer produces a maximum power density of 24.3W/m2 at 20.0bar by using 1M NaCl as the concentrated brine and deionized (DI) water as the feed. The proposed design strategy for ultrahigh power density membranes clearly advances the osmotic energy production close to commercialization with a quite cost-effective and practicable approach. © 2013 Elsevier B.V.

  6. Analyzing the effects of mechanical and osmotic loading on glycosaminoglycan synthesis rate in cartilaginous tissues.

    Science.gov (United States)

    Gao, Xin; Zhu, Qiaoqiao; Gu, Weiyong

    2015-02-26

    The glycosaminoglycan (GAG) plays an important role in cartilaginous tissues to support and transmit mechanical loads. Many extracellular biophysical stimuli could affect GAG synthesis by cells. It has been hypothesized that the change of cell volume is a primary mechanism for cells to perceive the stimuli. Experimental studies have shown that the maximum synthesis rate of GAG is achieved at an optimal cell volume, larger or smaller than this level the GAG synthesis rate decreases. Based on the hypothesis and experimental findings in the literature, we proposed a mathematical model to quantitatively describe the cell volume dependent GAG synthesis rate in the cartilaginous tissues. Using this model, we investigated the effects of osmotic loading and mechanical loading on GAG synthesis rate. It is found our proposed mathematical model is able to well describe the change of GAG synthesis rate in isolated cells or in cartilage with variations of the osmotic loading or mechanical loading. This model is important for evaluating the GAG synthesis activity within cartilaginous tissues as well as understanding the role of mechanical loading in tissue growth or degeneration. It is also important for designing a bioreactor system with proper extracellular environment or mechanical loading for growing tissue at the maximum synthesis rate of the extracellular matrix. Copyright © 2015 Elsevier Ltd. All rights reserved.

  7. Ultrathin and Ion-Selective Janus Membranes for High-Performance Osmotic Energy Conversion.

    Science.gov (United States)

    Zhang, Zhen; Sui, Xin; Li, Pei; Xie, Ganhua; Kong, Xiang-Yu; Xiao, Kai; Gao, Longcheng; Wen, Liping; Jiang, Lei

    2017-07-05

    The osmotic energy existing in fluids is recognized as a promising "blue" energy source that can help solve the global issues of energy shortage and environmental pollution. Recently, nanofluidic channels have shown great potential for capturing this worldwide energy because of their novel transport properties contributed by nanoconfinement. However, with respect to membrane-scale porous systems, high resistance and undesirable ion selectivity remain bottlenecks, impeding their applications. The development of thinner, low-resistance membranes, meanwhile promoting their ion selectivity, is a necessity. Here, we engineered ultrathin and ion-selective Janus membranes prepared via the phase separation of two block copolymers, which enable osmotic energy conversion with power densities of approximately 2.04 W/m 2 by mixing natural seawater and river water. Both experiments and continuum simulation help us to understand the mechanism for how membrane thickness and channel structure dominate the ion transport process and overall device performance, which can serve as a general guiding principle for the future design of nanochannel membranes for high-energy concentration cells.

  8. Laboratory investigation of steam transmission in unsaturated clayey soil under osmotic potential

    Directory of Open Access Journals (Sweden)

    Mehdi Jalili

    2017-01-01

    Full Text Available Liquids coming from different sources like wastewaters, agricultural and industrial activities and leakages of chemical substances often have high concentration of chemical compositions and the osmotic gradient generated around such sources causes a considerable transmission of the Contamination. The steam transmitted by non-polluted soils moves to polluted masses, causing an increase in the volume of pollution zone and movement of pollutants. Therefore, such physical and chemical processes should be taken into account in pollution transmission models. Using Crumb method, laboratory investigations were conducted on non-dispersive and dispersive clayey soil samples obtained from three areas in Zanjan Province of Iran. A simple experimental setup has been used and hereby introduced. The impact of osmotic force from salinities of 0.5, 1, and 1.5% on steam transmission in clayey soil was examined. Results indicate that for all samples between 5 to 15 days, the moisture content increased in the pollutant zone and decreased in the non-pollutant area. Also it was observed that for dispersive clayey soil, movement of steam among layers was observed to be orderly and its amount was higher than that of non-dispersive clayey soil.

  9. Irreversibility of a bad start: early exposure to osmotic stress limits growth and adaptive developmental plasticity.

    Science.gov (United States)

    Wu, Chi-Shiun; Gomez-Mestre, Ivan; Kam, Yeong-Choy

    2012-05-01

    Harsh environments experienced early in development have immediate effects and potentially long-lasting consequences throughout ontogeny. We examined how salinity fluctuations affected survival, growth and development of Fejervarya limnocharis tadpoles. Specifically, we tested whether initial salinity effects on growth and rates of development were reversible and whether they affected the tadpoles' ability to adaptively accelerate development in response to deteriorating conditions later in development. Tadpoles were initially assigned to either low or high salinity, and then some were switched between salinity levels upon reaching either Gosner stage 30 (early switch) or 38 (late switch). All tadpoles initially experiencing low salinity survived whereas those initially experiencing high salinity had poor survival, even if switched to low salinity. Growth and developmental rates of tadpoles initially assigned to high salinity did not increase after osmotic stress release. Initial low salinity conditions allowed tadpoles to attain a fast pace of development even if exposed to high salinity afterwards. Tadpoles experiencing high salinity only late in development metamorphosed faster and at a smaller size, indicating an adaptive acceleration of development to avoid osmotic stress. Nonetheless, early exposure to high salinity precluded adaptive acceleration of development, always causing delayed metamorphosis relative to those in initially low salinity. Our results thus show that stressful environments experienced early in development can critically impact life history traits, having long-lasting or irreversible effects, and restricting their ability to produce adaptive plastic responses.

  10. The effect of osmotic pretreatment on the density of hot-air-dried carrot

    Directory of Open Access Journals (Sweden)

    J Soleimani

    2012-02-01

    Full Text Available Consumption of large amounts of fruits and vegetables throughout the world, have encouraged the development of various methods for their processing. Drying is considers as the most common method for preservation of vegetable and fruits. Although drying extend the shelf-life, it has various side effects on keeping quality of these foods; including decreasing of the color and texture quality as well as missing the flavor and nutritional values. These negative effects have increased the demand for the discovering the alternative drying methods and consequently for the production of fresh-like products. The aim of this study was to introduce and optimize the novel method for the drying of carrot as well as to develop and optimize the quality of osmo-air-dried carrots with special respect to the color, flavor, texture, rehydration properties, density and shriveling of the product. For this, the effect of osmotic pretreatment on the density of carrot slices was investigated, using 50% glucose syrup +5% salt at 40°C with 150 rpm, followed by complementary drying step. The result of treated group was compared with control samples which were dried only by hot-air-drier. The results showed that using osmotic pretreatment could increase the density through inhibition of the product's shrinkage. Meanwhile, in air-dried samples the density was decreased considerably and high shrinkage was also observed.

  11. Design of robust hollow fiber membranes with high power density for osmotic energy production

    KAUST Repository

    Zhang, Sui

    2014-04-01

    This study highlights the design strategy of highly asymmetric hollow fiber membranes that possess both characteristics of high flux and high mechanical strength to effectively reap the osmotic energy from seawater brine with an ultrahigh power density. An advanced co-extrusion technology was employed to fabricate the polyethersulfone (PES) hollow fiber supports with diversified structures from macrovoid to sponge-like. The microstructure of the supports is found critical for the stability and water permeability of the thin film composite (TFC) membranes. A high porosity in the porous layer is needed to reduce internal concentration polarization, while a thick and relatively dense skin layer underneath the TFC layer is required to maintain good mechanical stability and stress dissipation. The pore size of the supporting layer underneath the TFC layer must be small with a narrow pore size distribution to ensure the formation of a less-defective, highly permeable and mechanically stable TFC layer. The newly developed hollow fiber comprising high asymmetry, high porosity, and a thick skin layer with a small and narrow pore size distribution underneath the TFC layer produces a maximum power density of 24.3W/m2 at 20.0bar by using 1M NaCl as the concentrated brine and deionized (DI) water as the feed. The proposed design strategy for ultrahigh power density membranes clearly advances the osmotic energy production close to commercialization with a quite cost-effective and practicable approach. © 2013 Elsevier B.V.

  12. Transcriptomic Profiling and Physiological Analysis of Haloxylon ammodendron in Response to Osmotic Stress

    Directory of Open Access Journals (Sweden)

    Hui-Juan Gao

    2017-12-01

    Full Text Available Haloxylon ammodendron, a perennial xero-halophyte, is an essential species for investigating the effects of drought on desert tree. To gain a comprehensive knowledge on the responses of H. ammodendron to drought stress, we specially performed the molecular and physiological analysis of H. ammodendron in response to −0.75 MPa osmotic stress for six and 24 h in lab condition via RNA-seq and digital gene expression (DGE. In total, 87,109 unigenes with a mean length of 680 bp and 13,486 potential simple sequence repeats (SSRs were generated, and 3353 differentially expressed genes (DEGs in shoots and 4564 in roots were identified under stress. These DEGs were mainly related to ion transporters, signal transduction, ROS-scavenging, photosynthesis, cell wall organization, membrane stabilization and hormones. Moreover, the physiological changes of inorganic ions and organic solute content, peroxidase (POD activity and osmotic potential were in accordance with dynamic transcript profiles of the relevant genes. In this study, a detailed investigation of the pathways and candidate genes identified promote the research on the molecular mechanisms of abiotic stress tolerance in the xero-halophytic species. Our data provides valuable genetic resources for future improvement of forage and crop species for better adaptation to abiotic stresses.

  13. Osmotically driven membrane process for the management of urban runoff in coastal regions.

    Science.gov (United States)

    Li, Zhenyu; Valladares Linares, Rodrigo; Abu-Ghdaib, Muhannad; Zhan, Tong; Yangali-Quintanilla, Victor; Amy, Gary

    2014-01-01

    An osmotic detention pond was proposed for the management of urban runoff in coastal regions. Forward osmosis was employed as a bridge to utilize natural osmotic energy from seawater for concentrating and reusing urban runoff water, and as a barrier to reject runoff-derived contaminants. The process was demonstrated by a lab scale testing using synthetic urban runoff (as the feed solution) and synthetic seawater (as the draw solution). The submerged forward osmosis process was conducted under neutral, acidic and natural organic matter fouling condition, respectively. Forward osmosis flux decline was mainly attributed to the dilution of seawater during a semi-batch process in lab scale testing. However, it is possible to minimize flux decrease by maintaining a constant salinity at the draw solution side. Various changes in urban runoff water quality, including acidic conditions (acid rain) and natural organic matter presence, did not show significant effects on the rejection of trace metals and phosphorus, but influenced salt leakage and the rejection of nitrate and total nitrogen. Rejection of trace metals varied from 98% to 100%, phosphorus varied from 97% to 100, nitrate varied from 52% to 94% and total nitrogen varied from 65% to 85% under different feed water conditions. The work described in this study contributes to an integrated system of urban runoff management, seawater desalination and possible power generation in coastal regions to achieve a sustainable solution to the water-energy nexus. Copyright © 2013 Elsevier Ltd. All rights reserved.

  14. Effects of an angelica extract on human erythrocyte aggregation, deformation and osmotic fragility.

    Science.gov (United States)

    Wang, X; Wei, L; Ouyang, J P; Muller, S; Gentils, M; Cauchois, G; Stoltz, J F

    2001-01-01

    In Chinese traditional medicine, angelica is widely used for its known clinical effects of ameliorating blood microcirculation. But the mechanism of these beneficial effects still remains unclear. In this work the rheological behaviour of human erythrocytes treated by angelica was studied in vitro. Normal RBCs incubated with an angelica extract at different concentrations (5, 10 or 20 mg/ml) for 60 min at 37 degrees C and then their aggregation, deformation and osmotic fragility were measured with different recently developed optical techniques, namely Erythroaggregometer (Regulest, Florange, France), LORCA (Mechatronics, Amsterdam) and Fragilimeter (Regulest, Florange, France). Experimental results show that angelica (20 mg/ml) significantly decreased normal RBCs' aggregation speed (p<0.01) and could inhibit the hyperaggregability caused by dextran 500. However, the strength of normal RBCs aggregates were not influenced by angelica. When a calcium ionophore A23187 (1.9 microM) was used to harden cell membrane, angelica (20 mg/ml) could significantly (p<0.01) protect erythrocytes against the loss of their deformability even it had no effects on normal RBCs deformation. Finally angelica (5 and 10 mg/ml) decreased significantly (p<0.01) normal RBCs osmotic fragility. In conclusion angelica plays a rheologically active role on human erythrocytes, and this study suggests a possible mechanism for angelica's positive effects against certain cardiovascular diseases.

  15. Screening for Osmotic Stress Responses in Rice Varieties under Drought Condition

    Directory of Open Access Journals (Sweden)

    Simon Swapna

    2017-09-01

    Full Text Available Drought is the major abiotic stress factor that limits rice production worldwide. To evaluate the osmotic stress responses in rice varieties under drought condition, a total of 42 high-yielding rice varieties were collected from various research stations of Kerala Agricultural University in India. The experimental setup comprises of initial hydroponic treatments at different osmotic potentials, artificially induced by desired strengths of polyethylene glycol (PEG6000, and followed by the pot planted experiments in the rain-out-zone. The activities of antioxidant enzymes, relative water content, cell membrane stability, photosynthetic pigments, proline content, along with plant growth parameters of the varieties under drought condition were evaluated. Moreover, the standard scores of these rice varieties were assessed under stress and recovery conditions based on the scoring scale of the Standard Evaluation System for rice. Among the 42 rice varieties, we identified 2 rice varieties, Swarnaprabha and Kattamodan, with less leaf rolling, better drought recovery ability as well as relative water content, increased membrane stability index, osmolyte accumulation, and antioxidant enzyme activities pointed towards their degree of tolerance to drought stress. The positive adaptive responses of these rice varieties towards drought stress can be used in the genetic improvement of rice drought resistance breeding program.

  16. Modulation of mouse macrophage polarization in vitro using IL-4 delivery by osmotic pumps.

    Science.gov (United States)

    Pajarinen, Jukka; Tamaki, Yasunobu; Antonios, Joseph K; Lin, Tzu-Hua; Sato, Taishi; Yao, Zhenyu; Takagi, Michiaki; Konttinen, Yrjö T; Goodman, Stuart B

    2015-04-01

    Modulation of macrophage polarization is emerging as promising means to mitigate wear particle-induced inflammation and periprosthetic osteolysis. As a model for continuous local drug delivery, we used miniature osmotic pumps to deliver IL-4 in order to modulate macrophage polarization in vitro from nonactivated M0 and inflammatory M1 phenotypes towards a tissue regenerative M2 phenotype. Pumps delivered IL-4 into vials containing mouse bone marrow macrophage (mBMM) media. This conditioned media (CM) was collected at seven day intervals up to four weeks (week 1 to week 4 samples). IL-4 concentration in the CM was determined by ELISA and its biological activity was assayed by exposing M0 and M1 mBMMs to week 1 or week 4 CM. The IL-4 concentration in the CM approximated the mathematically calculated amount, and its biological activity was well retained, as both M0 and M1 macrophages exposed to either the week 1 or week 4 CM assumed M2-like phenotype as determined by qRT-PCR, ELISA, and immunocytochemistry. The results show that IL-4 can be delivered using osmotic pumps and that IL-4 delivered can modulate macrophage phenotype. Results build a foundation for in vivo studies using our previously validated animal models and provide possible strategies to locally mitigate wear particle-induced macrophage activation and periprosthetic osteolysis. © 2014 Wiley Periodicals, Inc.

  17. Optimization of osmotic dehydration of chestnut (Castanea sativa Mill. slices using Response Surface Methodology

    Directory of Open Access Journals (Sweden)

    Teresa Delgado

    2018-04-01

    Full Text Available Osmotic dehydration of chestnut slices in sucrose was optimized for the first time by Response Surface Methodology (RSM. Experiments were planned according to a three-factor central composite design (α=1.68, studying the influence of sucrose concentration, temperature and time, on the following parameters: volume ratio, water activity, color variation, weight reduction, solids gain, water loss and normalized moisture content, as well as total moisture, ash and fat contents. The experimental data was adequately fitted into second-order polynomial models with coefficients of determination (R2 from 0.716 to 0.976, adjusted-R2 values from 0.460 to 0.954, and non-significant lacks of fit. The optimal osmotic dehydration process conditions for maximum water loss and minimum solids gain and color variation were determined by the “Response Optimizer” option: 83% sucrose concentration, 20 °C and 9.2 hours. Thus, the best operational conditions corresponded to high sugar concentration and low temperature, improving energy saving and decreasing the process costs.

  18. Effect of osmotic dehydration and vacuum-frying parameters to produce high-quality mango chips.

    Science.gov (United States)

    Nunes, Yolanda; Moreira, Rosana G

    2009-09-01

    Mango (Mangifera indica L.) is a fruit rich in flavor and nutritional values, which is an excellent candidate for producing chips. The objective of this study was to develop high-quality mango chips using vacuum frying. Mango ("Tommy Atkins") slices were pretreated with different maltodextrin concentrations (40, 50, and 65, w/v), osmotic dehydration times (45, 60, and 70 min), and solution temperatures (22 and 40 degrees C). Pretreated slices were vacuum fried at 120, 130, and 138 degrees C and product quality attributes (oil content, texture, color, carotenoid content) determined. The effect of frying temperatures at optimum osmotic dehydration times (65 [w/v] at 40 degrees C) was assessed. All samples were acceptable (scores > 5) to consumer panelists. The best mango chips were those pretreated with 65 (w/v) concentration for 60 min and vacuum fried at 120 degrees C. Mango chips under atmospheric frying had less carotenoid retention (32%) than those under vacuum frying (up to 65%). These results may help further optimize vacuum-frying processing of high-quality fruit-based snacks.

  19. Microwave-Osmotic/Microwave-Vacuum Drying of Whole Cranberries: Comparison with Other Methods.

    Science.gov (United States)

    Wray, Derek; Ramaswamy, Hosahalli S

    2015-12-01

    A novel drying method for frozen-thawed whole cranberries was developed by combining microwave osmotic dehydration under continuous flow medium spray (MWODS) conditions with microwave vacuum finish-drying. A central composite rotatable design was used to vary temperature (33 to 67 °C), osmotic solution concentration (33 to 67 °B), contact time (5 to 55 min), and flow rate (2.1 to 4.1 L/min) in order to the determine the effects of MWODS input parameters on quality of the dried berry. Quality indices monitored included colorimetric and textural data in addition to anthocyanin retention and cellular structure. Overall it was found that the MWODS-MWV process was able to produce dried cranberries with quality comparable to freeze dried samples in much shorter time. Additionally, cranberries dried via the novel process exhibited much higher quality than those dried via either vacuum or convective air drying in terms of color, anthocyanin content, and cellular structure. © 2015 Institute of Food Technologists®

  20. Influence of static magnetic fields in phototaxis and osmotic stress in Gymnodinium catenatum (Dinophyceae).

    Science.gov (United States)

    Vale, Paulo

    2017-07-01

    Phototaxis response of the toxic microalgae Gymnodinium catenatum was studied in vitro. The percentage of cells remaining at mid-depth 20 min after stirring increased with solar radio, X-ray and solar flares output. It also increased with geomagnetic activity and temperature, and was dependent on culture time. Increase in the local static magnetic field with a permanent magnet did not influence the positive phototaxis response. However, survival and growth to a provoked hypo-osmotic shock in an altered static magnetic field was dependent on culture time and geomagnetic activity at a threshold below 22 nT. The results from phototaxis and hypo-osmotic shock experiments were in line with the previous hypothesis for the existence of two separate deleterious mechanisms conditioning the natural blooms of G. catenatum: one that is dependent on solar radiation and the other that is related to geomagnetic activity. Variations in electromagnetic fields caused by tectonic activity were also capable of influencing G. catenatum phototaxis and growth response in vitro.

  1. Chloroplast osmotic adjustment allows for acclimation of photosynthesis to low water potentials

    International Nuclear Information System (INIS)

    Gupta, A.S.; Berkowitz, G.

    1987-01-01

    Previously in this laboratory, studies indicated that photosynthesis (PS) of chloroplasts isolated from spinach plants which underwent osmotic adjustment during in situ water deficits was inhibited less at low osmotic potentials (Psi/sub s/) in vitro than PS of plastids isolated from well watered plants. In this study, an attempt was made to determine if chloroplast acclimation to low Psi/sub s/ was associated with in situ stromal solute accumulation. During a 14d stress cycle, in situ stromal volume was estimated by measuring (using the 3 H 2 O, 14 C-sorbitol silicon oil centrifugation technique) the stromal space of plastids in solutions which had the Psi/sub s/ adjusted to the leaf Psi/sub s/. During the first lid of the cycle, stromal volume did not decline, despite a decrease of over 20% in the leaf RWC. After this time, stromal volume dropped rapidly. In situ stromal Psi/sub s/ was also estimated during a stress cycle. These studies indicated that stromal Psi/sub s/ was lowered by net solute accumulation. The data presented in this report suggest that chloroplast acclimation to low Psi/sub s/ may involve stromal solute accumulation and volume maintenance during cell water loss

  2. Oscillatory phase separation in giant lipid vesicles induced by transmembrane osmotic differentials

    Science.gov (United States)

    Oglęcka, Kamila; Rangamani, Padmini; Liedberg, Bo; Kraut, Rachel S; Parikh, Atul N

    2014-01-01

    Giant lipid vesicles are closed compartments consisting of semi-permeable shells, which isolate femto- to pico-liter quantities of aqueous core from the bulk. Although water permeates readily across vesicular walls, passive permeation of solutes is hindered. In this study, we show that, when subject to a hypotonic bath, giant vesicles consisting of phase separating lipid mixtures undergo osmotic relaxation exhibiting damped oscillations in phase behavior, which is synchronized with swell–burst lytic cycles: in the swelled state, osmotic pressure and elevated membrane tension due to the influx of water promote domain formation. During bursting, solute leakage through transient pores relaxes the pressure and tension, replacing the domain texture by a uniform one. This isothermal phase transition—resulting from a well-coordinated sequence of mechanochemical events—suggests a complex emergent behavior allowing synthetic vesicles produced from simple components, namely, water, osmolytes, and lipids to sense and regulate their micro-environment. DOI: http://dx.doi.org/10.7554/eLife.03695.001 PMID:25318069

  3. Osmotic Effect of Conditioning on Seeds of Tomato (Solanum Lycopersicum L. Santa Clara Variety

    Directory of Open Access Journals (Sweden)

    Brigitte Liliana Moreno Medina

    2013-12-01

    Full Text Available The tomato (Solanum lycopersicum L. is one of the most important vegetables in the world, taking into account its nutritional potential and high economic value. In this crop the quality of seed depends on various factors, one of which is its physiology, which is determined by a germination and viability test. Osmotic seed conditioning is reported to be a technique for improving the physiological quality through the uniformity of the germination percentage. For this reason, the objective of this research was to evaluate the osmotic conditioning on tomato seeds of the Santa Clara variety. Using treatments of four doses of potassium nitrate (0, 100, 200 and 400 mg L-1 , the seeds were imbibitioned for 24 hours in solution and then washed with distilled water. They were placed in petri dishes in random order with three replications for a total of 12 experimental units, consisting of 35 seeds. The method seeks to hydrate the seeds with a solution of given concentration and for a period of time, in order to activate the seed metabolism. The best result was obtained with the treatment of 200 mg L-1 of potassium nitrate, followed by 400 mg L-1 , represented by a lower TMG , lower and higher PG VMG.

  4. Osmotically driven membrane process for the management of urban runoff in coastal regions

    KAUST Repository

    Li, Zhenyu

    2014-01-01

    An osmotic detention pond was proposed for the management of urban runoff in coastal regions. Forward osmosis was employed as a bridge to utilize natural osmotic energy from seawater for concentrating and reusing urban runoff water, and as a barrier to reject runoff-derived contaminants. The process was demonstrated by a lab scale testing using synthetic urban runoff (as the feed solution) and synthetic seawater (as the draw solution). The submerged forward osmosis process was conducted under neutral, acidic and natural organic matter fouling condition, respectively. Forward osmosis flux decline was mainly attributed to the dilution of seawater during a semi-batch process in lab scale testing. However, it is possible to minimize flux decrease by maintaining a constant salinity at the draw solution side. Various changes in urban runoff water quality, including acidic conditions (acid rain) and natural organic matter presence, did not show significant effects on the rejection of trace metals and phosphorus, but influenced salt leakage and the rejection of nitrate and total nitrogen. Rejection of trace metals varied from 98% to 100%, phosphorus varied from 97% to 100, nitrate varied from 52% to 94% and total nitrogen varied from 65% to 85% under different feed water conditions. The work described in this study contributes to an integrated system of urban runoff management, seawater desalination and possible power generation in coastal regions to achieve a sustainable solution to the water-energy nexus. © 2013 Elsevier Ltd.

  5. Management Of Large Scale Osmotic Dehydration Solution Using The Pearsons Square Algorithm

    Directory of Open Access Journals (Sweden)

    Oladejo Duduyemi

    2015-01-01

    Full Text Available ABSTRACT Osmotic dehydration is a widely researched and advantageous pre-treatment process in food preservation but has not enjoyed industrial acceptance because if its highly concentrated and voluminous effluent. The Pearsons square algorithm was employed to give a focussed attack to the problem by developing a user-friendly template for reconstituting effluents for recycling purposes using Java script programme. Outflow from a pilot scale plant was reactivated and introduced into a scheme of operation for continuous OD of fruits and vegetables. Screened and re-concentrated effluent were subjected to statistical analysis in comparison to initial concentrations solution at confidence limit of p0.05. The template proven to be an adequate representation of the Pearsons square algorithm it is sufficiently good in reconstituting used osmotic solutions for repetitive usage. This protocol if adopted in the industry is not only environmentally friendly but also promises significant economic improvement of OD process. Application Recycling of non-reacting media and as a template for automation in continuous OD processing.

  6. Hematology and erythrocyte osmotic fragility of the Franquet's fruit bat (Epomops franqueti).

    Science.gov (United States)

    Ekeolu, Oyetunde Kazeem; Adebiyi, Olamide Elizabeth

    2018-03-15

    Hematological parameters are vital diagnostic tools for understanding health dynamics of humans and animals. Franquet's fruit bat (Epomops franqueti) is host to several parasites such as protozoa, bacteria, viruses and mites. Yet, studies exploring the values of its blood components with interest for research or food purposes are scarce. Thus, this study was carried out to investigate the hematological values of the adult E. franqueti. Seventeen (nine female and eight male) apparently healthy adult E. franqueti were captured from their roosting colony. Blood samples were collected for determination of erythrocyte indices [red blood cell count (RBC), packed cell volume (PCV), hemoglobin (Hb) concentration, mean corpuscular volume (MCV), mean corpuscular hemoglobin (MCH) and mean corpuscular hemoglobin concentration (MCHC)] and leukocyte indices [total white blood cell counts (WBC), lymphocytes, eosinophil, monocytes, neutrophil count and erythrocytes osmotic fragility]. There were no significant (p≥0.05) sex-related differences in RBC, PCV, Hb concentration, MCV, MCH, MCHC and total and differential WBC of E. franqueti. Erythrocyte osmotic fragility was significantly higher in female than in male E. franqueti at 0.1% NaCl. These considerations are critical in establishing reference ranges of blood parameters for E. franqueti and may provide insight to why they serve as reservoir hosts for several microorganisms.

  7. Osmotic distillation and quality evaluation of sucrose, apple and orange juices in hollow fiber membrane contactor

    Directory of Open Access Journals (Sweden)

    Rehman Waheed Ur

    2017-01-01

    Full Text Available Sucrose solution, apple and orange juices were concentrated through osmotic distillation (OD process using a mini-module Liqui-CelTM hollow fibre membrane contactor. Mass transport characteristics of water molecules from feed to stripping solution were studied. Process parameters such as feed temperature, feed flow rate and concentration of stripping solution (CaCl2 were varied. Sucrose solution was concentrated from 135 to 510 g TSS kg-1 in 340 min using feed-in- -lumen flow configuration at a start-up water flux of 0.250 L m-2 h-1 and a temperature of 30°C. Similarly, it was concentrated up to 510 g TSS kg-1 in 200 min using feed-in-shell flow configuration at a start-up water flux of 0.505 L m-2 hr1 and a temperature of 30°C. In a total recycle time of 340 min, clarified apple and orange juices were concentrated up to 500 g TSS kg-1 using feed-in-lumen flow configuration at a start-up water flux of 0.204 and 0.294 L m-2 hr1, respectively. It was found that quality parameters of fruit juices were well improved after the osmotic distillation process. The process therefore has good potential for application in the fruit processing industry for concentration of fruit juices.

  8. Application of Artificial Neural Network to Predict Colour Change, Shrinkage and Texture of Osmotically Dehydrated Pumpkin

    Science.gov (United States)

    Tang, S. Y.; Lee, J. S.; Loh, S. P.; Tham, H. J.

    2017-06-01

    The objectives of this study were to use Artificial Neural Network (ANN) to predict colour change, shrinkage and texture of osmotically dehydrated pumpkin slices. The effects of process variables such as concentration of osmotic solution, immersion temperature and immersion time on the above mentioned physical properties were studied. The colour of the samples was measured using a colorimeter and the net colour difference changes, ΔE were determined. The texture was measured in terms of hardness by using a Texture Analyzer. As for the shrinkage, displacement of volume method was applied and percentage of shrinkage was obtained in terms of volume changes. A feed-forward backpropagation network with sigmoidal function was developed and best network configuration was chosen based on the highest correlation coefficients between the experimental values versus predicted values. As a comparison, Response Surface Methodology (RSM) statistical analysis was also employed. The performances of both RSM and ANN modelling were evaluated based on absolute average deviation (AAD), correlation of determination (R2) and root mean square error (RMSE). The results showed that ANN has higher prediction capability as compared to RSM. The relative importance of the variables on the physical properties were also determined by using connection weight approach in ANN. It was found that solution concentration showed the highest influence on all three physical properties.

  9. Osmotic Adjustment in Leaves of VA Mycorrhizal and Nonmycorrhizal Rose Plants in Response to Drought Stress.

    Science.gov (United States)

    Augé, R M; Schekel, K A; Wample, R L

    1986-11-01

    Osmotic adjustment in Rosa hybrida L. cv Samantha was characterized by the pressure-volume approach in drought-acclimated and unacclimated plants brought to the same level of drought strain, as assayed by stomatal closure. Plants were colonized by either of the vesicular-arbuscular mycorrhizal fungi Glomus deserticola Trappe, Bloss and Menge or G. intraradices Schenck and Smith, or were nonmycorrhizal. Both the acclimation and the mycorrhizal treatments decreased the osmotic potential (Psi(pi)) of leaves at full turgor and at the turgor loss point, with a corresponding increase in pressure potential at full turgor. Mycorrhizae enabled plants to maintain leaf turgor and conductance at greater tissue water deficits, and lower leaf and soil water potentials, when compared with nonmycorrhizal plants. As indicated by the Psi(pi) at the turgor loss point, the active Psi(pi) depression which attended mycorrhizal colonization alone was 0.4 to 0.6 megapascals, and mycorrhizal colonization and acclimation in concert 0.6 to 0.9 megapascals, relative to unacclimated controls without mycorrhizae. Colonization levels and sporulation were higher in plants subjected to acclimation. In unacclimated hosts, leaf water potential, water saturation deficit, and soil water potential at a particular level of drought strain were affected most by G. intraradices. G. deserticola had the greater effect after drought preconditioning.

  10. Effect of temperature and cultivar on polyphenol retention and mass transfer during osmotic dehydration of apples.

    Science.gov (United States)

    Devic, Emilie; Guyot, Sylvain; Daudin, Jean-Dominique; Bonazzi, Catherine

    2010-01-13

    Several cultivars of apples (Malus domestica) were chosen for their variable concentrations and compositions in phenolic compounds. Cubed samples (1 cm3) were subjected to osmotic dehydration, and the effect of temperature was studied at 45 and 60 degrees C. Water loss, sucrose impregnation, and the evolution of some natural components of the product were followed to quantify mass transfer. Ascorbic acid and polyphenols were quantified by HPLC for several osmotic dehydration times and regardless of the quantity of impregnated sugar. Changes in antioxidant components differed as a function of the nature of molecules. Their concentrations decreased in line with temperature, and few differences were observed between cultivars. Processing at a lower temperature (45 degrees C) caused a total loss in ascorbic acid but allowed the retention of between 74 and 85% of initial polyphenols, depending on the cultivar. Cultivars containing highly polymerized procyanidins (such as Guillevic) experienced less loss. Hydroxycinnamic acids and monomeric catechins displayed the most marked changes. Leaching with water into the soaking solution was the principal mechanism retained to explain these losses.

  11. Subcellular membrane fluidity of Lactobacillus delbrueckii subsp. bulgaricus under cold and osmotic stress.

    Science.gov (United States)

    Meneghel, Julie; Passot, Stéphanie; Cenard, Stéphanie; Réfrégiers, Matthieu; Jamme, Frédéric; Fonseca, Fernanda

    2017-09-01

    Cryopreservation of lactic acid bacteria may lead to undesirable cell death and functionality losses. The membrane is the first target for cell injury and plays a key role in bacterial cryotolerance. This work aimed at investigating at a subcellular resolution the membrane fluidity of two populations of Lactobacillus delbrueckii subsp. bulgaricus when subjected to cold and osmotic stresses associated to freezing. Cells were cultivated at 42 °C in mild whey medium, and they were exposed to sucrose solutions of different osmolarities (300 and 1800 mOsm L -1 ) after harvest. Synchrotron fluorescence microscopy was used to measure membrane fluidity of cells labeled with the cytoplasmic membrane probe 1-[4 (trimethylamino) phenyl]-6-phenyl-1,3,5-hexatriene (TMA-DPH). Images were acquired at 25 and 0 °C, and more than a thousand cells were individually analyzed. Results revealed that a bacterial population characterized by high membrane fluidity and a homogeneous distribution of fluidity values appeared to be positively related to freeze-thaw resistance. Furthermore, rigid domains with different anisotropy values were observed and the occurrence of these domains was more important in the freeze-sensitive bacterial population. The freeze-sensitive cells exhibited a broadening of existing highly rigid lipid domains with osmotic stress. The enlargement of domains might be ascribed to the interaction of sucrose with membrane phospholipids, leading to membrane disorganization and cell degradation.

  12. Balancing Osmotic Pressure of Electrolytes for Nanoporous Membrane Vanadium Redox Flow Battery with a Draw Solute.

    Science.gov (United States)

    Yan, Ligen; Li, Dan; Li, Shuaiqiang; Xu, Zhi; Dong, Junhang; Jing, Wenheng; Xing, Weihong

    2016-12-28

    Vanadium redox flow batteries with nanoporous membranes (VRFBNM) have been demonstrated to be good energy storage devices. Yet the capacity decay due to permeation of vanadium and water makes their commercialization very difficult. Inspired by the forward osmosis (FO) mechanism, the VRFBNM battery capacity decrease was alleviated by adding a soluble draw solute (e.g., 2-methylimidazole) into the catholyte, which can counterbalance the osmotic pressure between the positive and negative half-cell. No change of the electrolyte volume has been observed after VRFBNM being operated for 55 h, revealing that the permeation of water and vanadium ions was effectively limited. Consequently, the Coulombic efficiency (CE) of nanoporous TiO 2 vanadium redox flow battery (VRFB) was enhanced from 93.5% to 95.3%, meanwhile, its capacity decay was significantly suppressed from 60.7% to 27.5% upon the addition of soluble draw solute. Moreover, the energy capacity of the VRFBNM was noticeably improved from 297.0 to 406.4 mAh remarkably. These results indicate balancing the osmotic pressure via the addition of draw solute can restrict pressure-dependent vanadium permeation and it can be established as a promising method for up-scaling VRFBNM application.

  13. Influence of osmotic processes on the excess-hydraulic head measured in the Toarcian/Domerian argillaceous formation of Tournemire

    International Nuclear Information System (INIS)

    Tremosa, J.

    2010-01-01

    In the framework of the studies dealing on ability to store radioactive wastes in argillaceous formations, signification of interstitial pressures is an important point to understand water and solutes transport. In very low permeability argillaceous formations, like those studied in the Callovo-Oxfordian of the Paris basin by ANDRA, pore pressure is frequently higher than the theoretical hydrostatic pressure or than the pressure in the surrounding aquifers. Such an overpressure is also measured in the Toarcian/Domerian argillaceous formation (k = 10 -21 m 2 ), studied by the IRSN in the underground research laboratory of Tournemire (Aveyron, France). The hydraulic head profile has been specified in this manuscript and found to present a 30 ±10 m excess head. This excess-head can be due to compaction disequilibrium of the argillaceous formation, diagenetic evolution of the rock, tectonic compression, changes in hydrodynamic boundary conditions or osmotic processes. Amongst these potential causes, chemical osmosis and thermo-osmosis, a fluid flow under a chemical concentration and a temperature gradient, respectively, are expected to develop owing to the small pore size and the electrostatic interactions related to the charged surface of clay minerals. The goal of the work presented here was to study and quantify the contribution of each cause to the measured excess-head. Chemo-osmotic and thermo-osmotic permeabilities were obtained by experiments and using theoretical models. Theoretical models are based on the reproduction of the interactions occurring between the charged surface of clay minerals and pore solution and their up-scaling at the representative elementary volume macroscopic scale. Chemical osmosis phenomenon is related to anionic exclusion and the determination of the chemo-osmotic efficiency requires the resolution of an electrical interactions model. A triple-layer-model which considers diffuse layers overlapping was improved during this thesis to be

  14. Calcium and Calmodulin Are Involved in Nitric Oxide-Induced Adventitious Rooting of Cucumber under Simulated Osmotic Stress.

    Science.gov (United States)

    Niu, Lijuan; Yu, Jian; Liao, Weibiao; Yu, Jihua; Zhang, Meiling; Dawuda, Mohammed M

    2017-01-01

    Osmotic stress is a major form of abiotic stress that adversely affects growth and development of plants and subsequently reduces yield and quality of crops. In this study, the effect of nitric oxide (NO) and calcium (Ca 2+ ) on the process of adventitious rooting in cucumber ( Cucumis sativus L.) under simulated osmotic stress was investigated. The results revealed that the effect of exogenous NO and Ca 2+ in promoting the development of adventitious roots in cucumber seedlings under simulated osmotic stress was dose-dependent, with a maximal biological response at 10 μM NO donor nitroprusside (SNP) or 200 μM Ca 2+ . The application of Ca 2+ chelators or channel inhibitors and calmodulin (CaM) antagonists significantly reversed NO-induced adventitious rooting, implying that endogenous Ca 2+ /CaM might be involved in NO-induced adventitious rooting under osmotic stress. Moreover, intracellular Ca amount was also increased by NO in cucumber hypocotyls during the development of adventitious roots under osmotic stress. This increase of endogenous Ca 2+ was inhibited by NO specific scavenger 2-(4-carboxyphenyl) -4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide potassium salt (cPTIO), nitrate reductase inhibitors tungstate (Na 2 WO 4 ) and sodium azide (NaN 3 ) . This gives an indication that Ca 2+ might be a downstream signaling molecule in the adventitious root development by NO under osmotic condition. The results also show that NO or Ca 2+ play a positive role in improving plant water status and photosynthetic system by increasing chlorophyll content and photochemical activity in leaves. Furthermore, NO and Ca 2+ treatment might alleviate the negative effects of osmotic stress by decreasing membrane damage and reactive oxygen species (ROS) production by enhancing the activities of superoxide dismutase (SOD), catalase (CAT) and ascorbate peroxidase (APX). Therefore, Ca 2+ /CaM may act as a downstream signaling molecule in NO-induced development of adventitious root

  15. Osmotic relations of the coelomic fluid and body wall tissues in Arenicola marina subjected to salinity change

    DEFF Research Database (Denmark)

    Weber, Roy E.; Spaargaren, D.H.

    1979-01-01

    nitrogenous organic molecules (ninhydrin-positive substances, NPS) in the body wall tissues and in the coelomic fluid of specimens of Arenicola in response to sudden changes in salinity. The coelomic solutes consist almost entirely of electrolytes and the osmotic contribution of NPS is essentially negligible....... In the body wall extracts, however, NPS accounts for at least one third of the osmotic concentration and for most of the substantial non-electrolyte fraction. There is no evidence from coelomic NPS measurements for extrusion of cellular amino acids during adaptation to lowered salinity. In diluted sea water...

  16. Modelling the Thin-Layer Drying Kinetics of Untreated and Blanch-Osmotic Pre-treated Tomato Slices

    OpenAIRE

    Samuel Enahoro Agarry

    2016-01-01

    The objective of this study was to investigate the effect of pre-treatment and drying temperature on the drying kinetics and nutritional quality of tomato (Lycopersicon esculantum L.) under hot air drying. Tomato samples were blanched at 80oC and osmotically dehydrated using 20% w/w sodium chloride solutions at 30oC for 20 min. The blanch-osmotic pre-treated and untreated tomato slices were dried at temperature of 40, 50, 60, 70 and 80oC, respectively in a hot air-dryer. The results showed th...

  17. Protein-polysaccharide interactions: The determination of the osmotic second virial coefficients in aqueous solutions of ß-lactoglobulin and dextran

    NARCIS (Netherlands)

    Schaink, H.M.; Smit, J.A.M.

    2007-01-01

    Solutions containing dextran and solutions containing mixtures of dextran +ß-lactoglobulin are studied by membrane osmometry. The low concentration range of these solutions is considered. From the measured osmotic pressures the virial coefficients are obtained. These are analyzed using the osmotic

  18. Modelling the coupled chemico-osmotic and advective-diffusive transport of nitrate salts in the Callovo-Oxfordian clay

    International Nuclear Information System (INIS)

    Baechler, S.; Croise, J.; Altmann, S.

    2010-01-01

    Document available in extended abstract form only. Fine-grained saturated porous materials can act as a semi-permeable osmotic membrane when exposed to a solute concentration gradient. The ions diffusion is hindered while water movement towards higher concentrations takes place in the semi-permeable membrane. The capacity of the fine-grained porous material to act as a semi permeable osmotic membrane is referred to as the osmotic efficiency (its value is 1 when the membranes is ideal, less than 1 when the membrane is leaky, allowing diffusion). The efficiency to retain ions in solution is dependent on the thickness of the diffuse double layer which itself depends on the solution concentration in the membrane. Clay rich formations have been shown to act as non-ideal semi-permeable membrane. Andra is investigating the Callovo-Oxfordian clay as a host rock for intermediate-level to high-level radioactive waste. In this context, it has been feared that osmotic water flows generated by the release of sodium nitrate salt in high concentrations, out of intermediate radioactive bituminous waste, could induce important over-pressures. The latest would eventually lead to fracturing of the host rock around the waste disposal drifts. The purpose of the present study was to develop a simulation code with the capacity to assess the potential impact of osmosis on: the re-saturation of the waste disposal drifts, the pressure evolution and the solute transport in and around a waste disposal drift. A chemo-osmotic coupled flow and transport model was implemented using the FlexPDE-finite element library. Our model is based on the chemo-osmotic formulation developed by Bader and Kooi, 2005. The model has been extended to highly concentrated solutions based on Pitzer's equation. In order to assess the impact of osmotic flow on the re-saturation time, the model was also designed to allow unsaturated flow modelling. The model configuration consists of an initially unsaturated 2D

  19. Improved water and sodium absorption from oral rehydration solutions based on rice syrup in a rat model of osmotic diarrhea.

    Science.gov (United States)

    Wapnir, R A; Litov, R E; Zdanowicz, M M; Lifshitz, F

    1991-04-01

    Rice syrup solids, rice protein, and casein hydrolysate were added to experimental oral rehydration solutions in various combinations and tested in a rat intestinal perfusion system. Chronic osmotic diarrhea was induced in juvenile rats by supplying the cathartic agents, magnesium citrate and phenolphthalein, in their drinking water for 1 week. The experimental oral rehydration solutions were compared with standard oral rehydration solutions containing 20 gm/L or 30 gm/L of glucose and with each other to determine if there were significant differences in net water, sodium, or potassium absorption. An oral rehydration solution containing 30 gm/L of rice syrup solids had a net water absorption rate significantly higher than that of the standard 20 gm/L glucose-based oral rehydration solution (2.1 +/- 0.62 versus 1.5 +/- 0.48 microliters/[min x cm], p less than 0.05). Casein hydrolysate did not significantly affect net water absorption. However, combinations of 30 gm/L rice syrup solids and 5 gm/L casein hydrolysate significantly increased (p less than 0.05) net sodium and potassium absorption compared with the 20 gm/L glucose-based oral rehydration solution but not versus rice syrup solids alone. Oral rehydration solutions containing 30 gm/L rice syrup solids plus 5 gm/L rice protein, and 30 gm/L rice syrup solids plus 5 gm/L casein hydrolysate, had net water absorption rates significantly higher than the rate of a 30 gm/L glucose-based oral rehydration solution (2.5 +/- 0.36 and 2.4 +/- 0.38, respectively, versus 0.87 +/- 0.40 microliters/[min x cm], p less than 0.05). Rice protein and casein hydrolysate, however, did not significantly affect net water, sodium, or potassium absorption when added to rice protein glucose-based oral rehydration solutions. An inverse correlation between osmolality and net water absorption was observed (r = -0.653, p less than 0.02). The data suggest that substitution of rice syrup solids for glucose in oral rehydration solutions will

  20. Delayed Administration of VEGF Rescues Spinal Motor Neurons from Death with a Short Effective Time Frame in Excitotoxic Experimental Models in Vivo

    Directory of Open Access Journals (Sweden)

    Luis B Tovar-y-Romo

    2012-02-01

    Full Text Available VEGF (vascular endothelial growth factor prevents neuronal death in different models of ALS (amyotrophic lateral sclerosis, but few studies have addressed the efficacy of VEGF to protect motor neurons after the onset of symptoms, a critical point when considering VEGF as a potential therapeutic target for ALS. We studied the capability of VEGF to protect motor neurons after an excitotoxic challenge in two models of spinal neurodegeneration in rats induced by AMPA (α-amino-3-hydroxy-5-methylisoxazole-4-propionic acid administered either chronically with osmotic minipumps or acutely by microdialysis. VEGF was administered through osmotic minipumps in the chronic model or injected intracerebroventricularly in the acute model, and its effects were assessed by immunohistochemical and histological analyses and motor performance tests. In the chronic model, VEGF stopped the progression of the paralysis and protected motor neurons when administered after AMPA before the onset of the motor symptoms, whereas no protection was observed when administered after the onset. VEGF was also protective in the acute model, but with a short time window, since the protection was effective when administered 1 h but not 2 h after AMPA. Our results indicate that while VEGF has an indubitable neuroprotective effect, its therapeutic potential for halting or delaying the progression of motor neuron loss in ALS would likely have a short effective time frame.

  1. Assessment of effects of a formula used in the traditional Chinese medicine (Buzhong Yi Qi Wan on the morphologic and osmotic fragility of red blood cells

    Directory of Open Access Journals (Sweden)

    Tania S. Giani

    Full Text Available Buzhong Yi Qi Wan (BYQW is a combination of some medicinal herbs widely used in traditional Chinese medicine to treat blood, spleen and stomach disorders. Morphometric analysis and osmotic fragility assay have been used to evaluate changes on membrane integrity of red blood cells. The aim of this work was to evaluate the effect of an aqueous BYQW extract on the morphology and osmotic fragility of red blood cells. Blood samples were treated with BYQW extract, quantitative/qualitative morphological analysis and osmotic fragility assay were carried out against control groups treated with saline. The data obtained indicated no modification on morphology but osmotic fragility assay suggested a significant (p<0.05 increasing of hemolysis in red blood cells isolated from blood treated with aqueous BYQW extract. In conclusion, the aqueous BYQW extract could affect the membrane integrity decreasing the osmotic resistance but without altering the shape of red blood cells.

  2. Osmotic pressure in Ca/Na montmorillonite dispersions: Monte Carlo simulations

    International Nuclear Information System (INIS)

    Joensson, Bo; Aakesson, T.; Segad, M.; Cabane, B.

    2010-01-01

    Document available in extended abstract form only. In the past, clay-water systems have been extensively studied. due to its importance in agricultural as well as technological applications. A more recent use of clay is as sealing material for nuclear waste. The success for such a containment depends on the clay structure and its swelling properties. This means that the clay should be able to sustain considerable changes in the surrounding ground water including salinities of glacial melt water as well as sea water, while still being an effective hydraulic barrier. We have approached this problem using statistical mechanical simulation techniques. The osmotic pressure in Ca/Na montmorillonite dispersions has been calculated via Monte Carlo simulations. For a clay system in equilibrium with pure water, Monte Carlo simulations predict a large swelling when the clay counterions are monovalent, while in presence of divalent counterions a limited swelling is predicted with an aqueous layer between the clay lamellae of about 1 nm - in excellent agreement with SAXS data. Montmorillonite in contact with a salt reservoir with e.g. both Na and Ca counterions will only show a modest swelling unless the Na + concentration in the bulk is several orders of magnitude larger than the Ca 2+ concentration. This is true both for a clay repository surrounded by ground water as well as sea water of high salinity. The limited swelling of clay in presence of divalent counterions is a consequence of ion-ion correlations, which both reduce the entropic repulsion and give rise to an attractive component in the total osmotic pressure. Ion-ion correlations also favour divalent counterions when competing with monovalent ones. This is an important aspect for the retention of radioactive charged species. A more fundamental result of ion-ion correlations is that the osmotic pressure as a function of clay sheet separation becomes non-monotonic - which indicates the possibility of a phase

  3. Comparison of different methods of osmotic shocks for extraction of Human Granulocyte Colony Stimulating Factor produced in periplasm

    Directory of Open Access Journals (Sweden)

    Sharareh Peymanfar

    2018-06-01

    Discussion and conclusion: Regarding the results, it is concluded that the MgSO4 with Tris buffer create a good osmotic pressure and accordingly is a more effective way for G-CSF protein extraction. As a result, this method could be used for production and simple separation of recombinant drug proteins.

  4. Identification of QTLs for shoot and root growth under ionic-osmotic stress in Lotus, using a RIL population

    DEFF Research Database (Denmark)

    Quero, Gastón; Gutíerrez, Lucía; Lascano, Ramiro

    2014-01-01

    The genus Lotus includes a group of forage legume species including genotypes of agronomic interest and model species. In this work, an experimental hydroponic growth system allowed the discrimination of growth responses to ionic-osmotic stress in a population of recombinant inbred lines (RILs...

  5. Upregulations of Clcn3 and P-Gp Provoked by Lens Osmotic Expansion in Rat Galactosemic Cataract

    Directory of Open Access Journals (Sweden)

    Lixia Ji

    2017-01-01

    Full Text Available Objective. Lens osmotic expansion, provoked by overactivated aldose reductase (AR, is the most essential event of sugar cataract. Chloride channel 3 (Clcn3 is a volume-sensitive channel, mainly participating in the regulation of cell fundamental volume, and P-glycoprotein (P-gp acts as its modulator. We aim to study whether P-gp and Clcn3 are involved in lens osmotic expansion of galactosemic cataract. Methods and Results. In vitro, lens epithelial cells (LECs were primarily cultured in gradient galactose medium (10–60 mM, more and more vacuoles appeared in LEC cytoplasm, and mRNA and protein levels of AR, P-gp, and Clcn3 were synchronously upregulated along with the increase of galactose concentration. In vivo, we focused on the early stage of rat galactosemic cataract, amount of vacuoles arose from equatorial area and scattered to the whole anterior capsule of lenses from the 3rd day to the 9th day, and mRNA and protein levels of P-gp and Clcn3 reached the peak around the 9th or 12th day. Conclusion. Galactosemia caused the osmotic stress in lenses; it also markedly leads to the upregulations of AR, P-gp, and Clcn3 in LECs, together resulting in obvious osmotic expansion in vitro and in vivo.

  6. The effect of step height on the performance of three-dimensional ac electro-osmotic microfluidic pumps.

    Science.gov (United States)

    Urbanski, John Paul; Levitan, Jeremy A; Burch, Damian N; Thorsen, Todd; Bazant, Martin Z

    2007-05-15

    Recent numerical and experimental studies have investigated the increase in efficiency of microfluidic ac electro-osmotic pumps by introducing nonplanar geometries with raised steps on the electrodes. In this study, we analyze the effect of the step height on ac electro-osmotic pump performance. AC electro-osmotic pumps with three-dimensional electroplated steps are fabricated on glass substrates and pumping velocities of low ionic strength electrolyte solutions are measured systematically using a custom microfluidic device. Numerical simulations predict an improvement in pump performance with increasing step height, at a given frequency and voltage, up to an optimal step height, which qualitatively matches the trend observed in experiment. For a broad range of step heights near the optimum, the observed flow is much faster than with existing planar pumps (at the same voltage and minimum feature size) and in the theoretically predicted direction of the "fluid conveyor belt" mechanism. For small step heights, the experiments also exhibit significant flow reversal at the optimal frequency, which cannot be explained by the theory, although the simulations predict weak flow reversal at higher frequencies due to incomplete charging. These results provide insight to an important parameter for the design of nonplanar electro-osmotic pumps and clues to improve the fundamental theory of ACEO.

  7. Osmotic dehydration of blueberries pretreated with pulsed electric fields: Effects on drying rate, and microbiological and nutritional qualities

    Science.gov (United States)

    Fresh blueberries were treated by pulsed electric fields (PEF) at 2 kV/cm before osmotic dehydration in 70% sugar syrup. The changes in water loss, solids gain, populations of native microorganisms, antioxidant activity, contents of anthocyanins, predominant phenolic acids and flavonols, and total p...

  8. Biochemical degradation and physical migration of nutritive compounds in blueberries after PEF and thermal pretreatments and osmotic dehydration

    Science.gov (United States)

    Fresh blueberries were pretreated by pulsed electric fields (PEF) at 3 kV/cm or thermal pretreatment at 90 degrees C for 5 min after which they were subject to osmotic dehydration. The changes in contents of anthocyanins, predominantly phenolic acids and flavonols, total phenolics, polyphenol oxidas...

  9. The Balance of Fluid and Osmotic Pressures across Active Biological Membranes with Application to the Corneal Endothelium.

    Directory of Open Access Journals (Sweden)

    Xi Cheng

    Full Text Available The movement of fluid and solutes across biological membranes facilitates the transport of nutrients for living organisms and maintains the fluid and osmotic pressures in biological systems. Understanding the pressure balances across membranes is crucial for studying fluid and electrolyte homeostasis in living systems, and is an area of active research. In this study, a set of enhanced Kedem-Katchalsky (KK equations is proposed to describe fluxes of water and solutes across biological membranes, and is applied to analyze the relationship between fluid and osmotic pressures, accounting for active transport mechanisms that propel substances against their concentration gradients and for fixed charges that alter ionic distributions in separated environments. The equilibrium analysis demonstrates that the proposed theory recovers the Donnan osmotic pressure and can predict the correct fluid pressure difference across membranes, a result which cannot be achieved by existing KK theories due to the neglect of fixed charges. The steady-state analysis on active membranes suggests a new pressure mechanism which balances the fluid pressure together with the osmotic pressure. The source of this pressure arises from active ionic fluxes and from interactions between solvent and solutes in membrane transport. We apply the proposed theory to study the transendothelial fluid pressure in the in vivo cornea, which is a crucial factor maintaining the hydration and transparency of the tissue. The results show the importance of the proposed pressure mechanism in mediating stromal fluid pressure and provide a new interpretation of the pressure modulation mechanism in the in vivo cornea.

  10. Osmotic Pressure of Aqueous Electrolyte Solutions via Molecular Simulations of Chemical Potentials: Application to NaCl.

    Czech Academy of Sciences Publication Activity Database

    Smith, W.R.; Moučka, F.; Nezbeda, Ivo

    2016-01-01

    Roč. 407, Sl (2016), s. 76-83 ISSN 0378-3812 Grant - others:NSERC(CA) OGP1041 Institutional support: RVO:67985858 Keywords : osmotic pressure * chemical potential * molecular simulation Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 2.473, year: 2016

  11. Model Dependency of TMAO's Counteracting Effect Against Action of Urea: Kast Model versus Osmotic Model of TMAO.

    Science.gov (United States)

    Borgohain, Gargi; Paul, Sandip

    2016-03-10

    Classical molecular dynamics simulation of GB1 peptide (a 16-residue β-hairpin) in different osmotic environments is studied. Urea is used for denaturation of the peptide, and trimethylamine-N-oxide (TMAO) is used to offset the effect of urea. Protein-urea electrostatic interactions are found to play a major role in protein-denaturation. To emphasize on protein protecting action of TMAO against urea, two different models of TMAO are used, viz., the Kast model and the Osmotic model. We observe that the Osmotic model of TMAO gives the best protection to counteract urea's action when used in ratio 1:2 of urea:TMAO (i.e., reverse ratio). This is because the presence of TMAO makes urea-protein electrostatic interactions more unfavorable. Preferential solvation of TMAO molecules by urea (and water) molecules is also observed, which causes depletion in the number of urea molecules in the vicinity of the protein. The calculations of intraprotein hydrogen bonds between different residues of protein further reveal the breaking of backbone hydrogen bonds of residues 2 and 15 in the presence of urea, and the same is preserved in the presence of TMAO. Free energy landscapes show that the narrowest distribution is obtained for the osmotic TMAO model when used in reverse ratio.

  12. Role of Arabidopsis ABF1/3/4 during det1 germination in salt and osmotic stress conditions.

    Science.gov (United States)

    Fernando, V C Dilukshi; Al Khateeb, Wesam; Belmonte, Mark F; Schroeder, Dana F

    2018-05-01

    Arabidopsis det1 mutants exhibit salt and osmotic stress resistant germination. This phenotype requires HY5, ABF1, ABF3, and ABF4. While DE-ETIOLATED 1 (DET1) is well known as a negative regulator of light development, here we describe how det1 mutants also exhibit altered responses to salt and osmotic stress, specifically salt and mannitol resistant germination. LONG HYPOCOTYL 5 (HY5) positively regulates both light and abscisic acid (ABA) signalling. We found that hy5 suppressed the det1 salt and mannitol resistant germination phenotype, thus, det1 stress resistant germination requires HY5. We then queried publically available microarray datasets to identify genes downstream of HY5 that were differentially expressed in det1 mutants. Our analysis revealed that ABA regulated genes, including ABA RESPONSIVE ELEMENT BINDING FACTOR 3 (ABF3), are downregulated in det1 seedlings. We found that ABF3 is induced by salt in wildtype seeds, while homologues ABF4 and ABF1 are repressed, and all three genes are underexpressed in det1 seeds. We then investigated the role of ABF3, ABF4, and ABF1 in det1 phenotypes. Double mutant analysis showed that abf3, abf4, and abf1 all suppress the det1 salt/osmotic stress resistant germination phenotype. In addition, abf1 suppressed det1 rapid water loss and open stomata phenotypes. Thus interactions between ABF genes contribute to det1 salt/osmotic stress response phenotypes.

  13. Hybrid Pressure Retarded Osmosis−Membrane Distillation (PRO−MD) Process for Osmotic Power and Clean Water Generation

    KAUST Repository

    Han, Gang

    2015-05-20

    A novel pressure retarded osmosis−membrane distillation (PRO−MD) hybrid process has been experimentally conceived for sustainable production of renewable osmotic power and clean water from various waters. The proposed PRO−MD system may possess unique advantages of high water recovery rate, huge osmotic power generation, well controlled membrane fouling, and minimal environmental impacts. Experimental results show that the PRO−MD hybrid process is promising that not only can harvest osmotic energy from freshwater but also from wastewater. When employing a 2 M NaCl MD concentrate as the draw solution, ultrahigh power densities of 31.0 W/m2 and 9.3 W/m2 have been demonstrated by the PRO subsystem using deionized water and real wastewater brine as the feeds, respectively. Simultaneously, high purity potable water with a flux of 32.5−63.1 L/(m2.h) can be produced by the MD subsystem at 40−60 °C without any detrimental effects of fouling. The energy consumption in the MD subsystem might be further reduced by applying a heat exchanger in the hybrid system and using low-grade heat or solar energy to heat up the feed solution. The newly developed PRO−MD hybrid process would provide insightful guidelines for the exploration of alternative green technologies for renewable osmotic energy and clean water production.

  14. Osmotic pressure-dependent release profiles of payloads from nanocontainers by co-encapsulation of simple salts

    Science.gov (United States)

    Behzadi, Shahed; Rosenauer, Christine; Kappl, Michael; Mohr, Kristin; Landfester, Katharina; Crespy, Daniel

    2016-06-01

    The encapsulation of payloads in micro- to nano-scale capsules allows protection of the payload from the surrounding environment and control of its release profile. Herein, we program the release of hydrophilic payloads from nanocontainers by co-encapsulating simple inorganic salts for adjusting the osmotic pressure. The latter either leads to a burst release at high concentrations of co-encapsulated salts or a sustained release at lower concentrations. Osmotic pressure causes swelling of the nanocapsule's shell and therefore sustained release profiles can be adjusted by crosslinking it. The approach presented allows for programing the release of payloads by co-encapsulating inexpensive salts inside nanocontainers without the help of stimuli-responsive materials.The encapsulation of payloads in micro- to nano-scale capsules allows protection of the payload from the surrounding environment and control of its release profile. Herein, we program the release of hydrophilic payloads from nanocontainers by co-encapsulating simple inorganic salts for adjusting the osmotic pressure. The latter either leads to a burst release at high concentrations of co-encapsulated salts or a sustained release at lower concentrations. Osmotic pressure causes swelling of the nanocapsule's shell and therefore sustained release profiles can be adjusted by crosslinking it. The approach presented allows for programing the release of payloads by co-encapsulating inexpensive salts inside nanocontainers without the help of stimuli-responsive materials. Electronic supplementary information (ESI) available. See DOI: 10.1039/c6nr01882c

  15. Adaptation of Bacillus subtilis carbon core metabolism to simultaneous nutrient limitation and osmotic challenge : a multi-omics perspective

    NARCIS (Netherlands)

    Kohlstedt, Michael; Sappa, Praveen K; Meyer, Hanna; Maaß, Sandra; Zaprasis, Adrienne; Hoffmann, Tamara; Becker, Judith; Steil, Leif; Hecker, Michael; van Dijl, Jan Maarten; Lalk, Michael; Mäder, Ulrike; Stülke, Jörg; Bremer, Erhard; Völker, Uwe; Wittmann, Christoph

    The Gram-positive bacterium Bacillus subtilis encounters nutrient limitations and osmotic stress in its natural soil ecosystem. To ensure survival and sustain growth, highly integrated adaptive responses are required. Here, we investigated the system-wide response of B.subtilis to different,

  16. Osmotic stress confers enhanced cell integrity to hydrostatic pressure but impairs growth in Alcanivorax borkumensis SK2

    Directory of Open Access Journals (Sweden)

    Alberto eScoma

    2016-05-01

    Full Text Available Alcanivorax is a hydrocarbonoclastic genus dominating oil spills worldwide. While its presence has been detected in oil-polluted seawaters, marine sediment and salt marshes under ambient pressure, its presence in deep-sea contaminated environments is negligible. Recent laboratory evidences highlighted the piezosensitive nature of some Alcanivorax species, whose growth yields are highly impacted by mild hydrostatic pressures (HPs. In the present study, osmotic stress was used as a tool to increase HP resistance in the type strain A. borkumensis SK2. Control cultures grown under standard conditions of salinity and osmotic pressure with respect to seawater (35.6 ppt or 1136 mOsm kg-1, respectively were compared with cultures subjected to hypo- and hyperosmosis (330 and 1720 mOsm kg-1, or 18 and 62 ppt in salinity, equivalent to brackish and brine waters, respectively, under atmospheric or increased HP (0.1 and 10MPa. Osmotic stress had a remarkably positive impact on cell metabolic activity in terms of CO2 production (thus, oil bioremediation and O2 respiration under hyperosmosis, as acclimation to high salinity enhanced cell activity under 10MPa by a factor of 10. Both osmotic shocks significantly enhanced cell protection by reducing membrane damage under HP, with cell integrities close to 100% under hyposmosis. The latter was likely due to intracellular water-reclamation as no trace of the piezolyte ectoine was found, contrary to hyperosmosis. Notably, ectoine production was equivalent at 0.1MPa in hyperosmosis-acclimated cells and at 10MPa under isosmotic conditions, supporting the hypothesis that ectoine synthesis may be primarily triggered by HP rather than osmotic stress. While stimulating cell metabolism and enhancing cell integrity, osmotic stress had always a negative impact on culture growth and performance. No net growth was observed during 4-day incubation tests, and CO2:O2 ratios and pH values indicated that culture performance in

  17. Alternative oxidase pathway optimizes photosynthesis during osmotic and temperature stress by regulating cellular ROS, malate valve and antioxidative systems

    Directory of Open Access Journals (Sweden)

    DINAKAR eCHALLABATHULA

    2016-02-01

    Full Text Available The present study reveals the importance of alternative oxidase (AOX pathway in optimizing photosynthesis under osmotic and temperature stress conditions in the mesophyll protoplasts of Pisum sativum. The responses of photosynthesis and respiration were monitored at saturating light intensity of 1000 µmoles m-2 s-1 at 25 oC under a range of sorbitol concentrations from 0.4 M to 1.0M to induce hyper-osmotic stress and by varying the temperature of the thermo-jacketed pre-incubation chamber from 25 oC to 10 oC to impose sub-optimal temperature stress. Compared to controls (0.4 M sorbitol and 25 OC, the mesophyll protoplasts showed remarkable decrease in NaHCO3-dependent O2 evolution (indicator of photosynthetic carbon assimilation, under both hyper-osmotic (1.0 M sorbitol and sub-optimal temperature stress conditions (10 OC, while the decrease in rates of respiratory O2 uptake were marginal. The capacity of AOX pathway increased significantly in parallel to increase in intracellular pyruvate and reactive oxygen species (ROS levels under both hyper-osmotic stress and sub-optimal temperature stress under the background of saturating light. The ratio of redox couple (Malate/OAA related to malate valve increased in contrast to the ratio of redox couple (GSH/GSSG related to antioxidative system during hyper-osmotic stress. Nevertheless, the ratio of GSH/GSSG decreased in the presence of sub-optimal temperature, while the ratio of Malate/OAA showed no visible changes. Also, the redox ratios of pyridine nucleotides increased under hyper-osmotic (NADH/NAD and sub-optimal temperature (NADPH/NADP stresses, respectively. However, upon restriction of AOX pathway by using salicylhydroxamic acid (SHAM, the observed changes in NaHCO3 dependent O2 evolution, cellular ROS, redox ratios of Malate/OAA, NAD(PH/NAD(P and GSH/GSSG were further aggravated under stress conditions with concomitant modulations in NADP-MDH and antioxidant enzymes. Taken together, the

  18. The lateral intercellular space as osmotic coupling compartment in isotonic transport

    DEFF Research Database (Denmark)

    Larsen, E.H.; Willumsen, N.J.; Mobjerg, N.

    2009-01-01

    coupling of water absorption to ion flow is energized by lateral Na+/K+ pumps. We show that the theory accounts quantitatively for steady- and time dependent states of solute-coupled fluid uptake by toad skin epithelium. Our experimental results exclude definitively three alternative theories of epithelial......Solute-coupled water transport and isotonic transport are basic functions of low- and high-resistance epithelia. These functions are studied with the epithelium bathed on the two sides with physiological saline of similar composition. Hence, at transepithelial equilibrium water enters...... the epithelial cells from both sides, and with the reflection coefficient of tight junction being larger than that of the interspace basement membrane, all of the water leaves the epithelium through the interspace basement membrane. The common design of transporting epithelia leads to the theory that an osmotic...

  19. Global Transcriptional Responses to Osmotic, Oxidative, and Imipenem Stress Conditions in Pseudomonas putida

    DEFF Research Database (Denmark)

    Bojanovic, Klara; D'Arrigo, Isotta; Long, Katherine

    2017-01-01

    functional roles in the cellular response to stress conditions. The data show a larger fraction of differentially expressed sRNAs than of mRNAs with >5-fold expression changes. The work provides detailed insights into the mechanisms through which P. putida responds to different stress conditions...... intergenic and antisense transcripts, were detected, increasing the number of identified sRNA transcripts in the strain by a factor of 10. Unique responses to each type of stress are documented, including both the extent and dynamics of the gene expression changes. The work adds rich detail to previous......Bacteria cope with and adapt to stress by modulating gene expression in response to specific environmental cues. In this study, the transcriptional response of Pseudomonas putida KT2440 to osmotic, oxidative, and imipenem stress conditions at two time points was investigated via identification...

  20. Effects of PEG-induced osmotic stress on growth and dhurrin levels of forage sorghum

    DEFF Research Database (Denmark)

    O'Donnell, Natalie H.; Møller, Birger Lindberg; Neale, Alan D.

    2013-01-01

    Sorghum (Sorghum bicolor L. Moench) is a valuable forage crop in regions with low soil moisture. Sorghum may accumulate high concentrations of the cyanogenic glucoside dhurrin when drought stressed resulting in possible cyanide (HCN) intoxication of grazing animals. In addition, high concentratio...... of plant growth and root activity, increasing the rate of nitrate uptake. Data presented in this article support a role for cyanogenic glucosides in mitigating oxidative stress....... of nitrate, also potentially toxic to ruminants, may accumulate during or shortly after periods of drought. Little is known about the degree and duration of drought-stress required to induce dhurrin accumulation, or how changes in dhurrin concentration are influenced by plant size or nitrate metabolism....... Given that finely regulating soil moisture under controlled conditions is notoriously difficult, we exposed sorghum plants to varying degrees of osmotic stress by growing them for different lengths of time in hydroponic solutions containing polyethylene glycol (PEG). Plants grown in medium containing 20...

  1. System analysis of salt and osmotic stress induced proteins in Nostoc muscorum and Bradyrhizobium japonicum

    Directory of Open Access Journals (Sweden)

    Vipin Kaithwas

    2017-06-01

    Full Text Available In this study the proteome response of the two diazotrophic organism’s viz. Nostoc muscorum and Bradyrhizobium japonicum exposed to salt (NaCl and osmotic (sucrose stresses was compared. Out of the total over expressed proteins; we have selected only three over expressed proteins viz. GroEL chaperonin, nitrogenase Mo-Fe protein and argininosuccinate synthase for further analysis, and then we analyzed the amino acid frequencies of all the three over expressed proteins. That led to the conclusion that amino acids e.g. alanine, glycine and valine that were energetically cheaper to produce were showing higher frequencies. This study would help in tracing the phylogenetic relationship between protein families.

  2. Measurement of water filtration in skeletal muscle in man by an osmotic transient method

    DEFF Research Database (Denmark)

    Palm, T; Nielsen, S L; Lassen, N A

    1983-01-01

    Water filtration in the human forearm was determined with a new method using a hyperoncotic transient of albumin solution infused into the brachial artery. Baseline dilution of labelled albumin in deep forearm vein plasma in excess of the contribution from arterial blood and from infusate...... was assumed to originate from extravascular water filtered into the blood by the transient. The filtration coefficient (Fc) was determined as the ratio between filtered water and increase in colloid osmotic pressure in the blood samples, and gives the filtrative water permeability in the exchange areas...... muscles, but it is of the same order of magnitude as the capillary filtration coefficient (CFC) determined plethysmographically for the entire forearm by the venous stasis technique....

  3. Theoretical prediction of fast 3D AC electro-osmotic pumps.

    Science.gov (United States)

    Bazant, Martin Z; Ben, Yuxing

    2006-11-01

    AC electro-osmotic (ACEO) pumps in microfluidics currently involve planar electrode arrays, but recent work on the underlying phenomenon of induced-charge electro-osmosis (ICEO) suggests that three-dimensional (3D) geometries may be exploited to achieve faster flows. In this paper, we present some new design principles for periodic 3D ACEO pumps, such as the "fluid conveyor belt" of ICEO flow over a stepped electrode array. Numerical simulations of these designs (using the standard low-voltage model) predict flow rates almost twenty times faster than existing planar ACEO pumps, for the same applied voltage and minimum feature size. These pumps may enable new portable or implantable lab-on-a-chip devices, since rather fast (mm s(-1)), tuneable flows should be attainable with battery voltages (<10 V).

  4. Design principle for improved three-dimensional ac electro-osmotic pumps

    Science.gov (United States)

    Burch, Damian; Bazant, Martin Z.

    2008-05-01

    Three-dimensional (3D) ac electro-osmotic (ACEO) pumps have recently been developed that are much faster and more robust than previous planar designs. The basic idea is to create a “fluid conveyor belt” by placing opposing ACEO slip velocities at different heights. Current designs involve electrodes with electroplated steps, whose heights have been optimized in simulations and experiments. Here, we consider changing the boundary conditions—rather than the geometry—and predict that flow rates can be further doubled by fabricating 3D features with nonpolarizable materials. This amplifies the fluid conveyor belt by removing opposing flows on the vertical surfaces, and it increases the slip velocities that drive the flow.

  5. Fatty acids from high rate algal pond's microalgal biomass and osmotic stress effects.

    Science.gov (United States)

    Drira, Neila; Dhouibi, Nedra; Hammami, Saoussen; Piras, Alessandra; Rosa, Antonella; Porcedda, Silvia; Dhaouadi, Hatem

    2017-11-01

    The extraction of oil from a wild microalgae biomass collected from a domestic wastewater treatment facility's high rate algal pond (HRAP) was investigated. An experiment plan was used to determine the most efficient extraction method, the optimal temperature, time and solvent system based on total lipids yield. Microwave-assisted extraction was the most efficient method whether in n-hexane or in a mixture of chloroform/methanol compared to Soxhlet, homogenization, and ultrasounds assisted extractions. This same wild biomass was cultivated in a photobioreactor (PBR) and the effect of osmotic stress was studied. The lipids extraction yield after 3days of stress increased by more than four folds without any significant loss of biomass, however, the quality of extracted total lipids in terms of saturated, monounsaturated and polyunsaturated fatty acids was not affected by salinity change in the culture medium. Copyright © 2017 Elsevier Ltd. All rights reserved.

  6. Force fluctuations of non-adherent cells: effects of osmotic pressure and motor inhibition

    Science.gov (United States)

    Rezvani, Samaneh; Schmidt, Christoph F.; Squires, Todd M.

    Cells sense their micro-environment through biochemical and mechanical interactions. They can respond to stimuli by undergoing shape- and possibly volume changes. Key components in determining the mechanical response of a cell are the viscoelastic properties of the actomyosin cortex, effective surface tension, and the osmotic pressure. We use custom-designed microfluidic chambers with integrated hydrogel micro windows to be able to rapidly change solution conditions for cells without active mixing, stirring or diluting of fluid. We use biochemical inhibitors and different osmolytes and investigate the time-dependent response of individual cells. Using a dual optical trap makes it possible to probe viscoelasticity of suspended cells by active and passive microrheology to quantify the response to the various stimuli. SFB 937, Germany.

  7. Electro-osmotic flow through nanopores in thin and ultrathin membranes

    Science.gov (United States)

    Melnikov, Dmitriy V.; Hulings, Zachery K.; Gracheva, Maria E.

    2017-06-01

    We theoretically study how the electro-osmotic fluid velocity in a charged cylindrical nanopore in a thin solid state membrane depends on the pore's geometry, membrane charge, and electrolyte concentration. We find that when the pore's length is comparable to its diameter, the velocity profile develops a concave shape with a minimum along the pore axis unlike the situation in very long nanopores with a maximum velocity along the central pore axis. This effect is attributed to the induced pressure along the nanopore axis due to the fluid flow expansion and contraction near the exit or entrance to the pore and to the reduction of electric field inside the nanopore. The induced pressure is maximal when the pore's length is about equal to its diameter while decreasing for both longer and shorter nanopores. A model for the fluid velocity incorporating these effects is developed and shown to be in a good agreement with numerically computed results.

  8. Competitive excitation and osmotic-pressure-mediated control of lasing modes in cholesteric liquid crystal microshells

    Science.gov (United States)

    Lin, Ya-Li; Gong, Ling-Li; Che, Kai-Jun; Li, Sen-Sen; Chu, Cheng-Xu; Cai, Zhi-Ping; Yang, Chaoyong James; Chen, Lu-Jian

    2017-05-01

    We examined the end-pumped lasing behaviors of dye doped cholesteric liquid crystal (DDCLC) microshells which were fabricated by glass capillary microfluidics. Several kinds of mode resonances, including distributed feedback, Fabry-Pérot (FP), and whispering gallery (WG) modes, can be robustly constructed in each individual DDCLC microshell by varying the beam diameter, namely, tuning the DDCLC gain area. The FP and WG modes were further confirmed experimentally, and the corresponding lasing mechanisms are clearly revealed from the unique material characteristics of DDCLC and the geometrical structure of the microshell. Additionally, we demonstrated that the osmotic pressure can be used to shrink/expand the microshell, productively tuning the excitation of lasing modes in a controlled manner. We wish our findings can provide a new insight into the design of DDCLC microlasers with tunable optical properties.

  9. The Response Strategy of Maize, Pea and Broad Bean Plants to Different Osmotic Potential Stress

    Directory of Open Access Journals (Sweden)

    Hamdia M. Abd El-Samad

    2013-08-01

    Full Text Available This investigation was conducted to study the tolerance strategy of maize, broad bean and pea plants to salinity stress with exogenous applications of proline or phenylalanine on seed germination and seedlings growth. From the results obtained, it can be observed that osmotic stress affected adversely the rate of germination in maize, broad bean and pea plants. The excessive inhibition was more prominent at higher concentration of NaCl. The seeds and grains tested were exhibited some differential responses to salinity, in a manner that the inhibitory effect of salinity on seed germination ran in the order, maize higher than broad bean and the later was higher than pea plant. Treatment with proline or phenylalanine (100 ppm significantly increased these seed germination and seedlings growth characteristics even at lowest salinity level tested.

  10. Global analysis of the yeast osmotic stress response by quantitative proteomics

    DEFF Research Database (Denmark)

    Soufi, Boumediene; Kelstrup, C.D.; Stoehr, G.

    2009-01-01

    a comprehensive, quantitative, and time-resolved analysis using high-resolution mass spectrometry of phospho-proteome and proteome changes in response to osmotic stress in yeast. We identified 5534 unique phosphopeptide variants and 3383 yeast proteins. More than 15% of the detected phosphorylation site status...... changed more than two-fold within 5 minutes of treatment. Many of the corresponding phosphoproteins are involved in the early response to environmental stress. Surprisingly, we find that 158 regulated phosphorylation sites are potential substrates of basophilic kinases as opposed to the classical proline......-directed MAP kinase network implicated in stress response mechanisms such as p38 and HOG pathways. Proteome changes reveal an increase in abundance of more than one hundred proteins after 20 min of salt stress. Many of these are involved in the cellular response to increased osmolarity, which include proteins...

  11. Biofouling behavior and performance of forward osmosis membranes with bioinspired surface modification in osmotic membrane bioreactor.

    Science.gov (United States)

    Li, Fang; Cheng, Qianxun; Tian, Qing; Yang, Bo; Chen, Qianyuan

    2016-07-01

    Forward osmosis (FO) has received considerable interest for water and energy related applications in recent years. Biofouling behavior and performance of cellulose triacetate (CTA) forward osmosis membranes with bioinspired surface modification via polydopamine (PD) coating and poly (ethylene glycol) (PEG) grafting (PD-g-PEG) in a submerged osmotic membrane bioreactor (OMBR) were investigated in this work. The modified membranes exhibited lower flux decline than the pristine one in OMBR, confirming that the bioinspired surface modification improved the antifouling ability of the CTA FO membrane. The result showed that the decline of membrane flux related to the increase of the salinity and MLSS concentration of the mixed liquid. It was concluded that the antifouling ability of modified membranes ascribed to the change of surface morphology in addition to the improvement of membrane hydrophilicity. The bioinspired surface modifications might improve the anti-adhesion for the biopolymers and biocake. Copyright © 2016 Elsevier Ltd. All rights reserved.

  12. Organization of cis-acting regulatory elements in osmotic- and cold-stress-responsive promoters.

    Science.gov (United States)

    Yamaguchi-Shinozaki, Kazuko; Shinozaki, Kazuo

    2005-02-01

    cis-Acting regulatory elements are important molecular switches involved in the transcriptional regulation of a dynamic network of gene activities controlling various biological processes, including abiotic stress responses, hormone responses and developmental processes. In particular, understanding regulatory gene networks in stress response cascades depends on successful functional analyses of cis-acting elements. The ever-improving accuracy of transcriptome expression profiling has led to the identification of various combinations of cis-acting elements in the promoter regions of stress-inducible genes involved in stress and hormone responses. Here we discuss major cis-acting elements, such as the ABA-responsive element (ABRE) and the dehydration-responsive element/C-repeat (DRE/CRT), that are a vital part of ABA-dependent and ABA-independent gene expression in osmotic and cold stress responses.

  13. Osmotically driven drug delivery through remote-controlled magnetic nanocomposite membranes

    KAUST Repository

    Zaher, A.

    2015-09-29

    Implantable drug delivery systems can provide long-term reliability, controllability, and biocompatibility, and have been used in many applications, including cancer pain and non-malignant pain treatment. However, many of the available systems are limited to zero-order, inconsistent, or single burst event drug release. To address these limitations, we demonstrate prototypes of a remotely operated drug delivery device that offers controllability of drug release profiles, using osmotic pumping as a pressure source and magnetically triggered membranes as switchable on-demand valves. The membranes are made of either ethyl cellulose, or the proposed stronger cellulose acetate polymer, mixed with thermosensitive poly(N-isopropylacrylamide) hydrogel and superparamagnetic iron oxide particles. The prototype devices\\' drug diffusion rates are on the order of 0.5–2 μg/h for higher release rate designs, and 12–40 ng/h for lower release rates, with maximum release ratios of 4.2 and 3.2, respectively. The devices exhibit increased drug delivery rates with higher osmotic pumping rates or with magnetically increased membrane porosity. Furthermore, by vapor deposition of a cyanoacrylate layer, a drastic reduction of the drug delivery rate from micrograms down to tens of nanograms per hour is achieved. By utilizing magnetic membranes as the valve-control mechanism, triggered remotely by means of induction heating, the demonstrated drug delivery devices benefit from having the power source external to the system, eliminating the need for a battery. These designs multiply the potential approaches towards increasing the on-demand controllability and customizability of drug delivery profiles in the expanding field of implantable drug delivery systems, with the future possibility of remotely controlling the pressure source.

  14. Nitrate-dependent shoot sodium accumulation and osmotic functions of sodium in Arabidopsis under saline conditions.

    Science.gov (United States)

    Álvarez-Aragón, Rocío; Rodríguez-Navarro, Alonso

    2017-07-01

    Improving crop plants to be productive in saline soils or under irrigation with saline water would be an important technological advance in overcoming the food and freshwater crises that threaten the world population. However, even if the transformation of a glycophyte into a plant that thrives under seawater irrigation was biologically feasible, current knowledge about Na + effects would be insufficient to support this technical advance. Intriguingly, crucial details about Na + uptake and its function in the plant have not yet been well established. We here propose that under saline conditions two nitrate-dependent transport systems in series that take up and load Na + into the xylem constitute the major pathway for the accumulation of Na + in Arabidopsis shoots; this pathway can also function with chloride at high concentrations. In nrt1.1 nitrate transport mutants, plant Na + accumulation was partially defective, which suggests that NRT1.1 either partially mediates or modulates the nitrate-dependent Na + transport. Arabidopsis plants exposed to an osmotic potential of -1.0 MPa (400 mOsm) for 24 h showed high water loss and wilting in sorbitol or Na/MES, where Na + could not be accumulated. In contrast, in NaCl the plants that accumulated Na + lost a low amount of water, and only suffered transitory wilting. We discuss that in Arabidopsis plants exposed to high NaCl concentrations, root Na + uptake and tissue accumulation fulfil the primary function of osmotic adjustment, even if these processes lead to long-term toxicity. © 2017 The Authors The Plant Journal © 2017 John Wiley & Sons Ltd.

  15. Applicability of a novel osmotic membrane bioreactor using a specific draw solution in wastewater treatment

    Energy Technology Data Exchange (ETDEWEB)

    Nguyen, Nguyen Cong [Institute of Environmental Engineering and Management, National Taipei University of Technology, No. 1, Sec. 3, Chung-Hsiao E. Rd., Taipei 106, Taiwan, ROC (China); Chen, Shiao-Shing, E-mail: f10919@ntut.edu.tw [Institute of Environmental Engineering and Management, National Taipei University of Technology, No. 1, Sec. 3, Chung-Hsiao E. Rd., Taipei 106, Taiwan, ROC (China); Nguyen, Hau Thi [Institute of Environmental Engineering and Management, National Taipei University of Technology, No. 1, Sec. 3, Chung-Hsiao E. Rd., Taipei 106, Taiwan, ROC (China); Ngo, Huu Hao, E-mail: h.ngo@uts.edu.au [School of Civil and Environmental Engineering, Faculty of Engineering and Information Technology, University of Technology Sydney, Broadway, NSW 2007 (Australia); Guo, Wenshan [School of Civil and Environmental Engineering, Faculty of Engineering and Information Technology, University of Technology Sydney, Broadway, NSW 2007 (Australia); Hao, Chan Wen [Institute of Environmental Engineering and Management, National Taipei University of Technology, No. 1, Sec. 3, Chung-Hsiao E. Rd., Taipei 106, Taiwan, ROC (China); Lin, Po-Hsun [New Materials Research and Development Dept., China Steel Corporation, Taiwan, ROC (China)

    2015-06-15

    This study aims to develop a new osmotic membrane bioreactor by combining a moving bed biofilm reactor (MBBR) with forward osmosis membrane bioreactor (FOMBR) to treat wastewater. Ethylenediaminetetraacetic acid disodium salt coupled with polyethylene glycol tert-octylphenyl ether was used as an innovative draw solution in this membrane hybrid system (MBBR–OsMBR) for minimizing the reverse salt flux and maintaining a healthy environment for the microorganism community. The results showed that the hybrid system achieved a stable water flux of 6.94 L/m{sup 2} h and low salt accumulation in the bioreactor for 68 days of operation. At a filling rate of 40% (by volume of the bioreactor) of the polyethylene balls used as carriers, NH{sub 4}{sup +}-N and PO{sub 4}{sup 3−}-P were almost removed (> 99%) while producing relatively low NO{sub 3}{sup −}-N and NO{sub 2}{sup −}-N in the effluent (e.g. < 0.56 and 0.96 mg/L, respectively). Furthermore, from analysis based on scanning electron microscopy, Fourier transform infrared spectroscopy, and fluorescence emission–excitation matrix spectrophotometry, there was a thin gel-like fouling layer on the FO membrane, which composed of bacteria as well as biopolymers and protein-like substances. Nonetheless, the formation of these fouling layers of the FO membrane in MBBR–OsMBR was reversible and removed by a physical cleaning technique. - Highlights: • A novel osmotic membrane bioreactor (MBBR–OsMBR) using a novel draw solution (DS) was developed. • The MBBR–OsMBR system successfully reduced membrane fouling. • EDTA sodium coupled with Triton X-100 as novel DS resulted in low salt accumulation. • Nitrification and denitrification were well performed in a biocarrier. • The MBBR–OsMBR could remarkably remove phosphorus.

  16. Applicability of a novel osmotic membrane bioreactor using a specific draw solution in wastewater treatment

    International Nuclear Information System (INIS)

    Nguyen, Nguyen Cong; Chen, Shiao-Shing; Nguyen, Hau Thi; Ngo, Huu Hao; Guo, Wenshan; Hao, Chan Wen; Lin, Po-Hsun

    2015-01-01

    This study aims to develop a new osmotic membrane bioreactor by combining a moving bed biofilm reactor (MBBR) with forward osmosis membrane bioreactor (FOMBR) to treat wastewater. Ethylenediaminetetraacetic acid disodium salt coupled with polyethylene glycol tert-octylphenyl ether was used as an innovative draw solution in this membrane hybrid system (MBBR–OsMBR) for minimizing the reverse salt flux and maintaining a healthy environment for the microorganism community. The results showed that the hybrid system achieved a stable water flux of 6.94 L/m 2 h and low salt accumulation in the bioreactor for 68 days of operation. At a filling rate of 40% (by volume of the bioreactor) of the polyethylene balls used as carriers, NH 4 + -N and PO 4 3− -P were almost removed (> 99%) while producing relatively low NO 3 − -N and NO 2 − -N in the effluent (e.g. < 0.56 and 0.96 mg/L, respectively). Furthermore, from analysis based on scanning electron microscopy, Fourier transform infrared spectroscopy, and fluorescence emission–excitation matrix spectrophotometry, there was a thin gel-like fouling layer on the FO membrane, which composed of bacteria as well as biopolymers and protein-like substances. Nonetheless, the formation of these fouling layers of the FO membrane in MBBR–OsMBR was reversible and removed by a physical cleaning technique. - Highlights: • A novel osmotic membrane bioreactor (MBBR–OsMBR) using a novel draw solution (DS) was developed. • The MBBR–OsMBR system successfully reduced membrane fouling. • EDTA sodium coupled with Triton X-100 as novel DS resulted in low salt accumulation. • Nitrification and denitrification were well performed in a biocarrier. • The MBBR–OsMBR could remarkably remove phosphorus

  17. Unlocking High-Salinity Desalination with Cascading Osmotically Mediated Reverse Osmosis: Energy and Operating Pressure Analysis.

    Science.gov (United States)

    Chen, Xi; Yip, Ngai Yin

    2018-02-20

    Current practice of using thermally driven methods to treat hypersaline brines is highly energy-intensive and costly. While conventional reverse osmosis (RO) is the most efficient desalination technique, it is confined to purifying seawater and lower salinity sources. Hydraulic pressure restrictions and elevated energy demand render RO unsuitable for high-salinity streams. Here, we propose an innovative cascading osmotically mediated reverse osmosis (COMRO) technology to overcome the limitations of conventional RO. The innovation utilizes the novel design of bilateral countercurrent reverse osmosis stages to depress the hydraulic pressure needed by lessening the osmotic pressure difference across the membrane, and simultaneously achieve energy savings. Instead of the 137 bar required by conventional RO to desalinate 70 000 ppm TDS hypersaline feed, the highest operating pressure in COMRO is only 68.3 bar (-50%). Furthermore, up to ≈17% energy saving is attained by COMRO (3.16 kWh/m 3 , compared to 3.79 kWh/m 3 with conventional RO). When COMRO is employed to boost the recovery of seawater desalination to 70% from the typical 35-50%, energy savings of up to ≈33% is achieved (2.11 kWh/m 3 , compared to 3.16 kWh/m 3 with conventional RO). Again, COMRO can operate at a moderate hydraulic pressure of 80 bar (25% lower than 113 bar of conventional RO). This study highlights the encouraging potential of energy-efficient COMRO to access unprecedented high recovery rates and treat hypersaline brines at moderate hydraulic pressures, thus extending the capabilities of membrane-based technologies for high-salinity desalination.

  18. Osmotic stress changes the expression and subcellular localization of the Batten disease protein CLN3.

    Directory of Open Access Journals (Sweden)

    Amanda Getty

    Full Text Available Juvenile CLN3 disease (formerly known as juvenile neuronal ceroid lipofuscinosis is a fatal childhood neurodegenerative disorder caused by mutations in the CLN3 gene. CLN3 encodes a putative lysosomal transmembrane protein with unknown function. Previous cell culture studies using CLN3-overexpressing vectors and/or anti-CLN3 antibodies with questionable specificity have also localized CLN3 in cellular structures other than lysosomes. Osmoregulation of the mouse Cln3 mRNA level in kidney cells was recently reported. To clarify the subcellular localization of the CLN3 protein and to investigate if human CLN3 expression and localization is affected by osmotic changes we generated a stably transfected BHK (baby hamster kidney cell line that expresses a moderate level of myc-tagged human CLN3 under the control of the human ubiquitin C promoter. Hyperosmolarity (800 mOsm, achieved by either NaCl/urea or sucrose, dramatically increased the mRNA and protein levels of CLN3 as determined by quantitative real-time PCR and Western blotting. Under isotonic conditions (300 mOsm, human CLN3 was found in a punctate vesicular pattern surrounding the nucleus with prominent Golgi and lysosomal localizations. CLN3-positive early endosomes, late endosomes and cholesterol/sphingolipid-enriched plasma membrane microdomain caveolae were also observed. Increasing the osmolarity of the culture medium to 800 mOsm extended CLN3 distribution away from the perinuclear region and enhanced the lysosomal localization of CLN3. Our results reveal that CLN3 has multiple subcellular localizations within the cell, which, together with its expression, prominently change following osmotic stress. These data suggest that CLN3 is involved in the response and adaptation to cellular stress.

  19. Cyclic di-AMP regulation of osmotic homeostasis is essential in Group B Streptococcus.

    Directory of Open Access Journals (Sweden)

    Laura Devaux

    2018-04-01

    Full Text Available Cyclic nucleotides are universally used as secondary messengers to control cellular physiology. Among these signalling molecules, cyclic di-adenosine monophosphate (c-di-AMP is a specific bacterial second messenger recognized by host cells during infections and its synthesis is assumed to be necessary for bacterial growth by controlling a conserved and essential cellular function. In this study, we sought to identify the main c-di-AMP dependent pathway in Streptococcus agalactiae, the etiological agent of neonatal septicaemia and meningitis. By conditionally inactivating dacA, the only diadenyate cyclase gene, we confirm that c-di-AMP synthesis is essential in standard growth conditions. However, c-di-AMP synthesis becomes rapidly dispensable due to the accumulation of compensatory mutations. We identified several mutations restoring the viability of a ΔdacA mutant, in particular a loss-of-function mutation in the osmoprotectant transporter BusAB. Identification of c-di-AMP binding proteins revealed a conserved set of potassium and osmolyte transporters, as well as the BusR transcriptional factor. We showed that BusR negatively regulates busAB transcription by direct binding to the busAB promoter. Loss of BusR repression leads to a toxic busAB expression in absence of c-di-AMP if osmoprotectants, such as glycine betaine, are present in the medium. In contrast, deletion of the gdpP c-di-AMP phosphodiesterase leads to hyperosmotic susceptibility, a phenotype dependent on a functional BusR. Taken together, we demonstrate that c-di-AMP is essential for osmotic homeostasis and that the predominant mechanism is dependent on the c-di-AMP binding transcriptional factor BusR. The regulation of osmotic homeostasis is likely the conserved and essential function of c-di-AMP, but each species has evolved specific c-di-AMP mechanisms of osmoregulation to adapt to its environment.

  20. Osmotically driven drug delivery through remote-controlled magnetic nanocomposite membranes

    KAUST Repository

    Zaher, Amir; Li, S.; Wolf, K. T.; Pirmoradi, F. N.; Yassine, Omar; Lin, L.; Khashab, Niveen M.; Kosel, Jü rgen

    2015-01-01

    Implantable drug delivery systems can provide long-term reliability, controllability, and biocompatibility, and have been used in many applications, including cancer pain and non-malignant pain treatment. However, many of the available systems are limited to zero-order, inconsistent, or single burst event drug release. To address these limitations, we demonstrate prototypes of a remotely operated drug delivery device that offers controllability of drug release profiles, using osmotic pumping as a pressure source and magnetically triggered membranes as switchable on-demand valves. The membranes are made of either ethyl cellulose, or the proposed stronger cellulose acetate polymer, mixed with thermosensitive poly(N-isopropylacrylamide) hydrogel and superparamagnetic iron oxide particles. The prototype devices' drug diffusion rates are on the order of 0.5–2 μg/h for higher release rate designs, and 12–40 ng/h for lower release rates, with maximum release ratios of 4.2 and 3.2, respectively. The devices exhibit increased drug delivery rates with higher osmotic pumping rates or with magnetically increased membrane porosity. Furthermore, by vapor deposition of a cyanoacrylate layer, a drastic reduction of the drug delivery rate from micrograms down to tens of nanograms per hour is achieved. By utilizing magnetic membranes as the valve-control mechanism, triggered remotely by means of induction heating, the demonstrated drug delivery devices benefit from having the power source external to the system, eliminating the need for a battery. These designs multiply the potential approaches towards increasing the on-demand controllability and customizability of drug delivery profiles in the expanding field of implantable drug delivery systems, with the future possibility of remotely controlling the pressure source.

  1. Azotemia protects the brain from osmotic demyelination on rapid correction of hyponatremia

    Directory of Open Access Journals (Sweden)

    Murtaza F Dhrolia

    2014-01-01

    Full Text Available Osmotic demyelination syndrome (ODS is a dreadful, irreversible and well-recognized clinical entity that classically occurs after rapid correction of hyponatremia. However, it has been observed that when hyponatremia is rapidly corrected in azotemic patients by hemodialysis (HD, patients do not necessarily develop ODS. We studied the effect of inadvertent rapid correction of hyponatremia with HD in patients with azotemia. Fifty-two azotemic patients, who underwent HD at the Sindh Institute of Urology and Transplantation, having pre-HD serum sodium level <125 mEq/L and post-HD serum sodium levels that increased by ≥12 mEq/L from their pre-dialysis level, were studied. Serum sodium was analyzed before and within 24 h after a HD session. HD was performed using bicarbonate solution, with the sodium concentration being 140 meq/L. The duration of the dialysis session was based on the discretion of the treating nephrologist. Patients were examined for any neurological symptoms or signs before and after HD and for up to two weeks. Magnetic resonance imaging was performed in required cases. None of the 52 patients with azotemia, despite inadvertent rapid correction of hyponatremia with HD, developed ODS. This study suggests that patients with azotemia do not develop ODS on rapid correction of hyponatremia by HD, which suggests a possible protective role of azotemia on the brain from osmotic demyelination. However, the mechanism by which azotemia protects the brain from demyelination in humans is largely hypothetical and further studies are needed to answer this question.

  2. Effect of ultrasound and centrifugal force on carambola (Averrhoa carambola L.) slices during osmotic dehydration.

    Science.gov (United States)

    Barman, Nirmali; Badwaik, Laxmikant S

    2017-01-01

    Osmotic dehydration (OD) of carambola slices were carried out using glucose, sucrose, fructose and glycerol as osmotic agents with 70°Bx solute concentration, 50°C of temperature and for time of 180min. Glycerol and sucrose were selected on the basis of their higher water loss, weight reduction and lowers solid gain. Further the optimization of OD of carambola slices (5mm thick) were carried out under different process conditions of temperature (40-60°C), concentration of sucrose and glycerol (50-70°Bx), time (180min) and fruit to solution ratio (1:10) against various responses viz. water loss, solid gain, texture, rehydration ratio and sensory score according to a composite design. The optimized value for temperature, concentration of sucrose and glycerol has been found to be 50°C, 66°Bx and 66°Bx respectively. Under optimized conditions the effect of ultrasound for 10, 20, 30min and centrifugal force (2800rpm) for 15, 30, 45 and 60min on OD of carambola slices were checked. The controlled samples showed 68.14% water loss and 13.05% solid gain in carambola slices. While, the sample having 30min ultrasonic treatment showed 73.76% water loss and 9.79% solid gain; and the sample treated with centrifugal force for 60min showed 75.65% water loss and 6.76% solid gain. The results showed that with increasing in treatment time the water loss, rehydration ratio were increased and solid gain, texture were decreased. Copyright © 2016 Elsevier B.V. All rights reserved.

  3. Removal of trace organic chemicals and performance of a novel hybrid ultrafiltration-osmotic membrane bioreactor.

    Science.gov (United States)

    Holloway, Ryan W; Regnery, Julia; Nghiem, Long D; Cath, Tzahi Y

    2014-09-16

    A hybrid ultrafiltration-osmotic membrane bioreactor (UFO-MBR) was investigated for over 35 days for nutrient and trace organic chemical (TOrC) removal from municipal wastewater. The UFO-MBR system uses both ultrafiltration (UF) and forward osmosis (FO) membranes in parallel to simultaneously extract clean water from an activated sludge reactor for nonpotable (or environmental discharge) and potable reuse, respectively. In the FO stream, water is drawn by osmosis from activated sludge through an FO membrane into a draw solution (DS), which becomes diluted during the process. A reverse osmosis (RO) system is then used to reconcentrate the diluted DS and produce clean water suitable for direct potable reuse. The UF membrane extracts water, dissolved salts, and some nutrients from the system to prevent their accumulation in the activated sludge of the osmotic MBR. The UF permeate can be used for nonpotable reuse purposes (e.g., irrigation and toilet flushing). Results from UFO-MBR investigation illustrated that the chemical oxygen demand, total nitrogen, and total phosphorus removals were greater than 99%, 82%, and 99%, respectively. Twenty TOrCs were detected in the municipal wastewater that was used as feed to the UFO-MBR system. Among these 20 TOrCs, 15 were removed by the hybrid UFO-MBR system to below the detection limit. High FO membrane rejection was observed for all ionic and nonionic hydrophilic TOrCs and lower rejection was observed for nonionic hydrophobic TOrCs. With the exceptions of bisphenol A and DEET, all TOrCs that were detected in the DS were well rejected by the RO membrane. Overall, the UFO-MBR can operate sustainably and has the potential to be utilized for direct potable reuse applications.

  4. Physiological adaptations to osmotic stress and characterization of a polyethylene glycol-responsive gene in Braya humilis

    Directory of Open Access Journals (Sweden)

    Wang Lirong

    2016-03-01

    Full Text Available Braya humilis (Brassicaceae is a widely distributed plant in arid and semi-arid regions of northern Asia. This plant is well adapted to extremely arid conditions and is a promising candidate species to discover novel drought tolerance strategies. However, not much information about the mechanism(s mediating drought resistance in this species is currently available. Therefore, the present study aimed to characterize the physiological traits and expression patterns of a polyethylene glycol (PEG-responsive gene in B. humilis responding to different levels of osmotic stress induced by PEG-6000. Several important physiological parameters were examined, including the levels of relative water content, soluble protein, malondialdehyde, and antioxidant enzyme activity. A tolerance threshold between 20 and 30% PEG-6000 was identified for B. humilis. The water status and oxidative damage below this threshold were maintained at a relatively constant level during the 12 h of treatment. However, once the threshold was exceeded, the water status and oxidative damage were obviously affected after treatment for 4 h. The soluble protein results suggest that B. humilis maintains a vigorous resistance to osmotic stress and that it may play a greater role in osmotic regulation at late stages of stress. Moreover, superoxide dismutase and catalase may be important at preventing oxidative damage in plants at early stages of stress, while peroxidase may be more involved in some biological processes that resist osmotic stress at the late stage, especially in severely damaged plants. Furthermore, a PEG-responsive gene, BhCIPK12, was identified by differential display reverse transcription-polymerase chain reaction (PCR, cloned, and characterized by quantitative real-time PCR. We hypothesized that this gene may play an important role in mediating osmotic stress or drought resistance in plants. Altogether, these results provide valuable insights into the mechanism

  5. Title: Potassium application regulates nitrogen metabolism and osmotic adjustment in cotton (Gossypium hirsutum L.) functional leaf under drought stress.

    Science.gov (United States)

    Zahoor, Rizwan; Zhao, Wenqing; Abid, Muhammad; Dong, Haoran; Zhou, Zhiguo

    2017-08-01

    To evaluate the role of potassium (K) in maintaining nitrogen metabolism and osmotic adjustment development of cotton functional leaves to sustain growth under soil drought and rewatering conditions, the plants of two cotton cultivars Siza 3 (low-K sensitive) and Simian 3 (low-K tolerant), were grown under three different K rates (K0, K1, and K2; 0, 150, and 300kgK 2 Oha -1 , respectively) and exposed to drought stress with 40±5% soil relative water content (SRWC). The drought stress was applied at flowering stage by withholding water for eight days followed by rewatering to a well-watered level (75±5% SRWC). The results showed that drought-stressed plants of both cultivars showed a decrease in leaf relative water content (RWC) and osmotic potential in the functional leaves and developed osmotic adjustment with an increase in the contents of free amino acids, soluble sugars, inorganic K, and nitrate as compared to well-watered plants. In drought-stressed plants, nitrogen-metabolizing enzyme activities of nitrogen reductase (NR), glutamine synthetase (GS), and glutamate synthase (GOGAT) were diminished significantly (P≤0.05) along with decreased chlorophyll content and soluble proteins. However, drought-stressed plants under K application not only exhibited higher osmotic adjustment with greater accumulation of osmolytes but also regulated nitrogen metabolism by maintaining higher enzyme activities, soluble proteins, and chlorophyll content in functional leaves as compared to the plants without K application. Siza 3 showed better stability in enzyme activities and resulted in 89% higher seed cotton yield under K2 as compared to K0 in drought-stressed plants, whereas this increase was 53% in the case of Simian 3. The results of the study suggested that K application enhances cotton plants' potential for sustaining high nitrogen-metabolizing enzyme activities and related components to supplement osmotic adjustment under soil drought conditions. Copyright © 2017

  6. Induction of labor in patients with an unfavorable cervix after a cesarean using an osmotic dilator versus vaginal prostaglandin.

    Science.gov (United States)

    Maier, Josefine T; Metz, Melanie; Watermann, Nina; Li, Linna; Schalinski, Elisabeth; Gauger, Ulrich; Rath, Werner; Hellmeyer, Lars

    2018-04-25

    Trial of labor after cesarean (TOLAC) is a viable option for safe delivery. In some cases cervical ripening and subsequent labor induction is necessary. However, the commonly used prostaglandins are not licensed in this subgroup of patients and are associated with an increased risk of uterine rupture. This cohort study compares maternal and neonatal outcomes of TOLAC in women (n=82) requiring cervical ripening agents (osmotic dilator vs. prostaglandins). The initial Bishop scores (BSs) were 2 (0-5) and 3 (0-5) (osmotic dilator and prostaglandin group, respectively). In this retrospective analysis, Fisher's exact test, the Kruskal-Wallis rank sum test and Pearson's chi-squared test were utilized. Vaginal birth rate (including operative delivery) was 55% (18/33) in the osmotic dilator group vs. 51% (25/49) in the dinoprostone group (P 0.886). Between 97% and 92% (32/33 and 45/49) (100%, 100%) of neonates had an Apgar score of >8 after 1 min (5, 10 min, respectively). The time between administration of the agent and onset of labor was 36 and 17.1 h (mean, Dilapan-S® group, dinoprostone group, respectively). Time from onset of labor to delivery was similar in both groups with 4.4 and 4.9 h (mean, Dilapan-S® group, dinoprostone group, respectively). Patients receiving cervical ripening with Dilapan-S® required oxytocin in 97% (32/33) of cases. Some patients presented with spontaneous onset of labor, mostly in the dinoprostone group (24/49, 49%). Amniotomy was performed in 64% and 49% (21/33 and 24/49) of cases (Dilapan-S® group and dinoprostone group, respectively). This pilot study examines the application of an osmotic dilator for cervical ripening to promote vaginal delivery in women who previously delivered via cesarean section. In our experience, the osmotic dilator gives obstetricians a chance to perform induction of labor in these women.

  7. Erythropoietin treatment does not compromise cardiovascular function in chronic renal failure

    DEFF Research Database (Denmark)

    Haedersdal, C; Mehlsen, J; Stenver, Doris Irene

    1994-01-01

    The anemia in patients with chronic renal failure can be corrected through treatment with recombinant human erythropoietin treatment. This correction is associated with changes in the rheologic variables, which could explain the changes in hemodynamics found by many investigators. The authors have...... followed up 11 patients with chronic renal failure on hemodialysis before and during six months of therapy with erythropoietin. The measurements were made before treatment, after four months of therapy, and after six months of therapy. The measurements included hematocrit, osmotic resistance of the red...

  8. Renal tolerance for iopromide (ultravist) in patients with chronic renal failure. Preliminary report

    International Nuclear Information System (INIS)

    Golebiowski, M.; Pruszynski, B.

    1993-01-01

    The authors present the renal tolerance for nonionic low-osmotic contrast agent iopromide (ultravist) on the ground of literature and of angiographic examinations in 10 patients with chronic renal failure. One patient only had significant temporary deterioration of renal function. The presented results showed that analyzed agent is less nephrotoxic than high osmolality contrast agents. The use of iopromide is strongly recommended in patients with chronic renal failure. The risk of depression of renal function after administration of contrast material is minimized. (author)

  9. Osmotic properties of binary mixtures 1-butyl-1-methylpyrrolidinium dicyanamide and 1-methyl-3-octylimidazolium chloride with water: Effect of aggregation of ions

    International Nuclear Information System (INIS)

    Ahmed, Sayeed Ashique; Chatterjee, Aninda; Maity, Banibrata; Seth, Debabrata

    2015-01-01

    Graphical abstract: Osmotic properties of binary mixture of two ionic liquids (ILs): 1-butyl-1-methyl pyrrolidinium dicyanamide and 1-methyl-3-octylimidazolium chloride with water was reported by using vapour pressure osmometry (VPO) method. - Highlights: • Osmotic properties of binary mixture of ionic liquids (ILs) with water by using vapour pressure osmometry (VPO) method. • The experimental osmotic coefficients were well correlated by Archer extension of Pitzer model. • From the experimental osmotic coefficient data the critical micellar concentration (cmc) of the ILs in water was estimated. • Mean molar activity coefficient and the excess Gibbs free energy was determine for the (ILs + water) binary mixture. - Abstract: In this work, the osmotic properties of the binary mixture of ionic liquids (ILs) and water were studied by using vapour pressure osmometry (VPO) method. We have used two ILs: 1-butyl-1-methyl pyrrolidinium dicyanamide and 1-methyl-3-octylimidazolium chloride. The aqueous solution of NaCl was used as the reference solution to precisely measure the osmotic coefficients of the above systems. We have calculated the activity of water in the above systems and the change of vapour pressure of water due to the addition of ILs in water. The experimental osmotic coefficients were correlated by the Archer extension of Pitzer model. The parameters of this Archer extension of Pitzer model were found from this data fitting. From the experimental osmotic coefficient value we have estimated the critical micellar concentration (cmc) of ILs in water. The experimental values of osmotic coefficient in the above systems were compared with the literature and the reason of variation was explained, in terms of the aggregation of ILs in water

  10. Environmental assessment of an osmotic power plant at Sunndalsoera; Miljoeutredning for et saltkraftverk i Sunndalsoera

    Energy Technology Data Exchange (ETDEWEB)

    Staalstroem, A.; Farmen, E.; Gitmark, J.

    2012-07-01

    In this report the environmental impact by running an osmotic power plant at Sunndalsoera is assessed. Osmotic power means that the osmotic pressure between fresh and saltwater is utilized. At Sunndalsoera it is planned that 4 m{sub 3}/s of freshwater will be pumped up from 30 m depth out in the fjord where the salinity is sufficient. From the power plant Aura 2 m{sub 3}/s of freshwater will be lead into the osmotic power plant, and the two water molecules and not the salt molecules through. To balance the osmotic pressure, fresh water is sucked through the membrane, and the pressure at the salt water side increase. This pressure is used to rotate a turbine. The mixture of 6 m{sub 3}/s will have typical salinity of 20 and a temperature of 5-10 celsius degrees depending on the time of the season. This volume will be discharged in the sea through 3 pipes with diameter 1,2 m, and the consequences of three different discharge locations are assessed in this report; in the lower parts of the river Litedalselva, in a nearby harbour for small boats or just outside the river mouth/harbour inlet. At the membranes fouling occurs that needs to be removed and certain types of chemicals might be necessary. The relevant chemicals are Trisodiumcitrate, Ufacid and Divos 80-5. The concentrations of chemicals mentioned in this report are based on the use of a dirty fresh water source at Sunndalsoera is much cleaner, and the aim is to not use chemicals at all. It is found that a discharge in the surface just outside the inlet to the harbour will have little affect on the environment, if about 1/200 of the concentration of trisodiumcitrate in the worst case scenario is used. A discharge in the harbour will have little effect concerning minerals, if 1/230 of the concentration of trisodiumcitrate in the worst case scenario is used, but it is a possibility of increased eutrophication effects in the occasions when the nutrient concentrations is high at 30 m. On the other hand a discharge

  11. Dehydration and osmotic adjustment in apple stem tissue during winter as it relates to the frost resistance of buds.

    Science.gov (United States)

    Pramsohler, Manuel; Neuner, Gilbert

    2013-08-01

    In deciduous trees, measurement of stem water potential can be difficult during the leafless period in winter. By using thermocouple psychrometry, osmotic water potentials (Ψo; actual Ψo: Ψo(act); Ψo at full saturation: Ψo(sat)) of expressed sap of bark and bud tissue were measured in order to test if the severity of winter desiccation in apple stems could be sufficiently assessed with Ψo. Water potentials were related to frost resistance and freezing behaviour of buds. The determination of Ψo reliably allowed winter desiccation and osmotic adjustments in apple stem tissue to be assessed. In winter in bark tissue, a pronounced decrease in Ψo(act) and Ψo(sat) was found. Decreased Ψo(sat) indicates active osmotic adjustment in the bark as observed earlier in the leaves of evergreen woody plants. In terminal bud meristems, no significant osmotic adjustments occurred and dehydration during winter was much less. Osmotic water potentials, Ψo(act) and Ψo(sat), of bud tissue were always less negative than in the bark. To prevent water movement and dehydration of the bud tissue via this osmotic gradient, it must be compensated for either by a sufficiently high turgor pressure (Ψp) in bark tissue or by the isolation of the bud tissue from the bark during midwinter. During freezing of apple buds, freeze dehydration and extra-organ freezing could be demonstrated by significantly reduced Ψo(act) values of bud meristems that had been excised in the frozen state. Infrared video thermography was used to monitor freezing patterns in apple twigs. During extracellular freezing of intact and longitudinally dissected stems, infrared differential thermal analysis (IDTA) images showed that the bud meristem remains ice free. Even if cooled to temperatures below the frost-killing temperature, no freezing event could be detected in bud meristems during winter. In contrast, after bud break, terminal buds showed a second freezing at the frost-killing temperature that indicates

  12. An unpopular geriatric syndrome: Management of chronic constipation in some European countries. Denmark, Estonia, Italy and Luxembourg

    DEFF Research Database (Denmark)

    Curiale, V.; Kolk, H.; Pedersen, Hanne K.

    2013-01-01

    , and care usually relies on patients by the use of over the counter laxatives or herbal remedies, with little or no physician control except for the most severe cases. This paper explores the epidemiology, screening, diagnosis and management of chronic constipation in old age in four very different European....... The choice of laxatives lies more on patients, with osmotic laxatives (lactulose and macrogol) being the most widely used group. The use of herbal remedies is highly variable and in many cases concealed....

  13. Chronic pancreatitis.

    Science.gov (United States)

    Kleeff, Jorg; Whitcomb, David C; Shimosegawa, Tooru; Esposito, Irene; Lerch, Markus M; Gress, Thomas; Mayerle, Julia; Drewes, Asbjørn Mohr; Rebours, Vinciane; Akisik, Fatih; Muñoz, J Enrique Domínguez; Neoptolemos, John P

    2017-09-07

    Chronic pancreatitis is defined as a pathological fibro-inflammatory syndrome of the pancreas in individuals with genetic, environmental and/or other risk factors who develop persistent pathological responses to parenchymal injury or stress. Potential causes can include toxic factors (such as alcohol or smoking), metabolic abnormalities, idiopathic mechanisms, genetics, autoimmune responses and obstructive mechanisms. The pathophysiology of chronic pancreatitis is fairly complex and includes acinar cell injury, acinar stress responses, duct dysfunction, persistent or altered inflammation, and/or neuro-immune crosstalk, but these mechanisms are not completely understood. Chronic pancreatitis is characterized by ongoing inflammation of the pancreas that results in progressive loss of the endocrine and exocrine compartment owing to atrophy and/or replacement with fibrotic tissue. Functional consequences include recurrent or constant abdominal pain, diabetes mellitus (endocrine insufficiency) and maldigestion (exocrine insufficiency). Diagnosing early-stage chronic pancreatitis is challenging as changes are subtle, ill-defined and overlap those of other disorders. Later stages are characterized by variable fibrosis and calcification of the pancreatic parenchyma; dilatation, distortion and stricturing of the pancreatic ducts; pseudocysts; intrapancreatic bile duct stricturing; narrowing of the duodenum; and superior mesenteric, portal and/or splenic vein thrombosis. Treatment options comprise medical, radiological, endoscopic and surgical interventions, but evidence-based approaches are limited. This Primer highlights the major progress that has been made in understanding the pathophysiology, presentation, prevalence and management of chronic pancreatitis and its complications.

  14. Global Transcriptional Responses to Osmotic, Oxidative, and Imipenem Stress Conditions in Pseudomonas putida.

    Science.gov (United States)

    Bojanovič, Klara; D'Arrigo, Isotta; Long, Katherine S

    2017-04-01

    Bacteria cope with and adapt to stress by modulating gene expression in response to specific environmental cues. In this study, the transcriptional response of Pseudomonas putida KT2440 to osmotic, oxidative, and imipenem stress conditions at two time points was investigated via identification of differentially expressed mRNAs and small RNAs (sRNAs). A total of 440 sRNA transcripts were detected, of which 10% correspond to previously annotated sRNAs, 40% to novel intergenic transcripts, and 50% to novel transcripts antisense to annotated genes. Each stress elicits a unique response as far as the extent and dynamics of the transcriptional changes. Nearly 200 protein-encoding genes exhibited significant changes in all stress types, implicating their participation in a general stress response. Almost half of the sRNA transcripts were differentially expressed under at least one condition, suggesting possible functional roles in the cellular response to stress conditions. The data show a larger fraction of differentially expressed sRNAs than of mRNAs with >5-fold expression changes. The work provides detailed insights into the mechanisms through which P. putida responds to different stress conditions and increases understanding of bacterial adaptation in natural and industrial settings. IMPORTANCE This study maps the complete transcriptional response of P. putida KT2440 to osmotic, oxidative, and imipenem stress conditions at short and long exposure times. Over 400 sRNA transcripts, consisting of both intergenic and antisense transcripts, were detected, increasing the number of identified sRNA transcripts in the strain by a factor of 10. Unique responses to each type of stress are documented, including both the extent and dynamics of the gene expression changes. The work adds rich detail to previous knowledge of stress response mechanisms due to the depth of the RNA sequencing data. Almost half of the sRNAs exhibit significant expression changes under at least one

  15. Osmotic dehydration and convective drying of coconut slices: Experimental determination and description using one-dimensional diffusion model

    Directory of Open Access Journals (Sweden)

    Wilton Pereira da Silva

    2014-06-01

    Full Text Available Mass migrations in coconut slices during osmotic dehydration and drying are described using a diffusion model with boundary condition of the third kind. The osmotic dehydration experiment was performed at 35°Brix (water and sucrose and 40 °C. The convective drying experiments were performed at 50, 60 and 70 °C. The one-dimensional solution of the diffusion equation for an infinite slab was coupled with an optimizer to determine the effective mass diffusivities D and convective mass transfer coefficients h of the five processes studied. The analyses of the obtained results indicate that there is a good agreement between each experimental dataset and the corresponding simulation using D and h determined by optimization.

  16. Osmotically and thermally isolated forward osmosis-membrane distillation (fo-md) integrated module for water treatment applications

    KAUST Repository

    Ghaffour, Noreddine

    2016-09-01

    An integrated forward osmosis-membrane distillation (FO-MD) module and systems and methods incorporating the module is disclosed providing higher efficiencies and using less energy. The FO-MD module is osmotically and thermally isolated. The isolation can prevent mixing of FO draw solution/FO permeate and MD feed, and minimize dilution of FO draw solution and cooling of MD feed. The module provides MD feed solution and FO draw solution streams that flow in the same module but are separated by an isolation barrier. The osmotically and thermally isolated FO-MD integrated module, systems and methods offer higher driving forces of both FO and MD processes, higher recovery, and wider application than previously proposed hybrid FO- MD systems.

  17. Osmolyte depletion viewed in terms of the dividing membrane and its work of expansion against osmotic pressure.

    Science.gov (United States)

    Shimizu, Seishi; Matubayasi, Nobuyuki

    2017-12-01

    How osmolytes enhance the folding, binding, and self-assembly of biological macromolecules at a microscopic scale has long been a matter of debate. Ambiguities persist on the key interpretive concepts, such as the "effective membrane" (which marks the boundary of the volume from which osmolytes are excluded) and the "free energy of exclusion" of osmolytes from biomolecular surfaces. In this paper, we formulate these elusive concepts based upon chemical thermodynamics and rigorous statistical thermodynamics (the Kirkwood-Buff theory). Positioning of the membrane at the osmotic dividing surface is crucial in order not to affect the thermodynamics of solvation. The notion of the free energy (work) of excluding osmolytes is refined to the expansion work against the osmotic pressure, which indeed describes the change of solvation free energy at dilute osmolyte concentrations. Copyright © 2017 Elsevier B.V. All rights reserved.

  18. Downregulation of the taurine transporter TauT during hypo-osmotic stress in NIH3T3 mouse fibroblasts

    DEFF Research Database (Denmark)

    Hansen, Daniel Bloch; Friis, Martin Barfred; Hoffmann, Else Kay

    2012-01-01

    The present work was initiated to investigate regulation of the taurine transporter TauT by reactive oxygen species (ROS) and the tonicity-responsive enhancer binding protein (TonEBP) in NIH3T3 mouse fibroblasts during acute and long-term (4 h) exposure to low-sodium/hypo-osmotic stress. Taurine...... are significantly increased following hyperosmotic exposure. Swelling-induced ROS production in NIH3T3 fibroblasts is generated by NOX4 and by increasing total ROS, by either exogenous application of H(2)O(2) or overexpressing NOX4, we demonstrate that TonEBP activity and taurine influx are regulated negatively...... by ROS under hypo-osmotic, low-sodium conditions, whereas the TauT mRNA level is unaffected. Acute exposure to ROS reduces taurine uptake as a result of modulated TauT transport kinetics. Thus, swelling-induced ROS production could account for the reduced taurine uptake under low...

  19. Osmotic coefficients of aqueous solutions of four ionic liquids at T = (313.15 and 333.15) K

    International Nuclear Information System (INIS)

    Gonzalez, Begona; Calvar, Noelia; Dominguez, Angeles; Macedo, Eugenia A.

    2008-01-01

    Measurements of osmotic coefficients of BmimCl (1-butyl-3-methylimidazolium chloride), HmimCl (1-hexyl-3-methylimidazolium chloride), MmimMeSO 4 (1,3-dimethylimidazolium methylsulfate), and BmimMeSO 4 (1-butyl-3-methylimidazolium methylsulfate) with water at T = (313.15 and 333.15) K are reported in this work. Vapour pressure and activity data of all the studied binary systems are obtained from experimental data. The osmotic coefficients data are correlated using the extended Pitzer model of Archer and the modified NRTL (MNRTL) model and standard deviations obtained with both models are given too. The parameters obtained with the extended Pitzer model of Archer are used to calculate the mean molal activity coefficients

  20. Osmotic regulation of the mitochondrial permeability transition pore investigated by light scattering, fluorescence and electron microscopy techniques.

    Science.gov (United States)

    Baev, Artyom Y; Elustondo, Pia A; Negoda, Alexander; Pavlov, Evgeny V

    2017-07-08

    Mitochondrial permeability transition (PT) is a phenomenon of an increase of the inner membrane permeability in response to an excessive matrix calcium accumulation. PTP is caused by the opening of the large weakly selective channel. Molecular composition and regulation of permeability transition pore (PTP) are not well understood. Here we used isolated mitochondria to investigate dependence of PTP activation on the osmotic pressure. We found that in low osmotic strength solution calcium-induced PTP is significantly inhibited. We propose that this effect is linked to the changes in the curvature of the mitochondrial inner membrane. This interpretation is consistent with the idea about the importance of ATP synthase dimerization in modulation of the PTP activity. Copyright © 2017. Published by Elsevier Inc.

  1. The osmotic significance of the heteroside floridoside in the mangrove alga Catenella nipae (Rhodophyta: Gigartinales) in Eastern Australia

    Science.gov (United States)

    Karsten, Ulf; Barrow, Kevin D.; Mostaert, Anika s.; King, Robert J.

    The effect of salinity on the intracellular floridoside concentration in the mangrove alga Catenella nipae (Rhodophyta: Gigartinales) was investigated using 13C nuclear magnetic resonance spectroscopy ( 13C-NMR), and gasliquid and high pressure liquid chromatography (GLC, HPLC). The floridoside content increased linearly with increasing salinity, and hence is strongly involved in osmotic acclimation in this species. In addition, during 13C-NMR analysis isethionic acid was identified as a new metabolite in C. nipae. The concentration of this compound also varied as a function of salinity. The steady-state contents of floridoside were also recorded in various geographically isolated field populations of C. nipae from mangroves along New South Wales coastline of Australia. All isolates contained very high floridoside levels. From these data, together with the physiological capability to accumulate floridoside under hypersaline conditions for osmotic acclimation, it is interpreted that floridoside is essential for survival in the extreme mangrove habitat.

  2. Investigating the role of polyols in Cladosporium fulvum during growth under hyper-osmotic stress and in planta.

    Science.gov (United States)

    Clark, Anthony J; Blissett, Kerry J; Oliver, Richard P

    2003-02-01

    The role of the large amounts of polyols accumulated by the fungal tomato pathogen, Cladosporium fulvum (syn. Fulvia fulva, Cooke) both in planta and in axenic cultures has been examined. Arabinitol and glycerol accumulated in response to hyper-osmotic stress in vitro. Mannitol levels were lower in osmo-stressed mycelium. (13)C NMR spectroscopy indicated that carbon flow from glucose to mannitol was redirected to arabinitol and glycerol in hyper-osmotic conditions. Infected tomato ( Lycopersicon esculentum Mill.) plants contained all three polyols whereas glycerol was the only polyol present in uninfected plants, suggesting that the mannitol and arabinitol were of fungal origin. Substantially higher levels of arabinitol and glycerol were present in infected plants that were subjected to a restricted watering regime compared to fully watered plants. The results suggest that a primary role of fungal arabinitol and glycerol, but not mannitol, is osmoregulation and that water acquisition is an important aspect of pathogenicity.

  3. Osmotically and thermally isolated forward osmosis-membrane distillation (fo-md) integrated module for water treatment applications

    KAUST Repository

    Ghaffour, NorEddine; Francis, Lijo; Li, Zhenyu; Valladares, Rodrigo; Alsaadi, Ahmad S.; Ghdaib, Muhannad Abu; Amy, Gary L.

    2016-01-01

    An integrated forward osmosis-membrane distillation (FO-MD) module and systems and methods incorporating the module is disclosed providing higher efficiencies and using less energy. The FO-MD module is osmotically and thermally isolated. The isolation can prevent mixing of FO draw solution/FO permeate and MD feed, and minimize dilution of FO draw solution and cooling of MD feed. The module provides MD feed solution and FO draw solution streams that flow in the same module but are separated by an isolation barrier. The osmotically and thermally isolated FO-MD integrated module, systems and methods offer higher driving forces of both FO and MD processes, higher recovery, and wider application than previously proposed hybrid FO- MD systems.

  4. Topotactic intercalation of a bulky organic anion (thiacalix[4]arene) into LDH through an osmotic swelling/restoration reaction in formamide.

    Science.gov (United States)

    Huang, Gailing; Ma, Shulan; Zhao, Xinhua; Yang, Xiaojing; Ooi, Kenta

    2009-01-21

    Utilizing the osmotic swelling of LDH in formamide, for the first time, the bulky thiacalix[4]arene anion is introduced, leading to the recovery of LDH layers, and the hexagonal prism morphology of the precursor is well retained.

  5. Comparison of Seed Germination and Recovery Responses of a Salt Marsh Halophyte Halopeplis Perfoliata to Osmotic and Ionic Treatments

    International Nuclear Information System (INIS)

    Rasool, S. G.; Hameed, A.; Ahmed, M. Z.; Khan, M. A.

    2016-01-01

    Salinity affects seed germination of halophytes by inducing ionic toxicity, osmotic constraint or both. Information about the effects of salinity on seed germination of a large number of halophytes exists, but generally little is known about the basis of salinity-induced germination inhibition. In order to partition salinity effects, we studied seed germination and recovery responses of a coastal salt marsh halophyte halopeplis perfoliata to different isotonic treatments (Psi/sub S/: -0.5, -1.0, -1.5, -2.0 and -2.5, MPa) of various salts and polythylene glycol (PEG) under two light regimes (12-h light photo period and 24-h complete darkness). Highest seed germination was observed in distilled water under 12-h light photo period and reduction in osmotic potential of the solution decreased seed germination. However, some seeds of H. perfoliata could germinate in as low as -2.5 MPa (600 mM NaCl), which is equivalent to seawater salinity. Sea-salt treatment was more inhibitory than isotonic NaCl at the lowest osmotic potential (Psi/sub S/ -2.5 MPa). Generally, chloride salts with lowest Psi/sub S/ inhibited germination more than the isotonic sulfate salts. Comparable germination responses of the seeds in NaCl and isotonic PEG treatments as well as high recovery of germination in un-germinated seeds after alleviation of NaCl salinity indicated prevalence of osmotic constraint. These results thus indicate that the seeds of H. perfoliata could tolerate high levels of a wide variety of salts found in soil. (author)

  6. Resolution of methylphenidate osmotic release oral system-induced hair loss in two siblings after dose escalation.

    Science.gov (United States)

    Ardic, Ulku Akyol; Ercan, Eyup Sabri

    2017-11-01

    This report describes the cases of two siblings who experienced hair loss after treatment with methylphenidate (MPH) osmotic release oral system (OROS). Hair loss was resolved after discontinuation of the drug, but the children re-initiated treatment, after which hair loss again occurred, but they continued the treatment. After dose escalation, the hair loss resolved. This is the first report to describe resolution of OROS-MPH-induced hair loss after dose escalation. © 2017 Japan Pediatric Society.

  7. Osmotic stress represses strigolactone biosynthesis in Lotus japonicus roots: exploring the interaction between strigolactones and ABA under abiotic stress

    KAUST Repository

    Liu, Junwei

    2015-02-26

    Main conclusion: Strigolactone changes and cross talk with ABA unveil a picture of root-specific hormonal dynamics under stress.Abstract: Strigolactones (SLs) are carotenoid-derived hormones influencing diverse aspects of development and communication with (micro)organisms, and proposed as mediators of environmental stimuli in resource allocation processes; to contribute to adaptive adjustments, therefore, their pathway must be responsive to environmental cues. To investigate the relationship between SLs and abiotic stress in Lotus japonicus, we compared wild-type and SL-depleted plants, and studied SL metabolism in roots stressed osmotically and/or phosphate starved. SL-depleted plants showed increased stomatal conductance, both under normal and stress conditions, and impaired resistance to drought associated with slower stomatal closure in response to abscisic acid (ABA). This confirms that SLs contribute to drought resistance in species other than Arabidopsis. However, we also observed that osmotic stress rapidly and strongly decreased SL concentration in tissues and exudates of wild-type Lotus roots, by acting on the transcription of biosynthetic and transporter-encoding genes and independently of phosphate abundance. Pre-treatment with exogenous SLs inhibited the osmotic stress-induced ABA increase in wild-type roots and down-regulated the transcription of the ABA biosynthetic gene LjNCED2. We propose that a transcriptionally regulated, early SL decrease under osmotic stress is needed (but not sufficient) to allow the physiological increase of ABA in roots. This work shows that SL metabolism and effects on ABA are seemingly opposite in roots and shoots under stress.

  8. Osmotic stress represses strigolactone biosynthesis in Lotus japonicus roots: exploring the interaction between strigolactones and ABA under abiotic stress

    KAUST Repository

    Liu, Junwei; He, Hanzi; Vitali, Marco; Visentin, Ivan; Charnikhova, Tatsiana V.; Haider, Imran; Schubert, Andrea; Ruyter-Spira, Carolien P.; Bouwmeester, Harro J J; Lovisolo, Claudio; Cardinale, Francesca

    2015-01-01

    Main conclusion: Strigolactone changes and cross talk with ABA unveil a picture of root-specific hormonal dynamics under stress.Abstract: Strigolactones (SLs) are carotenoid-derived hormones influencing diverse aspects of development and communication with (micro)organisms, and proposed as mediators of environmental stimuli in resource allocation processes; to contribute to adaptive adjustments, therefore, their pathway must be responsive to environmental cues. To investigate the relationship between SLs and abiotic stress in Lotus japonicus, we compared wild-type and SL-depleted plants, and studied SL metabolism in roots stressed osmotically and/or phosphate starved. SL-depleted plants showed increased stomatal conductance, both under normal and stress conditions, and impaired resistance to drought associated with slower stomatal closure in response to abscisic acid (ABA). This confirms that SLs contribute to drought resistance in species other than Arabidopsis. However, we also observed that osmotic stress rapidly and strongly decreased SL concentration in tissues and exudates of wild-type Lotus roots, by acting on the transcription of biosynthetic and transporter-encoding genes and independently of phosphate abundance. Pre-treatment with exogenous SLs inhibited the osmotic stress-induced ABA increase in wild-type roots and down-regulated the transcription of the ABA biosynthetic gene LjNCED2. We propose that a transcriptionally regulated, early SL decrease under osmotic stress is needed (but not sufficient) to allow the physiological increase of ABA in roots. This work shows that SL metabolism and effects on ABA are seemingly opposite in roots and shoots under stress.

  9. Development and Evaluation of High Bioavailable Sustained-Release Nimodipine Tablets Prepared with Monolithic Osmotic Pump Technology.

    Science.gov (United States)

    Kong, Hua; Yu, Fanglin; Liu, Yan; Yang, Yang; Li, Mingyuan; Cheng, Xiaohui; Hu, Xiaoqin; Tang, Xuemei; Li, Zhiping; Mei, Xingguo

    2018-01-01

    Frequent administration caused by short half-life and low bioavailability due to poor solubility and low dissolution rate limit the further application of poorly water-soluble nimodipine, although several new indications have been developed. To overcome these shortcomings, sophisticated technologies had to be used since the dose of nimodipine was not too low and the addition of solubilizers could not resolve the problem of poor release. The purpose of this study was to obtain sustained and complete release of nimodipine with a simple and easily industrialized technology. The expandable monolithic osmotic pump tablets containing nimodipine combined with poloxamer 188 and carboxymethylcellulose sodium were prepared. The factors affecting drug release including the amount of solubilizing agent, expanding agent, retarding agent in core tablet and porogenic agent in semipermeable film were optimized. The release behavior was investigated both in vitro and in beagle dogs. It was proved that the anticipant release of nimodipine could be realized in vitro. The sustained and complete release of nimodipine was also realized in beagles because the mean residence time of nimodipine from the osmotic pump system was longer and Cmax was lower than those from the sustained-release tablets in market while there was no difference in AUC(0-t) of the monolithic osmotic pump tablets and the sustained release tablets in market. It was reasonable to believe that the sustained and complete release of poorly watersoluble nimodipine could be realized by using simple expandable monolithic osmotic pump technology combined with surfactant. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  10. Silicon alleviates salt and drought stress of Glycyrrhiza uralensis seedling by altering antioxidant metabolism and osmotic adjustment.

    Science.gov (United States)

    Zhang, Wenjin; Xie, Zhicai; Wang, Lianhong; Li, Ming; Lang, Duoyong; Zhang, Xinhui

    2017-05-01

    This study was conducted to determine effect and mechanism of exogenous silicon (Si) on salt and drought tolerance of Glycyrrhiza uralensis seedling by focusing on the pathways of antioxidant defense and osmotic adjustment. Seedling growth, lipid peroxidation, antioxidant metabolism, osmolytes concentration and Si content of G. uralensis seedlings were analyzed under control, salt and drought stress [100 mM NaCl with 0, 10 and 20% of PEG-6000 (Polyethylene glycol-6000)] with or without 1 mM Si. Si addition markedly affected the G. uralensis growth in a combined dose of NaCl and PEG dependent manner. In brief, Si addition improved germination rate, germination index, seedling vitality index and biomass under control and NaCl; Si also increased radicle length under control, NaCl and NaCl-10% PEG, decreased radicle length, seedling vitality index and germination parameters under NaCl-20% PEG. The salt and drought stress-induced-oxidative stress was modulated by Si application. Generally, Si application increased catalase (CAT) activity under control and NaCl-10% PEG, ascorbate peroxidase (APX) activity under all treatments and glutathione (GSH) content under salt combined drought stress as compared with non-Si treatments, which resisted to the increase of superoxide radicals and hydrogen peroxide caused by salt and drought stress and further decreased membrane permeability and malondialdehyde (MDA) concentration. Si application also increased proline concentration under NaCl and NaCl-20% PEG, but decreased it under NaCl-10% PEG, indicating proline play an important role in G. uralensis seedling response to osmotic stress. In conclusion, Si could ameliorate adverse effects of salt and drought stress on G. uralensis likely by reducing oxidative stress and osmotic stress, and the oxidative stress was regulated through enhancing of antioxidants (mainly CAT, APX and GSH) and osmotic stress was regulated by proline.

  11. The co-action of osmotic and high temperature stresses results in a growth improvement of Debaryomyces hansenii cells

    Czech Academy of Sciences Publication Activity Database

    Papoušková, Klára; Sychrová, Hana

    2007-01-01

    Roč. 118, č. 1 (2007), s. 1-7 ISSN 0168-1605 R&D Projects: GA ČR(CZ) GD204/03/H066; GA ČR(CZ) GA206/05/0035; GA MŠk(CZ) LC531; GA AV ČR(CZ) IAA5011407 Institutional research plan: CEZ:AV0Z50110509 Keywords : D. hansenii * osmotic stress * temperature stress Subject RIV: EE - Microbiology, Virology Impact factor: 2.581, year: 2007

  12. Effect of packing on changes in erythrocyte osmotic fragility and malondialdehyde concentration in donkeys administered with ascorbic acid

    OpenAIRE

    Folashade Olaifa; Joseph O. Ayo; Suleiman F. Ambali; Peter I. Rekwot

    2012-01-01

    Experiments were performed with the aim of investigating the effect of packing on erythrocyte osmotic fragility (EOF) and malondialdehyde (MDA) concentration in donkeys, and the effect of ascorbic acid (AA). Twelve apparently healthy donkeys raised under the traditional extensive system served as experimental subjects. Six donkeys administered orally with AA (200 mg/kg) and subjected to packing were used as experimental animals, whilst six others not administered with AA served as contro...

  13. Effects of temperature and immersion time on diffusion of moisture and minerals during rehydration of osmotically treated pork meat cubes

    Directory of Open Access Journals (Sweden)

    Šuput Danijela Z.

    2015-01-01

    Full Text Available The aim of this work was to study the changes in osmotically treated pork meat during rehydration. Meat samples were osmotically treated in sugar beet molasses solution, at temperature of (23±2°C for 5 hours. After being osmotically treated, meat samples were rehydrated at constant temperature (20- 40°C during different times (15-60 min in distilled water. The effective diffusivity were between 8.35 and 9.11•10-10 (m2•s-1 for moisture, 6.30-6.94 • 10-10 (m2•s-1, for Na, 5.73-7.46 10-10 (m2•s-1, for K, 4.43-6.25 • 10-10 (m2•s-1, for Ca, 5.35-6.25 • 10-10 (m2•s-1, for Mg, 4.67-6.78 10-10 (m2•s-1, for Cu, 4.68-5.33 • 10-10 (m2•s-1, for Fe, 4.21-5.04 • 10-10 (m2•s-1, for Zn and 5.44-7.16 10-10 (m2•s-1, for Mn. Zugarramurdi and Lupin’s model was used to predict the equilibrium condition, which was shown to be appropriate for moisture uptake and solute loss during rehydration. [Projekat Ministarstva nauke Republike Srbije, br. TR-31055: Osmotic dehydration of food - energy and environmental aspects of sustainable production

  14. Water transport through the intestinal epithelial barrier under different osmotic conditions is dependent on LI-cadherin trans-interaction.

    Science.gov (United States)

    Weth, Agnes; Dippl, Carsten; Striedner, Yasmin; Tiemann-Boege, Irene; Vereshchaga, Yana; Golenhofen, Nikola; Bartelt-Kirbach, Britta; Baumgartner, Werner

    2017-04-03

    In the intestine water has to be reabsorbed from the chymus across the intestinal epithelium. The osmolarity within the lumen is subjected to high variations meaning that water transport often has to take place against osmotic gradients. It has been hypothesized that LI-cadherin is important in this process by keeping the intercellular cleft narrow facilitating the buildup of an osmotic gradient allowing water reabsorption. LI-cadherin is exceptional among the cadherin superfamily with respect to its localization along the lateral plasma membrane of epithelial cells being excluded from adherens junction. Furthermore it has 7 but not 5 extracellular cadherin repeats (EC1-EC7) and a small cytosolic domain. In this study we identified the peptide VAALD as an inhibitor of LI-cadherin trans-interaction by modeling the structure of LI-cadherin and comparison with the known adhesive interfaces of E-cadherin. This inhibitory peptide was used to measure LI-cadherin dependency of water transport through a monolayer of epithelial CACO2 cells under various osmotic conditions. If LI-cadherin trans-interaction was inhibited by use of the peptide, water transport from the luminal to the basolateral side was impaired and even reversed in the case of hypertonic conditions whereas no effect could be observed at isotonic conditions. These data are in line with a recently published model predicting LI-cadherin to keep the width of the lateral intercellular cleft small. In this narrow cleft a high osmolarity can be achieved due to ion pumps yielding a standing osmotic gradient allowing water absorption from the gut even if the faeces is highly hypertonic.

  15. Modelling the Thin-Layer Drying Kinetics of Untreated and Blanch-Osmotic Pre-treated Tomato Slices

    Directory of Open Access Journals (Sweden)

    Samuel Enahoro Agarry

    2016-10-01

    Full Text Available The objective of this study was to investigate the effect of pre-treatment and drying temperature on the drying kinetics and nutritional quality of tomato (Lycopersicon esculantum L. under hot air drying. Tomato samples were blanched at 80oC and osmotically dehydrated using 20% w/w sodium chloride solutions at 30oC for 20 min. The blanch-osmotic pre-treated and untreated tomato slices were dried at temperature of 40, 50, 60, 70 and 80oC, respectively in a hot air-dryer. The results showed that blanch-osmotic pre-treatment offered a higher drying rate and lower or faster drying time than untreated condition. The tomato drying regime was characteristically in the constant and falling rate period. The tomato drying rate curve showed characteristics of porous hygroscopic solids. The optimum drying temperature for tomato was found to be 60oC. Four semi-empirical drying models of Newton, Page, Henderson and Pabis, and Logarithmic were fitted to the drying data using non-linear regression analysis. The most appropriate model was selected using the coefficient of determination (R2 and root mean square error (RMSE. The Page model has shown a better fit to the drying kinetics data of tomato in comparison with other tested models. Transport of moisture during drying was described by Fick’s diffusion model application and the effective moisture diffusivity (Deff thus estimated. The Deff at 60oC was 4.43 × 10-11m2/s and 6.33 × 10-11m2/s for blanch-osmotic pre-treated and untreated tomato slices, respectively.

  16. Measurements of the osmotic pressure in liquid mixtures of 3He and 4He near the lambda line and tricritical point

    International Nuclear Information System (INIS)

    Gearhart, C.A. Jr.

    1977-01-01

    Values of the concentration susceptibility (par. deltax/par. deltaΔ)/sub T,P/ near the lambda line and tricritical point in liquid mixtures of 3He and 4 He were calculated from measurements of osmotic pressure differences. Measurements were made by inducing a small 3 He mole fraction difference Δx between two chambrs separated by a pressure transducer, and measuring the resulting osmotic pressure difference as a function of temperature

  17. Effect of salinity on hemolymph osmotic pressure, sodium concentration and Na+-K+-ATPase activity of gill of Chinese crab, Eriocheir sinensis

    Science.gov (United States)

    Liu, Hongyu; Pan, Luqing; Fu, Lü

    2008-02-01

    The effects of salinity on hemolymph osmotic pressure, Na+ concentration and Na+-K+-ATPase activity of gill of Chinese crab Eriocheir sinensis were studied. The results showed that hemolymph osmotic pressure and Na+ concentration increased significantly ( P0.05); However, the protein concentration decreased gradually with the increase of salinity from 0.25 d to 1 d, and then tended to be stable from day 1 to day 15.

  18. Sorbitol-based osmotic diarrhea: possible causes and mechanism of prevention investigated in rats.

    Science.gov (United States)

    Islam, Md Shahidul; Sakaguchi, Ei

    2006-12-21

    To study the possible causes of sorbitol (S)-based diarrhea and its mechanism of reduction by rice gruel (RG) in cecectomized rats. S was dissolved either in distilled water or in RG (50 g/L) and ingested as a single oral dose (1.2 g/kg body mass, containing 0.5 g/L phenol red as a recovery marker) by S (control) and S + RG groups (n = 7), respectively. This dose is over the laxative dose for humans. Animals were sacrificed exactly 1 h after dose ingestion, without any access to drinking water. The whole gastro-intestinal tract was divided into seven segments and sampled to analyze the S and marker remaining in its contents. Gastric-emptying and intestinal transit were comparatively slower in the S + RG group. Also, the S absorption index in the 3(rd) and last quarter of the small intestine (24.85 +/- 18.88% vs 0.0 +/- 0.0% and 39.09 +/- 32.75% vs 0.0 +/- 0.0%, respectively, P osmotic diarrhea. Where RG enhanced the absorption of S through passive diffusion, the degree of diarrhea was reduced in cecectomized rats.

  19. Cleft palate repair with the use of osmotic expanders: a preliminary report.

    Science.gov (United States)

    Kobus, Kazimierz F

    2007-01-01

    A new method of cleft palate repair by expansion of tissue by means of osmotic expanders implanted in the first stage of treatment is described. Self-expanding expanders manufactured by OSMED (Ilmenau, Germany) were implanted under the mucoperiosteal layer of the hard palate, on purpose to generate more tissue and provide facility for palate repair performed 24-48h later. Nineteen children aged from 2 to 3 years were operated from January 2004 to 15 April 2005. In clefts10mm, cleft palate repair was more difficult and the outcomes were less favourable. Despite more generous dissection of the neurovascular bundles and other adjunctive measures such as mucosal V-Y plasty [Bardach J, Salyer K. Surgical techniques in cleft lip and palate. Chicago, London: Year Book Medical Publishers, Inc.; 1987.] and suturing of the mucosal grafts at the border of the hard and soft palate, seven 2-4mm fistulae were noted, however. Concluding, in spite of some shortcomings and unacceptable rate of fistula in wide clefts, the above-presented method seems to be an attractive concept. Despite some technical problems related mostly to still tested optimal filling phase, tissue expansion makes palate repair easier, probably without relaxing incisions and bone denudation. Consequently, some adverse effects on facial growth may be reduced. So far, there is no evidence for it, however, and since this is a preliminary report, there is a need for longer observations and larger material.

  20. Effect of hydrodynamic slippage on electro-osmotic flow in zeta potential patterned nanochannels

    Energy Technology Data Exchange (ETDEWEB)

    Datta, S; Choudhary, J N, E-mail: subhra-datta@iitd.ac.in [Department of Mechanical Engineering, Indian Institute of Technology Delhi, Hauz Khas, New Delhi 110016 (India)

    2013-10-01

    The effect of hydrodynamic slippage on the electro-osmotic flow in a nanochannel with thick electrical double layers whose wall surface potential has a periodic axial variation is studied. The equations of Stokes flow are solved exactly with the help of the Navier slip boundary condition and the Debye-Huckel linearization of the equation governing the potential of the electrical double layer. Each periodic cell of the flow field consists of four counter-rotating vortices. The cross-channel profile of the axial velocity at the center of the cell exhibits three extrema and a reversed velocity zone near the channel axis of symmetry. The size of the extrema and that of the reversed velocity zone increases with increase in the degree of slippage. In the limit when the wavelength of axial variation in surface potential is much larger than the channel width, the flow characteristics are interpreted in terms of the lubrication approximation. In the limit when the electrical double layer is much thinner than the channel height, the effect of slip is modeled by a Helmholtz-Smoluchowski apparent slip boundary condition that depends on the pattern wavelength. (paper)