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Sample records for chronic osmotic minipump

  1. Osmotic flow through the placental barrier of chronically prepared sheep.

    Science.gov (United States)

    Armentrout, T; Katz, S; Thornburg, K L; Faber, J J

    1977-10-01

    An electromagnetic flow sensor was placed on the distal aorta of sheep fetuses in utero, and catheters were placed in a femoral artery and the common umbilical vein. Catheters were also placed in a carotid artery and a uterine vein of the pregnant ewe. Three days postoperatively maternal plasma was hyperosmotic with respect to fetal plasma by all methods: +5.8 +/- 1.4 SE by vapor-pressure osmometry, +2.2 +/- 0.7 SE by freezing-point depression osmometry corrected for bicarbonate loss; and +3.26 mosmol/liter by chemical measurement of plasma constituents. Maternal or fetal plasma was made hypertonic in vivo by infusion of concentrated solutions of mannitol, sucrose, or NaCl. Transplacental water flux was calculated from placental blood flows and arteriovenous differences in water content of the blood. The apparent osmotic conductivity of the placenta was 61 ml2-mosmol-1-kg-1, but this value should be divided by an unknown reflection coefficient to yield the true osmotic conductivity. Separate measurements were made of the placental diffusional permeability of Na+ and Cl- in five chronically prepared sheep fetuses: PSNa+ =0.20 +/- 0.04, PSCl- = 0.27 +/- 0.04 ml/(min-kg fetus). There was a highly significant positive regression between (total) placental permeability and fetal weight.

  2. Desensitisation of 5-HT autoreceptors upon pharmacokinetically monitored chronic treatment with citalopram

    NARCIS (Netherlands)

    Cremers, TIFH; Spoelstra, EN; Bosker, FJ; Mork, A; den Boer, JA; Westerink, BHC; Wikstrom, HV

    2000-01-01

    Rats were chronically treated with the selective serotonin re-uptake inhibitor citalopram [1-(3-dimethylaminopropyl)-1-(4-fluorophenyl)-5-phtalancarbonitril], by means of osmotic minipumps. Using an infusion concentration of 50 mg/ml citalopram, steady-state plasma concentrations of approximately 0.

  3. Effects of acute and chronic exercise on the osmotic stability of erythrocyte membrane of competitive swimmers.

    Science.gov (United States)

    Paraiso, Lara Ferreira; Gonçalves-E-Oliveira, Ana Flávia Mayrink; Cunha, Lucas Moreira; de Almeida Neto, Omar Pereira; Pacheco, Adriana Garcia; Araújo, Karinne Beatriz Gonçalves; Garrote-Filho, Mário da Silva; Bernardino Neto, Morun; Penha-Silva, Nilson

    2017-01-01

    This study aimed to evaluate the influence of acute and chronic exercise on erythrocyte membrane stability and various blood indices in a population consisting of five national-level male swimmers, over 18 weeks of training. The evaluations were made at the beginning and end of the 1st, 7th, 13th and 18th weeks, when volume and training intensity have changed. The effects manifested at the beginning of those weeks were considered due to chronic adaptations, while the effects observed at the end of the weeks were considered due to acute manifestations of the exercise load of that week. Acute changes resulting from the exercise comprised increases in creatine kinase activity (CK) and leukocyte count (Leu), and decrease in hematocrit (Ht) and mean corpuscular volume (MCV), at the end of the first week; increase in the activities of CK and lactate dehydrogenase (LDH), in the uric acid (UA) concentration and Leu count, at the end of the seventh week; increases in CK and LDH activities and in the mean corpuscular hemoglobin concentration (MCHC), at the end of the 13th week; and decrease in the value of the osmotic stability index 1/H50 and increases in the CK activity and platelets (Plt) count, at the end of the 18th week. Chronic changes due to training comprised increase in the values of 1/H50, CK, LDH, high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), serum iron (Fe), MCV and Plt. Although acute training has resulted in decrease in the osmotic stability of erythrocytes, possibly associated with exacerbation of the oxidative processes during intense exercise, chronic training over 18 weeks resulted in increased osmotic stability of erythrocytes, possibly by modulation in the membrane cholesterol content by low and high density lipoproteins.

  4. Novel Pharmacological Approaches for Treatment of Neurotoxicity Induced by Chronic Exposure to Depleted Uranium

    Science.gov (United States)

    2011-03-01

    hippocampal slices in 10 mM HEPES-sucrose buffer ( pH 7.4). The stimulus-evoked increase in endogenous glutamate was significantly enhanced by...state by the reductase and NADPH (11). The oxidation of NADPH to NADP+ is accompanied by a decrease in absorbance. Catalase activity was determined...cerebellar catalase activity in chronically DU-exposed animals receiving only vehicle via osmotic minipump for two months. There are no changes in

  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. Osmotic diuresis

    Science.gov (United States)

    ... page: //medlineplus.gov/ency/article/001266.htm Osmotic diuresis To use the sharing features on this page, please enable JavaScript. Osmotic diuresis is increased urination due to the presence of ...

  7. Osmotic demyelination syndrome in a normonatremic patient of chronic kidney disease

    Directory of Open Access Journals (Sweden)

    Atul Abhishek Jha

    2014-01-01

    Full Text Available Osmotic Demyelination Syndrome (ODS is associated with rapid correction of hyponatremia or fluid shifts, and is characterized by neurological involvement related to pons, brainstem or other areas of the brain. All possible measures should be taken to prevent this serious disorder. Diagnosing this condition early is very important and requires a high index of suspicion. The treatment is purely supportive and most patients may show dramatic recovery. ODS occurring in normonatremic and hypernatremic patients is very rare. We report a case of an 18-year-old boy of end-stage renal disease who presented with an episode of acute gastroenteritis. He was managed with aggressive intravenous fluids, hemodialysis and other supportive therapy. But, he developed altered sensorium and seizures that progressed to features of spastic quadriparesis and lower cranial nerve palsy. Neuroimaging showed hyperintensities in pons and midbrain suggestive of ODS. The patient had normal sodium levels at all times and had no evidence of hyponatremia. The patient was managed with hemodialysis, physiotherapy and other conservative measures and had a gradual clinical and radiological recovery.

  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. Osmotic fragility test

    Science.gov (United States)

    Spherocytosis - osmotic fragility; Thalassemia - osmotic fragility ... done to detect conditions called hereditary spherocytosis and thalassemia . Hereditary spherocytosis makes red blood cells more fragile ...

  11. Investigating depression-like and metabolic parameters in a chronic low-grade inflammation model

    DEFF Research Database (Denmark)

    Fischer, C. W.; Elfving, B.; Lund, S.

    2012-01-01

    values. However, a high dose of LPS caused an increase in liver weight. Analysis of cytokine and mRNA expression levels is currently being carried out and these results are pending. Our preliminary results indicate that a low dose of LPS can produce depression-like behavior, without inducing metabolic......Background: Depression has been associated with a low-grade inflammation and immune activation, as revealed by clinical studies showing elevated levels of pro-inflammatory cytokines and acute phase proteins in depressed patients. These patients are often treatment-resistant, and some studies show...... low-grade inflammation induced by lipopolysaccharide (LPS) on adult Sprague-Dawley rats on depression-like and metabolic parameters. Methods: Chronic infusion of LPS (at a high, medium and low dose) for 28 days was performed by using subcutaneously implanted osmotic minipumps (Alzet...

  12. Effects of acute and chronic aripiprazole treatment on choice between cocaine self-administration and food under a concurrent schedule of reinforcement in rats

    DEFF Research Database (Denmark)

    Thomsen, Morgane; Fink-Jensen, Anders; Woldbye, David

    2008-01-01

    the hypothesis that aripiprazole, both as acute and as chronic treatment, would preferentially decrease cocaine self-administration while sparing behavior maintained by a natural reinforcer, resulting in a shift in the allocation of behavior from cocaine-taking towards the alternative reinforcer. MATERIALS...... AND METHODS: Rats were trained to self-administer intravenous cocaine in a concurrent choice procedure, with a palatable food as the competing reinforcer, under a fixed ratio (FR) 1 FR 5 chain schedule. Aripiprazole was then administered as continuous infusion by osmotic minipumps for 5 days, during which...... performance in the choice procedure was assessed daily. RESULTS: An intermediate dose of aripiprazole decreased cocaine self-administration and shifted the cocaine choice curve to the right as an acute treatment. However, as a chronic treatment, aripiprazole failed to decrease cocaine self...

  13. The Osmotic Pump

    Science.gov (United States)

    Levenspiel, Octave; de Nevers, Noel

    1974-01-01

    Describes the principle involved in an osmotic pump used to extract fresh water from the oceans and in an osmotic power plant used to generate electricity. Although shown to be thermodynamically feasible, the osmotic principle is not likely to be used commerically for these purposes in the near future. (JR)

  14. 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.

  15. 豚鼠耳蜗微渗透压泵慢性灌注技术的改进%Technical improvement of chronic infusion of drugs intothe guinea pig cocMea by an osmotic pump

    Institute of Scientific and Technical Information of China (English)

    杨卫平; 胡博华; 王佩英; 郭维; 姜泗长

    2001-01-01

    Objeetive:To introduce an improved technique of chronic infusion of drugs into the guinea pig cochlea using an osmotic pump. Methods: A stainless steel tube was surgically implanted into the basal turn of the guinea pig cochlea and connected to the pump. Artificial perilymphatic fluid was infused into the cochlea. Auditory brainstem responses (ABRs) and hair cell morphology were examined. Results:In eight artificial perilymphatic fluid infused cochleas, the thresholds of ABRs were kept in the normal level and no hair cell loss was found 14 days after the beginning of infusion.Conclusion:This result indicates that the improved technique perfects the method of osmotic pump implant for chronic infusion of drugs into the inner ear.%目的:介绍应用改进的微渗透压泵进行豚鼠耳蜗慢性灌注的方法。方法:将徽渗透压泵埋置于8只豚鼠背部,经固定于耳蜗底回鼓阶内的改良微导管将人工外淋巴液缓慢注入内耳,观察豚鼠耳蜗对徽渗透压泵慢性灌注人工外淋巴液的反应。结果:动物术后M d脑干诱发电反应阈值(ABR)无明显的变化,耳蜗螺旋神经节细胞及毛细胞未见损伤。结论:改进后的微渗透压泵耳蜗灌流技术完善了内耳慢性给药的实验方法。

  16. The effect of chronic in vivo infusion of forskolin on noradrenergic receptor sensitivity.

    Science.gov (United States)

    Suzdak, P D; Browne, R G

    1985-01-01

    Forskolin, a diterpene isolated from the plant Coleus forskolii, activates the catalytic subunit of adenylate cyclase, resulting in a hormone receptor-independent increase in the intracellular production of cyclic AMP. This study was undertaken to assess the effect of chronic in vivo infusion of forskolin on noradrenergic neuronal activity. Forskolin was infused into the right lateral ventricle of male Sprague Dawley rats via Alzet osmotic minipumps (model 2001) for 7 days. Chronic infusion of forskolin resulted in a decrease in norepinephrine-stimulated cyclic AMP accumulation in the limbic forebrain. Chronic infusion of forskolin also resulted in a decrease in the Bmax for 3H-dihydroalprenolol (3H-DHA) binding to beta-adrenergic receptors in the cerebral cortex and hippocampus, with no apparent change in the Kd values. These data suggest the possibility of a novel therapeutic approach to modulating receptor sensitivity, and that chronic infusion of forskolin may be a useful model for studying the role of cyclic AMP in the control of neuronal activity.

  17. Chronic exposure to low dose bacterial lipopolysaccharide inhibits leptin signaling in vagal afferent neurons.

    Science.gov (United States)

    de La Serre, Claire B; de Lartigue, Guillaume; Raybould, Helen E

    2015-02-01

    Bacterially derived factors are implicated in the causation and persistence of obesity. Ingestion of a high fat diet in rodents and obesity in human subjects is associated with chronic elevation of low plasma levels of lipopolysaccharide (LPS), a breakdown product of Gram-negative bacteria. The terminals of vagal afferent neurons are positioned within the gut mucosa to convey information from the gut to the brain to regulate food intake and are responsive to LPS. We hypothesized that chronic elevation of LPS could alter vagal afferent signaling. We surgically implanted osmotic mini-pumps that delivered a constant, low-dose of LPS into the intraperitoneal cavity of rats (12.5 μg/kg/hr for 6 weeks). LPS-treated rats developed hyperphagia and showed marked changes in vagal afferent neuron function. Chronic LPS treatment reduced vagal afferent leptin signaling, characterized by a decrease in leptin-induced STAT3 phosphorylation. In addition, LPS treatment decreased cholecystokinin-induced satiety. There was no alteration in leptin signaling in the hypothalamus. These findings offer a mechanism by which a change in gut microflora can promote hyperphagia, possibly leading to obesity.

  18. Chronic spinal infusion of loperamide alleviates postsurgical pain in rats.

    Science.gov (United States)

    Kumar, Rakesh; Reeta, K H; Ray, Subrata Basu

    2014-04-01

    Plantar incision in rat generates spontaneous pain behaviour. The opioid drug, morphine used to treat postsurgical pain produces tolerance after long-term administration. Loperamide, a potent mu-opioid agonist, has documented analgesic action in various pain conditions. However, loperamide analgesia and associated tolerance following continuous spinal administration in postsurgical pain has not been reported. Chronic spinal infusion of drugs was achieved using intrathecal catheters connected to osmotic minipump. Coinciding with the onset of spinal infusion of loperamide or morphine, rats were subjected to plantar incision. Pain-related behaviour was assessed by Hargreaves apparatus (thermal hyperalgesia) and von Frey filaments (mechanical allodynia). Morphine and loperamide (0.5, 1 and 2 microL/h) induced analgesia was observed until 7th day post-plantar incision in Sprague-Dawley rats. Morphine and loperamide produced dose-dependent analgesia. Loperamide, in the highest dose, produced analgesia till 7th day. However, the highest dose of morphine produced inhibition of thermal hyperalgesia till 5th day and mechanical allodynia only till 3rd day post-plantar incision. Morphine and loperamide produced analgesia in postsurgical pain, which may be mediated through different mechanisms. Longer duration of analgesia with loperamide could probably be due sustained blockade of calcium channels.

  19. Chronic cocaine administration causes extensive white matter damage in brain: diffusion tensor imaging and immunohistochemistry studies.

    Science.gov (United States)

    Narayana, Ponnada A; Herrera, Juan J; Bockhorst, Kurt H; Esparza-Coss, Emilio; Xia, Ying; Steinberg, Joel L; Moeller, F Gerard

    2014-03-30

    The effect of chronic cocaine exposure on multiple white matter structures in rodent brain was examined using diffusion tensor imaging (DTI), locomotor behavior, and end point histology. The animals received either cocaine at a dose of 100mg/kg (N=19), or saline (N=17) for 28 days through an implanted osmotic minipump. The animals underwent serial DTI scans, locomotor assessment, and end point histology for determining the expressions of myelin basic protein (MBP), neurofilament-heavy protein (NF-H), proteolipid protein (PLP), Nogo-A, aquaporin-4 (AQP-4), and growth associated protein-43 (GAP-43). Differences in the DTI measures were observed in the splenium (scc) and genu (gcc) of the corpus callosum (cc), fimbria (fi), and the internal capsule (ic). A significant increase in the activity in the fine motor movements and a significant decrease in the number of rearing events were observed in the cocaine-treated animals. Reduced MBP and Nogo-A and increased GAP-43 expressions were most consistently observed in these structures. A decrease in the NF-H expression was observed in fi and ic. The reduced expression of Nogo-A and the increased expression of GAP-43 may suggest destabilization of axonal connectivity and increased neurite growth with aberrant connections. Increased GAP-43 suggests drug-induced plasticity or a possible repair mechanism response. The findings indicated that multiple white matter tracts are affected following chronic cocaine exposure.

  20. A REVIEW ON OSMOTIC DRUG DELIVERY SYSTEM

    Directory of Open Access Journals (Sweden)

    Harnish Patel

    2012-04-01

    Full Text Available 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 controlled drug delivery systems and could be employed as oral drug delivery systems. Various patents available for osmotic drug delivery system like Rose-Nelson pump, Higuchi leeper pump, Higuchi Theeuwes pump, Elementary Osmotic pump etc. ODDS are useful for poorly soluble drug, for pulsatile drug release, zero order release. Various techniques available for preparation of ODDS include push pull osmotic Pump, osmotic Brusting osmotic pump, liquid oral osmotic system, sandwiched osmotic tablets , delayed delivery osmotic device, monolithic osmotic System and controlled porosity osmotic Pump. Osmotically controlled oral drug delivery systems utilize osmotic pressure for controlled delivery of active agents. These systems can be utilized for systemic as well as targeted delivery of drugs. The release of drugs from osmotic systems is governed by various formulation factors such as solubility and osmotic pressure of the core components, size of the delivery orifice, and nature of the rate-controlling membrane. In this Paper mainly focused on the Osmotic System with example, the basic component of osmotic system and evaluation parameter of the osmotic drug delivery system.

  1. [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.

  2. Efficiency of osmotic pipe flows

    DEFF Research Database (Denmark)

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

    2013-01-01

    on the relative magnitude of radial diffusion and advection as well as the ratio of the osmotic velocity to pumping velocity, in very good agreement with experiments and with no adjustable parameters. Our analysis provides criteria that are useful for optimizing osmotic flow processes in, e.g., water purification......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. Distribution of cadmium in gravid CF-1 mice following chronic administration

    Energy Technology Data Exchange (ETDEWEB)

    Reihart, M.J.; Mahalik, M.P.; Hitner, H.W.; Prozialeck, W.C. (PCOM, Philadelphia, PA (United States))

    1991-03-11

    Previous studies, in which cadmium (Cd{sup 2+}) was administered via osmotic minipumps to gravid CF-1 mice showed that Cd{sup 2+} produces dose-dependent teratogenic effects. The present studies examined the patterns of distribution when Cd{sup 2+} is given by this route to gravid and non-gravid mice. A total dose of 5.6 umoles CdCl{sub 2} containing 1 uCi {sup 109}Cd{sup 2+} was administered via 14 day Alzet osmotic minipumps implanted subcutaneously on day 5 of gestation. On day 12 and day 18 of gestation, the animals were sacrificed. Samples of various tissues were removed, solubilized and counted for radioactivity in a liquid scintillation counter. The results showed that the highest levels of Cd were present in the maternal liver and kidney. The levels of Cd{sup 2+} in the kidney on day 18 were much higher than those on day 12 suggesting a gradual redistribution of Cd{sup 2+} accumulated in the placenta, little was present in the amnionic fluid or fetuses. These patterns of distribution for Cd{sup 2+} administered by osmotic minipumps are similar to those previously reported for other parenteral routes of administration. The authors finding that Cd{sup 2+} accumulates in the placenta but does not readily cross into the amniotic fluid or fetus is consistent with the hypothesis that Cd{sup 2+} may produce some of its teratogenic effects by selectively damaging the placenta.

  4. 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...

  5. Equilibrium Electro-osmotic Instability

    CERN Document Server

    Rubinstein, Isaak

    2014-01-01

    Since its prediction fifteen years ago, electro-osmotic instability has been attributed to non-equilibrium electro-osmosis related to the extended space charge which develops at the limiting current in the course of concentration polarization at a charge-selective interface. This attribution had a double basis. Firstly, it has been recognized that equilibrium electro-osmosis cannot yield instability for a perfectly charge-selective solid. Secondly, it has been shown that non-equilibrium electro-osmosis can. First theoretical studies in which electro-osmotic instability was predicted and analyzed employed the assumption of perfect charge-selectivity for the sake of simplicity and so did the subsequent numerical studies of various time-dependent and nonlinear features of electro-osmotic instability. In this letter, we show that relaxing the assumption of perfect charge-selectivity (tantamount to fixing the electrochemical potential in the solid) allows for equilibrium electro-osmotic instability. Moreover, we s...

  6. 真武汤对C-BSA渗透泵肾小球肾炎大鼠的治疗作用%Therapeutic Effect of Zhenwu Decoction on Chronic Glomerulonephritis Rat Model Induced by Cationization Bovine Serum Albumin Osmotic Pump

    Institute of Scientific and Technical Information of China (English)

    丑安; 周玖瑶; 周园; 华静; 吴俊标

    2012-01-01

    Objective To explore the therapeutic effect of Zhenwu decoction on chronic glomerulonephritis(CGN) rat model induced by cationization bovine serum albumin (C-BSA) osmotic pump. Methods Sixty healthy male SD rats were used for the experiment, 10 rats were in the blank control group received sham operation, and the other 50 rats were implanted C-BSA osmotic pump to induce CGN model. And then CGN model rats were randomly divided into model group, prednisone acetate (8 mg/kg) group , and high-dose (16.8 g/kg), middle-dose (8.4 g/kg) and low-dose (4.2 g/kg) Zhenwu decoction groups. Urinary protein within 24 hours were tested by using Coomassie brilliant blue method, blood biochemical parameters including serum total protein (TP), albumin (ALB), serum creatinine (SCr) , blood urea nitrogen ( BUN ) , total cholesterol (TC ) and triglycerides (TG) were detected by automatic biochemistry analyzer, and IgG expression in the glomerulus was determined by immunofluorescence method. Results Compared to the blank control group, the levels of 24-hour urinary protein, SCr, BUN, TC and TG were increased obviously(P < 0.01), TP and ALB were reduced significantly(P < 0.05 or P < 0.01), and IgG was deposited heavily in the glomerular mesangial area of the model group. Compared to the model group, the levels of 24-hour urinary protein, SCr, BUN, TC and TG were reduced obviously, TP and ALB were increased(P < 0.05 or P < 0.01), and the expression of IgG was decreased in Zhenwu decoction groups. The changes were especially significant in high-dose Zhenwu decoction group. Conclusion Zhenwu decoction can relieve the immunopathological damages in rats with CGN induced by C-BSA osmotic pump, reduce urinary protein content, improve renal function, and lower blood lipids, showing protective effect on the kidneys.%目的 在制备阳离子化小牛血清白蛋白(C-BSA)渗透泵致肾小球肾炎(CGN)大鼠模型的基础上,探讨真武汤对该模型大鼠的治疗作用.方法

  7. 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.

  8. 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

  9. Motor alterations induced by chronic 4-aminopyridine infusion in the spinal cord in vivo: role of glutamate and GABA receptors

    Directory of Open Access Journals (Sweden)

    Rafael eLazo-Gómez

    2016-05-01

    Full Text Available Motor neuron degeneration is the pathological hallmark of motor neuron diseases, a group of neurodegenerative disorders clinically manifested as muscle fasciculations and hyperreflexia, followed by paralysis, respiratory failure and death. Ample evidence supports a role of glutamate-mediated excitotoxicity in motor death. In previous work we showed that stimulation of glutamate release from nerve endings by perfusion of the K+-channel blocker 4-aminopyridine (4-AP in the rat hippocampus induces seizures and neurodegeneration, and that AMPA insusion in the spinal cord produces paralysis and motor neuron death. On these bases, in this work we have tested the effect of the chronic infusion of 4-AP in the spinal cord, using implanted osmotic minipumps, on motor activity and on motor neuron survival, and the mechanisms underlying this effect. 4-AP produced muscle fasciculations and motor deficits assessed in two motor tests, which start 2-3 h after the implant, which ameliorated spontaneously within 6-7 days, but no neurodegeneration. These effects were prevented by both AMPA and NMDA receptors blockers. The role of GABAA receptors was also explored, and we found that chronic infusion of bicuculline induced moderate motor neuron degeneration and enhanced the hyperexcitation produced by 4-AP. Unexpectedly, the GABAAR agonist muscimol also induced motor deficits and failed to prevent the MN death induced by AMPA. We conclude that motor alterations induced by chronic 4-AP infusion in the spinal cord in vivo is due to ionotropic glutamate receptor overactivation and that blockade of GABAergic neurotransmission induces motor neuron death under chronic conditions. These results shed light on the role of glutamatergic and GABAergic neurotransmission in the regulation of motor neuron excitability in the spinal cord.

  10. 渗透泵阳离子化小牛血清白蛋白肾小球肾炎大鼠模型研究%Study on Rat Model of Chronic Glomerulonephritis Induced by Osmotic Pump Containing Cationic Bovine Serum Albumin

    Institute of Scientific and Technical Information of China (English)

    华静; 周玖瑶; 丑安; 周园; 吴俊标; 梁春玲

    2013-01-01

    [目的]应用渗透压缓释泵技术建立新型阳离子化小牛血清白蛋白(C-BSA)慢性肾小球肾炎大鼠模型.[方法]将C-BSA装入渗透泵,植入右肾旁,制备新型C-BSA渗透泵肾小球肾炎模型,并用醋酸泼尼松(8 mg/kg)干预治疗,观察大鼠存活情况,并检测尿蛋白,血清尿素氮(BUN)、肌酐(SCr)及肾组织病理形态学改变.通过与尾静脉注射C-BSA的传统肾小球肾炎模型比较,评价新动物模型的可行性和优越性.[结果]与空白对照组比较,渗透泵C-BSA肾小球肾炎模型组大鼠24h尿蛋白,血清BUN、SCr含量均显著升高,差异具有统计学意义(P<0.01),且24 h尿蛋白,血清BUN、SCr含量均高于传统C-BSA肾小球肾炎模型组,但差异无统计学意义.与空白对照组比较,渗透泵C-BSA肾小球肾炎模型与传统C-BSA肾小球肾炎模型均出现严重的肾小球病理改变.与渗透泵C-BSA肾小球肾炎模型组比较,醋酸泼尼松组大鼠24h尿蛋白、血清BUN含量均显著降低(P<0.05或P<0.01),肾小球病理改变较轻.[结论]应用渗透压缓释泵恒释C-BSA能够成功制备稳定可靠的肾小球肾炎模型.%Objective To establish a new rat model of chronic glomerulonephritis ( CGN) by using osmotic controlled-release pump for cationic bovine serum albumin (C-BSA). Methods Osmotic pump containing C-BSA was implanted into the area beneath rat right kidney to induce the new C-BSA osmotic pump CGN rat model, and the experimental rats were given prednisone acetate (8mg/kg) for intervention during the experiment. Compared with traditional C-BSA CGN rat model which was induced by injection of C-BSA through the caudal vein, the feasibility and superiority of the new model was evaluated through observing the survival rale of the rats, urinary protein within 24 hours, blood urea nitrogen ( BUN) and serum creatinine ( SCr) as well as the renal pathological changes. Results Twenty-four hours later, the levels of urinary protein, BUN and

  11. 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...... been found that this model reproduces all known features of filtration dewatering and is found to be consistent with experimental data....

  12. Auxin response under osmotic stress.

    Science.gov (United States)

    Naser, Victoria; Shani, Eilon

    2016-08-01

    The phytohormone auxin (indole-3-acetic acid, IAA) is a small organic molecule that coordinates many of the key processes in plant development and adaptive growth. Plants regulate the auxin response pathways at multiple levels including biosynthesis, metabolism, transport and perception. One of the most striking aspects of plant plasticity is the modulation of development in response to changing growth environments. In this review, we explore recent findings correlating auxin response-dependent growth and development with osmotic stresses. Studies of water deficit, dehydration, salt, and other osmotic stresses point towards direct and indirect molecular perturbations in the auxin pathway. Osmotic stress stimuli modulate auxin responses by affecting auxin biosynthesis (YUC, TAA1), transport (PIN), perception (TIR/AFB, Aux/IAA), and inactivation/conjugation (GH3, miR167, IAR3) to coordinate growth and patterning. In turn, stress-modulated auxin gradients drive physiological and developmental mechanisms such as stomata aperture, aquaporin and lateral root positioning. We conclude by arguing that auxin-mediated growth inhibition under abiotic stress conditions is one of the developmental and physiological strategies to acclimate to the changing environment.

  13. Silk Fibroin under Osmotic Stress

    Science.gov (United States)

    Sohn, Sungkyun; Strey, Helmut H.; Gido, Samuel P.

    2003-03-01

    The osmotic stress method was applied to study the thermodynamics of supramolecular self-assembly phenomena in crystallizable segments of Bombyx mori silkworm silk fibroin. Controlling compositions and phases of silk fibroin solution, the method provided a means for the direct investigation of microscopic and thermodynamic details of these intermolecular interactions in aqueous media. It is apparent that as osmotic pressure increases, silk fibroin molecules get pressurized to align together to form a water-soluble crystalline mesophase (Silk-I), and then gradually become anti-parallel b-sheet structure (Silk-II) at higher osmotic pressure. This behavior becomes more sensitive as the salt concentration decreases. A partial ternary phase diagram of Water-Silk fibroin-LiBr was constructed based on the results. This phase diagram can be utilized to help design a new route for wet spinning of re-generated silk fibroin. Precise control of compositions and corresponding crystalline structure of a silk fibroin solution may enable us to simulate the natural Bombyx mori silkworm spinning process.

  14. Differential adaptation of REM sleep latency, intermediate stage and theta power effects of escitalopram after chronic treatment.

    Science.gov (United States)

    Vas, Szilvia; Kátai, Zita; Kostyalik, Diána; Pap, Dorottya; Molnár, Eszter; Petschner, Péter; Kalmár, Lajos; Bagdy, György

    2013-01-01

    The effects of the widely used selective serotonin reuptake inhibitor (SSRI) antidepressants on sleep have been intensively investigated. However, only a few animal studies examined the effect of escitalopram, the more potent S-enantiomer of citalopram, and conclusions of these studies on sleep architecture are limited due to the experimental design. Here, we investigate the acute (2 and 10 mg/kg, i.p. injected at the beginning of the passive phase) or chronic (10 mg/kg/day for 21 days, by osmotic minipumps) effects of escitalopram on the sleep and quantitative electroencephalogram (EEG) of Wistar rats. The first 3 h of EEG recording was analyzed at the beginning of passive phase, immediately after injections. The acutely injected 2 and 10 mg/kg and the chronically administered 10 mg/kg/day escitalopram caused an approximately three, six and twofold increases in rapid eye movement sleep (REMS) latency, respectively. Acute 2-mg/kg escitalopram reduced REMS, but increased intermediate stage of sleep (IS) while the 10 mg/kg reduced both. We also observed some increase in light slow wave sleep and passive wake parallel with a decrease in deep slow wave sleep and theta power in both active wake and REMS after acute dosing. Following chronic treatment, only the increase in REMS latency remained significant compared to control animals. In conclusion, adaptive changes in the effects of escitalopram, which occur after 3 weeks of treatment, suggest desensitization in the function of 5-HT(1A) and 5-HT(1B) receptors.

  15. Casein Micelle Dispersions under Osmotic Stress

    OpenAIRE

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

    2009-01-01

    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 press...

  16. 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.

  17. Chronic delivery of a thrombospondin-1 mimetic decreases skeletal muscle capillarity in mice.

    Science.gov (United States)

    Audet, Gerald N; Fulks, Daniel; Stricker, Janelle C; Olfert, I Mark

    2013-01-01

    Angiogenesis is an essential process for normal skeletal muscle function. There is a growing body of evidence suggesting that thrombospondin-1 (TSP-1), a potent antiangiogenic protein in tumorigenesis, is an important regulator of both physiological and pathological skeletal muscle angiogenesis. We tested the hypothesis that chronic exposure to a TSP-1 mimetic (ABT-510), which targets the CD36 TSP-1 receptor, would decrease skeletal muscle capillarity as well as alter the balance between positive and negative angiogenic proteins under basal conditions. Osmotic minipumps with either ABT-510 or vehicle (5% dextrose) were implanted subcutaneously in the subscapular region of C57/BL6 mice for 14 days. When compared to the vehicle treated mice, the ABT-510 group had a 20% decrease in capillarity in the superficial region of the gastrocnemius (GA), 11% decrease in the plantaris (PLT), and a 35% decrease in the soleus (SOL). ABT-510 also decreased muscle protein expression of vascular endothelial growth factor (VEGF) in both the GA (-140%) and SOL (-62%); however there was no change in VEGF in the PLT. Serum VEGF was not altered in ABT-510 treated animals. Endogenous TSP-1 protein expression in all muscles remained unaltered. Tunnel staining revealed no difference in muscle apoptosis between ABT-510 and vehicle treated groups. These data provide evidence that the anti-angiogenic effects of TSP-1 are mediated, at least in part, via the CD36 receptor. It also suggests that under physiologic conditions the TSP-1/CD36 axis plays a role in regulating basal skeletal muscle microvessel density.

  18. Chronic delivery of a thrombospondin-1 mimetic decreases skeletal muscle capillarity in mice.

    Directory of Open Access Journals (Sweden)

    Gerald N Audet

    Full Text Available Angiogenesis is an essential process for normal skeletal muscle function. There is a growing body of evidence suggesting that thrombospondin-1 (TSP-1, a potent antiangiogenic protein in tumorigenesis, is an important regulator of both physiological and pathological skeletal muscle angiogenesis. We tested the hypothesis that chronic exposure to a TSP-1 mimetic (ABT-510, which targets the CD36 TSP-1 receptor, would decrease skeletal muscle capillarity as well as alter the balance between positive and negative angiogenic proteins under basal conditions. Osmotic minipumps with either ABT-510 or vehicle (5% dextrose were implanted subcutaneously in the subscapular region of C57/BL6 mice for 14 days. When compared to the vehicle treated mice, the ABT-510 group had a 20% decrease in capillarity in the superficial region of the gastrocnemius (GA, 11% decrease in the plantaris (PLT, and a 35% decrease in the soleus (SOL. ABT-510 also decreased muscle protein expression of vascular endothelial growth factor (VEGF in both the GA (-140% and SOL (-62%; however there was no change in VEGF in the PLT. Serum VEGF was not altered in ABT-510 treated animals. Endogenous TSP-1 protein expression in all muscles remained unaltered. Tunnel staining revealed no difference in muscle apoptosis between ABT-510 and vehicle treated groups. These data provide evidence that the anti-angiogenic effects of TSP-1 are mediated, at least in part, via the CD36 receptor. It also suggests that under physiologic conditions the TSP-1/CD36 axis plays a role in regulating basal skeletal muscle microvessel density.

  19. Chronic escitalopram treatment caused dissociative adaptation in serotonin (5-HT) 2C receptor antagonist-induced effects in REM sleep, wake and theta wave activity.

    Science.gov (United States)

    Kostyalik, Diána; Kátai, Zita; Vas, Szilvia; Pap, Dorottya; Petschner, Péter; Molnár, Eszter; Gyertyán, István; Kalmár, Lajos; Tóthfalusi, László; Bagdy, Gyorgy

    2014-03-01

    Several multi-target drugs used in treating psychiatric disorders, such as antidepressants (e.g. agomelatine, trazodone, nefazodone, amitriptyline, mirtazapine, mianserin, fluoxetine) or most atypical antipsychotics, have 5-hydroxytryptamine 2C (5-HT2C) receptor-blocking property. Adaptive changes in 5-HT2C receptor-mediated functions are suggested to contribute to therapeutic effects of selective serotonin reuptake inhibitor (SSRI) antidepressants after weeks of treatment, at least in part. Beyond the mediation of anxiety and other functions, 5-HT2C receptors are involved in sleep regulation. Anxiety-related adaptive changes caused by antidepressants have been studied extensively, although sleep- and electroencephalography (EEG)-related functional studies are still lacking. The aim of this study was to investigate the effects of chronic SSRI treatment on 5-HT2C receptor antagonist-induced functions in different vigilance stages and on quantitative EEG (Q-EEG) spectra. Rats were treated with a single dose of the selective 5-HT2C receptor antagonist SB-242084 (1 mg/kg, i.p.) or vehicle at the beginning of passive phase following a 20-day-long SSRI (escitalopram; 10 mg/kg/day, osmotic minipump) or VEHICLE pretreatment. Fronto-parietal electroencephalogram, electromyogram and motility were recorded during the first 3 h of passive phase. We found that the chronic escitalopram pretreatment attenuated the SB-242084-caused suppression in rapid eye movement sleep (REMS). On the contrary, the 5-HT2C receptor antagonist-induced elevations in passive wake and theta (5-9 Hz) power density during active wake and REMS were not affected by the SSRI. In conclusion, attenuation in certain, but not all vigilance- and Q-EEG-related functions induced by the 5-HT2C receptor antagonist, suggests dissociation in 5-HT2C receptor adaptation.

  20. 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.

  1. 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

  2. Polyamine Metabolism and Osmotic Stress 1

    Science.gov (United States)

    Tiburcio, Antonio Fernández; Kaur-Sawhney, Ravindar; Galston, Arthur W.

    1986-01-01

    We have attempted to improve the viability of cereal mesophyll protoplasts by pretreatment of leaves with dl-α-difluoromethylarginine (DFMA), a specific `suicide' inhibitor of the enzyme (arginine decarboxylase) responsible for their osmotically induced putrescine accumulation. Leaf pretreatment with DFMA before a 6 hour osmotic shock caused a 45% decrease of putrescine and a 2-fold increase of spermine titer. After 136 hours of osmotic stress, putrescine titer in DFMA-pretreated leaves increased by only 50%, but spermidine and spermine titers increased dramatically by 3.2- and 6-fold, respectively. These increases in higher polyamines could account for the reduced chlorophyll loss and enhanced ability of pretreated leaves to incorporate tritiated thymidine, uridine, and leucine into macromolecules. Pretreatment with DFMA significantly improved the overall viability of the protoplasts isolated from these leaves. The results support the view that the osmotically induced rise in putrescine and blockage of its conversion to higher polyamines may contribute to the lack of sustained cell division in cereal mesophyll protoplasts, although other undefined factors must also play a major role. PMID:11539087

  3. Strange Attractors Characterizing the Osmotic Instability

    CERN Document Server

    Tzenov, Stephan I

    2014-01-01

    In the present paper a simple dynamical model for computing the osmotically driven fluid flow in a variety of complex, non equilibrium situations is derived from first principles. Using the Oberbeck-Boussinesq approximation, the basic equations describing the process of forward osmosis have been obtained. It has been shown that these equations are very similar to the ones used to model the free Rayleigh-Benard convection. The difference is that while in the case of thermal convection the volume expansion is driven by the coefficient of thermal expansion, the key role for the osmotic instability is played by the coefficient of isothermal compressibility. In addition, it has been shown that the osmotic process represents a propagation of standing waves with time-dependent amplitudes and phase velocity, which equals the current velocity of the solvent passing through the semi-permeable membrane. The evolution of the amplitudes of the osmotic waves is exactly following the dynamics of a strange attractor of Loren...

  4. Pulsatile lipid vesicles under osmotic stress

    CERN Document Server

    Chabanon, Morgan; Liedberg, Bo; Parikh, Atul N; Rangamani, Padmini

    2016-01-01

    The response of lipid bilayers to osmotic stress is an important part of cellular function. Previously, in [Oglecka et al. 2014], we reported that cell-sized giant unilamellar vesicles (GUVs) exposed to hypotonic media, respond to the osmotic assault by undergoing a cyclical sequence of swelling and bursting events, coupled to the membrane's compositional degrees of freedom. Here, we seek to deepen our quantitative understanding of the essential pulsatile behavior of GUVs under hypotonic conditions, by advancing a comprehensive theoretical model for vesicle dynamics. The model quantitatively captures our experimentally measured swell-burst parameters for single-component GUVs, and reveals that thermal fluctuations enable rate dependent pore nucleation, driving the dynamics of the swell-burst cycles. We further identify new scaling relationships between the pulsatile dynamics and GUV properties. Our findings provide a fundamental framework that has the potential to guide future investigations on the non-equili...

  5. Thermo-Osmotic Flow in Thin Films

    Science.gov (United States)

    Bregulla, Andreas P.; Würger, Alois; Günther, Katrin; Mertig, Michael; Cichos, Frank

    2016-05-01

    We report on the first microscale observation of the velocity field imposed by a nonuniform heat content along the solid-liquid boundary. We determine both radial and vertical velocity components of this thermo-osmotic flow field by tracking single tracer nanoparticles. The measured flow profiles are compared to an approximate analytical theory and to numerical calculations. From the measured slip velocity we deduce the thermo-osmotic coefficient for both bare glass and Pluronic F-127 covered surfaces. The value for Pluronic F-127 agrees well with Soret data for polyethylene glycol, whereas that for glass differs from literature values and indicates the complex boundary layer thermodynamics of glass-water interfaces.

  6. Thermo-osmotic flow in thin films

    CERN Document Server

    Bregulla, Andreas; Günther, Katrin; Mertig, Michael; Cichos, Frank

    2016-01-01

    We report on the first micro-scale observation of the velocity field imposed by a non-uniform heat content along the solid/liquid boundary. We determine both radial and vertical velocity components of this thermo-osmotic flow field by tracking single tracer nanoparticles. The measured flow profiles are compared to an approximate analytical theory and to numerical calculations. From the measured slip velocity we deduce the thermo-osmotic coefficient for both bare glass and Pluronic F-127 covered surfaces. The value for Pluronic F-127 agrees well with Soret data for polyethylene glycol, whereas that for glass differs from literature values and indicates the complex boundary layer thermodynamics of glass-water interfaces.

  7. Osmotically-assisted desalination method and system

    Science.gov (United States)

    Achilli, Andrea; Childress, Amy E.; Cath, Tzahi Y.

    2014-08-12

    Systems and methods for osmotically assisted desalination include using a pressurized concentrate from a pressure desalination process to pressurize a feed to the desalination process. The depressurized concentrate thereby produced is used as a draw solution for a pressure-retarded osmosis process. The pressure-retarded osmosis unit produces a pressurized draw solution stream that is used to pressurize another feed to the desalination process. In one example, the feed to the pressure-retarded osmosis process is impaired water.

  8. Osmotic and Heat Stress Effects on Segmentation

    Science.gov (United States)

    Weiss, Julian

    2016-01-01

    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. PMID:28006008

  9. 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.

  10. 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.

  11. Hypo-osmotic test in cat spermatozoa.

    Science.gov (United States)

    Comercio, E A; Monachesi, N E; Loza, M E; Gambarotta, M; Wanke, M M

    2013-10-01

    The hypo-osmotic (HOS) test has been used in other species as an indicator of the fertilising capacity of spermatozoa. The aims of this study were to assess the response of domestic cat spermatozoa to the hypo-osmotic test, to determine the type of solution, concentration and time of incubation needed to obtain a maximum percentage of swelling, to correlate the selected combination with the percentages of progressive motility and to evaluate whether dilution of the ejaculate alters the results. Incubation for 30 and 45 min in solutions of fructose and of citrate of 50 and 100 mOsmol kg⁻¹ was evaluated. The highest percentage of swelling was obtained using the 50 mOsmol kg⁻¹ solution, and no significant differences were observed between the times of exposure to the solutions. A positive correlation was observed between the percentage of individual progressive motility and the percentage of sperm swelling in a 50 mOsmol kg⁻¹ fructose solution, with no significant differences being observed between raw and diluted semen samples. The results of this study suggest that the HOS test could be useful for evaluating membrane function in domestic cat spermatozoa, both in raw semen and in samples diluted in the EZ Mixin® commercial extender, and thus could be incorporated into routine semen evaluation protocols.

  12. Characterization of Escherichia coli nucleoids released by osmotic shock.

    NARCIS (Netherlands)

    Wegner, A.S.; Alexeeva, S.; Odijk, T.; Woldringh, C.L.

    2012-01-01

    Nucleoids were isolated by osmotic shock from Escherichia coli spheroplasts at relatively low salt concentrations and in the absence of detergents. Sucrose-protected cells, made osmotically sensitive by growth in the presence of ampicillin or by digestion with low lysozyme concentrations (50-5 μg/ml

  13. Characterization of Escherichia coli nucleoids released by osmotic shock

    NARCIS (Netherlands)

    Wegner, S.; Alexeeva, S.V.; Odijk, T.; Woldringh, C.L.

    2012-01-01

    Nucleoids were isolated by osmotic shock from Escherichia coli spheroplasts at relatively low salt concentrations and in the absence of detergents. Sucrose-protected cells, made osmotically sensitive by growth in the presence of ampicillin or by digestion with low lysozyme concentrations (50–5 µg/ml

  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

    results and the predictions of the model. Our motivation for studying osmotically driven microflows is that they are believed to be responsible for the translocation of sugar in plants through the phloem sieve element cells. Also, we suggest that osmotic elements can act as on-chip integrated pumps...

  15. A peritoneal dialysis patient with osmotic demyelination syndrome

    Directory of Open Access Journals (Sweden)

    Hing Ming Cheng

    2016-04-01

    Full Text Available A peritoneal dialysis patient with cirrhosis presented with drowsiness, vomiting, and mild hyponatremia. Despite no active correction of hyponatremia, she developed convulsion and quadriplegia. Magnetic resonance imaging of the brain showed changes of osmotic demyelination syndrome. This case illustrates that osmotic demyelination syndrome may occur in peritoneal dialysis without rapid correction of hyponatremia.

  16. Analysing transfer phenomena in osmotic evaporation

    Directory of Open Access Journals (Sweden)

    Freddy Forero Longas

    2011-12-01

    Full Text Available Osmotic evaporation is a modification of traditional processes using membranes; by means of a vapour pressure differential, produced by a highly concentrated extraction solution, water is transferred through a hydrophobic membrane as vapour. This technique has many advantages over traditional processes, allowing work at atmospheric pressure and low temperatures, this being ideal for heatsensitive products. This paper presents and synthetically analyses the phenomena of heat and mass transfer which occurs in the process and describes the models used for estimating the parameters of interest, such as flow, temperature, heat transfer rate and the relationships that exist amongst them when hollow fibre modules are used, providing a quick reference tool and specific information about this process.

  17. Changes in pericytic expression of NG2 and PDGFRB and vascular permeability in the sensory circumventricular organs of adult mouse by osmotic stimulation.

    Science.gov (United States)

    Morita, Shoko; Hourai, Atsushi; Miyata, Seiji

    2014-01-01

    The blood-brain barrier (BBB) is a barrier that prevents free access of blood-derived substances to the brain through the tight junctions and maintains a specialized brain environment. Circumventricular organs (CVOs) lack the typical BBB. The fenestrated vasculature of the sensory CVOs, including the organum vasculosum of the lamina terminalis (OVLT), subfornical organ (SFO) and area postrema (AP), allows parenchyma cells to sense a variety of blood-derived information, including osmotic ones. In the present study, we utilized immunohistochemistry to examine changes in the expression of NG2 and platelet-derived growth factor receptor beta (PDGFRB) in the OVLT, SFO and AP of adult mice during chronic osmotic stimulation. The expression of NG2 and PDGFRB was remarkably prominent in pericytes, although these angiogenesis-associated proteins are highly expressed at pericytes of developing immature vasculature. The chronic salt loading prominently increased the expression of NG2 in the OVLT and SFO and that of PDGFRB in the OVLT, SFO and AP. The vascular permeability of low-molecular-mass tracer fluorescein isothiocyanate was increased significantly by chronic salt loading in the OVLT and SFO but not AP. In conclusion, the present study demonstrates changes in pericyte expression of NG2 and PDGFRB and vascular permeability in the sensory CVOs by chronic osmotic stimulation, indicating active participation of the vascular system in osmotic homeostasis.

  18. Optimisation of mass transfer kinetics during osmotic dehydration of pork meat cubes in complex osmotic solution

    Directory of Open Access Journals (Sweden)

    Filipović Vladimir

    2014-01-01

    Full Text Available This paper presents the effects of different process temperature (20, 35 and 50 °C, immersion time (1, 3 and 5 hours and the concentration of sugar beet molasses + NaCl + sucrose water solution on osmotic dehydration of pork meat (M. triceps brachii cubes, shaped 1 x 1 x 1 cm, at atmospheric pressure. The main objective was to examine the influence of different parameters on the mass transfer kinetics during osmotic treatment. The observed system’s responses were: water loss, solid gain, and water activity. The optimum osmotic conditions (temperature of 40 °C, treatment time of 4.1 h and concentration 67 %, were determined using response surface method, by superimposing the contour plots of each process variable, and the responses were: water loss=0.46, solid gain=0.15, and water activity=0.79. Transport coefficients, for both solids and water transfer and energy of activation for all samples were also determined. [Projekat Ministarstva nauke Republike Srbije, br. TR-31055

  19. 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.

  20. 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

  1. 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 expansi...... and designing actuator experiments and when comparing experimental results from different sources.......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...

  2. Osmotic pressure: resisting or promoting DNA ejection from phage

    CERN Document Server

    Jeembaeva, Meerim; Larsson, Frida; Evilevitch, Alex

    2008-01-01

    Recent in vitro experiments have shown that DNA ejection from bacteriophage can be partially stopped by surrounding osmotic pressure when ejected DNA is digested by DNase I on the course of ejection. We argue in this work by combination of experimental techniques (osmotic suppression without DNaseI monitored by UV absorbance, pulse-field electrophoresis, and cryo-EM visualization) and simple scaling modeling that intact genome (i.e. undigested) ejection in a crowded environment is, on the contrary, enhanced or eventually complete with the help of a pulling force resulting from DNA condensation induced by the osmotic stress itself. This demonstrates that in vivo, the osmotically stressed cell cytoplasm will promote phage DNA ejection rather than resisting it. The further addition of DNA-binding proteins under crowding conditions is shown to enhance the extent of ejection. We also found some optimal crowding conditions for which DNA content remaining in the capsid upon ejection is maximum, which correlates well...

  3. An evaluation of the osmotic method of controlling suction

    CERN Document Server

    Delage, Pierre

    2008-01-01

    Experimental techniques of testing the mechanical properties of unsaturated soils are complex and difficult to conduct. As a consequence, complete sets of parameters that characterise the behaviour of unsaturated soils remain scarce and necessary. In this context, it has been found useful to gather the information obtained after some years of practice of the osmotic technique of controlling suction. As compared to the more documented axis-translation technique, the osmotic technique has its own advantages and drawbacks that are discussed in this paper, together with some potential future developments. The osmotic method has been developed by soil scientists in the 1960s and adapted to geotechnical testing in the early 1970s. This paper presents the osmotic technique and comments on its advantages (including suction condition close to reality and higher suctions easily attained) and drawbacks (including some concern with the membrane resistance and some membrane effects in the suction/concentration calibration...

  4. 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.

  5. Erythrocyte osmotic fragility and oxidative stress in experimental hypothyroidism.

    Science.gov (United States)

    Dariyerli, Nuran; Toplan, Selmin; Akyolcu, Mehmet Can; Hatemi, Husrev; Yigit, Gunnur

    2004-10-01

    The present study was planned to explain the relation between erythrocyte osmotic fragility and oxidative stress and antioxidant statue in primary hypothyroid-induced experimental rats. Twenty-four Spraque Dawley type female rats were divided into two, as control (n = 12) and experimental (n = 12), groups weighing between 160 and 200 g. The experimental group animals have received tap water methimazole added standard fodder to block the iodine pumps for 30 d (75 mg/100 g). Control group animals were fed tap water and only standard fodder for the same period. At the end of 30 d blood samples were drawn from the abdominal aorta of the rats under ether anesthesia. T3, T4, and TSH levels were measured and the animals that had relatively lower T3, T4, and higher TSH levels were accepted as hypothyroid group. Hormone levels of the control group were at euthyroid conditions. Osmotic fragility, as a lipid peroxidation indicator malondialdehyde (MDA), antioxidant defense system indicators superoxide dismutase (SOD) and glutathione (GSH) levels were measured in the blood samples. Osmotic fragility test results: There was no statistically significant difference found between maximum osmotic hemolysis limit values of both group. Minimum osmotic hemolysis limit value of hypothyroid group was found to be higher than that of control group values (p proof of increased osmotic fragility of the erythrocytes in hypothyroidism. There is no statistically significant difference found between hypothyroid and control groups in the lipid peroxidation indicator MDA and antioxidant indicators SOD and GSH levels. As a result of our study it may be concluded that hypothyroidism may lead to an increase in osmotic fragility of erythrocytes. But the increase in erythrocyte osmotic fragility does not originate from lipid peroxidation.

  6. Movement disorders and the osmotic demyelination syndrome.

    Science.gov (United States)

    de Souza, Aaron

    2013-08-01

    With the advent of MRI, osmotic demyelination syndromes (ODS) are increasingly recognised to affect varied sites in the brain in addition to the classical central pontine lesion. Striatal involvement is seen in a large proportion of cases and results in a wide variety of movement disorders. Movement disorders and cognitive problems resulting from ODS affecting the basal ganglia may occur early in the course of the illness, or may present as delayed manifestations after the patient survives the acute phase. Such delayed symptoms may evolve over time, and may even progress despite treatment. Improved survival of patients in the last few decades due to better intensive care has led to an increase in the incidence of such delayed manifestations of ODS. While the outcome of ODS is not as dismal as hitherto believed - with the acute akinetic-rigid syndrome associated with striatal myelinolysis often responding to dopaminergic therapy - the delayed symptoms often prove refractory to medical therapy. This article presents a review of the epidemiology, pathophysiology, clinical features, imaging, and therapy of movement disorders associated with involvement of the basal ganglia in ODS. A comprehensive review of 54 previously published cases of movement disorders due to ODS, and a video recording depicting the spectrum of delayed movement disorders seen after recovery from ODS are also presented.

  7. 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.

  8. 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

  9. ANALISIS PERMEASI AIR PADA DEHIDRASI OSMOSIS PEPAYA (Carica papaya) Water Permeation Analysis on Osmotic Dehydration of Papaya (Carica papaya)

    OpenAIRE

    Sang Kompiang Wirawan; Natalia Anasta

    2013-01-01

    Fruit preservation using low temperature drying is commonly initiated by osmotic dehydration process. The osmotic time is strongly influenced by the water permeation from the fruit to the osmotic solution. This research aimed to study the osmotic dehydration process of papaya by finding out the permeation rate of water to the osmotic solution across a semi permeable membrane. The effect of temperature and osmotic solution concentration on the permeation rate were also observed. The osmotic te...

  10. Formulation and Evaluation of Controlled Porosity Osmotic Pump Tablet of Zaltoprofen

    Directory of Open Access Journals (Sweden)

    Jadav Mukesh M.

    2012-05-01

    Full Text Available Zaltoprofen is a non steroidal anti inflammatory class of drug which has excellent effect on post-surgeryor post trauma chronic inflammation of the drug. So, Zaltoprofen may serve as a potent and superioranalgesic for the treatment of pain. Zaltoprofen has the dose of 80 mg three times a day which reducepatient compliance. For that in this present study, an attempt has been made to prepare the controlledrelease CPOP tablet twice a day. An inclusion complex was prepared by kneading method using HP-β-CD in order to increase solubility of the poorly water soluble drug. Then, this complex is used forpreparing the tablet with accessorial material. CPOP tablet containing Zaltoprofen were prepared bydirect compression method by using various osmotic agent like sodium bicarbonate, sodium chloride,mannitol and potassium carbonate. Cellulose acetate, Sorbitol and Poly Ethylene Glycol 400 wereselected for coating materials, and acetone: methanol (65:35 co-solvent was employed as the coatingmedium with 3% and 5% weight gain. Initially compatibility study was carried out using DSC and FTIRSpectrometric method. The blend was examined for pre-compression parameters like angle of repose,density, compressibility index and Hausner’s ratio. Formulated tablet also passes the various tabletparameters like hardness, friability, drug content, weight variation. From the result of in-vitro drugrelease study it was observed that as the amount of osmotic agent increased, amount of drug releaseincreased. Also increased in % weight gain decreased the % drug release. Batch Z4 containing sodiumbicarbonate as osmotic agent has shown 98.08% drug release compare to other batches so, accepted asoptimized batch. The above optimized batch Z4 was also evaluated by different pharmacokinetic modelslike Zero order, First order, Higuchi, Korsmeyer Peppas, and Hixson Crowell model. The results ofthese models have shown that the batch Z4 controls the drug release for 12 hr and follows

  11. 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.

  12. 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.

  13. Ionic Origin of Electro-osmotic Flow Hysteresis

    Science.gov (United States)

    Lim, Chun Yee; Lim, An Eng; Lam, Yee Cheong

    2016-02-01

    Electro-osmotic flow, the driving of fluid at nano- or micro- scales with electric field, has found numerous applications, ranging from pumping to chemical and biomedical analyses in micro-devices. Electro-osmotic flow exhibits a puzzling hysteretic behavior when two fluids with different concentrations displace one another. The flow rate is faster when a higher concentration solution displaces a lower concentration one as compared to the flow in the reverse direction. Although electro-osmotic flow is a surface phenomenon, rather counter intuitively we demonstrate that electro-osmotic flow hysteresis originates from the accumulation or depletion of pH-governing minority ions in the bulk of the fluid, due to the imbalance of electric-field-induced ion flux. The pH and flow velocity are changed, depending on the flow direction. The understanding of electro-osmotic flow hysteresis is critical for accurate fluid flow control in microfluidic devices, and maintaining of constant pH in chemical and biological systems under an electric field.

  14. Modelling of mass transfer kinetic in osmotic dehydration of kiwifruit

    Science.gov (United States)

    Jabrayili, Sharokh; Farzaneh, Vahid; Zare, Zahra; Bakhshabadi, Hamid; Babazadeh, Zahra; Mokhtarian, Mohsen; Carvalho, Isabel S.

    2016-04-01

    Osmotic dehydration characteristics of kiwifruit were predicted by different activation functions of an artificial neural network. Osmotic solution concentration (y1), osmotic solution temperature (y2), and immersion time (y3) were considered as the input parameters and solid gain value (x1) and water loss value (x2) were selected as the outlet parameters of the network. The result showed that logarithm sigmoid activation function has greater performance than tangent hyperbolic activation function for the prediction of osmotic dehydration parameters of kiwifruit. The minimum mean relative error for the solid gain and water loss parameters with one hidden layer and 19 nods were 0.00574 and 0.0062% for logarithm sigmoid activation function, respectively, which introduced logarithm sigmoid function as a more appropriate tool in the prediction of the osmotic dehydration of kiwifruit slices. As a result, it is concluded that this network is capable in the prediction of solid gain and water loss parameters (responses) with the correlation coefficient values of 0.986 and 0.989, respectively.

  15. Electro-osmotic mobility of non-Newtonian fluids.

    Science.gov (United States)

    Zhao, Cunlu; Yang, Chun

    2011-03-23

    Electrokinetically driven microfluidic devices are usually used to analyze and process biofluids which can be classified as non-Newtonian fluids. Conventional electrokinetic theories resulting from Newtonian hydrodynamics then fail to describe the behaviors of these fluids. In this study, a theoretical analysis of electro-osmotic mobility of non-Newtonian fluids is reported. The general Cauchy momentum equation is simplified by incorporation of the Gouy-Chapman solution to the Poisson-Boltzmann equation and the Carreau fluid constitutive model. Then a nonlinear ordinary differential equation governing the electro-osmotic velocity of Carreau fluids is obtained and solved numerically. The effects of the Weissenberg number (Wi), the surface zeta potential (ψ¯s), the power-law exponent(n), and the transitional parameter (β) on electro-osmotic mobility are examined. It is shown that the results presented in this study for the electro-osmotic mobility of Carreau fluids are quite general so that the electro-osmotic mobility for the Newtonian fluids and the power-law fluids can be obtained as two limiting cases.

  16. Diffusion Magnetic Resonance Imaging May Provide Prognostic Information in Osmotic Demyelination Syndrome: Report of a Case

    Energy Technology Data Exchange (ETDEWEB)

    Dervisoglu, E.; Yegenaga, I.; Anik, Y.; Sengul, E.; Turgut, T. [Kocaeli Univ. (Turkey). Internal Medicine

    2006-03-15

    Hyponatremia and its rapid correction may cause osmotic demyelination syndrome (ODS) with damage to the pontine and extrapontine areas of the brain. The damage may become persistent or may regress and disappear during follow-up. We describe the case of a 35-year-old woman with chronic renal failure who was admitted to the emergency department with profound hyponatremia which was corrected rapidly after hemodialysis treatment. During follow-up, she developed quadriparesis and dysartria. Magnetic resonance imaging (MRI) demonstrated abnormalities characteristic of ODS in the pons as well as the basal ganglia with increased signal intensity on T2 and diffusion-weighted (DW) MRI and low apparent diffusion coefficient (ADC) values. After the sixth day, her clinical status improved progressively. Control MRI revealed rapid normalization of the ADC values during the first week and month parallel to the clinical improvement. However, the hyperintensities on T2-weighted images persisted. Four months later the MRI findings were completely normal. The close relationship between the ADC abnormality and the clinical status suggests that DW-MRI may be useful in predicting the prognosis of ODS. Keywords: Apparent diffusion coefficient; correction of hyponatremia; magnetic resonance imaging; osmotic demyelination.

  17. New Genes Involved in Osmotic Stress Tolerance in Saccharomyces cerevisiae

    Science.gov (United States)

    Gonzalez, Ramon; Morales, Pilar; Tronchoni, Jordi; Cordero-Bueso, Gustavo; Vaudano, Enrico; Quirós, Manuel; Novo, Maite; Torres-Pérez, Rafael; Valero, Eva

    2016-01-01

    Adaptation to changes in osmolarity is fundamental for the survival of living cells, and has implications in food and industrial biotechnology. It has been extensively studied in the yeast Saccharomyces cerevisiae, where the Hog1 stress activated protein kinase was discovered about 20 years ago. Hog1 is the core of the intracellular signaling pathway that governs the adaptive response to osmotic stress in this species. The main endpoint of this program is synthesis and intracellular retention of glycerol, as a compatible osmolyte. Despite many details of the signaling pathways and yeast responses to osmotic challenges have already been described, genome-wide approaches are contributing to refine our knowledge of yeast adaptation to hypertonic media. In this work, we used a quantitative fitness analysis approach in order to deepen our understanding of the interplay between yeast cells and the osmotic environment. Genetic requirements for proper growth under osmotic stress showed both common and specific features when hypertonic conditions were induced by either glucose or sorbitol. Tolerance to high-glucose content requires mitochondrial function, while defective protein targeting to peroxisome, GID-complex function (involved in negative regulation of gluconeogenesis), or chromatin dynamics, result in poor survival to sorbitol-induced osmotic stress. On the other side, the competitive disadvantage of yeast strains defective in the endomembrane system is relieved by hypertonic conditions. This finding points to the Golgi-endosome system as one of the main cell components negatively affected by hyperosmolarity. Most of the biological processes highlighted in this analysis had not been previously related to osmotic stress but are probably relevant in an ecological and evolutionary context. PMID:27733850

  18. Use of spent osmotic solutions for the production of fructooligosaccharides by Aspergillus oryzae N74.

    Science.gov (United States)

    Ruiz, Yolanda; Klotz, Bernadette; Serrato, Juan; Guio, Felipe; Bohórquez, Jorge; Sánchez, Oscar F

    2014-07-01

    In the food industry, osmotic dehydration can be an important stage to obtain partially dry foodstuffs. However, the remaining spent osmotic solution at the end of the process could become a waste with an important environmental impact due to the large amount of organic compounds that it might contain. Since one of the most important osmotic agents used in osmotic dehydration is sucrose, this spent osmotic solution could be used to be biotransformed to produce fructooligosaccharides by a fructosyltransferase. This study evaluated the production of fructooligosaccharides using the fructosyltransferase produced by Aspergillus oryzae N74, and the spent osmotic solution that resulted in the osmotic dehydration of Andes berry (Rubus glaucus) and tamarillo (Cyphomandra betacea). Assays were conducted at small and bioreactor scales, using spent osmotic solution with or without re-concentration. At small scale no significant difference (p > 0.05) was observed in the fructooligosaccharides production yield, ranging from 31.18% to 34.98% for spent osmotic solution from tamarillo osmotic dehydration, and from 33.16% to 37.52% for spent osmotic solution from Andes berry osmotic dehydration, using either the SOS with or without re-concentration. At bioreactor scale the highest fructooligosaccharides yield of 58.51 ± 1.73% was obtained with spent osmotic solution that resulted from tamarillo osmotic dehydration. With the spent osmotic solution from Andes berry osmotic dehydration the yield was 49.17 ± 2.82%. These results showed the feasibility of producing fructooligosaccharides from spent osmotic solution that is considered a waste in food industry.

  19. Electro-osmotic transport in wet processing of textiles

    Science.gov (United States)

    Cooper, John F.

    1998-01-01

    Electro-osmotic (or electrokinetic) transport is used to efficiently force a solution (or water) through the interior of the fibers or yarns of textile materials for wet processing of textiles. The textile material is passed between electrodes that apply an electric field across the fabric. Used alone or in parallel with conventional hydraulic washing (forced convection), electro-osmotic transport greatly reduces the amount of water used in wet processing. The amount of water required to achieve a fixed level of rinsing of tint can be reduced, for example, to 1-5 lbs water per pound of fabric from an industry benchmark of 20 lbs water/lb fabric.

  20. Osmotically induced cell swelling versus cell shrinking elicits specific changes in phospholipid signals in tobacco pollen tubes

    NARCIS (Netherlands)

    L.E. Zonia; T. Munnik

    2004-01-01

    Pollen tube cell volume changes rapidly in response to perturbation of the extracellular osmotic potential. This report shows that specific phospholipid signals are differentially stimulated or attenuated during osmotic perturbations. Hypo-osmotic stress induces rapid increases in phosphatidic acid

  1. 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.

  2. EFFECT OF TABLET FORMULATION VARIABLES ON TRAMADOL HCL ELEMENTARY OSMOTIC PUMP TABLET

    OpenAIRE

    Basani Gavaskar; Dilip Dodda; Subash Vijaya Kumar

    2010-01-01

    Osmotic drug delivery system utilize osmotic pressure as a energy source and driving force for delivery of drugs, pH presence of food under physiological factors may affect drug release from conventional controlled release system (Matrices and reservoirs), where as drug release from osmotic system is independent of these factors to a large extent. The aim of the current study was to formulate elementary osmotic pump tablets of water soluble Tramadol HCl. Formulation were prepared based on wet...

  3. Osmotic Stressing, Membrane Leakage, and Fluorescence: An Introductory Biochemistry Demonstration

    Science.gov (United States)

    Seu, Kalani J.

    2015-01-01

    A fluorescence demonstration is described that incorporates several fundamental aspects of an introductory biochemistry course. A variation of a known leakage assay is utilized to prepare vesicles containing a quenched fluorophore. The vesicles are exposed to several osmotic environments ranging from isotonic to hypotonic. The degree of vesicle…

  4. Mass Transfer During Osmotic Dehydration Using Acoustic Cavitation

    Institute of Scientific and Technical Information of China (English)

    孙宝芝; 淮秀兰; 姜任秋; 刘登瀛

    2005-01-01

    An experimental study on intensifying osmotic dehydration was carried out in a state of nature and with acoustic cavitation of different cavitating intensity (0.5A, 0.TA and 0.9A) respectively, in which the material is apple slice of 5 mm thickness. The result showed that acoustic cavitation remarkably enhanced the osmotic dehydration, and the water loss was accelerated with the increase of cavitating intensity. The water diffusivity coefficients ranged from 1.8 × 10-10 m2.s-1 at 0.5A to 2.6 × 10-10 m2.s-1 at 0.9A, and solute diffusivity coefficients ranged from 3.5×10-11 m2.s-1 at 0.5A to 4.6×10-11 m2.s-1 at 0.9A. On the basis of experiments, a mathematical model was established about mass transfer during osmotic dehydration, and the numerical simulation was carried out. The calculated results agree well with experimental data, and represent the rule of mass transfer during osmotic dehydration intensified by acoustic cavitation.

  5. Electro-osmotically controllable multi-flow microreactor

    NARCIS (Netherlands)

    Kohlheyer, Dietrich; Besselink, Geert A.J.; Lammertink, Rob G.H.; Schlautmann, Stefan; Unnikrishnan, Sandeep; Schasfoort, Richard B.M.

    2005-01-01

    An adjustable diffusion-based microfluidic reactor is presented here, which is based on electro-osmotic guiding of reagent samples. The device consists of a laminar flow chamber with two separate reagent inlets. The position and the width of the two sample streams in the flow chamber can be controll

  6. 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 hig...

  7. An Overview on Osmotic Controlled Drug Delivery System

    Directory of Open Access Journals (Sweden)

    Thummar A

    2013-06-01

    Full Text Available This paper reviews constructed drug delivery systems applying osmotic principles for controlled drugrelease from the formulation. Osmotic devices which are tablets coated with walls of controlled porosityare the most promising strategy based systems for controlled drug delivery. In contrast to commontablets, these pumps provide constant (zero order drug release rate. When these systems are exposed towater, low levels of water soluble additive is leached from polymeric material i.e. semipermeablemembrane and drug releases in a controlled manner over an extended period of time. The main clinicalbenefits of oral osmotic drug delivery system are their ability to improve treatment tolerability andpatient compliance. These advantages are mainly driven by the capacity to deliver drugs in a sustainedmanner, independent of the drug chemical properties, of the patient’s physiological factors or followingfood intake. This review brings out the theoretical concept of drug delivery, history, advantages anddisadvantages of the delivery systems, types of oral osmotic drug delivery systems, factors affecting thedrug delivery system and marketed products.

  8. 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...

  9. Self-consistent unstirred layers in osmotically driven flows

    DEFF Research Database (Denmark)

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

    2010-01-01

    on both sides of the membrane remain well mixed due to an external stirring mechanism. We investigate the effects of concentration boundary layers on the efficiency of osmotic pumping processes in the absence of external stirring, i.e. when all advection is provided by the osmosis itself. This case...

  10. Modeling and computational simulation of the osmotic evaporation process

    Directory of Open Access Journals (Sweden)

    Freddy Forero Longas

    2016-09-01

    Full Text Available Context: Within the processing technologies with membranes, osmotic evaporation is a promising alternative for the transformation of exotic fruits, generating concentrated products that can be used in the daily diet, being easier to consume, reducing transportation costs and increasing shelf life.Method: In this research, it was studied and developed a comprehensive strategy for multiphysics modeling and simulation of mass and momentum transfer phenomena in the process of osmotic evaporation through Comsol® and Matlab® software. It was used an axial geometry approach in two dimensions as simplifications of real module and the finite element method for the numerical solution. The simulations were validated experimentally in an osmotic evaporation system of laboratory scale.Results: The models used and the generated simulations were statistically significant (p <0,05 in predicting the flux behavior, taking into account the effect of flow and temperature feed together with the brine flow, being obtained correlations above 96% between experimental and calculated data.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.

  11. 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…

  12. Evaluation of total carotenoids and ascorbic acid in osmotic pretreated guavas during convective drying

    NARCIS (Netherlands)

    Sanjinez-Argandona, EJ; Cunha, RL; Menegalli, FC; Hubinger, MD

    2005-01-01

    Degradation of ascorbic acid and carotenoid content in osmotic pretreated and convective dried guavas was investigated. The osmotic dehydration was performed in a semi-continuous flow osmotic contactor at 40 degrees C for two hours with sucrose solution at 60% (w/ w). Pretreated guava sticks were dr

  13. Cryopreservation of coffee zygotic embryos: dehydration and osmotic rehydration

    Directory of Open Access Journals (Sweden)

    Maísa de Siqueira Pinto

    Full Text Available ABSTRACT Conservation of plant genetic resources is important to prevent genetic erosion. Seed banks are the most common method of ex situ conservation; however, coffee seeds can not be stored by conventional methods. Cryopreservation is a viable alternative for long-term conservation of species that produce intermediate or recalcitrant seeds, as coffee. The aim of this work was to cryopreserve Coffea arabica L. cv Catuaí Vermelho IAC 144 zygotic embryos, and analyse the effects of dehydration prior cryopreservation and osmotic rehydration after thawing, in embryos germination and seedlings formation after cryopreservation. Prior to cryopreservation, different dehydration times (0, 15, 30, 60 and 120 min were tested. Dehydrated embryos were cryopreserved in liquid nitrogen for 1 hour, and after thawing were rehydrated by osmotic solutions. Dehydrated and non-cryopreserved embryos were also analysed. The test with 2,3,5 triphenyl tetrazolium chloride (TTC was used to evaluate the embryos viability. Non-dehydrated embryos did not survive after freezing. Embryos that were dehydrated until 20% of the moisture content did not germinate when osmotic rehydration was not performed. In contrast, cryopreserved embryos with the same moisture content presented 98% germination when they were rehydrated slowly in osmotic solution. According to tetrazolium tests, embryos presented maximum viability (75% after dehydration for 60 minutes (23% moisture content. Therefore, coffee zygotic embryos (Coffea arabica L. cv. Catuaí Vermelho can be successfully cryopreserved using physical dehydration in silica gel for 60 minutes (23% moisture content, followed by osmotic rehydration after thawing. This method allowed a germination of 98% of cryopreserved zygotic embryos.

  14. Prostaglandin E2, thromboxane B2, and leukotriene B4 release from peritoneal macrophages by different osmotic agents in nonuremic guinea pigs.

    Science.gov (United States)

    Hain, H; Jörres, A; Kögel, B; Mahiout, A; Gahl, G M; Kessel, M

    1988-01-01

    Interleukin-1 (Il-1), prostaglandins, and leukotrienes have been identified as inflammatory parameters in the setting of peritoneal dialysis. Recently, it was postulated that chronic overstimulation of peritoneal macrophages (PM) may result in fibrosis and loss of ultrafiltration. The aim of the present study was to investigate whether alternative osmotic agents (polyglucose, amino acids, glycerol, bicarbonate/glucose, gelatine, hydroxyethyl starch) provoke greater eicosanoid release by PMs than glucose. Fifty milliliters of sterile dialysate containing different osmotic agents were injected intraperitoneally into nonuremic guinea pigs. After 4 hours of dwell time, prostaglandin E2 (PGE2), thromboxane B2 (TXB2), and leukotriene B4 (LTB4) production was analyzed in peritoneal effluents using specific radioimmunoassays (RIA) after liquid extraction. Cyclooxygenase products were generated with all osmotic agents: PGE2 concentrations ranged from 0.9 to 2.8 ng/4h, and TXB2 levels ranged from 39 to 49 ng/4h. In addition, the lipoxygenase product LTB4 was found in concentrations between 1.8 and 3.5 ng/4h. There were no significant differences in eicosanoid release among the osmotic agents. Thus, in this experimental setting, the capacity of PM to release inflammatory mediators did not correlate with the chemical composition of the dialysis solutions.

  15. Drying of red beetroot after osmotic pretreatment: Kinetics and quality considerations

    Directory of Open Access Journals (Sweden)

    Kowalski Stefan J.

    2015-09-01

    Full Text Available This article presents experimental studies on drying kinetics and quality effects of red beetroot (Beta vulgaris L. after convective drying with a preliminary osmotic pretreatment. The effects of the osmotic agent (NaCl concentration and the osmotic bath time on the product colour and nutrient content preservation, the water activity, and rehydration ability after drying were analysed. Osmotic dehydration curves and Solid Gain (SG, Water Loss (WL, Weight Reduction (WR were determined. It was proved that drying of beetroot with osmotic pretreatment contributes to shorter drying time, smaller water activity, higher retention of betanin, better colour preservation, and a greater degree of water resorption.

  16. Determination of Nucleic Acid Hydration Using Osmotic Stress

    Science.gov (United States)

    Rozners, Eriks

    2010-01-01

    Understanding the role water plays in biological processes requires detailed knowledge of the phenomena of biopolymer hydration. Crystal structures have identified exact sites occupied by the water molecules in immediate hydration layers. NMR and molecular modeling have provided information on dynamics of water molecules occupying these sites. However, these studies give little information on the thermodynamic contribution of water molecules to conformational equilibria and recognition affinity. This unit describes probing of nucleic acid hydration using osmotic stress, a method that provides thermodynamic information complementary to crystallography, NMR and molecular modeling. Osmotic stress monitors the depression of melting temperature upon decreasing the water activity and calculates the number of thermodynamically unique water molecules associated with the double helix and released from the single strands upon melting. PMID:21154532

  17. 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......, combinations of polyethylene glycol and electrolyte lavage solutions (PEG-ELS), and magnesium citrate. All these preparations give adequate cleansing results and have similar profiles in terms of the frequency and type of mild to moderate adverse effects. However, serious adverse events, such as severe...... 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...

  18. Osmotic stress affects functional properties of human melanoma cell lines

    CERN Document Server

    La Porta, Caterina A M; Pasini, Maria; Laurson, Lasse; Alava, Mikko J; Zapperi, Stefano; Amar, Martine Ben

    2015-01-01

    Understanding the role of microenvironment in cancer growth and metastasis is a key issue for cancer research. Here, we study the effect of osmotic pressure on the functional properties of primary and metastatic melanoma cell lines. In particular, we experimentally quantify individual cell motility and transmigration capability. We then perform a circular scratch assay to study how a cancer cell front invades an empty space. Our results show that primary melanoma cells are sensitive to a low osmotic pressure, while metastatic cells are less. To better understand the experimental results, we introduce and study a continuous model for the dynamics of a cell layer and a stochastic discrete model for cell proliferation and diffusion. The two models capture essential features of the experimental results and allow to make predictions for a wide range of experimentally measurable parameters.

  19. Self-consistent unstirred layers in osmotically driven flows

    Science.gov (United States)

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

    2010-11-01

    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 on both sides of the membrane remain well-mixed due to an external stirring mechanism. We investigate the effects of concentration boundary layers on the efficiency of osmotic pumping processes in the absence of external stirring i.e. when all advection is provided by the osmosis itself. This case is relevant in the study of intracellular flows, e.g. in plants. For such systems, we show that no well-defined boundary layer thickness exists and that the reduction in concentration can be estimated by a surprisingly simple mathematical relation across a wide range of geometries and P'eclet numbers. This work is accepted for publication in Journal of Fluid Mechanics.

  20. The safety of osmotically acting cathartics in colonic cleansing

    DEFF Research Database (Denmark)

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

    2010-01-01

    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......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...... function and water and electrolyte balance. The available evidence indicates that PEG-ELS-based products are the safest option. Magnesium-citrate-based, hypertonic products should be administered with caution to elderly individuals and patients who are prone to develop disturbances in water and electrolyte...

  1. Role of osmotic and hydrostatic pressures in bacteriophage genome ejection

    CERN Document Server

    Lemay, Serge G; Molineux, Ian J

    2012-01-01

    A critical step in the bacteriophage life cycle is genome ejection into host bacteria. The ejection process for double-stranded DNA phages has been studied thoroughly \\textit{in vitro}, where after triggering with the cellular receptor the genome ejects into a buffer. The experimental data have been interpreted in terms of the decrease in free energy of the densely packed DNA associated with genome ejection. Here we detail a simple model of genome ejection in terms of the hydrostatic and osmotic pressures inside the phage, a bacterium, and a buffer solution/culture medium. We argue that the hydrodynamic flow associated with the water movement from the buffer solution into the phage capsid and further drainage into the bacterial cytoplasm, driven by the osmotic gradient between the bacterial cytoplasm and culture medium, provides an alternative mechanism for phage genome ejection \\textit{in vivo}; the mechanism is perfectly consistent with phage genome ejection \\textit{in vitro}.

  2. Giant Osmotic Pressure in the Forced Wetting of Hydrophobic Nanopores.

    Science.gov (United States)

    Michelin-Jamois, Millan; Picard, Cyril; Vigier, Gérard; Charlaix, Elisabeth

    2015-07-17

    The forced intrusion of water in hydrophobic nanoporous pulverulent material is of interest for quick storage of energy. With nanometric pores the energy storage capacity is controlled by interfacial phenomena. With subnanometric pores, we demonstrate that a breakdown occurs with the emergence of molecular exclusion as a leading contribution. This bulk exclusion effect leads to an osmotic contribution to the pressure that can reach levels never previously sustained. We illustrate, on various electrolytes and different microporous materials, that a simple osmotic pressure law accounts quantitatively for the enhancement of the intrusion and extrusion pressures governing the forced wetting and spontaneous drying of the nanopores. Using electrolyte solutions, energy storage and power capacities can be widely enhanced.

  3. 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.

  4. Osmotic demyelination syndrome with a dysequilibrium syndrome: reversible MRI findings

    Energy Technology Data Exchange (ETDEWEB)

    Agildere, A.M.; Coskun, M.; Boyvat, F. [Baskent University Medical School Hospital, Radiology Department, Ankara (Turkey); Benli, S. [Baskent University Medical School Hospital, Neurology Department, Ankara (Turkey); Erten, Y.; Oezdemir, N. [Baskent University Medical School Hospital, Nephrology Department, Ankara (Turkey)

    1998-04-01

    Neurological disorders may be seen in end-stage renal disease patients due to uraemia or to complications of dialysis. A dysequilibrium syndrome may be seen, usually soon after or towards the end of haemodialysis. This group of patients has no particular findings on MRI. On the other hand, the osmotic demyelination syndrome has definitive MRI findings, not to date reported with the dysequilibrium syndrome. We report a patient with end-stage renal disease and the dysequilibrium syndrome who showed findings of osmotic demyelination on MRI. The patient had a convulsion after a first haemodialysis, with quadriparesis and hyperactive deep tendon reflexes and bilateral Babinski signs. The upper motor neurone signs lasted for a week. Meanwhile, he was also dysarthric and had dysphagia. He recovered neurologically without any residuum following appropriate treatment and there was improvement on MRI. (orig.) With 3 figs., 11 refs.

  5. An Osmotic Model of the Growing Pollen Tube

    OpenAIRE

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

    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 reg...

  6. Characterization of osmotically induced filaments of Salmonella enterica.

    Science.gov (United States)

    Pratt, Zachary L; Chen, Bingming; Czuprynski, Charles J; Wong, Amy C L; Kaspar, Charles W

    2012-09-01

    Salmonella enterica forms aseptate filaments with multiple nucleoids when cultured in hyperosmotic conditions. These osmotic-induced filaments are viable and form single colonies on agar plates even though they contain multiple genomes and have the potential to divide into multiple daughter cells. Introducing filaments that are formed during osmotic stress into culture conditions without additional humectants results in the formation of septa and their division into individual cells, which could present challenges to retrospective analyses of infectious dose and risk assessments. We sought to characterize the underlying mechanisms of osmotic-induced filament formation. The concentration of proteins and chromosomal DNA in filaments and control cells was similar when standardized by biomass. Furthermore, penicillin-binding proteins in the membrane of salmonellae were active in vitro. The activity of penicillin-binding protein 2 was greater in filaments than in control cells, suggesting that it may have a role in osmotic-induced filament formation. Filaments contained more ATP than did control cells in standardized cell suspensions, though the levels of two F(0)F(1)-ATP synthase subunits were reduced. Furthermore, filaments could septate and divide within 8 h in 0.2 × Luria-Bertani broth at 23°C, while nonfilamentous control cells did not replicate. Based upon the ability of filaments to septate and divide in this diluted broth, a method was developed to enumerate by plate count the number of individual, viable cells within a population of filaments. This method could aid in retrospective analyses of infectious dose of filamented salmonellae.

  7. Vitamin E effect on osmotic fragility in β thalassemia major

    Directory of Open Access Journals (Sweden)

    Agus Fitrianto

    2014-09-01

    Full Text Available Background Blood transfusion remains the main therapy for anemia in β thalassemia major patients. However, frequent transfusions can cause oxidative stress in response to iron overload. Vitamin E is considered to be the best lipid-soluble exogenous antioxidant in humans. It can protect phospholipid membrane from peroxidation. Erythrocyte osmotic fragility is a useful test to assess for the improvement of red blood cells in thalassemia patients after vitamin E supplementation. Objective To investigate the effect of vitamin E for improving erythrocyte osmotic fragility in β- thalassemia major and for decreasing the need for frequent transfusions. Methods This was a double blind placebo controlled randomized clinical trial on children aged 2-14 years with thalassemia major who received frequent blood transfusions. Fifty subjects were divided into 2 groups: group I with vitamin E supplementation and group II with placebo, as a control group, for a period of 1 month. Pre- and post-treatment data on erythrocyte osmotic fragility and hemoglobin level were analyzed with non-paired T-test. Results Improved erythrocyte osmotic fragility was found: in group I, pre-treatment 31.59 (SD 6.342% to post-treatment 38.08 (SD 7.165%, compared to the control group pre-treatment 34.40 (SD 6.985% to post-treatment 29.26 (SD 9.011% (P=0.0001. Comparison of the mean delta Hb level in group I was 0.94 (SD 0.605 gr% and that of group II was - 0.23 (SD 1.199 gr% (P= 0.0001. Conclusion Vitamin E supplementation improves erythrocyte fragility and Hb level in β-thalassemia major pediatric patients. [Paediatr Indones. 2014;54:280-3.].

  8. FORMULATION AND EVALUATION OF BACLOFEN CONTROLLED POROSITY OSMOTIC PUMP TABLETS

    Directory of Open Access Journals (Sweden)

    Indarapu Rajendra Prasad

    2013-06-01

    Full Text Available In the present study, attempts were made to develop and evaluate the controlled porosity osmotic pump (CPOP based drug delivery system of sparingly water soluble drug Baclofen. Formulation variables, such as, levels of solubility enhancer, ratio of drug to osmogents, coat thickness of semi permeable membrane (SPM and level of pore former were found to affect the drug release from the developed formulations. Cellulose acetate was used as the semi permeable membrane. Drug release was directly proportional to the level of the solubility enhancer, osmotic pressure generated by osmotic agent and level of pore former; however, was inversely proportional to the coat thickness of SPM. Drug release from developed formulations was independent of pH and agitation intensities of release media. Burst strength of the exhausted shells decreased with increase in the level of pore former. This system was found to deliver Baclofen at a zero-order rate. The optimized formulations were subjected to stability studies as per ICH guidelines, and formulations were found to be stable after 45days study.

  9. 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.

  10. 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.

  11. FORMULATION AND EVALUATION OF CONTROLLED POROSITY OSMOTIC TABLETS OF LORNOXICAM

    Directory of Open Access Journals (Sweden)

    A. Uma Maheswari*, K. Elango, Daisy Chellakumari, K. Saravanan and Anglina Jeniffer Samy

    2012-06-01

    Full Text Available The aim of the present study is to formulate and evaluate controlled release formulation of lornoxicam based on osmotic technology. Lornoxicam, a potent non-steroidal anti-inflammatory drug (NSAID with shorter half life, makes the development of sustained release (SR dosage forms extremely advantageous. However, due to its weak acidic nature, its release from SR delivery system is limited to the lower GIT which consequently leads to a delayed onset of its analgesic action. Basic pH modifier tromethamine and wicking agent SLS were incorporated into the core tablet to create basic environmental pH inside the tablets, which provide complete drug release that starts in the stomach to rapidly alleviate the painful symptoms and continue in the intestine to maintain protracted analgesic effect. The effect of different formulation variables namely level of osmogen (mannitol in the core tablet and level of pore former (sorbitol in the coating membrane on in-vitro release was studied. Lornoxicam release from controlled porosity osmotic pump was directly proportional to the pore former (sorbitol and level of osmogen (mannitol. Drug release from the developed formulations was independent of pH and agitational intensity and was dependent on osmotic pressure of the release media. Results of SEM studies showed the formation of pores in the membrane from where the drug release occurred. The optimized formulation was found to release the drug in zero order and found to be stable upon stability studies.

  12. Intravesical electro-osmotic administration of mitomycin C.

    Science.gov (United States)

    Di Stasi, Savino M; Verri, Cristian; Celestino, Francesco; De Carlo, Francesco; Pagliarulo, Vincenzo

    2016-10-04

    Bladder cancer is very common and most cases are diagnosed as nonmuscle invasive disease, which is characterized by its propensity to recur and progress. Intravesical therapy is used to delay recurrence and progression, while cystectomy is reserved for patients who are refractory to transurethral resection and intravesical therapy. There is an increasing interest in methods to enhance the delivery of intravesical chemotherapeutic agents to improve efficacy. In vitro and in vivo studies demonstrated that electro-osmosis of mitomycin C (MMC) is more effective in delivering this drug into the urothelium, lamina propria, and superficial muscle layers of the bladder wall than is passive transport. Higher MMC tissue concentrations might have a clinical impact in the treatment of nonmuscle invasive bladder cancer (NMIBC). In randomized trials, intravesical electro-osmotic MMC was associated with superior response rate in high-risk NMIBC cancer, compared with passive diffusion MMC transport. New strategies such as intravesical Bacillus Calmette-Guerin (BCG) combined with electro-osmotic MMC as well as intravesical pre-operative electro-osmotic MMC provided promising results in terms of higher remission rates and longer remission times.Device-assisted intravesical chemotherapy may be a useful ancillary procedure in the treatment of NMIBC. Its evaluation must be planned with respect to the technical functioning of equipment and their use for a clear purpose to avoid the financial and human costs associated with incorrect therapies.

  13. Enhancement of light in tissue using hyper-osmotic agents

    Science.gov (United States)

    Zaman, Raiyan T.; Chen, Bo; Parthasarathy, Ashwin B.; Estrada, Arnold D., Jr.; Ponticorvo, Ardien; Rylander, Henry G., III; Dunn, Andrew K.; Welch, Ashley J.

    2008-02-01

    Optical changes in skin blood flow due to the presence of glycerol were measured from a two-dimensional map of blood flow in skin blood vessels with a dynamic imaging technique using laser speckle. In this study a dorsal skin-flap window was implanted on the hamster skin with and without a hyper-osmotic agent i.e. glycerol. The hyper-osmotic drug was delivered to the skin through the open dermal end of the window model. A two-dimensional map of blood flow in skin blood vessels were obtained with very high spatial and temporal resolution by imaging the speckle pattern with a CCD camera. Preliminary studies demonstrated that hyper-osmotic agents such as glycerol not only make tissue temporarily translucent, but also reduce blood flow. The blood perfusion was measured every 3 minutes up to 36-60 minutes after diffusion of anhydrous glycerol. Small capillaries blood flow reduced significantly within 3-9 minutes. Perfusion rate in lager blood vessels i.e. all arteries and some veins decreased (speckle contrasts increased from 0.0115 to 0.384) over time. However, the blood flow in some veins reduced significantly in 36 minutes. After 24 hours the blood perfusion further reduced in capillaries. However, the blood flow increased in larger blood vessels in 24 hours compared to an hour after application of glycerol. For further investigation the speckle contrast measurement were verified with color Doppler optical coherence tomography.

  14. Chronic pancreatitis

    Science.gov (United States)

    Chronic pancreatitis - chronic; Pancreatitis - chronic - discharge; Pancreatic insufficiency - chronic; Acute pancreatitis - chronic ... alcohol abuse over many years. Repeated episodes of acute ... chronic pancreatitis. Genetics may be a factor in some cases. ...

  15. 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

  16. 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

  17. Storage of osmotically treated entomopathogenic nematode Steinernema carpocapsae

    Institute of Scientific and Technical Information of China (English)

    SHI-PENG FENG; RI-CHOU HAN; XUE-HONG QIU; LI CAO; JING-HUA CHEN; GUO-HONG WANG

    2006-01-01

    The infective juveniles (IJs) of Steinernema carpocapsae 'All' were osmotically stressed by a mixture of ionic (fortified artificial seawater) and non-ionic (3.2 mol/Lglycerol) solutions to establish a method for osmotic storage of entomopathogenic nematodes.Seven combinations (termed solution A to G) with different proportions of these two solutions were tested, with sterile extra pure water (sepH2O, termed solution H) as a control. The mortality of the IJs at a concentration of 5 × 105 IJ/mL in the solutions A to G, and H were 13.2%,16.2%, 16.7%, 13.5%, 25.2%, 31.6%, 44.6%, and 1.0%, respectively, after 21 days storage at 25℃. Most of the IJs shrunk and stopped motility after 6-9 hours incubation at 25℃ in solutions A to D. Based on the results, solutions A to D and H were chosen to further test the osmotic survival of the IJs at different IJ concentrations (5×105, 2.5 × 105, 2000 IJ/mL) and incubation temperature (30℃, 25℃, 10℃). The resulting IJs were exposed to a high temperature assay (45℃ for 4 h, HTA). Osmotically stressed IJs showed improved heat tolerance. The mortality of the IJs increased with the increasing concentrations of the test IJs and the storage temperatures after exposing to the HTA. More than 88.4%, 62.3% or 2.4% of the treated IJs died at the above three IJ concentrations, respectively. At the three IJ concentrations (2 000 IJs/mL, 2.5 × 105 IJs/mL or 5 × 105 IJs/mL), the highest mortality was recorded in solution D (11.6%, 85.9% or 98.0%, respectively), and the lowest mortality in solution B (2.4%, 62.3% or 86.6%, respectively). No untreated IJs survived after the heat treatment. During 42 days storage at 10℃, the IJs mortality in the solutions A to D and H were 7.19%, 5.97%,4.41%, 4.34%, and 4.34% respectively, and showed no significant differences. In conclusion,solutions enhances the heat tolerance. The mortality of the IJs after HTA increased with the increasing concentrations of the test IJs and the storage

  18. Ultrasound-assisted osmotic dehydration and convective drying of apples: Process kinetics and quality issues

    OpenAIRE

    Mierzwa Dominik; Kowalski Stefan J.

    2016-01-01

    The aim of the present theme issue was to study the influence of ultrasound enhancement on the kinetics of osmotic dehydration and the effect of convective drying from the point of view of drying time and quality of dried products. Apple fruit was used as the experimental material. The kinetics of osmotic dehydration with (UAOD) and without (OD) ultrasound enhancement were examined for 40% fructose and sorbitol solutions. The effective dehydration time of osmotic process was determined. Preli...

  19. 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.

  20. 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.

  1. Osmotic stress inhibits thymidine incorporation into soybean protoplast DNA.

    Science.gov (United States)

    Cress, D E

    1982-10-01

    DNA synthesis in protoplasts isolated from soybean cell suspension cultures has been investigated by [(3)H] thymidine uptake and incorporation kinetics. Initial rates of incorporation in exponential and 5-fluorodeoxyuridine synchronized protoplasts are inhibited by increased osmolarities of the medium. The inhibition was not readily reversible during 3 h culture in low osmotic medium. Velocity sedimentation analyses of replicating DNA from such protoplasts shows a complex pattern of inhibition. The inhibition probably effects replicon initiation as well as strand elongation and ligation of replication intermediates.

  2. Sporadic hypokalemic paralysis caused by osmotic diuresis in diabetes mellitus.

    Science.gov (United States)

    Vishnu, Venugopalan Y; Kattadimmal, Anoop; Rao, Suparna A; Kadhiravan, Tamilarasu

    2014-07-01

    A wide variety of neurological manifestations are known in patients with diabetes mellitus. We describe a 40-year-old man who presented with hypokalemic paralysis. On evaluation, we found that the cause of the hypokalemia was osmotic diuresis induced by marked hyperglycemia due to undiagnosed diabetes mellitus. The patient had an uneventful recovery with potassium replacement, followed by glycemic control with insulin. Barring a few instances of symptomatic hypokalemia in the setting of diabetic emergencies, to our knowledge uncomplicated hyperglycemia has not been reported to result in hypokalemic paralysis.

  3. Erythrocyte survival in chronic renal failure. Role of secondary hyperparathyroidism.

    OpenAIRE

    Akmal, M; Telfer, N; Ansari, A N; Massry, S G

    1985-01-01

    The human erythrocyte (RBC) is a target organ for parathyroid hormone (PTH) and the hormone increases RBC osmotic fragility and induces their hemolysis. The present study was undertaken to examine whether elevated blood levels of PTH affect RBC survival, and therefore whether PTH, being an extracorpuscular factor, is responsible for the shortened RBC survival in chronic renal failure. 51Cr-labeled RBC survival was elevated in six normal dogs, in six animals with chronic renal failure and seco...

  4. Osmotic and osmotic-loop diuresis in brain surgery. Effects on plasma and CSF electrolytes and ion excretion.

    Science.gov (United States)

    Schettini, A; Stahurski, B; Young, H F

    1982-05-01

    In 22 patients to be operated on for brain tumors or cerebral aneurysms, the effect of osmotic diuresis was compared with that of osmotic-loop diuresis on plasma and cerebrospinal fluid (CSF) electrolytes, and water and ion excretion. Mannitol or mannitol plus furosemide were used to reduce brain bulk. After treatment with thiopental and hyperventilation, patients received randomly a rapid infusion of mannitol (1.4 gm/kg), or mannitol (1.4 gm/kg) plus furosemide (0.3 mg/kg). Brain shrinkage was considerably greater and more consistent with mannitol plus furosemide than with mannitol alone. However, hyponatremia, hypokalemia, hypochloremia, and hyperosmolality were also more marked (p less than 0.05) with mannitol plus furosemide than with mannitol. The rate of water and ion excretion was even more striking. At 30 minutes after absorption of mannitol alone, water excretion peaked at 17 ml/min, and gradually decreased to 3.8 ml/min 70 minutes later. With mannitol plus furosemide, during an identical time course, initial water excretion was 30 ml/min, followed by a further rise to 42 ml/min and then a decline to 17 ml/min. At peak diuresis after mannitol, Na+ and Cl- excretion average 0.57 and 0.62 mEq/min, respectively. This compares with mean values of 3.7 and 4.12 mEq/min for Na+ and Cl-, respectively, after mannitol plus furosemide. Although optimum brain shrinkage is achieved with osmotic-loop diuresis, the rapid electrolyte depletion (Na+ and Cl-) must be corrected to avoid altered sensorium during the patients' postoperative course.

  5. Local adaptation of an anuran amphibian to osmotically stressful environments.

    Science.gov (United States)

    Gomez-Mestre, Ivan; Tejedo, Miguel

    2003-08-01

    Water salinity is an intense physiological stress for amphibians. However, some species, such as Bufo calamita, breed in both brackish and freshwater environments. Because selection under environmentally stressful conditions can promote local adaptation of populations, we examined the existence of geographic variation in water salinity tolerance among B. calamita populations from either fresh or brackish water ponds in Southern Spain. Comparisons were made throughout various ontogenetic stages. A combination of field transplant and common garden experiments showed that water salinity decreased survival probability of individuals in all populations, prolonged their larval period, and reduced their mass at metamorphosis. However, significant population x salinity interactions indicated that the population native to brackish water (Saline) had a higher salinity tolerance than the freshwater populations, suggesting local adaptation. Saline individuals transplanted to freshwater environments showed similar survival probabilities, length of larval period, and mass at metamorphosis than those native to freshwater. This indicates that increased tolerance to osmotic stress does not imply a loss of performance in freshwater, at least during the larval and juvenile phases. Despite the adaptive process apparently undergone by Saline, all populations still shared the same upper limit of embryonic stress tolerance (around 10 g/l), defining a window of salinity range within which selection can act. Significant differences in embryonic and larval survival in brackish water among sibships for all populations suggest the existence of a genetic basis for the osmotic tolerance.

  6. Process variables in the osmotic dehydration of sliced peaches

    Directory of Open Access Journals (Sweden)

    Sílvia Pimentel Marconi Germer

    2010-12-01

    Full Text Available This paper evaluated the influence of temperature and concentration of the sucrose syrup on the pre-osmotic dehydration of peaches. Physical (colour and texture and chemical variables (soluble solid content; total sugar, reducing and non-reducing sugar contents; and titratable acidity were investigated, as well as the osmotic dehydration parameters (loss of weight and water; solids incorporation. An experimental central composite design was employed varying the temperature (from 30 to 50 ºC and concentration (from 45 to 65 ºBrix and maintaining the syrup to fruit ratio (4:1, process time (4 hours, and format (slices. The degree of acceptance was used in the sensory analysis evaluating the following characteristics: appearance, taste, texture, colour, and overall quality using a hedonic scale. The results were modelled using the Statistica program (v. 6.0 and the Response Surface Methodology. The mathematical models of the following dimensionless variations yielded significant (p < 0.05 and predictive results: soluble solids content, total and non-reducing sugar contents, titratable acidity, colour parameter L*, and water loss. The models of the attributes colour and appearance yielded significant (p < 0.10 but not predictive results. Temperature was the prevalent effect in the models. The process conditions in the range from 50 to 54.1 ºC and from 45 to 65 ºBrix led to greater water losses and better sensory performances.

  7. Osmotic membrane bioreactor for phenol biodegradation under continuous operation.

    Science.gov (United States)

    Praveen, Prashant; Loh, Kai-Chee

    2016-03-15

    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 600-2000mg/L, and also at spiked concentrations of 2500mg/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 5500mg/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 7.4h. A washing cycle, comprising 1h osmotic backwashing using 0.5M NaCl and 2h washing with water, facilitated biofilm removal from the membranes. Characterization of the extracellular polymeric substances (EPS) through FTIR showed peaks between 1700 and 1500cm(-1), 1450-1450cm(-1) and 1200-1000cm(-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. 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.

  9. 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....... A solute-free paper disc was placed on the skin for sampling of the clear CSF uniformly covering the body surface. The osmolality measured in a Wescor Vapro Vapor Osmometer was, 173 ± 9 mosmol/Kg, mean ± se, n = 21 samples. The osmolality of CSF of isoproterenol injected frogs at 20 °C was, 149 ± 5 mosmol...

  10. Laboratory experiments for estimating chemical osmotic parameters of mudstones

    Science.gov (United States)

    Miyoshi, S.; Tokunaga, T.; Mogi, K.; Ito, K.; Takeda, M.

    2010-12-01

    Recent studies have quantitatively shown that mudstone can act as semi-permeable membrane and can generate abnormally high pore pressure in sedimentary basins. Reflection coefficient is one of the important properties that affect the chemical osmotic behavior of mudstones. However, not many quantitative studies on the reflection coefficient of mudstones have been done. We have developed a laboratory apparatus to observe chemical osmotic behavior, and a numerical simulation technique to estimate the reflection coefficient and other relating properties of mudstones. A core sample of siliceous mudstone obtained from the drilled core at Horonobe, Japan, was set into the apparatus and was saturated by 0.1mol/L sodium chloride solution. Then, the up-side reservoir was replaced with 0.05mol/L sodium chloride solution, and temporal changes of both pressure and concentration of the solution in both up-side and bottom-side reservoirs were measured. Using the data obtained from the experiment, we estimated the reflection coefficient, effective diffusion coefficient, hydraulic conductivity, and specific storage of the sample by fitting the numerical simulation results with the observed ones. A preliminary numerical simulation of groundwater flow and solute migration was conducted in the area where the core sample was obtained, using the reflection coefficient and other properties obtained from this study. The result suggested that the abnormal pore pressure observed in the region can be explained by the chemical osmosis.

  11. Water osmotic absorption in Coleus blumei plants under salinity stress

    Directory of Open Access Journals (Sweden)

    José Ozinaldo Alves de Sena

    2006-11-01

    Full Text Available Three month old Coleus blumei plants in pots were treated with different NaCl concentrations: 0.00, 0.25, 0.50 and 1.00%. To determine the water osmotic absorption, the plants had their stems cut at 10 cm from the soil surface. The remaining stems were linked to glass tubes by flexible rubber tubes. Readings of the water column level in the glass tubes were performed at each 30 minutes, corresponding to the water osmotic absorption, with a total of eleven readings. Other Coleus blumei, with the same age, received the NaCl concentrations, and were evaluated under field conditions in terms of transpiration and stomatal resistance. A randomized complete block analysis was used with five replications. An increase of osmotic absorption was verified for all treatments up to three hours after application. Then a proportional reversion of osmotic absorption to the increases on saline concentration was observed, with a higher effect in the treatment with NaCl 1.00%, showing the increase of water loss by the roots. During this period time, the treatment showed a normal linear growth of the osmotic absorption. Transpiration was reduced proportionally to the increase of salinity concentration.Mudas envasadas de Coleus blumei, com três meses de idade, foram submetidas a diferentes concentrações de cloreto de sódio (NaCl: 0,00; 0,25; 0,50 e 1,00%. Visando determinar a absorção osmótica, as mudas tiveram seus caules cortados a 10 cm acima do solo. Os caules remanescentes foram interligados a tubos de vidro por tubos flexíveis de borracha. Foram feitas leituras (cm a cada 30 minutos dos níveis das colunas de água nos capilares, correspondentes às absorções osmóticas de água, sendo ao todo realizadas onze leituras. Em outro momento, mudas de C. blumei, com a mesma idade das anteriores, receberam as mesmas concentrações de NaCl descritas anteriormente, e, ao ar livre, foram avaliadas em termos de transpiração e resistência estomática, usando

  12. Colloid osmotic pressure in decompensated cirrhosis. A 'mirror image' of portal venous hypertension

    DEFF Research Database (Denmark)

    Henriksen, J H

    1985-01-01

    in the interstitial space and ascitic fluid is related to and most likely secondary to the elevated portal pressure in decompensated cirrhosis. Effective colloid osmotic pressure may therefore be regarded as a 'mirror image' of transmural portal pressure. The role of colloid osmotic pressure in the genesis...

  13. Use of Osmotic Pumps to Establish the Pharmacokinetic-Pharmacodynamic Relationship and Define Desirable Human Performance Characteristics for Aggrecanase Inhibitors.

    Science.gov (United States)

    Wiley, Michael R; Durham, Timothy B; Adams, Lisa A; Chambers, Mark G; Lin, Chaohua; Liu, Chin; Marimuthu, Jothirajah; Mitchell, Peter G; Mudra, Daniel R; Swearingen, Craig A; Toth, James L; Weller, Jennifer M; Thirunavukkarasu, Kannan

    2016-06-23

    The development of reliable relationships between in vivo target engagement, pharmacodynamic activity, and efficacy in chronic disease models is beneficial for enabling hypothesis-driven drug discovery and facilitating the development of patient-focused candidate selection criteria. Toward those ends, osmotic infusion pumps can be useful for overcoming limitations in the PK properties of proof-of-concept (POC) compounds to accelerate the development of such relationships. In this report, we describe the application of this strategy to the development of hydantoin-derived aggrecanase inhibitors (eg, 3) for the treatment of osteoarthiritis (OA). Potent, selective inhibitors were efficacious in both chemical and surgical models of OA when exposures were sustained in excess of 10 times the plasma IC50. The use of these data for establishing patient-focused candidate selection criteria is exemplified with the characterization of compound 8, which is projected to sustain the desired level of target engagement at a dose of 45 mg qd.

  14. ENHANCING OSMOTIC DEHYDRATION WITH ACOUSTIC CAVITATION%声空化强化渗透脱水

    Institute of Scientific and Technical Information of China (English)

    孙宝芝; 姜任秋; 淮秀兰; 李斌; 刘登瀛

    2004-01-01

    An experimental study was carried out to enhance osmotic dehydration of fruits--apples using acoustic cavitation. The variation in water losses and dry matter gain rates of materials with solute concentration, cavitation intensity, the thickness of materials and treating time segment during osmotic dehydration was discussed, at the same time, the influence of different materials on mass transfer during osmotic dehydration using acoustic cavitation was investigated. The results showed that water losses rates of materials were remarkably increased during osmotic dehydration using acoustic cavitation, but dry matter gain rates increased very little. Meanwhile the physical mechanism of enhanced mass transfer during osmotic dehydration with acoustic cavitation was clarified on the basis of analyzing the experimental results.

  15. Design and Development of Osmotic Drug Delivery System for Anti-Hypertensive Agent

    Directory of Open Access Journals (Sweden)

    Shah N

    2013-04-01

    Full Text Available Controlled porosity osmotic tablet of Atenolol prepared and evaluated in this study. Atenolol is v lowsoluble drug. So it is difficult to formulate osmotic tablet of Atenolol which gives drug release up to 24hr at zero order. To get desired dissolution profile various formulation parameters like osmogenconcentration, level of weight gain and level of pore former concentration were studied. Polysorbate 80was added as solubilizer to increase its dissolution rate and get drug release up to 24 hr at zero order. Asconcentration of solubilizer increases, dissolution rate increases. Final optimized formulation wasstudied for effect of pH of dissolution media, agitation intensity and osmotic pressure of dissolutionmedia. There is no effect of pH of dissolution media and agitation intensity on dissolution. There issignificant effect of osmotic pressure on dissolution confirms that prepared Atenolol tablet gives drugrelease in osmotically control manner.

  16. A balanced JA/ABA status may correlate with adaptation to osmotic stress in Vitis cells.

    Science.gov (United States)

    Ismail, Ahmed; Seo, Mitsunori; Takebayashi, Yumiko; Kamiya, Yuji; Nick, Peter

    2015-08-01

    Water-related stress is considered a major type of plant stress. Osmotic stress, in particular, represents the common part of all water-related stresses. Therefore, plants have evolved different adaptive mechanisms to cope with osmotic-related disturbances. In the current work, two grapevine cell lines that differ in their osmotic adaptability, Vitis rupestris and Vitis riparia, were investigated under mannitol-induced osmotic stress. To dissect signals that lead to adaptability from those related to sensitivity, osmotic-triggered responses with respect to jasmonic acid (JA) and its active form JA-Ile, abscisic acid (ABA), and stilbene compounds, as well as the expression of their related genes were observed. In addition, the transcript levels of the cellular homeostasis gene NHX1 were examined. The data are discussed with a hypothesis suggesting that a balance of JA and ABA status might correlate with cellular responses, either guiding cells to sensitivity or to progress toward adaptation.

  17. Universality of osmotically driven sap-flow in plants

    Science.gov (United States)

    Bohr, Tomas; Hartvig Jensen, Kåre; Berg Sørensen, Kirstine; Mørch Friis, Søren; Liesche, Johannes; Schulz, Alexander

    2011-11-01

    Since Ernst Münch in the 1920s proposed that sugar transport in the phloem vascular system of plants is driven by passive osmotic pressure gradients, it has been strongly debated whether this hypothesis can account even for long distance translocation. Recently, it was shown that theoretical optimization of the Münch mechanism leads to surprisingly simple predictions for the dimensions of the phloem sieve elements in relation to those of the plants [Jensen et. al., J. Roy. Soc. Interface 8, pp. 1155-1165 (2011)]. We show that the theoretical results are very insensitive to the details of the sugar-loading (in leaves) and unloading (in shoots or roots) and can even be obtained from a simple coupled resistor model. We have compiled anatomical data for a wide group of plants and find good agreement with theory, even for conifer trees, in which the sugar translocation is substantially slower than hardwood trees.

  18. Osmotic Force-Controlled Microrheometry of Entangled Actin Networks

    Science.gov (United States)

    Uhde, Jorg; Feneberg, Wolfgang; Ter-Oganessian, N.; Sackmann, Erich; Boulbitch, Alexei

    2005-05-01

    In studying a magnetic bead’s creep response to force pulses in an entangled actin network we have found a novel regime where the bead motion obeys a power law x(t)˜t1/2 over two decades in time. It is flanked by a short-time regime with x(t)˜t3/4 and a viscous with x(t)˜t. In the intermediate regime the creep compliance depends on the actin concentration c as c-β with β≈1.1±0.3. We explain this behavior in terms of osmotic restoring force generated by the piling up of filaments in front of the moving bead. A model based on this concept predicts intermediate x(t)˜t1/2 and long-time regimes x(t)˜t in which the compliance varies as c-4/3, in agreement with experiment.

  19. 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

    2015-01-01

    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.

  20. 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.

  1. Chronic Constipation: Current Treatment Options

    Directory of Open Access Journals (Sweden)

    Louis Wing Cheong Liu

    2011-01-01

    Full Text Available Chronic constipation is a common functional gastrointestinal disorder that affects patients of all ages. In 2007, a consensus group of 10 Canadian gastroenterologists developed a set of recommendations pertaining to the management of chronic constipation and constipation-dominant irritable bowel syndrome. Since then, tegaserod has been withdrawn from the Canadian market. A new, highly selective serotonin receptor subtype 4 agonist, prucalopride, has been examined in several large, randomized, placebo-controlled trials demonstrating its efficacy and safety in the management of patients with chronic constipation. Additional studies evaluating the use of stimulant laxatives, polyethylene glycol and probiotics in the management of chronic constipation have also been published. The present review summarizes the previous recommendations and new evidence supporting different treatment modalities – namely, diet and lifestyle, bulking agents, stool softeners, osmotic and stimulant laxatives, prucalopride and probiotics in the management of chronic constipation. A brief summary of lubiprostone and linaclotide is also presented. The quality of evidence is presented by adopting the Grading of Recommendations, Assessment, Development and Evaluation system. Finally, a management pyramid for patients with chronic constipation is proposed based on the quality of evidence, impact of each modality on constipation and on general health, and their availabilities in Canada.

  2. 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.

  3. 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...

  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 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.

  6. Osmotic pressure of ionic liquids in an electric double layer: Prediction based on a continuum model.

    Science.gov (United States)

    Moon, Gi Jong; Ahn, Myung Mo; Kang, In Seok

    2015-12-01

    An analysis has been performed for the osmotic pressure of ionic liquids in the electric double layer (EDL). By using the electromechanical approach, we first derive a differential equation that is valid for computing the osmotic pressure in the continuum limit of any incompressible fluid in EDL. Then a specific model for ionic liquids proposed by Bazant et al. [M. Z. Bazant, B. D. Storey, and A. A. Kornyshev, Phys. Rev. Lett. 106, 046102 (2011)] is adopted for more detailed computation of the osmotic pressure. Ionic liquids are characterized by the correlation and the steric effects of ions and their effects are analyzed. In the low voltage cases, the correlation effect is dominant and the problem becomes linear. For this low voltage limit, a closed form formula is derived for predicting the osmotic pressure in EDL with no overlapping. It is found that the osmotic pressure decreases as the correlation effect increases. The osmotic pressures at the nanoslit surface and nanoslit centerline are also obtained for the low voltage limit. For the cases of moderately high voltage with high correlation factor, approximate formulas are derived for estimating osmotic pressure values based on the concept of a condensed layer near the electrode. In order to corroborate the results predicted by analytical studies, the full nonlinear model has been solved numerically.

  7. Experimental examination of the relationships among chemico-osmotic, hydraulic, and diffusion parameters of Wakkanai mudstones

    Science.gov (United States)

    Takeda, M.; Hiratsuka, T.; Manaka, M.; Finsterle, S.; Ito, K.

    2014-05-01

    Sequential permeability and chemical osmosis experiments on Wakkanai mudstones were performed to explore the relationships between the semipermeability of clayey rocks and the hydraulic and diffusion parameters as well as the pore structure characteristics. The wide ranges in osmotic efficiency (0.0004-0.046) and intrinsic permeability (8.92 × 10-20 to 1.24 × 10-17 m2) reflect the variation in the pore size distributions of the Wakkanai mudstones. A regression analysis between osmotic efficiency and permeability shows that the osmotic efficiency is proportional to the inverse of permeability, suggesting that the permeability is indeed indicative of the degree of semipermeability. Osmotic efficiency was determined invariant with the effective diffusion coefficient for the Wakkanai mudstones (3.59-8.36 × 10-11 m2/s) due to their small osmotic efficiencies (≤0.046). The wide variation in osmotic efficiencies and pore structure characteristics of Wakkanai mudstones indicates that the nanoscale pores enable semipermeability in Wakkanai mudstones. However, the pressure evolution caused by chemical osmosis is limited by the connected wide pores that are the main conduits for water, thus dissipating the osmotic pressure buildup induced by the semipermeability of nanoscale pores.

  8. [Osmotic shock induces expression of Vibrio fischeri lux genes in Escherichia coli cells].

    Science.gov (United States)

    Zavil'gel'skiĭ, G B; Kotova, V Iu

    2003-04-01

    The effect of osmotic shock on the expression of genes in the lux regulon of marine bacteria Vibrio fischeri was studied in cells of Escherichia coli. Bioluminescence of cells was shown to drastically increase, when cells were exposed to osmotic shock at the early logarithmic growth phase. The expression of lux genes induced by osmotic shock is determined by the two-component regulatory system RcsC-RcsB. A nucleotide sequence in the regulatory region of the luxR gene homologous to the RcsB-box consensus of E. coli is assumed to be a primary site for this system.

  9. 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...

  10. Osmotic stress-regulated the expression of glutathione peroxidase 3 in Arabidopsis

    Institute of Scientific and Technical Information of China (English)

    MIAO YuChen; GUO JingGong; LIU ErTao; LI Kun; DAI Jie; WANG PengCheng; CHEN Jia; SONG ChunPeng

    2007-01-01

    Gene expression of glutathione peroxidase 3 (ATGPX3) in response to osmotic stress was analyzed in Arabidopsis using ATGPX3 promoter-glucuronidase (GUS) transgenic plants. High levels of GUS expression were detected under osmotic stress in ATGPX3 promoter-GUS transgenic plants. Compared with the wild type, the growth and development of ATGPX3 mutants (atgpx3-1) were more sensitive to mannitol. In addition, the expression of RD29A, ABI1, ABI2 and RbohD in atgpx3-1 was induced by ABA stress. These results suggest that ATGPX3 might be involved in the signal transduction of osmotic stress.

  11. 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

    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...

  12. Selection and characterization of tomato plants for osmotic stress tolerance derived from a gamma ray irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Kwon Kyoo; Jung, Yu Jin [Hankyong National University, Anseong (Korea, Republic of)

    2010-09-15

    The present study has been performed to select the osmotic tolerant lines using polyethylene glycol (PEG 6000)through an in vitro and in vivo mutagensis with a gamma-ray. During the screening, we selected three mutant lines that seemed to confer elevated osmotic tolerance in high concentrations of PEG 6000. Fruits of these mutants (Os-HK101, Os-HK102 and Os-HK103) were those of the wild type. Also the chlorophyll contents were few decreased more in the three mutant lines than the WT plants. Our results suggest that the Os-HK101 is characterized as osmotic stress tolerance considering the sugar concentration and lycopine content. It is expected that the result of this study can be used for breeding more competitive species with respect to contents in sugar or functional chemicals from the selected osmotic resistant lines.

  13. Osmotic and oxidative/nitrosative stress in ammonia toxicity and hepatic encephalopathy.

    Science.gov (United States)

    Görg, Boris; Schliess, Freimut; Häussinger, Dieter

    2013-08-15

    Hepatic encephalopathy (HE) is a neuropsychiatric complication of acute or chronic liver failure. Currently, HE in cirrhotic patients is seen as a clinical manifestation of a low grade cerebral edema which exacerbates in response to a variety of precipitating factors after an ammonia-induced exhaustion of the volume-regulatory capacity of the astrocyte. Astrocyte swelling triggers a complex signaling cascade which relies on NMDA receptor activation, elevation of intracellular Ca(2+) concentration and prostanoid-driven glutamate exocytosis, which result in increased formation of reactive nitrogen and oxygen species (RNOS) through activation of NADPH oxidase and nitric oxide synthase. Since RNOS in turn promote astrocyte swelling, a self-amplifying signaling loop between osmotic- and oxidative stress ensues, which triggers a variety of downstream consequences. These include protein tyrosine nitration (PTN), oxidation of RNA, mobilization of zinc, alterations in intra- and intercellular signaling and multiple effects on gene transcription. Whereas PTN can affect the function of a variety of proteins, such as glutamine synthetase, oxidized RNA may affect local protein synthesis at synapses, thereby potentially interfering with protein synthesis-dependent memory formation. PTN and RNA oxidation are also found in post mortem human cerebral cortex of cirrhotic patients with HE but not in those without HE, thereby confirming a role for oxidative stress in the pathophysiology of HE. Evidence derived from animal experiments and human post mortem brain tissue also indicates an up-regulation of microglia activation markers in the absence of increased synthesis of pro-inflammatory cytokines. However, the role of activated microglia in the pathophysiology of HE needs to be worked out in more detail. Most recent observations made in whole genome micro-array analyses of post mortem human brain tissue point to a hitherto unrecognized activation of multiple anti

  14. The "Le Chatelier's principle"-governed response of actin filaments to osmotic stress.

    Science.gov (United States)

    Ito, Tadanao; Yamazaki, Masahito

    2006-07-13

    Actin filaments inhibit osmotic stress-driven water flow across a semipermeable membrane in proportion to the filament concentration (Ito, T.; Zaner, K. S.; Stossel, T. P. Biophys. J. 1987, 51, 745). When the filaments are cross-linked by F-actin binding protein, filamin A, this flow is stopped completely (Ito, T.; Suzuki, A.; Stossel, T. P. Biophys. J. 1992, 61, 1301). No conventional theory accurately accounts for these results. Here, this response is analyzed by formulating the entropy of the system under osmotic stress. Results demonstrate that the response of the actin filaments to osmotic stress is governed by the Le Chatelier's principle, which states that an external interaction that disturbs the equilibrium brings about processes in the body that tend to reduce the effects of this interaction. In the present case, disrupting equilibrium by osmotic stress brings about a reaction that decreases the chemical potential of water in the F-actin solution, reducing the effect of the applied osmotic disturbance. This decrease in the chemical potential of the water in the F-actin solution is caused by an increase in the chemical potential of F-actin, which is induced by isothermal absorption of heat by F-actin aided by work done by osmotic stress. As a result, F-actin has an inhibitory effect on the osmotic stress-driven water flow, and can even completely stop the flow when it is cross-linked. This is the first report demonstrating that the Le Chatelier's principle applies to the reaction of biopolymers against equilibrium disturbances such as osmotic stress.

  15. Interleukin-1 inhibits osmotically-induced calcium signaling and volume regulation in articular chondrocytes

    Science.gov (United States)

    Pritchard, Scott; Votta, Bartholomew J.; Kumar, Sanjay; Guilak, Farshid

    2011-01-01

    OBJECTIVE Articular chondrocytes respond to osmotic stress with transient changes in cell volume and the intracellular concentration of calcium ion ([Ca2+]i). The goal of this study was to examine the hypothesis that interleukin-1 (IL-1), a pro-inflammatory cytokine associated with osteoarthritis, influences osmotically-induced Ca2+ signaling. METHODS Fluorescence ratio imaging was used to measure [Ca2+]i and cell volume in response to hypo- or hyper-osmotic stress in isolated porcine chondrocytes, with or without pre-exposure to 10 ng/ml IL-1α. Inhibitors of IL-1 (IL-1 receptor antagonist, IL-Ra), Ca2+ mobilization (thapsigargin, an inhibitor of Ca-ATPases), and cytoskeletal remodeling (Toxin B, an inhibitor of the Rho family of small GTPases) were used to determine the mechanisms involved in increased [Ca2+]i, F-actin remodeling, volume adaptation and active volume recovery. RESULTS In response to osmotic stress, chondrocytes exhibited transient increases in [Ca2+]i, generally followed by decaying oscillations. Pre-exposure to IL-1 significantly inhibited regulatory volume decrease following hypo-osmotic swelling and reduced the change in cell volume and the time to peak [Ca2+]i in response to hyper-osmotic stress, but did not affect the peak magnitudes of [Ca2+]i in those cells that did response. Co-treatment with IL-1Ra, thapsigargin, or Toxin B restored these responses to control levels. The effects were associated with alterations in F-actin organization. CONCLUSIONS IL-1 alters the normal volumetric and Ca2+ signaling response of chondrocytes to osmotic stress through mechanisms involving F-actin remodeling via small Rho GTPases. These findings provide further insights into the mechanisms by which IL-1 may interfere with normal physiologic processes in the chondrocyte, such as the adaptation or regulatory responses to mechanical and osmotic loading. PMID:18495501

  16. The design of aided software for osmotic stress responding genes mining in plant genome

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    A software and algorithm which based on random sequence model uses osmotic stress responding cis elements from existing information sources of biology was designed. It can infer the genie downstream function of Arabidopsis thaliana through analyzing its promoter region, and can offer effective aided analysis to mine osmotic stress responding genes in Arabidopsis thaliana genome. The practical application proves that this software can aid to analyze vast genie data and offer important data evidence.

  17. Active Osmotic Exchanger for Efficient Nanofiltration Inspired by the Kidney

    Science.gov (United States)

    Marbach, Sophie; Bocquet, Lydéric

    2016-07-01

    In this paper, we investigate the physical mechanisms underlying one of the most efficient filtration devices: the kidney. Building on a minimal model of the Henle loop—the central part of the kidney filtration—we investigate theoretically the detailed out-of-equilibrium fluxes in this separation process in order to obtain absolute theoretical bounds for its efficiency in terms of separation ability and energy consumption. We demonstrate that this separation process operates at a remarkably small energy cost as compared to traditional sieving processes while working at much smaller pressures. This unique energetic efficiency originates in the double-loop geometry of the nephron, which operates as an active osmotic exchanger. The principles for an artificial-kidney-inspired filtration device could be readily mimicked based on existing soft technologies to build compact and low-energy artificial dialytic devices. Such a "kidney on a chip" also points to new avenues for advanced water recycling, targeting, in particular, sea-water pretreatment for decontamination and hardness reduction.

  18. Miniature osmotic actuators for controlled maxillofacial distraction osteogenesis

    Science.gov (United States)

    Li, Yu-Hsien; Su, Yu-Chuan

    2010-06-01

    We have successfully demonstrated miniature actuators that are capable of converting chemical potential directly into steady mechanical movements for maxillofacial distraction osteogenesis. Pistons and diaphragms powered by osmosis are employed to provide the desired linear and volumetric displacements for bone distraction and potentially the release of bone morphogenetic proteins, respectively. The cylindrical-shaped miniature actuators are composed of polymeric materials and fabricated by molding and assembly processes. In the prototype demonstration, vapor-permeable thermoplastic polyurethane was employed as the semi-permeable material. 3 cm long actuators with piston and diaphragm radii of 1 mm and 500 µm, respectively, were fabricated and characterized. The maximum distraction force from the piston-type actuator is found to be 6 N while the piston travels at a constant velocity of 32 µm h-1 (or 0.77 mm/day) for about 1 week. Meanwhile, the release rate from the diaphragm-type actuator is measured to be constant, 0.15 µl h-1 (or 3.6 µl/day), throughout the experiment. Moreover, the sizes and output characteristics of the self-regulating actuators could readily be tailored to realize optimal distraction rate, rhythm and osteogenic activity. As such, the demonstrated miniature osmotic actuators could potentially serve as versatile apparatuses for maxillofacial distraction osteogenesis and fulfill the needs of a variety of implantable and biomedical applications.

  19. 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.

  20. Osmotic shock as alternative method to control Acanthaster planci

    Institute of Scientific and Technical Information of China (English)

    Jairo Rivera-Posada; Leigh Owens

    2014-01-01

    Objective:To test six osmotic stressors as alternative methods to control Acanthaster planci (A. planci) outbreaks by exploiting their incapacity to tolerate drastic changes in osmolarity. Finding more effective ways to control A. planci outbreaks is one of the most immediate and effective ways by which to reverse rapid declines in the abundance of live coral cover in the Indo-Pacific. Methods: A total of 10 mL of each of the following chemicals: sodium chloride, ethylenediaminetetraacetic acid, sodium carbonate, sodium cholate, sodium deoxycholate, urea and mannitol were injected into individual healthy sea stars to examine which chemicals induced disease and death. Results:Four out of six chemicals used in this study induced disease. Sodium chloride, sodium cholate, sodium deoxycholate and ethylenediaminetetraacetic acid are capable of inducing death in injected sea stars offering an alternative option to control A. planci outbreaks. Conclusions: Hyperosmotic stress is a viable alternative to control A. planci outbreaks as massive cell death results when acute hypertonicity exceeds a certain level.

  1. [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).

  2. Rationalization of Sucrose Solution Using During the Fruit Osmotic Dehydration

    Directory of Open Access Journals (Sweden)

    Mirko Babić

    2009-12-01

    Full Text Available The model of sustainable energy production of dried fruit conducted by using combined technology – the model that has been developed at the Faculty of Agriculture in Novi Sad – includes osmotic dehydration of fruit in sucrose solution. During the process of dehydration the moisture content of the solution is increased due to mass transfer of moisture from fruit. This article examines different models of recycling and concentrating of the solution. Thus, the model for concentrating of the solution has been chosen according to this analysis, and it has been applied within its own technology. Evaporators of the low temperature solution have been used and they are based on the solar energy source. Two types of devices have been made on the basis of the heating process of evaporating. One type is filled with the stainless steel shavings, while the other type is based on the fillings by plates. The paper presents the evaluation model of the benefits of this concentrating manner as well as the evaluation criterion of the evaporators’ fillings types. The energy support used here was an original solar air heater of semi-concentrated type.

  3. Weak microwave can alleviate water deficit induced by osmotic stress in wheat seedlings.

    Science.gov (United States)

    Chen, Yi-Ping; Jia, Jing-Fen; Han, Xiao-Ling

    2009-01-01

    The aim of the investigation is to determine the effect of microwave pretreatment of wheat seeds on the resistance of seedlings to osmotic stress. Changes in biophysical, physiological and biochemical characters were measured. The results showed: (1) The magnetic field intensity and seeds temperature increased progressively with microwave pretreatments of 5, 10, 15, 20 s and 25 s compared with controls. Although each microwave pretreatment resulted in an increase in alpha-amylase activity and photon emission intensity, the increase of alpha-amylase activity and photon emission intensity was maximal at a microwave pretreatment of 10 s. (2) Osmotic stress induced by PEG treatment enhanced the concentration of malondialdehyde, while decreasing the activities of nitricoxide synthase, catalase, peroxidase, superoxide dismutase and the concentration of nitric oxide, ascorbic acid, glutathione in the seedlings compared with controls. However, compared to osmotic stress alone, in the seedlings treated with microwave irradiation plus osmotic stress the concentration of malondialdehyde decreased, while the activities of nitricoxide synthase, catalase, peroxidase, superoxide dismutase and the concentration of nitric oxide, ascorbic acid and glutathione increased. These results suggest that a suitable dose of microwave radiation can enhance the capability to eliminate free radicals induced by osmotic stress in wheat seedlings resulting in an increase in resistance to osmotic stress.

  4. Effect on effective diffusion coefficients and investigation of shrinkage during osmotic dehydration of apricot

    Energy Technology Data Exchange (ETDEWEB)

    Togrul, Inci Turk; Ispir, Ayse [Firat University, Engineering Faculty, Department of Chemical Engineering, 23279 Elazig (Turkey)

    2007-10-15

    This article represents the results of the variation in density and shrinkage of apricots during its osmotic dehydration. Shrinkage was investigated by means of dimensionless volume, diameter and length. Various osmotic agents such as sucrose, glucose, fructose, maltodextrin and sorbitol were used. It was found that the shrinkage of apricots could be well correlated with the moisture content of the sample during osmotic dehydration. The relationship between dimensionless parameters and moisture content was investigated by using eight non-linear models for each osmotic agent. It was find that the following proposed model can be confidently use for explaining the effect of shrinkage during osmotic dehydration of apricots.V/V{sub 0},D/D{sub 0},L/L{sub 0},{rho}/{rho}{sub 0}=a+b. exp (cX)+d. exp (e.X{sup f})In addition, the osmotic dehydration kinetics of apricots with and without shrinkage was studied. The effective diffusivities calculated from the diffusional model with and without shrinkage varied from 10.342 x 10{sup -9} m{sup 2}/s to 5.139 x 10{sup -9} and from 1.755 x 10{sup -10} and 0.767 x 10{sup -10} m{sup 2}/s, respectively. (author)

  5. A phloem-sap feeder mixes phloem and xylem sap to regulate osmotic potential.

    Science.gov (United States)

    Pompon, Julien; Quiring, Dan; Goyer, Claudia; Giordanengo, Philippe; Pelletier, Yvan

    2011-09-01

    Phloem-sap feeders (Hemiptera) occasionally consume the dilute sap of xylem, a behaviour that has previously been associated with replenishing water balance following dehydration. However, a recent study reported that non-dehydrated aphids ingested xylem sap. Here, we tested the hypothesis that the consumption of xylem sap, which has a low osmolality, is a general response to osmotic stresses other than dehydration. Alate aphids were subjected to different treatments and subsequently transferred onto a plant, where electrical penetration graph (EPG) was used to estimate durations of passive phloem sap consumption and active sucking of xylem sap. The proportion of time aphids fed on xylem sap (i.e., time spent feeding on xylem sap/total time spent feeding on phloem plus xylem sap) was used as a proxy of the solute concentration of the uptake. The proportion of time alate aphids fed on xylem sap increased: (1) with the time spent imbibing an artificial diet containing a solution of sucrose, which is highly concentrated in phloem sap and is mainly responsible for the high osmotic potential of phloem sap; (2) with the osmotic potential of the artificial diet, when osmotic potential excess was not related to sucrose concentration; and (3) when aphids were deprived of primary symbionts, a condition previously shown to lead to a higher haemolymph osmotic potential. All our results converge to support the hypothesis that xylem sap consumption contributes to the regulation of the osmotic potential in phloem-sap feeders.

  6. Chronic myelogenous leukemia (CML)

    Science.gov (United States)

    CML; Chronic myeloid leukemia; Chronic granulocytic leukemia; Leukemia - chronic granulocytic ... Chronic myelogenous leukemia is grouped into phases: Chronic Accelerated Blast crisis The chronic phase can last for ...

  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. The effects of La(III) on the peroxidation of membrane lipids in wheat seedling leaves under osmotic stress.

    Science.gov (United States)

    Zeng, F; An, Y; Zhang, H; Zhang, M

    1999-08-01

    The physiological effects of the rare earth ion La3+ on the peroxidation of membrane lipids in wheat (Triticum aestivum L.) seedling leaves under osmotic stress were determined. With the passage of time under osmotic stress, the inhibition ability of lanthanum ions to the relative membrane permeability and concentration of malondialdehyde, superoxide radicals, and hydrogen peroxide caused by osmotic stress increased substantially, but no changes were noted in ferrous and relative water content. It indicated that lanthanum ions could not retain the water content because of osmotic stress. However, La3+ appears to decrease the production of *OH by reducing the content of O2*- and H2O2 of Haber-Weiss and Fenton reactions, which efficiently alleviated peroxidation of membrane lipids under osmotic stress and, to some degree, protected the membrane from injury of free radicals. Thus, La3+ increased the tolerance ability of plant to osmotic stress, which could assure the function of membrane normal temporally after stressed.

  9. Osmotic Pressure: Conceptions & Misconceptions from Pfeffer, to Van't Hoff, to Einstein, to Fermi, to the Present

    Science.gov (United States)

    Reiff, Theodore R.

    2006-11-01

    A phenomenological approach to understanding osmotic pressure in terms of competing effects of solute-solvent, solute-solute, and solvent-solvent interactions helps to avoid the misconceptions about osmotic pressure that were held by Van't Hoff, Einstein, Fermi, and many others. It also provides a better understanding of the concept of ``negative'' osmotic pressure and its role in explaining water of crystallization, gel syneresis, and in biological tissue aging and pathological states. Negative osmotic pressure may be conceptualized as due to a transient metastable state wherein the chemical potential of solvent is temporally increased above that of pure solvent in the standard state. Measureable changes in differential osmotic pressure-volume relationships of osmotic systems are readily related to differential changes in solvent chemical potential and number of mols of solvent in a system.

  10. The Water to Solute Permeability Ratio Governs the Osmotic Volume Dynamics in Beetroot Vacuoles

    Science.gov (United States)

    Vitali, Victoria; Sutka, Moira; Amodeo, Gabriela; Chara, Osvaldo; Ozu, Marcelo

    2016-01-01

    Plant cell vacuoles occupy up to 90% of the cell volume and, beyond their physiological function, are constantly subjected to water and solute exchange. The osmotic flow and vacuole volume dynamics relies on the vacuole membrane -the tonoplast- and its capacity to regulate its permeability to both water and solutes. The osmotic permeability coefficient (Pf) is the parameter that better characterizes the water transport when submitted to an osmotic gradient. Usually, Pf determinations are made in vitro from the initial rate of volume change, when a fast (almost instantaneous) osmolality change occurs. When aquaporins are present, it is accepted that initial volume changes are only due to water movements. However, in living cells osmotic changes are not necessarily abrupt but gradually imposed. Under these conditions, water flux might not be the only relevant driving force shaping the vacuole volume response. In this study, we quantitatively investigated volume dynamics of isolated Beta vulgaris root vacuoles under progressively applied osmotic gradients at different pH, a condition that modifies the tonoplast Pf. We followed the vacuole volume changes while simultaneously determining the external osmolality time-courses and analyzing these data with mathematical modeling. Our findings indicate that vacuole volume changes, under progressively applied osmotic gradients, would not depend on the membrane elastic properties, nor on the non-osmotic volume of the vacuole, but on water and solute fluxes across the tonoplast. We found that the volume of the vacuole at the steady state is determined by the ratio of water to solute permeabilites (Pf/Ps), which in turn is ruled by pH. The dependence of the permeability ratio on pH can be interpreted in terms of the degree of aquaporin inhibition and the consequently solute transport modulation. This is relevant in many plant organs such as root, leaves, cotyledons, or stems that perform extensive rhythmic growth movements

  11. The water to solute permeability ratio governs the osmotic volume dynamics in beetroot vacuoles

    Directory of Open Access Journals (Sweden)

    Victoria Vitali

    2016-09-01

    Full Text Available Plant cell vacuoles occupy up to 90% of the cell volume and, beyond their physiological function, are constantly subjected to water and solute exchange. The osmotic flow and vacuole volume dynamics relies on the vacuole membrane -the tonoplast- and its capacity to regulate its permeability to both water and solutes. The osmotic permeability coefficient (Pf is the parameter that better characterizes the water transport when submitted to an osmotic gradient. Usually, Pf determinations are made in vitro from the initial rate of volume change, when a fast (almost instantaneous osmolality change occurs. When aquaporins are present, it is accepted that initial volume changes are only due to water movements. However, in living cells osmotic changes are not necessarily abrupt but gradually imposed. Under these conditions, water flux might not be the only relevant driving force shaping the vacuole volume response. In this study, we quantitatively investigated volume dynamics of isolated Beta vulgaris root vacuoles under progressively applied osmotic gradients at different pH, a condition that modifies the tonoplast Pf. We followed the vacuole volume changes while simultaneously determining the external osmolality time-courses and analyzing these data with mathematical modelling. Our findings indicate that vacuole volume changes, under progressively applied osmotic gradients, would not depend on the membrane elastic properties, nor on the non-osmotic volume of the vacuole, but on water and solute fluxes across the tonoplast. We found that the volume of the vacuole at the steady state is determined by the ratio of water to solute permeabilites (Pf/Ps, which in turn is ruled by pH. The dependence of the permeability ratio on pH can be interpreted in terms of the degree of aquaporin inhibition and the consequently solute transport modulation. This is relevant in many plant organs such as root, leaves, cotyledons or stems that perform extensive rhythmic

  12. Effect of monthly administration of GHRH (fragment 1-29) with osmotic pump on the rat anterior pituitary.

    Science.gov (United States)

    Motylewska, Ewelina; Mełeń-Mucha, Gabriela; Mucha, Sławomir; Pawlikowski, Marek

    2005-01-01

    Growth Hormone-Releasing Hormone (GHRH) is the main factor, which regulates GH secretion and somatotrope proliferation. However, its chronic effect on anterior pituitary gland is still unknown. It is known that excessive GHRH secretion in patients with gastroenteropancreatic tumors secreting GHRH results in acromegaly and somatotrope hyperplasia. In mice transgenic for GHRH somatotrope tumors develop. Thus, the aim of this paper was to examine the effect of GHRH chronic administration on somatotrope secretion, their percentage and cell proliferation in anterior pituitary gland in rats. The experiment was performed on male Fischer 344 rats weighing 200+/-20 g. The animals were divided into two groups: group I-controls (13 rats) received solvent for GHRH (5% ethanol in demineralized water); group II (10 rats) received GHRH (Growth Hormone Releasing Factor, fragment 1-29 amide) at a dose of 5 microg/day. The substances were given for 1 month via osmotic pump (ALZET), which were implanted subcutaneously in the dorsal region under ketamin anesthesia. After 4 weeks all rats were decapitated and the blood was collected. In the microscopic preparations of anterior pituitary gland the morphology of pituitary (Herlant staining) and the percentage of somatotrope cells and proliferation index based on PCNA staining were assessed. It was found that the chronic treatment with GHRH caused a statistically significant increase in serum rGH concentration and in percentage of somatotropes, but did not change proliferation index and did not induce pathological changes in the morphology of the anterior pituitary gland when compared to the control group. Summing up, monthly GHRH administration did not induce somatotrope adenomas but it caused serum GH level elevation, what seems to depend partially on the increase of somatotrope number.

  13. 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

  14. Membrane fluidity of halophilic ectoine-secreting bacteria related to osmotic and thermal treatment.

    Science.gov (United States)

    Bergmann, Sven; David, Florian; Clark, Wiebke; Wittmann, Christoph; Krull, Rainer

    2013-12-01

    In response to sudden decrease in osmotic pressure, halophilic microorganisms secrete their accumulated osmolytes. This specific stress response, combined with physiochemical responses to the altered environment, influence the membrane properties and integrity of cells, with consequent effects on growth and yields in bioprocesses, such as bacterial milking. The aim of this study was to investigate changes in membrane fluidity and integrity induced by environmental stress in ectoine-secreting organisms. The halophilic ectoine-producing strains Alkalibacillus haloalkaliphilus and Chromohalobacter salexigens were treated hypo- and hyper-osmotically at several temperatures. The steady-state anisotropy of fluorescently labeled cells was measured, and membrane integrity assessed by flow cytometry and ectoine distribution. Strong osmotic downshocks slightly increased the fluidity of the bacterial membranes. As the temperature increased, the increasing membrane fluidity encouraged more ectoine release under the same osmotic shock conditions. On the other hand, combined shock treatments increased the number of disintegrated cells. From the ectoine release and membrane integrity measurements under coupled thermal and osmotic shock conditions, we could optimize the secretion conditions for both bacteria.

  15. Day-night variations in malate concentration, osmotic pressure, and hydrostatic pressure in Cereus validus

    Energy Technology Data Exchange (ETDEWEB)

    Luettge, U.; Nobel, P.S.

    1984-07-01

    Malate concentration and stem osmotic pressure concomitantly increase during nighttime CO/sub 2/ fixation and then decrease during the daytime in the obligate Crassulacean acid metabolism (CAM) plant, Cereus validus (Cactaceae). Changes in malate osmotic pressure calculated using the Van't Hoff relation match the changes in stem osmotic pressure, indicating that changes in malate level affected the water relations of the succulent stems. In contrast to stem osmotic pressure, stem water potential showed little day-night changes, suggesting that changes in cellular hydrostatic pressure occurred. This was corroborated by direct measurements of hydrostatic pressure using the Juelich pressure probe where a small oil-filled micropipette is inserted directly into chlorenchyma cells, which indicated a 4-fold increase in hydrostatic pressure from dusk to dawn. A transient increase of hydrostatic pressure at the beginning of the dark period was correlated with a short period of stomatal closing between afternoon and nighttime CO/sub 2/ fixation, suggesting that the rather complex hydrostatic pressure patterns could be explained by an interplay between the effects of transpiration and malate levels. A second CAM plant, Agave deserti, showed similar day-night changes in hydrostatic pressure in its succulent leaves. It is concluded that, in addition to the inverted stomatal rhythm, the oscillations of malate markedly affect osmotic pressures and hence water relations of CAM plants. 13 references, 4 figures.

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

    Directory of Open Access Journals (Sweden)

    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.

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

    Directory of Open Access Journals (Sweden)

    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.

  18. Three dimensional structural insight of laser drilled orifices in osmotic pump tablets.

    Science.gov (United States)

    Wu, Li; Wang, Lebing; Wang, Shuxia; Xiao, Tiqiao; Chen, Min; Shao, Qun; York, Peter; Singh, Vikaramjeet; Yin, Xianzhen; Gu, Jingkai; Zhang, Jiwen

    2016-10-10

    The orifice drilled in the membrane as a channel for drug delivery is the key functional part of the osmotic pumps for a controlled drug release system. Reported conventional microscopic evaluations of these orifices have been limited to measurement of two-dimensional cross-section diameters. This study was aimed at establishing a novel method to measure quantitatively the three-dimensional architectures of orifices based on synchrotron radiation X-ray microcomputed tomography (SR-μCT). Quantitative analysis of architectures extracted from captopril osmotic pumps drilled by a range of operating parameters indicated that laser power correlated with the cross section area, volume, surface area and depth of the orifices, while scanning speed of laser beam showed inverse relationships with the above structure characters. The synchrotron radiation based Fourier transform infrared microspectroscopy mapping showed that there was no apparent chemical change in the surrounding area of the orifice compared with the normal membrane region. Thus SR-μCT was successfully applied to marketed felodipine osmotic pumps for architectural evaluation of the orifices. In conclusion, the first three-dimensional structural insight of orifices in osmotic pump tablets by SR-μCT and structural reconstruction for the architectures has provided deeper insight into improving the design of advanced osmotic pumps for controlled drug release.

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

    Science.gov (United States)

    Chandler-Brown, Devon; Choi, Haeri; Park, Shirley; Ocampo, Billie R; Chen, Shiwen; Le, Anna; Sutphin, George L; Shamieh, Lara S; Smith, Erica D; Kaeberlein, Matt

    2015-01-01

    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.

  1. Local calcium signals induced by hyper-osmotic stress in mammalian skeletal muscle cells.

    Science.gov (United States)

    Apostol, Simona; Ursu, Daniel; Lehmann-Horn, Frank; Melzer, Werner

    2009-01-01

    Strenuous activitiy of skeletal muscle leads to temporary osmotic dysbalance and isolated skeletal muscle fibers exposed to osmotic stress respond with characteristic micro-domain calcium signals. It has been suggested that osmotic stress targets transverse tubular (TT) dihydropyridine receptors (DHPRs) which normally serve as voltage-dependent activators of Ca release via ryanodine receptor (RyR1s) of the sarcoplasmic reticulum (SR). Here, we pursued this hypothesis by imaging the response to hyperosmotic solutions in both mouse skeletal muscle fibers and myotubes. Ca fluctuations in the cell periphery of fibers exposed to osmotic stress were accompanied by a substantial dilation of the peripheral TT. The Ca signals were completely inhibited by a conditioning depolarization that inactivates the DHPR. Dysgenic myotubes, lacking the DHP-receptor-alpha1-subunit, showed strongly reduced, yet not completely inhibited activity when stimulated with solutions of elevated tonicity. The results point to a modulatory, even though not essential, role of the DHP receptor for osmotic stress-induced Ca signals in skeletal muscle.

  2. Early osmotic adjustment responses in drought-resistant and drought-sensitive oilseed rape

    Institute of Scientific and Technical Information of China (English)

    Sarah Hatzig; L Irina Zaharia; Suzanne Abrams; Marie Hohmann; Laurie Legoahec; Alain Bouchereau; Nathalie Nesi; Rod J.Snowdon

    2014-01-01

    The impact of osmotic stress on growth, physiolo-gy, and metabolism of winter oilseed rape (Brassica napus L.) was investigated by detailed analysis of biomass traits, hormone metabolites and osmolytes in two genetical y unrelated drought-tolerant genotypes and two unrelated drought-sensitive genotypes. Seedlings were grown in vitro under control ed conditions and osmotic stress was simulated by applying a gradual treatment with polyethylene glycol (PEG 6000), fol owed by hypo-osmotic treatment of variants used for metabolite determination. The results provide a basis for the identification of reliable selection criteria for drought resistance in oilseed rape. The in vitro cultivation system established during this study enabled effective discrimination of early osmotic stress responses between drought-resistant and-susceptible oilseed rape genotypes that also show large differences in relative seed yield under drought conditions in the field. Clear physiological and metabolic differences were observed between the drought-resistant and drought-sensitive genotypes, suggesting that osmotic adjustment is a key component of drought response in oilseed rape. Unexpected-ly, however, the drought-resistant genotypes did not show typical hormonal adjustment and osmolyte accumulation, suggesting that they possess alternative physiological mech-anisms enabling avoidance of stress symptoms.

  3. Ions in mixed dielectric solvents: density profiles and osmotic pressure between charged interfaces.

    Science.gov (United States)

    Ben-Yaakov, Dan; Andelman, David; Harries, Daniel; Podgornik, Rudi

    2009-04-30

    The forces between charged macromolecules, usually given in terms of osmotic pressure, are highly affected by the intervening ionic solution. While in most theoretical studies the solution is treated as a homogeneous structureless dielectric medium, recent experimental studies concluded that, for a bathing solution composed of two solvents (binary mixture), the osmotic pressure between charged macromolecules is affected by the binary solvent composition. By adding local solvent composition terms to the free energy, we obtain a general expression for the osmotic pressure, in planar geometry and within the mean-field framework. The added effect is due to the permeability inhomogeneity and nonelectrostatic short-range interactions between the ions and solvents (preferential solvation). This effect is mostly pronounced at small distances and leads to a reduction in the osmotic pressure for macromolecular separations of the order 1-2 nm. Furthermore, it leads to a depletion of one of the two solvents from the charged macromolecules (modeled as planar interfaces). Lastly, by comparing the theoretical results with experimental ones, an explanation based on preferential solvation is offered for recent experiments on the osmotic pressure of DNA solutions.

  4. Changes of DHN1 expression and subcellular distribution in A. delicisoa cells under osmotic stress

    Institute of Scientific and Technical Information of China (English)

    QIU; Quansheng; (邱全胜); WANG; Zezhou(王泽宙); CAI; Qigui(蔡起贵); JIANG; Rongxi(姜荣锡)

    2002-01-01

    The changes of DHN1 expression and subcellular distribution in A. delicisoa cells under osmotic stress were studied by using GFP as a reporter molecule. Through creating the Xba I and BamH I restriction sites at the ends of dhn1 by PCR, the expression vector for the fusion protein DHN1-mGFP4 was constructed by cloning dhn1 into plasmid pBIN-35SmGFP4. Then the DHN1-mGFP4 expression vector was transformed into A. delicisoa suspension cells by microprojectile bombardment method. Bright green fluorescence of GFP which shows the high-level expression of DHN1-mGFP4 was visualized after culture for 10 h. However, the green fluorescence was only located within the nucleus. By increasing the culture medium osmotic potential, the green fluorescence was visualized in the cytoplasm (mainly around the plasma membranes). The generation of GFP fluorescence in the cytoplasm was also promoted by increasing the medium osmotic potential. Moreover, GFP green fluorescence was abolished by protein synthesis inhibitor dicyclohexylcarbodiimid, indicating that the cytoplasmic DHN1 was newly synthesized under osmotic stress. Furthermore, ABA promoted the presence of green fluorescence in the cytoplasm, and the GFP fluorescence was visualized within a shorter time under a higher osmotic potential.

  5. Deriving Second Osmotic Virial Coefficients from Equations of State and from Experiment.

    Science.gov (United States)

    Koga, K; Holten, Vincent; Widom, B

    2015-10-22

    The osmotic virial coefficients, which are measures of the effective interactions between solute molecules in dilute solution, may be obtained from expansions of the osmotic pressure or of the solute activity in powers of the solute concentration. In these expansions, the temperature is held fixed, and one additional constraint is imposed. When the additional constraint is that of fixed chemical potential of the solvent, the coefficient of the second-order term yields directly the second osmotic virial coefficient itself. Alternative constraints, such as fixed pressure, fixed solvent density, or the specification of liquid-vapor equilibrium, yield alternative measures of the solute-solute interaction, different from but related to the osmotic virial coefficient. These relations are summarized and, where new, are derived here. The coefficient in question may be calculated from equations of state in which the parameters have been obtained by fitting to other experimental properties. Alternatively, the coefficients may be calculated from direct experimental measurements of the deviations from Henry's law based on measurements of the activity of the solute in a coexisting gas phase. It is seen for propane in water as a test case that with the latter method, even with what appear to be the best available experimental data, there are still large uncertainties in the resulting second osmotic virial coefficient. With the former method, by contrast, the coefficient may be obtained with high numerical precision but then depends for its accuracy on the quality of the equation of state from which it is derived.

  6. Modulating Electro-osmotic Flow with Polymer Coatings

    Science.gov (United States)

    Hickey, Owen A.

    Micro- and nano-fluidic devices represent an exciting field with a wide range of possible applications. These devices, typically made of either silica or glass, ionize when placed in contact with water. Upon the application of an electric field parallel to the wall, a flow is produced by the charged walls called the electro-osmotic flow (EOF). Since electric fields are so often used as the driving force in these devices, EOF is an extremely common phenomenon. For this reason it is highly desirable to be able to control EOF in order to optimize the functioning of these devices. One method which is quite common experimentally is the modification of the surface using polymer coatings. These coatings can be either adsorbed or grafted, and charged or neutral. The first part of this thesis looks at the role of neutral adsorbed polymer coatings for the modulation of EOF. Specifically our simulation results show that for adsorbed coatings made from a dilute polymer solution the strongest quenching of EOF is found for an adsorption strength at the phase transition for adsorption of the polymers. Further evidence is presented that shows that by using a high density of polymer solution and a polymer which has a strong attraction to the surface a very thick polymer layer can be created. Next the case of charged grafted polymer coatings is examined. The variation of the EOF with respect to several key parameters which characterize the polymer coating is investigated and compared to theory. The prediction that the electrophoretic velocity of the polymers is the same as the EOF generated by a coating made up of the same polymers is found to be false though the two values are quite close. The last section presents results which show how hydrodynamic interactions in charged polymer systems can be modeled mesoscopically without the use of explicit charges by forcing a slip between monomers and the surrounding fluid. This model is validated by simulating some surprising predictions

  7. Analytical and numerical study of the electro-osmotic annular flow of viscoelastic fluids.

    Science.gov (United States)

    Ferrás, L L; Afonso, A M; Alves, M A; Nóbrega, J M; Pinho, F T

    2014-04-15

    In this work we present semi-analytical solutions for the electro-osmotic annular flow of viscoelastic fluids modeled by the Linear and Exponential PTT models. The viscoelastic fluid flows in the axial direction between two concentric cylinders under the combined influences of electrokinetic and pressure forcings. The analysis invokes the Debye-Hückel approximation and includes the limit case of pure electro-osmotic flow. The solution is valid for both no slip and slip velocity at the walls and the chosen slip boundary condition is the linear Navier slip velocity model. The combined effects of fluid rheology, electro-osmotic and pressure gradient forcings on the fluid velocity distribution are also discussed.

  8. Design and statistical optimization of osmotically driven capsule based on push-pull technology.

    Science.gov (United States)

    Shaikh, Wasim; Deshmukh, Prashant K; Patil, Ganesh B; Chatap, Vivekanand K; Bari, Sanjay B

    2013-01-01

    In present investigation attempt was made to develop and statistically optimize osmotically active capsule tailor made from the concept of bilayer (push-pull) osmotic tablet technology. The capsule was comprised of active (drug) and push (osmogen) layer. Active layer was compressed in form of tablet by mixing known amount of drug and formulation excipients. Similarly push layer was made by compressing Mannitol with formulation excipients. Finally, both layers were packed in hard gelatin capsule having small aperture at top and coated with semipermeable membrane to form osmotically active capsule. Formulated and optimized capsules were characterized for Fourier transform infrared (FT-IR) spectroscopy, differential scanning calorimetric (DSC), scanning electron microscopy, In-vitro drug release study and Release models and kinetics. Statistically optimized formulation showed good correlation between predicted and experimented results, which further confirms the practicability and validity of the model.

  9. Ultrasound-assisted osmotic dehydration and convective drying of apples: Process kinetics and quality issues

    Directory of Open Access Journals (Sweden)

    Mierzwa Dominik

    2016-09-01

    Full Text Available The aim of the present theme issue was to study the influence of ultrasound enhancement on the kinetics of osmotic dehydration and the effect of convective drying from the point of view of drying time and quality of dried products. Apple fruit was used as the experimental material. The kinetics of osmotic dehydration with (UAOD and without (OD ultrasound enhancement were examined for 40% fructose and sorbitol solutions. The effective dehydration time of osmotic process was determined. Preliminary dehydrated samples with OD and UAOD were next dried convectively with (CVUS and without (CV ultrasound assistance. The influence of OD and UAOD on the kinetics of CV and CVUS drying was analysed. The parameters of water activity and colour change were measured for the assessment of product quality after drying process.

  10. Development and Evaluation of Extended Release Formulation of Tramadol Hydrochloride Based on Osmotic Technology

    Directory of Open Access Journals (Sweden)

    Patel JB

    2013-05-01

    Full Text Available Extended release formulation of Tramadol Hydrochloride based on osmotic technology was developedand evaluated. Target release profile was selected and different variables were optimized to achieve it.Formulation variables such as osmotic agent, plasticizer and coating thickness of semi-permeablemembrane were found to markedly affect drug release. Tramadol hydrochloride release was directlyproportional to the level of osmogent and plasticizer but inversely proportional to the level of coatingthickness of semi-permeable membrane. Drug release from developed formulation was independent ofpH and agitation intensity but dependent on osmotic pressure of release media. The optimizedformulation was compared with marketed product CONTRAMAL SR and accelerated stability studywas also carried out for 6 months.

  11. New Equation of State for Osmotic Pressures in Aqueous Saline Solutions of Lysozyme

    Institute of Scientific and Technical Information of China (English)

    林阳政; 李以圭; 陆九芳

    2002-01-01

    A new equation of state is proposed to correlate the osmotic pressure data for aqueous lysozyme solutions with (NH4)2SO4, (NH4)2C2O4 and (NH4)2HPO4 at ionic strengths of 13.5 mol/kg and pH 4, 7 or 8 with only one adjustable parameter instead of the classical Derjaguin-Landau-Verwey-Overbeek (DLVO) theory. The Carnahan-Starling equation represents the contribution of the hard sphere repulsion to the osmotic pressure. The attractive dispersion interaction is represented by the Lennard-Jones potential expressed by the equation of Cotterman et al. based on perturbation theory. The double-layer repulsion interaction is represented by Yukawa potential expressed by the equation of state of Duh and Mier-Y-Teran based on mean spherical approximation. The total average relative deviation of the correlation of the osmotic pressure data is 1.68%.

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

    Directory of Open Access Journals (Sweden)

    Anna Chwastek

    2014-12-01

    Full Text Available 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.

  13. 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.

  14. Functional Characterization of TRPV4 As an Osmotically Sensitive Ion Channel in Articular Chondrocytes

    Science.gov (United States)

    Phan, Mimi N.; Leddy, Holly A.; Votta, Bartholomew J.; Kumar, Sanjay; Levy, Dana S.; Lipshutz, David B.; Lee, Sukhee; Liedtke, Wolfgang; Guilak, Farshid

    2010-01-01

    Objective Transient receptor potential vanilloid 4 (TRPV4) is a Ca2+ permeable channel that can be gated by tonicity (osmolarity) and mechanical stimuli. Chondrocytes, the cells in cartilage, respond to their osmotic and mechanical environments; however, the molecular basis of this signal transduction is not fully understood. The objective of this study was to demonstrate the presence and functionality of TRPV4 in chondrocytes. Methods TRPV4 protein expression was measured by immunolabeling and Western blotting. In response to TRPV4 agonist/antagonists, osmotic stress, and interleukin-1 (IL-1), changes in Ca2+ signaling, cell volume, and prostaglandin E2 (PGE2) production were measured in porcine chondrocytes using fluorescence microscopy, light microscopy, or immunoassay, respectively. Results TRPV4 was expressed abundantly at the RNA and protein level. Exposure to 4αPDD, a TRPV4 activator, caused Ca2+ signaling in chondrocytes, which was blocked by the selective TRPV4 antagonist, GSK205. Blocking TRPV4 diminished the chondrocytes' response to hypo-osmotic stress, reducing the fraction of Ca2+ responsive cells, regulatory volume decrease (RVD), and PGE2 production. Ca2+ signaling was inhibited by removal of extracellular Ca2+ or depletion of intracellular stores. Specific activation of TRPV4 restored defective RVD caused by IL-1. Chemical disruption of the primary cilium eliminated Ca2+ signaling in response to either 4αPDD or hypo-osmotic stress. Conclusion TRPV4 is present in articular chondrocytes, and chondrocyte response to hypo-osmotic stress is mediated by this channel, which involves both an extracellular Ca2+ and intracellular Ca2+ release. TRPV4 may also be involved in modulating the production or influence of pro-inflammatory molecules in response to osmotic stress. PMID:19790068

  15. Fate of Foodborne Pathogens During Osmotic Dehydration and Subsequent Storage of Apples.

    OpenAIRE

    Ramasamy, Thilahavathy

    2003-01-01

    The fate of E. coli O157:H7 and Salmonella spp. during osmotic dehydration of apples was determined at different processing temperatures, times and calcium chloride (CaCl2) concentrations. Apple slices were inoculated to achieve an 8 log CFU/ apple slice concentration of a five strain mixture of E. coli O157:H7 or Salmonella spp. and were soaked in sucrose solutions (60% w/w). In the first study, apple slices were subjected to osmotic dehydration at three different temperatures: 20°C, 45°C ...

  16. Use of Different Kinds of Solutes Alternative to Sucrose in Osmotic Dehydration of Yacon

    Directory of Open Access Journals (Sweden)

    Bethania Brochier

    2015-02-01

    Full Text Available The present work aimed to evaluate glycerol, maltodextrin, polydextrose and sorbitol for the osmotic dehydration of yacon for diabetics, keeping its properties as prebiotic. Osmotic dehydration was carried out using a yacon to 33% concentrated syrup weight ratio of 1:12, with magnetic stirring at 23ºC and atmospheric pressure. The best results were achieved for glycerol and sorbitol with 80 ± 4% and 81± 1% of water removal and increase of 3.73 ± 0.11 and 4.30 ± 0.16 times in total soluble solids respectively. Maltodextrin did not promote dehydration.

  17. Chronic cholecystitis

    Science.gov (United States)

    Cholecystitis - chronic ... Most of the time, chronic cholecystitis is caused by repeated attacks of acute (sudden) cholecystitis. Most of these attacks are caused by gallstones in the gallbladder. These ...

  18. 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. ...

  19. Chronic Pain

    Science.gov (United States)

    ... a problem you need to take care of. Chronic pain is different. The pain signals go on ... there is no clear cause. Problems that cause chronic pain include Headache Low back strain Cancer Arthritis ...

  20. 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.

  1. Chronic prostatitis

    OpenAIRE

    Le, Brian; Schaeffer, Anthony J.

    2011-01-01

    Chronic prostatitis can cause pain and urinary symptoms, and usually occurs without positive bacterial cultures from prostatic secretions (known as chronic abacterial prostatitis or chronic pelvic pain syndrome [CP/CPPS]). Bacterial infection can result from urinary tract instrumentation, but the cause and natural history of CP/CPPS are unknown.

  2. Chronic prostatitis

    OpenAIRE

    Erickson, Bradley A.; Schaeffer, Anthony J.; Le, Brian

    2008-01-01

    Chronic prostatitis can cause pain and urinary symptoms, and usually occurs without positive bacterial cultures from prostatic secretions (known as chronic abacterial prostatitis or chronic pelvic pain syndrome, CP/CPPS). Bacterial infection can result from urinary tract instrumentation, but the cause and natural history of CP/CPPS are unknown.

  3. ANALISIS PERMEASI AIR PADA DEHIDRASI OSMOSIS PEPAYA (Carica papaya Water Permeation Analysis on Osmotic Dehydration of Papaya (Carica papaya

    Directory of Open Access Journals (Sweden)

    Sang Kompiang Wirawan

    2013-11-01

    Full Text Available Fruit preservation using low temperature drying is commonly initiated by osmotic dehydration process. The osmotic time is strongly influenced by the water permeation from the fruit to the osmotic solution. This research aimed to study the osmotic dehydration process of papaya by finding out the permeation rate of water to the osmotic solution across a semi permeable membrane. The effect of temperature and osmotic solution concentration on the permeation rate were also observed. The osmotic temperatures were 30, 40, 50, and 60oC, and the osmotic solution concentration were 55, 60, 65, and 70%. In order to study the water permeation through the semi permeable membrane, a simple mass transfer mathematical models based on Fick’s and Van’t Hoff laws were applied. Generally, higher temperature and osmotic solution concentration, higher water permeation rate was achieved. The results also showed that osmotic dehydration has the same identity or characteristic as drying process at high temperature. The water removal from product slices into the osmotic solution increased by the increase of osmotic period. The mass transfer coefficient and effective diffusivity of water increased when temperature and osmotic solution concentration were increased. However, the membrane permeability has a special characteristic at the ranges conditions studied. Keywords: Osmotic, permeation, dehydration, permeable, membrane ABSTRAK Pengawetan buah dengan pengeringan suhu rendah pada umumnya diawali dengan proses dehidrasi osmosis. Lama waktu osmosis sangat dipengaruhi oleh permeasi air dari bahan ke larutan osmosis. Penelitian ini bertujuan untuk mempelajari proses dehidrasi osmosis dan kecepatan permeasi air dari pepaya ke larutan gula sebagai larutan osmosis melalui membran semipermeabel. Pengaruh suhu dan konsentrasi larutan osmosis terhadap kecepatan permeasi air juga diamati. Suhu osmosis adalah 30, 40, 50, dan 60oC, sedangkan konsentrasi larutan osmosis 55, 60

  4. 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.

  5. The hemolytic component of cancer anemia: effects of osmotic and metabolic stress on the erythrocytes of rats bearing multifocal inoculations of the Walker 256 tumor

    Directory of Open Access Journals (Sweden)

    Vido A.A.

    2000-01-01

    Full Text Available Cancer anemia is classified as an anemia of chronic diseases, although it is sometimes the first symptom of cancer. Cancer anemia includes a hemolytic component, important in the terminal stage when even transfused cells are rapidly destroyed. The presence of a chronic component and the terminal complications of the illness limit studies of the hemolytic component. A multifocal model of tumor growth was used here to simulate the terminal metastatic dissemination stage (several simultaneous inoculations of Walker 256 cells. The hemolytic component of anemia began 3-4 days after inoculation in 100% of the rats and progressed rapidly thereafter: Hb levels dropped from 14.9 ± 0.02 to 8.7 ± 0.06 from days 7 to 11 (~5 times the physiologically normal rate in rats in the absence of bleeding. The development of anemia was correlated (r2 = 0.86 with the development of other systemic effects such as anorexia. There was a significant decrease in the osmotic fragility of circulating erythrocytes: the NaCl concentration causing 50% lysis was reduced from 4.52 ± 0.06 to 4.10 ± 0.01 (P<0.01 on day 7, indicating a reduction in erythrocyte volume. However, with mild metabolic stress (4-h incubation at 37oC, the erythrocytes showed a greater increase in osmotic fragility than the controls, suggesting marked alteration of erythrocyte homeostasis. These effects may be due to primary plasma membrane alterations (transport and/or permeability and/or may be secondary to metabolic changes. This multifocal model is adequate for studying the hemolytic component of cancer anemia since it is rapid, highly reproducible and causes minimal animal suffering.

  6. Effect of chronic intracerebroventricular insulin administration in rats on the peripheral glucose metabolism and synaptic plasticity of CA1 hippocampal neurons.

    Science.gov (United States)

    Kamal, Amer; Ramakers, Geert M J; Gispen, Willem Hendrik; Biessels, Geert Jan

    2012-01-30

    In this study we examined the effects of sustained intracerebroventricular insulin infusion on hippocampal synaptic plasticity in rats. Insulin was infused intracerebroventricularly in male Wistar rats (n=12) for 3 months using osmotic minipumps. A control group (n=12) received a sham operation. Insulin infusion led to an initial reduction in food intake and body weight gain, but these differences attenuated over 12 weeks. Insulin infusion did not affect fasting or non-fasting blood glucose levels. Field synaptic potentials recording from the hippocampus demonstrated a defect in the expression of long-term potentiation. Sharp electrode current-clamp recording showed that CA1 pyramidal cells fire action potentials in response to prolonged depolarizing current injection and those action potentials showed progressive broadening. The action potential broadening in the insulin-perfused animals were significantly longer than the control. The amplitude of slow after hyperpolarization (sAHP) was measured after manually "clamping" the cells at -65 mV and injecting currents to evoke a train of four APs. The sAHP amplitude was significantly longer than in the control animals. We conclude that local insulin infusion into the brain of rats had significant effects on synaptic plasticity in the absence of marked effects on systemic glucose levels. These results indicate that long-term elevation of insulin levels can have adverse effects directly on the brain.

  7. 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.

  8. Osmotic Stress Modulates the Balance between Exocytosis and Clathrin-Mediated Endocytosis in Arabidopsis thaliana.

    Science.gov (United States)

    Zwiewka, Marta; Nodzyński, Tomasz; Robert, Stéphanie; Vanneste, Steffen; Friml, Jiří

    2015-08-01

    The sessile life style of plants creates the need to deal with an often adverse environment, in which water availability can change on a daily basis, challenging the cellular physiology and integrity. Changes in osmotic conditions disrupt the equilibrium of the plasma membrane: hypoosmotic conditions increase and hyperosmotic environment decrease the cell volume. Here, we show that short-term extracellular osmotic treatments are closely followed by a shift in the balance between endocytosis and exocytosis in root meristem cells. Acute hyperosmotic treatments (ionic and nonionic) enhance clathrin-mediated endocytosis simultaneously attenuating exocytosis, whereas hypoosmotic treatments have the opposite effects. In addition to clathrin recruitment to the plasma membrane, components of early endocytic trafficking are essential during hyperosmotic stress responses. Consequently, growth of seedlings defective in elements of clathrin or early endocytic machinery is more sensitive to hyperosmotic treatments. We also found that the endocytotic response to a change of osmotic status in the environment is dominant over the presumably evolutionary more recent regulatory effect of plant hormones, such as auxin. These results imply that osmotic perturbation influences the balance between endocytosis and exocytosis acting through clathrin-mediated endocytosis. We propose that tension on the plasma membrane determines the addition or removal of membranes at the cell surface, thus preserving cell integrity.

  9. How to deal with visco-elastic properties of cellular tissues during osmotic dehydration

    NARCIS (Netherlands)

    Oliver, L.; Betoret, N.; Fito, P.; Meinders, M.B.J.

    2012-01-01

    In this work, vacuum impregnated apple discs with different isotonic solutions (sucrose and trehalose) were equilibrated during osmotic dehydration (55°Brix glucose at 40 °C). Changes in sample composition (water and soluble solid contents), weight and volume are analysed. A mathematical model is pr

  10. 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.

  11. Effects of osmotic stress on the kinds, forms and levels of polyamines in wheat coleoptiles.

    Science.gov (United States)

    Liu, Huai-Pan; Zhu, Zi-Xue; Liu, Tian-Xue; Li, Chao-Hai

    2006-06-01

    The changes in levels and forms of polyamine (Pa) in the coleoptiles of two wheat (triticum aestivum L.) cultivars differing in drought tolerance were investigated under osmotic stress. The drought-tolerant 'Yumai 18' showed marked increases in free spermidine (Spd) and spermine (Spm) levels in coleoptiles after being treated with polyethylene glycol (PEG)-6000 for 2 d in the dark, while drought-sensitive 'Yangmai 9' showed a significant increase in free putrescine (Put) content. Treatment of coleoptiles with methylglyoxal-bis (guanylhydrazone) (MGBG), an S-adenosylmethionine decarboxylase (S-AMDC) inhibitor, resulted in reduction of free Spd and free Spm levels in coleoptiles and aggravation of PEG-induced injury to 'Yumai 18' coleoptile, while exogenous Spd treatment resulted in an increase in free Spd + free Spm content of coleoptiles, and an alleviation of PEG-induced injury to 'Yangmai 9' coleoptile. Osmotic stress induced significant increases in perchloric acid-soluble conjugated PA (PS conjugated PA) and perchloric acid-insoluble conjugated PA (PIS conjugated PA) levels in coleoptiles of 'Yumai 18' whereas osmotic stress affected only slightly the PS-conjugated PA and PIS-conjugated PA levels in 'Yangmai 9' coleoptiles. Treatment of coleoptiles with phenanthroline (o-Phen), an inhibitor of transglutaminase (TGase), also aggravated the PEG-induced injury to 'Yumai 18' coleoptiles, accompanied by the decreases in the level of PIS-conjugated PA. These results suggest that free Spd, free Spm and conjugated PA enhance the osmotic stress tolerance of wheat coleoptiles.

  12. 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.

  13. Polyamine metabolism and osmotic stress. II. Improvement of oat protoplasts by an inhibitor of arginine decarboxylase.

    Science.gov (United States)

    Tiburcio, A F; Kaur-Sawhney, R; Galston, A W

    1986-01-01

    We have attempted to improve the viability of cereal mesophyll protoplasts by pretreatment of leaves with DL-alpha-difluoromethylarginine (DFMA), a specific 'suicide' inhibitor of the enzyme (arginine decarboxylase) responsible for their osmotically induced putrescine accumulation. Leaf pretreatment with DFMA before a 6 hour osmotic shock caused a 45% decrease of putrescine and a 2-fold increase of spermine titer. After 136 hours of osmotic stress, putrescine titer in DFMA-pretreated leaves increased by only 50%, but spermidine and spermine titers increased dramatically by 3.2- and 6-fold, respectively. These increases in higher polyamines could account for the reduced chlorophyll loss and enhanced ability of pretreated leaves to incorporate tritiated thymidine, uridine, and leucine into macromolecules. Pretreatment with DFMA significantly improved the overall viability of the protoplasts isolated from these leaves. The results support the view that the osmotically induced rise in putrescine and blockage of its conversion to higher polyamines may contribute to the lack of sustained cell division in cereal mesophyll protoplasts, although other undefined factors must also play a major role.

  14. Translocation of DNA molecules through nanopores with salt gradients: the role of osmotic flow

    NARCIS (Netherlands)

    Hatlo, M.M.; Panja, D.; van Roij, R.

    2011-01-01

    Recent experiments of translocation of double stranded DNA through nanopores M. Wanunu textitet al. Nature Nanotech. 5, 160 (2010) 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

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

    NARCIS (Netherlands)

    Hatlo, M. M.; Panja, D.; van Roij, R.H.H.G.

    2011-01-01

    Recent experiments of translocation of double-stranded DNA through nanopores [ M. Wanunu et al. Nature Nanotech. 5 160 (2009)] 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 quan

  16. Glycine betaine fluxes in Lactobacillus plantarum during osmostasis and hyper- and hypo-osmotic shock

    NARCIS (Netherlands)

    Glaasker, E; Konings, W.N; Poolman, B.

    1996-01-01

    Bacteria respond to changes in medium osmolarity by varying the concentrations of specific solutes in order to maintain constant turgor. The primary response of Lactobacillus plantarum to an osmotic upshock involves the accumulation of compatible solutes such as glycine betaine, proline, and glutama

  17. Betaine and L-carnitine transport by Listeria monocytogenes Scott A in response to osmotic signals

    NARCIS (Netherlands)

    Verheul, Annette; Glaasker, Erwin; Poolman, Bert; Abee, Tjakko

    1997-01-01

    The naturally occurring compatible solutes betaine and L-carnitine allow the food-borne pathogen Listeria monocytogenes to adjust to environments of high osmotic strength. Previously, it was demonstrated that L. monocytogenes possesses an ATP-dependent L-carnitine transporter. The present study reve

  18. Proteomic Analysis of Rice Leaves Shows the Different Regulations to Osmotic Stress and Stress Signals

    Institute of Scientific and Technical Information of China (English)

    Lie-Bo Shu; Wei Ding; Jin-Hong Wu; Fang-Jun Feng; Li-Jun Luo; Han-Wei Mei

    2010-01-01

    Following the idea of partial root-zone drying(PRD)in crop cultivation,the morphological and physiological responses to partial root osmotic stress(PROS)and whole root osmotic stress(WROS)were investigated in rice.WROS caused stress symptoms like leaf rolling and membrane leakage.PROS stimulated stress signals,but did not cause severe leaf damage.By proteomic analysis,a total of 58 proteins showed differential expression after one or both treatments,and functional classification of these proteins suggests that stress signals regulate photosynthesis,carbohydrate and energy metabolism.Two other proteins(anthranilate synthase and submergence-induced nickel-binding protein)were upregulated only in the PROS plants,indicating their important roles in stress resistance.Additionally,more enzymes were involved in stress defense,redox homeostasis,lignin and ethylene synthesis in WROS leaves,suggesting a more comprehensive regulatory mechanism induced by osmotic stress.This study provides new insights into the complex molecular networks within plant leaves involved in the adaptation to osmotic stress and stress signals.

  19. 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.

  20. 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.

    2012-01-01

    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

  1. 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 o

  2. 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...

  3. 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.

  4. 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.

  5. The influence of osmotic pressure on the lifespan of cellularly inspired energy-relevant materials

    Science.gov (United States)

    Kapania, Esha; Guillen, Katherine; Freeman, Eric; Philen, Michael

    2014-04-01

    Bimolecular unit cells have recently become a focus for biologically-inspired smart materials. This is largely due their ability to exhibit many of the same properties as the natural cell membrane. In this study, two lipid monolayers formed at a water/oil interface are brought together, creating a lipid bilayer at their interface with each droplet containing a different concentration of ions. This ionic concentration gradient leads to the development of a membrane potential across the bilayer as ions begin to passively diffuse across the membrane at varying rates, providing the proof of concept for energy storage through cellular mechanics. The focus of the study is to determine the influence of osmotic pressure on the lifespan of the lipid bilayer. We hypothesize that the greater osmotic pressure that develops from a greater ionic concentration gradient will prove to have a negative impact on the lifespan of the bilayer membrane, causing it to rupture sooner. This is due to the substantial amount of osmotic swelling that will occur to compensate for the ionic concentration gradient. This study will demonstrate how osmotic pressure will continue to be a limiting factor in the effectiveness and stability of cellularly-inspired energy relevant materials.

  6. Colloid osmotic pressure in decompensated cirrhosis. A 'mirror image' of portal venous hypertension

    DEFF Research Database (Denmark)

    Henriksen, Jens Henrik Sahl

    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 ...... and perpetuation of ascites should be reconsidered in the light of these findings....

  7. The solubility-modulated osmotic pump: in vitro/in vivo release of diltiazem hydrochloride.

    Science.gov (United States)

    McClelland, G A; Sutton, S C; Engle, K; Zentner, G M

    1991-01-01

    A generalized method was investigated for conversion of controlled-porosity osmotic pump release profiles from first-order to zero-order kinetics using diltiazem.HCl as a model drug. Diltiazem.HCl has an aqueous solubility greater than 590 mg/ml (37 degrees C) and was released from controlled-porosity osmotic pump devices with first-order kinetics. This high solubility was markedly reduced (155 mg/ml; 37 degrees C) in the presence of NaCl (1 M). Based on theory for osmotically actuated drug release, this reduced solubility would be expected to result in a zero-order release profile of greater than 80% of an initial diltiazem.HCl load. Devices were prepared with cores that contained diltiazem.HCl and sufficient NaCl granules coated with a microporous cellulose acetate butyrate 381-20 film to maintain a 1 M NaCl concentration within the drug compartment over a 16-hr period. This resulted in release of approximately 75% of the initial diltiazem.HCl load with zero-order kinetics over a 14- to 16-hr period. The in vivo performance of these devices in beagle dogs was analyzed. The in vivo percentage diltiazem absorbed profiles were superimposable with the in vitro release profile. These results suggest that diltiazem release and absorption from the solubility modulated osmotic pump occur throughout the GI tract in a fashion predictable from in vitro dissolution data.

  8. Wheat-Aegilops biuncialis amphiploids have efficient photosynthesis and biomass production during osmotic stress.

    Science.gov (United States)

    Dulai, Sándor; Molnár, István; Szopkó, Dóra; Darkó, Éva; Vojtkó, András; Sass-Gyarmati, Andrea; Molnár-Láng, Márta

    2014-04-15

    Osmotic stress responses of water content, photosynthetic parameters and biomass production were investigated in wheat-Aegilops biuncialis amphiploids and in wheat genotypes to clarify whether they can use to improve the drought tolerance of bread wheat. A decrease in the osmotic pressure of the medium resulted in considerable water loss, stomatal closure and a decreased CO2 assimilation rate for the wheat genotypes, while the changes in these parameters were moderate for the amphiploids. Maximal assimilation rate was maintained at high level even under severe osmotic stress in the amphiploids, while it decreased substantially in the wheat genotypes. Nevertheless, the effective quantum yield of PS II was higher and the quantum yield of non-photochemical quenching of PS II and PS I was lower for the amphiploids than for the wheat cultivars. Parallel with this, higher cyclic electron flow was detected in wheat than in the amphiploids. The elevated photosynthetic activity of amphiploids under osmotic stress conditions was manifested in higher biomass production by roots and shoots as compared to wheat genotypes. These results indicate that the drought-tolerant traits of Ae. biuncialis can be manifested in the wheat genetic background and these amphiploids are suitable genetic materials for improving drought tolerance of wheat.

  9. Evidence that Clostridium perfringens theta-toxin induces colloid-osmotic lysis of erythrocytes.

    OpenAIRE

    Harris, R W; Sims, P J; Tweten, R K

    1991-01-01

    Clostridium perfringens theta-toxin was shown to lyse target erythrocytes by a colloid-osmotic mechanism. Analysis showed the onset of lysis of erythrocytes by theta-toxin could be temporarily stabilized with 0.3 M sucrose. Flow cytometry analysis of the size distribution of theta-toxin-treated erythrocytes showed swelling of the erythrocytes prior to lysis.

  10. FORMULATION AND EVALUATION OF CONTROLLED POROSITY OSMOTIC DRUG DELIVERY SYSTEM OF METOPROLOL SUCCINATE

    Directory of Open Access Journals (Sweden)

    Hardik Patel* and M. M. Patel

    2012-06-01

    Full Text Available Controlled porosity osmotic tablet of metoprolol succinate prepared and evaluated in this study. Metoprolol succinate is very high soluble drug, so complete drug release obtained very fast. It is difficult to formulate osmotic tablet of Metoprolol succinate which gives drug release up to 24 hr at zero order. To get desired dissolution profile various formulation parameters like osmogen concentration, level of weight gain and level of pore former concentration were studied. Hypromellose was added as release retardant to reduce its dissolution rate and get drug release up to 24 hr at zero order. As concentration of release retardant increases, dissolution rate decreases. Final optimized formulation with hypromellose was studied for effect of pH of dissolution media, agitation intensity and osmotic pressure of dissolution media. There is no effect of above variables on dissolution confirms that prepared metoprolol succinate tablet gives drug release with osmotic mechanism. Final optimized formulation complies with the USP criteria for the dissolution of metoprolol succinate extended release tablet.

  11. Controlled release of metformin hydrochloride and repaglinide from sandwiched osmotic pump tablet.

    Science.gov (United States)

    Qin, Chao; He, Wei; Zhu, Chunli; Wu, Mengmeng; Jin, Zhu; Zhang, Qiang; Wang, Guangji; Yin, Lifang

    2014-05-15

    The marketed compound tablet of metformin hydrochloride (MH) and repaglinide (RG) exhibits perfect multidrug therapeutic effect of type 2 diabetes. However, due to the short half life of the drugs, the tablet has to be administered 2 to 3 times a day, causing inconvenience to patient and fluctuations of plasma concentration. Here, a sandwiched osmotic pump tablet was developed to deliver the two drugs simultaneously at zero-order rate, in which MH and RG were loaded in different layers separated by a push layer. The osmotic pump tablet was prepared by a combination of three tableting procedure and film coating method. The factors including type and amount of propellant, osmotic active agents, amount of porogenic agent, coating weight, orifice diameter were optimized. The pharmacokinetic study was performed in beagle dogs, and the drug concentration in plasma samples was assayed by HPLC-MS/MS method. Simultaneous, controlled release of MH and RG in the first 12 and 8h was achieved from the optimized formulation. A significantly decreased Cmax, prolonged Tmax and satisfactory bioavailability of the osmotic pump tablet were obtained, and a good in vivo-in vitro correlation of the two drugs was also established. In summary, the sandwiched osmotic pump tablet released the MH and RG simultaneously at zero-order rate, and exhibited significant sustained release effect in vivo and good in vivo-in vitro correlation. The designed controlled release system for MH and RG proposed a promising replacement for the marked compound product in the therapy of type 2 diabetes.

  12. Simultaneous delivery of Nifedipine and Metoprolol tartarate using sandwiched osmotic pump tablet system.

    Science.gov (United States)

    Kumaravelrajan, R; Narayanan, N; Suba, V; Bhaskar, K

    2010-10-31

    The sandwiched osmotic tablet system that could deliver Nifedipine and Metoprolol tartarate simultaneously for extended period of time was developed in order to reduce the problems associated with multidrug therapy of hypertension. This system composed of a middle push layer and attached drug layers of Nifedipine and Metoprolol. The advantage of the sandwiched osmotic tablet system over the commercialized push-pull osmotic tablet system is its simplicity of preparation, as the surface identification was avoided. Polyethylene oxide 600,000 and 8,000,000 g/mole were used as thickening agent of drug layer and the expandable hydrogel of push layer, respectively. It has been observed that amount of polyethylene oxide (PEO) and KCL of the drug and push layer had profound influence on Nifedipine and Metoprolol release. Further, the release of drugs was optimized by the size of the delivery orifice, level of plasticizer and membrane thickness. The optimal osmotic pump tablet was found to deliver both drugs at a rate of approximately zero order for up to 16 h independent of pH and agitational intensity, but dependent on the osmotic pressure of the release media. The formulations were found to be stable after 3 months of accelerated stability studies. Prediction of steady-state levels showed the plasma concentrations of Nifedipine and Metoprolol to be within the desired range. Further sandwiched system had a good sustained effect in comparison with the conventional product. Hence the prototype design of the system could be applied to other combinations of drugs used for cardiovascular diseases, diabetes, etc.

  13. 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.

  14. 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.

  15. 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

  16. 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

  17. [Chronicity, chronicization, systematization of delusions].

    Science.gov (United States)

    Trapet, P; Fernandez, C; Galtier, M C; Gisselmann, A

    1984-05-01

    Chronicity in psychopathology is indicative of a term, a decay. Chronicization only leads the way to this term. Here, chronicization is taken literally as an inscription in the time course of delusions. The mechanism of systematization seems to be a central mark in the approach to chronic delusions. It is not an alienation or an irreversible closing but an attempted accommodation with reality in the life of psychotic subjects, irrespective of the delusional structure. The role of therapy and drug treatment as a follow-up may in that case assume another meaning.

  18. Chronic pancreatitis

    OpenAIRE

    Kocher, Hemant M.; Froeling, Fieke EM

    2008-01-01

    Chronic pancreatitis is characterised by long-standing inflammation of the pancreas owing to a wide variety of causes, including recurrent acute attacks of pancreatitis. Chronic pancreatitis affects 3–9 people in 100,000; 70% of cases are alcohol-induced.

  19. Chronic pancreatitis

    OpenAIRE

    Kocher, Hemant M.; Kadaba, Raghu

    2011-01-01

    Chronic pancreatitis is characterised by long-standing inflammation of the pancreas due to a wide variety of causes, including recurrent acute attacks of pancreatitis. Chronic pancreatitis affects between 3 and 9 people in 100,000; 70% of cases are alcohol-induced.

  20. Experimental Verification of Overlimiting Current by Surface Conduction and Electro-osmotic Flow in Microchannels

    CERN Document Server

    Nam, Sungmin; Heo, Joonseong; Lim, Geunbae; Bazant, Martin Z; Sung, Gunyong; Kim, Sung Jae

    2014-01-01

    Possible mechanisms of overlimiting current in unsupported electrolytes, exceeding diffusion limitation, have been intensely studied for their fundamental significance and applications to desalination, separations, sensing, and energy storage. In bulk membrane systems, the primary physical mechanism is electro-convection, driven by electro-osmotic instability on the membrane surface. It has recently been predicted that confinement by charged surfaces in microchannels or porous media favors two new mechanisms, electro-osmotic flow (EOF) and surface conduction (SC), driven by large electric fields in the depleted region acting on the electric double layers on the sidewalls. Here, we provide the first direct evidence for the transition from SC to EOF above a critical channel height, using in situ particle tracking and current-voltage measurements in a micro/nanofluidic device. The dependence of the over-limiting conductance on channel depth (d) is consistent with theoretical predictions, scaling as d^-1 for SC a...

  1. Lanthanide salts solutions: representation of osmotic coefficients within the binding mean spherical approximation.

    Science.gov (United States)

    Ruas, Alexandre; Moisy, Philippe; Simonin, Jean-Pierre; Bernard, Olivier; Dufrêche, Jean-François; Turq, Pierre

    2005-03-24

    Osmotic coefficients of aqueous solutions of lanthanide salts are described using the binding mean spherical approximation (BIMSA) model based on the Wertheim formalism for association. The lanthanide(III) cation and the co-ion are allowed to form a 1-1 ion pair. Hydration is taken into account by introducing concentration-dependent cation size and solution permittivity. An expression for the osmotic coefficient, derived within the BIMSA, is used to fit data for a wide variety of lanthanide pure salt aqueous solutions at 25 degrees C. A total of 38 lanthanide salts have been treated, including perchlorates, nitrates, and chlorides. For most solutions, good fits could be obtained up to high ionic strengths. The relevance of the fitted parameters has been discussed, and a comparison with literature values has been made (especially the association constants) when available.

  2. Dependence of the osmotic coefficients and average ionic activity coefficients on hydrophobic hydration in solutions

    Science.gov (United States)

    Sergievskii, V. V.; Rudakov, A. M.

    2016-08-01

    The model that considers the nonideality of aqueous solutions of electrolytes with allowance for independent contributions of hydration of ions of various types and electrostatic interactions was substantiated using the cluster ion model. The empirical parameters in the model equations were found to be the hydrophilic and hydrophobic hydration numbers of ions in the standard state and the dispersion of their distribution over the stoichiometric coefficients. A mathematically adequate description of the concentration dependences of the osmotic coefficients and average ion activity coefficients of electrolytes was given for several systems. The difference in the rate of the decrease in the hydrophilic and hydrophobic hydration numbers of ions leads to extremum concentration dependences of the osmotic coefficients, which were determined by other authors from isopiestic data for many electrolytes and did not find explanation.

  3. Sorbitol production in the lens: a means of counteracting glucose-derived osmotic stress.

    Science.gov (United States)

    Chylack, L T; Tung, W; Harding, R

    1986-01-01

    Heretofore, the intracellular accumulation of sorbitol has been associated exclusively with deleterious (cataractogenic) changes in the lens. This study demonstrates a beneficial role for the sorbitol pathway in the rabbit lens, namely that of counteracting extracellular, glucose-derived, osmotic stress with the intracellular production of osmotically active sorbitol. Large and sudden increases in the extracellular glucose concentration lead to dehydration of the lens, a response that can be diminished by intracellular sorbitol and fructose production. These results are discussed in light of the impact (beneficial/detrimental) of aldose reductase inhibitors on the lens. Sugar cataract formation appears to result from continuous, rather than cyclical, activity of a pathway which normally may have a protective function in the lens.

  4. Renal blood flow, early distal sodium, and plasma renin concentrations during osmotic diuresis

    DEFF Research Database (Denmark)

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

    2000-01-01

    .6 mmHg. Urine flow increased 10-fold, and sodium excretion increased by 177%. Plasma renin concentration (PRC) increased by 58%. Renal blood flow and glomerular filtration rate decreased, however end-proximal flow remained unchanged. After a similar volume of hypotonic glucose (152 mM), ED......(NaCl) increased by 3.6 mM, (P sodium excretion rate, or PRC. Infusion of 300 micromol NaCl in a smaller volume caused ED(NaCl) to increase by 6.4 mM without significant changes in PRC. Urine flow and sodium excretion increased significantly....... There was a significant inverse relationship between superficial nephron ED(NaCl) and PRC. We conclude that ED(Na) decreases during osmotic diuresis, suggesting that the increase in PRC was mediated by the macula densa. The results suggest that the natriuresis during osmotic diuresis is a result of impaired sodium...

  5. ESR (electron spin resonance)-determined osmotic behavior of bull spermatozoa

    Energy Technology Data Exchange (ETDEWEB)

    Du, J.; Kleinhans, F.W.; Spitzer, V.J.; Critser, J.K. (Methodist Hospital, Indianapolis, IN (USA). Dept. of Medical Research); Horstman, L. (Purdue Univ., Lafayette, IN (USA). School of Veterinary Medicine); Mazur, P. (Oak Ridge National Lab., TN (USA))

    1990-01-01

    Our laboratories are pursuing a fundamental approach to the problems of semen cryopreservation. For many cell types (human red cells, yeast, HeLa) it has been demonstrated that there is an optimum cooling rate for cryopreservation. Faster rates allow insufficient time for cell dehydration and result in intracellular ice formation and cell death. It is possible to predict this optimal rate provided that the cell acts as an ideal osmometer and several other cell parameters are known such as the membrane hydraulic conductivity. It is the purpose of this work to examine the osmotic response of bull sperm to sucrose and NaCl utilizing electron spin resonance (ESR) to measure cell volume. For calibration purposes we also measured the ESR response of human red cells (RBC), the osmotic response of which is well documented with other methods. 15 refs., 1 fig.

  6. From a thin film model for passive suspensions towards the description of osmotic biofilm spreading

    CERN Document Server

    Trinschek, Sarah; Thiele, Uwe

    2016-01-01

    Biofilms are ubiquitous macro-colonies of bacteria that develop at various interfaces (solid-liquid, solid-gas or liquid-gas). The formation of biofilms starts with the attachment of individual bacteria to an interface, where they proliferate and produce a slimy polymeric matrix - two processes that result in colony growth and spreading. Recent experiments on the growth of biofilms on agar substrates under air have shown that for certain bacterial strains, the production of the extracellular matrix and the resulting osmotic influx of nutrient-rich water from the agar into the biofilm are more crucial for the spreading behaviour of a biofilm than the motility of individual bacteria. We present a model which describes the biofilm evolution and the advancing biofilm edge for this spreading mechanism. The model is based on a gradient dynamics formulation for thin films of biologically passive liquid mixtures and suspensions, supplemented by bioactive processes which play a decisive role in the osmotic spreading o...

  7. Mass transfer and microbiological profile of pork meat dehydrated in two different osmotic solutions

    Directory of Open Access Journals (Sweden)

    Plavšić Dragana V.

    2012-01-01

    Full Text Available The effects of osmotic dehydration on mass transfer properties and microbiological profile were investigated in order to determine the usefulness of this technique as pre-treatment for further treatment of meat. Process was studied in two solutions (sugar beet molasses, and aqueous solution of sodium chloride and sucrose, at two temperatures (4 and 22°C at atmospheric pressure. The most significant parameters of mass transfer were determined after 300 minutes of the dehydration. The water activity (aw values of the processed meat were determined, as well as the change of the microbiological profile between the fresh and dehydrated meat. At the temperature of 22°C the sugar beet molasses proved to be most suitable as an osmotic solution, despite the greater viscosity.

  8. Particle Dynamics and Rapid Trapping in Electro-Osmotic Flow Around a Sharp Microchannel Corner

    CERN Document Server

    Zehavi, Matan

    2014-01-01

    We study here the curious particle dynamics resulting from electro-osmotic flow around a microchannel junction corner whose dielectric walls are weakly polarizable. The hydrodynamic velocity field is obtained via superposition of a linear irrotational term associated with the equilibrium zeta potentials of both the microchannel and particle surfaces and the non-linear induced-charge electro-osmotic flow which originates from the interaction of the externally applied electric field on the charge cloud it induces at the solid-liquid interface. The particle dynamics are analyzed by considering dielectrophoretic forces via the addition of a mobility term to the flow field in the limit of Stokes drag law. The former, non-divergence free term is responsible for migration of particles towards the sharp microchannel junction corner, where they can potentially accumulate. Experimental observations of particle trapping for various applied electric fields and microparticle size are rationalized in terms of the growing r...

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

    Science.gov (United States)

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

    2012-06-20

    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.

  10. Genetically modified cyanobacterium Nostoc muscorum overproducing proline in response to salinity and osmotic stresses

    Indian Academy of Sciences (India)

    Santosh Bhargava

    2006-06-01

    In the parent Nostoc muscorum an active proline oxidase enzyme is required to assimilate exogenous proline as a fixed nitrogen source. Cyanobacterial mutants, resistant to growth inhibitory action of proline analogue L-azetidine-2-carboxylate (Ac-R), were deficient in proline oxidase activity, and were over-accumulators of proline. Proline over-accumulation, resulting either from mutational acquisition of the Ac-R phenotype, or from salinity-induced uptake of exogenous proline, confirmed enhanced salinity/osmotic tolerance in the mutant strain. The nitrogenase activity and photosynthetic O2 evolution of the parent were sensitive to both salinity as well as osmotic stresses than of Ac-R mutant strain. In addition, the mutation to Ac-resistant phenotype showed no alteration in salinity inducible potassium transport system in the cyanobacterium

  11. Microfluidic analogy of the wheatstone bridge for systematic investigations of electro-osmotic flows.

    Science.gov (United States)

    Plecis, Adrien; Chen, Yong

    2008-05-15

    A microfluidic analogy of the electric Wheatstone Bridge has been developed for electrokinetic study of miscellaneous liquid-solid interfaces. By using an optimized glass-PDMS-glass device technology, microfluidic channels with well-controlled surface properties can be fabricated, forming an "H" shaped fluidic network. After solving a set of linear equations, the electro-osmotic flow rate in the center channel can be deduced from indirect measurement of flow rates in the lateral channels. Experimentally, we demonstrate that the electro-osmotic mobility can be monitored every 30 s with accuracy better than 3% for a large dynamic range of electric fields. The results obtained with a borosilicate glass (D-263) and several standard biological buffers are also shown to illustrate the capability of this high throughput method.

  12. Germination of Senna Occidentalis link: seed at different osmotic potential levels

    Directory of Open Access Journals (Sweden)

    Delachiave Maria Elena Aparecida

    2003-01-01

    Full Text Available The objective of this research was to study the effect of osmotic potential and salinity on the germination of seeds of Senna occidentalis, with and without a change of solutions. The percentage and rates of germination decreased according to decrease of potential, being more drastic when the substitutions of solutions were not made. The largest reductions were observed with the PEG solutions, with and without substitutions.

  13. How to Squeeze a Sponge: Casein Micelles under Osmotic Stress, a SAXS Study

    OpenAIRE

    Bouchoux, Antoine; Gésan-Guiziou, Geneviève; Pérez, Javier; Cabane, Bernard

    2010-01-01

    By combining the osmotic stress technique with small-angle x-ray scattering measurements, we followed the structural response of the casein micelle to an overall increase in concentration. When the aqueous phase that separates the micelles is extracted, they behave as polydisperse repelling spheres and their internal structure is not affected. When they are compressed, the micelles lose water and shrink to a smaller volume. Our results indicate that this compression is nonaffine, i.e., some p...

  14. Development and Evaluation of Swellable Elementary Osmotic Pump Tablet of Glipizide

    Directory of Open Access Journals (Sweden)

    Preethi N

    2013-10-01

    Full Text Available A novel type of elementary osmotic pump [EOP] tablet for efficient delivery of poorly water-soluble drug, glipizide has been designed. Drug release from the system, called Swellable Elementary Osmotic Pump [SEOP], is through a delivery orifice in the form of a very fine dispersion, ready for dissolution and absorption. SEOP tablets were prepared by compressing the mixture of micronized drug and excipients into convex tablet. The effect of wetting agent, swelling agent, osmotic agent and hydrophobic plasticizer on the release rate were investigated. The release behavior of glipizide from different formulations of this dosage forms were studied at pH 6.8 for a period of 24 hours. The drug release profile from osmotic devices showed that the type of polymer in the core formulation can markedly affect the drug release. When the amount of HPMC E50-LV was increased from 30 to 60 mg, decrease in drug release was observed. Increasing the amount of wetting agent to an optimum level of 45 mg significantly increased the release rate and improved zero order release pattern of glipizide. Increasing the concentration of Dibutylphthalate [DBP-30%] in the semi permeable membrane of the device retarded the release rate of glipizide but gave best results at the 20% concentration. Based on the SEM studies, optimized orifice diameter was found to be 500µm. Compared with the marketed Glipizide extended release tablet; GF2 gave the best release rate for 24 hours. The bioavailability studies for glipizide SEOP and Glipizide extended release tablet was carried out in albino rabbits and there was a good in-vivo and in-vitro correlation for GF2 as shown by the higher Cmax and AUC values. Thus a novel SEOP was successfully formulated for glipizide to achieve zero order drug release over a period of 24 hours.

  15. DEVELOPMENT AND IN-VITRO EVALUATION OF METOPROLOL SUCCINATE CONTROLLED POROSITY OSMOTIC PUMP TABLETS

    OpenAIRE

    Veeramalla Anil Kumar; Madishetty Vamshikrishna; Indarapu Rajendra Prasad; Gudikandula Raj Kumar; Kadari Srinivas

    2013-01-01

    In the present research work, attempts were made to develop and evaluate Sustained release formulation of Metoprolol succinate based on osmotic technology.As Metoprolol is a short acting drug, developed formulation provides the advantages of controlled release formulations. The developed formulation provides advantages of less steps of manufacturing procedure, no need of laser drilling, and economical. All of these made the procedure easily amenable to mass production using conventional table...

  16. From START to FINISH: the influence of osmotic stress on the cell cycle.

    Science.gov (United States)

    Radmaneshfar, Elahe; Kaloriti, Despoina; Gustin, Michael C; Gow, Neil A R; Brown, Alistair J P; Grebogi, Celso; Romano, M Carmen; Thiel, Marco

    2013-01-01

    The cell cycle is a sequence of biochemical events that are controlled by complex but robust molecular machinery. This enables cells to achieve accurate self-reproduction under a broad range of different conditions. Environmental changes are transmitted by molecular signalling networks, which coordinate their action with the cell cycle. The cell cycle process and its responses to environmental stresses arise from intertwined nonlinear interactions among large numbers of simpler components. Yet, understanding of how these pieces fit together into a coherent whole requires a systems biology approach. Here, we present a novel mathematical model that describes the influence of osmotic stress on the entire cell cycle of S. cerevisiae for the first time. Our model incorporates all recently known and several proposed interactions between the osmotic stress response pathway and the cell cycle. This model unveils the mechanisms that emerge as a consequence of the interaction between the cell cycle and stress response networks. Furthermore, it characterises the role of individual components. Moreover, it predicts different phenotypical responses for cells depending on the phase of cells at the onset of the stress. The key predictions of the model are: (i) exposure of cells to osmotic stress during the late S and the early G2/M phase can induce DNA re-replication before cell division occurs, (ii) cells stressed at the late G2/M phase display accelerated exit from mitosis and arrest in the next cell cycle, (iii) osmotic stress delays the G1-to-S and G2-to-M transitions in a dose dependent manner, whereas it accelerates the M-to-G1 transition independently of the stress dose and (iv) the Hog MAPK network compensates the role of the MEN network during cell division of MEN mutant cells. These model predictions are supported by independent experiments in S. cerevisiae and, moreover, have recently been observed in other eukaryotes.

  17. From START to FINISH: the influence of osmotic stress on the cell cycle.

    Directory of Open Access Journals (Sweden)

    Elahe Radmaneshfar

    Full Text Available The cell cycle is a sequence of biochemical events that are controlled by complex but robust molecular machinery. This enables cells to achieve accurate self-reproduction under a broad range of different conditions. Environmental changes are transmitted by molecular signalling networks, which coordinate their action with the cell cycle. The cell cycle process and its responses to environmental stresses arise from intertwined nonlinear interactions among large numbers of simpler components. Yet, understanding of how these pieces fit together into a coherent whole requires a systems biology approach. Here, we present a novel mathematical model that describes the influence of osmotic stress on the entire cell cycle of S. cerevisiae for the first time. Our model incorporates all recently known and several proposed interactions between the osmotic stress response pathway and the cell cycle. This model unveils the mechanisms that emerge as a consequence of the interaction between the cell cycle and stress response networks. Furthermore, it characterises the role of individual components. Moreover, it predicts different phenotypical responses for cells depending on the phase of cells at the onset of the stress. The key predictions of the model are: (i exposure of cells to osmotic stress during the late S and the early G2/M phase can induce DNA re-replication before cell division occurs, (ii cells stressed at the late G2/M phase display accelerated exit from mitosis and arrest in the next cell cycle, (iii osmotic stress delays the G1-to-S and G2-to-M transitions in a dose dependent manner, whereas it accelerates the M-to-G1 transition independently of the stress dose and (iv the Hog MAPK network compensates the role of the MEN network during cell division of MEN mutant cells. These model predictions are supported by independent experiments in S. cerevisiae and, moreover, have recently been observed in other eukaryotes.

  18. Application of a new contrast medium (iopamidol) of low osmotic activity in peripheric arteriography

    Energy Technology Data Exchange (ETDEWEB)

    Konya, A.; Kovacs, K.

    1985-06-01

    In 51 patients a total of 80 arteriographic examinations was carried out with a new contrast medium (iopamidol - Iopamirosup(R) Bracco) which has low osmotic activity. It is concluded that iopamidol is excellently suited for the purpose of peripheric angiography. The examination can be carried out without general or epidural anaesthesia and catheterization without premedication. In spite of the higher cost, its advantageous characteristics justify the application of this new contrast material.

  19. Bioequivalence of Sandoz methylphenidate osmotic-controlled release tablet with Concerta® (Janssen-Cilag)

    OpenAIRE

    Schapperer, Elisabeth; Daumann, Heike; Lamouche, Stéphane; Thyroff-Friesinger, Ursula; Viel, François; Weitschies, Werner

    2015-01-01

    The aim was to assess the bioequivalence of Sandoz methylphenidate osmotic-controlled release (OCR) tablets (Sandoz [Methylphenidate[ MPH OCR) with Concerta®, a methylphenidate formulation indicated for the treatment of attention deficit/hyperactivity disorder (ADHD). Four open-label, randomized, single-dose, two-way crossover bioequivalence studies were conducted in healthy subjects: three fasting studies with 54-, 36- and 18-mg doses of methylphenidate, and one fed study with the 54-mg dose...

  20. Gastroretentive drug delivery system of Ranitidine hydrochloride based on osmotic technology: development and evaluation.

    Science.gov (United States)

    Kumar, P; Singh, S; Mishra, B

    2008-10-01

    Gastroretentive drug delivery systems (GRDDS) of Ranitidine hydrochloride (RHC) has been designed based on the osmotic technology, with the floating and swelling features in order to prolong the gastric retention time. The developed system consisted of osmotic core (containing drug, osmotic agent and hydrophilic polymers), coated with semipermeable membrane (SPM) which is then further coated with compression coating of gelling agent (HPMC K4M) containing gas generating agent (citric acid). All the developed formulations were evaluated for floating lag time, duration of floating, drug content and in-vitro drug release profile. Formulation variables like levels of hydrophilic polymer (0-18.26%w/w), type of plasticizer (PEG-400, Dibutyl phthalate), coat thickness of SPM (60-100 microm), were found to affect the drug release from the developed formulations. Drug release was directly proportional to hydrophilic nature of plasticizer but inversely proportional to the levels of hydrophilic polymer and coat thickness of SPM. Drug release from developed formulations was independent of level of gas generating agent in compression coat, pH and agitation intensities of release media but dependent on osmotic pressure of the release media. All the developed formulation showed floating lag time of less than 2 min (desired) and were floated for more than 12 hr. Floating lag time was inversely related to level of citric acid in compression coat and directly related to the density of the developed formulations. The manufacturing procedure was found to be reproducible and formulations were stable after 3 months accelerated stability study. Prediction of steady state levels showed the plasma concentrations of RHC to be within desired range.

  1. Controlled assembly of single colloidal crystals using electro-osmotic micro-pumps

    OpenAIRE

    Niu, Ran; Oğuz, Erdal C.; Müller, Hannah; Reinmüller, Alexander; Botin, Denis; Löwen, Hartmut; Palberg, Thomas

    2016-01-01

    We assemble charged colloidal spheres at deliberately chosen locations on a charged unstructured glass substrate utilizing ion exchange based electro-osmotic micro-pumps. Using microscopy, a simple scaling theory and Brownian Dynamics simulations, we systematically explore the control parameters of crystal assembly and the mechanisms through which they depend on the experimental boundary conditions. We demonstrate that crystal quality depends crucially on the assembly distance of the colloids...

  2. 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.

  3. The Pepper CaOSR1 Protein Regulates the Osmotic Stress Response via Abscisic Acid Signaling.

    Science.gov (United States)

    Park, Chanmi; Lim, Chae Woo; Lee, Sung Chul

    2016-01-01

    Plants are sessile organisms, and their growth and development is detrimentally affected by environmental stresses such as drought and high salinity. Defense mechanisms are tightly regulated and complex processes, which respond to changing environmental conditions; however, the precise mechanisms that function under adverse conditions remain unclear. Here, we report the identification and functional characterization of the CaOSR1 gene, which functions in the adaptive response to abiotic stress. We found that CaOSR1 gene expression in pepper leaves was up-regulated after exposure to abscisic acid (ABA), drought, and high salinity. In addition, we demonstrated that the fusion protein of CaOSR1 with green fluorescent protein (GFP) is localized in the nucleus. We used CaOSR1-silenced pepper plants and CaOSR1-OX-overexpressing (OX) transgenic Arabidopsis plants to show that the CaOSR1 protein regulates the osmotic stress response. CaOSR1-silenced pepper plants showed increased drought susceptibility, and this was accompanied by a high transpiration rate. CaOSR1-OX plants displayed phenotypes that were hypersensitive to ABA and hyposensitive to osmotic stress, during the seed germination and seedling growth stages; furthermore, these plants exhibited enhanced drought tolerance at the adult stage, and this was characterized by higher leaf temperatures and smaller stomatal apertures because of ABA hypersensitivity. Taken together, our data indicate that CaOSR1 positively regulates osmotic stress tolerance via ABA-mediated cell signaling. These findings suggest an involvement of a novel protein in ABA and osmotic stress signalings in plants.

  4. The relationship between high gravity brewing, key performance indicators and yeast osmotic stress response

    OpenAIRE

    S. Zhuang

    2014-01-01

    High Gravity (HG) and Very High Gravity (VHG) fermentations are increasingly attractive within the brewing industry as a means of energy-saving and to optimise process efficiency. However, the use of highly concentrated worts is concomitant with a number of biological stress factors and in particular elevated osmotic pressure, which can impact on yeast quality and fermentation performance. In order to eliminate or reduce such negative effects, yeast cells often respond to their environment by...

  5. Trehalose enhances osmotic tolerance and suppresses lysophosphatidylcholine-induced acrosome reaction in ram spermatozoon.

    Science.gov (United States)

    Ahmad, E; Naseer, Z; Aksoy, M; Küçük, N; Uçan, U; Serin, I; Ceylan, A

    2015-09-01

    This study was aimed to investigate the influence of trehalose on osmotic tolerance and the ability of ram spermatozoon to undergo acrosome reaction induced by lysophosphatidylcholine (LPC). In experiment 1, the diluted ejaculates were exposed to anisosmotic fructose solutions (70, 500, 750 and 1000 mOsm l(-1) ) with or without 50 mm trehalose. The presence of trehalose in hyperosmotic conditions enhanced (P ram spermatozoon and suppresses their ability to undergo LPC and cryo-induced acrosome reaction.

  6. Relationship between osmotic stress and polyamines conjugated to the deoxyribonucleic acid-protein in wheat seedling roots

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    The contents of covalently conjugated polyamines (CC-PAs) and noncovalently conjugated polyamines (NCC-PAs) to deoxyribonucleic acid-protein (DNP) isolated from wheat (Triticum aestivum L.) seedling roots under osmotic stress were detected. Results showed that after osmotic stress treatment for 7 d, the levels in NCC-spermine (NCC-Spm) and NCC-spermidine (NCC-Spd) of drought-tolerant Yumai No. 18 cv. increased more markedly than that of drought-sensitive Yangmai No. 9 cv., while the NCC-putrescine (NCC-Put) could not be statistically detected in two cultivars. Exogenous Spm treatment alleviated osmotic stress injury to Yangmai No. 9 cv. seedlings, coupled with marked increases of NCC-Spm and NCC-Spd levels of this cultivar. Under PEG osmotic stress, the concomitant treatment of drought-tolerant Yumai No. 18 cv.seedlings with methylglyoxyl-bis (guanylhydrazone) (MGBG), an inhibitor of S-adenosylmethionine decarboxylase (SAMDC), aggravated osmotic stress injury to this cultivar, coupled with market decreases of the NCC-Spm and NCC- Spd levels. The levels in CC-Put and CC-Spd of drought-tolerant Yumai No. 18 cv. increased more markedly than that of drought-sensitive Yangmai No. 9 cv. Under osmotic stress. The treatment of drought-tolerant Yumai No. 18 cv. seedlings with phenanthrolin (o-Phen), an inhibitor of transglutaminase (TGase), aggravated osmotic stress injury to this cultivar, coupled with a reduction of sum contents of CC-Put+CC-Spd. These results suggested that NCC-Spm and NCC-Spd, together with CC-Put and CC-Spd, in DNP of roots could enhance tolerance of the wheat seedlings to osmotic stress.

  7. A study of the osmotic sensitivity of pike (Esox lucius, L., 1758) spermatozoa for the optimization of their cryopreservation

    OpenAIRE

    А. Puhovkin; Е. Kopeika; К. Mikson; V. Cherepnin; I. Hrytsyniak

    2016-01-01

    Purpose. The study of the osmotic sensitivity of pike (Esox lucius, L., 1758) spermatozoa. Methodology. The osmotic response of pike spermatozoa was investigated by spectrophotometry method based on the kinetics of light transmission of cells suspensions, which were placed in distilled water and 10–200 mOsm/kg solutions of NaCl . Measurements of light transmittance were carried out using photoelectrocolorimeter KF-77 (ZALIMP, Poland), equipped with a magnetic stirrer and thermostatted...

  8. Study on Osmotic Pressure and Liquid-Liquid Equilibria for Micelle, Colloid and Microemulsion Systems by Yukawa Potential

    Institute of Scientific and Technical Information of China (English)

    FU,Dong(付东); LU,Jiu-Fang(陆九芳); WU,Wei(吴畏); Li,Yi-Gui(李以圭)

    2004-01-01

    An equation of state (EOS) was established to study the osmotic pressure and liquid-liquid equilibria for micelle,colloid and microemulsion systems. The Carnahan-Starling equation was used for the hard sphere repulsion. The Yukawa potential was used to describe both the attractive dispersion and the double-layer repulsion. By using the established EOS, the osmotic pressures for charged colloid, uncharged micelle, uncharged and weakly charged microemuslion, the phase equilibria for uncharged micelle and charged colloid systems were studied.

  9. DEVELOPMENT AND EVALUATION OF PUSH-PULL BASED OSMOTIC DELIVERY SYSTEM FOR ROPINIROLE

    Directory of Open Access Journals (Sweden)

    Adarsh Shah et al

    2012-09-01

    Full Text Available Ropinirole hydrochloride is indicated in Parkinson’s disease and Restless leg syndrome. In advanced Parkinson’s disease the usual dose of Ropinirole hydrochloride is 0.25 to 5 mg three to four times a day. Hence, an attempt was made to develop a once-a-day controlled release Osmotic drug delivery system. This may offer significant patient benefits by providing enhanced efficacy and reduced side effects and may also reduce the number of daily doses compared to conventional therapies. An oral push-pull system that can deliver Ropinirole hydrochloride for extended period of time has been developed and characterized. A bilayer osmotic drug delivery system was developed using drilling technique. The push layer swells releasing the drug at a controlled rate. An optimized system was selected to study the effect of pH of dissolution medium and the effect of agitation intensity. The drug release was found to follow zero order kinetics. The developed push-pull osmotic system showed the desired once-a-day release kinetic.

  10. 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

    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 grad......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......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...

  11. Osmotic Ballasts Enhance Faradaic Efficiency in Closed-Loop, Membrane-Based Energy Systems.

    Science.gov (United States)

    Kingsbury, Ryan S; Coronell, Orlando

    2017-02-07

    Aqueous processes for energy storage and conversion based on reverse electrodialysis (RED) require a significant concentration difference across ion exchange membranes, creating both an electrochemical potential and an osmotic pressure difference. In closed-loop RED, which we recently demonstrated as a new means of energy storage, the transport of water by osmosis has a very significant negative impact on the faradaic efficiency of the system. In this work, we use neutral, nonpermeating solutes as "osmotic ballasts" in a closed-loop concentration battery based on RED. We present experimental results comparing two proof-of-concept ballast molecules, and show that the ballasts reduce, eliminate, or reverse the net transport of water through the membranes when cycling the battery. By mitigating osmosis, faradaic and round-trip energy efficiency are more than doubled, from 18% to 50%, and 7% to 15%, respectively in this nonoptimized system. However, the presence of the ballasts has a slightly negative impact on the open circuit voltage. Our results suggest that balancing osmotic pressure using noncharged solutes is a promising approach for significantly reducing faradaic energy losses in closed-loop RED systems.

  12. Putrescine, a fast-acting switch for tolerance against osmotic stress.

    Science.gov (United States)

    Kotakis, Christos; Theodoropoulou, Eleftheria; Tassis, Konstantinos; Oustamanolakis, Charalambos; Ioannidis, Nikolaos E; Kotzabasis, Kiriakos

    2014-01-15

    During the last decade we showed clearly that abiotic stress changes the cellular composition of polyamines, which in turn regulate the photochemical and non-photochemical quenching of the received light energy in the photosynthetic apparatus and that modulate substantially the level of plant tolerance. In the present contribution, we tried to change the bioenergetics of the leaf discs before the exposure to osmotic stress only by exogenously supplied putrescine, in order to enhance quickly the tolerance against the abiotic stress. Tobacco leaf discs treated with polyethylene-glycol reduced their water content about 24% within 1h. This relatively mild osmotic stress increased endogenous putrescine about 83% and decreased maximum photosystem II photochemical efficiency about 14%. In line with this, here we show that treatment with 1mM exogenous putrescine 1h before polyethylene-glycol addition protects the photochemical capacity and inhibits loss of water, confirming the key role of putrescine in the modulation of plant tolerance against osmotic stress. Furthermore, our recent works indicate that putrescine is accumulated in lumen during light reactions and may act as a permeable buffer and an osmolyte.

  13. Evaluation of the response of Lactobacillus rhamnosus VTT E-97800 to sucrose-induced osmotic stress.

    Science.gov (United States)

    Sunny-Roberts, E O; Knorr, D

    2008-02-01

    Environmental osmotic changes are one of the stresses live probiotics may encounter either in their natural habitats or as a result of usage in food formulations and processing. Response to osmotic stress, induced by sucrose, of the probiotic strain Lactobacillus rhamnosus VTT E-97800 (E800) was investigated. The fluorescence-based approach used, by combined staining with caboxyfluorescein (cFDA) and propidium iodide (PI) could give insights on the osmotic-induced changes of microbial esterase activity and membrane integrity; also the extrusion of intracellular accumulated carboxyfluorescein (cF) upon energizing with glucose. Comparison of the flowcytometric viability assessment with the conventional culture techniques revealed that sucrose-stressed cells had a slight loss of culturability (logN/N(0) approximately -0.3) at 1.2 and 1.5M sucrose concentration though they could perform an enzymatic conversion of cFDA into cF. The presence of such metabolically active bacteria in food might be critical as they may excrete toxic or food spoilage metabolites. Moreover, the perturbation of cF extrusion activities became a limiting factor for reproductive capacities. There was no change in the cell morphology. These results proved the ability of the strain of study to tolerate sucrose, even at extreme concentrations and these must be taken into consideration for its usage in the formulation/processing of sugar-based foods, e.g. jams, candies, etc.

  14. Controlled delivery of nanosuspensions from osmotic pumps: zero order and non-zero order kinetics.

    Science.gov (United States)

    Hill, Alexandra; Geissler, Simon; Weigandt, Markus; Mäder, Karsten

    2012-03-28

    Nanosuspensions have gained great interest in the last decade as a formulation tool for poorly soluble drugs. By decreasing particle sizes nanosuspensions enhance dissolution rate and bioavailability of the active pharmaceutical ingredient. Micro-osmotic pumps are widely used in experimental pharmacology and offer a tool of interest for the sustained release of nanosuspensions via the intraperitoneal or subcutaneous application site. The purpose of the present study was to investigate in-vitro the influence of (1) nanosuspension viscosity, (2) pump orifice position and (3) formulation osmolality on the delivery behavior of formulations in implantable osmotic systems. Therefore fenofibrate nanosuspension, methylene blue and fluorescein sodium solutions were chosen as model formulations. They were released in water or isotonic saline solution and drug/dye concentrations were determined by HPLC/UV. Release of nanosuspension particles in low viscous formulations resulted in a burst whereas increasing the viscosity led to the expected zero order delivery. Pumps with upward-positioned orifices released the nanosuspension in a zero order manner. Within the release of dyes, constant delivery could be ensured up to an osmolality of 486 mO sm/kg; above this value premature release of formulation was observed. The results indicate the requirement of in-vitro experiments prior to in-vivo animal testing for determining the release profiles of osmotic pumps.

  15. 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.

  16. Ectopic Expression of FaDREB2 Enhances Osmotic Tolerance in Paper Mulberry

    Institute of Scientific and Technical Information of China (English)

    Mei-Ru Li; Yan Li; Hong-Qing Li; Guo-Jiang Wu

    2011-01-01

    Dehydration-responsive element binding (DREB) proteins are a subfamily of AP2/ERF transcription factors that have been shown to improve tolerance to osmotic stresses in plants.To improve the osmotic stress tolerance of paper mulberry (Broussonetia papyrifera L.Vent),an economically important tree,we transformed it with a plasmid carrying tall fescue (Festuca arundinacea Schreb) FaDREB2 under the control of CaMV 35S.The ectopic expression of FaDREB2 did not cause growth retardation,and the paper mulberry seedlings expressing FaDREB2 showed higher salt and drought tolerance than wild-type plants (WT).After 13 d of withholding water,or 15 d in the presence of 250 mM NaCI,all the WT plants died,while the plants expressing FaDREB2 survived.The FaDREB2 transgenic plants had higher leaf water and chlorophyll contents,accumulated more proline and soluble sugars,and had less membrane damage than the WT plants under high salt and water-deficient conditions.Taken together,the results indicate the feasibility of improving tolerance to multiple environmental stresses in paper mulberry seedlings via genetic engineering,by introducing FaDREB2,which promotes the increased accumulation of osmolytes (soluble sugars and proline),to counter osmotic stresses caused by abiotic factors.

  17. Effect Of Permethrin, Pirimiphos Methyl And Bendiocarb On The Osmotic Resistance Of Rat Erythrocytes

    Directory of Open Access Journals (Sweden)

    Salwa A.Metwally and Hala M. Fawzy

    2004-06-01

    Full Text Available Environmental pollution by insecticides is one of the most important problems in the world. Some of the pesticides were found to exert carcinogenic, teratogenic and/or mutagenic effects even following normal agricultural use (U.S.Geological Survey, 1997. On the other hand residues from insecticides, herbicides and insect growth hormones are known to represent the most common food contaminants particularly in developing countries. Thus the wide spread use of insecticides in agriculture stimulated our interest for studying their possible toxic effect(s in man and animals. The aim of the present work was to study the effect of short term (for 2 weeks oral daily feeding with diet containing 10 times the human maximum acceptable daily intake (a concentration that may be faced by human of either permethrin, pirimiphos-methyl or bendiocarb on osmotic fragility of rat erythrocytes. Sprague Dawley male rats were divided into four groups, each consists of 10 animals. Animals of each group were fed either normal diet (control group, permethrin (21.7 ppm, pirimiphos-methyl (4.4 ppm or bendiocarb (2.0 ppm for 2 weeks. Twenty four hours later, blood samples were withdrawn and osmotic fragility was determined. The obtained results indicated that permethrin, pirimiphos-methyl and bendiocarb increase the osmotic fragility.

  18. 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.

  19. Efficient cyclic system to yield ectoine using Brevibacterium sp. JCM 6894 subjected to osmotic downshock.

    Science.gov (United States)

    Nagata, Shinichi; Wang, Yaoqiang; Oshima, Akinobu; Zhang, Linghua; Miyake, Hideyoshi; Sasaki, Hideaki; Ishida, Akio

    2008-03-01

    Brevibacterium sp. JCM 6894 cells grown in the presence of 1.5-2.5 M NaCl for 24 h at 30 degrees C were subjected to the osmotic downshock. Downshocked cells after ectoine release were grown for further 24 h in the fresh medium with same salinity as before shock. When this cyclic system was applied to the strain JCM 6894, the amount of ectoine in the cells increased with an increase of incubation time, which indicates that the cells manipulated by the present conditions were enough active to survive and synthesize ectoine after several times of osmotic downshock. In the presence of 2 M NaCl, the highest yield of ectoine released was achieved in this cyclic system, more than 2.4 g/L during 7 days of incubation. (1)H and (13)C-NMR analyses of solutes released from the cells by the osmotic downshock showed the presence of only ectoine with high purity. Release of ectoine from the cells was carried out within 5 min and its rates were increased by the dilution in the downshock treatment. For the convenience of operations, non-sterilized medium containing 2 M NaCl was examined for the cell growth in the present system, in which almost same level of ectoine yield, release rates, and cell viability were observed as those of sterilized medium.

  20. 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

  1. Interaction between osmotic and oxidative stress in diabetic precataractous lens: studies with a sorbitol dehydrogenase inhibitor.

    Science.gov (United States)

    Obrosova, I G; Fathallah, L; Lang, H J

    1999-12-15

    Both sorbitol accumulation-linked osmotic stress and "pseudohypoxia" [increase in NADH/NAD+, similar to that in hypoxic tissues, and attributed to increased sorbitol dehydrogenase (1-iditol:NAD+ 5-oxidoreductase; EC 1.1.1.14; SDH) activity] have been invoked among the mechanisms underlying oxidative injury in target tissues for diabetic complications. We used the specific SDH inhibitor SDI-157 [2-methyl-4(4-N,N-dimethylaminosulfonyl-1-piperazino)pyrimid ine] to evaluate the role of osmotic stress versus "pseudohypoxia" in oxidative stress occurring in diabetic precataractous lens. Control and diabetic rats were treated with or without SDI-157 (100 mg/kg/day for 3 weeks). Lens malondialdehyde (MDA) plus 4-hydroxyalkenals (4-HA), MDA, GSH, and ascorbate levels, as well as the GSSG/GSH ratios, were similar in SDI-treated and untreated control rats, thus indicating that SDI-157 was not a prooxidant. Intralenticular osmotic stress, manifested by sorbitol levels, was more severe in SDI-treated diabetic rats (38.2+/-6.8 vs 21.2+/-3.5 micromol/g in untreated diabetic and 0.758+/-0.222 micromol/g in control rats, PSDIs provide a valuable tool for exploring mechanisms of oxidative injury in sites of diabetic complications.

  2. 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.

  3. In vitro-in vivo evaluation of nanosuspension release from subcutaneously implantable osmotic pumps.

    Science.gov (United States)

    Hill, A; Geissler, S; Meyring, M; Hecht, S; Weigandt, M; Mäder, K

    2013-07-15

    Utilizing poorly soluble drug candidates in pharmacokinetic studies remains challenging in preclinical drug development. We investigated a nanosuspension-based delivery system to achieve constant drug plasma levels by applying the nanoparticles via subcutaneously implanted micro-osmotic pumps. Various nanosuspension formulations were characterized in vitro prior to Alzet® pump release by means of dynamic light scattering (DLS), scanning electron microscopy (SEM), differential scanning calorimetry (DSC) and rheological measurements. In vitro formulation release was checked by HPLC/UV. The in vivo experiments compared plasma-concentration time profiles of subcutaneously injected nanosuspensions with those of formulations delivered by pumps. Two Poloxamer 338 containing nanosuspensions with different viscosities were found to be stable over observation time, physically resistant against biorelevant media and showed only a low amorphous part after preparation. The more viscous nanosuspension with 31.65 mPas revealed in vitro the expected zero-order release, while the low viscous formulation with 2.18 mPas showed first order release. In in vivo experiments, the higher viscous nanosuspension released from osmotic pumps exhibited elevated plasma levels compared to the lower viscous formulation. Compared to bolus injected nanosuspensions constant plasma levels could be maintained by adapting the viscosity of the nanosuspension. Subcutaneously implanted osmotic pumps prove to be a valuable delivery system for nanosuspensions in pharmacokinetic studies by consideration of the key parameter viscosity in release kinetics.

  4. Effect of osmotic pressure on ganglioside-cholesterol-DOPC lipid mixture

    Energy Technology Data Exchange (ETDEWEB)

    Onai, Teruaki; Hirai, Mitsuhiro [Department of Physics, Gunma University, Maebashi 371-8510 (Japan)

    2007-10-15

    By means of small-angle X-ray scattering (SAXS) method, we have studied the structure of the lipid mixtures of monosialoganglioside (G{sub MI})-cholesterol-dioleoyl-phosphatidylcholine (DOPC) system as a model of lipid raft. The samples were small uni-lamellar vesicle (SUV) except for G{sub MI} sample. The osmotic pressure was changed with varying the polyvinylpyrrolidone (PVP) concentration in the range from 0 to 25 % w/w. The increase of the PVP concentration is known to reduce the lamellar spacing due to the increase of the osmotic pressure. On the other hand the polar head region of G{sub MI} was shown to be highly hydrophilic by the presence of oligosaccharide chain containing one sialic acid residue. In the cases of the G{sub MI} micelle and G{sub MI}-cholesterol SUV the presence of PVP affects little on those aggregate structures. In the case of the SUVs of cholesterol-DOPC the stacking of the bilayers was induced with the increase of PVP concentration, especially at high cholesterol content. In the case of the SUVs of G{sub MI}-cholesterol-DOPC the multi-lamellar stacking was suppressed, but a minor change of the SUV structure was induced. The present results suggest that the coexistence of G{sub MI} and cholesterol affords the lipid bilayer a resistance to the osmotic stress and avoids a multi-layered stacking.

  5. 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...... diuresis [1,147 +/- 32 (C) to 950 +/- 22 (P2) microliters.min-1.g kidney wt (KW)-1, P less than 0.01), whereas Li clearance (CLi) increased [377 +/- 21 (C) to 469 +/- 28 (P1, P less than 0.01) and 408 +/- 25 (P2, NS) microliters.min-1.gKW-1, respectively]. (TF/P)Na decreased from 0.98 +/- 0.02 (C) to 0...

  6. 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.

  7. 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.

  8. Isolation of viable porcine islets by selective osmotic shock without enzymatic digestion.

    Science.gov (United States)

    Atwater, I; Guajardo, M; Caviedes, P; Jeffs, S; Parrau, D; Valencia, M; Romero, C; Arriagada, C; Caamaño, E; Salas, A; Olguin, F; Atlagich, M; Maas, R; Mears, D; Rojas, E

    2010-01-01

    Islet transplantation is a potential cure for type 1 diabetes, but clinical results have been disappointing. Currently, islet isolation is by enzymatic digestion of the pancreas which has significant pitfalls: warm ischemia exposure, collagenase-induced damage to the islet mass and viability, poor reproducibility, high cost, a relatively low number of islets obtained per whole pancreas, and selection of islets for collagenase resistance rather than for glucose responsiveness. In the present study we performed a series of experiments in a porcine model to demonstrate the feasibility of a new isolation method based on selective osmotic shock (SOS) using very high glucose solutions, doubling or tripling physiological osmotic strength. The SOS method can be carried out at room temperature or in the cold eliminating warm ischemia time which damages the islets. The SOS method does not depend on the texture of the pancreas so all pancreases can be processed identically and the process can be fully automated. The SOS method isolates all the islets of the pancreas regardless of size and shape allowing a greater number of islets to be harvested. The SOS method avoids exposure to toxins in collagenase solutions, is inexpensive and selects for islets with high concentrations of Glut 2 transporters, representing the best glucose responding islets. The SOS method showed a comparable recovery of islets from young pig pancreas and the islets showed improved viability. We conclude that the selective osmotic shock (SOS) method of separating islets from the pancreatic tissue is superior to the collagenase method.

  9. Physiological and biochemical responses of green microalgae from different habitats to osmotic and matric stress.

    Science.gov (United States)

    Gustavs, Lydia; Eggert, Anja; Michalik, Dirk; Karsten, Ulf

    2010-07-01

    Growth of five aeroterrestrial green algal strains (Trebouxiophyceae) in response to changing water availabilities-caused by osmotic (ionic) and matric (desiccation) stresses-was investigated in comparison with a freshwater and a marine strain. All investigated algae displayed good growth under brackish conditions while four out of the five aeroterrestrial strains even grew well under full marine conditions (28-40 psu). The comparison between growth responses in liquid medium, on solid agarose, and on glass fiber filters at 100% air humidity indicated a broad growth tolerance of aeroterrestrial algae towards diminished water availability. While two aeroterrestrial strains even grew better on solid medium which mimics natural biofilm conditions, the aquatic strains showed significant growth inhibition under matric stress. Except Stichococcus sp., which contained the C6-polyol sorbitol, all other aeroterrestrial green algae investigated synthesized and accumulated the C5-polyol ribitol in response to osmotic stress. Using (13)C NMR spectroscopy and HPLC, it could be verified that ribitol functions as an osmotically regulated organic solute. This is the first proof of ribitol in free-living aeroterrestrial green algae. The biochemical capability to synthesize polyols under environmental stress conditions seems to support algal life outside aquatic habitats.

  10. Effect of seawater immersion on plasma osmotic pressure and electrolyte balance following open chest trauma

    Institute of Scientific and Technical Information of China (English)

    李辉; 鹿尔驯; 虞积耀; 王大鹏; 马聪

    2002-01-01

    To explore the effect of seawater immersion on serum osmotic pressure and electrolytes balance following chest trauma in dogs. Methods: Twenty-five healthy adult dogs were used in the experiment. A canine model of right open pneumothorax was established by chest puncturing on all animals. Animals were divided into three groups: a control group (n = 10) with chest trauma without any immersion;a seawater group ( n = 10) immersed in seawater after chest trauma and a normal saline group ( n = 5 ) immersed in normal saline solution following chest trauma. Blood samples were taken at different time intervals to determine plasma osmotic pressure and electrolytes. The hemodynamic changes were also recorded. Results: Mortality in the seawater group was much higher than that of the control group and the normal saline group. The mean survival time in the seawater group lasted only 45 minutes, while in the control group and the normal saline group the average survival time was more than 4 hours (P < 0.01 ). One of the most important causes of death was hypernatremia and high osmolality. Severe electrolytes imbalance was observed in seawater group.Hypernatremia and high osmolality were the most significant factors of high mortality in the seawater group. Conclusions: Seawater immersion after chest trauma appears to be associated with severe electrolyte imbalance as well as high osmotic pressure, These may be the risk factors leading to fatal outcome.

  11. 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.

  12. Design and Development of Clopidogrel Bisulfate Gastroretentive Osmotic Formulation Using Quality by Design Tools.

    Science.gov (United States)

    Desai, Nilesh; Purohit, Ravindra

    2017-02-28

    Clopidogrel bisulfate (CBS) is antiplatelet drug and it is becoming a drug of choice in the treatment and management of prevention of heart attacks and strokes. CBS is stable and soluble in acidic pH; therefore, retention in stomach for prolonged period appears to be beneficial for controlling the bioavailability. The gastroretentive osmotic system (GROS) facilitates prolonged retention of drug in stomach and provides zero-order drug release. A complex formulation like GROS poses many challenges, and QbD tools can help in designing robust formulation which takes all aspects of product and process development in order to deliver a robust product. The GROS was formulated in three steps: core tablet, osmotic tablet, and gastroretentive osmotic tablet. The design of experiment was used for screening and optimization of formulation and process-related parameters. The dissolution study was carried out to analyze the release pattern of tablet. The optimized batch O-4 showed cumulative drug release of 19.43, 30.49, 64.41, and 85.11% at 2, 4, 8, and 12 h which is in the range of QTPP predictions. The novel technique of GROS was implemented successfully which demonstrates robust design giving consistent and desired results.

  13. Formulation development and evaluation of controlled porosity osmotic pump delivery system for oral delivery of atenolol

    Directory of Open Access Journals (Sweden)

    Garvendra S Rathore

    2012-01-01

    Full Text Available In the present study, we developed and evaluated the controlled porosity osmotic pump (CPOP based drug delivery system of sparingly water soluble drug atenolol (ATL. We selected target release profile and optimized different variables to help us achieve this. Formulation variables, such as, the levels of solubility enhancer (0-15% w/w of drug, ratio of the drug to the osmogents, coat thickness of the semipermeable membrane (SPM and level of pore former (0-20% w/w of polymer were found to effect the drug release from the developed formulations. Cellulose acetate (CA 398-10 was used as the semipermeable membrane containing polyethylene glycol 400 as the Cplasticizer. ATL release was directly proportional to the level of the solubility enhancer, osmotic pressure generated by osmotic agent and level of pore former; however, was inversely proportional to the coat thickness of SPM. Drug release from developed formulations was independent of the pH and agitation intensities of release media. Burst strength of the exhausted shells decreased with increase in the level of pore former. The optimized formulations were subjected to stability studies as per International Conference on Harmonisation (ICH guidelines, and formulations were found to be stable after 3 months study. Steady-state plasma levels of drug were predicted by the method of superposition.

  14. [Half-molar sodium-lactate: The osmotic agent we are looking for?].

    Science.gov (United States)

    Aramendi, I; Manzanares, W; Biestro, A

    2016-03-01

    Intracranial hypertension (ICH) is the most important modifiable factor with predictive negative value in brain injury patients. Osmotherapy is the most important first level specific measure in the treatment of ICH. Mannitol 20%, and 3, 7.5, 10, and 23% hypertonic sodium chloride are the most commonly used osmotic agents in the neurocritical care setting. Currently, controversy about the best osmotic agent remains elusive. Therefore, over the past few years, half-molar sodium lactate has been introduced as a new osmotic agent to be administered in the critically ill. Lactate is able to prevent hyperchloremia, as well as its adverse effects such as hyperchloremic acidosis, systemic inflammation, and acute kidney injury. Furthermore, lactate may also be used by glia as energy substrate in brain injury patients. Half-molar sodium lactate would also have a more potent and long-lasting effect decreasing intracellular osmolarity and by inhibiting neuronal volume control mechanisms. Pioneering researches in patients with traumatic brain injury have shown a more significant effect than mannitol on the control of ICH. In addition, in this group of patients this solution appears to be beneficial in preventing episodes of ICH. However, future research is necessary to corroborate or not these promising results.

  15. Osmotic diuresis-induced hypernatremia: better explained by solute-free water clearance or electrolyte-free water clearance?

    Science.gov (United States)

    Popli, Subhash; Tzamaloukas, Antonios H; Ing, Todd S

    2014-01-01

    Hypernatremia may result from inadequate water intake, excessive water loss or a combination of the two. Osmotic diuresis leads to losses of both solute and water. The relationship between solute and water losses determines the resulting changes in serum osmolality and sodium concentration. Total solute loss is routinely higher than loss of water in osmotic diuresis. Theoretically, then, decreases in serum osmolality (and serum sodium concentration) should follow. In clinical situations of osmotic diuresis, however, reduction in osmolality can take place, but not reduction in serum sodium concentration. It is of note that serum sodium concentration changes are related to urinary losses of sodium and potassium but not to the loss of total solute. In osmotic diuresis, the combined loss of sodium and potassium per liter of urine is lower than the concurrent serum sodium level. Consequently, hypernatremia can ensue. A patient who presented with osmotic diuresis and hypernatremia is described here. In this patient, we have shown that electrolyte-free water clearance is a better index of the effect of osmotic diuresis on serum sodium concentration than the classic solute-free water clearance.

  16. Involvement of redox- and phosphorylation-dependent pathways in osmotic adaptation in sperm cells of euryhaline tilapia.

    Science.gov (United States)

    Morita, Masaya; Nakajima, Ayako; Takemura, Akihiro; Okuno, Makoto

    2011-06-15

    Sperm cells involved in fertilisation must tolerate hypo-osmotic and hyper-osmotic environments. Euryhaline tilapia (Oreochromis mossambicus) can acclimatise to and reproduce in freshwater and seawater because its sperm are able to adapt to these differing osmotic environments. In this study, we found that the dephosphorylation of sperm proteins in O. mossambicus correlated with the activation of flagellar motility when sperm were exposed to hypotonic or hypertonic conditions, and that differences in phosphorylation may reflect adaptations to a given osmotic environment. Of the sperm proteins that were dephosphorylated, the phosphorylation pattern of an 18 kDa protein, identified as the superoxide anion scavenger Cu/Zn superoxide dismutase (Cu/Zn SOD), was different in freshwater- and seawater-acclimatised tilapia sperm. Cu/Zn SOD was distributed from the sperm head to the flagellum. Additionally, differences were observed between freshwater and seawater tilapia in the nitration of tyrosine residues (which might be mediated by SOD) in sperm flagellar proteins in response to osmotic shock. These results demonstrate that reactive-oxygen-species-dependent mechanisms contribute to both osmotic tolerance and the activation of flagellar motility.

  17. Ear infection - chronic

    Science.gov (United States)

    Middle ear infection - chronic; Otitis media - chronic; Chronic otitis media; Chronic ear infection ... up. When this happens, infection can occur. A chronic ear infection develops when fluid or an infection ...

  18. 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

  19. Hemodynamic and cardiac effects of chronic eprosartan and moxonidine therapy in stroke-prone spontaneously hypertensive rats.

    Science.gov (United States)

    Mukaddam-Daher, Suhayla; Menaouar, Ahmed; Paquette, Pierre-Alexandre; Jankowski, Marek; Gutkowska, Jolanta; Gillis, Marc-Antoine; Shi, Yan-Fen; Calderone, Angelo; Tardif, Jean-Claude

    2009-05-01

    The renin-angiotensin and sympathetic nervous systems play critical interlinked roles in the development of left ventricular hypertrophy, fibrosis, and dysfunction. These studies investigated the hemodynamic and cardiac effects of monoblockade and coblockade of renin-angiotensin and sympathetic nervous systems. Stroke-prone spontaneously hypertensive rats (16 weeks old; male; n=12 per group) received the sympatholytic imidazoline compound, moxonidine (2.4 mg/kg per day); the angiotensin-receptor blocker eprosartan (30 mg/kg per day), separately or in combination; or saline vehicle for 8 weeks, SC, via osmotic minipumps. Blood pressure and heart rate were continuously measured by radiotelemetry. After 8 weeks, in vivo cardiac function and structure were measured by transthoracic echocardiography and a Millar conductance catheter, and the rats were then euthanized and blood and heart ventricles collected for various determinations. Compared with vehicle, the subhypotensive dose of moxonidine resulted in lower (P<0.01) heart rate, left ventricular hypertrophy, cardiomyocyte cross-sectional area, interleukin 1 beta, tumor necrosis factor-alpha, and mRNA for natriuretic peptides. Eprosartan reduced pressure (P<0.01), as well as extracellular signal-regulated kinase (ERK) 44 phosphorylation, Bax/Bcl-2, and collagen I/III, and improved left ventricular diastolic function (P<0.03). Combined treatment resulted in greater reductions in blood pressure, heart rate, left ventricular hypertrophy, collagen I/III, and inhibited inducible NO synthase and increased endothelial NO synthase phosphorylation, as well as reduced left ventricular anterior wall thickness, without altering the other parameters. Thus, in advanced hypertension complicated with cardiac fibrosis, sympathetic inhibition and angiotensin II blockade resulted in greater reduction in blood pressure and heart rate, inhibition of inflammation, and improved left ventricular pathology but did not add to the benefits of

  20. Osmotic tolerance limits and effects of cryoprotectants on the motility, plasma membrane integrity and acrosomal integrity of rat sperm.

    Science.gov (United States)

    Si, Wei; Benson, James D; Men, Hongsheng; Critser, John K

    2006-12-01

    Osmotic stress is an important factor that can result in cell damage during cryopreservation. The objectives of this study were to determine: (1) isosmotic sperm cell volume; (2) osmotically inactive volume; (3) osmotic tolerance limits of rat sperm; and (4) the effects of addition and removal of glycerol (Gly), ethylene glycol (EG), propylene glycol (PG) or dimethyl sulfoxide (Me(2)SO) on rat sperm function. Sperm from Fischer 344 and Sprague-Dawley rats were used in this study. An electronic particle counter was used to measure the cell volume of rat sperm. Computer-assisted sperm motility analysis and flow-cytometric analysis were used to assess sperm motility, plasma membrane and acrosomal integrity. The isosmotic sperm cell volumes of the two strains were 37.0+/-0.1 and 36.2+/-0.2 microm(3), respectively. Rat sperm behaved as linear osmometers from 260 to 450 mOsm, and the osmotically inactive sperm volumes of the two strains were 79.8+/-1.5% and 81.4+/-2.2%, respectively. Rat sperm have very limited osmotic tolerances. The sperm motility and the sperm plasma membranes of both strains were sensitive to anisosmotic treatments, but the acrosomes of both strains were more sensitive to hyposmotic than hyperosmotic conditions. The one-step addition and removal of Me(2)SO showed the most deleterious effect on rat sperm motility, plasma membrane integrity, and acrosomal integrity among the four cryoprotectants. These data characterizing rat sperm osmotic behavior, osmotic and cryoprotectant tolerance will be used to design cryopreservation protocols for rat sperm.

  1. Modelling coupled chemico-osmotic and advective-diffusive transport of nitrate salts in the Callovo-Oxfordian Clay

    Science.gov (United States)

    Baechler, S.; Croisé, J.; Altmann, S.

    2012-12-01

    Chemico-osmosis is a recognized phenomenon taking place in clay mineral-rich sedimentary formations and a number of questions have been raised concerning its potential effects on pressure fields in and around underground radioactive waste repositories installed in such formations. Certain radioactive waste packages contain large quantities of nitrate salts whose release might result in the presence of highly concentrated salt solutions in the disposal cells, during their resaturation after closure of the facility. This would lead to large solute concentration gradients within the formation's porewater which could then potentially induce significant chemico-osmotic fluxes. In this paper, we assess the impact of chemico-osmotic fluxes on the water pressure during the post-closure period of a typical disposal cell for intermediate-level, long-lived bituminised radioactive waste in the Callovo-Oxfordian Clay formation. A numerical model of chemico-osmotic water flow and solute transport has been developed based on the work of Bader and Kooi (2005) [5], and including Bresler's dependence of osmotic efficiency on concentration and compaction state [9]. Model validity has been extended to highly concentrated solutions by incorporating a concentration-dependent activity coefficient, based on the Pitzer's equations. Results show that due to the strong dependence of the osmotic coefficient on concentration, the impact of chemico-osmosis on water flow and on the pressure field around the disposal cell is relatively low. A maximum overpressure of the order of 1 MPa was obtained. No difference in the simulation results were noticed for disposal cell solutions having concentrations higher than 1 M NaNO3. Differences between simulations were found to be almost entirely due to Bresler's relationship i.e., the model of the dependence between osmotic efficiency and concentration, and only slightly on the activity coefficient correction. Questions remain regarding the appropriate

  2. [Chronic hepatitis].

    Science.gov (United States)

    Figueroa Barrios, R

    1995-01-01

    Medical literature about chronic hepatitis is reviewed. This unresolving disease caused by viruses, drugs or unknown factors may progress to in cirrhosis and hepatocarcinoma. A classification based on liver biopsy histology into chronic persistent and chronic active types has been largely abandoned and emphasis is placed on recognizing the etiology of the various types. One is associated with continuing hepatitis B virus infection; another is related to chronic hepatitis C virus infection and the third is termed autoinmune, because of the association with positive serum autoantibodies. A fourth type with similar clinical functional and morphologic features is found with some drug reactions. Long term corticoesteroid therapy is usually successful in autoinmune type. Associations between antibodies to liver-kidney microsomes and the hepatitis C virus can cause diagnostic difficulties. Antiviral treatment of chronic hepatitis B and C with interpheron alfa is employed, controlling symptoms and abnormal biochemistry and the progression to cirrhosis and liver cancer in 30 to 40% patients. Alternative therapies or combinations with interpheron are being evaluated waiting for final results.

  3. Plasmolysis effects and osmotic potential of two phylogenetically distinct alpine strains of Klebsormidium (Streptophyta).

    Science.gov (United States)

    Kaplan, Franziska; Lewis, Louise A; Wastian, Johann; Holzinger, Andreas

    2012-07-01

    The osmotic potential and effects of plasmolysis were investigated in two different Klebsormidium strains from alpine habitats by incubation in 300-2,000 (3,000) mM sorbitol. Several members of this genus were previously found to tolerate desiccation in the vegetative state yet information was lacking on the osmotic potentials of these algae. The strains were morphologically determined as Klebsormidium crenulatum and Klebsormidium nitens. These species belong to distinct clades, as verified by phylogenetic analysis of the rbcL gene. K. crenulatum is part of to the K. crenulatum/mucosum ('F' clade) and K. nitens of the 'E2' clade. Plasmolysis occurred in K. crenulatum at 800 mM sorbitol (961 mOsmol kg(-1), Ψ = -2.09 MPa) and in K. nitens at 600 mM sorbitol (720 mOsmol kg(-1), Ψ = -1.67 MPa). These are extraordinarily high osmotic values (very negative osmotic potentials) compared with values reported for other green algae. In K. crenulatum, the maximum photosynthetic rate (Pmax) in the light-saturated range was 116 μmol O(2) h(-1) mg(-1) chl a. Incubation in 1,000 mM sorbitol decreased Pmax to 74.1% of the initial value, whereas 2,000 mM sorbitol (Ψ = -5.87 MPa) lead to an almost complete loss of oxygen production. In K. nitens, Pmax was 91 μmol O(2) h(-1) mg(-1) chl a under control conditions and incubation in 800 mM sorbitol did not decrease Pmax, 2,000 mM sorbitol decreased Pmax only to about 62.6% of the initial value whereas 3,000 mM sorbitol stopped oxygen evolution. This indicated a broader amplitude for photosynthesis in the examined strain of K. nitens. Control samples and samples plasmolysed for 3 h in 800 mM sorbitol (K. nitens), 1,000 mM sorbitol (K. crenulatum), or 2,000 mM sorbitol were investigated by transmission electron microscopy after chemical or high-pressure freeze fixation. In cells undergoing plasmolysis the protoplasts were retracted from the cell wall, the cytoplasm appeared dense, vacuoles were small

  4. 声空强化渗透脱水过程质扩散研究%Mass Transfer During Osmotic Dehydration Using Acoustic Cavitation

    Institute of Scientific and Technical Information of China (English)

    孙宝芝; 淮秀兰; 姜任秋; 刘登瀛

    2005-01-01

    An experimental study on intensifying osmotic dehydration was carried out in a state of nature and with acoustic cavitation of different cavitating intensity (0.5A, 0.TA and 0.9A) respectively, in which the material is apple slice of 5 mm thickness. The result showed that acoustic cavitation remarkably enhanced the osmotic dehydration, and the water loss was accelerated with the increase of cavitating intensity. The water diffusivitymodel was established about mass transfer during osmotic dehydration, and the numerical simulation was carried out. The calculated results agree well with experimental data, and represent the rule of mass transfer during osmotic dehydration intensified by acoustic cavitation.

  5. The osmotic tolerance of boar spermatozoa and its usefulness as sperm quality parameter.

    Science.gov (United States)

    Yeste, Marc; Briz, Mailo; Pinart, Elisabeth; Sancho, Sílvia; Bussalleu, Eva; Bonet, Sergi

    2010-06-01

    Predicting the fertility outcome of ejaculates is very important in the field of porcine reproduction. The aims of this study were to determine the effects of different osmotic treatments on boar spermatozoa and to correlate them with fertility and prolificacy, assessed as non-return rates within 60 days (NRR(60d)) of the first inseminations, and litter size (LS), respectively. Sperm samples (n=100) from one hundred healthy Piétrain boars were used to assess 48 treatments combining different osmolalities (ranged between 100 and 4000 mOsm kg(-1)), different compounds used to prepare anisotonic solutions, and two different modalities: return and non-return to isotonic conditions. Sperm quality was evaluated before and after applying the treatments on the basis of analyses of sperm viability, motility, morphology and percentages of acrosome-intact spermatozoa. Statistical analyses were performed using a one-way ANOVA and post hoc Tukey's test, linear regression analyses (Pearson correlation and multiple regression) and Jackknife cross-validation. Although three conventional parameters: sperm viability, sperm morphology and the percentages of acrosome-intact spermatozoa were significantly correlated with NRR(60d) and with LS, their respective osmotic tolerance parameters (defined for each parameter and treatment regarding with negative control) presented a higher Pearson coefficient with both fertility and prolificacy in three treatments (150 mOsm kg(-1) with non-return to isotonic conditions, 200 mOsm kg(-1) with return and 500 mOsm kg(-1) using sodium citrate and non-return to isotonic conditions). We conclude that osmotic resistance in sperm viability, sperm morphology and acrosome-intactness in the treatments mentioned above could be assessed along with classical parameters to better predict the fertilising ability of a given ejaculate.

  6. 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.

  7. Relating reverse and forward solute diffusion to membrane fouling in osmotically driven membrane processes.

    Science.gov (United States)

    She, Qianhong; Jin, Xue; Li, Qinghua; Tang, Chuyang Y

    2012-05-01

    Osmotically driven membrane processes, such as forward osmosis (FO) and pressure retarded osmosis (PRO), are attracting increasing interest in research and applications in environment and energy related fields. In this study, we systematically investigated the alginate fouling on an osmotic membrane during FO operation using four types of draw solutions (NaCl, MgCl(2), CaCl(2) and Ca(NO(3))(2)) to elucidate the relationships between reverse (from draw solution to feed solution) and forward (from feed solution to draw solution) solute diffusion, and membrane fouling. At the same water flux level (achieved by adjusting the draw solution concentration), the greatest reverse solute diffusion rate was observed for NaCl draw solution, followed by Ca(NO(3))(2) draw solution, and then CaCl(2) draw solution and MgCl(2) draw solution, the order of which was consistent with that of their solute permeability coefficients. Moreover, the reverse solute diffusion of draw solute (especially divalent cation) can change the feed solution chemistry and thus enhance membrane fouling by alginate, the extent of which is related to the rate of the reverse draw solute diffusion and its ability to interact with the foulant. The extent of fouling for the four types of draw solution followed an order of Ca(NO(3))(2) > CaCl(2) > MgCl(2) > NaCl. On the other hand, the rate of forward diffusion of feed solute (e.g., Na(+)) was in turn promoted under severe membrane fouling in active layer facing draw solution orientation, which may be attributed to the fouling enhanced concentration polarization (pore clogging enhanced ICP and cake enhanced concentration polarization). The enhanced concentration polarization can lead to additional water flux reduction and is an important mechanism governing the water flux behavior during FO membrane fouling. Findings have significant implications for the draw solution selection and membrane fouling control in osmotically driven membrane processes.

  8. Protein Diffusion in the Periplasm of E. coli under Osmotic Stress

    OpenAIRE

    Sochacki, Kem A.; Shkel, Irina A.; Record, M. Thomas; Weisshaar, James C.

    2011-01-01

    The physical and mechanical properties of the cell envelope of Escherichia coli are poorly understood. We use fluorescence recovery after photobleaching to measure diffusion of periplasmic green fluorescent protein and probe the fluidity of the periplasm as a function of external osmotic conditions. For cells adapted to growth in complete medium at 0.14–1.02 Osm, the mean diffusion coefficient increases from 3.4 μm2 s−1 to 6.6 μm2 s−1 and the distribution of Dperi broadens as growth osmolali...

  9. 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 concentrations....... 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...

  10. 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.

  11. A COMPARATIVE STUDY WITH MURRAH BUFFALO AND INDIGENOUS GIR SPERMATOZOA TO HYPO-OSMOTIC SWELLING TEST

    Directory of Open Access Journals (Sweden)

    Sumit Chowdhury

    2013-12-01

    Full Text Available Hypo-Osmotic Swelling Test (HOST is a simple but authentic test to measure the integrity of sperm membrane. The present study was undertaken to evaluate the HOST value in Murrah buffalo and indigenous Gir bull in 150 mosm/l tri-sodium citrate and D-fructose HOST solution. Murrah buffalo was having more HOST (49±0.39 % reacted spermatozoa than indigenous Gir (42±0.57 % bulls suggesting lesser membrane damage during cryo-preservation and higher fertility rate in Murrah buffalo than Gir cattle.

  12. 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

    solute-water coupling: stoichiometric coupling at the molecular level by transport proteins like SGLT1, electro-osmosis and a 'junctional fluid transfer mechanism'. Convection-diffusion out of the lateral space constitutes the fundamental problem of isotonic transport by making the emerging fluid...... at transepithelial osmotic equilibrium as observed in toad skin epithelium in vitro. Our conclusions are further developed for discussing their application to solute-solvent coupling in other vertebrate epithelia such as small intestine, proximal tubule of glomerular kidney and gallbladder. Evidence is discussed...

  13. Establishment of HEK293 cell line expressing GFPAQP1 to determine water osmotic permeability

    Institute of Scientific and Technical Information of China (English)

    Jun-weiGAO; He-mingYU; Qian-liuSONG; Shu-xinLI; Xue-junLI

    2004-01-01

    AIM: To develop an osmotic water permeability assay.METHODS: We subcloned the rat AQP1 cDNA into pEGFPC3 vector. HEK293 cells were transfected with pEGFP-C3/AQP 1 or pEGFP-C3 and selected by G418. The expression of AQP1was detected by RT-PCR and Western blot. Confocal laser fluorescence microscopy was used to record the change of fluorescent density corresponding to the volume change of the cells

  14. Consolidation Properties of Highly Plastic Clay During Osmotic Pressure Consolidation Test

    Institute of Scientific and Technical Information of China (English)

    魏静; 王建华

    2003-01-01

    For the very soft clay with high water content, its void ratio, compressibility coefficient and permeability varied with stress during consolidation. It is necessary to use large strain consolidation based on the permeabilityvoid ratio relationship and effective stressvoid ratio relationship to analyze these properties. To overcome the disadvantages of conventional oedometer test, and determine the effective stressvoid relations of this kind of soil, osmotic pressure consolidation test for highly plastic clay study and the expression of permeabilityvoid ratio are performed. Therefore, the decided properties will be reasonably used for solving the large strain consolidation equation.

  15. Size and stability of liposomes: a possible role of hydration and osmotic forces.

    Science.gov (United States)

    Sabín, J; Prieto, G; Ruso, J M; Hidalgo-Alvarez, R; Sarmiento, F

    2006-08-01

    Dynamic light scattering and electrophoretic mobility measurements have been used to characterize the size, size distribution and zeta potentials (zeta-potentials) of egg yolk phosphatidylcholine (EYPC) liposomes in the presence of monovalent ions ( Na(+) and K(+)). To study the stability of liposomes the Derjaguin-Landau-Verwey-Overbeek (DLVO) theory has been extended by introducing the hydrated radius of the adsorbed ions onto the liposome surfaces. The decrease of liposome size is explained on the basis of the membrane impermeability to some ions which generate osmotic forces, which leads to evacuate water from liposome inside.

  16. Relationship between ATPase activity and conjugated polyamines in mitochondrial membrane from wheat seedling roots under osmotic stress

    Institute of Scientific and Technical Information of China (English)

    LIU Huai-pan; LIU Jun; ZHANG Yan-yan; LIU You-liang

    2004-01-01

    The effects of osmotic stress on the ATPase activity, the contents of -SH group and conjugated polyamines in mitochondrial membrane from wheat seedling [Triticum aestivum L. cv. Yumai No.18(drought-tolerant) and cv. Yumai No.9(drought-sensitive)] roots were investigated. The results showed that ATPase activity and -SH group content decreased with polyethylene glycol(PEG) 6000(-0.55 MPa) treatment for 7 d, in concert with the decrease of the ratio of noncovalently conjugated spermidine(NCC-Spd)/noncovalently conjugated putrescine(NCC-Put) and increase of the covalently conjugated putrescine(CC-Put). Osmotic stress injury to Yangmai No.9 seedlings was alleviated greatly with 1 mmol/L exogenous spermidined(Spd), in concert with marked increases of the ratio of NCC-Spd/NCC-Put, -SH group contents and ATPase activity in mitochondrial membrane. Under osmotic stress, the concomitant treatment of Yumai No.18 seedlings with methylglyoxyl bis(guanylhydrazone) (MGBG), an inhibitor of S-adenosyl methionine decarboxylase(SAMDC), and phenanthrolin (o-Phen), an inhibitor of transglutaminase(TGase), caused a significant decrease of the ratio of NCC-Spd / NCC-Put, CC-Put contents, respectively, in concert with the marked decreases of ATPase activity, -SH group content and its tolerance to osmotic stress. All the results above suggested that osmotic stress tolerance of wheat seedlings was associated with the ATPase activity, the contents of -SH group, NCC-Spd and CC-Put in mitochondrial membrane.

  17. Comparative analysis on the key enzymes of the glycerol cycle metabolic pathway in Dunaliella salina under osmotic stresses.

    Science.gov (United States)

    Chen, Hui; Lu, Yan; Jiang, Jian-Guo

    2012-01-01

    The glycerol metabolic pathway is a special cycle way; glycerol-3-phosphate dehydrogenase (G3pdh), glycerol-3-phosphate phosphatase (G3pp), dihydroxyacetone reductase (Dhar), and dihydroxyacetone kinase (Dhak) are the key enzymes around the pathway. Glycerol is an important osmolyte for Dunaliella salina to resist osmotic stress. In this study, comparative activities of the four enzymes in D. salina and their activity changes under various salt stresses were investigated, from which glycerol metabolic flow direction in the glycerol metabolic pathway was estimated. Results showed that the salinity changes had different effects on the enzymes activities. NaCl could stimulate the activities of all the four enzymes in various degrees when D. salina was grown under continuous salt stress. When treated by hyperosmotic or hypoosmotic shock, only the activity of G3pdh in D. salina was significantly stimulated. It was speculated that, under osmotic stresses, the emergency response of the cycle pathway in D. salina was driven by G3pdh via its response to the osmotic stress. Subsequently, with the changes of salinity, other three enzymes started to respond to osmotic stress. Dhar played a role of balancing the cycle metabolic pathway by its forward and backward reactions. Through synergy, the four enzymes worked together for the effective flow of the cycle metabolic pathways to maintain the glycerol requirements of cells in order to adapt to osmotic stress environments.

  18. Integrin-like Protein Is Involved in the Osmotic Stress-induced Abscisic Acid Biosynthesis in Arabidopsis thaliana

    Institute of Scientific and Technical Information of China (English)

    Bing Lü; Feng Chen; Zhong-Hua Gong; Hong Xie; Jian-Sheng Liang

    2007-01-01

    We studied the perception of plant cells to osmotic stress that leads to the accumulation of abscisic acid (ABA) in stressed Arabidopsis thaliana L. cells. A significant difference was found between protoplasts and cells in terms of their responses to osmotic stress and ABA biosynthesis, implying that cell wall and/or cell wall-plasma membrane interaction are essential in identifying osmotic stress. Western blotting and immunofluorescence localization experiments, using polyclonal antibody against human integrin β1, revealed the existence of a protein similar to the integrin protein of animals in the suspension-cultured cells located in the plasma membrane fraction.Treatment with a synthetic pentapeptide, Gly-Arg-Gly-Asp-Ser (GRGDS), which contains an RGD domain and interacts specifically with integrin protein and thus blocks the cell wall-plasma membrane interaction, significantly inhibited osmotic stress-induced ABA biosynthesis in cells, but not in protoplasts. These results demonstrate that cell wall and/or cell wall-plasma membrane interaction mediated by integrin-like proteins played important roles in osmotic stress-induced ABA biosynthesis in Arabidopsis thaliana.

  19. An experimental approach to assess Corbicula fluminea (Müller, 1774) resistance to osmotic stress in estuarine habitats

    Science.gov (United States)

    Ferreira-Rodríguez, Noé; Pardo, Isabel

    2016-07-01

    Corbicula fluminea arrived in the Miño Estuary in 1989 and, from there, colonized more than 150 km upstream. Our aim was to test the capacity of C. fluminea to cope with osmotic stress conditions previously to invade new freshwater habitats through estuaries. Based on previously collected information, the experiment aims to study the response of the species to marine osmotic stress, evaluated by survival and behaviour. Experiments determined the resistance by the species to various levels of osmotic stress, and recovery time after exposure to high salinity levels, representative of the temporal and spatial salinity variation existing in the estuary. Under osmotic stress the semi-maximum response was reached after 19 days exposure. The species tolerance range, measured by individual maintained activity, was at salinity ∼20 when exposed to winter temperatures, while when animals were exposed to summer ones its tolerance was reduced to salinity lower than 15. C. fluminea show a large physiological flexibility to cope with salinity variations in estuaries. In summer, the temperature increases the metabolic rate thus making the species more vulnerable to osmotic stress exposure. These findings are relevant to preventing new invasions through ship ballast waters ensuring complete mortality if individuals are retained for >26 days.

  20. 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...

  1. Chronic gastritis.

    Science.gov (United States)

    Sipponen, Pentti; Maaroos, Heidi-Ingrid

    2015-06-01

    Prevalence of chronic gastritis has markedly declined in developed populations during the past decades. However, chronic gastritis is still one of the most common serious pandemic infections with such severe killing sequelae as peptic ulcer or gastric cancer. Globally, on average, even more than half of people may have a chronic gastritis at present. Helicobacter pylori infection in childhood is the main cause of chronic gastritis, which microbial origin is the key for the understanding of the bizarre epidemiology and course of the disease. A life-long and aggressive inflammation in gastritis results in destruction (atrophic gastritis) of stomach mucosa with time (years and decades). The progressive worsening of atrophic gastritis results subsequently in dysfunctions of stomach mucosa. Atrophic gastritis will finally end up in a permanently acid-free stomach in the most extreme cases. Severe atrophic gastritis and acid-free stomach are the highest independent risk conditions for gastric cancer known so far. In addition to the risks of malignancy and peptic ulcer, acid-free stomach and severe forms of atrophic gastritis may associate with failures in absorption of essential vitamins, like vitamin B12, micronutrients (like iron, calcium, magnesium and zinc), diet and medicines.

  2. Chronic Bronchitis

    Science.gov (United States)

    ... breathing. You may also have other tests. Chronic bronchitis is a long-term condition that keeps coming back or never goes away completely. If you smoke, it is important to quit. Treatment can help with your symptoms. It often includes ...

  3. [Osmotic modification of thermal damage in Escherichia coli bacteria at various pH values of the media].

    Science.gov (United States)

    Morozov, I I; Petin, V G

    2000-01-01

    A study was made of the influence of media with different osmotic pressure on cell survival and on optic density of supernatants from Escherichia coli B/r and E. coli Bs-1 cell suspensions heated under different pH values of media. Hyperthermia induced cell death accompanied with the loss of optically active (lambda = 260 nm) material. Both cell damage effects were increased in acid and alkaline conditions, compared to neutral condition of heating. Hypertonic media results in a decrease in thermic cell death and loss of cell substances. Under this condition, the protection influence of high osmotic pressure was seen to increase significantly in acid and alkaline conditions of heating, compared to neutral condition. It has been proposed that a higher thermal damage of microorganisms in acid and alkaline beating conditions and protection influence of hypertonic media, especially expressed in acid and alkaline medium, is caused to a great extent by the status of osmotic cell homeostasis.

  4. Transcriptional and physiological study of the response of Burma mangrove (Bruguiera gymnorhiza) to salt and osmotic stress.

    Science.gov (United States)

    Miyama, Masashi; Tada, Yuichi

    2008-09-01

    We investigated the transcriptional response of Burma mangrove (Bruguiera gymnorhiza) to high salinity (salt stress; 500 mM NaCl) and hyperosmotic stress (osmotic stress; 1 M sorbitol) by microarray analysis. ANOVA (P Burma mangrove to salt stress was accompanied by the up-regulation of genes categorized for "cell communication," "signal transduction," "lipid metabolic process," "photosynthesis," "multicellular organismal development," and "transport," and by down-regulation of genes categorized for "catabolic process." Burma mangrove maintained its leaf water potential and recovered from its photosynthesis rate that declined temporarily under salt stress, but not under osmotic stress. These results demonstrated a fundamental difference between the response to salt and osmotic stress. Ion and sugar content analysis suggested that salt tolerance of Burma mangrove might be attributed to their ability to accumulate high concentrations of Na+ and Cl(-), even under non-stressed conditions; to uptake additional Na+ and Cl(-) for use as osmolytes; and to maintain K+ homeostasis under salt stress.

  5. 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.

  6. Heat transfer to fermentation systems in an air-lift fermenter Part II: Osmotic effects on heat transfer

    Energy Technology Data Exchange (ETDEWEB)

    Blakebrough, N.; McManamey, W.J.; Walker, G.

    1983-07-01

    Enhanced values of liquid film heat-transfer coefficients were found for mycelial suspensions in laminar flow in the down-flow tube of an air-lift fermenter, using a heat-flux meter. The influence of osmotic pressure was investigated, using suspensions as Aspergillus niger and Penicillium chrysogenum in sodium chloride solutions. Although large reductions in the heat-transfer coefficients (of the order of 50%) can be produced by increasing the osmotic pressure of the suspending medium from water saturation to the plasmolysis value, during an actual fermentation any changes in osmotic pressure which occur probably have a minor effect (of the order of 10%) and the major factor in the enhancement of the heat-transfer rate is the presence of mycelial solids.

  7. Protein diffusion in the periplasm of E. coli under osmotic stress.

    Science.gov (United States)

    Sochacki, Kem A; Shkel, Irina A; Record, M Thomas; Weisshaar, James C

    2011-01-05

    The physical and mechanical properties of the cell envelope of Escherichia coli are poorly understood. We use fluorescence recovery after photobleaching to measure diffusion of periplasmic green fluorescent protein and probe the fluidity of the periplasm as a function of external osmotic conditions. For cells adapted to growth in complete medium at 0.14-1.02 Osm, the mean diffusion coefficient increases from 3.4 μm² s⁻¹ to 6.6 μm² s⁻¹ and the distribution of D(peri) broadens as growth osmolality increases. This is consistent with a net gain of water by the periplasm, decreasing its biopolymer volume fraction. This supports a model in which the turgor pressure drops primarily across the thin peptidoglycan layer while the cell actively maintains osmotic balance between periplasm and cytoplasm, thus avoiding a substantial pressure differential across the cytoplasmic membrane. After sudden hyperosmotic shock (plasmolysis), the cytoplasm loses water as the periplasm gains water. Accordingly, increases threefold. The fluorescence recovery after photobleaching is complete and homogeneous in all cases, but in minimal medium, the periplasm is evidently thicker at the cell tips. For the relevant geometries, Brownian dynamics simulations in model cytoplasmic and periplasmic volumes provide analytical formulae for extraction of accurate diffusion coefficients from readily measurable quantities.

  8. Osmotic stress stimulates generation of superoxide anion by spermatozoa in horses.

    Science.gov (United States)

    Burnaugh, L; Ball, B A; Sabeur, K; Thomas, A D; Meyers, S A

    2010-02-01

    The objective of this study was to examine the interplay between osmotic and oxidative stress as well as to determine mechanisms by which osmotic stress increases superoxide generation in spermatozoa of horses. Superoxide production, as measured by dihydroethidium (DHE), increased when spermatozoa of horses were incubated under either hyperosmotic or hyposmotic conditions. This increase in superoxide production was inhibited by the MAP kinase p38 inhibitor, SB203580, and by the superoxide scavenger, tiron. Incubation of spermatozoa under hyperosmotic conditions increased overall protein tyrosine phosphorylation as measured by western blotting techniques; however, a similar increase was not detected when spermatozoa were incubated under hyposmotic conditions. The general protein kinase C (PKC) and protein tyrosine kinase (PTK) inhibitor staurosporine inhibited (P<0.05) tyrosine phosphorylation in samples from cells under hyperosmotic conditions. In addition, the NADPH oxidase inhibitor diphenyleneiodonium (DPI) also inhibited (P<0.05) protein tyrosine phosphorylation in cells under hyperosmotic conditions. In summary, these data indicate that incubation of equine spermatozoa under both hyposmotic and hyperosmotic conditions can increase superoxide anion generation. Under hyperosmotic conditions, this increased generation of superoxide anion was accompanied by increased protein tyrosine phosphorylation.

  9. Measuring the osmotic water permeability coefficient (Pf) of spherical cells: isolated plant protoplasts as an example.

    Science.gov (United States)

    Shatil-Cohen, Arava; Sibony, Hadas; Draye, Xavier; Chaumont, François; Moran, Nava; Moshelion, Menachem

    2014-10-08

    Studying AQP regulation mechanisms is crucial for the understanding of water relations at both the cellular and the whole plant levels. Presented here is a simple and very efficient method for the determination of the osmotic water permeability coefficient (P(f)) in plant protoplasts, applicable in principle also to other spherical cells such as frog oocytes. The first step of the assay is the isolation of protoplasts from the plant tissue of interest by enzymatic digestion into a chamber with an appropriate isotonic solution. The second step consists of an osmotic challenge assay: protoplasts immobilized on the bottom of the chamber are submitted to a constant perfusion starting with an isotonic solution and followed by a hypotonic solution. The cell swelling is video recorded. In the third step, the images are processed offline to yield volume changes, and the time course of the volume changes is correlated with the time course of the change in osmolarity of the chamber perfusion medium, using a curve fitting procedure written in Matlab (the 'PfFit'), to yield P(f).

  10. Mannitol and other osmotic diuretics as adjuncts for treating cerebral malaria

    Science.gov (United States)

    Okoromah, Christy AN; Afolabi, Bosede B; Wall, Emma CB

    2014-01-01

    Background Cerebral oedema occurs with cerebral malaria, and some clinicians think osmotic diuretics, such as mannitol or urea, may improve outcomes. Objectives To compare mannitol or urea to placebo or no diuretic for treating children or adults with cerebral malaria. Search methods We searched the Cochrane Infectious Diseases Group Specialized Register (Issue 4, 2010), CENTRAL (The Cochrane Library Issue 12, 2010), MEDLINE (1966 to November 2010), EMBASE (1974 to November 2010), LILACS (1982 to November 2010), and the reference lists of articles. We contacted relevant organizations and researchers. Selection criteria Randomized or quasi-randomized controlled trials comparing mannitol or urea to placebo or no treatment in children and adults with cerebral malaria. Primary outcomes were death, life-threatenining sequelae and major neurological sequelae at six months. Data collection and analysis Two authors applied the inclusion criteria, assessed risk of bias, and extracted data independently. Main results One trial met the inclusion criteria, comparing mannitol 20% to saline placebo in 156 Ugandan children. Allocation was concealed. No difference in mortality, time to regain consciousness, or neurological sequelae were detected. Authors’ conclusions There are insufficient data to know what the effects of osmotic diuretics are in children with cerebral malaria. Larger, multicentre trials are needed. PMID:21491391

  11. 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 TiO2 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.

  12. Species variation in osmotic, cryoprotectant, and cooling rate tolerance in poultry, eagle, and Peregrine Falcon spermatozoa

    Science.gov (United States)

    Blanco, J.M.; Gee, G.; Wildt, D.E.; Donoghue, A.M.

    2000-01-01

    Potential factors influencing spermatozoa survival to cryopreservation and thawing were analyzed across a range of the following avian species: domestic chicken (Gallus domesticus), domestic turkey (Meleagris gallopavo), golden eagle (Aquila chrysaetos), Bonelli's eagle (Hieraaetus fasciatus), imperial eagle (Aquila adalberti), and peregrine falcon (Falco peregrinus). Studies focused on spermatozoa tolerance to the following: 1) osmotic stress, 2) different extracellular concentrations of the cryoprotectant dimethylacetamide (DMA), 3) equilibration times of 1 versus 4 h, 4) equilibration temperature of 4 versus 21 degrees C, and 5) rapid versus slow cooling before cryopreservation and standard thawing. Sperm viability was assessed with the live/dead stain (SYBR14/ propidium iodine). Sperm viability at osmolalities >/=800 mOsm was higher (P: /=2.06 M), experienced decreased (P: < 0.05) spermatozoa survival in all species, except the golden eagle and peregrine falcon. Number of surviving spermatozoa diminished progressively with increasing DMA concentrations in all species. Increased equilibration temperature (from 4 to 21 degrees C) markedly reduced (P: < 0.05) spermatozoa survival in all species except the Bonelli's eagle and turkey. Rapid cooling was detrimental (P: < 0.05) to spermatozoa from all species except the imperial eagle and the chicken. These results demonstrate that avian spermatozoa differ remarkably in response to osmotic changes, DMA concentrations, equilibration time, temperature, and survival after fast or slow freezing. These differences emphasize the need for species-specific studies in the development and enhancement of assisted breeding for poultry and endangered species.

  13. Pulsed Vacuum Osmotic Dehydration of Cherry Tomatoes: Impact on Physicochemical Properties and Probiotics Entrapment

    Directory of Open Access Journals (Sweden)

    Pheeraya CHOTTANOM

    2016-03-01

    Full Text Available Osmotic dehydration (OD and pulsed vacuum osmotic dehydration (PVOD were employed to assess the various properties of partially-dehydrated tomatoes. Ascorbic acid and lycopene degradation and color and texture change were determined. The mastership incorporation of probiotics (Lactobacillus acidophilus TISTR 1338 into tomatoes was also investigated. OD mediums (20, 40 and 60 Brix consisted of a mixture of formulated tomato extract (FTE and probiotic cell suspension. PVOD promoting mass transfer was clearly observed in a short-time process compared with OD. The physical and chemical properties of the tomatoes changed significantly after the dehydration processes, especially those of ascorbic acid content compared with lycopene. A more than 50 % loss of ascorbic acid was noted, starting at 10 g /100 g tomatoes of water loss. The hardness values significantly increased, while chroma values decreased. The cell entrapment on the tomatoes was in the range of 8 - 9 log CFU/g tomatoes. The highest entrapment of the probiotic bacteria was found in the long-time process (12 h conducted with 20 Brix FTE for the PVOD and OD processes, while entrapment was decreased by the short-time process (6 h. Using high solution concentration resulted in lower cell entrapment. However, cell entrapment could be increased by using the vacuum process. These results will provide a platform that encourages the inclusion of probiotics in high quality fresh-cut products and semi-moist products. These products can then be considered as alternative probiotic food choice for consumers.

  14. Simulation of mass transfer during osmotic dehydration of apple: a power law approximation method

    Science.gov (United States)

    Abbasi Souraki, B.; Tondro, H.; Ghavami, M.

    2014-10-01

    In this study, unsteady one-dimensional mass transfer during osmotic dehydration of apple was modeled using an approximate mathematical model. The mathematical model has been developed based on a power law profile approximation for moisture and solute concentrations in the spatial direction. The proposed model was validated by the experimental water loss and solute gain data, obtained from osmotic dehydration of infinite slab and cylindrical shape samples of apple in sucrose solutions (30, 40 and 50 % w/w), at different temperatures (30, 40 and 50 °C). The proposed model's predictions were also compared with the exact analytical and also a parabolic approximation model's predictions. The values of mean relative errors respect to the experimental data were estimated between 4.5 and 8.1 %, 6.5 and 10.2 %, and 15.0 and 19.1 %, for exact analytical, power law and parabolic approximation methods, respectively. Although the parabolic approximation leads to simpler relations, the power law approximation method results in higher accuracy of average concentrations over the whole domain of dehydration time. Considering both simplicity and precision of the mathematical models, the power law model for short dehydration times and the simplified exact analytical model for long dehydration times could be used for explanation of the variations of the average water loss and solute gain in the whole domain of dimensionless times.

  15. Analysis of electro-osmotic flow in a microchannel with undulated surfaces

    CERN Document Server

    Yoshida, Hiroaki; Washizu, Hitoshi

    2016-01-01

    The electro-osmotic flow through a channel between two undulated surfaces induced by an external electric field is investigated. The gap of the channel is very small and comparable to the thickness of the electrical double layers. A lattice Boltzmann simulation is carried out on the model consisting of the Poisson equation for electrical potential, the Nernst--Planck equation for ion concentration, and the Navier--Stokes {\\color{black}equations} for flows of the electrolyte solution. An analytical model that predicts the flow rate is also derived under the assumption that the channel width is very small compared with the characteristic length of the variation along the channel. The analytical results are compared with the numerical results obtained by using the lattice Boltzmann method. In the case of a constant surface charge density along the channel, the variation of the channel width reduces the electro-osmotic flow, and the flow rate is smaller than that of a straight channel. In the case of a surface ch...

  16. Concomitant production of lipids and carotenoids in Rhodosporidium toruloides under osmotic stress using response surface methodology

    Directory of Open Access Journals (Sweden)

    Gunjan Singh

    2016-10-01

    Full Text Available As a replacement to existing fossil fuels, biofuels, have proven their worth; however, their widespread use is limited due to inconsistent yields, higher costs and poor productivity. An oleaginous yeast, Rhodosporidium toruloides has been reported to accumulate substantial amounts of lipids (that can be converted to biofuels and therefore, it was selected for study and optimization. Apart from lipids, R. toruloides is also reported to produce carotene that can be used as a therapeutic agent. In this study, the culture medium was statistically modelled and optimized for concomitant production of lipids and carotenoids and for improving and maximizing the productivity of lipids as well as carotenes. The two metabolites were expressed differentially in the growth cycle of this organism. Culture medium components were simultaneously varied at 5 different levels using statistical modelling employing RSM. Osmotic stress was introduced in order to simulate saline conditions and optimize the production process to be used in conditions with high salt contents. In this study, we demonstrate 36.2% (w/v lipid production and 27.2% (w/v carotenoid production, under osmotic stress with high salt concentrations, for the first time.

  17. Osmotic Second Virial Coefficients of Aqueous Solutions from Two-Component Equations of State.

    Science.gov (United States)

    Cerdeiriña, Claudio A; Widom, B

    2016-12-29

    Osmotic second virial coefficients in dilute aqueous solutions of small nonpolar solutes are calculated from three different two-component equations of state. The solutes are five noble gases, four diatomics, and six hydrocarbons in the range C1-C4. The equations of state are modified versions of the van der Waals, Redlich-Kwong, and Peng-Robinson equations, with an added hydrogen-bonding term for the solvent water. The parameters in the resulting equations of state are assigned so as to reproduce the experimental values and temperature dependence of the density, vapor pressure, and compressibility of the solvent, the gas-phase second virial coefficient of the pure solute, the solubility and partial molecular volume of the solute, and earlier estimates of the solutes' molecular radii. For all 15 solutes, the calculations are done for 298.15 K, whereas for CH4, C2H6, and C3H8 in particular, they are also done as functions of temperature over the full range 278.15-348.15 K. The calculated osmotic virial coefficients are compared with earlier calculations of these coefficients for these solutes and also with the results derived from earlier computer simulations of model aqueous solutions of methane. They are also compared with the experimental gas-phase second virial coefficients of the pure gaseous solutes to determine the effect the mediation of the solvent has on the resulting solute-solute interactions in the solution.

  18. Thermal and Osmotic Tolerance of ‘Irukandji’ Polyps: Cubozoa; Carukia barnesi

    Science.gov (United States)

    Courtney, Robert; Browning, Sally; Northfield, Tobin; Seymour, Jamie

    2016-01-01

    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. PMID:27441693

  19. Phase behavior and second osmotic virial coefficient for competitive polymer solvation in mixed solvent solutions.

    Science.gov (United States)

    Dudowicz, Jacek; Freed, Karl F; Douglas, Jack F

    2015-11-21

    We apply our recently developed generalized Flory-Huggins (FH) type theory for the competitive solvation of polymers by two mixed solvents to explain general trends in the variation of phase boundaries and solvent quality (quantified by the second osmotic virial coefficient B2) with solvent composition. The complexity of the theoretically predicted miscibility patterns for these ternary mixtures arises from the competitive association between the polymer and the solvents and from the interplay of these associative interactions with the weak van der Waals interactions between all components of the mixture. The main focus here lies in determining the influence of the free energy parameters for polymer-solvent association (solvation) and the effective FH interaction parameters {χαβ} (driving phase separation) on the phase boundaries (specifically the spinodals), the second osmotic virial coefficient B2, and the relation between the positions of the spinodal curves and the theta temperatures at which B2 vanishes. Our classification of the predicted miscibility patterns is relevant to numerous applications of ternary polymer solutions in industrial formulations and the use of mixed solvent systems for polymer characterization, such as chromatographic separation where mixed solvents are commonly employed. A favorable comparison of B2 with experimental data for poly(methyl methacrylate)/acetonitrile/methanol (or 1-propanol) solutions only partially supports the validity of our theoretical predictions due to the lack of enough experimental data and the neglect of the self and mutual association of the solvents.

  20. Controlled delivery of carvedilol nanosuspension from osmotic pump capsule: in vitro and in vivo evaluation.

    Science.gov (United States)

    Liu, Dandan; Yu, Shihui; Zhu, Zhihong; Lyu, Chunyang; Bai, Chunping; Ge, Huiqi; Yang, Xinggang; Pan, Weisan

    2014-11-20

    This study intended to develop a novel controlled delivery osmotic pump capsule of carvedilol nanosuspension. The capsule is assembled using a semi-permeable capsule shell with contents including nanosuspension drying powder, mannitol and Plasdone S-630. The physical characteristics of semi-permeable capsule walls were compared among different coating solutions under different temperature. The composition of the coating solution and drying temperature appeared to be important for the formation of the shells. Carvedilol nanosuspension was prepared by precipitation-ultrasonication technique and was further lyophilized. Response surface methodology was used to investigate the influence of factors on the responses. The optimized formulation displayed complete drug delivery and zero-order release rate. The TEM and particle size analysis indicated that the morphology of the resultant nanoparticle in the capsule was spherical shaped with a mean size of 252±19 nm. The in vivo test in beagle dogs demonstrated that the relative bioavailability of the novel system was 203.5% in comparison to that of the marketed preparation. The capsule successfully controlled the release of carvedilol and the fluctuation of plasma concentration was minimized. The system is a promising strategy to improve the oral bioavailability for poorly soluble drugs and preparing it into elementary osmotic pump conveniently.

  1. 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.

  2. Influence of β - cyclodextrin complexation on lovastatin release from osmotic pump tablets (OPT

    Directory of Open Access Journals (Sweden)

    Mehramizi A.

    2007-05-01

    Full Text Available An extended-release osmotic dosage form was designed and the effect of β-cyclodextrin (BCD inclusion complexation on the solubility of lovastatin in aqueous media was investigated. The lovastatin BCD solid systems were prepared by kneading method. The elementary osmotic pumps (EOPs were prepared with lovastatin BCD complex with cellulose acetate (CA and polyethylene glycol as plasticizer. The effect of the BCD molar ratio on enhancement of lovastatin dissolution rate and the influences of various parameters (e.g. drug –BCD ratio, molecular weight and amount of PVP, coating weight gain on drug release profiles were investigated. The solubility and dissolution rates of lovastatin were significantly increased by using inclusion complexation. It was found that PVP K90 was a suitable hydrophilic polymer with thickening effect and had profoundly positive effect on drug release. The present results confirmed that dissolution rate of lovastatin BCD were greatly enhanced and this system has suitable solubility behavior in EOP tablet formulations.

  3. Roles of an unconventional protein kinase and myosin II in amoeba osmotic shock responses.

    Science.gov (United States)

    Betapudi, Venkaiah; Egelhoff, Thomas T

    2009-12-01

    The contractile vacuole (CV) is a dynamic organelle that enables Dictyostelium amoeba and other protist to maintain osmotic homeostasis by expelling excess water. In the present study, we have uncovered a mechanism that coordinates the mechanics of the CV with myosin II, regulated by VwkA, an unconventional protein kinase that is conserved in an array of protozoa. Green fluorescent protein (GFP)-VwkA fusion proteins localize persistently to the CV during both filling and expulsion phases of water. In vwkA null cells, the established CV marker dajumin still localizes to the CV, but these structures are large, spherical and severely impaired for discharge. Furthermore, myosin II cortical localization and assembly are abnormal in vwkA null cells. Parallel analysis of wild-type cells treated with myosin II inhibitors or of myosin II null cells also results in enlarged CVs with impaired dynamics. We suggest that the myosin II cortical cytoskeleton, regulated by VwkA, serves a critical conserved role in the periodic contractions of the CV, as part of the osmotic protective mechanism of protozoa.

  4. 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.

  5. 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.

  6. Electro-osmotic-based catholyte production by Microbial Fuel Cells for carbon capture.

    Science.gov (United States)

    Gajda, Iwona; Greenman, John; Melhuish, Chris; Santoro, Carlo; Li, Baikun; Cristiani, Pierangela; Ieropoulos, Ioannis

    2015-12-01

    In Microbial Fuel Cells (MFCs), the recovery of water can be achieved with the help of both active (electro-osmosis), and passive (osmosis) transport pathways of electrolyte through the semi-permeable selective separator. The electrical current-dependent transport, results in cations and electro-osmotically dragged water molecules reaching the cathode. The present study reports on the production of catholyte on the surface of the cathode, which was achieved as a direct result of electricity generation using MFCs fed with wastewater, and employing Pt-free carbon based cathode electrodes. The highest pH levels (>13) of produced liquid were achieved by the MFCs with the activated carbon cathodes producing the highest power (309 μW). Caustic catholyte formation is presented in the context of beneficial cathode flooding and transport mechanisms, in an attempt to understand the effects of active and passive diffusion. Active transport was dominant under closed circuit conditions and showed a linear correlation with power performance, whereas osmotic (passive) transport was governing the passive flux of liquid in open circuit conditions. Caustic catholyte was mineralised to a mixture of carbonate and bicarbonate salts (trona) thus demonstrating an active carbon capture mechanism as a result of the MFC energy-generating performance. Carbon capture would be valuable for establishing a carbon negative economy and environmental sustainability of the wastewater treatment process.

  7. Response of Osmotic Adjustment of Lactobacillus bulgaricus to NaCl Stress

    Institute of Scientific and Technical Information of China (English)

    Li Chun; Liu Li-bo; Sun Di; Chen Jing; Liu Ning

    2012-01-01

    Growth and osmotic response of Lactobacillus bulgaricus ATCC 11842 under hyperosmotic constraint were investigated in a chemically defined medium (CDM) and MRS medium. NaCl could inhibit the growth of L. bulgaricus which decreased with increasing NaCl concentration. In the MRS, NaCl of 1.0 mol·L-1 was the biggest salt stress concentration; in the CDM, 0.8 mol·L-1 was the biggest inhibition concentration. In contrast to what was observed in other lactic acid bacteria, proline, glycine betaine and related molecules were unable to relieve inhibition of growth of L. bulgaricus under osmotic constraint. This was correlated to the absence of sequences homologous to the genes coding for glycine-betaine and/or proline transporters described in Lactococcus lactis and Bacillus subtilis. The amino acid aspartate and alanine were proved to be osmoprotective under NaCl stress. Addition of peptone (0.25% w/v) in the presence of salt led to a stimulation of the growth, as the decrease of the lag time and generation time, and the final biomass increased from 0.31 to 0.64.

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

    Energy Technology Data Exchange (ETDEWEB)

    Gregersen, M M; Okkels, F; Bruus, H [Department of Micro- and Nanotechnology, Technical University of Denmark, DTU Nanotech, Building 345 East, DK-2800 Kongens Lyngby (Denmark); Bazant, M Z [Departments of Chemical Engineering and Mathematics, MIT, Cambridge, MA 02139 (United States)], E-mail: Henrik.Bruus@nanotech.dtu.dk

    2009-07-15

    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 design field. Our results show the importance of the topology and shape of the dielectric solid in ICEO systems and point to new designs of ICEO micropumps with significantly improved performance.

  9. ZmMKK4 regulates osmotic stress through reactive oxygen species scavenging in transgenic tobacco.

    Science.gov (United States)

    Kong, Xiangpei; Sun, Liping; Zhou, Yan; Zhang, Maoying; Liu, Yang; Pan, Jiaowen; Li, Dequan

    2011-11-01

    Mitogen-activated protein kinase kinase (MAPKKs) are important components of MAPK cascades, which are universal signal transduction modules and play important role in regulating both plant development and biotic or abiotic stress responses. In this study, we identified the group C MAPKK gene, ZmMKK4, in maize (Zea mays L.). Overexpression of ZmMKK4 in tobacco enhanced tolerance to osmotic stress by increased proline content and antioxidant enzyme (POD) activities compared with wild-type plants. RT-PCR revealed that one peroxidase (POX) gene, NtPOX1, was higher in ZmMKK4-overexpressing plants than in the wild-type plants. In addition, the accumulation of reactive oxygen species (ROS) in ZmMKK4-overexpressing plants is much less than that of wild-type plants. These results suggest that ZmMKK4 may be involved in ROS signaling. Taken together, these results indicate that ZmMKK4 is a positive regulator of osmotic stress by regulating scavenging of ROS in plants.

  10. 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.

  11. Giant osmotic energy conversion measured in a single transmembrane boron nitride nanotube.

    Science.gov (United States)

    Siria, Alessandro; Poncharal, Philippe; Biance, Anne-Laure; Fulcrand, Rémy; Blase, Xavier; Purcell, Stephen T; Bocquet, Lydéric

    2013-02-28

    New models of fluid transport are expected to emerge from the confinement of liquids at the nanoscale, with potential applications in ultrafiltration, desalination and energy conversion. Nevertheless, advancing our fundamental understanding of fluid transport on the smallest scales requires mass and ion dynamics to be ultimately characterized across an individual channel to avoid averaging over many pores. A major challenge for nanofluidics thus lies in building distinct and well-controlled nanochannels, amenable to the systematic exploration of their properties. Here we describe the fabrication and use of a hierarchical nanofluidic device made of a boron nitride nanotube that pierces an ultrathin membrane and connects two fluid reservoirs. Such a transmembrane geometry allows the detailed study of fluidic transport through a single nanotube under diverse forces, including electric fields, pressure drops and chemical gradients. Using this device, we discover very large, osmotically induced electric currents generated by salinity gradients, exceeding by two orders of magnitude their pressure-driven counterpart. We show that this result originates in the anomalously high surface charge carried by the nanotube's internal surface in water at large pH, which we independently quantify in conductance measurements. The nano-assembly route using nanostructures as building blocks opens the way to studying fluid, ionic and molecule transport on the nanoscale, and may lead to biomimetic functionalities. Our results furthermore suggest that boron nitride nanotubes could be used as membranes for osmotic power harvesting under salinity gradients.

  12. DEVELOPMENT AND IN-VITRO EVALUATION OF METOPROLOL SUCCINATE CONTROLLED POROSITY OSMOTIC PUMP TABLETS

    Directory of Open Access Journals (Sweden)

    Veeramalla Anil Kumar

    2013-04-01

    Full Text Available In the present research work, attempts were made to develop and evaluate Sustained release formulation of Metoprolol succinate based on osmotic technology.As Metoprolol is a short acting drug, developed formulation provides the advantages of controlled release formulations. The developed formulation provides advantages of less steps of manufacturing procedure, no need of laser drilling, and economical. All of these made the procedure easily amenable to mass production using conventional tablet machines. Metoprolol 50mg core formulation was prepared using osmogents and coated with different coating formulae to optimize film former (cellulose acetate: pore former (sorbitol ratio. The effect of different formulation variables namely, membrane weight gain, and amount of pore former in the membrane, were studied. Metoprolol release was inversely proportional to the membrane weight (coating thickness but directly related to the initial amount of pore former (sorbitol in the membrane. All polymers and excipients used in optimized formula were found to be compatible with the drug and it was confirmed by FT-IR studies. Drug release from the developed formulations was independent of pH and agitational intensity. The drug release from formulation was proved as dependent on osmotic pressure only. The number of pores was directly proportional to the amount of pore former in the membrane. The manufactured formulations were stable after 45 days of accelerated stability studies.

  13. 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.

  14. Chronic Pancreatitis in Children

    Science.gov (United States)

    ... Information > Children/Pediatric > Chronic Pancreatitis in Children test Chronic Pancreatitis in Children What symptoms would my child ... pancreatitis will develop diabetes in adolescence. Who gets chronic pancreatitis? Those at risk for chronic pancreatitis are ...

  15. Chronic Beryllium Disease

    Science.gov (United States)

    ... Science Education & Training Home Conditions Chronic Beryllium Disease Chronic Beryllium Disease Make an Appointment Find a Doctor ... MD, MSPH, FCCP (February 01, 2016) What is chronic beryllium disease (CBD)? Chronic beryllium disease (CBD) is ...

  16. Chronic motor tic disorder

    Science.gov (United States)

    Chronic vocal tic disorder; Tic - chronic motor tic disorder ... Chronic motor tic disorder is more common than Tourette syndrome . Chronic tics may be forms of Tourette syndrome. Tics usually start ...

  17. Chronic Pelvic Pain

    Science.gov (United States)

    ... Education & Events Advocacy For Patients About ACOG Chronic Pelvic Pain Home For Patients Search FAQs Chronic Pelvic Pain ... Pelvic Pain FAQ099, August 2011 PDF Format Chronic Pelvic Pain Gynecologic Problems What is chronic pelvic pain? What ...

  18. Activate to eradicate: inhibition of Clostridium difficile spore outgrowth by the synergistic effects of osmotic activation and nisin.

    Directory of Open Access Journals (Sweden)

    Michelle M Nerandzic

    Full Text Available BACKGROUND: Germination is the irreversible loss of spore-specific properties prior to outgrowth. Because germinating spores become more susceptible to killing by stressors, induction of germination has been proposed as a spore control strategy. However, this strategy is limited by superdormant spores that remain unaffected by germinants. Harsh chemicals and heat activation are effective for stimulating germination of superdormant spores but are impractical for use in a hospital setting, where Clostridium difficile spores present a challenge. Here, we tested whether osmotic activation solutes will provide a mild alternative for stimulation of superdormant C. difficile spores in the presence of germinants as previously demonstrated in several species of Bacillus. In addition, we tested the hypothesis that the limitations of superdormancy can be circumvented with a combined approach using nisin, a FDA-approved safe bacteriocin, to inhibit outgrowth of germinated spores and osmotic activation solutes to enhance outgrowth inhibition by stimulating superdormant spores. PRINCIPAL FINDINGS: Exposure to germination solution triggered ~1 log(10 colony forming units (CFU of spores to germinate, and heat activation increased the spores that germinated to >2.5 log(10CFU. Germinating spores, in contrast to dormant spores, became susceptible to inhibition by nisin. The presence of osmotic activation solutes did not stimulate germination of superdormant C. difficile spores exposed to germination solution. But, in the absence of germination solution, osmotic activation solutes enhanced nisin inhibition of superdormant spores to >3.5 log(10CFU. The synergistic effects of osmotic activation solutes and nisin were associated with loss of membrane integrity. CONCLUSIONS: These findings suggest that the synergistic effects of osmotic activation and nisin bypass the limitations of germination as a spore control strategy, and might be a novel method to safely and

  19. Monitoring of jökulhlaups and element fluxes in proglacial Icelandic rivers using osmotic samplers

    Science.gov (United States)

    Jones, Morgan T.; Gałeczka, Iwona M.; Gkritzalis-Papadopoulos, Athanasios; Palmer, Martin R.; Mowlem, Matthew C.; Vogfjörð, Kristín; Jónsson, Þorsteinn; Gislason, Sigurður R.

    2015-01-01

    The quantification of volatile emissions from volcanoes is an integral part of understanding magmatic systems, with the exsolution and extent of volcanic degassing having a large impact on the nature of an eruption. Measurements of volatiles have traditionally focused on gas emissions into the atmosphere, but volatiles can also become dissolved in proximal water bodies en route to the surface. Thus the monitoring of rivers draining active volcanic areas can provide insights to identifying changes in activity. This process is particularly important for sub-glacial volcanoes in Iceland, where much of the volatile release is transported within glacial outbreak floods, termed jökulhlaups. Monitoring and characterising these phenomena is hampered by the dependence on spot sampling of stochastic events under challenging field conditions, which often leads to bias in the collected data. A recent technological advance is the osmotic sampler, an electricity-free pump that continuously collects water that can subsequently be divided into time-averaged samples. This technique allows for continued and unsupervised deployment of a sampler for weeks to months, representing a cost-efficient form of chemical monitoring. In this study we deployed osmotic samplers in two rivers in southern Iceland. Skálm is a proglacial river from Mýrdalsjökull glacier and Katla volcano, while Skaftá is a larger drainage system from the western part of Vatnajökull glacier. Both rivers are prone to jökulhlaups from geothermal and volcanic sources, and a small jökulhlaup of geothermal origin occurred during the second deployment in Skaftá in January 2014. The two deployments show that osmotic samplers are capable of delivering accurate chemical data in turbulent conditions for several key elements. Total dissolved fluxes for the deployment at Skaftá are calculated to be Na = 9.9 tonnes/day, Mg = 10.5 t/d, Si = 34.7 t/d, Cl = 11.0 t/d, Ca = 31.6 t/d, DIC = 50.8 t/d, and SO4 = 28.3 t/d, with

  20. Chronic thyroiditis (Hashimoto disease)

    Science.gov (United States)

    Hashimoto thyroiditis; Chronic lymphocytic thyroiditis; Autoimmune thyroiditis; Chronic autoimmune thyroiditis; Lymphadenoid goiter - Hashimoto; Hypothyroidism - Hashimoto; Type 2 polyglandular autoimmune ...

  1. 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...... 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-sodium...

  2. 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 v

  3. 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....

  4. Improving macroscopic modeling of the effect of water and osmotic stresses on root water uptake.

    Science.gov (United States)

    Jorda Guerra, Helena; Vanderborght, Jan

    2015-04-01

    Accurate modeling of water and salt stresses on root water uptake is critical for predicting impacts of global change and climate variability on crop production and soil water balances. Soil-hydrological models use reduction functions to represent the effect of osmotic stress in transpiration. However, these functions, which were developed empirically, present limitations in relation to the time and spatial scale at which they need to be used, fail to include compensation processes and do not agree on how water and salt stresses interact. This research intends to develop a macroscopic reduction function for water and osmotic stresses based on biophysical knowledge. Simulation experiments are conducted for a range of atmospheric conditions, soil and plant properties, irrigation water quality and scheduling using a 3-D physically-based model that resolves flow and transport to individual root segments and that couples flow in the soil and root system (Schröder et al., 2013). The effect of salt concentrations on water flow in the soil-root system is accounted for by including osmotic water potential gradients between the solution at the soil root interface and the root xylem sap in the hydraulic gradient between the soil and root. In a first step, simulation experiments are carried out in a soil volume around a single root segment. We discuss how the simulation setup can be defined so as to represent: (i) certain characteristics of the root system such as rooting depth and root length density, (ii) plant transpiration rate, (iii) leaching fraction of the irrigation, and (iii) salinity of the irrigation water. The output of these simulation experiments gives a first insight in the effect of salinity on transpiration and on the relation between the bulk salinity in the soil voxel, which is used in macroscopic salt stress functions of models that do not resolve processes at the root segment scale, and the salinity at the soil-root interface, which determines the actual

  5. Multi-detector CT enterography with iso-osmotic mannitol as oral contrast for detecting small bowel disease

    Institute of Scientific and Technical Information of China (English)

    Lian-He Zhang; Shi-Zheng Zhang; Hong-Jie Hu; Min Gao; Ming Zhang; Qian Cao; Qiao-wei Zhang

    2005-01-01

    AIM: To assess the feasibility and usefulness of multi-detector CT enterography with orally administered iso-osmotic mannitol as negative contrast in demonstrating small bowel disease.METHODS: Thirteen volunteers and 38 patients with various kinds of small bowel disease were examined. We administered about 1 500 mL iso-osmotic mannitol as negative contrast agent and then proceeded with helical CT scanning on a Siemens Sensation 16 scanner. All volunteers and patients were interviewed about their tolerance of the procedure. Two radiologists postprocessed imaging data with MPR, thin MIP, VRT and INSPACE when necessary and then interpreted the scans,and adequacy of luminal distention was evaluated on a four-point scale. Demonstration of features of various kinds of small bowel disease was analyzed.RESULTS: The taste of iso-osmotic mannitol is good (slightly sweet) and acceptable by all. Small bowel distention was excellent and moderate in most volunteers and patients. CT features of many kinds of diseases such as tumors, Crohn's disease,and small bowel obstruction,etc. were clearly displayed.CONCLUSION: Multi-detector CT enterography with iso-osmotic mannitol as negative contrast to distend the small bowel is a simple, rapid, noninvasive and effective method of evaluating small bowel disease.

  6. The use of the rapid osmotic fragility test as an additional test to diagnose canine immune-mediated haemolytic anaemia

    DEFF Research Database (Denmark)

    Paes, Geert; Paepe, Dominique; Meyer, Evelyne;

    2013-01-01

    Background: Diagnosing canine immune-mediated haemolytic anaemia (IMHA) is often challenging because all currently available tests have their limitations. Dogs with IMHA often have an increased erythrocyte osmotic fragility (OF), a characteristic that is sometimes used in the diagnosis of IMHA...

  7. 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.

  8. 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.

  9. 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.

  10. 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) d...

  11. 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

    2014-01-01

    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, simulta

  12. Osmotic and ionic effects of NaCl and Na2SO4 salinity on Phragmites australis

    DEFF Research Database (Denmark)

    Pagter, Majken; Bragato, Claudia; Malagoli, Mario

    2009-01-01

    -significant photosynthetic depression observed in plants grown at -1.74 MPa was mainly due to osmotically induced stomatal closure. This was supported by decreasing internal CO2 concentrations. Saline conditions increased the intrinsic water use efficiency and did not alter photosynthetic parameters derived from light...

  13. Changes in content of free, conjugated and bound polyamines and osmotic adjustment in adaptation of vetiver grass to water deficit.

    Science.gov (United States)

    Zhou, Qiang; Yu, Bingjun

    2010-06-01

    Osmotic adjustment and alteration of polyamines (PAs) have been suggested to play roles in plant adaptation to water deficit/drought stress. In this study, the changes in cell intactness, photosynthesis, compatible solutes and PAs [including putrescine (Put), spermidine (Spd) and spermine (Spm) each in free, conjugated and bound forms] were investigated in leaves of vetiver grass exposed to different intensity of water deficit stress and subsequent rewatering. The results showed that, when vetiver grass was exposed to the moderate (20% and 40% PEG-6000 solutions) and severe (60% PEG solution) water deficit for 6days, the plant injury degree (expressed as the parameters of plant growth, cell membrane integrity, water relations and photosynthesis) increased and contents of free and conjugated Put decreased with the rise of PEG concentration. Under the moderate water deficit, the plants could survive by the reduced osmotic potential (psi(s)), increased free and conjugated Spd and Spm in leaves. After subsequent rewatering, the osmotic balance was re-established, most of the above investigated physiological parameters were fully or partly recovered to the control levels. However, it was not the case for the severely-stressed and rewatering plants. It indicates that, vetiver grass can cope well with the moderate water deficit/drought stress by using the strategies of osmotic adjustment and maintenance of total contents of free, conjugated and bound PAs in leaves.

  14. Comparative physiological and transcriptomic analyses provide integrated insight into osmotic, cold, and salt stress tolerance mechanisms in banana

    Science.gov (United States)

    Hu, Wei; Ding, Zehong; Tie, Weiwei; Yan, Yan; Liu, Yang; Wu, Chunlai; Liu, Juhua; Wang, Jiashui; Peng, Ming; Xu, Biyu; Jin, Zhiqiang

    2017-01-01

    The growth, development, and production of banana plants are constrained by multiple abiotic stressors. However, it remains elusive for the tolerance mechanisms of banana responding to multiple abiotic stresses. In this study, we found that Fen Jiao (FJ) was more tolerant to osmotic, cold, and salt stresses than BaXi Jiao (BX) by phenotypic and physiological analyses. Comparative transcriptomic analyses highlighted stress tolerance genes that either specifically regulated in FJ or changed more than twofold in FJ relative to BX after treatments. In total, 933, 1644, and 133 stress tolerance genes were identified after osmotic, cold, and salt treatments, respectively. Further integrated analyses found that 30 tolerance genes, including transcription factor, heat shock protein, and E3 ubiquitin protein ligase, could be commonly regulated by osmotic, cold, and salt stresses. Finally, ABA and ROS signaling networks were found to be more active in FJ than in BX under osmotic, cold, and salt treatments, which may contribute to the strong stress tolerances of FJ. Together, this study provides new insights into the tolerance mechanism of banana responding to multiple stresses, thus leading to potential applications in the genetic improvement of multiple abiotic stress tolerances in banana. PMID:28223714

  15. PEG-mediated osmotic stress induces premature differentiation of the root apical meristem and outgrowth of lateral roots in wheat.

    Science.gov (United States)

    Ji, Hongtao; Liu, Ling; Li, Kexue; Xie, Qingen; Wang, Zhijuan; Zhao, Xuhua; Li, Xia

    2014-09-01

    Water stress is one of the major environmental stresses causing growth retardation and yield loss of plants. In the past decades, osmotic adjustment, antioxidant protection, and stomatal movement have been extensively studied, but much less attention has been paid to the study of root system reprogramming to maximize water absorption and survival under water stress. Here, it is shown that polyethylene glycol (PEG)-simulated mild and moderate osmotic stress induced premature differentiation of the root apical meristem (RAM). It is demonstrated that RAM premature differentiation is a conserved adaptive mechanism that is widely adopted by various plants to cope with osmotic stress simulated by PEG 8000, and the occurrence of RAM premature differentiation is directly related to stress tolerance of plants. It is shown that the osmotic stress-induced premature differentiation caused growth cessation of primary roots allowing outgrowth of lateral roots. This work has uncovered a key mechanism for controlling the plastic development of the root system by which plants are capable of survival, growth, or reproduction under water stress.

  16. Increased methane emissions from deep osmotic and buoyant convection beneath submarine seeps as climate warms

    CERN Document Server

    Cardoso, Silvana S S

    2016-01-01

    High speeds have been measured at seep and mud-volcano sites expelling methane-rich fluids from the seabed. Thermal or solute-driven convection alone cannot explain such high velocities in low-permeability sediments. Here, we demonstrate that in addition to buoyancy, osmotic effects generated by the adsorption of methane onto the sediments can create large overpressures, capable of recirculating seawater from the seafloor to depth in the sediment layer, then expelling it upwards at rates of up to a few hundreds of metres per year. In the presence of global warming, such deep recirculation of seawater can accelerate the melting of methane hydrates at depth from timescales of millennia to just decades, and can drastically increase the rate of release of methane into the hydrosphere and perhaps the atmosphere.

  17. Microbial fuel cells and osmotic membrane bioreactors have mutual benefits for wastewater treatment and energy production.

    Science.gov (United States)

    Hou, Dianxun; Lu, Lu; Ren, Zhiyong Jason

    2016-07-01

    This study demonstrates that microbial fuel cells (MFCs) and osmotic membrane bioreactors (OMBRs) can be mutually beneficial when integrated together for wastewater treatment. When connecting MFCs with OMBRs, the solute buildup increased conductivity and buffer capacity, which greatly increased MFC power density from 3 W/m(3) up to 11.5 W/m(3). In turn, the MFCs conditioned and reduced sludge production and therefore reduced forward osmosis (FO) membrane fouling. The MFC-OMBR equipped with new thin-film composite (TFC) membrane showed excellent organic (>95%) and phosphorus removal (>99%) and therefore maintained effluent sCOD below 20 mg/L. However, the nitrogen removal was limited due to the negative surface charge of the thin-film composite membrane and solution chemistry, which led to higher flux of ammonium toward the OMBR draw solution. Further studies are needed to improve nitrogen removal, reduce fouling, and optimize system integration.

  18. Nitric acid: modeling osmotic coefficients and acid-base dissociation using the BIMSA theory.

    Science.gov (United States)

    Ruas, Alexandre; Pochon, Patrick; Simonin, Jean-Pierre; Moisy, Philippe

    2010-11-14

    This work is aimed at a description of the thermodynamic properties of highly concentrated aqueous solutions of nitric acid salts at 25 °C within the binding mean spherical approximation (BIMSA) theory. The predictive capability of this model was examined. First, Raman spectroscopy was used to study the proportion of associated nitric acid as a function of concentration. The corresponding apparent association constant values were compared with literature values. Besides, the BIMSA model, taking into account complex formation, was used to represent literature experimental osmotic coefficient variation with concentration. This theoretical description led to an assessment of the degree of association. The so calculated amount of associated nitric acid coincides accurately with our Raman experimental results up to a high concentration of acid.

  19. Nitric acid: modeling osmotic coefficients and acid-base dissociation using the BIMSA theory

    Energy Technology Data Exchange (ETDEWEB)

    Ruas, A.; Pochon, P.; Moisy, Ph. [CEA Marcoule, Nucl Energy Div, RadioChem and Proc Dept, F-30207 Bagnols Sur Ceze (France); Simonin, J. P. [Univ Paris 06, CNRS, UMR 7195, Lab PECSA, F-75252 Paris 05, (France)

    2010-07-01

    This work is aimed at a description of the thermodynamic properties of highly concentrated aqueous solutions of nitric acid salts at 25 C within the binding mean spherical approximation (BIMSA) theory. The predictive capability of this model was examined. First, Raman spectroscopy was used to study the proportion of associated nitric acid as a function of concentration. The corresponding apparent association constant values were compared with literature values. Besides, the BIMSA model, taking into account complex formation, was used to represent literature experimental osmotic coefficient variation with concentration. This theoretical description led to an assessment of the degree of association. The so calculated amount of associated nitric acid coincides accurately with our Raman experimental results up to a high concentration of acid. (authors)

  20. Isolated extra pontine myelinolysis – a rare imaging appearance of osmotic demyelination syndrome

    Directory of Open Access Journals (Sweden)

    D. Rajitha

    2014-01-01

    Full Text Available Rapid correction of hyponatraemia leads to serious neurological complications, like osmotic demyelination syndrome (ODS. In ODS, magnetic resonance imaging (MRI often reveals features of pontine myelinolysis, that may occur in isolation or may, sometimes be associated with extrapontine myelinolysis. Isolated extrapontine myelinolysis is rare. We report the case of a 53-year-old lady brought to the emergency service with vomitings, and altered sensorium. She was found to have profound hyponatraemia (serum sodium 110 meq/L. Correction of hyponatremia was done with slow intravenous infusion of 3% sodium chloride. However, inadvertant, concomitant oral administration of salt led to overcorrection with serum sodium going upto 150 meq/L. She developed quadriplegia, depressed level of consciousness and respiratory failure and required ventilatory support. MRI brain showed features of isolated extrapontine myelinolysis.

  1. 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.

  2. Suppression of nano-channel ion conductance by electro-osmotic flow

    CERN Document Server

    Liu, Yang; Zhu, Xin; Ran, Qiushi; Dutton, Robert

    2016-01-01

    This theoretical study concerns a basic understanding of ion transport in nano-channels that have weakly overlapping electric double layers. Numerical simulations reveal that the electro-osmotic flow (EOF) interplays with the concentration-polarization process and drives the ion depletion zone into the channels, thus significantly suppressing the channel conductance. The conductance may be restored at high electrical biases in the presence of recirculating vortices within the channels. Further analysis are conducted based on a 1-D, long channel model, and analytic expressions derived to quantitatively account for the EOF-driven ion depletion process. A limiting-conductance behavior is revealed as intrinsically different from the classical limiting-current behavior.

  3. Effects of PEO-PPO-PEO triblock copolymers on phospholipid membrane integrity under osmotic stress.

    Science.gov (United States)

    Wang, Jia-Yu; Chin, Jaemin; Marks, Jeremy D; Lee, Ka Yee C

    2010-08-03

    The effects of PEO-PPO-PEO triblock copolymers, mainly Poloxamer 188, on phospholipid membrane integrity under osmotic gradients were explored using giant unilamellar vesicles (GUVs). Fluorescence leakage assays showed two opposing effects of P188 on the structural integrity of GUVs depending on the duration of their incubation time. A two-state transition mechanism of interaction between the triblock copolymers and the phospholipid membrane is proposed: an adsorption (I) and an insertion (II) state. While the triblock copolymer in state I acts to moderately retard the leakage, their insertion in state II perturbs the lipid packing, thus increasing the membrane permeability. Our results suggest that the biomedical application of PEO-PPO-PEO triblock copolymers, either as cell membrane resealing agents or as accelerators for drug delivery, is directed by the delicate balance between these two states.

  4. 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.

  5. Influence of osmotic distillation on membrane absorption for the treatment of high strength ammonia wastewater

    Institute of Scientific and Technical Information of China (English)

    WANG Guan-ping; SHI Han-chang; SHEN Zhi-song

    2004-01-01

    Osmotic distillation(OD) was found to be a coupled process in membrane absorption(MA) for the treatment of high strength ammonia wastewater. As a result, ammonia could not be concentrated in absorption solution(AS) as expected. The inhibition of the coupled OD in MA process was investigated as well as various factors affecting the inhibition. The results indicated that the coupled OD can be effectively inhibited by heating concentrated solution and cooling dilute solution. It was also found that experimental minimum inhibition temperature difference(MITD) between concentrated and dilute solutions was different when using polyvinylidene fluoride(PVDF)and polypropylene(PP) membranes respectively, which could be ascribed to material properties, such as OD and membrane distillation (MD) coefficients of the membranes. Experimental MITDs were found to be higher than theoretical MITDs which were calculated using a simplified method.

  6. 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...... of the microcirculation. In 10 normal volunteers, Fc was 0.00082 ml (ml mmHg)-1 (SD=0.00007). Multiplication of Fc by plasma flow in the forearm gave a filtration capacity (Kf) of 0.0036 ml (100 ml tissue min mmHg)-1 (SD=0.00137). This filtration capacity (Kf) represents that of fast flowing regions in the forearm...

  7. 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

  8. Electro-osmotic flow of a second-grade fluid in a porous microchannel subject to an AC electric field

    Institute of Scientific and Technical Information of China (English)

    MISRA J.C.; CHANDRA S.

    2013-01-01

    Studies on electro-osmotic flows of various types of fluids in microcharmel are of great importance owing to their multifold applications in the transport of liquids,particularly when the ionized liquid flows with respect to a charged surface in the presence of an external electric field.In the case of viscoelastic fluids,the volumetric flow rate differs significantly from that of Newtonian fluids,even when the flow takes place under the same pressure gradient and the same electric field.With this end in view,this paper is devoted to a study concerning the flow pattern of an electro-osmotic flow in a porous microchannel,which is under the action of an alternating electric field.The influence of various rheologieal and electro-osmotic parameters,e.g.,the Reynolds number,Debye-Huckel parameter,shape factor and fluid viscoelasticity on the kinematics of the fluid,has been investigated for a second-grade viscoelastic fluid.The problem is first treated by using analytical methods,but the quantitative estimates are obtained numerically with the help of the software MATHEMATICA.The results presented here are applicable to the cases where the channel height is much greater than the thickness of the electrical double layer comprising the Stern and diffuse layers.The study reveals that a larger value of the Debye-Huckel parameter creates sharper profile near the wall and also that the velocity of electro-osmotic flow increases as the permeability of the porous microchannel is enhanced.The study further shows that the electro-osmotic flow dominates at lower values of Reynolds number.The results presented here will be quite useful to validate the observations of experimental investigations on the characteristics of electro-osmotic flows and also the results of complex numerical models that are necessary to deal with more realistic situations,where electro-osmotic flows come into the picture,as in blood flow in the micro-circulatory system subject to an electric field.

  9. 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

  10. Filtration coefficient of the axon membrane as measured with hydrostatic and osmotic methods.

    Science.gov (United States)

    Vargas, F F

    1968-01-01

    The hydraulic conductivity of the membranes surrounding the giant axon of the squid, Dosidicus gigas, was measured. In some axons the axoplasm was partially removed by suction. Perfusion was then established by insertion of a second pipette. In other axons the axoplasm was left intact and only one pipette was inserted. In both groups hydrostatic pressure was applied by means of a water column in a capillary manometer. Displacement of the meniscus in time gave the rate of fluid flowing across the axon sheath. In both groups osmotic differences across the membrane were established by the addition of a test molecule to the external medium which was seawater. The hydraulic conductivity determined by application of hydrostatic pressure was 10.6 +/- 0.8.10(-8) cm/sec cm H(2)O in perfused axons and 3.2 +/- 0.6.10(-8) cm/sec cm H(2)O in intact axons. When the driving force was an osmotic pressure gradient the conductivity was 4.5 +/- 0.6 x 10(-10) cm/sec cm H(2)O and 4.8 +/- 0.9 x 10(-10) cm/sec cm H(2)O in perfused and intact axons, respectively. A comparable result was found when the internal solution was made hyperosmotic. The fluid flow was a linear function of the hydrostatic pressure up to 70 cm of water. Glycerol outflux and membrane conductance were increased 1.6 and 1.1 times by the application of hydrostatic pressure. These increments do not give an explanation of the difference between the filtration coefficients. Other possible explanations are suggested and discussed.

  11. 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.

  12. Direct relationship between osmotic and ionic conforming behavior and tissue water regulatory capacity in echinoids.

    Science.gov (United States)

    Santos, Ivonete A; Castellano, Giovanna C; Freire, Carolina A

    2013-03-01

    Echinoderms are considered marine osmoconforming invertebrates. However, many are intertidal or live next to estuaries, tolerating salinity changes and showing extracellular gradients to dilute seawater. Three species of echinoids - Lytechinus variegatus, which can occur next to estuarine areas, the rocky intertidal Echinometra lucunter, and the mostly subtidal Arbacia lixula - were submitted to a protocol of stepwise (rate of 2-3 psu/h) dilution, down to 15 psu, or concentration, up to 45 psu, of control seawater (35 psu). Coelomic fluid samples were obtained every hour. The seawater dilution experiment lasted 8h, while the seawater concentration experiment lasted 6h. Significant gradients (40-90% above value in 15 psu seawater) for osmolality, sodium, magnesium, and potassium were shown by L. variegatus and E. lucunter. A. lixula showed the smallest gradients, displaying the strongest conforming behavior. The esophagus of the three species was challenged in vitro with 20 and 50% osmotic shocks (hypo- and hyperosmotic). A. lixula, the most "conforming" species, showed the highest capacity to avoid swelling of its tissues upon the -50% hyposmotic shock, and was also the species less affected by salinity changes concerning the observation of spines and ambulacral feet movement in the whole-animal experiments. Thus, the most conforming species (A. lixula) displayed the highest capacity to regulate tissue water/volume, and was also the most euryhaline among the three studied species. In addition, tissues from all three species swelled much more than they shrank under osmotic shocks of same magnitude. This distinct trend to gain water, despite the capacity to hold some gradients upon seawater dilution, helps to explain why echinoderms cannot be fully estuarine, or ever enter fresh water.

  13. Effect of osmotic shock on the redox system in plasma membrane of Dunaliella salina

    Institute of Scientific and Technical Information of China (English)

    CHENSIXUE; CHICHIONGYEN; 等

    1996-01-01

    The unicellular halotolerant alga Dunaliella salina had the ability to oxidize NADH and reduce Fe(CN)63-.The redox reactions were to some extent stimulated by slight hyperosmotic shock (2.0mol/L→2.6mol/L NaCl),but markably inhibited by abrupt hyperosmotic shock (2.0mol/L→3.5mol/L NaCl) and hypoosmotic shock (2.0mol/L→1.0mol/L NaCl;2.0mol/L→0.67mol/L NaCl).With the adaptation of algal cells to osmotic shock by accumulating or degraging intracellular grycerol,the plasmalemma redox activities were also restored.The O2 uptake stimulated by NADH could be promoted by FA and SHAM.Hypoosmotic shock increases the basal respiration rate of alga cells,but weakened the stimulating effects of NADH,FA and SHAM on O2 uptake.On the other hand,hyperosmotic shock reduced the basal respiration rate,but relatively enhanced the above effects of NADH,FA and SHAM.H+ extrusion of alga cells was inhibited by NADH and stimulated by Fe(CN)63-.Vanadate and DES could inhibit H+ efflux,but had little effect in the presence of NADH and Fe(CN)63-.Both hyperand hypoosmotic shock stimulated H+ extrusion.This effect could be totally inhibited by vanadate and DES,but almost unaffected by 8-hydroxyquinoline.It was suggested that H+-ATPase probably played a more important role in H+ extrusion and osmoregulation under the conditions of osmotic shock.

  14. Effects of sodium on nitrate uptake and osmotic adjustment of Suaeda physophora

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    Na+ ions play an important role in the growth of halophyte. The effect of Na+ ions on nitrate uptake and osmotic adjustment in the euhalophyte Suaeda physophora was investigated under glasshouse conditions. Seedlings were exposed to 1 mmol/L NaCl (control),300 mmol/L NaCl,150 mmol/L NaCl plus 150 mmol/L KCl or 300 mmol/L KCl treatments for 24 d. Dry weight was not affected greatly by different salt treatments,but water content and succulence in leaves of S. physophora were significantly increased at 300 mmol/L NaCl and 150 mmol/L NaCl plus 150 mmol/L KCl treatments. The concentrations of Na+ and NO3’ in leaves of S. physophora were the highest at 150 mmol/L NaCl plus 150 mmol/L KCl,but lowest at 300 mmol/L KCl treatment. Moreover,the increase of NO3’ concentration did not result in the decrease of Cl-concentration at 150 mmol/L NaCl plus 150 mmol/L KCl treatments. The estimated contribution of NO3’ to osmotic potential (CNO3) in leaves of S. physophora was 9.8% at 150 mmol/L NaCl plus 150 mmol/L KCl,and CNa and CCl were 31.0% and 23.3%,respectively. However,CNO3,CNa and CCl were respectively 1.6%,7.9% and 11.9% at 300 mmol/L KCl treatment. It is concluded that Na+ stimulates NO3’ absorption and the stimulation is independent on the internal or the external Cl-concentration in the euhalophyte S. physo-phora. These characteristics may explain the high levels of N in leaves of saline desert plants in arid ecosystem.

  15. Multiple Osmotic Stress Responses in Acidihalobacter prosperus Result in Tolerance to Chloride Ions

    Science.gov (United States)

    Dopson, Mark; Holmes, David S.; Lazcano, Marcelo; McCredden, Timothy J.; Bryan, Christopher G.; Mulroney, Kieran T.; Steuart, Robert; Jackaman, Connie; Watkin, Elizabeth L. J.

    2017-01-01

    Extremely acidophilic microorganisms (pH optima for growth of ≤3) are utilized for the extraction of metals from sulfide minerals in the industrial biotechnology of “biomining.” A long term goal for biomining has been development of microbial consortia able to withstand increased chloride concentrations for use in regions where freshwater is scarce. However, when challenged by elevated salt, acidophiles experience both osmotic stress and an acidification of the cytoplasm due to a collapse of the inside positive membrane potential, leading to an influx of protons. In this study, we tested the ability of the halotolerant acidophile Acidihalobacter prosperus to grow and catalyze sulfide mineral dissolution in elevated concentrations of salt and identified chloride tolerance mechanisms in Ac. prosperus as well as the chloride susceptible species, Acidithiobacillus ferrooxidans. Ac. prosperus had optimum iron oxidation at 20 g L−1 NaCl while At. ferrooxidans iron oxidation was inhibited in the presence of 6 g L−1 NaCl. The tolerance to chloride in Ac. prosperus was consistent with electron microscopy, determination of cell viability, and bioleaching capability. The Ac. prosperus proteomic response to elevated chloride concentrations included the production of osmotic stress regulators that potentially induced production of the compatible solute, ectoine uptake protein, and increased iron oxidation resulting in heightened electron flow to drive proton export by the F0F1 ATPase. In contrast, At. ferrooxidans responded to low levels of Cl− with a generalized stress response, decreased iron oxidation, and an increase in central carbon metabolism. One potential adaptation to high chloride in the Ac. prosperus Rus protein involved in ferrous iron oxidation was an increase in the negativity of the surface potential of Rus Form I (and Form II) that could help explain how it can be active under elevated chloride concentrations. These data have been used to create a

  16. Development of asymmetric membrane capsules of metformin hydrochloride for oral osmotic controlled drug delivery

    Directory of Open Access Journals (Sweden)

    Venkatesh Teja Banala

    2014-01-01

    Full Text Available Asymmetric membrane capsules are one of the novel osmotic delivery devices which offer the delivery of a wide range of drugs in a controlled manner. In the present work, we developed a semi-automatic process by fabricating a hydraulic assisted mechanical robotic arm for the manufacturing of asymmetric membrane capsules and the process was validated in comparison with the manual procedure of manufacturing. The capsule walls were made by dip coating phase inversion process using cellulose acetate butyrate as polymer and propylene glycol as plasticizer/pore forming agent. The comparative examination of physical parameters in manual and semi-automatic process confirmed the consistency, reproducibility and efficiency of the semi-automatic process over manual procedure. The resulting asymmetric membrane wall was evaluated by scanning electron microscopy studies revealed the thin dense region supported on a thicker porous region. Fourier transform infrared studies showed phase inversion of the asymmetric membrane as compared to plain membrane. Osmotic release study and in vitro behavior was studied for controlled delivery of metformin hydrochloride as a model drug. In vitro release studies of the formulations showed that drug release was dependent on the concentration of pore forming agent, level of osmogents and independent of the media pH and agitation. The effect of the process variables on the drug release was optimized using 2 3 full factorial design and the release kinetics of the optimized formulation confirmed zero order kinetics with a controlled drug delivery of 13 h and the mechanism of drug release was found to be super case II transport.

  17. [Urine osmotic pressure and deficiency-excess syndrome of renal disease: analysis of 428 cases].

    Science.gov (United States)

    Zhang, S

    1990-05-01

    By means of TCM differentiation of symptom-complexes, the authors tested and analysed the urine osmotic pressure (UOP) and the urine and plasma osmotic ratio (UPOR) for 428 cases of renal disease, with the conclusion that the UOP and the UPOR were within the normal value range for not only the 36 cases lack of clinical symptoms so as to be unable to have TCM classification identified, but also for 24 cases of Wind edema excess syndrome mainly caused by pathogenic Wind's invasion to the Lung. But for 74 cases of damp-heat Kidney impairment and 294 cases with the main symptom being Kidney deficiency [including weakness of Qi of Kidney, Yang deficiency of Spleen and Kidney, Yin deficiency of Liver and Kidney], the value of their UOP and the UPOR had the tendency of reduction (P less than 0.01), among which the value of the patients of Kidney Yang deficiency reduced most obviously. The further observation showed that, for the nocturia patients caused by renal disease, the value of UOP and the UPOR reduced more obviously than usual. Therefore the authors assert that the test on UOP and UPOR will offer an objective index to patients' nocturia and Kidney-Qi weakness. 60 cases with renal disease of Kidney deficiency syndrome and 27 cases of damp-heat Kidney impairment syndrome under the diagnosis and treatment based on an overall analysis of symptoms and signs leads to the following conclusion: With the elimination of pathogenic factors and recovery of kidney, the damp-heat Kidney impairment patients' UOP will be increased. The low UOP of patients caused simply by Kidney deficiency, however, will recover slower.

  18. 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.

  19. Transport and reaction of nanoliter samples in a microfluidic reactor using electro-osmotic flow

    Science.gov (United States)

    Arumbuliyur Comandur, Kaushik; Bhagat, Ali Asgar S.; Dasgupta, Subhashish; Papautsky, Ian; Banerjee, Rupak K.

    2010-03-01

    The primary focus of the paper is to establish both numerical and experimental methods to control the concentration of samples in a microreactor well. The concentration of the reacting samples is controlled by varying the initial sample size and electric field. Further, the paper numerically investigates the feasibility of mixing and reacting nanoliter samples with a wide variation in reaction rates in the microreactor driven by electro-osmotic pumping. Two discrete samples are measured and transported to the microreactor simultaneously by electro-osmotic pinching and switching. The transported samples are mixed in the microreactor and floated for 4.5 s for reaction to occur. It is seen that the normalized concentration of the product increases from 0.25 to 0.45 during that period. Also the effects of sample size and applied electric field on sample concentration during the switching process are studied. It is found that the normalized final sample concentration increases from 0.03 to 0.11 with an increase in sample size from 60 to 150 µm, at a constant electric field. Further, by increasing the electric field from 100 to 1000 V cm-1, at a constant sample size, there is a significant decrease in the final concentration of the sample from 0.14 to 0.04. Our studies also show that the normalized product concentration depends on the reaction rate and increases from 0.28 to 0.48 as the reaction rate increases from 10 L mol-1 s-1 to 105 L mol-1 s-1. However, the increase in the reaction rate beyond 105 L mol-1 s-1 does not influence the product concentration for the present design of the microreactor. Our microreactor with improved mixing can be used for assessing reactions of biological samples. The optimized sample size along with a controlled electric field for sample injection forms the basis for developing a prototype of a microreactor device for high throughput drug screening.

  20. 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.

  1. 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.

  2. Identification of a retroelement from the resurrection plant Boea hygrometrica that confers osmotic and alkaline tolerance in Arabidopsis thaliana.

    Directory of Open Access Journals (Sweden)

    Yan Zhao

    Full Text Available Functional genomic elements, including transposable elements, small RNAs and non-coding RNAs, are involved in regulation of gene expression in response to plant stress. To identify genomic elements that regulate dehydration and alkaline tolerance in Boea hygrometrica, a resurrection plant that inhabits drought and alkaline Karst areas, a genomic DNA library from B. hygrometrica was constructed and subsequently transformed into Arabidopsis using binary bacterial artificial chromosome (BIBAC vectors. Transgenic lines were screened under osmotic and alkaline conditions, leading to the identification of Clone L1-4 that conferred osmotic and alkaline tolerance. Sequence analyses revealed that L1-4 contained a 49-kb retroelement fragment from B. hygrometrica, of which only a truncated sequence was present in L1-4 transgenic Arabidopsis plants. Additional subcloning revealed that activity resided in a 2-kb sequence, designated Osmotic and Alkaline Resistance 1 (OAR1. In addition, transgenic Arabidopsis lines carrying an OAR1-homologue also showed similar stress tolerance phenotypes. Physiological and molecular analyses demonstrated that OAR1-transgenic plants exhibited improved photochemical efficiency and membrane integrity and biomarker gene expression under both osmotic and alkaline stresses. Short transcripts that originated from OAR1 were increased under stress conditions in both B. hygrometrica and Arabidopsis carrying OAR1. The relative copy number of OAR1 was stable in transgenic Arabidopsis under stress but increased in B. hygrometrica. Taken together, our results indicated a potential role of OAR1 element in plant tolerance to osmotic and alkaline stresses, and verified the feasibility of the BIBAC transformation technique to identify functional genomic elements from physiological model species.

  3. Phosphate-induced-1 gene from Eucalyptus (EgPHI-1) enhances osmotic stress tolerance in transgenic tobacco.

    Science.gov (United States)

    Sousa, A O; Assis, E T C M; Pirovani, C P; Alvim, F C; Costa, M G C

    2014-03-12

    Environmental stresses such as drought, freezing, and high salinity induce osmotic stress in plant cells. The plant response to osmotic stress involves a number of physiological and developmental changes, which are made possible, in part, by the modulation of the expression of specific genes. Phosphate-induced-1 gene (PHI-1) was first isolated from phosphate-treated phosphate-starved tobacco cell cultures as a stress-inducible gene, which is presumably related to intracellular pH maintenance; however, the role of the PHI-1 gene product has not yet been clarified. A gene encoding a predicted protein with high similarity to tobacco PHI-1, named EgPHI-1, was previously identified in Eucalyptus by comparative transcriptome analysis of xylem cells from species of contrasting phenotypes for wood quality and growth traits. Here, we show that the overexpression of EgPHI-1 in transgenic tobacco enhances tolerance to osmotic stress. In comparison with wild-type plants, EgPHI-1 transgenic plants showed a significant increase in root length and biomass dry weight under NaCl-, polyethylene glycol, and mannitol-induced osmotic stresses. The enhanced stress tolerance of transgenic plants was correlated with increased endogenous protein levels of the molecular chaperone binding protein BiP, which in turn was correlated with the EgPHI-1 expression level in the different transgenic lines. These results provide evidence about the involvement of EgPHI-1 in osmotic stress tolerance via modulation of BiP expression, and pave the way for its future use as a candidate gene for engineering tolerance to environmental stresses in crop plants.

  4. Effects of acetazolamide and anordiol on osmotic water permeability in AQPI-cRNA injected Xenopus oocyte

    Institute of Scientific and Technical Information of China (English)

    BingMA; YangXIANG; Sheng-meiMU; TaoLI; He-mingYU; Xue-junLI

    2004-01-01

    AIM: To study the effects of acetazolamide and anordiol on osmotic water permeability in aquaporin 1 (AQP1)-cRNA injected Xenopus oocyte and their mechanisms. METHODS: AQP1 gene constructed in pBluescript was transcripted into cRNA in vitro and then the cRNA was injected in Xenopus oocytes. The effects of acetazolamide and anordiol on the water transport function of AQP1 were observed by assaying the osmotic swelling of oocytes.In addition, their effects on protein expression of AQP1 were quantitatively investigated by Western blotting method.RESULTS: After incubation for 15 min or 72 h, acetazolamide, a carbonic anhydrase inhibitor, equally reduced the water permeability of AQPI-cRNA injected oocyte in a dose-dependent manner. After incubation for 72 h, anordiol,an antiestrogen with partial estrogenic activity, reduced the osmotic water permeability dose dependently as well;however, no discernable action was observed after incubation with anordiol for 15 min. The Western blotting analysis showed that acetazolamide did not influence the protein expression of AQP1. However, after incubation for 72 h with anordiol (10 μmol/L), the quantity of AQP1 in the oocyte membrane was decreased dramatically(P<0.05). CONCLUSION: Both acetazolamide and anordiol inhibited the osmotic water permeability of AQP1-cRNA injected oocyte, but their mechanisms were different. Acetazolamide functionally inhibited the osmotic water permeability of AQP1, whereas anordiol primarily decreased the amount of AQP1 protein in the oocyte membrane.

  5. Germination response of grasspea (Lathyrus sativus L. and arugula (Eruca sativa L. to osmotic and salinity stresses

    Directory of Open Access Journals (Sweden)

    Fallahi Hamid-Reza

    2015-12-01

    Full Text Available The use of genetic potential of forgotten plants such as grasspea and arugula is an appropriate strategy for increasing of plants tolerance to environmental stresses. Therefore, in this laboratory study the effects of different levels of osmotic (0, -2, -4, -6, -8, -10, -12 and -14 bar caused by PEG and salinity (0, 50, 100, 150, 200, 250, 300 and 350 mmol induced by NaCl stresses were evaluated on germination indices of grasspea and arugula in four separate experiments. Arugula showed a suitable tolerance to osmotic stress, so that its germination percentage and rate at treatment of -10 bar were similar to control. Arugula had 79% germination at osmotic level of -14 bar, but its germination rate at this level was 60% lower than control. In addition, its radicle length until -8 bar and radicle dry weight up to -14 bar were higher than control treatment. However, all levels of salinity stress particularly treatments of more than 100-150 mmol decreased the germination indices of arugula. Germination percentage of arugula in 150 and 200 mmol treatments was 22 and 56% lower than control treatment, respectively. Grasspea had partially suitable tolerance to osmotic stress until -6 bar, but then intensified the reducing trends of its germination indices and finally reached to zero at -14 bar treatment. Moreover, salinity stress especially treatments of higher than 100 mmol decreased all germination indices of grasspea. Overall, arugula was a more tolerant plant especially to osmotic stress; therefore this forgotten plant can be used in agronomic and breeding programs in areas affected by drought stress.

  6. AtDsPTP1 acts as a negative regulator in osmotic stress signalling during Arabidopsis seed germination and seedling establishment.

    Science.gov (United States)

    Liu, Rui; Liu, Yinggao; Ye, Nenghui; Zhu, Guohui; Chen, Moxian; Jia, Liguo; Xia, Yiji; Shi, Lu; Jia, Wensuo; Zhang, Jianhua

    2015-03-01

    Dual-specificity protein phosphatases (DsPTPs) target both tyrosine and serine/threonine residues and play roles in plant growth and development. We have characterized an Arabidopsis mutant, dsptp1, which shows a higher seed germination rate and better root elongation under osmotic stress than the wild type. By contrast, its overexpression line, DsPTP1-OE, shows inhibited seed germination and root elongation; and its complemented line, DsPTP1-Com, resembles the wild type and rescues DsPTP1-OE under osmotic stress. Expression of AtDsPTP1 is enhanced by osmotic stress in seed coats, bases of rosette leaves, and roots. Compared with the wild type, the dsptp1 mutant shows increased proline accumulation, reduced malondialdehyde (MDA) content and ion leakage, and enhanced antioxidant enzyme activity in response to osmotic stress. AtDsPTP1 regulates the transcript levels of various dehydration-responsive genes under osmotic stress. Abscisic acid (ABA) accumulation in dsptp1 under osmotic stress is reduced with reduced expression of the ABA-biosynthesis gene NCED3 and increased expression of the ABA-catabolism gene CYP707A4. AtDsPTP1 also regulates the expression of key components in the ABA-signalling pathway. In conclusion, AtDsPTP1 regulates ABA accumulation, and acts as a negative regulator in osmotic stress signalling during Arabidospsis seed germination and seedling establishment.

  7. Chronic inflammatory demyelinating polyneuropathy

    Science.gov (United States)

    Polyneuropathy - chronic inflammatory; CIDP; Chronic inflammatory polyneuropathy; Guillain-Barré - CIDP ... Health care providers also consider CIDP as the chronic form of Guillain-Barré syndrome. The specific triggers ...

  8. Dealing with chronic cancer

    Science.gov (United States)

    ... medlineplus.gov/ency/patientinstructions/000933.htm Dealing with chronic cancer To use the sharing features on this ... be controlled for a period of time. Controlling Chronic Cancer When you have a chronic cancer, the ...

  9. 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

  10. Osmotic Stress Confers Enhanced Cell Integrity to Hydrostatic Pressure but Impairs Growth in Alcanivorax borkumensis SK2

    Science.gov (United States)

    Scoma, Alberto; Boon, Nico

    2016-01-01

    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 oil-contaminated environments is negligible. Recent laboratory studies 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 Alcanivorax 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 10 MPa). 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 10 MPa 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 0.1 MPa in hyperosmosis-acclimated cells and at 10 MPa under isosmotic conditions. 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-days incubation tests, and CO2:O2 ratios and pH values indicated that culture performance in terms of hydrocarbon degradation was lowered by the effects of osmotic stress alone or combined with increased HP

  11. Differentially Methylated Epiloci Generated from Numerous Genotypes of Contrasting Tolerances Are Associated with Osmotic-Tolerance in Rice Seedlings

    Science.gov (United States)

    Xia, Hui; Huang, Weixia; Xiong, Jie; Yan, Shuaigang; Tao, Tao; Li, Jiajia; Wu, Jinhong; Luo, Lijun

    2017-01-01

    DNA methylation plays an essential role in plant responses to environmental stress. Since drought develops into a rising problem in rice cultivation, investigations on genome-wide DNA methylation in responses to drought stress and in-depth explorations of its association with drought-tolerance are required. For this study, 68 rice accessions were used for an evaluation of their osmotic-tolerance related to 20% PEG6000 simulated physiological traits. The tolerant group revealed significantly higher levels of total antioxidant capacity and higher contents of H2O2 in both normal and osmotic-stressed treatments, as well as higher survival ratios. We furthermore investigated the DNA methylation status in normal, osmotic-stressed, and re-watering treatments via the methylation-sensitive amplification polymorphism (MSAP). The averaged similarity between two rice accessions from tolerant and susceptible groups was approximately 50%, similar with that between two accessions within the tolerant/susceptible group. However, the proportion of overall tolerance-associated epiloci was only 5.2% of total epiloci. The drought-tolerant accessions revealed lower DNA methylation levels in the stressed condition and more de-methylation events when they encountered osmotic stress, compared to the susceptible group. During the recovery process, the drought-tolerant accessions possessed more re-methylation events. Fourteen differentially methylated epiloci (DME) were, respectively, generated in normal, osmotic-stressed, and re-watering treatments. Approximately, 35.7% DME were determined as tolerance-associated epiloci. Additionally, rice accessions with lower methylation degrees on DME in the stressed conditions had a higher survival ratio compared to these with higher methylation degrees. This result is consistent with the lower DNA methylation levels of tolerant accessions observed in the stressed treatment. Methylation degrees on a differentially methylated epilocus may further

  12. Chronic mucus hypersecretion

    DEFF Research Database (Denmark)

    Harmsen, L; Thomsen, S F; Sylvan Ingebrigtsen, Truls;

    2010-01-01

    Chronic mucus hypersecretion (CMH) is a common condition in patients with chronic respiratory diseases. Little is known about the incidence, prevalence and determinants of CMH in younger individuals....

  13. Chronic endocannabinoid system stimulation induces muscle macrophage and lipid accumulation in type 2 diabetic mice independently of metabolic endotoxaemia.

    Directory of Open Access Journals (Sweden)

    Lucie Geurts

    Full Text Available AIMS: Obesity and type 2 diabetes are characterised by low-grade inflammation, metabolic endotoxaemia (i.e., increased plasma lipopolysaccharides [LPS] levels and altered endocannabinoid (eCB-system tone. The aim of this study was to decipher the specific role of eCB-system stimulation or metabolic endotoxaemia in the onset of glucose intolerance, metabolic inflammation and altered lipid metabolism. METHODS: Mice were treated with either a cannabinoid (CB receptor agonist (HU210 or low-dose LPS using subcutaneous mini-pumps for 6 weeks. After 3 weeks of the treatment under control (CT diet, one-half of each group of mice were challenged with a high fat (HF diet for the following 3-week period. RESULTS: Under basal conditions (control diet, chronic CB receptor agonist treatment (i.e., 6 weeks induced glucose intolerance, stimulated metabolic endotoxaemia, and increased macrophage infiltration (CD11c and F4/80 expression in the muscles; this phenomenon was associated with an altered lipid metabolism (increased PGC-1α expression and decreased CPT-1b expression in this tissue. Chronic LPS treatment tended to increase the body weight and fat mass, with minor effects on the other metabolic parameters. Challenging mice with an HF diet following pre-treatment with the CB agonist exacerbated the HF diet-induced glucose intolerance, the muscle macrophage infiltration and the muscle's lipid content without affecting the body weight or the fat mass. CONCLUSION: Chronic CB receptor stimulation under basal conditions induces glucose intolerance, stimulates metabolic inflammation and alters lipid metabolism in the muscles. These effects worsen following the concomitant ingestion of an HF diet. Here, we highlight the central roles played by the eCB system and LPS in the pathophysiology of several hallmarks of obesity and type 2 diabetes.

  14. Chronic urticaria

    Directory of Open Access Journals (Sweden)

    Sandeep Sachdeva

    2011-01-01

    Full Text Available Chronic urticaria (CU is a disturbing allergic condition of the skin. Although frequently benign, it may sometimes be a red flag sign of a serious internal disease. A multitude of etiologies have been implicated in the causation of CU, including physical, infective, vasculitic, psychological and idiopathic. An autoimmune basis of most of the ′idiopathic′ forms is now hypothesized. Histamine released from mast cells is the major effector in pathogenesis and it is clinically characterized by wheals that have a tendency to recur. Laboratory investigations aimed at a specific etiology are not always conclusive, though may be suggestive of an underlying condition. A clinical search for associated systemic disease is strongly advocated under appropriate circumstances. The mainstay of treatment remains H1 antihistaminics. These may be combined with complementary pharmacopeia in the form of H2 blockers, doxepin, nifedipine and leukotriene inhibitors. More radical therapy in the form of immunoglobulins, plasmapheresis and cyclophosphamide may be required for recalcitrant cases. Autologous transfusion and alternative remedies like acupuncture have prospects for future. A stepwise management results in favorable outcomes. An update on CU based on our experience with patients at a tertiary care centre is presented.

  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

    . 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...... 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...... the concentrations of the different solutes (including NPS) decrease by approximately similar rates and proportions, indicating responses to a common factor, such as tissue hydration. The concentration of chloride in the body wall tissues, however, showed distinctly greater decreases than that of other solutes...

  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. Transport phenomena in the crystallization of lysozyme by osmotic dewatering and liquid-liquid diffusion in low gravity

    Science.gov (United States)

    Todd, Paul; Sportiello, Michael G.; Gregory, Derek; Cassanto, John M.; Alvarado, Ulises A.; Ostroff, Robert; Korszun, Z. R.

    1993-01-01

    Two methods of protein crystallization, osmotic dewatering and liquid-liquid diffusion, like the vapor diffusion (hanging-drop and sessile-drop) methods allow a gradual approach to supersaturation conditions. The crystallization of hen egg-white lysozyme, an extensively characterized protein crystal, in the presence of sodium chloride was used as an experimental model with which to compare these two methods in low gravity and in the laboratory. Comparisons of crystal growth rates by the two methods under the two conditions have, to date, indicated that the rate of crystal growth by osmotic dewatering is nearly the same in low gravity and on the ground, while much faster crystal growth rates can be achieved by the liquid-liquid diffusion method in low gravity.

  18. Hypo-osmotic challenge stimulates transepithelial K+ secretion and activates apical IsK channel in vestibular dark cells.

    Science.gov (United States)

    Wangemann, P; Liu, J; Shen, Z; Shipley, A; Marcus, D C

    1995-10-01

    Volume regulation of vestibular dark cells from the gerbilline inner ear in response to a hypo-osmotic challenge depends on the presence of cytosolic K+ and Cl-. The present study addresses the questions: (i) whether and by what mechanism K+ is released during volume regulation, (ii) whether the osmolarity of the basolateral medium has an effect on the steady-state rate of transepithelial K+ transport and (iii) whether there is cross-talk between the basolateral membrane responsible for K+ uptake and the apical membrane responsible for K+ release. K+ secretion (JK+,probe) and current density (Isc,probe) were measured with vibrating probes in the vicinity of the apical membrane and the transepithelial potential (Vt) and resistance (Rt) were measured in a micro-Ussing chamber. The equivalent short-circuit current (Isc) was calculated. The current (IIsK), conductance (gIsK) and inactivation time constant (tau IsK) of the IsK channel and the apparent reversal potential of the apical membrane (Vr) were obtained with the cell-attached macropatch technique. Vr was corrected (Vrc) for the membrane voltage (Vm) measured separately with microelectrodes. A hypo-osmotic challenge (294 to 154 mosM by removal of 150 mM mannitol) on the basolateral side of the epithelium increased JK+,probe and Isc,probe by a factor of 2.7 and 1.6. When this hypo-osmotic challenge was applied to both sides of the epithelium Vt and Isc increased from 5 to 14 mV and from 189 to 824 microA/cm2 whereas Rt decreased from 27 to 19 omega-cm2. With 3.6 mM K+ in the pipette IIsK was outwardly directed, tau IsK was 267 msec and the hypo-osmotic challenge caused IIsK and gIsK to increase from 14 to 37 pA and from 292 to 732 pS. Vrc hyperpolarized from -44 to -76 mV. With 150 mM K+ in the pipette IIsK was inwardly directed, tau IsK was 208 msec and the hypo-osmotic challenge caused IIsK and gIsK to increase in magnitude from 0 to -21 pA and from 107 to 1101 pS. Vrc remained unchanged (-2 vs. 1 mV). These

  19. Calcium and ascorbic acid affect cellular structure and water mobility in apple tissue during osmotic dehydration in sucrose solutions.

    Science.gov (United States)

    Mauro, Maria A; Dellarosa, Nicolò; Tylewicz, Urszula; Tappi, Silvia; Laghi, Luca; Rocculi, Pietro; Rosa, Marco Dalla

    2016-03-15

    The effects of the addition of calcium lactate and ascorbic acid to sucrose osmotic solutions on cell viability and microstructure of apple tissue were studied. In addition, water distribution and mobility modification of the different cellular compartments were observed. Fluorescence microscopy, light microscopy and time domain nuclear magnetic resonance (TD-NMR) were respectively used to evaluate cell viability and microstructural changes during osmotic dehydration. Tissues treated in a sucrose-calcium lactate-ascorbic acid solution did not show viability. Calcium lactate had some effects on cell walls and membranes. Sucrose solution visibly preserved the protoplast viability and slightly influenced the water distribution within the apple tissue, as highlighted by TD-NMR, which showed higher proton intensity in the vacuoles and lower intensity in cytoplasm-free spaces compared to other treatments. The presence of ascorbic acid enhanced calcium impregnation, which was associated with permeability changes of the cellular wall and membranes.

  20. Exact matrix treatment of an osmotic ensemble model of adsorption and pressure induced structural transitions in metal organic frameworks.

    Science.gov (United States)

    Dunne, Lawrence J; Manos, George

    2016-03-14

    Here we present an exactly treated quasi-one dimensional statistical mechanical osmotic ensemble model of pressure and adsorption induced breathing structural transformations of metal-organic frameworks (MOFs). The treatment uses a transfer matrix method. The model successfully reproduces the gas and pressure induced structural changes which are observed experimentally in MOFs. The model treatment presented here is a significant step towards analytical statistical mechanical treatments of flexible metal-organic frameworks.

  1. Effect of various ions, pH, and osmotic pressure on oxidation of elemental sulfur by Thiobacillus thiooxidans

    Energy Technology Data Exchange (ETDEWEB)

    Suzuki, I.; Lee, D.; Mackay, B.; Harahuc, L.; Oh, J.K.

    1999-11-01

    The oxidation of elemental sulfur by Thiobacillus thiooxidans was studied at pH 2.3, 4.5, and 7.0 in the presence of different concentrations of various anions (sulfate, phosphate, chloride, nitrate, and fluoride) and cations (potassium, sodium, lithium, rubidium, and cesium). The results agree with the expected response of this acidophilic bacterium to charge neutralization of colloids by ions, pH-dependent membrane permeability of ions, and osmotic pressure.

  2. Effect of various ions, pH, and osmotic pressure on oxidation of elemental sulfur by Thiobacillus thiooxidans.

    Science.gov (United States)

    Suzuki, I; Lee, D; Mackay, B; Harahuc, L; Oh, J K

    1999-11-01

    The oxidation of elemental sulfur by Thiobacillus thiooxidans was studied at pH 2.3, 4.5, and 7.0 in the presence of different concentrations of various anions (sulfate, phosphate, chloride, nitrate, and fluoride) and cations (potassium, sodium, lithium, rubidium, and cesium). The results agree with the expected response of this acidophilic bacterium to charge neutralization of colloids by ions, pH-dependent membrane permeability of ions, and osmotic pressure.

  3. 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.

  4. Generation of Wheat Transcription Factor FOX Rice Lines and Systematic Screening for Salt and Osmotic Stress Tolerance.

    Directory of Open Access Journals (Sweden)

    Jinxia Wu

    Full Text Available Transcription factors (TFs play important roles in plant growth, development, and responses to environmental stress. In this study, we collected 1,455 full-length (FL cDNAs of TFs, representing 45 families, from wheat and its relatives Triticum urartu, Aegilops speltoides, Aegilops tauschii, Triticum carthlicum, and Triticum aestivum. More than 15,000 T0 TF FOX (Full-length cDNA Over-eXpressing rice lines were generated; of these, 10,496 lines set seeds. About 14.88% of the T0 plants showed obvious phenotypic changes. T1 lines (5,232 lines were screened for salt and osmotic stress tolerance using 150 mM NaCl and 20% (v/v PEG-4000, respectively. Among them, five lines (591, 746, 1647, 1812, and J4065 showed enhanced salt stress tolerance, five lines (591, 746, 898, 1078, and 1647 showed enhanced osmotic stress tolerance, and three lines (591, 746, and 1647 showed both salt and osmotic stress tolerance. Further analysis of the T-DNA flanking sequences showed that line 746 over-expressed TaEREB1, line 898 over-expressed TabZIPD, and lines 1812 and J4065 over-expressed TaOBF1a and TaOBF1b, respectively. The enhanced salt and osmotic stress tolerance of lines 898 and 1812 was confirmed by retransformation of the respective genes. Our results demonstrate that a heterologous FOX system may be used as an alternative genetic resource for the systematic functional analysis of the wheat genome.

  5. Synthesis of sorbitol by Zymomonas mobilis under high osmotic pressure Síntese de sorbitol por Zymomonas mobilis sob elevada pressão osmótica

    OpenAIRE

    Márcio de Barros; Maria Antonia Pedrine Colabone Celligoi

    2006-01-01

    The bacterium Zymomonas mobilis presents potential for sorbitol production when grown in culture medium with high sugar concentration. Sorbitol is produced and accumulated in the periplasma of the bacterium to protect the cells from the harmful effects of high osmotic pressure that results from the action of invertase on sucrose. The conversion of sucrose into glucose and fructose increases the osmolarity of the medium. However, an excessive increase in the osmotic pressure may decrease the s...

  6. 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

    OpenAIRE

    Tania S. Giani; Paoli,Severo de; Presta,Giuseppe A.; Adalgisa I. Maiworm; Santos-Filho, Sebastião D.; Fonseca,Adenilson S.; Bernardo-Filho, Mario

    2007-01-01

    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 morpholo...

  7. Theoretical and experimental studies on freezing point depression and vapor pressure deficit as methods to measure osmotic pressure of aqueous polyethylene glycol and bovine serum albumin solutions.

    Science.gov (United States)

    Kiyosawa, Keitaro

    2003-05-01

    For survival in adverse environments where there is drought, high salt concentration or low temperature, some plants seem to be able to synthesize biochemical compounds, including proteins, in response to changes in water activity or osmotic pressure. Measurement of the water activity or osmotic pressure of simple aqueous solutions has been based on freezing point depression or vapor pressure deficit. Measurement of the osmotic pressure of plants under water stress has been mainly based on vapor pressure deficit. However, differences have been noted for osmotic pressure values of aqueous polyethylene glycol (PEG) solutions measured by freezing point depression and vapor pressure deficit. For this paper, the physicochemical basis of freezing point depression and vapor pressure deficit were first examined theoretically and then, the osmotic pressure of aqueous ethylene glycol and of PEG solutions were measured by both freezing point depression and vapor pressure deficit in comparison with other aqueous solutions such as NaCl, KCl, CaCl(2), glucose, sucrose, raffinose, and bovine serum albumin (BSA) solutions. The results showed that: (1) freezing point depression and vapor pressure deficit share theoretically the same physicochemical basis; (2) theoretically, they are proportional to the molal concentration of the aqueous solutions to be measured; (3) in practice, the osmotic pressure levels of aqueous NaCl, KCl, CaCl(2), glucose, sucrose, and raffinose solutions increase in proportion to their molal concentrations and there is little inconsistency between those measured by freezing point depression and vapor pressure deficit; (4) the osmotic pressure levels of aqueous ethylene glycol and PEG solutions measured by freezing point depression differed from the values measured by vapor pressure deficit; (5) the osmotic pressure of aqueous BSA solution measured by freezing point depression differed slightly from that measured by vapor pressure deficit.

  8. In Situ Formed Phase Transited Drug Delivery System of Ketoprofen for Achieving Osmotic, Controlled and Level A In Vitro In Vivo Correlation

    OpenAIRE

    2008-01-01

    A dry process induced phase transited, non disintegrating, controlled release, in situ formed asymmetric membrane capsular system for poorly water soluble drug, ketoprofen, was developed and evaluated both in vitro and in vivo for osmotic and controlled release of the drug. In situ formed asymmetric membrane capsules were prepared using fabricated glass capsule holders via dry, phase inversion process. Effect of varying osmotic pressure of the dissolution medium on drug release was studied. M...

  9. Plasmolysis and cell wall deposition in wheat root hairs under osmotic stress.

    Science.gov (United States)

    Volgger, Michael; Lang, Ingeborg; Ovecka, Miroslav; Lichtscheidl, Irene

    2010-07-01

    We analysed cell wall formation in rapidly growing root hairs of Triticum aestivum under reduced turgor pressure by application of iso- and hypertonic mannitol solutions. Our experimental series revealed an osmotic value of wheat root hairs of 150 mOsm. In higher concentrations (200-650 mOsm), exocytosis of wall material and its deposition, as well as callose synthesis, still occurred, but the elongation of root hairs was stopped. Even after strong plasmolysis when the protoplast retreated from the cell wall, deposits of wall components were observed. Labelling with DiOC(6)(3) and FM1-43 revealed numerous Hechtian strands that spanned the plasmolytic space. Interestingly, the Hechtian strands also led towards the very tip of the root hair suggesting strong anchoring sites that are readily incorporated into the new cell wall. Long-term treatments of over 24 h in mannitol solutions (150-450 mOsm) resulted in reduced growth and concentration-dependent shortening of root hairs. However, the formation of new root hairs does occur in all concentrations used. This reflects the extraordinary potential of wheat root cells to adapt to environmental stress situations.

  10. Adaptation of Staphylococcus xylosus to nutrients and osmotic stress in a salted meat model

    Directory of Open Access Journals (Sweden)

    Aurore eVermassen

    2016-02-01

    Full Text Available Staphylococcus xylosus is commonly used as starter culture for meat fermentation. Its technological properties are mainly characterized in vitro, but the molecular mechanisms for its adaptation to meat remain unknown. A global transcriptomic approach was used to determine these mechanisms. S. xylosus modulated the expression of about 40% to 50% of the total genes during its growth and survival in the meat model. The expression of many genes involved in DNA machinery and cell division, but also in cell lysis, was up-regulated. Considering that the S. xylosus population remained almost stable between 24 and 72 h of incubation, our results suggest a balance between cell division and cell lysis in the meat model. The expression of many genes encoding enzymes involved in glucose and lactate catabolism was up-regulated and revealed that glucose and lactate were used simultaneously. S. xylosus seemed to adapt to anaerobic conditions as revealed by the overexpression of two regulatory systems and several genes encoding cofactors required for respiration. In parallel, genes encoding transport of peptides and peptidases that could furnish amino acids were up-regulated and thus concomitantly a lot of genes involved in amino acid synthesis were down-regulated. Several genes involved in glutamate homeostasis were up-regulated. Finally, S. xylosus responded to the osmotic stress generated by salt added to the meat model by overexpressing genes involved in transport and synthesis of osmoprotectants, and Na+ and H+ extrusion.

  11. [The dependence of the osmotic properties of Escherichia coli bacteria on temperature].

    Science.gov (United States)

    Morozov, I I; Morozova, G V; Petin, V G

    1996-01-01

    The influence of water solutions of NaCl on the osmoresistance and reproduction of E. coli B/r and E. coli Bs-1 at different temperatures was studied. The increase in cell resistance was studied. The increase in cell resistance to NaCl hypertonia was noticed after the temperature rise from 20 to 37 degrees C. In this case the concentration of NaCl in the medium, which made this medium isotonic, was seen to increase too. On the contrary, when the temperature decreased to 0 degrees, the cell resistance to high concentrations of NaCl was found suppressed. In this case the concentration of NaCl in the medium, which made this medium isotonic, was seen to decrease. The salt tolerance of bacteria reproduction was found to depend on the temperature: the tolerance increased with the temperature rise, and vice versa. It is concluded that the solution temperature was to be considered as one of the major factors governing the osmotic bacterial cell homeostasis.

  12. How to squeeze a sponge: casein micelles under osmotic stress, a SAXS study.

    Science.gov (United States)

    Bouchoux, Antoine; Gésan-Guiziou, Geneviève; Pérez, Javier; Cabane, Bernard

    2010-12-01

    By combining the osmotic stress technique with small-angle x-ray scattering measurements, we followed the structural response of the casein micelle to an overall increase in concentration. When the aqueous phase that separates the micelles is extracted, they behave as polydisperse repelling spheres and their internal structure is not affected. When they are compressed, the micelles lose water and shrink to a smaller volume. Our results indicate that this compression is nonaffine, i.e., some parts of the micelle collapse, whereas other parts resist deformation. We suggest that this behavior is consistent with a spongelike casein micelle having a triple hierarchical structure. The lowest level of the structure consists of the CaP nanoclusters that serve as anchors for the casein molecules. The intermediate level consists of 10- to 40-nm hard regions that resist compression and contain the nanoclusters. Those regions are connected and/or partially merged with each other, thus forming a continuous and porous material. The third level of structure is the casein micelle itself, with an average size of 100 nm. In our view, such a structure is consistent with the observation of 10- to 20-nm casein particles in the Golgi vesicles of lactating cells: upon aggregation, those particles would rearrange, fuse, and/or swell to form the spongelike micelle.

  13. Collagen intrafibrillar mineralization as a result of the balance between osmotic equilibrium and electroneutrality.

    Science.gov (United States)

    Niu, Li-Na; Jee, Sang Eun; Jiao, Kai; Tonggu, Lige; Li, Mo; Wang, Liguo; Yang, Yao-Dong; Bian, Ji-Hong; Breschi, Lorenzo; Jang, Seung Soon; Chen, Ji-Hua; Pashley, David H; Tay, Franklin R

    2017-03-01

    Mineralization of fibrillar collagen with biomimetic process-directing agents has enabled scientists to gain insight into the potential mechanisms involved in intrafibrillar mineralization. Here, by using polycation- and polyanion-directed intrafibrillar mineralization, we challenge the popular paradigm that electrostatic attraction is solely responsible for polyelectrolyte-directed intrafibrillar mineralization. As there is no difference when a polycationic or a polyanionic electrolyte is used to direct collagen mineralization, we argue that additional types of long-range non-electrostatic interaction are responsible for intrafibrillar mineralization. Molecular dynamics simulations of collagen structures in the presence of extrafibrillar polyelectrolytes show that the outward movement of ions and intrafibrillar water through the collagen surface occurs irrespective of the charges of polyelectrolytes, resulting in the experimentally verifiable contraction of the collagen structures. The need to balance electroneutrality and osmotic equilibrium simultaneously to establish Gibbs-Donnan equilibrium in a polyelectrolyte-directed mineralization system establishes a new model for collagen intrafibrillar mineralization that supplements existing collagen mineralization mechanisms.

  14. Growth and microtubule orientation of Zea mays roots subjected to osmotic stress

    Science.gov (United States)

    Blancaflor, E. B.; Hasenstein, K. H.

    1995-01-01

    Previous work has shown that microtubule (MT) reorientation follows the onset of growth inhibition on the lower side of graviresponding roots, indicating that growth reduction can occur independently of MT reorientation. To test this observation further, we examined whether the reduction in growth in response to osmotic stress is correlated with MT reorientation. The distribution and rate of growth in maize roots exposed to 350 mOsm sorbitol and KCl or 5 mM Mes/Tris buffer were measured with a digitizer. After various times roots were processed for indirect immunofluorescence microscopy. Application of sorbitol or KCl had no effect on the organization of MTs in the apical 2 mm of the root but resulted in striking and different effects in the basal region of the root. Sorbitol treatment caused rapid appearance of oval to circular holes in the microtubular array that persisted for at least 9 h. Between 30 min and 4 h of submersion in KCl, MTs in cortical cells 4 mm and farther from the quiescent center began to reorient oblique to the longitudinal axis. After 9 h, the alignment of MTs had shifted to parallel to the root axis but MTs of the epidermal cells remained transverse. In KCl-treated roots MT reorientation appeared to follow a pattern of development similar to that in controls but without elongation. Our data provide additional evidence that MT reorientation is not the cause but a consequence of growth inhibition.

  15. Predictive value of hypo-osmotic swelling test to identify viable non-motile sperm

    Institute of Scientific and Technical Information of China (English)

    WilliamM.Bucker

    2003-01-01

    Aim: To determine the predictive value of the hypo-osmotic swelling (HOS) test to identify viable, non-motile sperm. Methods: Semen samples from 20 men with severe asthenozoospermia underwent traditional seminal analysis, eosin-nigrosin (EN) staining and the HOS test. A further EN stain was then pexformed on a HOS pre-treated aliquot and a total of 2000 further sperm examined. Results: The median sperm density was 5.1 million/mL (IQR 4.3-13.1) and the median motility was 3.0 % (IQR 0-7). Seven samples showed complete asthenozoospermia. Initial EN staining showed 59 % viability (range 48-69) despite the poor standard parameters and 47 % (range 33-61) in thecomplete asthenozoospermia subgroup. The HOS test showed 49.9 % reacted overall (range 40-59) and 41.7 %(range 22-61) in the complete asthenozoospermia subgroup. The combined HOSfEN stain showed the positive pre-dictive value of the HOS test to identify viable sperm was 84.2 % overall and 79.7 % in the complete asthenozoospermia subgroup. Conclusion: The HOS test can effectively predict sperm viability in patients with severe and complete asthenozoospermia. ( Asian J Andro12003 Sep; 5: 209-212)

  16. 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.

    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™ 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.

  17. Efficient utilization of ectoine by halophilic Brevibacterium species and Escherichia coli subjected to osmotic downshock.

    Science.gov (United States)

    Nagata, Shinichi; Wang, Chenxiang

    2005-01-01

    Halophilic and non-halophilic bacteria subjected to osmotic downshock, from 0.7 M NaCl to deionized water, were examined for their survival, with the uptake and utilization of the cyclic amino acid ectoine, one of the representative compatible solutes, being taken into account. The uptake of ectoine added externally and survival of the cells were monitored as a function of incubation time in the presence and absence of NaCl. The halophilic Brevibacterium sp. JCM 6894 and B. epidermidis JCM 2593 actively accumulated ectoine regardless of the presence of NaCl, which led to cell survival. Brevibacterium casei JCM 2594 belonging to the same Brevibacterium species, however, revealed Na+-dependence of its uptake activity of ectoine. Non-halophilic Escherichia coli K-12 did not accumulate ectoine, and thereby this strain failed to survive irrespective of whether NaCl was present. The physiological meanings of the downshock procedure are discussed in connection with the uptake and the subsequent utilization of ectoine.

  18. Effects of Micromachining Processes on Electro-Osmotic Flow Mobility of Glass Surfaces

    Directory of Open Access Journals (Sweden)

    Norihisa Miki

    2013-03-01

    Full Text Available Silica glass is frequently used as a device material for micro/nano fluidic devices due to its excellent properties, such as transparency and chemical resistance. Wet etching by hydrofluoric acid and dry etching by neutral loop discharge (NLD plasma etching are currently used to micromachine glass to form micro/nano fluidic channels. Electro-osmotic flow (EOF is one of the most effective methods to drive liquids into the channels. EOF mobility is affected by a property of the micromachined glass surfaces, which includes surface roughness that is determined by the manufacturing processes. In this paper, we investigate the effect of micromaching processes on the glass surface topography and the EOF mobility. We prepared glass surfaces by either wet etching or by NLD plasma etching, investigated the surface topography using atomic force microscopy, and attempted to correlate it with EOF generated in the micro-channels of the machined glass. Experiments revealed that the EOF mobility strongly depends on the surface roughness, and therefore upon the fabrication process used. A particularly strong dependency was observed when the surface roughness was on the order of the electric double layer thickness or below. We believe that the correlation described in this paper can be of great help in the design of micro/nano fluidic devices.

  19. Permeability of phospholipid membrane for small polar molecules determined from osmotic swelling of giant phospholipid vesicles

    CERN Document Server

    Peterlin, Primoz; Diamant, Haim; Haleva, Emir

    2012-01-01

    A method for determining permeability of phospholipid bilayer based on the osmotic swelling of micrometer-sized giant unilamellar vesicles (GUVs) is presented as an alternative to the two established techniques, dynamic light scattering on liposome suspension, and electrical measurements on planar lipid bilayers. In the described technique, an individual GUV is transferred using a micropipette from a sucrose/glucose solution into an isomolar solution containing the solute under investigation. Throughout the experiment, vesicle cross-section is monitored and recorded using a digital camera mounted on a phase-contrast microscope. Using a least-squares procedure for circle fitting, vesicle radius R is computed from the recorded images of vesicle cross-section. Two methods for determining membrane permeability from the obtained R(t) dependence are described: the first one uses the slope of R(t) for a spherical GUV, and the second one the R(t) dependence around the transition point at which a flaccid vesicle trans...

  20. Evolution of quality parameters during red wine dealcoholization by osmotic distillation.

    Science.gov (United States)

    Liguori, Loredana; Russo, Paola; Albanese, Donatella; Di Matteo, Marisa

    2013-09-01

    Osmotic distillation technique was used for the total dealcoholization of a red wine (Aglianico grape variety) up to 0.19 vol.%. The dealcoholization process was performed in subsequent cycles which gave rise wine samples at different alcoholic degrees. The effect of processing on the main chemical and physical properties of Aglianico wine was evaluated. Among wine samples, no significant differences (p<0.05) of oenological parameters such as pH, total acidity were found. Similarly, the total phenolic, flavonoids and tartaric esters content and the composition of organic acids did not show significant differences (p<0.05) during the process. On the contrary, colour intensity and tonality of wine samples changed significantly when the alcohol reduction was over the 6.5 vol.%. Finally, the total dealcoholized wine showed properties similar to Aglianico wine except for the volatile compounds, which decreased over 98%. Hence, flavour enrichment may be required to produce a pleasurable and delicious non alcoholic beverage from wine.

  1. Phosphorus and water recovery by a novel osmotic membrane bioreactor-reverse osmosis system.

    Science.gov (United States)

    Luo, Wenhai; Hai, Faisal I; Price, William E; Guo, Wenshan; Ngo, Hao H; Yamamoto, Kazuo; Nghiem, Long D

    2016-01-01

    An osmotic membrane bioreactor-reverse osmosis (OMBR-RO) hybrid system integrated with periodic microfiltration (MF) extraction was evaluated for simultaneous phosphorus and clean water recovery from raw sewage. In this hybrid system, the forward osmosis membrane effectively retained inorganic salts and phosphate in the bioreactor, while the MF membrane periodically bled them out for phosphorus recovery with pH adjustment. The RO process was used for draw solute recovery and clean water production. Results show that phosphorus recuperation from the MF permeate was most effective when the solution pH was adjusted to 10, whereby the recovered precipitate contained 15-20% (wt/wt) of phosphorus. Periodic MF extraction also limited salinity build-up in the bioreactor, resulting in a stable biological performance and an increase in water flux during OMBR operation. Despite the build-up of organic matter and ammonia in the draw solution, OMBR-RO allowed for the recovery of high quality reused water.

  2. Numerical analysis of dynamic electro-osmotic flows of non-Newtonian fluids in rectangular microchannels

    CERN Document Server

    Zhao, Cunlu

    2010-01-01

    Numerical analyses of transient electro-osmosis of a typical non-Newtonian liquid induced by DC and AC electric fields in a rectangular microchannel are conducted in the framework of continuum fluid mechanics. The famous power-law constitutive model is used to express the fluid dynamic viscosity in terms of the velocity gradient. Transient start-up characteristics of electro-osmotic power-law liquid flow in rectangular microchannels are simulated by using finite element method. Under a DC electric field, it is found out and the fluid is more inert to the external electric field and the steady-state velocity profile becomes more plug-like with decrease of the flow behavior index of the power-law liquids. The numerical calculations also confirm the validity of the generalized Smoluchowski slip velocity which can serve as the counterpart for the classic Smoluchowski slip velocity when dealing with electrokinetic flow of non-Newtonian power-law fluids. Under AC electric fields, the fluid is more obviously acceler...

  3. Effects of Salinity on growth and osmotic regulation substances of callus induced from Reaumuria soongorica

    Science.gov (United States)

    Tan, Huijuan; Li, Xinrong; Liu, Yubing; Zhao, Xin

    2014-05-01

    Reaumuria soongorica (Pall.) Maxim is the strong xerophils plant in the northwest arid and semiarid regions in China. It plays very important roles in stabilizing sand dunes and in construction of agricultural shelter belts in north-west China.The present study aimed to evaluate the response to salinity of R. soongorica, which is more salt-resistant than other valuable shrub species used for afforestation on saline and alkaline desert, at the cellular level. To this purpose, callus was induced from shoot segments of R. soongorica on Murashige and Skoog (MS) medium supplemented with 0.2 mgL-16-benzyladenine (BA) and 2.0 mg mgL-1 2,4-Dichlorophenoxyacetic acid (2 ,4-D). The relative growth rate of callus reached a maximum in the presence of 100 mmol L-1NaCl and growth was inhibited with increasing NaCl concentrations. Examination of the changes of osmotic substances under salt stress showed that accumulation of proline, trehalose, Glycine betain and flavonoids increased with increasing salt concentrations. The results indicate that the response of the callus of R. soongorica to salt stress is similar to that of the whole plant. .

  4. Applicability of a novel osmotic membrane bioreactor using a specific draw solution in wastewater treatment.

    Science.gov (United States)

    Nguyen, Nguyen Cong; Chen, Shiao-Shing; Nguyen, Hau Thi; Ngo, Huu Hao; Guo, Wenshan; Hao, Chan Wen; Lin, Po-Hsun

    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(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, NH4(+)-N and PO4(3-)-P were almost removed (>99%) while producing relatively low NO3(-)-N and NO2(-)-N in the effluent (e.g. MBBR-OsMBR was reversible and removed by a physical cleaning technique.

  5. Water harvesting from municipal wastewater via osmotic gradient: An evaluation of process performance

    KAUST Repository

    Valladares Linares, Rodrigo

    2013-11-01

    Forward osmosis (FO) presents a unique opportunity for integrated wastewater treatment and seawater desalination. This study assesses the efficiency of a submerged FO system to reduce the volume of wastewater that needs to be treated while recovering high quality water that can be further treated for sustainable fresh water production. A semi-batch operation was employed with two membrane orientations in terms of active and support layers. A change of membrane orientation could improve the flux and slightly reduce the salt leakage from the draw solution to the feed solution. The formation of fouling on the membrane resulted in a decrease of the initial flux and average flux with both membrane orientations. The fouling layer on the membrane surface was determined to be caused by biopolymer-like substances. Osmotic backwash removed almost all organic foulants from the membrane surface, but did not improve the flux. There was a moderate to high retention of nutrients (N and P), varying from 56% to 99%, and almost a complete retention for trace metals regardless of membrane orientation. However the membrane showed a limited ability to retain low molecular weight acids and low molecular weight neutral compounds. This study identified a possible role of the FO process to integrate wastewater treatment and seawater desalination for a sustainable solution of the water-energy nexus for coastal cities. © 2013 Elsevier B.V..

  6. Transcriptional regulation of gene expression during osmotic stress responses by the mammalian target of rapamycin.

    Science.gov (United States)

    Ortells, M Carmen; Morancho, Beatriz; Drews-Elger, Katherine; Viollet, Benoit; Laderoute, Keith R; López-Rodríguez, Cristina; Aramburu, Jose

    2012-05-01

    Although stress can suppress growth and proliferation, cells can induce adaptive responses that allow them to maintain these functions under stress. While numerous studies have focused on the inhibitory effects of stress on cell growth, less is known on how growth-promoting pathways influence stress responses. We have approached this question by analyzing the effect of mammalian target of rapamycin (mTOR), a central growth controller, on the osmotic stress response. Our results showed that mammalian cells exposed to moderate hypertonicity maintained active mTOR, which was required to sustain their cell size and proliferative capacity. Moreover, mTOR regulated the induction of diverse osmostress response genes, including targets of the tonicity-responsive transcription factor NFAT5 as well as NFAT5-independent genes. Genes sensitive to mTOR-included regulators of stress responses, growth and proliferation. Among them, we identified REDD1 and REDD2, which had been previously characterized as mTOR inhibitors in other stress contexts. We observed that mTOR facilitated transcription-permissive conditions for several osmoresponsive genes by enhancing histone H4 acetylation and the recruitment of RNA polymerase II. Altogether, these results reveal a previously unappreciated role of mTOR in regulating transcriptional mechanisms that control gene expression during cellular stress responses.

  7. Mass transfer during osmotic dehydration of celery stalks in a batch osmo-reactor

    Science.gov (United States)

    Sareban, M.; Abbasi Souraki, B.

    2017-03-01

    In this study, dehydration behavior of bulk of celery stalks, during osmotic drying in a limited volume of salt solution, was investigated. Experiments were carried out in the three initial solution concentrations of 10, 18 and 25 % (w/w) and at the three temperatures of 35, 45 and 55 °C. The volume ratio of the fruit to the solution was considered 1:3. A two-parameter model was used for prediction of kinetics of mass transfer and values of equilibrium moisture loss and solid gain. Moisture and salt effective diffusivities in celery stalks were estimated by fitting the experimental data of moisture loss and solute gain to the analytical solution of Fick's second law of diffusion. The analytical model was solved by defining a partition factor, K, assuming that the concentration of solute just within the surface of the material is K times that in the solution. Results showed that moisture and salt effective diffusivities and equilibrium values of moisture loss and solute gain increased with increasing the temperature and solution concentration. Results showed a good agreement between the two parameter model (with mean relative error of 4.016 % for moisture loss and 5.977 % for solid gain), analytical solution of Fick's second law (with mean relative error of 8.924 % for moisture loss and 9.164 % for solid gain) and experimental data.

  8. Combining Electro-Osmotic Flow and FTA® Paper for DNA Analysis on Microfluidic Devices

    Directory of Open Access Journals (Sweden)

    Ryan Wimbles

    2016-07-01

    Full Text Available FTA® paper can be used to protect a variety of biological samples prior to analysis, facilitating ease-of-transport to laboratories or long-term archive storage. The use of FTA® paper as a solid phase eradicates the need to elute the nucleic acids from the matrix prior to DNA amplification, enabling both DNA purification and polymerase chain reaction (PCR-based DNA amplification to be performed in a single chamber on the microfluidic device. A disc of FTA® paper, containing a biological sample, was placed within the microfluidic device on top of wax-encapsulated DNA amplification reagents. The disc containing the biological sample was then cleaned up using Tris-EDTA (TE buffer, which was passed over the disc, via electro-osmotic flow, in order to remove any potential inhibitors of downstream processes. DNA amplification was successfully performed (from buccal cells, whole blood and semen using a Peltier thermal cycling system, whereupon the stored PCR reagents were released during the initial denaturing step due to the wax barrier melting between the FTA® disc and PCR reagents. Such a system offers advantages in terms of a simple sample introduction interface and the ability to process archived samples in an integrated microfluidic environment with minimal risk of contamination.

  9. Osmotic induction marking with Alizarin Red S on juveniles of pejerrey, Odontesthes bonariensis (Atherinopsidae

    Directory of Open Access Journals (Sweden)

    Daniela Campanella

    Full Text Available Juveniles of pejerrey, Odontesthes bonariensis, were exposed to 0.1% Alizarin Red S (ARS alone or with a previous immersion in 2.2% saline solution (Osmotic Induction, OI to enhance the ARS marking method. Fish were marked in the field and immediately released in 1 m3 cages in "La Salada de Monasterio" lagoon, Chascomús, Buenos Aires , Argentina. After 73 days, clear marks were observed in the otoliths, caudal fin rays and scales with both treatments, being the intensity of the signal in the scales of OI+ARS treated fish higher. On the other hand, no marks were observed in the control group on the same structures. Approximately one year post-treatment (385 days, only marks in caudal fin rays were found clearly in OI+ARS treated fish. After this period, no significant differences in total length or weight between marked or control fish were observed and the mortality ranged between 30-40 % in all cages. These results provide strong evidence for the potential applicability of this cost-effective marking technique in differentiation of wild and hatchery-produced pejerrey. The success in the caudal fin rays marking is also important because it is easy to do and does not require the sacrifice of fish.

  10. The role of forward osmosis and microfiltration in an integrated osmotic-microfiltration membrane bioreactor system.

    Science.gov (United States)

    Luo, Wenhai; Hai, Faisal I; Kang, Jinguo; Price, William E; Nghiem, Long D; Elimelech, Menachem

    2015-10-01

    This study investigates the performance of an integrated osmotic and microfiltration membrane bioreactor (O/MF-MBR) system for wastewater treatment and reclamation. The O/MF-MBR system simultaneously used microfiltration (MF) and forward osmosis (FO) membranes to extract water from the mixed liquor of an aerobic bioreactor. The MF membrane facilitated the bleeding of dissolved inorganic salts and thus prevented the build-up of salinity in the bioreactor. As a result, sludge production and microbial activity were relatively stable over 60 days of operation. Compared to MF, the FO process produced a better permeate quality in terms of nutrients, total organic carbon, as well as hydrophilic and biologically persistent trace organic chemicals (TrOCs). The high rejection by the FO membrane also led to accumulation of hydrophilic and biologically persistent TrOCs in the bioreactor, consequently increasing their concentration in the MF permeate. On the other hand, hydrophobic and readily biodegradable TrOCs were minimally detected in both MF and FO permeates, with no clear difference in the removal efficiencies between two processes.

  11. Integration of micro-filtration into osmotic membrane bioreactors to prevent salinity build-up.

    Science.gov (United States)

    Wang, Xinhua; Yuan, Bo; Chen, Yao; Li, Xiufen; Ren, Yueping

    2014-09-01

    The high salinity remains as one of major obstacles of the osmotic membrane bioreactor (OMBR). In this study, a new pathway was explored to prevent the salinity build-up by integrating the micro-filtration (MF) membrane to the OMBR (MF-OMBR). The results indicated that the salinity characterized by conductivity in the MF-OMBR was effectively alleviated and controlled at a lower value of about 5 mS/cm, and the stable flux of forward osmosis (FO) membrane correspondingly increased to approximately 5.5L/(m(2)h). Besides, the addition of MF membrane in the OMBR could increase the total organic carbon (TOC) and ammonium nitrogen (NH3-N) removals due to the activated sludge by improving the microbial activity. The membrane fouling especially the reversible fouling in the MF-OMBR was severer compared to that in the conventional OMBR, which resulted in a lower water flux than the expectation due to the increase of filtration resistance and external concentration polarization.

  12. Time-scale estimation of unstirred layer formation in osmotically driven flow

    Science.gov (United States)

    Itano, Tomoaki; Inagaki, Taishi; Konno, Keito; Sugihara-Seki, Masako

    2016-11-01

    We study the osmotic solvent flow driven by solute concentration difference across a semi-permeable membrane. The concentration difference across the membrane drives the solvent flow penetrating from the low concentration side through pores of the membrane. This spontaneous solvent flow transports solutes away from the membrane in the opposite side, which locally reduces the solute concentration in the vicinity of the membrane. The concentration boundary layer developed locally near the membrane in the case of absence of external stirring process was termed as "unstirred layer" in the previous studies, which has been recognized as a key of the unfavorable virtual resistance and membrane fouling in the water filtration of the desalination process. In the previous studies, the formation of the unstirred layer was analyzed under the assumption that the thickness of the unstirred layer is steady, which however contradicts the smoothness of the solute concentration at the end of the layer. In the present study, in order to resolve the contradiction, we assume the unsteadiness in the layer development so that the thickness of the unstirred layer may be estimated analytically.

  13. Mass transfer during osmotic dehydration of celery stalks in a batch osmo-reactor

    Science.gov (United States)

    Sareban, M.; Abbasi Souraki, B.

    2016-07-01

    In this study, dehydration behavior of bulk of celery stalks, during osmotic drying in a limited volume of salt solution, was investigated. Experiments were carried out in the three initial solution concentrations of 10, 18 and 25 % (w/w) and at the three temperatures of 35, 45 and 55 °C. The volume ratio of the fruit to the solution was considered 1:3. A two-parameter model was used for prediction of kinetics of mass transfer and values of equilibrium moisture loss and solid gain. Moisture and salt effective diffusivities in celery stalks were estimated by fitting the experimental data of moisture loss and solute gain to the analytical solution of Fick's second law of diffusion. The analytical model was solved by defining a partition factor, K, assuming that the concentration of solute just within the surface of the material is K times that in the solution. Results showed that moisture and salt effective diffusivities and equilibrium values of moisture loss and solute gain increased with increasing the temperature and solution concentration. Results showed a good agreement between the two parameter model (with mean relative error of 4.016 % for moisture loss and 5.977 % for solid gain), analytical solution of Fick's second law (with mean relative error of 8.924 % for moisture loss and 9.164 % for solid gain) and experimental data.

  14. AC electro-osmotic mixing induced by non-contact external electrodes.

    Science.gov (United States)

    Wang, Shau-Chun; Chen, Hsiao-Ping; Lee, Chia-Yu; Yu, Chun-Ching; Chang, Hsueh-Chia

    2006-10-15

    We demonstrate efficient mixing in a micro-fluidic reservoir smaller than 10 microL using ac electro-osmosis driven by field-induced polarization. Our mixing device, of that electrodes are outside of the mixing unit, consists of three circular reservoirs (3mm in diameter) connected by a 1 mm x 1 mm channel. Unlike dc electro-osmosis, whose polarization is from charged substrate functional groups, this new mechanism uses the external field to capacitively charge the surface and the surface capacitance becomes the key factor in the electrokinetic mobility. The charging and mixing are enhanced at tailor-designed channel corners by exploiting the high normal fields at geometric singularities. The induced surface dielectric polarization and the resulting electric counter-ion double layer produce an effective Zeta potential in excess of 1 V, over one order of magnitude larger than the channel Zeta potential. The resulting ac electro-osmotic slip velocity scales quadratically with respect to the applied field, in contrast to the linear scaling of dc electro-osmosis and at 1cm/s and larger, exceeds the classical dc values by two orders of magnitude. The polarization is non-uniform at the corners due to field leakage to the dielectric substrate and the inhomogeneous slip velocity produces intense mixing vortices that effectively homogenize solutes in 30s in a 3mm reservoir, in contrast to hour-long mixing by pure diffusion.

  15. Harvesting low-grade heat energy using thermo-osmotic vapour transport through nanoporous membranes

    Science.gov (United States)

    Straub, Anthony P.; Yip, Ngai Yin; Lin, Shihong; Lee, Jongho; Elimelech, Menachem

    2016-07-01

    Low-grade heat from sources below 100 ∘C offers a vast quantity of energy. The ability to extract this energy, however, is limited with existing technologies as they are not well-suited to harvest energy from sources with variable heat output or with a small temperature difference between the source and the environment. Here, we present a process for extracting energy from low-grade heat sources utilizing hydrophobic, nanoporous membranes that trap air within their pores when submerged in a liquid. By driving a thermo-osmotic vapour flux across the membrane from a hot reservoir to a pressurized cold reservoir, heat energy can be converted to mechanical work. We demonstrate operation of air-trapping membranes under hydraulic pressures up to 13 bar, show that power densities as high as 3.53 ± 0.29 W m-2 are achievable with a 60 ∘C heat source and a 20 ∘C heat sink, and estimate the efficiency of a full-scale system. The results demonstrate a promising process to harvest energy from low-temperature differences (<40 ∘C) and fluctuating heat sources.

  16. Reciprocal osmotic challenges reveal mechanisms of divergence in phenotypic plasticity in the killifish Fundulus heteroclitus.

    Science.gov (United States)

    Brennan, Reid S; Galvez, Fernando; Whitehead, Andrew

    2015-04-15

    The killifish Fundulus heteroclitus is an estuarine species with broad physiological plasticity, enabling acclimation to diverse stressors. Previous work suggests that freshwater populations expanded their physiology to accommodate low salinity environments; however, it is unknown whether this compromises their tolerance to high salinity. We used a comparative approach to investigate the mechanisms of a derived freshwater phenotype and the fate of an ancestral euryhaline phenotype after invasion of a freshwater environment. We compared physiological and transcriptomic responses to high- and low-salinity stress in fresh and brackish water populations and found an enhanced plasticity to low salinity in the freshwater population coupled with a reduced ability to acclimate to high salinity. Transcriptomic data identified genes with a conserved common response, a conserved salinity-dependent response and responses associated with population divergence. Conserved common acclimation responses revealed stress responses and alterations in cell-cycle regulation as important mechanisms in the general osmotic response. Salinity-specific responses included the regulation of genes involved in ion transport, intracellular calcium, energetic processes and cellular remodeling. Genes diverged between populations were primarily those showing salinity-specific expression and included those regulating polyamine homeostasis and the cell cycle. Additionally, when populations were matched with their native salinity, expression patterns were consistent with the concept of 'transcriptomic resilience', suggesting local adaptation. These findings provide insight into the fate of a plastic phenotype after a shift in environmental salinity and help to reveal mechanisms allowing for euryhalinity.

  17. Adaptation of Staphylococcus xylosus to Nutrients and Osmotic Stress in a Salted Meat Model.

    Science.gov (United States)

    Vermassen, Aurore; Dordet-Frisoni, Emilie; de La Foye, Anne; Micheau, Pierre; Laroute, Valérie; Leroy, Sabine; Talon, Régine

    2016-01-01

    Staphylococcus xylosus is commonly used as starter culture for meat fermentation. Its technological properties are mainly characterized in vitro, but the molecular mechanisms for its adaptation to meat remain unknown. A global transcriptomic approach was used to determine these mechanisms. S. xylosus modulated the expression of about 40-50% of the total genes during its growth and survival in the meat model. The expression of many genes involved in DNA machinery and cell division, but also in cell lysis, was up-regulated. Considering that the S. xylosus population remained almost stable between 24 and 72 h of incubation, our results suggest a balance between cell division and cell lysis in the meat model. The expression of many genes encoding enzymes involved in glucose and lactate catabolism was up-regulated and revealed that glucose and lactate were used simultaneously. S. xylosus seemed to adapt to anaerobic conditions as revealed by the overexpression of two regulatory systems and several genes encoding cofactors required for respiration. In parallel, genes encoding transport of peptides and peptidases that could furnish amino acids were up-regulated and thus concomitantly a lot of genes involved in amino acid synthesis were down-regulated. Several genes involved in glutamate homeostasis were up-regulated. Finally, S. xylosus responded to the osmotic stress generated by salt added to the meat model by overexpressing genes involved in transport and synthesis of osmoprotectants, and Na(+) and H(+) extrusion.

  18. Osmotic power. A great energy source for renewable energy; Una gran fuente de energia renovable para electricidad. Potencia osmotica

    Energy Technology Data Exchange (ETDEWEB)

    Alonso Alvarez, J.

    2009-07-01

    When freshwater meets saltwater, for example, where a river flows out into the sea, enormous quantities of energy can be utilised to generate power, through the natural phenomenon of osmosis. Osmotic power is based on the natural phenomenon of osmosis, defined as the transport of water through a semi-permeable membranes, enclosing their cells, and tho produce osmotic power one has to design similar, artificial membranes. In an osmotic power plant we feed freshwater into separate chambers, separated by an artificial membranes. The salt molecules in the seawater then draw the freshwater through the membranes, causing the pressure on the seawater side to increase. This pressure corresponds to a water column of 120 meters or a large waterfall, and can be utilised in a turbine which generated electricity. The idea to generate power through osmosis is originates from the 1970s. At the time, however, the membranes had low efficiency and power price were too low to enable anyone to profitable invest in such a project. many years later, research scientists al SINTEF brought the idea to STAT kraft. The collaboration was initiated in 1997, and the development of a new, renewable energy source was initiated. (Author)

  19. Simultaneous And Extended Delivery Of Stavudine, Lamivudine And Nevirapine In Fixed Dose Combination Using Sandwiched Osmotic Tablets For Hiv Therapy.

    Science.gov (United States)

    Priya, M Ranga; Rajendran, N N

    2015-01-01

    Current HIV-therapy recommends combination of stavudine, lamivudine and nevirapine. Stavudine and lamivudine are administered as fixed combination while nevirapine as separate dosage form which often results in poor compliance and adherence to therapy by patients and therefore, there is a need to develop dosage forms that can overcome the problems of currently available dosage forms for treatment of HIV infection. The present study developed a single unit osmotic system for simultaneous and extended delivery of stavudine, lamivudine and nevirapine that can ensure patients compliance and adherence to HIV-therapy. Sandwich osmotic pump tablets (SOPTs) of stavudine, lamivudine and nevirapine in fixed dose combination were designed and evaluated for the effect of variables such as PEO (polymer), KCl (osmogen), and orifice diameter on the physicochemical characteristics and the release behavior of the drugs. A 24 h zero order release of stavudine, lamivudine and nevirapine from the formulations was observed and the release rate of the drugs was found to be affected by PEO, KCl, and orifice diameter. The in vitro release data of SOPT correlated with in vivo predictions by super - position method. The results of the study propose that a single unit osmotic system (SOPT) of stavudine, lamivudine and nevirapine is beneficial to overcome the disadvantages of currently available dosage forms for effective control of HIV infection.

  20. Effects of osmotic stress on antioxidant enzymes activities in leaf discs of PSAG12-IPT modified gerbera

    Institute of Scientific and Technical Information of China (English)

    LAI Qi-xian; BAO Zhi-yi; ZHU Zhu-jun; QIAN Qiong-qiu; MAO Bi-zeng

    2007-01-01

    Leaf senescence is often caused by water deficit and the chimeric gene PSAG12-IPT is an auto-regulated gene delaying leaf senescence. Using in vitro leaf discs culture system, the changes of contents of chlorophylls, carotenoids, soluble protein and thiobarbituric acid reactive substance (TBARS) and antioxidant enzymes activities were investigated during leaf senescence of PSAG12-IPT modified gerbera induced by osmotic stress compared with the control plant (wild type). Leaf discs were incubated in 20%, 40% (w/v) polyethylene glycol (PEG) 6 000 nutrient solution for 20 h under continuous light [130 μmol/(m2·s)]. The results showed that the contents of chlorophylls, carotenoids and soluble protein were decreased by osmotic stress with the decrease being more pronounced at 40% PEG, but that, at the same PEG concentration the decrease in the transgenic plants was significantly lower than that in the control plant. The activities of superoxide dismutase (SOD), catalases (CAT), ascorbate peroxidase (APX),guaiacol peroxidase (GPX) and dehydroascorbate reductase (DHAR) were stimulated by PEG treatment. However, the increases were higher in PSAG12-IPT transgenic plants than in the control plants, particularly at 40% PEG treatment. Lipid peroxidation (TBARS content) was increased by PEG treatment with the increase being much lower in transgenic plant than in the control plant.It could be concluded that the increases in the activities of antioxidant enzymes including SOD, CAT, APX, GPX and DHAR were responsible for the delay of leaf senescence induced by osmotic stress.

  1. Sea Water Acidification Affects Osmotic Swelling, Regulatory Volume Decrease and Discharge in Nematocytes of the Jellyfish Pelagia noctiluca

    Directory of Open Access Journals (Sweden)

    Rossana Morabito

    2013-12-01

    Full Text Available Background: Increased acidification/PCO2 of sea water is a threat to the environment and affects the homeostasis of marine animals. In this study, the effect of sea water pH changes on the osmotic phase (OP, regulatory volume decrease (RVD and discharge of the jellyfish Pelagia noctiluca (Cnidaria, Scyphozoa nematocytes, collected from the Strait of Messina (Italy, was assessed. Methods: Isolated nematocytes, suspended in artificial sea water (ASW with pH 7.65, 6.5 and 4.5, were exposed to hyposmotic ASW of the same pH values and their osmotic response and RVD measured optically in a special flow through chamber. Nematocyte discharge was analyzed in situ in ASW at all three pH values. Results: At normal pH (7.65, nematocytes subjected to hyposmotic shock first expanded osmotically and then regulated their cell volume within 15 min. Exposure to hyposmotic ASW pH 6.5 and 4.5 compromised the OP and reduced or totally abrogated the ensuing RVD, respectively. Acidic pH also significantly reduced the nematocyte discharge response. Conclusion: Data indicate that the homeostasis and function of Cnidarians may be altered by environmental changes such as sea water acidification, thereby validating their use as novel bioindicators for the quality of the marine environment.

  2. The Effect of Iron Deficiency on Osmotic Sensitivity of Red Blood Cells from Neonatal Rats and Their Mothers.

    Science.gov (United States)

    Al-Hashimi, L Mossa; Gambling, Lorraine; McArdle, H J

    2015-12-01

    Iron deficiency during pregnancy has many effects on both the mother and her developing foetus. These can be both short and long term. One effect is an alteration in fatty acid metabolism and we hypothesised that these changes may result in alterations in membrane function and structure. In order to test this hypothesis, we measured osmotic sensitivity in red blood cells isolated from neonates and their mothers at different times following birth. We fed female rats control or iron-deficient diets for 4 weeks prior to mating and kept them on the same diet until term. At that time, we returned one group of deficient dams to the control diet. The others were kept on the same diet. We showed that iron deficiency results in a decrease in osmotic sensitivity in the mothers but not in their neonates. Returning the dams to the control diet resulted in a return of their red cell osmotic sensitivity to control levels. In the neonates, there was no recovery in haematocrit or in any other parameter, though they did not get any worse, in contrast to the pups being suckled by deficient mothers. The data show two things. The first is that following birth, the mother restores her own iron stores at the expense of the pups, and secondly, there are differences in properties and sensitivities between red cells from mothers and their neonates. This latter observation cannot be explained by differences in the membrane fatty acid profiles, which were not significantly different.

  3. The genome of the xerotolerant mold Wallemia sebi reveals adaptations to osmotic stress and suggests cryptic sexual reproduction

    Energy Technology Data Exchange (ETDEWEB)

    Mahajabeen, Padamsee; Kumas, T. K. Arun; Riley, Robert; Binder, Manfred; Boyd, Alex; Calvo, Ann M.; Furukawa, Kentaro; Hesse, Cedar; Hohmann, Stefan; James, Tim Y.; LaButti, Kurt; Lapidus, Alla; Lindquist, Erika; Lucas, Susan; Miller, Kari; Shantappa, Sourabha; Grigoriev, Igor V.; Hibbett, David S.; McLaughlin, David J.; Spatafora, Joseph W.; Aime, Mary C.

    2011-09-03

    Wallemia (Wallemiales, Wallemiomycetes) is a genus of xerophilic Fungi of uncertain phylogenetic position within Basidiomycota. Most commonly found as food contaminants, species of Wallemia have also been isolated from hypersaline environments. The ability to tolerate environments with reduced water activity is rare in Basidiomycota. We sequenced the genome of W. sebi in order to understand its adaptations for surviving in osmotically challenging environments, and we performed phylogenomic and ultrastructural analyses to address its systematic placement and reproductive biology. W. sebi has a compact genome (9.8 Mb), with few repeats and the largest fraction of genes with functional domains compared with other Basidiomycota. We applied several approaches to searching for osmotic stress-related proteins. In silico analyses identied 93 putative osmotic stress proteins; homology searches showed the HOG (High Osmolarity Glycerol) pathway to be mostly conserved. Despite the seemingly reduced genome, several gene family expansions and a high number of transporters (549) were found that also provide clues to the ability of W. sebito colonize harsh environments. Phylogenetic analyses of a 71-protein dataset support the position of Wallemia as the earliest diverging lineage of Agaricomycotina, which is conrmed by septal pore ultrastructure that shows the septal pore apparatus as a variant of the Tremella-type. Mating type gene homologs were idented although we found no evidence of meiosis during conidiogenesis, suggesting there may be aspects of the life cycle of W. sebi that remain cryptic

  4. Differential effects of salinity and osmotic stress on the plant growth-promoting bacterium Gluconacetobacter diazotrophicus PAL5.

    Science.gov (United States)

    De Oliveira, Marcos Vinicius V; Intorne, Aline C; Vespoli, Luciano de S; Madureira, Hérika C; Leandro, Mariana R; Pereira, Telma N S; Olivares, Fábio L; Berbert-Molina, Marília A; De Souza Filho, Gonçalo A

    2016-04-01

    Plant growth-promoting bacteria (PGPB) represent a promising alternative to the massive use of industrial fertilizers in agriculture. Gluconacetobacter diazotrophicus is a PGPB that colonizes several plant species. Although this bacterium is able to grow at high sucrose concentrations, its response to environmental stresses is poorly understood. The present study evaluated G. diazotrophicus PAL5 response to stresses caused by sucrose, PEG 400, NaCl, KCl, Na2SO4 and K2SO4. Morphological, ultrastructural and cell growth analysis revealed that G. diazotrophicus PAL5 is more sensitive to salt than osmotic stress. Growth inhibition and strong morphological changes were caused by salinity, in consequence of Cl ion-specific toxic effect. Interestingly, low osmotic stress levels were beneficial for bacterial multiplication, which was able to tolerate high sucrose concentrations, Na2SO4 and K2SO4. Our data show that G. diazotrophicus PAL5 has differential response to osmotic and salinity stress, which may influence its use as inoculant in saline environments.

  5. The Water Permeability Reduction After Successive Hypo-Osmotic Shocks in Kidney Principal Cells is Apically Regulated

    Directory of Open Access Journals (Sweden)

    Liubov E. Katkova

    2014-11-01

    Full Text Available Background/Aims: Renal principal cells maintain their intracellular water and electrolyte content despite significant fluctuations of the extracellular water and salt concentrations. Their water permeability decreases rapidly (within a few seconds after successive hypo-osmotic shocks. Our aim was to investigate the contribution of the apical and basolateral surface to this effect and the potential influence of fast reduction in AQP-2, -3 or -4 plasma membrane content. Methods: Rat principal cells of kidney collecting duct fragments underwent hypo-osmotic challenge applied apically or basolaterally and the regulatory volume decrease (RVD was measured by the calcein quenching method. The AQP -2, -3 and -4 content of the plasma membrane fraction was quantified by Western blotting. Results: The hypo-osmotic shock applied apically causes rapid swelling with high apparent water permeability and fast RVD. An identical successive shock after 15-20 sec causes significantly lower swelling rate with 3-fold reduction in apparent water permeability. This reaction is accompanied by AQP2 decrease in the plasma membrane while AQP3 and AQP4 are unaffected. The contribution of the basolateral cell surface to RVD is significantly lower than the apical. Conclusion: These results indicate that in principal cells the effective mechanism of RVD is mainly regulated by the apical cell plasma membrane.

  6. The build-up of osmotic stress responses within the growing root apex using kinematics and RNA-sequencing.

    Science.gov (United States)

    Royer, Mathilde; Cohen, David; Aubry, Nathalie; Vendramin, Vera; Scalabrin, Simone; Cattonaro, Federica; Bogeat-Triboulot, Marie-Béatrice; Hummel, Irène

    2016-11-01

    Molecular regulation of growth must include spatial and temporal coupling of cell production and cell expansion. The underlying mechanisms, especially under environmental challenge, remain obscure. Spatial patterns of cell processes make the root apex well suited to deciphering stress signaling pathways, and to investigating both processes. Kinematics and RNA-sequencing were used to analyze the immediate growth response of hydroponically grown Populus nigra cuttings submitted to osmotic stress. About 7400 genes and unannotated transcriptionally active regions were differentially expressed between the division and elongation zones. Following the onset of stress, growth decreased sharply, probably due to mechanical effects, before recovering partially. Stress impaired cell expansion over the apex, progressively shortened the elongation zone, and reduced the cell production rate. Changes in gene expression revealed that growth reduction was mediated by a shift in hormone homeostasis. Osmotic stress rapidly elicited auxin, ethylene, and abscisic acid. When growth restabilized, transcriptome remodeling became complex and zone specific, with the deployment of hormone signaling cascades, transcriptional regulators, and stress-responsive genes. Most transcriptional regulations fit growth reduction, but stress also promoted expression of some growth effectors, including aquaporins and expansins Together, osmotic stress interfered with growth by activating regulatory proteins rather than by repressing the machinery of expansive growth.

  7. GERMINATION ASSESSMENT ON DIFFERENT OSMOTIC POTENTIALS AND SEED AND SEEDLING MORPHOLOGIC CHARACTERIZATION OF THE Ateleia glazioviana BAILL (TIMBO

    Directory of Open Access Journals (Sweden)

    Lucas Scheidt da Rosa

    2005-09-01

    Full Text Available Ateleia glazioviana Bail species is an arboreal of Fabaceae family, it is used for recovering degraded areas by showinga raised plasticity and rusticity growth. The objective of this work was to: (i evaluate the effect of polietilenoglicol 6000 on thegermination and (ii characterize the external and internal morphology of the seed and seedling. The study was carried out in TheForest Seeds Laboratory- Universidade Federal do Paraná (UFPR, in Parana State-Brazil. The experiment was established ingerbox (40 seeds on 6 filter papers with 20 mL of osmotic solution. Gerbox was sealed with PVC plastic film and led to germinate inMangelsdorf type chamber (under light at 25ºC . Six osmotic potential was tested: 0.0; -0.2; -0.4; -0.6; -0.8 and 1.0 MPa. It wasshowed that the germination is inversely proportional to the PEG concentration, no germination occurred at 1.0 MPa. External andinternal morphology of the seed and seedling was described and illustrated to the species. In conclusion, Ateleia glaziovianagermination is affected by osmotic potential, low level of percentage and speed germination occurred with increase of osmoticpotential. The germination was severely decreased at 0.4 Mpa.

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

    KAUST Repository

    Xiong, Jun Ying

    2016-12-29

    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 properties and operation parameters and (2) analyse their individual and combined impacts on PRO module performance. A state-of-the-art inner-selective thin-film composite (TFC) hollow fiber membrane was employed in the modelling. The analyses of mass transfer and Gibbs free energy of mixing indicate that the asymmetric nature of hollow fibers results in more significant external concentration polarization (ECP) in the lumen side of the inner-selective hollow fiber membranes. In addition, a trade-off relationship exists between the power density (PD) and the specific energy (SE). The PD vs. SE trade-off upper bound may provide a useful guidance whether the flowrates of the feed and draw solutions should be further optimized in order to (1) minimize the boundary thickness and (2) maximize the osmotic power generation. Two new terms, mass transfer efficiency and power harvesting efficiency for osmotic power generation, have been proposed. This work may provide useful insights to design and operate PRO modules with enhanced performance so that the PRO process becomes more promising in real applications in the near future.

  9. Effects of mannitol induced osmotic stress on proline accumulation, pigment degradation, photosynthetic abilities and growth characters in C3 rice and C4 sorghum

    Institute of Scientific and Technical Information of China (English)

    Suriyan CHA-UM; Souvanh THADAVONG; Chalermpol KIRDMANEE

    2009-01-01

    Osmotic stress is one of the most important abiotic factors which inhibit growth and development in both the vegetative and reproductive stages of many plant species. The aim of this investigation was to compare the biochemical and physiological responses in C3 rice and C4 sorghum to water deficit. Chlorophyll a (Chla), chlorophyll b (Chlb), total chlorophyll (TC) and total carotenoid (Cx+c) contents in both rice and sorghum seedlings under osmotic stress were adversely affected, related to increasing osmotic pressure in the culture media. In addition, the chlorophyll's fluorescence parameters and net photosynthetic rate (Pn) decreased, leading to growth reduction. Also, a positive correlation was found between physiological and biochemical data, while proline accumulation showed a negative relationship. The Chlb, Pn and fresh weight were maintained better in osmotic-stressed (-1.205 MPa) C4 sorghum seedlings than those in C3 rice seedlings. The growth and physiological responses of C3 rice and C4 sorghum decreased depending on the plant species, the osmotic pressure in the media and their interactions. Pigment content and Pn ability in C4 sorghum grown under mannitol-induced osmotic stress increased to a greater degree than in C3 rice, resulting in maintenance of growth.

  10. Does Glycine Betaine and Salicylic Acid Ameliorate the Negative Effect of Drought on Wheat by Regulating Osmotic Adjustment through Solutes Accumulation?

    Directory of Open Access Journals (Sweden)

    Heshmat S. Aldesuquy

    2013-08-01

    Full Text Available A pot experiment was conducted to evaluate the beneficial effect of foliar application of glycine betaine (10mM, grain presoaking in salicylic acid (0.05 M and their interaction on drought tolerance of two wheat (Triticum aestivum L. cultivars (sensitive, Sakha 94 and resistant, Sakha 93. Osmotic pressure, some osmolytes concentration and grain yield were determined. Water stress caused an increase in osmotic pressure, proline, total soluble nitrogen, total soluble sugars, organic acids, ions (Na+, K+, Ca+2, Mg+2 and Cl- content as well as Na+/K+ ratio in cell sap flag leaves of both wheat cultivars. The resistant variety had higher values of osmotic pressure, proline, organic acids and ions content than the sensitive one. On the other hand, water stress induced marked decrease (P<0.05 in grain yield. The applied chemicals mitigated the effect of water stress on the used wheat cultivars. The effect was more pronounced with glycine betaine + salicylic acid treatment. The applied chemicals increased the osmotic pressure, the osmolytes concentrations as well as the grain yield. Furthermore, the osmotic pressure of flag leaf sap appeared to depend on proline, TSN, TSS, organic acids and the ions content. The economic yield (grain yield was positively correlated with proline, keto-acids and osmotic pressure but negatively correlated with TSN, TSS and citric acid.

  11. Chronic pain after hysterectomy

    DEFF Research Database (Denmark)

    Brandsborg, B.; Nikolajsen, L.; Kehlet, H.;

    2008-01-01

    BACKGROUND: Chronic pain is a well-known adverse effect of surgery, but the risk of chronic pain after gynaecological surgery is less established. METHOD: This review summarizes studies on chronic pain following hysterectomy. The underlying mechanisms and risk factors for the development of chronic...... post-hysterectomy pain are discussed. RESULTS AND CONCLUSION: Chronic pain is reported by 5-32% of women after hysterectomy. A guideline is proposed for future prospective studies Udgivelsesdato: 2008/3...

  12. Chronic pain after hysterectomy

    DEFF Research Database (Denmark)

    Brandsborg, B; Nikolajsen, L; Kehlet, Henrik;

    2008-01-01

    BACKGROUND: Chronic pain is a well-known adverse effect of surgery, but the risk of chronic pain after gynaecological surgery is less established. METHOD: This review summarizes studies on chronic pain following hysterectomy. The underlying mechanisms and risk factors for the development of chronic...... post-hysterectomy pain are discussed. RESULTS AND CONCLUSION: Chronic pain is reported by 5-32% of women after hysterectomy. A guideline is proposed for future prospective studies. Udgivelsesdato: 2008-Mar...

  13. [Chronic otitis mediaChronic Otitis Media].

    Science.gov (United States)

    Kohles, N; Schulz, T; Eßer, D

    2015-11-01

    There are 2 different kinds of chronic otitis media: Otitis media chronica mesotympanalis and otitis media chronica epitympanalis (cholesteatoma). The incidence of chronic otitis media as reported in literature differs in a wide range. The incidence rates vary between 0.45 and 46%. Both, otitis media chronica mesotympanalis and cholesteatoma, lead to eardrum perforation due to lengthy and recurring inflammations. Furthermore, chronic otitis media is characterized by frequently recurring otorrhea and conductive hearing loss.

  14. Sorbitol-based osmotic diarrhea: Possible causes and mechanism of prevention investigated in rats

    Institute of Scientific and Technical Information of China (English)

    Md Shahidul Islam; Ei Sakaguchi

    2006-01-01

    AIM: To study the possible causes of sorbitol (S)-based diarrhea and its mechanism of reduction by rice gruel (RG)in cecectomized rats.METHODS: 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.RESULTS: Gastric-emptying and intestinal transit were comparatively slower in the S + RG group. Also, the S absorption index in the 3rd 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 < 0.05) was significantly higher in the S + RG group than in the control group. The S absorption index and the intestinal fluid volume are inversely related to each other.CONCLUSION: The intestinal mai-absorption of S is the main reason for S-based osmotic diarrhea. Where RG enhanced the absorption of S through passive diffusion, the degree of diarrhea was reduced in cecectomized rats.

  15. Boldine enhances bile production in rats via osmotic and Farnesoid X receptor dependent mechanisms

    Energy Technology Data Exchange (ETDEWEB)

    Cermanova, Jolana [Department of Pharmacology, Charles University in Prague, Faculty of Medicine in Hradec Kralove (Czech Republic); Kadova, Zuzana [Department of Pharmacology, Charles University in Prague, Faculty of Medicine in Hradec Kralove (Czech Republic); Deparment of Pharmacology and Toxicology, Charles University in Prague, Faculty of Pharmacy in Hradec Kralove (Czech Republic); Zagorova, Marie [Department of Pharmacology, Charles University in Prague, Faculty of Medicine in Hradec Kralove (Czech Republic); Hroch, Milos [Department of Pharmacology, Charles University in Prague, Faculty of Medicine in Hradec Kralove (Czech Republic); Department of Medical Biochemistry, Charles University in Prague, Faculty of Medicine in Hradec Kralove (Czech Republic); Tomsik, Pavel [Department of Medical Biochemistry, Charles University in Prague, Faculty of Medicine in Hradec Kralove (Czech Republic); Nachtigal, Petr; Kudlackova, Zdenka [Department of Biological and Medical Sciences, Charles University in Prague, Faculty of Pharmacy in Hradec Kralove (Czech Republic); Pavek, Petr; Dubecka, Michaela; Ceckova, Martina; Staud, Frantisek [Deparment of Pharmacology and Toxicology, Charles University in Prague, Faculty of Pharmacy in Hradec Kralove (Czech Republic); Laho, Tomas [Department of Pharmacology, Charles University in Prague, Faculty of Medicine in Hradec Kralove (Czech Republic); Micuda, Stanislav, E-mail: micuda@lfhk.cuni.cz [Department of Pharmacology, Charles University in Prague, Faculty of Medicine in Hradec Kralove (Czech Republic)

    2015-05-15

    Boldine, the major alkaloid from the Chilean Boldo tree, is used in traditional medicine to support bile production, but evidence to support this function is controversial. We analyzed the choleretic potential of boldine, including its molecular background. The acute- and long-term effects of boldine were evaluated in rats either during intravenous infusion or after 28-day oral treatment. Infusion of boldine instantly increased the bile flow 1.4-fold in healthy rats as well as in animals with Mrp2 deficiency or ethinylestradiol induced cholestasis. This effect was not associated with a corresponding increase in bile acid or glutathione biliary excretion, indicating that the effect is not related to stimulation of either bile acid dependent or independent mechanisms of bile formation and points to the osmotic activity of boldine itself. We subsequently analyzed bile production under conditions of changing biliary excretion of boldine after bolus intravenous administration and found strong correlations between both parameters. HPLC analysis showed that bile concentrations of boldine above 10 μM were required for induction of choleresis. Importantly, long-term pretreatment, when the bile collection study was performed 24-h after the last administration of boldine, also accelerated bile formation despite undetectable levels of the compound in bile. The effect paralleled upregulation of the Bsep transporter and increased biliary clearance of its substrates, bile acids. We consequently confirmed the ability of boldine to stimulate the Bsep transcriptional regulator, FXR receptor. In conclusion, our study clarified the mechanisms and circumstances surrounding the choleretic activity of boldine. - Highlights: • Boldine may increase bile production by direct as well as indirect mechanisms. • Biliary concentrations of boldine above 10 μM directly stimulate bile production. • Long-term oral boldine administration increases bile acid (BA) biliary secretion. • Boldine

  16. The transcriptional activator LdtR from 'Candidatus Liberibacter asiaticus' mediates osmotic stress tolerance.

    Directory of Open Access Journals (Sweden)

    Fernando A Pagliai

    2014-04-01

    Full Text Available The causal agent of Huanglongbing disease, 'Candidatus Liberibacter asiaticus', is a non-culturable, gram negative, phloem-limited α-proteobacterium. Current methods to control the spread of this disease are still limited to the removal and destruction of infected trees. In this study, we identified and characterized a regulon from 'Ca. L. asiaticus' involved in cell wall remodeling, that contains a member of the MarR family of transcriptional regulators (ldtR, and a predicted L,D-transpeptidase (ldtP. In Sinorhizobium meliloti, mutation of ldtR resulted in morphological changes (shortened rod-type phenotype and reduced tolerance to osmotic stress. A biochemical approach was taken to identify small molecules that modulate LdtR activity. The LdtR ligands identified by thermal shift assays were validated using DNA binding methods. The biological impact of LdtR inactivation by the small molecules was then examined in Sinorhizobium meliloti and Liberibacter crescens, where a shortened-rod phenotype was induced by growth in presence of the ligands. A new method was also developed to examine the effects of small molecules on the viability of 'Ca. Liberibacter asiaticus', using shoots from HLB-infected orange trees. Decreased expression of ldtRLas and ldtPLas was observed in samples taken from HLB-infected shoots after 6 h of incubation with the LdtR ligands. These results provide strong proof of concept for the use of small molecules that target LdtR, as a potential treatment option for Huanglongbing disease.

  17. Quantitative analysis of glycerol accumulation, glycolysis and growth under hyper osmotic stress.

    Directory of Open Access Journals (Sweden)

    Elzbieta Petelenz-Kurdziel

    Full Text Available We provide an integrated dynamic view on a eukaryotic osmolyte system, linking signaling with regulation of gene expression, metabolic control and growth. Adaptation to osmotic changes enables cells to adjust cellular activity and turgor pressure to an altered environment. The yeast Saccharomyces cerevisiae adapts to hyperosmotic stress by activating the HOG signaling cascade, which controls glycerol accumulation. The Hog1 kinase stimulates transcription of genes encoding enzymes required for glycerol production (Gpd1, Gpp2 and glycerol import (Stl1 and activates a regulatory enzyme in glycolysis (Pfk26/27. In addition, glycerol outflow is prevented by closure of the Fps1 glycerol facilitator. In order to better understand the contributions to glycerol accumulation of these different mechanisms and how redox and energy metabolism as well as biomass production are maintained under such conditions we collected an extensive dataset. Over a period of 180 min after hyperosmotic shock we monitored in wild type and different mutant cells the concentrations of key metabolites and proteins relevant for osmoadaptation. The dataset was used to parameterize an ODE model that reproduces the generated data very well. A detailed computational analysis using time-dependent response coefficients showed that Pfk26/27 contributes to rerouting glycolytic flux towards lower glycolysis. The transient growth arrest following hyperosmotic shock further adds to redirecting almost all glycolytic flux from biomass towards glycerol production. Osmoadaptation is robust to loss of individual adaptation pathways because of the existence and upregulation of alternative routes of glycerol accumulation. For instance, the Stl1 glycerol importer contributes to glycerol accumulation in a mutant with diminished glycerol production capacity. In addition, our observations suggest a role for trehalose accumulation in osmoadaptation and that Hog1 probably directly contributes to the

  18. Correlation between Different Patterns of Hypo-Osmotic Swelling and Sperm Functional Tests

    Directory of Open Access Journals (Sweden)

    Farzaneh Bassiri

    2013-01-01

    Full Text Available Background: Sperm membrane integrity is not only important as a barrier between intraandextra-cellular spaces, but also it can be considered as a sign of DNA integrity. Hypoosmoticswelling test reflects membrane integrity and has been used to evaluate spermquality. Intracytoplasmic sperm injection (ICSI in adjunct with hypo-osmotic swellingtest (HOST has been used for treatment of males with asthenozoospermia. Therefore,this study aims to evaluate correlation of different pattern of HOST with sperm parameters,protamine deficiency and apoptosis.Materials and Methods: In this case-control study, sixteen semen samples were randomlycollected from infertile normozospermic men. Semen samples were divided intotwo portions as follows: one portion was assessed for sperm parameters according toWorldHealth Organization (WHO-2010, while the other portion, after applying HOSTprocedure, was used for assessment of sperm morphology, protamine deficiency and lateor early apoptosis. Statistical analysis was carried out using the Statistical Package forthe Social Studies (SPSS 11.5.Results: Our results showed that, the lowest odds ratio (OR of abnormal sperm headmorphology and abnormal acrosome was in d-sperm as compared to a-pattern or nonviablespermatozoa (p=0.00, p=0.01. In addition, a significant correlation was observedbetween d-sperm with sperm concentration and percentage of DNA damage (p=0.03and p=0.04, respectively. A significant correlation was observed between percentageof sperm motility and DNA fragmentation (r=-0.56; p=0.01. Furthermore, significantcorrelations were observed between percentages of early apoptotic sperm with protaminedeficiency and sperm concentration (p=0.009 and p=0.01, respectively.Conclusion: Significant correlations exist between d-pattern and sperm DNA integrity.Semen samples with low sperm concentration have low percentage of d-sperm which aremature and intact sperms.

  19. Osmotic measurements in whole megagametophytes and embryos of loblolly pine (Pinus taeda) during seed development.

    Science.gov (United States)

    Pullman, Gerald S; Johnson, Shannon

    2009-06-01

    Water potential (Psi) and osmotic potential (Psis) were measured weekly through the sequence of seed development in megagametophytes of loblolly pine (Pinus taeda L.). A Wescor 5500XRS vapor pressure osmometer, modified with a cycle hold switch, was used to measure Psi for whole megagametophytes containing embryos. The Psi measurements for megagametophytes with embryos removed were also attempted but readings were distorted due to cell lysates from the cut surfaces. Six seasonal sets of megagametophyte Psi profiles were generated. Megagametophytes from most of the trees examined showed a consistent Psi pattern: low measurements of -1.0 to -0.75 MPa during early embryo development in late June to early July when embryo Stages 1-2 occur; an increase for one to several weeks to levels of -0.5 to -0.75 MPa, beginning at Stages 3-5 when apical dome formation occurs; followed by a steady drop from -0.85 to -1.7 to -2.0 MPa from Stage 6 onward from late August until just before cone seed release. The Psis was measured for supernatant from centrifuged frozen-thawed megagametophyte tissue (embryos removed). Megagametophyte Psis profiles were similar for seeds analyzed from two trees and resembled Psi observations starting low, rising around Stages 4-7 and then undergoing a major reduction indicating a strong solute accumulation beginning at Stages 7-9.1. Somatic embryos stop growth prematurely in vitro at Stages 8-9.1. The major change in the accumulation of megagametophyte solutes at Stages 8-9.1 correlates with the halt in somatic embryo maturation and suggests that identifying, quantifying and using the major natural soluble compounds that accumulate during mid- to late-stage seed development may be important to improve conifer somatic embryo maturation.

  20. Genome-Wide Analysis of the TORC1 and Osmotic Stress Signaling Network in Saccharomyces cerevisiae

    Directory of Open Access Journals (Sweden)

    Jeremy Worley

    2016-02-01

    Full Text Available The Target of Rapamycin kinase Complex I (TORC1 is a master regulator of cell growth and metabolism in eukaryotes. Studies in yeast and human cells have shown that nitrogen/amino acid starvation signals act through Npr2/Npr3 and the small GTPases Gtr1/Gtr2 (Rags in humans to inhibit TORC1. However, it is unclear how other stress and starvation stimuli inhibit TORC1, and/or act in parallel with the TORC1 pathway, to control cell growth. To help answer these questions, we developed a novel automated pipeline and used it to measure the expression of a TORC1-dependent ribosome biogenesis gene (NSR1 during osmotic stress in 4700 Saccharomyces cerevisiae strains from the yeast knock-out collection. This led to the identification of 440 strains with significant and reproducible defects in NSR1 repression. The cell growth control and stress response proteins deleted in these strains form a highly connected network, including 56 proteins involved in vesicle trafficking and vacuolar function; 53 proteins that act downstream of TORC1 according to a rapamycin assay—including components of the HDAC Rpd3L, Elongator, and the INO80, CAF-1 and SWI/SNF chromatin remodeling complexes; over 100 proteins involved in signaling and metabolism; and 17 proteins that directly interact with TORC1. These data provide an important resource for labs studying cell growth control and stress signaling, and demonstrate the utility of our new, and easily adaptable, method for mapping gene regulatory networks.

  1. FORMULATION AND EVALUATION OF ASYMMETRIC MEMBRANE CAPSULE OSMOTIC PUMP OF GLICLAZIDE

    Directory of Open Access Journals (Sweden)

    Teraiya Sandip R

    2012-05-01

    Full Text Available The aim of this study was to demonstrate that the asymmetric membrane capsule can be used to deliver apoorly water soluble drug with a pH sensitive solubility such as gliclazide. In order to obtain the desireddelivery duration, the drug was solubilized with the use of a pH-controlling excipient. The capsule wallmembrane was made by a phase inversion process, in which asymmetric membrane was formed on glassmold pins by dipping the mold pins into a coating solution containing a polymeric material followed bydipping into a quench solution. This study evaluates the influence of coating formulation that wascellulose acetate (CA, ethyl cellulose (EC, and plasticizer (glycerin and PEG 600. Results showcapsule that made by CA with glycerol and PEG 600(F8, which appear in asymmetric structure and areable to release gliclazide(GLZ in significant percentage. Results show that sodium bicarbonate and Dmannitolis able to promote the release of GLZ from polymeric capsules prepared with CA withasymmetrical membrane. The addition of solubilizer, sodium lauryl sulphate (SLS could enhance therelease of GLZ by micelle formation of GLZ. Based on these results, influence of core formulationvariables, including D-mannitol, sodium bicarbonate and the added amount of SLS were examined onthe release of GLZ. It was found that HPMC 15cp was suitable to be a thickening agent and both addedamount of HPMC and SLS showed a comparable and profoundly positive effect. In vitro release studiesfor all the prepared formulations were done (n=3. Statistical test (Dunnett’s multiple comparison testwas applied for in vitro drug release at P>0.05. The best formulation closely corresponded to themarketed formulation by a similarity (f2 value of 78.36 and difference (f1 value of 4.49. The drugrelease was independent of pH but dependent on the osmotic pressure of the dissolution medium. Therelease kinetics followed the First order model and the mechanism of release was anomalous type.

  2. Interplay between Iron Homeostasis and the Osmotic Stress Response in the Halophilic Bacterium Chromohalobacter salexigens▿ †

    Science.gov (United States)

    Argandoña, Montserrat; Nieto, Joaquín J.; Iglesias-Guerra, Fernando; Calderón, Maria Isabel; García-Estepa, Raúl; Vargas, Carmen

    2010-01-01

    In this study, the connection between iron homeostasis and the osmostress response in the halophile Chromohalobacter salexigens was investigated. A decrease in the requirement for both iron and histidine and a lower level of siderophore synthesis were observed at high salinity, and these findings were correlated with a lower protein content in salt-stressed cells. A six-gene operon (cfuABC-fur-hisI-orf6 operon) located downstream of the ectABC ectoine synthesis genes was characterized. A fur strain (in which the ferric iron uptake regulator Fur was affected) had the Mn resistance phenotype typical of fur mutants, was deregulated for siderophore production, and displayed delayed growth under iron limitation conditions, indicating that fur encodes a functional iron regulator. hisI was essential for histidine synthesis, which in turn was necessary for siderophore production. Fur boxes were found in the promoters of the cfuABC-fur-hisI-orf6 and ectABC operons, suggesting that Fur directly interacts with DNA in these regions. Fur mediated the osmoregulated inhibition of cfuABC-fur-hisI-orf6 operon expression by iron and functioned as a positive regulator of the ectABC genes under high-salinity conditions, linking the salt stress response with iron homeostasis. Excess iron led to a higher cytoplasmic hydroxyectoine content, suggesting that hydroxyectoine protects against the oxidative stress caused by iron better than ectoine. This study provides the first evidence of involvement of the iron homeostasis regulator Fur as part of the complex circuit that controls the response to osmotic stress in halophilic bacteria. PMID:20363778

  3. SYNCHRONIZING THE in vitro GERMINATION OF Psidium guineense Sw. SEEDS BY MEANS OF OSMOTIC PRIMING

    Directory of Open Access Journals (Sweden)

    Márcia Adriana Carvalho dos Santos

    Full Text Available ABSTRACT The Brazilian guava (Psidium guineense Swartz is seed-propagated and, being native to the Caatinga biome, may frequently have uneven germination.Thus, we aimed to evaluate the synchronization of the in vitro seed germination of three accessions of the Brazilian guava, using water, polyethyleneglycol (PEG 6000, and potassium nitrate (KNO3 at different potentials and times of osmotic priming. Seeds from three accessions of the Brazilian guava (Y85, Y93,and Y97 from the UNEB/BA Germplasm Active Bank were subjected to the following pretreatments: -0.6, -1.0, -1.4, and -1,8 MPa PEG 6000; 10 and 20% KNO3 for 24h; 10 and 20% KNO3 for 48h; water for 24 and 48h; and non-primed seeds as the control. The experimental design was therefore a 10x3+1 factorial scheme. We assessed the germination percentage (G, mean germination time (MGT, germination speed (GS, and germination speed index (GSI. Data was subjected to analysis of variance followed by a means test (Duncan at 5% probability and regression. There was interaction between the priming treatments and accessions for all evaluated features, except G. PEG 6000 decreased the MGT (from 6 to 8 days and increased GS and GSI of seeds from all three accessions at potentials -1.0 to -1.5 MPa.Water-priming had a positive effect on MGT, GS, and GSI of accession Y85 seeds. KNO3 negatively affected germination of seeds from all three accessions. Thereby, we could synchronize seed germination of accessions Y85 and Y97 with PEG 6000.

  4. Sensitization of Listeria monocytogenes to Low pH, Organic Acids, and Osmotic Stress by Ethanol

    Science.gov (United States)

    Barker, Clive; Park, Simon F.

    2001-01-01

    The killing of Listeria monocytogenes following exposure to low pH, organic acids, and osmotic stress was enhanced by the addition of 5% (vol/vol) ethanol. At pH 3, for example, the presence of this agent stimulated killing by more than 3 log units in 40 min of exposure. The rate of cell death at pH 3.0 was dependent on the concentration of ethanol. Thus, while the presence 10% (vol/vol) ethanol at pH 3.0 stimulated killing by more than 3 log units in just 5 min, addition of 1.25% (vol/vol) ethanol resulted in less than 1 log unit of killing in 10 min. The ability of 5% (vol/vol) ethanol to stimulate killing at low pH and at elevated osmolarity was also dependent on the amplitude of the imposed stress, and an increase in the pH from 3.0 to 4.0 or a decrease in the sodium chloride concentration from 25 to 2.5% led to a marked reduction in the effectiveness of 5% (vol/vol) ethanol as an augmentative agent. Combinations of organic acids, low pH, and ethanol proved to be particularly effective bactericidal treatments; the most potent combination was pH 3.0, 50 mM formate, and 5 % (vol/vol) ethanol, which resulted in 5 log units of killing in just 4 min. Ethanol-enhanced killing correlated with damage to the bacterial cytoplasmic membrane. PMID:11282610

  5. Bioequivalence of Sandoz methylphenidate osmotic-controlled release tablet with Concerta® (Janssen-Cilag).

    Science.gov (United States)

    Schapperer, Elisabeth; Daumann, Heike; Lamouche, Stéphane; Thyroff-Friesinger, Ursula; Viel, François; Weitschies, Werner

    2015-02-01

    The aim was to assess the bioequivalence of Sandoz methylphenidate osmotic-controlled release (OCR) tablets (Sandoz [Methylphenidate[ MPH OCR) with Concerta®, a methylphenidate formulation indicated for the treatment of attention deficit/hyperactivity disorder (ADHD). Four open-label, randomized, single-dose, two-way crossover bioequivalence studies were conducted in healthy subjects: three fasting studies with 54-, 36- and 18-mg doses of methylphenidate, and one fed study with the 54-mg dose. The d- and l-threo-methylphenidate plasma levels were quantified using liquid chromatographic methods with tandem mass spectrometry (LC MS/MS). Bioequivalence of the formulations was accepted if the 90% geometric confidence intervals of the ratio of least-squares means of Sandoz MPH OCR to Concerta® of ln-transformed area under the curve (AUC0-t ) and C max were within the acceptance range of 80-125%. All studies met the bioequivalence criteria, and 90% geometric confidence intervals for AUC0-t and C max were within the predefined range. All plasma concentration time curves for Sandoz MPH OCR under fasting conditions showed a biphasic profile comparable with Concerta®, confirmed by bioequivalence of the partial metrics AUC0-2h, AUC2-24 h, C max(0-2 h) and C max(2-24 h). Both products were well tolerated and no relevant differences in the safety profiles were observed. It was concluded that Sandoz MPH OCR is bioequivalent to Concerta® in terms of rate and extent of absorption when administered as a single dose of one extended-release tablet of 54, 36, or 18 mg under fasting conditions and at a dose of 54 mg under fed conditions.

  6. Reduction of cerebral edema after traumatic brain injury using an osmotic transport device.

    Science.gov (United States)

    McBride, Devin W; Szu, Jenny I; Hale, Chris; Hsu, Mike S; Rodgers, Victor G J; Binder, Devin K

    2014-12-01

    Traumatic brain injury (TBI) is significant, from a public health standpoint, because it is a major cause of the morbidity and mortality of young people. Cerebral edema after a TBI, if untreated, can lead to devastating damage of the remaining tissue. The current therapies of severe TBI (sTBI), as outlined by the Brain Trauma Foundation, are often ineffective, thus a new method for the treatment of sTBI is necessary. Herein, the reduction of cerebral edema, after TBI, using an osmotic transport device (OTD) was evaluated. Controlled cortical impact (CCI) was performed on adult female CD-1 mice, and cerebral edema was allowed to form for 3 h, followed by 2 h of treatment. The treatment groups were craniectomy only, craniectomy with a hydrogel, OTD without bovine serum albumin (BSA), and OTD. After CCI, brain water content was significantly higher for animals treated with a craniectomy only, craniectomy with a hydrogel, and OTD without BSA, compared to that of control animals. However, when TBI animals were treated with an OTD, brain water content was not significantly higher than that of controls. Further, brain water content of TBI animals treated with an OTD was significantly reduced, compared to that of untreated TBI animals, TBI animals treated with a craniectomy and a hydrogel, and TBI animals treated with an OTD without BSA. Here, we demonstrate the successful reduction of cerebral edema, as determined by brain water content, after TBI using an OTD. These results demonstrate proof of principle for direct water extraction from edematous brain tissue by direct osmotherapy using an OTD.

  7. Importance of Seminal Hyaluronidase Activity and Hypo-Osmotic Swelling Test in Male Infertility

    Directory of Open Access Journals (Sweden)

    A.S. Tambe

    2011-07-01

    Full Text Available The conventional seminal parameters like sperm density, motility, morphology, etc. are not perfect indicators of seminal functional quality. Hence, Seminal Hyaluronidase Activity (SHA and Hypo-osmotic Swelling (HOS score of sperms that evaluate healthy sperms of fertilizing potential, were studied in male partners of infertile couples. The semen samples were obtained, by masturbation after 4 days of abstinence, from recently Fertility Proven Males (Group-I, n=30 and Male Partners of Infertile Couples Normozoospermic (Group-II, n=30 and Oligozoospermic (Group-III, n=30]. After performing routine seminal analysis, the semen samples were subjected for SHA and HOS score assessment. The mean  standard deviation values of SHA (mm of ring diameter were 9.901.65, 8.771.87 and 6.501.33 in Group-I, Group-II and Group-III, respectively. Similarly, the mean  standard deviation values of HOS score (% were 65.508.69, 58.7715.95 and 39.009.78 in Group-I, Group-II and Group-III, respectively. The difference in values of SHA and HOS score amongst different Groups was very highly significant statistically (p0.001. Also, we found significant correlation of SHA and HOS score with sperm density, % motility and % normal morphology. This study shows that Normozoospermic Infertile Males, although having normal conventional seminal parameters, have lower SHA and HOS score than Fertility Proven Males. Thus, it emphasizes the importance of SHA and HOS score assessment in infertile males.

  8. A Golgi-localized MATE transporter mediates iron homoeostasis under osmotic stress in Arabidopsis.

    Science.gov (United States)

    Seo, Pil Joon; Park, Jungmin; Park, Mi-Jeong; Kim, Youn-Sung; Kim, Sang-Gyu; Jung, Jae-Hoon; Park, Chung-Mo

    2012-03-15

    Iron is an essential micronutrient that acts as a cofactor in a wide variety of pivotal metabolic processes, such as the electron transport chain of respiration, photosynthesis and redox reactions, in plants. However, its overload exceeding the cellular capacity of iron binding and storage is potentially toxic to plant cells by causing oxidative stress and cell death. Consequently, plants have developed versatile mechanisms to maintain iron homoeostasis. Organismal iron content is tightly regulated at the steps of uptake, translocation and compartmentalization. Whereas iron uptake is fairly well understood at the cellular and organismal levels, intracellular and intercellular transport is only poorly understood. In the present study, we show that a MATE (multidrug and toxic compound extrusion) transporter, designated BCD1 (BUSH-AND-CHLOROTIC-DWARF 1), contributes to iron homoeostasis during stress responses and senescence in Arabidopsis. The BCD1 gene is induced by excessive iron, but repressed by iron deficiency. It is also induced by cellular and tissue damage occurring under osmotic stress. The activation-tagged mutant bcd1-1D exhibits leaf chlorosis, a typical symptom of iron deficiency. The chlorotic lesion of the mutant was partially recovered by iron feeding. Whereas the bcd1-1D mutant accumulated a lower amount of iron, the iron level was elevated in the knockout mutant bcd1-1. The BCD1 protein is localized to the Golgi complex. We propose that the BCD1 transporter plays a role in sustaining iron homoeostasis by reallocating excess iron released from stress-induced cellular damage.

  9. Calcium-acting drugs modulate expression and development of chronic tolerance to nicotine-induced antinociception in mice.

    Science.gov (United States)

    Damaj, M I

    2005-11-01

    Initial studies in our laboratory suggested that tolerance to nicotine is thought to involve neuronal adaptation not only at the level of the drug-receptor interaction but at postreceptor events such as calcium-dependent second messengers. The present study was undertaken to investigate the hypothesis that L-type calcium channels and calcium-dependent calmodulin protein kinase II are involved in the development and expression of nicotine tolerance. To that end, the effects of modulation of L-type calcium channels (through the use of inhibitors or activators) as well as calcium-dependent calmodulin protein kinase II inactivation were studied in a mouse model of tolerance where mice were infused with nicotine in minipumps (24 mg/kg/day) for 14 days. In addition, the activity of calcium-dependent calmodulin protein kinase II in the lumbar spinal cord region obtained from nicotine-tolerant mice was measured. Our data showed that chronic administration of L-type calcium channel antagonists nimodipine (1 and 5 mg/kg) and verapamil (10 mg/kg) prevented the development of tolerance to nicotine-induced antinociception. In contrast, chronic exposure of BAYK8644 [(+/-)-1,4-dihydro-2,6-dimethyl-5-nitro-4-[2-(trifluoromethyl)-phenyl]-3-pyridine carboxylic acid methyl ester], a calcium channel activator, enhanced nicotine's tolerance. Moreover, a significant increase in both dependent and independent calcium-dependent calmodulin protein kinase II activity was seen in the spinal cord in nicotine-tolerant mice. Finally, spinal administration of 1-[N,O-bis(5-isoquinolinesulfonyl)-N-methyl-tyrosyl]-4-phenylpiperazine (KN-62), a calcium-dependent calmodulin protein kinase II antagonist, reduced the expression of tolerance to nicotine-induced antinociception in mice. In conclusion, our data indicate that calcium-dependent mechanisms such as L-type calcium channels and calcium-dependent calmodulin protein kinase II activation are involved in the expression and development of nicotine

  10. Thiazide diuretics in advanced chronic kidney disease.

    Science.gov (United States)

    Agarwal, Rajiv; Sinha, Arjun D

    2012-01-01

    Chronic kidney disease (CKD) is prevalent in 3%-4% of the adult population in the United States, and the vast majority of these people are hypertensive. Compared with those with essential hypertension, hypertension in CKD remains poorly controlled despite the use of multiple antihypertensive drugs. Hypervolemia is thought to be a major cause of hypertension, and diuretics are useful to improve blood pressure control in CKD. Non-osmotic storage of sodium in the skin and muscle may be a novel mechanism by which sodium may modulate hypertension; further work is need to study this novel phenomenon with diuretics. Among people with stage 4 CKD, loop diuretics are recommended over thiazides. Thiazide diuretics are deemed ineffective in people with stage 4 CKD. Review of the literature suggests that thiazides may be useful even among people with advanced CKD. They cause a negative sodium balance, increasing sodium excretion by 10%-15% and weight loss by 1-2 kg in observational studies. Observational data show improvement in seated clinic blood pressure of about 10-15 mm Hg systolic and 5-10 mm Hg diastolic, whereas randomized trials show about 15 mm Hg improvement in mean arterial pressure. Volume depletion, hyponatremia, hypokalemia, hypercalcemia, and acute kidney injury are adverse effects that should be closely monitored. Our review suggests that adequately powered randomized trials are needed before the use of thiazide diuretics can be firmly recommended in those with advanced CKD.

  11. Assessment of pharmacokinetics and pharmacodynamic effects related to abuse potential of a unique oral osmotic-controlled extended-release methylphenidate formulation in humans.

    Science.gov (United States)

    Parasrampuria, Dolly A; Schoedel, Kerri A; Schuller, Reinhard; Gu, Joan; Ciccone, Patrick; Silber, Steven A; Sellers, Edward M

    2007-12-01

    This was a double-blind, placebo-controlled, randomized, 5-period crossover study in 49 healthy subjects with a history of light (occasional) recreational stimulant use, to evaluate the abuse-related subjective effects of oral osmotic-controlled extended-release methylphenidate with comparable doses of immediate-release methylphenidate. Healthy subjects with a history of light recreational stimulant use were enrolled in the study if they demonstrated a positive response to a 20-mg dose of d-amphetamine and a negative placebo response. Enrolled subjects received single doses of placebo, 54 and 108 mg osmotic-controlled extended-release methylphenidate, and 50 and 90 mg immediate-release methylphenidate. For each treatment, pharmacokinetics, pharmacodynamics, and safety were assessed for 24 hours. Subjective data were collected through standard questionnaires and visual analog scales for positive, stimulant, negative, and other effects. Immediate-release and osmotic-controlled extended-release methylphenidate produced expected plasma concentration-time profiles of d-methylphenidate. Both doses of immediate-release methylphenidate (50 and 90 mg) produced statistically significantly higher subjective effects (eg, positive, stimulant) with respect to placebo for all measures. The higher osmotic-controlled extended-release methylphenidate dose of 108 mg also produced statistically significant differences from placebo for most measures. However, the most commonly prescribed therapeutic dose of osmotic-controlled extended-release methylphenidate (54 mg) did not produce significant differences from placebo for most measures. In addition, for comparable dose levels, osmotic-controlled extended-release methylphenidate produced lower positive and stimulant subjective effects than immediate-release methylphenidate, and low-dose immediate-release methylphenidate (50 mg) produced greater subjective effects than high-dose osmotic-controlled extended-release methylphenidate, with

  12. Chondroprotective role of the osmotically-sensitive ion channel TRPV4: Age- and sex-dependent progression of osteoarthritis in Trpv4 deficient mice

    Science.gov (United States)

    Clark, Andrea L.; Votta, Bartholomew J.; Kumar, Sanjay; Liedtke, Wolfgang; Guilak, Farshid

    2010-01-01

    Objectives Mechanical loading significantly influences the physiology and pathology of articular cartilage, although the mechanisms of mechanical signal transduction are not fully understood. Transient receptor potential vanilloid 4 (TRPV4) is a calcium (Ca++) permeable ion channel that is highly expressed by articular chondrocytes and can be gated by osmotic and mechanical stimuli. The goal of this study was to determine the role of Trpv4 on the structure of the mouse knee joint and to determine whether Trpv4−/− mice exhibit altered Ca++ signaling in response to osmotic challenge. Methods Knee joints of Trpv4−/− mice were examined using histology and micro-computed tomography for osteoarthritic changes and bone structure at 4, 6, 9, and 12 months of age. Fluorescence imaging was used to quantify chondrocytic Ca++ signaling within intact femoral cartilage in response to osmotic stimuli. Results Deletion of Trpv4 resulted in severe osteoarthritic changes, including cartilage fibrillation, eburnation, and loss of proteoglycans that were dependent on age and the male sex. Subchondral bone mass and calcified meniscal volume were greatly increased, again in male mice. Chondrocytes from Trpv4+/+ mice demonstrated significant Ca++ responses to hypo-osmotic stress, but not hyper-osmotic stress. The response to hypo-osmotic stress or the TRPV4 agonist 4α-PDD was eliminated in Trpv4−/− mice. Conclusions Deletion of Trpv4 leads to a lack of osmotically-induced Ca++ signaling in articular chondrocytes, accompanied by progressive, sex-dependent increases in bone density and osteoarthritic joint degeneration. These findings suggest a critical role for TRPV4-mediated Ca++ signaling in the maintenance of joint health and normal skeletal structure. PMID:20583100

  13. Chronic Kidney Diseases

    Science.gov (United States)

    ... Room? What Happens in the Operating Room? Chronic Kidney Diseases KidsHealth > For Kids > Chronic Kidney Diseases Print ... re talking about your kidneys. What Are the Kidneys? Your kidneys are tucked under your lower ribs ...

  14. Diet - chronic kidney disease

    Science.gov (United States)

    ... page: //medlineplus.gov/ency/article/002442.htm Diet - chronic kidney disease To use the sharing features on this page, ... make changes to your diet when you have chronic kidney disease. These changes may include limiting fluids, eating a ...

  15. Chronic granulomatous disease

    Science.gov (United States)

    CGD; Fatal granulomatosis of childhood; Chronic granulomatous disease of childhood; Progressive septic granulomatosis ... In chronic granulomatous disease (CGD), immune system cells called phagocytes are unable to kill some types of bacteria and ...

  16. Chronic mucus hypersecretion

    DEFF Research Database (Denmark)

    Ulrik, Charlotte Suppli; von Linstow, Marie-Louise; Nepper-Christensen, Steen;

    2005-01-01

    To investigate if chronic mucus hypersecretion (CMH) can be used as a marker of asthma in young adults.......To investigate if chronic mucus hypersecretion (CMH) can be used as a marker of asthma in young adults....

  17. Chronic tophaceous gout

    Directory of Open Access Journals (Sweden)

    Thappa D

    1993-01-01

    Full Text Available A rare case of chronic tophaceous gout, in a 27-year-old female on diuretics for chronic congestive cardiac failure with characteristic histopathological and radiological changes is reported.

  18. Chronic Pancreatitis in Children

    Science.gov (United States)

    ... maintaining good health. Can chronic pancreatitis give my child cancer? If your child has chronic pancreatitis, he or she will be at an increased risk of developing pancreatic cancer compared to the general population. The degree of ...

  19. People Experiencing Chronic Homelessness

    Science.gov (United States)

    ... Goals Ending Chronic Homelessness Share This: Ending Chronic Homelessness Last updated on January 19, 2017 We can ... the USICH newsletter. We know how to end homelessness. Let's do it, together. Sign up for our ...

  20. Osmotic adjustment and the growth response of seven vegetable crops following water-deficit stress. [Phaseolus vulgaris L. ; Beta vulgaris L. ; Abelmoschus esculentus; Pisum sativum L. ; Capsicum annuum L. ; Spinacia oleracea L. ; Lycopersicon esculentum Mill

    Energy Technology Data Exchange (ETDEWEB)

    Wullschleger, S.D. (Oak Ridge National Lab., TN (United States)); Oosterhuis, D.M. (Univ. of Arkansas, Fayetteville (United States))

    1991-09-01

    Growth-chamber studies were conducted to examine the ability of seven vegetable crops- Blue Lake beam (Phaseolus vulgaris L.) Detroit Dark Red beet (Beta vulgaris L.) Burgundy okra (Abelmoschus esculentus) (Moench), Little Marvel pea (Pisum sativum L), California Wonder bell pepper (Capsicum annuum L), New Zealand spinach (Spinacia oleracea L), and Beefsteak tomato (Lycopersicon esculentum Mill.) - to adjust osmotically in response to water-deficit stress. Water stress was imposed by withholding water for 3 days, and the adjustment of leaf and root osmotic potentials upon relief of the stress and rehydration were monitored with thermocouple psychrometers. Despite similar reductions in leaf water potential and stomatal conductance among the species studied reductions in lead water potential an stomatal conductance among the species, crop-specific differences were observed in leak and root osmotic adjustment. Leaf osmotic adjustment was observed for bean, pepper, and tomato following water-deficit stress. Root osmotic adjustment was significant in bean, okra, pea and tomato. Furthermore, differences in leaf and root osmotic adjustment were also observed among five tomato cultivars. Leaf osmotic adjustment was not associated with the maintenance of leaf growth following water-deficit stress, since leaf expansion of water-stressed bean and pepper, two species capable of osmotic adjustment, was similar to that of spinach, which exhibited no leaf osmotic adjustment.