Search results for "Sodium chloride"

A simple helical macrocyclic polyazapyridinophane as a stereoselective receptor of biologically important dicarboxylates under physiological conditio…

2007

The interaction of a synthetic enantiopure azamacrocyclic receptor (L) with biologically important chiral dicarboxylates (A, 1-7) has been studied by means of potentiometric titrations in 0.15 M NaCl aqueous solution in a wide pH range. This macrocycle forms strong complexes of the type [HnLA](n-2) (with n = 0-5). As a general trend, the binding is much tighter at basic or neutral pH than in acidic medium. Interestingly, nonprotected excitatory amino acids (Asp and Glu) are strongly bound even at acidic pH. Regarding selectivity, the receptor showed stereoselective binding toward those substrates bearing an H-bonding donor at Calpha, being S-selective in most of the cases, except for glutam…

Solubility of NH3 and apparent pK of NH4+ in human plasma, isotonic salt solutions and water at 37 degrees C.

1998

The solubility of ammonia, alphaNH3 (mM/mmHg), was determined at 37 degrees C and low ammonia partial pressure (0.02-1 mmHg) in pure water (n =24) as 46.70+/-0.40; aqueous isotonic salt solutions (n = 7) as 46.8+/-0.81; and human plasma (n = 5) as 42.0+/-0.66. The last figure increases to 45.3+/-0.63 if expressed in molal units (mmol/kg plasma water x mmHg) instead of molarity with respect to the water content of the plasma (mean from four healthy and fasting donors: 0.908+0.005 kg H2O/kg plasma; mean density at 37 degrees C: 1.020+/-0.002 kg/l). In pure water, the solubility value is the mean of three different methods: (a) extrapolation of the salting-out effect of ammonia in aqueous NaOH…

Molecular diversity and growth features of Flavobacterium columnare strains isolated in Finland

2006

ABSTRACT: Columnaris disease caused by Flavobacterium columnare is a problem in fish farmingworldwide. During the last 15 yr, outbreaks have started to emerge in Finland. Flavobacteriumcolumnare Type Strain NCIMB 2248 T and 30 Finnish F. columnare isolates were studied usinganalysis of 16S rDNA by restriction-fragment length polymorphism (16S RFLP), length heterogeneityanalysis of polymerase chain reaction (LH-PCR) products, automated ribosomal intergenic spaceranalysis (ARISA), and 16S rDNA sequence analysis. All isolates fell into RFLP Genomovar I and hadthe same length in the LH-PCR analysis. Based on ARISA, 8 genetically different strains wereselected for further analyses. The growth of…

Iontophoretic Transdermal Delivery of Sumatriptan: Effect of Current Density and Ionic Strength

2005

ABSTRACT: Iontophoretic transdermal delivery of sumatriptan was investigated in vitro . Among the conditions tested, 0.25 mA/cm 2 and low ionic strength (NaCl 25 mM) was the best experimental condition to increase its transport across the skin. The flux increased 385-fold respective to passive diffusion, thus resulting in a transdermal flux of sumatriptan of 1273 ± 83 nmol/cm 2 h. © 2005 Wiley-Liss, Inc. and the American Pharmacists Association

Uptake of an Endocytic Marker by Rice Cells: Variations Related to Osmotic and Saline Stress

2003

Saline and osmotic stress are the main abiotic factors limiting the productivity of rice and other crop plants. Although both coincide in generating water deficit and affect many aspects of plant growth and development similarly, some effects of salinity are distinctively related to the ionic component of salt stress. At the cellular level, dessication tolerance is largely dependent on the cell's ability for osmotic adjustment. Here, we have studied the effects of saline and osmotic stress on endocytosis by rice cells, to investigate the common and distinctive effects of saline-generated stress and osmotically generated stress, and the possible involvement of endocytosis in tolerance mechan…

Changes of the renin-angiotensin and of the kallikrein-kinin system after administration of saline, christalloid and colloid solution in the rat. Eff…

1988

The ionic dependence of calcium efflux from guinea pig auricles.

1968

K+ and Na+ effects on the gelation properties of κ-Carrageenan

2004

The effects of K(+), Na(+) ions and their mixture on the conformational transition and macroscopic gel properties of kappa-Carrageenan system have been studied using different experimental techniques. The macroscopic gelation properties of kappa-Carrageenan were found to be dependent upon cosolute type. Indeed, a more ordered and strong gel was obtained in the presence of K(+) with respect to Na(+) ions. The gel properties obtained using mixtures of two cosolutes are shown to depend on the [K(+)]/[Na(+)] ratio.

Real-time and low-cost sensing technique based on photonic bandgap structures

2011

[EN] A technique for the development of low-cost and high-sensitivity photonic biosensing devices is proposed and experimentally demonstrated. In this technique, a photonic bandgap structure is used as transducer, but its readout is performed by simply using a broadband source, an optical filter, and a power meter, without the need of obtaining the transmission spectrum of the structure; thus, a really low-cost system and real-time results are achieved. Experimental results show that it is possible to detect very low refractive index variations, achieving a detection limit below 2 x 10(-6) refractive index units using this low-cost measuring technique. (C) 2011 Optical Society of America[

A relationship between tolerance to dehydration of rice cell lines and ability for ABA synthesis under stress

2005

Plant dehydration is commonly caused by some adverse environmental conditions such as salinity, drought and freezing. As the plant hormone abscisic acid (ABA) is involved in responses to water stress, we studied its putative relationship with the degree of tolerance to these abiotic stresses. For this purpose we used cell lines that had been established from mature embryos of rice (Oryza sativa L, cvs. Bahia and Bomba), and selected by their high (L-T) or low (L-S) levels of tolerance to each type of stress. Tolerance of rice calli to either osmotic, saline, or freezing stress was generally improved by a previous treatment with ABA. This ABA effect was evident in those callus lines with low…