Sodium Bromide Concentration Research Articles

Extracellular fluid and total body water changes in neonates undergoing extracorporeal membrane oxygenation

After being placed on extracorporeal life support (ECLS), newborn patients typically weight 5% to 30% more than their birthweight. Recovery and eventual decannulation from ECLS is associated with a return to baseline weight or birthweight values after a pronounced diuresis. It has been assumed that the increases in weight in these patients are due to increases in extracellular fluid (ECF) and total body water (TBW). This study was undertaken to prove or disprove this hypothesis. ECF space was measured using the compound sodium bromide and TBW was determined with the use of deuterium oxide (nonradioactive heavy water). Fluid compartment measurements were made prior to the institution of ECLS, immediately after placement on bypass, approximately every other day while on bypass, and a final measurement was made once the patient was off bypass. Sodium bromide concentration was analyzed by high-pressure liquid chromatography, and deuterium oxide concentration was measured by the falling drop method. Eight newborns with respiratory failure were placed on either venoarterial (4 patients) or venovenous (4 patients) ECLS for an average of 106 hours (range, 71 to 219 hours). Pre-ECLS TBW was high in the neonates (87% of total body weight v the normal of 75% to 80%). Mean values for each fluid compartment were corrected for the additional volume of the bypass circuit when the patient was on bypass. ECF increased immediately after the institution of ECLS; however, both ECF and TBW decreased during the bypass run, and post-ECLS levels of ECF and TBW were similar to those found prior to ECLS. Body weight increased significantly at the onset of ECLS and returned to near pre-ECLS (birthweight) levels at the conclusion of bypass. We conclude that neonates with respiratory distress, once placed on ECLS, have increased body weight, ECF, and TBW, which decrease during the course of ECLS, and reach baseline levels. These decreases in weight, ECF, and TBW appear to be associated with lung recovery.

The influence of sodium bromide in the corrosion and passivity of copper in borate buffer

The electrodissolution, passivity and pitting corrosion of copper in borate buffer containing sodium bromide is studied by using potentiodynamic and potentiostatic techniques complemented with scanning electron microscopy. The voltammogram involves three regions. The first one corresponds to the electrodissolution of copper and the electroformation of a complex passive film containing Cu(I) and Cu(II) oxides and presumably some bromide ions. The second region involves the passivity of copper. In this region the transport of copper ions through the passive film is enhanced as the bromide ion concentration and temperature increase. The third region extends from a critical potential associated with the pitting corrosion of copper upwards. The critical potential decreases linearly with the sodium bromide concentration and in a complex way with temperature. Large hemispherical pits are observed in this potential region growing on the copper surface. The kinetics of pitting corrosion for high NaBr concentration can be described in terms of an instantaneous nucleation 3-D growth under diffusion control as previously reported for other metals and alloys in electrolytes containing other aggressive anions.

Effect of sodium bromide on endocrine parameters in the rat as studied by immunocytochemistry and radioimmunoassay

Male rats were fed a normal or sodium bromide-enriched diet for 4 or 12 weeks. Sodium bromide concentrations were 0, 20, 75, 300, 1200 and 19,200 mg/kg diet. At the end of the experiments the pituitary gland, thyroid and testes were examined by histopathological and immunocytochemical techniques, while serum hormone levels were established by radioimmunoassay. Histopathological examination revealed an activation of the thyroid and a decreased spermatogenesis in the testes in the highest dose group. Using immunocytochemical techniques a decrease was noted in the amount of thyroxine in the thyroid. No effect was found in growth hormone-producing cells in the pituitary gland, while immunoreactivity for thyroid-stimulating hormone and for adrenocorticotropic hormone was increased. The concentration of thyroxine, testosterone and corticosterone in the serum appeared to be decreased. Due to feedback regulation, the pituitary gland was stimulated to produce and release thyroid-stimulating hormone, follicle-stimulating hormone, adrenocorticotropic hormone and insulin, whereas the release of growth hormone was suppressed. Most of these changes were restricted to rats on the highest treatment level. It is concluded that sodium bromide, at least in high doses, directly disturbs the function of the thyroid, testes and adrenals.

Further studies on the epoxidation of propylene in a bipolar trickle bed

Further studies on the epoxidation of propylene via electrogenerated hypobromite in a trickle bed have been carried out with the aim of increasing the space-time yield. Factors which have been studied in more detail include electrode material, applied voltage, sense of polarity, cell packing arrangements, electrolyte flow rate and sodium bromide concentration. By suitable choice of conditions a significant increase in space-time yield can be obtained, up to a limit set by the depletion of propylene, without a large increase in energy consumption.

Mechanism of action of 2-haloethylnitrosoureas on deoxyribonucleic acid: Nature of the intermediates from nitrosourea decomposition

Direct current (DC) and differential pulse polarographic analyses were used to measure the rates of decomposition of a series of 2-haloethylnitrosoureas in aqueous solution. Measured by these methods, the rates of the first and rate-determining step which show a marked pH and solvent dependence agree with the overall rate of decomposition measured by gas evolution. In the 1,3-bis(haloethyl)-1-nitrosourea series, changing the nature of the halogen X has a small effect on the rate of decomposition. In the 3-cyclohexyl-1-(2-haloethyl)-1-nitrosourea series, changing X for OH or OCH 3 results in the rate of hydrolysis being reduced considerably. A free—NH 2 group in the nitrosourea structure as in CNU, MNU, ENU, CPNU, 4-CBNU and 5-CPNU accelerates considerably the rate of decomposition relative to the BCNU and CCNU series. Arrhenius parameters for the decomposition in aqueous pH 7.1 solution in the temperature range 28–47° were obtained for BFNU, BCNU and BBNU: log A, −20.1± 1.4,−21.6± 0.7 and −22.3±1.6; E a , 24.4 ± 2.0, 26.5± 1.0 and 27.2 m 2.3 kcal/ mole. The corresponding values for BINU were estimated as log A,−23.3± 3.0; E a , 28.0± 3.0 kcal/ mole. Examination of the decomposition products of 1,3-bis(2-chloropropyl)-1-nitrosourea (BCNU-β-Me) and 1,3-bisl 1-(chloromethyl)ethyl]-1-nitrosourea (BCNU-α-Me) favors decomposition pathway B via the diazohydroxide and cyclic chloronium ion for BCNU-β-Me and via the diazohydroxide and/or 2-chloro-1-methylethyl carbonium ion for BCNU-α-Me. While there is no evidence for the contribution of pathway A via a 2-imino- N-nitrosooxazolidinone for these compounds, consideration of product type and yields implicates a third decomposition pathway, via a 1,2,3-oxadiazoline intermediate. Additional evidence for an oxadiazoline intermediate is obtained by the isolation of 2-bromoethanol when BCNU is decomposed in the presence of a high concentration of sodium bromide.

The effect of fluorination on surfactant aggregation number and dye solubilization efficiency

Micellar aggregation numbers of 12,12,12-trifluorododecyltrimethylammonium bromide (TDTAB) and dodecyltrimethylammonium bromide (DTAB) were measured in several sodium bromide solutions by light scattering. At all sodium bromide concentrations from 0.1 to 1.5 m, DTAB micelles were found to be the larger. DTAB micelles were also found to have about twice the solubilizing power for the dye orange-OT as TDTAB micelles. Mutual phobicity between terminal CF 2 groups and hydrocarbon regions of surfactant ions and the dye provides a basis for understanding these observations.

Quantitative phosphorescence study of interactions of cytosine and cytidine and its nucleotides in frozen aqueous solution: Evidence for anomalous heavy-atom effect

Phosphorescence vs. pH titration curves of cytosine, cytidine, cytidine-5′-mono-phosphate (CMP), -diphosphate (CDP) and -triphosphate (CTP) were obtained in methanol/water 10/90 v/v and in various aqueous sodium halide solutions frozen at 77°K. As shown by the shape of the titration curve, molecular aggregates or “puddles” of cytosine and cytidine were shown to occur only in relatively concentrated frozen solution (10 −3 M), these aggregates being dissociated in dilute frozen solutions (≤10 −4 M) or in ∼ 1 M sodium chloride. No molecular aggregation could be found even in concentrated solutions of CMP, CDP, and CTP. Lower concentrations of sodium bromide or iodide (10 −1 M) were demonstrated to give “reversed” sigmoidal phosphorescence titration curves in the case of cytidine, due to an anomalously large heavy-atom enhancement factor in acidic solution, ranging between 30 and 50.

Enthalpy of micellization II. n-dodecyltrimethylammonium bromide

The enthalpy of micellization of n-dodecyltrimethylammonium bromide has been measured using a Beckman 190B microcalorimeter at 23, 25, and 30 °C, in water and in sodium bromide solution as a function of surfactant concentration up to 20 times the critical micelle concentration. Dilution of these micellar solutions was found to be endothermic, the endothermicity decreasing with increasing salt concentration. Micellization was found to be exothermic, and the exothermicity increased with sodium bromide concentration and with temperature. The change in enthalpy of micellization between 23 and 30 °C is in accord with enthalpies deduced from the variation of the critical micelle concentration with temperature.

Radiotracer studies on soap films

The areas per surfactant ion at the liquid-air interfaces of first and second black soap films formed from solutions of n-cetyltrimethylammonium bromide (CTAB) and sodium n-dodecylsulphate (SDS) containing added salts have been measured using radioactive surfactants. For CTAB the area is 44±2 × 10–20 m2 ion–1 and is independent of sodium bromide concentration over the range 0.15–0.5 M. For SDS films areas between 36 and 42 × 10–20 m2 ion–1 have been found depending on the ionic composition of the solutions. No significant change in the areas per ion on traversing the first black-second black film transition have been observed.

Formaldehyde Resins. LXVII. On the Reaction Order of Sodium Hydroxide and on the Salt-effect of Sodium Bromide in the Base-catalyzed Reaction of Benzamide with Formaldehyde

Abstract A kinetic study of the reaction of benzamide with formaldehyde in the presence of sodium hydroxide has been made. The following results have been obtained: (1) A linear relationship is obtained between the concentration of sodium hydroxide and the critical bending concentration of formaldehyde where the reaction-order changes from one to zero. (2) The pH value is constant throughout the reaction. (3) The rate of the reaction decreases upon the addition of sodium bromide. However, the decrease reaches a miuimum at a definite concentration of sodium bromide. After this point, the salt has no effect on the rate. (4) The activation energy has been computed as 8.25 kcal./mol. The findings (1) and (3) have been explained by the solvated cage theory.