Search results for "solution"
showing 10 items of 5638 documents
Tolerability and efficacy of high-dose furosemide and small-volume hypertonic saline solution in refractory congestive heart failure
2000
Thirty patients aged 65-85 years, with refractory New York Heart Association (NYHA) class IV congestive heart failure (CHF) were treated with an intravenous infusion of furosemide (250-2000 mg/d) and small-volume hypertonic saline solution (150 mL of 1.4-4.6% NaCl) twice a day for 6 to 12 days. A daily fluid oral intake of 1000 mL and previous cardiac therapy were maintained. Clinical signs and symptoms of CHF, such as dyspnea, edema and weakness, improved, as did severity of illness as defined by NYHA class. The infusion was well tolerated. After a 12-month follow-up, 24 patients (80%) were alive and in the NYHA class assigned on discharge from the hospital. This therapeutic combination is…
Trade is not necessary for agglomeration to arise
2003
We develop a spatial general equilibrium model in which the absence of trade is an endogenous outcome and we show that trade is not a necessarycondition for agglomeration to arise. More precisely, extending the modeldeveloped by Ottaviano et al. [13], we show that equilibria without tradediffer significantly from those obtained in the presence of trade. Somewhatsurprisingly, equilibrium structures without trade are richer than those withtrade, since partial agglomeration becomes a feasible outcome. Equilibrianow depend on the ratio of mobile to immobile factors and an increase in thatratio triggers a process of spatial agglomeration.
Formation of supramolecular aggregates by hydrogen bonding based on bispyrimidine and bisbarbituric acid
1997
Hydrogen bonds between bispyrimidine and bisbarbituric acid in equal molar ratio can lead to the formation of supramolecular aggregates. This is established by TEM, IR and DSC measurements. Additionally, WAXS pattern showed that the aggregate is of laminar structure. Both the hydrolysis of this system and termination of the aggregate's growth were studied.
Thermodynamic Behavior of Non-Ionic Tri-block Copolymers in Water at Three Temperatures
2006
Apparent molar volumes (V Φ) of aqueous solutions of some copolymers, based on ethylene oxide (EO) and propylene oxide (PO) units, were determined as functions of concentration at three temperatures. Viscosity measurements were also carried out on some of these systems. The effects studied include how the molecular architecture and the molecular weight affect the aggregation of the copolymer, keeping constant the EO/PO ratio. Modeling of the volumetric data yielded the partial molar volume of the copolymer in the standard (V°) and the aggregated (V M) states, as well as the equilibrium constant for micellization and the aggregation number. Analysis of the viscosity data supported the insigh…
Thermodynamic properties of alcohols in a micellar phase. Binding constants and partial molar volumes of pentanol in sodium dodecylsulfate micelles a…
1984
Densities of the ternary system water-sodium dodecylsulfate (NaDS)-pentanol and of the binary systems butanol-octane and pentanol-octane were measured at 15, 25, and 35 °C. The apparent molar volume of pentanol in the ternary system was analyzed using a mass-action model for the alcohol distribution in micellar solutions. The partial molar volume of alcohol bound to the micelles and the ratio between the binding constant and the aggregation number of the surfactant are calculated. The partial molar volume binding constant, is discussed in terms of solubilization sites of the alcohol in the micelles whereas the binding constant is compared with that derived from the Nernstian partition const…
Electrocatalytic properties of ferrooctacarboxyphthalocyanine(II). Electrocatalytic oxygen reduction on the mercury electrode in aqueous solutions
1996
Electrocatalytic reduction of oxygen in aqueous solutions in the presence of ferrooctacarboxyphthalocyanine was investigated. The decay of catalytic properties is attributed to the phthalocyanine aggregation. The mechanism for the four-electron electrocatalytic O2-reduction in neutral and basic media involving FePc(COOH)8 is proposed. It has been found that monomers of phthalocyanine, which are able to form μ-peroxo structures, are the catalytically active forms. The adsorption of various phthalocyanine forms on the mercury electrode plays a very important role in the overall catalytic reaction.
Spectral properties and aggregation of ferrooctacarboxyphthalocyanine(II) in aqueous solutions
1996
Spectral properties of ferrooctacarboxyphthalocyanine(II) in aqueous solutions are discussed. A special attention is paid to aggregation in the presence of electrolytes. The influence of many factors (concentration, pH etc.) on forms of its occurence is presented.
Beyond Biodegradability of Poly(lactic acid): Physical and Chemical Stability in Humid Environments
2017
International audience; Poly(lactic acid) (PLA) is the most traded biodegradable and biobased material. It is largely used as ecofriendly substitute of conventional plastics. Nevertheless, one of the main limiting factors is its water sensitivity. PLA reacts with water and is hydrolyzed during time, which determines its performance. Limited information related to the hydrolysis mechanism driven by water in vapor state is available in scientific literature. Literature is mainly focused on the effects of water in liquid state. This lack of information is of significant importance, since PLA interacts with water in both phases. This work was aimed to give a full depiction of the chemical and p…
Cardiac Micro–Computed Tomography Imaging of the Aging Coronary Vasculature
2012
Background— Alterations at the level of the coronary circulation with aging may play an important role in the evolution of age-associated changes in left ventricular (LV) fibrosis and function. However these age-associated changes in the coronary vasculature remain poorly defined primarily due to the lack of high resolution imaging technologies. The current study was designed to utilize cardiac micro–computed tomography (micro-CT) technology as a novel imaging strategy, to define the 3-dimensional coronary circulation in the young and aged heart and its relationship to LV fibrosis and function. Methods and Results— Young (2 months old; n=10) and aged (20 months old; n=10) Fischer rats unde…
Effect of divalent cations on KCl- and noradrenaline-induced contractile responses in rat aorta after nifedipine treatment.
1999
Abstract Nifedipine (1 μM) relaxed the sustained contractile responses induced by 1 μM noradrenaline or 60 mM KCl in rat aortic strips. After washing, a second addition of the spasmogens gave smaller tonic contractions than the first one. Even more, a third addition of KCl also gave a smaller contraction than the first one, but a complete recovery of the contractile response to noradrenaline was obtained by a third addition of this agonist. Application of cumulative amounts of Ca2+ or Ba2+ (2.4–24 mM) on the residual contraction in response to these agents after nifedipine treatment, but in the absence of the blocker, restored the magnitude of the contractile responses. Addition of cumulati…