Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C1832588 (PSS)
 2,979 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The complained gastrointestinal symptoms in PSS are probably caused by several complex disturbances like intestinal transit disturbances (ITD), bacterial overgrowth of the small intestine caused malabsorption of bile acids and altered kinetics of intestinal hormones. 25 patients with PSS and eleven healthy controls were tested for the existence of ITD by use of the metal-detector test (MDT). Twelve patients were also tested for a malabsorption of primary bile acids by radioimmunological measurement of clolylglycine serum levels before and after a meal. In addition serum concentrations of gastrin (nine patients) and plasma concentrations of cholecystokinin (CCK) (eight patients) and motilin (eleven patients) were measured by radioimmunoassay pre- and postprandial. Interdigestive gastric emptying was accelerated in patients with PSS (53 +/- 3 min. vs. 73 +/- 7 min.; p<0.01). Small intestinal transit times were similar in both groups (115 +/- 17 min. vs. 121 +/- 13 min.). Colonic transit in patients with PSS was significant prolonged (63 +/- 6 h vs. 39 +/- 5 h; p<0.05). There were no significant differences between the two groups concerning the pre- and postprandial levels of cholylglycin. Basic and postprandial levels of gastrin, CCK and motilin were higher in the PSS group. In contrast to scintigraphic studies using semisolid meals gastric emptying of the copper pellet in PSS was accelerated. A general malabsorption of primary bile acids was not found. Prolonged colonic transit times correlate well with frequently complained obstipation. Gastric hypacidity could be the reason of elevated gastrin levels. The high motilin-levels in PSS could be due to a lack of the feed-back inhibition as a result of diminished phase-III activity of the interdigestive migrating motor complex. The elevation of CCK-levels could reflect compensation of neurogenic or myogenic disturbances of gallbladder contraction.
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PMID:[Gastrointestinal involvement in progressive systemic scleroderma]. 860 Jun 62

Low molecular weight complexing molecules may be indirectly analyzed by ultrafiltration with the aid of a water-soluble polymer. The theory concerned is developed and the analysis of iminodiacetic acid (IDAA) is performed by ultrafiltration of aqueous solutions containing poly(sodium-4-styrenesulfonate) (PSS), Cu(NO3)2, and IDAA in variable concentrations. The technique allows measuring IDAA in a range of concentrations between 10(-4) M and 10(-5) M when a 1.6 x 10(-4) M Cu2+ solution is ultrafiltered in the presence of PSS and IDAA.
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PMID:Use of ultrafiltration on the analysis of low molecular weight complexing molecules. Analysis of iminodiacetic acid at constant ionic strength. 1181 75

A diffusive gradients in thin films (DGT) technique for measuring Cd and Cu is described using, for the first time, a liquid phase binding layer and a dialysis membrane diffusive layer. The binding phase was a 0.020 M solution of poly(4-styrenesulfonate) (PSS) polyelectrolyte using a specially designed DGT deployment device. The binding properties of Cd2+, Cu2+, and a range of alkali and alkaline earth metal ions to the PSS solution were characterized. The PSS behaved like a cation exchanger with preferential binding to Cd2+ (6.0 micromol mL(-1), log K = 9.0) and Cu2+ (2.5 micromol mL(-1), log K = 8.1) under competitive binding conditions. PSS had a substantial binding capacity at pH > 3 and at competitive Na+ concentrations up to 1.0 M. The DGT devices were successfully validated for Cd2+ (accumulated mass vs time r2 = 0.969, recovery compared with predicted values = 98%) and Cu2+ (r2 = 0.980, recovery = 98%) in synthetic lake water (Windermere). Validation was also undertaken for Cu in a spiked local lake water (Parkwood Pond) (r2 = 0.981, recovery = 46%). The low recovery here was due to complexation of Cu by natural organic matter (14 mg C L(-1)). Field deployments of the DGT devices were successful at measuring Cu concentrations of 0.031-0.63 microg L(-1) in local fresh and salt waterways. These DGT-labile measurements were 0.05-39% of the 0.45-microm-filtered Cu values.
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PMID:Application of a poly(4-styrenesulfonate) liquid binding layer for measurement of Cu2+ and Cd2+ with the diffusive gradients in thin-films technique. 1294 23

Electrochromic multilayer films consisting of polyoxometalate (POM) cluster alpha-K(10)[P(2)W(17)O(61)].17H(2)O (P(2)W(17)), copper(II) complex [Cu(II)(phen)(2)](NO(3))(2) (phen = 1,10-phenithroline), and iron complex [Fe(II)(phen)(3)](ClO(4))(2) were fabricated on silicon, quartz and ITO substrates by layer-by-layer self-assembly method. The multilayer films, PSS/Cu(II)(phen)(2)/[(P(2)W(17)/Cu(II)(phen)(2))](n) and PSS/Fe(II)(phen)(3)/[(P(2)W(17)/Fe(II) (phen)(3))](n) were characterized by UV-vis spectra, X-ray photoelectron spectra, cyclic voltammetry (CV), chronoamperometric (CA) and in-situ spectral electrochemical measurements. The interesting feature of the electrochromic film is its adjustable color by reduction of both transition metal complex and polyoxometalate at different potentials. The multilayer films also exhibit high optical contrast, suitable response time and low operation potential due to the presence of mono-lacunary-substituted polyoxometalate and transition metal complex. This is the first example that the color of electrochromic film can be adjustable, which gives valuable information for exploring new electrochromic materials with tunable colors.
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PMID:Electrochromic multilayer films of tunable color by combination of copper or iron complex and monolacunary dawson-type polyoxometalate. 1685 64

The additivity rule of counterion activity or osmotic pressure in rodlike polyelectrolyte solutions has been discussed on the basis of the Fokker-Planck and Poisson equations in relation to the fluctuation of counterion distribution. This new theory has concluded that the additivity rule of counterion activity is less applicable than that of osmotic pressure due to the electric expansion force acting on the free-volume surface resulting from the fluctuation of counterion distribution. The theory has introduced an approximate relation between the counterion activities in the mixture solution of divalent and monovalent counterions, such that Deltaa+ = DeltaC++ - Deltaa++, in which Deltaa+ represents the increase of activity of monovalent counter-ions resulting from the addition of divalent counterionsDeltaC++, (in molar) to the solution, and Deltaa++ means the increase of the divalent counterion activity (in molar) in this process. This relation has been experimentally examined for Na-PSS solutions in the process of Cu2+ ion addition by the use of Na+ and Cu2+ sensitive electrodes, and it has been turned out that the relation is established in the low charge state of polyion.
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PMID:The release of monovalent counterions by addition of divalent counterions in coulombic interaction system. 1699 53

We have investigated the influence of the poly(3,4-ethylenedioxythiophene)-blend-poly(styrene-sulfonate) (PEDOT:PSS) layer on the short-circuit current density (J(sc)) of single planar heterojunction organic solar cells based on a copper phthalocyanine (CuPc)-buckminsterfullerene (C(60)) active layer. Complete optical and electrical modeling of the cell has been performed taking into account optical interferences and exciton diffusion. Comparison of experimental and simulated external quantum efficiency has allowed us to estimate the exciton diffusion length to be 37 nm for the CuPc and 19 nm for the C(60). The dependence of short-circuit current densities versus the thickness of the PEDOT:PSS layer is analyzed and compared with experimental data. It is found that the variation in short-circuit current densities could be explained by optical interferences.
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PMID:Optical modeling of organic solar cells based on CuPc and C60. 1844 54

The speciation measurements of trace metals by the diffusive gradients in thin-films technique (DGT) using a poly(4-styrenesulfonate) (PSS) aqueous solution as a binding phase and a cellulose dialysis membrane (CDM) as a diffusive layer, CDM-PSS DGT, were investigated and showed good agreement with computer modelling calculations. The diffusion coefficients of ethylenediaminetetraacetic acid (EDTA) complexes with Cd(2+) and Cu(2+) were measured and compared with those of the inorganic metal ions. CDM-PSS DGT device was tested for speciation measurement in sample solutions containing EDTA, tannic acid (TA), glucose (GL), dodecylbenzenesulfonic acid (DBS) and humic acid (HA) as complexing ligands forming organic complexes with varying stability constants. Lower percentages of DGT labile copper concentrations over total filterable copper concentrations obtained from the deployments in freshwater sites indicated that copper complexes with organic matter were basically not measured by the devices.
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PMID:Trace metal speciation measurements in waters by the liquid binding phase DGT device. 1897 Feb 8

The present work describes the preparation, optimization and characterization of mixed polyelectrolyte coatings of poly-l-lysine (PLL) and poly(sodium 4-styrenesulfonate) (PSS) for the modification of thin mercury film electrodes (MFEs). The novel-modified electrodes were applied in the direct analysis of trace metals in estuarine waters by square-wave anodic stripping voltammetry (SWASV). The effects of the coating morphology and thickness and also of the monomeric molar ratio PLL/PSS on the cation-exchange ability of the PLL-PSS polyelectrolyte coatings onto glassy carbon (GC) were evaluated using target cationic species such as dopamine (DA) or lead cation. Further, the semi-permeability of the PLL-PSS-coated electrodes based both on electrostatic interactions and on molecular size leads to an improved anti-fouling ability against several tensioactive species. The analytical usefulness of the PLL-PSS-mixed polyelectrolyte coatings on thin mercury film electrodes is demonstrated via SWASV measurements of trace metals (lead, copper and cadmium at the low nanomolar level; accumulation time of 180s) in estuarine waters containing moderate levels of dissolved organic matter, resulting in a fast and direct methodology requiring no sample pretreatment.
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PMID:Mixed polyelectrolyte coatings on glassy carbon electrodes: Ion-exchange, permselectivity properties and analytical application of poly-l-lysine-poly(sodium 4-styrenesulfonate)-coated mercury film electrodes for the detection of trace metals. 1897 May 11

The attenuation of endothelium-dependent nitric oxide (NO) mediated vasodilation is a consistent finding in both conduit and resistance vessels during dietary copper (Cu) deficiency. Although the effect is well established, evidence for the mechanism remains circumstantial. This study was designed to determine the relative amount of NO produced in and released from the vascular endothelium. Using the fluorescent NO indicator, 4-amino-5-methylamino-2',7'-difluorofluorescein (DAF-FM), we now demonstrate the effect of a Cu-deficient diet on the production of NO from the endothelium of resistance arterioles. In one group of experiments, control and Cu-chelated lung microvascular endothelial cells (ECs) were used to assay NO production and fluorescence was observed by confocal microscopy. Weanling Sprague-Dawley rats were fed purified diets that were either Cu adequate (6.3 micrograms Cu per gram of food) or Cu deficient (0.3 micrograms Cu per gram of food) for 4 weeks. In the second series of experiments, first-order arterioles were microsurgically isolated from the rat cremaster muscle, cannulated, and pressurized with (3[N-morpholino]propanesulfonic acid) physiologic salt solution (MOPS-PSS). DAF-FM (5 micromol.L-1) was added in the lumen of the vessel to measure NO release. Baseline DAF-FM fluorescence was significantly lower in Cu-chelated ECs than in controls. In response to 10-6 mol.L-1 acetylcholine, fluorescent intensity was significantly less in chelated ECs and in the lumen of Cu-deficient arterioles. The results suggest that production and release of NO by the vascular endothelium is inhibited by a restriction of Cu. This inhibition may account for the attenuated vasodilation previously reported in Cu-deficient rats.
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PMID:Endothelial cell-derived nitric oxide mobilization is attenuated in copper-deficient rats. 1908 64

5-Mercapto-2,2'-bithiophene functionalized metal nanoparticles BTSMs [M: copper (Cu), silver (Ag), and gold (Au)] of different diameters (2-8 nm) were synthesized. Conductive polymeric metal nanoparticles were formed from BTSM by UV irradiation. The photopolymerization mechanism was investigated using transient absorption measurements. Intramolecular electron transfer from the ligand to the metal nano-core was confirmed. Nanoparticle size, as well as plasmon electronic interactions, are important factors. The smaller the nanoparticle and the stronger the electronic interactions, the faster the electron transfer is. The three-dimensional structure of the polymerized BTSM was identified using transmission electron microscopy (TEM) and scanning electron microscopy (SEM). The conductivity of polymerized BTSM measured in poly(3,4-ethylenedioxythiophene)/poly(styrenesulfonate) (PEDOT/PSS) film is higher than that of the nonpolymerized BTSM.
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PMID:Photopolymerization of conductive polymeric metal nanoparticles. 1986 15


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