1,720,967 research outputs found
Copper, iron, zinc and other element concentrations in cerebrospinal fluid of Parkinson's disease patients - considerations on literature data
No full textTrace elements in cerebrospinal fluid of patientsaffected by neurodegenerative diseases:an overview of analytical data
No full textThe available analytical data regarding trace elements in cerebrospinal fluid of patients affected by neurodegenerative diseases are scarce; moreover, many factors can influence the results. Therefore the comparison among the literature values is difficult and hampers the individuation of possible increasing or decreasing trends in trace elements concentrations
Copper, iron, zinc and other element concentrations in cerebrospinal fluid of Parkinson's diseasepatients - considerations on literature data
No full textAn overview on the literature concentration data of Copper, Iron, Zinc and other elements in cerebrospinal fluid of Parkinson’s disease patients and paired controls was undertaken. Some indications to make investigations as meaningful as possible are suggested; every biological and clinical datum regarding each subject enrolled should be reported. In this way the results of the various trials could constitute a unique data base valuable for retrospective studies, like meta-analysis
Minor and Trace Elements in Cerebrospinal Fluid of Parkinson's Patients – Suggestions After a Critical Review of the Analytical Data
No full textA review on minor and trace elements levels in the cerebrospinal fluid of Parkinson's disease patients
Solution chemistry in noncoordinating solvents (methylene chloride, chloroform) of nickel(II) and nickel(III) complexes of the lipophilic macrocycle 1-hexadecyl-1,4,8,11-tetraazacyclotetradecane. The emphasized role of the anion coordination
No full textNiLX2 (X = ClO4, BF4, I, Cl, Br, SCN, NO3; L = the lipophilic tetramine macrocycle 1-hexadecyl-1,4,8,11-tetraazacyclotetradecane) were prepd. and dissolve in noncoordinating solvents such as CH2Cl2 and CHCl3 as intact NiLX2, whose spin state and color depend on the coordinating tendencies of the apically bound X- anions: Cl-, and SCN-, blue, high-spin complexes; ClO4-, BF4-, and L-, yellow, low-spin complexes. NiLBr2 exists in soln. as an equil. mixt. of the blue and yellow species and the blue-to-yellow conversion is exothermic; moreover, the equil. is displaced to the right on further addn. of the background electrolyte, R4NBr (R = alkyl) or Et4PBr. A general model is proposed to explain the thermodn. aspects of the high-spin/low-spin interconversion in both coordinating (e.g. water) and noncoordinating media. Finally, NiLX2 in CH2Cl2 soln. (0.1 mol dm-3 Bu4NX) undergo reversible 1-electron oxidn. processes to give [NiLX2]X. The NiIII-NiII redox potential decreases dramatically with increasing coordinating tendency of the X- ions. A spectrochem. series was obtained for electrochem. inert inorg. anions. On this basis, it appears that ClO4- is a more strongly coordinating ligand than BF4-
SELECTIVE TRANSPORT OF ANIONS ACROSS LIQUID MEMBRANES USING THE FERROCENIUM FERROCENE REDOX COUPLE
No full textAbstract: Anions can be selectively transported across a bulk liquid membrane by the 1-hexadecylferrocenium ion through a process driven by a chemically generated redox potential gradient. The liquid membrane, a solution in dichloromethane, acts as a filter for anions, being permeable to perchlorate ions and impermeable to choride ions. The alkyl substitution of the ferrocenium ion serves to confine the ion to the membrane phase
Design of redox systems for the selective transport of electrons across liquid membranes: nickel(II,III) tetraaza macrocyclic complexes
No full textNiLX2 (L = N-cetylcyclam; X = Cl, ClO4) were prepd. to be used as carriers for the transport of electrons across a CH2Cl2 bulk liq. membrane, through the NiII/NiIII redox change. Two-phase (H2O/CH2Cl2) expts. showed that aq. peroxydisulfate ion is able to oxidize NiLCl2, but not NiL(ClO4)2, due to the very large difference of the NiIII,II redox potentials. On the other hand, [NiLCl2]Cl in the org. layer was reduced by aq. cationic reducing agents, according to a rate sequence (TiIII > CrII > FeII > [CoII cage] complex) that does not correlate with their redox potential values. The anionic reducing agent I- does not reduce [NiLCl2]Cl under 2-phase conditions, whereas it does in homogeneous conditions. Three-phase expts. were performed in which electrons are transported from an aq. reducing phase, contg. the metal-centered agents mentioned above, to an aq. oxidizing phase, contg. peroxydisulfate and chloride, across a CH2Cl2 membrane contg. the [NiLCl2]/[NiLCl2]Cl redox couple. A counterflow of Cl- is coupled to the flow of electrons. Under the conditions employed, the electron transport is complete in a time ranging from minutes (TiIII) to several hours ([CoII cage] complex)
Carrier mediated transport of anions across liquid membranes driven by a gradient of redox potential
No full textLiquid membrane selective transport of ClO4- ions in presence of Cl- ions, driven by a gradient of redox potential and mediated by a ferrocene - based carrier
No full textFerrocene based carriers for the selective transport of electrons and anions across liquid membranes
No full text- …
