Synthesis and characterization of some new ruthenium (II) complexes as photosensitizers in dye-sensitized solar cells

New ruthenium (II) complexes, [Ru(DHZ)2(bpy)], [Ru(SCN)2(bpy)(DMSO)2], [Ru(SCN)2(dmbpy)(DMSO)2] and [RuCl2(salen)]-2, where bpy = 2,2'- bipyridine, DHZ = 1,5-diphenylthiocarbazone, dmbpy = 4,4'-dimethyl-2,2' bipyridine and salen = 2,2'- ethylenebis(nitrilomethylidene)diphenol were synthesized and characterized by elemental analysis, FTIR, UV-Vis spectroscopy and thermal analysis. From data of these investigations the structural formula and the mode of bonding were obtained. These complexes were successfully applied to sensitization of nano-crystalline TiO2 based solar cells (DSSCs). The photovoltaic efficiencies of the studied DSSCs increase in the following order [Ru(DHZ)2(bpy)]< [Ru(SCN)2(bpy)(DMSO)2]< [Ru(SCN)2(dmbpy)(DMSO)2]< [RuCl2(salen)]-2. This increase is in agreement with the light harvesting of these complexes as indicated from their absorption spectra. Ferrioxalate complex enhanced the performance of some investigated cells. Therefore, a mechanism of this improvement has been postulated. Polyaniline as well as iodine doped polyaniline modified FTO electrode has been tested as promising counter electrodes. The efficiencies of the cells using iodine doped polyaniline is higher than that of polyaniline, which is assignable to the high conductivity of iodine

Diabetes mellitus in Egypt: glycaemic control and microvascular and neuropathic complications

We performed a cross-sectional, population-based survey of persons 20 years of age and older living in Cairo and surrounding rural villages. The purpose was to describe glycaemic control and the prevalence of microvascular and neuropathic complications among Egyptians with diagnosed diabetes, previously undiagnosed diabetes, impaired glucose tolerance, and normal glucose tolerance. A total of 6052 households were surveyed. The response rate was 76 % for the household survey and 72 % for the medical examination. Among people with previously diagnosed diabetes, mean haemoglobin A 1c was 9.0 %. Forty-two per cent had retinopathy, 21 % albuminuria, and 22 % neuropathy. Legal blindness was prevalent (5 %) but clinical nephropathy (7 %) and foot ulcers (1 %) were uncommon in persons with diagnosed diabetes. Among people with diagnosed diabetes, microvascular and neuropathic complications were associated with hyperglycaemia. Retinopathy was also associated with duration of diabetes; albuminuria with hypertension and hypercholesterolaemia; and neuropathy with age, female sex, and hypercholesterolaemia. Albuminuria was as common in people with previously undiagnosed diabetes (22 %) as those with diagnosed disease (21 %). Mean haemoglobin A 1c was lower (7.8 %) and retinopathy (16 %) and neuropathy (14 %) were less prevalent in people with previously undiagnosed disease. Ocular conditions, blindness, and neuropathy were prevalent in the non-diabetic population. The microvascular and neuropathic complications of diabetes are a major clinical and public health problem in Egypt. Copyright © 1998 John Wiley & Sons, Ltd.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/34940/1/696_ftp.pd