Carbon quantum dots and chitosan-based heterogeneous silver catalyst for reduction of nitroaromatic compounds.

Chitosan plays a crucial role in catalysis, environmental remediation, and sustainable chemistry as a renewable and cationic polysaccharide. Chitosan-based metal catalysts are used in a broad range of chemical transformations. In the study, carbon quantum dots (CQDs) were derived from Momordica charantia fruits by microwave irradiation following a green chemistry approach. Three catalysts were designed: Ag(0)-chitosan, Ag(0)-chitosan-M. charantia fruit powder, and Ag(0)-chitosan-CQDs. The catalyst supports were prepared by stabilizing CQDs or M. charantia powder within the polymeric matrix of chitosan beads. Metallic silver particles were anchored onto glutaraldehyde cross-linked chitosan beads from the aqueous solution of silver nitrate. The heterogeneous silver catalysts were used to reduce toxic nitroaromatics (4-nitrophenol, 2-nitroaniline, 1,2-diamino-4-nitrobenzene, 2,4-dinitrophenol). The regeneration of catalysts was also covered. The reused catalysts retained their catalytic activities after ten cycles. The study suggested that presence of CQDs or M. charantia powder could improve the efficiency of the chitosan-based metallic silver catalysts.

BrightOcular® Cosmetic Iris Implant: A Spectrum from Tolerability to Severe Morbidity.

PURPOSE: The BrightOcular® implants are the newest model of cosmetic iris devices that are currently advertised as safe. The previous generation known as NewColorIris® have had severe ocular side effects and were subsequently withdrawn from the market. There is little literature on the safety profile of BrightOcular® implants. CASE REPORT: Herein we describe two cases with varying degrees of ocular tolerability. The first case had a normal ocular exam 1 year after implantation, whereas the second case had unilateral severe corneal edema requiring explantation of the iris device and Descemet membrane endothelial keratoplasty 9 months after bilateral implantation. CONCLUSIONS: These two cases attest to the unpredictability of the results of these cosmetic surgeries. Patients should be counseled about the vision-threatening complications of iris implants.

CADASIL in Arabs: clinical and genetic findings.

BACKGROUND: Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is increasingly recognized as an inherited arterial disease leading to a step-wise decline and eventually to dementia. CADASIL is caused by mutations in NOTCH3 epidermal growth factor-like repeat that maps to chromosome 19. CADASIL cases have been identified in most countries of Western and Central Europe, the Americas, Japan, Australia, the Caribbean, South America, Tanzania, Turkey, South Africa and Southeast Asia, but not in Arabs. METHODS: We studied three families from Saudi Arabia (Family A), Kuwait (Family B) and Yemen (Family C) with 19 individuals affected by CADASIL. RESULTS: The mean age of onset was 31 +/- 6 and the clinical presentation included stroke in 68%, subcortical dementia in 17% and asymptomatic leukoariosis detected by MRI in 15%. Migraine and depression were frequently associated, 38% and 68% respectively. The mean age of death was 56 +/- 11. All NOTCH3 exons were screened for mutations, which revealed the presence of previously reported mutations c.406C>T (p.Arg110>Cys) in two families (family A&B) and c.475C>T (p.Arg133>Cys) mutation in family C. CONCLUSION: CADASIL occurs in Arabs, with clinical phenotype and genotype similar to that in other ethnic groups.

Tratamento das lesöes crônicas do ligamento cruzado anterior com prótese artificial de partes moles / Treatment of chronic anterior cruciate ligament lesions with artificial soft tissue prosthesis

Os autores apresentam 22 casos de instabilidade crônica do joelho submetidos à reconstruçäo do ligamento cruzado anterior, com prótese artificial de partes moles. Os pacientes, 19 do sexo masculino e 3 do feminino, foram operados entre novembro de 1988 e novembro de 1994. Todos foram avaliados clinicamente, dando-se ênfase à avaliaçäo subjetiva. A grande maioria dos pacientes estava satisfeita com o tratamento.