clavulanic acid is produced industrially by fermentation of streptomyces clavuligerus and researches have increased its production by strain improvement, recombinant dna technology, and media composition and growth condition optimization. the main objective of this study was to increase the level of clavulanic acid production from streptomyces clavuligerus (dsm 738), using uv irradiation. after...

in this paper, we have described the size-controlled synthesis of gold nanoparticles based on the reduction of au3+ (haucl4 ) using molybdophosphoric acid (h3[pmo12o40 ], hpmo) under uv-irradiation. in the process, hpmo plays the role of photocatalyst, reducing agent and stabilizer and propan-2-ol acts as a sacrificial agent. this method allows the synthesis of uniform hexagonal nanoparticles w...

the aim of this study was to degrade furfural by a new nanotube system. to degrade some organic pollutants as well as to reduce the amount of furfural which is a well-known pollutant in oil industry, the photocatalytic process along with ultraviolet (uv) irradiation may be employed. in this study, the uv/tio2/pd system in which the nanoparticles of palladium doped into the titanium dioxide was ...

collagen is the major protein component of cartilage, bone, skin and connective tissue and constitutes the major part of the extracellular matrix. collagen type i has complex structural hierarchy, which consists of treepolypeptide α-chains wound together in a rod-like helical structure. collagen is an important biomaterial, finding many applications in the field of tissue engineering. it has be...

background: haemonchus contortus causes severe economic losses in small ru-minants, so this study was conducted to study the uv effect on h. contortus larvae and its protective effect. methods: sixteen male goats were divided into 5 groups, control infected, con-trol uninfected and uv 30minutes exposure; uv 60minutes exposure and uv booster 60minutes exposure. the uv groups were exposed to uv i...

introduction: textile industries produce large volume of colored dye effluents which are toxic and removal of dyes from wastewater is a significant environmental issue. advanced oxidation process (aops) is alternative method for the complete degradation many organic pollutants. zno and tio2 are important photocatalysts with high catalytic activity that have attracted much research attention. ma...

OBJECTIVES The surface of pure titanium (Ti) shows decreased histocompatibility over time; this phenomenon is known as biological ageing. UV irradiation enables the reversal of biological ageing through photofunctionalisation, a physicochemical alteration of the titanium surface. Ti implants are sterilised by UV irradiation in dental surgery. However, orthopaedic biomaterials are usually compos...

IMPORTANCE Solar UV irradiation causes photoaging, characterized by fragmentation and reduced production of type I collagen fibrils that provide strength to skin. Exposure to UV-B irradiation (280-320 nm) causes these changes by inducing matrix metalloproteinase 1 and suppressing type I collagen synthesis. The role of UV-A irradiation (320-400 nm) in promoting similar molecular alterations is l...

The purpose of the present study was to evaluate how ultraviolet light (UV) irradiation using an ordinary UV sterilizer would affect the bonding of experimental composite resins to an autopolymerizing acrylic resin. To this end, three composite resins and one unfilled resin--of which the compositions were similar to commercial composite resin artificial teeth--were prepared as repair composites...

Transforming growth factor-β (TGF-β) is a major regulator of collagen gene expression in human skin fibroblasts. Cellular responses to TGF-β are mediated primarily through its cell surface type I (TβRI) and type II (TβRII) receptors. Ultraviolet (UV) irradiation impairs TGF-β signalling largely due to reduced TβRII gene expression, thereby decreasing type I procollagen synthesis, in human skin ...