جستجوی مقالات مرتبط با کلیدواژه "spectroflourimetry" در نشریات گروه "پزشکی"

One of the problems in chemical dosimeters such as Trimesic acid is the liquid environment which makes it difficult to use. Chemical dosimeter merged into a bed of gel can help to partly overcome this problem.According to the importance of stability of dosimeter response after irradiation, in this study, the parameters of gelatin- Trimesic acid dosimeter in the range of doses of a one fraction of radiotherapy was assessed in days one, two, three and four after irradiation.
After the gel construction at a concentration of 1 mM and a pH of 2.2, it was poured into Perspex vials which opening was tight with parafilm and wrapped in an aluminum foil to eliminate light and was divided into 5 groups to be irradiated with 6 MV photons of linac 24h after the gel synthesis. To do so, vials were place at the isocenter of the linac in a SSD of 100cm and field size of 10×10 cm2. The delivered doses were from 0-200 cGy and vials were kept at the temperature of 4˚C after the irradiation. The procedure of reading the vials were performed using a spectroflourimeter (Jasco 6200) from one to four days after irradiation in excitation wavelengths of 370, 380, 390, 410, 420 and 450 nm.
After obtaining the emission spectrum from the spectroflourimeter, the emission spectrum was analyzed and it was found that there is a peak in the wavelengths of 377, 387, 396, 416, 427 and 457 nm seen in one day after irradiation and the most stable response belongs to the first day after irradiation.
The results of this study showed that the combined gelatin- Trimesic acid dosimeter in the first day after irradiation has the highest and most stable response and according to its characteristics, has the potential to be assessed as a clinical dosimeter

Calprotectin, S100A8 and S100A9 are involved in important processes including cell signaling and regulation of inflammatory responses. In this study, recombinant expression, purification and structural characterization of S100A8 and S100A9 were accomplished. In this experimental study, pET15b was used as vector of human S100A8 and S100A9 coding sequences, hosted by E.coli BL21 (DE3). Gene expression and purification attempts were evaluated using SDS-PAGE. Protein purification was accomplished using Ni-NTA resin based on its affinity for His-tag present on recombinant proteins. Tertiary structure of proteins were evaluated using spectrofluorimetry. The subunits were over expressed 3-4 hours following induction at 37 °C. S100A9 was expressed mainly as inclusion body while S100A8 was found to be expressed mainly as a soluble protein. Purification of S100A8 and S100A9 was achieved at 100 mM imidazole. Spectroscopic studies showed that the amino acid tryptophan is in the internal structures and is less exposed to the aqueous environment. In this study, a recombinant S100A8 and S100A9 subunits were expressed and purified and also their structures were confirmed.