Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto

About: Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto is a based out in . It is known for research contribution in the topics: Population & Genus. The organization has 2143 authors who have published 3674 publications receiving 71071 citations. The organization is also known as: FFCLRP & FFCLRP-USP.

Nitric oxide release from the S-nitrosothiol zinc phthalocyanine complex by flash photolysis

Abstract: The photogeneration of nitric oxide (NO) using laser flash photolysis was investigated for S-nitroso-glutathione (GSNO) and S-nitroso-N-acetylcysteine (NacySNO) at pH 6.4 (PBS/HCl) and 7.4 (PBS). Irradiation of S-nitrosothiol with light (lambda = 355 nm followed by absorption spectroscopy) resulted in the homolytic decomposition of NacySNO and GSNO to generate radicals (GS and NacyS ) and NO. The release of NO from donor compounds measured with an ISO-Nometer apparatus was larger at pH 7.4 than pH 6.4. NacySNO was also incorporated into dipalmitoyl-phosphatidylcholine liposomes in the presence and absence of zinc phthalocyanine (ZnPC), a well-known photosensitizer useful for photodynamic therapy. Liposomes are usually used as carriers for hydrophobic compounds such as ZnPC. Inclusion of ZnPC resulted in a decrease in NO liberation in liposomal medium. However, there was a synergistic action of both photosensitizers and S-nitrosothiols resulting in the formation of other reactive species such as peroxynitrite, which is a potent oxidizing agent. These data show that NO release depends on pH and the medium, as well as on the laser energy applied to the system. Changes in the absorption spectrum were monitored as a function of light exposure.

Optimization of standard patient radiographic images for chest, skull and pelvis exams in conventional x-ray equipment.

Abstract: Optimized radiographic techniques for clinical images of chest, skull and pelvis using conventional single-phase, three-phase and high-frequency x-ray units for a standard patient have been developed. Optimization of image contrast and optical density was obtained by using a homogeneous phantom (PEP) and an Anderson Rando anthropomorphic phantom. Image quality was evaluated by nine radiologists in independent analyses, leading to the choice of the optimized technique. A course of action to implement and validate these techniques in other radiographic systems has also been introduced. A realistic-analytic phantom (RAP) was constructed to certify the validation process. The optimized radiographic technique was implemented in the routine of our home hospital radiodiagnostic routine, enabling a reduction in patient doses around 25, 14 and 72%, respectively, for chest, skull and pelvis exams when compared with the previously used techniques. In addition, a corresponding reduction in the x-ray tube load of 68, 14 and 62% for the respective mentioned exams has been observed. In conclusion, implemented optimal techniques can lead to a reduction in the rate of film rejection, thus contributing to a better risk-benefit relationship for the patient and cost-benefit for the radiodiagnostic facility.