62 research outputs found

    SOLVENT EFFECTS ON THE ABSORPTION AND FLUORESCENCE SPECTRA OF Er(III) (AZO-DYES AND SCHIFF BASES) COMPLEXES: DETERMINATION OF GROUND AND EXCITED STATE DIPOLE MOMENT

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    Absorption and fluorescence emission spectra of some thermally stable Er(III) mononuclear complexes of azo dyes, namely o, o` -dihydroxy azobenzene (DAB), o, o` -dihydroxy 4-Cl-phenylazonaphatalene (P1) and Schiff bases o, o` -dihydroxy phenylazomethinnaphatalene (D2), o-hidroxy -o` -carboxy (D3), were recorded in solvents with different solvent dielectric constant ε and refractive index n. The solvatochromic shift method was used to determine the experimental ground and excited state dipole moments of the complexes. All the complexes were proved to be more polar in the excited state as compared with the ground state

    Advancing the scientific study of prehospital mass casualty response through a Translational Science process: the T1 scoping literature review stage

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    PurposeThe European Union Horizon 2020 research and innovation funding program awarded the NIGHTINGALE grant to develop a toolkit to support first responders engaged in prehospital (PH) mass casualty incident (MCI) response. To reach the projects' objectives, the NIGHTINGALE consortium used a Translational Science (TS) process. The present work is the first TS stage (T1) aimed to extract data relevant for the subsequent modified Delphi study (T2) statements.MethodsThe authors were divided into three work groups (WGs) MCI Triage, PH Life Support and Damage Control (PHLSDC), and PH Processes (PHP). Each WG conducted simultaneous literature searches following the PRISMA extension for scoping reviews. Relevant data were extracted from the included articles and indexed using pre-identified PH MCI response themes and subthemes.ResultsThe initial search yielded 925 total references to be considered for title and abstract review (MCI Triage 311, PHLSDC 329, PHP 285), then 483 articles for full reference review (MCI Triage 111, PHLSDC 216, PHP 156), and finally 152 articles for the database extraction process (MCI Triage 27, PHLSDC 37, PHP 88). Most frequent subthemes and novel concepts have been identified as a basis for the elaboration of draft statements for the T2 modified Delphi study.ConclusionThe three simultaneous scoping reviews allowed the extraction of relevant PH MCI subthemes and novel concepts that will enable the NIGHTINGALE consortium to create scientifically anchored statements in the T2 modified Delphi study

    Exposure to wind turbine noise: Perceptual responses and reported health effects

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    Health Canada, in collaboration with Statistics Canada, and other external experts, conducted the Community Noise and Health Study to better understand the impacts of wind turbine noise (WTN) on health and well-being. A cross-sectional epidemiological study was carried out between May and September 2013 in southwestern Ontario and Prince Edward Island on 1238 randomly selected participants (606 males, 632 females) aged 18-79 years, living between 0.25 and 11.22 km from operational wind turbines. Calculated outdoor WTN levels at the dwelling reached 46 dBA. Response rate was 78.9% and did not significantly differ across sample strata. Self-reported health effects (e.g., migraines, tinnitus, dizziness, etc.), sleep disturbance, sleep disorders, quality of life, and perceived stress were not related to WTN levels. Visual and auditory perception of wind turbines as reported by respondents increased significantly with increasing WTN levels as did high annoyance toward several wind turbine features, including the following: noise, blinking lights, shadow flicker, visual impacts, and vibrations. Concern for physical safety and closing bedroom windows to reduce WTN during sleep also increased with increasing WTN levels. Other sample characteristics are discussed in relation to WTN levels. Beyond annoyance, results do not support an association between exposure to WTN up to 46 dBA and the evaluated health-related endpoints

    3-hydroxyflavone-bovine serum albumin interaction in Dextran medium

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    Spectroscopic analysis of a bioactive flavonol, 3-Hydroxyflavone (3-HF), in systems based on Dextran 70 (Dx70) (an important bio-relevant polysacharide) and Bovine Serum Albumin (BSA) (a carrier protein), have been studied by fluorescence and circular dichroism. Changes produced by different concentrations of Dx70 on the fluorescent characteristics of 3-HF, and on the excited - state intramolecular proton transfer (ESIPT) process were studied. The influence of 3-HF binding and of Dx70 on the secondary structure of BSA were investigated by circular dichroism spectroscopy. The influence of temperature (30-80°C range) on the intrinsic Tryptophan fluorescence in 3-HF/BSA/Dx70 systems, was investigated. The results are discussed with relevance to 3-HF as a sensitive fluorescence probe for exploring flavone-protein interaction in plasma expander media and also for its biological evaluation

    3-hydroxyflavone-bovine serum albumin interaction in Dextran medium

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    Spectroscopic analysis of a bioactive flavonol, 3-Hydroxyflavone (3-HF), in systems based on Dextran 70 (Dx70) (an important bio-relevant polysacharide) and Bovine Serum Albumin (BSA) (a carrier protein), have been studied by fluorescence and circular dichroism. Changes produced by different concentrations of Dx70 on the fluorescent characteristics of 3-HF, and on the excited - state intramolecular proton transfer (ESIPT) process were studied. The influence of 3-HF binding and of Dx70 on the secondary structure of BSA were investigated by circular dichroism spectroscopy. The influence of temperature (30-80°C range) on the intrinsic Tryptophan fluorescence in 3-HF/BSA/Dx70 systems, was investigated. The results are discussed with relevance to 3-HF as a sensitive fluorescence probe for exploring flavone-protein interaction in plasma expander media and also for its biological evaluation

    3-hydroxyflavone-bovine serum albumin interaction in Dextran medium

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    Evaluation of the oxidative activity of some free base porphyrins by a chemiluminescence method

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    Due to their spectral characteristics, phototoxicity and high affinity for tumour tissues, porphyrins and their derivatives are widely used in modern medicine as contrast agents for cancer diagnostics and as sensitizers in photodynamic therapy, where they kill tumours via enhancement of tumour oxidative stress. The aim of this work was to simulate in vitro the effects caused by oxidation of two free base porphyrins, 5,10,15,20-tetraphenylporphyrin (TPP) and 5,10,15,20‑tetra(4‑methoxyphenyl)porphyrin (TMOPP). The kinetic study was monitored using spectral techniques and chemiluminescence. The effect of both porphyrins on an oxidation process was evidenced using the chemilumi-nescent system, luminal–hydrogen peroxide, in a phosphate buffer at pH 7. It was found that at low concentration, TPP exerts the anti-oxidative effect in the employed chemiluminescent system, while at higher concentrations; its effect is pro-oxidative. TMOPP exerts a pro-oxidant effect, which was more pronounced than TPP. The results are discussed with respect to oxidative stress

    Spectroscopic Study on the Riboflavin -Plant Extracts Interaction

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    The Riboflavin (Vitamin B 2 ) -plant extracts interaction was investigated by spectrophotometric methods, i.e., absorption and fluorescence emission and excitation spectra. Plant extracts were obtained by ultrasound assisted extraction. The quenching of the Riboflavin fluorescence at its interaction with the plant extracts is discussed. Keywords: plant extract, natural extraction, riboflavin, fluorescence, antioxidant activity Free radical induced lipid oxidation in human bodies has been related to the pathological process of many diseases, such as cardiovascular disease It is well known that vegetable tissues contain several substances having antioxidant properties due to the phenolic compounds (antocyaninis, flavanols, flavonols, isoflavones, flavan-3-ols and hidroxycinamic acids). Antioxidant activity of polyphenols from plants is based on their radical-scavenging capacity and on the capacity to chelate transition metals ions. Fruits, vegetables and cereals have been explored due to their high abundance in the human diet and due to the prevention of various diseases as cancer and cardiovascular diseases * email: [email protected] (chemiluminescence and fluorescence) methods Our attention was focused on the antioxidant activity of natural plant-extracts The plant extracts that were the subject of our investigation are as follows
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