The mechanism of inhibition of insulin-based amyloid gel formation by metal derivatives of tetrakis(4-sulfonatophenyl)porphyrin has been investigated. Time-course UV/vis measurements in conjunction ...with atomic force microscopy (AFM) were used to study the correlation between observed kinetics and amyloid structure for various concentration ranges of added metalloporphyrins. Observed structures include fibrils as well as circular, ring-like structures formed as a result of the interaction of insulin with porphyrin. In addition, binding studies demonstrate that the effectiveness of inhibition of the various metalloporphyrins is directly related to the strength of binding to insulin. It is suggested that both the electron distribution in the porphyrin core and the tendency to form porphyrin dimers affect both the structure of amyloid formed and the kinetic profile of the reaction.
Fluorescence of substituted pyrrolyl pyridines Sibley, Scott P; Saunders, Anne; Crum, Pamela ...
Journal of photochemistry and photobiology. A, Chemistry.,
05/2004, Letnik:
163, Številka:
3
Journal Article
Recenzirano
The absorbance and fluorescence of 2-(1-pyrrolyl)-pyridine and three methylated derivatives have been studied in a variety of solvents. Absorbance spectra of the molecules were found to exhibit minor ...solvent dependence. The fluorescence spectra for all derivatives, however, show large red shifts in more polar solvents. Dual fluorescence has also been observed, consistent with locally excited and twisted intramolecular charge transfer (TICT) emission. Fluorescence intensity was also found to diminish in more polar solvents, consistent with a twisted excited state geometry for these molecules. The position and number of methyl substituents were found to affect the degree of charge-transfer emission. Quantum mechanical density functional calculations of ground state and vertical transition energies are presented to describe observed spectral behavior. Calculations include bulk solvation effects.
A lesson plan is presented for teaching science students about the wave theory of light, including phosphorescence properties, emission spectrums, and photoelectric effects. Students use ...glow-in-the-dark cutout stars to perform optical calculations.
The equilibrium constants for complexation of C
60 with naphthalene, phenanthrene and pyrene in toluene have been determined by UV/visible spectroscopy. The magnitude of the equilibrium constants was ...found to increase with decreasing ionization potential of the donor. Values for complexation enthalpy have been determined for the first time for C
60/aromatic hydrocarbons. Well-defined charge transfer (C-T) bands have been observed for complexes of C
60 with a variety of aromatic hydrocarbons, with C-T band maxima moving to higher frequency with increasing donor ionization potential.
The equilibrium constants for complexation of C60 with naphthalene, phenanthrene and pyrene in toluene have been determined by UV visible spectroscopy. The magnitude of the equilibrium constants was ...found to increase with decreasing ionization potential of the donor. Values for complexation enthalpy have been determined for the first time for C60/aromatic hydrocarbons. Well-defined charge transfer (C-T) bands have been observed for complexes of C60 with a variety of aromatic hydrocarbons, with C-T band maxima moving to higher frequency with increasing donor ionization potential.
RNA viruses exhibit a variety of genome organization strategies, including multicomponent genomes in which each segment is packaged separately. Although multicomponent genomes are common among ...viruses infecting plants and fungi, their prevalence among those infecting animals remains unclear. We characterize a multicomponent RNA virus isolated from mosquitoes, designated Guaico Culex virus (GCXV). GCXV belongs to a diverse clade of segmented viruses (Jingmenvirus) related to the prototypically unsegmented Flaviviridae. The GCXV genome comprises five segments, each of which appears to be separately packaged. The smallest segment is not required for replication, and its presence is variable in natural infections. We also describe a variant of Jingmen tick virus, another Jingmenvirus, sequenced from a Ugandan red colobus monkey, thus expanding the host range of this segmented and likely multicomponent virus group. Collectively, this study provides evidence for the existence of multicomponent animal viruses and their potential relevance for animal and human health.
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•Multicomponent viruses, formerly seen only in plants/fungi, can infect animal hosts•GCXV is an enveloped, multicomponent virus that infects mosquitoes•GCXV has five segments, one optional for replication and variably present in isolates•An evolutionarily related, segmented virus was observed in a non-human primate host
Multicomponent viruses, which separately package different genome segments, were thought to be restricted to plant and fungal hosts. Ladner et al. characterize a multicomponent mosquito virus and describe an evolutionarily related, segmented virus in a nonhuman primate. These findings provide evidence for multicomponent animal viruses and suggest relevance to animal health.
Background: Over the past 10-15 years, a substantial amount of work has been done by the scientific, regulatory, and business communities to elucidate the effects and risks of pharmaceuticals and ...personal care products (PPCPs) in the environment. Objective: This review was undertaken to identify key outstanding issues regarding the effects of PPCPs on human and ecological health in order to ensure that future resources will be focused on the most important areas. Data Sources: To better understand and manage the risks of PPCPs in the environment, we used the "key question" approach to identify the principle issues that need to be addressed Initially, were solicited from academic government, and business communities around the world. A list of 101 questions was then discussed at an international expert workshop, and a top-20 list was developed. Following the workshop, workshop attendees ranked the 20 questions by importance. Data Synthesis: The top 20 priority questions fell into seven categories: a) prioritization or substances for assessment, b) pathways of exposure, c) bioavailability and uptake, d) effects characterization, e) risk and relative risk, f) antibiotic resistance, and g) risk management. Conclusions: A large body of information is now available on PPCPs in the environment. This exercise prioritized the most critical questions to aid in development of future research programs on the topic.
Internal family systems (IFS) therapy is an experiential model of therapy and views individuals as having numerous "parts" inside of them. These parts maintain a specific role in a client's life and ...fall under one of the three categories - managers, exiles, and firefighters. Due to the experiential aspect of IFS and the concept of blending, visualizing the parts inside of a client can become challenging at best and impossible, at worst. This article provides a framework for integrating sandtray therapy with IFS to help clients name, visualize, and see the progress of their parts.
Celotno besedilo
Dostopno za:
BFBNIB, DOBA, IZUM, KILJ, NUK, OILJ, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK, VSZLJ
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