Search results for "Ituri"

Molecular Recognition via Hydrogen Bonding at the Air−Water Interface:  An Isotherm and Fourier Transform Infrared Reflection Spectroscopy Study

1997

Molecular recognition in Langmuir monolayers at the air−water interface as a function of headgroup orientation and substrate using isotherms and in-situ Fourier transform infrared (FT-IR) reflection spectroscopy has been investigated. Isotherm measurements show that urea and 2,4,6-triaminopyrimidine (TAP) are specifically bound to barbituric acid lipid monolayers. As expected, TAP causes a larger shift in the limiting area of the isotherms than urea due to steric requirements. The peak positions of the CH stretching vibrations of the barbituric acid lipids indicate that the alkyl chains of barbituric acid lipids 1−3 are in a close-packed all-trans conformation both before and after the reco…

Even free radicals should follow some rules: a guide to free radical research terminology and methodology.

2014

Free radicals and oxidants are now implicated in physiological responses and in several diseases. Given the wide range of expertise of free radical researchers, application of the greater understanding of chemistry has not been uniformly applied to biological studies. We suggest that some widely used methodologies and terminologies hamper progress and need to be addressed. We make the case for abandonment and judicious use of several methods and terms and suggest practical and viable alternatives. These changes are suggested in four areas: use of fluorescent dyes to identify and quantify reactive species, methods for measurement of lipid peroxidation in complex biological systems, claims of…

Optimistit opintiellä : opinnoissaan menestyvien nuorten hyvinvointi lukiosta jatko-opintoihin

2007

Sirpa Vahtera tutki väitöstyössään opinnoissaan menestyvien nuorten ajattelu- ja toimintastrategioita ja psyykkistä hyvinvointia lukiosta jatko-opintoihin. - Lukioissa kannattaa vaalia oppimisen ja yhdessä tekemisen iloa. Optimistinen suhtautuminen tulevaisuuteen ja omien tietojen ja taitojen positiivinen arviointi ovat lukiolaisen psyykkistä hyvinvointia varsinkin Suomessa, jossa jatko-opintoihin siirtyminen on monelle nuorelle pitkä ja raskas prosessi, Vahtera kertoo. Vahtera etsi tutkimuksessaan nuorten psyykkistä hyvinvointia ja opiskelua parhaiten tukevia ajattelu- ja toimintatapoja. Opinnoissaan menestyvät nuoret käyttivät optimistista ajattelu- ja toimintastrategiaa. Optimistinen str…

Fructose-enriched diet modifies antioxidant status and lipid metabolism in spontaneously hypertensive rats

2005

Abstract Objective High-fructose consumption in industrial countries has been shown to induce metabolic abnormalities or syndrome X. Changes in antioxidant defense are unknown in hypertension associated with metabolic disorders induced by high-fructose feeding. Methods Twenty spontaneously hypertensive rats were assigned to one of two groups; one received a fructose-enriched diet (60% fructose) and the other a starch diet. After a 13-wk diet period, total antioxidant status was assessed in the blood and liver by monitoring the rate of free radical-induced red blood cell hemolysis. Antioxidants (enzymes and vitamins) were determined in blood and liver. Gene expression of antioxidant enzymes …

Strong Emission Enhancement in pH-Responsive 2:2 Cucurbit[8]uril Complexes

2019

Organic fluorophores, particularly stimuli-responsive molecules, are very interesting for biological and material sciences applications, but frequently limited by aggregation- and rotation-caused photoluminescence quenching. A series of easily accessible bipyridinium fluorophores, whose emission is quenched by a twisted intramolecular charge-transfer (TICT) mechanism, is reported. Encapsulation in a cucurbit[7]uril host gave a 1:1 complex exhibiting a moderate emission increase due to destabilization of the TICT state inside the apolar cucurbituril cavity. A much stronger fluorescence enhancement is observed in 2:2 complexes with the larger cucurbit[8]uril, which is caused by additional con…

Pregnenolone sulfate, a naturally occurring excitotoxin involved in delayed retinal cell death.

2002

The present study was designed to investigate the neurosteroid pregnenolone sulfate (PS), known for its ability to modulate NMDA receptors and interfere with acute excitotoxicity, in delayed retinal cell death. Three hours after exposure of the isolated and intact retina to a 30-min PS pulse, DNA fragmentation as assessed by genomic DNA gel electrophoresis and a modified in situ terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end-labeling (TUNEL) method appeared concurrently with an increase in superoxide dismutase (SOD) activity and thiobarbituric acid-reactive substances (TBARS) levels. At 7 h, the increased amount of DNA laddering was accompanied by a higher number of TUN…

Assessing foreign language listening comprehension by means of the multiple-choice format : processes and products

2011

N-3 fatty acids modulate antioxidant status in diabetic rats and their macrosomic offspring.

2006

We investigated the role of dietary n-3 polyunsaturated fatty acids (n-3 PUFA) in the modulation of total antioxidant status in streptozotocin (STZ)-induced diabetic rats and their macrosomic offspring. Female wistar rats, fed on control diet or n-3 PUFA diet, were rendered diabetic by administration of five mild doses of STZ on day 5 and were killed on days 12 and 21 of gestation. The macrosomic (MAC) pups were killed at the age of 60 and 90 days. Lipid peroxidation was measured as the concentrations of plasma thiobarbituric acid reactive substances (TBARS), and the total antioxidant status was determined by measuring (i) plasma oxygen radical absorbance capacity (ORAC), (ii) plasma vitami…

Effect of Running Exercise on Oxidative Stress Biomarkers: A Systematic Review

2021

Background: Exercise induced health benefits are limited by the overaccumulation of reactive oxygen species (ROS). ROS and further oxidative stress could potentially induce muscle damage which could result in poor exercise performance. However, predicting ROS induced oxidative stress in response to endurance training has several limitations in terms of selecting biomarkers that are used to measure oxidative stress.Objective: The purpose of this study was to systematically investigate the suitable biomarkers that predict oxidative stress status among runners.Methods: According to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement, a search for relevant …

Characterization of the interaction of the antifungal and cytotoxic cyclic glycolipopeptide hassallidin with sterol-containing lipid membranes.

2019

Hassallidins are cyclic glycolipopeptides produced by cyanobacteria and other prokaryotes. The hassallidin structure consists of a peptide ring of eight amino acids where a fatty acid chain, additional amino acids, and sugar moieties are attached. Hassallidins show antifungal activity against several opportunistic human pathogenic fungi, but does not harbor antibacterial effects. However, they have not been studied on mammalian cells, and the mechanism of action is unknown. We purified hassallidin D from cultured cyanobacterium Anabaena sp. UHCC 0258 and characterized its effect on mammalian and fungal cells. Ultrastructural analysis showed that hassallidin D disrupts cell membranes, causin…