Search results for "HYDROGEN"
showing 10 items of 4254 documents
Polyazapodands Derived from Biphenyl. Study of their Behaviour as Conformationally Regulated Fluorescent Sensors
2004
Eight new polyazapodands containing a 4,4′-substituted biphenyl moiety have been synthesised. Four (7, 8, 9 and 11) are functionalised on positions 4 and 4′ with a nitro group and four (1, 2, 3 and 10) with a dimethylamino substituent. Comparison of the emission behaviour of 1, 2, 3 with that of the reference compounds 10 and tetramthylbenzidine, clearly suggests that a modification in the dihedral angle between the biphenyl rings is an important factor in determining the fluorescent response of the molecule. The fluorescence is pH dependent, due to the formation of intramolecular hydrogen bonds between protonated aliphatic nitrogens and a carbonyl oxygen, which influences the aforementione…
Biowaiver Monograph for Immediate-Release Solid Oral Dosage Forms: Bisoprolol Fumarate
2014
Abstract Literature data relevant to the decision to allow a waiver of in vivo bioequivalence (BE) testing for the approval of immediate-release (IR) solid oral dosage forms containing bisoprolol as the sole active pharmaceutical ingredient (API) are reviewed. Bisoprolol is classified as a Class I API according to the current Biopharmaceutics Classification System (BCS). In addition to the BCS class, its therapeutic index, pharmacokinetic properties, data related to the possibility of excipient interactions, and reported BE/bioavailability problems are taken into consideration. Qualitative compositions of IR tablet dosage forms of bisoprolol with a marketing authorization (MA) in ICH (Inter…
Bisphenol A removal from water by biomass-based carbon: isotherms, kinetics and thermodynamics studies
2018
Biomass-based carbon was modified and used as an efficient bisphenol A (BPA) sorbent. The simple and environmentally friendly modification method produced sorbent with a capacity of 41.5 mg/g. The ...
Hydrogen Peroxide Diffusion through Enamel and Dentin
2018
The purpose of this study was to evaluate the in vitro diffusion of commercial bleaching products (hydrogen peroxide (HP) or carbamide peroxide (CP) based) with different application protocols. Human enamel-dentin discs were obtained and divided into 20 groups. Four commercial products based on HP (Pola Office+(PO), Perfect Bleach (PB), Norblanc Office-automix (NO), and Boost (BT)), and one based on CP (PolaDay CP (PD)), were evaluated with different application protocols (3 applications ×
Postnatal overfeeding in rats leads to moderate overweight and to cardiometabolic and oxidative alterations in adulthood.
2011
In contrast to the masses of data on obesity, few data are available concerning the cardiometabolic and oxidative consequences of moderate overweight. The model of postnatal overfeeding (OF) induces an increase in body weight at weaning that remains during adult life. Litters of Wistar rats were either maintained at 12 pups (normal-fed group, NF), or reduced to 3 pups at birth in order to induce OF. At 6 months of age, metabolic parameters, circulating oxidative stress and aortic and coronary vasoreactivity were assessed. Cardiac susceptibility to ischemia-reperfusion injury was also evaluated ex vivo as were markers of cardiac remodeling. OF led to an increase in body weight at weaning (+5…
Microregional distributions of glucose, lactate, ATP and tissue pH in experimental tumours upon local hyperthermia and/or hyperglycaemia
1993
Microregional distributions of glucose, lactate and ATP concentrations as well as tissue pH values were determined in subcutaneous rat tumours during normothermia and normoglycaemia, and upon local hyperthermia (HT) and/or hyperglycaemia (HG). Experiments were performed in order to investigate whether, and to what extent, these adjuvant therapeutic measures applied alone or in combination can modify the bioenergetic and metabolic status, parameters that are known to markedly influence the therapeutic response of tumours to heat. Local HT was performed in a saline bath (44 degrees C/2 h) and HG was induced by i.v. infusion of glucose for 2.5 h (blood glucose levels during heating: 35-40 mM).…
Acute changes of systemic parameters in tumour-bearing rats, and of tumour glucose, lactate, and ATP levels upon local hyperthermia and/or hyperglyca…
1991
Arterial blood pressure and relevant parameters of the arterial blood (O2 and CO2 tensions, pH, haematocrit, serum electrolytes and osmolality) were determined in tumour-bearing rats upon local hyperthermia (HT) and/or hyperglycaemia (HG). Tumour heating was performed in a saline bath (44 degrees C) for 120 min; hyperglycaemia was induced by i.v. infusion of 40% glucose solution for 150 min [blood glucose levels: 35-40 mM during heating; total amount of glucose: 1.19 g/100 g body wt.; infusion rates: 0.31 ml (100 g body wt.)-1 min-1 for 2 min, 0.02 ml (100 g body wt.)-1 min-1 for 88 min, and 0.01 ml (100 g body wt.)-1 min-1 for 60 min]. Immediately after treatment, glucose, lactate and ATP …
Evidence for a dysfunction and disease-promoting role of the circadian clock in the diabetic retina.
2021
Diabetic retinopathy is a major complication of chronic hyperglycemia and a leading cause of blindness in developed countries. In the present study the interaction between diabetes and retinal clocks was investigated in mice. It was seen that in the db/db mouse - a widely used animal model of diabetic retinopathy - clock function and circadian regulation of gene expression was disturbed in the retina. Remarkably, elimination of clock function by Bmal1-deficiency mitigates the progression of pathophysiology of the diabetic retina. Thus high-fat diet was seen to induce histopathology and molecular markers associated with diabetic retinopathy in wild type but not in Bmal1-deficient mice. The d…
Properties of erythrocyte light refraction in diabetic patients.
2001
Since hyperglycaemia changes the erythrocyte cell membrane fluidity and impairs cell deformity, our goal was to characterize hemoglobin and red blood cell (RBC) light refractive property changes in diabetic patients. Microscopic investigation was carried out on intact and fixed RBCs. To determine the refractive index (RI): smears of peripheral blood were air dried and fixed for 3 min in methanol. Mixtures of polyvinylpyrolidine and buffer of different pH (1:1) were used as embedding media. Intact RBCs were mixed with a buffered embedding medium, placed on a slide and overlaid with a coverslip. Interference microscopy was used for RI measurements at 18 different pH (pH=2-13). The results sho…
Comparative study on biological effects of the guinea pig complement-peptide C3a and C3a-related synthetic oligopeptides
1980
Dose-response experiments with guinea pig C3a and a synthetic hexapeptide (amino acid residues 72–77), representing the COOH-terminal sequence of human C3a, were performed in two recently described bioassay systems for C3a, i.e. cytotoxicity against tumor cells measured as LDH and 51Cr-release and non cytolytic serotonin release from guinea pig platelets. Compared to the classical anaphylatoxic assay (guinea pig ileum contraction), nearly identical reactivities were observed in all three test systems with C3a and, although quantitatively different, with hexapeptide.