109 research outputs found

    PERIPHERAL BONE MINERAL DENSITY - NORMAL VALUES FOR HEALTHY BULGARIAN WOMEN IN THE BLACK SEA REGION

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    In the last three years in Bulgaria it became possible to determine the peripheral bone mass by x-ray absorptiometry (Osteometer DTX 100/200 ) and to perform screening examinations among women at risk of developing postmenopausal osteoporosis. As a reference database in our everyday practice we used the established criteria for Danish population. Keeping the study protocol of Osteometer A/S we summarized our data in order to define the age related variations of bone mineral density (BMD) and to determine normal values for healthy Bulgarian women. A total of234 women aged 20-70 years were included in the study. They were informed about the trial and gave their written consent to participate. BMD was measured by dual x-ray absorptiometry at distal (D-BMD) and ultradistal (U-BMD) sites of forearm with Osteometer DTX 200. The attained peak bone mass in youth (at the age of 30) declined normally slowly and after the menopause the loss accelerated - both D-BMD and U-BMD. The accelerated bone loss after menopause changed the ratio (normal BMD: osteopenia: osteoporosis) and with age the number of women with osteoporosis increased. Screening the women near menopause and monitoring the postmenopausal bone loss is important to identify patients at risk (the so-called fast bone losers ) . It will enable to start early preventive therapy. The established normal values for age-related changes in BMD can be used as reference base for healthy Bulgarian women and will help for correct interpretation of the results

    Antiproliferative Activity of Natural Flavonoid Fustin Isolated from the Heartwood of Cotinus Coggygria Scop. Against Breast and Colon Cancer Cell Lines

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    Background and objective: Cotinus coggygria Scop. is a valuable medicinal plant species with pronounced pharmacological potential due to its numerous biological activities. The herb is characterized by a high content of polyphenols among which is fustin. The anticancer activities of fustin, however, are extremely weakly studied. The aim of the present study was to investigate the in vitro antiproliferative potential of fustin isolated from the heartwood of C. coggygria against cell lines originating from two of the most common cancer types – breast (MDA-MB-231 and MCF7), and colon cancer (Colon 26). Materials and methods: Cell growth inhibitory properties of fustin were examined by MTT assay. Subsequently, phase-contrast and fl uorescence microscopy analysis as well as colonyforming assay were carried out on the most sensitive to the cytostatic action of the fustin cell line. Results: The obtained results showed that fustin reduced the proliferation of all studied cell lines. The highest cytostatic eff ect was registered towards breast cancer MDA-MB-231 cells with a half maximal inhibitory concentration (IC50) value of 56.02 μg/ ml followed by colon cancer cells with an IC50 of 78.07 μg/ml. MCF7 cell proliferation was least aff ected with a calculated IC50 of 187.8 μg/ml. Further investigations on breast cancer MDA-MB-231 cells indicated decreased density of cell monolayer and some morphological alterations, signifi cant attenuation in the number of viable cells, and diminished clonogenic ability of cells after fustin exposure. Conclusion: It could be concluded that fustin isolated from the heartwood of medicinal plant C. coggygria possesses marked antiproliferative properties against breast cancer cell line MDA-MB-231 which will be a subject of our more detailed future investigations

    Influence of Matrix Polarity on the Properties of Ethylene Vinyl Acetate–Carbon Nanofiller Nanocomposites

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    A series of ethylene vinyl acetate (EVA) nanocomposites using four kinds of EVA with 40, 50, 60, and 70 wt% vinyl acetate (VA) contents and three different carbon-based nanofillers—expanded graphite (EG), multi-walled carbon nanotube (MWCNT), and carbon nanofiber (CNF) have been prepared via solution blending. The influence of the matrix polarity and the nature of nanofillers on the morphology and properties of EVA nanocomposites have been investigated. It is observed that the sample with lowest vinyl acetate content exhibits highest mechanical properties. However, the enhancement in mechanical properties with the incorporation of various nanofillers is the highest for EVA with high VA content. This trend has been followed in both dynamic mechanical properties and thermal conductivity of the nanocomposites. EVA copolymer undergoes a transition from partial to complete amorphousness between 40 and 50 wt% VA content, and this changes the dispersion of the nanofillers. The high VA-containing polymers show more affinity toward fillers due to the large free volume available and allow easy dispersion of nanofillers in the amorphous rubbery phase, as confirmed from the morphological studies. The thermal stability of the nanocomposites is also influenced by the type of nanofiller

    Antiinflammatory Therapy with Canakinumab for Atherosclerotic Disease

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    Background: Experimental and clinical data suggest that reducing inflammation without affecting lipid levels may reduce the risk of cardiovascular disease. Yet, the inflammatory hypothesis of atherothrombosis has remained unproved. Methods: We conducted a randomized, double-blind trial of canakinumab, a therapeutic monoclonal antibody targeting interleukin-1β, involving 10,061 patients with previous myocardial infarction and a high-sensitivity C-reactive protein level of 2 mg or more per liter. The trial compared three doses of canakinumab (50 mg, 150 mg, and 300 mg, administered subcutaneously every 3 months) with placebo. The primary efficacy end point was nonfatal myocardial infarction, nonfatal stroke, or cardiovascular death. RESULTS: At 48 months, the median reduction from baseline in the high-sensitivity C-reactive protein level was 26 percentage points greater in the group that received the 50-mg dose of canakinumab, 37 percentage points greater in the 150-mg group, and 41 percentage points greater in the 300-mg group than in the placebo group. Canakinumab did not reduce lipid levels from baseline. At a median follow-up of 3.7 years, the incidence rate for the primary end point was 4.50 events per 100 person-years in the placebo group, 4.11 events per 100 person-years in the 50-mg group, 3.86 events per 100 person-years in the 150-mg group, and 3.90 events per 100 person-years in the 300-mg group. The hazard ratios as compared with placebo were as follows: in the 50-mg group, 0.93 (95% confidence interval [CI], 0.80 to 1.07; P = 0.30); in the 150-mg group, 0.85 (95% CI, 0.74 to 0.98; P = 0.021); and in the 300-mg group, 0.86 (95% CI, 0.75 to 0.99; P = 0.031). The 150-mg dose, but not the other doses, met the prespecified multiplicity-adjusted threshold for statistical significance for the primary end point and the secondary end point that additionally included hospitalization for unstable angina that led to urgent revascularization (hazard ratio vs. placebo, 0.83; 95% CI, 0.73 to 0.95; P = 0.005). Canakinumab was associated with a higher incidence of fatal infection than was placebo. There was no significant difference in all-cause mortality (hazard ratio for all canakinumab doses vs. placebo, 0.94; 95% CI, 0.83 to 1.06; P = 0.31). Conclusions: Antiinflammatory therapy targeting the interleukin-1β innate immunity pathway with canakinumab at a dose of 150 mg every 3 months led to a significantly lower rate of recurrent cardiovascular events than placebo, independent of lipid-level lowering. (Funded by Novartis; CANTOS ClinicalTrials.gov number, NCT01327846.

    Dielectric property of NiTiO 3

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    Thin mesoporous polyaniline films manifesting a water-promoted photovoltaic effect

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    Photovoltaic cells composed of thin mesoporous polyaniline films sandwiched between an indium-tin oxide anode and aluminium cathode have been fabricated. The cells show an increase in the photo-generated open-circuit voltage (V oc) from 0.2 V to 0.6 V and stable-in-time V oc generation following the addition of water containing highly hydrated ions, e.g. tap water.We explain the waterpromoted photo-voltaic effect by the polarity of the water environment. Theoretical calculations show that increasing the solvent polarity increases the energy of the electronic transition related to the measured V oc. The stable-in-time V oc generation could be explained by the increase in the lifetime of the excitons as well as by their more efficient dissociation in the interpenetrating network of polyaniline and water. The penetration of water into the mesoporous polyaniline films is promoted by the presence of highly hydrated ions. © 2012 Institute of Chemistry, Slovak Academy of Sciences

    Thin mesoporous polyaniline films manifesting a water-promoted photovoltaic effect

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    Photovoltaic cells composed of thin mesoporous polyaniline films sandwiched between an indium-tin oxide anode and aluminium cathode have been fabricated. The cells show an increase in the photo-generated open-circuit voltage (V oc) from 0.2 V to 0.6 V and stable-in-time V oc generation following the addition of water containing highly hydrated ions, e.g. tap water.We explain the waterpromoted photo-voltaic effect by the polarity of the water environment. Theoretical calculations show that increasing the solvent polarity increases the energy of the electronic transition related to the measured V oc. The stable-in-time V oc generation could be explained by the increase in the lifetime of the excitons as well as by their more efficient dissociation in the interpenetrating network of polyaniline and water. The penetration of water into the mesoporous polyaniline films is promoted by the presence of highly hydrated ions. © 2012 Institute of Chemistry, Slovak Academy of Sciences

    Polyaniline-water interactions: A theoretical investigation with the polarisable continuum model

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    The simulations of emeraldine hydrochloride tetramers were performed for the first time in implicit water solvent using the polarisable continuum model (PCM) with the density functional theory (DFT) method. This approach should be more appropriate for the study of the conducting form of polyaniline as all known processes of synthesis and further transformations take place in polar medium. Our results confirm this hypothesis and clearly indicate that the geometry and electronic structure of the emeraldine salt depend on the dielectric properties of the medium. In polar environment the protons are bound tighter to the chains compared to vacuum and this leads to stronger impact of the dopant on the structural parameters of PANI. As a consequence, the density distribution in the emeraldine hydrochloride obtained by PCM is more realistic compared to vacuum estimates. The stability in polar medium of two possible salt configurations with respect to counterions position is assessed. Each configuration is simulated in singlet and triplet state (bipolaron and polaron). The results show that at the tetramer level the bipolaron form is always preferred in accordance to available experimental results. © 2010 Elsevier B.V. All rights reserved

    Solvent polarity and dopant effect on the electronic structure of the emeraldine salt

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    Quantum mechanical simulations of a variety of inorganic and organic emeraldine salts (doping agents HCl, HBr, H2SO4, MSA, BSA, and CSA) in bipolaron and polaron form with account of solvents of different polarity (chloroform, m-cresol, and water) are reported for the first time. The models are based on tetramers, and the calculations are performed with the DFT method. The polarizable continuum model is used for the treatment of solute-solvent interaction. The effect of the different dopants and polarity of the solvents on the electronic structure and properties of the salts is evaluated and interpreted from the standpoint of the available experimental data. © 2010 Wiley Periodicals, Inc
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