265 research outputs found

    Chitosan-Gold Nanoparticle Composites for Biomedical Application

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    The aim of this work is to synthesize chitosan-gold nanoparticles films by direct chemical reduction of HAuCl4 in a chitosan solution and to investigate the influence of gold nanoparticles concentration on the structure of films, conductivity and healing effect on mice skin after surgery. Results obtained have shown that new chitosan-gold nanoparticle-collagen bionananocomposites demonstrated better healing effect on the mice skin after surgery than control performed on commercial TheraFormTM material. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3540

    Evaluation of bone marrow and blood cultures for the recovery of mycobacteria in the diagnosis of disseminated mycobacterial infections

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    AbstractThis study evaluated the validity of bone marrow (BM) and blood specimens for the diagnosis of disseminated mycobacterial infections (DMIs). From 1990 to February 1997, all specimens were processed with the lysis-centrifugation procedure; thereafter (until December 2001), they were processed with the BACTEC Myco/F Lytic system. Twenty-three paired BM-blood specimens with mycobacteria in at least one specimen were studied from 23 patients. The strains isolated were 14 Mycobacterium avium complex (MAC) and nine M. tuberculosis complex (MTBC). Blood specimens had a statistically significant greater sensitivity for the isolation of MAC than BM (100% vs. 57.1%, respectively), whereas sensitivity for the isolation of MTBC was equal for the two specimen types (66.7%). Although not statistically significant, the times required to detect mycobacteria from blood specimens were lower than those from BM in the MycoF/Lytic system. Overall, blood cultures represented a more sensitive and less invasive alternative to BM cultures for the diagnosis of disseminated mycobacteriosis caused by MAC, especially when the MycoF/Lytic system was used, but provided no advantage for the diagnosis of DMI caused by MTBC

    Homoeologous chromosomal location of the genes encoding thionins in wheat and rye

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    Thionins are high sulphur basic polypeptides present in the endosperm of Gramineae. In wheat there are three thionins encoded by genes located in the long arms of chromosomes 1A, 1B and 1D. Rye has one thionin encoded by a gene which has been assigned to chromosome 1R after analysis of the Imperial-Chinese Spring rye-wheat disomic addition lines. Commercial varieties and experimental stocks with a 1B/1R substitution carry the thionin from rye ( R) instead of the B thionin from wheat. The R thionin gene is not located in the large chromosomal segment representing most of the short arm of chromosome 1R

    The Degasperis-Procesi equation as a non-metric Euler equation

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    In this paper we present a geometric interpretation of the periodic Degasperis-Procesi equation as the geodesic flow of a right invariant symmetric linear connection on the diffeomorphism group of the circle. We also show that for any evolution in the family of bb-equations there is neither gain nor loss of the spatial regularity of solutions. This in turn allows us to view the Degasperis-Procesi and the Camassa-Holm equation as an ODE on the Fr\'echet space of all smooth functions on the circle.Comment: 17 page

    Bactericidal Activity, Isolation and Identification of Most Active Compound from 20 Plants used in Traditional Mexican Medicine Against Multidrug-Resistant Bacteria

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    Abstract Background and Objective: Plants are used in Mexico as traditional medicine for the treatment of diverse illnesses such as stomach pain, fever, diarrhea, insomnia, flu and other respiratory diseases. Twenty were selected to determine their bactericidal activity. The aim of this study was the isolation of molecules from plants used in Mexican traditional medicine. Materials and Methods: Using chromatographic procedures, the responsible bactericidal molecules from rosemary was extracted and then identified by spectroscopic analysis IR, 1H NMR, 13C NMR, DEPT, HSQC and GC-MS. Measures of central tendency were determined by statistical analysis. Results: Ten of these plants showed bactericidal activity against multidrug-resistant bacteria. This biological activity was reported for Carya illinoensis against Pseudomonas aeruginosa , also for Equisetum robustum , Stevia rebaudiana and Castela texana against Methicillin resistant Staphylococcus aureus (MRSA). The methanolic extract of Rosmarinus officinalis (rosemary) showed important bactericidal activity against MRSA (ATCC BAA-44) and clinically isolated MRSA. Conclusion: Rosemary’s bactericidal molecules were isolated and then identified as a mixture of betulinic, oleanolic and ursolic acid (MIC = 725 µg mLG1). Key words: Rosmarinus officinalis , multidrug-resistance, MRSA, thin layer chromatography, flash chromatography, 1H NMR, 13C NMR, triterpenic acid

    Extreme scenarios: the tightest possible constraints on the power spectrum due to primordial black holes

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    Observational constraints on the abundance of primordial black holes (PBHs) constrain the allowed amplitude of the primordial power spectrum on both the smallest and the largest ranges of scales, covering over 20 decades from 1 - 10^20=Mpc. Despite tight constraints on the allowed fraction of PBHs at their time of formation near horizon entry in the early Universe, the corresponding constraints on the primordial power spectrum are quite weak, typically PR . 10<~2 assuming Gaussian perturbations. Motivated by recent claims that the evaporation of just one PBH would destabilise the Higgs vacuum and collapse the Universe, we calculate the constraints which follow from assuming there are zero PBHs within the observable Universe. Even if evaporating PBHs do not collapse the Universe, this scenario represents the ultimate limit of observational constraints. Constraints can be extended on to smaller scales right down to the horizon scale at the end of in ation, but where power spectrum constraints already exist they do not tighten significantly, even though the constraint on PBH abundance can decrease by up to 46 orders of magnitude. This shows that no future improvement in observational constraints can ever lead to a significant tightening in constraints on in ation (via the power spectrum amplitude). The power spectrum constraints are weak because an order unity perturbation is required in order to overcome pressure forces. We therefore consider an early matter dominated era, during which exponentially more PBHs form for the same initial conditions. We show this leads to far tighter constraints, which approach PR . 10^-9, albeit over a smaller range of scales and are very sensitive to when the early matter dominated era ends. Finally, we show that an extended early matter era is incompatible with the argument that an evaporating PBH would destroy the Universe, unless the power spectrum amplitude decreases by up to ten orders of magnitude

    Recent experimental results in sub- and near-barrier heavy ion fusion reactions

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    Recent advances obtained in the field of near and sub-barrier heavy-ion fusion reactions are reviewed. Emphasis is given to the results obtained in the last decade, and focus will be mainly on the experimental work performed concerning the influence of transfer channels on fusion cross sections and the hindrance phenomenon far below the barrier. Indeed, early data of sub-barrier fusion taught us that cross sections may strongly depend on the low-energy collective modes of the colliding nuclei, and, possibly, on couplings to transfer channels. The coupled-channels (CC) model has been quite successful in the interpretation of the experimental evidences. Fusion barrier distributions often yield the fingerprint of the relevant coupled channels. Recent results obtained by using radioactive beams are reported. At deep sub-barrier energies, the slope of the excitation function in a semi-logarithmic plot keeps increasing in many cases and standard CC calculations over-predict the cross sections. This was named a hindrance phenomenon, and its physical origin is still a matter of debate. Recent theoretical developments suggest that this effect, at least partially, may be a consequence of the Pauli exclusion principle. The hindrance may have far-reaching consequences in astrophysics where fusion of light systems determines stellar evolution during the carbon and oxygen burning stages, and yields important information for exotic reactions that take place in the inner crust of accreting neutron stars.Comment: 40 pages, 63 figures, review paper accepted for EPJ

    Fungal Planet description sheets: 1042–1111

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    Novel species of fungi described in this study include those from various countries as follows: Antarctica, Cladosporium arenosum from marine sediment sand. Argentina, Kosmimatamyces alatophylus (incl. Kosmimatamyces gen. nov.) from soil. Australia, Aspergillus banksianus, Aspergillus kumbius, Aspergillus luteorubrus, Aspergillus malvicolor and Aspergillus nanangensis from soil, Erysiphe medicaginis from leaves of Medicago polymorpha, Hymenotorrendiella communis on leaf litter of Eucalyptus bicostata, Lactifluus albopicri and Lactifluus austropiperatus on soil, Macalpinomyces collinsiae on Eriachne benthamii, Marasmius vagus on soil, Microdochium dawsoniorum from leaves of Sporobolus natalensis, Neopestalotiopsis nebuloides from leaves of Sporobolus elongatus, Pestalotiopsis etonensis from leaves of Sporobolus jacquemontii, Phytophthora personensis from soil associated with dying Grevillea mccutcheonii. Brazil, Aspergillus oxumiae from soil, Calvatia baixaverdensis on soil, Geastrum calycicoriaceum on leaf litter, Greeneria kielmeyerae on leaf spots of Kielmeyera coriacea. Chile, Phytophthora aysenensis on collar rot and stem of Aristotelia chilensis. Croatia, Mollisia gibbospora on fallen branch of Fagus sylvatica. Czech Republic, Neosetophoma hnaniceana from Buxus sempervirens. Ecuador, Exophiala frigidotolerans from soil. Estonia, Elaphomyces bucholtzii in soil. France, Venturia paralias from leaves of Euphorbia paralias. India, Cortinarius balteatoindicus and Cortinarius ulkhagarhiensis on leaf litter. Indonesia, Hymenotorrendiella indonesiana on Eucalyptus urophylla leaf litter. Italy, Penicillium taurinense from indoor chestnut mill. Malaysia, Hemileucoglossum kelabitense on soil, Satchmopsis pini on dead needles of Pinus tecunumanii. Poland, Lecanicillium praecognitum on insects' frass. Portugal, Neodevriesia aestuarina from saline water. Republic of Korea, Gongronella namwonensis from freshwater. Russia, Candida pellucida from Exomias pellucidus, Heterocephalacria septentrionalis as endophyte from Cladonia rangiferina, Vishniacozyma phoenicis from dates fruit, Volvariella paludosa from swamp. Slovenia, Mallocybe crassivelata on soil. South Africa, Beltraniella podocarpi, Hamatocanthoscypha podocarpi, Coleophoma podocarpi and Nothoseiridium podocarpi (incl. Nothoseiridium gen. nov.)from leaves of Podocarpus latifolius, Gyrothrix encephalarti from leaves of Encephalartos sp., Paraphyton cutaneum from skin of human patient, Phacidiella alsophilae from leaves of Alsophila capensis, and Satchmopsis metrosideri on leaf litter of Metrosideros excelsa. Spain, Cladophialophora cabanerensis from soil, Cortinarius paezii on soil, Cylindrium magnoliae from leaves of Magnolia grandiflora, Trichophoma cylindrospora (incl. Trichophoma gen. nov.) from plant debris, Tuber alcaracense in calcareus soil, Tuber buendiae in calcareus soil. Thailand, Annulohypoxylon spougei on corticated wood, Poaceascoma filiforme from leaves of unknown Poaceae. UK, Dendrostoma luteum on branch lesions of Castanea sativa, Ypsilina buttingtonensis from heartwood of Quercus sp. Ukraine, Myrmecridium phragmiticola from leaves of Phragmites australis. USA, Absidia pararepens from air, Juncomyces californiensis (incl. Juncomyces gen. nov.) from leaves of Juncus effusus, Montagnula cylindrospora from a human skin sample, Muriphila oklahomaensis (incl. Muriphila gen. nov.)on outside wall of alcohol distillery, Neofabraea eucalyptorum from leaves of Eucalyptus macrandra, Diabolocovidia claustri (incl. Diabolocovidia gen. nov.)from leaves of Serenoa repens, Paecilomyces penicilliformis from air, Pseudopezicula betulae from leaves of leaf spots of Populus tremuloides. Vietnam, Diaporthe durionigena on branches of Durio zibethinus and Roridomyces pseudoirritans on rotten wood. Morphological and culture characteristics are supported by DNA barcodes
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