366 research outputs found

    338. Brachyterapia paliatywna PDR i HDR w leczeniu nawrotów miejscowych nowotworów głowy i szyi

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    Cel pracyW pracy przedstawiono wstępne wyniki paliatywnej brachyterapii HDR i PDR wznów nowotworów głowy i szyi.Materiał i metody47 chorych ze wznową miejscową nowotworu głowy i szyi leczonych było metodą brachyterapii HDR i PDR w okresie od 05.06.2001 do 31.12.2002 w Wielkopolskim Centrum Onkologii. Wszyscy chorzy zdyskwalifikowani zostali od leczenia chirurgicznego i radioterapii wiązkami zewnętrznymi ze względu na zaawansowanie choroby oraz przebyte leczenie. Wiek chorych sięgał od 38 do 75 (średnio 51.2 lat), w grupie było 10 kobiet i 37 mężczyzn. Umiejscowienie wznowy nowotworu: dno jamy ustnej i język – 20 chorych, gardło środkowe – 12 chorych, węzły chłonne szyi – 5 chorych, krtań – 3 chorych, nosogardło – 3 chorych, ślinianki – 2 chorych, szczęka górna – 2 chorych. Średni okres pomiędzy rozpoznaniem guza pierwotnego oraz wznowy wynosił 9.7 miesięcy. 34 chorych leczonych było metodą brachyterapii HDR dawką frakcyjną od 4 do 6 Gy, w 5 do 10 frakcjach, 13 chorych leczonych było metodą brachyterapii PDR dawka łączną 2000 cGy, w jednej (n=4) lub dwóch fazach leczenia (n=9). Ocenie poddano stopień remisji po 1, 3 i 6-iu miesiącach od zakończenia leczenia oraz powikłania wczesne.WynikiPo 4-ech tygodniach od zakończenia leczenia całkowitą remisję (CR) stwierdzono u 15% chorych, częściową remisję (PR) u 65.1% chorych, brak remisji (NR) u 10.9% chorych i progresję (Progr) u 9% chorych. Odpowiednie odsetki odpowiedzi wynosiły: po 3 i 6 miesiącach CR – 10.3 i 5.6%, PR – 54% i 36.3%), NR i Progr – 35.7% i 58.1%. W 74.6% przypadkach wystąpiła powierzchowna martwica w okresie 6 miesięcy obserwacji. Inne najczęstsze powikłania to nasilenie bólu (25%), infekcja miejscowa (44.3%), przetoka (6%). Obie metody brachyterapii były w równym stopniu dobrze tolerowane.Wnioski1. Brachyterapia HDR lub PDR może być efektywnym paliatywnym leczeniem wznowy nowotworu głowy i szyi. 2. Powikłania wczesne związane z wysoką dawką sumaryczną napromieniania są częste i wymagają intensywnego leczenia farmakologicznego

    Factors shaping species richness and biodiversity of riverine macroinvertebrate assemblages at the local and regional scale

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    The biodiversity and species richness of benthic macroinvertebrate assemblages are under the strong pressure of environmental variables compounded with geographical and historical processes. Numerous studies that have investigated biodiversity and assemblage stability have shown the importance of choosing proper methodologies and paradigms. Consequently, the use of diversity measures and the partitioning of biodiversity at different spatial and temporal scales are of particular significance. Within habitats, only those species whose preferences remain within a tolerable range of the variability of abiotic factors are able to survive. The structure of biocoenosis at the local scale is determined mainly by current velocity/discharge, granulometry of the inorganic bottom substrate, quantity and quality of particulate organic matter, as well as water quality variables. Dispersion plays a key role in shaping regional diversity gradients, which supports the permanent inflow of individuals and their exchange between riverine basins. However, dispersion is also one of the basic aspects of the saturation/non-saturation of local communities with species from the regional species pool; a respective concept tries to determine how, why and to what degree local species richness is dependent on regional species richness

    Atomically Precise Expansion of Unsaturated Silicon Clusters

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    Small- to medium-sized clusters occur in various areas of chemistry, for example, as active species of heterogeneous catalysis or as transient intermediates during chemical vapor deposition. The manipulation of stable representatives is mostly limited to the stabilizing ligand periphery, virtually excluding the systematic variation of the property-determining cluster scaffold. We now report the deliberate expansion of a stable unsaturated silicon cluster from six to seven and finally eight vertices. The consecutive application of lithium/naphthalene as the reducing agent and decamethylsilicocene as the electrophilic source of silicon results in the expansion of the core by precisely one atom with the potential of infinite repetition

    Dopant clustering and vacancy ordering in neodymium doped ceria

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    Lanthanide doped cerias, show fast oxide ion conduction and have applications as electrolytes in intermediate temperature solid oxide fuel cells. Here, we examine the long- and short-range structures of Ce1−xNdxO2−x/2 (0.05 ≤ x ≤ 0.30, NDC) using reverse Monte Carlo modelling of total neutron scattering data, supported by measurements of electrical behaviour using a.c. impedance spectroscopy. Three distinct features are evident in the local structure of NDC, viz.: clustering of Nd3+ cations, preferred Nd3+-oxide ion vacancy association and oxide ion vacancy clustering with preferential alignment in the 〈100〉 direction. Interestingly, the presence of preferential dopant cation-oxide ion vacancy association is also observed at 600 °C, although diminished compared to the level at room temperature. This suggests a continued contribution of defect association enthalpy to activation energy at elevated temperatures and is reflected in similar compositional variation of high- and low-temperature activation energies

    One Solar Cycle of Heliosphere Observations with the Interstellar Boundary Explorer: Energetic Neutral Hydrogen Atoms Observed with IBEX-Lo from 10 eV to 2 keV

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    The Interstellar Boundary Explorer (IBEX) is a NASA satellite in Earth orbit, dedicated to observing both interstellar neutral atoms entering the heliosphere and energetic neutral atoms (ENAs) from the interstellar boundaries from roughly 10 eV to 6 keV. This work presents the averaged maps, energy spectra, and temporal variability of heliospheric ENA intensities measured with the IBEX-Lo instrument at 1 au at energies between 10 eV and 2 keV, covering one entire solar cycle from 2009 through 2019. These results expand the range in time and energy for studying the globally distributed ENA flux and the IBEX Ribbon. The observed ENA intensities exceed model predictions, in particular below 500 eV. Moreover, the ENA intensities between 50–200 eV energy show an unexpected rise and fall around the year 2015 in most sky regions

    Differential Cathelicidin Expression in Duodenal and Gastric Biopsies from Tanzanian and German Patients

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    Epithelial surfaces such as the gastrointestinal mucosa depend on expression of antimicrobial peptides like cathelicidin for immune defence against pathogens. The mechanisms behind mucosal cathelicidin regulation are incompletely understood. Cathelicidin expression was analysed in duodenal, antral and corpus/fundic mucosal biopsies from African and German patients. Additionally, cathelicidin expression was correlated with Helicobacter pylori (HP) infection and the inflammatory status of the mucosa. High cathelicidin transcript abundance was detected in duodenal biopsies from African subjects. On the contrary, cathelicidin mRNA expression was either undetectable or very low in tissue specimens from German patients. Also, in the antrum and corpus/fundus regions of the stomach significantly higher cathelicidin transcript levels were measured in Tanzanian compared to German patients. In gastric biopsies from African patients cathelicidin expression was increased in HP positive compared to HP negative subjects. Additionally, the inflammatory status measured by IL-8 expression correlated well with the HP infection status. A higher duodenal and gastric cathelicidin expression in African (compared with European) individuals may be due to upregulation by antigenic stimulation and may confer a higher resistance against enteric infections

    A combination of three surface modifiers for the optimal generation and application of natural hybrid nanopigments in a biodegradable resin

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    Our purpose was to improve the thermal, mechanical and optimal properties of an epoxy bioresin using optimum hybrid natural pigments previously synthesised in our lab. Next, we searched for the best combinations of factors in the synthesis of natural hybrid nanopigments and then incorporated them into the bioresin. We combined three structural modifiers in the nanopigment synthesis, surfactant, coupling agent (silane) and a mordant salt (alum), selected to replicate mordant textile dyeing with natural dyes. We used Taguchi s design L8 to seek final performance optimisation. We selected three natural dyes, chlorophyll, beta-carotene and beetroot extract, and used two laminar nanoclay types, montmorillonite and hydrotalcite. The thermal, mechanical and colorimetric characterisation of the composite obtained by mixing natural hybrid nanopigments (bionanocomposite) was made. The natural dye interactions with both nanoclays improved the thermal stabilities, colour performance and UV VIS light exposure stability of natural dyes and bioresins. The best bionanocomposite materials were found in an acidic pH [3, 4] environment and by modifying nanoclays with mordant and surfactant during the nanopigment synthesis processWe thank the Spanish Ministry of Economy and Competitiveness for funding Projects DPI2011-30090-C02-02 and DPI2015-68514-R.Micó Vicent, B.; Jordán Núñez, J.; Martinez Verdu, FM.; Balart Gimeno, RA. (2017). A combination of three surface modifiers for the optimal generation and application of natural hybrid nanopigments in a biodegradable resin. Journal of Materials Science. 52(2):889-898. https://doi.org/10.1007/s10853-016-0384-8S889898522Majdzadeh-Ardakani K, Nazari B (2010) Improving the mechanical properties of thermoplastic starch/poly(vinyl alcohol)/clay nanocomposites. Compos Sci Technol 70(10):1557–1563. doi: 10.1016/j.compscitech.2010.05.022Najafi N, Heuzey MC, Carreau PJ (2012) Polylactide (PLA)-clay nanocomposites prepared by melt compounding in the presence of a chain extender. Compos Sci Technol 72(5):608–615. doi: 10.1016/j.compscitech.2012.01.005Acharya H, Srivastava SK, Bhowmick AK (2007) Synthesis of partially exfoliated EPDM/LDH nanocomposites by solution intercalation: structural characterization and properties. Compos Sci Technol 67(13):2807–2816. doi: 10.1016/j.compscitech.2007.01.030Marras SI, Zuburtikudis I, Panayiotou C (2007) Nanostructure vs. microstructure: morphological and thermomechanical characterization of poly(L-lactic acid)/layered silicate hybrids. Eur Polymer J 43(6):2191–2206. doi: 10.1016/j.eurpolymj.2007.03.013Leszczyńska A, Njuguna J, Pielichowski K, Banerjee JR (2007) Polymer/montmorillonite nanocomposites with improved thermal properties: Part I. Factors influencing thermal stability and mechanisms of thermal stability improvement. Thermochim Acta 453(2):75–96. doi: 10.1016/j.tca.2006.11.002Park HM, Lee WK, Park CY, Cho WJ, Ha CS (2003) Environmentally friendly polymer hybrids Part I Mechanical, thermal, and barrier properties of thermoplastic starch/clay nanocomposites. J Mater Sci 38(5):909–915. doi: 10.1023/a:1022308705231Porter D, Metcalfe E, Thomas MJK (2000) Nanocomposite fire retardants—a review. Fire Mater 24(1):45–52. doi: 10.1002/(sici)1099-1018(200001/02)24:13.0.co;2-sRay SS, Okamoto M (2003) Polymer/layered silicate nanocomposites: a review from preparation to processing. Prog Polym Sci 28(11):1539–1641. doi: 10.1016/j.progpolymsci.2003.08.002Gao D, Li R, Lv B, Ma J, Tian F, Zhang J (2015) Flammability, thermal and physical-mechanical properties of cationic polymer/montmorillonite composite on cotton fabric. Compos B Eng 77:329–337. doi: 10.1016/j.compositesb.2015.03.061LeBaron PC, Wang Z, Pinnavaia TJ (1999) Polymer-layered silicate nanocomposites: an overview. Appl Clay Sci 15(1–2):11–29. doi: 10.1016/s0169-1317(99)00017-4Karuntarut Sermsantiwanita SP (2012) Preparation of bio-based nanocomposite emulsions: effect of clay type. Prog Org Coat 74:660–666Pascual J, Fages E, Fenollar O, Garcia D, Balart R (2009) Influence of the compatibilizer/nanoclay ratio on final properties of polypropylene matrix modified with montmorillonite-based organoclay. Polym Bull 62(3):367–380. doi: 10.1007/s00289-008-0018-7Beltrán MI, Benavente V, Marchante V, Marcilla A (2013) The influence of surfactant loading level in a montmorillonite on the thermal, mechanical and rheological properties of EVA nanocomposites. Appl Clay Sci 83–84:153–161. doi: 10.1016/j.clay.2013.08.028Bitinis N, Verdejo R, Maya EM, Espuche E, Cassagnau P, Lopez-Manchado MA (2012) Physicochemical properties of organoclay filled polylactic acid/natural rubber blend bionanocomposites. Compos Sci Technol 72(2):305–313. doi: 10.1016/j.compscitech.2011.11.018Sanchez-Garcia MD, Lopez-Rubio A, Lagaron JM (2010) Natural micro and nanobiocomposites with enhanced barrier properties and novel functionalities for food biopackaging applications. Trends Food Sci Technol 21(11):528–536. doi: 10.1016/j.tifs.2010.07.008Huskić M, Žigon M, Ivanković M (2013) Comparison of the properties of clay polymer nanocomposites prepared by montmorillonite modified by silane and by quaternary ammonium salts. Appl Clay Sci 85:109–115. doi: 10.1016/j.clay.2013.09.004Osman MA, Rupp JEP, Suter UW (2005) Effect of non-ionic surfactants on the exfoliation and properties of polyethylene-layered silicate nanocomposites. Polymer 46(19):8202–8209. doi: 10.1016/j.polymer.2005.06.101Wang H, Fang P, Chen Z, Wang S, Xu Y, Fang Z (2008) Effect of silane grafting on the microstructure of high-density polyethylene/organically modified montmorillonite nanocomposites. Polym Int 57(1):50–56. doi: 10.1002/pi.2310Montgomery DC (2008) Design and analysis of experiments. Wiley, HobokenBaena-Murillo E, Micó-Vicent B, Martínez-Verdú FM (2013) Method for the synthesis of nanostructured hybrid pigments having properties that can be syntonized. https://patentscope.wipo.int/search/en/detail.jsf?docId=WO2013110841&recNum=229&docAn=ES2013070026&queryString=(ANA:ES)&maxRec=25813Kohno Y, Inagawa M, Ikoma S, Shibata M, Matsushima R, Fukuhara C, Tomita Y, Maeda Y, Kobayashi K (2011) Stabilization of a hydrophobic natural dye by intercalation into organo-montmorillonite. Appl Clay Sci 54(3):202–205. doi: 10.1016/j.clay.2011.09.001Kaneko Y, Iyi N, Bujdak J, Sasai R, Fujita T (2004) Effect of layer charge density on orientation and aggregation of a cationic laser dye incorporated in the interlayer space of montmorillonites. J Colloid Interface Sci 269(1):22–25. doi: 10.1016/s0021-9797(03)00602-7Silva AA, Dahmouche K, Soares BG (2011) Nanostructure and dynamic mechanical properties of silane-functionalized montmorillonite/epoxy nanocomposites. Appl Clay Sci 54(2):151–158. doi: 10.1016/j.clay.2011.08.002Park S-J, Kim B-J, Seo D-I, Rhee K-Y, Lyu Y-Y (2009) Effects of a silane treatment on the mechanical interfacial properties of montmorillonite/epoxy nanocomposites. Mater Sci Eng A 526(1–2):74–78. doi: 10.1016/j.msea.2009.07.023Khraisheh MAM, Al-Ghouti MA, Allen SJ, Ahmad MN (2005) Effect of OH and silanol groups in the removal of dyes from aqueous solution using diatomite. Water Res 39(5):922–932. doi: 10.1016/j.watres.2004.12.008Fahn R, Fenderl K (1983) Reaction-products of organic-dye molecules with acid-treated montmorillonite. Clay Miner 18(4):447–458. doi: 10.1180/claymin.1983.018.4.10Kohno Y, Totsuka K, Ikoma S, Yoda K, Shibata M, Matsushima R, Tomita Y, Maeda Y, Kobayashi K (2009) Photostability enhancement of anionic natural dye by intercalation into hydrotalcite. J Colloid Interface Sci 337(1):117–121. doi: 10.1016/j.jcis.2009.04.065Capilla P, Pujol J (2002) Fundamentos de Colorimetría. Universitat de ValenciaGilabert EJ, Verdú FMM (2007) Medida de la luz y el color. Editorial de la UPV. In: Color psicofísico, pp 185–221Zhao H, Nagy KL (2004) Dodecyl sulfate–hydrotalcite nanocomposites for trapping chlorinated organic pollutants in water. J Colloid Interface Sci 274(2):613–624. doi: 10.1016/j.jcis.2004.03.05
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