38 research outputs found

    A versatile characterization of poly(N-isopropylacrylamideco- N,N'-methylene-bis-acrylamide) hydrogels for composition, mechanical strength, and rheology

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    Poly(N-isopropylacrylamide-co-N,N"-methylene-bisacrylamide) (P(NIPAAm-co-MBA)) hydrogels were prepared in water using redox initiator. The copolymer composition at high conversion (> 95%) was determined indirectly by HPLC (high performance liquid chromatography) analysis of the leaching water and directly by solid state 13C CP MAS NMR (cross polarization magic angle spinning nuclear magnetic resonance) spectroscopy of the dried gels, and was found to be close to that of the feed. The effect of cross-linker (MBA) content in the copolymer was investigated in the concentration range of 1.1–9.1 mol% (R:90–10; R = mol NIPAAm/mol MBA) on the rheological behaviour and mechanical strength of the hydrogels. Both storage and loss modulus decreased with decreasing cross-linker content as revealed by dynamic rheometry. Gels R70 and R90 with very low cross-linker content (1.2–1.5 mol% MBA) have a very loose network structure, which is significantly different from those with higher cross-linker content manifesting in higher difference in storage modulus. The temperature dependence of the damping factor served the most accurate determination of the volume phase transition temperature, which was not affected by the cross-link density in the investigated range of MBA concentration. Gel R10 with highest cross-linker content (9.1 mol% MBA) behaves anomalously due to heterogeneity and the hindered conformation of the side chains of PNIPAAm

    Magnesium incorporation into primary dental enamel and its effect on mechanical properties

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    Cross-sectional study of sound primary dental enamel revealed hardness zonation and, in parallel, significant change in the Mg content below the prismless layer. Mg content is known to play an important role in enamel apatite biomineralization, therefore, Mg ion exchange experiments were carried out on the outer surface of sound primary molars and on reference abiogenic Ca-phosphates using MgCl2 solution. Effects of Mg incorporation on crystal/particle size, ionic ratio and morphology were compared and the observed changes were explained by parallel diffusion and dissolution/reprecipitation processes. Based on depth profile analysis and high resolution electron microscopy of the Mg-exchanged dental enamel, a poorly ordered surface layer of approximately 10–15 nanometer thickness was identified. This thin layer is strongly enriched in Mg and has non-apatitic structure. Below the surface layer, the Mg content increased only moderately (up to ~3 at%) and the apatite crystal structure of enamel was preserved. As a common effect of the Mg exchanged volume, primary dental enamel exhibited about 20% increase of nanohardness, which is intrepreted by strengthening of both the thin surface layer and the region below due to the decreased crystallite size and the effect of incorporated Mg, respectively

    Investigation of the Tetrakis(dimethylamino)hafnium and H2S ALD Process: Effects of Deposition Temperature and Annealing

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    HfS2 has recently emerged as a promising 2D semiconductor, but the lack of a reliable method to produce continuous films on a large scale has hindered its spreading. The atomic layer deposition of the material with the precursor tetrakis-dimethylamino-hafnium with H2S is a rela- tively novel solution to this problem. This paper shows that it is a facile approach to synthesizing homogeneous and smooth HfS2 layers in a controlled and reproducible manner. The deposition is examined at different temperatures and layer thicknesses, exploring the ALD window of the deposition and the chemical, morphological and electronic properties of the films. The method yielded films with wafer-sized uniformity and controlled properties and is, thus, a promising way to prepare this important transition metal dichalcogenide material

    Predicting the Number of GHB-Related Toxicologic Admissions Using Google Trends Data

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    Abstract In the era of novel psychoactive substances (NPS), the internet became a relevant source of information and purchase for those who consume psychoactive drugs. Parallelly, a growing body of research aim to utilize web search metrics (most commonly by relying on Google Trends data) in the prediction of substance use-related trends, including epidemiological forecasting. The main goal of the current study was to assess the utility of web search queries in the prediction of Gamma-hydroxybutyrate (GHB)-related toxicologic admissions in Hungary by performing additive decomposition of time series to identify trend and seasonal components. Monthly data identified GHB-related search volume representing nationwide web interest towards this substance was found to be a significant covariate of admission rates; the seasonal component showed two peaks in the admission rates: one in December/January and another one in May, whereas more admissions on the weekends were observed as compared to weekday data in Hungary. By taking into account the subtle effect sizes of this study, these results suggest that Google Trends data may be useful in forecasting toxicologic admissions on a monthly level, yet a number of limitations should be considered when interpreting these associations. Web search metrics can therefore be used for early warning purposes in the field of toxicology as well. An external validation approach is also suggested by the authors

    Reactive Sputter Deposition of Ga2O3 Thin Films Using Liquid Ga Target

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    Ga2O3 is a promising material in the optoelectronics and semiconductor industry. In this work, gallium oxide thin films were deposited via radio frequency (RF) sputtering, using a liquid Ga target. The reactive sputtering was carried out using different oxygen flow rates and DC target potentials induced via the RF power. The thickness of the samples varied between 160 nm and 460 nm, depending on the preparation conditions. The composition and the refractive index of the layers were investigated via energy-dispersive spectroscopy, X-ray photoelectron spectroscopy, and spectroscopic ellipsometry, respectively. It was found that, through the use of a lower DC target potential, a better film quality and higher oxygen content can be achieved. The reactive sputtering was modeled based on the Berg model, with the aim of determining the sputtering yields and the sticking coefficient. It was shown that an increase in DC target potential leads to the preferential sputtering of gallium

    Kosztolányi nemzedéke és a háború (1914--1918)

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    SZEGEDY-MASZÁK MIHÁLY Az első világháború a prózairodalomban * DOBOS ISTVÁN Történelem és retorika – Kosztolányi háborús írásai a zsidóságról – * BUCSICS KATALIN Két pékről – Kosztolányi történelemszemléletéhez * FAGYAS RÓBERT „Menj haza gyermekem és halj meg az álomban” Kosztolányi Dezső Beteg lelkek című, 1912-ben megjelent kötetének olvasati lehetőségei az első világháború idején keletkezett Pokol című novella tükrében * GYŐREI ZSOLT „Anno 1916” Kabaré a világháborúban – Kosztolányi a kabaréban * HUTVÁGNER ÉVA Emberek és automaták a Káin kötetében (Kosztolányi Dezső A szörny című bábjátékáról) * PINTÉR BORBÁLA A személyiség önazonosságának kérdése Kosztolányi Dezső Káin kötetének novelláiban * TAKÁCS LÁSZLÓ Kosztolányi és a császárok * BALOGH GERGELY Antropológia, technicitás, nyelv és irodalom Karinthy Frigyes: Utazás Faremidóba * BORBÁS ANDREA „Akadozott lélegzetvételek” – Az Ady-líra és -próza beszédmódjai az első világháborús cenzúra szorításában * BUDA ATTILA Ambrus Zoltán háborús jegyzetei a Nyugat-ban (1915–1917) * KELEVÉZ ÁGNES „Azon a napon derékba törve, kétfelé oszlik az életem” Babits és a háború vihara * MOLNÁR ESZTER EDINA „… főbe lövöm magam, hogy elkerüljem a halálra kínoztatást…” Csáth Géza halálhoz való viszonya az első világháború vonatkozásában * SULYOK BERNADETT Tersánszky Józsi Jenő első világháborús élményeinek megjelenése primer és szekunder szinten, levelezésében és három regényében * VARGA KINGA A háború, mint kötetkompozíciós tényező Kaffka Margit és Szép Ernő I. világháború alatt megjelent köteteiben * VERES MIKLÓS Egy új világháborútól a tökéletes társadalomig – Az első világháború hatása a hazai utópisztikus és sci-fi irodalomra * Képmellékle

    In situ ductails emlőcarcinoma kombinált sebészi- és sugárkezelése: Multicentrikus prospektív randomizált vizsgálat = Combined surgical and radiotherapy treatment of ductal carcinoma in situ of the breast: Multicentric prospective randomized study

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    289 duktális in situ emlőrák (DCIS) miatt emlőmegtartó műtéttel kezelt beteget randomizáltunk a lokális recidíva szempontjából meghatározott rizikó csoportok szerinti besorolás után. Immunhisztokémiai (IHK) módszerrel vizsgáltuk a lehetséges molekuláris prognosztikai markerek (ER, PR, Her2, p53, Bcl2 és Ki-67) expresszióját. A pozitív IHK reakció a Her2 (38%), p53 (36%) és Ki-67 (47%) markereknél a nukleáris grade-del korrelált. Ezzel szemben az ER (77%), PR (67%) és Bcl2 (67%) pozitivitás szignifikáns inverz összefüggésben volt a grade-del. A klinikai eredményeket 3 éves medián követési idő után 278 betegnél elemeztük. A magas rizikójú betegcsoportban emlőmegtartó műtét és sugárkezelés után 4 (1,7%) lokális recidíva és 1 (0,4%) távoli áttét alakult ki, emlődaganatos haláleset nem volt. A helyi daganatkiújulás 3 és 5 éves valószínűsége 1,1% és 3,1% volt. Tapasztalataink alapján a DCIS egyértelmű diagnózisa esetén az őrszem nyirokcsomó biopszia rutinszerű elvégzése nem indokolt. Korai eredményeink alapján az emlő DCIS kezelésében az emlőmegtartó műtét és posztoperatív sugárkezelés alkalmazásával a helyi daganatkiújulás éves aránya 1% alatt marad. A tumorágy "boost" kezelés hatékonyságának megítélésére és a vizsgált molekuláris markerek prognosztikai/prediktív értékének elemzésére hosszabb követési idő után lesz lehetőségünk. A molekuláris prognosztikai faktorok IHK vizsgálata segítségünkre lehet a DCIS biológiai heterogenitásának feltérképezésében. | 289 patients with ductal carcinoma in situ (DCIS) treated by breast-conserving surgery were randomised according to predetermined risk groups. Immunohistochemistry (IHC) was performed to detect the expression of potential molecular prognostic markers (ER, PR, Her2, p53, Bcl2, and Ki-67). The positive immunostaining for Her2 (38%), p53 (36%), and Ki-67 (47%) correlated with a high nuclear grade. Significant inverse correlation was found between the expression of ER (77%), PR (67%), Bcl2 (67%) and grade. Clinical results was analysed for 278 patients at a median follow-up of 36 months. In the high-risk patient group 4 (1.7%) local recurrences and 1 (0.4%) distant metastasis occurred. No patient died of breast cancer. The 3- and 5-year probability of local recurrence was 1.1% and 3.1%, respectively. Based on our experience, the definitive diagnosis of DCIS does not warrant sentinel lymph node biopsy. Preliminary results suggest that breast-conserving surgery followed by radiotherapy yields an annual local recurrence rate of less than 1% in patients with DCIS. Further follow-up is needed to define the clinical benefit of tumour bed boost irradiation and to analyse the prognostic/predictive value of molecular prognostic factors. IHC of molecular prognostic markers can assist to gain insight into the biologic heterogeneity of DCIS
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