Non-calorimetric determination of absorbed power during magnetic nanoparticle based hyperthermia

Nanomagnetic hyperthermia (NMH) is intensively studied with the prospect of cancer therapy. A major challenge is to determine the dissipated power during in vivo conditions and conventional methods are either invasive or inaccurate. We present a non-calorimetric method which yields the heat absorbed during hyperthermia: it is based on accurately measuring the quality factor change of a resonant radio frequency circuit which is employed for the irradiation. The approach provides the absorbed power in real-time, without the need to monitor the sample temperature as a function of time. As such, it is free from the problems caused by the non-adiabatic heating conditions of the usual calorimetry. We validate the method by comparing the dissipated power with a conventional calorimetric measurement. We present the validation for two types of resonators with very different filling factors: a solenoid and a so-called birdcage coil. The latter is a volume coil, which is generally used in magnetic resonance imaging (MRI) under in vivo condition. The presented method therefore allows to effectively combine MRI and thermotherapy and is thus readily adaptable to existing imaging hardware.Comment: 7 pages, 3 figures+Supplementary Material (2 pages, 3 figures

A királis felismerés heterogén katalitikus hidrogénezésekben = Chiral recognition in heterogeneous catalytic hydrogenations

A kutatómunka elsősorban a prolin nitrogénen alkilezett származékainak előállítására és ezekből észteresítéssel kondenzált aromás származékaik szintézisére irányult. A feladat célkitűzése onnan ered, hogy voltak korábbi kísérleteink a karboxil csoportján észteresített prolinnal, mint királis módosítóval, ezeket az ígéretes molekulákat akartuk továbbfejleszteni oly módon, hogy a nitrogénen alkilezzük őket. Az alkilezésre a reduktív alkilezés módszerét választottuk és olyan ketonokat (izoforon, etilpiruvát, benzálaceton) használtunk, amelyek prokirálisak. Az alkilezett prolin származékok alkil csoportja pedig az enantioszelektív reakcióban hidrogénezendő vegyületekből származik. Ezzel a reszolválásnál jól ismert, un. ?saját származék hatást? akartuk tanulmányozni, javítja-e a szubsztrátum molekulához hasonló alkil csoport a királis módosító hatást. Előállítottuk a tiszta 3,3,5-trimetilciklohexanont és ennek tiszta enantiomerjeit is. Továbbá a reduktív alkilezéssel megkaptuk az N-(3,3,5-trimetilciklohexil)prolint is enantiomertiszta formában. A kísérleti eredmények alapján valószínűsítettük a reakció mechanizmusát. | The aim of the research was to synthesize the alkylated derivatives of proline and its condensed aromatic derivatives with esterification. This objective originated from our earlier experiments with proline esters as chiral modifiers. These promising molecules could be developed further with alkylation at their N atom. Reductive alkylation was the method of choice, for alkylation such ketones were chosen (isophorone, ethyl pyruvate, benzilydene acetone) which are prochiral. The alkyl group is originating from those substrates, which are hydrogenated in the asymmetric reactions. With this method we wanted to study the so called ''own derivative'' effect which is known from optical resolution, whether the similar alkyl group improves the asymmetric effect, the chiral modification. The pure 3,3,5-trimethyl cyclohexanone and its pure enantiomers were prepared, furthermore the N-(3,3,5-trimethylcyclohexyl)proline was also the product in enantiomerically pure form. A reaction mechanism was proposed

Tomka Béla: Szociálpolitika:Fejlődés, formák, összehasonlítások

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Photometric Determination of Trace Amounts of Aluminum in Nearly Saturated Rock Salt Solutions Used by Chlor-alkali Industry

The previously widespread mercury cell technology in chlorine production has now been replaced by more environmentally friendly membrane cell electrolysis which is a Best Available Techniques (BAT) technology. However, this requires a much cleaner brine containing contaminants (Al, Ca, Mg, etc.) in the order of ng/g at most. For this reason, it’s very important to detect trace amounts of aluminum in concentrated saline media in the simplest and fastest way. To the best of our knowledge, no one has previously developed a spectrophotometric method capable of detecting aluminum in ionic forms selectively in the order of ng/g in concentrated saline media, without any preconcentration or separation step. Our advanced analytical method provides an opportunity for this. During the analytical procedure, a colored complex ion is formed from the dissolved aluminum content of the sample with eriochrome cyanine R (ECR) ligand in buffered pH medium. The sensitivity of the measurement is increased by adding quaternary ammonium salt. The colored complex ion is formed in 15 minutes, then the absorbance measurement can be performed for 90 minutes. The effect of rock salt interference was eliminated by proper calibration. In our work the dependence of the signal on temperature, pH, time elapsed after the addition of reactants, the dosing sequence, the salinity of the medium was examined, furthermore, we studied which wavelength-absorbance values give the best fit (highest R2 value) and the highest sensitivity in case of linear calibration. Surprisingly, increasing the salinity significantly improves the sensitivity of the measurement

Abandoned Hungarian workers and the political economy of care work in Austria

In an era of globalization, the institutional system of mass migration is being substantially reorganized: its intensity and the variation in its forms are increasing. Global production chains combine diverse areas and different forms of work with varying wage levels by forming worldwide networks. In the Eastern European region, the growing level of emigration and relatively low fertility are leading to population loss. Hungary is not among the Eastern European countries with a high level of emigration; nevertheless, it faces serious challenges, particularly in some regions where after the transition losses of jobs were massive, and a greater proportion of people live under the poverty line than the national average. Our analysis is based on interviews, containing narrative and semi-structured parts, among domestic workers working mainly in Austria and Germany. The paper reveals possible causal mechanisms and the political economic structures behind this type of labour migration. We seek to understand how migrationrelated decisions are embedded in a global and highly unequal economic order