Studia Musicologica Academiae Scientiarum Hungaricae. Register. Tomi XXI–XL (1979–1999)

Chapter I constitutes an alphabetic catalogue of all studies and reviews included in the twenty volumes of Studia Musicologica, according to authors. Chapter II lists the publications (books, music etc.) reviewed in Studia Musicologica. Chapter III provides a name and subject index, with numbers referring to Chapter I

Surface charge characterization of metal oxides by potentiometric acid–base titration, revisited theory and experiment

The increased interest in architecting nanocomposites and in clarifying their impact on health and environment necessitates a standardized method of surface characterization, because the behaviour of nanoparticles is governed largely by their surface free energy and interfacial chemistry. Potentiometric acid–base titration has been used for decades to determine surface charge density of oxides, tremendously useful in understanding and modelling oxide/electrolyte interfaces. The method has solid theoretical and experimental foundation. Yet, published values of the point of zero charge (PZC) of chemically identical oxides scatter widely: the deviation of seven units of pH is the rule, rather than an exception. The PZC must reflect the inherent charging behaviour, linked exclusively to the protonation, and determined by the chemistry of the oxides. Assignment of PZC (just like assignment of equilibrium constant of any chemical reaction) requires strict conditions and consistent protocol. We present here such a protocol, and some examples of application. The protocol leads through the basic steps: pH buffer calibration, proton concentration calibration in the background electrolytes, and titrations of oxides. Built-in tests help to eliminate artificial side effects simultaneously from the measurement of pH and from the oxide/electrolyte interfacial equilibria. Although these may seem self-evident, literature survey proves the need to go back to basics in order to obtain precise, reliable and comparable pH-dependent charging of oxides. It is most general that the oxides contain some unrecognized surface impurities and have a strongly pH-dependent dissolution. These distort the results of titrations; their effect increases with decreasing particle size and can become dominant for nanoparticles. The protocol presented here contains the necessary feedback loops to easily recognize and exclude these side effects

Kompozit nanofilmek előállítása a komponensek rétegenkénti önrendeződéses adszorpciójával = Preparation of composite nanofilms using layer-by-layer self-assembly

A kutatási munka ereményeit a következő megállapításokban foglalom össze: 1) kidolgoztuk a kompozit nanofilmek felépítésében a hordozó felülethez rögzítés optimális módszerét 2) a részecske-polielektrolit multiréteges nanofilmek felépítéséhez alacsony disszociációfokú polielektrolitra van szükség 3) a részecske-polielektrolit filmek rétegszámát a részecske szuszpenzió töménysége befolyásolja 4) felületmódosított Stöber szilika részecskék alkalmasak rendezett szerkezetű mono- és multirétegek felépítésére L-B technikával 5) a Stöber szilika L-B filmek rendezettségét csökkentik a felületaktív adalékanyagok 6) új Stöber szilika felületmódosítási eljárást dolgoztunk ki 7) multiréteges nanofilmek L-B technikával történő kialakításakor a rétegek síkjára merőleges irányban a rendezettség egyenletes 8) a globuláris protein - agyagásvány filmekben a multiréteg képződés kizárólag az elektrosztatikai vonzó lölcsönhatásokra épül 9) a globuláris protein-agyagásvány filmekben a rétegek közötti összetartó erő a két egymást követő agyagásvány réteg részecskéinek horizontális átlapolódásából származik 10) a globuláris proteinek adszorpciója az agyagásvány lamella-réteggel borított felületen nő a protein molekulatömegének csökkeésével és töltéssűrűségének növekedésével 11) a multiréteges globuláris protein-agyagásvány lamella szerkezetek felületi durvasága a beépülő protein méretével nő | The project results are summarized as follows: 1) the anchoring method of film bilding strategy was optimized 2) particle-polyelectrolyte films can be build using weakly dissociated, low-charge polyelectrolytes 3) the particle suspension concentration infulences the possible number of layers that can be built 4) ordered two-dimensional nanofilms can be built with surface modified Stöber silica particles by using the Langmuir-Blodgett method 5) surfactant additives will decrease the ordering quality in the 2-D Stöber films 6) a new method of surface modification of Stöber silica particles has been worked out, for L-B deposition 7) in L-B deposition technique, the ordering of layers is of high quality, orthogonally to the plane of the layers 8) the multilayer formation from globular proteins with lamellar clay particles is vased solely on the electrostatic attraction forces 9) in the globular protein-layered clay particle multilayered films the film coherence is due to horizontal overlapping of the particles in the subsequent layers 10) the adsorption of globular proteins on the clay particle layer is governed by the size and the charge density of the protein 11) the size of the globular proteins directs the surface roughness of protein lamellar clay particle film

Genetic background of neurological diseases

4.1 The MTHFR A1298C variant in leukoaraiosis Previous studies demonstrated that an elevated serum homocysteine level may be associated with LA. Also, an elevated serum homocysteine level is presumed to be associated with an endothelial dysfunction or microangiopathy. The genetic studies relating to the MTHFR C677T variant suggest that, although the 677T variant is unfavourable because it raises the serum homocysteine level, it does not increase the risk of contracting LA if it is present on its own. We also demonstrated earlier that the 677T variant in combination with other genetic variants increases the risk of contracting LA. The present study reveals that a person carrying either a heterozygous A1298C or a homozygous 1298CC variant is at a higher risk of contracting LA than one carrying neither of them. This genetic variant has not been examined so far in any LA case–control study. Our findings therefore suggest for the first time that the A1298C variant may be more important than the C677T variant in the evolution of LA. We also found that the heterozygous C677T and A1298C variants do 8 not pose a risk of contracting LA if they are present by themselves. However, their combination in the same person leads to a marked risk of contracting LA. Here, although the number of patients displaying the combination of the two heterozygous MTHFR variants was low, the significance level relating to the approximately tenfold increase in the unfavourable combination in the LA group compared with that in the control group suggests that there is a definite link. At present the exact cause of this synergistic effect is not known. However, two possible explanations readily emerge. They are: (1) the two variants can potentially increase the serum homocysteine level in an additive manner and (2) the co-occurrence of the two unfavourable MTHFR genetic variants may influence the regulation of the enzyme. A properly balanced regulation of the MTHFR may be a key factor that can define the daily shifts in the serum homocysteine level. The clustering of the A1298C and C677T variants might give rise to an unfavourable regulatory nature in the dynamically changing activity of the MTHFR. Then the presence of the two heterozygous variants might result in a significantly unfavourable phenotype of the conformation of the enzyme protein. 4.2 The absolute number of mitochondria per cell in leukocyte cells in leukoaraiosis The basic contents for mDNA and dmDNA were found to be statistically the same in the LA group and control group, and the K value was significantly lower for the LA group than that for the control group. This suggested that there was a larger proportion of dmDNA present. Having dmDNA may possibly lead to a mitochondrial malfunction in the following way: a, lower energy production; b, a lower free radical scavenging capacity; c, a lower rate of adaptation to the prevailing demand for energy production; d, a narrower range in the adjustment to the prevailing energy demand; e, a lower metabolic function capacity in general; f, a greater extent of free radical production; and g, a general malfunction of the mitochondrial genetic regulation. No genetic or biochemical data is available to suggest which of these postulated mechanisms actually exist, but a lower and narrower energy capacity appears probable as the main pathomechanism behind LA. It was demonstrated earlier at the molecular level that LA can arise from a very slight, but chronic level of hypoxia, which may be caused by various environmental and genetic susceptibility factors. Our present findings agree with the earlier ones that uncoupling protein genetic variants play a role in the development of LA. The uncoupling proteins govern the electro-chemical gradient between the inner and outer spaces of the mitochondria, this gradient being essential for the energy production of the mitochondria. If dmDNA is associated with any kind of biochemical malfunction, an uncompensated and larger proportion of dmDNA in the cells may be unfavourable from an energetic viewpoint. Our results appear to indicate that the lower the difference between the contents of mDNA (which compensates for malfunctions of the dmDNA) and dmDNA, the larger the risk of contracting LA in a given individual..

A kerecsensólyom (Falco cherrug) élőhely-preferencia vizsgálatának tapasztalatai a Hevesi-sík mintaterületen

Cikkünkben egy jeladóval felszerelt hím kerecsensólyom mozgásterület meghatározásáról és élőhely-preferencia vizsgálatáról számolunk be. Eredményeinkkel támpontot szeretnénk nyújtani egy kerecsensólyom élőhely-védelmi agrár-környezeti célprogram megvalósításához. Vizsgálatainkat térinformatikai és biostatisztikai elemzési módszerek alkalmazásával végeztük mintaterületünkön, a Hevesi-síkon. A Kernel-módszerrel meghatározott mozgáskörzeten belül Ivlev-index számításával végeztük el a különböző mezőgazdasági kultúrák preferenciájának vizsgálatát. Eredményeink egyrészt azt mutatták, hogy az alkalmazott módszerek használata egyszerű, de körültekintést igényel, másrészt a vizsgált mintaterület esetében a jelenlegi vegetáció struktúra a kerecsensólyom számára jó élőhelyet biztosít, hiszen a madár a mozaikos, különböző mezőgazdasági kultúrák alkotta élőhelyen mindig talált vadászatra alkalmas területet. Munkánkat – A kerecsensólyom védelme a Kárpát-medencében – című LIFE program (LIFE06 NAT/HU/000096) támogatta

Mechanism of in situ surface polymerization of gallic acid in an environmental-inspired preparation of carboxylated core-shell magnetite nanoparticles.

Magnetite nanoparticles (MNPs) with biocompatible coatings are good candidates for MRI (magnetic resonance imaging) contrasting, magnetic hyperthermia treatments, and drug delivery systems. The spontaneous surface induced polymerization of dissolved organic matter on environmental mineral particles inspired us to prepare carboxylated core-shell MNPs by using a ubiquitous polyphenolic precursor. Through the adsorption and in situ surface polymerization of gallic acid (GA), a polygallate (PGA) coating is formed on the nanoparticles (PGA@MNP) with possible antioxidant capacity. The present work explores the mechanism of polymerization with the help of potentiometric acid-base titration, dynamic light scattering (for particle size and zeta potential determination), UV-vis (UV-visible light spectroscopy), FTIR-ATR (Fourier-transformed infrared spectroscopy by attenuated total reflection), and XPS (X-ray photoelectron spectroscopy) techniques. We observed the formation of ester and ether linkages between gallate monomers both in solution and in the adsorbed state. Higher polymers were formed in the course of several weeks both on the surface of nanoparticles and in the dispersion medium. The ratio of the absorbances of PGA supernatants at 400 and 600 nm (i.e., the E4/E6 ratio commonly used to characterize the degree of polymerization of humic materials) was determined to be 4.3, similar to that of humic acids. Combined XPS, dynamic light scattering, and FTIR-ATR results revealed that, prior to polymerization, the GA monomers became oxidized to poly(carboxylic acid)s due to ring opening while Fe(3+) ions reduced to Fe(2+). Our published results on the colloidal and chemical stability of PGA@MNPs are referenced thoroughly in the present work. Detailed studies on biocompatibility, antioxidant property, and biomedical applicability of the particles will be published

PEGylation of surfacted magnetite core–shell nanoparticles for biomedical application

The surface of oleate double layer coated (surfacted) magnetite nanoparticles (OA@MNPs) was coated by PEG (poly(ethylene glycol) of Mw=1000, 4000 or 20,000Da, respectively, to get core-shell structured nanomagnets. The oleate bilayers were prepared in two different ways; (i) oleic acid was added directly into the magnetite co-precipitation mixture containing the MNPs to obtain OA@s-MNP samples - s-MNP standing for "as-synthesized MNP" and (ii) sodium oleate (oleate anion, OA) was added to the purified MNPs to obtain OA@p-MNP samples - p-MNP standing for "purified MNP". The effect of the surfactant addition method on the pH- and ionic strength-dependent stability (dynamic laser light scattering and laser-Doppler electrophoresis experiments), the biomedical applicability (MRI measurements) and the biocompatibility (blood sedimentation and blood smear tests) of the core-shell MNPs was studied. Different mechanisms of oleate adsorption were found in ATR FT-IR experiments (inner sphere surface complexation via ligand exchange for the s-MNPs and additional H-bonding for the p-MNPs), suggesting different behaviour. The colloidal stability and salt tolerance of the two kinds of OA@MNPs were similar, but the hydrodynamic diameter of the OA@s-MNP was considerably larger than that of OA@p-MNP. In accordance with this, the r2 relaxation was also higher for the s-MNP samples (~400 and ~200mM-1s-1, respectively). The physico-chemical tests indicate that the OA-coated MNPs form clusters and the degree of clustering of OA@s-MNPs is significantly greater than that of OA@p-MPNs. PEGylation does not appear to affect colloidal stability and salt tolerance meaningfully. The adsorption of PEG was proved experimentally. We have found that the PEG top layer decreases the electrostatic contribution, nevertheless increases the steric contribution of the original electrosteric stabilization caused by the OA double layer. However, an increase in the molecular weight above 1000Da and the amount of added PEG above 5mmol/g gradually reduces the salt tolerance of the samples. The results indicate strong potential for biomedical application and biocompatibility of the PEGylated MNPs

Az antocianin összetétel és kivonhatóság, valamint a szőlőbogyók textúra változásának vizsgálata az érés folyamán különböző termőhelyeken és évjáratokban

Az Egri borvidék két eltérő jellegű termőhelyén (Nagy Eged-hegy, Kőlyuktető), két évjáratban vizsgáltuk a Kékfrankos szőlőfajta fenolos érésdinamikai sajátosságait. Három szüreti időpontban néztük a bogyóhéj és a borok antocianin koncentrációját és összetételét. Vizsgáltuk továbbá azt is, hogy milyen összefüggés van a bogyók érése során bekövetkezett textúra változások és az antocianinok kivonhatósága között. A termőhelyeket és az évjáratokat kihelyezett automata meteorológiai állomások által gyűjtött klimatikus adatok, valamint helyben végzett fotoszintézis mérések segítségével jellemeztük. A bogyó textúra paraméterek mérése nagy felbontású textúra elemzővel történt. Kísérleti borok mindkét évben három szüreti időpontban készültek, mindkét termőhelyről. A szüreti alapanalitikát kiegészítve, az egyes szüreti időpontokban bogyóhéj kivonatok is készültek, amelyekből HPLC segítségével az antocianin koncentráció és összetétel is meghatározásra került. A 2012-ben lehullott nagyobb csapadékmennyiség ellenére, ez az év szárazabb volt, mint 2011. Ez a magasabb hőmérséklet miatt bekövetkezett intenzívebb párolgásnak volt köszönhető. Nagy Eged-hegy termőhelyen mindkét évben enyhe, közepesen erős vízhiány alakult ki, amit az élettani mérések is igazoltak. A termőhelyek eltérő bogyó textúra paramétereket mutattak mindkét évben. A bogyóhéj rugalmasságának változása azonban mindkét termőhelyen és mindkét évjáratban azonos trendet képviselt és erős összefüggést mutatott a színanyagok kivonhatóságával évjárattól függetlenül. Az érési időszak elején a bogyóhéj antocianin koncentrációja általában magasabb volt a síkvidéki termőhelyen, de ez különbség a szüret előrehaladtával fokozatosan kiegyenlítődött a két hely között. A boroknál azonban, a lejtős, déli kitettségű termőhely mutatott jelentősen magasabb antocianin koncentrációt minden szüreti időpontban és mindkét vjáratban. Mivel a termőhelyek között nem volt különbség a bogyóhús/héj arányában, ezért feltételezhető, hogy a kialakult különbség az eltérő kivonhatóságnak volt köszönhető. A bogyóhéj és a borok antocianin összetétele elsősorban az évjárattól függött, a termőhelynek nem volt jelentős hatása annak kialakításában

Striking analogies and dissimilarities between graphene oxides and humic acids: pH-dependent charging and colloidal stability

This study provides a comparative framework on the elucidation of analogies and differences in the interfacial protolytic processes and the associated colloidal behaviour of a typical humic acid (HA) and a set of singlelayer graphene oxide (SLGO) and (multi-layered) graphite oxide samples in aqueous electrolyte media. The pH dependence of the surface charge densities of HA and SLGO was explored at three different salt concentrations by potentiometric acid-base titration, along with simultaneous determination of zeta potential and hydrodynamic sizes. Charging curves obtained in the pH range of 3 to 10 by cyclic titrations reveal the presence of a small hysteresis, proving the chemical stability of SLGO and graphite oxides in weakly acidic and alkaline solutions. HAand SLGOdisplay a parallel shift of the pH-dependencies of their negative charge densities with increasing ionic strength, demonstrating a unique combination of particle and polyelectrolyte-like behaviour, which is absent formulti-layered graphite oxide exhibiting charging curves that resemble to “classical” colloidal particles. An accurate purification of SLGO results in inherent change in its surface properties; however, the salt tolerance of aqueous HA solutions is still superior to that of SLGO dispersions