1,267 results on '"Természettudományok"'
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2. Die Aczél--Benzsche Funktionalgleichung auf der additiven Gruppe der ganzen Zahlen
- Author
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Daróczy, Zoltán and Kotora, E.
- Subjects
Természettudományok ,General Mathematics ,Matematika- és számítástudományok - Published
- 2022
3. Climatic effects on the distribution of ant- and bat fly-associated fungal ectoparasites (Ascomycota, Laboulbeniales)
- Author
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Edvárd Mizsei, András Tartally, Ferenc Báthori, Philippe Christe, Olivier Glaizot, Walter P. Pfliegler, Danny Haelewaters, Zoltán Rádai, and Tamara Szentiványi
- Subjects
0106 biological sciences ,Ecology ,biology ,Obligate ,Host (biology) ,Ecological Modeling ,Laboulbeniales ,Laboulbeniomycetes ,Zoology ,Biológiai tudományok ,Plant Science ,Hymenoptera ,biology.organism_classification ,010603 evolutionary biology ,01 natural sciences ,Myrmica scabrinodis ,Nycteribiidae ,Természettudományok ,Myrmica ,Ecology, Evolution, Behavior and Systematics ,010606 plant biology & botany - Abstract
Laboulbeniales (Ascomycota: Laboulbeniomycetes) are obligate ectoparasitic fungi of arthropods with a worldwide distribution. Their effects on host physiology and behaviour as well as their ecology have recently gained wider attention. One aspect that is virtually unknown regarding Laboulbeniales and arthropod-associated fungi in general, is how abiotic factors shape the distribution of these parasites. We used ant- and bat fly-associated Laboulbeniales to study whether climatic elements play a role in the distribution of fungal species. We collected uninfected and Laboulbeniales-infected insects belonging to three species: bat flies Nycteribia schmidlii and Penicillidia conspicua (Diptera: Nycteribiidae) and the ant Myrmica scabrinodis (Hymenoptera: Formicidae). We used climatic variables and performed statistical analyses to explain the distribution of Laboulbeniales infection. Our results show a higher likelihood of Laboulbeniales presence in habitats with low annual mean temperature and humidity, suggesting that climatic elements can considerably shape the distribution of Laboulbeniales species.
- Published
- 2019
4. Photocatalytic properties of TiO2@polymer and TiO2@carbon aerogel composites prepared by atomic layer deposition
- Author
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János Mizsei, V. Takáts, Bence Parditka, Zoltán Erdélyi, Krisztina László, Balázs Vince Nagy, Gergő János Mikula, Nóra Justh, László Péter Bakos, and Imre Miklós Szilágyi
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chemistry.chemical_classification ,Materials science ,Supercritical drying ,chemistry.chemical_element ,Fizikai tudományok ,Aerogel ,02 engineering and technology ,General Chemistry ,Polymer ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,0104 chemical sciences ,Atomic layer deposition ,chemistry.chemical_compound ,Természettudományok ,chemistry ,Photocatalysis ,Methyl orange ,General Materials Science ,Composite material ,0210 nano-technology ,Pyrolysis ,Carbon - Abstract
Monolithic structured TiO2/aerogel composites were prepared from resorcinol-formaldehyde polymer aerogel (RFA) and its carbon aerogel (RFCA) derivative. A resorcinol-formaldehyde hydrogel was synthesized in a sol-gel reaction and transformed into polymer aerogel by supercritical drying. The RFA was converted to carbon aerogel by pyrolysis at 900 °C in dry N2. Amorphous and crystalline TiO2 layers were grown from TiCl4 and H2O precursors by atomic layer deposition (ALD) at 80 °C and 250 °C, respectively, on both RFA and RFCA. The substrates and the composites were studied by N2 adsorption, TG/DTA-MS, Raman, SEM-EDX and TEM techniques. Their photocatalytic activity was compared in the UV catalyzed decomposition reaction of methyl orange dye.
- Published
- 2019
5. NDVI dynamics as reflected in climatic variables: spatial and temporal trends – a case study of Hungary
- Author
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Kovács, Kertész, Balázs, Elemér, Szabó, Püspöki, and Singh
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Természettudományok ,Climatology ,General Earth and Planetary Sciences ,Climatic variables ,Environmental science ,Földtudományok ,Normalized Difference Vegetation Index - Abstract
Understanding climate change and revealing its future paths on a local level is a great challenge for the future. Beside the expanding sets of available climatic data, satellite images provide a valuable source of information. In our study we aimed to reveal whether satellite data are an appropriate way to identify global trends, given their shorter available time range. We used the CARPATCLIM (CC) database (1961–2010) and the MODIS NDVI images (2000–2016) and evaluated the time period covered by both (2000–2010). We performed a regression analysis between the NDVI and CC variables, and a time series analysis for the 1961–2008 and 2000–2008 periods at all data points. The results justified the belief that maximum temperature (TMAX), potential evapotranspiration and aridity all have a strong correlation with the NDVI; furthermore, the short period trend of TMAX can be described with a functional connection with its long period trend. Consequently, TMAX is an appropriate tool as an explanatory variable for NDVI spatial and temporal variance. Spatial pattern analysis revealed that with regression coefficients, macro-regions reflected topography (plains, hills and mountains), while in the case of time series regression slopes, it justified a decreasing trend from western areas (Transdanubia) to eastern ones (The Great Hungarian Plain). This is an important consideration for future agricultural and land use planning; i.e. that western areas have to allow for greater effects of climate change.
- Published
- 2019
6. Studies on the reversible enzyme reaction of rabbit muscle glycogen phosphorylase b using isothermal titration calorimetry
- Author
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Lili Kandra, Gyöngyi Gyémánt, and Kármen Szabó
- Subjects
Calorimetry ,010402 general chemistry ,01 natural sciences ,Biochemistry ,Reversible reaction ,Analytical Chemistry ,Structure-Activity Relationship ,Glycogen phosphorylase ,chemistry.chemical_compound ,Természettudományok ,Animals ,Humans ,Enzyme Inhibitors ,Kémiai tudományok ,Chromatography, High Pressure Liquid ,Phosphorolysis ,chemistry.chemical_classification ,Chromatography ,Dose-Response Relationship, Drug ,Glycogen ,010405 organic chemistry ,Muscles ,Organic Chemistry ,Substrate (chemistry) ,Isothermal titration calorimetry ,General Medicine ,0104 chemical sciences ,Kinetics ,Enzyme ,chemistry ,Glycogen Phosphorylase, Muscle Form ,Rabbits ,Caffeine - Abstract
Glycogen phosphorylase enzymes (GP) catalyse reversible reactions; the glucose transfer from glycogen to inorganic phosphate (Pi, phosphorolysis) or the reverse glucose transfer from glucose-1-phosphate (G-1-P) to glycogen (synthesis). Rabbit muscle GPb (rmGPb) was used as a model enzyme to study the reversible enzyme reaction. To follow both directions of this reversible reaction, we have developed a novel isothermal titration calorimetry (ITC) method for the determination of the direct reaction rate. The preference of forward or reverse reaction was ensured by the 0.1 or 10 concentration ratios of G-1-P/Pi, respectively. Substrate specificity was studied using different maltooligosaccharides and glycogen. Based on the KM values, glycogen and 2-chloro-4-nitrophenyl maltoheptaoside (CNP-G7) were found to be analogous substrates, which allowed to optimize the method by taking advantage of the CNP chromophore being detectable in HPLC. In case of CNP-G7, substrate inhibition was observed and characterised by Ki of 23 ± 7 mM. Inhibition of human GP is a promising strategy for the treatment of diabetes. Our ITC measurements have confirmed that caffeine and glucopyranosylidene-spiro-thiohydantoin (GTH), as known GPb inhibitors, inhibit the rmGPb-catalysed reversible reaction in both directions. Ki values obtained in the direction of synthesis (1.92 ± 0.14 mM for caffeine and 11.5 ± 2.0 μM for GTH) have been shown to be in good agreement with the Ki values obtained in the direction of phosphorolysis (4.05 ± 0.26 mM for caffeine and 13.8 ± 1.6 μM for GTH). The higher difference between the inhibition constants of caffeine was explained by the non-competitive mechanism. The described ITC method using the developed experimental design and reaction conditions is suitable for activity measurements of different phosphorylase enzymes on various substrates and is applicable for inhibition studies as well.
- Published
- 2019
7. Mapping the efficiency of international scientific collaboration between cities worldwide
- Author
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György Csomós and Balázs Lengyel
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FOS: Computer and information sciences ,Physics - Physics and Society ,05 social sciences ,FOS: Physical sciences ,Computer Science - Digital Libraries ,Physics and Society (physics.soc-ph) ,Library and Information Sciences ,Földtudományok ,050905 science studies ,Természettudományok ,Phenomenon ,Political science ,Regional science ,Digital Libraries (cs.DL) ,0509 other social sciences ,050904 information & library sciences ,Information Systems - Abstract
International scientific collaboration, a fundamental phenomenon of science, has been studied from several perspectives for decades. In the spatial aspect of science of science, cities have been considered by their publication output or by their citation impact. In this visualization, we go beyond these well-known approaches and map international scientific collaboration patterns of the most prominent science hubs considering both the quantity and the impact of papers produced in the collaboration. The analysis involves 245 cities and the collaboration matrix contains a total number of 7,718 international collaboration links. Results show that US-Europe co-publication links are more efficient in terms of producing highly cited papers than those international links that Asian cities have built in scientific collaboration., 4 pages, 1 figure
- Published
- 2019
8. Attack of Microcystis aeruginosa bloom on a Ceratophyllum submersum field: Ecotoxicological measurements in real environment with real microcystin exposure
- Author
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Milán Riba, Márta M-Hamvas, Gábor Vasas, Gyöngyi Gyémánt, György Vereb, Tamás Garda, Andrea Zsuzsanna Ujvárosi, and Csaba Máthé
- Subjects
Cyanobacteria ,Microcystis ,Environmental Engineering ,Microcystins ,010504 meteorology & atmospheric sciences ,Harmful Algal Bloom ,Biológiai tudományok ,Microcystin ,010501 environmental sciences ,01 natural sciences ,Algal bloom ,Magnoliopsida ,chemistry.chemical_compound ,Természettudományok ,Aquatic plant ,Environmental Chemistry ,Microcystis aeruginosa ,Waste Management and Disposal ,0105 earth and related environmental sciences ,chemistry.chemical_classification ,Hungary ,biology ,fungi ,food and beverages ,Biotic stress ,biology.organism_classification ,Pollution ,Lakes ,chemistry ,Biochemistry ,Chlorophyll ,Shoot - Abstract
Overproduction of toxic cyanobacteria is a type of harmful algal blooms (HABs). The heptapeptide microcystins (MCs) are one of the most common cyanotoxins. There is increasing research concerning the effects of MCs on growth and physiology of vascular plants, however there is a lack of studies on their direct effects on aquatic macrophytes in the real environment. Here we report the occurrence of a MC producing HAB in Lake Bardos, Hungary in 2012 with harmful effects on cytological, histological and biochemical parameters of Ceratophyllum submersum (soft hornwort) plants naturally growing at the blooming site. Blue-Green Sinapis Test (BGST) showed high toxicity of HAB samples. Cell-free water samples contained a significant amount of MCs (7.31 ± 0.17 μg L−1) while C. submersum plants contained 1.01 ± 0.21 μg g DW−1 MCs. Plants showed significant increases of protein content and decreases of anthocyanin content and carotenoid/chlorophyll ratio, indicating physiological stress- as compared to plants from the control (MC free) sampling site of the same water body. Histological and cytological studies showed (i) radial swelling and the abnormal formation of lateral buds at the shoot tip leading to abnormal development; (ii) the fragmentation of nuclei as well as accumulation of phenolics in the nucleus indicating that the HAB induced cell death and stress reactions at the nuclear level. The most relevant effect was the increase of histone H3 phosphorylation in metaphase chromosomes: since MCs are strong inhibitors of protein phosphatases, this alteration is related to the biochemical targets of these toxins. The HAB decreased peroxidase activity, but increased nuclease and protease activities, showing the decreased capacity of plants to face biotic stress and as the cytological changes, the induction of cell death. This study is one of the first to show the complex harmful changes in aquatic plants that co-exist with HABs.
- Published
- 2019
9. 14-Noreudesmanes and a phenylpropane heterodimer from sea buckthorn berry inhibit Herpes simplex type 2 virus replication
- Author
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Timea Rafai, Katalin Burián, Judit Hohmann, Attila Csorba, Attila Mándi, Norbert Kúsz, Dóra Rédei, Anita Bogdanov, Andrea Vasas, and Tibor Kurtán
- Subjects
biology ,010405 organic chemistry ,Stereochemistry ,Elaeagnus ,Chemistry ,Organic Chemistry ,Absolute configuration ,Hippophae rhamnoides ,Buckthorn Berry ,010402 general chemistry ,biology.organism_classification ,medicine.disease_cause ,01 natural sciences ,Biochemistry ,Virus ,0104 chemical sciences ,Herpes simplex virus ,Természettudományok ,Viral replication ,Yield (chemistry) ,Drug Discovery ,medicine ,Kémiai tudományok - Abstract
Two new 14-noreudesmane sesquiterpenes, one new phenylpropane heterodimer, caulilexin C, and uvaol were isolated from the 70% MeOH extract of the fruit peel of Elaeagnus rhamnoides. The structures of the compounds were elucidated by HRESIMS and advanced NMR methods. The absolute configuration of (R)-6,9-dihydroxy-1-oxo-14-noreudesm-5,7,9-triene was determined by the TDDFT-ECD method. The new compounds, together with structurally similar naphthalenes (musizin, musizin-8-O-glucoside, torachrysone-8-O-glucoside) and 1,4-naphthoquinone (2-methylstipandrone), isolated previously from Rumex aquaticus, were investigated for their antiviral activity against Herpes simplex virus type 2 (HSV-2) using two different methods. Applying the traditional virus yield reduction test, (R)-6,9-dihydroxy-1-oxo-14-noreudesm-5,7,9-triene, 1-[3-methoxy-4-(2-methoxy-4-(1E)-propenyl-phenoxy)-phenyl]-propane-1,2-diol, and musizin caused a 2.00 log10, 3.49 log10, and 2.33 log10 reduction of HSV-2 yield, respectively, at a concentration of 12.5 μM. 2-Hydroxy-1-methoxy-6,9-dioxo-14-noreudesm-1,3,5(10),7-tetraene exhibited an antiviral effect at concentration of 50 μM only. Similar results were obtained when the qPCR method was used to test the antiviral activity of the compounds.
- Published
- 2019
10. Pyrone derivatives from Helichrysum italicum
- Author
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Zhen Liu, Weaam Ebrahim, Mona El-Neketi, Peter Proksch, Ferhat Can Özkaya, Tibor Kurtán, Attila Mándi, and Julia Werner
- Subjects
Helichrysum ,Pharmacology ,Molecular Structure ,biology ,Stereochemistry ,Dimer ,Phytochemicals ,Absolute configuration ,General Medicine ,Plant Components, Aerial ,biology.organism_classification ,Helichrysum italicum ,Pyrone ,Anti-Bacterial Agents ,chemistry.chemical_compound ,Italy ,Természettudományok ,chemistry ,Pyrones ,Drug Discovery ,Kémiai tudományok ,Two-dimensional nuclear magnetic resonance spectroscopy - Abstract
Chemical investigation of aerial parts of Helichrysum italicum yielded two new pyrone derivatives (1 and 2) along with ten known compounds. The structures of the new compounds were established by 1D and 2D NMR spectra as well as by HRESIMS data. Compound 1 represented a rare dimer of substituted α- and γ-pyrone units. DFT-NMR and TDDFT-ECD calculations were carried out to determine the absolute configuration of 1 but failed, representing the limitation of TDDFT-ECD calculation for the configurational assignment. All compounds were measured for their antibacterial and cytotoxic activity but proved to be inactive.
- Published
- 2019
11. Thermal, acoustic and magnetic noises emitted during martensitic transformation in single crystalline Ni45Co5Mn36.6In13.4 meta-magnetic shape memory alloy
- Author
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N.E. Barta, Nora Mohareb Samy, Y.I. Chumlyakov, Dezső L. Beke, László Zoltán Tóth, M.K. Bolgár, Ibrahim Karaman, and Lajos Daróczi
- Subjects
Materials science ,Condensed matter physics ,Mechanical Engineering ,Metals and Alloys ,Fizikai tudományok ,02 engineering and technology ,Shape-memory alloy ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,Power law ,0104 chemical sciences ,Magnetic field ,Magnetization ,Természettudományok ,Magnetic shape-memory alloy ,Mechanics of Materials ,Diffusionless transformation ,Materials Chemistry ,0210 nano-technology ,Critical exponent ,Noise (radio) - Abstract
Meta-magnetic shape memory alloys (MMSMAs) display an abrupt change in magnetization across the martensitic transformation. Simultaneous detection and statistical analysis of the emitted acoustic and magnetic noises, accompanied with martensitic transformations are important for better understanding of the magneto-structural coupling, and for utilization of well-characterized acoustic and magnetic signals for practical applications. In the present work, characteristics of thermal, acoustic and magnetic noises, detected during martensitic transformation in the Ni45Co5Mn36.6In13.4 MMSMA single crystals, were investigated for the first time. Statistical analysis of the thermal spikes, appeared during the calorimetric measurements at low cooling rates (typically below 1 K/min) showed that the energy distributions followed a power law with e = 2.0 ± 0.3 exponent, which is in good agreement with the exponents of energy distribution of acoustic and magnetic emission events (e = 1.7 ± 0.1 and e = 1.7 ± 0.2, respectively). The above exponents were independent of the external magnetic field between B = 0 and 230 mT. Interestingly, the acoustic and magnetic exponents during cooling and heating were the same in contrast to the expected asymmetry based on the fact that the transformation demonstrates an isothermal character during cooling and an athermal one for heating. Upon interrupting cooling, and dwelling at a temperature above the martensite finish temperature, practically no acoustic and magnetic noises were detected, while upon continued cooling the noise appeared again, with the same critical exponents. This indicates that the main discontinuous events, leading to noise emissions, should be the same before and after dwelling as well as during cooling and heating. In magnetic noise measurements, under zero external field, the magnetic noise packets contained voltage peaks in the detector coils in both (positive and negative) directions. Under small external magnetic fields (between 20 and 230 mT), the activity of magnetic signals increased and the magnetic peaks, during both heating and cooling, appeared more and more unidirectional (i.e. peaks only in one direction were observed) which can be attributed to the increased magnetization of the austenite.
- Published
- 2019
12. Simplest quartic and simplest sextic Thue equations over imaginary quadratic fields
- Author
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Borka Jadrijević, István Gaál, and László Remete
- Subjects
Algebra and Number Theory ,Mathematics - Number Theory ,relative Thue equations ,simplest quartic fields ,simplest sextic fields ,010102 general mathematics ,010103 numerical & computational mathematics ,01 natural sciences ,Mathematics::Algebraic Geometry ,Quadratic equation ,11D59, 11D57 ,Természettudományok ,Computer Science::Discrete Mathematics ,Simple (abstract algebra) ,Quartic function ,FOS: Mathematics ,Number Theory (math.NT) ,Matematika- és számítástudományok ,0101 mathematics ,Computer Science::Formal Languages and Automata Theory ,Mathematics ,Mathematical physics - Abstract
The families of simplest cubic, simplest quartic and simplest sextic fields and the related Thue equations are well known, see G. Lettl, A. Pethő and P. Voutier, Simple families of Thue inequalities, Trans. Amer. Math. Soc. 351 (1999) 1871–1894, On the arithmetic of simplest sextic fields and related Thue equations, in Number Theory: Diophantine, Computational and Algebraic Aspects, eds. K. Győry et al. (de Gruyter, Berlin, 1998), pp. 331–348. The family of simplest cubic Thue equations was already studied in the relative case, over imaginary quadratic fields. In the present paper, we give a similar extension of simplest quartic and simplest sextic Thue equations over imaginary quadratic fields. We explicitly give the solutions of these infinite parametric families of Thue equations over arbitrary imaginary quadratic fields.
- Published
- 2019
13. Induction of Secondary Metabolites from the Marine-Derived Fungus Aspergillus versicolor through Co-cultivation with Bacillus subtilis
- Author
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Zhen Liu, Sebastian Scharf, Mohamed Kamel, Ferhat Can Özkaya, Attila Mándi, Mostafa A. Fouad, Tibor Kurtán, Nada M. Abdel-Wahab, Georgios Daletos, Peter Proksch, Weaam Ebrahim, Wenhan Lin, Werner E.G. Müller, and Rainer Kalscheuer
- Subjects
Circular dichroism ,Magnetic Resonance Spectroscopy ,Stereochemistry ,Pharmaceutical Science ,Anthraquinones ,Microbial Sensitivity Tests ,Bacillus subtilis ,Quinolones ,Gram-Positive Bacteria ,Peptides, Cyclic ,Mass Spectrometry ,Analytical Chemistry ,Mice ,chemistry.chemical_compound ,Természettudományok ,Cell Line, Tumor ,Drug Discovery ,Animals ,Kémiai tudományok ,Axenic ,Pharmacology ,Dose-Response Relationship, Drug ,biology ,Cytotoxins ,Chemistry ,Circular Dichroism ,Organic Chemistry ,Absolute configuration ,biology.organism_classification ,Coculture Techniques ,Anti-Bacterial Agents ,Aspergillus ,Complementary and alternative medicine ,Molecular Medicine ,Aspergillus versicolor ,Antibacterial activity ,Bacteria - Abstract
A new cyclic pentapeptide, cotteslosin C (1), a new aflaquinolone, 22-epi-aflaquinolone B (3), and two new anthraquinones (9 and 10), along with thirty known compounds (2, 4 – 8, 11 – 34) were isolated from a co-culture of the sponge-associated fungus Aspergillus versicolor with Bacillus subtilis. The new metabolites were only detected in the co-culture extract, but not when the fungus was grown under axenic conditions. Furthermore, the co-culture extract exhibited an enhanced accumulation of the known constituents versicolorin B (14), averufin (16), and sterigmatocyctin (19) by factors of 1.5, 2.0, and 4.7, respectively, compared to the axenic fungal culture. The structures of the isolated compounds were elucidated on the basis of 1D and 2D NMR spectra and mass spectrometry as well as by comparison with literature data. The absolute configuration of compounds 3, 9, and 10 was determined by ECD (electronic circular dichroism) analysis aided by TDDFT-ECD (time-dependent density functional theory electronic circular dichroism) calculations. Compounds 15, 18 – 21, and 26 exhibited strong to moderate cytotoxic activity against the mouse lymphoma cell line L5178Y, with IC50 values ranging from 2.0 to 21.2 µM, while compounds 14, 16, 31, 32, and 33 displayed moderate inhibitory activities against several gram-positive bacteria, with MIC values ranging from 12.5 to 50 µM.
- Published
- 2019
14. Antropogén hatások becslése hazai talajokban felszínborítási adatok és WRB diagnosztika alapján
- Author
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József Incze and Tibor József Novák
- Subjects
Természettudományok ,010504 meteorology & atmospheric sciences ,040103 agronomy & agriculture ,0401 agriculture, forestry, and fisheries ,Soil Science ,Forestry ,04 agricultural and veterinary sciences ,Biology ,Földtudományok ,01 natural sciences ,Agronomy and Crop Science ,0105 earth and related environmental sciences - Abstract
A WRB diagnosztikai elemeit és a felszínborítási adatokat kombinálva a talajokat ért antropogén hatás mértéke szerint négy csoportot alkottunk: 1. nincs talaj, 2. antropogén eredetű talaj, 3. természetes talaj, de lényeges antropogén bélyegekkel, illetve 4. természetes talaj. A négy csoport valamelyikéhez egyértelműen hozzárendelhető a felszínborítási osztályok mindegyike. Az általunk kidolgozott módszer segítségével értékeltük Magyarország talajtakarójának természetességét. Az ország területének 2%-án nem számolhatunk a FAO által definiált értelemben talaj létével, 6%-án antropogén talajok várhatók (Anthrosol, vagy Technosol), 66%-án a természetes talajok antropogén átalakítottsága eléri a WRB diagnosztikai határértékeit, és mindössze 26% azon talajok aránya, amelyekben antropogén hatások a diagnosztikában nem jelennek meg, azaz természetes vagy természetközeli állapotúként értékelhetők. Talajtípusok tekintetében legnagyobb mértékű emberi hatással a csernozjomok, réti és öntés talajok esetében számolhatunk, míg természetközeli állapotú talajok legnagyobb kiterjedésben a kőzethatású és váztalajokon maradtak fenn. A területi különbségek is jelentősek: míg legnagyobb arányban a Hajdúságon és a Körös-Maros közén találunk antropogén hatásokkal érintett talajokat, addig a természetközeli állapotú talajok aránya az Északi-középhegység egyes hegyvidéki területein a legnagyobb. Módszerünk csak becslésre alkalmas, mégis jó áttekintést ad a hazai talajok antropogén átalakítottságának mértékéről, az emberi tevékenység, mint hatodik talajképző tényező jelentőségéről, intenzitásának térbeli eloszlásáról, amely a hazai talajtani adottságoknak egy eddig kevéssé vizsgált aspektusa.
- Published
- 2018
15. Peculiar properties of preferential sputtering of PbTe, SnTe, and GeTe by Ar+ ion plasma
- Author
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V.E. Slynko, D.M. Zayachuk, and Attila Csik
- Subjects
Materials science ,Analytical chemistry ,chemistry.chemical_element ,Fizikai tudományok ,02 engineering and technology ,Mass spectrometry ,01 natural sciences ,Ion ,Metal ,Természettudományok ,Sputtering ,0103 physical sciences ,Atom ,General Materials Science ,010302 applied physics ,Spectrometer ,Mechanical Engineering ,Plasma ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,chemistry ,Mechanics of Materials ,visual_art ,visual_art.visual_art_medium ,0210 nano-technology ,Tellurium - Abstract
Sputtering of PbTe, SnTe and GeTe compounds having both small and large differences in the individual components’ masses by Ar+ plasma under Secondary Neutral Mass Spectrometry (SNMS) conditions are investigated. The effect of preferential sputtering and its peculiar features caused by the different ratios between masses of the IVB atoms and tellurium were observed. The method and the empirical relationships for determination of the relative detection factor (RDF) of the intrinsic components of the compounds are suggested. It is shown that RDF of Te and metal species of the investigated samples isn’t a constant, but depends on sputtering energy. These dependences are explained by the changes of the sputtering surface morphology and the impact of mass of the sputtered species on the fraction of the species flux ejected into the solid angle collected by the spectrometer mass analyzer. The limits of applicability of SNMS for quantitative analysis of composite samples with big differences in masses of their constituents are established. A possible solution for such cases is proposed. It is shown that in the sequence of PbTe-SnTe-GeTe compounds the surface binding energy of the metal components decreases in the direction from lighter to heavier atom.
- Published
- 2018
16. Synthesis of thiomaltooligosaccharides by a thio-click approach
- Author
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László Lázár, László Somsák, and Anikó Borbás
- Subjects
biology ,010405 organic chemistry ,Chemistry ,Organic Chemistry ,Oligosaccharides ,Thio ,Stereoisomerism ,General Medicine ,Photochemical Processes ,010402 general chemistry ,biology.organism_classification ,01 natural sciences ,Biochemistry ,Combinatorial chemistry ,Coupling reaction ,0104 chemical sciences ,Analytical Chemistry ,Természettudományok ,Carbohydrate Conformation ,Tetra ,Click Chemistry ,Stereoselectivity ,Sulfhydryl Compounds ,Kémiai tudományok ,Protecting group - Abstract
Phenyl 2,3,6,2′,3′,6′-hexa-O-acetyl-4′-S-acetyl-1,4,4′-trithio-β- d -maltoside and its tri-, tetra- and pentasaccharide homologues were prepared by completely regio- and stereoselective photoinitiated thiol-ene coupling reactions of 2-acetoxy-glucal and 4-thioglucose type reaction partners. Complex protecting group strategies could be avoided since all thiols and glucals were prepared from a single starting material, phenyl 2,3,6-tri-O-acetyl-4-S-acetyl-1,4-dithio-β- d -glucopyranoside. The method represents a simple alternative to the known syntheses of similar products.
- Published
- 2018
17. Synergistic reinforcement of surface modification on improving the bonding of veneering ceramics to zirconia
- Author
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Shinn-Jyh Ding, Chun-Chuan Yang, Yun Luo, Min Yan, Attila Csik, and Tamás Fodor
- Subjects
Materials science ,Fizikai tudományok ,02 engineering and technology ,03 medical and health sciences ,chemistry.chemical_compound ,0302 clinical medicine ,Természettudományok ,Materials Chemistry ,Surface roughness ,Cubic zirconia ,Ceramic ,Composite material ,Reinforcement ,Process Chemistry and Technology ,030206 dentistry ,021001 nanoscience & nanotechnology ,Shear bond ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials ,Silicon nitride ,chemistry ,visual_art ,Phase composition ,Ceramics and Composites ,visual_art.visual_art_medium ,Surface modification ,0210 nano-technology - Abstract
Veneering ceramics should be strongly bonded to zirconia core in order to achieve successfully long-term clinical practice. Indeed, to pursue the high zirconia core–veneering ceramic bonding is still a concerned issue. In this regard, this study was to treat zirconia surface using a 3 wt% Si3N4 solution in 4 M NaOH and to investigate the effect of soaking time (5, 10, and 20 days) on the surface properties of zirconia and shear bond strength between zirconia and veneering ceramics. The residual veneering ceramics on zirconia surfaces and failure modes were also examined after fracture. The results showed that the phase composition of zirconia before and after surface modification was not changed. The elemental mapping and depth profiling consistently revealed the soaking-time-dependent Si content on the zirconia surface. The surface roughness of zirconia was significantly (P
- Published
- 2018
18. Importance of the lowest-lying Π electronic state in the photodissociation dynamics of LiF
- Author
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Attila Tóth, Péter Badankó, Ágnes Vibók, András Csehi, and Gábor J. Halász
- Subjects
Population ,Transition dipole moment ,General Physics and Astronomy ,Fizikai tudományok ,02 engineering and technology ,01 natural sciences ,Dissociation (chemistry) ,Electronic states ,law.invention ,chemistry.chemical_compound ,Természettudományok ,law ,0103 physical sciences ,Molecule ,Physical and Theoretical Chemistry ,010306 general physics ,education ,01.03. Fizikai tudományok ,education.field_of_study ,Photodissociation ,Lithium fluoride ,021001 nanoscience & nanotechnology ,Laser ,chemistry ,Atomic physics ,0210 nano-technology - Abstract
In addition to the well-known 1 1 Σ + and 2 1 Σ + electronic states which are nonadiabatically coupled and responsible for the ionic-covalent transition in lithium fluoride (LiF), the lowest-lying Π state is included in the present dynamical treatment. Although this purely repulsive 1 1 Π state lies energetically close to the 2 1 Σ + one and has a remarkable transition dipole moment with the 1 1 Σ + ground electronic state in the Franck-Condon region, it is often excluded in studies on the photodissociation of LiF. Here we demonstrate the important role of 1 1 Π by comparing two-state ( 1 1 Σ + and 2 1 Σ + ) and three-state ( 1 1 Σ + , 2 1 Σ + and 1 1 Π ) nuclear dynamical simulations focusing on the electronic state populations. Both for short (τ = 20 fs) and long (τ = 100 fs) laser pulses in the energy interval of ℏ ω = 6.2 eV – 7.35 eV we find that the population of 1 1 Π can significantly exceed that of 2 1 Σ + . Furthermore we consider rotating molecules and reveal a faster dissociation compared to the case where only the vibration of the molecules are treated (recently found in J. Chem. Phys. 144 (2016) 044107).
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- 2018
19. Retrospective evaluation of in vitro effect of gentamicin B1 against Fusarium species
- Author
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Gaspar Banfalvi
- Subjects
0301 basic medicine ,Fusariosis ,Antifungal Agents ,medicine.drug_class ,Administration, Topical ,030106 microbiology ,Antibiotics ,Microbial Sensitivity Tests ,Biológiai tudományok ,Biology ,Applied Microbiology and Biotechnology ,Microbiology ,Structure-Activity Relationship ,03 medical and health sciences ,Minimum inhibitory concentration ,Fusarium ,Természettudományok ,medicine ,Tobramycin ,Aspergillosis ,Humans ,Aminoglycoside ,General Medicine ,medicine.disease ,Anti-Bacterial Agents ,Sisomicin ,Gentamicin ,Gentamicins ,Nebramycin ,Biotechnology ,medicine.drug - Abstract
The in vitro susceptibility of gentamicin fractions against Fusarium growth was the subject of this retrospective study. Fusariosis was earlier an exceptionally rare human disease and an unrealistic idea to treat soil saprophytes and plant pathogens with expensive antibiotics such as gentamicins or their minor components. Disseminated fusariosis is now the second most frequent lethal fungal infection after aspergillosis especially in neutropenic patients with hematologic malignancy. Results of this study obtained between May and November 1973 were interesting but not practicable and remained unpublished. Seven Fusarium and 28 other fungal strains were tested for their susceptibility to gentamicin B1. The anti-Fusarium activity of gentamicin B1 was between 0.2 and 3.1 μg/ml minimum inhibitory concentration (MIC) values. The MIC values of clotrimazol and amphotericin B against Fusarium species were significantly higher, 3.1-12.5 μg/ml and 3.1-50 μg/ml, respectively. Gentamicin B1 and its structurally related congeners including hygromycin B, paromomycin, tobramycin (nebramycin factor 5'), nebramycin (nebramycin factor 4), and sisomicin exerted strong in vitro inhibition against Fusarium species between 0.2 and 12.5 μg/ml concentrations. The antibacterial MIC concentration of gentamicin B1 tested on 20 bacterial strains ranged between 0.1 and 50 μg/ml. Gentamicin B1, a minor fraction of the gentamicin complex, inhibited effectively the growth of Gram-positive (Staphylococcus, Streptococcus, Bacillus subtilis) bacteria and Gram-negative (Escherichia coli, Salmonella, Proteus, Pseudomonas) pathogens. Gentamicins and related aminoglycoside antibiotics are used in medical practice. It is proposed that due to the increasing incidence of fusariosis and drug resistance, gentamicin components, particularly minor fraction B1 and related aminoglycoside antibiotics, could be tested for their in vivo activity against fusariosis and aspergillosis either alone or in combination with other antifungal agents.
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- 2018
20. Interdiffusion along grain boundaries – Diffusion induced grain boundary migration, low temperature homogenization and reactions in nanostructured thin films
- Author
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Yuri Kaganovskii, Gábor Katona, and Dezső L. Beke
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010302 applied physics ,Materials science ,Intermetallic ,Thermodynamics ,Fizikai tudományok ,02 engineering and technology ,021001 nanoscience & nanotechnology ,01 natural sciences ,Homogenization (chemistry) ,Grain size ,Természettudományok ,0103 physical sciences ,Melting point ,Grain boundary diffusion coefficient ,General Materials Science ,Grain boundary ,0210 nano-technology ,Solid solution ,Phase diagram - Abstract
Interdiffusion along grain boundaries can lead to shift of grain boundaries in form of Grain Boundary Diffusion Induced Grain Boundary Migration, DIGM, in systems forming wide range solid solutions, and to the Grain Boundary Diffusion Induced Solid State Reactions, in systems containing intermetallic phases. If, during above processes, the grain size of the sample is smaller than the double of the migration distance complete homogenization can also be reached (cold homogenization). Atomic mechanisms and phenomenological description of such alloying are reviewed. The main driving force, at low temperatures where the bulk diffusion is completely frozen out, arises from the unequality of the grain boundary atomic fluxes, leading to stress accumulations. The cold homogenization is the manifestation of such stress relaxations. Reviewing experimental data, we illustrate that DIGM takes place on both sides of a binary AB thin film and the solute content in the DIGM zone is higher on the side of the component of higher melting point (i.e. in the slower component). In binary systems containing intermetallic compounds the cold homogenization can lead, either to the formation of a given stoichiometric compound, or to two phase equilibrium, in accordance with the phase diagram. Different possible applications are likewise surveyed.
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- 2018
21. Karhunen–Loève expansion for a generalization of Wiener bridge
- Author
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Rezső L Lovas and Matyas Barczy
- Subjects
Combinatorics ,010104 statistics & probability ,Number theory ,Természettudományok ,Generalization ,General Mathematics ,010102 general mathematics ,Matematika- és számítástudományok ,0101 mathematics ,01 natural sciences ,Mathematics - Abstract
We derive a Karhunen–Loeve expansion of the Gauss process $$ {B}_t-g(t){\int}_0^1{g}^{\hbox{'}}(u)\mathrm{d}{B}_u,t\in \left[0,1\right] $$ , where (Bt)t ∈ [0, 1] is a standardWiener process, and g : [0, 1] → ℝ is a twice continuously differentiable function with g(0) = 0 and $$ {\int}_0^1{\left(g\hbox{'}(u)\right)}^2\mathrm{d}u=1 $$ . This process is an important limit process in the theory of goodness-of-fit tests. We formulate two particular cases with the functions $$ g(t)=\left(\sqrt{2}/\pi \right)\sin \left(\pi t\right),t\in \left[0,1\right] $$ , and g(t) = t, t ∈ [0, 1]. The latter corresponds to the Wiener bridge over [0, 1] from 0 to 0.
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- 2018
22. Study of factors controlling the amount of 0.01 M CaCl2 extractable Norg fraction
- Author
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Emese Bertáné Szabó and Jakab Loch
- Subjects
Természettudományok ,Chemistry ,Environmental chemistry ,General Earth and Planetary Sciences ,Fraction (chemistry) ,Kémiai tudományok ,General Environmental Science - Abstract
The use of new methods describing the “readily available” nutrient content of the soil is spreading on a global scale. The 0.01 M CaCl2 extractant is a dilute salt solution in which the easily soluble inorganic (nitrate-N and ammonium-N) and organic N fractions, P, K and micronutrients are also measurable. The 0.01 M CaCl2 has been tested in the University of Debrecen, Institute of Agricultural Chemistry and Soil Sciences since the 90’s. The results of the researches related to organic N fraction, performed in the last decades, and the results of the present study (originating from the long-term experiment of Karcag, 2007–2009) can be concluded as follows: The measurement of easily soluble and oxidizable organic nitrogen (Norg), besides inorganic fractions, could improve the nutrient management. The amount of the Norg fraction is determined by the soil conditions, therefore it is considered to be a site-specific parameter. Management practices and cropyear affect the amount of Norg as well. The present research confirmed that, the effect of fertilization on the amount of Norg can be explained by the changing of the yield (related to total biomass production), while the effect of cropyear is related to the differences in mineralization circumstances and yield as well. The measurement of the Norg fraction is increases the accuracy of N-supply, therefore it could prevent the environmentally harmful excess N application as well.
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- 2018
23. Stimulation of energy willow biomass with triacontanol and seaweed extract
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István Molnár, Tamás Digruber, Kenny Paul, Imre Vass, Csaba Gyuricza, A. Nagy, András Cseri, Dénes Dudits, László Sass, Judit Remenyik, and Otto Toldi
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0106 biological sciences ,0301 basic medicine ,Willow ,ved/biology.organism_classification_rank.species ,Biomass ,Photosynthesis ,01 natural sciences ,Shrub ,03 medical and health sciences ,Cutting ,chemistry.chemical_compound ,Természettudományok ,Kémiai tudományok ,biology ,ved/biology ,fungi ,Triacontanol ,food and beverages ,biology.organism_classification ,Horticulture ,030104 developmental biology ,chemistry ,Shoot ,Agronomy and Crop Science ,010606 plant biology & botany ,Woody plant - Abstract
Biomass productivity of shrub willow plants grown in short rotation system can be improved by genetic means or by innovative cropping technologies. In the present study we analyzed the growth and physiological responses of willow plants to plant biostimulators, such as 1-triacontanol (TRIA), a saturated primary alcohol and seaweed extract (Kelpak®). Testing a novel approach, we soaked stem cuttings in TRIA or Kelpak solutions for 48 h before plantation. These treatments enlarged height and diameter of stems, furthermore increased stem and leaf weights in comparison to the water control. In agreement with these greenhouse observations, field tests showed statistically significant enhancement in height and diameter of woody stems harvested in winter. Application of 25% Kelpak solution was the most effective in stimulating all traits including stem weight per plant after pre-planting treatment of cuttings. In an alternative treatment protocol, Kelpak was applied as foliar treatment or in combination between TRIA (10 mg L−1) treatment of cuttings and foliar spray with Kelpak 1 or 2% solutions in the greenhouse. The green pixel numbers revealed variable degrees of stimulation in shoot growth. These treatments resulted in an increase in stem and leaf weights. Improvement of photosynthetic functions was indicated by more efficient electron transport rates (ETRs) of photosystems. An increased nicotinamide and thiamine contents were detected in the leaves of stimulated plants. The present study can serve as a foundation for additional laboratory and field studies optimizing the application of these stimulators in energy plantations.
- Published
- 2018
24. Flabellipparicine, a Flabelliformide-Apparicine-Type Bisindole Alkaloid from Tabernaemontana divaricata
- Author
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Ariel M. Sarotti, Congkui Tian, Tibor Kurtán, Attila Mándi, Ze-Hong Miao, Guofu Qiu, Sheng Ping Yang, You Sheng Cai, Shugeng Cao, Ting Lan Zhou, and Rong Huang
- Subjects
Apparicine ,Magnetic Resonance Spectroscopy ,Tabernaemontana ,Stereochemistry ,Tabernaemontana divaricata ,Pharmaceutical Science ,010402 general chemistry ,Ring (chemistry) ,01 natural sciences ,NATURAL PRODUCTS ,Indole Alkaloids ,Analytical Chemistry ,Alkaloids ,Természettudományok ,Cell Line, Tumor ,Drug Discovery ,Humans ,BIOACTIVE ,Kémiai tudományok ,Cytotoxicity ,Pharmacology ,Plant Stems ,biology ,010405 organic chemistry ,Chemistry ,Alkaloid ,Organic Chemistry ,Ciencias Químicas ,Absolute configuration ,Nuclear magnetic resonance spectroscopy ,biology.organism_classification ,NMR ,0104 chemical sciences ,Química Orgánica ,Complementary and alternative medicine ,Monoterpenes ,Molecular Medicine ,FLABELLIPPARICINE ,CIENCIAS NATURALES Y EXACTAS ,Human cancer - Abstract
Four new monoterpenoid bisindole alkaloids, flabellipparicine (1), 19,20-dihydrovobparicine (2), 10′-demethoxy-19,20-dihydrovobatensine D (3), and 3′-(2-oxopropyl)ervahanine A (4), and 10 known monoterpenoid indole alkaloids were isolated from the stems of Tabernaemontana divaricata. All structures were elucidated based on spectroscopic methods, and the absolute configuration of 1 was established using conformational analysis and TDDFT-ECD calculation of selected stereoisomers. Compound 1 represents the first flabelliformide-apparicine-type bisindole alkaloid, in which the flabelliformide-like unit connects to the apparicine-like unit with a C-3-C-22′ bond and an N-1-C-16′ bond to form an uncommon five-membered ring between the two monomers. All alkaloids were evaluated for their cytotoxicity against two human cancer cell lines, MCF-7 and A-549. Compounds 2, 4, and 14 exhibited cytotoxicity against MCF-7 and A-549 with IC50 values in the range of 2 nM to 8 μM. Fil: Cai, You Sheng. Wuhan University; China Fil: Sarotti, Ariel Marcelo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Instituto de Química Rosario. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas. Instituto de Química Rosario; Argentina Fil: Zhou, Ting Lan. Wuhan University; China Fil: Huang, Rong. Wuhan University; China Fil: Qiu, Guofu. Wuhan University; China Fil: Tian, Congkui. Hubei University For Nationalities; China Fil: Miao, Ze Hong. Chinese Academy of Sciences; República de China Fil: Mándi, Attila. University of Debrecen; Hungría Fil: Kurtán, Tibor. University of Debrecen; Hungría Fil: Cao, Shugeng. University Of Hawaii At Hilo; Estados Unidos Fil: Yang, Sheng Ping. Wuhan University; China
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- 2018
25. Diversity and concordance in the composition of butterfly assemblages of the Transcarpathian (Bereg) plain (SW Ukraine)
- Author
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Zoltán Varga, Szabolcs Szanyi, and Antal Nagy
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0106 biological sciences ,Land use ,Ecology ,010604 marine biology & hydrobiology ,Biodiversity ,Biológiai tudományok ,Cell Biology ,Plant Science ,Generalist and specialist species ,010603 evolutionary biology ,01 natural sciences ,Biochemistry ,Geography ,Természettudományok ,Habitat ,Indicator species ,Butterfly ,Genetics ,Dominance (ecology) ,Animal Science and Zoology ,Transect ,Molecular Biology ,Ecology, Evolution, Behavior and Systematics - Abstract
In eastern Central Europe the abandonment of traditional land use represents a major threat for biodiversity. Evidence on species loss and shifts in assemblages is often based on butterfly surveys since these are known as sensitive indicators of habitat changes. Butterfly assemblages were studied in meadows of the Transcarpathian lowland in three consecutive years (2012–2014) with standard transect walks in six different sites (two transects/site). More than 6500 individuals of 66 species were recorded. The less disturbed habitats surrounded by natural forests have shown the highest diversity (Shannon-Wiener, dominance profiles). In faunal types the widely distributed, generalist Euro-Siberian species predominated with significant presence of Holo-Mediterranean and southern Continental elements. Three main types of habitats were separated and characterised by indicator species, i.e. we hierarchically classified the species according to their fidelity by the IndVal method. The dry sites were characterised by a few generalist species only, while the humid ones and mostly the transitional sites were inhabited by numerous habitat and/or food plant specialists. The assemblages were compared with multivariate analysis and the concordance of inter-annual changes of the assemblages were surveyed. The concordance profiles of the less diverse dry habitats were clearly separated from others while other sites with dominance profiles with longer sequence of scarce species have also shown similar concordance profiles. The importance of nature-like forest fringe structures was pointed out for both habitat and species conservation. Conservation efforts should be focused to sustain the general level of biodiversity by the preservation of nature-like habitats and the possible re-establishment of some kinds of traditional use.
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- 2018
26. Granulometric characterization of paleosols in loess series by automated static image analysis
- Author
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György Varga, Gábor Újvári, János Kovács, Zoltán Szalai, and Csaba Cserháti
- Subjects
Diffraction ,010504 meteorology & atmospheric sciences ,Stratigraphy ,Perspective (graphical) ,Mineralogy ,Fizikai tudományok ,Geology ,010502 geochemistry & geophysics ,01 natural sciences ,Sizing ,Grain size ,Characterization (materials science) ,Természettudományok ,Dimension (vector space) ,Loess ,Siliciclastic ,0105 earth and related environmental sciences - Abstract
An automated image analysis method is proposed here to study the size and shape of siliciclastic sedimentary particles of paleosols of Central European loess sequences. Several direct and indirect measurement techniques are available for grain size measurements of sedimentary mineral particles. Indirect techniques involve the use of some kind of physical laws, however, all requirements for calculations are in many cases not known. Even so, the direct manual microscopic observation and measurement of large, representative number of grains is time-consuming and sometimes rather subjective. Therefore, automated image analyses techniques provide a new and perspective way to analyse grain size and shape sedimentary particles. Here we test these indirect (laser diffraction) and direct (automated static image analysis) techniques and provide new granulometric (size and shape) data of paleosols. Our results demonstrate that grain size data of the mineral dust samples are strongly dependent on shape parameters of particles, and shape heterogeneity was different between different size classes. Due to the irregular grain shape parameters, uncertainties have arisen also for determination of grain sizes. In this paper we present a possible correction procedure to reduce the differences among the results of the laser diffraction and image analysis methods. By applying new correction factors, results of the two approaches could become closer but the unknown thickness of particles remains a problem to solve. The other presented correction procedure to assess the uncertain 3rd dimension of particles by their intensity-size relationships makes us able to reduce further the deviations of the two sizing methods.
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- 2018
27. Colonisation processes in benthic algal communities are well reflected by functional groups
- Author
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Viktória B-Béres, Enikő T-Krasznai, Péter Török, Gábor Várbíró, Gábor Borics, Béla Tóthmérész, Áron Lukács, Zsuzsanna Kókai, and István Bácsi
- Subjects
0106 biological sciences ,Ecology ,010604 marine biology & hydrobiology ,Functional features ,Biológiai tudományok ,Aquatic Science ,Biology ,010603 evolutionary biology ,01 natural sciences ,Cell size ,Colonisation ,Természettudományok ,Benthos ,Benthic zone ,Aquatic environment ,Trait ,Ecosystem ,sense organs - Abstract
Single-trait analyses are used to select the most appropriate species characteristics for an effective indication of changes in multiple stressors, but they are robust to detect fine-scale functional changes in biofilms. The combination of single traits may appropriately reflect ecological properties of changing benthic assemblages. We studied colonisation processes of benthic algal assemblages focusing on the changes in trait composition using life forms, type of attachments, cell size and mobility as single traits in a small lowland stream. We tested the descriptive power of single-trait groups (STGs) and also combined trait groups (CTGs). We assumed that STGs would be significantly affected by environmental factors, but compositional changes in biofilms would be described more easily by using CTGs rather than STGs. Our hypotheses were confirmed by the results. While some STGs correlated positively to environmental factors indicating disturbances, others correlated to environmental factors indicating the stable conditions. The fast settlement of large-sized groups was also relevant determining the compositional changes in the studied benthic community. Despite the strong correlation between STGs and environmental variables, CTGs analyses revealed important functional relations in the ecosystem, since CTGs display more sophisticated functional features of the organisms, which may provide more realistic responses.
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- 2018
28. Efficiency of local minima and GLM techniques in sinkhole extraction from a LiDAR-based terrain model
- Author
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Szilárd Szabó, Melinda Pap, Péter Enyedi, Zoltán Kovács, and László Takács-Szilágyi
- Subjects
geography ,geography.geographical_feature_category ,010504 meteorology & atmospheric sciences ,Sinkhole ,0211 other engineering and technologies ,Raised-relief map ,02 engineering and technology ,Földtudományok ,Karst ,01 natural sciences ,Computer Science Applications ,Maxima and minima ,Lidar ,Természettudományok ,General Earth and Planetary Sciences ,Extraction (military) ,Digital elevation model ,Software ,Geology ,021101 geological & geomatics engineering ,0105 earth and related environmental sciences ,Remote sensing - Abstract
The aim of this paper was to study reliable automated delineation possibilities of karst sinkholes using a LiDAR-based digital terrain model (DTM) with pixel-based classifications. We applied two a...
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- 2018
29. Selective etching of PDMS: Etching as a negative tone resist
- Author
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Laura Juhász and S.Z. Szilasi
- Subjects
Materials science ,FOS: Physical sciences ,General Physics and Astronomy ,Fizikai tudományok ,Applied Physics (physics.app-ph) ,02 engineering and technology ,010402 general chemistry ,01 natural sciences ,Fluence ,chemistry.chemical_compound ,Természettudományok ,Etching (microfabrication) ,Irradiation ,Composite material ,Sulfuric acid ,Physics - Applied Physics ,Surfaces and Interfaces ,General Chemistry ,Microbeam ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,Hydrogen fluoride ,Microstructure ,0104 chemical sciences ,Surfaces, Coatings and Films ,chemistry ,Resist ,0210 nano-technology - Abstract
In this work authors present for the first time how to apply the additive-free, cured PDMS as a negative tone resist material, demonstrate the creation of PDMS microstructures and test the solvent resistivity of the created microstructures. The PDMS layers were 45 um and 100 um thick, the irradiations were done with a focused proton microbeam with various fluences. After irradiation, the samples were etched with sulfuric acid that removed the unirradiated PDMS completely but left those structures intact that received high enough fluences. The etching rate of the unirradiated PDMS was also determined. Those structures that received at least 7.5*10^15 ion*cm-2 fluence did not show any signs of degradation even after 19 hours of etching. As a demonstration, 45 um and 100 um tall, high aspect ratio, good quality, undistorted microstructures were created with smooth and vertical sidewalls. The created microstructures were immersed into numerous solvents and some acids to test their compatibility. It was found that the unirradiated PDMS cannot, while the irradiated PDMS microstructures can resist to chloroform, n-hexane, toluene and sulfuric acid. Hydrogen fluoride etches both the unirradiated and the irradiated PDMS., Comment: full paper
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- 2018
30. Induced secondary metabolites from the endophytic fungus Aspergillus versicolor through bacterial co-culture and OSMAC approaches
- Author
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Zhen Liu, Peter Proksch, Tibor Kurtán, Mohamed Kamel, Mostafa A. Fouad, Miada F. Abdelwahab, Georgios Daletos, Weaam Ebrahim, Werner E.G. Müller, and Attila Mándi
- Subjects
Circular dichroism ,biology ,010405 organic chemistry ,Chemistry ,Stereochemistry ,Organic Chemistry ,Ethyl acetate ,Diastereomer ,Bacillus subtilis ,Nuclear magnetic resonance spectroscopy ,biology.organism_classification ,01 natural sciences ,Biochemistry ,0104 chemical sciences ,010404 medicinal & biomolecular chemistry ,chemistry.chemical_compound ,Természettudományok ,Drug Discovery ,Aspergillus versicolor ,Epimer ,Kémiai tudományok ,Conformational isomerism - Abstract
Two new cryptic 3,4-dihydronaphthalen-(2H)-1-one (1-tetralone) derivatives, aspvanicin A (1) and its epimer aspvanicin B (2), as well as several known cryptic metabolites (3–8), were obtained from the ethyl acetate extract of the co-culture of the endophytic fungus Aspergillus versicolor KU258497 with the bacterium Bacillus subtilis 168 trpC2 on solid rice medium. When A. versicolor was cultured axenically in liquid Wickerham medium supplemented with 3.5% DMSO, an additional three known secondary metabolites (9–11) were isolated that were lacking when the fungus was fermented on rice medium. The structures of the new compounds were elucidated using one- and two-dimensional NMR spectroscopy as well as HRESIMS. The relative and absolute configurations of 1 and 2 were determined by the combination of NMR and electronic circular dichroism (ECD) analysis aided by DFT conformational analysis and TDDFT-ECD calculations. The ECD calculations revealed that although the sign of the blue-shifted overlapping n-π∗ ECD transition follows the helicity rule of cyclic aryl ketones, the calculation of low-energy conformers and ECD spectra was necessary to determine the stereochemistry. All metabolites were assessed for their antibacterial and cytotoxic activities; one of the new diastereomers, compound 2, showed moderate cytotoxic activity against the mouse lymphoma cell line L5178Y.
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- 2018
31. Adoption and Evaluation of a sample Pretreatment Protocol for Radiocarbon Dating of Cremated Bones at HEKAL
- Author
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Viktória Kiss, Marianna Túri, István Major, Katalin Hubay, A. J. Timothy Jull, István Futó, Róbert Patay, Géza Szabó, Eszter Melis, Mihály Molnár, János Dani, and Róbert Huszánk
- Subjects
010506 paleontology ,Archeology ,060102 archaeology ,Age differences ,Sample (material) ,Radiochemistry ,06 humanities and the arts ,Környezettudományok ,Chemical cleaning ,01 natural sciences ,law.invention ,Természettudományok ,law ,General Earth and Planetary Sciences ,Environmental science ,0601 history and archaeology ,Radiocarbon dating ,0105 earth and related environmental sciences ,Accelerator mass spectrometry - Abstract
A comparative study was undertaken to adopt and evaluate a radiocarbon (14C) preparation procedure for accelerator mass spectrometry (AMS) measurements of cremated bones at our laboratory, including different types of archaeological samples (cremated bone, bone, charcoal, charred grain). All 14C analyses were performed using the EnvironMICADAS AMS instrument at the Hertelendi Laboratory of Environmental Studies (HEKAL) and the ancillary analyses were also performed at the Institute for Nuclear Research (ATOMKI). After the physical and chemical cleaning of cremated bones, CO2 was extracted by acid hydrolysis followed by sealed-tube graphitization and 14C measurement. The supplementary δ13C measurements were also performed on CO2 gas while FTIR was measured on the powder fraction. Based on the FTIR and 14C analyses, our chemical pretreatment protocol was successful in removing contamination from the samples. Good reproducibility was obtained for the 0.2–0.3 mm fraction of blind-tested cremated samples and a maximum age difference of only 150 yr was found for the remaining case studies. This confirms the reliability of our procedure for 14C dating of cremated bones. However, in one case study, the age difference of 300 yr between two cremated fragments originating from the same urn shows that other processes affecting the cremated samples in the post-burial environment can substantially influence the 14C age, so caution must be exercised.
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- 2018
32. On the invariance equation for two-variable weighted nonsymmetric Bajraktarević means
- Author
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Zsolt Páles and Amr Zakaria
- Subjects
Weight function ,39B12, 39.35, 26E60 ,Applied Mathematics ,General Mathematics ,010102 general mathematics ,Hyperbolic function ,Zero (complex analysis) ,010103 numerical & computational mathematics ,01 natural sciences ,Combinatorics ,Monotone polygon ,Természettudományok ,Mathematics - Classical Analysis and ODEs ,Functional equation ,Discrete Mathematics and Combinatorics ,Matematika- és számítástudományok ,0101 mathematics ,Mathematics ,Variable (mathematics) - Abstract
The purpose of this paper is to investigate the invariance of the arithmetic mean with respect to two weighted Bajraktarevic means, i.e., to solve the functional equation $$\begin{aligned} \left( \frac{f}{g}\right) ^{\!\!-1}\!\!\left( \frac{tf(x)+sf(y)}{tg(x)+sg(y)}\right) +\left( \frac{h}{k}\right) ^{\!\!-1}\!\!\left( \frac{sh(x)+th(y)}{sk(x)+tk(y)}\right) =x+y \qquad (x,y\in I), \end{aligned}$$ where $$f,g,h,k:I\rightarrow \mathbb {R}$$ are unknown continuous functions such that g, k are nowhere zero on I, the ratio functions f / g, h / k are strictly monotone on I, and $$t,s\in \mathbb {R}_+$$ are constants different from each other. By the main result of this paper, the solutions of the above invariance equation can be expressed either in terms of hyperbolic functions or in terms of trigonometric functions and an additional weight function. For the necessity part of this result, we will assume that $$f,g,h,k:I\rightarrow \mathbb {R}$$ are four times continuously differentiable.
- Published
- 2018
33. Surprising diversity in the Pannonian populations of Marsh Fritillary (Euphydryas aurinia, Lepidoptera: Nymphalidae): Morphometric and molecular aspects
- Author
-
Zoltán Varga, Gergely Katona, Andrea Tóth, Janos Toth, Katalin Pecsenye, and Judit Bereczki
- Subjects
0106 biological sciences ,0301 basic medicine ,biology ,Ecology ,Biológiai tudományok ,biology.organism_classification ,010603 evolutionary biology ,01 natural sciences ,Nymphalidae ,Lepidoptera genitalia ,Marsh fritillary ,03 medical and health sciences ,030104 developmental biology ,Természettudományok ,Aurinia ,Genetics ,Animal Science and Zoology ,Molecular Biology ,Ecology, Evolution, Behavior and Systematics ,Euphydryas - Abstract
LB
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- 2018
34. Age–depth relationship and accumulation rates in four sediment sequences from the Retezat Mts, South Carpathians (Romania)
- Author
-
Ildikó Orbán, Katalin Hubay, Mihály Molnár, Tamás Biró, Mihály Braun, and Enikő Magyari
- Subjects
Hydrology ,010506 paleontology ,010504 meteorology & atmospheric sciences ,Macrofossil ,Sediment ,Környezettudományok ,01 natural sciences ,Deposition (geology) ,law.invention ,Altitude ,Természettudományok ,law ,Erosion ,Glacial period ,Radiocarbon dating ,Holocene ,Geology ,0105 earth and related environmental sciences ,Earth-Surface Processes - Abstract
This study summarizes the results of radiocarbon dating and age-depth modelling in four mountain lakes (Brazi, Gales, Bucura and Lia) in the Retezat Mountains. Altogether 69 AMS 14 C measurements were performed on these deposits, mostly on terrestrial plant macrofossils. In several cases, plant macrofossils, aquatic animal remains (Cladoceran eggs) and bulk sediment were measured from the same depth allowing for the comparison of various sediment components in terms of their dating potential. Age-depth models were developed using both Bayesian modelling with the BACON and smooth spline curve fitting with the CLAM software. In this study Bayesian models are applied to identify outlier 14 C dates, while smooth spline models are used to model sediment accumulation age-depth relations, as these are more likely to follow natural deposition time changes of lake sediments. Changes in sediment deposition times (DT) in relation to catchment size and climate are also studied. DT varied considerably in the late glacial (LG) part of the records. The sediment sequence characterised by high deposition rates during the late glacial (DT maximum around 100–110 years cm −1 ) was defined by small catchment size (Lake Brazi, 6 ha; surface area: 0.5 ha). In contrast, much slower LG sediment deposition in the southern slope lake characterised by large catchment area (Lake Lia, 171 ha, 20 years cm −1 ), principally reflecting strong erosion in these catchment areas at times when vegetation cover was scarce. Holocene was characterised again by variable DT values, but only Lake Gales showed extreme values: 62–110 years between 10,900 and 6050 cal yr BP, followed by much slower sediment deposition in the last 6000 years (av. 29 years cm −1 ). Generally, sediment deposition times were largely dependent on the stability and vegetation cover of the slope in the case of high altitude deep lakes, while lower altitude, shallow lakes showed slower sediment deposition time in the early and mid-Holocene, when summer insolation was higher than today. This reflects that in these shallow lakes in-lake organic production probably increased with summer insolation, which was a significant driver in the rate of deposition.
- Published
- 2018
35. Effects of vacuum and ageing on Zr4/Cr3 based conversion coatings on aluminium alloys
- Author
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Pál Bárczy, Kalaivanan Thirupathi, Kálmán Vad, Béla M. Somosvári, and Attila Csik
- Subjects
Materials science ,020209 energy ,Ultra-high vacuum ,General Physics and Astronomy ,chemistry.chemical_element ,Fizikai tudományok ,02 engineering and technology ,Zinc ,engineering.material ,Természettudományok ,Coating ,Aluminium ,0202 electrical engineering, electronic engineering, information engineering ,Dissolution ,Deposition (law) ,Surfaces and Interfaces ,General Chemistry ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,Copper ,Surfaces, Coatings and Films ,chemistry ,Chemical engineering ,Conversion coating ,engineering ,0210 nano-technology - Abstract
In this study, we investigate the impact of ageing and high vacuum on existing environmentally friendly Zr4/Cr3-based conversion coatings. The freshly formed coating undergoes several changes during ageing and exposure to high vacuum. Based on the present data, we propose that the coating formed over AA6082 and AA7075 alloys is sol-gel in nature, confirmed by secondary neutral mass spectroscopy (SNMS) using the depth profiling technique. Our findings reveal that there are elemental level changes that result in shrinkage of the coating. Most Zr ions in the coating are in the solute form, with lesser number of Cr and Al ions that disappear under high vacuum over a certain period of time. The remaining Cr, Zr and O atoms exist in a gelatinous state. During ageing, there is a continuous transition of ions from solute to gelatinous state. In addition, the deposition of coating ions is directly influenced by the substrates and their constituents. The extent of dissolution of aluminium in the conversion bath determines both Zr and Cr ion deposition. For a highly alloyed metal like AA7075, the dissolution rate is disturbed by copper and zinc.
- Published
- 2018
36. Rényi–Fisher entropy product as a marker of topological phase transitions
- Author
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Ágnes Nagy, Juan Carlos Bolívar, and Elvira Romera
- Subjects
Statistics and Probability ,Physics ,Phase transition ,Charge neutrality ,Fizikai tudományok ,Position and momentum space ,02 engineering and technology ,Electron ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,Quantum number ,Topology ,01 natural sciences ,Upper and lower bounds ,Természettudományok ,Topological insulator ,0103 physical sciences ,010306 general physics ,0210 nano-technology ,Maxima - Abstract
The combined Renyi–Fisher entropy product of electrons plus holes displays a minimum at the charge neutrality points. The Stam–Renyi difference and the Stam–Renyi uncertainty product of the electrons plus holes, show maxima at the charge neutrality points. Topological quantum numbers capable of detecting the topological insulator and the band insulator phases, are defined. Upper and lower bounds for the position and momentum space Renyi–Fisher entropy products are derived.
- Published
- 2018
37. Review of habitats occupied by Urocoras longispinus: a little-known spider species, and responses to grassland management
- Author
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Tünde Szmatona-Túri, Gábor Magos, Blanka Gál, András Weiperth, and Diána Vona-Túri
- Subjects
0106 biological sciences ,Spider ,Ecology ,ved/biology ,Phenology ,ved/biology.organism_classification_rank.species ,Biológiai tudományok ,Cell Biology ,Plant Science ,Biology ,010603 evolutionary biology ,01 natural sciences ,Biochemistry ,Shrub ,010602 entomology ,Természettudományok ,Habitat ,Abundance (ecology) ,Genetics ,Animal Science and Zoology ,Species richness ,Natura 2000 ,Molecular Biology ,Ecology, Evolution, Behavior and Systematics ,Woody plant - Abstract
The main objective of this paper is to report habitat occupancy, naturalness status and phenology of Urocoras longispinus (Chyzer and Kulczynski 1897), a little-known spider species. Sampling was conducted in Natura 2000 habitats of the Matra Mountains, and four disturbed mainroad verges in Hungary between 2012 and 2015. We recorded 356 adult specimens active throughout the year, but abundance was highest in autumn. In the Matra Mountains shrub removal negatively affected the abundance of U. lonsgspinus: the species preferred shaded habitats. The intensity of mowing maintenance caused changes in the species’ abundance in mainroad verges: the number of individual spiders increased as a result of both without maintenance and enhanced maintenance. We conclude that U. longispinus is a stenochronous spider species which lives in both human-disturbed and undisturbed habitats. However, the nature of the disturbance influenced the abundance of this species to varying degrees.
- Published
- 2018
38. Urban tree leaves’ chlorophyll-a content as a proxy of urbanization
- Author
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Vanda Éva Molnár, Szilárd Szabó, Béla Tóthmérész, and Edina Simon
- Subjects
Atmospheric Science ,Chlorophyll a ,010504 meteorology & atmospheric sciences ,Health, Toxicology and Mutagenesis ,Air pollution ,010501 environmental sciences ,Management, Monitoring, Policy and Law ,Környezettudományok ,medicine.disease_cause ,01 natural sciences ,Rainwater harvesting ,chemistry.chemical_compound ,Természettudományok ,Tap water ,Celtis ,Urbanization ,medicine ,Acer campestre ,Air quality index ,0105 earth and related environmental sciences ,biology ,biology.organism_classification ,Pollution ,Horticulture ,chemistry ,Environmental science - Abstract
We tested the effect of urbanization on air pollution based on the chlorophyll-a content of Celtis occidentalis leaves along an urbanization gradient (urban, suburban and rural areas) in Debrecen, Hungary. Chlorophyll-a content of Celtis occidentalis, Acer campestre, and Corylus avellana were compared to test which species is the most useful to study the effects of urbanization. Furthermore, the effects of washing solutions (distilled water, tap water, and rainwater) on chlorophyll-a content of tree leaves were also tested during sample preparation. Chlorophyll-a was extracted from leaf samples with acetone, and it was measured using a spectrophotometer. Along the urbanization gradient, chlorophyll-a content of C. occidentalis leaves was the lowest in the urban area; thus, this species proved to be an effective indicator of anthropogenic emission load. Differences were not significant among species in the suburban and rural areas, where the level of air pollution was moderate. We found that effects of the washing solutions on chlorophyll-a content did not differ significantly from each other. Thus, tap water can be used safely to clean the leaf surface, without significant influence on chlorophyll-a. Our study demonstrated that the chlorophyll-a content of leaves was a useful indicator to assess the level of air pollution.
- Published
- 2018
39. Structural, stereochemical, and bioactive studies of cembranoids from Chinese soft coral Sarcophyton trocheliophorum
- Author
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Li Gong Yao, Tibor Kurtán, Jia Li, Yue-Wei Guo, Le Fu Lan, Attila Mándi, and Lin Fu Liang
- Subjects
010405 organic chemistry ,Chemistry ,Stereochemistry ,Coral ,Organic Chemistry ,Absolute configuration ,Time-dependent density functional theory ,010402 general chemistry ,01 natural sciences ,Biochemistry ,Nmr data ,0104 chemical sciences ,chemistry.chemical_compound ,Természettudományok ,Drug Discovery ,Sarcophyton trocheliophorum ,Moiety ,Specific rotation ,Kémiai tudományok ,Antibacterial activity - Abstract
A series of highly oxidative new cembranoids with diverse structural features such as a dienoate moiety (sarcophytonolides S – U, 1–3) or an α,β-unsaturated e-lactone (sartrolides H – J, 4–6) were obtained from Hainan soft coral Sarcophyton trocheliophorum, along with known related analogues 7–13. It is an extremely challenging work to determine the absolute configurations of these metabolites. For compounds 1, 3 and 4, solution TDDFT calculation of ECD and specific rotation were applied in combination with conformational analysis and NMR data to determine their relative and absolute configurations, leading to the revision of relative configuration of 14. The absolute configurations of compounds 8–10 were determined by the solid-state TDDFT-ECD approach, and that of 8 was further confirmed by single-crystal X-ray diffraction experiment with Cu Kα radiation. In the bioassays, compound 8 exhibited not only moderate protein tyrosine phosphatase 1B (PTP1B) inhibitory activity (IC50 = 15.4 μM) but also moderate antibacterial activity against Staphylococcus aureus Newman strain (MIC50 = 250 μM).
- Published
- 2018
40. Particle-based immobilized enzymatic reactors in microfluidic chips
- Author
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Adam Kecskemeti and Attila Gáspár
- Subjects
Analyte ,Immobilized enzyme ,Protein digestion ,Microfluidics ,Nanotechnology ,02 engineering and technology ,01 natural sciences ,Analytical Chemistry ,Matrix (chemical analysis) ,Természettudományok ,Lab-On-A-Chip Devices ,Animals ,Humans ,Kémiai tudományok ,Chemistry ,010401 analytical chemistry ,Proteolytic enzymes ,Equipment Design ,Enzymes, Immobilized ,021001 nanoscience & nanotechnology ,Microspheres ,0104 chemical sciences ,Proteolysis ,Nanoparticles ,Microreactor ,0210 nano-technology ,Biosensor - Abstract
The research and applications of immobilized enzyme reactors (IMERs) have become more and more widespread due to the numerous advantages like reusability, easy handling, prolonged lifetime, easy separation from products and substrate specificity. The miniaturized form of these reactors (microchip IMERs) received outstanding attention due to their special features and advantages over the traditional, larger analytical systems. Large specific surface is essential for the efficient operation of the microreactors, thus these devices include one of the several types of porous solid supports, but in this work only the particle based microchip IMERs are reviewed. A very large variety of micro- or nanoparticles (beads) have been used in the microchip IMERs, however, incorporating these particles into microchips is still a challenge, because the common procedures used for the preparation of chromatographic columns are not well applicable at the microscopic level. Many detection systems were applied with microchip IMERs using on-chip or off-chip arrangement. The combination of microchip IMERs with mass spectrometry is particularly popular, because in these systems high-throughput analysis can be achieved by which the proteomic studies can be largely accelerated. In most chip IMER-MS systems, the chips are used for sample pretreatment including analyte (protein) digestion, preconcentration of analyte, removal of matrix materials. Additional applications of the IMERs - like the rapid protein digestion with proteolytic enzymes, the transformation of analytes to a more easily or more sensitively measurable form (detection signal amplification) and the design of microarrays/biosensors to analyze antigens based on specific interactions in immunoanalytical studies - are also reviewed.
- Published
- 2018
41. MICAN, a new fluorophore for vital and non-vital staining of human cells
- Author
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Sándor Kéki, Péter Könczöl, Zsolt Bacsó, Gaspar Banfalvi, Miklós Nagy, Alexandra Kiss, Csaba Bankó, Gábor Szemán-Nagy, Dávid Rácz, Zsolt Nagy, and Beatrix Barna
- Subjects
0301 basic medicine ,Tissue Fixation ,Fluorophore ,Cell Survival ,Apoptosis ,Naphthalenes ,Toxicology ,Stain ,Cell Line ,Necrosis ,03 medical and health sciences ,chemistry.chemical_compound ,0302 clinical medicine ,Természettudományok ,Toxicity Tests ,Image Processing, Computer-Assisted ,Fluorescence microscope ,Humans ,Kémiai tudományok ,Fluorescent Dyes ,Staining and Labeling ,Chemistry ,Endoplasmic reticulum ,General Medicine ,Photobleaching ,Extracellular Matrix ,Staining ,HaCaT ,030104 developmental biology ,Microscopy, Fluorescence ,Vital stain ,030220 oncology & carcinogenesis ,Biophysics - Abstract
Fluorescence time-lapse microscopy is in connection with the invasive properties of fluorochrome applied, and with the toxicity of the excitation energy and wavelength of the dye itself. Experiments with the newly synthesized fluorescent dye 1-N-methylamino-5-isocyanonaphthalene (MICAN) served to test its cytotoxicity on human HaCaT keratinocyte cell cultures. Experiments related to staining capability were performed with paraformaldehyde (PFA) fixed cells and observed with fluorescence microscope. It was assumed that the fluorophore 1-amino-5-isocyanonaphthalene (ICAN) and especially its N-methylamino derivative MICAN, containing condensed aromatic rings could serve as a nonselective fluorescent dye capable to stain cellular structures of fixed, living, damaged and dead cells. This notion was confirmed by the MICAN staining of cytoplasmic proteins primarily rough endoplasmic reticulum (RER), smooth endoplasmic reticulum (SEM) and less efficiently nuclear proteins suggesting the involvement of staining of subcellular structures involved in protein synthesis. MICAN was not only well tolerated by living cells but turned out to be a strong heterochromatin and RER staining agent. This led to the development of a MICAN staining protocol for native and living samples. Relative to other fluorescent dyes, MICAN is not only useful but also cost-effective. Toxicology tests were performed using 30, 10, 5, 0.5 μg/ml MICAN concentrations. Time-lapse videomicroscopy at near-infrared (NIR) illumination has been used for the examination of MICAN effect on cell division. It was found that MICAN as a vital stain had no significant harmful effect on HaCaT cells. MICAN turned out to be a non-toxic, highly quantum-efficient vital stain with minimal, or no photobleaching, and can be applied to co-stain with propidium-iodide due the strong spectral separation.
- Published
- 2018
42. Host age determines parasite load of Laboulbeniales fungi infecting ants: Implications for host-parasite relationship and fungal life history
- Author
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András Tartally, Zoltán Rádai, Ferenc Báthori, and Walter P. Pfliegler
- Subjects
0106 biological sciences ,biology ,Ascomycota ,Host (biology) ,Laboulbeniales ,Zoology ,Biológiai tudományok ,Hymenoptera ,biology.organism_classification ,010603 evolutionary biology ,01 natural sciences ,Parasite load ,Myrmecophily ,010602 entomology ,Természettudományok ,Myrmica ,Arthropod ,Ecology, Evolution, Behavior and Systematics - Abstract
Arthropod-parasitic fungi of the order Laboulbeniales are known to exhibit specialization to individual host taxa in most cases. Some species exhibit ecological specificity to multiple, often unrelated hosts in certain microhabitats; and often position specificity to different host body parts. The myrmecophilous Rickia wasmannii (Ascomycota: Laboulbeniales) infects Myrmica species (Hymenoptera: Formicidae) (host specificity), and occasionally other arthropod inquilines inside the ant nest (ecological specificity). An effect of the position of infection on the thallus densities has also been reported. Another determinative factor that may also exist in the Rickia-Myrmica host-parasite system, the chronological age of ant worker hosts, has also been linked to parasite load. Comprehensive studies on the age-related infection intensity, however, are still lacking. Here we investigated whether the level of infection correlates with the age of the M. scabrinodis host consistently. We found that older hosts exhibited higher parasite load, even though the infection level of the different colonies varied widely. The results highlight that the level of R. wasmannii infections are strongly influenced by host individual and host colony factors.
- Published
- 2018
43. Promoter effect of bicarbonate in hydrogenation of cinnamaldehyde catalyzed by a water-soluble Ru(II)-phosphine complex
- Author
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Gábor Papp, Imre Szatmári, Ferenc Joó, and Ágnes Kathó
- Subjects
Aqueous solution ,010405 organic chemistry ,Bicarbonate ,Inorganic chemistry ,chemistry.chemical_element ,010402 general chemistry ,01 natural sciences ,Medicinal chemistry ,Cinnamaldehyde ,0104 chemical sciences ,Ruthenium ,Catalysis ,Inorganic Chemistry ,chemistry.chemical_compound ,Természettudományok ,chemistry ,Materials Chemistry ,Formate ,Physical and Theoretical Chemistry ,Triphenylphosphine ,Kémiai tudományok ,Phosphine - Abstract
The highly selective formation of cinnamalcohol in hydrogenation of trans-cinnamaldehyde with [{RuCl2(mtppms)2}2] + mtppms as catalyst (mtppms = monosulfonated triphenylphosphine) in aqueous solution was substantially accelerated by NaHCO3 (in 20–50 mol% quantities relative to cinnamaldehyde). More than double conversion compared to bicarbonate-free systems was observed at n(NaHCO3)/n(Ru) = 20. Prehydrogenation of the reaction mixture before the addition of cinnamaldehyde resulted in further rate increase (45.3% conversion vs. 13.1% in water). 1H , 13C and 31P NMR studies revealed that formate produced in hydrogenation of bicarbonate facilitated formation of trans-[Ru(H)2(H2O)(mtppms)3], a better catalyst than cis-fac-[Ru(H)2(H2O)(mtppms)3] which is the product of the reaction of [{RuCl2(mtppms)2}2] + mtppms with H2 in the absence of formate (or bicarbonate). Accordingly, NaHCO2 produced even higher rate increase than the same amount of NaHCO3.
- Published
- 2018
44. Thermodynamical transcription of density functional theory with minimum Fisher information
- Author
-
Ágnes Nagy
- Subjects
Physics ,010304 chemical physics ,General Physics and Astronomy ,Inverse temperature ,Fizikai tudományok ,Shannon information entropy ,Kinetic energy ,01 natural sciences ,symbols.namesake ,Természettudományok ,Transcription (biology) ,0103 physical sciences ,symbols ,Density functional theory ,Statistical physics ,Physical and Theoretical Chemistry ,010306 general physics ,Fisher information - Abstract
Ghosh, Berkowitz and Parr designed a thermodynamical transcription of the ground-state density functional theory and introduced a local temperature that varies from point to point. The theory, however, is not unique because the kinetic energy density is not uniquely defined. Here we derive the expression of the phase-space Fisher information in the GBP theory taking the inverse temperature as the Fisher parameter. It is proved that this Fisher information takes its minimum for the case of constant temperature. This result is consistent with the recently proven theorem that the phase-space Shannon information entropy attains its maximum at constant temperature.
- Published
- 2018
45. Tuning the redox potentials of ternary cobalt(III) complexes containing various hydroxamates
- Author
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Imre Zs.-Nagy, Etelka Farkas, Éva Kováts, István Kacsir, Máté Kozsup, Attila Bényei, Sándor Nagy, and Péter Buglyó
- Subjects
010405 organic chemistry ,Stereochemistry ,Ligand ,Substituent ,chemistry.chemical_element ,010402 general chemistry ,01 natural sciences ,Medicinal chemistry ,Redox ,0104 chemical sciences ,Inorganic Chemistry ,chemistry.chemical_compound ,Deprotonation ,Természettudományok ,chemistry ,Oxidation state ,Materials Chemistry ,Nitro ,Moiety ,Physical and Theoretical Chemistry ,Kémiai tudományok ,Cobalt - Abstract
Sixteen cobalt(III) complexes incorporating one of the investigated 4N donor tripodal amines in the presence or absence of differently substituted hydroxamates have been synthesized and the effect of the nature of the N-donor, size of the chelates formed and the effect of the type of the substituent(s) at the hydroxamate moiety on the redox properties of the complexes have been studied. The crystal and molecular structures of the new complexes, [Co(uns-penp)(H 2 O)Cl]Cl 2 ·H 2 O ( 4 ), [Co(tren)(phebha)](ClO 4 ) 2 ( 11 ), [Co(tpa)(bha)](ClO 4 ) 2 ·C 2 H 5 OH·H 2 O ( 15 ) and [Co(tpa)(phebha)](ClO 4 ) 2 ( 16 ) have also been determined by single crystal X-ray diffraction method. Cyclic voltammetric (CV) results indicated the irreversible reduction of Co(III) in all the investigated complexes. Out of the four studied tripodal amines, abap was found to decrease the Co(III/II) reduction potential far below the region of bioreductants. Decreasing of two of the chains by one CH 2 in tren compared to abap resulted in less negative reduction potential of the corresponding complex. Further positive shift was observed by introducing two (uns-penp), and especially three (tpa) π-back-bonding pyridyl rings into the chains of tetramines. In agreement with literature results, the 3+ oxidation state of the central cobalt ion was found to be extremely stabilized in the ternary complexes containing the doubly deprotonated benzohydroximate, but the metal ion is significantly more reducible in the ternary complexes with mono-deprotonated benzohydroxamate/derivative ligands. Measurable effect was not found on the redox potential via introduction of chloro or nitro substituents in para position into the phenyl moiety of bha − (Cl-bha − and NO 2 -bha − ). Significant positive shift (ca. 200 mV) was obtained, however, when R N = H was replaced by a phenyl ring in phebha − therefore complexes with this latter ligand can be likely candidates for the in vitro releasing of hydroxamates with proven biological activity.
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- 2018
46. Remarkable differences and similarities between the isomeric Mn(II)- cis - and trans- 1,2-diaminocyclohexane- N , N , N ′, N ′-tetraacetate complexes
- Author
-
Richárd Botár, Enikő Molnár, Imre Tóth, Gyula Tircsó, Carlos Platas-Iglesias, Zoltán Garda, Éva Tóth, Ernő Brücher, Ferenc K. Kálmán, and Balázs Váradi
- Subjects
010405 organic chemistry ,Stereochemistry ,Ligand ,Metal ions in aqueous solution ,Protonation ,Water exchange ,010402 general chemistry ,01 natural sciences ,Dissociation (chemistry) ,0104 chemical sciences ,Inorganic Chemistry ,Solvent ,chemistry.chemical_compound ,Crystallography ,Természettudományok ,chemistry ,Materials Chemistry ,DOTA ,Physical and Theoretical Chemistry ,Kémiai tudományok ,Cis–trans isomerism - Abstract
Equilibrium, kinetic (solvent exchange and dissociation of the complex) and relaxometric studies (1H and 17O NMR) have been performed with the [M(II)(c-cdta)]2− complexes (c-cdta = cis-1,2-diaminocyclohexane-N,N,N′,N′-tetraacetic acid, M(II) = Mn(II), Zn(II), Cu(II),Ca(II), Mg(II)) and the physico-chemical data are compared to the isomeric complexes with trans-1,2-cdta (t-cdta) with the aim of searching appropriate ligands for Mn(II) complexation for safe MRI contrast agents. The total basicity (Σ log KiH) of the c-cdta ligand appears to be very similar to that of the trans-derivative under the conditions applied (I = 0.15 M NaCl and 25 °C), but the first two protonation constants notably differ. log K1H is 1.5 log units higher, while the log K2H is 0.8 log units lower than those determined for the trans-derivative. Similar basicity of the ligands results in similar complex stability (log K[Mn(L)] values are 14.19(2) and 14.32), whereas the conditional stabilities near to physiological pH are different (pMn values are 7.82 and 8.68) for the [Mn(c-cdta)]2− and the [Mn(t-cdta)]2− derivatives, respectively. Dissociation kinetic studies revealed that the [Mn(c-cdta)]2− dissociates 250 times faster than the [Mn(t-cdta)]2− complex. The water exchange rate (kex298) of [Mn(c-cdta)]2− is ca. 60% higher than that of [Mn(t-cdta)]2−. The differences can likely be attributed to the different distances between the individual donor atoms, and the arrangement of the donor atoms around the metal ions in the cis- and trans- isomers. Interestingly, the relaxivity values of the Mn(II) complexes are very close (r1p = 3.79 mM−1 s−1 and 3.62 mM−1 s−1; 20 MHz, 25 °C for the cis- and trans-isomers, respectively). DFT calculations were used to gain insight into the different properties of the [Mn(c-cdta)]2− and the [Mn(t-cdta)]2− complexes. The results gained in our studies confirm that the trans-1,2-cyclohexanediamine “building block” displays better features for further ligand development.
- Published
- 2018
47. Lead(II) complexes of oligopeptides containing two cysteine residues
- Author
-
Györgyi Szunyog and Katalin Várnagy
- Subjects
010405 organic chemistry ,Chemistry ,Stereochemistry ,Ligand ,chemistry.chemical_element ,Metal Binding Site ,Zinc ,010402 general chemistry ,01 natural sciences ,Medicinal chemistry ,0104 chemical sciences ,Inorganic Chemistry ,Metal ,Természettudományok ,visual_art ,Materials Chemistry ,visual_art.visual_art_medium ,Molecule ,Chelation ,Physical and Theoretical Chemistry ,Binding site ,Kémiai tudományok ,Cysteine - Abstract
The complex formation processes of three oligopeptides (CysSerSerAlaCysSer-NH2, CSSACS-NH2; AlaCysSerSerAlaCysSer-NH2, ACSSACS-NH2; SerSerCysSerSerAlaCysSer-NH2, SSCSSACS-NH2) were studied in the presence of toxic lead(II) ions and compared to those of toxic cadmium(II) and essential zinc(II) ions. The stoichiometry and stability constants of the metal complexes were determined by potentiometry, while their structures were supported by means of UV- and NMR-spectroscopy. For hexapeptide containing cysteine in N-terminal position the (NH2,S−) donor groups are the primary metal binding site forming 5-membered chelate ring, and the coordination of C-terminal thiolate group contributes the stability of mono(ligand) complex excluding the formation of bis(ligand) species. The (S−,S−) donor set is, however, the main binding site, if the –CSSAC– sequence is farther from N-terminal amino group in the molecules, and mono- and bis(ligand) complexes are formed. The metal binding affinity of all three ligands are higher for lead(II) ion than zinc(II) ion resulting good selectivity of ligands for lead(II) over zinc(II).
- Published
- 2018
48. Geometric phase of light-induced conical intersections: adiabatic time-dependent approach
- Author
-
Péter Badankó, Ágnes Vibók, and Gábor J. Halász
- Subjects
Mathematics::Dynamical Systems ,Biophysics ,Born–Oppenheimer approximation ,Fizikai tudományok ,02 engineering and technology ,01 natural sciences ,Electronic states ,law.invention ,symbols.namesake ,Természettudományok ,law ,Physics - Chemical Physics ,Quantum mechanics ,0103 physical sciences ,Physical and Theoretical Chemistry ,010306 general physics ,Adiabatic process ,Molecular Biology ,Computer Science::Databases ,Physics ,Conical surface ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,Laser ,Geometric phase ,symbols ,Light induced ,0210 nano-technology - Abstract
Conical intersections are degeneracies between electronic states and are very common in nature. It has been found that they can also be created both by standing or by running laser waves. The latter are called light-induced conical intersections. It is well known that conical intersections are the sources for numerous topological effects which are manifested e.g. in the appearance of the geometric or Berry phase. In one of our former works by incorporating the diabatic-to-adiabatic transformation angle with the line-integral technique we have calculated the Berry-phase of the light-induced conical intersections. Here we demonstrate that by using the time dependent adiabatic approach suggested by Berry the geometric phase of the light-induced conical intersections can also be obtained and the results are very similar to those of the time-independent calculations.
- Published
- 2018
49. A Coordination Chemistry Approach to Fine-Tune the Physicochemical Parameters of Lanthanide Complexes Relevant to Medical Applications
- Author
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Gyula Tircsó, David Esteban-Gómez, Mariane Le Fur, Olivier Rousseaux, Raphaël Tripier, Ferenc K. Kálmán, Enikő Molnár, Maryline Beyler, Olivier Fougère, Carlos Platas-Iglesias, Chimie, Electrochimie Moléculaires et Chimie Analytique (CEMCA), Institut Brestois Santé Agro Matière (IBSAM), Université de Brest (UBO)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC), University of Debrecen Egyetem [Debrecen], Guerbet research group, Guerbet, Departamento de Química Fundamental, and Universidade da Coruña
- Subjects
Steric effects ,Lanthanide ,Magnetic Resonance Spectroscopy ,Contrast Media ,Gadolinium ,Ligands ,010402 general chemistry ,Lanthanoid Series Elements ,NMR Spectroscopy ,01 natural sciences ,Catalysis ,Dissociation (chemistry) ,Ion ,Coordination complex ,Természettudományok ,Water Exchange ,Lanthanides ,[CHIM]Chemical Sciences ,Molecule ,[CHIM.COOR]Chemical Sciences/Coordination chemistry ,Picolinic Acids ,Kémiai tudományok ,chemistry.chemical_classification ,010405 organic chemistry ,Ligand ,Organic Chemistry ,Water ,General Chemistry ,0104 chemical sciences ,3. Good health ,Kinetics ,Crystallography ,chemistry ,Thermodynamics ,Macrocycles ,Order of magnitude ,MRI - Abstract
International audience; The geometric features of two pyclen-based ligands possessing identical donor atoms but different site organization have a profound impact in their complexation properties toward lanthanide ions. The ligand containing two acetate groups and a picolinate arm arranged in a symmetrical fashion (L1) forms a Gd3+ complex being two orders of magnitude less stable than its dissymmetric analogue GdL2. Besides, GdL1 experiences a much faster dissociation following the acid-catalyzed mechanism than GdL2. On the contrary, GdL1 exhibits a lower exchange rate of the coordinated water molecule compared to GdL2. These very different properties are related to different strengths of the Gd ligand bonds associated to steric effects, which hinder the coordination of a water molecule in GdL2 and the binding of acetate groups in GdL1.
- Published
- 2018
50. Investigation of the performance of thermally generated gold nanoislands for LSPR and SERS applications
- Author
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Judit Kaman, L. Himics, Istvan Csarnovics, Miklós Veres, Attila Csik, Laszlo Balazs, Sándor Kökényesi, and Attila Bonyár
- Subjects
Materials science ,Scanning electron microscope ,Physics::Optics ,Fizikai tudományok ,Nanotechnology ,02 engineering and technology ,010402 general chemistry ,01 natural sciences ,Condensed Matter::Materials Science ,symbols.namesake ,Természettudományok ,Materials Chemistry ,Electrical and Electronic Engineering ,Surface plasmon resonance ,Instrumentation ,Plasmon ,Thin layers ,Nanocomposite ,Metals and Alloys ,Surface-enhanced Raman spectroscopy ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,0104 chemical sciences ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials ,Colloidal gold ,symbols ,0210 nano-technology ,Raman spectroscopy - Abstract
In this work, the performance of gold nanoislands was investigated for Localized Surface Plasmon Resonance (LSPR) and Surface Enhanced Raman Spectroscopy (SERS) applications. Nanoislands were generated by thermally annealing thin layers of gold (having thickness in the 6–12 nm range), which was previously deposited by vacuum thermal evaporation onto glass substrates. Gold nanoparticles (AuNP) were evaluated based on their plasmonic and SERS performance and morphological properties. Scanning Electron Microscopy (SEM) was used to measure the average particle size and average interparticle distance in order to correlate them with the obtained plasmonic/Raman capabilities. The technological parameters of nanoisland fabrication for optimal performances were also determined.
- Published
- 2018
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