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The impact of radical political changes had a surprisingly strong impact upon the universities in Hungary. In the twentieth century, Hungary was part of two empires (the Habsburg and the Soviet empires), suffered from two World Wars, lived under two totalitarian regimes (communism twice, Nazism once), and experienced several revolutions. One would expect that universities would provide asylums, hiding places for professionals to defend themselves in such stormy atmosphere. In fact, however, the universities proved to be one of the first points to which political changes were extended. Besides showing data about the political influences on the number of universities, personnel, and curricula, this paper intends to provide an analysis of this transition, and illustrate the mechanism of change on the basis of the Technical University of Budapest, focusing on the period of 1945–1953. This is the period of the introduction of the Soviet university model to replace the traditional German one. The paper aims to prove that the myth of expertise does not shield universities from political intrusion but it helps to make the intrusion somewhat endurable.

A new copper-catalyzed oxidative ring closure of ethynyl anilides with diaryliodonium salts is developed for the highly modular construction of benzoxazines bearing a fully substituted exo double bond.

Entering the final phase of the preparation for negotiations on EU accession, the main area of work of our department is the co-ordination of the adaptation of European legislation in the Hungarian agricultural and foodstuffs sectors. Our specific field is the assessment of the EU's horizontal and vertical foodstuffs quality provisions, and the elaboration of their possible application in Hungary. This paper focuses particularly on the scientific analysis of the adoption of EC provisions regarding speciality products that are of high importance from the point of view of the exportability of Hungarian foodstuffs.

This chapter approaches various occurrences of scientific nationalism in nineteenth-century Hungary; the term ‘scientific nationalism’ stands for both nationalism occurring within science and nationalism based on science. The latter form of nationalism, which used science directly for political purposes as an argument and justification for nationalist politics, had gradually become a widespread ideology in Hungary in the second part of the nineteenth century. It was not science, but politics, that was nationalist; however, science could not stay neutral on this central political issue. It developed a national character manifested both in its institutional structure and in its cognitive contents.

In the early history of surface chemistry, in the 1920s, the nature of gas adsorption was a pivotal subject. A theory created by Michael Polanyi in the peripheral Hungary contradicted the received view originating from the American Irving Langmuir. When working out his theory, Polanyi had not even heard of Langmuir's rival description. However, Polanyi emigrated from Hungary to Germany, the centre of his field, and tried to defend his adsorption theory in the circle of the leading experts, including Einstein and Fritz Haber. This controversy seemed vital to his survival as a scientist and as an immigrant. The aim of this article is to recapitulate this controversy, with its sad undercurrents, the role of local science, methods of argumentation, and the work of a central scientific community.

Ambient level of gamma -aminobutyric acid (GABA), the major inhibitory neurotransmitter of the brain is mediated by neuronal and glial GABA transporters (GATs), members of the sodium and chloride ion-dependent solute carrier family. The neuronal GABA transporter subtype (GAT-1) has already been proven to be the target for the antiepileptic drug Tiagabine. However, druggability of glial GAT-2 and GAT-3 is yet to be established. Recent advances in structure elucidation of a bacterial orthologue leucine transporter in complex with different substrates substantiate homology modeling of human GATs (hGATs). These modeling studies can provide mechanistic clues for structure-based prediction of the potential of medicinal chemistry campaigns. A recently identified characteristic structural feature of the occluded conformation of hGATs is that similar extra- and intracellular gates are formed by middle-broken transmembrane helices TM1 and TM6. Binding crevice formed by unwound segments of broken helices facilitates symport of GABA with Na+ ion via fitting of GABA to TM1-bound Na+ closely inside. Favored accommodation of substrate inhibitors with high docking score predicts efficient inhibition of the neuronal hGAT-1 if the TM1-TM8 binding prerequisite for GABA was used. Docking, molecular dynamics and transport data indicate, that amino acids participating in substrate binding of the neuronal hGAT-1 and the glial hGAT-2 and hGAT-3 subtypes are different. By contrast, substrate binding crevices of hGAT-2 and hGAT-3 cannot be distinguished, avoiding sensible prediction of efficient selective substrate inhibitors. Glial subtypes might be specifically distinguished by interfering Zn2+ binding in the second extracellular loop of hGAT-3. Formation of the unique ring-like Na+-GABA complex in the occluded binding crevices anticipates family member symporters exploring chemiosmotic energy via reversible chemical coupling of Na+ ion.

Crystal structures of transmembrane transport proteins belonging to the important families of neurotransmitter-sodium symporters reveal how they transport neurotransmitters across membranes. Substrate-induced structural conformations of gated neurotransmitter-sodium symporters have been in the focus of research, however, a key question concerning the mechanism of Na(+) ion coupling remained unanswered. Homology models of human glial transporter subtypes of the major inhibitory neurotransmitter gamma-aminobutyric acid were built. In accordance with selectivity data for subtype 2 vs. 3, docking and molecular dynamics calculations suggest similar orthosteric substrate (inhibitor) conformations and binding crevices but distinguishable allosteric Zn(2+) ion binding motifs. Considering the occluded conformational states of glial human gamma-aminobutyric acid transporter subtypes, we found major semi-extended and minor ring-like conformations of zwitterionic gamma-aminobutyric acid in complex with Na(+) ion. The existence of the minor ring-like conformation of gamma-aminobutyric acid in complex with Na(+) ion may be attributed to the strengthening of the intramolecular H-bond by the electrostatic effect of Na(+) ion. Coupling substrate uptake into cells with the thermodynamically favorable Na(+) ion movement through substrate-Na(+) ion complex formation may be a mechanistic principle featuring transmembrane neurotransmitter-sodium symporter proteins.

This paper presents a framework for the study of George Hevesy's research in the 1910s by distinguishing two styles of radioactivity research: the analytical (as practices in Manchester and Vienna in some extent) and the natural historical styles (as practiced in Hungary). Georg Hevesy's approach combined the two types. Indeed, by studying Hevesy's research in context, I show that the earliest applications of isotopes were born in parallel with the establishment of the isotope theory of matter.

Ligand-bound and free structures of brain membrane targets for L-glutamate (Glu) suggest the view, that quaternary rearrangements are associated with ligand binding. Rearrangement of the machinery of the signaling apparatus, such as molecular switches, recognition sites and the target structures for ligand binding of Glu-operated ion channel and heptahelical G-protein-coupled family receptors have been quantified and compared with the use of the root mean square (RMS) values. In addition to conformational rearrangement of the Glu receptor structures in complex with a series of ligands, conformations of Glu in various target structures became available. High resolution data revealed that the extended Glu conformation is conserved in the binding crevice of all ionotropic Glu receptors (iGluRs). Furthermore, the extended conformations of Glu that characterize iGluRs and mGluRs are distinguishable by distance and torsion angle parameters, such as deltaC1-C2 and Calpha-Cbeta-Cgamma-C2. By contrast, a bent Glu conformation is recognized in Glu transporters.

It is widely accepted that the catalytic activity of serine proteases depends primarily on the Asp-His-Ser catalytic triad and other residues within the vicinity of this motif. Some of these residues form the oxyanion binding site that stabilizes the tetrahedral intermediate by hydrogen bonding to the negatively charged oxyanion. In acylaminoacyl peptidase from the thermophile Aeropyrum pernix, the main chain NH group of Gly369 is one of the hydrogen bond donors forming the oxyanion binding site. The side chain of His367, a conserved residue in acylaminoacyl peptidases across all species, fastens the loop holding Gly369. Determination of the crystal structure of the H367A mutant revealed that this loop, including Gly369, moves away considerably, accounting for the observed three orders of magnitude decrease in the specificity rate constant. For the wild-type enzyme ln(k(cat)/K(m)) vs. 1/T deviates from linearity indicating greater rate enhancement with increasing temperature for the dissociation of the enzyme-substrate complex compared with its decomposition to product. In contrast, the H367A variant provided a linear Arrhenius plot, and its reaction was associated with unfavourable entropy of activation. These results show that a residue relatively distant from the active site can significantly affect the catalytic activity of acylaminoacyl peptidase without changing the overall structure of the enzyme.

A természettudományok, a technika és az orvoslás tárgyi, képi és írott forrásai (az 1997. évi ankét anyaga). Tanulmányok a természettudományok, a technika és az orvoslás történetéből = Studies into the History of Science, Technology and Medicine

A mérnök, a természettudós és az orvos szerepe a társadalomban (az 1995. évi ankét anyaga). Tanulmányok a természettudományok, a technika és az orvoslás történetéből = Studies into the History of Science, Technology and Medicine

A magyar műszaki-, természet- és orvostudományok kommunikációs formái (Az 1993. évi ankét anyaga). Műszaki, természettudományos és orvosi gyűjtők és gyűjtemények (Az 1994. évi ankét anyaga). Tanulmányok a természettudományok, a technika és az orvoslás történetéből = Studies into the History of Science, Technology and Medicine

Tanulmányok a természettudományok, a technika és az orvoslás történetéből. Tanulmányok a természettudományok, a technika és az orvoslás történetéből = Studies into the History of Science, Technology and Medicine

According to a joke circulating among American scientists around the time of the Second World War, some physicists were discussing the chances of a possible visit to Earth by extraterrestrial beings armed with superior intelligence. One of the physicists, perhaps Enrico Fermi, remarked that the aliens were already among them but they called themselves Hungarians. This joke inspired the title of Istvan Hargittai's book The Martians of Science: Five Physicists who Changed the Twentieth Century, in which, like a modern-day Plutarch, he relates the parallel biographies of five Hungarian scientists who emigrated to the US and played major roles in science and the development of the atomic bomb.

The UV absorption of KCl crystals grown at different rates from aqueous solutions containing SnCl2 and PbCl2 in various concentrations was investigated as a function of the concentration of dopants built-in into the crystal. With increasing dopant concentration characteristic changes were observed in the absorption spectra at about 10−2 mole% concentration in the case of the non-isomorphic Sn dopant, and at 2×10−1 mole% in the case of the isomorphic Pb. The changes indicate that the manner in which the dopants are incorporated into and distributed within the crystal differs from that at lower dopant concentrations.