584 research outputs found
Szintetikus és NMR kutatások peptidek és szénhidrátok körében = Synthetic and NMR studies of peptides and carbohydrates
Egy immunomoduláns peptidoglikán-monomer (PGM) lipofil származĂ©kainak konformáciĂłját 2D NMR Ă©s molekulamodellezĂ©s segĂtsĂ©gĂ©vel határoztuk meg. A szubsztituensek okozta konformáciĂł változások a biolĂłgiai aktivitást nem befolyásolják. Bakteriális endotoxinokat (LPS) gátlĂł LALF-14 hexadekapeptid LPS-kötĹ‘dĂ©sĂ©t hasonlĂł mĂłdszerekkel vizsgálva kimutattuk, hogy a teljes LALF protein lipid-A-kötĹ‘ ?-lemez rĂ©giĂłja nem elĹ‘feltĂ©tele a LALF-14 - LPS-kötĹ‘dĂ©snek. Dodekapeptidekben NOE-mĂ©rĂ©sekkel Ă©s molekulamodellezĂ©ssel aromás gyűrű - amid-H kölcsönhatásokat mutattunk ki amelyek a helikális tĂ©rszerkezettel kapcsolatosak. Ăšj tĂpusĂş, háromkötĂ©ses glikozidos hidat tartalmazĂł glikomimetikumok elsĹ‘ kĂ©pviselĹ‘ikĂ©nt glikozil-diszulfidokat Ă©s -szulfĂ©namidokat szintetizáltunk. Hidrazino-pirimidinek Ă©s aromás aldehidek acilezĂ©si reakciĂłban nukleozid-analĂłg [1,2,4]triazolo[4,5-a]pirimidin-4-on származĂ©kokat eredmĂ©nyeznek. Javaslatot tettĂĽnk ezen Ăşj gyűrűzárási reakciĂł mechanizmusára. Javasoltuk a Lipari-SzabĂł NMR relaxáciĂłs mĂłdszer kiterjesztĂ©sĂ©t. MĂłdszerĂĽnkkel fehĂ©rjĂ©kben meghatározhatĂł a kĂ©miai eltolĂłdások anizotrĂłpiája (CSA) Ă©s az Ăşn. geometriai faktor is. Ăšj TROSY mĂłdszert javasoltunk az NH-H? csatolási állandĂłk mĂ©rĂ©sĂ©re fehĂ©rjĂ©kben. ÉrzĂ©keny, Ă©s pontos NMR mĂłdszereket fejlesztettĂĽnk ki gyengĂ©n orientált közegben maradĂ©k dipoláris csatolások, Ă©s diasztereotĂłp metilĂ©n-proton csatolások dipoláris járulĂ©kainak mĂ©rĂ©sĂ©vel az Ăşj glikomimetikumok tĂ©rszerkezetĂ©nek jellemzĂ©sĂ©re. | 2D NMR and molecular modelling studies of lipophilic derivatives of peptidoglycan monomer (PGM) indicate that conformational changes induced by the substituents do not affect the biological activities of these compounds. Using similar approaches it was shown that binding of the LALF-14 inhibitor peptide to bacterial endotoxins (LPS) does not require the -sheet structure in the lipid-A binding region of full-size LALF protein as a prerequisite. Interactions between amide protons and side chain aromatic rings in helical dodecapeptides were identified by NOE-restrained molecular modelling. Diglycosyl disulfides and glycosyl sulfenamides were synthesized as the first representatives of novel glycomimetics with three-bond glycosidic linkages. Hydrazino-pyrimidines react with aromatic aldehydes under acylating conditions to furnish nucleoside analog [1,2,4]triazolo[4,5-a]pyrimidin-4-ones. A mechanism was proposed for these novel ring closing reactions. The Lipari-SzabĂł formalism for NMR relaxation data was extended for the determination of individual chemical shift anisotropies (CSA) and the geometry factors in proteins. A new TROSY sequence was developed to measure NH-H? couplings in proteins. Novel NMR methods were proposed to measure residual dipolar couplings and the dipolar contribution to the scalar coupling between diastereotopic protons in weakly aligned media. These NMR methods are of importance in the structural studies of the novel glycomimetics
MEDICAL IMAGE PROCESSING METHODS FOR THE DEVELOPMENT OF A VIRTUAL ENDOSCOPE
Virtual endoscopes give internal views of the human body without penetrating
it, based on a set of parallel cross-sections produced with any computed
tomography method. This paper presents some ideas concerning the design and
implementation of a software system, which acts like a virtual endoscope. It
takes into account the general requirements of the system, gives a solution
that uses a multi-step algorithm, and finally shows the resulting 3-D
images. Most of the algorithmic steps have several possible solutions. Some
comparisons are made among them where appropriate. The quality of service
provided by the chosen method mainly depends on the resolution of the input
images
Non-normal affine monoids, modules and Poincaré series of plumbed 3-manifolds
We construct a non-normal affine monoid together with its modules associated with a negative definite plumbed 3-manifold M. In terms of their structure, we describe the H1(M, Z) -equivariant parts of the topological Poincaré series. In particular, we give combinatorial formulas for the Seiberg–Witten invariants of M and for polynomial generalizations defined in [17]. © 2017, Akadémiai Kiadó, Budapest, Hungary
INVESTIGATION OF THE CHANGES OF THE MASS MOMENTS OF INERTIA DURING A DOUBLE STEP OF RUNNING
INTRODUCTION: A new method for the investigation of athletes' motion takes into consideration the changes of the principal moments of inertia and their directions during the interval of the motion, because these characterize both the changes and the loss of energy. This paper investigates the motion of a runner. The applied model is a refined Hanavan model [1], representing the human body with 16 simple geometric solids determined by the spatial co-ordinates of 20 key points. METHODS AND PROCEDURES: The records were made by The Biomechanics Department of the Hungarian University of Physical Education with several video cameras. For the digitalization of the frames the APAS (Ariel Performance Analysis System) was used. The data of the digitized key points were analyzed by the system (MAS = Motion Analyzing System), developed for PC at the Department of Applied Mechanics of the Technical University of Budapest. Fig. 1 shows 11 different phases of the motion in the same picture. The time interval between the first and last phase is 0.9 sec. During the analysis 46 frames were digitized with a time-interval of 0.02 sec. This paper investigates the changes of the eigensystem for the mass moments of inertia of the whole human body with respect to the center of mass during the interval of the motion
Non-normal affine monoids, modules and Poincaré series of plumbed 3-manifolds
We construct a non-normal affine monoid together with its modules associated with a negative definite plumbed 3-manifold M. In terms of their structure, we describe the -equivariant parts of the topological Poincaré series. In particular, we give combinatorial formulas for the Seiberg–Witten invariants of M and for polynomial generalizations defined in [17]
Atrial Remodeling in Atrial Fibrillation. Comorbidities and Markers of Disease Progression Predict Catheter Ablation Outcome
Atrial fibrillation is the most common supraventricular arrhythmia affecting an increasing proportion of the population in which mainstream therapy, i.e. catheter ablation, provides freedom from arrhythmia in only a limited number of patients. Understanding the mechanism is key in order to find more effective therapies and to improve patient selection. In this review, the structural and electrophysiological changes of the atrial musculature that constitute atrial remodeling in atrial fibrillaton and how risk factors and markers of disease progression can predict catheter ablation outcome will be discussed in detail
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