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Search results for: MOLECULAR EPIDEMIOLOGY
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Electron scattering by trimethylene oxide, c-(CH2)3O, molecules
PublicationZmierzono całkowity przekrój czynny na rozproszenie elektronów na drobinach c-(CH2)3O w zakresie energii 1 - 400 eV. Wyniki porównano z elastycznymi i jonizacyjnymi przekrojami czynnymi obliczonymi dla tej drobiny. Przedyskutowano energetyczną zależność całkowitego przekroju czynnego na rozproszenie dla rodziny eterów cyklicznych (CH2)nO, n=2-4.
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Electron energy-loss spectroscopy of excited states of the pyridine molecules
PublicationElectron energy-loss spectra of the pyridine, C5H5N, molecules in the gas phase have been measured to investigate electronic excitation in the energy range 3.5–10 eV. The applied wide range of residual electron energy and the scattering angle range from 10 ◦ to 180 ◦ enabled to differentiate between optically-allowed and -forbidden transitions. These measurements have allowed vertical excitation energies of the triplet excited...
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Charge transfer and formation of complexes in the He+ collisions with the furan molecules
PublicationCharge transfer and formation of the collision complexes have been studied experimentally in fragmentation of the furan molecules in collisions with He+ cations. The excited atomic and diatomic fragments of furan have been identified using collision-induced luminescence spectroscopy. Charge transfer ionization of the furan molecules has been observed in production of helium atoms in the excited 1s4d 1D2, 3D1,2,3 states. The fragmentation...
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Proton affinity and proton transfer energy for selected organic molecules
PublicationThe Hartree-Fock method in 6-311G** molecular orbitals basis set has been applied to calculations of proton affinities and proton transfer reaction energies for water, methanol, acetaldehyde, ethanol, acetone, acetic acid, methyl acetate and ethyl acetate.
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Elimination and migration of hydrogen in the vacuum-ultraviolet photodissociation of pyridine molecules
PublicationElimination of the excited hydrogen atoms H(n), n = 4–7, and hydrogen migration in formation of the excited NH(A 3Π) free radicals in the photodissociation of pyridine, C5H5N, molecules have been studied over the 17.5–70 eV photon energy range. In the measurements the photon-induced fluorescence spectroscopy technique has been applied. Both fragments are produced through excitation of pyridine molecules into higher-lying superexcited...
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Application of molecularly imprinted polymers in analytical chiral separations and analysis
PublicationOver the last two decades the process of development and application of a new types of molecular imprinted polymer (MIP) sorbents in the field of analytical chemistry have been widely described in the literature. One of the new trends in analytical chemistry practice is the use of new types of MIP sorbents as specific sorption materials constituting the stationary phase in advanced separation techniques. The following review paper...
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Nonlinear Influence of Sound on the Vibrational Energy of Molecules in a Relaxing Gas
PublicationDynamics of a weakly nonlinear and weakly dispersive flow of a gas where molecular vibrational relaxation takes place is studied. Variations in the vibrational energy in the field of intense sound is considered. These variations are caused by a nonlinear transfer of the acoustic energy into energy of vibrational degrees of freedom in a relaxing gas. The final dynamic equation which describes this is instantaneous, it includes a...
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The electronic structure of p-xylylene and its reactivity with vinyl molecules
PublicationThe electronic states of p-xylylene molecule were described at the multi-configurational CASSCF/MRMP2 level of theory. The closed-shell singlet state representing the quinoidal p-xylylene molecule was pre-dicted to be the ground electronic state whereas the triplet (benzoidal) and the singlet open-shell states were found to be much higher in energy (by 159 and 423 kJ/mol, respectively, as found at the CASSCF(8,8)/6-31+G(d) level)....
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Positron collisions with molecular hydrogen: cross sections and annihilation parameters calculated using theR-matrix with pseudo-states method
PublicationThe molecular R-matrix with pseudo-states (MRMPS) method is employed to study positron collisions with H2. The calculations employ pseudo-continuum orbital sets containing up to h (l = 5) functions. Use of these high l functions is found to give converged eigenphase sums. Below the positronium formation threshold, the calculated cross sections agree with other high-accuracy theories and generally with the measurements. Calculation...
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Molecular Heteroconjugation Equilibria in (n-Butylamine + Acetic Acid) Systems in Binary (Dimethyl Sulfoxide + 1,4-Dioxane) Solvent Mixtures
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The use of fast molecular descriptors and artificial neural networks approach in organochlorine compounds electron ionization mass spectra classification
PublicationDeveloping of theoretical tools can be very helpful for supporting new pollutant detection. Nowadays, a combination of mass spectrometry and chromatographic techniques are the most basic environmental monitoring methods. In this paper, two organochlorine compound mass spectra classification systems were proposed. The classification models were developed within the framework of artificial neural networks (ANNs) and fast 1D and...
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The impact of training and neurotrophins on functional recovery after spinal cord transection: cellular and molecular mechanisms contributing to motor improvement
PublicationBeneficial effects of locomotor training on the functional recovery after complete transection of the spinal cord indicate that in chronic spinal animals spontaneous recovery processes are enhanced and shaped by the training. The mechanisms of that use-dependent improvement are still not fully understood. This review tackles three aspects of this issue: (1) neurochemical attributes of functional improvement...
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A comparative study of the molecular lipophilicity indices of vitamins A and E, and of some precursors of vitamin A, estimated by HPLC and by different computation methods
PublicationIndeksy lipofilowości witamin A i E oraz wybranych prekursorów witaminy A zostały obliczone na podstawie wyników badań z wykorzystaniem wysokosprawnej chromatografii cieczowej z odwróconym układem faz (RPHPLC) i kolumn chromatograficznych typu C-8 i C-18.Uzyskano doskonałe współczynniki korelacji (>0,9999) dla wyników uzyskanych dla tych dwóch typów kolumn chromatograficznych.
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THE EFFECTS OF APPLYING CHITOSAN OF DIFFERENT MOLECULAR WEIGHTS ON THE GROWTH AND QUALITY OF KAMCHATKA BERRIES (LONICERA CAERULEA L.): PART 1
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Update on the molecular pathogenesis and clinical treatment of Mantle Cell Lymphoma (MCL): minutes of the 9th European MCL Network conference
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Co-crystals of iodopentafluorobenzene with nitrogen donors: 2-D molecular assemblies through halogen bonding and aryl-perfluoroaryl interactions
PublicationWspółkrystalizacja pentafluorojodobenzenu z metylowymi pochodnymi pirydyny prowadzi do powstania heterodimerów stabilizowanych wiązaniem halogenowym C-I...N, które organizują się w dwuwymiarowe struktury typu brick-wall, utrzymywane oddziaływaniami pi-pi pomiędzy jednostkami arylowymi i perfluoroarylowymi.
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Molecular and structural basis of inner core lipopolysaccharide alterations in Escherichia coli: incorporation of glucuronic acid and phosphoethanolamine in the heptose region.
PublicationIt is well established that lipopolysaccharide (LPS) often carries nonstoichiometric substitutions in lipid A and in the inner core. In this work, the molecular basis of inner core alterations and their physiological significance are addressed. A new inner core modification of LPS is described, which arises due to the addition of glucuronic acid on the third heptose with a concomitant loss of phosphate on the second heptose. This...
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Synthesis and reactivity of 2,2,4,4-Tetrakis(tri-tertbutoxysilane-thiolato)-1,3,2,4-dithiadistannetane - crystal and molecular structures of two polymorphic forms
PublicationTytułowy związek [Sn(μ-S){SSi(OtBu)3}2]2 (1), zawierający dwa, 4-koordynacyjne atomy cyny, krystalizuje w dwóch odmianach polimorficznych. Forma ortorombowa-1a, została otrzymana w reakcji (tBuO)3SiSH i Et3N z SnCl2, podczas gdy forma trójskośna-1b, w reakcji z SnCl4 jako substratem. Struktura krystaliczna i cząsteczkowa obydwu odmian polimorficznych została wyznaczona przez badania metodą Rentgenowskiej Analizy Strukturalnej,...
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Molecular heteroconjugation equilibria in (n-butylamine + acetic acid) systems in binary (dimethyl sulfoxide + 1,4-dioxane) solvent mixtures
PublicationWyznaczono stałe kwasowe Ka(HA), Ka(BH+) oraz stałe równowagi KAHA-, KBHE+ i KAHB, w układach (n-butyloamina + kwas octowy) bez przeniesienia protonu w binarnych mieszaninach rozpuszczalników (DMSO + 1,4-dioksan). Wartości stałych wyznaczono z wykorzystaniem metody miareczkowania potencjometrycznego przy stałej sile jonowej. Stwierdzono, iż stałe heterokoniugacji molekularnej w badanych mieszaninach rozpuszczalników są liniowo...
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Conformational studies of vasopressin and mesotocin using NMR spectroscopy and molecular modelling methods. Part II: studies in the SDS micelle
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Morphological and molecular genetic diversity analysis using SSR markers in Jackfruit (Artocarpus heterophyllus Lam.) genotypes for pulp colour
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Influence of bulky 3,3′-diphenylalanine enantiomers replacing position 2 of AVP analogues on their conformations: NMR and molecular modeling studies
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Molecular structures and supramolecular architectures of two chromogenic 13-membered azobenzocrown ethers with a peripheral hydroxyl group in the benzene ring.
PublicationOkreślono strukturę krystaliczną dwóch pochodnych 13-członowego eteru azobenzokoronowego z peryferyjną grupą hydroksylową, metodą analizy rentgenostrukturalnej monokryształów. W stanie stałym 13-członowy eter azobenzokoronowy zawierający grupę OH jako podstawnik w pierścieniu aromatycznym w pozycji para do grupy azowej występuje w formie chinono-hydrazonu. Forma ta stabilizowana jest przez silne wewnątrzcząsteczkowe wiązanie wodorowe....
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Molecular modeling of Gram-positive bacteria peptidoglycan layer, selected glycopeptide antibiotics and vancomycin derivatives modified with sugar moieties
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Molecular dynamics study of 4-OH-phenylacetyl- D -Y(Me)FQNRPR-NH 2 selectivity to V1a receptor
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Characterization of the interactions between human high-molecular-mass kininogen and cell wall proteins of pathogenic yeasts, Candida tropicalis
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Hopping or Tunneling? Tailoring the Electron Transport Mechanisms through Hydrogen Bonding Geometry in the Boron-Doped Diamond Molecular Junctions
PublicationMechanisms of charge transport in molecular junctions involving hydrogen bonds are complex and remain mostly unclear. This study is focused on the elucidation of the electron transfer in a molecular device consisting of two boron-doped diamond interfaces bound with an aromatic linker and a hydrogen bonding surrogating molecule. The projected local density of states (PLODS) analysis coupled with transmission spectra and current−voltage...
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How the configurational changes influence on molecular characteristics. The alkyl 3-azido-2,3-dideoxy-D-hexopyranosides - Theoretical approach
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Intramolecular transformation of an antifungal antibiotic nystatin A1 into its isomer, iso-nystatin A1 - structural and molecular modeling studies
PublicationNystatin A1, a polyene macrolide antifungal antibiotic, in a slightly basic or acidic solution undergoes an intramolecular transformation, yielding a structural isomer, the translactonization product, iso-nystatin A1 with lactone ring diminished by two carbon atoms. Structural evidence is provided by advanced NMR and Mass Spectrometry (MS) studies. Molecular dynamics simulations and quantum mechanics calculations gave the insight...
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Nickel(II) tri-tert-butoxysilanethiolates with N-heterocyclic bases as additional ligands: Synthesis, molecular structure and spectral studies
PublicationW publikacji przedstawiono metodę syntezy trzech kompleksów silanotiolanowych z takimi N-heterocyklicznymi zasadami jak: pirydyna, 2-metylopirydyna i 3,5-dimetylopirydyna. Dla tych kompleksów przeprowadzono badania X-Ray, analizy elementarnej. Przy pomocy rentgenowskiej analizy strukturalnej wykazano różną koordynację atomu centralnego - niklu.
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A dipole-driven path for electron and positron attachments to gas-phase uracil and pyrimidine molecules: a quantum scattering analysis
PublicationElectron and positron scattering processes in the gas-phase are analysed for uracil and pyrimidine molecules using a multichannel quantum approach at energies close to threshold. The special effects on the scattering dynamics induced by the large dipole moments in both molecules on the spatial features of the continuum leptonic wavefunctions are here linked to the possible bound states of the Rydberg-like molecular anions or ‘positroned’...
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DMSO hydration redefined: Unraveling the hydrophobic hydration of solutes with a mixed hydrophilic–hydrophobic characteristic
PublicationHydrophobic hydration of solutes with a mixed hydrophilic--hydrophobic characteristics is still poorly understood. This is because both experimental and theoretical methods find it difficult to see the ice-like water structure around the nonpolar solute groups, unlike hydrogen bonds with the hydrophilic groups. In order to unravel this problem, we have investigated DMSO hydration by means of infrared spectroscopy and theoretical...
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Determination of LFER descriptors of 30 cations of ionic lquids - progress in understanding their molercular interaction potentials
PublicationW celu zrozumienia interakcji molekularnych trzydziestu kationów cieczy jonowych, zastosowano powszechnie znaną koncepcję liniowej zależności energii swobodnej (LFER). Deskryptory LFER dla nadmiarowej refrakcji molowej i objętości molowej, zostały obliczone in silico, natomiast kwasowość i zasadowość wiązań wodorowych, i polaryzowalność/dipoloarność kationów cieczy jonowych zostały oznaczone eksperymentalnie za pomocą wysokosprawnej...
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On the new possibility of applying oscillating liquid membrane systems for melecular recognition substances responsible for taste.
PublicationSugerowano wczesniej, że układy osylacyjne z membraną ciekłą mogą być uzyte do opracowania sensora smaku. zbadano wpływ substancji odpowiedzialnych za smak należacych do czterech klas samku na charakterystyki osylacyjne oscylatora z mambrana ciekłą i kationowym surfaktantem chlorkiem benzylodimetylotetradecyloamonionowym. Wykazano,że niezaleznie od natury rozpuszczalnika organicznego w membranie ciekłej charkterystyki oscylacyjne...
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Enzymatic cross-linking of β-lactoglobulin in solution and at air–water interface: Structural constraints
PublicationEffective and controlled use of cross-linking enzymes in structure engineering of food systems depends on characterization of the favorable conditions for enzyme-substrate complex and the limiting factors for the desired modification. In this respect, we analyzed the susceptibility of bovine β-lactoglobulin (BLG) to enzymatic cross-linking by Trichoderma reesei tyrosinase (TrTyr) and transglutaminase (TG). Changes in BLG molecular...
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Water Behavior Near the Lipid Bilayer
PublicationIn this chapter, we focus on the dynamics of water molecules situated in the vicinity of a phospholipid bilayer. Using a molecular dynamics simulation method, we studied interactions between water and the bilayer and tracked trajectories of the water molecules. Based on the hypothesis that molecules trapped inside the bilayer make different motions than the ones which are either attached to the surface or move freely in the water...
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Determination of energy-transfer distributions in ionizing ion-molecule collisions
PublicationThe main objective of this study is to determine the energy transfer occuring in ion-molecule collisions. In order to solve this problem, we followed two approaches; the first one by validating a purely experimental method and the second one by testing a new theoretical model M3C (Microcanonical Metropolis Monte Carlo).
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Symmetry-controlled negative differential resistance effect in a triangular molecule
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Generalized Zero Range Potentials and Multichannel Electron Molecule Scattering.
PublicationZagadnienie o rozpraszaniu elektronów na molekułach rozwiązuje się w sposób jawny w modelu potencjałów o zerowym promieniu. Uwzględniając stany wzbudzone wprowadzamy potencjał macierzowy. Dla przykładu stanów wibracyjnych e+H_2 porównujemy wyniki obliczeń przekrojów czynnych z innymi (ab initio) oraz z doświadczeniem.
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Zero-range potentials in multi-channel diatomic molecule scattering
PublicationZagadnienie o rozpraszaniu elektronów na molekułach rozwiązuje się w sposób jawny w modelu potencjałów o zerowym promieniu. Uwzględniając stany wzbudzone wprowadzamy potencjał macierzowy. Dla przykładu e+H_2 porównujemy wyniki obliczeń przekrojów czynnych z innymi (ab initio) oraz z doświadczeniem.
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Theoretical studies of fragmentation processes of neutral and ionized furan molecule
PublicationThis PhD thesis focuses on the fragmentation mechanism of the furan molecule in the gas phase. The approach taken in this work comprised of three theoretical methodologies considering the dynamical, energetical and entropic aspects of the studied process. First, molecular dynamics simulations were performed. Next, the potential energy surfaces were explored at the DFT/B3LYP level of theory. Finally, a new statistical Microcanonical...
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Scattering of electrons by a 1,2-butadiene (C4H6) molecule: measurements and calculations
PublicationWe present the results of experimental and theoretical study on electron collisions with a 1,2-butadiene (H2C=C=CHCH3) molecule. Absolute grand-total cross sections (TCSs) were measured using a linear electron-transmission method for collision energies in the 0.5–300 eV range. Two distinct features in the TCS energy curve were detected: a narrow peak located at 2.3 eV and a broad enhancement centered around 9 eV. We attributed...
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The adiabatic potentials of low-lying electronic states of the NaRb molecule
PublicationAdiabatic potential energy curves and spectroscopic constants have been calculated for the NaRb molecule. The results of ten states of the symmetry Σ+, six states of the symmetry Π, and two states of the symmetry Δ are obtained by the nonrelativistic quantum chemical method used with pseudopotentials describing the interaction of valence electrons with atomic cores. Analysis is based on a comparison with the results of other theoretical...
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Structural and dynamic properties of water within the solvation layer around various conformations of the glycine-based polypeptide
PublicationSeveral conformations of the solvated glycine-based polypeptides were investigated using molecular dynamics simulations. Some properties of water in the neighbouring space around these molecules were investigated. It was found, that water forms a well-defined layer - the first solvation shell - around the peptide molecule, and thickness of this layer is independent of the peptide structure, and it equals to approximately 0.28 nm....
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Electron energy-loss spectroscopy of excited states of the diazine molecules: Pyridazine
PublicationExcitation of the valence electronic states of the pyridazine molecules in the gas phase have been studied using the technique of electron energy-loss spectroscopy. Varying the electron scattering conditions, the residual electron energy and scattering angle, enabled the optically-allowed and -forbidden excitations to be differentiated. The measured energy-loss spectra enabled the vertical excitation energies of the observed states...
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Excited states of isoxazole molecules studied by electron energy-loss spectroscopy
PublicationElectron energy-loss spectra were measured in isoxazole in the excitation energy range 3.5−10 eV to investigate the valence excited states. Spectra recorded at different scattering conditions enabled the identification of the singlet and triplet states and the determination of their vertical excitation energies. The two lowest energy triplet bands, ππ* 13A' and ππ* 23A' at 4.20 and 5.30 eV, respectively show vibrational progressions....
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Recent total cross section measurements in electron scattering from molecules
PublicationThe grand-total cross sections (TCSs) for electron scattering from a range of molecules, measured over the period 2009-2019 in various laboratories, with the use of different electron transmission systems, are reviewed. Where necessary, the presented TCS data are also compared to earlier results. Collection of investigated molecular targets (biomolecules, biofuels, molecules of technological application,hydrocarbons) reflects their...
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Electron impact fragmentation of pyrrole molecules studied by fluorescence emission spectroscopy
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Fragmentation of isoxazole molecules by electron impact in the energy range 10–85eV
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Bimolecular excited species in optical emission from organic electroluminescent devices
PublicationW pracy dokonano przeglądu dwu-molekularnych stanów wzbudzonych emitujących światło (ekscymery, ekscypleksy, elektromery, elektropleksy) w organicznych diodach EL