Browsing Complete repository Arts & humanities   Archaeology   Art & art history   Classical & oriental studies   History   Languages & linguistics   Literature   Performing arts   Philosophy & ethics   Religion & theology   Multidisciplinary, general & others Business & economic sciences   Accounting & auditing   Production, distribution & supply chain management   Finance   General management & organizational theory   Human resources management   Management information systems   Marketing   Strategy & innovation   Quantitative methods in economics & management   General economics & history of economic thought   International economics   Macroeconomics & monetary economics   Microeconomics   Economic systems & public economics   Social economics   Special economic topics (health, labor, transportation…)   Multidisciplinary, general & others Engineering, computing & technology   Aerospace & aeronautics engineering   Architecture   Chemical engineering   Civil engineering   Computer science   Electrical & electronics engineering   Energy   Geological, petroleum & mining engineering   Materials science & engineering   Mechanical engineering   Multidisciplinary, general & others Human health sciences   Alternative medicine   Anesthesia & intensive care   Cardiovascular & respiratory systems   Dentistry & oral medicine   Dermatology   Endocrinology, metabolism & nutrition   Forensic medicine   Gastroenterology & hepatology   General & internal medicine   Geriatrics   Hematology   Immunology & infectious disease   Laboratory medicine & medical technology   Neurology   Oncology   Ophthalmology   Orthopedics, rehabilitation & sports medicine   Otolaryngology   Pediatrics   Pharmacy, pharmacology & toxicology   Psychiatry   Public health, health care sciences & services   Radiology, nuclear medicine & imaging   Reproductive medicine (gynecology, andrology, obstetrics)   Rheumatology   Surgery   Urology & nephrology   Multidisciplinary, general & others Law, criminology & political science   Civil law   Criminal law & procedure   Criminology   Economic & commercial law   European & international law   Judicial law   Metalaw, Roman law, history of law & comparative law   Political science, public administration & international relations   Public law   Social law   Tax law   Multidisciplinary, general & others Life sciences   Agriculture & agronomy   Anatomy (cytology, histology, embryology...) & physiology   Animal production & animal husbandry   Aquatic sciences & oceanology   Biochemistry, biophysics & molecular biology   Biotechnology   Entomology & pest control   Environmental sciences & ecology   Food science   Genetics & genetic processes   Microbiology   Phytobiology (plant sciences, forestry, mycology...)   Veterinary medicine & animal health   Zoology   Multidisciplinary, general & others Physical, chemical, mathematical & earth Sciences   Chemistry   Earth sciences & physical geography   Mathematics   Physics   Space science, astronomy & astrophysics   Multidisciplinary, general & others Social & behavioral sciences, psychology   Animal psychology, ethology & psychobiology   Anthropology   Communication & mass media   Education & instruction   Human geography & demography   Library & information sciences   Neurosciences & behavior   Regional & inter-regional studies   Social work & social policy   Sociology & social sciences   Social, industrial & organizational psychology   Theoretical & cognitive psychology   Treatment & clinical psychology   Multidisciplinary, general & others      by title 0-9 A B C D E F G H I J K L M N O P Q R S T U V W X Y Z or enter first few letters:    OK Showing results 27941 to 27960 of 32139     1393 1394 1395 1396 1397 1398 1399 1400 1401 1402 1403     Structural properties of poly(N-isopropyl acrylamide)-based systemsPhilipp, Martine ; Magerl, D.; Aleksandrova, Ralitsa et alPoster (2011, June 01)Detailed reference viewed: 28 (3 UL) Structural Relaxations in the Rotator Phase of N-EicosaneDi Giambattista, Carlo Doctoral thesis (2015)We present relaxations of the heat capacity of the n-alkane n-eicosane (C20H42) in the metastable rotator phase. These relaxations are not connected to melting but rather to structural changes. A ... [more ▼]We present relaxations of the heat capacity of the n-alkane n-eicosane (C20H42) in the metastable rotator phase. These relaxations are not connected to melting but rather to structural changes. A comparative study of the relaxation times with calorimetry in the time and frequency domain shows a slowing down of the dynamics on approaching the melting temperature of the rotator phase. Relaxation behaviour is also observed in the lattice structure by investigations with X-ray diffraction. It is shown that the angular position of the two most relevant X-ray lines relaxes on different time scales. One of these two relaxations can be related to the relaxations found in calorimetry. The relaxing behaviour is discussed in the framework of conformational defect formation and compared to known phenomena in literature. [less ▲]Detailed reference viewed: 57 (4 UL) Structural requirements of the interleukin-6 signal transducer gp130 for its interaction with Janus kinase 1: the receptor is crucial for kinase activationHaan, Claude ; Heinrich, P. C.; Behrmann, Iris in Biochemical Journal (2001), 361(Pt 1), 105-11We analysed the interaction of gp130, the common signal-transducing receptor chain of interleukin (IL)-6 type cytokines, with Jak1, the Janus family kinase which is crucial for signal transduction of this ... [more ▼]We analysed the interaction of gp130, the common signal-transducing receptor chain of interleukin (IL)-6 type cytokines, with Jak1, the Janus family kinase which is crucial for signal transduction of this group of cytokines. With a truncated chimaeric IL-5Rbeta-gp130 receptor expressed in COS-7 cells, we show that the membrane-proximal 69 amino acids are sufficient to mediate Jak1 binding and activation. Deletion of box2 drastically reduced binding of endogenous, but not of overexpressed, Jak1. Several point mutations in the membrane-proximal region of gp130 (W652A, P671/P672A, F676A, Y683F, where W, A, P, F and Y are tryptophan, alanine, proline, phenylalanine and tyrosine) did not affect Jak1 association. However, stimulation of chimaeric receptors with the mutations P671/P672A and F676A in the interbox1/box2 region resulted in a reduced activation of STAT (signal transducer and activator of transcription) transcription factors. Most importantly, signalling by the receptor with the box1 mutation W652A was totally abrogated. Although this mutation did not affect Jak1 association, stimulation-dependent phosphorylation of Jak1 was prevented. The W652 mutation acts dominantly, since no signalling occured even when only a single cytoplasmic chain of a gp130 dimer contained the mutation. Our data demonstrate that the mere proximity of Jaks in an activated receptor complex is not sufficient to mediate their activation. Rather, it seems that parts of the receptor, including the box1 region, are involved in positioning Jaks correctly so that ligand-induced receptor dimerization and reorientation can lead to their mutual activation and subsequently to downstream signalling events. [less ▲]Detailed reference viewed: 25 (1 UL) Structural Transition in a Fluid of Spheroids: A Low-Density Vestige of JammingCohen, A. P.; Dorosz, S.; Schofield, A. B. et alin Physical Review Letters (2016), 116(9), A thermodynamically equilibrated fluid of hard spheroids is a simple model of liquid matter. In this model, the coupling between the rotational degrees of freedom of the constituent particles and their ... [more ▼]A thermodynamically equilibrated fluid of hard spheroids is a simple model of liquid matter. In this model, the coupling between the rotational degrees of freedom of the constituent particles and their translations may be switched off by a continuous deformation of a spheroid of aspect ratio t into a sphere (t=1). We demonstrate, by experiments, theory, and computer simulations, that dramatic nonanalytic changes in structure and thermodynamics of the fluids take place, as the coupling between rotations and translations is made to vanish. This nonanalyticity, reminiscent of a second-order liquid-liquid phase transition, is not a trivial consequence of the shape of an individual particle. Rather, free volume considerations relate the observed transition to a similar nonanalyticity at t=1 in structural properties of jammed granular ellipsoids. This observation suggests a deep connection to exist between the physics of jamming and the thermodynamics of simple fluids. © 2016 American Physical Society. [less ▲]Detailed reference viewed: 62 (10 UL) Structuration et transformation (De la difficulté de rendre compte du sens d’un film si l’on conçoit ce dernier comme un système de significations)Tore, Gian Maria in Sémiotique et diachronie (2013)Detailed reference viewed: 13 (0 UL) Structure and determinants of urbanization change around Moscow, 1991-2010Pavlinova, Olga Doctoral thesis (2012)Detailed reference viewed: 39 (4 UL) Structure and energetics of benzene adsorbed on transition-metal surfaces: density-functional theory with van der Waals interactions including collective substrate responseLiu, Wei; Ruiz, Victor G.; Zhang, Guo-Xu et alin NEW JOURNAL OF PHYSICS (2013), 15The adsorption of benzene on metal surfaces is an important benchmark system for hybrid inorganic/organic interfaces. The reliable determination of the interface geometry and binding energy presents a ... [more ▼]The adsorption of benzene on metal surfaces is an important benchmark system for hybrid inorganic/organic interfaces. The reliable determination of the interface geometry and binding energy presents a significant challenge for both theory and experiment. Using the Perdew-Burke-Ernzerhof (PBE), PBE+vdW (van der Waals) and the recently developed PBE+vdW(surf) (density-functional theory with vdW interactions that include the collective electronic response of the substrate) methods, we calculated the structures and energetics for benzene on transition-metal surfaces: Cu, Ag, Au, Pd, Pt, Rh and Ir. Our calculations demonstrate that vdW interactions increase the binding energy by more than 0.70 eV for physisorbed systems (Cu, Ag and Au) and by an even larger amount for strongly bound systems (Pd, Pt, Rh and Ir). The collective response of the substrate electrons captured via the vdW(surf) method plays a significant role for most substrates shortening the equilibrium distance by 0.25 angstrom for Cu and decreasing the binding energy by 0.27 eV for Rh. The reliability of our results is assessed by comparison with calculations using the random-phase approximation including renormalized single excitations and the experimental data from temperature-programmed desorption microcalorimetry measurements and low-energy electron diffraction. [less ▲]Detailed reference viewed: 54 (0 UL) Structure and formation of synthetic hemozoin: Insights from first-principles calculationsMarom, N.; Tkatchenko, Alexandre ; Kapishnikov, S. et alin Crystal Growth and Design (2011), 11(8), 3332-3341Malaria, an infectious disease once considered eradicated, has reemerged in recent years, primarily due to parasite resistance to commonly used synthetic antimalarial drugs. These drugs act by inhibiting ... [more ▼]Malaria, an infectious disease once considered eradicated, has reemerged in recent years, primarily due to parasite resistance to commonly used synthetic antimalarial drugs. These drugs act by inhibiting crystallization of the malaria pigment, hemozoin (HZ). Thus, there is a vital need for understanding the process of HZ nucleation. In a companion paper, the pseudopolymorphic behavior of β-hematin, the synthetic form of HZ, has been characterized by X-ray diffraction (XRD) (Straasø, T.; Kapishnikov, S.; Kato, K.; Takata, M.; Als-Nielsen, J.; Leiserowitz, L.Cryst. Growth Des. 2011, 11, DOI: 10.1021/cg200410b). Here, we employ van der Waals (vdW)-corrected density functional theory (DFT) to study the two β-hematin crystal structures and their repeat unit, a heme dimer. We find that vdW interactions play a major role in the binding of the heme dimer and the β-hematin crystal. In addition, accounting for the periodic nature of the system is essential to obtaining the correct geometry of the heme dimer, which is affected by vdW interactions with adjacent dimers in the β-hematin crystal. The different stereoisomers of the heme dimer and their molecular crystals are close in energy, which is consistent with pseudopolymorphism in β-hematin, in agreement with recent XRD experiments. Finally, we use our results to comment on β-hematin crystallization mechanisms. This work demonstrates the viability of vdW-corrected DFT as a tool for gaining valuable insight into pertinent problems involving biological systems. © 2011 American Chemical Society. [less ▲]Detailed reference viewed: 54 (0 UL) Structure and Stability of Molecular Crystals with Many-Body Dispersion-Inclusive Density Functional Tight BindingMortazavi, Majid; Brandenburg, Jan Gerit; Maurer, Reinhard J. et alin Journal of Physical Chemistry Letters (2018), 9Accurate prediction of structure and stability of molecular crystals is crucial in materials science and requires reliable modeling of long-range dispersion interactions. Semiempirical electronic ... [more ▼]Accurate prediction of structure and stability of molecular crystals is crucial in materials science and requires reliable modeling of long-range dispersion interactions. Semiempirical electronic structure methods are computationally more efficient than their ab initio counterparts, allowing structure sampling with significant speedups. We combine the Tkatchenko−Scheffler van der Waals method (TS) and the many-body dispersion method (MBD) with third-order density functional tight-binding (DFTB3) via a charge population-based method. We find an overall good performance for the X23 benchmark database of molecular crystals, despite an underestimation of crystal volume that can be traced to the DFTB parametrization. We achieve accurate lattice energy predictions with DFT+MBD energetics on top of vdW-inclusive DFTB3 structures, resulting in a speedup of up to 3000 times compared with a full DFT treatment. This suggests that vdW-inclusive DFTB3 can serve as a viable structural prescreening tool in crystal structure prediction. [less ▲]Detailed reference viewed: 94 (3 UL) La structure de la légitimité démocratique : entre monisme et pluralisme, entre symbolique du sujet et ingénierie des pouvoirsHeuschling, Luc in Revue Universelle des Droits de l'Homme (2004), 16Detailed reference viewed: 72 (0 UL) La structure des représentations sociales de la médiation au Luxembourg et en EuropeHoussemand, Claude Scientific Conference (2007, May)Detailed reference viewed: 10 (1 UL) Structure diagram of binary Lennard-Jones clustersMravlak, Marko ; Kister, Thomas; Kraus, Tobias et alin Journal of Chemical Physics (2016), 145(024302), We analyze the structure diagram for binary clusters of Lennard-Jones particles by means of a global optimization approach for a large range of cluster sizes, compositions, and interaction energies and ... [more ▼]We analyze the structure diagram for binary clusters of Lennard-Jones particles by means of a global optimization approach for a large range of cluster sizes, compositions, and interaction energies and present a publicly accessible database of 180 000 minimal energy structures (http://softmattertheory. lu/clusters.html). We identify a variety of structures such as core-shell clusters, Janus clusters, and clusters in which the minority species is located at the vertices of icosahedra. Such clusters can be synthesized from nanoparticles in agglomeration experiments and used as building blocks in colloidal molecules or crystals. We discuss the factors that determine the formation of clusters with specific structures. [less ▲]Detailed reference viewed: 40 (5 UL) Structure factor of interacting one-dimensional helical systemsGangadharaiah, Suhas; Schmidt, Thomas ; Loss, Danielin Phys. Rev. B (2014), 89We calculate the dynamical structure factor $S(q,\omega)$ of a weakly interacting helical edge state in the presence of a magnetic field $B$. The latter opens a gap of width $2B$ in the single-particle ... [more ▼]We calculate the dynamical structure factor $S(q,\omega)$ of a weakly interacting helical edge state in the presence of a magnetic field $B$. The latter opens a gap of width $2B$ in the single-particle spectrum, which becomes strongly nonlinear near the Dirac point. For chemical potentials $|\mu|>B$, the system then behaves as a nonlinear helical Luttinger liquid, and a mobile-impurity analysis reveals power-law singularities in $S(q,\omega)$ which depend on the interaction strength as well as on the spin texture of the edge states. For \$|\mu| 1.44 kb) separated by eight introns (152 bp to approximately 12 kb). The boundaries of exon 2 to 5 encoding the extracellular region do not match the boundaries of the three APO-1 protein subdomains. Exon structure and functional protein domains correspond for exon 6 encoding the transmembrane region and for exon 9 encoding the "death domain". By a polymerase chain reaction-based approach we localized major transcriptional start sites in human spleen cells 77 and 73 nucleotides upstream of the translation initiation codon of the human APO-1 gene. Minor initiation sites were found at positions -128, -111, -91, and -74. The 5' flanking sequence of the human APO-1 gene is GC rich, contains a high number of CpG dinucleotides and lacks a consensus TATA box. Consensus binding sites for the transcription factors Sp1, AP-1, AP-2, GAF, NF-kappa B, and NF-AT were found. The elucidation of the human APO-1 gene structure will facilitate the study of its involvement in various diseases such as in autoimmunity. [less ▲]Detailed reference viewed: 17 (0 UL)