A small molecule that induces assembly of a four way DNA junction at low temperature

Small molecules that induce the formation of higher order DNA structures have potential therapeutic and nanotechnology applications. Screening of a click library has identified the first compound to induce the formation of a Holliday junction structure at room temperature without the need for a high temperature annealing step.     

Structures of trimetallic molybdenum and tungsten suboxide cluster anions

Anion photoelectron spectra of Mo(3)O(y)(-) and W(3)O(y)(-) (y = 3-6) are reported and analyzed using density functional theory results in an attempt to determine whether electronic and structural trends in the less oxidized clusters (y = 3, 4) could elucidate the disparate chemical properties of the M(3)O(y)(-) (M = Mo, W, y = 5, 6) species. In general, cyclic structures are calculated to be more stable by at least 1 eV than extended structures, and the lowest energy structures calculated for the most reduced species favor M = O terminal bonds. While the numerous low-energy structures found for Mo(3)O(y)(-)/Mo(3)O(y) and W(3)O(y)(-)/W(3)O(y) were, in general, similar, various structures of W(3)O(y)(-)/W(3)O(y) were found to be energetically closer lying than analogous structures of Mo(3)O(y)(-)/Mo(3)O(y). Additionally, the Mo-O-Mo bridge bond was found to be a more stabilizing structural motif than the W-O-W bridge bond, with the oxygen center in the former having the highest negative charge. Based on this, the observation of trapped intermediates in reactions between Mo(3)O(y)(-) and water or CO(2) that are not observed in analogous W(3)O(y)(-) reactivity studies may be partially attributed to the role of bridge bond fluxionality.     

Modelling of Technical Systems: Application to Hydrodynamic Torque Converters and Couplings

First a short survey of modelling of technical systems is presented. The different methods of modelling are applied to hydrodynamic torque converters and couplings. The results of linear modelling around an operating point, of nonlinear modelling for larger operating areas and of hybrid modelling using simplified physical laws are illustrated. Simulations for large excitations show the validity of the models. The advantages and disadvantages of the different methods are discussed.     

Investigation of internal radionuclide contamination from the analysis of nasal swabs and facial swipes

Nasal swabs and facial swipes have been used to screen potential internal radioactive contamination for decades. However, the ratio between the lung intake and the activity on a swab or a swipe varies according to the nature of the contaminant involved and the exposure conditions such as particle sizes of the contaminant and the humidity in the air. This paper reports the experimental results using stable La₂O₃ as an analog for actinide oxides, focusing on the most important parameters such as humidity, plume velocity, and facial condition at a fixed room temperature of 23 ± 2 °C. The results showed that the effects of humidity, plume velocity, and facial condition vary more on orofacial swipe/lung deposition ratios compared to nasal swab/lung deposition ratios. The amounts on nasal swabs tended to show smaller change with respect to parameters such as plume velocity, humidity, and skin moisture. The amounts on orofacial swipes varied by a factor of 10–15 among the samples collected across all parameters. Such variability would be expected to be even greater in a real-world scenario with a larger range of physiological and environmental conditions.     

The <Emphasis Type="Italic">Adhesion</Emphasis> GPCR GPR125 is specifically expressed in the choroid plexus and is upregulated following brain injury

Background  

GPR125 belongs to the family of Adhesion G protein-coupled receptors (GPCRs). A single copy of GPR125 was found in many vertebrate genomes. We also identified a Drosophila sequence, DmCG15744, which shares a common ancestor with the entire Group III of Adhesion GPCRs, and also contains Ig, LRR and HBD domains which were observed in mammalian GPR125.     

Orientable polymer fluids—suggestions from Ericksen's theory of anisotropic fluids

Ericksen's theory incorporates in the constitutive equations a vector n_i that characterizes the anisotropy of a fluid particle arising from flow induced orientation. The present study is an appraisal of the potential of such an approach in studying orientable polymeric fluids. The behavior of a normalized version of n_i (n_i → 0 at rest and n_i → 1 when fully stretched) is studied in simple shear, elongational, and converging flow fields. Following a discussion of the merits and the problems with this approach, a modification is proposed where directional anisotropy and stretching of a fluid particle are separated. Empirical extensions include the incorporation of a simple structure parameter in viscoelastic fluid theories.     

Temperature dependence of the penetration depth in Sr2RuO4: evidence for nodes in the gap function

We report measurements of the magnetic penetration depth in single crystals of Sr2RuO4 down to 0.04 K using a tunnel-diode based, self-inductive technique. We observe a power law temperature dependence below 0.8 K, with no sign of a second phase transition nor of a crossover predicted for a multiband superconductor. A power law dependence suggests that the gap function has nodes, inconsistent with candidate p-wave states. We argue that nonlocal effects, rather than impurity scattering, can explain the observed T2 dependence instead of the T-linear behavior expected for line nodes.     

Zur Behandlung von Zufallssehwingungen mechanischer Bauteile infolge mehrfachkorrelierter stochastischer Erregungen

Übersicht Neben der zur Behandlung mechanischer Zufallsschwingungen gebräuchlichen Spektralmethode wird die Kovarianzanalyse mit ihrer vorteilhaften Schwingungsvarianzberechnung vorgestellt. Es wird gezeigt, daß diese Methode auch für mehrfachkorrelierte, in der Natur meßbare Zufallsvorgänge genutzt werden kann. Am Beispiel eines winderregten Turmtragwerks wird ein Vergleich zwischen Spektralmethode und Kovarianzanalyse gezogen.

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On the analysis of random vibrations caused by multi-correlated excitations

Summary In comparison with the wellknown method for calculating variances of random vibrations using spectral densities the method of the covariance analysis is illustrated. The efficiency of this method is demonstrated for multi-correlated random excitations which can be found in nature. An example with windinfluenced vibrations of a televisiontower is discussed for both methods.

     

Derivations, isomorphisms, and second cohomology of generalized Witt algebras

Generalized Witt algebras, over a field of characteristic , were defined by Kawamoto about 12 years ago. Using different notations from Kawamoto's, we give an essentially equivalent definition of generalized Witt algebras over , where the ingredients are an abelian group , a vector space over , and a map which is linear in the first variable and additive in the second one. In this paper, the derivations of any generalized Witt algebra
, with the right kernel of being , are explicitly described; the isomorphisms between any two simple generalized Witt algebras are completely determined; and the second cohomology group for any simple generalized Witt algebra is computed. The derivations, the automorphisms and the second cohomology groups of some special generalized Witt algebras have been studied by several other authors as indicated in the references.