SciCombinator

Discover the most talked about and latest scientific content & concepts.

Concept: Contract bridge

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The aerial view of the concept of data sharing is beautiful. What could be better than having high-quality information carefully reexamined for the possibility that new nuggets of useful data are lying there, previously unseen? The potential for leveraging existing results for even more benefit pays appropriate increased tribute to the patients who put themselves at risk to generate the data. The moral imperative to honor their collective sacrifice is the trump card that takes this trick. However, many of us who have actually conducted clinical research, managed clinical studies and data collection and analysis, and curated data sets have . . .

Concepts: Experimental design, Clinical trial, Medical statistics, Avicenna, Clinical research, Morality, Contract bridge, Donald Trump

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A small library of divalent fucosidase inhibitors containing pyrrolidine motifs and separated by polyamino and triazole-benzylated spacers was prepared and evaluated as α-fucosidase inhibitors. Although a weak multivalent effect was observed in polyamino derived dimers, useful structural information can be deduced about the length of the bridge, the number of nitrogen atoms present and the moieties close to the pyrrolidine. Within these investigations one of the best α-fucosidase inhibitors containing a pyrrolidine framework was obtained (, Ki = 3.7 nM).

Concepts: Nitrogen, .NET Framework, Bridge, Contract bridge

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Diffuse idiopathic skeletal hyperostosis (DISH) is characterized by flowing bony bridges on the right side of the spine. Knowledge of the development of these spinal bridges is limited. The current longitudinal computed tomography (CT) study was designed to bridge this gap.

Concepts: Vertebral column, Learning, The Current, Thoracic vertebrae, Animal anatomy, The Spine, Bridge, Contract bridge

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Treatment of Λ-fac-[Co(d-pen-N,S)3]3- (d-H2pen = d-penicillamine) with Cu+ in water gave a stable CoCu complex, ΛΛ-[Co2Cu3(d-pen)6]3- ([1]3-), having three thiolato-copper(i)-thiolato moieties that bridge two cobalt(iii) centres. Complex [1]3- was isolated as a coordination polymer of Na3[1], which was converted to a complex salt of [Cr(H2O)6][1] by treatment with Cr(NO3)3.

Concepts: Water, Coordination chemistry, Bridge, Contract bridge

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Deck inclination and vertical displacements are among the most important technical parameters to evaluate the health status of a bridge and to verify its bearing capacity. Several methods, both conventional and innovative, are used for structural rotations and displacement monitoring; however, none of these allow, at the same time, precision, automation, static and dynamic monitoring without using high cost instrumentation. The proposed system uses a common laser pointer and image processing. The elastic line inclination is measured by analyzing the single frames of an HD video of the laser beam imprint projected on a flat target. For the image processing, a code was developed in Matlab® that provides instantaneous rotation and displacement of a bridge, charged by a mobile load. An important feature is the synchronization of the load positioning, obtained by a GNSS receiver or by a video. After the calibration procedures, a test was carried out during the movements of a heavy truck maneuvering on a bridge. Data acquisition synchronization allowed us to relate the position of the truck on the deck to inclination and displacements. The inclination of the elastic line at the support was obtained with a precision of 0.01 mrad. The results demonstrate the suitability of the method for dynamic load tests, and the control and monitoring of bridges.

Concepts: Measurement, Laser, Laser diode, Laser pointer, C, Rigid body, Laser applications, Contract bridge

0

The potential of intramolecular π-π interactions to influence the photophysical properties of diiridium complexes is an unexplored topic, and provides the motivation for the present study. A series of diarylhydrazide-bridged diiridium complexes functionalised with phenylpyridine (ppy)-based cyclometalating ligands is reported. It is shown by NMR studies in solution and single crystal X-ray analysis that intramolecular π-π interactions between the bridging and cyclometalating ligands rigidify the complexes leading to high luminescence quantum efficiencies in solution and in doped films. Fluorine substituents on the phenyl rings of the bridge promote the intramolecular π-π interactions. Notably, these non-covalent interactions are harnessed in the rational design and synthesis of the first examples of highly emissive sky-blue diiridium complexes featuring conjugated bridging ligands, for which they play a vital role in the structural and photophysical properties. Experimental results are supported by computational studies.

Concepts: Present, Chemistry, Chemical bonding, Phenyl group, Bridge, Contract bridge

0

Regioselective meta-mercuration followed by Pd-catalysed intramolecular bridging gave birth to a novel type of calixarene bearing a single bond bridge between the meta positions of the neighboring aromatic subunits. These bridged derivatives possess extremely distorted cavities that imply possible amended properties over common calix[4]arenes. This new type of calixarene reactivity can be documented by acid-/electrophile-mediated cleavage of the basic macrocyclic skeleton leading to open oligomeric structures-the behavior of which has never been observed before in classic calix[4]arenes bearing alkoxy groups on the lower rim.

Concepts: Typography, Bridge, Contract bridge

0

Mammalian fertilization relies on sperm finding the egg and penetrating the egg vestments. All steps in a sperm’s lifetime crucially rely on changes in the second messenger cAMP (cyclic adenosine monophosphate). In recent years, it has become clear that signal transduction in the sperm is not a continuum, but rather organized in subcellular domains, e.g. the sperm head and the sperm flagellum, with the latter being further separated into the midpiece, principal piece,and endpiece. To understand the underlying signaling pathways controlling sperm function in more detail, experimental approaches are needed that allow to study sperm signaling with spatial and temporal precision. Here,we will give a comprehensive overview on cAMP signaling in mammalian sperm, describing the molecular players involved in these pathways and the sperm functions that are controlled by cAMP. Furthermore, we will highlight recent advances in analyzing and manipulating sperm signaling with spatial-temporal precision using light.

Concepts: Signal transduction, Adenosine triphosphate, Sperm, Spermatozoon, Second messenger system, Cyclic adenosine monophosphate, Adenosine monophosphate, Contract bridge

0

Four new copper complexes, viz. [{Cu(2-aminopyridine)(N3)2(H2O)}2]n (1), [Cu3(3-aminopyridine)2(N3)6]n (2), [{Cu(3-aminopyridine)(N3)2}2]n (3), and [Cu(4-aminopyridine)2(N3)2]n (4), have been synthesized with isomeric aminopyridines, viz. 2-aminopyridine (2-ap), 3-aminopyridine (3-ap), and 4-aminopyridine (4-ap), to probe the role of ligand and reactant molar ratios in directing the polynuclear assemblage and the associated magnetic properties. Ligand geometry is quite influential as can be seen through the versatile structures formed, viz. a hydrogen bonded layer of μ-1,1 azide bridged Cu dimers in 1; a network of two different types of dimers (Cu1-Cu2 & Cu3-Cu3') involving μ-1,1; μ-1,3; μ-1,1,3; & μ-1,1,3,3 azide bridges in 2; a ladder structure in which μ-1,1 azide bridges form the rungs and μ-1,3 azide bridges form the rails of the ladder in 3; and a 1-D polymer chain involving μ-1,1 azide bridges in 4. Consistent with the bridge geometry, compounds 1 & 2 display ferromagnetic interactions, while 3 & 4 display antiferromagnetic interactions. The rather unexpected antiferromagnetic interactions in 3, in spite of μ-1,1 azide bridged rungs may be due to the crossover near the bridge angle. The ferromagnetic interactions in 1 and 2 are supported by DFT calculations.

Concepts: Structure, Magnetism, Ferromagnetism, Copper, Antiferromagnetism, 4-Aminopyridine, Bridge, Contract bridge

0

Receptor tyrosine kinases (RTK) have been demonstrated to signal via regulated intramembrane proteolysis (RIP), in which ectodomain shedding and subsequent intramembrane cleavage by gamma-secretase leads to release of a soluble intracellular receptor fragment with functional activity. For most RTKs, however, it is not known whether they can exploit this new signaling mechanism or not. Here we used a system-wide screen to address the frequency of susceptibility to gamma-secretase cleavage among human RTKs. The screen covering 45 of the 55 human RTKs identified 12 new as well as all 9 previously published gamma-secretase substrates. The screen was biochemically validated by demonstrating that the release of a soluble intracellular fragment from endogenous AXL was dependent on the sheddase ADAM10 and the gamma-secretase component presenilin-1. Functional analysis of the cleavable RTKs indicated that proliferation promoted by overexpression of the TAM family members AXL or TYRO3 was dependent on gamma-secretase cleavage. Taken together, these data indicate that gamma-secretase-mediated cleavage provides an additional signaling mechanism for numerous human RTKs.

Concepts: Signal transduction, Receptor tyrosine kinase, Protein kinase, Signal, Vector space, Demonstration, Contract bridge