3,842 research outputs found
Volterra Series identification Based on State Transition Algorithm with Orthogonal Transformation
A Volterra kernel identification method based on state transition algorithm with orthogonal transformation (called OTSTA) was proposed to solve the hard problem in identifying Volterra kernels of nonlinear systems. Firstly, the population with chaotic sequences was initialized by using chaotic strategy. Then the orthogonal transformation was used to finish the mutation operator of the selected individual. OTSTA was used on the identification of Volterra series, and compared with particle swarm optimization (called PSO) and state transition algorithm (STA). The simulation results showed that OTSTA has better identification precision and convergence than PSO and STA under non-noise interference. And when there is noise, the identification precision, convergence and anti-interference of OTSTA are also superior to PSO and STA
1,1′-Dimethyl-1,1′-(butane-1,4-diyl)dipyrrolidinium dibromide methanol disolvate
In the title compound, C14H30N2
2+·2Br−·2CH3OH, two terminal C atoms of the butane chain are connected to two N atoms of the 1-methylpyrollidines, forming a linear diquaternary ammonium cation. The cation lies across a centre of inversion located between the two central C atoms of the butane chain. The asymmetric unit therefore comprises one half-cation, a bromide anion and a methanol solvent molecule. In the crystal structure, the bromide anions are linked to the methanol solvent molecules by O—H⋯Br hydrogen bonds
A redetermination of bis(5,5′-diethylbarbiturato)bis(imidazole)cobalt(II)
The title complex, [Co(C8H12N2O3)2(C3H4N2)2], whose structure was first determined by Wang & Craven [(1971). J. Chem. Soc. D, pp. 290–291], has been redetermined with improved precision. A crystallographic twofold rotation axis passes through the Co atom, which is tetrahedrally coordinated by two N atoms from two barbital ligands and two N atoms from two imidazole ligands. The molecules are self-assembled via intermolecular N—H⋯O hydrogen-bonding interactions into a supramolecular network
Discovery of six high-redshift quasars with the Lijiang 2.4m telescope and the Multiple Mirror Telescope
Quasars with redshifts greater than 4 are rare, and can be used to probe the
structure and evolution of the early universe. Here we report the discovery of
six new quasars with -band magnitudes brighter than 19.5 and redshifts
between 2.4 and 4.6 from the YFOSC spectroscopy of the Lijiang 2.4m telescope
in February, 2012. These quasars are in the list of quasar candidates
selected by using our proposed criterion and the photometric redshift
estimations from the SDSS optical and UKIDSS near-IR photometric data. Nine
candidates were observed by YFOSC, and five among six new quasars were
identified as quasars. One of the other three objects was identified as
a star and the other two were unidentified due to the lower signal-to-noise
ratio of their spectra. This is the first time that quasars have been
discovered using a telescope in China. Thanks to the Chinese Telescope Access
Program (TAP), the redshift of 4.6 for one of these quasars was confirmed by
the Multiple Mirror Telescope (MMT) Red Channel spectroscopy. The continuum and
emission line properties of these six quasars, as well as their central black
hole masses and Eddington ratios, were obtained.Comment: 7 pages, 2 figures, published in Research in Astronomy and
Astrophysics (RAA) as a lette
Aquabis(1H-imidazole-κN 3)bis(4-methylbenzoato)-κO;κO,O′-nickel(II)
In the mononuclear title compound, [Ni(C8H7O2)2(C3H4N2)2(H2O)], the NiII atom is coordinated by three carboxylate O atoms (from a bidentate 4-methylbenzoate ligand and a monodentate 4-methylbenzoate ligand), two N atoms (from two imidazole ligands) and a water molecule in an octahedral geometry. Intermolecular O—H⋯O hydrogen-bonding interactions lead to infinite chains, which are further self-assembled into a supramolecular network through intermolecular N—H⋯O hydrogen-bonding interactions and π–π stacking [centroid–centroid distance = 3.717 (2) Å]
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Dexmedetomidine post-treatment attenuates cardiac ischaemia/reperfusion injury by inhibiting apoptosis through HIF-1α signalling.
Hypoxia-inducible factor 1α (HIF-1α) plays a critical role in the apoptotic process during cardiac ischaemia/reperfusion (I/R) injury. This study aimed to investigate whether post-treatment with dexmedetomidine (DEX) could protect against I/R-induced cardiac apoptosis in vivo and in vitro via regulating HIF-1α signalling pathway. Rat myocardial I/R was induced by occluding the left anterior descending artery for 30 minutes followed by 6-hours reperfusion, and cardiomyocyte hypoxia/reoxygenation (H/R) was induced by oxygen-glucose deprivation for 6 hours followed by 3-hours reoxygenation. Dexmedetomidine administration at the beginning of reperfusion or reoxygenation attenuated I/R-induced myocardial injury or H/R-induced cell death, alleviated mitochondrial dysfunction, reduced the number of apoptotic cardiomyocytes, inhibited the activation of HIF-1α and modulated the expressions of apoptosis-related proteins including BCL-2, BAX, BNIP3, cleaved caspase-3 and cleaved PARP. Conversely, the HIF-1α prolyl hydroxylase-2 inhibitor IOX2 partly blocked DEX-mediated cardioprotection both in vivo and in vitro. Mechanistically, DEX down-regulated HIF-1α expression at the post-transcriptional level and inhibited the transcriptional activation of the target gene BNIP3. Post-treatment with DEX protects against cardiac I/R injury in vivo and H/R injury in vitro. These effects are, at least in part, mediated via the inhibition of cell apoptosis by targeting HIF-1α signalling
Animal Models of Burn Wound Management
Burn injury is known as the most traumatic wound. In the clinical, most patients with burn injury suffer from extreme pain during wound management; hence, the effective treatment that involved advanced medication is needed. In the evaluation of burn wound care devices, the use of animal model is considered suitable as valuable tools to investigate the burn pathophysiology as well as the efficacy of treatment strategies due to the complexity and heterogeneous nature of the burn. This chapter aimed to review the preclinical small and large animal models of burn injury for translational applications and to highlight their benefits and limitations for the burn treatment design that are clinically applicable to humans
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