1,111 research outputs found
Optical Monitoring of the Seyfert Galaxy NGC 4151 and Possible Periodicities in the Historical Light Curve
We report B, V, and R band CCD photometry of the Seyfert galaxy NGC 4151
obtained with the 1.0-m telescope at Weihai Observatory of Shandong University
and the 1.56-m telescope at Shanghai Astronomical Observatory from 2005
December to 2013 February. Combining all available data from literature, we
have constructed a historical light curve from 1910 to 2013 to study the
periodicity of the source using three different methods (the Jurkevich method,
the Lomb-Scargle periodogram method and the Discrete Correlation Function
method). We find possible periods of P_1=4\pm0.1, P_2=7.5\pm0.3 and
P_3=15.9\pm0.3 yr.Comment: 8 pages, 5 figures, Accepted by Research in Astronomy and
Astrophysic
Diaquabis(1-methyl-1H-imidazole-κN 3)bis[2-(naphthalen-1-yl)acetato-κO]cobalt(II)
In the title compound, [Co(C12H9O2)2(C4H6N2)2(H2O)2], the CoII ion is located on an inversion centre and displays a distorted octahedral coordination geometry. Two O atoms from two water molecules and two carboxylate O atoms from two 2-(naphthalen-1-yl)acetate ligands are in the equatorial plane and two N atoms from two 1-methyl-1H-imidazole ligands are in the axial positions. The structure is stabilized by intramolecular O—H⋯O hydrogen bonds. Intermolecular O—H⋯O hydrogen bonds link the complex molecules into chains along [100]
Bis(1H-benzimidazole-κN 3)bis[2-(naphthalen-1-yl)acetato-κ2 O,O′]nickel(II) monohydrate
In the title compound, [Ni(C12H9O2)2(C7H6N2)2]·H2O, The NiII cation is located on a twofold rotation axis and is six-coordinated in a distorted NiN2O4 octahedral geometry. The asymmetric unit consists of a nickel(II) ion, one 2-(naphthalen-1-yl)acetate anion, a neutral benzotriazole ligand and one half of a lattice water molecule. The crystal packing is stabilized by O—H⋯O and N—H⋯O hydrogen bonds. The title compound is isotypic with its CdII analogue
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Bioinspired and bristled microparticles for ultrasensitive pressure and strain sensors
Biological sensory organelles are often structurally optimized for high sensitivity. Tactile hairs or bristles are ubiquitous mechanosensory organelles in insects. The bristle features a tapering spine that not only serves as a lever arm to promote signal transduction, but also a clever design to protect it from mechanical breaking. A hierarchical distribution over the body further improves the signal detection from all directions. We mimic these features by using synthetic zinc oxide microparticles, each having spherically-distributed, high-aspect-ratio, and high-density nanostructured spines resembling biological bristles. Sensors based on thin films assembled from these microparticles achieve static-pressure detection down to 0.015 Pa, sensitivity up to 121 kPa−1, and a strain gauge factor \u3e104, showing supreme overall performance. Other properties including a robust cyclability \u3e2000, fast response time ~7 ms, and low-temperature synthesis compatible to various integrations further indicate the potential of this sensor technology in applying to wearable technologies and human interfaces
Prognostic Value of Survivin in Patients with Non-Small Cell Lung Carcinoma: A Systematic Review with Meta-Analysis
The potential prognostic value of survivin in resected non-small cell lung carcinoma (NSCLC) is variably reported. The objective of this study was to conduct a systematic review of literatures evaluating survivin expression in resected NSCLC as a prognostic indicator.Relevant literatures were identified using PubMed, EMBASE and Chinese Biomedicine Databases. We present the results of a meta-analysis of the association between survivin expression and overall survival (OS) in NSCLC patients. Studies were pooled and summary hazard ratios (HR) were calculated. Subgroup analyses and publication bias were also conducted. = 26.9%). Its effect also appeared significant when stratified according to the studies categorized by histological type, HR estimate, patient race, cutoff point (5%, 10%), detection methods and literature written language except for disease stage. Survivin was identified as a prognostic marker of advanced-stage NSCLC (HR = 1.93, 95%CI: 1.49-2.51), but not early-stage NSCLC (HR = 1.97, 95%CI: 0.76-5.14), in spite of the combined data being relatively small.This study shows that survivin expression appears to be a pejorative prognostic factor in terms of overall survival in surgically treated NSCLC. Large prospective studies are now needed to confirm the clinical utility of survivin as an independent prognostic marker
Tetrakis(μ-naphthalene-1-acetato-κ2 O:O′)bis[(N,N-dimethylformamide-κO)copper(II)]
The asymmetric unit of the title compound, [Cu2(C12H9O2)4(C3H7NO)2], contains two independent centrosymmetric dinuclear copper(II) complexes. The central paddle-wheel units are formed by four bridging bidentate naphthalene-1-acetate ligands with two dimethylformamide ligands in the axial positions. The unique CuII ions have slightly distorted square-pyramidal coordination geometries. One of the naphthalene rings is disordered over two sets of sites, with refined occpancies of 0.535 (4) and 0.465 (4)
Pyrrolidin-1-ium 2-(naphthalen-1-yl)acetate–2-(naphthalen-1-yl)acetic acid (1/1)
In the title compound, C4H10N+·C12H9O2
−·C12H10O2, the pyrrolidine ring adopts an envelope conformation and the dihedral angle between the planes of the two naphthalene ring systems is 8.34 (10)°. The crystal structure is stabilized by O—H⋯O and N—H⋯O hydrogen bonds
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