ABSTRACT
Heterometallic Ag6@Ti12 and Ag8@Ti12 oxo clusters were prepared through a strategy of protecting polynuclear silver cores by a hollow Ti-O module. The introduction of alkyne ligands has shown significant influence on their structures and optical limiting effects.
ABSTRACT
In this study, we present an application of neural network and image processing techniques for detecting the defects of an internal micro-spray nozzle. The defect regions were segmented by Canny edge detection, a randomized algorithm for detecting circles and a circle inspection (CI) algorithm. The gray level co-occurrence matrix (GLCM) was further used to evaluate the texture features of the segmented region. These texture features (contrast, entropy, energy), color features (mean and variance of gray level) and geometric features (distance variance, mean diameter and diameter ratio) were used in the classification procedures. A back-propagation neural network classifier was employed to detect the defects of micro-spray nozzles. The methodology presented herein effectively works for detecting micro-spray nozzle defects to an accuracy of 90.71%.
Subject(s)
Equipment Failure Analysis/instrumentation , Equipment Failure Analysis/methods , Image Processing, Computer-Assisted/methods , Neural Networks, Computer , Algorithms , Equipment Design , Microtechnology/instrumentationABSTRACT
A new benzohydrazone compound N'-(3-bromo-2-hydroxybenzylidene)-4-methoxybenzohydrazide (H2L) was prepared. Reaction of H2L and acetohydroxamic acid (HAHA) with VO(acac)2 in methanol gave the complex [VOL(AHA)]. Both H2L and the oxovanadium complex were characterized by elemental analysis, IR, UV-vis and (1)H NMR spectra, and single crystal X-ray diffraction. H2L was also characterized by high-resolution mass spectrum. Thermal analysis of the oxovanadium complex was carried out. The benzohydrazone ligand, in its dianionic form, coordinates to V atom through the phenolate oxygen, imino nitrogen and enolate oxygen. The acetohydroxamic acid coordinates to V atom through the carbonyl oxygen and deprotonated hydroxyl oxygen. The V atom is in octahedral coordination. H2L, HAHA and the oxovanadium complex were tested for their urease inhibitory activities. The percent inhibition at concentration of 100 µmol·L(-1) on Helicobacter pylori urease is 78% for the oxovanadium complex. The IC50 value for the complex is 36.5 µmol·L(-1). Molecular docking study was performed to study the inhibition.
Subject(s)
Benzylidene Compounds/chemistry , Enzyme Inhibitors/pharmacology , Hydrazones/chemistry , Hydroxamic Acids/pharmacology , Organometallic Compounds/pharmacology , Urease/antagonists & inhibitors , Vanadates/pharmacology , Crystallography, X-Ray , Dose-Response Relationship, Drug , Enzyme Inhibitors/chemical synthesis , Enzyme Inhibitors/chemistry , Helicobacter pylori/enzymology , Hydroxamic Acids/chemistry , Models, Molecular , Molecular Structure , Organometallic Compounds/chemical synthesis , Organometallic Compounds/chemistry , Structure-Activity Relationship , Urease/metabolism , Vanadates/chemistryABSTRACT
A new series of tanshinone IIA (DIIA) derivatives were synthesized through the reaction of brominated tanshinone IIA (1-Br DIIA) and aromatic acids in the presence of K(2)CO(3). Twenty compounds were synthesized, and all of them were novel. Vasodilative activities for synthesized compounds were valuated in vitro on the contractile response of vascular thoracic aorta smooth muscle from Wistar rats. The results showed that most compounds exhibited a concentration-dependent inhibition on the contractile response of norepinephrine. Four prepared compounds, 4, 5, 8 and 13 revealed relatively remarkable vasodilative activity.
Subject(s)
Abietanes/chemistry , Drug Design , Vasodilator Agents/chemical synthesis , Animals , Aorta, Thoracic/drug effects , Male , Muscle Contraction/drug effects , Norepinephrine/pharmacology , Rats , Rats, Wistar , Structure-Activity Relationship , Vasodilator Agents/chemistry , Vasodilator Agents/pharmacologyABSTRACT
In this paper, a new controlled release system of superoxide dismutase was developed by electrospun composite fibers. Highly loading efficacy of sod from 85.6 to 98.0% was achieved. The superoxide dismutase can be released from the system for 234 h, and obvious initial burst release of superoxide dismutase in vitro was not observed. In vitro release rate of superoxide dismutase in the first 66 h basically is faster than the corresponding rate at a later stage. Antioxidant activity of the released superoxide dismutase was still high, and it remained stable during the preparation by electrospinning and release experiment. We hope this composite system be used as an implanted form, in the treatment for several disease involved with the superoxide radical in the future.
