Characterization of blaOxA-23 gene regions in isolates of Acinetobacter baumannii

Background/purposeTo investigate the characterization of blaOxA-23 gene regions in isolates of Acinetobacter baumannii from Taizhou Municipal Hospital.MethodsFifty-nine non-repetitive, multiresistant (including imipenem-resistant) isolates of A. baumannii were recovered from clinical infections in hospitalized patients from January 2010 to August 2011 in Taizhou Municipal Hospital (affiliated with Taizhou University) in China. These isolates were genotyped using pulsed-field gel electrophoresis (PFGE). blaOxA-23 β-lactamase and associated genetic structures were analyzed using polymerase chain reaction (PCR), and recombination plasmids were analyzed by BamHI- or SacI- restriction enzyme digestion; predicted promoter structures of blaOxA-23 genes were determined and compared using protein-protein BLAST analysis.ResultsFifteen out of 59 isolates expressing imipenem-resistant A. baumannii clinical isolates acquired either a blaOxA-23 β-lactamase gene. A new gene cluster (ISAba1-blaOxA-23-AMP) with three previously identified transposons (Tn2006, Tn2007, and Tn2008) and one previously identified gene cluster (ISAba1- blaOxA-23) was found in the isolates. Recombination plasmids were analyzed by restriction enzyme digestion.ConclusionOur results indicate that pattern A was the most prevalent molecular type based on PFGE, and that different clones might be widespread with a majority of ISAba1-blaOxA-23 clonal lineages in the 15 PCR positive isolates of A. baumannii in the hospital

The pro-competitive gains from trade with variable markup and multiple factors

The paper investigates the welfare gains from trade liberalization in the presence of multiple factors, multiple industries and variable markup. We extend Bernard, Redding and Schott (2007) to incorporate variable markup, using additively separable utility. We then characterize the equilibrium under costly trade and discuss the welfare implications of Heckscher-Ohlin mechanism, as well as the variable markup. Our main nding is that gains from trade liberalization are higher in models with variable markup than those with constant markup when the Heckscher-Ohlin force is strong enough. The larger the trade cost decreases, the stronger the Heckscher-Ohlin force is. We conclude that the pro-competitive e ect of trade liberalization does exist in the presence of Heckscher-Ohlin comparative advantage and variable markup.Bachelor of Art

Design of Lumped Disturbance Observer in Current Loop of IPMSM Based on Recursive Integral Sliding Mode Surface

To overcome the problem of current control effect being reduced by unideal factors in a motor control system, such as motor parameter variation, inverter dead time, nonlinearity of the system, etc., a sliding mode disturbance observer for an interior permanent magnet synchronous motor is proposed in this paper. The model of an interior permanent magnet synchronous motor with unideal factors is designed, and the unideal factors are unified into lumped disturbances of motor stator voltage. Then, the observer for lumped disturbance is designed. A recursive integral sliding surface is used to replace the terminal sliding surface to avoid the noise sensitivity and singularity problem of the traditional terminal sliding mode observer. The observer can estimate the lumped disturbance of the current loop without relying on the accurate system model in finite time. Moreover, the structure of the current loop does not need to be adjusted while using the observer to observe and compensate for disturbances. Experiments are carried out to verify the effectiveness of the proposed observer

Characterization of a novel qepA3 variant in Enterobacter aerogenes

Five isolates harboring qepA were studied by polymerase chain reaction (PCR) amplification and relevant methods. One was determined to be a novel qepA3 from Enterobacter aerogenes, and four involved three qepA1 and one qepA2 determinants from Escherichia coli; the qepA3 changed five amino acids. These results characterized genetic structures A, B, C, D, and E

The Secondary Optical Design and Fabrication for the Uniform Illuminating LED Spotlight Using TIR Lens

Different with the fact that the traditional imaging optics emphasizes its ability to get clear image on the image plane, the purpose of LED illumination design is to meet the requirement of high availability of optical energy and homogeneity of illumination. As the study object, the LED track lighting has been designed with secondary optical design by the Lighttools design software. After using TIR lens which has two ways of concentrating: reflectors and lenses, the exit light of the spotlight will be adjusted and the illuminated surface will be with high homogeneity. Therefore, it will reduce the harm of the light to human’s eyes. In this study, the LED spotlights have been produced and tested with the corresponding test results: Lighting power is 7W, luminous efficiency is 82.57lm/W, color rendering index is 83.7, the main wavelength is 488.2nm, the ratio of red, green, blue is 13.1: 83.0: 3.9

The Secondary Optical Design and Fabrication for the Uniform Illuminating LED Spotlight Using TIR Lens

Different with the fact that the traditional imaging optics emphasizes its ability to get clear image on the image plane, the purpose of LED illumination design is to meet the requirement of high availability of optical energy and homogeneity of illumination. As the study object, the LED track lighting has been designed with secondary optical design by the Lighttools design software. After using TIR lens which has two ways of concentrating: reflectors and lenses, the exit light of the spotlight will be adjusted and the illuminated surface will be with high homogeneity. Therefore, it will reduce the harm of the light to human’s eyes. In this study, the LED spotlights have been produced and tested with the corresponding test results: Lighting power is 7W, luminous efficiency is 82.57lm/W, color rendering index is 83.7, the main wavelength is 488.2nm, the ratio of red, green, blue is 13.1: 83.0: 3.9

The Secondary Optical Design and Fabrication for the Uniform Illuminating LED Spotlight Using TIR Lens

Different with the fact that the traditional imaging optics emphasizes its ability to get clear image on the image plane, the purpose of LED illumination design is to meet the requirement of high availability of optical energy and homogeneity of illumination. As the study object, the LED track lighting has been designed with secondary optical design by the Lighttools design software. After using TIR lens which has two ways of concentrating: reflectors and lenses, the exit light of the spotlight will be adjusted and the illuminated surface will be with high homogeneity. Therefore, it will reduce the harm of the light to human’s eyes. In this study, the LED spotlights have been produced and tested with the corresponding test results: Lighting power is 7W, luminous efficiency is 82.57lm/W, color rendering index is 83.7, the main wavelength is 488.2nm, the ratio of red, green, blue is 13.1: 83.0: 3.9

Melittin Tryptophan Substitution with a Fluorescent Amino Acid Reveals the Structural Basis of Selective Antitumor Effect and Subcellular Localization in Tumor Cells

Melittin is a membrane-active peptide with strong anticancer activity against various cancers. Despite decades of research, the role of the singular Trp in the anticancer activity and selectivity of melittin remains poorly understood. Here, we propose a theranostic solution based on the substitution of Trp19 with a noncanonical fluorescent amino acid (DapAMCA). The introduction of DapAMCA residue in melittin stabilized the helical structure of the peptide, as evaluated by circular dichroism spectra and molecular dynamics simulations. In vitro hemolytic and anticancer activity assays revealed that introducing DapAMCA residue in melittin changed its mode of action with the cell membrane, resulting in reduced hemolytic toxicity and an improved the selectivity index (SI), with up to a five-fold increase compared to melittin. In vitro fluorescence imaging of DapAMCA-labeled melittin (MELFL) in cancer cells demonstrated high membrane-penetrating activity, with strong nuclear and nucleolar localization ability. These findings provide implications for novel anticancer therapies based on Trp-substituted designs and nuclear/nucleolar targeted therapy