Members of the genus Aeromonas are opportunistic pathogen of a variety of aquatic animals that exhibits multidrug resistance, phenotypes, virulence genes and virulence. The present study described ...the species distribution and the potential pathogenicity of Aeromonas isolated from healthy Northern snakehead (Channa argus) in China. Molecular identification revealed that A. veronii biovar veronii (69/167; 41·3%) and A. hydrophila (41/167; 24·6%) were the most common species found in Northern snakehead intestine based on sequencing of the 16S rRNA gene and DNA gyrase subunit B protein. The distribution of seven virulence factors including aer (84·4%), act (80·8%), ser (40·1%), Aha (27·5%), lip (23·4%), exu (15·0%) and LuxS (12·6%) were determined exclusively in Aeromonas isolates. All the seven virulence genes were present in 9·6% (16/167), among which 11 strains were identified as A. veronii biovar veronii. For the strains harbouring seven virulence genes, the 50% lethal doses (LD50) of isolates were lower compared to the isolates carrying two virulence genes. The challenge tests revealed that isolate W31 had the lowest lethal dose, causing 50% mortality at 4·5 × 103 colony‐forming units (CFU) per ml. Furthermore, histopathology of Northern snakehead infected with Aeromonas strains showed necrosis and congestion in liver, spleen and kidney and also damage to the intestine. This study confirms that the Aeromonas strains isolated from healthy Northern snakehead may be a cause of concern for public health.
Significance and Impact of the Study
Aeromonas species are widely distributed in aquatic environments and have considerable virulence potential. The aim of this study was to identify Aeromonas strains isolated from healthy Northern snakehead, and to investigate if Aeromonas species isolated from healthy fish potential pathogenicity with special reference to virulence and epidemiology studies.
Significance and Impact of the Study: Aeromonas species are widely distributed in aquatic environments and have considerable virulence potential. The aim of this study was to identify Aeromonas strains isolated from healthy Northern snakehead, and to investigate if Aeromonas species isolated from healthy fish potential pathogenicity with special reference to virulence and epidemiology studies.
There remain great challenges in developing highly efficient electrocatalysts with both high activity and good stability for the ethanol oxidation reaction in alkaline media. Herein, two ...architectures of tri-metallic PdIrAu/C electrocatalysts are designed and the promoting effect of Au and Ir on Pd toward the ethanol oxidation reaction (EOR) in alkaline media is investigated in detail. On the one hand, the tri-metallic Pd 7Au 7Ir/C electrocatalyst with a solid solution alloy architecture is less active relative to Pd 7Ir/C and Pd/C while the stabilizing effect of Au leads to both a higher activity and a lower degradation percentage after 3000 cycles of the accelerated degradation test (ADT) on Pd 7Au 7Ir/C than those on Pd 7Ir/C. On the other hand, the tri-metallic Pd 7Ir@(1/3Au)/C electrocatalyst with a near surface alloy architecture delivers a much higher activity with an improvement up to 50.4% compared to Pd 7Ir/C. It is speculated that for the tri-metallic Pd 7Ir@(1/3Au)/C electrocatalyst, certain Au atoms are well designed on surfaces to introduce an electronic modification, thus leading to an anti-poisoning effect and improving the EOR activity.
The coalescence rate in immiscible polymer blends predicted by all existing models is two or three orders of magnitude lower than that observed experimentally. The model developed in this study ...considers for the first time that coarsening is driven by van der Waals forces and there is slippage at the interfacial boundaries between the moving particles and the matrix. The growth rate of the average radius of the particles, R, can be approximately expressed as
\documentclass{article}\pagestyle{empty}\begin{document}$$\frac{{dR}}{{dt}} = \frac{{A\exp (- \sigma ^2)}}{{9\pi \eta \beta R^2 }}$$\end{document}
where β is a function of the interfacial slippage length b, R, and the average surface distance between the particles h. The parameter b depends on the incompatibility and the degree of entanglement at the interface between the two polymers of the blend. The fact that the coarsening rate is decreased by the presence of a copolymer can be explained by a decrease in the value of b.
Electron beams with the lowest, normalized transverse emittance recorded so far were produced and confirmed in single-bunch-mode operation of the Accelerator Test Facility at KEK. We established a ...tuning method of the damping ring which achieves a small vertical dispersion and small x-y orbit coupling. The vertical emittance was less than 1% of the horizontal emittance. At the zero-intensity limit, the vertical normalized emittance was less than 2.8 x 10(-8) rad m at beam energy 1.3 GeV. At high intensity, strong effects of intrabeam scattering were observed, which had been expected in view of the extremely high particle density due to the small transverse emittance.
In order to understand the characteristics of recombinant protein expression and sublocalization in rice (Oryza sativa L.) endosperm, we examined the expression level of human lysozyme protein and ...its subcellular location in transgenic rice seeds driven by rice glutelin and globulin promoters and signal peptides. A time course of human lysozyme expression during endosperm development was analyzed. The results showed that the expression profile of recombinant protein accumulation in endosperm paralleled that of the two storage proteins. Immunofluorescence microscopy revealed that human lysozyme and storage proteins colocalized to type-II protein bodies. Both promoter—signal peptide parings targeted recombinant protein to the protein bodies. In addition, a transgenic line with a higher lysozyme expression level exhibited morphologically different protein bodies with an unbalanced composition of lysozyme and native storage proteins. The high-level expression of recombinant protein distorted the trafficking and sorting of native storage proteins in rice endosperm and affected the expression of native storage protein.
The field efficacy of two transgenic rice lines, containing the Cry1Ac gene from Bacillus thuringiensis (Bt) and the CpTI (cowpea trypsin inhibitor) gene, on the striped stem borer, Chilo ...suppressalis (Walker), and population variation in susceptibility of C. suppressalis to the Bt insecticidal protein Cry1Ac were evaluated in Fuzhou, Fujian Province of China. The results of an open field test showed that the two transgenic lines exhibited high efficacy against natural infestations of C. suppressalis. In contrast, the untransformed parental control line showed serious damage symptoms not only in untreated plots, but also in plots treated with insecticides. The cumulative number of C. suppressalis adults derived from transgenic rice lines was significantly lower than that from control lines with and without chemical control treatments. Our results show that transgenic rice lines expressing Cry1Ac and CpTI have great potential for protecting rice from C. suppressalis damage with reduced use of insecticides. Comparison of pupal weight and fecundity of C. suppressalis between transgenic and control treatments indicated that pupal weight significantly decreased after continuously feeding on transgenic rice lines, but there was no significant effect on fecundity. Adult females of C. suppressalis were collected from light traps to ascertain population variation in susceptibility to Bt toxins. Each female producing enough fertile eggs for bioassays was used as the parent of an isofemale line. Of 1,100 females collected, 395 isofemale lines produced enough offspring to be screened on a diet assay treated with Cry1Ac. The results showed that 51.7% of isofemale lines were differentiated as highly susceptible, 23.0% as moderately susceptible, and 23.8% with low susceptibility; 1.5% were nonsusceptible, with a survival rate >70% and similar development as on the non-Bt control diet. The results indicated significant variation in susceptibility to Cry1Ac in the C. suppressalis population, which should be considered for insect resistance management of Bt rice in the future.
The aim of this study was to investigate the biomechanical stability provided by a novel, polylactic acid/nano-sized, β-tricalcium phosphate, bioabsorbable, self-retaining cervical fusion cage ...(BCFC).
Quasistatic nonconstraining torques (maximum 1.5 NM) induced flexion, extension, lateral bending (±1.5 NM), and axial rotation (±1.5 NM) on 32 sheep cervical spines (C2-C5). The motion segment C3-C4 was first tested intact; the following groups were tested after complete discectomy: autologous tricortical iliac crest bone graft, Medtronic-Wego polyetheretherketone (PEEK) cage, Solis PEEK cage, and BCFC. The autologous bone graft group was tested with an anterior plate. The mean range of motion (ROM) was calculated from the load-displacement curves.
BCFC significantly decreased ROM in lateral bending and axial rotation compared to other implants, and no significant difference in ROM between two types of PEEK cages and BCFC could be observed in flexion and extension. Anterior cervical plate (ACP) significantly decreased ROM in flexion and extension, but no significant difference in ROM between BCFC and bone graft plus ACP could be determined in lateral bending and axial rotation.
The BCFC device showed better stability to autologous tricortical iliac crest bone graft and PEEK cages in single-level anterior cervical discectomy and fusion models and thus may be a potential alternative to the current PEEK cages.
A broad range of scientific and technological problems involves multi-scales and complex systems. This paper reviews some of unique and interesting nano-scale phenomena and applications relevant to ...polymer processing. It addresses four subjects. The first one is concerned with the dynamics of polymer chains in confined geometries. In contrary to intuition one may have, polymer chains may diffuse much faster in confined geometries than in the bulk. The second subject deals with extruder processing of polymer nanocomposites. Understanding of the dynamics of polymer chains in confined geometries helps shade light on how nanoparticles may be dispersed in polymer matrices in a nanometer scale. The third one is on the use of nano-objects as nano-reactors. An example is given to show how one may take the advantage of nano-reactors to improve reaction yield and/or reaction selectivity. The last subject deals with reaction kinetics at polymer–polymer interfaces of a few nanometers in thickness, a very important issue in reactive polymer blending processes.
Sini Tang, a Chinese traditional prescription containing three herbs, has been widely used for Yang-deficiency. Recent clinical studies have shown that Sini Tang could treat and improve depression ...symptoms, but the mechanisms underlying the antidepressant effect of Sini Tang remains unknown. In rats with chronic unpredictable stress (CUS), we examined the effects of Sini Tang on sucrose preference and open field exploratory behavior. The levels of corticosterone level in plasma and corticotropin-releasing hormone (CRH) mRNA expression in hypothalamus were also measured by enzyme-linked immunosorbent assays (ELISA) and real-time reverse transcription PCR (RT-PCR), respectively. Rats subjected to CUS exhibited decreases in sucrose preference and ambulation in the open field test. These were all attenuated by Sini Tang in a dose-dependent manner. Biochemically, Sini Tang also reversed CUS-induced increases in corticosterone in plasma and CRH mRNA in the hypothalamus. The behavioral effects of the Sini Tang were correlated to the biochemical actions. These results suggest that Sini Tang produces an antidepressant-like effect, which appears to involve CRH in the brain.
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