207 research outputs found

    Characterization of Francisella species isolated from the cooling water of an air conditioning system.

    Get PDF
    Strains of Francisella spp. were isolated from cooling water from an air conditioning system in Guangzhou, China. These strains are Gram negative, coccobacilli, non-motile, oxidase negative, catalase negative, esterase and lipid esterase positive. In addition, these bacteria grow on cysteine-supplemented media at 20 °C to 40 °C with an optimal growth temperature of 30 °C. Analysis of 16S rRNA gene sequences revealed that these strains belong to the genus Francisella. Biochemical tests and phylogenetic and BLAST analyses of 16S rRNA, rpoB and sdhA genes indicated that one strain was very similar to Francisella philomiragia and that the other strains were identical or highly similar to the Francisella guangzhouensis sp. nov. strain 08HL01032 we previously described. Biochemical and molecular characteristics of these strains demonstrated that multiple Francisella species exist in air conditioning systems

    Architecture Considerations of LTE/WCDMA Wideband Power Amplifier for Efficiency Improvement

    Get PDF
    An enhanced architecture for a broadband power amplifier (PA) for LTE and WCDMA handsets using In GaP/Ga As hetero-junction bipolar transistor (HBT) process is presented. A two-stage PA solution adopting switchable driver-stage amplifier without employing input switch is proposed to reduce loss and help with power efficiency improvement. Furthermore, in order to enhance the power-added efficiency (PAE) at the low output power level, a two-chain amplifying structure in parallel has been implemented. For wideband 1.71-1.98GHz, the fabricated PA shows 27dB of Gain and 38% of PAE with 80mA of quiescent current (Icq) at the output power (Pout) of 28dBm for high-power mode operation, as well as 16dB of Gain and 13% of PAE with 20mA of Icqat the Pout of 17dBm for low-power mode operation. The system power usage efficiency are obviously enhanced with the presented two-stage dual-chain PA architecture

    Fine mapping of a QTL for ear size on porcine chromosome 5 and identification of high mobility group AT-hook 2 (HMGA2) as a positional candidate gene

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>Ear size and shape are distinct conformation characteristics of pig breeds. Previously, we identified a significant quantitative trait locus (QTL) influencing ear surface on pig chromosome 5 in a White Duroc × Erhualian F<sub>2 </sub>resource population. This QTL explained more than 17% of the phenotypic variance.</p> <p>Methods</p> <p>Four new markers on pig chromosome 5 were genotyped across this F<sub>2 </sub>population. RT-PCR was performed to obtain expression profiles of different candidate genes in ear tissue. Standard association test, marker-assisted association test and F-drop test were applied to determine the effects of single nucleotide polymorphisms (SNP) on ear size. Three synthetic commercial lines were also used for the association test.</p> <p>Results</p> <p>We refined the QTL to an 8.7-cM interval and identified three positional candidate genes i.e. <it>HMGA2</it>, <it>SOX5 </it>and <it>PTHLH </it>that are expressed in ear tissue. Seven SNP within these three candidate genes were selected and genotyped in the F<sub>2 </sub>population. Of the seven SNP, <it>HMGA2 </it>SNP (JF748727: g.2836 A > G) showed the strongest association with ear size in the standard association test and marker-assisted association test. With the F-drop test, F value decreased by more than 97% only when the genotypes of <it>HMGA2 </it>g.2836 A > G were included as a fixed effect. Furthermore, the significant association between g.2836 A > G and ear size was also demonstrated in the synthetic commercial Sutai pig line. The haplotype-based association test showed that the phenotypic variance explained by <it>HMGA2 </it>was similar to that explained by the QTL and at a much higher level than by <it>SOX5</it>. More interestingly, <it>HMGA2 </it>is also located within the dog orthologous chromosome region, which has been shown to be associated with ear type and size.</p> <p>Conclusions</p> <p><it>HMGA2 </it>was the closest gene with a potential functional effect to the QTL or marker for ear size on chromosome 5. This study will contribute to identify the causative gene and mutation underlying this QTL.</p

    Effect of annealing in O2 or N2 on the aging of Fe0.5Mn1.84Ni0.66O4 NTC-ceramics

    Get PDF
    Fe0.5Mn1.84Ni0.66O4 NTC ceramic thermistors were annealed in nitrogen or oxygen atmosphere at 600 °C. The change of the electrical properties of the thermistors with time was reduced sharply by annealing in N2, whereas it was enhanced upon annealing in O2. N2-annealed samples exhibited a less degree of redistribution of cations in the lattice as compared with O2-annealed samples. The aging of the electrical properties is believed to result from the cation redistribution which in turn is favoured by the presence of cation vacancies. And the improved aging behaviour of the N2-annealed thermistor is explained by the reduction of the concentration of the cation vacancy upon annealing under lower oxygen partial pressure and the suppression of cation redistribution

    Mechanistic elucidation of two catalytically versatile iron(II)- and α-ketoglutarate-dependent enzymes: cases beyond hydroxylation

    Full text link
    Iron(II)- and α-ketoglutarate-dependent (Fe/αKG) enzymes catalyze a large array of reactions. Although hydroxylation reaction catalyzed by these enzymes has been investigated in great details, involving the ferryl (FeIV=O) as a key reactive intermediate. The mechanisms of reactions other than hydroxylation are still largely unknown. By using a combined biochemical, bio-organic, and spectroscopic approach, we have studied the mechanisms of two newly discovered Fe/αKG enzymes, FtmOx1 (endoperoxidase) and AsqJ (desaturase/epoxidase), revealing their strategies in controlling reactivity, namely the effect of redox/polar residues near the iron center, the electronic properties of the substrate, and the intrinsic reactivity of the ferryl intermediate.Accepted manuscrip

    Modern Biotechnologies: Innovative and Sustainable Approaches for the Improvement of Sugarcane Tolerance to Environmental Stresses

    Full text link
    [EN] Sugarcane (Saccharum spp.) is one of the most important industrial cash crops, contributing to the world sugar industry and biofuel production. It has been cultivated and improved from prehistoric times through natural selection and conventional breeding and, more recently, using the modern tools of genetic engineering and biotechnology. However, the heterogenicity, complex polyaneuploid genome and susceptibility of sugarcane to different biotic and abiotic stresses represent impediments that require us to pay greater attention to the improvement of the sugarcane crop. Compared to traditional breeding, recent advances in breeding technologies (molecular marker-assisted breeding, sugarcane transformation, genome-editing and multiple omics technologies) can potentially improve sugarcane, especially against environmental stressors. This article will focus on efficient modern breeding technologies, which provide crucial clues for the engineering of sugarcane cultivars resistant to environmental stressesThis research was funded by the Natural Science Foundation, PR China (grant numbers: KF2015080, KF2015118, KFA17263A, KJG16005R).Shabbir, R.; Javed, T.; Afzal, I.; El Sabagh, A.; Ali, A.; Vicente, O.; Chen, P. (2021). Modern Biotechnologies: Innovative and Sustainable Approaches for the Improvement of Sugarcane Tolerance to Environmental Stresses. Agronomy. 11(6):1-20. https://doi.org/10.3390/agronomy11061042S12011
    corecore