1,525 research outputs found

    Three halacarid mites of the genus <i>Copidognathus</i> (Acari: Halacaridae) from Zanzibar, Tanzania

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    Three new halacarid species belonging to the genus Copidognathus are described from the east coast of Zanzibar, Tanzania. Copidognathus corallicolus sp. nov. is characterized by dorsal setae 2 on membranous cuticle between anterodor­sal plate and ocular plate, posterodosal plate with two single-rosette-pore wide costae, panels on posterodorsal plate sub­divided, long rostrum extending to base of fourth palpal segment, tibia IV with a ventromedial pectinate seta, and tarsi III and IV with 4:3 dorsal setae. Copidognathus fungiae sp. nov. is a member of C. tamaeus group, and characterized by all ventral plates fused in male, posterodorsal plate with two 2- to 3-rosette-pores wide costae, palp a little surpassing anterior end of rostrum, second palpal segment with spinular lamella ventrodistally, ventrolateral lamella of telofemur I with medial edge slightly protruded, and patella IV with 4 setae. Copidognathus ungujaensis sp. nov., a member of C. bairdi group s. str., is closely allied with C. sidellus Bartsch, but differs from it by the presence of areola below second coxal region, almost straight anterior margin of posterodorsal plate, 2 rosette pores between gland pores on posterodorsal plate, lateral and middle costae not joining anteriorly, and more elongated anterior areola on anterodorsal plate

    Characterization of 13 multi-drug resistant Salmonella serovars from different broiler chickens associated with those of human isolates

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    <p>Abstract</p> <p>Background</p> <p><it>Salmonella </it>are frequently isolated from chickens and their products. Prevalent serogroups and serovars of <it>Salmonella </it>as well as their genotypes and antibiograms were determined for cloacal samples from 1595 chickens. To understand the possible serovar and H antigens for transmission between chicken and human, serovars and their H antigens of 164 chicken and 5314 human isolates were compared.</p> <p>Results</p> <p>Prevalence of <it>Salmonella </it>differed among chicken lines and ages. Chicken and human isolates belonged mainly to serogroup B, C1, C2-C3, D, and E. 13 serovars and 66 serovars were identified for chicken and human isolates respectively. The common serovars for chicken and human isolates were <it>S</it>. Typhimurium, <it>S</it>. Enteritidis, <it>S</it>. Albany, <it>S</it>. Derby, and <it>S</it>. Anatum and shared common H1 antigens "g complex; i; e,h; and z4,z24" and H2 antigens "1 complex and -". In human isolates, H1 antigen "i" and H2 antigen "-" were common in all serogroups. In chicken, antimicrobial susceptibility differed among serogroups, serovars and three counties. All isolates were susceptible to cefazolin and ceftriaxone, but highly resistant to ampicillin, chloramphenicol, flumequine, streptomycin, sulfamethoxazole-trimethoprim, and tetracycline. Except those isolates of serogroup C1 of Chick group and serogroup G, all isolates were multi-drug resistance. Only <it>S</it>. Kubacha, <it>S</it>. Typhimurium, <it>S</it>. Grampian, and <it>S</it>. Mons were resistant to ciprofloxacin and/or enrofloxacin.</p> <p>Conclusion</p> <p>In chicken, prevalent serogroups and serovars were associated with chicken ages, lines and regions; and flouroquinolone-resistant and MDR isolates emerged. H1 antigens "g complex and i" and H2 antigens "1 complex and -" might be important for transmission of <it>Salmonella </it>between chicken and human.</p

    Rhenium complex as emitting material in highly efficient phosphorescent organic light-emitting diodes

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    Interest in luminescent materials able to efficiently emit in the solid state is continuously growing, because in most applications the dyes are used as solid films. This is the case of the Organic Light Emitting Diodes (OLEDs), where electroluminescent metal complexes have been widely investigated as dopants, able to increase their performances [1]. We present here a dinuclear Re(I) complexes (1, see Scheme 1) whose emission is higher in solid state and in PMMA matrix than in solution and is used as dopant in OLEDs. This complex belong to the family of neutral Re(I) complexes with general formula [Re2(CO)6(\u3bc-1,2-diazine)(\u3bc-X)2], where X is halogen. Some of them have recently gained interest for their intense yellow/green emission, occurring from triplet metal-to-ligand charge transfer (3MLCT) states [2], showing a modulation effect of the diazine substituents on wavelengths, lifetimes and quantum yields of the emission. \u3a6 up to 0.53 has been measured for the di-chloro complexes containing diazines bearing alkyl groups in both the \u3b2 positions [3]. At variance with the chloro derivatives, the bromo analogue 1 is almost not-emitting in solution (\u3a6em 0.002 in deareated toluene). We have now found that in the solid state 1 shows intense yellow-orange emission (\u3a6em 0.50 in neat powder), blue shifted with respect to the solution (560 nm vs. 620 nm). The emission is intense also in PMMA matrix (\u3a6em 0.19 in PMMA at 10% w/w, 556 nm). This very high aggregated emission here is discussed in terms of the restriction of the intramolecular roto-vibrational motions of the \u201cRe2(CO)6(\u3bc-Br)2\u201d scaffold imposed by the rigid environment, as evidenced by the strong decrease of the knr. Moreover a parallel increase of kr is noticed, which clearly shows the influence of the halides in determining not only the energy of the excited state, but also the nature of the lowest (emitting) state. These properties allowed its successful use as a phosphorescent dopant in OLEDs and here we report the performances of OLED devices prepared both by solution- and vacuumprocessing. The values of the external quantum efficiency are 1.7% (4.3 cd/A and 1.7 lm/W) and 10% (29.1 cd/A and 22.1 lm/W) respectively and are the highest ever reported for rhenium-based devices, comparable to state-of-the-art devices employing Ir(III)- and Pt(II)- based metal complexes. The combination of synthetic strategy and encouraging results in potential OLEDs applications should make these dinuclear Re(I) complexes highly attractive to a broad spectrum of research fields. 1. \u201cHighly efficient OLEDs with Phosphorescent Materials\u201d H. Yersin Ed. Wiley-VCH, (2008). 2. D. Donghi, G. D\u2019Alfonso, M. Mauro, M. Panigati, P. Mercandelli, A. Sironi, P. Mussini, L. D\u2019Alfonso, Inorg. Chem. 28 (2008) 4243-4255. 3. M. Mauro, E. Quartapelle Procopio, Y. Sun, C. H. Chien, D. Donghi, M. Panigati, P. Mercandelli, P. Mussini, G. D\u2019Alfonso, L. De Cola, Adv. Funct. Mater. 19 (2009) 2607-2614

    Characterization study of GaN-based epitaxial layer and light-emitting diode on nature-patterned sapphire substrate

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    [[abstract]]Chemical wet etching on c-plane sapphire wafers by three etching solutions (H3PO4, H2SO4, and H3PO4/H2SO4 mixing solution) was studied. Among these etching agents, the mixing H3PO4/H2SO4 solution has the fastest etching rate (1.5 μm/min). Interestingly, we found that H2SO4 does not etch the c-plane sapphire wafer in thickness; instead, a facet pyramidal pattern is formed on the c-plane sapphire wafer. GaN light-emitting diode (LED) epitaxial structure was grown on the sapphire wafer with the pyramidal pattern and the standard flat sapphire wafer. X-ray diffraction and photoluminescence measurement show that the pyramidal pattern on the sapphire wafer improved crystalline quality but augmented the compressive stress level in the GaN LED epilayer. The horizontal LED chips fabricated on the pyramidal-patterned sapphire wafer have a larger light output than the horizontal LED chips fabricated on the standard flat sapphire wafer by 20%.[[notice]]補正完畢[[incitationindex]]SCI[[booktype]]紙本[[booktype]]電子

    Understorey plant community and light availability in conifer plantations and natural hardwood forests in Taiwan

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    Questions: What are the effects of replacing mixed species natural forests with Cryptomeria japonica plantations on understorey plant functional and species diversity? What is the role of the understorey light environment in determining understorey diversity and community in the two types of forest? Location: Subtropical northeast Taiwan. Methods: We examined light environments using hemispherical photography, and diversity and composition of understorey plants of a 35‐yr C. japonica plantation and an adjacent natural hardwood forest. Results: Understorey plant species richness was similar in the two forests, but the communities were different; only 18 of the 91 recorded understorey plant species occurred in both forests. Relative abundance of plants among different functional groups differed between the two forests. Relative numbers of shade‐tolerant and shade‐intolerant seedling individuals were also different between the two forest types with only one shade‐intolerant seedling in the plantation compared to 23 seedlings belonging to two species in the natural forest. In the natural forest 11 species of tree seedling were found, while in the plantation only five were found, and the seedling density was only one third of that in the natural forest. Across plots in both forests, understorey plant richness and diversity were negatively correlated with direct sunlight but not indirect sunlight, possibly because direct light plays a more important role in understorey plant growth. Conclusions: We report lower species and functional diversity and higher light availability in a natural hardwood forest than an adjacent 30‐yr C. japonica plantation, possibly due to the increased dominance of shade‐intolerant species associated with higher light availability. To maintain plant diversity, management efforts must be made to prevent localized losses of shade‐adapted understorey plants

    Identifying the Technology Position on Patent Acquisition of Cardiovascular Stent by Complementarity and Supplementary Knowledge

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    [[abstract]]The most common way for an organization to expand its innovation capability is to acquire technological patent. Consequently, it is an important issue for firms to identify and estimate the target patent. Before acquiring, firms also have to make sure whether the target patents is matching the strategic purpose, and whether the target patent is suitable for the adopting after acquiring. And the result of patent citation analysis can be referred for estimating target patent as the result reveals the technology relationship between firms, the market value of technologies and the technology development strategy. Moreover, technology network analysis can visualize the overall social structure of actors in the technology network and illuminate their relationships and roles. However, few scholars have examined the relative positions of firms in technology networks from the viewpoint of individual social networks. This research uses the idea of the "ego-network", defining the firm's core technology patent portfolio as "ego" while patents which directly cite core patents are defined as the "neighborhood. The purpose of this research is to understand how the firm, through patent transfers, alters its technology position and performs inductive analysis as a reference for future changes in its patent portfolio strategies. The results of this research demonstrate that irrespective of patent transfer strategy, the relative position of firms in the technology network is displaced by patent transfers. By dividing the trajectory of displacement into quadrants the data set may be named as pioneers, leaders, followers, and laggards. And the result shows firms may exit markets, reduce internal subdivisions, carry out cost control, or sell off patents, moving their position to the left or downward and making them followers or laggards. By the same token, when firms enter a new technology area or market, increase their technological capabilities, or acquire technology patents, their position shits to the right or downward, and they become leaders or pioneers.[[notice]]補正完

    Efficient magneto-optical trapping of Yb atoms with a violet laser diode

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    We report the first efficient trapping of rare-earth Yb atoms with a high-power violet laser diode (LD). An injection-locked violet LD with a 25 mW frequency-stabilized output was used for the magneto-optical trapping (MOT) of fermionic as well as bosonic Yb isotopes. A typical number of 4×1064\times 10^6 atoms for 174^{174}Yb with a trap density of 1×108/\sim 1\times10^8/cm3^3 was obtained. A 10 mW violet external-cavity LD (ECLD) was used for the one-dimensional (1D) slowing of an effusive Yb atomic beam without a Zeeman slower resulting in a 35-fold increase in the number of trapped atoms. The overall characteristics of our compact violet MOT, e.g., the loss time of 1 s, the loading time of 400 ms, and the cloud temperature of 0.7 mK, are comparable to those in previously reported violet Yb MOTs, yet with a greatly reduced cost and complexity of the experiment.Comment: 5 pages, 3 figures, 1 table, Phys. Rev. A (to be published

    Optical Properties and Enhanced Photothermal Conversion Efficiency of SiO2/A-Dlc Selective Absorber Films for A Solar Energy Collector Fabricated by Unbalance Sputter

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    AbstractSolar energy could become the most attractive alternative energy source. In this study we test an attractive new candidate material for solar energy collectors. It can be found that the higher the gas pressure is, the higher the sp2/sp3 area ratio, the greater the sputtering rate and the greater the optical absorption. The photothermal conversion efficiency of a SiO2 coating on the amorphous diamond-like carbon (a-DLC) selective absorber films deposited on the Cr/mirror like Al substrate is 93.2% as the film thickness of a SiO2 coating is 105nm. The coatings also increase the protective properties for a longer service life. This makes the SiO2 coated a-DLC film a promising new candidate material for solar selective absorber films. The SiO2/a-DLC selective absorber films also were deposited on the Al extrusion substrates
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