280 research outputs found

    Acinetobacterlwoffii Induced Cellulitis with Allergy-like Symptoms

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    Few reports document the misdiagnosis of Acinetobacterlwoffii skin infections for allergic reactions. In addition, A. lwoffii is frequently misidentified when applying conventional diagnostic methods. The bacterium has been reported to cause a multitude of diseases including skin and wound infections. The application of the newly established method “The Universal Method” allowed definite identification of the bacterium isolated from a leg and foot cellulitis case (Isolate QUBC mk1) that was misdiagnosed as an allergic reaction and was treated with intramuscular injections of diclofeneac sodium, anonsteroidal antiinflammatory drug.The isolate was identified as A. lwoffii, it failed to grow on MacConkey agar, and it was sensitive to ciprofloxacin but resistant to cefazolin. The 51-year old male patient was successfully treated with intravenous administration of ciprofloxacin, doxacillin, and cefazolin. He was released in good health after ten days.This work emphasizes the importance of distinguishing between skin infections and allergies. It also stresses the importance of prompt and accurate identification of A. Lwoffii and its possible relationship to allergic reactions. Misdiagnosis isdiscussed in the context of “The Hygiene Hypothesis”

    Design and testing of amplifiers for the CTF3 Photo-Injector Laser

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    The seed laser system of the FERMI free-electron laser: design, performance and near future upgrades

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    Abstract An important trend in extreme ultraviolet and soft X-ray free-electron laser (FEL) development in recent years has been the use of seeding by an external laser, aimed to improve the coherence and stability of the generated pulses. The high-gain harmonic generation seeding technique was first implemented at FERMI and provided FEL radiation with high coherence as well as intensity and wavelength stability comparable to table-top ultrafast lasers. At FERMI, the seed laser has another very important function: it is the source of external laser pulses used in pump–probe experiments allowing one to achieve a record-low timing jitter. This paper describes the design, performance and operational modes of the FERMI seed laser in both single- and double-cascade schemes. In addition, the planned upgrade of the system to meet the challenges of the upgrade to echo-enabled harmonic generation mode is presented

    15-03 Real Time Bicycle Simulation Study of Bicyclists\u27 Behaviors and their Implication on Safety

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    The main goal of this study was to build a bicycle simulator and study the interaction between cyclists and other roadway users. The simulator developed was used in conjunction with Oculus Rift googles to create a virtual cycling environment. The virtual riding environment contained roadway infrastructures and features such as intersections, crosswalks, bicycle lanes, shared-lanes, etc. It also contained both motor vehicles and pedestrians that interacted with cyclists. The rider’s perception and reactions to different situations were investigated based on their performance during four virtual simulation scenarios with an electroencephalogram (EEG) readings. In addition to the results on interactions of cyclists and other roadway users and the infrastructure obtained from this study, the simulator developed can be used for future studies

    Observation and control of hybrid spin-wave-Meissner-current transport modes

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    Superconductors are materials with zero electrical resistivity and the ability to expel magnetic fields known as the Meissner effect. Their dissipationless diamagnetic response is central to magnetic levitation and circuits such as quantum interference devices. Here, we use superconducting diamagnetism to shape the magnetic environment governing the transport of spin waves - collective spin excitations in magnets that are promising on-chip signal carriers - in a thin-film magnet. Using diamond-based magnetic imaging, we observe hybridized spin-wave-Meissner-current transport modes with strongly altered, temperature-tunable wavelengths. We extract the temperature-dependent London penetration depth from the wavelength shifts and realize local control of spin-wave refraction using a focused laser. Our results demonstrate the versatility of superconductor-manipulated spin-wave transport and have potential applications in spin-wave gratings, filters, crystals and cavities.Comment: main: 8 pages, 5 figures, supp: 15 pages, 6 figure

    The PHIN photoinjector for the CTF3 Drive beam

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    A new photoinjector for the CTF3 drive beam has been designed and is now being constructed by a collaboration among LAL, CCLRC and CERN within PHIN, the second Joint Research Activity of CARE. The photoinjector will provide a train of 2332 pulses at 1.5 GHz with a complex timing structure (sub-trains of 212 pulses spaced from one another by 333 ps or 999 ps) to allow the frequency multiplication scheme, which is one of the features of CLIC, to be tested in CTF3. Each pulse of 2.33 nC will be emitted by a Cs2Te photocathode deposited by a co-evaporation process to allow high quantum efficiency in operation (>3% for a minimum of 40 h). The 3 GHz, 2 1/2 cell RF gun has a 2 port coupler to minimize emittance growth due to asymmetric fields, racetrack profile of the irises and two solenoids to keep the emittance at the output below 20 p.mm.mrad. The laser has to survive very high average powers both within the pulse train (15 kW) and overall (200 W before pulse slicing). Challenging targets are also for amplitude stability (<0.25% rms) and time jitter from pulse to pulse (<1ps rms). An offline test in a dedicated line is foreseen at CERN in 2007

    Short-wavelength four wave mixing experiments using single and two-color schemes at FERMI

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    The development of ultra-bright extreme ultraviolet (EUV) and X-ray free electron laser (FEL) sources has enabled the extension of wave-mixing approaches into the short wavelength regime. Such a class of experiments relies upon nonlinear interactions among multiple light pulses offering a unique tool for exploring the dynamics of ultrafast processes and correlations between selected excitations at relevant length and time scales adding elemental and site selectivity as well. Besides the availability of a suitable photon source, the implementation of wave mixing methodology requires efforts in developing the instrumental set-up. We have realized at the FERMI FEL two dedicated set-ups to handle multiple FEL beams with preselected parameters in a non-collinear fashion and control their interaction sequence at the target. These unique apparatuses, combined with the exceptional characteristics of the seeded FERMI FEL, have allowed us to make the first steps into this field and further advances are foreseen in the near future

    Ultra-Low Threshold cw Lasing in Tensile Strained GeSn Microdisk Cavities

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    GeSn is proven as a good candidate to achieve CMOS-compatible laser sources on silicon. Lasing demonstrations in this alloy were based on directness of the band structure, this directness being increased with increasing the Sn content above 8 at.%. These past few years the research were consequently focused on incorporating the highest Sn content as possible to achieve high directness and high temperature laser operation. This unfortunately results is increased threshold. In this contribution we discuss the advantages in combining tensile strain engineering with lower Sn content alloys. This approach is motivated by the higher material quality in lower Sn content. The case with Sn content as small as 5.4 at.% Sn will be discussed. The alloy is initially compressively strained, and exhibits an indirect band gap that is turned to direct by applying tensile strain. A specific technology based on transfer On Insulator stressor layer on metal was developed to address strain engineering, thermal cooling and defective interface with the Ge-VS. This led to lasing in Ge0.95Sn0.05 microdisk cavities with dramatically reduced thresholds, by two order of magnitude, as compared to the case with high Sn alloys and as consequence enables cw operation

    Towards jitter-free pump-probe measurements at seeded free electron laser facilities

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    X-ray free electron lasers (FEL) coupled with optical lasers have opened unprecedented opportunities for studying ultrafast dynamics in matter. The major challenge in pump-probe experiments using FEL and optical lasers is synchronizing the arrival time of the two pulses. Here we report a technique that benefits from the seeded-FEL scheme and uses the optical seed laser for nearly jitter-free pump-probe experiments. Timing jitter as small as 6 fs has been achieved and confirmed by measurements of FEL-induced transient reflectivity changes of Si3N4 using both collinear and non-collinear geometries. Planned improvements of the experimental set-up are expected to further reduce the timing jitter between the two pulses down to fs level
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