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The microstructure of Y1Ba2Cu3Oy films and Y1Ba2Cu3Oy / Pr1Ba2Cu3Oy multilayers prepared by a pulsed organometallic beam epitaxy (POMBE) technique have been characterized by transmission electron microscopy (TEM). The microstructure of the films is observed to vary as a function of substrate temperature. At low temperatures, films are polycrystalline and exhibit some impurity phases. At higher substrate temperatures, films grow epitaxially with smooth surfaces and few impurities. Controlled growth at sufficiently high substrate temperatures allows uniform growth of alternating Y1Ba2Cu3Oy and Pr1Ba2Cu3Oy layers.
We report the results of a pulsed organo-metallic beam epitaxy (POMBE) process for growing complex oxide films at low background gas pressure (10-4 -10-2 torr) and low substrate temperature (600 to 700 C) using organo-metallic precursors in an oxygen plasma environment. Our results show that POMBE can extend the capability of organo-metallic chemical vapor deposition to growing complex oxide films with high precision both in composition and structure without the need for post-deposition oxidation and heat treatments. The growth of phase-pure, highly oriented Y-Ba-Cu-O superconducting oxide films ([Tc (R=0)=90.5K] and Jc (77K, 50K gauss)=l.l×105 A/cm2) is given as an example. Similar to the pulsed laser deposition process, the POMBE method has the potential for in-situ processing of multilayer structures (e.g. junctions).
Non-pharmaceutical interventions (NPI) such as facemasks and intensified hand hygiene may be effective in preventing influenza infections in households. It may be equally important that household members, especially children, can learn to use, maintain and tolerate these measures. We monitored adherence and tolerability of these NPI within a cluster-randomized trial in households with influenza index patients. We recruited 147 participants in 41 households, 39 (95%) out of 41 index patients were children (aged <14 years). In households assigned to wear facemasks, their use peaked on day 4 after symptom onset of the index patient at 73% and at 65% for children and adults, respectively. Mean daily frequency of hand disinfection in households assigned to intensified hand hygiene measures peaked at 7·7 (day 6) for children and at 10·1 (day 5) for adults. The majority of participants reported no problems with mask wearing. Data suggest that usage of NPI can be taught and that measures are well tolerated by adults and even sick children alike.
Eight cases of Legionnaires' disease were identified among the 215 German passengers after a cruise to the Nordic Sea in August 2003. An unmatched case-control study was conducted to identify risk factors and the source of infection. In total, eight passengers fulfilled the case definition, one of these died. Forty-two passengers served as controls. The attack rate was 4%. The mean age was 60 years for cases and 62 years for controls. Prolonged exposure to the spa pool seemed to be a risk factor of infection (OR 4·85, P=0·09). Legionella pneumophila serogroup 1, monoclonal antibody (mAb) subgroup ‘Knoxville’ was isolated from clinical and environmental samples. DNA sequence-based typing revealed that these isolates were indistinguishable from each other. The investigation showed the importance of an interdisciplinary approach of microbiology and epidemiology as not all sites on the ship that tested positive for L. pneumophila actually posed a relevant risk for the passengers.
The photographs displayed above show the impact, spreading, and boiling history of n-heptane droplets on a stainless steel surface. The impact velocity, Weber number, and initial droplet diameter are constant (values of 1 m/s, 43 and 1.5 mm respectively), and the view is looking down on the surface at an angle of about 30°. The photographs were taken using a spark flash method and the flash duration was 0.5 μs. The dynamic behavior illustrated in the photographs is a consequence of varying the initial surface temperature.
The effect of surface temperature on droplet shape may be seen by reading across any row; the evolution of droplet shape at various temperatures may be seen by reading down any column. An entrapped air bubble can be seen in the drop when the surface temperature is 24°C. At higher temperatures vigorous bubbling, rather like that of a droplet sizzling on a frying pan, is seen (the boiling point of n-heptane is 98°C) but the bubbles disappear as the Leidenfrost temperature of n-heptane (about 200°C) is exceeded because the droplet become levitated above a cushion of its own vapor and does not make direct contact with the surface. The droplet shape is unaffected by surface temperature in the early stage of the impact process (t≤0.8 ms) but is affected by temperature at later time (cf. t≥ 1.6 ms) because of the progressive influence of intermittent solid-liquid contact as temperature is increased.
We have used pulsed organometallic beam epitaxy (POMBE) to simultaneously deposit â- and ĉ-axis oriented Y1Ba2Cu3O7−x (YBCO) thin films at arbitrary locations on LaAlO3(100) substrates. Using photolithography and ion milling, several types of â-ĉ weak links have been fabricated at the boundary between the two films. The current-voltage (I-V) characteristics show a flux flow type behavior. The resistive transitions are broad and the critical current density is low, indicating weak coupling across these boundaries. With magnetic field applied parallel to the grain boundary plane, nonhysteretic I-V curves are obtained and the critical current goes to zero at an applied magnetic field of ∼7500 G.
Angelman syndrome (AS) is caused by the loss of function of yet unidentified gene(s) which map within 15q 11-13 and show monoallelic expression from the maternal allele. Lack of the maternal allele(s), due to either a deletion on the maternal chromosome 15 (about 70% of AS patients) or a paternal uniparental disomy (UPD)15 (<5%), are the most common molecular defects in AS. Prader-Willi syndrome (PWS) also maps to proximal 15q, but is caused by the loss of function of paternally expressed gen(s) . Here we describe clinical, cytogenetic and molecular data for two non-related patients with AS who carry a nonmosaic extra cromosome inv dup(15).
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