1,738 research outputs found

    Low-temperature characterization of Nb-Cu-Nb weak links with Ar ion-cleaned interfaces

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    We characterize niobium-based lateral Superconductor (S) - Normal metal (N) - Superconductor weak links through low-temperature switching current measurements and tunnel spectroscopy. We fabricate the SNS devices in two separate lithography and deposition steps, combined with strong argon ion cleaning before the normal metal deposition in the last step. Our SNS weak link consists of high-quality sputtered Nb electrodes that are contacted with evaporated Cu. The two-step fabrication flow enables great flexibility in the choice of materials and pattern design. A comparison of the temperature-dependent equilibrium critical supercurrent with theoretical predictions indicates that the quality of the Nb-Cu interface is similar to that of evaporated Al-Cu weak links. Aiming at increased sensitivity, range of operation temperatures, and thermal isolation, we investigate how these SNS structures can be combined with shadow-evaporated aluminum tunnel junctions for sensor applications that utilize the superconducting proximity effect. To this end, we demonstrate a hybrid magnetic flux sensor based on a Nb-Cu-Nb SNS junction, where the phase-dependent normal metal density of states is probed with an Al tunnel junction.Comment: 5 pages, 3 figure

    Matematiikka = vieras kieli, suomi = vieras kieli:vieras kieli = matikkasuomi

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    TiivistelmÀ. TÀssÀ tutkielmassa tutkimme kielitaidon vaikutusta matematiikan oppimiseen. Matematiikan oppiaineesta ajatellaan yleisesti universaalina tieteenÀ, joka on samanlaista kaikkialla. Matematiikan kielestÀ voidaan olla montaa mieltÀ, juuri matematiikka voi tuntua vieraalta, vaikkei kieli aiheuttaisikaan minkÀÀnlaista estettÀ. Matematiikan termistöÀ ei puhuta tai kÀytetÀ lasten muussa arkielÀmÀssÀ, eivÀtkÀ kÀsitteet ja sanasto vÀlttÀmÀttÀ ole tuttua koulun ulkopuolelta. TÀmÀn tutkimuksen yhteydessÀ löysimme useita viitteitÀ siitÀ, ettÀ matemaattinen ilmaisutapa on myös kulttuurisesti muotoutunutta johtuen kielestÀ ja sen suomista mahdollisuuksista, perinteistÀ ja totutuista tilanteista. Tutkimuksemme perusteella voidaan pÀÀtellÀ, ettei suomen kielen oppiminen sinÀllÀÀn aiheuta oppilaille mitÀÀn ylimÀÀrÀistÀ kielellistÀ taakkaa, ja ettÀ minkÀ tahansa luonnollisen kielen oppiminen vaatii kognitiivista ponnistelua. Matematiikan oppimisen kannalta tulisi suomi toisena kielenÀ -oppilaita opettaessa huomioida sanaston merkitys. Kielen ja sanaston oppimisessa muisti on keskeisessÀ osiossa ja tutkimuksessa tarkastelimme erityisesti työmuistin toimintaa matematiikan ja kielten oppimisen kannalta

    Genomic variation in a global village: Report of the 10th annual Human Genome Variation Meeting 2008

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    The Centre for Applied Genomics of the Hospital for Sick Children and the University of Toronto hosted the 10th Human Genome Variation (HGV) Meeting in Toronto, Canada, in October 2008, welcoming about 240 registrants from 34 countries. During the 3 days of plenary workshops, keynote address, and poster sessions, a strong cross-disciplinary trend was evident, integrating expertise from technology and computation, through biology and medicine, to ethics and law. Single nucleotide polymorphisms (SNPs) as well as the larger copy number variants (CNVs) are recognized by ever-improving array and next-generation sequencing technologies, and the data are being incorporated into studies that are increasingly genome-wide as well as global in scope. A greater challenge is to convert data to information, through databases, and to use the information for greater understanding of human variation. In the wake of publications of the first individual genome sequences, an inaugural public forum provided the opportunity to debate whether we are ready for personalized medicine through direct-to-consumer testing. The HGV meetings foster collaboration, and fruits of the interactions from 2008 are anticipated for the 11th annual meeting in September 2009. Hum Mutat 30:1–5, 2009. © 2009 Wiley-Liss, Inc.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/63049/1/21008_ftp.pd

    Mediterranean diet or extended fasting's influence on changing the intestinal microflora, immunoglobulin A secretion and clinical outcome in patients with rheumatoid arthritis and fibromyalgia: an observational study

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    BACKGROUND: Alterations in the intestinal bacterial flora are believed to be contributing factors to many chronic inflammatory and degenerative diseases including rheumatic diseases. While microbiological fecal culture analysis is now increasingly used, little is known about the relationship of changes in intestinal flora, dietary patterns and clinical outcome in specific diseases. To clarify the role of microbiological culture analysis we aimed to evaluate whether in patients with rheumatoid arthritis (RA) or fibromyalgia (FM) a Mediterranean diet or an 8-day fasting period are associated with changes in fecal flora and whether changes in fecal flora are associated with clinical outcome. METHODS: During a two-months-period 51 consecutive patients from an Integrative Medicine hospital department with an established diagnosis of RA (n = 16) or FM (n = 35) were included in the study. According to predefined clinical criteria and the subjects' choice the patients received a mostly vegetarian Mediterranean diet (n = 21; mean age 50.9 +/-13.3 y) or participated in an intermittent modified 8-day fasting therapy (n = 30; mean age 53.7 +/- 9.4 y). Quantitative aerob and anaerob bacterial flora, stool pH and concentrations of secretory immunoglobulin A (sIgA) were analysed from stool samples at the beginning, at the end of the 2-week hospital stay and at a 3-months follow-up. Clinical outcome was assessed with the DAS 28 for RA patients and with a disease severity rating scale in FM patients. RESULTS: We found no significant changes in the fecal bacterial counts following the two dietary interventions within and between groups, nor were significant differences found in the analysis of sIgA and stool ph. Clinical improvement at the end of the hospital stay tended to be greater in fasting vs. non-fasting patients with RA (p = 0.09). Clinical outcome was not related to alterations in the intestinal flora. CONCLUSION: Neither Mediterranean diet nor fasting treatments affect the microbiologically assessed intestinal flora and sIgA levels in patients with RA and FM. The impact of dietary interventions on the human intestinal flora and the role of the fecal flora in rheumatic diseases have to be clarified with newer molecular analysis techniques. The potential benefit of fasting treatment in RA and FM should be further tested in randomised trials

    Disposable Nafion-Coated Single-Walled Carbon Nanotube Test Strip for Electrochemical Quantitative Determination of Acetaminophen in a Finger-Prick Whole Blood Sample

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    A disposable electrochemical test strip for the quantitative point-of-care (POC) determination of acetaminophen (paracetamol) in plasma and finger-prick whole blood was fabricated. The industrially scalable dry transfer process of single-walled carbon nanotubes (SWCNTs) and screen printing of silver were combined to produce integrated electrochemical test strips. Nafion coating stabilized the potential of the Ag reference electrode and enabled the selective detection in spiked plasma as well as in whole blood samples. The test strips were able to detect acetaminophen in small 40 mu L samples with a detection limit of 0.8 mu M and a wide linear range from 1 mu M to 2 mM, well within the required clinical range. After a simple 1:1 dilution of plasma and whole blood, a quantitative detection with good recoveries of 79% in plasma and 74% in whole blood was achieved. These results strongly indicate that these electrodes can be used directly to determine the unbound acetaminophen fraction without the need for any additional steps. The developed test strip shows promise as a rapid and simple POC quantitative acetaminophen assay.Peer reviewe
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