1,735 research outputs found

    Spatial confinement of muonium atoms

    Full text link
    We report the achievement of spatial confinement of muonium atoms (the bound state of a positive muon and an electron). Muonium emitted into vacuum from mesoporous silica reflects between two SiO2_2 confining surfaces separated by 1 mm. From the data, one can extract that the reflection probability on the confining surfaces kept at 100 K is about 90% and the reflection process is well described by a cosine law. This technique enables new experiments with this exotic atomic system and is a very important step towards a measurement of the 1S-2S transition frequency using continuous wave laser spectroscopy.Comment: 5 pages, 6 figure

    Fc-fusion mimetics

    Get PDF
    The Fc-fusion mimetic RpR 2 was prepared by disulfide bridging conjugation using a PEG in the place of the Fc. RpR 2 displayed higher affinity for VEGF than aflibercept caused primarily by a slower dissociation rate, which can prolong a drug at its site of action. RpRs have considerable potential for development as stable, organ specific therapeutics

    Dual acting therapeutic proteins for intraocular use

    Get PDF
    Antibody-based medicines that target vascular endothelial growth factor (VEGF) are administered by intravitreal injection to treat chronic neovascular retinal diseases. Much ongoing effort is focused on enhancing therapeutic outcome of these medicines. One strategy is the use of dual acting drugs (e.g. bispecific antibodies) to simultaneously bind to more than one intraocular biological target. A dual acting molecule targeting components within the vitreal cavity could also potentially extend vitreous residence time. In this review, the applications of bispecific antibodies within the eye are described with consideration to potential targets, applications and suitable bispecific formats

    Muonium emission into vacuum from mesoporous thin films at cryogenic temperatures

    Full text link
    We report on Muonium (Mu) emission into vacuum following {\mu}+ implantation in mesoporous thin SiO2 films. We obtain a yield of Mu into vacuum of (38\pm4)% at 250 K temperature and (20\pm4)% at 100 K for 5 keV {\mu}+ implantation energy. From the implantation energy dependence of the Mu vacuum yield we determine the Mu diffusion constants in these films: D250KMu = (1.6 \pm 0.1) \times 10-4 cm2/s and D100KMu = (4.2\pm0.5)\times10-5 cm2/s. Describing the diffusion process as quantum mechanical tunneling from pore-to-pore, we reproduce the measured temperature dependence T^3/2 of the diffusion constant. We extract a potential barrier of (-0.3 \pm 0.1) eV which is consistent with our computed Mu work-function in SiO2 of [-0.3,-0.9] eV. The high Mu vacuum yield even at low temperatures represents an important step towards next generation Mu spectroscopy experiments.Comment: 5 pages, 5 Figure

    Penetrating eyelid injury: a case report and review of literature

    Get PDF
    <p>Abstract</p> <p>Introduction</p> <p>In literature, many different types of foreign objects have been found to have caused eye injuries. These objects can range from organic to inorganic matter such as glass, wood, pencil, nails and fishhooks. Once the injury is recognized, removal of the foreign body and technique used in the management of the injury is very important to reduce further ocular damage. This case report investigates an injury caused by an object similar to a fishhook that pierced into the eyelid in the opposite direction to normal.</p> <p>Case presentation</p> <p>A 19 year old man presented with a one hour history of the right upper eyelid injury from a wire fence. The loose end of the wire penetrated the full thickness of the eyelid in the direction opposite to the normal. The wire passed from under the eyelid, through the centre of the upper lid, to the external surface. After the application of topical anesthetic drops, the eye could be opened manually, the lid averted, and the wire passed out through the defect. No complications were observed. Post removal, the acuity increased to 6/9 and there was no intraocular penetration. Full recovery was observed as well.</p> <p>Conclusion</p> <p>A severe eyelid penetrating injury can be uncomplicated with a full recovery when there is no intraocular penetration. It is also possible to have an injury pass under the lower margin of the lid and penetrate from inside to out, with no associated corneal injury.</p

    Blood pressure and risk of renal cell carcinoma in the European prospective investigation into cancer and nutrition.

    Get PDF
    Elevated blood pressure has been implicated as a risk factor for renal cell carcinoma (RCC), but prospective studies were confined to men and did not consider the effect of antihypertensive medication. The authors examined the relation among blood pressure, antihypertensive medication, and RCC in the European Prospective Investigation into Cancer and Nutrition (EPIC). Blood pressure was measured in 296,638 women and men, recruited in eight European countries during 1992-1998, 254,935 of whom provided information on antihypertensive medication. During a mean follow-up of 6.2 years, 250 cases of RCC were identified. Blood pressure was independently associated with risk of RCC. The relative risks for the highest versus the lowest category of systolic (>/=160 mmHg vs. /=100 mmHg vs. <80 mmHg) blood pressures were 2.48 (95% confidence interval: 1.53, 4.02) and 2.34 (95% confidence interval: 1.54, 3.55). Risk estimates did not significantly differ according to sex or use of antihypertensive medication. Individuals taking antihypertensive drugs were not at a significantly increased risk unless blood pressure was poorly controlled. These results support the hypothesis that hypertension, rather than its medications, increases the risk of RCC in both sexes, while effective blood pressure control may lower the risk. Udgivelsesdato: 2008-Feb-1

    Welcoming low testosterone as a cardiovascular risk factor

    Get PDF
    Male hypogonadism now has a new spectrum of complications. They are mainly cardiometabolic in nature. Low serum testosterone levels are a risk factor for diabetes, metabolic syndrome, inflammation and dyslipidemia. These metabolic and inflammatory complications are not without consequences. Recent studies have shown low serum testosterone levels to be an independent risk factor of cardiovascular and all-cause mortality. It is time to welcome low serum testosterone levels as a cardiovascular risk factor

    Design and Performance of SiPM-Based Readout of PbF\u3csub\u3e2\u3c/sub\u3e Crystals for High-Rate, Precision Timing Applications

    Get PDF
    We have developed a custom amplifier board coupled to a large-format 16-channel Hamamatsu silicon photomultiplier device for use as the light sensor for the electromagnetic calorimeters in the Muon g - 2 experiment at Fermilab. The calorimeter absorber is an array of lead-fluoride crystals, which produces short-duration Cherenkov light. The detector sits in the high magnetic field of the muon storage ring. The SiPMs selected, and their accompanying custom electronics, must preserve the short pulse shape, have high quantum efficiency, be non-magnetic, exhibit gain stability under varying rate conditions, and cover a fairly large fraction of the crystal exit surface area. We describe an optimized design that employs the new-generation of thru-silicon via devices. The performance is documented in a series of bench and beam tests

    Cohort profile: design and methods in the eye and vision consortium of UK Biobank

    Get PDF
    PURPOSE: To describe the rationale, methods and research potential of eye and vision measures available in UK Biobank. PARTICIPANTS: UK Biobank is a large, multisite, prospective cohort study. Extensive lifestyle and health questionnaires, a range of physical measures and collection of biological specimens are collected. The scope of UK Biobank was extended midway through data collection to include assessments of other measures of health, including eyes and vision. The eye assessment at baseline included questionnaires detailing past ophthalmic and family history, measurement of visual acuity, refractive error and keratometry, intraocular pressure (IOP), corneal biomechanics, spectral domain optical coherence tomography (OCT) of the macula and a disc-macula fundus photograph. Since recruitment, UK Biobank has collected accelerometer data and begun multimodal imaging data (including brain, heart and abdominal MRI) in 100 000 participants. Dense genotypic data and a panel of 20 biochemistry measures are available, and linkage to medical health records for the full cohort has begun. FINDINGS TO DATE: A total of 502 665 people aged between 40 and 69 were recruited to participate in UK Biobank. Of these, 117 175 took part in baseline assessment of vision, IOP, refraction and keratometry. A subgroup of 67 321 underwent OCT and retinal photography. The introduction of eye and vision measures in UK Biobank was accompanied by intensive training, support and a data monitoring quality control process. FUTURE PLANS: UK Biobank is one of the largest prospective cohorts worldwide with extensive data on ophthalmic diseases and conditions. Data collection is an ongoing process and a repeat of the baseline assessment including the questionnaires, measurements and sample collection will be performed in subsets of 25 000 participants every 2-3 years. The depth and breadth of this dataset, coupled with its open-access policy, will create a powerful resource for all researchers to investigate the eye diseases in later life
    corecore