2,174 research outputs found

    Integrated photonic quantum gates for polarization qubits

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    Integrated photonic circuits have a strong potential to perform quantum information processing. Indeed, the ability to manipulate quantum states of light by integrated devices may open new perspectives both for fundamental tests of quantum mechanics and for novel technological applications. However, the technology for handling polarization encoded qubits, the most commonly adopted approach, is still missing in quantum optical circuits. Here we demonstrate the first integrated photonic Controlled-NOT (CNOT) gate for polarization encoded qubits. This result has been enabled by the integration, based on femtosecond laser waveguide writing, of partially polarizing beam splitters on a glass chip. We characterize the logical truth table of the quantum gate demonstrating its high fidelity to the expected one. In addition, we show the ability of this gate to transform separable states into entangled ones and vice versa. Finally, the full accessibility of our device is exploited to carry out a complete characterization of the CNOT gate through a quantum process tomography.Comment: 6 pages, 4 figure

    Low alanine aminotransferase and higher cardiovascular events in type 2 diabetes: analysis of the Fenofibrate Intervention and Event Lowering in Diabetes (FIELD) study

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    Aims Non-alcoholic fatty liver disease (NAFLD) is common in type 2 diabetes and associated with higher risk of cardiovascular disease. This study aimed to determine whether alanine aminotransferase (ALT) or gamma-glutamyltransferase (GGT), as markers of liver health and NAFLD, might predict cardiovascular events in this population. Methods Data from the Fenofibrate Intervention and Event Lowering in Diabetes (FIELD) study were analysed to examine the relationship between liver enzymes and incident cardiovascular events (nonfatal myocardial infarction, stroke, coronary and other cardiovascular death, coronary or carotid revascularization) over 5 years. Results ALT had a linear inverse relationship with the first cardiovascular event on study. After adjustment, for every standard deviation higher baseline ALT (13.2U/L), the risk of an event was 7%(95%CI 4–13, P=0.02) lower. Participants with ALT below and above the reference range 8–41 U/L for women and 9–59 U/L for men, had a hazard ratio of an event of 1.86(95%CI, 1.12–3.09) and 0.65(95%CI, 0.49–0.87), respectively (P=0.001). No relationship was found for GGT. Conclusions The data may indicate that in type 2 diabetes — associated with higher ALT due to prevalent NAFLD — lower ALT is a marker of hepatic or systemic frailty rather than health

    Successful long-term monotherapy with rituximab in a patient with chronic lymphocytic leukemia of the B-cell-lineage: a case report

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    <p>Abstract</p> <p>Introduction</p> <p>Treatment of chronic lymphocytic leukemia of the B-cell-lineage is strongly based upon clinical staging because of the heterogeneous clinical course of this disease.</p> <p>Case presentation</p> <p>We describe a 62-year-old patient with newly diagnosed chronic lymphocytic leukemia of the B-cell-lineage who did not respond to several chemotherapy regimens including chlorambucil, fludarabine and cyclophosphamide, developing a marked neutropenia and thrombocytopenia with life-threatening infections. Further chemotherapy appeared not feasible because of bone marrow toxicity. The patient was treated with 600 mg/m<sup>2 </sup>rituximab weekly followed by eight courses of biweekly therapy and then by long-term maintenance therapy, achieving almost complete remission of the symptoms and disease control.</p> <p>Conclusion</p> <p>After resistance to standard chemotherapy with chlorambucil and fludarabine, a patient with chronic lymphocytic leukemia of the B-cell-lineage was successfully treated with rituximab.</p

    Cone-beam CT reconstruction with gravity-induced motion.

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    Fixed-gantry cone-beam computed tomography (CBCT), where the imaging hardware is fixed while the subject is continuously rotated 360° in the horizontal position, has implications for building compact and affordable fixed-gantry linear accelerators (linacs). Fixed-gantry imaging with a rotating subject presents a challenging image reconstruction problem where the gravity-induced motion is coupled to the subject's rotation angle. This study is the first to investigate the feasibility of fixed-gantry CBCT using imaging data of three live rabbits in an ethics-approved study. A novel data-driven motion correction method that combines partial-view reconstruction and motion compensation was developed to overcome this challenge. Fixed-gantry CBCT scans of three live rabbits were acquired on a standard radiotherapy system with the imaging beam fixed and the rabbits continuously rotated using an in-house programmable rotation cradle. The reconstructed images of the thoracic region were validated against conventional CBCT scans acquired at different cradle rotation angles. Results showed that gravity-induced motion caused severe motion blur in all of the cases if unaccounted for. The proposed motion correction method yielded clinically usable image quality with  <1 mm gravity-induced motion blur for rabbits that were securely immobilized on the rotation cradle. Shapes of the anatomic structures were correctly reconstructed with  <0.5 mm accuracy. Translational motion accounted for the majority of gravity-induced motion. The motion-corrected reconstruction represented the time-averaged location of the thoracic region over a 360° rotation. The feasibility of fixed-gantry CBCT has been demonstrated. Future work involves the validation of imaging accuracy for human subjects, which will be useful for emerging compact fixed-gantry radiotherapy systems

    Outcomes for patients with chronic lymphocytic leukemia and acute leukemia or myelodysplastic syndrome

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    Acute leukemia (AL) and myelodysplastic syndrome (MDS) are uncommon in chronic lymphocytic leukemia (CLL). We retrospectively identified 95 patients with CLL, also diagnosed with AL (n=38) or MDS (n=57), either concurrently (n=5) or subsequent (n=90) to CLL diagnosis and report their outcomes. Median number of CLL treatments prior to AL and MDS was 2 (0-9) and 1 (0-8), respectively; the most common regimen was purine analog combined with alkylating agent±CD20 monoclonal antibody. Twelve cases had no prior CLL treatment. Among 38 cases with AL, 33 had acute myelogenous leukemia (AML), 3 had acute lymphoid leukemia (ALL; 1 Philadelphia chromosome positive), 1 had biphenotypic and 1 had extramedullary (bladder) AML. Unfavorable AML karyotype was noted in 26, and intermediate risk in 7 patients. There was no association between survival from AL and number of prior CLL regimens or karyotype. Expression of CD7 on blasts was associated with shorter survival. Among MDS cases, all International Prognostic Scoring System (IPSS) were represented; karyotype was unfavorable in 36, intermediate in 6 and favorable in 12 patients; 10 experienced transformation to AML. Shorter survival from MDS correlated with higher risk IPSS, poor-risk karyotype and increased number of prior CLL treatments. Overall, outcomes for patients with CLL subsequently diagnosed with AL or MDS were very poor; AL/MDS occurred without prior CLL treatment. Effective therapies for these patients are desperately needed

    Effects of an exercise programme with people living with HIV: Research in a disadvantaged setting

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    This study aimed to analyse the physical health effects of a community based 10-week physical activity programme with people living with HIV. It was developed, implemented and evaluated in a disadvantaged community in South Africa. A pre-post research design was chosen. Major recruitment and adherence challenges resulted in a small sample. Among the 23 participants who took part in both baseline and final testing, compliant participants (n = 12) were compared to non-compliant participants (n = 11). Immunological (CD4, viral load), anthropometric (height, weight, skinfolds and waist to hip ratio), muscular strength (h1RM) and cardiopulmonary fitness (time on treadmill) parameters were measured. The compliant and non-compliant groups were not different at baseline. Muscular strength was the parameter most influenced by compliance with the physical activity programme (F = 4.516, p = 0.047). Weight loss and improvement in cardiopulmonary fitness were restricted by the duration of the programme, compliance and influencing factors (e.g. nutrition, medication). The increase in strength is significant and meaningful in the context, as the participants goals were to look healthy and strong to avoid HIV related stigma. The improvements in appearance were a motivational factor, especially since the changes were made visible in a short time. Practical implications for health promotion are described. More research contextualised in disadvantaged settings is needed.DHE

    Long-term halocarbon observations from a coastal and an inland site in Sabah, Malaysian Borneo

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    Abstract. Short-lived halocarbons are believed to have important sources in the tropics, where rapid vertical transport could provide a significant source to the stratosphere. In this study, quasi-continuous measurements of short-lived halocarbons are reported for two tropical sites in Sabah (Malaysian Borneo), one coastal and one inland (rainforest). We present the observations for C2Cl4, CHBr3, CH2Br2* (actually ~80% CH2Br2 and ~20% CHBrCl2) and CH3I from November 2008 to January 2010 made using our μDirac gas chromatographs with electron capture detection (GC-ECD). We focus on the first 15 months of observations, showing over one annual cycle for each compound and therefore adding significantly to the few limited-duration observational studies that have been conducted thus far in southeast Asia. The main feature in the C2Cl4 behaviour at both sites is its annual cycle, with the winter months being influenced by northerly flow with higher concentrations, typical of the Northern Hemisphere, and with the summer months influenced by southerly flow and lower concentrations representative of the Southern Hemisphere. No such clear annual cycle is seen for CHBr3, CH2Br2* or CH3I. The baseline values for CHBr3 and CH2Br2* are similar at the coastal (overall median: CHBr3 1.7 ppt, CH2Br2* 1.4 ppt) and inland sites (CHBr3 1.6 ppt, CH2Br2* 1.1 ppt), but periods with elevated values are seen at the coast (overall 95th percentile: CHBr3 4.4 ppt, CH2Br2ast 1.9 ppt), presumably resulting from the stronger influence of coastal emissions. Overall median bromine values from [CHBr3 × 3] + [CH2Br2* × 2] are 8.0 ppt at the coast and 6.8 ppt inland. The median values reported here are largely consistent with other limited tropical data and imply that southeast Asia generally is not, as has been suggested, a hot spot for emissions of these compounds. These baseline values are consistent with the most recent emissions found for southeast Asia using the p-TOMCAT (Toulouse Off-line Model of Chemistry And Transport) model. CH3I, which is only observed at the coastal site, is the shortest-lived compound measured in this study, and the observed atmospheric variations reflect this, with high variability throughout the study period. This work was supported by a NERC consortium grant to the OP3 team, by NCAS, by the European Commission through the SCOUT-O3 project (505390-GOCE-CF2004) and by NERC western Pacific grant number NE/F020341/1 and NERC CAST grant number NE/J006246/1. L. M. O’Brien and M. J. Ashfold thank NERC for research studentships. A. D. Robinson acknowledges NERC for their support through small grant project NE/D008085/1. N. R. P. Harris is supported by a NERC Advanced Research Fellowship. We thank the Sabah Foundation, Danum Valley Field Centre and the Royal Society (Glen Reynolds) for field site support. The research leading to these results has received funding from the European Union’s Seventh Framework Programme FP7/2007–2013 under grant agreement no. 226224 – SHIVA. We thank David Oram and Stephen Humphrey at UEA for their assistance in checking the calibration of our Aculife cylinder in May 2009. This is paper number 626 of the Royal Society’s South East Asian Rainforest Research Programme.This is the final published version. It first appeared at http://www.atmos-chem-phys.net/14/8369/2014/acp-14-8369-2014.html
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