82 research outputs found

    Experimental method for measuring classical concurrence of generic beam shapes

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    Classical entanglement is a powerful tool which provides a neat numerical estimate for the study of classical correlations. Its experimental investigation, however, has been limited to special cases. Here, we demonstrate that the experimental quantification of the level of classical entanglement can be carried out in more general instances. Our approach enables the extension to arbitrarily shaped transverse modes and hence delivering a suitable quantification tool to describe concisely the modal structure

    Geometrical bounds on irreversibility in open quantum systems

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    Clausius inequality has deep implications for reversibility and the arrow of time. Quantum theory is able to extend this result for closed systems by inspecting the trajectory of the density matrix on its manifold. Here we show that this approach can provide an upper and lower bound to the irreversible entropy production for open quantum systems as well. These provide insights on the thermodynamics of the information erasure. Limits of the applicability of our bounds are discussed, and demonstrated in a quantum photonic simulator

    Bridging thermodynamics and metrology in non-equilibrium Quantum Thermometry

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    Single-qubit thermometry presents the simplest tool to measure the temperature of thermal baths with reduced invasivity. At thermal equilibrium, the temperature uncertainty is linked to the heat capacity of the qubit, however the best precision is achieved outside equilibrium condition. Here, we discuss a way to generalize this relation in a non-equilibrium regime, taking into account purely quantum effects such as coherence. We support our findings with an experimental photonic simulation.Comment: 7 pages, 4 figure

    The entropic cost of quantum generalized measurements

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    Landauer’s principle introduces a symmetry between computational and physical processes: erasure of information, a logically irreversible operation, must be underlain by an irreversible transformation dissipating energy. Monitoring micro- and nano-systems needs to enter into the energetic balance of their control; hence, finding the ultimate limits is instrumental to the development of future thermal machines operating at the quantum level. We report on the experimental investigation of a lower bound to the irreversible entropy associated to generalized quantum measurements on a quantum bit. We adopted a quantum photonics gate to implement a device interpolating from the weakly disturbing to the fully invasive and maximally informative regime. Our experiment prompted us to introduce a bound taking into account both the classical result of the measurement and the outcoming quantum state; unlike previous investigation, our entropic bound is based uniquely on measurable quantities. Our results highlight what insights the information-theoretic approach provides on building blocks of quantum information processors

    Compressively certifying quantum measurements

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    We introduce a reliable compressive procedure to uniquely characterize any given low-rank quantum measurement using a minimal set of probe states that is based solely on data collected from the unknown measurement itself. The procedure is most compressive when the measurement constitutes pure detection outcomes, requiring only an informationally complete number of probe states that scales linearly with the system dimension. We argue and provide numerical evidence showing that the minimal number of probe states needed is even generally below the numbers known in the closely-related classical phase-retrieval problem because of the quantum constraint. We also present affirmative results with polarization experiments that illustrate significant compressive behaviors for both two- and four-qubit detectors just by using random product probe states.Comment: 9 pages, 7 figures, 1 table (updated content and 2 new figures since last version

    Adaptive two-phase estimation on a photonic integrated device

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    Efficient adaptive multiphase estimation has been demonstrated experimentally on an integrated three-arm interferometer injected by single photons. Bayesian learning and Sequential Monte Carlo approximation have been employed as machine learning tools to achieve this goal

    Single-photon Calibration of an Integrated Multiarm Interferometer via Neural Netowrks

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    Technological quantum sensors requires the development of a calibration procedure that is self-consistent and easily adaptable to different scenarios. Neural networks provide a handy solution in particular when dealing with large systems operating in a noisy environment

    Flow Cytometric microsphere-based immunoassay as a novel non-radiometric method for the detection of glutamic acid decarboxylase autoantibodies in type 1 Diabetes Mellitus

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    The first measurable sign of arising autoimmunity in Type 1 Diabetes Mellitus is the detection of autoantibodies against beta-cell antigens, such as glutamic acid decarboxylase (GAD65). GAD65 autoantibodies (GADA) are usually measured by Radioligand Binding Assay (RBA). The aim of this work was to develop protocols of Flow Cytometric microsphere-based immunoassays (FloCMIA) which involved glutamic acid decarboxylase fused to thioredoxin (TrxGAD65) adsorbed on polystyrene microspheres. Detection of bound GADA was accomplished by the use of anti-human IgG-Alexa Fluor 488 (Protocol A), anti-human IgG-biotin and streptavidindichlorotriazinyl aminofluorescein (DTAF) (Protocol B) or TrxGAD65-biotin and streptavidin- DTAF (Protocol C). Serum samples obtained from 46 patients assayed for routine autoantibodies at Servicios Tecnológicos de Alto Nivel (STAN-CONICET) were analyzed by RBA, ELISA and three alternative FloCMIA designs. Protocol C exhibited the highest specificity (97.8%) and sensitivity (97.4%) and a wide dynamic range (1.00-134.40 SDs). Samples obtained from 40 new-onset diabetic patients were also analyzed to further evaluate the performance of protocol C. The latter protocol showed a sensitivity of 58.6% and a prevalence of 47.5%. Two patients resulted positive only by FloCMIA protocol C and its SDs were higher than RBA and ELISA, showing a significantly wide dynamic range. In conclusion, FloCMIA proved to be highly sensitive and specific, requiring a low sample volume; it is environmentally adequate, innovative and it represents a cost-effective alternative to traditional GADA determination by RBA and/or ELISA; making it applicable to most medium-complexity laboratories.Fil: Guerra, Luciano Lucas. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Oficina de Coordinacion Administrativa Houssay. Instituto de Estudios de la Inmunidad Humoral "Profesor R. A. Margni"; ArgentinaFil: Trabucchi, Aldana. Consejo Nacional de Investigaciones Cientiâ­ficas y Tecnicas. Oficina de Coordinacion Administrativa Houssay. Instituto de Estudios de la Inmunidad Humoral "profesor R. A. Margni"; ArgentinaFil: Faccinetti, Natalia Ines. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Oficina de Coordinacion Administrativa Houssay. Instituto de Estudios de la Inmunidad Humoral "Profesor R. A. Margni"; ArgentinaFil: Iacono, Ruben Francisco. Consejo Nacional de Investigaciones Cientiâ­ficas y Tecnicas. Oficina de Coordinacion Administrativa Houssay. Instituto de Estudios de la Inmunidad Humoral "profesor R. A. Margni"; ArgentinaFil: Ureta, Daniela Beatriz. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Oficina de Coordinacion Administrativa Houssay. Instituto de Estudios de la Inmunidad Humoral "Profesor R. A. Margni"; ArgentinaFil: Poskus, Edgardo. Consejo Nacional de Investigaciones Cientiâ­ficas y Tecnicas. Oficina de Coordinacion Administrativa Houssay. Instituto de Estudios de la Inmunidad Humoral "profesor R. A. Margni"; ArgentinaFil: Valdez, Silvina Noemi. Consejo Nacional de Investigaciones Cientiâ­ficas y Tecnicas. Oficina de Coordinacion Administrativa Houssay. Instituto de Estudios de la Inmunidad Humoral "profesor R. A. Margni"; Argentin

    Novel prokaryotic expression of thioredoxin-fused insulinoma associated protein tyrosine phosphatase 2 (IA-2), its characterization and immunodiagnostic application

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    Background The insulinoma associated protein tyrosine phosphatase 2 (IA-2) is one of the immunodominant autoantigens involved in the autoimmune attack to the beta-cell in Type 1 Diabetes Mellitus. In this work we have developed a complete and original process for the production and recovery of the properly folded intracellular domain of IA-2 fused to thioredoxin (TrxIA-2ic) in Escherichia coli GI698 and GI724 strains. We have also carried out the biochemical and immunochemical characterization of TrxIA-2icand design variants of non-radiometric immunoassays for the efficient detection of IA-2 autoantibodies (IA-2A). Results The main findings can be summarized in the following statements: i) TrxIA-2ic expression after 3 h of induction on GI724 strain yielded ≈ 10 mg of highly pure TrxIA-2ic/L of culture medium by a single step purification by affinity chromatography, ii) the molecular weight of TrxIA-2ic (55,358 Da) could be estimated by SDS-PAGE, size exclusion chromatography and mass spectrometry, iii) TrxIA-2ic was properly identified by western blot and mass spectrometric analysis of proteolytic digestions (63.25 % total coverage), iv) excellent immunochemical behavior of properly folded full TrxIA-2ic was legitimized by inhibition or displacement of [35S]IA-2 binding from IA-2A present in Argentinian Type 1 Diabetic patients, v) great stability over time was found under proper storage conditions and vi) low cost and environmentally harmless ELISA methods for IA-2A assessment were developed, with colorimetric or chemiluminescent detection. Conclusions E. coli GI724 strain emerged as a handy source of recombinant IA-2ic, achieving high levels of expression as a thioredoxin fusion protein, adequately validated and applicable to the development of innovative and cost-effective immunoassays for IA-2A detection in most laboratories.Fil: Guerra, Luciano Lucas. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Estudios de la Inmunidad Humoral Prof. Ricardo A. Margni. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Instituto de Estudios de la Inmunidad Humoral Prof. Ricardo A. Margni; ArgentinaFil: Faccinetti, Natalia Ines. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Estudios de la Inmunidad Humoral Prof. Ricardo A. Margni. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Instituto de Estudios de la Inmunidad Humoral Prof. Ricardo A. Margni; ArgentinaFil: Trabucchi, Aldana. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Estudios de la Inmunidad Humoral Prof. Ricardo A. Margni. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Instituto de Estudios de la Inmunidad Humoral Prof. Ricardo A. Margni; ArgentinaFil: Rovitto, Bruno David. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Estudios de la Inmunidad Humoral Prof. Ricardo A. Margni. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Instituto de Estudios de la Inmunidad Humoral Prof. Ricardo A. Margni; ArgentinaFil: Sabljic, Adriana Victoria. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Estudios de la Inmunidad Humoral Prof. Ricardo A. Margni. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Instituto de Estudios de la Inmunidad Humoral Prof. Ricardo A. Margni; ArgentinaFil: Poskus, Edgardo. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Estudios de la Inmunidad Humoral Prof. Ricardo A. Margni. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Instituto de Estudios de la Inmunidad Humoral Prof. Ricardo A. Margni; ArgentinaFil: Iacono, Ruben Francisco. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Estudios de la Inmunidad Humoral Prof. Ricardo A. Margni. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Instituto de Estudios de la Inmunidad Humoral Prof. Ricardo A. Margni; ArgentinaFil: Valdez, Silvina Noemi. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Estudios de la Inmunidad Humoral Prof. Ricardo A. Margni. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Instituto de Estudios de la Inmunidad Humoral Prof. Ricardo A. Margni; Argentin

    Association of polymorphisms in survivin gene with the risk of hepatocellular carcinoma in Chinese han population: a case control study

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    <p>Abstract</p> <p>Background</p> <p>Survivin, one of the strongest apoptosis inhibitors, plays a critical role in the development and progression of hepatocellular carcinoma (HCC). By comparison, relatively little is known about the effect of <it>survivin </it>gene polymorphisms on HCC susceptibility. Our study aimed to investigate the association of <it>survivin </it>gene polymorphisms with the risk of HCC in Chinese han population.</p> <p>Methods</p> <p>A case-control study was conducted in Chinese han population consisting of 178 HCC cases and 196 cancer-free controls. Information on demographic data and related risk factors was collected for all subjects. Polymorphisms of the <it>survivin </it>gene, including three loci of rs8073069, rs9904341 and rs1042489, were selected and genotyped by a polymerase chain reaction- restriction fragment length polymorphism (PCR-RFLP) technique. Association analysis of genotypes/alleles and haplotypes from these loci with the risk of HCC was conducted under different genetic models.</p> <p>Results</p> <p>Using univariate analysis of rs8073069, rs9904341 and rs1042489 under different genetic models, no statistically significant difference was found in genotype or allele distribution of HCC cases relative to the controls (<it>P </it>> 0.05). Linkage disequilibrium (LD) analysis showed that these loci were in LD. Multivariate logistic regression indicated that with no G-C-T haplotype as reference, the haplotype of G-C-T from these loci was associated with a lower risk for HCC under the recessive model (<it>OR = </it>0.46, 95% confidence interval (<it>CI</it>): 0.24~0.90, <it>P </it>= 0.023). Both HBsAg+ and the medical history of viral hepatitis type B were risk factors for HCC. However, no statistically significant haplotype-environment interaction existed.</p> <p>Conclusions</p> <p>No association between rs8073069, rs9904341 or rs1042489 in <it>survivin </it>gene and the risk of HCC is found in Chinese han population, but rs8073069G-rs9904341C- rs1042489T is perhaps a protective haplotype for HCC.</p
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