429 research outputs found
Experimental demonstration of Aharonov-Casher interference in a Josephson junction circuit
A neutral quantum particle with magnetic moment encircling a static electric
charge acquires a quantum mechanical phase (Aharonov-Casher effect). In
superconducting electronics the neutral particle becomes a fluxon that moves
around superconducting islands connected by Josephson junctions. The full
understanding of this effect in systems of many junctions is crucial for the
design of novel quantum circuits. Here we present measurements and quantitative
analysis of fluxon interference patterns in a six Josephson junction chain. In
this multi-junction circuit the fluxon can encircle any combination of charges
on five superconducting islands, resulting in a complex pattern. We compare the
experimental results with predictions of a simplified model that treats fluxons
as independent excitations and with the results of the full diagonalization of
the quantum problem. Our results demonstrate the accuracy of the fluxon
interference description and the quantum coherence of these arrays
Biosorption of Selected Heavy Metals by Green Algae, Spirogyra Species and Its Potential as a Pollution Biomonitor
In this paper, adsorption features of freshwater green algae as a function of contact time, initial pH and initial metal ion concentrations were studied using model solutions of metal ions with subsequent determination by flame atomic absorption spectrometry (FAAS). Green algae samples were employed as bioindicators of selected heavy metals in environmental water samples with determination using FAAS and ICP-OES (inductively-coupled plasma-optical emission spectrometry). The optimum pH for cadmium (Cd), chromium (Cr), copper (Cu) and lead (Pb) biosorption were found to be 5.5, 5.8, 5.9 and 5.0, respectively. The biosorption process follows second order kinetics and is well described by the Langmuir isotherm model. Adsorption capacities were found to be 22.52, 38.19, 35.59 and 94.34 mg/g for Cd, Cr, Cu and Pb, respectively, at contact times of 15-50 minutes and initial metal ion concentrations of 500-700 mg/L. Biomonitoring studies revealed great potential for freshwater green algae as a bioindicator with mean concentration factors in the range of 367-7154 for the selected elements, the uptake being mainly via a metabolically mediated pathway. This work has demonstrated the potential of freshwater green algae as both a biosorbent and a bioindicator for heavy metal pollution in water systems. Keywords: Green algae, Biosorption, Biomonitoring, Toxic metals, FTIR, ICP-OES
Chronic bacterial prostatitis: efficacy of short-lasting antibiotic therapy with prulifloxacin (Unidrox®) in association with saw palmetto extract, lactobacillus sporogens and arbutin (Lactorepens®)
Bacterial prostatitis (BP) is a common condition accounting responsible for about 5-10% of all prostatitis cases; chronic bacterial prostatitis (CBP) classified as type II, are less common but is a condition that significantly hampers the quality of life, (QoL) because not only is it a physical condition but also a psychological distress. Commonly patients are treated with antibiotics alone, and in particular fluoroquinolones are suggested by the European Urology guidelines. This approach, although recommended, may not be enough. Thus, a multimodal approach to the prolonged antibiotic therapy may be helpful.210 patients affected by chronic bacterial prostatitis were enrolled in the study. All patients were positive to Meares-Stamey test and symptoms duration was > 3 months. The purpose of the study was to evaluate the efficacy of a long lasting therapy with a fluoroquinolone in association with a nutraceutical supplement (prulifloxacin 600 mg for 21 days and an association of Serenoa repens 320 mg, Lactobacillus Sporogens 200 mg, Arbutin 100 mg for 30 days). Patients were randomized in two groups (A and B) receiving respectively antibiotic alone and an association of antibiotic plus supplement.Biological recurrence at 2 months in Group A was observed in 21 patients (27.6%) and in Group B in 6 patients (7.8%). Uropathogens found at the first follow-up were for the majority Gram - (E. coli and Enterobacter spp.). A statistically significant difference was found at the time of the follow-up between Group A and B in the NIH-CPSI questionnaire score, symptoms evidence and serum PSA.Broad band, short-lasting antibiotic therapy in association with a nutritional supplement (serenoa repens, lactobacillus sporogens and arbutin) show better control and recurrence rate on patients affected by chronic bacterial prostatitits in comparison with antibiotic treatment alone.NCT02130713Date of trial Registration: 30/04/2014
Fabrication of stable and reproducible sub-micron tunnel junctions
We have performed a detailed study of the time stability and reproducibility
of sub-micron tunnel junctions, fabricated using standard
double angle shadow evaporations. We have found that by aggressively cleaning
the substrate before the evaporations, thus preventing any contamination of the
junction, we obtained perfectly stable oxide barriers. We also present
measurements on large ensembles of junctions which prove the reproducibility of
the fabrication process. The measured tunnel resistance variance in large
ensembles of identically fabricated junctions is in the range of only a few
percents. Finally, we have studied the effect of different thermal treatments
on the junction barrier. This is especially important for multiple step
fabrication processes which imply annealing the junction.Comment: 4 pages, 3 figure
Synchronous collecting duct carcinoma and papillary renal cell carcinoma: A case report and review of the literature
The coexistence of multiple and synchronous primary neoplasms in the same organ (including kidney) has only rarely been described in the literature. We herein present a case of collecting duct carcinoma (CDC) combined with papillary renal carcinoma (RCC) having a 57-month disease-free survival. CDC is a rather rare and aggressive neoplasm of the kidney. Sharing probably the same embryological origin, synchronous or metachronous association with in situ or papillary transitional cell carcinoma (TCC) may be found; association with RCC has been only once reported in the literature. The high incidence of c-erbB-2 oncogene amplification in CDC further characterizes this tumor as a separate entity from renal cell carcinoma, and shows some genetic characteristics in common with TCC. The histohgical diagnosis of Bellini CDC can be confirmed by the positive immuno-histochemical staining with a collecting duct marker and distal tubule marker and negative staining with a proximal tubule marker
GENERAL CONSIDERATIONS CONCERNING THE EFFECTS OF ELECTRO-OSMOSIS ON DECREASING THE FORCES AND THE ENERGY NEEDED FOR TILLING THE SOIL
Electro-osmosis principle consists in the application of a direct current voltage for an anode-cathode system introduced into soil. The effect of this system consists of the mobilization of water particles from the soil and their transport, in a very short time, from the anode to cathode. The soil water transported from the anode to cathode, on the tool-soil contact surface, in consequence, will produce a lubrication of the active surface and thereby a considerable reduction of the friction forces and implicitly of the energy necessary to move the tool through the soil
Coherent frequency conversion in a superconducting artificial atom with two internal degrees of freedom
By adding a large inductance in a dc-SQUID phase qubit loop, one decouples
the junctions' dynamics and creates a superconducting artificial atom with two
internal degrees of freedom. In addition to the usual symmetric plasma mode
({\it s}-mode) which gives rise to the phase qubit, an anti-symmetric mode
({\it a}-mode) appears. These two modes can be described by two anharmonic
oscillators with eigenstates and for the {\it s}
and {\it a}-mode, respectively. We show that a strong nonlinear coupling
between the modes leads to a large energy splitting between states
and . Finally, coherent frequency
conversion is observed via free oscillations between the states
and
Conclave: secure multi-party computation on big data (extended TR)
Secure Multi-Party Computation (MPC) allows mutually distrusting parties to
run joint computations without revealing private data. Current MPC algorithms
scale poorly with data size, which makes MPC on "big data" prohibitively slow
and inhibits its practical use.
Many relational analytics queries can maintain MPC's end-to-end security
guarantee without using cryptographic MPC techniques for all operations.
Conclave is a query compiler that accelerates such queries by transforming them
into a combination of data-parallel, local cleartext processing and small MPC
steps. When parties trust others with specific subsets of the data, Conclave
applies new hybrid MPC-cleartext protocols to run additional steps outside of
MPC and improve scalability further.
Our Conclave prototype generates code for cleartext processing in Python and
Spark, and for secure MPC using the Sharemind and Obliv-C frameworks. Conclave
scales to data sets between three and six orders of magnitude larger than
state-of-the-art MPC frameworks support on their own. Thanks to its hybrid
protocols, Conclave also substantially outperforms SMCQL, the most similar
existing system.Comment: Extended technical report for EuroSys 2019 pape
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