486 research outputs found

    Schwarz Lemma and Schwarz-Pick Lemma for solutions of the α\alpha-harmonic equation

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    In this paper, the Schwarz type and Schwarz-Pick type inequalities for solutions of α\alpha-harmonic equation for α>−1\alpha>-1 are investigated. By making use of the integral of trigonometric functions, we obtain the two types of inequalities in terms of hypergeometric functions which improve the corresponding results due to Khalfallah et al. (Complex Var. Elliptic Equ., 2023) and Li et al. (Bull. Malays. Math. Sci. Soc., 2022).Comment: 14 pages, 1 figur

    Measurement-device-independent QKD with Modified Coherent State

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    The measurement-device-independent quantum key distribution (MDI-QKD) protocol has been proposed for the purpose of removing the detector side channel attacks. Due to the multi-photon events of coherent states sources, real-life implementations of MDI-QKD protocol must employ decoy states to beat the photon-number-splitting attack. Decoy states for MDI-QKD based on the weak coherent states have been studied recently. In this paper, we propose to perform MDI-QKD protocol with modified coherent states (MCS) sources. We simulate the performance of MDI-QKD with the decoy states based on MCS sources. And our simulation indicates that both the secure-key rate and transmission distance can be improved evidently with MCS sources.The physics behind this improvement is that the probability of multi-photon events of the MCS is lower than that of weak coherent states while at the same time the probability of single-photon is higher

    Measurement-device-independent quantum key distribution with uncharacterized qubit sources

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    Measurement-device-independent quantum key distribution (MDIQKD) is proposed to be secure against any possible detection attacks. The security of the original proposal relies on the assumption that the legitimate users can fully characterize the encoding systems including sources. Here, we propose a MDIQKD protocol where we allow uncharacterized encoding systems as long as qubit sources are used. A security proof of the MDIQKD protocol is presented that does not need the knowledge of the encoding states. Simulation results show that the scheme is practical

    Mismatched-basis statistics enable quantum key distribution with uncharacterized qubit sources

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    In the postprocessing of quantum key distribution, the raw key bits from the mismatched-basis measurements, where two parties use different bases, are normally discarded. Here, we propose a postprocessing method that exploits measurement statistics from mismatched-basis cases, and prove that incorporating these statistics enables uncharacterized qubit sources to be used in the measurement-device-independent quantum key distribution protocol and the Bennett-Brassard 1984 protocol, a case which is otherwise impossible.Comment: Part of this article contains a significant improvement over arXiv:1309.381

    Laparoscopic versus open distal pancreatectomy: A meta-analysis

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    SummaryObjectiveLaparoscopic distal pancreatectomy (LDP) is a minimally invasive surgical technique. The aim of the present study was to evaluate the currently available literature and compare the short-term clinical outcomes of patients who underwent LDP for left-sided pancreatic pathology with patients who underwent traditional open surgery.MethodsA literature search was performed to identify and compare studies that reported the clinical outcomes of both LDP and open distal pancreatectomy (ODP). Pooled odds ratios (OR) and weighted mean differences (WMD) with 95% confidence intervals (95% CI) were calculated using either fixed-effects or random-effects models.ResultsNineteen nonrandomized controlled studies were identified that matched the selection criteria and reported the clinical outcomes of 1935 patients, of whom 805 underwent LDP and 1130 underwent ODP. Compared with open surgery, reports on laparoscopic resection indicate potentially favorable outcomes in terms of operative blood loss (WMD: -273.11; 95% CI: -404.61 to -141.61), the requirement of a blood transfusion (OR: 0.28; 95% CI: 0.11–0.71), postoperative time until oral intake (WMD: -1.19; 95% CI: -1.87 to -0.50), time to first flatus (WMD: -1.03, 95% CI: -1.93 to -0.12), length of hospital stay (WMD: -3.87, 95% CI: -5.06 to -2.68), and overall morbidity (OR: 0.70, 95% CI: 0.56–0.87). There were no differences in terms of the extent of oncologic clearance and postoperative mortality.ConclusionLDP results in a faster postoperative recovery and a comparable oncologic clearance in comparison with open surgery. Additional large trials are required to delineate the long-term clinical outcomes of patients diagnosed with malignant neoplasms who undergo either of these two surgeries

    (Amino­acetato-κ2 O,N)bis­(quinolin-8-olato-κ2 O,N)cobalt(III) methanol solvate

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    In the crystal structure of the title compound, [Co(C2H4NO2)(C9H6NO)2]·CH3OH, the CoIII atom is chelated by two quinolin-8-olate and one glycinate anions in a distorted octa­hedral coordination geometry. The five-membered chelating glycinate ring assumes an envelope conformation. The complex mol­ecules are assembled by inter­molecular N—H⋯O hydrogen bonding
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