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Abstract Background Mycobacterium obuense (M. obuense) is a rapidly growing mycobacterium (RGM) which has been considered nonpathogenic. Here, we report a case of disseminated non-tuberculous mycobacterial (NTM) infection caused by M. obuense in an immunocompromised patient. Case presentation A 16-year-old boy was referred to our hospital due to acute myeloid leukemia. During the treatment of leukemia, the patient exhibited continuous fever, and diffuse miliary nodules with random distribution were found on chest computed tomography. Repeated examinations of bacterial culture tests revealed sputum and urine samples to be smear-positive for acid-fast bacillus, and blood culture from a peripherally inserted central catheter line showed the growth of NTM. The NTM species was identified as M. obuense by mass spectrometry and confirmed by genome sequencing. Combination therapy with amikacin, rifampicin, azithromycin, and moxifloxacin significantly improved the patient’s symptoms and radiological findings. Conclusion We report a case of disseminated NTM infection caused by M. obuense for which combination anti-microbial therapy was effective. An immunocompromised host indwelling catheter is at risk of RGM bloodstream infections. Although relatively rare, M. obuense may be considered as a potential pathogen causing infectious diseases, especially in high-risk patients.

Abstract Background Nivolumab, an immune checkpoint inhibitor (ICI), has changed the treatment paradigm for advanced non‐small cell lung cancer (NSCLC). However, factors associated with long‐term survival in NSCLC patients treated with ICIs remain unknown. This study aimed to evaluate patient characteristics and clinical laboratory changes related to long‐term survival in NSCLC patients treated with nivolumab, using real‐world data. Methods We retrospectively reviewed the medical records of consecutive patients with advanced NSCLC with Eastern Cooperative Oncology Group performance status (ECOG‐PS) ≤1 treated with nivolumab. We defined patients with overall survival (OS) ≥3 years as long‐term survivors. We evaluated the differences in patient characteristics and tumor response between nonlong‐term survivors and long‐term survivors and performed univariate and multivariate analyses of factors associated with long‐term survival. Results Out of 213 patients with advanced NSCLC treated with nivolumab, 162 patients with ECOG‐PS ≤1 were included in the study. Young age, ECOG‐PS 0, absolute neutrophil count decrease, lymphocyte percentage increase, and neutrophil‐to‐lymphocyte ratio (NLR) change (ΔNLR)

In this study, we propose a method for predicting the occurrence of brittle fractures in the beam-to-column joints of steel structures, considering different crack opening modes. We conducted experiments on beam-to-diaphragm joint specimens with varying plastically constrained cracks to reproduce brittle fractures. The experiments’ results demonstrated the effectiveness of the toughness scale model and the Weibull stress approach. In addition, we propose the mixed-mode ratio, which is a quantitative index of the mode difference, and we applied it to the finite element models of the specimens. In this study, we evaluate the validity of the mixed-mode ratio and explore the differences in crack opening modes, as they pertain to the occurrence of brittle fractures.

Abstract Quantum key distribution (QKD) offers a reliable solution to communication problems that require long-term data security. For its widespread use, however, the rate and reach of QKD systems must be improved. Twin-field (TF) QKD is a step forward toward this direction, with early demonstrations suggesting it can beat the current rate-versus-distance records. A recently introduced variant of TF-QKD is particularly suited for experimental implementation, and has been shown to offer a higher key rate than other variants in the asymptotic regime, where users exchange an infinite number of signals. Here, we extend the security of this protocol to the finite-key regime, showing that it can overcome the fundamental bounds on point-to-point QKD with ~1010 transmitted signals. In many practical regimes of interest, our analysis offers higher key rates than those of alternative variants. Moreover, some of the techniques we develop are applicable to the finite-key analysis of other QKD protocols.

Storage-free quantum repeaters represent a viable alternative to quantum-memory-based ones. Here, the authors propose a modified scheme for Bell state measurements which reduces the necessary resources for realising such an all-photonic repeater, and show a proof-of-principle implementation.

In this paper, the shear strength of circular reinforced concrete (RC) columns was obtained using numerical models based on a modified compression field theory that enabled the sectional analysis of the beams. By comparing the computational results with previous experimental results, we were able to assess the suitability of this numerical model for estimating the shear strength of circular RC columns. Additionally, the validity range of the shear strengths was evaluated by substituting rectangular column sections for circular column sections. The relationship between the shear strength of the circular RC columns and the shear span-depth ratio were also discussed. On a final note, we examined by calculating the shear strength of the numerical models by using equations to estimate the concrete strength of confined concrete.

In a future quantum internet, entanglement or a secret key should be efficiently provided between two points via intermediate nodes connected by optical channels. Here the authors derive general rate-loss trade-off for such protocols, that is applicable to any network topology.

Surpassing the repeaterless bound is a crucial task on the way towards realizing long-distance quantum key distribution. In this paper, we focus on the protocol proposed by Azuma et al (2015 Nat. Commun. 6 10171), which can beat this bound with idealized devices. We investigate the robustness of this protocol against imperfections in realistic setups, particularly the multiple-photon pair components emitted by practical entanglement sources. In doing so, we derive necessary conditions on the photon-number statistics of the sources in order to beat the repeaterless bound. We show, for instance, that parametric down-conversion sources do not satisfy the required conditions and thus cannot be used to outperform this bound.

We provide a versatile upper bound on the number of maximally entangled qubits, or private bits, shared by two parties via a generic adaptive communication protocol over a quantum network when the use of classical communication is not restricted. Although our result follows the idea of Azuma et al (2016 Nat. Commun. 7 13523) of splitting the network into two parts, our approach relaxes their strong restriction, consisting of the use of a single entanglement measure in the quantification of the maximum amount of entanglement generated by the channels. In particular, in our bound the measure can be chosen on a channel-by-channel basis, in order to make it as tight as possible. This enables us to apply the relative entropy of entanglement, which often gives a state-of-the-art upper bound, on every Choi-simulable channel in the network, even when the other channels do not satisfy this property. We also develop tools to compute, or bound, the max-relative entropy of entanglement for channels that are invariant under phase rotations. In particular, we present an analytical formula for the max-relative entropy of entanglement of the qubit amplitude damping channel.

Quantum mechanics emerged a century ago. It abandoned the deterministic worldview that underlies classical mechanics for a more general theoretical system. It is now believed that everything should be described by quantum mechanics. Furthermore, in our efforts to rethink the theoretical system for information processing based on the classical worldview within the framework of quantum mechanics, it has become clear that even information processing tasks that were previously considered intractable can now be performed within the framework of quantum mechanics. For this issue, we interviewed NTT Distinguished Researcher Koji Azuma, a leader in the field of quantum network research at NTT, about his current research and his mindset as a researcher. [ABSTRACT FROM AUTHOR]

A quantum internet holds promise for accomplishing quantum metrology and quantum computer networks as well as quantum communication among arbitrary clients all over the globe. Its actualization is an important long-term scientific and technological goal. In this article, I explain what a quantum internet is and what is needed for its actualization as well as recent relevant progress in the field of quantum information. [ABSTRACT FROM AUTHOR]

OBJECTIVE: This study evaluated the relationship between end-tidal carbon dioxide (EtCO2) measured with a portable capnometer and PaCO2 in respiratory disease patients. MATERIAL AND METHODS: We retrospectively reviewed patients whose EtCO2, measured with a portable capnometer using a mouth- piece, and PaCO2 were simultaneously assessed at a single center from August 2017 to September 2018. The primary outcome was the relationship between EtCO2 and PaCO2. We conducted subgroup analyses in patients with interstitial lung disease (ILD), with and without O2 supplementation. The relationship between EtCO2 and PaCO2 was analyzed using Spearman's rank test and Bland--Altman analysis. RESULTS: A total of 100 patients were registered in this study. There was a moderate correlation between EtCO2 and PaCO2 (rho = 0.41). The Bland--Altman plot showed that the mean bias was 0.32 mmHg (95% CI: -1.28 to 1.92), the limits of agreement (LOA) were -15.48 and 16.13 mmHg, and the percent error was 38.49%. The LOA in patients with ILD were -15.12 and 13.75 mmHg. In patients with O2 supplementation, the mean bias was greater, and the LOA were wider than in those without O2 supplementation (mean bias: 7.17 vs. -1.18 mmHg, respectively; LOA: -14.29 and 28.62 mmHg vs. -13.82 and 11.46 mmHg, respectively). CONCLUSION: In the clinical setting, the relationship between EtCO2 and PaCO2 was poor in patients with respiratory disease, espe- cially in those receiving O2 supplementation, compared with that reported in previous studies. It may be difficult to precisely estimate PaCO2 in patients with respiratory disease based on measurements of EtCO2. [ABSTRACT FROM AUTHOR]

Quantum networks will enable the implementation of communication tasks with qualitative advantages with respect to the communication networks known today. While it is expected that the first demonstrations of small scale quantum networks will take place in the near term, many challenges remain to scale them. To compare different solutions, optimize over parameter space, and inform experiments, it is necessary to evaluate the performance of concrete quantum network scenarios. Here, the authors review the state-of-the-art of tools for evaluating the performance of quantum networks. The authors present them from three different angles: information-theoretic benchmarks, analytical tools, and simulation. [ABSTRACT FROM AUTHOR]

We present an uncertainty-relation-type quantum benchmark for continuous-variable (CV) quantum channels that works with an input ensemble of Gaussian-distributed coherent states and homodyne measurements. It determines an optimal trade-off relation between canonical quadrature noises that is unbeatable by entanglement breaking channels and refines the notion of two quantum duties introduced in the original papers of CV quantum teleportation. This benchmark can verify the quantum-domain performance for all one-mode Gaussian channels. We also address the case of stochastic channels and the effect of asymmetric gains. [ABSTRACT FROM AUTHOR]