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We present an interesting relationship between the orthogonality catastrophe (OC) and the quantum speed limit (QSL) for a spin chain with uniform nearest neighbour couplings perturbed by an impurity spin. We thoroughly study the catastrophic QSL that specifies a bound on the evolution time between the initial and final states and in this respect, link it to the emerging OC effect. It is found that the speed of state evolution subtle but fundamental, and the bound characterized by QSL shows the same behaviours as the OC effect in the thermodynamic limit. It allows us to reveal some universal properties, in particular finite temperature effects. Significantly, the threshold of temperature and system size is clearly demonstrated for the QSL under finite temperature.

The orthogonality catastrophe (OC) of quantum many-body systems is an important phenomenon in condensed matter physics. Recently, an interesting relationship between the OC and the quantum speed limit (QSL) was shown (Fogarty 2020 Phys. Rev. Lett. 124 110601). Inspired by the remarkable feature, we provide a quantitative version of the quantum average speed as another different method to investigate the measure of how it is close to the OC dynamics. We analyze the properties of an impurity qubit embedded into an isotropic Lipkin-Meshkov-Glick spin model, and show that the OC dynamics can also be characterized by the average speed of the evolution state. Furthermore, a similar behavior of the actual speed of quantum evolution and the theoretical maximal rate is shown which can provide an alternative speed-up protocol allowing us to understand some universal properties characterized by the QSL.

Objective: Percutaneous transluminal balloon angioplasty (PTA) is recommended as the first choice to treat stenosis of Brescia-Cimino arteriovenous fistulas (B-C AVFs). The ability to predict which B-C AVFs are at risk for recurrent stenosis post-PTA would allow closer monitoring of patients, and possibly result in surgical intervention rather than repeat PTA. The purpose of this study was to identify predictive factors of primary patency after PTA in B-C AVFs. Methods: Patients diagnosed with B-C AVF primary stenosis and treated by PTA between November 2013 and March 2018 were included in the study. Patient and stenotic lesion characteristics and PTA procedure factors were included in the analysis. The Kaplan–Meier method was used to analyze the primary patency rate. Cox proportional hazard regression analysis was used to identify factors predictive of decreased primary patency. Results: 74 patients (35 males, 39 females) with a mean age of 61.68 ± 11.44 years (range, 36–84 years) were included in the study. The mean B-C AVF age was 16.34 ± 12.93 months (range, 2–84 months), and the median primary patency time was 7.79 ± 0.48 months. Cox proportional hazard regression analysis revealed stenosis location at the inflow artery [hazard ratio (HR)=3.83, 95% confidence interval (CI): 1.46–10.09] or anastomosis (HR = 1.90, 95% CI: 1.09–3.32), dilation >2 times during PTA (HR = 2.30, 95% CI: 1.22–4.34), and residual stenosis >30% (HR = 2.42, 95% CI: 1.26–4.63) were significantly associated with decreased patency. Conclusion: In conclusion, the primary patency rate of PTA for B-C AVF dysfunction is reduced by dilation >2 times, residual stenosis >30%, and stenosis located at the inflow artery or anastomosis. These results may help in tailoring surveillance programs, multiple PTA, or a proximal re-anastomosis surgery in patients with AVF dysfunction. Advances in knowledge: A number of studies have been conducted to examine the predictors of primary patency after PTA, however, no definitive conclusions have been reached. Our study revealed that stenosis location at the inflow artery or anastomosis, dilation >2 times during PTA, and residual stenosis >30% were the predictors of primary patency after PTA, which may help in tailoring surveillance programs, multiple PTA, or a proximal re-anastomosis surgery in patients with arteriovenous fistulas dysfunction.

This paper presents the experimental and numerical results of the ultimate bearing capacity of partially overlapped tubular N-joints, which have circular hollow section (CHS) brace members welded to a square hollow section (SHS) chord member. Two partially overlapped N-joints were tested to failure under overlapping brace axial loading and chord axial loading. The failure mode of specimen N1 was the overlapping brace local bucking, and the failure mode of specimen N2 was the chord face plastification with chord side wall buckling. Meanwhile, weld fracture occurred on both specimens. Then, making use of finite element package program ANSYS, in which twenty nodes solid element was employed and the weld was simulated, elastic-plastic large deflection finite element analysis of the experimental joints was conducted. The experimental data were compared with the results acquired by finite element analysis and it was proved that ANSYS is feasible to simulate the connecting weld and analyze the static behavior of partially overlapped CHS-to-SHS welded N-joints.

The asymmetric unit of the title compound, C(22)H(16)ClN(3)O(5), consists of two crystallographically independent mol-ecules. The fused rings of the imidazo[1,2-a]benzo[4,5]furo[3,2-d]pyrimidine system are nearly coplanar and the chlorophenyl rings are twisted with respect to the two pyrimidinone ring systems by 71.00 (2) and 62.59 (2)°. The C atoms of the ethyl side chain are disordered and were refined using a split model. In the crystal structure, the mol-ecules are connected via weak intra- and inter-molecular C-H⋯O inter-actions are present. The ethyl group in one molecule is disordered over two positions, with site occupancy factors 0.55 and 0.45; in the other molecule only the methyl group is disordered over two positions, with site occupancy factors 0.6 and 0.4.

In the molecule of the title compound, C22H22ClN3O2, the three fused rings of the benzofuro[3,2-d]pyrimidine system are almost coplanar. This ring system is oriented with respect to the substituted benzene ring at a dihedral angle of 79.05 (3)°. Intramolecular C—H...N hydrogen bonding results in the formation of a six-membered ring. In the crystal structure, π–π stacking interactions involving the furan, pyrimidinone and benzene rings are present [centroid-to-centroid distances in the range 3.258 (1)–3.870 (1) Å].