(E,E)-2,5-Bis(5-chloro-2-methoxyphenyl)-3,4-diazahexa-2,4-diene

The title compound, C18H18Cl2N2O2, was synthesized by the reaction of 1-(5-chloro-2-methoxy­phen­yl)ethanone with hydrazine hydrate. The mol­ecule lies on a crystallographic twofold axis passing through the mid-point of the N—N bond with one half-mol­ecule in the asymmetric unit. The dihedral angle between the two aromatic rings is 44.33 (4)°. In the crystal, inter­molecular C—H⋯O inter­actions link the mol­ecules into columns along the c axi

A retrospective study evaluating the correlation between the severity of intervertebral disc injury and the anteroposterior type of thoracolumbar vertebral fractures

OBJECTIVE: To evaluate the correlation between the severity of intervertebral disc injury and the anteroposterior type of thoracolumbar vertebral fractures. METHODS: Fifty-six cases of thoracolumbar vertebral fractures treated in our trauma center from October 2012 to October 2013 were included in this study. The fractures were classified by the anteroposterior classification, whereas the severity of intervertebral disc injury was evaluated using magnetic resonance imaging. The Spearman correlation coefficient was used to analyze the correlation between the severity of intervertebral disc injury and the anteroposterior type of thoracolumbar fractures, whereas a χ2 test was adopted to measure the variability between different fracture types and upper and lower adjacent disc injuries. RESULTS: The Spearman correlation coefficients between fracture types and the severity of the upper and lower adjacent disc injuries were 0.739 (P

Arena: Multi-leader Synchronous Byzantine Fault Tolerance

Byzantine fault-tolerant state machine replication (BFT-SMR) replicates a state machine across a set of replicas, and processes requests as a single machine even in the presence of Byzantine faults. Recently, synchronous BFT-SMRs have received tremendous attention due to their simple design and high fault-tolerance threshold. In this paper, we propose Arena, the first multi-leader synchronous BFT-SMR. Thanks to the synchrony assumption, Arena gains the performance benefit from multi-leader with a much simpler design (compared to other partially synchronous multi-leader designs). Furthermore, it is more robust: ``no progress\u27\u27 of a leader will not trigger a view-change. Our experimental results show that Arena achieves a peak throughput of up to 7.7$\times$ higher than the state-of-the-art

Aurora: Leaderless State-Machine Replication with High Throughput

State-machine replication (SMR) allows a state machine to be replicated across a set of replicas and handle clients\u27 requests as a single machine. Most existing SMR protocols are leader-based, i.e., requiring a leader to order requests and coordinate the protocol. This design places a disproportionately high load on the leader, inevitably impairing the scalability. If the leader fails, a complex and bug-prone fail-over protocol is needed to switch to a new leader. An adversary can also exploit the fail-over protocol to slow down the protocol. In this paper, we propose a crash-fault tolerant SMR named Aurora, with the following properties: • Leaderless: it does not require a leader, hence completely get rid of the fail-over protocol. • Scalable: it can scale to a large number of replicas. • Robust: it behaves well even under a poor network connection. We provide a full-fledged implementation of Aurora and systematically evaluate its performance. Our benchmark results show that Aurora achieves a peak throughput of around two million TPS, up to 8.7$\times$ higher than the state-of-the-art leaderless SMR

N′-[(1E)-1-(5-Chloro-2-hydroxy­phen­yl)propyl­idene]-4-methoxy­benzohydrazide

The title compound, C17H17ClN2O3, has a trans conformation about the C=N double bond and an intra­molecular O—H⋯N occurs. The crystal structure is stabilized by inter­molecular N—H⋯O hydrogen bonds

Stratosphere-troposphere coupling during stratospheric extremes in the 2022/23 winter

Using the ERA5 reanalysis, sea surface temperature, sea ice observations, and the real-time multivariate Madden-Julian Oscillation (MJO) index, the evolution of the stratospheric extreme circulation in the winter of 2022/2023 is explored. The stratospheric polar vortex was disturbed three times in the 2022/23 winter, contrasted with only one disturbance during the other three recent winters with an SSW. Possible favorable conditions for the strong stratospheric disturbances and their effects on stratospheric ozone, water vapor distribution, and near-surface temperature were examined. Around 7 December 2022 when a short but strong pulse of planetary wavenumber 2 appeared from the troposphere to stratosphere, a weakened and elongated stratospheric polar vortex formed at 10 hPa. This pulse is related to the intensifying Ural ridge and the deepening East Asian trough. After the first stratospheric disturbance, a large fraction of cold anomalies occurred in the Eurasian continent. A lagged impact after these stratospheric disturbances was observed as strong cold anomalies formed in North America from 13 to 23 December. On 28 January 2023, a minor SSW event occurred due to a displacement of the stratospheric polar vortex. A strong pulse of eddy heat flux contributed alternately by planetary wavenumber 1 and 2 showed a large accumulative effect on the stratospheric disturbance. However, the downward impact of this second disturbance was weak, and cold surges were not noticeable after this minor SSW. The third stratospheric disturbance this winter is a major displace-type SSW that occurred on 16 February 2023, and the total eddy heat flux primarily contributed by planetary wavenumber 1 increased rapidly. Following the major SSW, the North American continent was covered by large patches of strong cold anomalies until the end of March. During the three disturbances, the residual circulation correspondingly strengthened. The water vapor and ozone in the middle and lower layers of the polar stratosphere showed positive anomaly disturbances, especially after the major SSW onset. The unprecedented frequent stratospheric disturbances in winter 2022/23 were accompanied by severe loss of Barents-Laptev Sea ice and anomalously cold tropical Pacific sea surface temperatures (La Niña), which have been reported to be conducive to the enhancement of planetary waves 1 and 2 respectively. Further, two weeks before the major SSW, existing MJO developed into phases 4–6, also contributing to the occurrence of major SSW