Collapse simulation of a typical super-tall RC frame-core tube building exposed to extreme fire

The previous fire accidents proofed that reinforced concrete (RC) structures may experience progressive collapse subjected to extreme fires. In consequence, the study on the extreme fire-induced progressive collapse of RC structures is important for the safety of buildings. However, limited study has been performed on the extreme fire-induced progressive collapse of super-tall buildings. In this work, a finite element (FE) model and the corresponding elemental deactivation technology is proposed to simulate the extreme fire-induced progressive collapse of a typical super-tall RC frame-core tube building. The simulation discovered that the collapse of the building is initiated by the flexural failure of perimeter columns because of the thermal expansion of the floor system. The mechanism that discovered can provide a reference for related research of the fire safety of RC buildings

Single-photon-triggered quantum chaos

We demonstrate how to manipulate quantum chaos with a single photon in a hybrid quantum device combining cavity QED and optomechanics. Specifically, we show that this system changes between integrable and chaotic relying on the photon-state of the injected field. This onset of chaos originates from the photon-dependent chaotic threshold of the qubit-field coupling induced by the optomechanical interaction. By deriving the Loschmidt Echo we observe clear differences in the sensitivity to perturbations in the regular versus chaotic regimes. We also present classical analog of this chaotic behavior, and find good correspondence between chaotic quantum dynamics and classical physics. Our work opens up a new route to achieve quantum manipulations, which are crucial elements in engineering new types of on-chip quantum devices and quantum information science.Comment: 11 pages, 4 figure

Preimplantation Genetic Screening: An Effective Testing for Infertile and Repeated Miscarriage Patients?

Aneuploidy in pregnancy is known to increase with advanced maternal age (AMA) and associate with repeated implantation failure (RIF), and repeated miscarriage (RM). Preimplantation genetic screening (PGS) has been introduced into clinical practice, screening, and eliminating aneuploidy embryos, which can improve the chance of conceptions for infertility cases with poor prognosis. These patients are a good target group to assess the possible benefit of aneuploidy screening. Although practiced widely throughout the world, there still exist some doubts about the efficacy of this technique. Recent randomized trials were not as desirable as we expected, suggesting that PGS needs to be reconsidered. The aim of this review is to discuss the efficacy of PGS

Enhancing the hydrolysis of excess sludge using thermophilic Bacillus sp. Hnu under different oxygen supply conditions

A thermophilic Bacillus strain was isolated from excess sludge in the present study. The 16S rDNA analysis indicated that this strain was a Bacillus sp. and has not been reported previously (named Bacillus sp. Hnu). The aim of this paper was to investigate the enhanced efficiency of excess sludge hydrolysis by the addition of thermophilic Bacillus sp. Hnu under different oxygen supply conditions. The results indicated that higher temperature and more oxygen supply was advantageous to the volatile suspended solid removal ratio with the same effect to that of protease activity. The maximum volatile suspended solid removal ratio was achieved at 21.5 %, 42.5 %, and 54.4 % after 108 h digestion at pH 6.9 and 60°C and increased by 17.2 %, 38 %, and 45.4 % under anaerobic, microaerobic, and aerobic conditions compared with the control test, respectively. The hydrolysis rate constants for the anaerobic, microaerobic, and aerobic conditions were 3, 4.8, and 7 times (40°C) and 3.5, 9.8, and 11.8 times (50°C) and 2.7, 7.2, and 10.3 times (60°C). Hydrolysis performance indicated that the Bacillus sp. Hnu could accelerate the hydrolysis rate. The kinetic study showed that the hydrolysis of sludge with Bacillus sp. Hnu and the control test followed the first-order kinetics except at 60°C

8β-Acet­oxy-14α-benzo­yloxy-N-methyl-13β,15α-dihy­droxy-1α,6α,16β-trimeth­oxy-4β-(meth­oxy­meth­yl)aconitane: hypaconitine isolated from ‘fuzi’

The title compound, C33H45NO10, has an aconitine carbon skeleton with four six-membered rings and two five-membered rings. The five-membered rings adopt envelope configurations and the six-membered N-containing heterocyclic ring displays a chair conformation. Two intra­molecular O—H⋯O hydrogen bonds occur

DNMT3a in the hippocampal CA1 is crucial in the acquisition of morphine self‐administration in rats

Drug‐reinforced excessive operant responding is one fundamental feature of long-lasting addiction‐like behaviors and relapse in animals. However, the transcriptional regulatory mechanisms responsible for the persistent drug‐specific (not natural rewards) operant behavior are not entirely clear. In this study, we demonstrate a key role for one of the de novo DNA methyltransferase, DNMT3a, in the acquisition of morphine self‐administration (SA) in rats. The expression of DNMT3a in the hippocampal CA1 region but not in the nucleus accumbens shell was significantly up‐regulated after 1‐ and 7‐day morphine SA (0.3 mg/kg/infusion) but not after the yoked morphine injection. On the other hand, saccharin SA did not affect the expression of DNMT3a or DNMT3b. DNMT inhibitor 5‐aza‐2‐deoxycytidine (5‐aza) microinjected into the hippocampal CA1 significantly attenuated the acquisition of morphine SA. Knockdown of DNMT3a also impaired the ability to acquire the morphine SA. Overall, these findings suggest that DNMT3a in the hippocampus plays an important role in the acquisition of morphine SA and may be a valid target to prevent the development of morphine addiction. Includes Supplemental informatio

(25R)-5a-Spiro­stane-3,12-dione

The title compound, C27H40O4, was obtained from the oxidation of (25R)-3b-hydr­oxy-5a-spiro­stan-12-one (Hecogenin) by Jone’s reagent. The mol­ecule contains six alicyclic and heterocyclic rings, all trans-fused, among which four six-membered rings adopt similar chair conformations while two five-membered rings assume an envelope conformation