Normal modes and time evolution of a holographic superconductor after a quantum quench

We employ holographic techniques to investigate the dynamics of the order parameter of a strongly coupled superconductor after a perturbation that drives the system out of equilibrium. The gravity dual that we employ is the ${\rm AdS}_5$ Soliton background at zero temperature. We first analyze the normal modes associated to the superconducting order parameter which are purely real since the background has no horizon. We then study the full time evolution of the order parameter after a quench. For sufficiently a weak and slow perturbation we show that the order parameter undergoes simple undamped oscillations in time with a frequency that agrees with the lowest normal model computed previously. This is expected as the soliton background has no horizon and therefore, at least in the probe and large $N$ limits considered, the system will never return to equilibrium. For stronger and more abrupt perturbations higher normal modes are excited and the pattern of oscillations becomes increasingly intricate. We identify a range of parameters for which the time evolution of the order parameter become quasi chaotic. The details of the chaotic evolution depend on the type of perturbation used. Therefore it is plausible to expect that it is possible to engineer a perturbation that leads to the almost complete destruction of the oscillating pattern and consequently to quasi equilibration induced by superposition of modes with different frequencies.Comment: 10 pages, 7 figures, corrected typos, expanded section on chaotic oscillations and new results for other quenc

Conformational Dynamics of Insulin

We have exploited a prandial insulin analog to elucidate the underlying structure and dynamics of insulin as a monomer in solution. A model was provided by insulin lispro (the active component of Humalog®; Eli Lilly and Co.). Whereas NMR-based modeling recapitulated structural relationships of insulin crystals (T-state protomers), dynamic anomalies were revealed by amide-proton exchange kinetics in D2O. Surprisingly, the majority of hydrogen bonds observed in crystal structures are only transiently maintained in solution, including key T-state-specific inter-chain contacts. Long-lived hydrogen bonds (as defined by global exchange kinetics) exist only at a subset of four α-helical sites (two per chain) flanking an internal disulfide bridge (cystine A20–B19); these sites map within the proposed folding nucleus of proinsulin. The anomalous flexibility of insulin otherwise spans its active surface and may facilitate receptor binding. Because conformational fluctuations promote the degradation of pharmaceutical formulations, we envisage that “dynamic re-engineering” of insulin may enable design of ultra-stable formulations for humanitarian use in the developing world

Analysis and Discussion on the Formula of Classical Monitoring Method for Chemical Oxygen Demand (CODCr)

In this paper, the calculation formula of the classical monitoring method of COD (CODCr) is deducted and analyzed in detail by analyzing the calculation formula of the method for the classical monitoring of CODCr, and the difficult points of the CODCr, calculation formula is discussed, and the general doubts about the existence of this formula are solved in the environment monitoring industry. Keywords: chemical oxygen demand; Formula of calculation; Parsing; misgiving

Developing a novel rabbit model of atherosclerotic plaque rupture and thrombosis by cold-induced endothelial injury

<p>Abstract</p> <p>Background</p> <p>It is widely believed that atherosclerotic plaque rupture and subsequent thrombosis leads to acute coronary events and stroke. However, study of the mechanism and treatment of human plaque rupture is hampered by lack of a suitable animal model. Our aim was to develop a novel animal model of atherosclerotic plaque rupture to facilitate the study of human plaque disruption and thrombosis.</p> <p>Methods</p> <p>28 healthy male New Zealand white rabbits were randomly divided into two groups: rabbits in group A (n = 12) were only fed a high-fat diet for eight weeks; rabbits in group B (n = 16) underwent cold-induced endothelial injury with liquid nitrogen, then were given a high-fat diet for eight weeks. After completion of the preparatory regimen, triggering of plaque rupture was attempted by local injection of liquid nitrogen in both groups.</p> <p>Results</p> <p>All rabbits in group B had disrupted plaques or rupture-driven occlusive thrombus formation, but none in group A showed any effects. More importantly, the cold-induced plaques in our model were reminiscent of human atherosclerotic plaques in terms of architecture, cellular composition, growth characteristics, and patterns of lipid accumulation.</p> <p>Conclusion</p> <p>We successfully developed a novel rabbit model of atherosclerotic plaque rupture and thrombosis, which is simple, fast, inexpensive, and reproducible, and has a low mortality and a high yield of triggering. This model will allow us to better understand the mechanism of human plaque rupture and also to develop plaque-stabilizing therapies.</p

Photoplethysmographic imaging and analysis of pulsatile pressure wave in palmar artery at 10 wavelengths

CC BY: © The Authors. Published by SPIE under a Creative Commons Attribution 4.0 International License. Distribution or reproduction of this work in whole or in part requires full attribution of the original publication, including its DOI.Significance As a noncontact method, imaging photoplethysmography (iPPG) may provide a powerful tool to measure pulsatile pressure wave (PPW) in superficial arteries and extract biomarkers for monitoring of artery wall stiffness. Aim We intend to develop a approach for extraction of the very weak cardiac component from iPPG data by identifying locations of strong PPW signals with optimized illumination wavelength and determining pulse wave velocity (PWV). Approach Monochromatic in vivo iPPG datasets have been acquired from left hands to investigate various algorithms for retrieval of PPW signals, distribution maps and waveforms, and their dependence on arterial location and wavelength. Results A robust algorithm of pixelated independent component analysis (pICA) has been developed and combined with spatiotemporal filtering to retrieve PPW signals. Spatial distributions of PPW signals have been mapped in 10 wavelength bands from 445 to 940 nm and waveforms were analyzed at multiple locations near the palmar artery tree. At the wavelength of 850 nm selected for timing analysis, we determined PWV values from 12 healthy volunteers in a range of 0.5 to 5.8 m/s across the hand region from wrist to midpalm and fingertip.ECU Open Access Publishing Support Fun

Exploration of Training Mode of Applied Talents in Environmental Engineering Specialty

According to the characteristics of environmental engineering in universities, combined with the characteristics of social requirements, a new type of environmental engineering specialty curriculum system is constructed. The curriculum system agrees with the position of running a school and aims of personnel training in the application- oriented universities, providing practical and suitable way to cultivate high- level application- oriented talents for the market and production. Keywords:Application teaching, Environmental engineering specialty, curriculum syste

Clinical study of intraocular pressure and retinal thickness affected by residual triamcinolone acetonide after vitrectomy

AIM: To study the effect of residual triamcinolone acetonide(TA)to intraocular pressure(IOP)and retinal thickness in patients after vitrectomy. METHODS: Retrospective study. The medical data of 83 patients(83 eyes)after vitrectomy in our hospital from October 2016 to October 2017 were analyzed retrospectively. The 83 patients were treated with TA as vitreous dyeing. Vitreous cavity was not filled with silicone oil or gas. Totally 32 eyes were observed that triamcinolone acetonide was residual in vitreous cavity, 51 eyes were not observed the residual, and after 1wk and 3mo, intraocular pressure and macular center concave thickness(CMT)of two groups was compared. RESULTS: There was no statistical difference in preoperative average intraocular pressure between two groups(t=0.56, P>0.05). After 1wk, IOP of no residual group was 15.48±3.8mmhg, IOP of residual Group was 20.09±6.14mmhg. IOP of residual group were higher than IOP of no residual group, the difference was statistically significant(t=3.81,Pt=4.54, Pt=3.75,Pt=0.21, P>0.05). CONCLUSION: The residual triamcinolone acetonide as a dyeing agent during vitrectomy may raise the risk of postoperative intraocular pressure in short term, and after 3mo without any significant effect on the thickness of macular center