Stationary states and quantum quench dynamics of Bose-Einstein condensates in a double-well potential

We consider the properties of stationary states and the dynamics of Bose-Einstein condensates (BECs) in a double-well (DW) potential with pair tunneling by using a full quantum-mechanical treatment. Furthermore, we study the quantum quench dynamics of the DW system subjected to a sudden change of the Peierls phase. It is shown that strong pair tunneling evidently influences the energy spectrum structure of the stationary states. For relatively weak repulsive interatomic interactions, the dynamics of the DW system with a maximal initial population difference evolves from Josephson oscillations to quantum self-trapping as one increases the pair tunneling strength, while for large repulsion the strong pair tunneling inhibits the quantum self-trapping. In the case of attractive interatomic interactions, strong pair tunneling tends to destroy the Josephson oscillations and quantum self-trapping, and the system eventually enters a symmetric regime of zero population difference. Finally, the effect of the Peierls phase on the quantum quench dynamics of the system is analyzed and discussed. These new features are remarkably different from the usual dynamical behaviors of a BEC in a DW potential.Comment: 9 pages,7 figures,accepted for publication in Journal of Physics

Dynamics of cold pulses induced by super-sonic molecular beam injection in the EAST tokamak

Evolution of electron temperature, electron density and its fluctuation with high spatial and temporal resolutions are presented for the cold pulse propagation induced by super-sonic molecular beam injection (SMBI) in ohmic plasmas in the EAST tokamak. The non-local heat transport occurs for discharges with plasma current $I_p$=450 kA ($q_{95}\sim5.55$), and electron density $n_{e0}$ below a critical value of $(1.35\pm0.25)\times10^{19}~\mathrm{m^{-3}}$. In contrary to the response of core electron temperature and electron density (roughly 10 ms after SMBI), the electron density fluctuation in the plasma core increases promptly after SMBI and reaches its maximum around 15 ms after SMBI. The electron density fluctuation in the plasma core begins to decrease before the core electron temperature reaches its maximum (roughly 30 ms). It was also observed that the turbulence perpendicular velocity close to the inversion point of the temperature perturbation changes sign after SMBI

Validation of internal control for gene expression study in soybean by quantitative real-time PCR

<p>Abstract</p> <p>Background</p> <p>Normalizing to housekeeping gene (HKG) can make results from quantitative real-time PCR (qRT-PCR) more reliable. Recent studies have shown that no single HKG is universal for all experiments. Thus, a suitable HKG should be selected before its use. Only a few studies on HKGs have been done in plants, and none in soybean, an economically important crop. Therefore, the present study was conducted to identify suitable HKG(s) for normalization of gene expression in soybean.</p> <p>Results</p> <p>All ten HKGs displayed a wide range of Ct values in 21 sample pools, confirming that they were variably expressed. GeNorm was used to determine the expression stability of the HGKs in seven series sets. For all the sample pools analyzed, the stability rank was <it>ELF1B</it>, <it>CYP2 </it>> <it>ACT11 </it>> <it>TUA </it>> <it>ELF1A </it>> <it>UBC2 </it>> <it>ACT2/7 </it>> <it>TUB </it>> <it>G6PD </it>> <it>UBQ10</it>. For different tissues under the same developmental stage, the rank was <it>ELF1B</it>, <it>CYP2 </it>> <it>ACT2/7 </it>> <it>UBC2 </it>> <it>TUA </it>> <it>ELF1A </it>> <it>ACT11 </it>> <it>TUB </it>> <it>G6PD </it>> <it>UBQ10</it>. For the developmental stage series, the stability rank was <it>ACT2/7</it>, <it>TUA </it>> <it>ELF1A </it>> <it>UBC2 </it>> <it>ELF1B </it>> <it>TUB </it>> <it>CYP2 </it>> <it>ACT11 </it>> <it>G6PD </it>> <it>UBQ10</it>. For photoperiodic treatments, the rank was <it>ACT11</it>, <it>ELF1B </it>> <it>CYP2 </it>> <it>TUA </it>> <it>ELF1A </it>> <it>UBC2 </it>> <it>ACT2/7 </it>> <it>TUB </it>> <it>G6PD </it>> <it>UBQ10</it>. For different times of the day, the rank was <it>ELF1A</it>, <it>TUA </it>> <it>ELF1B </it>> <it>G6PD </it>> <it>CYP2 </it>> <it>ACT11 </it>> <it>ACT2/7 </it>> <it>TUB </it>> <it>UBC2 </it>> <it>UBQ10</it>. For different cultivars and leaves on different nodes of the main stem, the ten HKGs' stability did not differ significantly. ΔCt approach and 'Stability index' were also used to analyze the expression stability in all 21 sample pools. Results from ΔCt approach and geNorm indicated that <it>ELF1B </it>and <it>CYP2 </it>were the most stable HKGs, and <it>UBQ10 </it>and <it>G6PD </it>the most variable ones. Results from 'Stability index' analysis were different, with <it>ACT11 </it>and <it>CYP2 </it>being the most stable HKGs, and <it>ELF1A </it>and <it>TUA </it>the most variable ones.</p> <p>Conclusion</p> <p>Our data suggests that HKGs are expressed variably in soybean. Based on the results from geNorm and ΔCt analysis, <it>ELF1B </it>and <it>CYP2 </it>could be used as internal controls to normalize gene expression in soybean, while <it>UBQ10 </it>and <it>G6PD </it>should be avoided. To achieve accurate results, some conditions may require more than one HKG to be used for normalization.</p

Recurrence of odontogenic keratocysts and possible prognostic factors : review of 455 patients

To describe epidemiological features of 565 Chinese patients with odontogenic keratocysts (OKC), to investigate possible prognostic factors related to recurrence, and to analyse features of recurrent OKC (rOKC). A retrospective chart review of 565 cases of OKC treated between 2003 and 2015 was undertaken. The probability of recurrence related to prognostic factors including large size, cortical perforation combined with involved teeth in the lumen of the cyst, inflammation, sites of the involved lesion, sex, and daughter cyst variables were analysed. The subsequent relapse of each OKC was compared. Patients ranged in age from 7 to 81 years (mean age, 28.4 years) and, of those affected, 66.9% were male and 33.1% were female. Mandibular OKC occurred in 63.01% and 36.99% occurred in the maxilla, 80.53% of patients had non-rOKC, 10.44% rOKC, and 9.03% had multiple OKC lesions. Enucleation with preservation of the involved teeth in the cystic lesion combined with cortical perforation was statistically associated with high recurrence rate, as were daughter cysts, and multilocular lesions. The number of recurrences and the average time (in years) to relapse decreased from the first relapse of OKC to the third relapse, and the difference was significant (P<.05). Preservation of the involved teeth combined with cortical perforation appeared to be a potential prognostic factor associated with high recurrence. The follow-up evaluation period for rOKC with ? 2 previous treatments should be shorter than for first-time rOKC. The decreasing average duration (years postoperatively) to relapse was related to the number of rOKCs, timing of relapse, and rOKC type

Agrobacterium rhizogenes-mediated transformation of Superroot-derived Lotus corniculatus plants: a valuable tool for functional genomics

<p>Abstract</p> <p>Background</p> <p>Transgenic approaches provide a powerful tool for gene function investigations in plants. However, some legumes are still recalcitrant to current transformation technologies, limiting the extent to which functional genomic studies can be performed on. <it>Superroo</it>t of <it>Lotus corniculatus </it>is a continuous root cloning system allowing direct somatic embryogenesis and mass regeneration of plants. Recently, a technique to obtain transgenic <it>L. corniculatus </it>plants from <it>Superroot</it>-derived leaves through <it>A. tumefaciens-</it>mediated transformation was described. However, transformation efficiency was low and it took about six months from gene transfer to PCR identification.</p> <p>Results</p> <p>In the present study, we developed an <it>A. rhizogenes</it>-mediated transformation of <it>Superroot</it>-derived <it>L. corniculatus </it>for gene function investigation, combining the efficient <it>A. rhizogenes</it>-mediated transformation and the rapid regeneration system of <it>Superroot</it>. The transformation system using <it>A. rhizogenes </it>K599 harbouring pGFPGUS<it>Plus </it>was improved by validating some parameters which may influence the transformation frequency. Using stem sections with one node as explants, a 2-day pre-culture of explants, infection with K599 at OD₆₀₀= 0.6, and co-cultivation on medium (pH 5.4) at 22°C for 2 days enhanced the transformation frequency significantly. As proof of concept, <it>Superroot</it>-derived <it>L. corniculatus </it>was transformed with a gene from wheat encoding an Na⁺/H⁺antiporter (<it>TaNHX2</it>) using the described system. Transgenic <it>Superroot </it>plants were obtained and had increased salt tolerance, as expected from the expression of <it>TaNHX2</it>.</p> <p>Conclusion</p> <p>A rapid and efficient tool for gene function investigation in <it>L. corniculatus </it>was developed, combining the simplicity and high efficiency of the <it>Superroot </it>regeneration system and the availability of <it>A. rhizogenes</it>-mediated transformation. This system was improved by validating some parameters influencing the transformation frequency, which could reach 92% based on GUS detection. The combination of the highly efficient transformation and the regeneration system of <it>Superroot </it>provides a valuable tool for functional genomics studies in <it>L. corniculatus</it>.</p

Salmonella produce microRNA-like RNA fragment Sal-1 in the infected cells to facilitate intracellular survival.

Salmonella have developed a sophisticated machinery to evade immune clearance and promote survival in the infected cells. Previous studies were mostly focused on either bacteria itself or host cells, the interaction mechanism of host-pathogen awaits further exploration. In the present study, we show that Salmonella can exploit mammalian cell non-classical microRNA processing machinery to further process bacterial small non-coding RNAs into microRNA-like fragments. Sal-1, one such fragment with the highest copy number in the infected cells, is derived from Salmonella 5-leader of the ribosomal RNA transcript and has a stem structure-containing precursor. Processing of Sal-1 precursors to mature Sal-1 is dependent on host cell Argonaute 2 (AGO2) but not Dicer. Functionally, depleting cellular Sal-1 strongly renders the Salmonella bacteria less resistant to the host defenses both in vitro and in vivo. In conclusion, we demonstrate a novel strategy for Salmonella evading the host immune clearance, in which Salmonella produce microRNA-like functional RNA fragments to establish a microenvironment facilitating bacterial survival

In Situ Characterization of 17-4PH Stainless Steel by Small-Angle Neutron Scattering

17-4PH martensitic steel is usually used as valve stems in nuclear power plants and it suffers from thermal aging embrittlement due to long-time service in a high-temperature and high-pressure environment. Here, we characterized the evolution of microstructures at the nano-scale in 17-4PH steel by in situ small-angle neutron scattering (SANS) with a thermo-mechanically coupled loading device. The device could set different temperatures and tensile so that an in situ SANS experiment could dynamically characterize the process of nanoscale structural changes. The results showed that with increasing thermal aging time, the ε-Cu phase precipitates and grows as the temperature is 475 °C and 590 °C, and the ε-Cu phase is spherical at 475 °C but became elongated cylinders at 590 °C. Moreover, the loading stress could aid in the growth of the ε-Cu phase at 475 °C

Semi-supervised authentically distorted image quality assessment with consistency-preserving dual-branch convolutional neural network

Recently, convolutional neural networks (CNNs) have provided a favoured prospect for authentically distorted image quality assessment (IQA). For good performance, most existing CNN-based methods rely on a large amount of labeled data for training, which is time-consuming and cumbersome to collect. By simultaneously exploiting few labeled data and many unlabeled data, we make a pioneering attempt to propose a semi-supervised framework (termed SSLIQA) with consistency-preserving dual-branch CNN for authentically distorted IQA in this paper. The proposed SSLIQA introduces a consistency-preserving strategy and transfers two kinds of consistency knowledge from the teacher branch to the student branch. Concretely, SSLIQA utilizes the sample prediction consistency to train the student to mimic output activations of individual examples represented by the teacher. Considering that subjects often refer to previous analogous cases to make scoring decisions, SSLIQA computes the semantic relation among different samples in a batch and encourages the consistency of sample semantic relation between two branches to explore extra quality-related information. Benefiting from the consistency-preserving strategy, we can exploit numerous unlabeled data to improve network's effectiveness and generalization. Experimental results on three authentically distorted IQA databases show that the proposed SSLIQA is stably effective under different student-teacher combinations and different labeled-to-unlabeled data ratios. In addition, it points out a new way on how to achieve higher performance with a smaller network

Adverse Effects of Simulated Hyper- and Hypo-Phosphatemia on Endothelial Cell Function and Viability

Dysregulation of phosphate homeostasis as occurs in chronic kidney disease is associated with cardiovascular complications. It has been suggested that both hyperphosphatemia and hypophosphatemia can cause cardiovascular disease. The molecular mechanisms by which high or low serum phosphate levels adversely affect cardiovascular function are poorly understood. The purpose of this study was to explore the mechanisms of endothelial dysfunction in the presence of non-physiologic phosphate levels.We studied the effects of simulated hyper- and hypophosphatemia in human umbilical vein endothelial cells in vitro. We found both simulated hyperphosphatemia and hypophosphatemia decrease eNOS expression and NO production. This was associated with reduced intracellular calcium, increased protein kinase C β2 (PKCβ2), reduced cell viability, and increased apoptosis. While simulated hyperphosphatemia was associated with decreased Akt/p-Akt, Bcl-xl/Bax ratios, NFkB-p65 and p-Erk abundance, simulated hypophosphatemia was associated with increased Akt/p-Akt and Bcl-xl/Bax ratios and p-Mek, p38, and p-p38 abundance.This is the first demonstration of endothelial dysfunction with hypophosphatemia. Our data suggests that both hyperphosphatemia and hypophosphatemia decrease eNOS activity via reduced intracellular calcium and increased PKCβ2. Hyperphosphatemia also appears to reduce eNOS transcription via reduced signaling through PI3K/Akt/NF-kB and MAPK/NF-kB pathways. On the other hand, hypophosphatemia appears to activate these pathways. Our data provides the basis for further studies to elucidate the relationship between altered phosphate homeostasis and cardiovascular disease. As a corollary, our data suggests that the level of phosphate in the culture media, if not in the physiologic range, may inadvertently affect experimental results

Designing nano-aluminum laden fuel pump for aviation applications

In view of the fact that traditional liquid propellants cannot meet the design requirements of large-thrust flight vehicle, it has become a new trend to add nano-metal powder to liquid propellants to greatly increase density and specific impulse. In order to achieve the variable flow-rate and variable-proportion transportation of aviation fuel with nano-aluminum, a new type of solid-liquid mixing pumping system is designed, including powder conveying device, stirring device, pump and corresponding drive and transmission system. For the purpose of avoiding the frictional contact between the rotors, which will bring potential hazard to nano-aluminum powder, a non-contact twin-screw pump with synchronous gears is designed. Among them, based on the considerations of flow pulsation, volumetric efficiency and manufacturing difficulty, cycloid profile is adopted for screw rotors. After completing the functional design, geometric parameter design, structural design, 3D modeling, prototype manufacturing and preliminary performance estimation of the mixing pumping system, the performance of the screw feeder, agitator, screw pump was tested through experiments to meet the expected design requirements. The designed agitator can achieve sufficient mixing at 500 rpm in less than 10 s. Even though 50-micron clearances are designed with a relatively small rotor diameter, the volumetric efficiency of screw pump can reach above 50% when the discharge pressure is below 450 kPa and the flow rate is set as 10 L/min, the power of the screw pump is less than 700 W. This design facilitates the rapid real-time preparation of metallized propellants and provides a reference for further improving the design and control methods of nanoparticle two-phase flow pumping