bluuebunny/crossref_metadata_2025 huggingface dataset:
MiR-144inhibits growth and metastasis in colon cancer by down-regulating SMAD4
Authors: Sheng Shihou , Xie Lin , Wu Yuanyu , Ding Meng , Zhang Tao , Wang Xu
Published: February 2019

MicroRNAs (MiRs) are thought to display regulator action in tumor suppression and oncogenesis. miR-144 plays an important role in the development of various cancers, such as colorectal cancer, breast cancer, and lung cancer, by targetting different molecules potentially involved in many signaling pathways. SMAD4 is a common signaling during tumor progression, and it can inhibit cell proliferation and promote cell motility in most epithelial cells. The present study focused on the effect of miR-144 and SMAD4 on colon cancer in order to find the novel gene therapy target for the treatment of colon cancer. Quantitative real-time polymerase chain reaction was used to assess the expression level of miR-144 in colon cancer tissues and SW620 cells. MTT assay, scratch test, and transwell assay were used to evaluate cell proliferation, migration, and invasion, respectively. Moreover, luciferase assays were utilized to identify the predictive effect of miR-144 on SMAD4. Western blotting was performed to determine the relative expression of protein related to SMAD4. We found miR-144 level was significantly lower in colon cancer tissues and SW620 cells. Moreover, SMAD4 level, both in mRNA and protein, was obviously elevated in colon cancer tissues. Further, miR-144 mimics treatment inhibited cells proliferation, invasion, and migration. Fluorescence intensity of miR-144 mimics group in wild type cells was decreased. MiR-144 mimics repressed the SMAD4 expression both in mRNA and protein. These findings about miR-144/SMAD4 pair provide a novel therapeutic method for colon cancer patients.
Ablation of both Cx40 and Panx1 results in similar cardiovascular phenotypes exhibited in Cx40 knockout mice
Authors: Novielli-Kuntz Nicole M. , Jelen Meghan , Barr Kevin , DeLalio Leon J. , Feng Qingping , Isakson Brant E. , Gros Robert , Laird Dale W.
Published: February 2019

Connexins (Cxs) and pannexins (Panxs) are highly regulated large-pore channel-forming proteins that participate in cellular communication via small molecular exchange with the extracellular microenvironment, or in the case of connexins, directly between cells. Given the putative functional overlap between single membrane-spanning connexin hemichannels and Panx channels, and cardiovascular system prevalence, we generated the first Cx40−/−Panx1−/− mouse with the anticipation that this genetic modification would lead to a severe cardiovascular phenotype. Mice null for both Cx40 and Panx1 produced litter sizes and adult growth progression similar to wild-type (WT), Cx40−/− and Panx1−/− mice. Akin to Cx40−/− mice, Cx40−/−Panx1−/− mice exhibited cardiac hypertrophy and elevated systolic, diastolic, and mean arterial blood pressure compared with WT and Panx1−/− mice; however assessment of left ventricular ejection fraction and fractional shortening revealed no evidence of cardiac dysfunction between groups. Furthermore, Cx40−/−, Panx1−/−, and Cx40−/−Panx1−/− mice demonstrated impaired endothelial-mediated vasodilation of aortic segments to increasing concentrations of methacholine (MCh) compared with WT, highlighting roles for both Cx40 and Panx1 in vascular endothelial cell (EC) function. Surprisingly, elevated kidney renin mRNA expression, plasma renin activity, and extraglomerular renin-producing cell populations found in Cx40−/− mice was further exaggerated in double knockout mice. Thus, while gestation and gross development were conserved in Cx40−/−Panx1−/− mice, they exhibit cardiac hypertrophy, hypertension, and impaired endothelial-mediated vasodilation that phenocopies Cx40−/− mice. Nevertheless, the augmented renin homeostasis observed in the double knockout mice suggests that both Cx40 and Panx1 may play an integrative role.
Four GRB supernovae at redshifts between 0.4 and 0.8
Authors: Klose S. , Schmidl S. , Kann D. A. , Nicuesa Guelbenzu A. , Schulze S. , Greiner J. , Olivares E. F. , Krühler T. , Schady P. , Afonso P. M. J. , Filgas R. , Fynbo J. P. U. , Rau A. , Rossi A. , Takats K. , Tanga M. , Updike A. C. , Varela K.
Published: February 2019

Twenty years ago, GRB 980425/SN 1998bw revealed that long gamma-ray bursts (GRBs) are physically associated with broad-lined type-Ic supernovae (SNe). Since then more than 1000 long GRBs have been localized to high angular precision, but only in ∼50 cases has the underlying SN component been identified. Using the Gamma-Ray Burst Optical Near-Infrared Detector (GROND) multi-channel imager at ESO/La Silla, during the last ten years we have devoted a substantial amount of observing time to reveal and study SN components in long-GRB afterglows. Here we report on four more GRB SNe (associated with GRBs 071112C, 111228A, 120714B, and 130831A) which were discovered and/or followed-up with GROND and whose redshifts lie between z = 0.4 and 0.8. We study their afterglow light curves, follow the associated SN bumps over several weeks, and characterize their host galaxies. Using SN 1998bw as a template, the derived SN explosion parameters are fully consistent with the corresponding properties of the currently known GRB-SN ensemble, with no evidence for an evolution of their properties as a function of redshift. In two cases (GRB 120714B/SN 2012eb at z = 0.398 and GRB 130831A/SN 2013fu at z = 0.479) additional Very Large Telescope (VLT) spectroscopy of the associated SNe revealed a photospheric expansion velocity at maximum light of about 40 000 and 20 000 km s−1, respectively. For GRB 120714B, which was an intermediate-luminosity burst, we find additional evidence for a black-body component in the light of the optical transient at early times, similar to what has been detected in some GRB SNe at lower redshifts.
The kinematics of local thick discs do not support an accretion origin
Authors: Comerón S. , Salo H. , Knapen J. H. , Peletier R. F.
Published: February 2019

Thick discs are nearly ubiquitous components of the discs of present-day galaxies. It has been proposed that a fraction of their stars have been accreted. Here, we aim to find whether accretion of satellites is the main formation mechanism of thick discs. To do so, we observed a sample of eight nearby edge-on galaxies with the Multi-Unit Spectroscopic Explorer (MUSE) integral field unit at the Very Large Telescope (VLT). Six of the galaxies have a distinct thick disc. We derived thick-disc velocities and velocity dispersions for the galaxies in our sample. We devise a formalism to estimate the fractions of retrograde material in the thick discs by using kinematical maps and thin/thick disc decompositions. None of the galaxies in our sample show strong evidence for retrograde material at large distances from the centre. Including those found in the literature, there are seventeen thick discs with studied kinematics, with only one showing unambiguous signatures of retrograde material. Literature numerical studies of dynamical friction allow us to estimate that at the current cosmic time about one in six mergers for which the stars of the accreted galaxy ended in a thick disc were retrograde. This is in tension with the observed fraction of galaxies with a partly retrograde thick disc (one in seventeen). We conclude that satellite accretion is not favoured by observations to be the main formation mechanism of thick discs.
Satellite dwarf galaxies: stripped but not quenched
Authors: Hausammann Loic , Revaz Yves , Jablonka Pascale
Published: February 2019

In the Local Group, quenched gas-poor dwarfs galaxies are most often found close to the Milky Way and Andromeda, while star forming gas-rich ones are located at greater distances. This so-called morphology-density relation is often interpreted as the consequence of the ram pressure stripping of the satellites during their interaction with the Milky Way hot halo gas. While this process has been often investigated, self-consistent high resolution simulations were still missing. In this study, we have analysed the impact of both the ram pressure and tidal forces induced by a host galaxy on dwarf models as realistic as possible emerging from cosmological simulations. These models were re-simulated using both a wind tunnel and a moving box technique. The secular mass growth of the central host galaxy, as well as the gas density and temperature profiles of its hot halo have been taken into account. We show that while ram pressure is very efficient at stripping the hot and diffuse gas of the dwarf galaxies, it can remove their cold gas (T <  103 K) only in very specific conditions. Depending on the infall time of the satellites relatively to the build-up stage of the massive host, star formation can thus be prolonged instead of being quenched. This is the direct consequence of the clumpy nature of the cold gas and the thermal pressure the hot gas exerts onto it. We discuss the possibility that the variety in satellite populations among Milky Way-like galaxies reflects their accretion histories.
Problems and Countermeasures in Environmental Cost Accounting: A Case Study of China's Coal Industry
Authors: Zeng Li-Xia , He Peng , Shi Jin-Ping
Published: February 2019

In recent years, many scholars have carried out research on improving the environmental cost accounting of coal enterprises. Through the research, the traditional product cost accounting and environmental cost accounting are standardized. But the current cost accounting system still exists problems like wrong calculation of the cost of environmental damage and fraudulent accounting problems. In order to enhance the enterprise's environmental protection consciousness and improve the level of cost control management for the enterprise to provide scientific decision basis, this paper aims to find out the main composition of coal enterprise environment cost, analysis of the problems existing in coal enterprise environment cost accounting and puts forward corresponding solutions.
Experimental Study on the Treatment of 1, 4 butanediol Mixed Wastewater by Ferro-carbon Micro-electrolysis
Authors: Lei Jie , Zhang Xiaodong , Zhou Zhenglin , Fan Shaohui , Jiang Bo , Tian Xianlan
Published: February 2019

The mixed wastewater of 1, 4 butanediol was tested with iron filings and carbon powder as catalyst by aeration to provide oxygen. The effects of carbon powder, pH value and reaction time on wastewater treatment were studied. The optimal experimental condition was that the mesh number of activated carbons was 20, the pH value was 5, the reaction time was 30min, and the Chemical Oxygen Demand (COD) removal efficiency reached 36.2%. At the same time, The response surface method was used to analyze and optimize the experimental results, and the relation formula of each influencing factor on removal efficiency was established, and the order of influence degree of each factor on removal efficiency (pH> activated carbon mesh number > reaction time) was obtained, in which pH had the greatest influence on the treatment rate of ferro-carbon micro-electrolysis treatment of 1, 4-butanediol wastewater.
Analysis of possibilities to improve quality of spatial wind speed forecasts for efficient forecasting of electric energy production in onshore wind farms in Poland
Authors: Piotrowski Paweł , Baczyński Dariusz , Kopyt Marcin , Szafranek Karolina
Published: February 2019

The most important factor responsible for the quality of energy production forecasts in wind farms is the accurate wind speed forecast. An extensive statistical analysis of meteorological data (NWP) from 16 base nodes of the "300" grid in the "Łódź" area was made. The intention of the statistical analysis was to select potential explanatory variables for models predicting wind speed in the remaining 206 nodes of the grid’s mesh. Next, tests of selected prognostic methods were performed in order to compare their effectiveness with bilinear method which is not computationally complex. It should be emphasized that the main problem in spatial wind speed forecasting is the very large number of nodes for which the forecasts are calculated. As a consequence, more advanced and computationally complex forecasting methods cannot be applied in practice due to too long calculations time and difficulties in huge amounts of data processing. Conclusions with proposals of preferred forecasting methods that could be used in practice were developed.
Short-term load forecasting using Theta method
Authors: Dudek Grzegorz
Published: February 2019

The Theta method attracted the attention of researchers and practitioners in recent years due to its simplicity and superior forecasting accuracy. Its performance has been confirmed by many empirical studies as well as forecasting competitions. In this article the Theta method is tested in short-term load forecasting problem. The load time series expressing multiple seasonal cycles is decomposed in different ways to simplify the forecasting problem. Four variants of input data definition are considered. The standard Theta method is uses as well as the dynamic optimised Theta model proposed recently. The performances of the Theta models are demonstrated through an empirical application using real power system data and compared with other popular forecasting methods.
Calculating electric power and energy generated in small wind turbine-generator sets in very short-term horizon
Authors: Parol Mirosław , Arendarski Bartłomiej , Parol Rafał
Published: February 2019

The issue of very short-term forecasting of power generated in renewable energy sources, including small wind turbine-generator sets, is getting more and more important. Because it is crucial/necessary to ensure reliable electricity supplies to consumers, it is a subject of a great significance in small energy micro-systems, which are commonly called microgrids. Small wind turbine-generator sets will be shortly characterized in this paper. Further on, typical characteristics of power generated by these units, dependent on the wind velocity, will be presented. Then results of sample calculations of electric power and energy generated by several wind turbine-generator sets of small installed capacity, in relation to the wind velocity and time intervals assumed for calculations, will be presented. On the basis of these calculations, estimation errors resulting from the magnitude of time intervals, assumed in the process of wind velocity averaging, will be determined. Some qualitative analysis of obtained estimates of electric powers and energies, in context of very short-term forecasts of these quantities, will be carried out. At the end of the paper observations and conclusions concerning analyzed subject, i.e. calculating the electric power and energy generated in small wind turbine- generator sets in a very short-term horizon, will be provided.
Application of similarity analysis in PV sources generation forecasting for energy clusters
Authors: Rogus Radomir , Sołtysik Maciej , Czapaj Rafał
Published: February 2019

The resultant photovoltaic installation powers significantly affect the process of cluster coordination in terms of balancing, which is associated with the need for the most accurate forecast of photovoltaic generation. This article describes the application of similarity analysis in order to use commonly available meteorological data for predicting generation level from photovoltaic sources on the example of several selected installations and their corresponding real production profiles.
Mathematical model of electrical system including transformer and electrical drives based on induction motors and synchronous motors
Authors: Lis Marek , Chaban Andriy
Published: February 2019

On the basis of interdisciplinary modelling methods the mathematical model of the electromechanical system, including power transformer, induction motors and synchronous motors, is formulated and presented in the paper. The motors are joined with the driven objects through a mechanical power transmission system. In addition, the transformer is loaded by nonlinear circuit RL. Differential state equations of the studied system are given as the Cauchy’s formulas. Numerical simulations of the system operation have been made for the selected cases. The results of computer simulation are presented in a graphic form.
Determination of reliability indices of the distribution network based on data from AMI
Authors: Kornatka Mirosław , Gawlak Anna , Dudek Grzegorz
Published: February 2019

Improving reliability of a power network is an issue of great importance for power distribution companies. The aim stated by the President of Energy Regulatory Office to improve the reliability of the distribution network includes steps towards improving the monitoring and control of the network managed by distribution companies. Ensuring continuity of energy supply is one of distribution companies’ duties and one of the criteria used to assess the effectiveness of network operation. Distribution companies all over the world employ indices SAIDI, SAIFI and MAIFI to determine mean values concerning the number of time of interruptions per consumer in a year. The paper deals with methods of correct and precise determination of the values of the reliability indices SAIDI, SAIFI and MAIFI by means of the application Advanced Metering Infrastructure in the distribution network.
The application of the CLONALG algorithm in the process of optimal operation control of hybrid AC/DC low voltage microgrid
Authors: Rokicki Łukasz
Published: February 2019

The issue of optimal operation control of microgrids is a very important problem. As a result of changing weather conditions and the demand for the power of individual consumers, generation units and energy storage devices must constantly adjust their operation states. The optimization of the microgrid operation states can simultaneously provide the required level of power and energy and, for example, minimization of power losses or costs associated with the operation of this type of system. Among many available optimization methods, author of a paper decided to test the CLONALG algorithm, which is an implementation of artificial immune system. The article will presents the characteristics of selected CLONALG algorithm, and the description of the test microgrid together with the considered optimization criteria and constraints. The presentation and analysis of the obtained results from optimization calculations will be the main part of the paper. At the end of the paper observations and conclusion will be presented.
Mathematical model of a drive system with synchronous motors and vertical pumps
Authors: Szafraniec Andrzej
Published: February 2019

The paper presents a mathematical model of an electrical load node consisting of a power transformer and synchronous motors which rotate vertical pumps using non-rigid transmission. Modified principle of Hamilton–Ostrogradsky served as the basis for construction of the model. Using the developed mathematical model of the node, electromechanical transients in the object are studied. The resultant system of dynamic state nonlinear differential equations is introduced in the normal Cauchy’s form. Computer simulation findings are displayed by means of figures; they are under ongoing analysis.
Application Research of BIM Technology in Green Building Construction
Authors: Xiao Liangli , Du Zhuang , Liu Yan , Yang Zhao , Xu Kai
Published: February 2019

Due to the complexity of the building and the comprehensiveness of multiple majors, a large number of uncertain factors, such as collision problems and construction schedule, often occur in the construction and lead to many resource waste problems which cannot be solved. The introduction of BIM technology into the construction of engineering projects can well overcome the collision in construction and complete the process of optimized construction schedule scheme through construction simulation to realize green building construction.
Using Boundary Element Method to Calculate the Bending Center of General Section
Authors: Tang Xinyan
Published: February 2019

Using Siant — Venant bending theory, transverse bending of a general section cylinder, it comes down to solving two boundary integral equations of the same type, the bending function and additional torsion function of the cylinder are obtained. On this basis, using boundary element method to determine the bending center of general section. Finally, to illustrate the application of the method, a numerical example is given.
Design and Implementation of an Intelligent Water Regime Detection System
Authors: Dai Weijun , Tang Yanni , Qiu Shijie
Published: February 2019

An intelligent water regime detection system was designed for water detection. In the designed system, water level is detected by a pressure sensor and water pH is detected by a pH meter. After being processed by the AD chip TLC2543, the data are sent to the MCU via serial communication and the detection result is displayed on OLED screen or Bluetooth mobile phone. The software adopts time-sharing and power-down operation modes, and combines the relay to turn on/off the MCU peripheral circuit to reduce power consumption. The measurement deviations of water level, pH, and voltage were respectively less than 2 mm, 0.1, and 0.01 V and the minimum operating current was less than 6 mA. The low-power, high-precision and intelligent water regime detection is realized by the designed system.
Auf Fixierungen kann in der klinischen Praxis verzichtet werden – ohne dass auf Zwangsmedikation oder Isolierungen zurückgegriffen wird
Authors: Zinkler Martin , Waibel Michael
Published: February 2019

Ausgehend von der Situation der Heidenheimer Klinik beschreiben wir die notwendigen Veränderungen, um völlig auf Fixierungen in der Allgemeinpsychiatrie einschließlich Gerontopsychiatrie und Suchtbehandlung zu verzichten, ohne auf andere Zwangsmaßnahmen wie Isolierung oder Zwangsmedikation zurückzugreifen. Dabei werden die bisherigen Fixierungen durch 2:1- oder 3:1-Betreuungen ersetzt. Die Klinik erfasst die Fixierungshäufigkeit und -dauer minutengenau. Dies erlaubt die Bestimmung der Zeiten für intensive Einzelbetreuungen. Die Anlässe für die bislang durchgeführten Fixierungen und individuelle Besonderheiten bei der Begleitung erlauben eine Einschätzung der Betreuungsintensität und damit des erforderlichen Personalaufwands. Die Personalressourcen und dafür erforderlichen Kosten werden mit den üblichen Ausfallzeiten und Personalkosten für qualifiziertes Pflegepersonal errechnet und ergeben einen zusätzlichen Bedarf von 4 % des jährlichen Klinikbudgets. Problematisch für die Umsetzung erscheint der Fachkräftemangel in der Krankenpflege in Deutschland.
Fallstudie: Entwicklung von symbolischen Alternativen zur physischen Zwangsanwendung in Gefährdungssituationen – PART IV: „Simulation und Reduktion von Zwangsmaßnahmen in der Psychiatrie“ (SRZP)
Authors: Ahrens Ullrich , Haage Jens , Luzycki Thomas , Milark Susanne , Debus Stephan
Published: February 2019

Insgesamt 38 Krankenpflegerinnen und Krankenpfleger haben mithilfe von Videoaufzeichnungen von psychiatrischen Gefährdungssituationen eine Zwang vermeidende Alternative, die sogenannte „Hilfs-Ich-Strategie“ (HIS) entwickelt. In dieser Fallstudie zeigen sich im empirischen Vergleich zwischen Zwangsanwendung (Fixierung) und Alternativstrategie (HIS) signifikante Differenzen in den Kommunikationsprofilen. Die zugehörige Ethnotheorie der Krankenpflegenden zu HIS enthält folgende Merkmale: Formen des HIS, Wirkfaktoren, Patienten-, Situations- und Teamvoraussetzungen.
Brazilian Plants: An Unexplored Source of Endophytes as Producers of Active Metabolites
Authors: Savi Daiani Cristina , Aluizio Rodrigo , Glienke Chirlei
Published: February 2019

Brazil has an extraordinary biodiversity, and for many years, has been classified as the first of 17 countries with a mega diversity, with 22% of the total plants in the world (more than 55 000 species). Considering that some endophytes are host-specific, the incomparable plant diversity found in Brazil encompasses an immeasurable variety of habitats and may represent a repository of unexplored species. As a result of the endophyte-host interaction, plant-associated microorganisms have an enormous biosynthetic potential to produce compounds with novelties in structure and bioactivity. Numerous studies have been published over the years describing the endophytic species isolated in Brazil. Identification of these species is generally performed via DNA sequencing. However, many of the genera to which the described taxa belong were reviewed phylogenetically and many species were reclassified. Thus, there is a gap in the real biodiversity of endophytes isolated in Brazil in the last decade. In this scenario, the present study reviewed the biodiversity of endophytes isolated from plants found in different Brazilian biomes from 2012 to 2017, including the following topics: (i) species diversity, (ii) species identification challenges, (iii) biotechnological aspects, and (iv) identified metabolites. Endophytes of 54 species of plants were studied from 2012 to 2017, resulting in the identification of 300 genera, with Diaporthe and Bacillus being the most frequent fungal and bacterial genera, respectively.
Preoperative Chronic Opioid Use and Its Effects on Total Knee Arthroplasty Outcomes
Authors: Kim Kelvin , Chen Kevin , Anoushiravani Afshin A. , Roof Mackenzie , Long William J. , Schwarzkopf Ran
Published: February 2019

Unsafe opioid distribution remains a major concern among the total knee arthroplasty (TKA) population. Perioperative opioid use has been shown to be associated with poorer outcomes in patients undergoing TKA including longer length of stay (LOS) and discharges to extended care facilities. The current study aims to detail perioperative opioid use patterns and investigate the effects of preoperative chronic opioid use on perioperative quality outcomes in TKA patients. A retrospective analysis was performed on 338 consecutive TKAs conducted at our institution. Two cohorts were compared in this study—preoperative chronic opioid users and nonchronic opioid users. Opioid usage patterns and quality metrics were collected and analyzed over a 3-month preoperative and a 6-month postoperative period. Fifty-four (16.0%) preoperative chronic opioid users were identified out of the total 338 patients included in the study. Preoperative chronic opioid users experienced significantly longer LOS (2.9 vs 2.6 days; p = 0.026). Patients who remained persistent chronic users throughout the preoperative and postoperative stages demonstrated a significantly longer LOS (3.4 days vs 2.5 days; p = 0.017) compared with those who were no longer chronically using opioids by the 6 months postoperative period. By the 6 months postoperative time point, preoperative chronic users were consuming eight times the morphine-equivalents (mg/day) compared with nonchronic users (p < 0.001). Preoperative chronic opioid use was associated with substantially higher usage patterns throughout the postoperative stages. Such opioid use patterns were associated with longer LOS. Given that perioperative chronic opioid use has shown to negatively impact TKA outcomes, future studies refining current perioperative management strategies are warranted. This is a Level II, prognostic study.
To Maintain or Cease Non–Vitamin K Antagonist Oral Anticoagulants Prior to Minimal Bleeding Risk Procedures: A Review of Evidence and Recommendations
Authors: Favaloro Emmanuel , Curnow Jennifer , Brennan Yvonne
Published: February 2019

For procedures associated with minimal bleeding risk, there are data and experience to support the practice of continuing vitamin K antagonists rather than interrupting therapy, to prevent exposing patients to the undue risk of developing thromboembolism during anticoagulation cessation. Despite the increasing use of non–vitamin K oral anticoagulants (NOACs), there is little evidence to guide the management of these drugs around minimal bleeding risk procedures. This review examines and discusses the major society guidelines and recommendations addressing the management of NOACs around minimal bleeding risk procedures. Additionally, it summarizes the existing evidence, and highlights the gaps in knowledge where evidence is not yet available. Finally, recommendations are made to assist the proceduralist deal with this area of limited evidence.
Fabrication of graphene-like carbon films on 6H-SiC substrates via chlorination-annealing at low temperature
Authors: Hu Yanfei , Guo Lixin , Dou Wentao , Chong Laiyuan , Guo Hui , Zhang Yuming
Published: February 2019

Graphene-like carbon films have been fabricated by annealing carbide-derived carbons on 6H-SiC (0001¯) at lower temperature in Ar ambience. Those films show a moderate interaction with substrates and an ordered stacking along c-axis and exhibit the same Raman spectra as that of epitaxial graphene on SiC. This carbon film growth process developed here will provide a new approach to obtain graphene epitaxially grown on SiC substrate at lower cost compared with the traditional access.
On a topological classification of recurrence plots: Application to noise perturbed molecular dynamics time series
Authors: Karakasidis Theodoros E. , Andreadis Ioannis , Fragkou Athanasios D.
Published: February 2019

In the present paper, a topological classification of recurrence plots of time series that are constructed with equal embedding dimension and delay time is proposed by defining a metric structure in the set of those recurrence plots. To achieve this, the Recurrence Plot deviation distance and the Recurrence deviation plot are introduced along with qualitative and quantitative indices, which allows for a detailed comparison of the recurrence plots of two time series and their corresponding dynamical systems. In the range of values studied, the application of additive noise on the thermostat results in a less deterministic system behavior, quite close to that of the system with the unperturbed thermostat. On the other hand, multiplicative noise of small strength results in a less deterministic system quite close to the unperturbed system behavior. For a larger strength, the system presents a behavior which is significantly different from that of the unperturbed system. The new methodology introduced here provides detailed quantitative and graphical insights for the way that noise, additive and multiplicative, influences on the morphology of recurrence plots of the unperturbed and noise perturbed time series. The results are encouraging for potential future applications on the analysis of complex dynamical systems.
MHD tangent hyperbolic nanofluid with chemical reaction, viscous dissipation and Joule heating effects
Authors: Shahzad F. , Sagheer M. , Hussain S.
Published: February 2019

In this article, the motion of a non-Newtonian tangent hyperbolic nanofluid past a stretching sheet is analyzed. Nanofluid is comprised of thermophoresis and Brownian motion effects. Magnetic field is implemented in vertical direction under the assumption of low magnetic Reynolds number. The phenomenon of heat transfer has been examined subject to the viscous dissipation and Joule heating whereas the mass transfer has been analyzed under the effect of chemical reaction. The partial differential equations (PDEs) governing the flow, heat and mass transport are re-framed in the form ordinary differential equations (ODEs) by means of the similarity solutions. A numerical procedure known as the Keller-box method has been implemented to obtain the solutions for the accomplished ODEs. The effects of the variations of different involved parameters on fluid temperature, velocity and concentration distributions are disclosed through graphs and analyzed in detail. The features of skin friction, heat and mass transfer coefficient are tabulated and graphed in order to perceive the flow, heat and mass transport processes. It is noticed that an increment in the Weissenberg number results in a reduction in the velocity field.
Relation between concentration fluctuations and dynamical heterogeneities in binary glass-forming liquids: A molecular dynamics simulation study
Authors: Müller Niels , Vogel Michael
Published: February 2019

We perform molecular dynamics simulations of binary glass-forming liquids with high dynamical contrast. In detail, we mix water-like molecules with various polarities, which exhibit strongly different dynamics but very similar structures as neat liquids. It is found that these mixtures show concentration fluctuations, which strongly grow upon cooling towards an expected mixing-demixing phase transition. Because of the developing microphase segregation, the composition and temperature ranges accessible to our approach are limited, but the studied mixtures are ideal models to ascertain the relation between concentration fluctuations and molecular dynamics, in particular, the glassy slowdown of binary liquids, including aqueous solutions. We find that the dynamics of the components decouple upon cooling. While the dynamics of the slow component resembles that of neat glass formers, that of the fast component shows different features, including sub-linear diffusion on length and time scales beyond that of local particle cages and quasi-logarithmic decays of correlation functions. We show that this “anomalous dynamics” of the fast component receives a simple explanation based on a strong dependence of the particle mobility on the local concentration in combination with microphase segregation and dynamical contrast. Explicitly, spatially heterogeneous dynamics, which are more extended and tenacious than in neat glass formers, result from growing concentration fluctuations upon cooling. Due to a high dynamical asymmetry of the components at low temperatures, the slow species sustains the microphase segregation in the mixture, while the fast component moves along the concentration and mobility gradients, leading to remarkable dynamical features.
A compact radiofrequency drive based on interdependent resonant circuits for precise control of ion traps
Authors: Detti Amelia , De Pas Marco , Duca Lucia , Perego Elia , Sias Carlo
Published: February 2019

Paul traps are widely used to confine electrically charged particles like atomic and molecular ions by using an intense radiofrequency (RF) field, typically obtained by a voltage drop on capacitative electrodes placed in vacuum. We present a RF drive realized on a compact printed circuit board and providing a high-voltage RF signal to a quadrupole Paul trap. The circuit is formed by using four interdependent resonant circuits — each of which is connected to an electrode of a Paul trap — fed by low-noise amplifiers, leading to an output voltage of peak-to-peak amplitude up to 200 V at 3.23 MHz. The presence of a single resonant circuit for each electrode ensures a strong control on the voltage drop on each electrode, e.g., by applying a DC field through a bias tee. Additionally, the moderate quality factor Q = 67 of the resonant circuits ensures a fast operation of the drive, which can be turned on and off in less than 10 μs. Finally, the RF lines are equipped with pickups that sample the RF in phase and amplitude, thus providing a signal that can be used to actively control the voltage drop at the trap’s electrodes.
The half-metallicity and the spin filtering, NDR and spin Seebeck effects in 2D Ag-doped SnSe2 monolayer
Authors: Wu Xuming , Xiong Lun , Feng Yulin , Wang Cong , Gao Guoying
Published: February 2019

Two-dimensional SnSe2 has become more and more attractive due to the excellent electronic, optoelectronic, and thermoelectric properties. However, the study on magnetic properties is rare. Inspired by the recent experimental synthesis of SnSe2 monolayer and Ag-doped SnSe2 thin films, we use the first-principles calculations combined with the nonequilibrium Green’s function method to investigate the structural, electronic, magnetic, and spin transport properties of an Ag-doped SnSe2 monolayer. It is found that the doped system exhibits half-metallic ferromagnetism with the energy gap of about 0.5 eV in the spin-down channel. The spin-polarized transport properties based on Ag-doped SnSe2 monolayers show an excellent spin filtering effect and a negative differential resistance effect under a bias voltage. Interestingly, under a temperature gradient, the spin Seebeck effect and the temperature-controlled reverse of spin polarization are also observed. These perfect spin transport properties can be understood from the calculated spin-polarized band structure and the spin-polarized transport spectrum. These studies indicate the potential spintronic and spin caloritronic applications for Ag-doped SnSe2 monolayer.
A versatile micro-reflectivity setup for probing the optical properties of photonic nanostructures
Authors: Sharma Sachin , Priya  , Saini Sudhir Kumar , Nair Rajesh V.
Published: February 2019

The spatial- and spectral-dependent optical reflectivity measurements are essential to characterize various natural as well as artificial micron-scale photonic nanostructures. However, it is onerous to measure spatially and spectrally resolved reflectivity values from such photonic nanostructures due to their size limitations. Here, we discuss the development of a versatile micro-reflectivity setup with an in situ optical microscope combined with high-resolution actuators to measure the reflectivity from areas as small as 25 × 25 µm2. We illustrate the reflectivity measurements from natural as well as artificially prepared ordered and disordered photonic nanostructures. The optical features that are hidden in the conventional reflectivity measurements are clearly resolved using the micro-reflectivity measurements. The proposed setup is also capable of measuring the polarization-dependent reflectivity and transmission of light.
Darcy-Forchheimer flow of MHD CNTs nanofluid radiative thermal behaviour and convective non uniform heat source/sink in the rotating frame with microstructure and inertial characteristics
Authors: Khan Arshad , Shah Zahir , Islam Saeed , Dawar Abdullah , Bonyah Ebenezer , Ullah Hakeem , Khan Aurangzeb
Published: February 2019

In this research paper we examined Darcy-Forchheimer three-dimensional micro-polar nanofluid flow of carbon nanotubes (CNTs) based on water. The nanofluid flow is examined between parallel and horizontal plates in a rotating system. The thermal radiation impact is taken to be varying in the absorption/generation for the purpose, to see the concentration as well as the temperature modifications between the nanofluid and the surfaces. The micro-polar nanofluid in permeable media is designated by assuming the Darcy-Forchheimer model where drenching permeable space obeys the Darcy-Forchheimer expression. For Skin friction coefficient it is perceived to be larger for weak concentration and smaller for strong concentration. The impacts of the porosity, rotation and inertia coefficient analysis have been mainly focused in present investigation. Plots have been presented in order to study how the velocities and temperature profile get affected by various flow parameters. The leading equations are converted to a system of nonlinear differential equations and then homotopic method is employed for solution. The other physical features of flow such as Skin friction, heat flux and mass flux have been studied. The impacts of the porosity, rotation and inertia coefficient have been mainly focused in this research.
Molecular dynamics study on thermal energy transfer in bulk polyacrylic acid
Authors: Kawagoe Yoshiaki , Surblys Donatas , Kikugawa Gota , Ohara Taku
Published: February 2019

We performed non-equilibrium molecular dynamics (NEMD) simulations on bulk amorphous polyacrylic acid (PAA) with three polymer chain lengths to investigate molecular mechanism of thermal energy transfer in heat conduction. Thermal conductivity obtained by NEMD simulations increased as the polymer chain length of PAA increased, and its dependence on polymer chain length exhibited a saturation behavior. By decomposing heat flux into each contribution of molecular interactions, it was found that dominant mechanism of the thermal energy transfer in PAA was intramolecular interaction, and contribution of the intramolecular interaction to thermal conductivity increased as the polymer chain length increased, and resulted in increase in total thermal conductivity. On the other hand, coiled conformation of PAA advanced in response to elongation of the polymer chain length; and this coiled conformation inhibited further increase of thermal conductivity due to the polymer chain elongation. Consequently, the elongation of the polymer chain length had two conflicting effects: increasing and suppression of thermal conductivity, due to increase in intramolecular interaction and change in conformation, respectively. This is the reason of the saturation tendency of thermal conductivity as a function of the polymer chain length. Detailed understanding of the molecular mechanism of thermal energy transfer obtained in the present study provided the in-depth knowledge to clarify the thermal energy transfer mechanism and will lead to the characterization of thermal energy transfer in more complicated materials such as a layer-by-layer membrane.
The evolution of acidic and ionic aggregates in ionomers during microsecond simulations
Authors: Frischknecht Amalie L. , Winey Karen I.
Published: February 2019

We performed microsecond-long, atomistic molecular dynamics simulations on a series of precise poly(ethylene-co-acrylic acid) ionomers neutralized with lithium, with three different spacer lengths between acid groups on the ionomers and at two temperatures. Ionic aggregates form in these systems with a variety of shapes ranging from isolated aggregates to percolated aggregates. At the lower temperature of 423 K, the ionic aggregate morphologies do not reach a steady-state distribution over the course of the simulations. At the higher temperature of 600 K, the aggregates are sufficiently mobile that they rearrange and reach steady state after hundreds of nanoseconds. For systems that are 100% neutralized with lithium, the ions form percolated aggregates that span the simulation box in three directions, for all three spacer lengths (9, 15, and 21). In the partially neutralized systems, the morphology includes lithium ion aggregates that may also include some unneutralized acid groups, along with a coexisting population of acid group aggregates that form through hydrogen bonding. In the lithium ion aggregates, unneutralized acid groups tend to be found on the ends or sides of the aggregates.
Unusual self-diffusion behaviors of polymer adsorbed on rough surfaces
Authors: Li Jiaxiang , Zhang Ran , Ding Mingming , Shi Tongfei
Published: February 2019

We investigate the diffusion dynamics of a single polymer strongly adsorbed on surfaces in an extremely broad chain length and surface roughness by means of molecular dynamics simulations. Our simulations demonstrate that with the increase in chain length, the diffusion dynamics of polymer chains exhibits three regimes: the Rouse dynamics with D ∼ N−1 when the lateral size of polymer chains is smaller than a half of distance between obstacles on rough surfaces; the reptationlike dynamics with D ∼ N−1.5 and τr ∼ N3 when the obstacles inhibit the freely Rouse behavior of polymer chains; and the quasi-Rouse dynamics with D ∼ N−1 and τr ∼ N2.5 when the height of obstacles is smaller than twice the vertical size of polymer chains, where D, N, and τr are the diffusion coefficient, chain length, and end-to-end vector relaxation time of polymer chains, respectively. The long chains have sufficient conformation entropy to form loops to hop over short obstacles, which could dramatically reduce the confinement from obstacles on the rough surfaces and changes the diffusion and relaxation dynamics of polymer chains from the reptationlike dynamics to the quasi-Rouse dynamics. Our results reveal the whole diffusion dynamics of polymer chains strongly adsorbed on rough surfaces and clarify the corresponding transition mechanism, which is significant for the understanding of the physical nature and the development of the corresponding applications.
A review on biogenic amines in food and feed: toxicological aspects, impact on health and control measures
Authors: Feddern V. , Mazzuco H. , Fonseca F. N. , de Lima G. J. M. M.
Published: February 2019

Biogenic amines (BAs) represent a considerable toxicological risk in some food and feed products. They are formed under unhygienic conditions during storage and processing; therefore, an increase in the concentrations of those metabolites is related to putrefaction. Because BAs are thermostable, they remain in food and feed that have undergone heat treatment. There are several toxicological effects, especially caused by histamine, when high concentrations of BAs are ingested by humans, depending on the food itself and also on individual susceptibility and individual health status. The present paper reviews the main BAs in meat products, their use as spoilage indicators, the risk on human health and also the contamination of by-product meals. Furthermore, we highlight the state of art regarding impact of BAs on poultry, meat and eggs.
Isobaric tags for relative and absolute quantitation-based quantitative proteomics analysis provides novel insights into the mechanism of cross-incompatibility between tree peony and herbaceous peony
Authors: He Dan , Lou Xue-Yuan , He Song-Lin , Lei Ya-Kai , Lv Bo-Va , Wang Zheng , Zheng Yun-Bing , Liu Yi-Ping
Published: February 2019

Interspecific hybridisation is the main method for improvement and breeding of tree peony (Paeonia ostii T.Hong & J.X.Zhang), but cross-incompatibility as the major factor restricting the rapid development of interspecific hybridisation. To better understand the molecular mechanisms involved in cross-incompatibility between tree peony (Paeonia ostii cv. Fengdanbai) and herbaceous peony (Paeonia lactiflora Pall. cv. Fenyunu), a quantitative proteomic analysis using isobaric tags for relative and absolute quantitation (iTRAQ) technology was performed on the stigma 24h after pollination. Of the 2900 proteins whose levels were quantitated, 685 proteins were differentially expressed in the stigma after hybrid pollination, in contrast to self-pollination. Functional annotation analysis showed that dysregulated proteins involved in RNA degradation, the Ca signalling pathway, the phosphatidylinositol signalling system and the mitogen-activated protein kinase (MAPK) signalling pathway may have made contributions to cross-incompatibility. The downregulated expression of enolase, DnaK (Heat Shock Proteins, HSP70), GroEL (Heat Shock Proteins, HSP60), calmodulin and glyoxalase I, and the upregulated expression of adenine nucleotide translocator indicated that the energy synthesis required by pollen tube growth, the signal pathway and the metabolic pathway related to the growth polarity of the pollen tube were blocked after hybrid pollination. Eight genes were selected to confirm their expression by quantitative real-time PCR. Compared with the STRING database, a protein–protein interaction network of the chosen proteins was constructed. These results provide fundamental and important information for research into the molecular mechanisms of cross-incompatibility in peony and should facilitate interspecific hybridisation in agricultural practice.