bluuebunny/crossref_metadata_2025 huggingface dataset:
Rapid characterization of nonpolar or low‐polarity solvent extracts from herbal medicines by solvent‐assisted electrospray ionization mass spectrometry
Authors: Zhang Qiang , Su Yue , Liu Xiaopan , Guo Yinlong
Published: November 2017

Rationale

The direct detection of nonpolar and low‐polarity solvent extracts of herbal medicine is difficult by conventional electrospray ionization mass spectrometry (ESI‐MS). This problem can be solved by solvent‐assisted electrospray ionization mass spectrometry (SAESI‐MS). With the help of assisted solvents (ESI‐friendly solvents) at the tip of the spray needle, compounds (especially the low‐polarity compounds) in nonpolar and low‐polarity solvent extracts can be ionized directly.

Methods

Herbal medicines were ultrasonically extracted with nonpolar or low‐polarity solvents, such as petroleum ether. Thereafter, the extracts were analyzed by conventional ESI‐MS, atmospheric pressure chemical ionization mass spectrometry (APCI‐MS) and SAESI‐MS. The mass spectra obtained from these three methods were compared and analyzed.

Results

Unstable ion signals, and even no ion signals, were observed when the nonpolar and low‐polarity solvent extracts were detected directly by conventional ESI‐MS. Better specificity, higher sensitivity or cleaner spectra were acquired from SAESI‐MS by comparing with the performance of conventional ESI‐MS. The ion signals generated by SAESI‐MS and APCI‐MS were observed in clearly different m/z ranges. A variety of potential compounds were detected in the petroleum ether extracts of Pogostemon cablin and Ligusticum chuanxiong. The relative abundances and signal intensities of the same ion signals from the stems, leaves and decoction pieces of Pogostemon cablin were significantly different by SAESI‐MS.

Conclusions

As a convenient and efficient method, SAESI‐MS can be used to directly detect compounds (especially the low‐polarity compounds) in nonpolar or low‐polarity solvent extracts of herbal medicines, providing abundant chemical information for pharmacological studies. SAESI‐MS allows the simultaneous qualitative analysis of multiple compounds in the same complex samples and is thus particularly suitable for the preliminary screening of compounds in complex samples. SAESI‐MS can be used to differentiate the different parts of herbal medicines.
Cascading ripples: Contagion effects of entrepreneurial activity on self‐employment attitudes and choices in regional cohorts
Authors: Nikolaev Boris N. , Wood Matthew S.
Published: November 2017

Research Summary: We introduce a contagion model of self‐employment that relates regional cohort self‐employment to individuals’ preferences for and decisions toward engaging in entrepreneurial action. We test the predictions of our model via evidence from two studies. Study 1 uses cross‐sectional data from the U.S. General Social Survey (GSS) and examines the correlation between regional cohort self‐employment and individuals’ attitudes for self‐employment. Study 2 uses longitudinal data from the Household, Income, and Labour Dynamics in Australia (HILDA) survey and examines the likelihood of transitioning into self‐employment as a function of regional cohort entrepreneurship. Our results provide evidence that individuals who belong to regional cohorts with a greater proportion of entrepreneurs are more likely to express favorable attitudes toward self‐employment and to enter into self‐employment.

Managerial Summary: A large literature in the social sciences indicates that people's preferences and actions are influenced by the behaviors of those around them. We find this is true when it comes to entrepreneurship. Specifically, we document that people who live in regions with higher proportions of entrepreneurs are more likely to express favorable attitudes toward self‐employment and are more likely to start new business ventures. This suggests that people embedded in environments where there is a lot of entrepreneurial activity are more likely to “catch the bug” of self‐employment, as they use already‐established entrepreneurs in the region as a roadmap for their own thinking and action.
Growing with the market: How changing conditions during market growth affect formation and evolution of interfirm ties
Authors: Ozcan Pinar
Published: November 2017

Research Summary: Market conditions are known to matter for firm performance and growth. This study explores how changing levels of uncertainty and competition affect interfirm ties of entrepreneurial firms as markets transition from nascent to growth stage. Tracing six entrepreneurial game publishers during the growth stage of the U.S. wireless gaming market, the findings reveal that in a growth stage market, as uncertainty decreases, certain ties of entrepreneurial firms are terminated. First, existing partners may cut ties and become competitors after entering the market directly. This is a “winner's curse” as more successful firms are more likely to entice their partners to enter the market directly. Second, ties may be terminated as prominent firms that are “overwhelmed” with too many partners cut ties with low to mediocre performance, while their remaining partners enter a positive spiral of tie strength and performance. Finally, as uncertainty decreases, new firms may enter the market as competitors to prominent firms. While entrepreneurial firms with high‐ and low‐performing ties to prominent partners may find ties with these new entrants attractive, those with mediocre ties to few prominent partners find this move too risky and wait for a first mover to legitimate it. Overall, the findings show that changing levels of uncertainty and competition in growth stage markets can have different consequences for firms due to heterogeneity in their ties and power relative to partners. The findings provide several contributions to literature regarding the relationship among interfirm ties, firm performance, and market evolution.

Managerial Summary: Based on interviews at six entrepreneurial game publishers in the United States and their partners, this study shows how changing levels of uncertainty and competition in growing markets can have different consequences for firms based on the different types of alliances in their portfolio and their power relative to partners. The findings highlight the importance of managing partners differently based on alliance type and goal of the partner. They advocate remaining flexible in alliance management as information asymmetries, intentions and bargaining power of partners can change and lead to abrupt alliance dissolution. They show that alliance portfolio management goes beyond a firm's capability of managing individual alliances, and provide a tool for managers to evaluate their alliance portfolios and take the necessary precautions.
Low Osteogenic Yield in Human Pluripotent Stem Cells Associates with Differential Neural Crest Promoter Methylation
Authors: Sparks Nicole Renee Lee , Martinez Ivann Kenneth Carvajal , Soto Cristina Helen , zur Nieden Nicole Isolde
Published: November 2017

Human pluripotent stem cell-derived osteoblasts possess great potential for use in bone disorder elucidation and repair; however, while the general ability of human pluripotent stem cells to differentiate into osteoblasts and lay down bone-specific matrix has been shown, previous studies lack the complete characterization of the process whereby such osteoblasts are derived as well as a comparison between the osteogenic efficiency of multiple cell lines. Here, we compared the osteogenic potential of two human induced pluripotent stem cell lines (RIV9 and RIV4) to human H9 embryonic stem cells. Generally capable of osteogenic differentiation, the overall osteogenic yield was lower in the RIV9 and RIV4 lines and correlated with differential expression of osteocalcin (OCN) in mature cultures and PAX7 and TWIST1 during early differentiation. In the undifferentiated cells, the promoters of the latter two genes were differentially methylated potentially explaining the variation in differentiation efficiency. Furthermore, the expression signatures of selected neural crest and mesodermal genes and proteins suggested that H9 cells preferentially gave rise to neural crest-derived osteoblasts, whereas the osteoblasts in the RIV9 cultures were generated both through a mesodermal and a neural crest route although each at a lower rate. These data suggest that epigenetic dissimilarities between multiple PSC lines may lead to differences in lineage derivation and mineralization. Since osteoblast progenitors from one origin inadequately repair a defect in the other, these data underscore the importance of screening human pluripotent stem cells lines for the identity of the osteoprogenitors they lay down.
An exactly solvable quench protocol for integrable spin models
Authors: Das Diptarka , Das Sumit R. , Galante Damián A. , Myers Robert C. , Sengupta Krishnendu
Published: November 2017

Abstract

Quantum quenches in continuum field theory across critical points are known to display different scaling behaviours in different regimes of the quench rate. We extend these results to integrable lattice models such as the transverse field Ising model on a one-dimensional chain and the Kitaev model on a two-dimensional honeycomb lattice using a nonlinear quench protocol which allows for exact analytical solutions of the dynamics. Our quench protocol starts with a finite mass gap at early times and crosses a critical point or a critical region, and we study the behaviour of one point functions of the quenched operator at the critical point or in the critical region as a function of the quench rate. For quench rates slow compared to the initial mass gap, we find the expected Kibble-Zurek scaling. In contrast, for rates fast compared to the mass gap, but slow compared to the inverse lattice spacing, we find scaling behaviour similar to smooth fast continuum quenches. For quench rates of the same order of the lattice scale, the one point function saturates as a function of the rate, approaching the results of an abrupt quench. The presence of an extended critical surface in the Kitaev model leads to a variety of scaling exponents depending on the starting point and on the time where the operator is measured. We discuss the role of the amplitude of the quench in determining the extent of the slow (Kibble-Zurek) and fast quench regimes, and the onset of the saturation.
Differential distributions for t-channel single top-quark production and decay at next-to-next-to-leading order in QCD
Authors: Berger Edmond L. , Gao Jun , Zhu Hua Xing
Published: November 2017

Abstract

We present a detailed phenomenological study of the next-to-next-to-leading order (NNLO) QCD corrections for t-channel single top (anti-)quark production and its semi-leptonic decay at the CERN Large Hadron Collider (LHC). We find the NNLO corrections for the total inclusive rates at the LHC with different center of mass energies are generally smaller than the NLO corrections, indicative of improved convergence. However, they can be large for differential distributions, reaching a level of 10% or more in certain regions of the transverse momentum distributions of the top (anti-)quark and the pseudo-rapidity distributions of the leading jet in the event. In all cases the perturbative hard-scale uncertainties are greatly reduced after the NNLO corrections are included. We also show a comparison of the normalized parton-level distributions to recent data from the 8 TeV measurement of the ATLAS collaboration. The NNLO corrections tend to shift the theoretical predictions closer to the measured transverse momentum distribution of the top (anti)-quark. Importantly, for the LHC at 13 TeV, we present NNLO cross sections in a fiducial volume with decays of the top quark included.
Entanglement shadows in LLM geometries
Authors: Balasubramanian Vijay , Lawrence Albion , Rolph Andrew , Ross Simon F.
Published: November 2017

Abstract

We find a new example of an asymptotically AdS
5 × S
5 geometry which has an entanglement shadow: that is, a region of spacetime which no Ryu-Takayanagi minimal surface enters. Our example is a particular case of the supersymmetric LLM geometries. Our results illustrate how minimal surfaces, which holographically geometrize entanglement entropy, can fail to probe the whole of spacetime, posing a challenge for attempts to directly reconstruct holographic geometries from the entanglement entropies of the dual field theory. We also comment on the relation to previous investigations of minimal surfaces localised in the S
5 factor of AdS5 × S
5.
Amplitudes on plane waves from ambitwistor strings
Authors: Adamo Tim , Casali Eduardo , Mason Lionel , Nekovar Stefan
Published: November 2017

Abstract

In marked contrast to conventional string theory, ambitwistor strings remain solvable worldsheet theories when coupled to curved background fields. We use this fact to consider the quantization of ambitwistor strings on plane wave metric and plane wave gauge field backgrounds. In each case, the worldsheet model is anomaly free as a consequence of the background satisfying the field equations. We derive vertex operators (in both fixed and descended picture numbers) for gravitons and gluons on these backgrounds from the worldsheet CFT, and study the 3-point functions of these vertex operators on the Riemann sphere. These worldsheet correlation functions reproduce the known results for 3-point scattering amplitudes of gravitons and gluons in gravitational and gauge theoretic plane wave backgrounds, respectively.
Onset of hydrodynamics for a quark-gluon plasma from the evolution of moments of distribution functions
Authors: Blaizot Jean-Paul , Yan Li
Published: November 2017

Abstract

The pre-equilibrium evolution of a quark-gluon plasma produced in a heavy-ion collision is studied in the framework of kinetic theory. We discuss the approach to local thermal equilibrium, and the onset of hydrodynamics, in terms of a particular set of moments of the distribution function. These moments quantify the momentum anisotropies to a finer degree than the commonly used ratio of longitudinal to transverse pressures. They are found to be in direct correspondence with viscous corrections of hydrodynamics, and provide therefore an alternative measure of these corrections in terms of the distortion of the momentum distribution. As an application, we study the evolution of these moments by solving the Boltzmann equation for a boost invariant expanding system, first analytically in the relaxation time approximation, and then numerically for a quark-gluon plasma with a collision kernel given by leading order 2 ↔ 2 QCD matrix elements in the small angle approximation.
Slepton non-universality in the flavor-effective MSSM
Authors: López-Ibáñez M. Luisa , Melis Aurora , Pérez M. Jay , Vives Oscar
Published: November 2017

Abstract

Supersymmetric theories supplemented by an underlying flavor-symmetry

$$ {\mathcal{G}}_f $$

G
f

provide a rich playground for model building aimed at explaining the flavor structure of the Standard Model. In the case where supersymmetry breaking is mediated by gravity, the soft-breaking Lagrangian typically exhibits large tree-level flavor violating effects, even if it stems from an ultraviolet flavor-conserving origin. Building on previous work, we continue our phenomenological analysis of these models with a particular emphasis on leptonic flavor observables. We consider three representative models which aim to explain the flavor structure of the lepton sector, with symmetry groups

$$ {\mathcal{G}}_f=\Delta (27) $$

G
f

=
Δ

27

, A
4, and S
3.
A generic anti-QCD jet tagger
Authors: Aguilar-Saavedra J. A. , Collins Jack , Mishra Rashmish K.
Published: November 2017

Abstract

New particles beyond the Standard Model might be produced with a very high boost, for instance if they result from the decay of a heavier particle. If the former decay hadronically, then their signature is a single massive fat jet which is difficult to separate from QCD backgrounds. Jet substructure and machine learning techniques allow for the discrimination of many specific boosted objects from QCD, but the scope of possibilities is very large, and a suite of dedicated taggers may not be able to cover every possibility — in addition to making experimental searches cumbersome. In this paper we describe a generic model-independent tagger that is able to discriminate a wide variety of hadronic boosted objects from QCD jets using N -subjettiness variables, with a significance improvement varying between 2 and 8. This is in addition to any improvement that might come from a cut on jet mass. Such a tagger can be used in model-independent searches for new physics yielding fat jets. We also show how such a tagger can be applied to signatures over a wide range of jet masses without sculpting the background distributions, allowing to search for new physics as bumps on jet mass distributions.
Breakdown of the equal area law for holographic entanglement entropy
Authors: McCarthy Fiona , Kubizňák David , Mann Robert B.
Published: November 2017

Abstract

We investigate a holographic version of Maxwell’s equal area law analogous to that for the phase transition in the black hole temperature/black hole entropy plane of a charged AdS black hole. We consider proposed area laws for both the black hole temperature/holographic entanglement entropy plane and the black hole temperature/2- point correlation function plane. Despite recent claims to the contrary, we demonstrate numerically that neither proposal is valid. We argue that there is no physical reason to expect such a construction in these planes.
ABJM θ-Bremsstrahlung at four loops and beyond: non-planar corrections
Authors: Bianchi Marco S. , Mauri Andrea
Published: November 2017

Abstract

We consider the Bremsstrahlung function associated to a 1/6-BPS Wilson loop in ABJM theory, with a cusp in the couplings to scalar fields. We non-trivially extend its recent four-loop computation at weak coupling to include non-planar corrections. We have recently proposed a conjecture relating this object to supersymmetric circular Wilson loops with multiple windings, which can be computed via localization. We find agreement between this proposal and the perturbative computation of the Bremsstrahlung function, including color sub-leading corrections. This supports the conjecture and hints at its validity beyond the planar approximation.
On non-supersymmetric conformal manifolds: field theory and holography
Authors: Bashmakov Vladimir , Bertolini Matteo , Raj Himanshu
Published: November 2017

Abstract

We discuss the constraints that a conformal field theory should enjoy to admit exactly marginal deformations, i.e. to be part of a conformal manifold. In particular, using tools from conformal perturbation theory, we derive a sum rule from which one can extract restrictions on the spectrum of low spin operators and on the behavior of OPE coefficients involving nearly marginal operators. We then focus on conformal field theories admitting a gravity dual description, and as such a large-N expansion. We discuss the relation between conformal perturbation theory and loop expansion in the bulk, and show how such connection could help in the search for conformal manifolds beyond the planar limit. Our results do not rely on supersymmetry, and therefore apply also outside the realm of superconformal field theories.
Phylogeographic testing of alternative histories of single‐origin versus parallel evolution of early flowering serpentine populations of Picris hieracioides L. (Asteraceae) in Japan
Authors: Sakaguchi Shota , Horie Kenji , Kimura Takuma , Nagano Atsushi J. , Isagi Yuji , Ito Motomi
Published: November 2017

Serpentine, a chemically extreme substrate with a discontinuous distribution, supports a high proportion of endemic plant species. The evolutionary pathway of edaphic endemics in isolated areas may be of parallel origin (convergence), but this can be difficult to detect due to similar sets of phenotypic traits repeatedly selected for by the extreme conditions of serpentine environments. Testing the alternative histories of single origin vs. parallel evolution in serpentine plant populations provides insight into the ability of plants to adapt to extreme serpentine environments and to disperse between isolated serpentine areas. In this study, we focused on the herb Picris hieracioides L. (Asteraceae), which includes early‐flowering serpentine populations surrounded by later flowering, non‐serpentine populations on Hokkaido Island, Japan. We performed population genetic analysis based on genome‐wide SNPs markers and quantified temporal overlap of flowering times under natural conditions. Phylogeographic analysis confirmed the occurrence of two genetic groups, corresponding to the serpentine and non‐serpentine races. Although the two races were found to occur in close parapatry over multiple paired soil sites, little evidence for hybridization was detected. The flowering times of the two races showed significant divergence, with flowering peaks separated by more than 1 month. Overall, this study supported the single origin of serpentine Picris populations, and showed the role of divergent flowering time as a strong prezygotic barrier to maintain the edaphic races over short spatial distances.
A Simplified Simulation Model of Ship Navigation for Safety and Collision Avoidance in Heavy Traffic Areas
Authors: Fang Ming-Chung , Tsai Kun-Yuan , Fang Chih-Chung
Published: November 2017

Based on our previously developed ship collision avoidance steering system, this paper develops a more extensive collision avoidance decision-making system for non-uniformly moving ships. A real-time simulator based on the Six-Dimensional (6D) Manoeuvring Modelling Group (MMG) model is used to simulate the ship's motion. To validate the manoeuvring mathematical model, sea trial measurements of a container ship (C-3) have been selected. This study incorporates Nomoto's second-order model into a numerical model to calculate the turning characteristics of the ship. The manoeuvring indices of Nomoto's model are the knowledge base of the simplified ship simulation model. To verify the ship collision avoidance system with respect to different traffic factors, simple and complex collision avoidance cases have been designed in fast-time simulations with multi-ship encounter conditions. The simplified simulation model developed here can quickly determine the helm angle when the ship makes a collision avoidance manoeuvre, which is helpful for the safety of ship navigation in heavy traffic areas.
Long noncoding RNAs that respond to Fusarium oxysporum infection in ‘Cavendish’ banana (Musa acuminata)
Authors: Li Wenbin , Li Chunqiang , Li Shuxia , Peng Ming
Published: November 2017

Long noncoding RNAs (lncRNAs) are a class of genes that influence a variety of biological functions through acting as signal, decoy, guide, and scaffold molecules. In banana (Musa spp.), an important economic fruit crop, particularly in Southeast Asia, the wilt disease caused by Fusarium oxysporum f. sp. cubense (Foc), especially strain Foc TR4, is disastrous. In banana, how the biogenesis of these lncRNAs is regulated in response to pathogen infection is still largely unknown. In this study, strand-specific paired-end RNA sequencing of banana samples was performed on susceptible and resistant cultivars inoculated with Foc, with three biological replicates and at two different times after infection. Overall, 5,294 lncRNAs were predicted with high confidence through strict filtration, including long intergenic ncRNA (lincRNA) and antisense lncRNA. Differentially expressed (DE) lncRNAs were identified in response to Foc infection in the inoculated versus the mock-inoculated banana of the susceptible ‘BX’ and resistant ‘NK’ cultivars. Through KEGG, GO, and the expression levels of the DE lncRNAs, some DE lncRNAs were predicted to be involved in plant-pathogen interactions and phytohormone signal transduction. In this study, this catalog of lncRNAs and their properties will facilitate further experimental studies and functional classifications of these genes.
Sublethal effects of buprofezin on development and reproduction in the white-backed planthopper, Sogatella furcifera (Hemiptera: Delphacidae)
Authors: Ali Ehsan , Liao Xun , Yang Peng , Mao Kaikai , Zhang Xiaolei , Shakeel Muhammad , Salim Abdalla M. A. , Wan Hu , Li Jianhong
Published: November 2017

In the present study, the effects of sublethal concentrations of buprofezin on life-table traits ofS. furciferawere evaluated for two consecutive generations (F0 and F1). Our results exhibited that the fecundity, life span (longevity) and hatchability of the F0 and F1 generations were significantly decreased at LC30compared to the control. However, copulation was not significantly affected for the F0 or F1 generations at sublethal concentrations. The female life span was affected negatively at both treatments in F0 and at LC30in F1, compared to the control. Furthermore, significant effects of the sublethal concentrations were found on the developmental rate of all instars except the 3rdinstar of F1. However, the pre-adult period, total pre-oviposition period (TPOP) and adult pre-oviposition period (APOP) significantly increased in F1 individuals at LC30and LC10compared to the control. Our findings revealed that demographic characters (survival rate, intrinsic rate of increase (ri), finite rate of increase (λ), net reproductive rate (R0), and gross reproductive rate (GRR)) of the F1 generation (from F0 parents) significantly decreased compared to the untreated group; however, the generation time (T) increased at LC10. Therefore, the results suggested that buprofezin could adversely affect individuals in the successive generation.
Molecular dynamics simulation of geminal dicationic ionic liquids [Cn(mim)2][NTf2]2– structural and dynamical properties
Authors: Moosavi Majid , Khashei Fatemeh , Sedghamiz Elaheh
Published: November 2017

The structural and dynamical properties of two dicationic ionic liquids,i.e.[Cn(mim)2][NTf2]2withn= 3 and 5, have been studied to obtain a fundamental understanding of the molecular basis of the macroscopic and microscopic properties of the bulk liquid phase.
Self-assembled uracil complexes containing tautomeric uracils: an IRMPD spectroscopic and computation study of the structures of gaseous uracilnCa2+ (n = 4, 5, or 6) complexes
Authors: Cheng Ruodi , Rose Victoria E. , Power Barry , Fridgen Travis D.
Published: November 2017

The structures of doubly-charged uracil (U) complexes with Ca2+, UnCa2+ (n = 4, 5, 6), were studied by infrared multiphoton dissociation (IRMPD) spectroscopy and computational methods.
Synthesis of carbon-based fluorescent polymers driven by catalytically active magnetic bioconjugates
Authors: Rodríguez-Padrón Daily , Jodlowski Alexander D. , de Miguel Gustavo , Puente-Santiago Alain R. , Balu Alina M. , Luque Rafael
Published: November 2017

Bioconjugates based on a redox protein and iron oxide magnetic nanoparticles were employed in the catalytic polymerization of phenylenediamines to obtain carbon-based fluorescent polymers.
Relating motivation and student outcomes in general organic chemistry
Authors: Austin Ara C. , Hammond Nicholas B. , Barrows Nathan , Gould Deena L. , Gould Ian R.
Published: November 2017

A central tenet of self-regulated learning theories is that students are motivated towards learning in order to self-regulate. It is thus important to identify student motivations in order to inform efforts to improve instructional strategies that encourage self-regulation. Here we describe a study aimed at characterizing the important motivation factors for students taking general organic chemistry, and how they connect to, and correlate with student performance. A cross-sectional study was conducted involving 2648 undergraduate student participants at two institutions over five semesters and four instructors. Motivation was measured using the Organic Chemistry Motivation Survey (OCMS), a modified form of Glynnet al.(2011)'s Science Motivation Questionnaire II (SMQ-II). The results suggest that the students were highly motivated towards earning a high grade, but that this grade motivation correlated only weakly with performance. Other intrinsic and extrinsic motivation factors were found to be low, suggesting that the students perceived organic chemistry to have little relevance to their interests and careers. However, student performance was strongly correlated with self-efficacy, and, to a lesser extent, self-determination. This finding implies that high-performing students tended to be self-regulated learners who are not motivated primarily by the relevance of the course content. Alternate sources of motivation that can drive self-regulation are discussed.
Effect of surfactant tail length and ionic strength on the interfacial properties of nanoparticle–surfactant complexes
Authors: Kirby Stephanie M. , Anna Shelley L. , Walker Lynn M.
Published: November 2017

Mixed nanoparticle–surfactant systems are effective foam stabilizing agents, but the lack of colloidal stability of the bulk dispersions makes interfacial characterization challenging.
Up-regulatedmiR-500aenhances hepatocarcinoma metastasis by repressing PTEN expression
Authors: Zhao Yufeng , Wang Yuehui , Wang Yaqiang
Published: November 2017

It has been shown that miR-500a may play an important role in the metastasis of hepatocarcinoma. The present study is to explore the influence of miR-500a on hepatocarcinoma proliferation and metastasis, and the related molecular mechanism. The levels of miR-500a in the serum and tissues of patients with metastatic or non-metastatic hepatocarcinoma or normal people were determined by quantitative reverse transcription-PCR (qRT-PCR). The proliferation, invasion, and cloning of hepatocarcinoma cell lines SMMC-7721 after transfection with mimic miR-500a or inhibitor miR-500a were determined. Luciferase reported assay was used to explore the relationship between miR-500a and phosphatase and tensin homologue (PTEN). Then, the protein expression of PTEN, p-Akt (S473), p-Akt (T308), Akt, p-mTOR, mTOR, p-4E-BP1, 4E-BP1, p-S6K, and S6K in SMMC-7721 cells were also determined by Western blotting. The expression of miR-500a in patients with metastatic hepatocarcinoma was significantly higher than the non-metastatic hepatocarcinoma. Overexpression of miR-500a promoted the proliferation, invasion, and cloning of SMMC-7721 cells. Luciferase reported assay showed miR-500a could directly target at 3′-UTR of PTEN. Overexpression of miR-500a significantly reduced the expression of PTEN, and enhanced phosphorylation of Akt, mTOR, S6K, and 4E-BP1. In conclusion, the expression of miR-500a was related to the proliferation and metastasis of hepatocarcinoma, which may be partly because of the activation of AKT/mTOR pathway through targetting PTEN.
Effects of GABAB receptor activation on spatial cognitive function and hippocampal neurones in rat models of type 2 diabetes mellitus
Authors: Cai Xiao-Jun , Wang Lei , Hu Chun-Mei
Published: November 2017

The present study was conducted with the aim being to investigate the effect γ-aminobutyric acid type B (GABAB) receptor activation have on spatial cognitive function and hippocampal neurones found in the rat models of type 2 diabetes mellitus (T2DM). T2DM rat models were then established, randomized, and subsequently assigned into normal control (NC), T2DM, T2DM + chemical grade propylene (CGP), T2DM + baclofen, and T2DM + CGP + baclofen groups. T2DM rats’ weight and blood sugar concentrations were monitored. The DMS-2 Morris water maze testing system was performed in order to figure out the spatial cognitive function of these rats. Reverse-transcription quantitative PCR (RT-qPCR) and Western blotting were also performed in order to detect GABAB mRNA and protein expressions. We used the Nissl staining method in order to detect the number of hippocampal neurones, TUNEL (terminal deoxyribonucleotidy transferase-mediated dUTP nick labeling) staining to detect cell apoptosis, and Western blotting method in order to measure the expressions of the apoptosis-related proteins (Bax, cytochrome c (Cyt-c), Caspase-3, and Bcl-2). In comparison with the T2DM group, the weight decreased, blood sugar concentration increased, and spatial cognitive function as well as hippocampal neurones were both impaired in the T2DM + CGP group, contrary to the rats in the T2DM + baclofen group who showed an opposite trend. The situation in the T2DM + CGP + baclofen group was better than that found in the T2DM + CGP group while proving to be more serious than that of the NC and T2DM + baclofen groups. Conclusively, activating the GABAB receptor improved spatial cognitive function and hippocampal neurones in the T2DM rats.
Modern fertility awareness methods: wrist wearables capture the changes in temperature associated with the menstrual cycle
Authors: Shilaih Mohaned , Goodale Brianna M. , Falco Lisa , Kübler Florian , De Clerck Valerie , Leeners Brigitte
Published: November 2017

Core and peripheral body temperatures are affected by changes in reproductive hormones during the menstrual cycle. Women worldwide use the basal body temperature (BBT) method to aid and prevent conception. However, prior research suggests that taking one’s daily temperature can prove inconvenient and subject to environmental factors. We investigate whether a more automatic, non-invasive temperature measurement system can detect changes in temperature across the menstrual cycle. We examined how wrist skin temperature (WST), measured with wearable sensors, correlates with urinary tests of ovulation and may serve as a new method of fertility tracking. One hundred and thirty-six eumenorrheic, non-pregnant women participated in an observational study. Participants wore WST biosensors during sleep and reported their daily activities. An at-home luteinizing hormone (LH) test was used to confirm ovulation. WST was recorded across 437 cycles (mean cycles/participant = 3.21, S.D. = 2.25). We tested the relationship between the fertile window and WST temperature shifts, using the BBT three-over-six rule. A sustained 3-day temperature shift was observed in 357/437 cycles (82%), with the lowest cycle temperature occurring in the fertile window 41% of the time. Most temporal shifts (307/357, 86%) occurred on ovulation day (OV) or later. The average early-luteal phase temperature was 0.33°C higher than in the fertile window. Menstrual cycle changes in WST were impervious to lifestyle factors, like having sex, alcohol, or eating prior to bed, that, in prior work, have been shown to obfuscate BBT readings. Although currently costlier than BBT, the present study suggests that WST could be a promising, convenient parameter for future multiparameter fertility awareness methods.
Hypertrophied myocardium is vulnerable to ischemia/reperfusion injury and refractory to rapamycin-induced protection due to increased oxidative/nitrative stress
Authors: Ma Lei-Lei , Li Yang , Yin Pei-Pei , Kong Fei-Juan , Guo Jun-Jie , Shi Hong-Tao , Zhu Jian-Bing , Zou Yun-Zeng , Ge Jun-Bo
Published: November 2017

Left ventricular hypertrophy (LVH) is causally related to increased morbidity and mortality following acute myocardial infarction (AMI) via still unknown mechanisms. Although rapamycin exerts cardioprotective effects against myocardial ischemia/reperfusion (MI/R) injury in normal animals, whether rapamycin-elicited cardioprotection is altered in the presence of LVH has yet to be determined. Pressure overload induced cardiac hypertrophied mice and sham-operated controls were exposed to AMI by coronary artery ligation, and treated with vehicle or rapamycin 10 min before reperfusion. Rapamycin produced marked cardioprotection in normal control mice, whereas pressure overload induced cardiac hypertrophied mice manifested enhanced myocardial injury, and was refractory to rapamycin-elicited cardioprotection evidenced by augmented infarct size, aggravated cardiomyocyte apoptosis, and worsening cardiac function. Rapamycin alleviated MI/R injury via ERK-dependent antioxidative pathways in normal mice, whereas cardiac hypertrophied mice manifested markedly exacerbated oxidative/nitrative stress after MI/R evidenced by the increased iNOS/gp91phox expression, superoxide production, total NO metabolites, and nitrotyrosine content. Moreover, scavenging superoxide or peroxynitrite by selective gp91phox assembly inhibitor gp91ds-tat or ONOO− scavenger EUK134 markedly ameliorated MI/R injury, as shown by reduced myocardial oxidative/nitrative stress, alleviated myocardial infarction, hindered cardiomyocyte apoptosis, and improved cardiac function in aortic-banded mice. However, no additional cardioprotective effects were achieved when we combined rapamycin and gp91ds-tat or EUK134 in ischemic/reperfused hearts with or without LVH. These results suggest that cardiac hypertrophy attenuated rapamycin-induced cardioprotection by increasing oxidative/nitrative stress and scavenging superoxide/peroxynitrite protects the hypertrophied heart from MI/R.
Improving data rate of indoor users through time sharing access of femtocell service in underlay heterogeneous network
Authors: Karar S. , Das Barman A.
Published: November 2017

This Letter proposes a cooperation policy between a macrocell and a hybrid access femtocell in an underlay heterogeneous network to improve the achievable data rate of an indoor macrocell user (MU) through time sharing access of the femtocell service together with mitigating cross‐tier interference through price‐based power control. Through numerical examples it is proved that the authors’ proposed cooperation policy is more beneficial to the macrocell not only for providing a higher achievable data rate for its MU but also for earning a higher revenue compared with the incentive‐based cooperation policy proposed earlier without much degradation of the achievable data rate performance of any associated femtocell user.
Adaptive sliding mode synchronisation for fractional‐order non‐linear systems in the presence of time‐varying actuator faults
Authors: Bataghva Meysam , Hashemi Mahnaz
Published: November 2017

This study presents an adaptive sliding mode synchronisation scheme for a class of fractional‐order non‐linear systems in the presence of unknown parameters, actuator faults, and disturbances. The designed adaptive controller compensates a general class of actuator faults without the need for any explicit fault detection. The parameters, times, and patterns of the considered faults are completely unknown. The proposed adaptive sliding mode synchronisation scheme can guarantee the asymptotic convergence of the synchronisation error to the origin despite the presence of actuator faults and uncertainties. The simulation results show the correctness and effectiveness of the proposed adaptive sliding mode fault compensation approach.
Analysis on the dynamic behaviours and interactions of VSC‐MTDC grid
Authors: Yuan Zheng , Zhengchun Du , Li Guiyuan
Published: November 2017

Different from the synchronisation stability for alternating current (AC) systems, the potential risk caused by the interaction between different terminals in voltage source converter‐based multi‐terminal direct current (VSC‐MTDC) grids is emerging, which may impose negative influences on system operation and control. Focusing on this topic, a comprehensive modal analysis is presented to analyse and characterise the dynamic behaviours and interactions of VSC‐MTDC grids. The state‐space model of VSC‐MTDC grids associated with AC systems is developed and participation factor analysis is utilised to identify the physical source of the oscillation modes. This study investigates the voltage fluctuations in VSC‐MTDC grids induced by the oscillation modes with the application of extended participation factors. A Monte Carlo‐based statistic method has been adopted for the calculations. The interactions between different terminals are identified using mode shape analysis, and quantitative calculation of eigenvalue sensitivities is presented to assess the effect of parameter variation on modal shift. Furthermore, an approach based on the singular value decomposition is proposed for the quantitative analysis of the interaction strength among different control loops. Simulations on a multi‐terminal test system are carried out to verify the analytical results.
Adaptive overcurrent protection against ferroresonance
Authors: Rezaei Salman
Published: November 2017

Catastrophic equipment failures continue to occur today due to ferroresonance even though this phenomenon has been extensively studied over the past 90 years. Ferroresonance may also cause mal operation of some protective devices like overcurrent protection. Manitoba hydro network is analysed in PSCAD/EMTDC to recognise ferroresonance in case of line and plant outage. Impact of ferroresonance on mal operation of current‐based protective relays is analysed. Then, an adaptive algorithm is designed in the relay to recognise ferroresonance and prevent mal operation of the relay.
Efficient and accurate hybrid model of modular multilevel converters for large MTDC systems
Authors: Yu Siqi , Zhang Shuqing , Wei Yingdong , Zhu Yanan , Sun Yubo
Published: November 2017

Modular multilevel converters (MMCs) play a critical role in the future energy Internet pattern. Therefore, proper models for the simulation of complex systems with multiple MMCs are required. This study proposes a simplified equivalent model (SEM) based on the implicit trapezoidal method and Thevenin equivalent. The model can accurately simulate arm voltages of the MMC and is thus capable of simulating system‐level transients after faults and disturbances, circulating currents and subsynchronous oscillation components. Subsequently, a hybrid model combining SEM and a detailed equivalent model (DEM) is built to improve the overall simulation speed in scenarios where submodule‐level transients are mixed with system‐level ones. Finally, this study notes that the major difference between DEM and SEM results only from the voltage‐balancing cycle. An experiential formula is given to regulate SEM when the voltage‐balancing cycle is large, where the difference may become obvious/insufferable.
Analytical solutions for the self‐ and mutual inductances of arbitrary triangular coils with rectangular cross‐section
Authors: Wu Dehui , He Tianfu , Wang Xiaohong , Sun Qisheng
Published: November 2017

A new analytical solution for the self‐ and mutual inductances of arbitrary triangular coils with rectangular cross‐section is presented. Firstly, the electromagnetic field problem of a filamentary triangular coil is solved based on second‐order vector potential. Then, the solution is effectively extended to the arbitrary triangular coil with different track widths by changing the radius of its inscribed circle. A series of new formulae are given for calculating electromagnetic field, self‐ and mutual inductances of triangular coils with different shapes, separation distances, lateral misalignments or angular misalignments. Finally, the verification experiments are carried out on a series of irregular and regular triangular coils. Also, the experimental results show that the measured values are in good accordance with the calculated ones.
The hantenna: experimental assessment of the human hand as an antenna
Authors: Rueda Linares Sergio , Martin Garcia David , Yan Sen , Volski Vladimir , Vandenbosch Guy A.E.
Published: November 2017

The objective of this work is to address the issue of using the human hand as an antenna, the hantenna. The method used is based on an experiment involving a wireless link between a traditional antenna and the human hand functioning as an antenna. Measurements were performed over six subjects in an anechoic chamber. The results show very clear trends. In the frequency band 800 MHz–2 GHz the human hand does improve the link performance, mainly by providing a better matching to the feeding cable. The main conclusion is that expressed in realised gain, the improvement of the link may go up to 15–20 dB, which is very considerable. The significance of the work is that it shows how to use the human hand as an antenna in certain non‐critical telecom applications.
Fully dielectric interference‐based SPDT with liquid crystal phase shifters
Authors: Jost Matthias , Reese Roland , Nickel Matthias , Maune Holger , Jakoby Rolf
Published: November 2017

This study presents the first continuously tuneable, interference‐based W‐band single‐pole double‐throw (SPDT), fully implemented in subwavelength (sWL) dielectric fibre topology. Key components are the phase shifters in the two branches of the SPDT, which are realised as line sections filled with liquid crystal. They allow not only to adjust the signal ratios at the two output ports but also to tune the operating frequency between 93 and 110 GHz with isolation >25 dB. The first proof‐of‐concept SPDT demonstrator is realised and characterised at W‐band. However, concept and technology are scalable to higher frequencies. The complete SPDT with the WR10‐to‐sWL fibre transitions exhibits an insertion loss (IL) at the thru‐port between 5 and 7 dB in the frequency range from 85 to 110 GHz, where back‐to‐back measurements of the transitions itself already indicate an IL of up to 1.6 dB. The measurements at the isolated port of the SPDT exhibit transmission coefficients of less than −25 dB between 93 and 110 GHz with a minimum of −40 dB.
Low‐cost mechanism to reconfigure the operating frequency band of a Vivaldi antenna for cognitive radio and spectrum monitoring applications
Authors: Borda‐Fortuny Cristina , Tong Kin‐Fai , Chetty Kevin
Published: November 2017

A frequency agile Vivaldi antenna whose operating frequency band can be switched between two selected bands is proposed in this study for spectrum monitoring and cognitive radio applications. A radiofrequency (RF) switch is introduced into the back‐slot of a Vivaldi antenna to allow switching of the operational band. The realised gains of the antenna are 10.5 dBi in the low band around 3.1 GHz, and 12 dBi in high band around 4.1 GHz. The radiation pattern is stable and its direction is consistent across the two bands. This design can be applied to multiple reconfigurable bands by using more RF switches to tune the desired operating frequency. A set of reliable design equations has been provided as well. This reconfigurable antenna offers improved gain and isolation over multiple, wideband and multiband antennas without increasing the cost and size when compared with those designs reported.
Joint registration and multi‐target tracking based on labelled random finite set and expectation maximisation
Authors: Li Minzhe , Jing Zhongliang , Pan Han , Dong Peng
Published: November 2017

A new analytical algorithm is developed to address the problem of joint sensor registration and multi‐target tracking with varying target number and observation uncertainty based on the labelled random finite set (RFS) and expectation maximisation (EM). A new complete data log‐likelihood function is derived with the measurement and state RFS variables, and the EM approach is employed to jointly estimate the sensor biases and target states. Moreover, a recursive implementation is provided to deal with the measurement accumulation, and the situation of the time‐varying biases is handled. Since the estimates of the bias and state are analytically calculated, the performance of the proposed method is better than that of the traditional methods. The effectiveness and superiority of the proposed algorithm are verified using numerical simulations.