bluuebunny/crossref_metadata_2025 huggingface dataset:
Nanoemulsions for food fortification with lipophilic vitamins: Production challenges, stability, and bioavailability
Authors: Öztürk Bengü
Published: January 2017

Essential micronutrients, such as lipophilic vitamins are vital for human health and wellbeing. There is a growing demand on consuming vitamin‐fortified foods due to the increasing awareness of consumers to common life‐treating diseases. People may not take the required daily intake (RDI) amount of these vitamins due to the limited natural sources, malnutrition facts, and loss of their chemical stability during food production, storage, and transportation. Protective encapsulation technologies are required during food fortification to prevent vitamins from degradation and enhance their bioavailability in human gastrointestinal system. Oil‐in‐water nanoemulsions are described as promising delivery systems by the researchers to encapsulate and stabilize lipophilic vitamins and thus enhance their bioavailability. This review covers the challenges in production methods and factors affecting the stability of lipophilic vitamins and nanoemulsion delivery systems as well and the most recent studies on bioavailability evaluation of vitamins A, D, E encapsulated in oil‐in‐water nanoemulsions.

Practical applications: Food fortification with essential micronutrients, such as vitamins A, D, and E contributes to human health by providing the intake of sufficient amounts to prevent diseases (e.g., osteoporosis, osteomalacia, suppressed immune system, cancer, loss of vision, cardiovascular diseases) treating the quality of the life and the survival. Lipid‐based nanoemulsion delivery systems can be used to encapsulate these lipophilic vitamins to increase their solubility, stability, and bioavailability, and also they provide an advantage as to be fortified in aqueous‐based food/beverages rather than only lipid‐based formulations. Staple foods and beverages, such as orange juice, milk, cheese, and bread, could be fortified with stabilized vitamin enriched nanoemulsions, so that human can get greater benefit from these micronutrients.

Oil‐in‐water nanoemulsions are consisted of a lipophilic core (oil phase) where lipophilic bioactive compound is entrapped and hydrophilic shell (aqueous phase), and an amphiphilic interfacial layer composed of the emulsifier/surfactant. Nanoemulsions produced by both low‐ and high‐energy methods are promising delivery systems to encapsulate and stabilize the lipophilic vitamins during food fortification and enhance their bioavailability. The challenges in production methods, factors affecting the stability, and the most recent studies on bioavailability evaluation of vitamins A, D, E encapsulated in oil‐in‐water nanoemulsions are covered in this review.
Molecular Structure, Intramolecular Hydrogen Bonding, Solvent‐Induced Isomerization, and Tautomerism in Azolylmethylidene Derivatives of 2‐Indanone
Authors: Sigalov Mark V. , Shainyan Bagrat A. , Chipanina Nina N. , Oznobikhina Larisa P.
Published: January 2017

Bis adducts of 2‐indanone with 1H‐pyrrole‐2‐carbaldehyde, 1H‐imidazole‐2‐carbaldehyde, 1H‐imidazole‐5‐carbaldehyde, and 1H‐indazole‐3‐carbaldehyde 3–6 have been synthesized and the intertwined processes of tautomeric NH proton transfer, intra‐ and intermolecular H‐bond rupture and formation, and Z/Z, Z/E, and E/E‐isomerization have been studied by NMR and FTIR spectroscopy and by conducting DFT calculations. Pyrrole derivative 3 both in chloroform and in dimethyl sulfoxide (DMSO) exists exclusively in the form of the Z,Z‐isomer stabilized by two intramolecular N–H···O hydrogen bonds. For derivatives 4–6, the isomeric composition depends on the solvent so that in polar media such as DMSO and pyridine the Z,E‐ and E,E‐isomers predominate. The driving force for isomerization of 4–6 is stabilization of the Z,E‐ and E,E‐isomers in basic polar solvents due to formation of intermolecular NH···B and intramolecular C–H···N hydrogen bonds. The suggested mechanism of isomerization includes proton transfer from nitrogen to oxygen in the Z‐moiety followed by rotation about the C–C bond in the formed enol and isomerization of the latter to the E‐moiety of the ketone tautomer.
Depth‐averaged non‐hydrostatic extension for shallow water equations with quadratic vertical pressure profile: equivalence to Boussinesq‐type equations
Authors: Jeschke Anja , Pedersen Geir K. , Vater Stefan , Behrens Jörn
Published: January 2017

We reformulate the depth‐averaged non‐hydrostatic extension for shallow water equations to show equivalence with well‐known Boussinesq‐type equations. For this purpose, we introduce two scalars representing the vertical profile of the non‐hydrostatic pressure. A specific quadratic vertical profile yields equivalence to the Serre equations, for which only one scalar in the traditional equation system needs to be modified. Equivalence can also be demonstrated with other Boussinesq‐type equations from the literature when considering variable depth, but then the non‐hydrostatic extension involves mixed space–time derivatives. In case of constant bathymetries, the non‐hydrostatic extension is another way to circumvent mixed space–time derivatives arising in Boussinesq‐type equations. On the other hand, we show that there is no equivalence when using the traditionally assumed linear vertical pressure profile. Linear dispersion and asymptotic analysis as well as numerical test cases show the advantages of the quadratic compared with the linear vertical non‐hydrostatic pressure profile in the depth‐averaged non‐hydrostatic extension for shallow water equations. Copyright © 2017 John Wiley & Sons, Ltd.
Ethnic differences in the incidence of cancer in Norway
Authors: Hjerkind Kirsti V , Qureshi Samera A , Møller Bjørn , Weiderpass Elisabete , Deapen Dennis , Kumar Bernadette , Ursin Giske
Published: January 2017

Traditionally there have been differences in cancer incidence across geographic regions. When immigrants have moved from low‐income to high‐income countries, their incidence have changed as they have adapted to the lifestyle in the new host country. Given worldwide changes in lifestyle factors over time, we decided to examine cancer incidence in immigrant groups in Norway, a country with a recent immigration history, complete cancer registration and universal public health care. We linked immigration history for the complete population to information on cancer diagnosis from the Cancer Registry of Norway for the period 1990–2012. Age‐standardized (world) overall and site‐specific cancer incidence were estimated for different immigrant groups and compared to incidence among individuals born in Norway. Among 850,008 immigrants, 9,158 men and 10,334 women developed cancer, and among 5,508,429 Norwegian‐born, 263,316 men and 235,020 women developed cancer. While incidence of breast and colorectal cancer were highest among individuals born in Norway and other high‐income countries, other cancer types were higher in immigrants from low‐income countries. Lung cancer incidence was highest in Eastern European men, and men and women from Eastern Europe had high incidence of stomach cancer. Incidence of liver cancer was substantially higher in immigrants from low‐income countries than in individuals born in Norway and other high‐income countries. Our results mirror known cancer challenges across the world. Although cancer incidence overall is lower in immigrants from low‐income countries, certain cancers, such as lung, liver and stomach cancer, represent major challenges in specific immigrant groups.
Regulation of chondrocyte functions by transient receptor potential cation channel V6 in osteoarthritis
Authors: Song Tengfei , Ma Jun , Guo Lei , Yang Peng , Zhou Xuhui , Ye Tianwen
Published: January 2017

Transient receptor potential vanilloid (TRPV) channels function to maintain the dynamic balance of calcium signaling and calcium metabolism in bones. The goal of this study was to determine the potential role of TRPV6 in regulation of chondrocytes. The level of TRPV6 expression was analyzed by western blot in articular cartilage derived from the knee joints of osteoarthritis (OA) rat models and OA patients. Bone structure and osteoarthritic changes in the knee joints of TRPV6 knockout mice were examined using micro‐computed and histological analysis at the age of 6 and 12 months old. Furthermore, to investigate the effects of TRPV6 on chondrocyte extracellular matrix secretion, the release of matrix degrading enzymes, cell proliferation, and apoptosis, we decreased and increased TRPV6 expression in chondrocytes with lentiviral constructs encoding shRNA targeting TRPV6 and encoding TRPV6, respectively. The results showed that the level of TRPV6 expression in an OA rat model was markedly down‐regulated. TRPV6 knockout mice showed severe osteoarthritis changes, including cartilage fibrillation, eburnation, and loss of proteoglycans. In addition, deficiency of TRPV6 clearly affected chondrocyte function, such as extracellular matrix secretion, the release of matrix degrading enzymes, cell proliferation, and apoptosis. Taken together, our results implicated that TRPV6 channel, as a chondro‐protective factor, was involved in the pathogenesis of OA.
Novel circulating biomarkers for non‐alcoholic fatty liver disease: A systematic review
Authors: Sahebkar Amirhossein , Sancho Elena , Abelló David , Camps Jordi , Joven Jorge
Published: January 2017

Currently, a liver biopsy remains the only reliable way to precisely diagnose non‐alcoholic fatty liver disease (NAFLD) and establish the severity of liver injury, presence of fibrosis, and architecture remodeling. However, the cost and the intrinsic invasive procedure of a liver biopsy rules it out as a gold standard diagnostic test, and the imaging test are not the best choice due to the price, and currently is being refined. The lack of a biomarker of NAFLD pushes to develop this new line of research. The aim of the present systematic review is to clarify and update all the NAFLD biomarkers described in the literature until recently. We highlight α‐ketoglutarate and CK18‐F as currently the best potential biomarker of NAFLD. However, due to methodological differences, we propose the implementation of international, multicenter, multiethnic studies with larger population size, and biopsy proven NAFLD diagnosis to analyze and compare α‐ketoglutarate and CK18‐F as potential biomarkers of the silent evolution of NAFLD.
Reciprocal regulation between βTrCP and Smurf1 suppresses proliferative capacity of liver cancer cells
Authors: Zhang Yue , Wang Wenhua , Cai Si , Chen Yan , Wang Qinwan , Pan Qiuhui , Sun Fenyong , Wang Jiayi
Published: January 2017

We previously reported that both the ubiquitin E3 ligases βTrCP (beta‐transducin repeat‐containing E3 ubiquitin protein ligase) and Smurf1 (SMAD‐specific E3 ubiquitin protein ligase 1) play similar antitumorigenic roles in liver cancer cells. However, whether and how they are reciprocally regulated remains elusive. Here, we show that βTrCP interacts with Smurf1 through the 7 × tryptophan (W) aspartic acid (D)(WD) 40 and the region homologous to the E6‐AP carboxyl terminus (HECT) domains, which are the E3 ligase domains of βTrCP and Smurf1, respectively. The E3 ligase domains of βTrCP and Smurf1 are also critical for maintaining the protein expressions of Smurf1 and βTrCP. Moreover, a positive correlation between βTrCP and Smurf1 was also revealed by tissue microarray analysis, indicating that this relationship might be important in liver cancer. Further, we found that Smurf1 increases the protein stability of βTrCP, possibly by reducing autoubiquitination of βTrCP, and vice versa. Interestingly, such effects depended on the presence of E3 ligase domains. Importantly, depletion of Smurf1‐ or βTrCP‐enhanced proliferative capacity of liver cancer cells could be partially reversed by overexpression of wild‐type βTrCP or Smurf1 but not their E3 ligase‐dead mutants. Collectively, a reciprocal post‐translational regulation between βTrCP and Smurf1 has been uncovered in this study. Simultaneous enhancement of βTrCP and Smurf1 functions might be helpful in the treatment of liver cancer.
Cyclic‐glycine‐proline accelerates mammary involution by promoting apoptosis and inhibiting IGF‐1 function
Authors: Singh‐Mallah Gagandeep , McMahon Christopher D. , Guan Jian , Singh Kuljeet
Published: January 2017

In rodents, post‐lactational involution of mammary glands is characterized by the loss of mammary epithelial cells via apoptosis, which is associated with a decline in the expression of insulin‐like growth factor‐1 (IGF‐1). Overexpression of IGF‐1 delays involution by inhibiting apoptosis of epithelial cells and preserving the remaining secretory alveoli. Cyclic‐glycine‐proline (cGP), a metabolite of IGF‐1, normalizes IGF‐1 function under pathological conditions by regulating the bioavailability of IGF‐1. The present study investigated the effect of cGP on the physiological decline in IGF‐1 function during post‐lactational mammary involution. Rat dams were gavaged with either cGP (3 mg/kg) or saline once per day from post‐natal d8‐22. Before collecting tissue on post‐natal d23, a pair of mammary glands were sealed on d20 (72 hr‐engorgement, thus representative of late‐involution) and d22 (24 hr‐engorgement, thus representative of mid‐involution), while the remaining glands were allowed to involute naturally (early‐involution). During early‐involution, cGP accelerated the loss of mammary cells through apoptosis, resulting in an earlier clearance of intact secretory alveoli compared with the control group. This coincided with an earlier up‐regulation of the cell survival factors, Bcl‐xl and IGF‐1R, in the early‐involution cGP glands compared with the control glands. During late‐involution, cGP reduced the bioactivity of IGF‐1, which was evident through decreased phosphorylation of IGF‐1R in the regressed alveoli. Maternal administration of cGP did not alter milk production and composition during early‐, peak‐, or late‐stage of lactation. These data show that cGP accelerates post‐lactational involution by promoting apoptosis and the physiological decline in IGF‐1 function.
Purification of small molecule‐induced cardiomyocytes from human induced pluripotent stem cells using a reporter system
Authors: Hwang Geun Hye , Park So Mi , Han Ho Jae , Kim Joong Sun , Yun Seung Pil , Ryu Jung Min , Lee Ho Jin , Chang Woochul , Lee Su‐Jin , Choi Jeong‐Hee , Choi Jin‐Sung , Lee Min Young
Published: January 2017

In order to realize the practical use of human pluripotent stem cell (hPSC)‐derived cardiomyocytes for the purpose of clinical use or cardiovascular research, the generation of large numbers of highly purified cardiomyocytes should be achieved. Here, we show an efficient method for cardiac differentiation of human induced pluripotent stem cells (hiPSCs) in chemically defined conditions and purification of hiPSC‐derived cardiomyocytes using a reporter system. Regulation of the Wnt/β‐catenin signaling pathway is implicated in the induction of the cardiac differentiation of hPSCs. We increased cardiac differentiation efficiency of hiPSCs in chemically defined conditions through combined treatment with XAV939, a tankyrase inhibitor and IWP2, a porcupine inhibitor and optimized concentrations. Although cardiac differentiation efficiency was high (>80%), it was difficult to suppress differentiation into non‐cardiac cells, Therefore, we applied a lentiviral reporter system, wherein green fluorescence protein (GFP) and Zeocin‐resistant gene are driven by promoter activation of a gene (TNNT2) encoding cardiac troponin T (cTnT), a cardiac‐specific protein, to exclude non‐cardiomyocytes from differentiated cell populations. We transduced this reporter construct into differentiated cells using a lentiviral vector and then obtained highly purified hiPSC‐derived cardiomyocytes by treatment with the lowest effective dose of Zeocin. We significantly increased transgenic efficiency through manipulation of the cells in which the differentiated cells were simultaneously infected with virus and re‐plated after single‐cell dissociation. Purified cells specifically expressed GFP, cTnT, displayed typical properties of cardiomyocytes. This study provides an efficient strategy for obtaining large quantities of highly purified hPSC‐derived cardiomyocytes for application in regenerative medicine and biomedical research.
Functional and structural studies on the Neisseria gonorrhoeae GmhA, the first enzyme in the glycero‐manno‐heptose biosynthesis pathways, demonstrate a critical role in lipooligosaccharide synthesis and gonococcal viability
Authors: Wierzbicki Igor H. , Zielke Ryszard A. , Korotkov Konstantin V. , Sikora Aleksandra E.
Published: January 2017

Sedoheptulose‐7‐phosphate isomerase, GmhA, is the first enzyme in the biosynthesis of nucleotide‐activated‐glycero‐manno‐heptoses and an attractive, yet underexploited, target for development of broad‐spectrum antibiotics. We demonstrated that GmhA homologs in Neisseria gonorrhoeae and N. meningitidis (hereafter called GmhAGC and GmhANM, respectively) were interchangeable proteins essential for lipooligosaccharide (LOS) synthesis, and their depletion had adverse effects on neisserial viability. In contrast, the Escherichia coli ortholog failed to complement GmhAGC depletion. Furthermore, we showed that GmhAGC is a cytoplasmic enzyme with induced expression at mid‐logarithmic phase, upon iron deprivation and anaerobiosis, and conserved in contemporary gonococcal clinical isolates including the 2016 WHO reference strains. The untagged GmhAGC crystallized as a tetramer in the closed conformation with four zinc ions in the active site, supporting that this is most likely the catalytically active conformation of the enzyme. Finally, site‐directed mutagenesis studies showed that the active site residues E65 and H183 were important for LOS synthesis but not for GmhAGC function in bacterial viability. Our studies bring insights into the importance and mechanism of action of GmhA and may ultimately facilitate targeting the enzyme with small molecule inhibitors.
Separation of scatter from small MV beams and its effect on detector response
Authors: Wegener Sonja , Sauer Otto A.
Published: January 2017

Purpose

Separating the scatter from the primary component of a MV beam to study detector response separately in each case for a better understanding of the role of different effects influencing the response in nonstandard fields.

Methods

Detector response in three different experimental setups was investigated for a variety of different types (diamond, shielded and unshielded diodes, ionization chamber and film): (a). Detectors positioned in water under a thin steel pole blocking the central part of the beam, yielding only the response to the scatter part of the beam. (b). Detectors positioned in air under a PMMA cap to approximate the contribution of the primary beam without scatter. (c). Detectors positioned in water in the standard open field configuration to obtain a superposition of both.

Results

Detector differences became more clearly observable when the primary beam was blocked and detector behavior heavily depended on the construction type. It was possible to calculate the response in the open fields from the values measured in the blocked configuration with 1% accuracy for all studied field sizes between 0.8 and 10 cm and for all detectors.

Conclusions

The limitations of clinically used detectors in nonstandard situations were illustrated in the extreme situation of just scattered radiation reaching the detector. By experimentally separating scatter from the primary beam, the roles of different effects on the detector response were observed.
Maternal acculturation and the growth of impoverished Mexican American infants
Authors: Luecken Linda J. , Jewell Shannon L. , MacKinnon David P.
Published: January 2017

Objective

Identification of early life risk factors that predispose low‐income Hispanic children to obesity is critical. For low‐income Mexican American mothers, the cultural context may influence maternal experience and behaviors relevant to infant weight and growth.

Methods

In a longitudinal study of 322 low‐income Mexican American mother‐infant dyads, linear growth modeling examined the relation of maternal acculturation to infant weight gain across the first year and evaluated birth outcomes, breastfeeding, and maternal BMI as mediators.

Results

There was a high prevalence (36% >95th percentile) of infants with obesity at 1 year. Higher maternal acculturation was associated with lower birth weight, higher infant weight at 6 weeks, and a lower prevalence of breastfeeding. Mediation analyses supported formula‐feeding as a mediator of the relation between higher maternal acculturation and an increasing slope of infant weight gain across the first year.

Conclusions

Breastfeeding may have measurable benefits for Mexican American child obesity status in this high‐risk population, particularly among those with more acculturated mothers.
The Impact of Mathematical Modeling in Understanding the Mechanisms Underlying Neurodegeneration: Evolving Dimensions and Future Directions
Authors: Lloret‐Villas A , Varusai TM , Juty N , Laibe C , Le NovÈre N , Hermjakob H , Chelliah V
Published: January 2017

Neurodegenerative diseases are a heterogeneous group of disorders that are characterized by the progressive dysfunction and loss of neurons. Here, we distil and discuss the current state of modeling in the area of neurodegeneration, and objectively compare the gaps between existing clinical knowledge and the mechanistic understanding of the major pathological processes implicated in neurodegenerative disorders. We also discuss new directions in the field of neurodegeneration that hold potential for furthering therapeutic interventions and strategies.
Clinical, MRI and electrographic characteristics of three children with Hemiconvulsion-Hemiplegia/Hemiconvulsion-Hemiplegia-Epilepsy (HH/HHE) syndrome–A rare childhood epileptic encephalopathy
Authors: Singh Sudan Yeeshu , Vinayan K. , Roy Arun
Published: January 2017

Hemi convulsion-Hemiplegia-Epilepsy (HH/HHE) syndrome is a very rare catastrophic epileptic syndrome in childhood which follows a prolonged focal motor status epilepticus in infancy and early childhood. Here we are describing the clinical, MRI and electrographic characteristics along with long term outcome of three children with HH/HHE syndrome. A review of the current literature on HH/HHE syndrome is attempted stressing on the diagnostic features and the neurobiological relationship between prolonged focal motor status epilepticus and subsequent development of HH/HHE syndrome. Early identification of this syndrome may help the treating physician in providing families with a relatively accurate prognosis regarding the functional outcome and subsequent development of epilepsy.
Conocimientos nutricionales en estudiantes universitarios del sector público del Estado de Chiapas, México
Authors: López Gutiérrez Patricia Paulina , Rejón Orantes José Del Carmen , Escobar Castillejos Daisy , Roblero Ochoa Sonia Rosa , Dávila Esquivel María Teresa , Mandujano Trujillo Zally Patricia
Published: January 2017

Introducción: Los conocimientos en nutrición son vitales para obtener y conservar la salud, y por ello es fundamental que los profesionales de la salud obtengan durante su formación un nivel adecuado de conocimientos en este campo, puesto que son los principales responsables de transmitirlo a la población en general, jugando de esta manera un papel esencial en la salud.
Objetivo: Se analizaron los conocimientos básicos en nutrición de alumnos de las áreas de enfermería, medicina humana y nutriología.
Método: Se aplicó un cuestionario de conocimientos de nutrición a 82 alumnos de las licenciaturas en enfermería, medicina y nutrición del sector público del Estado de Chiapas, México, que ya hubieran recibido la asignatura de nutrición o su similar.
Resultados: Se identificó que existen conocimientos insuficientes sobre nutrición en los alumnos de licenciaturas relacionadas con la salud del sector público del Estado de Chiapas, México, dado que la media de respuestas correctas de todos los grupos fue menor del 80%. Los promedios más altos correspondieron a alumnos de la licenciatura en nutriología; por otra parte, los estudiantes de medicina tuvieron significativamente mejor puntaje que los de enfermería, siendo estos últimos los que mostraron menores conocimientos.
Conclusiones: Se concluyó que es necesaria una revisión de los programas académicos, proponiendo la inclusión de la nutriología como una cátedra de primer nivel de importancia, la cualdeberá ser impartida en más de un semestre a lo largo de las licenciaturas en enfermería ymedicina humana.
Boulders Limit Transport of Sand and Gravel in Steep Rivers
Authors: Branscombe Alexandra
Published: January 2017

Mountain rivers and streams actively reshape landscapes by eroding material from uplands and depositing it in lowlands. Scientists can now predict this transport in very steep streams.
NASA's New Discovery Missions Will Look Back to Our Origins
Authors: Jacobsen Elizabeth
Published: January 2017

Two recently approved missions will explore our solar system's early history, looking at asteroids near Jupiter and an odd object that may be a planetary core.
Near-infrared fluorescence probe: BSA-protected gold nanoclusters for the detection of metronidazole and related nitroimidazole derivatives
Authors: Meng Lei , Yin Jian-hang , Yuan Yaqing , Xu Na
Published: January 2017

BSA-protected gold nanoclusters (AuNCs@BSA), as near infrared fluorescence probes, are synthesized to detect metronidazole (MTZ) and nitroimidazole derivatives, based on a photon-induced electron transfer (PET) process.
Charge transport in organic donor–acceptor mixed-stack crystals: the role of nonlocal electron–phonon couplings
Authors: Zhu Lingyun , Geng Hua , Yi Yuanping , Wei Zhixiang
Published: January 2017

The influence of nonlocal electron–phonon couplings on charge transport is found to be very small in organic donor–acceptor mixed-stack crystals.
Protective effects of dietary glycine and glutamic acid toward the toxic effects of oxidized mustard oil in rabbits
Authors: Zeb Alam , Rahman Saleem Ur
Published: January 2017

Glycine and glutamic acid have protective effects against the toxic effects of oxidized lipids in rabbits.
Soluble epoxide hydrolase inhibitors might prevent ischemic arrhythmias via microRNA-1 repression in primary neonatal mouse ventricular myocytes
Authors: Liu Qiong , Zhao Xuan , Peng Ran , Wang Mi , Zhao Wang , Gui Ya-jun , Liao Cai-xiu , Xu Dan-yan
Published: January 2017

Ischemic arrhythmias are the main causes of sudden cardiac death.
Carbon-based materials as heterogeneous antioxidants for biodiesel: efficiency and synergy with soluble antioxidants
Authors: Jesus Monique R. , Soares Tais da C. , Silva Paulo R. M. , Romeiro Gilberto A. , Fonseca Mauricio G. , Batista Luciano N.
Published: January 2017

The interaction of biochar and aromatic amines showed an unexpected, but excellent synergy improving the oxidation stability of biodiesel.
First-principles study of the initial oxygen reduction reaction on stoichiometric and reduced CeO2(111) surfaces as a cathode catalyst for lithium–oxygen batteries
Authors: Li Xinyu , Li Zongbao , Yang Xiaofeng , Jia Lichao , Fu Yong Qing , Chi Bo , Pu Jian , Li Jian
Published: January 2017

The initial oxygen reduction reactions on stoichiometric and reduced CeO2(111) surfaces as a cathode catalyst for lithium-oxygen batteries have been investigated by a first-principles method.
Phase noise performance comparison between microwaves generated with Kerr optical frequency combs and optoelectronic oscillators
Authors: Saleh K. , Chembo Y.K.
Published: January 2017

Kerr optical frequency combs and optoelectronic oscillators are microwave photonic systems that can generate ultra‐pure radio‐frequency signals in the gigahertz range. We comparatively investigate the phase noise performances of both microwave generators and analyse as well their specific spectral features.
Rheological monitoring of tau protein polymerisation with acoustic waves sensor
Authors: Didier P. , Razan F. , Caplain E. , Michiel M. , Delamarche C. , Nogues C. , Le Huerou J.Y. , Serfaty S. , Larzabal P.
Published: January 2017

Among acoustic waves sensors, the thickness shear mode resonator presents high sensitivity for the measurement of liquid viscoelastic properties, enabling the monitoring of the shear moduli, G′ G″, by using a suitable physical model. The development of an instrumental system for detecting the tau protein involved in Alzheimer's disease is proposed which will aid in understanding the mechanisms of this disease. The tau protein is present in complex products such as blood and cerebrospinal fluid. The experimental results show that the acoustic wave system allows to differentiate between tau protein solutions with different states of polymerisation.
Correlation characteristic analysis in diversity multiple‐input multiple‐output radar
Authors: Liu Jieyi , Zhang Linrang , Zhao Shanshan , Liu Nan , Zhang Juan
Published: January 2017

A huge limitation of the correlation analysis in existing scatterer model is that only uniformly distributed scatterers are considered ignoring the variability of scattering intensity in the real situation. In fact, each part of the target has a diverse scattering architecture, thus, the scattering intensity varies with the target surface structure. To make a better equivalent of the real target, the echo correlation coefficient is studied for scattering model which has several variable dominant scatterers to make an equivalent of different scattering architecture in spatial–frequency diversity MIMO radar. The proposed analysis enhances the authenticity of scattering model and expounds the correlation coefficient varying with the scattering intensity and the position of each dominant scatterer. Simulation results are presented to validate the proposed analysis.
Efficient wide‐band droop compensation for CIC filters: ad hoc and reconfigurable FIR architectures
Authors: Romero D.E.T. , Jimenez M.G.C.
Published: January 2017

Novel finite impulse response architectures for wide passband droop compensation of cascaded integrator‐comb filters are presented. Compared with the recent wide‐band compensators introduced in the literature, the proposed systems achieve better passband droop correction with lower power dissipation, lower hardware utilisation and higher maximum frequency of operation, as validated with post‐place‐and‐route information from FPGA‐based implementations.
APWM adapted half‐bridge LLC converter with voltage doubler rectifier for improving light load efficiency
Authors: Kim J.‐W. , Han J.‐K. , Lai J.‐S.
Published: January 2017

LLC converter is widely used in various applications due to its simple structure and zero voltage switching capability. To achieve high efficiency, LLC converter is usually designed to operate near the resonant frequency over the entire load conditions. However, a constant core loss of the main transformer due to the constant frequency operation has a bad effect on the efficiency in a light load condition where the core loss dominates the total loss. Therefore, it is essential to reduce transformer core loss in order to improve light load efficiency. Adapting asymmetric pulse‐width modulation (APWM) in a half‐bridge LLC resonant converter with voltage doubler rectifier for improving light load efficiency has been proposed. By adapting APWM, the core loss can be reduced dramatically in the light load condition, because both the switching frequency and the flux swing of the transformer are reduced. Furthermore, the proposed method does not affect the design of the converter. The experimental results with 400–250 V input and 100 V/2 A output prototype converter support the effectiveness of the proposed method.
3.125 Gbit/s CMOS transceiver for duobinary modulation over 50‐m SI‐POF channels
Authors: Aguirre J. , Sánchez‐Azqueta C. , Guerrero E. , Gimeno C. , Celma S.
Published: January 2017

This Letter presents a novel CMOS transceiver for short‐reach multigigabit communication over step‐index plastic optical fibre (SI‐POF), a very interesting transmission medium for industrial and home‐end applications due to its low cost, ease of handling and inherent immunity to electromagnetic interference. The transceiver uses amplitude duobinary modulation, which is added to continuous‐time equalisation. For that purpose, a duobinary precoder and a duobinary decoder have been fabricated in a standard 0.18‐µm CMOS technology, consuming only 28.4 mW. The system enables a 50‐m SI‐POF channel bandlimited to 100 MHz to operate at a data bit rate of 3.125 Gbit/s.
Long‐term integration based on two‐stage differential acquisition for weak direct sequence spread spectrum signal
Authors: Guo Yichao , Huan Hao , Tao Ran , Wang Yue
Published: January 2017

Fast acquisition in space telemetry and telecontrol communication system is challenged significantly by the high dynamic and low signal‐to‐noise ratio. Increasing the dwell time to obtain better acquisition sensitivity, based on two‐dimensional time‐frequency search, is impossible because of resource limitation in receiver. To tackle these problems, this study proposes a two‐stage differential acquisition (TSDA) algorithm. The differential coherent integration is employed by the first stage of TDSA to extend integration time, during which keystone transform and fast Fourier transform are used to compensate the linear code phase drift and obtain high accumulation gain. The carrier‐frequency offset is estimated in terms of the code phase difference between the two parts of received signal divided by the second stage of TSDA in which the two‐dimensional searching process is avoided. The proposed TSDA algorithm and the traditional acquisition methods are compared under the same acquisition time and typical parameters of S‐band space telemetry and telecontrol communication system. Simulation results demonstrate that the proposed TSDA algorithm attains a higher acquisition probability and better acquisition sensitivity than the traditional acquisition methods.
Distributed containment control of Euler–Lagrange systems over directed graphs via distributed continuous controllers
Authors: Cheng Bin , Li Zhongkui , Shen Lincheng
Published: January 2017

This study considers the distributed containment problem of Euler–Lagrange systems over directed graphs in the presence of multiple dynamic leaders having varying vectors of generalised coordinate derivatives and accelerations. A distributed continuous algorithm is proposed, which can guarantee the containment error is uniformly ultimately bounded and converges to a small adjustable residual set. The authors also design adaptive protocols for the case where the physical parameters are unknown. Then, as a special case, they design a continuous distributed protocol for Euler–Lagrange systems to solve the coordinated tracking consensus problem over directed graphs containing a directed spanning tree with the leader as the root node. Compared to the previous related works, the authors' main contribution is that the proposed distributed continuous algorithms, using the sliding mode control and the boundary layer technique, can avoid the undesirable chattering effect and meanwhile are applicable to general directed graphs.
Co‐design of stabilisation and transmission scheduling for wireless control systems
Authors: Lyu Ling , Chen Cailian , Hua Cunqing , Zhu Shanying , Guan Xinping
Published: January 2017

Wireless control system (WCS) refers to the feedback control system with state and (or) control information transmitted over wireless channels. The control system stability is severely affected by the wireless transmission reliability, which in turn relies heavily on the scheduling of limited wireless communication resources, such as channel, time and power. Therefore, co‐design of control stabilisation and transmission scheduling is of vital importance. In this study, the authors firstly explore the effect of wireless transmission reliability on control performance for a WCS with multiple subsystems, local sensors and a remote combination of controller–scheduler. Then a feedback control method is designed to mitigate the impact of unreliable transmission in the loop of sensor‐to‐controller and controller‐to‐actuator. Stabilisation and transmission scheduling are co‐designed to stabilise the system and minimise the control‐communication cost by solving a mixed‐integer non‐linear programming problem. A decomposition scheme is finally proposed to optimise the control performance by minimising the gap with standard linear quadratic regulator controller as well as the communication cost by allocating the transmission channels, time‐slots and power. The effectiveness and advantage of the proposed scheme are demonstrated by the simulation results for a slab temperature control system in hot rolling process.
Adaptive finite‐time control for a class of uncertain high‐order non‐linear systems based on fuzzy approximation
Authors: Wang Honghong , Chen Bing , Lin Chong , Sun Yumei , Wang Fang
Published: January 2017

The problem of adaptive practical finite‐time control is considered for a class of single‐input and single‐output non‐linear systems, in which the system non‐linear functions are assumed to be unknown. By combining adaptive fuzzy control approach with the backstepping technology, a backstepping‐based adaptive fuzzy finite‐time control scheme is proposed. In the control design procedure, fuzzy logic systems are employed to identify the non‐linear uncertainties. The stability analysis of the adaptive closed‐loop systems is proposed based on the finite‐time Lyapunov stability theory. The proposed adaptive fuzzy controller guarantees that all the closed signals are semi‐global practical finite‐time stability while the tracking error converges to a small neighbourhood of the origin. Finally, simulation results are presented to validate the effectiveness of our results.
Efficient coverage algorithm for mobile sensor network with unknown density function
Authors: Zuo Lei , Yan Weisheng , Yan Maode
Published: January 2017

This study investigates the coverage control problems for the mobile sensor network in a given domain, in which the density function characterising the distribution of the information of interest is unknown. To approximate the density function, we develop an adaptive spatial estimation algorithm for the mobile sensor network. Then, a distributed coverage control strategy is proposed to drive the sensors to the optimal locations. To further improve the efficiency of the coverage process, the authors apply the consensus mechanism into the spatial estimation algorithm and propose an improved control strategy such that the coverage system can converge to the optimal deployment effectively. The convergences of the proposed coverage systems are proved through Lyapunov stability theorem. Moreover, the authors show that the convergence rate of the consensus‐based spatial estimation algorithm is faster than the distributed case. Finally, numerical simulations are provided to illustrate the proposed approaches.
Relaxed stability and stabilisation conditions for continuous‐time Takagi–Sugeno fuzzy systems using multiple‐parameterised approach
Authors: Hu Guolin , Liu Xiaodong , Wang Likui , Li Hongxing
Published: January 2017

This study deals with the problem of stability analysis and control design for continuous‐time Takagi–Sugeno fuzzy systems. Based on generalised fuzzy Lyapunov function (FLF) and fuzzy controller, relaxed stability and stabilisation conditions in terms of linear matrix inequalities are obtained. The generalised FLF is homogeneous polynomially parameter dependent on MFs with arbitrary degree. As the degree of the Lyapunov function increases, the conservatism of the obtained stability and stabilisation conditions is gradually reduced. In addition, it can be proved that the conditions generated in this study can include the existing ones found in the literature as special cases. Compared with the existing methods, no additional slack variables are introduced in stability analysis, and hence the same or less conservative results can be obtained with a lower computational cost. Numerical examples illustrate the effectiveness of the proposed method.
Trajectory‐based small gain theorems for ISpS and ISS of large‐scale networks of switched systems with arbitrary switchings
Authors: Dashkovskiy Sergey N. , Pavlichkov Svyatoslav S.
Published: January 2017

The authors consider a large‐scale switched non‐linear system which is composed as an interconnection of N non‐linear switched systems. Having assumed that every subsystem is stable uniformly with respect to the unobservable switching signals, it can happen that the entire interconnection is unstable. This study provides a sufficient condition for the uniform stability of the entire large‐scale interconnection. The framework of input‐to‐state stability (ISS) is used for this purpose and the stability condition is of the small‐gain type which is given in terms of trajectory‐based ISS gains. To prove this result we extend the well‐known result by Sontag and Wang on characterisations of the ISS property in terms of simpler stability notions to the case of switched systems with arbitrary switchings.
Robust consensus of Lur'e networks with uncertain communications
Authors: Liu Miao , Li Zhongkui
Published: January 2017

This study addresses the robust consensus problem of a network of Lur'e systems coordinating over uncertain communication channels. The authors model each communication channel of the network as an ideal transmission system with the unitary transfer function perturbed by a norm‐bounded uncertainty, which is particularly susceptible to describe quantisation errors and communication noises. Based on the uncertain relative state information among neighbouring agents, a distributed consensus protocol is proposed and designed in terms of linear matrix inequalities to ensure robust consensus for both undirected connected graphs and leader‐follower graphs containing a directed spanning tree.
Further results on computation of topological indices of certain networks
Authors: Liu Jia‐Bao , Wang Shaohui , Wang Chunxiang , Hayat Sakander
Published: January 2017

There are various topological indices such as degree based topological indices, distance based topological indices and counting related topological indices etc. These topological indices correlate certain physicochemical properties such as boiling point, stability of chemical compounds. In this study, the authors compute the sum‐connectivity index and multiplicative Zagreb indices for certain networks of chemical importance such as silicate networks, hexagonal networks, oxide networks, and honeycomb networks. Moreover, a comparative study using computer‐based graphs has been made to clarify their nature for these families of networks.
Adaptive DSC of stochastic non‐linear systems with input unmodelled dynamics
Authors: Xia Meizhen , Zhang Tianping , Yang Yuequan , Zhu Jiaming
Published: January 2017

An adaptive dynamic surface control (DSC) method is proposed for a class of stochastic non‐linear systems with input and state unmodelled dynamics in this paper. A normalisation signal is introduced to restrict the input unmodelled dynamics. By introducing a non‐linear transformation, modified DSC is extended and applied to a class of more general stochastic non‐linear systems. By theoretical analysis, it is shown that all the signals in the closed‐loop system are bounded in probability. Two simulation examples further demonstrate the effectiveness of the proposed control approach.
Effective and simplified method in maximum efficiency control of interior permanent magnet synchronous motors
Authors: Pairo Hamidreza , Shoulaie Abbas
Published: January 2017

In this study, an easily implementable and effective method in loss‐minimisation control of interior permanent‐magnet synchronous motors (IPMSMs) is proposed. Complication of loss‐minimisation condition and its implementation are main problems in model‐based control methods of IPMSMs. To resolve these problems, an approximate‐model is used for simplification of loss‐minimisation condition and a proportional–integral‐controller is utilised to directly solve the loss‐minimisation condition. Also, saturation and iron loss resistance variation due to frequency variation are considered in the proposed method. Furthermore, results show the high precision of the proposed method in comparison with accurate model. Steady‐state performance of the proposed method is compared with look‐up table‐based loss‐minimisation and maximum torque per ampere (MTPA) control methods. Also, experimental results verify performance, good dynamic response and effectiveness in loss reduction of the proposed method under different conditions in comparison with look‐up table‐based loss‐minimisation and MTPA control methods.
Optimal scheduling of independently operated, locally controlled energy storage systems as dispatchable assets in a competitive electricity market
Authors: Khani Hadi , Dadash Zadeh Mohammad R. , Varma Rajiv K.
Published: January 2017

Independently operated energy storage can exploit arbitrage opportunities available due to inter‐temporal variation of electricity prices. Storage can be utilised as a dispatchable or non‐dispatchable asset. In this study, a new optimal scheduling algorithm is proposed to enable independently operated, locally controlled storage to accept dispatch instructions issued by independent system operators (ISOs). Storage in this case is referred to as dispatchable storage. In addition, a new index is proposed to measure the storage dispatchability. While the operation of locally controlled storage is optimally scheduled at the owner's end, using the proposed algorithm, storage is fully dispatchable at the ISO's end. Dispatchable storage units have great potential to enhance the flexibility of electric grids and are key elements envisioned to enable smart grid realisation. The proposed algorithm outperforms previous algorithms in which storage is either locally controlled at the owner's end and cannot optimally accept ISO's instructions; or storage is centrally controlled by the grid operator to achieve some technical objectives. The efficacy and feasibility of the proposed algorithm are validated using real‐world data. It is demonstrated that the proposed algorithm can enable the storage to accept all ISO's instructions. Revenue values of dispatchable and non‐dispatchable storage are computed and compared.
Multidimensional droop control for wind resources in dc microgrids
Authors: Bunker Kaitlyn J. , Weaver Wayne W.
Published: January 2017

Two important and upcoming technologies, wind resources and microgrids, are increasingly being combined. Various control strategies can be implemented, and droop control provides a simple option without requiring communication between microgrid components. However, traditional droop control does not allow the microgrid to maximise the power available from the wind. This study proposes a novel droop control strategy, which implements a droop surface in higher dimension than the traditional strategy. Simulation results show that power from the wind can be maximised, while maintaining the system's bus voltage around a nominal value using a distributed multidimensional droop approach. Selection of the optimal droop relationship is discussed and simulation results are presented.