bluuebunny/crossref_metadata_2025 huggingface dataset:
Contact application of neonicotinoids suppresses the predation rate in different densities of prey and induces paralysis of common farmland spiders
Authors: Řezáč Milan , Řezáčová Veronika , Heneberg Petr
Published: April 2019

Neonicotinoids are very effective in controlling crop pests but have adverse effects on predators and pollinators. Spiders are less sensitive to neonicotinoids compared to insects because of the different structure of their acetylcholine receptors, the binding targets of neonicotinoids. We tested whether short-term exposure to neonicotinoids affected the predation rate in different densities of prey of spiders and led to their paralysis or eventual death. To examine these effects, we topically exposed dominant epigeic, epiphytic and sheet-weaving farmland spiders to four widely used neonicotinoids (imidacloprid, thiamethoxam, acetamiprid and thiacloprid). We applied the neonicotinoids at concentrations recommended by the manufacturers for spray application under field conditions. Short-term exposure to the formulations of all four tested neonicotinoids had adverse effects on the predation rate of spiders, with imidacloprid (Confidor) associated with the most severe effects on the predation rate and exhibiting partial acute lethality after one hour (15–32%). Acetamiprid also displayed strong sublethal effects, particularly when applied dorsally to Philodromus cespitum. Day-long exposure to dorsally applied acetamiprid or thiacloprid led to paralysis or death of multiple Linyphiidae spp., with the effects particularly prominent in males. To conclude, we provided multiple lines of evidence that short-term exposure to neonicotinoids, which were applied at recommended field concentrations, caused severe health effects or death in multiple families of spiders. Even acetamiprid caused strong effects, despite being subject to less strict regulations in the European Union, compared with those for imidacloprid because of claims of its negligible off-target toxicity.
Radiomic features and multilayer perceptron network classifier: a robust MRI classification strategy for distinguishing glioblastoma from primary central nervous system lymphoma
Authors: Yun Jihye , Park Ji Eun , Lee Hyunna , Ham Sungwon , Kim Namkug , Kim Ho Sung
Published: April 2019

We aimed to establish a high-performing and robust classification strategy, using magnetic resonance imaging (MRI), along with combinations of feature extraction and selection in human and machine learning using radiomics or deep features by employing a small dataset. Using diffusion and contrast-enhanced T1-weighted MR images obtained from patients with glioblastomas and primary central nervous system lymphomas, classification task was assigned to a combination of radiomic features and (1) supervised machine learning after feature selection or (2) multilayer perceptron (MLP) network; or MR image input without radiomic feature extraction to (3) two neuro-radiologists or (4) an end-to-end convolutional neural network (CNN). The results showed similar high performance in generalized linear model (GLM) classifier and MLP using radiomics features in the internal validation set, but MLP network remained robust in the external validation set obtained using different MRI protocols. CNN showed the lowest performance in both validation sets. Our results reveal that a combination of radiomic features and MLP network classifier serves a high-performing and generalizable model for classification task for a small dataset with heterogeneous MRI protocols.
Differences in glutamate uptake between cortical regions impact neuronal NMDA receptor activation
Authors: Romanos Jennifer , Benke Dietmar , Saab Aiman S. , Zeilhofer Hanns Ulrich , Santello Mirko
Published: April 2019

Removal of synaptically-released glutamate by astrocytes is necessary to spatially and temporally limit neuronal activation. Recent evidence suggests that astrocytes may have specialized functions in specific circuits, but the extent and significance of such specialization are unclear. By performing direct patch-clamp recordings and two-photon glutamate imaging, we report that in the somatosensory cortex, glutamate uptake by astrocytes is slower during sustained synaptic stimulation when compared to lower stimulation frequencies. Conversely, glutamate uptake capacity is increased in the frontal cortex during higher frequency synaptic stimulation, thereby limiting extracellular buildup of glutamate and NMDA receptor activation in layer 5 pyramidal neurons. This efficient glutamate clearance relies on Na+/K+-ATPase function and both GLT-1 and non-GLT-1 transporters. Thus, by enhancing their glutamate uptake capacity, astrocytes in the frontal cortex may prevent excessive neuronal excitation during intense synaptic activity. These results may explain why diseases associated with network hyperexcitability differentially affect individual brain areas.
Ruthenium, Osmium and Iridium in the Fight Against Cancer
Authors: Romero-Canelón Isolda
Published: April 2019

DNA-targeting chemotherapeutic agents are widely used in cancer treatment. However, high incidence of resistance and deleterious side effects are still a challenging medical issue. Novel complexes based on precious metals are being developed as viable alternatives, with the aim of overcoming resistance and minimising unwanted side effects. This chapter looks at complexes with ruthenium, osmium and iridium metal centres. These complexes exhibit a wide range of structural variances that allow for the fine-tuning of chemical and biological properties. Within this chemical space, this chapter explores the importance of different building blocks in relevant coordination spheres, paying particular attention to structures such as organometallic piano-stools and other octahedral coordination motifs. It further examines some of the most prominent aspects of the mechanisms of action responsible for the antiproliferative activity of the complexes, with special focus on mechanisms that are redox centred and those that involve, to some degree, modifications of mitochondrial function. It concludes with some of the physicochemical challenges faced when looking into the mechanism of action of metal-based drugs at the cellular level. Furthermore, it provides examples of how novel analytical techniques are helping to generate new knowledge on localisation, activation and general subcellular behaviour of metal complexes.
Iron Compounds as Anticancer Agents
Authors: Vessieres Anne
Published: April 2019

Many ferrocene complexes have been prepared for their oncological potential. Some derive from molecules with known biological effects (taxanes, podophyllotoxine, artemisine, SAHA, etc.) while others are synthetic molecules selected for their cytotoxic effects (N-alkylaminoferrocenes and ferrocenyl alkylpyridinium). Although these complexes have received a great deal of attention, the field of iron metallodrugs is not limited to them. A number of inorganic complexes of iron(ii) and iron(iii) with possible anticancer effects have also been published, although research into their biological effects is often only at an early stage. This chapter also includes iron chelators, molecules that are administered in non-metallic form but whose cytotoxic species are their coordination complexes of iron generated in vivo. The most emblematic molecule of this family is bleomycin, used as an anticancer agent in many chemotherapies. To these can be added the iron chelates originally synthesized to treat iron overload, some of which have been shown to possess interesting anticancer properties. They have been, and continue to be, the subject of many clinical trials, whether alone or in combination. Thus, the area of iron metallodrugs includes molecules with very different structures and reactivity, studied from a number of different perspectives, but focused on increasing the number of molecules at our disposal for combatting cancer.
Recent Advances in Anticancer Copper Compounds
Authors: Kellett Andrew , Molphy Zara , McKee Vickie , Slator Creina
Published: April 2019

There have been significant advances in the discovery of developmental copper complexes for the treatment of human cancer. The enzyme-active sites of several copper-containing enzymes suggest a starting point for metallodrug development and successful strategies have, so far, employed phenanthroline or bipyridine ligands to supply two pyridyl donors (modelling histidine residues) along with other oxygen or nitrogen donor ligands that tune specific properties. Suitably designed copper(ii) metallodrugs can generate reactive oxygen species (ROS) and reactive nitrogen species (RNS) that overwhelm innate cellular antioxidant defences to trigger oxidative damage and cell death. Recently, several complexes of this class were screened by the National Cancer Institute's (NCI) Developmental Therapeutics Program (DTP). The 60-cancer cell line screening results indicate copper(ii) metallodrug leads have unique activity and alternative mechanisms to clinically established anticancer agents such as cisplatin and bleomycin. Although DNA is a valid cellular target, mechanistic evidence suggests cell death is triggered by metal-catalysed pro-apoptotic ROS and RNS that damage cytoplasmic, mitochondrial, and genome function. In addition to copper complexes screened within the DTP, a number of other structurally relevant compounds are described, along with mechanistic aspects of their chemotherapeutic activity.
Arsenic-based Anticancer Agents
Authors: Gibaud Stéphane
Published: April 2019

Arsenic-based drugs were widely used in the treatment of infectious diseases in the 1900s, but cancer treatment has advanced with the marketing of Trisenox® (INN: arsenic trioxide) for treatment of acute promyelocytic leukemia in the 2000s. In this chapter, I first review the history of the treatment of cancer by arsenic. In the 17th century, some physicians were convinced that an external application of powder could reduce breast cancer cells. Those adventurous applications led only to tissue necrosis, and we now understand how dangerous it was for the patient. An important step forward was also made with Fowler's solution, which would be orally administered. Afterwards, Cutler and Bradford demonstrated that this solution drastically reduced the number of neutrophils in myelogenous leukemia. The more recent marketing of Trisenox® and its unique efficacy in the treatment of acute promyelocytic leukemia raised questions about the mechanism of action of arsenic in cancer treatment. Finally, this chapter summarizes the major mechanisms that lead to the reduction in growth and proliferation of cancer cells. At a molecular level, arsenic is thought to link to numerous proteins (i.e., via the thiol groups of the amino acid side-chains). We know now that some very specific targets exist that are worthy of study.
Supramolecular Metal-based Structures for Applications in Cancer Therapy
Authors: Wenzel Margot N. , Woods Benjamin , Casini Angela
Published: April 2019

Discrete supramolecular constructs continue to attract important research interest because of their myriad of applications, including in biology. The biomedical application of supramolecular coordination complexes (SCCs) is still an emergent field of study, but the pioneering examples discussed in this chapter confirm that these scaffolds hold promise as novel anticancer drugs, endowed with different mechanisms of action compared to classical small-molecule and metal-based cytotoxic agents, often linked to their peculiar molecular recognition properties. Moreover, the host–guest chemistry of SCCs can also be exploited to design a new generation of drug delivery systems for anticancer chemotherapeutics. In fact, the robustness of supramolecular metal-based complexes allows incorporation of different functionalities in the same scaffold to enable imaging in cells, as well as targeting and stimuli responsiveness. Certainly, the myriad of possible SCCs and their almost limitless modularity and tunability, without significant synthetic penalty, suggests that the biomedical applications of such species will continue along this already promising path. In this chapter, we aim to summarize the main concepts in this fascinating research area, illustrating representative examples and providing a critical discussion of the state-of-the-art.
Enabling Methods to Elucidate the Effects of Metal-based Anticancer Agents
Authors: Kreutz D. , Gerner C. , Meier-Menches S. M.
Published: April 2019

Next-generation metal-based pharmaceuticals are considered promising therapeutic agents, which may follow novel modes of action and engage with different targets compared to classical platinum(ii) anticancer agents. However, appropriate methods and assays are required to provide evidence of such unprecedented drug effects. Mass spectrometry (MS) has proved useful in probing the reactivity and selectivity of metal-based anticancer agents on a molecular level and recently also in the cellular context, especially with regard to the proteome. This chapter will discuss the design and use of competitive experiments to investigate activation pathways and binding preferences of metal-based anticancer agents by identifying reaction products via different MS setups. Moreover, cell-based approaches are described to obtain insights into novel potential targets and modes of action. Thus, mass spectrometry emerges as an enabling technology that connects molecules to mechanisms, highlighting the broad applicability of this analytical technique to the discovery and understanding of metal-based anticancer agents.
Challenges and Chances in the Preclinical to Clinical Translation of Anticancer Metallodrugs
Authors: Pötsch Isabella , Baier Dina , Keppler Bernhard K. , Berger Walter
Published: April 2019

Despite being “sentenced to death” for quite some time, anticancer platinum compounds are still the most frequently prescribed cancer therapies in the oncological routine and recent exciting news from late-stage clinical studies on combinations of metallodrugs with immunotherapies suggest that this situation will not change soon. It is perhaps surprising that relatively simple molecules like cisplatin, discovered over 50 years ago, are still widely used clinically, while none of the highly sophisticated metal compounds developed over the last decade, including complexes with targeting ligands and multifunctional (nano)formulations, have managed to obtain clinical approval. In this book chapter, we summarize the current status of ongoing clinical trials for anticancer metal compounds and discuss the reasons for previous failures, as well as new opportunities for the clinical translation of metal complexes.
Highly enantioselective epoxidation of olefins by H2O2 catalyzed by a non-heme Fe(ii) catalyst of a chiral tetradentate ligand
Authors: Mitra Mainak , Cusso Olaf , Bhat Satish S. , Sun Mingzhe , Cianfanelli Marco , Costas Miquel , Nordlander Ebbe
Published: April 2019

A new chiral Fe(ii)-complex mediates the asymmetric epoxidation of prochiral olefins with good enantioselectivity.
Piperazic acid-containing natural products: structures and biosynthesis
Authors: Morgan Kalindi D. , Andersen Raymond J. , Ryan Katherine S.
Published: April 2019

Piperazic acid is a cyclic hydrazine and a non-proteinogenic amino acid found in diverse non-ribosomal peptide (NRP) and hybrid NRP–polyketide (PK) structures.
Utility of macrophages in an antitumor strategy based on the vectorization of iron oxide nanoparticles
Authors: Dalzon Bastien , Guidetti Mélanie , Testemale Denis , Reymond Solveig , Proux Olivier , Vollaire Julien , Collin-Faure Véronique , Testard Isabelle , Fenel Daphna , Schoehn Guy , Arnaud Josiane , Carrière Marie , Josserand Véronique , Rabilloud Thierry , Aude-Garcia Catherine
Published: April 2019

Anticancer using Fe2O3-laden macrophages. Macrophages derived from patients are treated by Fe2O3 nanoparticles and reinjected into the bloodstream. They are attracted by the tumor where they accumulate. Low-intensity radiation activates iron NPs, which release toxic photoelectrons in the tumor, leaving the surrounding tissue undamaged.
Acquisition of time–frequency localized mechanical properties of biofilms and single cells with high spatial resolution
Authors: López-Guerra Enrique A. , Shen Hongchen , Solares Santiago D. , Shuai Danmeng
Published: April 2019

History-dependent viscoelastic analysis by atomic force microscopy delivers highly spatial-localized biofilm properties within a wide time–frequency window.
Temperature-induced transport changes in molecular junctions based on a spin crossover complex
Authors: Poggini Lorenzo , Gonidec Mathieu , Canjeevaram Balasubramanyam Ram Kumar , Squillantini Lorenzo , Pecastaings Gilles , Caneschi Andrea , Rosa Patrick
Published: April 2019

This work describes the study of molecular junctions embedding the spin crossover complex [Fe(H2B(pz)2)2(phen)] as an active switchable thin film.
Redox-probe-free scanning electrochemical microscopy combined with fast Fourier transform electrochemical impedance spectroscopy
Authors: Valiūnienė Aušra , Petroniene Jurate , Morkvenaite-Vilkonciene Inga , Popkirov Georgi , Ramanaviciene Almira , Ramanavicius Arunas
Published: April 2019

Scanning electrochemical microscopy (SECM) hybridized with fast Fourier transform-based electrochemical impedance spectroscopy (FFT-EIS) seems to be a powerful variation of scanning electrochemical impedance microscopy (SEIM).
Imaging inelastic scattering of CO with argon: polarization dependent differential cross sections
Authors: Sun Zhong-Fa , Bishwakarma Chandan K. , Song Lei , van der Avoird Ad , van Hemert Marc C. , Suits Arthur G. , McBane George C. , Parker David H.
Published: April 2019

Rotationally inelastic scattering of carbon monoxide (CO) with argon at a collision energy of 700 cm−1 has been investigated by measuring polarization dependent differential scattering cross sections (PDDCSs) for rotationally excited CO molecules using a crossed molecular beam apparatus coupled with velocity-map ion imaging.
How water flips at charged titanium dioxide: an SFG-study on the water–TiO2 interface
Authors: Schlegel Simon J. , Hosseinpour Saman , Gebhard Maximilian , Devi Anjana , Bonn Mischa , Backus Ellen H. G.
Published: April 2019

Photocatalytic splitting of water into hydrogen and oxygen by utilizing sunlight and a photocatalyst is a promising way of generating clean energy.
Vibronic interaction in CO3− photo-detachment: Jahn–Teller effects beyond structural distortion and general formalisms for vibronic Hamiltonians in trigonal symmetries
Authors: Seidu Issaka , Goel Prateek , Wang Xiao-Gang , Chen Bo , Wang Xue-Bin , Zeng Tao
Published: April 2019

Expansion formalisms for trigonal Jahn–Teller and pseudo-Jahn–Teller vibronic Hamiltonians are developed and used to study and correctly interpret the photoelectron spectrum of CO3−.
Structural analysis of the initial lithiation of NiO thin film electrodes
Authors: Evmenenko Guennadi , Fister Timothy T. , Castro Fernando C. , Chen Xinqi , Lee Byeongdu , Buchholz D. Bruce , Dravid Vinayak P. , Fenter Paul , Bedzyk Michael J.
Published: April 2019

Our results reveal that conversion reactions and structural changes in NiO thin film electrodes begin near the theoretical lithiation potential.
Enhanced 1.5 μm emission of Er3+-doped multifunctional Bi2ZnOB2O6 microcrystals
Authors: Jaroszewski Konrad , Zhezhera Taras , Gluchowski Pawel , Marciniak Lukasz , Chrunik Maciej , Majchrowski Andrzej , Kasprowicz Dobroslawa
Published: April 2019

The efficiency of the 1.5 μm emission associated with the 4I13/2 → 4I15/2 transition of Er3+ ions of a series of Er3+ and Yb3+/Er3+-doped Bi2ZnOB2O6 microcrystalline powders was investigated.
Dramatic impact of auxiliary ligands on the two-step magnetic relaxation process in Dy4(iii) single-molecule magnets
Authors: Zhang Kun , Li Gao-Peng , Zhang Cheng , Wang Yao-Yu
Published: April 2019

Two-step relaxation processes are modulated in two Dy(iii)4SMMs through modifying the auxiliary ligands on the changeable coordination sites.
Copper(ii) triflate-mediated synthesis of functionalized silsesquioxanesviadehydrogenative coupling of POSS silanols with hydrosilanes
Authors: Kaźmierczak Joanna , Hreczycho Grzegorz
Published: April 2019

A novel, effective catalytic methodology for modification of silsesquioxanes is reported, which is based on dehydrogenative coupling between POSS silanols and commercially available hydrosilanes mediated by inexpensive Cu(OTf)2.
Highly regioselective and sustainable solar click reaction: a new post-synthetic modified triazole organic polymer as a recyclable photocatalyst for regioselective azide–alkyne cycloaddition reaction
Authors: Yadav Dolly , Singh Nem , Kim Tae Wu , Kim Jae Young , Park No-Joong , Baeg Jin-Ook
Published: April 2019

Sustainable and highly regioselective solar light-assisted approach for the azide–alkyne cycloaddition reaction using a perylene-derived post-synthetic modified triazole-linked organic polymer photocatalyst.
Correction: Polyhydroxyalkanoates as biomaterials
Authors: Thorat Gadgil Bhagyashri S. , Killi Naresh , Rathna Gundloori V. N.
Published: April 2019

Correction for ‘Polyhydroxyalkanoates as biomaterials’ by Bhagyashri S. Thorat Gadgil et al., Med. Chem. Commun., 2017, 8, 1774–1787.
Reactivity of Cu(ii)–, Zn(ii)– and Fe(ii)–thiosemicarbazone complexes with glutathione and metallothionein: from stability to dissociation to transmetallation
Authors: Santoro Alice , Vileno Bertrand , Palacios Òscar , Peris-Díaz Manuel David , Riegel Gilles , Gaiddon Christian , Krężel Artur , Faller Peter
Published: April 2019

Thiosemicarbazones (TSCs) are a class of strong metal ion ligands, which are currently being investigated for several applications, such as anticancer treatment. In addition to these ligands only, which exert their activity upon interaction with metal ions in cells, preformed metal–TSC complexes are also widely studied, predominantly with the essential metal ions iron, copper and zinc. Currently, it is unclear what the active species are, which complexes are present and what are their biological targets. Herein, we study the complexes of copper(ii), zinc(ii) and iron(ii) with three TSCs, PT, 3-AP (triapine) and Dp44mT, (latter two are currently in clinical trials), concerning their reactivity with glutathione (GSH) and Zn7-metallothionein (Zn7MT-1, 2 and 3). These two cysteine-containing molecules can have a major impact on metal–TSC complexes because they are abundant in the cytosol and nucleus, they are strong metal ligands and have the potential to reduce Cu(ii) and Fe(iii). Our results indicate that Fe(ii)–TSC is stable in the presence of typical cytosolic concentrations of GSH and Zn7MT. In contrast, all three Cu(ii)–TSCs react rapidly due to the reduction of Cu(ii) to Cu(i), which is then transferred to MT. This suggests that Cu(ii)–TSCs are rapidly dissociated in a cytosolic-type environment and the catalytic generation of reactive oxygen species by Cu(ii)–TSCs is stopped. Moreover, in the case Cu(ii)–Dp44mT, transmetallation with Zn(ii) from MT occurs. The reaction of Zn(ii)–TSCs is ligand dependent, from predominant dissociation for PT and 3-AP, to very little dissociation of Zn(ii)–Dp44mT2. These results indicate that GSH and Zn7MT may be important factors in the fate of Cu(ii)– and Zn(ii)–TSCs. In particular, for Cu, its chemistry is complex, and these reactions may also occur for other families of Cu-complexes used in cancer treatment or for other applications.
Gradient-band-gap strategy for efficient solid-state PbS quantum-dot sensitized solar cells
Authors: Ma Chengfeng , Shi Chengwu , Lv Kai , Ying Chao , Fan Shasha , Yang Yang
Published: April 2019

Solid-state gradient-band-gap PbS QDSCs achieved a PCE of 6.29% under 1 sun and 7.21% under 0.5 sun.
Optically healable polyurethanes with tunable mechanical properties
Authors: Yan Rui , Jin Bixin , Luo Yunjun , Li Xiaoyu
Published: April 2019

The mechanical properties of polyurethanes can be nicely tuned by UV irradiation in a reversible way, endowing the polyurethanes with optical healing properties.
Investigation of the electrochemical oxidation of 2,3′-bisindolylmethanes in positive-ion electrospray ionization mass spectrometry
Authors: Xu Xu , He Guangyun , Xu Xiaoying , Wu Zhijun , Cai Tian
Published: April 2019

The electrochemical oxidation reactions of 2,3′-bisindolylmethanes were affected by the solvent in the positive-ion electrospray ionization mass spectrometry (ESI-MS).
Synthesis of Mg and Zn diolates and their use in metal oxide deposition
Authors: Frenzel Peter , Preuß Andrea , Bankwitz Jörn , Georgi Colin , Ganss Fabian , Mertens Lutz , Schulz Stefan E. , Hellwig Olav , Mehring Michael , Lang Heinrich
Published: April 2019

Mg and Zn containing precursors for the generation of metal oxide layers by CVD and/or spin-coating are described.
Temperature and initial composition dependence of pattern formation and dynamic behavior in phase separation under deep-quenched conditions
Authors: Zhang Liang , Peng Yinli , Zhang Li , Lei Xiaowei , Yao Wenjing , Wang Nan
Published: April 2019

Temperature and initial composition influence the pattern formations and dynamic behaviors of the second phase in phase separation.
Single-step multivalent capture assay for nucleic acid detection with dual-affinity regulation using mutation inhibition and allosteric activation
Authors: Lu Xing , Zhou Guobao , Zeng Yanbo , Yin Zhengzhi , Zhang Zulei , Guo Liping , Zhai Yunyun , Yang Yiwen , Wang Hailong , Li Lei
Published: April 2019

A single-step electrocatalytic biosensor with dual-affinity regulation enables a tunable dynamic range and tunable single nucleotide resolution for nucleic acid detection.
Porous three-dimensional carbon foams with interconnected microchannels for high-efficiency solar-to-vapor conversion and desalination
Authors: Qiu Pengxiang , Liu Fengling , Xu Chenmin , Chen Huan , Jiang Fang , Li Yang , Guo Zhaobing
Published: April 2019

Carbon foams were fabricated from wood via alkali activation for solar steam generation.
The role of substituents in determining the redox potential of organic electrode materials in Li and Na rechargeable batteries: electronic effects vs. substituent-Li/Na ionic interaction
Authors: Lee Sechan , Kwon Ji Eon , Hong Jihyun , Park Soo Young , Kang Kisuk
Published: April 2019

The competition between electronic effects and the ionic interaction is suggested as the governing factor determining the redox voltages through analysis on the voltage trend of chemically tuned Na2TP derivatives.
Oxygen-deficient titanium dioxide as a functional host for lithium–sulfur batteries
Authors: Wang Hong-En , Yin Kaili , Qin Ning , Zhao Xu , Xia Fan-Jie , Hu Zhi-Yi , Guo Guanlun , Cao Guozhong , Zhang Wenjun
Published: April 2019

Engineering oxygen vacancies in mesoporous TiO2 effectively enhanced its ability to trap polysulfides and simultaneously propelled the redox conversion of polysulfides.
Compact SIW cavity MIMO antenna with enhanced bandwidth and high isolation
Authors: Niu Bing‐Jian , Tan Jie‐Hong
Published: April 2019

A compact substrate‐integrated‐waveguide (SIW) cavity multiple‐input–multiple‐output (MIMO) antenna with enhanced bandwidth and high isolation is proposed. It is based on a triangle half‐mode SIW cavity with one open edge and two edges shorted by metallic vias. By etching three slots, the single cavity can be divided into four eighth‐mode sub‐cavities. Two large sub‐cavities with the same size are excited by two coaxial ports to construct two antenna elements and a wide slot between them is utilised as the de‐coupler. Therefore, high isolation can be obtained. On the other hand, cavity energy can be coupled from the excited sub‐cavities to the unexcited sub‐cavities due to two narrow T‐shaped slots serving as the couplers. Therefore, enhanced bandwidth can be achieved by merging two coupled modes into the required operating band. A fabricated prototype centring at 3.51 GHz has been measured. With a compact size of 0.59λ0 × 0.59λ0, enhanced bandwidth of 160 MHz, high isolation of 19.5 dB, the antenna gain of 4.9 dBi, and radiation efficiency of 72.8%, the proposed design has potential applications for fifth‐generation communication.
Flatness‐based control approach to networked control under sensor delays
Authors: Rigatos Gerasimos
Published: April 2019

A new control method based on differential flatness theory is developed in this article, aiming at solving the problem of networked control under sensor delays. A sensor network comprising N sensors and N control inputs is considered. Time delays between the control inputs and the system's outputs (sensor readings) are taken into account. Using the principle of dynamic extension, which means that by considering certain control inputs and their derivatives as additional state variables, a state‐space description for the networked control system is obtained. It is proven that the dynamic model of the networked control system is a differentially flat one. This enables its transformation into a linear canonical and decoupled form, for which the design of a stabilising feedback controller becomes possible. The proposed feedback controller is of proven stability and assures fast and accurate tracking of the reference setpoints by the outputs of the network control system. Moreover, by using a Kalman‐filter‐based disturbances' estimator, it becomes possible to estimate in real time and compensate for parametric uncertainty, external perturbation inputs, and variation in sensor delays that may appear in the networked control system.
On performance analysis of hybrid FSO/RF systems
Authors: Shakir Wafaa Mohammed Ridha
Published: April 2019

In this work, the author investigate the performance of the hybrid free‐space optical/radio frequency (FSO/RF) communication systems where RF links are subject to Nakagami‐m distribution fading effects. The author derive the statistical characteristics of the hybrid FSO/RF systems in closed‐form in terms of Meijer's G‐function and the extended generalised bivariate Meijer's G‐function. Then, the author rely on these new results to present the performance analysis of the selection combining diversity based on hybrid FSO/RF systems. Also, the author consider a Gamma–Gamma turbulence distribution under the impact of pointing errors and subject to both types of detection techniques (i.e. heterodyne detection and intensity modulation with direct detection (IM/DD)) in the FSO link. Computer‐based Monte–Carlo simulations are proved the accuracy of the new analytical results.
Multipath data transmission in WSN using exponential cat swarm and fuzzy optimisation
Authors: Kulkarni Pramod Kumar H. , Malathi Jesudason P.
Published: April 2019

This study proposes a technique for multipath data transmission in Wireless Sensor Network (WSN) by proposing a novel optimisation algorithm, named exponential cat swarm optimisation (ECSO), by integrating the exponential weighted moving average and CSO. Initially, the CH is selected by the penguin fuzzy‐based ant colony optimisation (PFuzzyACO) technique, which is the integration of fuzzy, ACO and penguin search optimisation algorithm (PeSOA). After the selection of the optimal CH, the multipath transmission is done by the proposed ECSO algorithm. Here, an optimal path is selected for transmitting the routeing information from source to destination based on various parameters such as trust, energy, distance, delay, traffic density and link lifetime (LLT). Thus, the CHs with maximum trust, energy and LLT, and minimum distance, delay and traffic density are adapted for multipath data transmission using the proposed ECSO algorithm. The proposed ECSO algorithm shows 18.75, 2.99 and 29.87% improvements in terms of number of alive nodes, throughput and network energy, respectively, than the existing PFuzzyACO, which has high performance than the other comparative methods such as artificial bee colony, ACO, fractional artificial bee colony, Low‐Energy Adaptive Clustering Hierarchy (LEACH), FuzzyACO and PeSOA.
Multicast scheduling for delay‐energy trade‐off under bursty request arrivals in cellular networks
Authors: Zhou Yifan , Zhao Zhifeng , Qi Chen , Li Rongpeng , Louet Yves , Palicot Jacques , Zhang Honggang
Published: April 2019

In this study, the authors consider the utilisation of multicast technology in cellular networks given different arrival patterns for the content requests of mobile users. Traditionally, the performance evaluation of multicast in the literature usually depends on the adoption of temporal Poisson processes for content requests, which is not accurate any more according to many real data measurements. Therefore, to make use of the bursty nature of content requests, they propose a hybrid unicast/multicast strategy where the base station (BS) can perform the unicast or multicast procedure according to its serving status. By modelling the complete process into a circular Markov chain, they derive the average latency of content requests and the average power consumption of BSs under different arrival patterns and serving configurations in theoretical and/or simulative ways. Moreover, the multicast threshold introduced in their strategy can be dynamically adjusted to achieve a joint optimisation between average latency and power consumption when confronted with varied demands. Numerous results show that the proposed strategy can not only reduce the average latency of content requests but also decrease the average power consumption of BSs, especially under the bursty request arrival patterns.
Design and implementation of aerial communication using directional antennas: learning control in unknown communication environments
Authors: Li Songwei , He Chenyuan , Liu Mushuang , Wan Yan , Gu Yixin , Xie Junfei , Fu Shengli , Lu Kejie
Published: April 2019

To support an increasing number of commercial multi‐unmanned aerial vehicle (UAV) applications, robust UAV‐to‐UAV communication is critical. A promising solution is aerial communication using directional antennas (ACDA), with features like long communication distance, low power consumption, broad bandwidth, and interference rejection. Nevertheless, ACDA requires the automatic alignment of directional antennas, which is not easy to achieve considering the imperfect communication environment unknown in advance and the limited sensing devices onboard due to the constrained payloads and power sources. In this study, the authors design and implement a new ACDA system, including the platform, communication, computing, control, middleware, and interface components. Practical implementation issues for the emergency response application are also considered. The ACDA system features a communication and control co‐design, where the communication quality indicator, received signal strength indicator, serves as the goal function for antenna alignment. The solution also features a reinforcement learning‐based directional antenna control algorithm that learns the unknown communication environment models. The performance of the ACDA system is verified using simulation studies, field tests, and disaster drills.
Multi‐mode control and operation of a self‐sufficient multi‐microgrid system
Authors: Sahoo Saroja Kanti , Kishore Nudurupati Krishna , Sinha∗ Avinash Kumar
Published: April 2019

In this study, a ring‐type multi‐microgrid (MG) system comprising of three MGs with solar energy‐based generation, wind energy‐based generation, and static synchronous compensator as primary sources along with batteries as emergency back‐up is proposed. The voltage‐source converters at the individual MG level serve as the interface between the neighbouring MGs and the grid. An augmented proportional sliding‐mode‐control‐based approach is proposed in the primary control level to improve the power quality of the system during balanced and unbalanced loading conditions. A negative‐sequence controller is also included to mitigate the negative‐sequence voltage from the inverter output voltage. The multi‐MG (MMG) system is capable of operation in grid‐connected, islanded, or interconnected mode with balanced and unbalanced loads. The bidirectional DC ‐DC converters interfacing the batteries at the DC link is controlled by a hysteresis‐function‐based sliding‐mode control. A comparison of the proposed inverter primary control with proportional ‐integral controller, quasi‐proportional ‐resonant controller, and hysteresis‐band current controller is carried out. The comparison reveals that the total harmonic distortion and voltage unbalance factor improves by employing the proposed control when compared with conventional control. The proposed MMG system with its control strategies is modelled in MATLAB/Simulink environment and is experimentally verified using OP4510 from OPAL‐RT.
Optimal shared mobility planning for electric vehicles in the distribution network
Authors: Fan Vivienne Hui , Wang Shu , Meng Ke , Dong Zhao Yang
Published: April 2019

Shared electric vehicle (EV) is an emerging component across interdependent power and transportation networks that affect economic, environmental and societal benefits. Studies on how to collaboratively enable the optimal planning of these interacted networks is less explored. In this work, a joint distribution network expansion planning framework integrated with a shared EV charging station is proposed. One of the objectives is to minimise overall investment cost considering operational waiting cost of shared EV charging service and power loss, while the other aims to maximise the utilisation of charging infrastructures. To overcome the difficulties in solving the multi‐objective mixed‐integer non‐linear problem, Tchebycheff decomposition based evolutionary algorithm is modified to find the Pareto front showing the trade‐offs between goals above. Besides, stochastic traffic assignment model is used to obtain traffic distribution and travel demand. The final optimal solution is decided by the fuzzy satisficing method. The performance of the proposed approach is evaluated on a 54‐node test system. Sensitivity analysis is performed to assess the impact of key parameters from the perspectives of transportation and distribution network sectors. The numerical results demonstrate the capability and feasibility of the proposed method.
Miniaturised and harmonic‐suppressed rat‐race couplers based on slow‐wave transmission lines
Authors: Selga Jordi , Coromina Jan , Vélez Paris , Fernández‐Prieto Armando , Bonache Jordi , Martín Ferran
Published: April 2019

In this study, a compact rat‐race hybrid coupler with harmonic suppression based on slow‐wave transmission lines (SW‐TLs) is presented. Such artificial lines are implemented by periodic loading a host microstrip line with series meandered inductors and shunt patch capacitors. The presence of both loading elements has a twofold effect, i.e. phase velocity reduction (due to the enhancement of the effective inductance and capacitance of the periodic line), and the generation of a controllable stopband in the frequency response (due to the Bragg effect, inherent to periodicity). It is shown that by designing the unit cell of the periodic line with an electrical length of 45°, at least the first five harmonic bands of the rat‐race coupler are efficiently suppressed, keeping the band of interest unaltered. Moreover, 79% size reduction, as compared to the ordinary coupler, is achieved in the reported SW‐TL‐based prototype.
Large electromagnetic activity metamaterial composed of five‐segment cranks
Authors: García‐Collado Angel J. , Molina‐Cuberos Gregorio J. , Margineda José , Barba Ismael
Published: April 2019

A new chiral material composed of a two‐dimensional lattice of five‐segment cranks, with the same handedness is experimentally and numerically studied. The sample, formed by a single layer of such structures, exhibits huge electromagnetic activity and a negative refraction index for linearly polarised waves. Both the chirality parameter and the bandwidth with the negative refraction index are larger than those observed in chiral media composed of three‐segment cranks. The material also shows pronounced electromagnetic activity (larger than 250° per wavelength). This observed behaviour is attributed to the fact that the five‐segment configuration enhances the electromagnetic coupling compared with the three‐segment configuration.
Field transformation‐based multifunctional and wide‐angle polariser for antenna polarisation characteristics manipulation
Authors: Shi Hongyu , Giddens Henry , Hao Yang
Published: April 2019

The field transformation (FT) method provides a design approach for artificial media which manipulate wave radiation and propagation with both parallel and perpendicular polarisations at wide incidence angles. Here, the authors study radiation characteristics of antennas with such an artificial medium. Specifically, a wide‐angle FT polariser was applied as an antenna superstrate to control its polarisation characteristics at a broadband of frequencies with little impact on the gain and the radiation pattern. The resulting antenna demonstrates stable multi‐polarised radiation states at a wide angular range. The measurement results are in good agreement with theoretical predictions and numerical simulations.
Risk‐based stochastic day‐ahead operation for data centre virtual power plants
Authors: Zhang Haifeng , Xu Ting , Wu Hongyu , Liu Bo , Nazif Faqiry M.
Published: April 2019

Data centres (DCs) have rapidly expanded in recent years due to increasing demand for cloud services. The costs incurred by electricity and water consumption contribute to a major portion of DC operating costs. This article addresses the day‐ahead operation of a DC in the context of a virtual power plant (VPP) under the grid‐connected mode. The day‐ahead operation problem is formulated as a two‐stage stochastic mixed integer linear programming (MILP) model that considers workload schedules among server clusters, water consumption, and uncertainties of onsite renewable energy and electricity prices. In addition, the conditional value at risk (CVaR) is utilised to manage the risk caused by various uncertainties that challenge DCs, especially electricity prices. The impacts of the risk level, the water price, and uncertainty on the day‐ahead operation of the DC are studied. The numerical test results show that the proposed model can efficiently generate optimal day‐ahead schedules.
Analysis of the spectrum of electromagnetic radiation generated by electrical discharges
Authors: Nagi Łukasz , Kozioł Michał , Wotzka Daria
Published: April 2019

The stidy presents research results considering measurement and detection of electromagnetic radiation (EMR) generated by partial discharges (PDs) in the air and during breakdown. The key objective of the works was to develop a methodology of detection of ionising radiation generated by electrical discharges. This includes design of experimental setup for simulation of discharges under laboratory conditions and selection of appropriate measuring devices. For measurements of visible light and UV radiation, a HR‐4000 spectrophotometer was chosen. The high energy ionising radiation was detected by means of a scintillation counter by own production. The experimental studies involved registration of EMR emitted by both PD and electrical breakdowns of the measuring system for various point–point electrodes arrangements. Then, characteristic spectra were defined in bands from visible light, through UV to the X‐ray radiation frequencies. The use of high‐energy radiation detection for determining basic forms of discharges and the potential possibility of the detailed specification of their power balance are curtail achievements of the presented article. The other contributions lie in the simultaneously application of two independent discharge detection methods.
Wave propagation in fluid‐conveying nanotubes under multi‐physical fields based on non‐local higher‐order strain gradient model
Authors: Pang Miao , Wang Peng , Zhang Yongqiang
Published: April 2019

This work studies the wave propagation in embedded single‐walled carbon nanotubes (CNTs) conveying fluid and placed in multi‐physical fields based on the non‐local higher‐order strain gradient model with surface effect considered. The nanotubes are modelled as Timoshenko beams. Utilising Hamilton's principle, the governing equations of wave motion in CNTs are derived. The solution for the phase velocity of wave motion is obtained, which can not only consider the stiffness softening effect but also reflect the stiffness enhancement effect of scale parameter observed by experiments. The numerical simulations are conducted to compare the results on the basis of different order non‐local strain gradient models. It is shown that the behaviours of wave propagation based on the non‐local higher‐order strain gradient models are quite different from those based on the classical continuum model. In addition, the scale and surface effects and influences of various external factors including inner flow, surrounding medium, temperature field, and magnetic field on the wave dispersion are investigated.
Das Deutsche Zentrum für Kinder- und Jugendgesundheit: eine Chance für die Forschung im Bereich Sozialmedizin, Gesundheitsförderung und Prävention
Authors: Butler Jeffrey , Geene Raimund , Loss Julika , Schneider Sven ,   für den Vorstand der Deutschen Gesellschaft für Sozialmedizin und Prävention e.V.
Published: April 2019

Im Koalitionsvertrag der Bundesregierung 2018 wurde der Ausbau der Deutschen Zentren für Gesundheitsforschung vereinbart. In Umsetzung der Regierungsvereinbarung wird nun durch das Bundesministerium für Bildung und Forschung die Gründung eines Deutschen Zentrums für Kinder- und Jugendgesundheit (DZKJ) geplant. Dieses Zentrum soll nach dem Modell der sechs bestehenden Deutschen Zentren konzipiert werden, indem deutschlandlandweit wissenschaftliche Expertise gebündelt wird. Im Laufe des Jahres 2019 soll das Antragsverfahren für die zukünftigen Partner/innen dieses neuen Zentrums starten.
„Professionelles Reasoning macht uns zu guten Therapeuten“ – Professionelles und klinisches Reasoning in der Ergotherapie
Authors: Gritsch Simone
Published: April 2019

Für ihr neues Buch hat Maria Feiler Autoren aus der internationalen Ergotherapie zusammengetrommelt: Jennifer Creek, Helene Polatajko, Ursula Costa, Johanna Stadler-Grillmaier und Bettina Weber sind nur einige davon. Warum sie das Professionelle Reasoning Berufsanfängern und alten Hasen als ein hilfreiches Instrument ans Herz legt, erzählt Maria Feiler im Interview.
Fabrication of L1-type FeCo ordered structure using a periodic Ni buffer layer
Authors: Ito Hisaaki , Saito Masahiro , Miyamachi Toshio , Komori Fumio , Koganezawa Tomoyuki , Mizuguchi Masaki , Kotsugi Masato
Published: April 2019

We experimentally prepared a ferromagnet with an L10-FeCo ordered structure by inserting a periodic buffer layer to suppress the B2 structural transition and to maintain the L10 structure. The sample was fabricated by utilizing a technique involving the deposition of alternating monoatomic layers using pulsed laser deposition (PLD). This technique was used to deposit a thin film of (7 ML-FeCo/3 ML-buffer)3, in which either Cu or Ni was utilized as buffer layer. We characterized the surface roughness, surface morphology, lattice structure, and magnetic properties of the specimens by RHEED, AFM, SR-XRD, and SQUID, respectively. As a result, we successfully confirmed the construction of the L10-FeCo superstructure with a periodic Ni buffer layer for the first time. Both the magnetic moment and magnetic anisotropy were also increased by replacing Cu with Ni.