bluuebunny/crossref_metadata_2025 huggingface dataset:
Novel application of discrete choice experiment methodology to understand how clinicians around the world triage palliative care needs: A research protocol
Authors: Russell Bethany , Vogrin Sara , Philip Jennifer , Hennessy-Anderson Nicole , Collins Anna , Burchell Jodie , Le Brian , Brand Caroline , Hudson Peter , Sundararajan Vijaya
Published: January 2019

Objective

As referrals to specialist palliative care (PC) grow in volume and diversity, an evidence-based triage method is needed to enable services to manage waiting lists in a transparent, efficient, and equitable manner. Discrete choice experiments (DCEs) have not to date been used among PC clinicians, but may serve as a rigorous and efficient method to explore and inform the complex decision-making involved in PC triage. This article presents the protocol for a novel application of an international DCE as part of a mixed-method research program, ultimately aiming to develop a clinical decision-making tool for PC triage.

Method

Five stages of protocol development were undertaken: (1) identification of attributes of interest; (2) creation and (3) execution of a pilot DCE; and (4) refinement and (5) planned execution of the final DCE.

Result

Six attributes of interest to PC triage were identified and included in a DCE that was piloted with 10 palliative care practitioners. The pilot was found to be feasible, with an acceptable cognitive burden, but refinements were made, including the creation of an additional attribute to allow independent analysis of concepts involved. Strategies for recruitment, data collection, analysis, and modeling were confirmed for the final planned DCE.

Significance of results

This DCE protocol serves as an example of how the sophisticated DCE methodology can be applied to health services research in PC. Discussion of key elements that improved the utility, integrity, and feasibility of the DCE provide valuable insights.
Separating the North and South Pacific Meridional Modes Contributions to ENSO and Tropical Decadal Variability
Authors: Liguori Giovanni , Di Lorenzo Emanuele
Published: January 2019

North and South Pacific Meridional Modes (NPMM and SPMM) are known precursors of El Niño–Southern Oscillation (ENSO) and Tropical Pacific decadal variability (TPDV). However, the relative importance of these precursors and the timescale on which they impact the tropics remain unclear. Using a 30‐member ensemble of the Community Earth System Model as the control climate, we generate two additional members where the NPMM and SPMM are selectively suppressed. We find that both meridional modes energize the tropical variance independently on different timescales. The absence of NPMM leads to a significant reduction of the tropical interannual variability (~35%), while the absence of the SPMM has no appreciable impact on ENSO but significantly reduces the TPDV (~30%). While the relative importance of the NPMM and SPMM may be model dependent, the stochastic atmospheric variability in the extratropics that energizes the meridional modes emerges as a key source of TPDV.
Estimation of the Variation in Specific Discharge Over Large Depth Using Distributed Temperature Sensing (DTS) Measurements of the Heat Pulse Response
Authors: des Tombe Bas F. , Bakker Mark , Smits Frank , Schaars Frans , van der Made Kees‐Jan
Published: January 2019

An approach is presented to determine groundwater flow in unconsolidated aquifers with a heat pulse response test using a heating cable and a fiber‐optic cable. The cables are installed together using direct push so that the cables are in direct contact with the aquifer. The temperature response is measured for multiple days along the fiber‐optic cable with Distributed Temperature Sensing (DTS). The new approach fits a two‐dimensional analytical solution to the temperature measurements, so that the specific discharge can be estimated without knowledge of the position of the fiber‐optic cable relative to the heating cable. Two case studies are presented. The first case study is at a managed aquifer recharge system where fiber‐optic cables are inserted 15 m deep at various locations to test the fitting procedure. Similar and relatively large specific discharges are found at the different locations with little vertical variation (0.4–0.6 m/day). The second case study is at a polder, where the water level is maintained 2 m below the surrounding lakes, resulting in significant groundwater flow. The heating and fiber‐optic cables are inserted to a depth of 45 m. The specific discharge varies 0.07–0.1 m/day and is significantly larger in a thin layer at 30‐m depth. It is shown with numerical experiments that the estimated specific discharge is smoother than in reality due to vertical conduction, but the peak specific discharge is estimated correctly for layers thicker than ∼1.5 m.
Evolutionary constraints on species diversity in marine bacterioplankton communities
Authors: Lu Hsiao-Pei , Yeh Yi-Chun , Shiah Fuh-Kwo , Gong Gwo-Ching , Hsieh Chih-hao
Published: January 2019

Variation in microbial species diversity has typically been explained as the outcome of local ecological factors driving species coexistence, overlooking the roles of evolutionary constraints. Here, we argue that macro-evolutionary niche conservatism and unequal diversification rates among phylum-level lineages are strong determinants of diversity–environment relationships in bacterial systems. That is, apart from stochasticity, environmental effects operate most strongly on phylum composition, which in turn dictates the species diversity of bacterial communities. This concept is demonstrated using bacterioplankton in the surface seawaters of the East China Sea. Furthermore, we show that the species richness of a local bacterioplankton community can generally be estimated based on the relative abundances of phyla and their contributions of species numbers in the global seawater pool—highlighting the important influence of evolutionary constraints on local community diversity.
Molecular signatures of multiple myeloma progression through single cell RNA-Seq
Authors: Jang Jin Sung , Li Ying , Mitra Amit Kumar , Bi Lintao , Abyzov Alexej , van Wijnen Andre J. , Baughn Linda B. , Van Ness Brian , Rajkumar Vincent , Kumar Shaji , Jen Jin
Published: January 2019

We used single cell RNA-Seq to examine molecular heterogeneity in multiple myeloma (MM) in 597 CD138 positive cells from bone marrow aspirates of 15 patients at different stages of disease progression. 790 genes were selected by coefficient of variation (CV) method and organized cells into four groups (L1–L4) using unsupervised clustering. Plasma cells from each patient clustered into at least two groups based on gene expression signature. The L1 group contained cells from all MGUS patients having the lowest expression of genes involved in the oxidative phosphorylation, Myc targets, and mTORC1 signaling pathways (p < 1.2 × 10−14). In contrast, the expression level of these pathway genes increased progressively and were the highest in L4 group containing only cells from MM patients with t(4;14) translocations. A 44 genes signature of consistently overexpressed genes among the four groups was associated with poorer overall survival in MM patients (APEX trial, p < 0.0001; HR, 1.83; 95% CI, 1.33–2.52), particularly those treated with bortezomib (p < 0.0001; HR, 2.00; 95% CI, 1.39–2.89). Our study, using single cell RNA-Seq, identified the most significantly affected molecular pathways during MM progression and provided a novel signature predictive of patient prognosis and treatment stratification.
Size-dependent kinetics during non-equilibrium lithiation of nano-sized zinc ferrite
Authors: Li Jing , Meng Qingping , Zhang Yiman , Peng Lele , Yu Guihua , Marschilok Amy C. , Wu Lijun , Su Dong , Takeuchi Kenneth J. , Takeuchi Esther S. , Zhu Yimei , Stach Eric A.
Published: January 2019

Spinel transition metal oxides (TMOs) have emerged as promising anode materials for lithium-ion batteries. It has been shown that reducing their particle size to nanoscale dimensions benefits overall electrochemical performance. Here, we use in situ transmission electron microscopy to probe the lithiation behavior of spinel ZnFe2O4 as a function of particle size. We have found that ZnFe2O4 undergoes an intercalation-to-conversion reaction sequence, with the initial intercalation process being size dependent. Larger ZnFe2O4 particles (40 nm) follow a two-phase intercalation reaction. In contrast, a solid-solution transformation dominates the early stages of discharge when the particle size is about 6–9 nm. Using a thermodynamic analysis, we find that the size-dependent kinetics originate from the interfacial energy between the two phases. Furthermore, the conversion reaction in both large and small particles favors {111} planes and follows a core-shell reaction mode. These results elucidate the intrinsic mechanism that permits fast reaction kinetics in smaller nanoparticles.
Ultrasonic sculpting of virtual optical waveguides in tissue
Authors: Chamanzar Maysamreza , Scopelliti Matteo Giuseppe , Bloch Julien , Do Ninh , Huh Minyoung , Seo Dongjin , Iafrati Jillian , Sohal Vikaas S. , Alam Mohammad-Reza , Maharbiz Michel M.
Published: January 2019

Optical imaging and stimulation are widely used to study biological events. However, scattering processes limit the depth to which externally focused light can penetrate tissue. Optical fibers and waveguides are commonly inserted into tissue when delivering light deeper than a few millimeters. This approach, however, introduces complications arising from tissue damage. In addition, it makes it difficult to steer light. Here, we demonstrate that ultrasound can be used to define and steer the trajectory of light within scattering media by exploiting local pressure differences created by acoustic waves that result in refractive index contrasts. We show that virtual light pipes can be created deep into the tissue (>18 scattering mean free paths). We demonstrate the application of this technology in confining light through mouse brain tissue. This technology is likely extendable to form arbitrary light patterns within tissue, extending both the reach and the flexibility of light-based methods.
A miniature multi-contrast microscope for functional imaging in freely behaving animals
Authors: Senarathna Janaka , Yu Hang , Deng Callie , Zou Alice L. , Issa John B. , Hadjiabadi Darian H. , Gil Stacy , Wang Qihong , Tyler Betty M. , Thakor Nitish V. , Pathak Arvind P.
Published: January 2019

Neurovascular coupling, cerebrovascular remodeling and hemodynamic changes are critical to brain function, and dysregulated in neuropathologies such as brain tumors. Interrogating these phenomena in freely behaving animals requires a portable microscope with multiple optical contrast mechanisms. Therefore, we developed a miniaturized microscope with: a fluorescence (FL) channel for imaging neural activity (e.g., GCaMP) or fluorescent cancer cells (e.g., 9L-GFP); an intrinsic optical signal (IOS) channel for imaging hemoglobin absorption (i.e., cerebral blood volume); and a laser speckle contrast (LSC) channel for imaging perfusion (i.e., cerebral blood flow). Following extensive validation, we demonstrate the microscope’s capabilities via experiments in unanesthetized murine brains that include: (i) multi-contrast imaging of neurovascular changes following auditory stimulation; (ii) wide-area tonotopic mapping; (iii) EEG-synchronized imaging during anesthesia recovery; and (iv) microvascular connectivity mapping over the life-cycle of a brain tumor. This affordable, flexible, plug-and-play microscope heralds a new era in functional imaging of freely behaving animals.
A chemical biology screen identifies a vulnerability of neuroendocrine cancer cells to SQLE inhibition
Authors: Mahoney Christopher E. , Pirman David , Chubukov Victor , Sleger Taryn , Hayes Sebastian , Fan Zi Peng , Allen Eric L. , Chen Ying , Huang Lingling , Liu Meina , Zhang Yingjia , McDonald Gabrielle , Narayanaswamy Rohini , Choe Sung , Chen Yue , Gross Stefan , Cianchetta Giovanni , Padyana Anil K. , Murray Stuart , Liu Wei , Marks Kevin M. , Murtie Joshua , Dorsch Marion , Jin Shengfang , Nagaraja Nelamangala , Biller Scott A. , Roddy Thomas , Popovici-Muller Janeta , Smolen Gromoslaw A.
Published: January 2019

Aberrant metabolism of cancer cells is well appreciated, but the identification of cancer subsets with specific metabolic vulnerabilities remains challenging. We conducted a chemical biology screen and identified a subset of neuroendocrine tumors displaying a striking pattern of sensitivity to inhibition of the cholesterol biosynthetic pathway enzyme squalene epoxidase (SQLE). Using a variety of orthogonal approaches, we demonstrate that sensitivity to SQLE inhibition results not from cholesterol biosynthesis pathway inhibition, but rather surprisingly from the specific and toxic accumulation of the SQLE substrate, squalene. These findings highlight SQLE as a potential therapeutic target in a subset of neuroendocrine tumors, particularly small cell lung cancers.
Observation of dissociative quasi-free electron attachment to nucleoside via excited anion radical in solution
Authors: Ma Jun , Kumar Anil , Muroya Yusa , Yamashita Shinichi , Sakurai Tsuneaki , Denisov Sergey A. , Sevilla Michael D. , Adhikary Amitava , Seki Shu , Mostafavi Mehran
Published: January 2019

Damage to DNA via dissociative electron attachment has been well-studied in both the gas and condensed phases; however, understanding this process in bulk solution at a fundamental level is still a challenge. Here, we use a picosecond pulse of a high energy electron beam to generate electrons in liquid diethylene glycol and observe the electron attachment dynamics to ribothymidine at different stages of electron relaxation. Our transient spectroscopic results reveal that the quasi-free electron with energy near the conduction band effectively attaches to ribothymidine leading to a new absorbing species that is characterized in the UV-visible region. This species exhibits a nearly concentration-independent decay with a time constant of ~350 ps. From time-resolved studies under different conditions, combined with data analysis and theoretical calculations, we assign this intermediate to an excited anion radical that undergoes N1-C1′ glycosidic bond dissociation rather than relaxation to its ground state.
The ecdysone receptor complex is essential for the reproductive success in the female desert locust, Schistocerca gregaria
Authors: Lenaerts Cynthia , Marchal Elisabeth , Peeters Paulien , Vanden Broeck Jozef
Published: January 2019

Ecdysteroid hormones influence the development and reproduction of arthropods by binding a heterodimeric complex of nuclear receptors, the ecdysone receptor (EcR) and the retinoid-X-receptor/ultraspiracle (RXR/USP). Here, we report on the in vivo role(s) of the ecdysone receptor complex, SchgrEcR/SchgrRXR, in the female reproductive physiology of a major phytophagous pest insect, i.e. the desert locust, Schistocerca gregaria. Tissue and temporal distribution profiles were analysed during the first gonadotrophic cycle of adult female locusts. RNA interference was used as a reverse genetics tool to investigate the in vivo role of the ecdysone receptor complex in ovarian maturation, oogenesis, fertility and fecundity. We discovered that silencing the ecdysone receptor complex in S. gregaria resulted in impaired ovulation and oviposition, indicative for a crucial role of this complex in chorion formation. We also found evidence for a feedback of SchgrEcR/SchgrRXR on juvenile hormone biosynthesis by the corpora allata. Furthermore, we observed a tissue-dependent effect of the SchgrEcR/SchgrRXR knockdown on the transcript levels of the insulin receptor and neuroparsin 3 and 4. The insulin receptor transcript levels were upregulated in the brain, but not the fat body and gonads. Neuroparsins 3 and 4 transcript levels were down regulated in the brain and fat body, but not in the gonads.
The (R)-enantiomer of the 6-chromanol derivate SUL-121 improves renal graft perfusion via antagonism of the α1-adrenoceptor
Authors: Nakladal D. , Buikema H. , Romero A. Reyes , Lambooy S. P. H. , Bouma J. , Krenning G. , Vogelaar P. , van der Graaf A. C. , Groves M. R. , Kyselovic J. , Henning R. H. , Deelman L. E.
Published: January 2019

SUL-compounds are protectants from cold-induced ischemia and mitochondrial dysfunction. We discovered that adding SUL-121 to renal grafts during warm machine reperfusion elicits a rapid improvement in perfusion parameters. Therefore, we investigate the molecular mechanisms of action in porcine intrarenal arteries (PIRA). Porcine kidneys were stored on ice overnight and perfusion parameters were recorded during treatment with SUL-compounds. Agonist-induced vasoconstriction was measured in isolated PIRA after pre-incubation with SUL-compounds. Receptor binding and calcium transients were assessed in α1-adrenoceptor (α1-AR) transgenic CHO cells. Molecular docking simulation was performed using Schrödinger software. Renal pressure during warm reperfusion was reduced by SUL-121 (−11.9 ± 2.50 mmHg) and its (R)-enantiomer SUL-150 (−13.2 ± 2.77 mmHg), but not by the (S)-enantiomer SUL-151 (−1.33 ± 1.26 mmHg). Additionally, SUL-150 improved renal flow (16.21 ± 1.71 mL/min to 21.94 ± 1.38 mL/min). SUL-121 and SUL-150 competitively inhibited PIRA contraction responses to phenylephrine, while other 6-chromanols were without effect. SUL-150 similarly inhibited phenylephrine-induced calcium influx and effectively displaced [7-Methoxy-3H]-prazosin in CHO cells. Docking simulation to the α1-AR revealed shared binding characteristics between prazosin and SUL-150. SUL-150 is a novel α1-AR antagonist with the potential to improve renal graft perfusion after hypothermic storage. In combination with previously reported protective effects, SUL-150 emerges as a novel protectant in organ transplantation.
Microbial embryonal colonization during pipefish male pregnancy
Authors: Beemelmanns Anne , Poirier Maude , Bayer Till , Kuenzel Sven , Roth Olivia
Published: January 2019

While originally acquired from the environment, a fraction of the microbiota is transferred from parents to offspring. The immune system shapes the microbial colonization, while commensal microbes may boost host immune defences. Parental transfer of microbes in viviparous animals remains ambiguous, as the two transfer routes (transovarial vs. pregnancy) are intermingled within the maternal body. Pipefishes and seahorses (syngnathids) are ideally suited to disentangle transovarial microbial transfer from a contribution during pregnancy due to their maternal egg production and their unique male pregnancy. We assessed the persistency and the changes in the microbial communities of the maternal and paternal reproductive tracts over proceeding male pregnancy by sequencing microbial 16S rRNA genes of swabs from maternal gonads and brood pouches of non-pregnant and pregnant fathers. Applying parental immunological activation with heat-killed bacteria, we evaluated the impact of parental immunological status on microbial development. Our data indicate that maternal gonads and paternal brood pouches harbor distinct microbial communities, which could affect embryonal development in a sex-specific manner. Upon activation of the immune system, a shift of the microbial community was observed. The activation of the immune system induced the expansion of microbiota richness during late pregnancy, which corresponds to the time point of larval mouth opening, when initial microbial colonization must take place.
Polymer Dispersed Liquid Crystals
Authors: Rumi Mariacristina , Bunning Timothy J. , De Sio Luciano
Published: January 2019

Low molar mass liquid crystals (LCs) are typically not soluble in polymer systems to any great degree. When the two different materials are mixed, this leads to two-phase systems whose morphology depends on a variety of factors including, primarily, the concentration. The resulting two-phase structures can have inclusions with nanometer through macroscopic dimensions. Although there are a large number of variants, these structures are generically called ‘polymer dispersed liquid crystals’ (PDLCs) when the resulting morphologies lead to systems that scatter light. This is often achieved in the intermediate concentration region (30–70% LC), in which morphologies with large mesoscale inclusions are typically formed. If the refractive index matching is done correctly, upon application of an electric field, the scattering can be turned off by an electric field, leading to dynamic transparency. This is a review of past literature with a focus on the type of morphologies that can be exhibited. Basic electro-optic properties are discussed as is the large variety of morphologies that can be induced. Also included is the related research area of ‘periodic’ PDLC systems, wherein the phase separation process is induced spatially. This leads to anisotropic systems where an electric field can control diffraction, instead of scattering.
Electropolymerisation of (Meth)acrylic Mesogenic Monomers
Authors: Soto-Bustamante E. A.
Published: January 2019

The more uncommon method of polymer stabilization through electro-polymerization is outlined, and demonstrated for different phases, with an emphasis on the polymer stabilization of nematic and ferroelectric liquid crystals. Polymerization mechanisms, polymer morphology, and texture appearance will be discussed.
Polymer-stabilized Frustrated Phases
Authors: Dierking Ingo
Published: January 2019

The stabilization of Blue Phases has recently attracted much interest for the production of fast displays based on the Kerr effect. One method to stabilize Blue Phases, and frustrated liquid crystal phases in general, is by dispersing monomers and subsequent photo-polymerization. In this chapter we discuss the effects of polymer networks on the width of the generally very narrow Blue Phases, as well as Twist Grain Boundary (TGB) phases. Within the framework of polymer modified liquid crystals, the method of dispersing polymers in frustrated phases is also discussed.
Crystal structure of LepI, a multifunctional SAM-dependent enzyme which catalyzes pericyclic reactions in leporin biosynthesis
Authors: Chang Zhenying , Ansbacher Tamar , Zhang Lilan , Yang Yong , Ko Tzu-Ping , Zhang Guimin , Liu Weidong , Huang Jian-Wen , Dai Longhai , Guo Rey-Ting , Major Dan Thomas , Chen Chun-Chi
Published: January 2019

Crystal structure of LepI, a SAM-dependent enzyme which can catalyze seteroselective dehydration, Diels–Alder reaction, and retro-Claisen rearrangement.
Charge transfer complexation boosts molecular conductance through Fermi level pinning
Authors: Wang Kun , Vezzoli Andrea , Grace Iain M. , McLaughlin Maeve , Nichols Richard J. , Xu Bingqian , Lambert Colin J. , Higgins Simon J.
Published: January 2019

Efficient charge transport across long molecular wires enabled by charge-transfer complexation, through Fermi level pinning of interference features.
Macrocyclisation of small peptides enabled by oxetane incorporation
Authors: Roesner Stefan , Saunders George J. , Wilkening Ina , Jayawant Eleanor , Geden Joanna V. , Kerby Paul , Dixon Ann M. , Notman Rebecca , Shipman Michael
Published: January 2019

Head-to-tail peptide macrocyclisations are significantly improved, as measured by isolated yields, reaction rates and product distribution, by substitution of one of the backbone amide CO bonds with an oxetane ring.
Anomalous transport of magnetic colloids in a liquid crystal–magnetic colloid mixture
Authors: Shrivastav Gaurav P. , Klapp Sabine H. L.
Published: January 2019

In a liquid crystal–magnetic colloid mixture, magnetic colloids show a crossover from normal diffusive to subdiffusive behavior at long times as the dipolar coupling strength is increased.
Super metal hydrogels constructed from a simple tripodal gelator and rare earth metal ions and its application in highly selective and ultrasensitive detection of histidine
Authors: Liu Juan , Fan Yan-Qing , Zhang Qin-Peng , Yao Hong , Zhang You-Ming , Wei Tai-Bao , Lin Qi
Published: January 2019

A series of easily synthesized multi-functional super supramolecular metal hydrogel materials with high selectivity and ultrasensitivity are presented.
Asymmetric electrodes with a transition metal disulfide heterostructure and amorphous bimetallic hydroxide for effective alkaline water electrolysis
Authors: Wang Xiao Hu , Ling Yu , Li Bang Lin , Li Xiao Lin , Chen Guo , Tao Bai Xiang , Li Ling Jie , Li Nian Bing , Luo Hong Qun
Published: January 2019

Rational design of asymmetric electrodes synthesized by the hydro- and solvothermal method and in situ growth strategy to acquire TMDs@hydroxide composites for water electrolysis.
A sunlight self-healable transparent strain sensor with high sensitivity and durability based on a silver nanowire/polyurethane composite film
Authors: Song Yi Xi , Xu Wei Min , Rong Min Zhi , Zhang Ming Qiu
Published: January 2019

A strain sensor based on a silver nanowire/polyurethane composite film has successfully integrated high transparency, sensitivity, durability, sunlight self-healability and flexibility together.
Au nanoparticle in situ decorated RGO nanocomposites for highly sensitive electrochemical genosensors
Authors: Ingrosso Chiara , Corricelli Michela , Bettazzi Francesca , Konstantinidou Evgenia , Bianco Giuseppe V. , Depalo Nicoletta , Striccoli Marinella , Agostiano Angela , Curri M. Lucia , Palchetti Ilaria
Published: January 2019

A novel hybrid nanocomposite formed by RGO flakes, surface functionalized by 1-pyrene carboxylic acid (PCA), densely and uniformly in situ decorated by Au NPs, is reported, for miRNA detection.
Targeted and NIR light-controlled delivery of nitric oxide combined with a platinum(iv) prodrug for enhanced anticancer therapy
Authors: Shi Shu-Wen , Li Yan-Hui , Zhang Qian-Ling , Yang Shi-Ping , Liu Jin-Gang
Published: January 2019

A multifunctional nanoplatform exhibits selective intracellular co-delivery of Pt(ii) and NO under 808 nm light irradiation, accompanied by photothermal therapy.
Pressure-induced emission enhancement in hexaphenylsilole: a computational study
Authors: Zhang Tian , Shi Wen , Wang Dong , Zhuo Shuping , Peng Qian , Shuai Zhigang
Published: January 2019

The pressure-induced emission enhancement in hexaphenylsilole is a consequence of restricted low-frequency molecular rotations. Excessive pressurization over 5.06 GPa hampers the high-frequency molecular vibrations without further limitation of molecular rotations.
Correlation of recombination and open circuit voltage in planar heterojunction perovskite solar cells
Authors: Prochowicz Daniel , Tavakoli Mohammad Mahdi , Solanki Ankur , Goh Teck Wee , Sum Tze Chien , Yadav Pankaj
Published: January 2019

The effect of Cs cation addition on the intrinsic and interfacial dynamics of state-of-the-art planar TiO2-based PSCs is investigated.
A sub-10 nm monolayer ReS2 transistor for low-power applications
Authors: Quhe Ruge , Chen Jianxiu , Lu Jing
Published: January 2019

Improvement of the energy efficiency is an imperative need for electronics towards the Internet of Things (IoT).
Two-dimensional (PEA)2PbBr4 perovskite single crystals for a high performance UV-detector
Authors: Zhang Yunxia , Liu Yucheng , Xu Zhuo , Ye Haochen , Li Qingxian , Hu Mingxin , Yang Zhou , Liu Shengzhong (Frank)
Published: January 2019

A centimeter-sized high-quality two-dimensional (PEA)2PbBr4 single crystal was prepared, which exhibited superior UV photo-response performance.
Simultaneous suppression of torque ripple and flexible load vibration for PMSM under stator current vector orientation
Authors: Yu Yang , Cong Leyao , Tian Xia , Mi Zengqiang , Tang Jingqiu , Lu Jianbin , Xie Renjie
Published: January 2019

Torque ripple of permanent magnet synchronous motor (PMSM) will result in the distortion of current waveform and the load flexibility of spiral torsion spring (STS) will affect the control performance of driving system. This study focuses on a new control problem of simultaneous suppression of PMSM's torque ripple and flexible load's vibration. First, the Lagrange equation is used to establish the dynamic model of STS to describe its vibration mode. The overall model of STS directly derived by PMSM under stator current vector orientation is built. Then, based on the magnetic co‐energy model of electromagnetic torque of PMSM, the constraint relation of optimal stator harmonic current under the condition of torque ripple minimisation is derived, and the controller based on stator current oriented closed‐loop I/f control to suppress load vibration and torque ripple simultaneously is presented through backstepping control. A wide speed range identification method based on the least‐square algorithm with a forgetting factor is also designed. The simulation and experiment show that the speed identification algorithm can estimate the speed accurately in a wide range. The proposed control scenario improves control performance, smoothes current waveform and inhibits torque ripple and load vibration effectively.
High‐performance balun for a dual‐polarised dipole antenna
Authors: Wolosinski Grzegorz , Fusco Vincent , Rulikowski Pawel
Published: January 2019

This study proposes a detailed analysis on the operation of a high‐performance balun for a dual‐polarised dipole antenna. The main feature of this balun is to transform a coaxial feed into a differential feed which can enable very high performance for dual‐polarised configurations. First, the authors identify the key factors that allow the new balun to achieve better differential properties with respect to the feeding approach typically found in the literature. Second, they investigate the balun properties and the achievable antenna performance with extensive simulations. Next, they prototype and measure the antenna proving that very high port‐to‐port isolation and low cross‐polarisation level can be achieved over a broadband operation by means of this balun. Finally, they further investigate the operation of the balun through its physical decomposition revealing the minimum requirement to achieve high port‐to‐port isolation in dual‐polarised dipole antennas.
Two methods for controlling three‐time fundamental frequency neutral‐point voltage oscillation in a hybrid VIENNA rectifier
Authors: Song Wei‐zhang , Dai Zhi‐hao , Xie Nan , Wang You‐yun , Wheeler Pat
Published: January 2019

This study presents two methods of controlling neutral‐point voltage oscillation in a hybrid VIENNA rectifier, which is composed of the parallel association of a three‐phase single‐switch Boost rectifier with a VIENNA‐type rectifier. The neutral‐point oscillation reason has been analysed with a mathematical model. Meanwhile, the two neutral‐point control methods of a simplified method based on a zero‐sequence component injection and a dual‐carrier pulse‐width modulation (PWM) method are proposed to control the voltage deviation of the split DC‐link and three‐time fundamental frequency neutral‐point voltage fluctuation with a decrease from ±1.6 to ±1 V, respectively. Moreover, the significant oscillation in the neutral‐point voltage caused by unbalanced loads or asymmetric capacitor parameters can also be effectively suppressed by using the dual‐carrier PWM method. Furthermore, the performance comparison between these two methods is provided. The experimental results show that the system after being introduced the proposed two methods still exhibits a low‐order input current harmonic such as second, third, and fourth harmonics as well as the input current total harmonic distortion is lower than the standard 5%.
Detection and identification of multiple IGBT open‐circuit faults in PWM inverters for AC machine drives
Authors: Bae Cheol‐Ju , Lee Dong‐Choon , Nguyen Thanh Hai
Published: January 2019

This study proposes a new scheme for online detection and identification of single and multiple insulated‐gate bipolar transistor (IGBT) open‐circuit faults in three‐phase pulse‐width modulation (PWM) inverters of AC machine drives, which is based on Park's vector of machine phase currents. First, the switch open‐circuit faults are detected by monitoring dwell times of the vector of the actual phase currents expressed in the stationary reference frame in each sector, where the normalisation of the current to its reference value is utilised, by which the immunity to the false alarms in transient conditions is improved significantly. Then, the IGBT open‐circuit faults are identified, where leg open‐circuit conditions are in the first place determined based on the average values of the normalised line‐to‐line currents. Next, the single open‐circuit IGBT is located from the polarity of the corresponding phase current. By the proposed diagnosis method, the fault detection time is at the longest about 52.3 and 54% of a fundamental period in the simulation and experimental tests, respectively, and the 27 possible cases of IGBT open‐circuit faults combined for all IGBTs in the inverter can be identified. In addition, this algorithm can be implemented without any additional hardware and computational burden.
Double‐step model predictive direct power control with delay compensation for three‐level converter
Authors: Hu Bihua , Kang Longyun , Cheng Jiancai , Zhang Zhi , Zhang Jianbin , Luo Xuan
Published: January 2019

Model‐predictive direct‐power control (MPDPC) has attracted increasing attention from scholars because of its outstanding dynamic response and high‐power factor. However, its major shortcoming is the high‐computational cost, which limits its application in three‐level (3L) converters. By dividing the conventional MPDPC into two steps, a double‐step MPDPC (DMPDPC) algorithm is presented to address this problem. The first step of this algorithm is dedicated to searching a sector including an optimal switching state (OSS). In the second step, the OSS in a chosen sector is gained. Furthermore, its driver signals are changed as soon as the OSS is gained and their delay time is detected. Then, the corresponding delay compensation is also proposed to improve the steady‐state performance of the 3L‐converter. The validity of the proposed approach is demonstrated by the experimental platform with 4 kVA rated power. The experimental results show that the computing time in DMPDPC is 50.82% of that in conventional MPDPC. In addition, the proposed DMPDPC decreases the 3L converter's active and reactive powers ripples, reduces its current harmonic and strengthens its robustness against parameter variation.
Frequency‐domain modelling and stability analysis of a DFIG‐based wind energy conversion system under non‐compensated AC grids: impedance modelling effects and consequences on stability
Authors: Zhang Chen , Cai Xu , Molinas Marta , Rygg Atle
Published: January 2019

Impedance‐based frequency‐domain method is an effective tool for the stability assessment of a doubly fed induction generator (DFIG) system. Several impedance models have been proposed recently; however, these models are usually associated with model reductions since the complexity in achieving a detailed DFIG model. This may lead to unreliable stability results under certain conditions, and a clarification of this modelling effect is lacking in the literature. Therefore, this study aims to address this issue by developing a detailed DFIG impedance model. To achieve this target, a modular modelling technique is proposed instead of the conventional linearisation by parts, for which the components of a DFIG system are modelled as multi‐port modules. Through this method, the detailed DFIG model together with four types of reduced‐order models can be derived efficiently. The detailed DFIG model is verified by the measured frequency responses in PSCAD™/EMTDC™, along with its correctness in Nyquist‐based stability analysis. Subsequently, four types of the reduced‐order models are compared with the detailed one in terms of Nyquist plots, so that their performance and effectiveness for stability analysis are clarified. Besides, conclusions regarding the reduced‐order models are also verified by time‐domain simulations.
Modularised non‐isolated two‐switch equaliser using full‐wave voltage multiplier for series‐connected battery/super‐capacitor
Authors: Li Xiaolong , Xu Jianping , Xu Shungang , Qin Fuban , Zhuang Shengxian
Published: January 2019

Conventional battery/super‐capacitor (SC) cell voltage equalisers require numerous switches and/or a multi‐winding transformer, which are not desired in terms of circuit complexity and extendibility. In this study, a modularised non‐isolated two‐switch cell voltage equaliser for series‐connected lithium‐ion battery/SC is proposed. The proposed equaliser consists of a non‐isolated front‐end dc–dc converter and a full‐wave voltage multiplier circuit. Without coupled‐inductor, multi‐winding transformer and multiple active switches, the proposed equaliser uses only two active switches and two magnetic components, thus it benefits from reduced complexity and circuit volume. Meanwhile, the modularised full‐wave voltage multiplier circuit makes it flexible to extend to more battery/SC cells. Furthermore, it can work under open‐loop without cell monitoring circuit, which makes its control simple. The equalisation current of the proposed equaliser can be limited automatically. Compared with conventional non‐isolated equalisers using half‐wave voltage multiplier, it benefits from faster equalisation speed and lower equalisation loss. High efficiency is achieved by zero voltage switching of all switches. Experimental results are provided to verify analysis results of the proposed equaliser.
FCS‐MPC for a single‐phase two‐stage grid‐connected PV inverter
Authors: Liu Jiang , Cheng Shanmei , Liu Ying , Shen Anwen
Published: January 2019

The high‐efficiency inverter in a wide input voltage range is expected to be a solution for the distributed generation system. This study gives a high‐efficiency two‐stage topology and proposes a finite‐control‐set model predictive control (FCS‐MPC) strategy. The main objectives of the proposed model predictive controller are: (i) simultaneously controlling multi‐variables in the complex buck‐boost current controller, (ii) optimal design calculation for predictive current and voltage, (iii) normalisation of the state variables for cost function formulation, and (iv) low correlation between the dc‐link capacitor and control algorithm. A more reasonable operation mode of high‐frequency switches is provided for the two‐stage topology improving system performance. In order to optimise the total harmonic distortion of the output current and the error of the dc‐link voltage, a suitable weighting factor could be designed in the proposed FCS‐MPC method. The steady‐state characteristics of the proposed controller are simulated based on MATLAB/Simulink. Experimental results demonstrate the validity and practicability of the proposed control strategy.
Complexity of inheritance of ℱ-convexity for restricted games induced by minimum partitions
Authors: Skoda A.
Published: January 2019

Let G = (N, E, w) be a weighted communication graph. For any subset A ⊆ N, we delete all minimum-weight edges in the subgraph induced by A. The connected components of the resultant subgraph constitute the partition 𝒫min(A) of A. Then, for every cooperative game (N, v), the 𝒫min-restricted game (N, v̅) is defined by v̅(A)=∑F∈𝒫min(A)v(F)
for all A ⊆ N. We prove that we can decide in polynomial time if there is inheritance of ℱ-convexity, i.e., if for every ℱ-convex game the 𝒫min-restricted game is ℱ-convex, where ℱ-convexity is obtained by restricting convexity to connected subsets. This implies that we can also decide in polynomial time for any unweighted graph if there is inheritance of convexity for Myerson’s graph-restricted game.
Use of Targeted High-Throughput Sequencing for Genetic Classification of Patients with Bleeding Diathesis and Suspected Platelet Disorder
Authors: Andres Oliver , König Eva-Maria , Althaus Karina , Bakchoul Tamam , Bugert Peter , Eber Stefan , Knöfler Ralf , Kunstmann Erdmute , Manukjan Georgi , Meyer Oliver , Strauß Gabriele , Streif Werner , Thiele Thomas , Wiegering Verena , Klopocki Eva , Schulze Harald ,   on Behalf of the THROMKIDplus Study Group of the Society of Paediatric Oncology Haematology (Gesellschaft für Pädiatrische Onkologie und Hämatologie, GPOH) and the Society of Thrombosis Haemostasis Research (Gesellschaft für Thrombose- und Hämostaseforschung, GTH)
Published: December 2018

Inherited platelet disorders (IPD) form a rare and heterogeneous disease entity that is present in about 8% of patients with non-acquired bleeding diathesis. Identification of the defective cellular pathway is an important criterion for stratifying the patient's individual risk profile and for choosing personalized therapeutic options. While costs of high-throughput sequencing technologies have rapidly declined over the last decade, molecular genetic diagnosis of bleeding and platelet disorders is getting more and more suitable within the diagnostic algorithms. In this study, we developed, verified, and evaluated a targeted, panel-based next-generation sequencing approach comprising 59 genes associated with IPD for a cohort of 38 patients with a history of recurrent bleeding episodes and functionally suspected, but so far genetically undefined IPD. DNA samples from five patients with genetically defined IPD with disease-causing variants in WAS, RBM8A, FERMT3, P2YR12, and MYH9 served as controls during the validation process. In 40% of 35 patients analyzed, we were able to finally detect 15 variants, eight of which were novel, in 11 genes, ACTN1, AP3B1, GFI1B, HPS1, HPS4, HPS6, MPL, MYH9, TBXA2R, TPM4, and TUBB1, and classified them according to current guidelines. Apart from seven variants of uncertain significance in 11% of patients, nine variants were classified as likely pathogenic or pathogenic providing a molecular diagnosis for 26% of patients. This report also emphasizes on potentials and pitfalls of this tool and prospectively proposes its rational implementation within the diagnostic algorithms of IPD.
Surface modification of XLPE films by CF4 DBD for dielectric properties
Authors: Zhao Ai-xuan , Chen Xi , Chen Si-le , Yao Cong-wei , Zhao Xue-feng , Deng Jun-bo , Zhang Guan-jun
Published: January 2019

Cross-linked polyethylene (XLPE) is often manufactured as pipe, film and foam products and used as electric insulation material. To improve the dielectric properties of XLPE film, CF4 dielectric barrier discharge (DBD) is applied as a surface modification method. The surface of XLPE film was modified at the low pressure of 1 kPa with different treatment time (15s, 30s, 60s, 120s, 240s and 480s). Electrical and optical characteristics are observed during DBD process, including applied voltage, measured current, photograph and emission spectra. Then, the surface properties, which are hydrophobicity, chemical composition, surface morphology, trap depth, dielectric loss and AC breakdown voltage, have been measured or observed by water contact angle test, X-ray photoelectron spectroscopy (XPS), scanning electron microscope (SEM), isothermal relaxation current (IRC), frequency domain spectroscopy (FDS) and withstand voltage test. After the surface modification, the water contact angle, trap depth and breakdown voltage increase first and then decrease with treatment time extending. Meanwhile, the dielectric loss has an opposite trend, which represents better dielectric properties. The reason is that fluorine can reduce the surface energy, which can significantly influence the water contact angle. Better hydrophobicity can restrain the accumulation of outside pollution on the surface. Moreover, fluorine has strong electronegativity, so amorphous crystalline and impurities interface trap depth become deeper and the dielectric loss becomes lower. Therefore, appropriate DBD treatment conditions can apparently improve XLPE dielectric properties.
Recent Trends Concerning Upconversion Nanoparticles and Near-IR Emissive Lanthanide Materials in the Context of Forensic Applications
Authors: Gee William J.
Published: January 2019

Upconversion nanoparticles (UCNPs) are materials that, upon absorbing multiple photons of low energy (e.g. infrared radiation), subsequently emit a single photon of higher energy, typically within the visible spectrum. The physics of these materials have been the subject of detailed investigations driven by the potential application of these materials as medical imaging devices. One largely overlooked application of UCNPs is forensic science, wherein the ability to produce visible light from infrared light sources would result in a new generation of fingerprint powders that circumvent background interference which can be encountered with visible and ultraviolet light sources. Using lower energy, infrared radiation would simultaneously improve the safety of forensic practitioners who often employ light sources in less than ideal locations. This review article covers the development of UCNPs, the use of infrared radiation to visualise fingerprints by the forensic sciences, and the potential benefits of applying UCNP materials over current approaches.
Concise synthesis of (±)-litseaones A and B
Authors: Kageji Hideaki , Mori Naoki , Takikawa Hirosato , Watanabe Hidenori
Published: December 2018

A concise synthesis of litseaones A and B, which were isolated from the stem barks of Litsea rubescens and L. pedunculata, is described in this study. Litseaone A was synthesized in just three steps from a known phloroglucinol derivative. The direct conversion of litseaone A into litseaone B was also achieved.
Low noise sensitivity analysis of -minimization in oversampled systems
Authors: Weng Haolei , Maleki Arian
Published: December 2018

The class of $\ell _q$-regularized least squares (LQLS) are considered for estimating $\beta \in \mathbb{R}^p$ from its $n$ noisy linear observations $y=X\beta + w$. The performance of these schemes are studied under the high-dimensional asymptotic setting in which the dimension of the signal grows linearly with the number of measurements. In this asymptotic setting, phase transition (PT) diagrams are often used for comparing the performance of different estimators. PT specifies the minimum number of observations required by a certain estimator to recover a structured signal, e.g. a sparse one, from its noiseless linear observations. Although PT analysis is shown to provide useful information for compressed sensing, the fact that it ignores the measurement noise not only limits its applicability in many application areas, but also may lead to misunderstandings. For instance, consider a linear regression problem in which $n>p$ and the signal is not exactly sparse. If the measurement noise is ignored in such systems, regularization techniques, such as LQLS, seem to be irrelevant since even the ordinary least squares (OLS) returns the exact solution. However, it is well known that if $n$ is not much larger than $p$, then the regularization techniques improve the performance of OLS. In response to this limitation of PT analysis, we consider the low-noise sensitivity analysis. We show that this analysis framework (i) reveals the advantage of LQLS over OLS, (ii) captures the difference between different LQLS estimators even when $n>p$, and (iii) provides a fair comparison among different estimators in high signal-to-noise ratios. As an application of this framework, we will show that under mild conditions LASSO outperforms other LQLS even when the signal is dense. Finally, by a simple transformation, we connect our low-noise sensitivity framework to the classical asymptotic regime in which $n/p \rightarrow \infty$, and characterize how and when regularization techniques offer improvements over ordinary least squares, and which regularizer gives the most improvement when the sample size is large.