bluuebunny/crossref_metadata_2025 huggingface dataset:
Polyubiquitination of p62/SQSTM1 is a prerequisite for Fas/CD95 aggregation to promote caspase-dependent apoptosis in cadmium-exposed mouse monocyte RAW264.7 cells
Authors: Jung Ki-Tae , Oh Seon-Hee
Published: August 2019

Cadmium(Cd) induces cytotoxicity via autophagy-induced apoptosis in non-activated mouse monocytes; however, the molecular mechanism remains unclear. Here, we show that autophagy induces Fas (CD95/APO-1)-mediated apoptosis by promoting accumulation of p62/SQSTM1 in response to Cd. Cd produced tumor necrosis factor (TNF)-α, peaking at 6 h, and exhibiting a concentration-dependent increase. Immunoblot analysis revealed polyubiquitinated (polyUb) full-length Fas (antibody clone G-9) and reduced cytosolic Fas (antibody clone M-20) in Cd-exposed RAW264.7 cells. The accumulation of polyUb-Fas was transient and positively correlated with polyUb-p62 and polyUb-proteins. Autophagy inhibition via chemical and genetic modulation suppressed Cd-induced polyUb-p62, polyUb-Fas, and polyUb-protein levels, whereas the level of cytosolic Fas recovered to that of the control. Immunofluorescence (IF) staining for full-length Fas, p62, and ubiquitin revealed an aggregated pattern in Cd-induced apoptotic cells, which was inhibited by blocking autophagy. Fas colocalized with microtubule-associated protein 1 light chain (LC)-3B. IF staining and immunoprecipitation assays revealed colocalization and interaction among p62, Ub, and Fas. Knockdown of p62 reduced the binding of Ub and Fas. Together, these data suggest that polyUb-p62 targets Fas and recruits it to autophagosomes, where Fas transiently aggregates to promote apoptosis and is degraded with polyUb-p62. In conclusion, autophagy regulates C-terminal cytosolic Fas aggregation via p62 polyubiquitination, which is required for apoptosis and may play a critical role in the production of select cytokines.
Formation of the Francisella tularensis Biofilm is Affected by Cell Surface Glycosylation, Growth Medium, and a Glucan Exopolysaccharide
Authors: Champion Anna E. , Catanzaro Kelly C. Freudenberger , Bandara Aloka B. , Inzana Thomas J.
Published: August 2019

Biofilms are matrix-associated communities that enable bacteria to colonise environments unsuitable for free-living bacteria. The facultative intracellular pathogen Francisella tularensis can persist in water, amoebae, and arthropods, as well as within mammalian macrophages. F. tularensis Types A and B form poor biofilms, but F. tularensis mutants lacking lipopolysaccharide O-antigen, O-antigen capsule, and capsule-like complex formed up to 15-fold more biofilm than fully glycosylated cells. The Type B live vaccine strain was also 50% less capable of initiating surface attachment than mutants deficient in O-antigen and capsule-like complex. However, the growth medium of all strains tested also influenced the formation of biofilm, which contained a novel exopolysaccharide consisting of an amylose-like glucan. In addition, the surface polysaccharide composition of the bacterium affected the protein:DNA:polysaccharide composition of the biofilm matrix. In contrast, F. novicida attached to surfaces more efficiently and made a more robust biofilm than Type A or B strains, but loss of O-antigen or capsule-like complex did not significantly affect F. novicida biofilm formation. These results indicated that suppression of surface polysaccharides may promote biofilm formation by F. tularensis Types A and B. Whether biofilm formation enhances survival of F. tularensis in aquatic or other environmental niches has yet to be determined.
Analyses of virus/viroid communities in nectarine trees by next-generation sequencing and insight into viral synergisms implication in host disease symptoms
Authors: Xu Yunxiao , Li Shifang , Na Chengyong , Yang Lijuan , Lu Meiguang
Published: August 2019

We analyzed virus and viroid communities in five individual trees of two nectarine cultivars with different disease phenotypes using next-generation sequencing technology. Different viral communities were found in different cultivars and individual trees. A total of eight viruses and one viroid in five families were identified in a single tree. To our knowledge, this is the first report showing that the most-frequently identified viral and viroid species co-infect a single individual peach tree, and is also the first report of peach virus D infectingPrunusin China. Combining analyses of genetic variation and sRNA data for co-infecting viruses/viroid in individual trees revealed for the first time that viral synergisms involving a few virus genera in theBetaflexiviridae,Closteroviridae,and Luteoviridaefamilies play a role in determining disease symptoms. Evolutionary analysis of one of the most dominant peach pathogens, peach latent mosaic viroid (PLMVd), shows that the PLMVd sequences recovered from symptomatic and asymptomatic nectarine leaves did not all cluster together, and intra-isolate divergent sequence variants co-infected individual trees. Our study provides insight into the role that mixed viral/viroid communities infecting nectarine play in host symptom development, and will be important in further studies of epidemiological features of host-pathogen interactions.
Evaluation of the safety of using propofol for paediatric procedural sedation: A systematic review and meta-analysis
Authors: Kim Sunhee , Hahn Seokyung , Jang Myoung-jin , Choi Yunhee , Hong Hyunsook , Lee Ji-Hyun , Kim Hee-Soo
Published: August 2019

Propofol is one of the most widely used drugs for paediatric procedural sedation owing to its known advantages, but some concerns remain regarding respiratory and/or cardiac complications in patients receiving propofol. Although a considerable number of randomised controlled clinical trials (RCTs) have been conducted to compare it with other sedative agents or opioids for children undergoing various procedures, propofol is still being used off-label for this indication in many countries. We performed a systematic review and meta-analysis of those RCTs to provide an overall summation of evidence that can potentially be considered for further regulatory decisions, including reimbursement policies. We searched for RCTs in MEDLINE, Embase, and the Cochrane Central Register of Controlled Trials from their inception to January 31, 2018. Our meta-analysis of 30 RCTs confirmed that propofol sedation had advantages in recovery time when compared with other drugs, without excessive concerns for cardiovascular or respiratory adverse events. Its safety profile regarding coughing, nausea or vomiting, and emergence delirium was also similar to that of other drugs. The overall evidence suggests that propofol sedation for paediatric procedures should be considered more positively in the context of regulatory decisions.
Neonicotinoid insecticides limit the potential of spiders to re-colonize disturbed agroecosystems when using silk-mediated dispersal
Authors: Řezáč Milan , Řezáčová Veronika , Heneberg Petr
Published: August 2019

Agroecosystems are subject to regular disturbances that cause extinction or migration of much of their fauna, followed by recolonization from surrounding refuges. In small-sized aeronaut spiders, such recolonization is potentiated by their ability to rappel and balloon. These are complex behaviors that we hypothesized to be affected by neurotoxins, namely, neonicotinoids. We tested this hypothesis using two common farmland spider species,Oedothorax apicatus(Linyphiidae) andPhylloneta impressa(Theridiidae). The spiders were topically exposed by dorsal wet application or tarsal dry exposure to commercial neonicotinoid formulations Actara 25 WG, Biscaya 240 OD, Mospilan 20 SP and Confidor 200 OD at concentrations that are recommended for application in agriculture. Contact exposure to neonicotinoids suppressed the ability of spiders to produce the major ampullate fiber and anchor it to the substratum by piriform fibrils. Contact exposure to neonicotinoids also suppressed the ballooning behavior that was manifested by climbing to elevated places, adopting a tiptoe position and producing silk gossamer in the wind. Impaired ability of affected common farmland spiders to quickly recolonize disturbed agroecosystems by silk-mediated dispersal may explain their decline in multiple farmland ecosystems, in which neonicotinoids are applied.
Ultrasound- versus landmark-guided subclavian vein catheterization: a prospective observational study from a tertiary referral hospital
Authors: Sidoti Anna , Brogi Etrusca , Biancofiore Giandomenico , Casagli Sergio , Guarracino Fabio , Malacarne Paolo , Tollapi Lara , Borselli Matteo , Santori Gregorio , Corradi Francesco , Forfori Francesco
Published: August 2019

This was a single-center, observational, prospective study designed to compare the effectiveness of a real-time, ultrasound- with landmark-guided technique for subclavian vein cannulation. Two groups of 74 consecutive patients each underwent subclavian vein catheterization. One group included patients from intensive care unit, studied by using an ultrasound-guided technique. The other group included patients from surgery or emergency units, studied by using a landmark technique. The primary outcome for comparison between techniques was the success rate of catheterization. Secondary outcomes were the number of attempts, cannulation failure, and mechanical complications. Although there was no difference in total success rate between ultrasound-guided and landmark groups (71 vs. 68, p = 0.464), the ultrasound-guided technique was more frequently successful at first attempt (64 vs. 30, p < 0.001) and required less attempts (1 to 2 vs. 1 to 6, p < 0.001) than landmark technique. Moreover, the ultrasound-guided technique was associated with less complications (2 vs. 13, p < 0.001), interruptions of mechanical ventilation (1 vs. 57, p < 0.001), and post-procedure chest X-ray (43 vs. 62, p = 0.001). In comparison with landmark-guided technique, the use of an ultrasound-guided technique for subclavian catheterization offers advantages in terms of reduced number of attempts and complications.
Inhibition of NLRP3 inflammasome in tumor microenvironment leads to suppression of metastatic potential of cancer cells
Authors: Lee Hye Eun , Lee Jin Young , Yang Gabsik , Kang Han Chang , Cho Yong-Yeon , Lee Hye Suk , Lee Joo Young
Published: August 2019

Tumor microenvironment favors tumor cells to promote their growth and metastasis such as migration, invasion, and angiogenesis. IL-1β, one of the inflammatory cytokines released from myeloid cells in tumor microenvironment, plays an important role in development and progress of tumor. The activation of inflammasome is a critical step to secrete mature IL-1β through stepwise reactions to activate capspase-1. Therefore, we investigated whether the inhibition of NACHT, LRR and PYD domains-containing protein 3 (NLRP3) inflammasome in macrophages regulated the metastatic potential of tumor cells. NLRP3 inflammasome was activated by ATP in bone marrow-derived primary mouse macrophages. The metastatic potential of mouse melanoma cell line (B16F10) was determined by migration and invasion assays with transwell system. ATP-treated wild-type macrophages increased the migration and invasion of melanoma cells. However, NLRP3- or caspase-1-knockout macrophages exhibited greatly diminished ability to promote the migration and invasion of melanoma cells. In addition, treatment with celastrol, an inhibitor of NLRP3 inflammasome, reduced the potency of macrophages to stimulate migration and invasion of melanoma cells. The results demonstrate that inhibition of the NLRP3 inflammasome in macrophages by genetic deficiency or a pharmacological inhibitor is linked to suppression of the metastatic potential of tumor cells. The results would provide a novel anti-cancer strategy to modulate tumor microenvironment by suppressing NLRP3 inflammasome and consequently reducing IL-1β production.
Composites of Bimetallic Platinum-Cobalt Alloy Nanoparticles and
Reduced Graphene Oxide for Electrochemical Determination of Ascorbic Acid, Dopamine, and
Uric Acid
Authors: Demirkan Buse , Bozkurt Sait , Şavk Aysun , Cellat Kemal , Gülbağca Fulya , Nas Mehmet Salih , Alma Mehmet Hakkı , Sen Fatih
Published: August 2019

The ultimate aim of this study is to produce a composite of bimetallic
platinum-cobalt nanoparticles and reduced graphene oxide (Pt-Co@rGO) based biosensor
for the detection of ascorbic acid (AA), dopamine (DA) and uric acid (UA). Those are
biologically important molecules with the key functions for the human body.
Pt-Co@rGO was synthesized using a microwave-assisted technique and utilized for the
production of a highly sensitive and stable electrochemical biosensor. Detailed
spectral XPS and Raman analysis, XRD, and TEM/HR-TEM characterization were also
studied. Due to the superior activity and excellent conductivity of rGO,
well-separated oxidation peaks of these biomolecules is proven by DPV (differential
pulse voltammetry) and CV (cyclic voltammetry) measurements. The prepared
Pt-Co@rGO-based biosensor showed high electrochemical activity, a broad linear
response, high sensitivity, and acceptable limit of detection values for individual
and simultaneous determination of AA, DA, and UA, under optimized conditions. The
linear range of Pt-Co@rGO was found to be 170–200; 35–1500 and 5–800 µM for AA, DA,
and UA, respectively. Moreover, the detection limit of the prepared composite was
calculated as 0.345; 0.051; 0.172 µM for AA, DA, and UA, respectively. In the field
of electrochemical biosensors, Pt-Co@rGO based sensor is highly promising due to its
superior sensitivity and good selectivity properties.
Theoretical and experimental investigations of BiOCl for electrochemical adsorption of cesium ions
Authors: Zhang Huixin , Alameen Ayman , An Xiaowei , Shen Qianyao , Chang Lutong , Ding Shengqi , Du Xiao , Ma Xuli , Hao Xiaogang , Peng Changjun
Published: August 2019

BiOCl was found to have excellent electrochemical adsorption properties for cesium ions (Cs+) in electrochemically switched ion exchange (ESIX).
Application of metal oxide semiconductors in light-driven organic transformations
Authors: Riente Paola , Noël Timothy
Published: August 2019

Herein, we provide an up-to-date overview of metal oxide semiconductors (MOS) as versatile and inexpensive photocatalysts to enable light-driven organic transformations.
Tetrakis(1,2,5-thiadiazolo)porphyrazines. 9. Synthesis and spectral and theoretical studies of the lithium(i) complex and its unusual behaviour in aprotic solvents in the presence of acids
Authors: Stuzhin Pavel A. , Ivanova Svetlana S. , Hamdoush Mahmoud , Kirakosyan Gayane A. , Kiselev Aleksej , Popov Anton , Sliznev Valerij , Ercolani Claudio
Published: August 2019

The tetra(1,2,5-thiadiazolo)porphyrazine macrocycle coordinates Li+ forming an anionic lithate complex, which undergoes acid-catalyzed delithiation in aprotic solvents affording a dianion – a reactive precursor for the complexation reaction.
Green synthesis of nanoscale cobalt(ii)-based MOFs: highly efficient photo-induced green catalysts for the degradation of industrially used dyes
Authors: Mandal Arnab , Ganguly Sumi , Mukherjee Somali , Das Debasis
Published: August 2019

Solvothermally synthesized CoII based MOFs have been exploited as visible light induced dye degradation catalyst having real life applicability where introduction of H2O2 enhances the efficiency markedly.
Reversible turn-on fluorescent Cu(ii) sensors: rather dream than reality?
Authors: Falcone Enrico , Sour Angélique , Lebrun Vincent , Ulrich Gilles , Raibaut Laurent , Faller Peter
Published: August 2019

Reversible turn-on fluorescent Cu(ii) sensors are of high interest to understand copper metabolism in biology and medicine. However, they are intrinsically difficult to build, and careful studies are needed to exclude Cu(ii)-induced sensor oxidation.
A single-ion single-electron cerrous magnet
Authors: Gupta Sandeep K. , Shanmugan Swaminathan , Rajeshkumar Thayalan , Borah Aditya , Damjanović Marko , Schulze Michael , Wernsdorfer Wolfgang , Rajaraman Gopalan , Murugavel Ramaswamy
Published: August 2019

A monometallic Ce(iii) complex derived from bulky phosphonic diamide behaves as a single-ion single-electron magnet.
Characterization of polymethoxyflavone demethylation during drying processes of citrus peels
Authors: Zhang Huijuan , Tian Guifang , Zhao Chengying , Han Yanhui , DiMarco-Crook Christina , Lu Chang , Bao Yuming , Li Chengxiu , Xiao Hang , Zheng Jinkai
Published: August 2019

First time to report mechanisms of polymethoxyflavone demethylation during citrus peel drying, as well as effects of different drying processes.
Homogeneous versus heterogeneous catalysis in Cu2O-nanoparticle-catalyzed C–C coupling reactions
Authors: Addanki Tirumala Ravi Teja , P. Dadgar Andishaeh , Mohammadparast Farshid , Ramakrishnan Sundaram Bhardwaj , Mou Tong , Wang Bin , Andiappan Marimuthu
Published: August 2019

Copper based nanocatalysts have recently emerged as attractive catalysts for a diversity of bond formations, such as C–C, C–N, C–O, C–S, and C–Se.
Copper complexes of synthetic peptides mimicking neurotrophin-3 enhance neurite outgrowth and CREB phosphorylation
Authors: Naletova Irina , Grasso Giuseppa Ida , Satriano Cristina , Travaglia Alessio , La Mendola Diego , Arena Giuseppe , Rizzarelli Enrico
Published: August 2019

In this work we report on the synthesis and physiochemical/biological characterization of a peptide encompassing the first thirteen residues of neurotrophin-3 (NT-3). The protein capability to promote neurite outgrowth and axonal branching by a downstream mechanism that involves the increase of the cAMP response element-binding level (CREB) was found for the NT3(1–13) peptide, thus validating its protein mimetic behaviour. Since copper ions are also involved in neurotransmission and their internalization may be an essential step in neuron differentiation and CREB phosphorylation, the peptide and its copper complexes were characterized by potentiometric and spectroscopic techniques, including UV-visible, CD and EPR. To have a detailed picture of the coordination features of the copper complexes with NT3(1–13), we also scrutinized the two peptide fragments encompassing the shorter sequences 1–5 and 5–13, respectively, showing that the amino group is the main anchoring site for Cu(ii) at physiological pH. The peptide activity increased in the presence of copper ions. The effect of copper(ii) addition is more marked for NT3(1–13) than the other two peptide fragments, in agreement with its higher affinity for metal ions. Confocal microscopy measurements carried out on fluorescently labelled NT3(1–13) indicated that copper ions increase peptide internalization.
Reconfigurable assembly of charged polymer-modified Janus and non-Janus particles: from half-raspberries to colloidal clusters and chains
Authors: Marschelke Claudia , Diring Olga , Synytska Alla
Published: August 2019

pH-triggered, reconfigurable assembly of binary mixtures of hybrid hairy Janus and non-Janus colloids to half-raspberry-like constructs, colloidal clusters and colloidal chains depending on particle size ratio and numerical ratio.
Structure, properties, and biological functions of nonribosomal lipopeptides from pseudomonads
Authors: Götze Sebastian , Stallforth Pierre
Published: August 2019

Bacteria of the genusPseudomonasdisplay a fascinating metabolic diversity. In this review, we focus our attention on the natural product class of nonribosomal lipopeptides, which help pseudomonads to colonize a wide range of ecological niches.
The preparation of Ni/Mo-based ternary electrocatalysts by the self-propagating initiated nitridation reaction and their application for efficient hydrogen production
Authors: Hou Mengjie , Lan Ruyue , Hu Zhibiao , Chen Zuofeng
Published: August 2019

This work introduces a novel strategy via the in situ thermal decomposition initiated nitridation reaction for synthesizing Ni/Mo-based ternary HER electrocatalysts.
Proton-induced fluorescence in modified quino[7,8-h]quinolines: dual sensing for protons and π-donors
Authors: Pozharskii Alexander F. , Ozeryanskii Valery A. , Mikshiev Vladimir Y. , Chernyshev Anatoly V. , Metelitsa Anatoly V. , Antonov Alexander S.
Published: August 2019

Expanded quino-quinoline and quinazolino-quinazoline ligands change their emission upon protonation and π-coordination, model proton transfer and work in biphasic solvent systems.
Palladium-catalyzed cascade reactions of alkene-tethered carbamoyl chlorides with N-tosyl hydrazones: synthesis of alkene-functionalized oxindoles
Authors: Sun Wan , Chen Chen , Qi Yuan , Zhao Jinghui , Bao Yinwei , Zhu Bolin
Published: August 2019

An efficient approach for the construction of alkene-functionalized oxindoles was developed via palladium-catalyzed cascade reactions of alkene-tethered carbamoyl chlorides with N-tosyl hydrazones.
Synthesis and identification of heteroaromaticN-benzyl sulfonamides as potential anticancer agents
Authors: Hopkins Megan D. , Abebe Felagot A. , Scott Kristina A. , Ozmer Garett L. , Sheir Alec A. , Schroeder Lucas J. , Sheaff Robert J. , Lamar Angus A.
Published: August 2019

The regioselective incorporation of a sulfonamide unit to a broad range of heteroarene scaffolds has been developed. SynthesizedN-benzyl sulfonamides have been screened against a variety of cancer cell lines for cytotoxicity effects.
Increase in the apparent intercalation ability of a platinum complex via multivalency by installation into the sidechain of a graft copolymer and observation of structural changes in the intercalated DNA
Authors: Osawa Shigehito , Takahashi Riichi , Watanabe Remi , Kubo Sayaka , Otsuka Hidenori
Published: August 2019

Pt complexes increase their apparent binding constant by grafting on sidechains of polymer segments via multivalent effect.
Construction of antifungal dual-target (SE, CYP51) pharmacophore models and the discovery of novel antifungal inhibitors
Authors: Dong Yue , Liu Min , Wang Jian , Ding Zhuang , Sun Bin
Published: August 2019

Fungal infections and drug-resistance are rapidly increasing with the deterioration of the external environment.
Transition metal atom (Ti, V, Mn, Fe, and Co) anchored silicene for hydrogen evolution reaction
Authors: Sun Yongxiu , Huang Aijian , Wang Zhiguo
Published: August 2019

Ti, V, Mn, Fe, and Co anchored silicene as low-cost catalysts for hydrogen evolution reaction.
Measuring capillary wave dynamics using differential dynamic microscopy
Authors: Wang Jing , McGorty Ryan
Published: August 2019

We report a novel extension of differential dynamic microscopy to measure the interfacial fluctuations in a colloid–polymer mixture.
Sleepiness, Exertion Fatigue, Arousal, and Vigilant Attention in Persons With Chronic Aphasia
Authors: Riley Ellyn A. , Owora Arthur , McCleary Joshua , Anderson Alyssa
Published: August 2019

Purpose

Individuals in the acute and chronic stages of stroke recovery often report more daytime sleepiness (
Sterr, Herron, Dijk, & Ellis, 2008
) and fatigue that qualitatively differs from “normal” feelings of fatigue they experienced prestroke (
De Doncker, Dantzer, Ormstad, & Kuppuswamy, 2018
). Speech-language pathologists frequently observe signs of fatigue in their clients with aphasia and perceive that client fatigue impedes therapeutic interventions (
Riley, 2017
). The current study aimed to quantify daytime sleepiness, exertion fatigue, and physiologically measured arousal and vigilant attention in persons with aphasia.

Method

We measured sleepiness, exertion fatigue, arousal, and vigilant attention in 10 participants with aphasia and 10 neurologically healthy adults. Daytime sleepiness was measured using the Epworth Sleepiness Scale (
Johns, 1991
). Exertion fatigue was measured using the Visual Analog Fatigue Scale (
B. Y. Tseng, Gajewski, & Kluding, 2010
) before and after a 72-min computer-administered language task. Arousal was measured using heart rate and variability (
Shaffer & Ginsberg, 2017
). Vigilant attention was measured using electroencephalography and subsequently classified into 1 of 4 levels of vigilant attention using a classification algorithm (
Berka et al., 2004
).

Results

Persons with aphasia did not show significant differences from controls in reported amount of daytime sleepiness, exertion fatigue, or overall physiological arousal but demonstrated different patterns of electroencephalography-measured vigilant attention and error production as compared to controls.

Conclusions

Although overall sleepiness, exertion fatigue, and overall arousal did not differ between groups, physiological measures of vigilant attention may be more sensitive to differences and may explain feelings of fatigue that persons with chronic aphasia experience.
Improving the Derivational Morphological Skills of a Ninth Grader With Language and Reading Disabilities: A Public School Case Study
Authors: Green Laura , Steele Rebecca
Published: August 2019

Purpose

This article details the implementation of a morphological awareness intervention program to improve the use and spelling of derivational suffixes (e.g., the “ful” in careful) for a 9th-grade student with a language impairment and reading disability in a public school setting.

Method

The unpublished morphological intervention program was implemented via a 30-min, once-weekly therapy schedule across 10 weeks. Careful data collection, which included establishment of stable baseline performance on a morphological measure prior to treatment and administration of the same measure during and after intervention, was utilized to measure progress over time. Additionally, pre- and posttreatment measures of morphological awareness and social validity were also administered.

Results

The participant demonstrated an increase in correct use and spelling of targeted derivational suffixes, and social validity data provided qualitative support of treatment outcomes.

Conclusion

The treatment program and data collection were successfully conducted in a high school setting and within the confines of a typical public school speech therapy schedule and caseload.
Efficient design of quantisers for distributed estimation
Authors: Kim Y.H.
Published: August 2019

An efficient design algorithm for local quantisers at nodes that optimises the global metric (i.e. estimation error) for distributed estimation systems is proposed. Noting that the quantisation partitions constructed to minimise the estimation error are not independently encodable at each node, a novel technique of compressing the partitions into sets of codewords while ensuring a perfect independent encoding is presented, leading to the sets with reasonable cardinality, which enables transmission of multiple codewords at nodes for estimation. Experiments demonstrate a significantly improved performance over various quantiser designs while achieving about reduction in the size of codeword sets compared with a recent design.
Optical digital‐to‐analogue conversion for 2‐bit BPSK‐modulated signal based on delay line interferometer with balanced photodetector
Authors: Aikawa Y.
Published: August 2019

Optical digital‐to‐analogue (DA) conversion has the potential to realise fully‐transparent optical communication systems, as it is considered to be fundamental in the most of operations, including packet switching and label processor. However, most DA converters have been confined to on–off keying modulation as opposed to phase‐shift keying (PSK) modulation. In this Letter, the author provides an optical DA converter for binary PSK (BPSK) signal. The proposed scheme converts a digitised information into an optical intensity by using delay line interferometer and balanced photodetector. The scheme generates a quadrature PSK (QPSK) signal from two BPSK signals, then, the generated QPSK signal is coupled with a ‐shifted signal. The four constellations of the QPSK signal are converted into four levels at equal intervals when the angle is set at and . It is concluded that the optical 2‐bit DA conversion is experimentally demonstrated for BPSK signal at 10 Gbps.
Twelve port MIMO antenna with polarisation diversity for cognitive radio applications
Authors: Srikar D. , Anuradha S.
Published: August 2019

In this letter, to overcome the drawbacks in reconfigurable antennas and maintain all the advantages in planar antennas, a compact 12 port integrated UWB and narrow band (NB)/wideband antennas for cognitive radio MIMO applications with polarisation diversity is presented. The proposed system has one pair of UWB antennas for sensing the spectrum and five pairs of NB/wideband antennas for communication. Each pair has two identical antennas, which are orthogonal to each other for polarisation diversity. Sensing antennas linked with ports (P1 and P7) have operating bandwidth of 3–11 GHz, whereas the antennas linked with ports (P2 and P8), (P3 and P9), (P4 and P10), (P5 and P11), and (P6 and P12) have operating bandwidths of 3.5–5.8 GHz, 2.8–3.5 GHz and 5.6–8 GHz (dual band), 8–8.4 GHz and 9–9.8 GHz (dual band), 8.4–9 GHz, and 9.8–11 GHz, respectively. Moreover, the overall volume of the antenna is 58mm × 50mm × 1.6 mm and the entire UWB spectrum is covered by NB/wideband antennas. Also, without any decoupling network, isolation of better than 20 and 15 dB is achieved between every two identical and non‐identical antennas, respectively.
Full‐period suspension force accurate modelling for a novel bearingless switched reluctance motor
Authors: Yuan Ye , Ma Yiqing , Xu Jie , Yang Fan , Xie Kai
Published: August 2019

In the traditional bearingless switched reluctance motor (BSRM) system, the electromagnetic coupling between the torque system and suspension system is unavoidable. In this Letter, the present BSRM has the advantages of electromagnetic decouple with independent torque‐suspension magnetic circuit design. However, the further in‐depth study shows that the BSRM has an obvious suspension force fluctuation according to its asymmetry structure. Thus, it is necessary to build an accurate suspension force mathematical model considering commutation ripple. In this frame, a magnetic field segmentation method is proposed and the accurate suspension force model is built with Maxwell stress method and its reliability and precision are verified, modified based on finite element analysis.
Fractional order sliding mode approach for chattering free direct power control of dc/ac converter
Authors: Kumar Vivek , Ali Ikbal
Published: August 2019

A control approach of sliding mode category is applied in this study for direct control of active and reactive power in a grid connected three‐phase dc/ac converter. A fractional order sliding mode (FOSM) control is proposed to suppress chattering from power and current signals. The chattering reduction is achieved through fractional order mathematical modelling which has control over the fractional error tolerance and instantaneous error, while all attributes of conventional sliding mode remain intact. FOSM controller drastically reduces signal chattering that is a low order system noise in conventional sliding mode control (CSMC). The controller is designed using active–reactive power errors as input to get reference voltage vector under sliding mode fractional law. The controller uses stationary frame of reference and simplifies the design process in a manner to rule out extra proportional integral (PI)‐controlled current loops. The FOSM reduces half of the switching losses as per the fractional reference to switching modulation. Lyapunov candidate function is investigated to prove stability of the proposed controller. Simulation and experiment are carried out to check chattering free response of the proposed controller as compared to CSMC. The transient behaviour and robustness of FOSM controller is investigated and compared to PI‐based control.
Fluctuation of PV array global maximum power point voltage during irradiance transitions caused by clouds
Authors: Lappalainen Kari , Valkealahti Seppo
Published: August 2019

In well‐designed photovoltaic (PV) power plants, such as in typical utility‐scale PV plants, operational conditions are quite stable and homogeneous apart from the fast irradiance transitions caused by cloud shadings. These partial shading events cause fast power fluctuations leading even to stability and quality problems in power networks. Fast non‐homogeneous irradiance transitions cause also mismatch losses in PV generators and the occurrence of multiple maximum power points (MPPs), which appear in a wide voltage range of the PV generator. In consequence, the global MPP can fluctuate in a wide voltage region causing possible MPP tracking problems and power losses. This article presents a study of the behaviour of the global MPP voltage of various PV arrays during irradiance transitions caused by clouds. The global MPP voltage, its rate of change and the differences in voltage and available energy between the global MPP and the MPP with the highest voltage of the PV generators have been analysed comprehensively, for the first time, by using the characteristics of around 8000 measured irradiance transitions. The global MPP voltage was found to vary between 28 and 112% of the nominal MPP voltage of the array.
Observer manoeuvre control to track multiple targets considering Doppler‐bearing measurements in threat environments
Authors: Kim Jonghoek
Published: August 2019

Tracking a target using Doppler‐bearing measurements is called the Doppler‐bearing target motion analysis (DBTMA) problem. In order to improve the estimation performance of the DBTMA, this study introduces observer manoeuvre controls under the constraint that the turn rate of the observer is bounded above. The proposed approach is unique in considering the following factors: (i) approach a target while localising the target; (ii) track multiple targets simultaneously; (iii) avoid threat environments; (iv) bearing standard deviation varies as ship‐relative bearing varies. The authors demonstrate the performance of the proposed approach under MATLAB simulations.
Photometric and spectroscopic diversity of Type II supernovae
Authors: Hillier Desmond John , Dessart Luc
Published: August 2019

Hydrogen-rich (Type II) supernovae (SNe) exhibit considerable photometric and spectroscopic diversity. Extending previous work that focused exclusively on photometry, we simultaneously model the multi-band light curves and optical spectra of Type II SNe using red supergiant (RSG) progenitors that are characterized by their H-rich envelope masses or the mass and extent of an enshrouding cocoon at the star’s surface. Reducing the H-rich envelope mass yields faster declining light curves, a shorter duration of the photospheric phase, and broader line profiles at early times. However, there is only a modest boost in early-time optical brightness. Increasing the mass of the circumstellar material (CSM) is more effective at boosting the early-time brightness and producing a fast-declining light curve while leaving the duration of the photospheric phase intact. It also makes the optical color bluer, delays the onset of recombination, and can severely reduce the speed of the fastest ejecta material. The early ejecta interaction with CSM is conducive to producing featureless spectra at 10−20 d and a weak or absent Hα absorption during the recombination phase. The slow decliners SNe 1999em, 2012aw, and 2004et can be explained with a 1.2 × 1051 erg explosion in a compact (∼600 R⊙) RSG star from a 15 M⊙ stellar evolution model. A small amount of CSM (<0.2 M⊙) improves the match to the SN photometry before 10 d. With more extended RSG progenitors, models predict lower ejecta kinetic energies, but the SN color stays blue for too long and the spectral line widths are too narrow. The fast decliners SNe 2013ej and 2014G may require 0.5−1.0 M⊙ of CSM, although this depends on the CSM structure. A larger boost to the luminosity (as needed for the fast decliners SNe 1979C or 1998S) requires interaction with a more spatially extended CSM, which might also be detached from the star.
The biasing phenomenon
Authors: Einasto J. , Liivamägi L. J. , Suhhonenko I. , Einasto M.
Published: August 2019

Context. We study biasing as a physical phenomenon by analysing geometrical and clustering properties of density fields of matter and galaxies.

Aims. Our goal is to determine the bias function using a combination of geometrical and power spectrum analyses of simulated and real data.

Methods. We apply an algorithm based on the local densities of particles, δ, to form simulated, biased models using particles with δ ≥ δ0. We calculate the bias function of model samples as functions of the particle-density limit δ0. We compare the biased models with Sloan Digital Sky Survey (SDSS) luminosity-limited samples of galaxies using the extended percolation method. We find density limits δ0 of biased models that correspond to luminosity-limited SDSS samples.

Results. The power spectra of biased model samples allow estimation of the bias function b(> L) of galaxies of luminosity L. We find the estimated bias parameter of L* galaxies, b* = 1.85 ± 0.15.

Conclusions. The absence of galaxy formation in low-density regions of the Universe is the dominant factor of the biasing phenomenon. The second-largest effect is the dependence of the bias function on the luminosity of galaxies. Variations in gravitational and physical processes during the formation and evolution of galaxies have the smallest influence on the bias function.
Thermal energy storage in combined cycle power plants: comparing finite volume to finite element methods
Authors: Gkoutzamanis Vasilis G. , Chiu Justin N. W. , Martin Guillaume , Kalfas Anestis I.
Published: August 2019

The research in thermal energy storage (TES) systems has a long track record. However, there are several technical challenges that need to be overcome, to become omnipresent and reach their full potential. These include performance, physical size, weight and dynamic response. In many cases, it is also necessary to be able to achieve the foregoing at greater and greater scale, in terms of power and energy. One of the applications in which these challenges prevail is in the integration of a thermal energy storage with the gas turbine (GT) compressor inlet conditioning system in a combined cycle power plant. The system is intended to provide either GT cooling or heating, based on the operational strategy of the plant. As a contribution to tackle the preceding, this article describes a series of 3-dimensional (3D) numerical simulations, employing different Computational Fluid Dynamics (CFD) methods, to study the transient effects of inlet temperature and flow rate variation on the performance of an encapsulated TES with phase change materials (PCM). A sensitivity analysis is performed where the heat transfer fluid (HTF) temperature varies from -7°C to 20°C depending on the operating mode of the TES (charging or discharging). The flow rate ranges from 50% to 200% of the nominal inflow rate. Results show that all examined cases lead to instant thermal power above 100kWth. Moreover, increasing the flow rate leads to faster solidification and melting. The increment in each process depends on the driving temperature difference between the encapsulated PCM and the HTF inlet temperature. Lastly, the effect of the inlet temperature has a larger effect as compared to the mass flow rate on the efficiency of the heat transfer of the system.
Development and installation of control system for a test rig interconnecting a micro Gas Turbine, a Heat Pump and a PCM Storage system
Authors: Rossi Iacopo , Caillere Romain
Published: August 2019

The need to enhance flexibility on current power plant is linked to the strong penetration of non-dispatchable sources in the current energy network, which causes a dramatic need for ancillary services to sustain the grid operability. A framework including a micro Gas Turbine (mGT), a Heat Pump (HP) and a PCM Storage is considered to enhance plant flexibility while facing grid and price fluctuations during day operations. The system so composed is devoted to electrical energy production only. A proper use of the HP allows, for instance, to heat up the compressor intake temperature whilst the system is operating at minimum load. The system can then produce a lower amount of energy in order to be more competitive in the infra-day energy market. At the same time, the cold storage is charged and the stored energy can be later used to power up the system during the peak hours by cooling the compressor intake. This work presents then the installation of the control system devoted to the management and the control of such complex system. The test-bed is defined to test different operating conditions and to validate the operating framework of the whole compound.
Future directions for CHP plants using biomass and waste – adding production of vehicle fuels
Authors: Awais Salman Chaudhary , Dahlquist Erik , Thorin Eva , Kyprianidis Konstantinos , Avelin Anders
Published: August 2019

In Northern Europe, the production of many biobased CHP plants is getting affected due to the enormous expansion of wind and solar power. In addition, heat demand varies throughout the year, and existing CHP plants show less technical performance and suffer economically. By integrating the existing CHP plants with other processes for the production of chemicals, they can be operated more hours, provide operational and production flexibility and thus increase efficiency and profitability. In this paper, we look at a possible solution by converting an existing CHP plant into integrated biorefinery by retrofitting pyrolysis and gasification process. Pyrolysis is retrofitted in an existed CHP plant. Bio-oil obtained from pyrolysis is upgraded to vehicle grade biofuels. Gasification process located upfront of CHP plant provides the hydrogen required for upgradation of biofuel. The results show that a pyrolysis plant with 18 ton/h feed handling capacity (90 MWth), when integrated with gasification for hydrogen requirement and CHP plant for heat can produce 5.2 ton/h of gasoline/diesel grade biofuels. The system integration gives positive economic benefits too but the annual operating hours can impact economic performance.
Assessment of a solar plant solution interconnected to national grid system in Paraguay
Authors: Lindstrom Frankz , Riveros Gustavo , Rivarolo Massimo , Arevalos Gustavo
Published: August 2019

Paraguay has abundant hydroelectric energy (around 99%, in 2017 a generation reached 96,387 GWh) and it is currently exporting part of this energy. Some studies carried out by the National Electricity Administration indicate an increase in the demand for electric power where it is observed that the Reserve Generation Margin would be affected by the year 2025. To face this scenario, Paraguay is investigating alternative sources to diversify its energy production mix: this paper focuses on solar plants. Within the Electric System Master Plan, Paraguay aims to expand and improve the electric power supply system, mainly in the western part of the country in the central region of the Paraguayan Chaco. In this context and based on the experience of the Itaipu Technology Park in the installation and operation of the first two solar plants in the country, already in operation in the mentioned region, the aim of this paper is the evaluation of a future photovoltaic solar plant in the area of Loma Plata, which will be connected to the national interconnected grid system, with a power around of 10 MWp. For this purpose, a thermoeconomic analysis with a software tool is used to evaluate the viability of the proposal, evaluate different configurations and select the best option for the case study.
High Efficiency Operational Reserve by SOFC for the Effective Grid Integration of Variable Renewable Energies
Authors: Yoshiba Fumihiko , Yamamoto Tohru , Morita Hiroshi , Hanai Yuji , Watanabe Isamu , Mugikura Yoshihiro
Published: August 2019

For an effective grid integration of a large share of intermittent renewable energy sources such as a photovoltaic and a wind power, the flexible operation of the centralized or decentralized thermal power plants are required as a control reserve of demandsupply balance (frequency control). It is cleared that the Solid Oxide Fuel Cell and Gas Turbine (SOFC/GT) with additional air compressor system offers high efficiency in the wide range load operation. The efficiencyload ratio curve of the Gas Turbine Combined Cycle (GTCC) and SOFC/GT with air compressor system are applied to the secondary control reserve (SCR) operation units, and the daily schedule of power units in the modelled power grid is calculated. Since the efficiency at low load is high in SOFC/GT with air compressor system, the total fuel cost of the modelled power grid diminishes in the case that the SOFC/GT with air compressor system is operated at low load as a load frequency control (LFC) unit for the SCR.
Thermodynamic analysis of a gas turbine combined cycle integration with a high-temperature nuclear reactor
Authors: Jaszczur Marek , Dudek Michał
Published: August 2019

The recently a large number of various companies from the energy sector have to follow new very restrictive regulations which protect the natural environment against pollution and degradation. At the same time, the efficiency of energy conversion and the cost of energy remain important economic aspects. One of the solutions for today's challenges can be power generation based on Gas Turbine Combined Cycle proposed in this paper which is the most efficient and environmentally friendly cycle. What is more important this solution can be easily integrated with a High-Temperature nuclear Reactor. The proposed in this work systems consist of the reactor combined with a gas turbine as well as steam turbine. The results show that it is possible to obtain for proposed cycle an efficiency higher than 50% which is not only more than could be offered by traditional coal power plant but much more than can be proposed by any other nuclear technology.
Experimental, numerical and theoretical investigations of Tesla turbines
Authors: Klingl Stefan , Lecheler Stefan , Pfitzner Michael
Published: August 2019

We use analytical, numerical and experimental methods to characterize the laminar flow inside a Tesla turbine rotor gap. A comparison based on one particular set of operating conditions mutually validates the three approaches. The simplicity of the analytical flow model allows for a cost efficient optimization of the underlying turbine parameters. Performance charts exhibit general trends and serve as a guide for preliminary turbine design and optimization. In terms of the ratio of half the gap width to inlet radius and the ratio of outletto inlet radius, the designer of a tesla turbine has to find a compromise between optimal efficiency and optimal power output.
Micro-turbine applied to seismology: towards a power supply safe from lightning
Authors: Scafidi Davide , Roncallo Francesco , Traverso Alberto , Ferretti Gabriele , Pasta Marco , Pavan Mauro , Barani Simone , Spallarossa Daniele
Published: August 2019

The present work aims to suggest an innovative solution for seismic monitoring stations’ endurance. These stations are characterized by many different problems, such as lightning vulnerability, energy independence and noises disturbance. The suggested technology, for this type of application, is an improved bladeless turbo-expander patented by Nikola Tesla in the early 20th century, the Tesla turbine.