bluuebunny/crossref_metadata_2025 huggingface dataset:
Metabolomic profiling of reactive persulfides and polysulfides in the aqueous and vitreous humors
Authors: Kunikata Hiroshi , Ida Tomoaki , Sato Kota , Aizawa Naoko , Sawa Tomohiro , Tawarayama Hiroshi , Murayama Namie , Fujii Shigemoto , Akaike Takaaki , Nakazawa Toru
Published: February 2017

We investigate the metabolomic profile of reactive persulfides and polysulfides in the aqueous and vitreous humors. Eighteen eyes of 18 consecutive patients with diabetes mellitus (DM) and diabetic retinopathy underwent microincision vitrectomy combined with cataract surgery. Samples of the aqueous and vitreous humors were collected and underwent mass spectrometry-based metabolomic profiling of reactive persulfides and polysulfides (polysulfidomics). The effect of reactive polysulfide species on the viability of immortalized retinal cells (the RGC-5 cell line) under oxidative stress (induced with H2O2) was also evaluated with an Alamar Blue assay. The experiments showed that cysteine persulfides (CysSSH), oxidized glutathione trisulfide (GSSSG) and cystine were elevated in the aqueous humor, and CysSSH, Cys, and cystine were elevated in the vitreous. Furthermore, GSSSG, cystine, and CysSSH levels were correlated in the aqueous and vitreous humors. A comparison, in DM and control subjects, of plasma levels of reactive persulfides and polysulfides showed that they did not differ. In vitro findings revealed that reactive polysulfide species increased cell viability under oxidative stress. Thus, various reactive persulfides and polysulfides appear to be present in the eye, and some reactive sulfide species, which have a protective effect against oxidative stress, are upregulated in the aqueous and vitreous humors of DM eyes.
Searching for new loci and candidate genes for economically important traits through gene-based association analysis of Simmental cattle
Authors: Xia Jiangwei , Fan Huizhong , Chang Tianpeng , Xu Lingyang , Zhang Wengang , Song Yuxin , Zhu Bo , Zhang Lupei , Gao Xue , Chen Yan , Li Junya , Gao Huijiang
Published: February 2017

Single-marker genome-wide association study (GWAS) is a convenient strategy of genetic analysis that has been successful in detecting the association of a number of single-nucleotide polymorphisms (SNPs) with quantitative traits. However, analysis of individual SNPs can only account for a small proportion of genetic variation and offers only limited knowledge of complex traits. This inadequacy may be overcome by employing a gene-based GWAS analytic approach, which can be considered complementary to the single-SNP association analysis. Here we performed an initial single-SNP GWAS for bone weight (BW) and meat pH value with a total of 770,000 SNPs in 1141 Simmental cattle. Additionally, 21836 cattle genes collected from the Ensembl Genes 83 database were analyzed to find supplementary evidence to support the importance of gene-based association study. Results of the single SNP-based association study showed that there were 11 SNPs significantly associated with bone weight (BW) and two SNPs associated with meat pH value. Interestingly, all of these SNPs were located in genes detected by the gene-based association study.
Collagen scaffold microenvironments modulate cell lineage commitment for differentiation of bone marrow cells into regulatory dendritic cells
Authors: Fang Yongxiang , Wang Bin , Zhao Yannan , Xiao Zhifeng , Li Jing , Cui Yi , Han Sufang , Wei Jianshu , Chen Bing , Han Jin , Meng Qingyuan , Hou Xianglin , Luo Jianxun , Dai Jianwu , Jing Zhizhong
Published: February 2017

The microenvironment plays a pivotal role for cell survival and functional regulation, and directs the cell fate determination. The biological functions of DCs have been extensively investigated to date. However, the influences of the microenvironment on the differentiation of bone marrow cells (BMCs) into dendritic cells (DCs) are not well defined. Here, we established a 3D collagen scaffold microenvironment to investigate whether such 3D collagen scaffolds could provide a favourable niche for BMCs to differentiate into specialised DCs. We found that BMCs embedded in the 3D collagen scaffold differentiated into a distinct subset of DC, exhibiting high expression of CD11b and low expression of CD11c, co-stimulator (CD40, CD80, CD83, and CD86) and MHC-II molecules compared to those grown in 2D culture. DCs cultured in the 3D collagen scaffold possessed weak antigen uptake ability and inhibited T-cell proliferation in vitro; in addition, they exhibited potent immunoregulatory function to alleviate allo-delay type hypersensitivity when transferred in vivo. Thus, DCs differentiated in the 3D collagen scaffold were defined as regulatory DCs, indicating that collagen scaffold microenvironments probably play an important role in modulating the lineage commitment of DCs and therefore might be applied as a promising tool for generation of specialised DCs.
Cross-modal noise compensation in audiovisual words
Authors: Baart Martijn , Armstrong Blair C. , Martin Clara D. , Frost Ram , Carreiras Manuel
Published: February 2017

Perceiving linguistic input is vital for human functioning, but the process is complicated by the fact that the incoming signal is often degraded. However, humans can compensate for unimodal noise by relying on simultaneous sensory input from another modality. Here, we investigated noise-compensation for spoken and printed words in two experiments. In the first behavioral experiment, we observed that accuracy was modulated by reaction time, bias and sensitivity, but noise compensation could nevertheless be explained via accuracy differences when controlling for RT, bias and sensitivity. In the second experiment, we also measured Event Related Potentials (ERPs) and observed robust electrophysiological correlates of noise compensation starting at around 350 ms after stimulus onset, indicating that noise compensation is most prominent at lexical/semantic processing levels.
Enhancement of 5-aminolevulinic acid-based fluorescence detection of side population-defined glioma stem cells by iron chelation
Authors: Wang Wenqian , Tabu Kouichi , Hagiya Yuichiro , Sugiyama Yuta , Kokubu Yasuhiro , Murota Yoshitaka , Ogura Shun-ichiro , Taga Tetsuya
Published: February 2017

Cancer stem cells (CSCs) are dominantly responsible for tumor progression and chemo/radio-resistance, resulting in tumor recurrence. 5-aminolevulinic acid (ALA) is metabolized to fluorescent protoporphyrin IX (PpIX) specifically in tumor cells, and therefore clinically used as a reagent for photodynamic diagnosis (PDD) and therapy (PDT) of cancers including gliomas. However, it remains to be clarified whether this method could be effective for CSC detection. Here, using flow cytometry-based analysis, we show that side population (SP)-defined C6 glioma CSCs (GSCs) displayed much less 5-ALA-derived PpIX fluorescence than non-GSCs. Among the C6 GSCs, cells with ultralow PpIX fluorescence exhibited dramatically higher tumorigenicity when transplanted into the immune-deficient mouse brain. We further demonstrated that the low PpIX accumulation in the C6 GSCs was enhanced by deferoxamine (DFO)-mediated iron chelation, not by reserpine-mediated inhibition of PpIX-effluxing ABCG2. Finally, we found that the expression level of the gene for heme oxygenase-1 (HO-1), a heme degradation enzyme, was high in C6 GSCs, which was further up-regulated when treated with 5-ALA. Our results provide important new insights into 5-ALA-based PDD of gliomas, particularly photodetection of SP-defined GSCs by iron chelation based on their ALA-PpIX-Heme metabolism.
Fast and Quantitative T1ρ-weighted Dynamic Glucose Enhanced MRI
Authors: Schuenke Patrick , Paech Daniel , Koehler Christina , Windschuh Johannes , Bachert Peter , Ladd Mark E. , Schlemmer Heinz-Peter , Radbruch Alexander , Zaiss Moritz
Published: February 2017

Common medical imaging techniques usually employ contrast agents that are chemically labeled, e.g. with radioisotopes in the case of PET, iodine in the case of CT or paramagnetic metals in the case of MRI to visualize the heterogeneity of the tumor microenvironment. Recently, it was shown that natural unlabeled D-glucose can be used as a nontoxic biodegradable contrast agent in Chemical Exchange sensitive Spin-Lock (CESL) magnetic resonance imaging (MRI) to detect the glucose uptake and potentially the metabolism of tumors. As an important step to fulfill the clinical needs for practicability, reproducibility and imaging speed we present here a robust and quantitative T1ρ-weighted technique for dynamic glucose enhanced MRI (DGE-MRI) with a temporal resolution of less than 7 seconds. Applied to a brain tumor patient, the new technique provided a distinct DGE contrast between tumor and healthy brain tissue and showed the detailed dynamics of the glucose enhancement after intravenous injection. Development of this fast and quantitative DGE-MRI technique allows for a more detailed analysis of DGE correlations in the future and potentially enables non-invasive diagnosis, staging and monitoring of tumor response to therapy.
Human CD64-targeted non-viral siRNA delivery system for blood monocyte gene modulation
Authors: Yong Seok-Beom , Kim Hyung Jin , Kim Jang Kyoung , Chung Jee Young , Kim Yong-Hee
Published: February 2017

A subset of phagocytes including inflammatory monocytes in blood migrate and give rise to macrophages in inflammatory tissues which generated the idea that blood monocytes are the therapeutic targets for drug delivery. Fc gamma receptor I (CD64) is a membrane receptor for the Fc region of immunoglobulin G, primarily expressed on monocyte-lineage, and H22 a monoclonal antibody for human CD64 had shown rapid blood monocyte binding and occupation in clinical studies. Small interfering RNA-mediated gene silencing as a therapeutic has been proposed and is a promising strategy in terms of its “knock-down” ability on the target gene prior to translation. However, its instability and off-targeting effect must be overcome for success in clinical studies. In this study, we developed a non-viral delivery system composed of oligo-nona-arginine (9R) and anti-human CD64 single chain antibodies (H22) for human monocyte-specific siRNA delivery. A targeted and efficient siRNA delivery mediated by anti-CD64 scFv-9R was observed in CD64 positive human leukemia cells, THP-1. With primary human blood cells, anti-CD64 scFv-9R mediated gene silencing was quantitatively confirmed representing blood monocyte selective gene delivery. These results demonstrate the potential of anti-CD64 scFv-9R mediated siRNA delivery for the treatment of human inflammatory diseases via blood monocytes gene delivery.
Shrimp AHPND-causing plasmids encoding the PirAB toxins as mediated by pirAB-Tn903 are prevalent in various Vibrio species
Authors: Xiao Jinzhou , Liu Liyuan , Ke Yiyun , Li Xiefei , Liu Yunfei , Pan Yingjie , Yan Shuling , Wang Yongjie
Published: February 2017

Acute hepatopancreatic necrosis disease (AHPND) is a newly emerging shrimp disease caused by pirAB toxins encoded by a plasmid found in Vibrio parahaemolyticus. The pirAB toxins are the homologs of the Photorhabdus insect-related (Pir) toxins. Here, we report the complete sequences of the AHPND-causing plasmid isolated from V. owensii, as well as those of its 11 siblings (pVH family). In addition, we also included 13 related plasmids (pVH-r family) without the pirAB genes isolated from a variety of species within the Vibrio Harveyi clade. Furthermore, the pirAB-Tn903 composite transposon was identified in pVH, and both ends of the transposon appeared to have inserted simultaneously into the ancestor plasmid at different sites. The homologue counterparts of pirAB were also detected in a non-pVH plasmid in V. campbellii. Taken together, our results provide novel insights into the acquisition and evolution of pirAB as well as related plasmids in the Vibrio Harveyi clade.
Bronchoalveolar Lavage Proteomics in Patients with Suspected Lung Cancer
Authors: Carvalho Ana Sofia , Cuco Célia Marina , Lavareda Carla , Miguel Francisco , Ventura Mafalda , Almeida Sónia , Pinto Paula , de Abreu Tiago Tavares , Rodrigues Luís Vaz , Seixas Susana , Bárbara Cristina , Azkargorta Mikel , Elortza Felix , Semedo Júlio , Field John K. , Mota Leonor , Matthiesen Rune
Published: February 2017

Lung cancer configures as one of the deadliest types of cancer. The future implementation of early screening methods such as exhaled breath condensate analysis and low dose computed tomography (CT) as an alternative to current chest imaging based screening will lead to an increased burden on bronchoscopy units. New approaches for improvement of diagnosis in bronchoscopy units, regarding patient management, are likely to have clinical impact in the future. Diagnostic approaches to address mortality of lung cancer include improved early detection and stratification of the cancers according to its prognosis and further response to drug treatment. In this study, we performed a detailed mass spectrometry based proteome analysis of acellular bronchoalveolar lavage (BAL) fluid samples on an observational prospective cohort consisting of 90 suspected lung cancer cases which were followed during two years. The thirteen new lung cancer cases diagnosed during the follow up time period clustered, based on liquid chromatography-mass spectrometry (LC-MS) data, with lung cancer cases at the time of BAL collection. Hundred and thirty-tree potential biomarkers were identified showing significantly differential expression when comparing lung cancer versus non-lung cancer. The regulated biomarkers showed a large overlap with biomarkers detected in tissue samples.
Quality Evaluation Focusing on Tissue Fractal Dimension and Chemical Changes for Frozen Tilapia with Treatment by Tangerine Peel Extract
Authors: He Qi , Yang Zhao , Gong Bin , Wang Jingjing , Xiao Kaijun , Yang Shang-Tian
Published: February 2017

This work aimed to establish an effective approach to evaluate the quality of frozen fish, focusing on changes in fish tissue structure and chemical composition during storage. Fresh tilapia samples were treated by coating with tangerine peel (TP) extract and then stored at −4, −8 and −18 °C, respectively, for 40 days. The frozen fish tissues were analyzed for structural and chemical changes. Fractal dimension, which quantifies the porous structure formed in the tissue samples, texture properties including hardness and springiness, and moisture content and water activity all decreased during the storage, while the extents of lipid oxidation, measured as peroxide value and thiobarbituric acid concentration, and protein degradation, monitored with total volatile basic nitrogen and trichloroacetic acid soluble peptides, increased. The change rates of these parameters decreased with decreasing the storage temperature and by applying TP extract. A model was developed for predicting fractal dimension, which indicated the quality of preserved tilapia and thus can be used to predict the shelf life under different storage temperatures. The results demonstrated that TP extract could extend the shelf life of frozen tilapia by 35–45% by inhibiting changes in tissue structure, moisture loss, lipid oxidation and protein degradation during frozen storage.
Development of a Novel Simulation Reactor for Chronic Exposure to Atmospheric Particulate Matter
Authors: Ye Jianhuai , Salehi Sepehr , North Michelle L. , Portelli Anjelica M. , Chow Chung-Wai , Chan Arthur W. H.
Published: February 2017

Epidemiological studies have shown that air pollution is associated with the morbidity and mortality from cardiopulmonary diseases. Currently, limited experimental models are available to evaluate the physiological and cellular pathways activated by chronic multi-pollutant exposures. This manuscript describes an atmospheric simulation reactor (ASR) that was developed to investigate the health effects of air pollutants by permitting controlled chronic in vivo exposure of mice to combined particulate and gaseous pollutants. BALB/c mice were exposed for 1 hr/day for 3 consecutive days to secondary organic aerosol (SOA, a common particulate air pollutant) at 10–150 μg/m3, SOA (30 μg/m3) + ozone (65 ppb) or SOA + ozone (65 ppb) + nitrogen dioxide (NO2; 100 ppb). Daily exposure to SOA alone led to increased airway hyperresponsiveness (AHR) to methacholine with increasing SOA concentrations. Multi-pollutant exposure with ozone and/or NO2 in conjunction with a sub-toxic concentration of SOA resulted in additive effects on AHR to methacholine. Inflammatory cell recruitment to the airways was not observed in any of the exposure conditions. The ASR developed in this study allows us to evaluate the chronic health effects of relevant multi-pollutant exposures at ‘real-life’ levels under controlled conditions and permits repeated-exposure studies.
Copulatory courtship by internal genitalia in bushcrickets
Authors: Wulff Nadja C. , van de Kamp Thomas , dos Santos Rolo Tomy , Baumbach Tilo , Lehmann Gerlind U. C.
Published: February 2017

Male genital organs are among the fastest evolving morphological structures. However, large parts of the male’s genitalia are often hidden inside the female during mating. In several bushcricket species, males bear a pair of sclerotized genital appendices called titillators. By employing synchrotron-based in vivo X-ray cineradiography on mating couples, we were able to visualize titillator movement and spermatophore attachment inside the female. Titillators are inserted and retracted rhythmically. During insertion the titillator processes tap the soft and sensillae-covered dorsal side of the female’s flap-like genital fold, which covers the opening of the female’s genitalia, without tissue penetration. Titillators thus appear to be initially used for stimulation; later they may apply pressure that forces the female’s genital fold to stay open, thereby aiding mechanically in spermatophore transfer.
Detection, inhibition and disintegration of amyloid fibrils: the role of optical probes and macrocyclic receptors
Authors: Bhasikuttan Achikanath C. , Mohanty Jyotirmayee
Published: February 2017

This article provides a brief account of the recent reports on the early detection of amyloid fibril formation using fluorescent dyes and inhibition and disintegration of fibrils using macrocyclic receptors, which find applications in the treatment of fibril associated neurodegenerative diseases.
Poly(vinyl alcohol) as a water protecting agent for silver nanoparticles: the role of polymer size and structure
Authors: Kyrychenko Alexander , Pasko Dmitry A. , Kalugin Oleg N.
Published: February 2017

In the present work, an atomistic model for the classical MD simulation of silver nanoparticles grafted with single-chain PVA of various lengths from 220 up to 1540 repeating units was developed.
Chemical memory with states coded in light controlled oscillations of interacting Belousov–Zhabotinsky droplets
Authors: Gizynski Konrad , Gorecki Jerzy
Published: February 2017

The information storing potential of droplets, in which an oscillatory, photosensitive Belousov–Zhabotinsky (BZ) reaction proceeds, is investigated experimentally.
Adsorption behaviors and vibrational spectra of hydrogen peroxide molecules at quartz/water interfaces
Authors: Lv Yeqing , Wang Xinran , Yu Xiaobin , Zheng Shili , Wang Shaona , Zhang Yi , Du Hao
Published: February 2017

Before saturation, the adsorbed H2O2 molecules formed multiple H-bonds with silanols; once saturated, they would be adsorbed at longer distances, away from the surface.
Anticipating hyperthermic efficiency of magnetic colloids using a semi-empirical model: a tool to help medical decisions
Authors: Fernández van Raap M. B. , Coral D. F. , Yu S. , Muñoz G. A. , Sánchez F. H. , Roig A.
Published: February 2017

Semi-empirical modeling of small nanoparticle heat dissipation helps the designing of medical decisions for clinical cancer magnetic hyperthermia.
Probing the origins of vibrational mode specificity in intramolecular dynamics through picosecond time-resolved photoelectron imaging studies
Authors: Davies Julia A. , Whalley Laura E. , Reid Katharine L.
Published: February 2017

Enhanced torsion-vibration coupling associated with a selected vibrational mode is shown to accelerate intramolecular energy flow in p-fluorotoluene.
Influence of the excitation light intensity on the rate of fluorescence quenching reactions: pulsed experiments
Authors: Angulo Gonzalo , Milkiewicz Jadwiga , Kattnig Daniel , Nejbauer Michał , Stepanenko Yuriy , Szczepanek Jan , Radzewicz Czesław , Wnuk Paweł , Grampp Günter
Published: February 2017

The rate constant of photo-induced bimolecular reactions depend on the intensity of light too!
Implicating the contributions of surface and bulk states on carrier trapping and photocurrent performance of BiVO4 photoanodes
Authors: Pattengale B. , Huang J.
Published: February 2017

We report the correlation of the surface and bulk structure with carrier dynamics and photocurrent performance of bare BiVO4 photoanodes.
Antiscaling efficacy of CaCO3and CaSO4on polyethylene glycol (PEG)-modified reverse osmosis membranes in the presence of humic acid: interplay of membrane surface properties and water chemistry
Authors: Ray Jessica R. , Wong Whitney , Jun Young-Shin
Published: February 2017

A specific polyethylene glycol (PEG)–humic acid–SO42−interaction results in promoted CaSO4colloidal formation on PEG reverse osmosis membrane surfaces.
The dynamic mechanism of RASSF5 and MST kinase activation by Ras
Authors: Liao Tsung-Jen , Jang Hyunbum , Tsai Chung-Jung , Fushman David , Nussinov Ruth
Published: February 2017

As a tumor suppressor, RASSF5 (NORE1A) activates MST1/2 thereby modulating the Hippo pathway.
Improved bovine embryo production in an oviduct-on-a-chip system: prevention of poly-spermic fertilization and parthenogenic activation
Authors: Ferraz Marcia A. M. M. , Henning Heiko H. W. , Costa Pedro F. , Malda Jos , Melchels Ferry P. , Wubbolts R. , Stout Tom A. E. , Vos Peter L. A. M. , Gadella Bart M.
Published: February 2017

The use of 3D-printing in bovine oviduct epithelial cell cultures allows better bio-mimicking of embryo production than classicalin vitrofertilization.
Predicting brain network changes in Alzheimer's disease with link prediction algorithms
Authors: Sulaimany Sadegh , Khansari Mohammad , Zarrineh Peyman , Daianu Madelaine , Jahanshad Neda , Thompson Paul M. , Masoudi-Nejad Ali
Published: February 2017

Assessment of the predictability power of link prediction algorithms in their basic form for brain network changes during Alzheimer's disease.
High performance of TiO2/CdS quantum dot sensitized solar cells with a Cu–ZnS passivation layer
Authors: Lee Young-Seok , Gopi Chandu V. V. M. , Eswar Reddy Araveeti , Nagaraju Chandu , Kim Hee-Je
Published: February 2017

A Cu–ZnS passivation layer effectively suppresses the charge recombination and increases the light harvesting in QDSSCs.
Direct access to the optically active VAChT inhibitor vesamicol and its analogues via the asymmetric aminolysis of meso-epoxides with secondary aliphatic amines
Authors: Sharma Arun , Agarwal Jyoti , Peddinti Rama Krishna
Published: February 2017

The VAChT inhibitor vesamicol and its analogues were synthesized in impressive chemical and optical yields via the catalytic asymmetric aminolysis of meso-epoxides.
Role of chain ends in coil deformation of driven single polymer
Authors: Tao Huachen , Gao Huanhuan , Hu Wenbing
Published: February 2017

Driven single ring polymer deforms as well as linear polymers, proving that the chain ends are not responsible for coil deformation.
Hydrothermal liquefaction of blackcurrant pomace and model molecules: understanding of reaction mechanisms
Authors: Déniel Maxime , Haarlemmer Geert , Roubaud Anne , Weiss-Hortala Elsa , Fages Jacques
Published: February 2017

Hydrothermal liquefaction (HTL) refers to the conversion of carbonaceous resources into oily substances in hot pressurized liquid water.
Hydrogen weakens interlayer bonding in layered transition metal sulfide Fe1+xS
Authors: Krishnamoorthy Aravind , Dinh Minh A. , Yildiz Bilge
Published: February 2017

The presence of interlaminar interstitial defects like hydrogen affects the mechanical properties of van der Waals-bonded layered materials such as transition metal chalcogenides.
Hydration of Bombyx mori silk cocoon, silk sericin and silk fibroin and their interactions with water as studied by13C NMR and2H NMR relaxation
Authors: Asakura Tetsuo , Endo Masanori , Tasei Yugo , Ohkubo Takahiro , Hiraoki Toshifumi
Published: February 2017

The effect of hydration on the structure and dynamics ofBombyx morisilk was clarified at the molecular level.
A universal fluorometric assay strategy for glycosidases based on functional carbon quantum dots: β-galactosidase activity detection in vitro and in living cells
Authors: Tang Cong , Zhou Jin , Qian Zhaosheng , Ma Yanyan , Huang Yuanyuan , Feng Hui
Published: February 2017

A general assay strategy for glycosidase was developed based on functional CQDs, and the assay shows a good analytical performance in vitro and in cells.
Monodisperse and size-tunable PbS colloidal quantum dots via heterogeneous precursors
Authors: Chan Samuel , Liu Maning , Latham Kay , Haruta Mitsutaka , Kurata Hiroki , Teranishi Toshiharu , Tachibana Yasuhiro
Published: February 2017

Monodisperse and size-tunable PbS QDs were synthesized via the diffusion controlled reaction of turbid suspensions of reactive N,N′-diphenylthiourea and PbCl2 precursors.
An unusual nitride network of aluminum-centered octahedra and phosphorus-centered tetrahedra and structure determination from microcrystalline samples
Authors: Neudert Lukas , Heinke Frank , Bräuniger Thomas , Pucher Florian J. , Vaughan Gavin B. , Oeckler Oliver , Schnick Wolfgang
Published: February 2017

Aluminum coordinated by six nitrogen atoms was realized in a new highly condensed network which was obtainedviaHP–HT synthesis at 5 GPa.
Oxidative couplings on tryptophan-based diketopiperazines leading to fused and bridged chemotypes
Authors: Mendive-Tapia Lorena , Albornoz-Grados Arantxa , Bertran Alexandra , Albericio Fernando , Lavilla Rodolfo
Published: February 2017

Selective C–C and C–N oxidative couplings on tryptophan-based diketopiperazines allow the direct access to two novel scaffolds.
Diffusive confinement of free radical intermediates in the OH radical oxidation of semisolid aerosols
Authors: Wiegel Aaron A. , Liu Matthew J. , Hinsberg William D. , Wilson Kevin R. , Houle Frances A.
Published: February 2017

Reaction–diffusion simulations show that interfacial confinement of the reactions results in reactivity distinct from that in liquid hydrocarbon aerosol.
Unavoidable food supply chain waste: acid-free pectin extraction from mango peel via subcritical water
Authors: Xia H. , Matharu A. S.
Published: February 2017

Mango peel is the major by-product of mango processing, and compromises 7–24% of the total mango weight. In this study, pectin was extracted from mango peel waste by using subcritical water extraction (SWE) in the absence of mineral acid. A highest yield of 18.34% was achieved from the Kesar variety and the pectin was characterised using ATR-IR spectroscopy, TGA and 13C solid-state NMR spectroscopy to confirm the structure. The degree of esterification (DE) of the pectin was analysed with both titrimetry and 13C solid-state NMR spectroscopy, and a high DE (>70%) was observed for all three varieties (Keitt, Sindhri and Kesar). This is the first report on acid-free subcritical water extraction of pectin from mango peel, which provides a green route for the valorisation of mango peel waste and contributes to a source of biobased materials and chemicals for a sustainable 21st century.
A stereoselective synthesis of (E)- or (Z)-β-arylvinyl halides via a borylative coupling/halodeborylation protocol
Authors: Szyling Jakub , Franczyk Adrian , Pawluć Piotr , Marciniec Bogdan , Walkowiak Jędrzej
Published: February 2017

A new highly selective method for the synthesis of (E)-arylvinyl iodides and (E)- or (Z)-β-arylvinyl bromides from easily accessible styrenes and vinyl boronates, on the basis of a one-pot procedure via borylative coupling/halodeborylation is reported.
Peptide Weinreb amide derivatives as thioester precursors for native chemical ligation
Authors: Rao Chang , Liu Chuan-Fa
Published: February 2017

Peptide C-ter Weinreb amide derivatives are excellent thioester surrogates for native chemical ligation.
2D lateral heterostructures of monolayer and bilayer phosphorene
Authors: Lin Heng-Fu , Liu Li-Min , Zhao Jijun
Published: February 2017

Bilayer/monolayer phosphorene lateral heterostructures with tunable band alignment.
Robust simultaneous finite‐time control and fault detection for uncertain linear switched systems with time‐varying delay
Authors: Shokouhi‐Nejad Hossein , Ghiasi Amir Rikhtehgar , Badamchizadeh Mohammad Ali
Published: February 2017

This study deals with the problem of simultaneous finite‐time control and fault detection for linear switched systems with state delay and parameter uncertainties. Delay is assumed to vary in an interval with a nonzero lower bound and specified range. Uncertainties are norm‐bounded time‐varying and exist in the matrix of the system. Based on average dwell time approach and using delay‐dependent method, new sufficient conditions are given in terms of linear matrix inequalities to design a controller/detector unit. The detector is an observer and the controller is an observer‐based controller. This problem is formulated as finite‐time H∞ optimisation problem and both finite‐time stability and fault detection are considered through certain performance indexes. The effectiveness of the proposed method is verified by a numerical example.
Dwell‐time‐dependent stability results for impulsive systems
Authors: Shao Hanyong , Zhao Jianrong
Published: February 2017

This study is concerned with the dwell‐time stability for impulsive systems under periodic or aperiodic impulses. A Lyapunov‐like functional approach is established to study the stability for impulsive systems. The Lyapunov‐like functional is time‐varying and decreasing but is not imposed definite positive nor continuous. A specific Lyapunov‐like functional is constructed by introducing the integral of state together with the cross‐terms of the integral and impulsive states. A tight bounding is obtained for the derivative of this functional with the help of the improved Jensen inequality reported recently and the integral equation of the impulsive system. On the basis of the Lyapunov‐like functional approach, new dwell‐time‐dependent stability results with ranged dwell‐time, maximal dwell‐time and minimal dwell‐time are derived for periodic or aperiodic impulsive systems. The stability results have less conservatism than some existing ones, which are illustrated by numerical examples.
Method for accurately measuring the power‐frequency parameters of EHV/UHV transmission lines
Authors: Yang Xiangguo , Geng Guangchao , Wang Yang , Ding Tianyu
Published: February 2017

Power‐frequency parameters of long‐distance extreme‐high‐voltage (EHV) and ultra‐high‐voltage (UHV) transmission lines are the basis of power system modelling and analysis, but these parameters are especially difficult to accurately measure due to the reactance‐dominated nature and strong external interference. An accurate power‐frequency parameter measurement approach is proposed in this study. The idea is to utilise frequency response curve to indirectly extrapolate transmission line parameters at power frequency. As no direct measurement is conducted at power frequency, the potential power‐frequency interference is avoided. A resonance‐based measurement method is employed to eliminate the effect of large impedance phase angle of EHV/UHV systems and identify positive‐ and zero‐sequence resistance with enhanced accuracy. In order to validate the effectiveness of the proposed approach, a prototype instrument was developed and used to measure power‐frequency parameters of a scale‐down laboratory transmission line system. Comparative results confirmed the accuracy priority of the proposed approach over existing power‐frequency measurement methods. In addition, the anti‐interference performance in terms of the impact of the parallel in‐service transmission line also indicates the proposed approach is more advantageous as it has lower capacity requirement on the measurement device.
Travelling waves‐based identification of sub‐health condition of feeders in power distribution system
Authors: Shi Shenxing , Hu Zhonghong , Ma Zhao , Dong Xinzhou
Published: February 2017

The majority of faults in power distribution system are caused by natural degradation of feeders. In addition, travelling waves will be generated during degradation of feeders. This study proposes a method based on travelling waves to identify sub‐health condition, which represents the degradation of feeder before the feeder fails into a permanent fault. In the method, traveling waves in the power distribution system are monitored in real time. Then, the location of travelling wave source is determined by the polarity of travelling waves, which is extracted using wavelet transform. Finally, the degradation of feeder is identified when all the other possibilities to generate travelling waves are ruled out using the characteristics of power‐frequency voltages and currents accompanied with travelling waves. Simulation results have verified that the proposed method is feasible and effective.
ST TD outlier detection
Authors: Sun Dihua , Zhao Hongzhuan , Yue Hang , Zhao Min , Cheng Senlin , Han Weijian
Published: February 2017

Through vehicle‐to‐everything traffic information propagation often causes data outliers, due to data delay, data loss, inaccurate data and inconsistent data. Traffic data (TD) with outliers may incorrectly describe traffic conditions and decline the reliability and stability of transportation cyber physical system. This study develops some research approaches to detect spatiotemporal (ST) data outliers for the development of transportation systems. These research approaches include the theorisation of ST traffic outliers, the creation of an innovative firefly algorithm (IFA), the discussion of TD synchronisation methods and the development of the FA‐based ST outlier detection mechanism (IFA‐STODM). The experimental results show that the proposed IFA‐STODM is an effective and efficient method for the detection of ST TD outliers.
Application of SRR to achieve performance improvement and multi‐band characteristics in aperture antennas
Authors: Chandra Avinash , Das Sushrut
Published: February 2017

This study presents a split‐ring resonator (SRR) loaded tri‐band open‐ended waveguide (OEW) antenna that has higher gain, higher front‐to‐back radiation ratio and lower mutual coupling characteristics compared to a simple OEW antenna.Tri‐band response of the proposed OEW antenna has been achieved by placing three SRRs on the waveguide transverse plane with uniform spacing between them. The reduced mutual coupling makes the antenna suitable for array applications. Lumpled element equivalent circuit of the proposed antenna has also been presented.
Pd(OAc)2-Catalyzed Desulfinative Cross-Coupling of Sodium Sulfinates with β-Bromostyrenes: Synthesis of Tamoxifen
Authors: Chang Meng-Yang , Cheng Yu- , Sun Pei-
Published: February 2017

A Pd(OAc)2-catalyzed desulfinative cross-coupling of (Z)-β-halostyrenes with sodium sulfinates in the presence of PPh3 and Na2CO3 at reflux in good yields is reported. The stereocontrolled cross-coupling process provides a series of sulfonylmethyl (Z)-stilbenes. A synthesis of tamoxifen was studied.
Attosecond-controlled photoemission from metal nanowire tips in the few-electron regime
Authors: Ahn B. , Schötz J. , Kang M. , Okell W. A. , Mitra S. , Förg B. , Zherebtsov S. , Süßmann F. , Burger C. , Kübel M. , Liu C. , Wirth A. , Di Fabrizio E. , Yanagisawa H. , Kim D. , Kim B. , Kling M. F.
Published: February 2017

Metal nanotip photoemitters have proven to be versatile in fundamental nanoplasmonics research and applications, including, e.g., the generation of ultrafast electron pulses, the adiabatic focusing of plasmons, and as light-triggered electron sources for microscopy. Here, we report the generation of high energy photoelectrons (up to 160 eV) in photoemission from single-crystalline nanowire tips in few-cycle, 750-nm laser fields at peak intensities of (2-7.3) × 1012 W/cm2. Recording the carrier-envelope phase (CEP)-dependent photoemission from the nanowire tips allows us to identify rescattering contributions and also permits us to determine the high-energy cutoff of the electron spectra as a function of laser intensity. So far these types of experiments from metal nanotips have been limited to an emission regime with less than one electron per pulse. We detect up to 13 e/shot and given the limited detection efficiency, we expect up to a few ten times more electrons being emitted from the nanowire. Within the investigated intensity range, we find linear scaling of cutoff energies. The nonlinear scaling of electron count rates is consistent with tunneling photoemission occurring in the absence of significant charge interaction. The high electron energy gain is attributed to field-induced rescattering in the enhanced nanolocalized fields at the wires apex, where a strong CEP-modulation is indicative of the attosecond control of photoemission.
Atomic clusters with addressable complexity
Authors: Wales David J.
Published: February 2017

A general formulation for constructing addressable atomic clusters is introduced, based on one or more reference structures. By modifying the well depths in a given interatomic potential in favour of nearest-neighbour interactions that are defined in the reference(s), the potential energy landscape can be biased to make a particular permutational isomer the global minimum. The magnitude of the bias changes the resulting potential energy landscape systematically, providing a framework to produce clusters that should self-organise efficiently into the target structure. These features are illustrated for small systems, where all the relevant local minima and transition states can be identified, and for the low-energy regions of the landscape for larger clusters. For a 55-particle cluster, it is possible to design a target structure from a transition state of the original potential and to retain this structure in a doubly addressable landscape. Disconnectivity graphs based on local minima that have no direct connections to a lower minimum provide a helpful way to visualise the larger databases. These minima correspond to the termini of monotonic sequences, which always proceed downhill in terms of potential energy, and we identify them as a class of biminimum. Multiple copies of the target cluster are treated by adding a repulsive term between particles with the same address to maintain distinguishable targets upon aggregation. By tuning the magnitude of this term, it is possible to create assemblies of the target cluster corresponding to a variety of structures, including rings and chains.
Relevant parameter space and stability of spherical tokamaks with a plasma center column
Authors: Lampugnani L. G. , Garcia-Martinez P. L. , Farengo R.
Published: February 2017

A spherical tokamak (ST) with a plasma center column (PCC) can be formed inside a simply connected chamber via driven magnetic relaxation. From a practical perspective, the ST-PCC could overcome many difficulties associated with the material center column of the standard ST reactor design. Besides, the ST-PCC concept can be regarded as an advanced helicity injected device that would enable novel experiments on the key physics of magnetic relaxation and reconnection. This is because the concept includes not only a PCC but also a coaxial helicity injector (CHI). This combination implies an improved level of flexibility in the helicity injection scheme required for the formation and sustainment phases. In this work, the parameter space determining the magnetic structure of the ST-PCC equilibria is studied under the assumption of fully relaxed plasmas. In particular, it is shown that the effect of the external bias field of the PCC and the CHI essentially depends on a single parameter that measures the relative amount of flux of these two entities. The effect of plasma elongation on the safety factor profile and the stability to the tilt mode are also analyzed. In the first part of this work, the stability of the system is explained in terms of the minimum energy principle, and relevant stability maps are constructed. While this picture provides an adequate insight into the underlying physics of the instability, it does not include the stabilizing effect of line-tying at the electrodes. In the second part, a dynamical stability analysis of the ST-PCC configurations, including the effect of line-tying, is performed by numerically solving the magnetohydrodynamic equations. A significant stability enhancement is observed when the PCC contains more than the 70% of the total external bias flux, and the elongation is not higher than two.
Diffusion dominated evaporation in multicomponent lattice Boltzmann simulations
Authors: Hessling Dennis , Xie Qingguang , Harting Jens
Published: February 2017

We present a diffusion dominated evaporation model using the popular pseudopotential multicomponent lattice Boltzmann method introduced by Shan and Chen. With an analytical computation of the diffusion coefficients, we demonstrate that Fick’s law is obeyed. We then validate the applicability of our model by demonstrating the agreement of the time evolution of the interface position of an evaporating planar film to the analytical prediction. Furthermore, we study the evaporation of a freely floating droplet and confirm that the effect of Laplace pressure is significant for predicting the time evolution of small droplet radii.
Surface fine structure influence on saturated random packings
Authors: Cieśla Michał , Barbasz Jakub
Published: February 2017

Random packings of disks on a mesh are studied numerically using random sequential adsorption algorithm. The mesh is built of straight horizontal and vertical one-dimensional lines of a given distance between them. The packing fraction and structure as well as the kinetics of packing growth dependence on mesh size are analyzed to provide information, whether surface inhomogeneity will affect the properties of random packings. It has been shown that the number of disks in a packing slightly decreases with growing distance between mesh lines while the kinetics may change significantly even for very dense meshes. As packings obtained in random sequential adsorption resemble monolayers produced by irreversible adsorption processes, results of this study show that by measuring properties of a random packing it may be possible to determine fine structure of an underlying surface.
Thermal management and prototype testing of Compton scattering X-ray beam position monitor for the Advanced Photon Source Upgrade
Authors: Lee S. H. , Yang B. X. , Collins J. T. , Ramanathan M.
Published: February 2017

Accurate and stable x-ray beam position monitors (XBPMs) are key elements in obtaining the desired user beam stability in the Advanced Photon Source Upgrade. In the next-generation XBPMs for the canted-undulator front ends, where two undulator beams are separated by 1.0 mrad, the lower beam power (<10 kW) per undulator allows us to explore lower-cost solutions based on Compton scattering from a diamond placed edge-on to the x-ray beam. Because of the high peak power density of the x-ray beams, this diamond experiences high temperatures and has to be clamped to a water-cooled heat spreader using thermal interface materials (TIMs), which play a key role in reducing the temperature of the diamond. To evaluate temperature changes through the interface via thermal simulations, the thermal contact resistance (TCR) of TIMs at an interface between two solid materials under even contact pressure must be known. This paper addresses the TCR measurements of several TIMs, including gold, silver, pyrolytic graphite sheet, and 3D graphene foam. In addition, a prototype of a Compton-scattering XBPM with diamond blades was installed at APS Beamline 24-ID-A in May 2015 and has been tested. This paper presents the design of the Compton-scattering XBPM, and compares thermal simulation results obtained for the diamond blade of this XBPM by the finite element method with in situ empirical measurements obtained by using reliable infrared technology.
Analytical model of photon reabsorption in ZnO quantum dots with size and concentration dependent dual-color photoluminescence
Authors: Fan Baolu , Guo Xiaoxiao , Zhang Yumeng , Fan Jiyang
Published: February 2017

We investigate the concentration and size dependent UV/green photoluminescence properties of the ZnO quantum dots (QDs) with sizes in the strong confinement regime. The luminescence characteristics of an ensemble of colloidal semiconductor QDs with quantum confinement effect depend sensitively on particle concentration but this has only been qualitatively understood. By taking ZnO QDs as an ideal prototype, we construct a material-independent theoretical model to study the photon reabsorption phenomenon. The theoretical result agrees well with the experiment. This model can be used to quantitatively study the concentration-dependent luminescence properties of any collection of QDs with considerable size dispersion. On the other hand, the origin of green emission in ZnO QDs remains debated. The comparative study of the size dependence of UV and green emissions in conjunction with the effective-mass approximation calculation suggests that the green emission in the ZnO QDs originates from the conduction band to the deep level transition.
Role of interface roughness scattering, temperature, and structural parameters on the performance characteristics of III-nitride quantum cascade detectors
Authors: Saha S. , Kumar J.
Published: February 2017

A III-nitride quantum cascade detector (QCD) for the fiber optic communication wavelength (∼1.5 μm) has been designed, and the effect of intersubband scattering processes such as longitudinal-optical phonon scattering, ionized impurity scattering, and more importantly interface roughness scattering on responsivity performance has been analyzed. Carrier transport in the detector is modeled using a simplified rate equation approach. It is observed that inclusion of interface roughness scattering in the carrier transport model significantly enhances the responsivity performance of the detector. The effects of roughness conditions for instance mean roughness height and correlation length on responsivity have been examined. The responsivity of the designed detector drops by 2.16 mA/W at 400 K compared to its low temperature value at 50 K and the detection wavelength change with temperature is insignificant, which are very helpful for the stable detection of the radiation for a wide range of operating temperatures and show the thermal stability of III-nitride QCDs. The effects of active well widths, extractor barrier widths, and extractor well widths have been further investigated. A higher responsivity performance is observed for narrower barrier widths. It is noticed that change in the active well width significantly modifies the responsivity of the detector and the wavelength gets red shifted for larger active well widths.