bluuebunny/crossref_metadata_2025 huggingface dataset:
Protein Kinase C Epsilon Promotes Cerebral Ischemic Tolerance Via Modulation of Mitochondrial Sirt5
Authors: Morris-Blanco Kahlilia C. , Dave Kunjan R. , Saul Isabel , Koronowski Kevin B. , Stradecki Holly M. , Perez-Pinzon Miguel A.
Published: July 2016

Sirtuin 5 (SIRT5) is a mitochondrial-localized NAD+-dependent lysine desuccinylase and a major regulator of the mitochondrial succinylome. We wanted to determine whether SIRT5 is activated by protein kinase C epsilon (PKCε)-mediated increases in mitochondrial Nampt and whether SIRT5 regulates mitochondrial bioenergetics and neuroprotection against cerebral ischemia. In isolated mitochondria from rat cortical cultures, PKCε activation increased SIRT5 levels and desuccinylation activity in a Nampt-dependent manner. PKCε activation did not lead to significant modifications in SIRT3 activity, the major mitochondrial lysine deacetylase. Assessments of mitochondrial bioenergetics in the cortex of wild type (WT) and SIRT5−/− mice revealed that SIRT5 regulates oxygen consumption in the presence of complex I, complex II and complex IV substrates. To explore the potential role of SIRT5 in PKCε-mediated protection, we compared WT and SIRT5−/− mice by employing both in vitro and in vivo ischemia paradigms. PKCε-mediated decreases in cell death following oxygen-glucose deprivation were abolished in cortical cultures harvested from SIRT5−/− mice. Furthermore, PKCε failed to prevent cortical degeneration following MCAO in SIRT5−/− mice. Collectively this demonstrates that SIRT5 is an important mitochondrial enzyme for protection against metabolic and ischemic stress following PKCε activation in the brain.
Quantification of Somatic Chromosomal Rearrangements in Circulating Cell-Free DNA from Ovarian Cancers
Authors: Harris Faye R. , Kovtun Irina V. , Smadbeck James , Multinu Francesco , Jatoi Aminah , Kosari Farhad , Kalli Kimberly R. , Murphy Stephen J. , Halling Geoffrey C. , Johnson Sarah H. , Liu Minetta C. , Mariani Andrea , Vasmatzis George
Published: July 2016

Recently, the use of a liquid biopsy has shown promise in monitoring tumor burden. While point mutations have been extensively studied, chromosomal rearrangements have demonstrated greater tumor specificity. Such rearrangements can be identified in the tumor and subsequently detected in the plasma of patients using quantitative PCR (qPCR). In this study we used a whole-genome mate-pair protocol to characterize a landscape of genomic rearrangements in the primary tumors of ten ovarian cancer patients. Individualized tumor-specific primer panels of aberrant chromosomal junctions were identified for each case and detected by qPCR within the cell-free DNA. Selected chromosomal junctions were detected in pre-surgically drawn blood in eight of the ten patients. Of these eight, three demonstrated the continued presence of circulating tumor DNA (ctDNA) post-surgery, consistent with their documented presence of disease, and in five ctDNA was undetectable in the post-surgical blood collection, consistent with their lack of detectable disease. The ctDNA fraction was calculated using a novel algorithm designed for the unique challenges of quantifying ctDNA using qPCR to allow observations of real-time tumor dynamics. In summary, a panel of individualized junctions derived from tumor DNA could be an effective way to monitor cancer patients for relapse and therapeutic efficacy using cfDNA.
The abrupt onset of the modern South Asian Monsoon winds
Authors: Betzler Christian , Eberli Gregor P. , Kroon Dick , Wright James D. , Swart Peter K. , Nath Bejugam Nagender , Alvarez-Zarikian Carlos A. , Alonso-García Montserrat , Bialik Or M. , Blättler Clara L. , Guo Junhua Adam , Haffen Sébastien , Horozal Senay , Inoue Mayuri , Jovane Luigi , Lanci Luca , Laya Juan Carlos , Mee Anna Ling Hui , Lüdmann Thomas , Nakakuni Masatoshi , Niino Kaoru , Petruny Loren M. , Pratiwi Santi D. , Reijmer John J. G. , Reolid Jesús , Slagle Angela L. , Sloss Craig R. , Su Xiang , Yao Zhengquan , Young Jeremy R.
Published: July 2016

The South Asian Monson (SAM) is one of the most intense climatic elements yet its initiation and variations are not well established. Dating the deposits of SAM wind-driven currents in IODP cores from the Maldives yields an age of 12. 9 Ma indicating an abrupt SAM onset, over a short period of 300 kyrs. This coincided with the Indian Ocean Oxygen Minimum Zone expansion as revealed by geochemical tracers and the onset of upwelling reflected by the sediment’s content of particulate organic matter. A weaker ‘proto-monsoon’ existed between 12.9 and 25 Ma, as mirrored by the sedimentary signature of dust influx. Abrupt SAM initiation favors a strong influence of climate in addition to the tectonic control, and we propose that the post Miocene Climate Optimum cooling, together with increased continentalization and establishment of the bipolar ocean circulation, i.e. the beginning of the modern world, shifted the monsoon over a threshold towards the modern system.
Pollination and seed dispersal are the most threatened processes of plant regeneration
Authors: Neuschulz Eike Lena , Mueller Thomas , Schleuning Matthias , Böhning-Gaese Katrin
Published: July 2016

Plant regeneration is essential for maintaining forest biodiversity and ecosystem functioning, which are globally threatened by human disturbance. Here we present the first integrative meta-analysis on how forest disturbance affects multiple ecological processes of plant regeneration including pollination, seed dispersal, seed predation, recruitment and herbivory. We analysed 408 pairwise comparisons of these processes between near-natural and disturbed forests. Human impacts overall reduced plant regeneration. Importantly, only processes early in the regeneration cycle that often depend on plant-animal interactions, i.e. pollination and seed dispersal, were negatively affected. Later processes, i.e. seed predation, recruitment and herbivory, showed overall no significant response to human disturbance. Conserving pollination and seed dispersal, including the animals that provide these services to plants, should become a priority in forest conservation efforts globally.
SOX9 directly Regulates CTGF/CCN2 Transcription in Growth Plate Chondrocytes and in Nucleus Pulposus Cells of Intervertebral Disc
Authors: Oh Chun-do , Yasuda Hideyo , Zhao Weiwei , Henry Stephen P. , Zhang Zhaoping , Xue Ming , de Crombrugghe Benoit , Chen Di
Published: July 2016

Several lines of evidence indicate that connective tissue growth factor (CTGF/CCN2) stimulates chondrocyte proliferation and maturation. Given the fact that SOX9 is essential for several steps of the chondrocyte differentiation pathway, we asked whetherCtgf(Ccn2) is the direct target gene of SOX9. We found thatCtgfmRNA was down-regulated in primary sternal chondrocytes fromSox9flox/floxmice infected with Ad-CMV-Cre.We performed ChIP-on-chip assay using anti-SOX9 antibody, covering theCtgfgene from 15 kb upstream of its 5′-end to 10 kb downstream of its 3′-end to determine SOX9 interaction site. One high-affinity interaction site was identified in theCtgfproximal promoter by ChIP-on-chip assay. An important SOX9 regulatory element was found to be located in −70/−64 region of theCtgfpromoter. We found the same site for SOX9 binding to theCtgfpromoter in nucleus pulposus (NP) cells. The loss ofSox9in growth plate chondrocytes in knee joint and in NP cells in intervertebral disc led to the decrease in CTGF expression. We suggest thatCtgfis the direct target gene of SOX9 in chondrocytes and NP cells. Our study establishes a strong link between two regulatory molecules that have a major role in cartilaginous tissues.
Methylomes of renal cell lines and tumors or metastases differ significantly with impact on pharmacogenes
Authors: Winter Stefan , Fisel Pascale , Büttner Florian , Rausch Steffen , D’Amico Debora , Hennenlotter Jörg , Kruck Stephan , Nies Anne T. , Stenzl Arnulf , Junker Kerstin , Scharpf Marcus , Hofmann Ute , van der Kuip Heiko , Fend Falko , Ott German , Agaimy Abbas , Hartmann Arndt , Bedke Jens , Schwab Matthias , Schaeffeler Elke
Published: July 2016

Current therapies for metastatic clear cell renal cell carcinoma (ccRCC) show limited efficacy. Drug efficacy, typically investigated in preclinical cell line models during drug development, is influenced by pharmacogenes involved in targeting and disposition of drugs. Here we show through genome-wide DNA methylation profiling, that methylation patterns are concordant between primary ccRCC and macro-metastases irrespective of metastatic sites (rs ≥ 0.92). However, 195,038 (41%) of all investigated CpG sites, including sites within pharmacogenes, were differentially methylated (adjusted P < 0.05) in five established RCC cell lines compared to primary tumors, resulting in altered transcriptional expression. Exemplarily, gene-specific analyses of DNA methylation, mRNA and protein expression demonstrate lack of expression of the clinically important drug transporter OCT2 (encoded by SLC22A2) in cell lines due to hypermethylation compared to tumors or metastases. Our findings provide evidence that RCC cell lines are of limited benefit for prediction of drug effects due to epigenetic alterations. Similar epigenetic landscape of ccRCC-metastases and tumors opens new avenue for future therapeutic strategies.
Interaction of ARF-1.1 and neuronal calcium sensor-1 in the control of the temperature-dependency of locomotion in Caenorhabditis elegans
Authors: Todd Paul A. C. , McCue Hannah V. , Haynes Lee P. , Barclay Jeff W. , Burgoyne Robert D.
Published: July 2016

Neuronal calcium sensor-1 (NCS-1) mediates changes in cellular function by regulating various target proteins. Many potential targets have been identified but the physiological significance of only a few has been established. Upon temperature elevation, Caenorhabditis elegans exhibits reversible paralysis. In the absence of NCS-1, worms show delayed onset and a shorter duration of paralysis. This phenotype can be rescued by re-expression of ncs-1 in AIY neurons. Mutants with defects in four potential NCS-1 targets (arf-1.1, pifk-1, trp-1 and trp-2) showed qualitatively similar phenotypes to ncs-1 null worms, although the effect of pifk-1 mutation on time to paralysis was considerably delayed. Inhibition of pifk-1 also resulted in a locomotion phenotype. Analysis of double mutants showed no additive effects between mutations in ncs-1 and trp-1 or trp-2. In contrast, double mutants of arf-1.1 and ncs-1 had an intermediate phenotype, consistent with NCS-1 and ARF-1.1 acting in the same pathway. Over-expression of arf-1.1 in the AIY neurons was sufficient to rescue partially the phenotype of both the arf-1.1 and the ncs-1 null worms. These findings suggest that ARF-1.1 interacts with NCS-1 in AIY neurons and potentially pifk-1 in the Ca2+ signaling pathway that leads to inhibited locomotion at an elevated temperature.
Plasma matrix metalloproteinase 1 improves the detection and survival prediction of esophageal squamous cell carcinoma
Authors: Chen Yu-Kuei , Tung Chun-Wei , Lee Jui-Ying , Hung Yi-Chun , Lee Chien-Hung , Chou Shah-Hwa , Lin Hung-Shun , Wu Ming-Tsang , Wu I-Chen
Published: July 2016

This study aimed to identify noninvasive protein markers capable of detecting the presence and prognosis of esophageal squamous-cell carcinoma (ESCC). Analyzing microarray expression data collected from 17-pair ESCC specimens, we identified one protein, matrix metalloproteinase-1 (MMP1), as a possibly useful marker. Plasma MMP1 was then measured by enzyme-linked immunosorbent assay (ELISA) in 210 ESCC patients and 197 healthy controls. ESCC patients had higher mean levels of MMP1 than controls (8.7 ± 7.5 vs. 6.7 ± 4.9 ng/mL, p < 0.0001). Using the highest quartile level (9.67 ng/mL) as cut-off, we found a 9.0-fold risk of ESCC in those with higher plasma MMP1 after adjusting for covariates (95% confidence interval = 2.2, 36.0). Heavy smokers and heavy drinkers with higher plasma MMP1 had 61.4- and 31.0 times the risk, respectively, than non-users with lower MMP1. In the survival analysis, compared to those with MMP1 ≤ 9.67 ng/mL, ESCC patients with MMP1 > 9.67 ng/mL had a 48% increase in the risk of ESCC death (adjusted hazard ratio = 1.48; 95% CI = 1.04–2.10). In conclusion, plasma MMP1 may serve as a noninvasive marker of detecting the presence and predicting the survival of ESCC.
Switching of magnetic easy-axis using crystal orientation for large perpendicular coercivity in CoFe2O4 thin film
Authors: Shirsath Sagar E. , Liu Xiaoxi , Yasukawa Yukiko , Li Sean , Morisako Akimitsu
Published: July 2016

Perpendicular magnetization and precise control over the magnetic easy axis in magnetic thin film is necessary for a variety of applications, particularly in magnetic recording media. A strong (111) orientation is successfully achieved in the CoFe2O4 (CFO) thin film at relatively low substrate temperature of 100 °C, whereas the (311)-preferred randomly oriented CFO is prepared at room temperature by the DC magnetron sputtering technique. The oxygen-deficient porous CFO film after post-annealing gives rise to compressive strain perpendicular to the film surface, which induces large perpendicular coercivity. We observe the coercivity of 11.3 kOe in the 40-nm CFO thin film, which is the highest perpendicular coercivity ever achieved on an amorphous SiO2/Si substrate. The present approach can guide the systematic tuning of the magnetic easy axis and coercivity in the desired direction with respect to crystal orientation in the nanoscale regime. Importantly, this can be achieved on virtually any type of substrate.
Narrowband random lasing in a Bismuth-doped active fiber
Authors: Lobach Ivan A. , Kablukov Sergey I. , Skvortsov Mikhail I. , Podivilov Evgeniy V. , Melkumov Mikhail A. , Babin Sergey A. , Dianov Evgeny M.
Published: July 2016

Random fiber lasers operating via the Rayleigh scattering (RS) feedback attract now a great deal of attention as they generate a high-quality unidirectional laser beam with the efficiency and performance comparable and even exceeding those of fiber lasers with conventional cavities. Similar to other random lasers, both amplification and random scattering are distributed here along the laser medium being usually represented by a kilometers-long passive fiber with Raman gain. However, it is hardly possible to utilize normal gain in conventional active fibers as they are usually short and RS is negligible. Here we report on the first demonstration of the RS-based random lasing in an active fiber. This became possible due to the implementation of a new Bi-doped fiber with an increased amplification length and RS coefficient. The realized Bi-fiber random laser generates in a specific spectral region (1.42 μm) exhibiting unique features, in particular, a much narrower linewidth than that in conventional cavity of the same length, in agreement with the developed theory. Lasers of this type have a great potential for applications as Bi-doped fibers with different host compositions enable laser operation in an extremely broad range of wavelengths, 1.15–1.78 μm.
Neurogenic differentiation factor NeuroD confers protection against radiation-induced intestinal injury in mice
Authors: Li Ming , Du Aonan , Xu Jing , Ma Yanchao , Cao Han , Yang Chao , Yang Xiao-Dong , Xing Chun-Gen , Chen Ming , Zhu Wei , Zhang Shuyu , Cao Jianping
Published: July 2016

The gastrointestinal tract, especially the small intestine, is particularly sensitive to radiation and is prone to radiation-induced injury as a result. Neurogenic differentiation factor (NeuroD) is an evolutionarily-conserved basic helix-loop-helix (bHLH) transcription factor. NeuroD contains a protein transduction domain (PTD), which allows it to be exogenously delivered across the membrane of mammalian cells, whereupon its transcription activity can be unleashed. Whether NeuroD has therapeutic effects for radiation-induced injury remains unclear. In the present study, we prepared a NeuroD-EGFP recombinant protein and explored its protective effects on the survival and intestinal damage induced by ionizing radiation. Our results showed that NeuroD-EGFP could be transduced into small intestine epithelial cells and tissues. NeuroD-EGFP administration significantly increased overall survival of mice exposed to lethal total body irradiation (TBI). This recombinant NeuroD also reduced radiation-induced intestinal mucosal injury and apoptosis and improved crypt survival. Expression profiling of NeuroD-EGFP-treated mice revealed upregulation of tissue inhibitor of metalloproteinase 1 (TIMP-1), a known inhibitor of apoptosis in mammalian cells. In conclusion, NeuroD confers protection against radiation-induced intestinal injury and provides a novel therapeutic clinical option for the prevention of intestinal side effects of radiotherapy and the treatment of victims of incidental exposure.
A self-healing photoinduced-deformable material fabricated by liquid crystalline elastomers using multivalent hydrogen bonds as cross-linkers
Authors: Ni Bin , Xie He-Lou , Tang Jun , Zhang Hai-Liang , Chen Er-Qiang
Published: July 2016

A self-healing photoinduced-deformable polymeric material using multivalent hydrogen bonds as cross-linkers was successfully fabricated.
Intermolecular iodofunctionalization of allenamides with indoles, pyrroles, and furans: synthesis of iodine-substituted Z-enamides
Authors: Li Honghe , Li Xiaoxiao , Zhao Zhigang , Ma Ting , Sun Chenyang , Yang Bowen
Published: July 2016

A new method was developed to synthesize iodine-substituted Z-enamides through N-iodosuccinimide-mediated intermolecular iodofunctionalization of allenamides with indoles, pyrroles, and furans.
Synthesis of homopropargylamines from 2-cyanoazetidines
Authors: Quinodoz P. , Wright K. , Drouillat B. , David O. , Marrot J. , Couty F.
Published: July 2016

Mild generation of vinylidene carbene from α-amino nitrile is the basis of a new synthesis of homopropargylamines.
Aminotroponiminates as tunable, redox-active ligands: reversible single electron transfer and reductive dimerisation
Authors: Lichtenberg C. , Krummenacher I.
Published: July 2016

Aminotroponiminates are shown to be redox-active ligands with their properties being tunable by choice of the ligand-bound metal.
Interface-enhanced Li ion conduction in a LiBH4–SiO2 solid electrolyte
Authors: Choi Yong Seok , Lee Young-Su , Oh Kyu Hwan , Cho Young Whan
Published: July 2016

We have developed a fast solid state Li ion conductor composed of LiBH4 and SiO2 by means of interface engineering.
Upconverting nanoparticles for the near infrared photoactivation of transition metal complexes: new opportunities and challenges in medicinal inorganic photochemistry
Authors: Ruggiero Emmanuel , Alonso-de Castro Silvia , Habtemariam Abraha , Salassa Luca
Published: July 2016

The article highlights the emergent use of upconverting nanoparticles as tools for the near infrared photoactivation of transition metal complexes.
Contrasting coordination behavior of Group 12 perchlorate salts with an acyclic N3O2donor ligand by X-ray crystallography and1H NMR
Authors: Tice Daniel B. , Pike Robert D. , Bebout Deborah C.
Published: July 2016

Four heteroleptic Group 12 perchlorate complexes of 2,6-bis[((2-pyridinylmethyl)oxy)methyl]pyridine with coordination numbers between six and nine were prepared and investigated.
Effects of equol on deoxycorticosterone acetate salt-induced hypertension and associated vascular dementia in rats
Authors: Liu Te-Hua , Tsai Tsung-Yu
Published: July 2016

Oxidative stress is the major cause of neuronal cell degeneration observed in neurodegenerative diseases including vascular dementia (VaD), and hypertension has been found to increase the probability of VaD.
Design, synthesis and characterization of novel dioxime ligand-based cobaloxime compounds for application in the coupling of CO2 with epoxides
Authors: Kilic Ahmet , Akdag Seyithan , Aytar Emine , Durgun Mustafa , Ulusoy Mahmut
Published: July 2016

Novel dioxime-based cobaloxime complexes have been obtained by click chemistry and used as catalysts for the conversion of CO2 to a cyclic carbonate without using any solvent.
A simple approach for the synthesis of bi-functional Fe3O4@MgO core–shell nanoparticles with magnetic-microwave to heat responsive properties
Authors: Peng Hongxia , Wang Xiang , Hu Chuanyue , Hu Jilin , Tian Xiuying
Published: July 2016

We prepared Fe3O4@MgO nanoparticles with magnetic and microwave to heat responsive properties by a direct precipitation method.
High-affinity host–guest chemistry of large-ring cyclodextrins
Authors: Assaf Khaleel I. , Gabel Detlef , Zimmermann Wolfgang , Nau Werner M.
Published: July 2016

Unprecedented affinities for large-ring cyclodextrins have been achieved with purely inorganic guest molecules (dodecaborate cluster anions).
Aggregation-induced emission polymer nanoparticles with pH-responsive fluorescence
Authors: Zhao Yuming , Zhu Wen , Ren Lixia , Zhang Ke
Published: July 2016

A convenient and efficient method was developed to prepare stable polymer nanoparticles with varied morphology and pH-responsive AIE properties, based on the amphiphilic block copolymer self-assembly, crosslinking, and post-functionalization techniques.
Synthesis of hydrogel polyHIPEs from functionalized glycidyl methacrylate
Authors: Pahovnik David , Majer Janja , Žagar Ema , Kovačič Sebastijan
Published: July 2016

Highly porous hydrogels based on functionalized glycidyl methacrylate (GMA) have been successfully prepared through the high internal phase oil-in-water emulsions.
Effective cementation and removal of arsenic with copper powder in a hydrochloric acid system
Authors: Wu Lian-Kui , Xia Jie , Zhang Yu-Feng , Li Ying-Ying , Cao Hua-Zhen , Zheng Guo-Qu
Published: July 2016

This work investigated the removal and cementation of arsenic from a hydrochloric acid system with copper powder.
Small molecule therapeutic-loaded liposomes as therapeutic carriers: from development to clinical applications
Authors: Hwang Jae Yoon , Li Zibiao , Loh Xian Jun
Published: July 2016

In this review, various methods and mechanisms for encapsulation of small therapeutic molecules in liposomes for targeted delivery and triggered release, as well as their potential in the clinical uses, are discussed.
QSAR aided design and development of biopolymer-based SPE phase for liquid chromatographic analysis of polycyclic aromatic hydrocarbons in environmental water samples
Authors: Okoli Chukwunonso Peter , Adewuyi Gregory Olufemi , Zhang Qian , Guo Qingjun
Published: July 2016

A solid-phase extraction method, using a starch based biopolymer as an adsorbent, coupled with high performance liquid chromatography-fluorescence/UV detectors was developed for the determination of 16 polycyclic aromatic hydrocarbons in environmental water samples.
Multiple value storage based on a nano-electronic–mechanical mechanism using graphene flakes
Authors: Wan Neng , Pan Wei , Tang Shao-chun
Published: July 2016

We report here a nano-electronic–mechanical storage mechanism with graphene flakes (GFs) revealed by in situ transmission electron microscopy observations accompanied by nano-manipulation and probing of electrical properties.
Synthesis and electrochemical performance of Co2TiO4and its core–shell structure of Co2TiO4@C as negative electrodes for Li-ion batteries
Authors: Yuvaraj S. , Vignesh R. Hari , Vasylechko L. , Lee Y. S. , Selvan R. Kalai
Published: July 2016

Spinel Co2TiO4is synthesised using a polymeric precursor method and used as an efficient negative electrode for Li-ion batteries.
Crystallization behaviors of polyarylene ether nitrile filled in multi-walled carbon nanotubes
Authors: You Yong , Wei Renbo , Yang Ruiqi , Yang Wei , Hua Xiufu , Liu Xiaobo
Published: July 2016

The isothermal and dynamic crystallization behaviors of PEN filled in CNT are studied. The PEN filled in CNT cannot crystallize without shearing. By shearing, the shear stress transmits from CNT to the PEN and induces the crystallization of it.
Selective photocatalytic oxidation of aromatic alcohols into aldehydes by tungsten blue oxide (TBO) anchored with Pt nanoparticles
Authors: Qamar M. , Fawakhiry M. O. , Azad A.-M. , Ahmed M. I. , Khan A. , Saleh T. A.
Published: July 2016

Hypostoichiometric Pt/WO3 shows efficient, selective and stable conversion of aromatic alcohols into corresponding aldehydes under simulated sunlight in aqueous solution.
Catalytic effect of CuO nanoplates, a graphene (G)/CuO nanocomposite and an Al/G/CuO composite on the thermal decomposition of ammonium perchlorate
Authors: Fertassi Meriem Amina , Alali Khaled Tawfik , Liu Qi , Li Runze , Liu Pingan , Liu Jingyuan , Liu Lianhe , Wang Jun
Published: July 2016

DTA results show that CuO nanoplates, G/CuO nanocomposite and AL/G/CuO composite have a strong catalytic activity on improving the thermal decomposition of ammonium perchlorate by reducing its HTD from 432 °C to 350 °C, 325 °C, and 315 °C respectively.
Triamidoamine-supported zirconium: hydrogen activation, Lewis acidity, and rac-lactide polymerization
Authors: Leshinski Sarah E. , Wheaton Craig A. , Sun Hongsui , Roering Andrew J. , Tanski Joseph M. , Fox Daniel J. , Hayes Paul G. , Waterman Rory
Published: July 2016

Investigation of a triamidoamine-supported zirconium hydride intermediate, important to a range of catalytic reactions, revealed the potential Lewis acidity of [κ5-N,N,N,N,C-(Me3SiNCH2CH2)2NCH2CH2NSiMe2CH2]Zr (1).
Methanation of residual syngas after LPG synthesis: identifying the main effects on catalytic performance with Plackett–Burman screening design
Authors: Krebs Florian , Bliznuk Vitaliy , Baik Joon Hyun , Palkovits Regina , Simeonov Kalin
Published: July 2016

Seven factors in catalyst development were selected and rated towards their impact on methanation as a downstream process.
Au–Pt alloy nanoparticles site-selectively deposited on CaIn2S4nanosteps as efficient photocatalysts for hydrogen production
Authors: Ding Jianjun , Li Xiangyang , Chen Lin , Zhang Xian , Sun Song , Bao Jun , Gao Chen , Tian Xingyou
Published: July 2016

Au–Pt/CaIn2S4composites were site-selectively synthesized for the first time and demonstrated to show excellent visible photocatalytic activity for hydrogen production compared to that of CaIn2S4, Au/CaIn2S4and Pt/CaIn2S4.
Interlaced NiS2–MoS2 nanoflake-nanowires as efficient hydrogen evolution electrocatalysts in basic solutions
Authors: An Tiance , Wang Yang , Tang Jing , Wei Wei , Cui Xiaoqi , Alenizi Abdullah M. , Zhang Lijuan , Zheng Gengfeng
Published: July 2016

NiS2–MoS2 interlaced nanoflake-nanowires were synthesized by the thermal conversion of NiMoO4 nanowire precursors as attractive hydrogen evolution catalysts in basic solutions.
Investigation of an erasing method for synaptic behaviour in a phase change device using Ge1Cu2Te3 (GCT)
Authors: An J.S. , Choi C.M. , Shindo Y. , Sutou Y. , Jeong H.S. , Song Y.H.
Published: July 2016

The gradual erasing operation from reset state to set state adjusting pulse amplitude, duration time and falling time respectively in phase change device using Ge1Cu2Te3 is investigated. For this procedure, a relatively high voltage and increased falling time, which was able to produce both long‐term potential and long‐term depression in the time interval between pre‐spike and post‐spike is choosing. The results suggested that the presence of synaptic behaviour was due to controlled falling time rather than pulse amplitude.
Energy‐aware quality of information maximisation for wireless sensor networks
Authors: Du Pengfei , Yang Qinghai , He Qingsu , Kwak Kyung Sup
Published: July 2016

In this study, the authors investigate the energy‐aware quality of information (QoI) maximisation problem by jointly optimising the sensor selection, sampling rate, packet‐dropped rate, and transmit power in wireless sensor networks. By introducing the weight parameters, the authors first present a revenue‐cost (RC) function which combines the optimisation objectives of the QoI and energy expenditure into a single objective to capture the tradeoff between them. Then, a stochastic optimisation programming is formulated to maximise the long‐term average RC value subject to the network stability constraint. Using the Lyapunov drift theory, the authors develop a collaborative sensing and transmit power control algorithm that can guarantee the worst‐case delay for each packet. Simulation results demonstrate the advantages of the proposed algorithm.
Joint complex regularised zero‐forcing equalisation and CFO compensation for MIMO SC‐FDMA systems
Authors: Mostafa Mohamed , Newagy Fatma , Hafez Ismail
Published: July 2016

In single carrier frequency division multiple access (SC‐FDMA) systems, frequency domain equalisers suffer performance degradation due to several channel impairments such as inter‐symbol interference, inter‐carrier interference (ICI), especially in multiple access/multiple input multiple output (MIMO) systems. This study presents a joint complex regularised zero forcing (JCRZF) equaliser that is able to compensate the channel impairments and to mitigate the ICI induced by the carrier frequency offset (CFO) in mobile channel environments. JCRZF equaliser is also able to eliminate the inter antenna interference resulting from the MIMO channel coupling by transforming the MIMO channel into equivalent SISO channels. Simulation results show that the JCRZF equaliser outperforms ZF based equalisers in terms of bit error rate while preserving their potential complexity and appropriate robustness to CFO estimation errors.
Reactive power control of DFIG wind turbines for power oscillation damping under a wide range of operating conditions
Authors: Edrah Mohamed , Lo Kwok L. , Anaya‐Lara Olimpo
Published: July 2016

This study analyses the effect of replacing existing synchronous generators (SGs) equipped with power system stabilisers (PSS) by doubly fed induction generator (DFIG) based wind farms on the damping of power system oscillations in a multi‐machine power system. A power system stabiliser was designed to enhance the capability of DFIG to damp power systems oscillations. The validity and effectiveness of the proposed controller are demonstrated on the widely used New England 10‐machine 39‐bus test system that combines conventional SGs and DFIG based wind farms using eigenvalue analysis and non‐linear simulation. The non‐linear simulation is used to demonstrate how the damping contribution of DFIG based wind farms is affected by different operating conditions within the same wind farm and stochastic wind speed behaviour. The results show that installing conventional fixed parameters PSS within reactive power control loop of DFIG rotor side converter has a positive damping contribution for a wide range of operating conditions. Furthermore, the results clearly show that DFIG based wind farms equipped with the proposed farm level PSS can damp power system oscillations more effectively than SGs PSS.
Optimal placement and sizing of DGs in RDS using chaos embedded SOS algorithm
Authors: Saha Subhodip , Mukherjee Vivekananda
Published: July 2016

Distributed generators (DGs) play an important role to reduce the real power loss and to improve the voltage stability of the power system. However, proper placement and sizing of DGs in the distribution network is a vital issue, as any improper location and size of DGs may increase the overall system loss. In this study, a novel chaotic symbiotic organisms search (CSOS) algorithm is proposed to find out the optimal location and sizes of real power DGs in a radial distribution system (RDS) considering constant load models. This DG siting and sizing problem is associated with real power loss minimisation and voltage stability improvement objectives. The effectiveness of the proposed algorithm is tested on benchmark test functions as well as on 33‐, 69‐ and 118‐bus RDS. The simulation results obtained by the proposed CSOS algorithm are compared with the results offered by the basic SOS and other nature inspired algorithms to establish the superiority of the proposed CSOS algorithm over the others in terms of quality of solution and convergence mobility.
Electro- and photoluminescence imaging as fast screening technique of the layer uniformity and device degradation in planar perovskite solar cells
Authors: Soufiani Arman Mahboubi , Tayebjee Murad J. Y. , Meyer Steffen , Ho-Baillie Anita , Sung Yun Jae , MacQueen Rowan W. , Spiccia Leone , Green Martin A. , Hameiri Ziv
Published: July 2016

In this study, we provide insights into planar structure methylammonium lead triiodide (MAPbI3) perovskite solar cells (PSCs) using electroluminescence and photoluminescence imaging techniques. We demonstrate the strength of these techniques in screening relatively large area PSCs, correlating the solar cell electrical parameters to the images and visualizing the features which contribute to the variation of the parameters extracted from current density-voltage characterizations. It is further used to investigate one of the major concerns about perovskite solar cells, their long term stability and aging. Upon storage under dark in dry glovebox condition for more than two months, the major parameter found to have deteriorated in electrical performance measurements was the fill factor; this was elucidated via electroluminescence image comparisons which revealed that the contacts' quality degrades. Interestingly, by deploying electroluminescence imaging, the significance of having a pin-hole free active layer is demonstrated. Pin-holes can grow over time and can cause degradation of the active layer surrounding them.
Design of compact Marx module with square pulse output
Authors: Liu Hongwei , Xie Weiping , Yuan Jianqiang , Wang Lingyun , Ma Xun , Jiang Ping
Published: July 2016

Compact pulsed power system based on compact Marx generator is widely used in terms of drive resistance and capacitive loads. This system usually adopts high performance components such as high energy density capacitors, compact switches, and integrated structure. Traditional compact Marx generator can only output double-exponential pulse profile. In this paper a compact, low-impedance Marx module which can output rectangular pulse profile is design and tested. This module has multiple circuits of different discharge frequencies in parallel to generate quasi-rectangular pulse. Discharge characteristic of an ideal module with infinite branches is calculated theoretically. A module with two branches has been designed and tested. Test results show that the impedance of the module is 1.2 Ω. When charging voltage is 100.6 kV and load resistance is 1 Ω, the peak output pulse is 45.2 kV voltage, the peak power is about 2 GW, the pulse width is about 130 ns, and the rise time is about 35 ns. The energy density and power density of the module are 15 kJ/m3 and 140 GW/m3, respectively.
Temperature scaling of effective polaron mobility in energetically disordered media
Authors: Seki Kazuhiko , Wojcik Mariusz
Published: July 2016

We study effective mobility in 2 dimensional (2D) and 3 dimensional (3D) systems, where hopping transitions of carriers are described by the Marcus equation under a Gaussian density of states in the dilute limit. Using an effective medium approximation (EMA), we determined the coefficient Cd for the effective mobility expressed by μeff∝exp−λ/4kBT−Cdσ2/kBT2/λ(kBT)3/2, where λ is the reorganization energy, σ is the standard deviation of the Gaussian density of states, and kBT takes its usual meaning. We found Cd = 1/2 for both 2D and 3D. While various estimates of the coefficient Cd for 3D systems are available in the literature, we provide for the first time the expected Cd value for a 2D system. By means of kinetic Monte-Carlo simulations, we show that the effective mobility is well described by the equation shown above under certain conditions on λ. We also give examples of analysis of experimental data for 2D and 3D systems based on our theoretical results.
Black holes, information, and the universal coefficient theorem
Authors: Patrascu Andrei T.
Published: July 2016

General relativity is based on the diffeomorphism covariant formulation of the laws of physics while quantum mechanics is based on the principle of unitary evolution. In this article, I provide a possible answer to the black hole information paradox by means of homological algebra and pairings generated by the universal coefficient theorem. The unitarity of processes involving black holes is restored by the demanding invariance of the laws of physics to the change of coefficient structures in cohomology.
Nanocrystalline Cu2ZnSnSe4 thin films for solar cells application: Microdiffraction and structural characterization
Authors: Quiroz Heiddy P. , Dussan A.
Published: July 2016

This work presents a study of the structural characterization of Cu2ZnSnSe4 (CZTSe) thin films by X-ray diffraction (XRD) and microdiffraction measurements. Samples were deposited varying both mass (MX) and substrate temperature (TS) at which the Cu and ZnSe composites were evaporated. CZTSe samples were deposited by co-evaporation method in three stages. From XRD measurements, it was possible to establish, with increased Ts, the presence of binary phases associated with the quaternary composite during the material's growth process. A stannite-type structure in Cu2ZnSnSe4 thin films and sizes of the crystallites varying between 30 and 40 nm were obtained. X-ray microdiffraction was used to investigate interface orientations and strain distributions when deposition parameters were varied. It was found that around the main peak, 2ϴ = 27.1°, the Cu1.8Se and ZnSe binary phases predominate, which are formed during the subsequent material selenization stage. A Raman spectroscopy study revealed Raman shifts associated with the binary composites observed via XRD.
Configurational entropy of polar glass formers and the effect of electric field on glass transition
Authors: Matyushov Dmitry V.
Published: July 2016

A model of low-temperature polar liquids is constructed that accounts for the configurational heat capacity, entropy, and the effect of a strong electric field on the glass transition. The model is based on the Padé-truncated perturbation expansions of the liquid state theory. Depending on parameters, it accommodates an ideal glass transition of vanishing configurational entropy and its avoidance, with a square-root divergent enumeration function at the point of its termination. A composite density-temperature parameter ργ/T, often used to represent combined pressure and temperature data, follows from the model. The theory is in good agreement with the experimental data for excess (over the crystal state) thermodynamics of molecular glass formers. We suggest that the Kauzmann entropy crisis might be a signature of vanishing configurational entropy of a subset of degrees of freedom, multipolar rotations in our model. This scenario has observable consequences: (i) a dynamical crossover of the relaxation time and (ii) the fragility index defined by the ratio of the excess heat capacity and excess entropy at the glass transition. The Kauzmann temperature of vanishing configurational entropy and the corresponding glass transition temperature shift upward when the electric field is applied. The temperature shift scales quadratically with the field strength.
Enhanced piezoelectricity in plastically deformed nearly amorphous Bi12TiO20-BaTiO3 nanocomposites
Authors: Yu Dan , Zhao Minglei , Wang Chunlei , Wang Lihai , Su Wenbin , Gai Zhigang , Wang Chunming , Li Jichao , Zhang Jialiang
Published: July 2016

Bulk Bi12TiO20-BaTiO3 (BTO-BT) nanocomposites are fabricated through the high-temperature interfacial reaction between nanometer-sized BaTiO3 particles and melting Bi12TiO20. Although the obtained BTO-BT nanocomposites are nearly amorphous and display very weak ferroelectricity, they exhibit relatively strong piezoelectricity without undergoing the electrical poling process. The volume fraction of crystalline Bi12TiO20 is reduced to less than 10%, and the piezoelectric constant d33 is enhanced to 13 pC/N. Only the presence of the macroscopic polar amorphous phases can explain this unusual thermal stable piezoelectricity. Combining the results from X-ray diffraction, Raman spectroscopy, and thermal annealing, it can be confirmed that the formation of macroscopic polar amorphous phases is closely related to the inhomogeneous plastic deformation of the amorphous Bi12TiO20 during the sintering process. These results highlight the key role of plastically deformed amorphous Bi12TiO20 in the Bi12TiO20-based polar composites, and the temperature gradient driven coupling between the plastic strain gradient and polarization in amorphous phases is the main poling mechanism for this special type of bulk polar material.
Determination of band offsets at GaN/single-layer MoS2 heterojunction
Authors: Tangi Malleswararao , Mishra Pawan , Ng Tien Khee , Hedhili Mohamed Nejib , Janjua Bilal , Alias Mohd Sharizal , Anjum Dalaver H. , Tseng Chien-Chih , Shi Yumeng , Joyce Hannah J. , Li Lain-Jong , Ooi Boon S.
Published: July 2016

We report the band alignment parameters of the GaN/single-layer (SL) MoS2 heterostructure where the GaN thin layer is grown by molecular beam epitaxy on CVD deposited SL-MoS2/c-sapphire. We confirm that the MoS2 is an SL by measuring the separation and position of room temperature micro-Raman E12g and A1g modes, absorbance, and micro-photoluminescence bandgap studies. This is in good agreement with HRTEM cross-sectional analysis. The determination of band offset parameters at the GaN/SL-MoS2 heterojunction is carried out by high-resolution X-ray photoelectron spectroscopy accompanying with electronic bandgap values of SL-MoS2 and GaN. The valence band and conduction band offset values are, respectively, measured to be 1.86 ± 0.08 and 0.56 ± 0.1 eV with type II band alignment. The determination of these unprecedented band offset parameters opens up a way to integrate 3D group III nitride materials with 2D transition metal dichalcogenide layers for designing and modeling of their heterojunction based electronic and photonic devices.
Unconventional ratiometric-enhanced optical sensing of oxygen by mixed-phase TiO2
Authors: Lettieri S. , Pallotti D. K. , Gesuele F. , Maddalena P.
Published: July 2016

We show that mixed-phase titanium dioxide (TiO2) can be effectively employed as an unconventional, inorganic, dual-emitting, and ratiometric optical sensor of O2. Simultaneous availability of rutile and anatase TiO2 photoluminescence (PL) and their peculiar “anti-correlated” PL responses to O2 allow using their ratio as a measurement parameter associated with the O2 concentration, leading to an experimental responsivity being by construction larger than the one obtainable for single-phase PL detection. A proof of this concept is given, showing a two-fold enhancement of the optical responsivity provided by the ratiometric approach. Besides the peculiar ratiometric-enhanced responsivity, other characteristics of mixed phase TiO2 can be envisaged as favorable for O2 optical probing, namely (a) low production costs, (b) absence of heterogeneous components, and (c) self-supporting properties. These characteristics encourage experimenting with its use for applications requiring high indicator quantities at a competitive price, possibly also tackling the need to develop supporting matrixes that carry the luminescent probes and avoiding issues related to the use of different components for ratiometric sensing.
High-performance silicon nanowire bipolar phototransistors
Authors: Tan Siew Li , Zhao Xingyan , Chen Kaixiang , Crozier Kenneth B. , Dan Yaping
Published: July 2016

Silicon nanowires (SiNWs) have emerged as sensitive absorbing materials for photodetection at wavelengths ranging from ultraviolet (UV) to the near infrared. Most of the reports on SiNW photodetectors are based on photoconductor, photodiode, or field-effect transistor device structures. These SiNW devices each have their own advantages and trade-offs in optical gain, response time, operating voltage, and dark current noise. Here, we report on the experimental realization of single SiNW bipolar phototransistors on silicon-on-insulator substrates. Our SiNW devices are based on bipolar transistor structures with an optically injected base region and are fabricated using CMOS-compatible processes. The experimentally measured optoelectronic characteristics of the SiNW phototransistors are in good agreement with simulation results. The SiNW phototransistors exhibit significantly enhanced response to UV and visible light, compared with typical Si p-i-n photodiodes. The near infrared responsivities of the SiNW phototransistors are comparable to those of Si avalanche photodiodes but are achieved at much lower operating voltages. Compared with other reported SiNW photodetectors as well as conventional bulk Si photodiodes and phototransistors, the SiNW phototransistors in this work demonstrate the combined advantages of high gain, high photoresponse, low dark current, and low operating voltage.
Hiding objects in AC magnetic fields of power grid frequency by two-shell ferromagnetic/superconducting cloak
Authors: Šouc J. , Solovyov M. , Gömöry F.
Published: July 2016

Performance of magnetic cloak made from commercially available materials has been tested by verifying its ability to suppress the magnetic signatures of metallic and ferromagnetic objects. The range of magnetic field amplitudes from 0.1 to 10 mT and frequencies around 50–60 Hz were used. The cloak combines the inner tube from high-temperature superconductor that should be cooled by liquid nitrogen, with the outer tube made from MnZn ferrite powder mixed in plastic matter. Superconductor is in the form of tapes wound in helical manner on a round former. Such design is promising when the objects with dimensions reaching several centimeters should be cloaked. Performance of the small model manufactured following this design was demonstrated by observing ∼20 times reduction of the magnetic signature of metallic or ferromagnetic objects.
Direct targeting of membrane fusion by SNARE mimicry: Convergent evolution ofLegionellaeffectors
Authors: Shi Xingqi , Halder Partho , Yavuz Halenur , Jahn Reinhard , Shuman Howard A.
Published: July 2016

Significance

Legionellapneumophila, the bacterium causing Legionnaires’ disease, invades lung cells by creating intracellular vacuoles where it is protected and where it can multiply. For expansion, the vacuoles must hijack intracellular vesicles while avoiding destruction by lysosomes. To achieve these goals,Legionellaexports effector proteins into the cytoplasm and into the membrane of the vacuole. Here we report that certainLegionellaeffectors mimic intracellular fusion proteins of the SNARE family, allowing them to selectively fuse with specific intracellular transport vesicles, thus providing more space for the dividing bacteria. In contrast to SNAREs, however, theLegionellaproteins can be used only once, thus allowing the bacteria to control the amount of hijacked vesicles.
Selectivity of ORC binding sites and the relation to replication timing, fragile sites, and deletions in cancers
Authors: Miotto Benoit , Ji Zhe , Struhl Kevin
Published: July 2016

Significance

The origin recognition complex (ORC) binds sites from which DNA replication is initiated. By mapping binding sites in human cells, we show that ORC binds selectively to open (DNase I-hypersensitive) regions containing active chromatin marks. There are far more ORC sites in early replicating regions of the genome, and computational simulation based on ORC binding indicates that replication timing is due primarily to ORC density and stochastic initiation of DNA replication from origins. Large genomic regions with a paucity of ORC sites are strongly associated with common fragile sites and recurrent deletions in cancers. Thus, replication origins, replication timing, and replication-dependent chromosome breaks are determined ultimately by the genomic distribution of activator proteins at enhancers and promoters.