bluuebunny/crossref_metadata_2025 huggingface dataset:
The mRNA capping enzyme of Saccharomyces cerevisiae has dual specificity to interact with CTD of RNA Polymerase II
Authors: Bharati Akhilendra Pratap , Singh Neha , Kumar Vikash , Kashif Md. , Singh Amit Kumar , Singh Priyanka , Singh Sudhir Kumar , Siddiqi Mohammad Imran , Tripathi Timir , Akhtar Md. Sohail
Published: August 2016

RNA Polymerase II (RNAPII) uniquely possesses an extended carboxy terminal domain (CTD) on its largest subunit, Rpb1, comprising a repetitive Tyr1Ser2Pro3Thr4 Ser5Pro6Ser7 motif with potential phosphorylation sites. The phosphorylation of the CTD serves as a signal for the binding of various transcription regulators for mRNA biogenesis including the mRNA capping complex. In eukaryotes, the 5 prime capping of the nascent transcript is the first detectable mRNA processing event and is crucial for the productive transcript elongation. The binding of capping enzyme, RNA guanylyltransferases to the transcribing RNAPII is known to be primarily facilitated by the CTD, phosphorylated at Ser5 (Ser5P). Here we report that the Saccharomyces cerevesiae RNA guanylyltransferase (Ceg1) has dual specificity and interacts not only with Ser5P but also with Ser7P of the CTD. The Ser7 of CTD is essential for the unconditional growth and efficient priming of the mRNA capping complex. The Arg159 and Arg185 of Ceg1 are the key residues that interact with the Ser5P, while the Lys175 with Ser7P of CTD. These interactions appear to be in a specific pattern of Ser5PSer7PSer5P in a tri-heptad CTD (YSPTSPPS YSPTSPSPYSPTSPPS) and provide molecular insights into the Ceg1-CTD interaction for mRNA transcription.
Nanolithography using Bessel Beams of Extreme Ultraviolet Wavelength
Authors: Fan Daniel , Wang Li , Ekinci Yasin
Published: August 2016

Bessel beams are nondiffracting light beams with large depth-of-focus and self-healing properties, making them suitable as a serial beam writing tool over surfaces with arbitrary topography. This property breaks the inherent resolution vs. depth-of-focus tradeoff of photolithography. One approach for their formation is to use circularly symmetric diffraction gratings. Such a ring grating was designed and fabricated for the extreme ultraviolet (EUV) wavelength of 13.5 nm, a candidate wavelength for future industrial lithography. Exposure of the aerial images showed that a Bessel beam with an approximately 1 mm long z-invariant central core of 223 nm diameter had been achieved, in good agreement with theory. Arbitrary patterns were written using the Bessel spot, demonstrating possible future application of Bessel beams for serial beam writing. Lithographic marks of ~30 nm size were also observed using a high resolution Bessel beam.
Environmental selection of planktonic methanogens in permafrost thaw ponds
Authors: Crevecoeur Sophie , Vincent Warwick F. , Lovejoy Connie
Published: August 2016

The warming and thermal erosion of ice-containing permafrost results in thaw ponds that are strong emitters of methane to the atmosphere. Here we examined methanogens and other Archaea, in two types of thaw ponds that are formed by the collapse of either permafrost peat mounds (palsas) or mineral soil mounds (lithalsas) in subarctic Quebec, Canada. Using high-throughput sequencing of a hypervariable region of 16S rRNA, we determined the taxonomic structure and diversity of archaeal communities in near-bottom water samples, and analyzed the mcrA gene transcripts from two sites. The ponds at all sites were well stratified, with hypoxic or anoxic bottom waters. Their archaeal communities were dominated by Euryarchaeota, specifically taxa in the methanogenic orders Methanomicrobiales and Methanosarcinales, indicating a potentially active community of planktonic methanogens. The order Methanomicrobiales accounted for most of the mcrA transcripts in the two ponds. The Archaeal communities differed significantly between the lithalsa and palsa ponds, with higher alpha diversity in the organic-rich palsa ponds, and pronounced differences in community structure. These results indicate the widespread occurrence of planktonic, methane-producing Archaea in thaw ponds, with environmental selection of taxa according to permafrost landscape type.
p-Hydroxylcinnamaldehyde induces the differentiation of oesophageal carcinoma cells via the cAMP-RhoA-MAPK signalling pathway
Authors: Ma Ming , Zhao Lian-mei , Yang Xing-xiao , Shan Ya-nan , Cui Wen-xuan , Chen Liang , Shan Bao-en
Published: August 2016

p-Hydroxylcinnamaldehyde (CMSP) has been identified as an inhibitor of the growth of various cancer cells. However, its function in oesophageal squamous cell carcinoma (ESCC) and the underlying mechanism remain unclear. The aim of the present study was to characterize the differentiation effects of CMSP, as well as its mechanism in the differentiation of ESCC Kyse30 and TE-13 cells. The function of CMSP in the viability, colony formation, migration and invasion of Kyse30 and TE-13 cells was determined by MTS, colony-formation, wound healing and transwell assays. Western blotting and pull-down assays were used to investigate the effect of CMSP on the expression level of malignant markers of ESCC, as well as the activity of MAPKs, RhoA and GTP-RhoA in Kyse30 and TE-13 cells. We found that CMSP could inhibit proliferation and migration and induce Kyse30 and TE-13 cell differentiation, characterized by dendrite-like outgrowth, decreased expression of tumour-associated antigens, as well as the decreased expression of malignant markers. Furthermore, increased cAMP, p-P38 and decreased activities of ERK, JNK and GTP-RhoA, were detected after treatment with CMSP. These results indicated that CMSP induced the differentiation of Kyse30 and TE-13 cells through mediating the cAMP-RhoA-MAPK axis, which might provide new potential strategies for ESCC treatment.
Japanese secular trends in birthweight and the prevalence of low birthweight infants during the last three decades: A population-based study
Authors: Takemoto Yo , Ota Erika , Yoneoka Daisuke , Mori Rintaro , Takeda Satoru
Published: August 2016

Since low birthweight has been correlated with both neonatal and long-term health, we performed this epidemiological study to evaluate the Japanese secular trends in mean birthweight and the prevalence of preterm/term low birthweight infants during the last three decades. We used population-based birth certificate data from January 1979 to December 2010. Time trends were analysed using a linear regression model. During the study period, we observed a significant decrease in the mean birthweight for singleton live births (3,152 ± 436 g in 1979 and 3,018 ± 421 g in 2010 p < 0.001) and an increase in the prevalence of preterm/term low birthweight infants. A 96.3% increase in the proportion of term low birthweight infants was observed during the study period (2.7% in 1979 and 5.3% in 2010). In addition, an increased proportion of preterm/low birthweight infants born to younger women was observed (<35 years vs. ≥35 years). These trends may be related to changing patterns in Japanese women’s nutritional status and the relatively strict recommended limit on weight gain during pregnancy. Understanding the long-term trends for singleton births may allow us to identify the associated risk factors and reduce the future socioeconomic burden that is associated with low birthweight infants.
A hole inversion layer at the BiVO4/Bi4V2O11 interface produces a high tunable photovoltage for water splitting
Authors: dos Santos Wayler S. , Rodriguez Mariandry , Afonso André S. , Mesquita João P. , Nascimento Lucas L. , Patrocínio Antônio O. T. , Silva Adilson C. , Oliveira Luiz C. A. , Fabris José D. , Pereira Márcio C.
Published: August 2016

The conversion of solar energy into hydrogen fuel by splitting water into photoelectrochemical cells (PEC) is an appealing strategy to store energy and minimize the extensive use of fossil fuels. The key requirement for efficient water splitting is producing a large band bending (photovoltage) at the semiconductor to improve the separation of the photogenerated charge carriers. Therefore, an attractive method consists in creating internal electrical fields inside the PEC to render more favorable band bending for water splitting. Coupling ferroelectric materials exhibiting spontaneous polarization with visible light photoactive semiconductors can be a likely approach to getting higher photovoltage outputs. The spontaneous electric polarization tends to promote the desirable separation of photogenerated electron- hole pairs and can produce photovoltages higher than that obtained from a conventional p-n heterojunction. Herein, we demonstrate that a hole inversion layer induced by a ferroelectric Bi4V2O11 perovskite at the n-type BiVO4 interface creates a virtual p-n junction with high photovoltage, which is suitable for water splitting. The photovoltage output can be boosted by changing the polarization by doping the ferroelectric material with tungsten in order to produce the relatively large photovoltage of 1.39 V, decreasing the surface recombination and enhancing the photocurrent as much as 180%.
Quantitative trait gene Slit2 positively regulates murine hematopoietic stem cell numbers
Authors: Waterstrat Amanda , Rector Kyle , Geiger Hartmut , Liang Ying
Published: August 2016

Hematopoietic stem cells (HSC) demonstrate natural variation in number and function. The genetic factors responsible for the variations (or quantitative traits) are largely unknown. We previously identified a gene whose differential expression underlies the natural variation of HSC numbers in C57BL/6 (B6) and DBA/2 (D2) mice. We now report the finding of another gene, Slit2, on chromosome 5 that also accounts for variation in HSC number. In reciprocal chromosome 5 congenic mice, introgressed D2 alleles increased HSC numbers, whereas B6 alleles had the opposite effect. Using gene array and quantitative polymerase chain reaction, we identified Slit2 as a quantitative trait gene whose expression was positively correlated with the number of HSCs. Ectopic expression of Slit2 not only increased the number of the long-term colony forming HSCs, but also enhanced their repopulation capacity upon transplantation. Therefore, Slit2 is a novel quantitative trait gene and a positive regulator of the number and function of murine HSCs. This finding suggests that Slit2 may be a potential therapeutic target for the effective in vitro and in vivo expansion of HSCs without compromising normal hematopoiesis.
N-Heterocyclic carbene phosphaketene adducts as precursors to carbene–phosphinidene adducts and a rearranged π-system
Authors: Li Zhongshu , Chen Xiaodan , Li Yaqi , Su Cheng-Yong , Grützmacher Hansjörg
Published: August 2016

Sodium phosphaethynolate, Na(OCP), is demonstrated to be successful for the synthesis of NHC–phosphinidene adducts and a linear π-conjugated molecule.
Photochemistry of Zr-based MOFs: ligand-to-cluster charge transfer, energy transfer and excimer formation, what else is there?
Authors: Gutierrez Mario , Cohen Boiko , Sánchez Félix , Douhal Abderrazzak
Published: August 2016

A photoexcited Zr-based MOF having two different linkers shows excimer formation, energy transfer and ligand-to-cluster charge transfer reactions.
A novel 1,3,5-triaminocyclohexane-based tripodal ligand forms a unique tetra(pyrazolate)-bridged tricopper(ii) core: solution equilibrium, structure and catecholase activity
Authors: Szorcsik Attila , Matyuska Ferenc , Bényei Attila , Nagy Nóra V. , Szilágyi Róbert K. , Gajda Tamás
Published: August 2016

A polydentate tripodal ligand forms a series of tricopper(ii) complexes, that feature unique pyrazolate-bridged linear core. The Cu3H−3L2complex is an efficient catecholase mimic with a surprisingly low pH optimum at pH = 5.6.
Hierarchical design of synthetic gel composites optimized to mimic the impact energy dissipation response of brain tissue
Authors: Qing Bo , Van Vliet Krystyn J.
Published: August 2016

Bilayered polymer design significantly enhances mechanical tunability, allowing the composite to replicate the impact energy dissipation response of brain tissue.
Panchromatic chromophore–tetrapyrrole light-harvesting arrays constructed from Bodipy, perylene, terrylene, porphyrin, chlorin, and bacteriochlorin building blocks
Authors: Hu Gongfang , Liu Rui , Alexy Eric J. , Mandal Amit Kumar , Bocian David F. , Holten Dewey , Lindsey Jonathan S.
Published: August 2016

Five new chromophore–tetrapyrrole arrays bearing an ethynyl linker have been synthesized to explore the effects of chromophore nature and tetrapyrrole attachment site on panchromatic spectral properties.
Total synthesis based on the originally claimed structure of mucosin
Authors: Gallantree-Smith Harrison C. , Antonsen Simen G. , Görbitz Carl H. , Hansen Trond V. , Nolsøe Jens M. J. , Stenstrøm Yngve H.
Published: August 2016

The first total synthesis aimed at the naturally occurring eicosanoid bicycle mucosin is reported. A practical synthesis has been devised giving full control of stereochemistry.
Unique quenching of fluorescent copper nanoclusters based on target-induced oxidation effect: a simple, label-free, highly sensitive and specific bleomycin assay
Authors: Li Haiyin , Wang Chuanfeng , Gai Panpan , Hou Ting , Ge Lei , Li Feng
Published: August 2016

A novel label-free fluorescence biosensor for bleomycin (BLM) detection was developed by combining the excellent fluorescence behavior of copper nanoclusters (CuNCs) and the unique oxidation capability of BLM–Fe2+ complex toward CuNCs.
Catalytic conversion of cellulose for efficient ethylene glycol production and insights into the reaction pathways
Authors: Zhang Kai , Wu Shubin , Yang He , Yin Huimin , Li Gang
Published: August 2016

A highly active mixed catalyst consisting of PTA and Ru/AC was used for one-pot hydrothermal conversion of cellulose for EG production, and insights into the reaction pathways were obtained with the aid of cellobiose as a model compound.
Self-assembled nanoparticles covalently consisting of doxorubicin and EDB fibronectin specific peptide for solid tumour treatment
Authors: Han G. Y. , Cui Z. , Guo B. , Mei X. F.
Published: August 2016

We developed a facile modality to prepare nanoparticles consisting of doxorubicin and ZD2 motif for treating solid tumours. The nanoparticles showed great preferential cellular uptake in PC3 cells, high cell suppression, and strong anti-tumour ability.
Hydrophobic mesoporous adsorbent based on cyclic amine–divinylbenzene copolymer for highly efficient siloxane removal
Authors: Noshadi Iman , Kanjilal Baishali , Jafari Tahereh , Moharreri Ehsan , Khakpash Nasser , Jiang Ting , Suib Steven L.
Published: August 2016

This paper presents a new class of octamethylcyclotetrasiloxane (D4 siloxane) adsorbent based on the copolymer of divinylbenzene and a novel methacrylate monomer.
Strain effects on the electronic and transport properties of TiO2 nanotubes
Authors: Yu Xiaohui , Dong Huilong , Wang Lu , Li Youyong
Published: August 2016

The band gap of TiO2 nanotubes can be effectively reduced or enhanced by applying isotropic strain along the axial direction. ΔE for the armchair (n,n) TiO2 nanotubes is reduced with tensile strain.
Enhancing mechanical performance of epoxy thermosets via designing a block copolymer to self-organize into “core–shell” nanostructure
Authors: Heng Zhengguang , Zeng Zhong , Zhang Bin , Luo Yinfu , Luo Jiemin , Chen Yang , Zou Huawei , Liang Mei
Published: August 2016

A rigid-flexible amphiphilic pentablock copolymer, polystyrene-block-poly(ε-caprolactone)-block-polydimethylsiloxane-block-poly(ε-caprolactone)-block-polystyrene (PS-PCL-PDMS-PCL-PS, SLDLS), was designed.
Carbon nitride quantum dot-based chemiluminescence resonance energy transfer for iodide ion sensing
Authors: Fan Xiaoqing , Su Yingying , Deng Dongyan , Lv Yi
Published: August 2016

Schematic illustration of the CL process and mechanism of Ce(iv)–sulfite and g-CNQDs–Ce(iv)–sulfite system.
Improved dispersibility of nano-graphene oxide by amphiphilic polymer coatings for biomedical applications
Authors: Imani Rana , Shao Wei , Emami Shahriar Hojjati , Faghihi Shahab , Prakash Satya
Published: August 2016

The poor dispersibility of graphene-based nano-materials in aqueous media is a crucial limitation in their biological applications.
New zinc(ii) dyes with enhanced two-photon absorption cross sections based on the imidazolyl ligand
Authors: Liu Dan , Zhang Na , Zhang Xinyu , Kong Shuai , Yu Jianhua , Wu Zhichao , Wu Jieying , Tian Yupeng , Zhou Hongping
Published: August 2016

The effective TPA cross sections of Dyes 1–3 revealed that the exceeding TPA behavior may attributed to form the new D–π–A type compound that enhanced the intramolecular ICT progress. Dyes 1–3 were successfully applied in bio-imaging.
Toward synergy of carbon and La2O3 in their hybrid as an efficient catalyst for the oxygen reduction reaction
Authors: Wang Nan , Liu Jingjun , Gu Weiwei , Song Ye , Wang Feng
Published: August 2016

The interficial covalent bonds formed in La2O3/C hybrid are responsible for its enhanced ORR activity.
3-Aminopropyltrimethoxysilane and graphene oxide/reduced graphene oxide-induced generation of gold nanoparticles and their nanocomposites: electrocatalytic and kinetic activity
Authors: Pandey P. C. , Shukla Shubhangi , Pandey Yashashwa
Published: August 2016

The role of graphene oxide (GO)/reduced graphene oxide (rGO) in the 3-aminopropyltrimethoxysilane-mediated synthesis of gold nanoparticles in the presence of formaldehyde is reported.
Bridging the performance gap between electric double-layer capacitors and batteries with high-energy/high-power carbon nanotube-based electrodes
Authors: Coromina Helena Matabosch , Adeniran Beatrice , Mokaya Robert , Walsh Darren A.
Published: August 2016

The energy/power density of EDLCs containing high surface area carbon nanotube-based electrodes bridges the performance gap between conventional EDLCs and batteries.
Conformal oxide nanocoatings on electrodeposited 3D porous Ni films by atomic layer deposition
Authors: Zhang J. , Coll M. , Puig T. , Pellicer E. , Sort J.
Published: August 2016

A versatile chemical synthesis procedure to obtain Al2O3and Co2FeO4nanolayers by conformally coating a three-dimensional (3D) porous Ni film is presented.
Gsk3β and Tomm20 are substrates of the SCFFbxo7/PARK15 ubiquitin ligase associated with Parkinson's disease
Authors: Teixeira Felipe Roberti , Randle Suzanne J. , Patel Shachi P. , Mevissen Tycho E.T. , Zenkeviciute Grasilda , Koide Tie , Komander David , Laman Heike
Published: August 2016

Fbxo7 is a clinically relevant F-box protein, associated with both cancer and Parkinson's disease (PD). Additionally, SNPs within FBXO7 are correlated with alterations in red blood cell parameters. Point mutations within FBXO7 map within specific functional domains, including near its F-box domain and its substrate recruiting domains, suggesting that deficiencies in SCFFbxo7/PARK15 ubiquitin ligase activity are mechanistically linked to early-onset PD. To date, relatively few substrates of the ligase have been identified. These include HURP (hepatoma up-regulated protein), whose ubiquitination results in proteasome-mediated degradation, and c-IAP1 (inhibitor of apoptosis protein 1), TNF receptor-associated factor 2 (TRAF2), and NRAGE, which are not destabilized as a result of ubiquitination. None of these substrates have been linked directly to PD, nor has it been determined whether they would directly engage neuronal cell death pathways. To discover ubiquitinated substrates of SCFFbxo7 implicated more directly in PD aetiology, we conducted a high-throughput screen using protein arrays to identify new candidates. A total of 338 new targets were identified and from these we validated glycogen synthase kinase 3β (Gsk3β), which can phosphorylate α-synuclein, and translocase of outer mitochondrial membrane 20 (Tomm20), a mitochondrial translocase that, when ubiquitinated, promotes mitophagy, as SCFFbxo7 substrates both in vitro and in vivo. Ubiquitin chain restriction analyses revealed that Fbxo7 modified Gsk3β using K63 linkages. Our results indicate that Fbxo7 negatively regulates Gsk3β activity, rather than its levels or localization. In addition, Fbxo7 ubiquitinated Tomm20, and its levels correlated with Fbxo7 expression, indicating a stabilizing effect. None of the PD-associated mutations in Fbxo7 impaired Tomm20 ubiquitination. Our findings demonstrate that SCFFbxo7 has an impact directly on two proteins implicated in pathological processes leading to PD.
Long non-coding RNAs–towards precision medicine in diabetic kidney disease?
Authors: Panchapakesan Usha , Pollock Carol
Published: August 2016

Diabetic kidney disease (DKD) is escalating and is the major cause of end stage kidney failure. There is increasing evidence to support the role of epigenetic factors and metabolic memory in linking the environmental and genetic causes of this disease. Although our understanding of this disease has improved, there has been no significant efficacious therapeutic translation in the last decade. Current sequencing technology has allowed interrogation of the human transcriptome. It is evident that although approximately 80% of the genome is transcribed, only 1–2% is read and coded into protein. The remaining non-coding RNA, historically assumed to be ‘junk’, is now known to have key roles in regulating gene function and orchestrate how and when coding genes are expressed. This largest subset of non-coding RNAs called long non-coding RNAs (LNCRNAs) drives epigenetic changes and has functional relevance best characterized in cancers and cardiovascular disease. This understanding, coupled with the availability and affordability of RNA sequencing, has shifted our therapeutic strategies towards genomic therapy in DKD. The role of LNCRNAs with respect to DKD is only just emerging. In this review we summarize the role of LNCRNAs in DKD and the existing antisense oligonucleotide therapy that may provide precise and targeted medicine to treat DKD in this postgenomic era.
Wideband multilayer Sierpinski carpet array radar absorber
Authors: Noor A. , Hu Z.
Published: August 2016

A novel multilayered wideband microwave absorber based on lossy Sierpinski carpet array has been proposed. The absorber consists of four layers of Sierpinski carpet arrays composed of lossy materials with varying conductivities. The absorber has −10 dB absorption bandwidth of more than two octaves for normally incident wave and p‐polarised obliquely incident wave, from 6 to 40 GHz. The thickness of the absorber is 7.2 mm. The structure does not contain any lumped elements and hence can be realised using 3D printing technology.
A novel nanopin model based on a Y-junction carbon nanotube
Authors: Zhang Zhong-Qiang , Zhong Jun , Ye Hong-Fei , Liu Zhen , Cheng Guang-Gui , Ding Jian-Ning
Published: August 2016

A prototype of nanopin based on a Y-junction carbon nanotube (CNT) is first proposed. The loading and unloading processes are investigated by using classical molecular dynamics, considering the influences of the fit dimension, positioning error, thermal effect, and the loading/unloading velocity on the performance of the proposed nanopin. The optimum size of the gap between the nanopin and the through hole in a silicon component is obtained, which is responsible for a desired fixity with the acceptable install resistance. It is found that a proper positioning error in a certain direction associated with the branched structure of the nanopin will facilitate the installation process. The performance of the proposed nanopin is not sensitive to thermal and normal axial velocity of the nanopin, while the unloading direction affects appreciably on the service performance of the nanopin attributed to the orientation of the branched CNT. Particularly, the service performance of the proposed nanopin considerably depends on several special deforming configurations in the loading and unloading processes.
First results from the Thomson scattering diagnostic on proto-MPEX
Authors: Biewer T. M. , Meitner S. , Rapp J. , Ray H. , Shaw G.
Published: August 2016

A Thomson scattering (TS) diagnostic has been successfully implemented on the prototype Material Plasma Exposure eXperiment (Proto-MPEX) at Oak Ridge National Laboratory. The diagnostic collects the light scattered by plasma electrons and spectroscopically resolves the Doppler shift imparted to the light by the velocity of the electrons. The spread in velocities is proportional to the electron temperature, while the total number of photons is proportional to the electron density. TS is a technique used on many devices to measure the electron temperature (Te) and electron density (ne) of the plasma. A challenging aspect of the technique is to discriminate the small number of Thomson scattered photons against the large peak of background photons from the high-power laser used to probe the plasma. A variety of methods are used to mitigate the background photons in Proto-MPEX, including Brewster angled windows, viewing dumps, and light baffles. With these methods, first results were measured from argon plasmas in Proto-MPEX, indicating Te ∼ 2 eV and ne ∼ 1 × 1019 m−3. The configuration of the Proto-MPEX TS diagnostic will be described and plans for improvement will be given.
Density-functional theory computer simulations of CZTS0.25Se0.75 alloy phase diagrams
Authors: Chagarov E. , Sardashti K. , Haight R. , Mitzi D. B. , Kummel A. C.
Published: August 2016

Density-functional theory simulations of CZTS, CZTSe, and CZTS0.25Se0.75 photovoltaic compounds have been performed to investigate the stability of the CZTS0.25Se0.75 alloy vs. decomposition into CZTS, CZTSe, and other secondary compounds. The Gibbs energy for vibrational contributions was estimated by calculating phonon spectra and thermodynamic properties at finite temperatures. It was demonstrated that the CZTS0.25Se0.75 alloy is stabilized not by enthalpy of formation but primarily by the mixing contributions to the Gibbs energy. The Gibbs energy gains/losses for several decomposition reactions were calculated as a function of temperature with/without intermixing and vibration contributions to the Gibbs energy. A set of phase diagrams was built in the multidimensional space of chemical potentials at 300 K and 900 K temperatures to demonstrate alloy stability and boundary compounds at various chemical conditions. It demonstrated for CZTS0.25Se0.75 that the chemical potentials for stability differ between typical processing temperature (∼900 K) and operating temperature (300 K). This implies that as cooling progresses, the flux/concentration of S should be increased in MBE growth to maintain the CZTS0.25Se0.75 in a thermodynamically stable state to minimize phase decomposition.
A frequency measurement algorithm for non-stationary signals by using wavelet transform
Authors: Seo Seong-Heon , Oh Dong Keun
Published: August 2016

Scalogram is widely used to measure instantaneous frequencies of non-stationary signals. However, the basic property of the scalogram is observed only for stationary sinusoidal functions. A property of the scalogram for non-stationary signal is analytically derived in this paper. Based on the property, a new frequency measurement algorithm is proposed. In addition, a filter that can separate two similar frequency signals is developed based on the wavelet transform.
Development of beam emission spectroscopy for turbulence transport study in Heliotron J
Authors: Kobayashi S. , Ohshima S. , Matsuda H. , Lu X. X. , Kokubu D. , Ida K. , Kobayashi T. , Yoshinuma M. , Kado S. , Oishi T. , Nagasaki K. , Okada H. , Minami T. , Yamamoto S. , Nakamura Y. , Ishizawa A. , Kenmochi N. , Otani Y. , Konoshima S. , Mizuuchi T.
Published: August 2016

This paper describes the development study of the beam emission spectroscopy (BES) for the turbulent transport study in Heliotron J. Modification of the sightlines (10 × 4 for edge and 10 × 2 for edge) enables us to obtain 2-dimensional BES imaging. The cooling effect on the reduction in the electrical noise of avalanche photodiode (APD) assembly has been investigated using a refrigerant cooling system. When the temperature of the APD element has set to be −20 °C, the electrical noise can be reduced more than 50%. The measurement error of the phase difference in the case of low signal level has been tested by two light-emitting diode lamps. The APD cooling has an effect to improve the measurement error at the low signal level of APD.
Sensitivity of chemical vapor deposition diamonds to DD and DT neutrons at OMEGA and the National Ignition Facility
Authors: Kabadi N. V. , Sio H. , Glebov V. , Gatu Johnson M. , MacPhee A. , Frenje J. A. , Li C. K. , Seguin F. , Petrasso R. , Forrest C. , Knauer J. , Rinderknecht H. G.
Published: August 2016

The particle-time-of-flight (pTOF) detector at the National Ignition Facility (NIF) is used routinely to measure nuclear bang-times in inertial confinement fusion implosions. The active detector medium in pTOF is a chemical vapor deposition diamond. Calibration of the detectors sensitivity to neutrons and protons would allow measurement of nuclear bang times and hot spot areal density (ρR) on a single diagnostic. This study utilizes data collected at both NIF and Omega in an attempt to determine pTOF’s absolute sensitivity to neutrons. At Omega pTOF’s sensitivity to DT-n is found to be stable to within 8% at different bias voltages. At the NIF pTOF’s sensitivity to DD-n varies by up to 59%. This variability must be decreased substantially for pTOF to function as a neutron yield detector at the NIF. Some possible causes of this variability are ruled out.
Detector-device-independent quantum key distribution: Security analysis and fast implementation
Authors: Boaron Alberto , Korzh Boris , Houlmann Raphael , Boso Gianluca , Lim Charles Ci Wen , Martin Anthony , Zbinden Hugo
Published: August 2016

One of the most pressing issues in quantum key distribution (QKD) is the problem of detector side-channel attacks. To overcome this problem, researchers proposed an elegant “time-reversal” QKD protocol called measurement-device-independent QKD (MDI-QKD), which is based on time-reversed entanglement swapping. However, MDI-QKD is more challenging to implement than standard point-to-point QKD. Recently, an intermediary QKD protocol called detector-device-independent QKD (DDI-QKD) has been proposed to overcome the drawbacks of MDI-QKD, with the hope that it would eventually lead to a more efficient detector side-channel-free QKD system. Here, we analyze the security of DDI-QKD and elucidate its security assumptions. We find that DDI-QKD is not equivalent to MDI-QKD, but its security can be demonstrated with reasonable assumptions. On the more practical side, we consider the feasibility of DDI-QKD and present a fast experimental demonstration (clocked at 625 MHz), capable of secret key exchange up to more than 90 km.
Immobilization of a bubble in water by nanoelectrolysis
Authors: Hammadi Zoubida , Lapena Laurent , Morin Roger , Olives Juan
Published: August 2016

A surprising phenomenon is presented: a bubble, produced from water electrolysis, is immobilized in the liquid (as if the Archimedes' buoyant force were annihilated). This is achieved using a nanoelectrode (1 nm to 1 μm of curvature radius at the apex) and an alternating electric potential with adapted values of amplitude and frequency. A simple model based on “nanoelectrolysis” (i.e., nanolocalization of the production of H2 and O2 molecules at the apex of the nanoelectrode) and an “open bubble” (i.e., exchanging H2 and O2 molecules with the solution) explains most of the observations.
FOB-SH: Fragment orbital-based surface hopping for charge carrier transport in organic and biological molecules and materials
Authors: Spencer J. , Gajdos F. , Blumberger J.
Published: August 2016

We introduce a fragment orbital-based fewest switches surface hopping method, FOB-SH, designed to efficiently simulate charge carrier transport in strongly fluctuating condensed phase systems such as organic semiconductors and biomolecules. The charge carrier wavefunction is expanded and the electronic Hamiltonian constructed in a set of singly occupied molecular orbitals of the molecular sites that mediate the charge transfer. Diagonal elements of the electronic Hamiltonian (site energies) are obtained from a force field, whereas the off-diagonal or electronic coupling matrix elements are obtained using our recently developed analytic overlap method. We derive a general expression for the exact forces on the adiabatic ground and excited electronic state surfaces from the nuclear gradients of the charge localized electronic states. Applications to electron hole transfer in a model ethylene dimer and through a chain of ten model ethylenes validate our implementation and demonstrate its computational efficiency. On the larger system, we calculate the qualitative behaviour of charge mobility with change in temperature T for different regimes of the intermolecular electronic coupling. For small couplings, FOB-SH predicts a crossover from a thermally activated regime at low temperatures to a band-like transport regime at higher temperatures. For higher electronic couplings, the thermally activated regime disappears and the mobility decreases according to a power law. This is interpreted by a gradual loss in probability for resonance between the sites as the temperature increases. The polaron hopping model solved for the same system gives a qualitatively different result and underestimates the mobility decay at higher temperatures. Taken together, the FOB-SH methodology introduced here shows promise for a realistic investigation of charge carrier transport in complex organic, aqueous, and biological systems.
Relaxation times in deformed polymer glasses: A comparison between molecular simulations and two theories
Authors: Rottler Jörg
Published: August 2016

Relaxation times in polymer glasses are computed with molecular dynamics simulations of a coarse-grained polymer model during creep and constant strain rate deformation. The dynamics is governed by a competition between physical aging that increases relaxation times and applied load or strain rate which accelerates dynamics. We compare the simulation results quantitatively to two recently developed theories of polymer deformation, which treat aging and rejuvenation in an additive manner. Through stress release and strain rate reversal simulations, we then show that the quantity governing mechanical rejuvenation is the rate of irreversible work performed on the polymer.
Observation of runaway electrons by infrared camera in J-TEXT
Authors: Tong R. H. , Chen Z. Y. , Zhang M. , Huang D. W. , Yan W. , Zhuang G.
Published: August 2016

When the energy of confined runaway electrons approaches several tens of MeV, the runaway electrons can emit synchrotron radiation in the range of infrared wavelength. An infrared camera working in the wavelength of 3-5 μm has been developed to study the runaway electrons in the Joint Texas Experimental Tokamak (J-TEXT). The camera is located in the equatorial plane looking tangentially into the direction of electron approach. The runaway electron beam inside the plasma has been observed at the flattop phase. With a fast acquisition of the camera, the behavior of runaway electron beam has been observed directly during the runaway current plateau following the massive gas injection triggered disruptions.
Optimal configuration for isolated hybrid renewable energy systems
Authors: Eltamaly Ali M. , Al-Shamma'a Abdullrahman A.
Published: August 2016

The configuration of hybrid energy systems has a great influence on the cost of generated energy from the system. This paper introduces a design, simulation, assessment, and selection of optimum autonomous hybrid renewable energy configuration out of three different configurations. The proposed hybrid system contains photovoltaic (PV), wind, diesel, and battery energy systems. A new computer program has been designed to simulate different configurations of hybrid energy systems. A genetics optimization smart technique using a genetic algorithm has been used to calculate the optimum sizing for each component at different configurations of the hybrid system for minimum cost and highest reliability. The optimum penetration ratio of renewable energy systems (PV and wind) will be selected according to the lowest price. Actual data for one remote site in Saudi Arabia has been used in the input data of this computer program. Sensitivity analysis has been carried out to show the conditions for selecting any configuration under study. The results obtained from this study can help researchers, designers, and decision makers to answer many open questions regarding the design and installations of hybrid renewable energy systems.
Far-infrared tangential interferometer/polarimeter design and installation for NSTX-U
Authors: Scott E. R. , Barchfeld R. , Riemenschneider P. , Domier C. W. , Muscatello C. M. , Sohrabi M. , Kaita R. , Ren Y. , Luhmann N. C.
Published: August 2016

The Far-infrared Tangential Interferometer/Polarimeter (FIReTIP) system has been refurbished and is being reinstalled on the National Spherical Torus Experiment—Upgrade (NSTX-U) to supply real-time line-integrated core electron density measurements for use in the NSTX-U plasma control system (PCS) to facilitate real-time density feedback control of the NSTX-U plasma. Inclusion of a visible light heterodyne interferometer in the FIReTIP system allows for real-time vibration compensation due to movement of an internally mounted retroreflector and the FIReTIP front-end optics. Real-time signal correction is achieved through use of a National Instruments CompactRIO field-programmable gate array.
Electrochemomechanics with flexoelectricity and modelling of electrochemical strain microscopy in mixed ionic-electronic conductors
Authors: Yu Pengfei , Hu Shuling , Shen Shengping
Published: August 2016

Recently, a new scanning probe microscopy approach, referred to as electrochemical strain microscopy (ESM), for probing local ionic flows and electrochemical reactions in solids based on the bias-strain coupling was proposed by Morozovska et al. Then, a series of theoretical papers for analyzing the image formation and spectroscopic mechanism of ESM were published within the framework of Fermi-Dirac statistics, the Vegard law, the direct flexoelectric coupling effect, the electrostriction effect, and so on. However, most of the models in these papers are limited to the partial coupling or particular process, and numerically solved by using decoupling approximation. In this paper, to model the ESM measurement with the coupling electrical-chemical-mechanical process, the chemical Gibbs function variational principle for the thermal electrical chemical mechanical fully coupling problem is proposed. The fully coupling governing equations are derived from the variational principle. When the tip concentrates the electric field within a small volume of the material, the inhomogeneous electric field is induced. So, both direct and inverse flexoelectric effects should be taken into account. Here, the bulk defect electrochemical reactions are also taken into account, which are usually omitted in the existing works. This theory can be used to deal with coupling problems in solids, including conductors, semiconductors, and piezoelectric and non-piezoelectric dielectrics. As an application of this work, a developed initial-boundary value problem is solved numerically in a mixed ion-electronic conductor. Numerical results show that it is meaningful and necessary to consider the bulk defect chemical reaction. Besides, the chemical reaction and the flexoelectric effect have an interactive influence on each other. This work can provide theoretical basis for the ESM as well as investigating the bulk chemical reaction process in solids.
Solution of second order supersymmetrical intertwining relations in Minkowski plane
Authors: Ioffe M. V. , Kolevatova E. V. , Nishnianidze D. N.
Published: August 2016

Supersymmetrical (SUSY) intertwining relations are generalized to the case of quantum Hamiltonians in Minkowski space. For intertwining operators (supercharges) of second order in derivatives, the intertwined Hamiltonians correspond to completely integrable systems with the symmetry operators of fourth order in momenta. In terms of components, the intertwining relations correspond to the system of nonlinear differential equations which are solvable with the simplest—constant—ansatzes for the “metric” matrix in second order part of the supercharges. The corresponding potentials are built explicitly both for diagonalizable and nondiagonalizable form of “metric” matrices, and their properties are discussed.
Electrochemical characterization of organosilane-functionalized nanostructured ITO surfaces
Authors: Pruna R. , Palacio F. , López M. , Pérez J. , Mir M. , Blázquez O. , Hernández S. , Garrido B.
Published: August 2016

The electroactivity of nanostructured indium tin oxide (ITO) has been investigated for its further use in applications such as sensing biological compounds by the analysis of redox active molecules. ITO films were fabricated by using electron beam evaporation at different substrate temperatures and subsequently annealed for promoting their crystallization. The morphology of the deposited material was monitored by scanning electron microscopy, confirming the deposition of either thin films or nanowires, depending on the substrate temperature. Electrochemical surface characterization revealed a 45 % increase in the electroactive surface area of nanostructured ITO with respect to thin films, one third lower than the geometrical surface area variation determined by atomic force microscopy. ITO surfaces were functionalized with a model organic molecule known as 6-(ferrocenyl)hexanethiol. The chemical attachment was done by means of a glycidoxy compound containing a reactive epoxy group, the so-called 3-glycidoxypropyltrimethoxy-silane. ITO functionalization was useful for determining the benefits of nanostructuration on the surface coverage of active molecules. Compared to ITO thin films, an increase in the total peak height of 140 % was observed for as-deposited nanostructured electrodes, whereas the same measurement for annealed electrodes resulted in an increase of more than 400 %. These preliminary results demonstrate the ability of nanostructured ITO to increase the surface-to-volume ratio, conductivity and surface area functionalization, features that highly benefit the performance of biosensors.
Fabrication and characterization of a co-planar detector in diamond for low energy single ion implantation
Authors: Abraham J. B. S. , Aguirre B. A. , Pacheco J. L. , Vizkelethy G. , Bielejec E.
Published: August 2016

We demonstrate low energy single ion detection using a co-planar detector fabricated on a diamond substrate and characterized by ion beam induced charge collection. Histograms are taken with low fluence ion pulses illustrating quantized ion detection down to a single ion with a signal-to-noise ratio of approximately 10. We anticipate that this detection technique can serve as a basis to optimize the yield of single color centers in diamond. The ability to count ions into a diamond substrate is expected to reduce the uncertainty in the yield of color center formation by removing Poisson statistics from the implantation process.
Improved operation of a microwave pulse compressor with a laser-triggered high-pressure gas plasma switch
Authors: Shlapakovski A. , Gorev S. , Krasik Ya. E.
Published: August 2016

The influence of laser beam parameters on the output pulses of a resonant microwave compressor with a laser-triggered plasma switch was investigated. The S-band compressor, consisting of a rectangular waveguide-based cavity and H-plane waveguide tee with a shorted side arm, was filled with pressurized dry air and pumped by 1.8-μs-long microwave pulses of up to 450 kW power. A Nd:YAG laser was used to ignite the gas discharge in the tee side arm for output pulse extraction. The laser beam (at 213 nm or 532 nm) was directed along the RF electric field lines. It was found that the compressor operated most effectively when the laser beam was focused at the center of the switch waveguide cross-section. In this case, the power extraction efficiency reached ∼47% at an output power of ∼14 MW, while when the laser beam was not focused the maximal extraction efficiency was only ∼20% at ∼6 MW output power. Focusing the laser beam resulted also in a dramatic decrease (down to <1 ns) in the delay of the output pulses' appearance with respect to the time of the beam's entrance into the switch, and the jitter of the output pulses' appearance was minimized. In addition, the quality of the output pulses' waveform was significantly improved.
Arsenic detoxification in two populations of Borreria verticillata (Rubiaceae) with differential tolerance to the metalloid
Authors: Arcanjo-Silva Samara , Campos Naiara V. , Becari-Viana Ivan , da Silva Luzimar C. , Ribeiro Cleberson , Azevedo Aristéa A.
Published: August 2016

Arsenic (As) is toxic to most living things. However, plants growing in environments contaminated by this pollutant may exhibit tolerance strategies such as restrictions to its absorption and intracellular detoxification. In the present study we compared morphophysiological responses between Borreria verticillata (L.) G.F.W. Mayer (Rubiaceae) populations from an As-contaminated site (CS) and a non-contaminated site (NCS) in order to clarify their mechanisms of As detoxification and their differential tolerance to the metalloid. Plants were grown in nutrient solution without As addition (control) and with 66 µM As for 4 days. Arsenic accumulated in plant roots, and neither bioaccumulation nor translocation factors differed between the populations. Exposure to the metalloid promoted damage to the morphology and anatomy of both roots and shoots, particularly in plants from the NCS. These plants showed more severe phytotoxic symptoms, as well as greater reduction in shoot growth and fresh biomass accumulation. Plants from the CS showed fewer toxicity symptoms due to mechanisms that favoured As detoxification and scavenging of reactive oxygen species in roots (e.g. increases in Ca and S root concentrations, higher number of phenolic and crystalliferous idioblasts and increased antioxidant enzyme activity) and the prevention of oxidative stress in leaves (through increased superoxide dismutase activity). Thus, we verified that besides the differences in P metabolism that have been reported in the literature, plants from the CS are more As-tolerant due to their higher efficiency for As detoxification, and are therefore more well suited for the revegetation of As-contaminated areas.
Differential lipid binding of vinculin isoforms promotes quasi-equivalent dimerization
Authors: Chinthalapudi Krishna , Rangarajan Erumbi S. , Brown David T. , Izard Tina
Published: August 2016

Significance

Debilitating heart conditions, dilated cardiomyopathy (DCM) and hypertrophic cardiomyopathy (HCM), are often due to inherited or acquired mutations in genes that encode specific components of adhesion complexes. In muscle tissue, some of these adhesion complexes have specialized structures, called intercalated discs, which are important for contraction and coordinated movement. Here we provide molecular insights into the cytoskeletal protein metavinculin, which is necessary for the proper development and maintenance of heart tissue and is mutated in human DCM and HCM. We show that the binding of lipid causes metavinculin to dimerize and involves a specific metavinculin amino acid associated with severe DCM/HCM. Collectively, our studies provide insight into how such metavinculin mutations in components of adhesion complexes lead to cardiomyopathies.