bluuebunny/crossref_metadata_2025 huggingface dataset:
Transition metal binding selectivity in proteins and its correlation with the phylogenomic classification of the cation diffusion facilitator protein family
Authors: Barber-Zucker Shiran , Shaanan Boaz , Zarivach Raz
Published: November 2017

Divalent d-block metal cations (DDMCs), such as Fe, Zn and Mn, participate in many biological processes. Understanding how specific DDMCs are transported to and within the cell and what controls their binding selectivity to different proteins is crucial for defining the mechanisms of metalloproteins. To better understand such processes, we scanned the RCSB Protein Data Bank, performed a de novo structural-based comprehensive analysis of seven DDMCs and found their amino acid binding and coordination geometry propensities. We then utilized these results to characterize the correlation between metal selectivity, specific binding site composition and phylogenetic classification of the cation diffusion facilitator (CDF) protein family, a family of DDMC transporters found throughout evolution and sharing a conserved structure, yet with different members displaying distinct metal selectivity. Our analysis shows that DDMCs differ, at times significantly, in terms of their binding propensities, and that in each CDF clade, the metal selectivity-related binding site has a unique and conserved sequence signature. However, only limited correlation exists between the composition of the DDMC binding site in each clade and the metal selectivity shown by its proteins.
Multi-scale Molecular Simulations on Respiratory Complex I
Authors: Kaila Ville R. I.
Published: November 2017

Complex I (NADH:ubiquinone oxidoreductase) is a redox-driven proton pump that powers synthesis of adenosine triphosphate (ATP) and active transport in most organisms. This gigantic enzyme reduces quinone (Q) to quinol (QH2) in its hydrophilic domain, and transduces the released free energy into pumping of protons across its membrane domain, up to ca. 200 Å away from its active Q-reduction site. Recently resolved molecular structures of complex I from several species have made it possible for the first time to address the energetics and dynamics of the complete complex I using multi-scale methods of computational biochemistry. Here it is described how molecular simulations can provide important mechanistic insights into the function of the remarkable pumping machinery in complex I and stimulate new experiments.
Advances in Understanding Mechanism and Physiology of Cytochromes bc
Authors: Borek Arkadiusz , Ekiert Robert , Osyczka Artur
Published: November 2017

Cytochrome bc-type complexes are the key proteins of respiratory and photosynthetic electron transport chains involved in conservation of energy. They use quinone redox chemistry to translocate protons across the membrane. Here we describe mechanistic and physiologic aspects of operation of these enzymes focusing on new structural and kinetic elements of action of the catalytic sites inferred from recent experimental studies and molecular dynamics simulations. In particular, we discuss the possible mechanism of control of superoxide generation by one of the catalytic sites in the context of recently discovered radical intermediate states of catalysis.
Rapid and selective determination of melamine from eggs and milk based on magnetic surface molecularly imprinting technology
Authors: Wang Li , Qiu Fen , Li Jian , Pan Jiarong
Published: November 2017

Fe3O4@SiO2@MIPs, which have strong magnetic responsiveness and high selectivity, were synthesized and applied towards the rapid extraction of MEL from milk and eggs.
Determination of methylmercury in sediment and cyanobacteria samples: method validation and application to methylation investigation
Authors: Mendes Louise Aparecida , Franco Maione Wittig , Rodrigues Barbosa Francisco Antônio , Aires de Carvalho Paula Iannarelli , Carvalho de Lena Jorge , Windmöller Cláudia Carvalhinho
Published: November 2017

The aim of this work was to validate methods for methylmercury (CH3Hg+) determination in sediments and cyanobacteria.
Amino-thiacalix[4]arene modified screen-printed electrodes as a novel electrochemical interface for Hg(ii) quantification at a pico-molar level
Authors: Adarakatti Prashanth Shivappa , Banks Craig E. , Malingappa Pandurangappa
Published: November 2017

A simple amino-thiacalix[4]arene modified graphitic carbon has been prepared by a microwave-irradiation process and employed for the quantification of Hg(ii) ions immobilized on screen-printed graphite macroelectrodes (SPEs) as a novel voltammetric sensor.
Melanin-manganese nanoparticles with ultrahigh efficient clearance in vivo for tumor-targeting T1 magnetic resonance imaging contrast agent
Authors: Xu Wen , Sun Jinghua , Li Liping , Peng Xiaoyang , Zhang Ruiping , Wang Binquan
Published: November 2017

A magnetic resonance imaging contrast agent, based on Mn2+-chelating melanin nanoparticles, that has ultrahigh efficient clearance in vivo for tumor-targeted imaging.
Efficient light hydrocarbon separation and CO2 capture and conversion in a stable MOF with oxalamide-decorated polar tubes
Authors: Li Xiu-Yuan , Li Yong-Zhi , Yang Yun , Hou Lei , Wang Yao-Yu , Zhu Zhonghua
Published: November 2017

A Sr-MOF possessing polar tubes and open acidic sites shows outstanding performance for light hydrocarbon separation and CO2 capture and conversion.
Correction: Direct N–H/α,α,β,β-C(sp3)–H functionalization of piperidine via an azomethine ylide route: synthesis of spirooxindoles bearing 3-substituted oxindoles
Authors: Du Yanlong , Yu Aimin , Jia Jiru , Zhang Youquan , Meng Xiangtai
Published: November 2017

Correction for ‘Direct N–H/α,α,β,β-C(sp3)–H functionalization of piperidine via an azomethine ylide route: synthesis of spirooxindoles bearing 3-substituted oxindoles’ by Yanlong Du et al., Chem. Commun., 2017, 53, 1684–1687.
The role of PbI2 in CH3NH3PbI3 perovskite stability, solar cell parameters and device degradation
Authors: Gujar Tanaji P. , Unger Thomas , Schönleber Andreas , Fried Martina , Panzer Fabian , van Smaalen Sander , Köhler Anna , Thelakkat Mukundan
Published: November 2017

We report a systematic investigation on the role of excess PbI2 content in CH3NH3PbI3 perovskite film properties, solar cell parameters and device storage stability.
Mapping of exciton–exciton annihilation in MEH-PPV by time-resolved spectroscopy: experiment and microscopic theory
Authors: Hader Kilian , Consani Cristina , Brixner Tobias , Engel Volker
Published: November 2017

Transient absorption traces taken on samples of the polymer MEH-PPV are measured as a function of the laser intensity.
Zinc(ii), cobalt(ii) and manganese(ii) networks with phosphoserine ligand: synthesis, crystal structures and magnetic and proton conductivity properties
Authors: Vallejo J. , Salcedo I. R. , Colodrero R. M. P. , Cabeza A. , Świtlicka A. , Cano J. , Viciano-Chumillas M.
Published: November 2017

A series of zinc(ii), cobalt(ii) and manganese(ii) coordination networks with phosphoserine ligand (H3PSer) are synthesized and characterized.
High quality and high performance adsorption of Congo red using as-grown MWCNTs synthesized over a Co-MOF as a catalyst precursor via the CVD method
Authors: Lin Hong-Yan , Zhao Jing , Song Ge , Luan Jian , Liu Xiang-Xiang , Liu Guo-Cheng
Published: November 2017

A Co-MOF has been synthesized and characterized, which was firstly used as a combined catalyst precursor to synthesize MWCNTs with high performance in the adsorption of CR.
Real-time detection of oxalyl chloride based on a long-lived iridium(iii) probe
Authors: Wu Chun , Li Guodong , Han Quan-Bin , Pei Ren-Jun , Liu Jin-Biao , Ma Dik-Lung , Leung Chung-Hang
Published: November 2017

A series of luminescent iridium(iii) complexes were designed and evaluated for their ability to detect oxalyl chloride ((COCl)2) at ambient temperature.
Interfacial electronic effects of palladium nanocatalysts on the by-product ammonia selectivity during nitrite catalytic reduction
Authors: Zhang Zhiqiang , Shi Wenxin , Wang Wei , Xu Yongpeng , Bao Xian , Zhang Ruijun , Zhang Bing , Guo Yuan , Cui Fuyi
Published: November 2017

Modulating the electronic structure of catalyst atoms (Pd) can significantly influence the selectivity for ammonia during the catalytic reduction of nitrite.
Highly stretchable polymer conductors based on as-prepared PEDOT:PSA/n-PAA hydrogels
Authors: Ma Xiangyan , Cai Wanping , Zhang Sai , Guo Jiahong , Peng Xing , Qiu Zhoutong , Ying Jie , Wang Jikui
Published: November 2017

The co-crosslinking network structure endows PEDOT:PSA/n-PAA hydrogels highly electrical conductivity and stretchability.
Post-targeting strategy for ready-to-use targeted nanodelivery post cargo loading
Authors: Zhu J. Y. , Hu J. J. , Zhang M. K. , Yu W. Y. , Zheng D. W. , Wang X. Q. , Feng J. , Zhang X. Z.
Published: November 2017

A ready-to-use post-targeting methodology has been developed to endow the nanodelivery with the desired targeting functionality post cargo loading.
Enhanced and synergistic downregulation of oncogenic miRNAs by self-assembled branched DNA
Authors: Nahar S. , Nayak A. K. , Ghosh A. , Subudhi U. , Maiti S.
Published: November 2017

Simultaneous targeting of multiple miRNAs by a single self-assembled branch DNA harbouring sites for miRNA binding.
Stabilizing benzene-like planar N6rings to form a single atomic honeycomb BeN3sheet with high carrier mobility
Authors: Li Xiaoyin , Zhang Shunhong , Zhang Cunzhi , Wang Qian
Published: November 2017

Global structure search and theoretical calculations suggest the possibility of stabilizing planar hexagonal N6rings in a honeycomb BeN3sheet.
The direct and highly diastereoselective synthesis of 3,4-epoxy-2-piperidones. Application to the total synthesis and absolute configurational assignment of 3α,4α-epoxy-5β-pipermethystine
Authors: Osorio-Nieto Urbano , Vázquez-Amaya Laura Y. , Höpfl Herbert , Quintero Leticia , Sartillo-Piscil Fernando
Published: November 2017

The substrate-controlled asymmetric total synthesis and absolute configurational assignment of biologically active 3α,4α-epoxy-5β-pipermethystine is reported.
Synthesis of α-keto imides through copper-catalyzed oxidation of N-sulfonyl ynamides
Authors: Liu Xin , Zhang Zhi-Xin , Zhou Bo , Wang Ze-Shu , Zheng Ren-Hua , Ye Long-Wu
Published: November 2017

A novel copper-catalyzed N-oxide oxidation of N-sulfonyl ynamides has been developed, allowing the facile synthesis of various α-keto imides in generally moderate to good yields.
One-pot and gram-scale synthesis of biodegradable polyglycerols under ambient conditions: nanocarriers for intradermal drug delivery
Authors: Mohammadifar Ehsan , Zabihi Fatemeh , Tu Zhaoxu , Hedtrich Sarah , Nemati Kharat Ali , Adeli Mohsen , Haag Rainer
Published: November 2017

Biodegradable and biocompatible hyperbranched polymers are synthesized and their potential for dermal drug delivery is investigated.
Acetylcholinesterase biosensor based on electrochemically inducing 3D graphene oxide network/multi-walled carbon nanotube composites for detection of pesticides
Authors: Li Yanping , Zhao Ruixia , Shi Lingyun , Han Gaoyi , Xiao Yaoming
Published: November 2017

A sensitive electrochemical biosensor for determining organophosphates and carbamate pesticides has been achieved by immobilizing acetylcholinesterase on electrochemically inducing 3D graphene oxide network/multi-walled carbon nanotubes composites.
Effects of nano-grooved gelatin films on neural induction of human adipose-derived stem cells
Authors: Tsai Chen-Yu , Lin Chih-Ling , Cheng Nai-Chen , Yu Jiashing
Published: November 2017

The extra cellular matrix (ECM) and cell–cell interactions facilitate the survival, self-renewing and differentiation capabilities of stem cells.
Controllable domain morphology in coated poly(lactic acid) films for high-efficiency and high-precision transportation of water droplet arrays
Authors: Wang Yongtao , Yang Huige , Liu Hongzhi , Zhang Li , Duan Ruixia , Liu Xuying , Chen Jinzhou
Published: November 2017

Construction of superhydrophobic surfaces with tunable adhesion force has attracted considerable attention in past decades.
Denitrification of groundwater using a biodegradable polymer as a carbon source: long-term performance and microbial diversity
Authors: Chu Libing , Wang Jianlong
Published: November 2017

Nitrate pollution in groundwater is a worldwide problem.
Luminescent zero-dimensional organic metal halide hybrids with near-unity quantum efficiency
Authors: Zhou Chenkun , Lin Haoran , Tian Yu , Yuan Zhao , Clark Ronald , Chen Banghao , van de Burgt Lambertus J. , Wang Jamie C. , Zhou Yan , Hanson Kenneth , Meisner Quinton J. , Neu Jennifer , Besara Tiglet , Siegrist Theo , Lambers Eric , Djurovich Peter , Ma Biwu
Published: November 2017

Single crystalline zero-dimensional organic metal halide hybrids have been developed.
Cobaloxime anchored MoS2 nanosheets as electrocatalysts for the hydrogen evolution reaction
Authors: Cai Ming , Zhang Fan , Zhang Chao , Lu Chenbao , He Yafei , Qu Yang , Tian Hao , Feng Xinliang , Zhuang Xiaodong
Published: November 2017

Cobaloxime anchored MoS2 nanosheets.
Chemical intuition for high thermoelectric performance in monolayer black phosphorus, α-arsenene and aW-antimonene
Authors: Peng Bo , Zhang Hao , Shao Hezhu , Xu Ke , Ni Gang , Li Jing , Zhu Heyuan , Soukoulis Costas M.
Published: November 2017

We approach two-dimensional thermoelectric material design by using chemical intuition.
Photoluminescence, optical gain, and lasing threshold in CH3NH3PbI3 methylammonium lead-halide perovskites obtained by ab initio calculations
Authors: Filippetti A. , Caddeo C. , Delugas P. , Mattoni A.
Published: November 2017

Net recombination rate and optical gain at varying injected charge densities for lead-iodide perovskites obtained by ab initio calculations.
Perylene diimide arrays: promising candidates for non-fullerene organic solar cells
Authors: Wang Helin , Chen Lingcheng , Xiao Yi
Published: November 2017

Herein, two different perylene diimides trimer arrays have been investigated for high-efficiency non-fullerene organic solar cells (OSCs).
A VST and VISTA study of globular clusters in NGC 253
Authors: Cantiello Michele , Grado Aniello , Rejkuba Marina , Arnaboldi Magda , Capaccioli Massimo , Greggio Laura , Iodice Enrica , Limatola Luca
Published: November 2017

Context. Globular clusters (GCs) are key to our understanding of the Universe, as laboratories of stellar evolution, fossil tracers of the past formation epoch of the host galaxy, and effective distance indicators from local to cosmological scales.

Aim. We analyze the properties of the sources in the NGC 253 with the aim of defining an up to date catalog of GC candidates in the galaxy. Given the distance of the galaxy, GCs in NGC 253 are ideal targets for resolved color-magnitude diagram studies of extragalactic GCs with next-generation diffraction limited ground-based telescopes.

Methods. Our analysis is based on the science verification data of two ESO survey telescopes, VST and VISTA. Using ugri photometry from VST and JKs from VISTA, GC candidates were selected using as reference the morpho-photometric and color properties of spectroscopically confirmed GCs available in the literature. The strength of the results was verified against available archival HST/ACS data from the GHOSTS survey: all but two of the selected GC candidates appear as star clusters in HST footprints.

Results. The adopted GC selection leads to the definition of a sample of ∼350 GC candidates. At visual inspection, we find that 82 objects match all the requirements for selecting GC candidates and 155 are flagged as uncertain GC candidate; however, 110 are unlikely GCs, which are most likely background galaxies. Furthermore, our analysis shows that four of the previously spectroscopically confirmed GCs, i.e., ∼20% of the total spectroscopic sample, are more likely either background galaxies or high-velocity Milky Way stars. The radial density profile of the selected best candidates shows the typically observed r1∕4-law radial profile. The analysis of the color distributions reveals only marginal evidence of the presence of color bimodality, which is normally observed in galaxies of similar luminosity. The GC luminosity function does not show the typical symmetry, mainly because of the lack of bright GCs. Part of the bright GCs missing might be at very large galactocentric distances or along the line of sight of the galaxy dusty disk. As an alternative possibility, we speculate that a fraction of low luminosity GC candidates might instead be metal-rich, intermediate age clusters, but fall in a similar color interval of old, metal-poor GCs.

Conclusions. Defining a contaminant-free sample of GCs in extragalactic systems is not a straight forward exercise. Using optical and near-IR photometry we purged the list of GCs with spectroscopic membership and photometric GC candidates in NGC 253. Our results show that the use of either spectroscopic or photometric data only does not generally ensure a contaminant-free sample and a combination of both spectroscopy and photometry is preferred.
Detection of CS in Neptune’s atmosphere from ALMA observations
Authors: Moreno R. , Lellouch E. , Cavalié T. , Moullet A.
Published: November 2017

Context. The large and vertically non-uniform abundance of CO in Neptune’s atmosphere has been interpreted as the result of past cometary impact(s), either single or distributed in size and time, which could also be at the origin of Neptune’s HCN.

Aims. We aim to provide observational support for this scenario by searching for other comet-induced species, in particular carbon sulfide (CS) which has been observed continuously in Jupiter since the 1994 Shoemaker-Levy 9 impacts.

Methods. In April 2016 we used the ALMA interferometer to search for CS(7-6) at 342.883 GHz in Neptune.

Results. We report on the detection of CS in Neptune’s atmosphere, the first unambiguous observation of a sulfur-bearing species in a giant planet beyond Jupiter. Carbon sulfide appears to be present only at submillibar levels, with a column density of (2.0–3.1) × 1012 cm-2, and a typical mixing ratio of (2−20) × 10-11 that depends on its precise vertical location. The favoured origin of CS is deposition by a putative large comet impact several centuries ago, and the strong depletion of CS with respect to CO – compared to the Jupiter case – is likely due to the CS sticking to aerosols or clustering to form polymers in Neptune’s lower stratosphere.

Conclusions. The CS detection, along with recent analyses of the CO profile, reinforces the presumption of a large comet impact into Neptune ~1000 yr ago, that delivered CO, CS, and HCN at the same time.
Brønsted Acid Catalyzed Domino 1,6-Addition/Intramolecular Cyclization­ Reactions: Diastereoselective Synthesis of Dihydro­coumarin Frameworks
Authors: Mei Guang-Jian , Cao Zheng , Zhou Gui-Xiang , Ma Chun , Jiang Kang
Published: November 2017

An efficient domino 1,6-addition/intramolecular cyclization reaction between para-quinone methides (p-QMs) and azlactones under Brønsted acid catalysis was established. A series of highly functionalized dihydrocoumarins were constructed in good to excellent yields (up to 96%) with excellent diastereoselectivities (all >20:1 d.r.). In this process, the Brønsted acid plays a crucial role not only in activating the two substrates, but also in controlling the diastereoselectivity of the reaction via hydrogen-bonding interactions. In addition, this protocol demonstrates the great practicability of utilizing p-QMs in domino reactions.
Clinical impact of prophylactic clip closure of mucosal defects after colorectal endoscopic submucosal dissection
Authors: Harada Hideaki , Suehiro Satoshi , Murakami Daisuke , Nakahara Ryotaro , Ujihara Tetsuro , Shimizu Takanori , Miyama Yasunaga , Katsuyama Yasushi , Hayasaka Kenji , Tounou Shigetaka
Published: November 2017

Background and study aims Endoscopic submucosal dissection (ESD) is useful for en bloc resection of superficial colorectal neoplasms to ensure accurate histologic diagnoses. However, colorectal ESD is associated with a high frequency of adverse events (AEs). We aimed to investigate the effectiveness of prophylactic clip closure (PCC) of mucosal defects for AEs after colorectal ESD.

Patients and methods This study included 197 patients with 211 lesions who underwent colorectal ESD between June 2010 and August 2016. Patients who had delayed perforation, delayed bleeding, abdominal pain, or fever were defined as AEs after colorectal ESD. Complete PCC was defined as completely sutured mucosal defect using endoclips following colorectal ESD, whereas incomplete PCC was defined as the mucosal defects that did not enable PCC or were partially sutured. Clinical records were retrospectively reviewed and clinical outcomes evaluated.

Results AEs occurred in 29 lesions (13.7 %), including 12 with delayed bleeding, 12 with fever, 2 with abdominal pain, 2 with fever and abdominal pain, and 1 with delayed bleeding and fever. Delayed perforation was not observed in any patient. The frequency of AEs was significantly lower in the group with complete PCC than in the group with incomplete PCC (7.3 % [9/123] vs. 22.7 % [20/88]; P < 0.001). Multivariate analysis revealed that AEs after colorectal ESD were significantly associated with tumor size and submucosal fibrosis. Subgroup analysis among the resected specimen size of < 40 mm revealed that there was no significant difference in AEs between the 2 groups (5.6 % [6/107] vs. 17.8 % [8/45]; P = 0.069). However, the frequency of fever with complete PCC was significantly lower than that with incomplete PCC (2.8 % [3/107] vs. 13.3 % [6/45]; P = 0.020).

Conclusions Tumor size and submucosal fibrosis were independent risk factors for AEs after colorectal ESD. PCC may be effective in minimizing AEs after colorectal ESD, especially the frequency of fever.
„Vom ersten Tag an faszinierend“
Authors: Rau Fritz-Stefan
Published: November 2017

Interview Bisher haben wir uns in diesem Schwerpunkt mit der Vergangenheit der psychiatrischen Pflege beschäftigt. Nun wollen wir
beleuchten, ob die Saat der Vordenker aufgegangen ist: Wie erleben Auszubildende der „Generation Y“ die Arbeit in der heutigen Psychiatrie,
welche Vorbilder und Ideale haben sie? Im Gespräch mit der PPH berichten zwei Schüler über ihre Eindrücke und Erfahrungen.
Stability of ideal and non-ideal edge localized infernal mode
Authors: Dong G. Q. , Liu Y. Q. , Wang S. , Zhang N. , Yu D. L. , Liu Y. , Wang Z. R.
Published: November 2017

Stability of a special class of the infernal mode, i.e., the one which is localized near the plasma edge, is numerically investigated for a toroidal plasma, using the single fluid code MARS-F [Liu et al., Phys. Plasmas 7, 3681 (2000)] and magneto-hydrodynamic-kinetic hybrid code MARS-K [Liu et al., Phys. Plasmas 15, 112503 (2008)]. Unlike the peeling-ballooning instabilities, which are thought to be responsible for the onset of type-I edge localized modes, the edge localized infernal mode may be responsible for accessing certain quiescent H-mode regimes in tokamak discharges. The finite plasma pressure near the plasma edge drives this instability. The local flattening of the safety factor near a rational surface at the plasma edge region, due to the large bootstrap current contribution in H-mode plasmas, is a necessary condition for the mode instability. It is found that the plasma toroidal flow shear in the pedestal region, as well as the plasma resistivity, further destabilizes the edge localized infernal mode. The drift kinetic effects from thermal particles, on the other hand, partially stabilize the mode. The flow shear and the drift kinetic effects also modify the symmetry of the mode spectrum, by enlarging the unstable domain towards higher local qmin value. No substantial modification of the mode eigen-structure is observed by the plasma flow, resistivity, or the kinetic effects. These results can be relevant to understanding physics of certain quiescent H-mode regimes.
Magnetic reversal dynamics of NiFe-based artificial spin ice: Effect of Nb layer in normal and superconducting state
Authors: Kaur M. , Gupta Anurag , Varandani D. , Verma Apoorva , Senguttuvan T. D. , Mehta B. R. , Budhani R. C.
Published: November 2017

Square arrays of artificial spin ice (ASI) constituting weakly interacting NiFe nano-islands, with length ∼312 nm, width ∼125 nm, thickness ∼20 nm, and lattice constant ∼570 nm, were fabricated on Nb thin film and on thermally grown 300 nm SiO2 on silicon. Detailed investigations of magnetic force microscopy (MFM) at room temperature, and magnetization M(H) loops and relaxation of remanent magnetization (Mr) at various temperatures were carried out in two in-plane field geometries, namely, parallel (“P”-parallel to the square lattice) and diagonal (“D”- 45° to the square lattice). The magnetic response of the ASI samples shows striking difference for insulating (SiO2), metallic (Nb, T > 6.6 K) and superconducting (Nb, T < 6.6 K) bases, and the field geometry. For instance, with the Nb base in the normal metallic state (T > 6.6 K), (1) in “P” geometry the M(H) loops are found to be more “S” shaped in comparison with that for SiO2 base; (2) the ratio of magnetic vertex population of Type II to Type III vertices extracted from MFM studies in “P”(“D”) geometry is ∼1:1.1(1.2:1) that changed for the SiO2 base to ∼2.1:1 (4: 1). However, the NiFe-ASI on both metallic Nb and SiO2 bases exhibit a highly athermal decay of magnetization, and the % change in Mr in about two hours at T = 10 K (300 K) lies in a range of ∼1.07–1.80 (0.25–0.62). With Nb base in superconducting state (T < 6.6 K), the M(H) loops not only look radically different from those with SiO2 and metallic Nb as bases but also show significant difference in “P” and “D” geometries. These results are discussed in terms of inter-island magnetostatic energy as influenced by field geometry, presence of metallic Nb base and competing vortex pinning energy of superconducting Nb base.
Electrostatics of lateral p-n junctions in atomically thin materials
Authors: Nipane Ankur , Jayanti Sirisha , Borah Abhinandan , Teherani James T.
Published: November 2017

The lack of analytical expressions for the electrostatics of asymmetrically doped 2D lateral junctions complicates the design and analysis of devices based on atomically thin materials. In this work, we provide analytical expressions for the electric field, electrostatic potential, and depletion width across 2D lateral p-n junctions with arbitrary, but spatially uniform doping configurations. We also extend these expressions for use in lateral 3D metal-2D semiconductor junctions and lateral 2D heterojunctions. The results show a significantly larger depletion width (∼2 to 20×) for our 2D method compared to a conventional 3D approach due to the presence of a large out-of-plane electric field. For asymmetrically doped p-n junctions, the 2D depletion width shows a logarithmic dependence on the doping density of the highly doped side, in sharp contrast with conventional electrostatics for 3D junctions. Further, we show that 2D lateral depletion widths can be significantly modulated by changing the surrounding dielectric environment and, hence, can be tuned to realize optimum device structures. Finally, we show that even though the long depletion tails in 2D lateral p-n junctions carry a significant amount of total net charge, they do not significantly affect the electric field and electrostatic potential profiles, supporting the validity of the depletion approximation in analytical modeling of 2D lateral p-n junctions.
Nonlinear saturation of the Weibel instability
Authors: Cagas P. , Hakim A. , Scales W. , Srinivasan B.
Published: November 2017

The growth and saturation of magnetic fields due to the Weibel instability (WI) have important implications for laboratory and astrophysical plasmas, and this has drawn significant interest recently. Since the WI can generate a large magnetic field from no initial field, the maximum magnitudes achieved can have significant consequences for a number of applications. Hence, an understanding of the detailed dynamics driving the nonlinear saturation of the WI is important. This work considers the nonlinear saturation of the WI when counter-streaming populations of initially unmagnetized electrons are perturbed by a magnetic field oriented perpendicular to the direction of streaming. Previous works have found magnetic trapping to be important [Davidson et al., Phys. Fluids 15, 317 (1972)] and connected electron skin depth spatial scales to the nonlinear saturation of the WI [Califano et al., Phys. Rev. E 57, 7048 (1998)]. The results presented in this work are consistent with these findings for a high-temperature case. However, using a high-order continuum kinetic simulation tool, this work demonstrates that when the electron populations are colder, a significant electrostatic potential develops that works with the magnetic field to create potential wells. The electrostatic field develops due to transverse flows induced by the WI and in some cases is strengthened by a secondary instability. This field plays a key role in saturation of the WI for colder populations. The role of the electrostatic potential in Weibel instability saturation has not been studied in detail previously.
Nonlinear electric conductivity and thermal conductivity of WS2/EPDM field grading materials
Authors: Han Peng , Zha Jun-Wei , Zheng Ming-Sheng , Wen Yong-Qiang , Dang Zhi-Min
Published: November 2017

In this work, composites with different flake-like WS2 filler contents were prepared, using ethylene propylene diene monomer as matrix. The nonlinear electric conductivity of composites at 25, 50, and 80 °C was measured, and the mechanisms were analyzed. It is found that exfoliation of WS2 and testing temperature both have a direct influence on composites' electric conductivity. The inflection point and nonlinear coefficient of composites' nonlinear conductivity are also analyzed. The low WS2 content (4.31 vol. %) composite started to show nonlinear conductivity. Direct current dielectric breakdown strength was also measured. The thermal conductivity of composites was measured to verify the improvement of thermal conductivity. The obtained data show that the thermal conductivity of the composite can be increased to about 45% and 40% at 25 and 75 °C, respectively.
Extraction of effective solid-liquid interfacial free energies for full 3D solid crystallites from equilibrium MD simulations
Authors: Zepeda-Ruiz L. A. , Sadigh B. , Chernov A. A. , Haxhimali T. , Samanta A. , Oppelstrup T. , Hamel S. , Benedict L. X. , Belof J. L.
Published: November 2017

Molecular dynamics simulations of an embedded atom copper system in the isobaric-isenthalpic ensemble are used to study the effective solid-liquid interfacial free energy of quasi-spherical solid crystals within a liquid. This is within the larger context of molecular dynamics simulations of this system undergoing solidification, where single individually prepared crystallites of different sizes grow until they reach a thermodynamically stable final state. The resulting equilibrium shapes possess the full structural details expected for solids with weakly anisotropic surface free energies (in these cases, ∼5% radial flattening and rounded [111] octahedral faces). The simplifying assumption of sphericity and perfect isotropy leads to an effective interfacial free energy as appearing in the Gibbs-Thomson equation, which we determine to be ∼177 erg/cm2, roughly independent of crystal size for radii in the 50–250 Å range. This quantity may be used in atomistically informed models of solidification kinetics for this system.
Research on the correlation between corona current spectrum and audible noise spectrum of HVDC transmission line
Authors: Liu Yingyi , Zhou Lijuan , Liu Yuanqing , Yuan Haiwen , Ji Liang
Published: November 2017

Audible noise is closely related to corona current on a high voltage direct current (HVDC) transmission line. In this paper, we measured a large amount of audible noise and corona current waveforms simultaneously based on the largest outdoor HVDC corona cage all over the world. By analyzing the experimental data, the related statistical regularities between a corona current spectrum and an audible noise spectrum were obtained. Furthermore, the generation mechanism of audible noise was analyzed theoretically, and the related mathematical expression between the audible noise spectrum and the corona current spectrum, which is suitable for all of these measuring points in the space, has been established based on the electro-acoustic conversion theory. Finally, combined with the obtained mathematical relation, the internal reasons for these statistical regularities appearing in measured corona current and audible noise data were explained. The results of this paper not only present the statistical association regularities between the corona current spectrum and the audible noise spectrum on a HVDC transmission line, but also reveal the inherent reasons of these associated rules.
Controlling hybrid-polarization surface plasmon polaritons in dielectric-transparent conducting oxides metamaterials via their effective properties
Authors: Gric Tatjana , Hess Ortwin
Published: November 2017

Diversiform hybrid-polarization surface plasmon polaritons (HSPPs) at metamaterial (MM)–dielectric interfaces have initially been predicted by theoretical considerations based on dispersion equations. Here, we discuss hybrid HSPPs at the interface between (1) transparent conducting oxide (TCO)/dielectric MMs and TCO or (2) MMs and dielectrics through a detailed numerical analysis based on a Drude-Lorentz model for the permittivity of the TCO-layer. We show that the introduction of a MM/TCO interface leads to a transformation of the traditional-like SPPs. As a consequence, the new types of surface waves are found, and we reveal the existence of a new type of surface wave which is closely related to the presence of the TCO layers in the MM structure.
Asymmetrical quantum well degradation of InGaN/GaN blue laser diodes characterized by photoluminescence
Authors: Wen Pengyan , Liu Jianping , Zhang Shuming , Zhang Liqun , Ikeda Masao , Li Deyao , Tian Aiqin , Zhang Feng , Cheng Yang , Zhou Wei , Yang Hui
Published: November 2017

The temperature, power, and voltage dependent photoluminescence spectra are studied in InGaN/GaN double quantum well blue laser diodes. Emissions from the two quantum wells can be distinguished at low temperature at low excitation power density due to the different built-in electric field in the two quantum wells. This finding is utilized to study the degradation of InGaN/GaN blue laser diodes. Two peaks are observed for the non-aged laser diode (LD), while one peak for the aged LD which performed 3200 h until no laser output is detected. The disappearance of the high energy peak in the photoluminescence spectra indicates a heavier degradation of the quantum well on the p-side, which agrees with our previous observation that both the linewidth and the potential fluctuation of InGaN quantum wells (QWs) reduced for the aged LDs.
Steric effect in CO oxidation on Pt(111)
Authors: Ueta Hirokazu , Kurahashi Mitsunori
Published: November 2017

We present experimental evidence showing that the rate of CO oxidation on Pt(111) depends strongly on the geometry of an incident O2 molecule. The O2 sticking probability and the CO2 production rate on CO-covered Pt(111) surfaces during the alignment-controlled O2 beam irradiation were simultaneously monitored at a surface temperature of 330 K. The results indicate that, at the translational energy of 0.1-0.2 eV and at the CO coverage of <0.4 monolayers, both O2 adsorption and CO oxidation proceed exclusively when the O2 molecular axis is nearly parallel to the surface.
Reduction of thermal conductivity in YxSb2–xTe3 for phase change memory
Authors: Li Zhen , Miao Naihua , Zhou Jian , Xu Huibin , Sun Zhimei
Published: November 2017

Thermal conductivity (κ) is one of the fundamental properties of materials for phase change memory (PCM) application, as the set/reset processes strongly depend upon heat dissipation and transport. The κ of phase change materials in both amorphous and crystalline phases should be quite small, because it determines how energy-efficient the PCM device is during programming. At a high temperature, the electronic thermal conductivity (κe) is always notable for semiconductors, which is still lacking for antimony telluride under doping in the literature as far as we know. In this paper, using density functional theory and Boltzmann transport equations, we report calculations of lattice thermal conductivity κL and electronic thermal conductivity κe of the yttrium doped antimony telluride. We show that the average value of thermal conductivity decreases from ∼2.5 W m−1 K−1 for Sb2Te3 to ∼1.5 W m−1 K−1 for Y0.167Sb1.833Te3. This can be attributed to the reduced κL and κe, especially the κe at high temperature (near melting point). We further point out that the increased effective mass of carriers and the flat valance band edge are responsible for the decrease of κe. The reduced thermal conductivity is highly desirable for the decrease of heat dissipation and transport in PCM operations, which can increase the density of memory and reduce energy consumption.
Molecular dynamics simulation of a nanoscale feedback-free fluidic oscillator
Authors: Zhang Yunxiao , Fu Qingfei , Mo Chaojie , Yang Lijun
Published: November 2017

We present a molecular dynamics simulation study of a feedback-free fluidic oscillator model. Using the molecular dynamics simulations, it is demonstrated that the oscillation can be self-induced and sustained in a large range of flow rate and two very different jet directions. The oscillation mechanism of the nanoscale fluidic oscillator is physically similar to that in macroscale in which the dome vortex plays a crucial role. The thermal fluctuation is not significant enough to submerged the effect of hydrodynamics in the nanoscale feedback-free fluidic oscillator. The linear relationship between the oscillation frequency and the flow rate revealed by macroscopic experiments was also found in our simulations. Two of the three oscillation regimes found in macroscopic studies are shown to be able to be reproduced in our simulation. Our results show that molecular dynamics simulation is fully capable of studying the complicated flow in a feedback-free fluidic oscillator.
Nodeless vibrational amplitudes and quantum nonadiabatic dynamics in the nested funnel for a pseudo Jahn-Teller molecule or homodimer
Authors: Peters William K. , Tiwari Vivek , Jonas David M.
Published: November 2017

The nonadiabatic states and dynamics are investigated for a linear vibronic coupling Hamiltonian with a static electronic splitting and weak off-diagonal Jahn-Teller coupling through a single vibration with a vibrational-electronic resonance. With a transformation of the electronic basis, this Hamiltonian is also applicable to the anti-correlated vibration in a symmetric homodimer with marginally strong constant off-diagonal coupling, where the non-adiabatic states and dynamics model electronic excitation energy transfer or self-exchange electron transfer. For parameters modeling a free-base naphthalocyanine, the nonadiabatic couplings are deeply quantum mechanical and depend on wavepacket width; scalar couplings are as important as the derivative couplings that are usually interpreted to depend on vibrational velocity in semiclassical curve crossing or surface hopping theories. A colored visualization scheme that fully characterizes the non-adiabatic states using the exact factorization is developed. The nonadiabatic states in this nested funnel have nodeless vibrational factors with strongly avoided zeroes in their vibrational probability densities. Vibronic dynamics are visualized through the vibrational coordinate dependent density of the time-dependent dipole moment in free induction decay. Vibrational motion is amplified by the nonadiabatic couplings, with asymmetric and anisotropic motions that depend upon the excitation polarization in the molecular frame and can be reversed by a change in polarization. This generates a vibrational quantum beat anisotropy in excess of 2/5. The amplitude of vibrational motion can be larger than that on the uncoupled potentials, and the electronic population transfer is maximized within one vibrational period. Most of these dynamics are missed by the adiabatic approximation, and some electronic and vibrational motions are completely suppressed by the Condon approximation of a coordinate-independent transition dipole between adiabatic states. For all initial conditions investigated, the initial nonadiabatic electronic motion is driven towards the lower adiabatic state, and criteria for this directed motion are discussed.
Characterisation of nutritional quality traits of a chickpea (Cicer arietinum) germplasm collection exploited in chickpea breeding in Europe
Authors: Serrano Carmo , Carbas Bruna , Castanho Ana , Soares Andreia , Patto Maria Carlota Vaz , Brites Carla
Published: November 2017

Seed and flour characteristics of 79 chickpea (Cicer arietinum L.) accessions from a representative collection of the germplasm used by European breeders were evaluated. The accessions were grouped according to desi or kabuli types and by different seed traits (size, shape, colour, surface). The variation in nutritional composition was assessed by principal component analysis (PCA) of data from 13 quality parameters. The first PCA component discriminated the accessions by basic composition (protein, fibre, fat) plus δ-tocopherol, and the second by carotenoid composition (zeaxanthin). Whereas desi types showed higher protein and fibre, kabuli accessions exhibited higher fat contents. The majority of accessions analysed showed very low (<1%) resistant starch content. Higher carotenoid concentration was obtained in desi-type accessions and it was related to specific seed traits: small seed size, angular shape and black colour. Besides discrimination between desi and kabuli groups, the detected associations of classes of shape, size and colour seed traits can be explored in chickpea-quality breeding programs. Several accessions showed higher concentrations of α-tocopherol (>200 μg g–1). LEGCA728, with green colouring in the seed coat and cotyledons, showed exceptional lutein concentration (28.32 μg g–1). We conclude that the chickpea germplasm in use by European breeders presents high potential for improvement of nutritional and health-benefit components not yet routinely implemented in the breeding of this important pulse crop.
In planta functions of cytochrome P450 monooxygenase genes in the phytocassane biosynthetic gene cluster on rice chromosome 2
Authors: Ye Zhongfeng , Yamazaki Kohei , Minoda Hiromi , Miyamoto Koji , Miyazaki Sho , Kawaide Hiroshi , Yajima Arata , Nojiri Hideaki , Yamane Hisakazu , Okada Kazunori
Published: November 2017

In response to environmental stressors such as blast fungal infections, rice produces phytoalexins, an antimicrobial diterpenoid compound. Together with momilactones, phytocassanes are among the major diterpenoid phytoalexins. The biosynthetic genes of diterpenoid phytoalexin are organized on the chromosome in functional gene clusters, comprising diterpene cyclase, dehydrogenase, and cytochrome P450 monooxygenase genes. Their functions have been studied extensively using in vitro enzyme assay systems. Specifically, P450 genes (CYP71Z6, Z7; CYP76M5, M6, M7, M8) on rice chromosome 2 have multifunctional activities associated with ent-copalyl diphosphate-related diterpene hydrocarbons, but the in planta contribution of these genes to diterpenoid phytoalexin production remains unknown. Here, we characterized cyp71z7 T-DNA mutant and CYP76M7/M8 RNAi lines to find that potential phytoalexin intermediates accumulated in these P450-suppressed rice plants. The results suggested that in planta, CYP71Z7 is responsible for C2-hydroxylation of phytocassanes and that CYP76M7/M8 is involved in C11α-hydroxylation of 3-hydroxy-cassadiene. Based on these results, we proposed potential routes of phytocassane biosynthesis in planta.
MRCKα is activated by caspase cleavage to assemble an apical actin ring for epithelial cell extrusion
Authors: Gagliardi Paolo Armando , Somale Desiana , Puliafito Alberto , Chiaverina Giulia , di Blasio Laura , Oneto Michele , Bianchini Paolo , Bussolino Federico , Primo Luca
Published: November 2017

Extrusion of apoptotic cells from epithelial tissues requires orchestrated morphological rearrangements of the apoptotic cell and its neighbors. However, the connections between the apoptotic cascade and events leading to extrusion are not fully understood. Here, we characterize an apoptotic extrusion apical actin ring (EAAR) that is assembled within the apoptotic cell and drives epithelial extrusion. Caspase-mediated cleavage of myotonic dystrophy kinase–related CDC42-binding kinase-α (MRCKα) triggers a signaling pathway that leads to the assembly of EAAR that pulls actin bundles, resulting in the compaction and removal of the cell body. We provide a detailed portrait of the EAAR including F-actin flow, the contribution of myosin contraction, and actin polymerization at bundles' terminals when the product of MRCKα cleavage is expressed. These results add to our understanding of the mechanisms controlling the process of epithelial extrusion by establishing a causal relationship between the triggering events of apoptosis, the activation of MRCKα, and its subsequent effects on the dynamics of actomyosin cytoskeleton rearrangement.
Response of plasma rotation to resonant magnetic perturbations in J-TEXT tokamak
Authors: Yan W , Chen Z Y , Huang D W , Hu Q M , Shi Y J , Ding Y H , Cheng Z F , Yang Z J , Pan X M , Lee S G , Tong R H , Wei Y N , Dong Y B
Published: November 2017

The response of plasma toroidal rotation to the external resonant magnetic perturbations (RMP) has been investigated in Joint Texas Experimental Tokamak (J-TEXT) ohmic heating plasmas. For the J-TEXT’s plasmas without the application of RMP, the core toroidal rotation is in the counter-current direction while the edge rotation is near zero or slightly in the co-current direction. Both static RMP experiments and rotating RMP experiments have been applied to investigate the plasma toroidal rotation. The core toroidal rotation decreases to lower level with static RMP. At the same time, the edge rotation can spin to more than 20 km s−1 in co-current direction. On the other hand, the core plasma rotation can be slowed down or be accelerated with the rotating RMP. When the rotating RMP frequency is higher than mode frequency, the plasma rotation can be accelerated to the rotating RMP frequency. The plasma confinement is improved with high frequency rotating RMP. The plasma rotation is decelerated to the rotating RMP frequency when the rotating RMP frequency is lower than the mode frequency. The plasma confinement also degrades with low frequency rotating RMP.
Dynamic ASEP, Duality, and Continuous q−1-Hermite Polynomials
Authors: Borodin Alexei , Corwin Ivan
Published: November 2017

We demonstrate a Markov duality between the dynamic asymmetric simple exclusion process (ASEP) and the standard ASEP. We then apply this to step initial data, as well as a half-stationary initial data (which we introduce). While investigating the duality for half-stationary initial data, we uncover and utilize connections to the continuous q−1-Hermite polynomials. Finally, we introduce a family of stationary initial data which are related to the indeterminate moment problem associated with these q−1-Hermite polynomials.