bluuebunny/crossref_metadata_2025 huggingface dataset:
Polymeric nanocapsules with up-converting nanocrystals cargo make ideal fluorescent bioprobes
Authors: Bazylińska U. , Wawrzyńczyk D. , Kulbacka J. , Frąckowiak R. , Cichy B. , Bednarkiewicz A. , Samoć M. , Wilk K. A.
Published: July 2016

An innovative approach for up-converting nanoparticles adaptation for bio-related and theranostic applications is presented. We have successfully encapsulated multiple, ~8 nm in size NaYF4 nanoparticles inside the polymeric nanocarriers with average size of ~150 nm. The initial coating of nanoparticles surfaces was preserved due to the hydrophobic environment inside the nanocapsules, and thus no single nanoparticle surface functionalization was necessary. The selection of biodegradable and sugar-based polyelectrolyte shells ensured biocompatibility of the nanostructures, while the choice of Tm3+ and Yb3+ NaYF4 nanoparticles co-doping allowed for near-infrared to near-infrared bioimaging of healthy and cancerous cell lines. The protective role of organic shell resulted in not only preserved high up-converted emission intensity and long luminescence lifetimes, without quenching from water environment, but also ensured low cytotoxicity and high cellular uptake of the engineered nanocapsules. The multifunctionality of the proposed nanocarriers is a consequence of both the organic exterior part that is accessible for conjugation with biologically important molecules, and the hydrophobic interior, which in future application may be used as a container for co-encapsulation of inorganic nanoparticles and anticancer drug cargo.
The RNA-binding protein repertoire of Arabidopsis thaliana
Authors: Marondedze Claudius , Thomas Ludivine , Serrano Natalia L. , Lilley Kathryn S. , Gehring Chris
Published: July 2016

RNA-binding proteins (RBPs) have essential roles in determining the fate of RNA from synthesis to decay and have been studied on a protein-by-protein basis, or computationally based on a number of well-characterised RNA-binding domains. Recently, high-throughput methods enabled the capture of mammalian RNA-binding proteomes. To gain insight into the role of Arabidopsis thaliana RBPs at the systems level, we have employed interactome capture techniques using cells from different ecotypes grown in cultures and leaves. In vivo UV-crosslinking of RNA to RBPs, oligo(dT) capture and mass spectrometry yielded 1,145 different proteins including 550 RBPs that either belong to the functional category ‘RNA-binding’, have known RNA-binding domains or have orthologs identified in mammals, C. elegans, or S. cerevisiae in addition to 595 novel candidate RBPs. We noted specific subsets of RBPs in cultured cells and leaves and a comparison of Arabidopsis, mammalian, C. elegans, and S. cerevisiae RBPs reveals a common set of proteins with a role in intermediate metabolism, as well as distinct differences suggesting that RBPs are also species and tissue specific. This study provides a foundation for studies that will advance our understanding of the biological significance of RBPs in plant developmental and stimulus specific responses.
Inactivation of Fam20B in Joint Cartilage Leads to Chondrosarcoma and Postnatal Ossification Defects
Authors: Ma Pan , Yan Wenjuan , Tian Ye , Wang Jingya , Feng Jian Q. , Qin Chunlin , Cheng Yi-Shing Lisa , Wang Xiaofang
Published: July 2016

During endochondral ossification, chondrocytes embed themselves in a proteoglycan-rich matrix during the proliferation-maturation transition. Accumulating evidence shows that proteoglycans are essential components for chondrocyte proliferation and differentiation. When we conditionally inactivated FAM20B (Family with sequence similarity 20 member-B), which is a newly identified xylose kinase essential for glycosaminoglycan (GAG) formation on the protein core of proteoglycans, from the dental mesenchyme using Osr2-Cre, which is also strongly expressed in joint cartilage, we found chondrosarcoma in the knee joint and remarkable defects of postnatal ossification in the long bones. Mechanistic analysis revealed that the defects were associated with gain of function in multiple signaling pathways in the epiphyseal chondrocytes, such as those derived by WNT, BMP, and PTHrP/IHH molecules, suggesting that the FAM20B-catalyzed proteoglycans are critical mediators for a signaling balance in the regulatory network controlling chondrocyte differentiation and proliferation. In particular, we demonstrated that the WNT inhibitor was able to rescue part of the bone defects in Osr2-Cre;Fam20Bfl/fl mice, indicating that FAM20B-catalyzed proteoglycans regulate postnatal endochondral ossification partially through the mediation of WNT signaling.
Identification of an NDM-5-producing Escherichia coli Sequence Type 167 in a Neonatal Patient in China
Authors: Zhu Yuan-qi , Zhao Jing-yi , Xu Cha , Zhao Hui , Jia Nan , Li Yan-nian
Published: July 2016

Emergence of New Delhi metallo-β-lactamase-producing Enterobacteriaceae has become a challenging threat to public health. Two carbapenem-resistant Escherichia coli, strain QD28 and QD29, were recovered from the aspirating sputum of a neonate and the urine of an adult in a Chinese hospital in 2013. Molecular typing revealed that both isolates belonged to the sequence type 167, but they were clonally diverse. Both isolates exhibited resistance to carbapenems, cephalosporins, ciprofloxacin, gentamicin, piperacillin-tazobactam and trimethoprim-sulfamethoxazole. In addition, strain QD28 was also resistant to aztreonam and strain QD29 was resistant to amikacin, fosfomycin and minocycline. Antimicrobial resistance gene screening revealed that strain QD28 harbored aac(6′)-Ib, blaCTX-M-14, blaNDM-5, blaTEM-1 and sul1 genes and strain QD29 harbored aac(6′)-Ib, blaCTX-M-3, blaNDM-5, blaTEM-1, rmtB, sul1 and sul2 genes. The blaNDM-5 gene was found to be located on a 46-kb plasmid in two isolates and further sequence analysis showed that this plasmid was highly similar to the previously reported IncX3 plasmid pNDM-MGR194 in India. This is the first identification of blaNDM-5-carrying E. coli in the neonatal infection.
First evidence of metal transfer into hydrophobic deep eutectic and low-transition-temperature mixtures: indium extraction from hydrochloric and oxalic acids
Authors: Tereshatov E. E. , Boltoeva M. Yu. , Folden C. M.
Published: July 2016

This is the first report on metallic species transfer from aqueous hydrochloric and oxalic acid media into hydrophobic deep eutectic and low-transition-temperature mixtures composed of quaternary ammonium salts or menthol and carboxylic acids.
Profiles of phenolic compounds by FT-ICR MS and antioxidative and antiproliferative activities of Stryphnodendron obovatum Benth leaf extracts
Authors: da Costa M. F. , Galaverna R. S. , Pudenzi Marcos A. , Ruiz A. L. T. G. , de Carvalho J. E. , Eberlin M. N. , Santos C. dos
Published: July 2016

The main phenolic constituents of S. obovatum leaf extracts, analyzed by FT-ICR MS, were correlated with their antioxidant and in vitro antiproliferative activities.
An ultrasensitive label-free immunoassay for C-reactive protein detection in human serum based on electron transfer
Authors: Zhang Xi , Hu Rong , Zhang Kunlei , Bai Ruyan , Li Delei , Yang Yunhui
Published: July 2016

A rapid, ultrasensitive, and practical label-free electrochemical immunoassay for measuring C-reactive protein (CRP) in real serum samples was developed.
Nanoparticle-based highly sensitive MRI contrast agents with enhanced relaxivity in reductive milieu
Authors: Sigg Severin J. , Santini Francesco , Najer Adrian , Richard Pascal U. , Meier Wolfgang P. , Palivan Cornelia G.
Published: July 2016

A gadolinium containing nanoparticle exhibiting a 10-fold higher r1 relaxivity than Dotarem® and further increase in relaxivity in reductive milieu is proposed.
Contrasted photochromic and luminescent properties in dinuclear Pt(ii) complexes linked through a central dithienylethene unit
Authors: Boixel Julien , Zhu Yifan , Le Bozec Hubert , Benmensour Mohamed Ali , Boucekkine Abdou , Wong Keith Man-Chung , Colombo Alessia , Roberto Dominique , Guerchais Véronique , Jacquemin Denis
Published: July 2016

Two unprecedented photochromic complexes, Pt-A and Pt-B, have been characterised.
SERS of meso-droplets supported on superhydrophobic wires allows exquisitely sensitive detection of dipicolinic acid, an anthrax biomarker, considerably below the infective dose
Authors: Cheung Melody , Lee Wendy W. Y. , Cowcher David P. , Goodacre Royston , Bell Steven E. J.
Published: July 2016

SERS of <1 μL colloid meso-droplets on superhydrophobic supports allowed detection of a total mass of dipicolinic acid equivalent to 18 anthrax spores.
Focusing on probe-modified peptides: a quick and effective method for target identification
Authors: Sun Huan , Ren Yan , Hou Weijie , Li Lin , Zeng Fanqi , Li Sisi , Ma Yongfen , Liu Xiao , Chen She , Zhang Zhiyuan
Published: July 2016

BTC-ABPP was developed by converting the reactants of a click conjugation from proteins (biochemistry) to peptides (chemistry) to identify the modified peptides.
Impact of Ho3+-doping on 13C dynamic nuclear polarization using trityl OX063 free radical
Authors: Kiswandhi Andhika , Niedbalski Peter , Parish Christopher , Kaur Pavanjeet , Martins André , Fidelino Leila , Khemtong Chalermchai , Song Likai , Sherry A. Dean , Lumata Lloyd
Published: July 2016

We have investigated the effects of Ho-DOTA doping on the dynamic nuclear polarization (DNP) of [1-13C] sodium acetate using trityl OX063 free radical at 3.35 T and 1.2 K.
syn-Bimane as a chelating O-donor ligand for palladium(ii)
Authors: Das Partha Jyoti , Diskin-Posner Yael , Firer Michael , Montag Michael , Grynszpan Flavio
Published: July 2016

The first example of a metal-coordinated bimane scaffold, a cationic Pd(ii)-syn-bimane complex, was prepared and characterized. Its crystal structure reveals a nonplanar bimane framework. Spectroscopic evidence shows that bimane coordination is reversible in solution.
Tetraphenylethylene derivative capped CH3NH3PbBr3 nanocrystals: AIE-activated assembly into superstructures
Authors: Zhang Feng , Zhou Tianye , Liu Guogang , Shi Jianbing , Zhong Haizheng , Dong Yuping
Published: July 2016

The surfaces of semiconductor nanocrystals have been known to be a very important factor in determining their optical properties. The introduction of functionalized ligands can further enhance the interactions between nanocrystals, which is beneficial for the assembly of nanocrystals. In a previous report, we developed a ligand-assisted reprecipitation method to fabricate organometal halide perovskite nanocrystals capped with octylamine and oleic acid. Here, a TPE derivative 3-(4-(1,2,2-triphenylvinyl)phenoxy)propan-1-amine, which shows a typical aggregation induced emission feature, is applied to replace octylamine to fabricate CH3NH3PbBr3 nanocrystals. The obtained CH3NH3PbBr3 nanocrystals were nanocubes (average diameter ∼ 11.1 nm) and are likely to assemble into ordered superstructures. By adjusting the chain length of the TPE derivative, we found that the assembly of the CH3NH3PbBr3 nanocrystals was correlated with the interactions between the TPE groups. This provides a new platform to investigate the ligand effects in nanocrystal solids and may potentially achieve enhanced optical and electrical properties.
Preparation and characterization of single and dual propylene oxide and octenyl succinic anhydride modified starch carriers for the microencapsulation of essential oils
Authors: Baranauskienė Renata , Rutkaitė Ramunė , Pečiulytė Laura , Kazernavičiūtė Rita , Venskutonis Petras Rimantas
Published: July 2016

Modification with propylene oxide and octenyl succinic anhydride was used to produce modified potato starch derivatives suitable for the encapsulation of essential oils.
Laser direct-write for fabrication of three-dimensional paper-based devices
Authors: He P. J. W. , Katis I. N. , Eason R. W. , Sones C. L.
Published: July 2016

Schematics of 3D devices formed by either stacking of multiple 2D devices or designing polymer blocks within a single substrate.
Novel and less explored chemotypes of natural origin for the inhibition of Hsp90
Authors: Pellati Federica , Rastelli Giulio
Published: July 2016

This review focuses on novel classes of natural products whose structures have not yet been thoroughly explored for medicinal chemistry purposes. These novel chemotypes may be useful starting points to develop compounds that alter Hsp90 functionvianovel mechanisms.
Temperature and pH dual-responsive poly(vinyl lactam) copolymers functionalized with amine side groups via RAFT polymerization
Authors: Peng Huan , Xu Wenjing , Pich Andrij
Published: July 2016

A series of statistical copolymers based on cyclic N-vinyl lactams and N-vinylformamide were synthesized via RAFT polymerization. Tempertaure/pH dual responsive polymers were obtained via hydrolysis the copolymers in alkaline conditions.
Simultaneous enhancement of performance and insensitivity to active layer thickness for OPVs by functionalizing π-spacer's side chain
Authors: Yang Dalei , Zhang Tong , Zhao Xiaoli , Zeng Guang , Li Zidong , Tian Yumeng , He Fagui , Zhang Jidong , Yang Xiaoniu
Published: July 2016

A novel BTI based copolymer was designed by incorporating a decylthio modified π-spacer into the backbone for improving the photovoltaic performance.
Correction: A dual stimuli responsive fluorescent probe carrier from a double hydrophilic block copolymer capped with β-cyclodextrin
Authors: Yang Guang , Yang Zhen , Mu Chengguang , Fan Xiaodong , Tian Wei , Abidian Mohammad Reza , Wang Qing
Published: July 2016

Correction for ‘A dual stimuli responsive fluorescent probe carrier from a double hydrophilic block copolymer capped with β-cyclodextrin’ by Guang Yang et al., Polym. Chem., 2015, 6, 3382–3386.
Selective Pd-catalyzed α- and β-arylations of the furan rings of (ortho-bromophenyl)furan-2-yl-methanones: C(CO)–C bond cleavage with a furan ring as a leaving group and synthesis of furan-derived fluorenones
Authors: Zhang Xiaoting , Liu Jianchao , Yang Yongjie , Wang Furong , Jiang Huanfeng , Yin Biaolin
Published: July 2016

Selective palladium diacetate-catalyzed α- and β-arylations of the furan rings of (ortho-bromophenyl)furan-2-yl-methanones 1 under two different conditions are reported.
A series of transition metal–organic frameworks: crystal structures, luminescence properties, and sensitizing for luminescent Ln(iii) ions in aqueous solution
Authors: Qu Xiang-Long , Zheng Xiao-Li , Li Xia
Published: July 2016

A series of transition metal–organic frameworks were assembled. Crystal structures, luminescence and sensitizing for Ln(iii) ions were studied.
Epoxide hydrolysis and alcoholysis reactions over crystalline Mo–V–O oxide
Authors: Zhang Xiaochen , Wang Min , Zhang Chaofeng , Lu Jianmin , Wang Yehong , Wang Feng
Published: July 2016

The new utilization in the hydrolysis and alcoholysis of epoxides for the Mo–V–O material was discovered. It showed a preferable catalytic performance.
Synthesis and characterization of polyethersulfone with intrinsic microporosity
Authors: Lee Kyuchul , Jeon Jun Woo , Maeng Bo Mi , Huh Kang Moo , Chan Won Jong , Yoo Youngjae , Kim Yong Seok , Kim Byoung Gak
Published: July 2016

A new non-ladder-type polyethersulfone-type PIM that incorporated a linear sulfone moiety was synthesized.
Environmentally friendly approach to α-acyloxy carboxamides via a chemoenzymatic cascade
Authors: Paprocki Daniel , Koszelewski Dominik , Żądło Anna , Walde Peter , Ostaszewski Ryszard
Published: July 2016

A new, green route for the synthesis of α-acyloxy carboxamides from an alcohol, a carboxylic acid and an isocyanide was developed.
Fabrication of TiO2@MIL-53 core–shell composite for exceptionally enhanced adsorption and degradation of nonionic organics
Authors: Chang Na , He Dong-Ying , Li Yi-Xin , Tang Zhi-Wei , Huang Yan-Feng
Published: July 2016

We report new strategy based on non-aqueous sol–gel reaction for in situ fabrication of TiO2@MIL-53 core–shell composites, and show excellent performance of the composites for exceptionally enhanced adsorption and degradation of nonionic organics.
Fluorescence alarming ON–OFF–ON switch derived from biocompatible carbon nanoparticle–hemoglobin–H2O2interaction
Authors: Singh Rana Prem Jyoti , Singh Pallavi , Kar Prasenjit
Published: July 2016

The present study comprises a deeper comprehension on the applicability of environmentally benign water soluble fluorescent Carbon Nanoparticles (CNs) synthesised from jamun (Syzygium cumini).
Nanosorbcats of methylene blue on novel Fe2O3 nanorods for photocatalytic water oxidation
Authors: Chen Qiu-Yun , Huang Dong-liang , Wang Yin-Bing , Shao Jian , Qu Ling-Ling
Published: July 2016

MB@pfa@Fe2O3 nanorods are efficient recyclable nanosorbcats for LED light driven dioxygen generation using water as oxygen source.
Mesoporous SnO2–SiO2 and Sn–silica–carbon nanocomposites by novel non-hydrolytic templated sol–gel synthesis
Authors: Skoda David , Styskalik Ales , Moravec Zdenek , Bezdicka Petr , Bursik Jiri , Mutin P. Hubert , Pinkas Jiri
Published: July 2016

A novel non-hydrolytic sol–gel (NHSG) synthesis of mesoporous tin silicate xerogels is presented.
Luminescence thermometry and imaging in the second biological window at high penetration depth with Nd:KGd(WO4)2 nanoparticles
Authors: Savchuk Ol. , Carvajal J. J. , De la Cruz L. G. , Haro-González P. , Aguiló M. , Díaz F.
Published: July 2016

Nd:KGd(WO4)2 nanoparticles were used as luminescent thermometers operating in the biological windows and NIR imaging with high penetration depth.
High performance thermoelectric materials and devices based on GeTe
Authors: Perumal Suresh , Roychowdhury Subhajit , Biswas Kanishka
Published: July 2016

This review summarizes the past and recent developments in the thermoelectric properties, nano/microstructure modulations, and mechanical and thermal stability of GeTe based materials and thermoelectric devices based on GeTe.
Structural insights into the interaction of p97 N-terminus domain and VBM in rhomboid protease, RHBDL4
Authors: Lim Jia Jia , Lee Youngjin , Ly Tue Tu , Kang Jung Youn , Lee Jung-Gyu , An Jun Yop , Youn Hyung-Seop , Park Kyoung Ryoung , Kim Tae Gyun , Yang Jin Kuk , Jun Youngsoo , Eom Soo Hyun
Published: July 2016

RHBDL4 is an active rhomboid that specifically recognizes and cleaves atypical, positively charged transmembrane endoplasmic reticulum-associated degradation (ERAD) substrates. Interaction of valosin-containing protein (p97/VCP) and RHBDL4 is crucial to retrotranslocate polyubiquitinated substrates for ERAD pathway. Here, we report the first complex structure of VCP-binding motif (VBM) with p97 N-terminal domain (p97N) at 1.88 Å resolution. Consistent with p97 adaptor proteins including p47-ubiquitin regulatory X (UBX), gp78-VCP-interacting motif (VIM), OTU1-UBX-like element, and FAF1-UBX, RHBDL4 VBM also binds at the interface between the two lobes of p97N. Notably, the RF residues in VBM are involved in the interaction with p97N, showing a similar interaction pattern with that of FPR signature motif in the UBX domain, although the directionality is opposite. Comparison of VBM interaction with VIM of gp78, another α-helical motif that interacts with p97N, revealed that the helix direction is inversed. Nevertheless, the conserved arginine residues in both motifs participate in the majority of the interface via extensive hydrogen bonds and ionic interactions with p97N. We identified novel VBM-binding mode to p97N that involves a combination of two types of p97–cofactor specificities observed in the UBX and VIM interactions. This highlights the induced fit model of p97N interdomain cleft upon cofactor binding to form stable p97–cofactor complexes. Our mutational and biochemical analyses in defining the specific interaction between VBM and p97N have elucidated the importance of the highly conserved VBM, applicable to other VBM-containing proteins. We also showed that RHBDL4, ubiquitins, and p97 co-operate for efficient substrate dislocation.
A meta-analysis of copper level and risk of preeclampsia: evidence from 12 publications
Authors: Fan Yuqin , Kang Yan , Zhang Min
Published: July 2016

The association between copper level and risk of preeclampsia (PE) has produced inconsistent results. Thus, a meta-analysis was conducted to summarize the evidence from epidemiological studies for copper level and PE risk. Pertinent studies were identified by a search of PubMed and Web of Knowledge up to April 2016. Standardized mean difference (SMD) was performed to combine the results. Random-effect model (REM) was used. Publication bias was estimated using Egger's regression asymmetry test. Twelve articles (10 case–control studies and 2 cross-sectional studies) involving 442 PE cases and 463 health controls were included in this meta-analysis. Our pooled results suggested that PE patients had a higher copper level compared with healthy pregnancy controls [summary SMD=0.69, 95% CI: 0.54–0.84, I2=96.7%; P<0.001]. The association was also significant in Asian population [SMD=0.73, 95% CI=0.57–0.90, I2=97.3%] and European populations [SMD=0.50, 95% CI=0.14–0.86, I2=58.9%]. After conducting the subgroup analysis and sensitive analysis, the results showed consistent significant association with the one based on all studies. No publication biases were found. Our analysis indicated that plasma or serum copper level in PE patients was significantly higher than that in healthy pregnancy women.
E‐plane metallic RWG‐to‐SIW transition for large‐scale MM‐wave phased array antenna applications
Authors: Abdel‐Wahab W.M. , Ehsandar A. , Al‐Saedi H. , Safavi‐Naeini S.
Published: July 2016

A novel air‐filled E‐plane rectangular waveguide (RWG) to substrate integrated waveguide (SIW) transition, which is suitable for Ka‐band large‐scale antenna arrays, is presented. The power is coupled between the RWG and SIW through two slots: one etched on the SIW ground plane and the other cut through metallic RWG narrow side wall (E‐plane). A back‐to‐back transition is designed, fabricated, assembled, and tested. Measured results show a good agreement with the simulated ones. An SIW attenuation loss ≤0.33 dB/1 cm and a transition return loss better than 10 dB have been experimentally obtained over the band 28.30–30.8 GHz.
Compact QB‐BPF based on single PMR
Authors: Zhu Chuanming , Xu Jin , Kang Wei , Wu Wen
Published: July 2016

Compact quint‐band bandpass filter (QB‐BPF) based on a novel penta‐mode resonator (PMR) is presented. The first five resonant modes of the proposed PMR can be independently controlled by shorted high‐impedance section of quarter‐wave stepped impedance resonators, and four loaded open stubs resulting in the independency of centre frequencies and quality factors of five passbands. Meanwhile, due to the multipath propagation induced from cross‐coupling, 11 transmission zeros are realised around five passbands, resulting in high passband selectivity. As an example, a QB‐BPF operating at 0.63/1.2/1.8/2.45/3.5 GHz is designed and fabricated. The fabricated QB‐BPF also has a compact size of 0.18λg × 0.12λg.
Human action recognition based on tensor shape descriptor
Authors: Li Jianjun , Mao Xia , Wu Xingyu , Liang Xiaogeng
Published: July 2016

Human action recognition is an important task. This study presents an efficient framework for recognising action with a 3D skeleton kinematic joint model in less computational time for practical usage. First, a tensor shape descriptor (TSD) is proposed in this study, which takes advantage of the spatial independence of body joints, avoids a lot of difficult problem of the explicit motion estimation required in traditional methods, reserves the spatial information of each frame. Thus, the new TSD is a complete and view‐invariant descriptor. Second, a novel tensor dynamic time warping (TDTW) method is proposed to measure joint‐to‐joint similarity of 3D skeletal body joints locally in the temporal extent, which is implemented by extending DTW to that of two multiway data arrays (or tensors). Then, a multi‐linear projection process is employed to map the TSD to a low‐dimensional tensor subspace, which is classified by the nearest neighbour classifier. The experiment results on the public action data set (MSR‐Action3D) and motion capture data set (CMU_Mocap) show that the proposed method can achieve a comparable or better performance in recognition accuracy compared with the state‐of‐the‐art approaches.
Tilted‐wire scatterer model for narrowband radar imaging of rotating blades
Authors: Kodituwakku Sandun , Melino Rocco , Berry Paul E. , Tran Hai‐Tan
Published: July 2016

The authors propose a technique for the imaging of fast‐rotating blades such as those of a helicopter rotor, based on the use of the novel tilted‐wire scatterer model, rather than the traditional point‐scatterer model, combined with the well‐known technique of orthogonal matching pursuit for parameter estimation. The tilted wire incorporating a six‐parameter set is a flexible scattering model that can most efficiently represent objects such as rotating blades in three dimensions. Parameters of the model atoms are directly used for target imaging, or can be used to provide new efficient metrics for automatic target classification of such type of targets. Results are demonstrated with Squirrel helicopter data.
Design of a high‐speed electrothermal linear micromotor for microelectromechanical systems safety‐and‐arming devices
Authors: Li Xiuyuan , Zhao Yulong , Hu Tengjiang , Bai Yingwei
Published: July 2016

The design, fabrication and characterisation of a high‐speed electrothermal linear micromotor for microelectromechanical systems safety‐and‐arming devices are presented. The micromotor consists of a microspring, a barrier plate and four V‐shaped electrothermal actuators with microlever amplifications. The whole device is fabricated on a silicon‐on‐insulator wafer with a 50 µm device layer and the fabrication process is introduced. The micromotor has been successfully operated at a speed of 35.66 mm/s over a range of 500 µm with an output force of 5.27 mN under the applied voltage of 23 V. The chip area of the fabricated micromotor is about 19.20 mm2, which means the micromotor can be easily integrated with other microdevices. The linear micromotor performs well in driving force, mechanical strength and working speed, which signifies the proposed device is suitable for safety‐and‐arming devices.
One‐step modification method to fabricate wettability patterns on aluminium substrate
Authors: Zheng Huanxi , Huang Shuai , Liu Jiyu , Chen Faze , Yang Xiaolong , Liu Xin , Sun Jing , Xu Wenji
Published: July 2016

Since there is currently no method to selectively fabricate superhydrophobic regions on superhydrophilic surfaces of metal substrates, wettability patterns on metal substrates are prepared via the three‐step technique including superhydrophilic, superhydrophobic and selectively superhydrophilic modifications. Here, an innovative method that can selectively lower surface energy of superhydrophilic surfaces, and thereby makes it more convenient to fabricate the wettability patterns, is proposed. Chemical etching is used to formulate micro/nanoscale rough structures and fabricate superhydrophilic aluminium (Al) surface, which is then covered by patterned mask whose main composition is siloxane. Removing the mask after 80°C water bath heating for 20 s, the covered Al surface has been modified to become superhydrophobic (contact angles >165°, sliding angles <1.5°), while the uncovered region is still superhydrophilic, and wettability patterns are therefore obtained. Fourier transform infrared spectrophotometer and Raman spectra indicate that the change of wettability is induced by hydrophobic groups on the modified surfaces. The superhydrophobic surfaces fabricated by this method have excellent high‐temperature resistance. The method proposed is simple, rapid and environmental‐friendly.
On controlling networks of limit-cycle oscillators
Authors: Skardal Per Sebastian , Arenas Alex
Published: July 2016

The control of network-coupled nonlinear dynamical systems is an active area of research in the nonlinear science community. Coupled oscillator networks represent a particularly important family of nonlinear systems, with applications ranging from the power grid to cardiac excitation. Here, we study the control of network-coupled limit cycle oscillators, extending the previous work that focused on phase oscillators. Based on stabilizing a target fixed point, our method aims to attain complete frequency synchronization, i.e., consensus, by applying control to as few oscillators as possible. We develop two types of controls. The first type directs oscillators towards larger amplitudes, while the second does not. We present numerical examples of both control types and comment on the potential failures of the method.
Dynamics of a molecular glass former: Energy landscapes for diffusion in ortho-terphenyl
Authors: Niblett S. P. , de Souza V. K. , Stevenson J. D. , Wales D. J.
Published: July 2016

Relaxation times and transport processes of many glass-forming supercooled liquids exhibit a super-Arrhenius temperature dependence. We examine this phenomenon by computer simulation of the Lewis-Wahnström model for ortho-terphenyl. We propose a microscopic definition for a single-molecule cage-breaking transition and show that, when correlation behaviour is taken into account, these rearrangements are sufficient to reproduce the correct translational diffusion constants over an intermediate temperature range in the supercooled regime. We show that super-Arrhenius behaviour can be attributed to increasing negative correlation in particle movement at lower temperatures and relate this to the cage-breaking description. Finally, we sample the potential energy landscape of the model and show that it displays hierarchical ordering. Substructures in the landscape, which may correspond to metabasins, have boundaries defined by cage-breaking transitions. The cage-breaking formulation provides a direct link between the potential energy landscape and macroscopic diffusion behaviour.
On the structure of the two-stream instability–complex G-Hamiltonian structure and Krein collisions between positive- and negative-action modes
Authors: Zhang Ruili , Qin Hong , Davidson Ronald C. , Liu Jian , Xiao Jianyuan
Published: July 2016

The two-stream instability is probably the most important elementary example of collective instabilities in plasma physics and beam-plasma systems. For a warm plasma with two charged particle species, the instability diagram of the two-stream instability based on a 1D warm-fluid model exhibits an interesting band structure that has not been explained. We show that the band structure for this instability is the consequence of the Hamiltonian nature of the warm two-fluid system. Interestingly, the Hamiltonian nature manifests as a complex G-Hamiltonian structure in wave-number space, which directly determines the instability diagram. Specifically, it is shown that the boundaries between the stable and unstable regions are locations for Krein collisions between eigenmodes with different Krein signatures. In terms of physics, this rigorously implies that the system is destabilized when a positive-action mode resonates with a negative-action mode, and that this is the only mechanism by which the system can be destabilized. It is anticipated that this physical mechanism of destabilization is valid for other collective instabilities in conservative systems in plasma physics, accelerator physics, and fluid dynamics systems, which admit infinite-dimensional Hamiltonian structures.
Torsionally mediated spin-rotation hyperfine splittings at moderate to high J values in methanol
Authors: Belov S. P. , Golubiatnikov G. Yu. , Lapinov A. V. , Ilyushin V. V. , Alekseev E. A. , Mescheryakov A. A. , Hougen J. T. , Xu Li-Hong
Published: July 2016

This paper presents an explanation based on torsionally mediated proton-spin–overall-rotation interaction for the observation of doublet hyperfine splittings in some Lamb-dip sub-millimeter-wave transitions between ground-state torsion-rotation states of E symmetry in methanol. These unexpected doublet splittings, some as large as 70 kHz, were observed for rotational quantum numbers in the range of J = 13 to 34, and K = − 2 to +3. Because they increase nearly linearly with J for a given branch, we confined our search for an explanation to hyperfine operators containing one nuclear-spin angular momentum factor I and one overall-rotation angular momentum factor J (i.e., to spin-rotation operators) and ignored both spin-spin and spin-torsion operators, since they contain no rotational angular momentum operator. Furthermore, since traditional spin-rotation operators did not seem capable of explaining the observed splittings, we constructed totally symmetric “torsionally mediated spin-rotation operators” by multiplying the E-species spin-rotation operator by an E-species torsional-coordinate factor of the form e±niα. The resulting operator is capable of connecting the two components of a degenerate torsion-rotation E state. This has the effect of turning the hyperfine splitting pattern upside down for some nuclear-spin states, which leads to bottom-to-top and top-to-bottom hyperfine selection rules for some transitions, and thus to an explanation for the unexpectedly large observed hyperfine splittings. The constructed operator cannot contribute to hyperfine splittings in the A-species manifold because its matrix elements within the set of torsion-rotation A1 and A2 states are all zero. The theory developed here fits the observed large doublet splittings to a root-mean-square residual of less than 1 kHz and predicts unresolvable splittings for a number of transitions in which no doublet splitting was detected.
CMOS compatible electrode materials selection in oxide-based memory devices
Authors: Zhuo V. Y.-Q. , Li M. , Guo Y. , Wang W. , Yang Y. , Jiang Y. , Robertson J.
Published: July 2016

Electrode materials selection guidelines for oxide-based memory devices are constructed from the combined knowledge of observed device operation characteristics, ab-initio calculations, and nano-material characterization. It is demonstrated that changing the top electrode material from Ge to Cr to Ta in the Ta2O5-based memory devices resulted in a reduction of the operation voltages and current. Energy Dispersed X-ray (EDX) Spectrometer analysis clearly shows that the different top electrode materials scavenge oxygen ions from the Ta2O5 memory layer at various degrees, leading to different oxygen vacancy concentrations within the Ta2O5, thus the observed trends in the device performance. Replacing the Pt bottom electrode material with CMOS compatible materials (Ru and Ir) further reduces the power consumption and can be attributed to the modification of the Schottky barrier height and oxygen vacancy concentration at the electrode/oxide interface. Both trends in the device performance and EDX results are corroborated by the ab-initio calculations which reveal that the electrode material tunes the oxygen vacancy concentration via the oxygen chemical potential and defect formation energy. This experimental-theoretical approach strongly suggests that the proper selection of CMOS compatible electrode materials will create the critical oxygen vacancy concentration to attain low power memory performance.
Round impinging jets with relatively large stand-off distance
Authors: Shademan Mehrdad , Balachandar Ram , Roussinova Vesselina , Barron Ron
Published: July 2016

Large eddy simulation and particle image velocimetry measurements have been performed to evaluate the characteristics of a turbulent impinging jet with large nozzle height-to-diameter ratio (H/D = 20). The Reynolds number considered is approximately 28 000 based on the jet exit velocity and nozzle diameter. Mean normalized centerline velocity in both the free jet and impingement regions and pressure distribution over the plate obtained from simulations and experiments show good agreement. The ring-like vortices generated due to the Kelvin-Helmholtz instabilities at the exit of the nozzle merge, break down and transform into large scale structures while traveling towards the impingement plate. A Strouhal number of 0.63 was found for the vortices generated at the exit of the nozzle. However, this parameter is reduced along the centerline towards the impingement zone. A characteristic frequency was also determined for the large scale structures impinging on the plate. The expansion, growth, tilt, and three-dimensionality of the impinging structures cause dislocation of the impinging flow from the centerline, which is significantly larger when compared with flows having small H/D ratios. Contrary to the behavior of impinging jets with small stand-off distance, due to the loss of coherence, the large scale structures do not result in significant secondary vortices in the wall jet region and consequently less fluctuations were observed for wall shear stress.
Imaging studies of temperature dependent photodegradation and self-healing in disperse orange 11 dye-doped polymers
Authors: Anderson Benjamin R. , Hung Sheng-Ting , Kuzyk Mark G.
Published: July 2016

Using confocal transmission imaging microscopy, we measure the temperature dependence of photodegradation and self-healing in disperse orange 11 (DO11) dye-doped (poly)methyl-methacrylate (PMMA) and polystyrene (PS). In both dye-doped polymers, an increase in sample temperature results in a greater photodegradation rate and degree of degradation, while also resulting in a slower recovery rate and larger recovery fraction. These results confirm the temperature dependence predictions of the modified correlated chromophore domain model (mCCDM) [B. R. Anderson and M. G. Kuzyk, Phys. Rev. E 89, 032601 (2014)]. Additionally, using quantitative fitting of the imaging data for DO11/PMMA, we determine the domain density parameter to be ρ = 1.19 (±0.25) × 10−2 and the domain free energy advantage to be λ = 0.282 ± 0.015 eV, which are within the uncertainty of the values previously determined using amplified spontaneous emission as the probe method [S. K. Ramini et al., Polym. Chem. 4, 4948 (2013)]. Finally, while we find photodegradation and self-healing of DO11/PS to be qualitatively consistent with the mCCDM, we find that it is quantitatively incompatible with the mCCDM as recovery in DO11/PS is found to behave as a stretched (or double) exponential as a function of time.
Free films of a partially wetting liquid under the influence of a propagating MHz surface acoustic wave
Authors: Altshuler Gennady , Manor Ofer
Published: July 2016

We use both theory and experiment to study the response of thin and free films of a partially wetting liquid to a MHz vibration, propagating in the solid substrate in the form of a Rayleigh surface acoustic wave (SAW). We generalise the previous theory for the response of a thin fully wetting liquid film to a SAW by including the presence of a small but finite three phase contact angle between the liquid and the solid. The SAW in the solid invokes a convective drift of mass in the liquid and leaks sound waves. The dynamics of a film that is too thin to support the accumulation of the sound wave leakage is governed by a balance between the drift and capillary stress alone. We use theory to demonstrate that a partially wetting liquid film, supporting a weak capillary stress, will spread along the path of the SAW. A partially wetting film, supporting an appreciable capillary stress, will however undergo a concurrent dynamic wetting and dewetting at the front and the rear, respectively, such that the film will displace, rather than spread, along the path of the SAW. The result of the theory for a weak capillary stress is in agreement with the previous experimental and theoretical studies on the response of thin silicon oil films to a propagating SAW. No corresponding previous results exist for the case of an appreciable capillary stress. We thus complement the large capillary limit of our theory by undertaking an experimental procedure where we explore the response of films of water and a surfactant solutions to a MHz SAW, which is found to be in qualitative agreement with the theory at this limit.
Generation of constant-amplitude radio-frequency sweeps at a tunnel junction for spin resonance STM
Authors: Paul William , Baumann Susanne , Lutz Christopher P. , Heinrich Andreas J.
Published: July 2016

We describe the measurement and successful compensation of the radio-frequency transfer function of a scanning tunneling microscope over a wide frequency range (15.5–35.5 GHz) and with high dynamic range (>50 dB). The precise compensation of cabling resonances and attenuations is critical for the production of constant-voltage frequency sweeps for electric-field driven electron spin resonance (ESR) experiments. We also demonstrate that a well-calibrated tunnel junction voltage is necessary to avoid spurious ESR peaks that can arise due to a non-flat transfer function.
First results from gamma ray diagnostics in EAST Tokamak
Authors: Zhou R. J. , Hu L. Q. , Zhong G. Q. , Cao H. R. , Liu G. Z. , Li K. , Zhang Y. , Lin S. Y. , Zhang J. Z. ,   EAST Team
Published: July 2016

Gamma ray diagnostics has been developed in the EAST tokamak recently. Six BGO scintillator detectors are arranged on the down-half cross-section and pointed at the up-half cross-section of plasma, with space resolution about 15 cm and energy range from 0.3 MeV to 6 MeV. Three main gamma ray peaks in the energy spectra have been observed and are identified as the results of nuclear reactions 207Pb(n, n′)207mPb, H(n, γ) D, and D(p, γ)3He, respectively. Upgrading of the system is in progress by using LaBr3(Ce) scintillator, fast photo-multiplier tubes, and a fully digital data acquisition system based on high sample frequency digitizers with digital pulse processing algorithms.
Laser cooling of the AlCl molecule with a three-electronic-level theoretical model
Authors: Wan Mingjie , Yuan Di , Jin Chengguo , Wang Fanhou , Yang Yujie , Yu You , Shao Juxiang
Published: July 2016

Feasibility of laser-cooling AlCl molecule is investigated using ab initio quantum chemistry. Potential energy curves, permanent dipole moments, and transition dipole moments for the X1Σ+, a3Π, and A1Π states are studied based on multi-reference configuration interaction plus Davidson corrections (MRCI+Q) method with ACVQZ basis set, spin-orbit coupling effects are considered at the MRCI+Q level. Highly diagonally distributed Franck–Condon factors (f00 = 0.9988 and f11 = 0.9970) and branching ratios (R00 = 0.9965, R01 = 2.85 × 10−3, R02 = 6.35 × 10−4, and R03 = 2.05 × 10−6) for the A1Π1(ν′=0)→X1Σ0++(ν″=0) transition are determined. A sufficiently radiative lifetime τ (A1Π1) = 4.99 ns is predicted for rapid laser cooling. The proposed cooling wavelength is deep in the ultraviolet region at λ00 = 261.75 nm. Total emission rates for the a3Π0+→X1Σ0++, a3Π1→X1Σ0++, A1Π1 → a3Π0+, and A1Π1 → a3Π1 transitions are particularly small (∼10 s−1–650 s−1). The calculated vibrational branching loss ratio to the intermediate a3Π0+ and a3Π1 states can be negligible. The results imply the probability of laser cooling AlCl molecule with three-electronic-level.
Direct gap Ge1-ySny alloys: Fabrication and design of mid-IR photodiodes
Authors: Senaratne C. L. , Wallace P. M. , Gallagher J. D. , Sims P. E. , Kouvetakis J. , Menéndez J.
Published: July 2016

Chemical vapor deposition methods were developed, using stoichiometric reactions of specialty Ge3H8 and SnD4 hydrides, to fabricate Ge1-ySny photodiodes with very high Sn concentrations in the 12%–16% range. A unique aspect of this approach is the compatible reactivity of the compounds at ultra-low temperatures, allowing efficient control and systematic tuning of the alloy composition beyond the direct gap threshold. This crucial property allows the formation of thick supersaturated layers with device-quality material properties. Diodes with composition up to 14% Sn were initially produced on Ge-buffered Si(100) featuring previously optimized n-Ge/i-Ge1-ySny/p-Ge1-zSnz type structures with a single defected interface. The devices exhibited sizable electroluminescence and good rectifying behavior as evidenced by the low dark currents in the I-V measurements. The formation of working diodes with higher Sn content up to 16% Sn was implemented by using more advanced n-Ge1-xSnx/i-Ge1-ySny/p-Ge1-zSnz architectures incorporating Ge1-xSnx intermediate layers (x ∼ 12% Sn) that served to mitigate the lattice mismatch with the Ge platform. This yielded fully coherent diode interfaces devoid of strain relaxation defects. The electrical measurements in this case revealed a sharp increase in reverse-bias dark currents by almost two orders of magnitude, in spite of the comparable crystallinity of the active layers. This observation is attributed to the enhancement of band-to-band tunneling when all the diode layers consist of direct gap materials and thus has implications for the design of light emitting diodes and lasers operating at desirable mid-IR wavelengths. Possible ways to engineer these diode characteristics and improve carrier confinement involve the incorporation of new barrier materials, in particular, ternary Ge1-x-ySixSny alloys. The possibility of achieving type-I structures using binary and ternary alloy combinations is discussed in detail, taking into account the latest experimental and theoretical work on band offsets involving such materials.
Influence of impact conditions on plasma generation during hypervelocity impact by aluminum projectile
Authors: Song Weidong , Lv Yangtao , Li Jianqiao , Wang Cheng , Ning Jianguo
Published: July 2016

For describing hypervelocity impact (relative low-speed as related to space debris and much lower than travelling speed of meteoroids) phenomenon associated with plasma generation, a self-developed 3D code was advanced to numerically simulate projectiles impacting on a rigid wall. The numerical results were combined with a new ionization model which was developed in an early study to calculate the ionized materials during the impact. The calculated results of ionization were compared with the empirical formulas concluded by experiments in references and a good agreement was obtained. Then based on the reliable 3D numerical code, a series of impacts with different projectile configurations were simulated to investigate the influence of impact conditions on hypervelocity impact generated plasma. It was found that the form of empirical formula needed to be modified. A new empirical formula with a critical impact velocity was advanced to describe the velocity dependence of plasma generation and the parameters of the modified formula were ensured by the comparison between the numerical predictions and the empirical formulas. For different projectile configurations, the changes of plasma charges with time are different but the integrals of charges on time almost stayed in the same level.
Extreme multistability in a memristor-based multi-scroll hyper-chaotic system
Authors: Yuan Fang , Wang Guangyi , Wang Xiaowei
Published: July 2016

In this paper, a new memristor-based multi-scroll hyper-chaotic system is designed. The proposed memristor-based system possesses multiple complex dynamic behaviors compared with other chaotic systems. Various coexisting attractors and hidden coexisting attractors are observed in this system, which means extreme multistability arises. Besides, by adjusting parameters of the system, this chaotic system can perform single-scroll attractors, double-scroll attractors, and four-scroll attractors. Basic dynamic characteristics of the system are investigated, including equilibrium points and stability, bifurcation diagrams, Lyapunov exponents, and so on. In addition, the presented system is also realized by an analog circuit to confirm the correction of the numerical simulations.