bluuebunny/crossref_metadata_2025 huggingface dataset:
Evidence of long-term NAO influence on East-Central Europe winter precipitation from a guano-derived δ15N record
Authors: Cleary Daniel M. , Wynn Jonathan G. , Ionita Monica , Forray Ferenc L. , Onac Bogdan P.
Published: October 2017

Currently there is a scarcity of paleo-records related to the North Atlantic Oscillation (NAO), particularly in East-Central Europe (ECE). Here we report δ15N analysis of guano from a cave in NW Romania with the intent of reconstructing past variation in ECE hydroclimate and examine NAO impacts on winter precipitation. We argue that the δ15N values of guano indicate that the nitrogen cycle is hydrologically controlled and the δ15N values likely reflect winter precipitation related to nitrogen mineralization prior to the growing season. Drier conditions indicated by δ15N values at AD 1848–1852 and AD 1880–1930 correspond to the positive phase of the NAO. The increased frequency of negative phases of the NAO between AD 1940–1975 is contemporaneous with higher δ15N values (wetter conditions). A 4‰ decrease in δ15N values at the end of the 1970’s corresponds to a strong reduction in precipitation associated with a shift from negative to positive phase of the NAO. Using the relationship between NAO index and δ15N values in guano for the instrumental period, we reconstructed NAO-like phases back to AD 1650. Our results advocate that δ15N values of guano offer a proxy of the NAO conditions in the more distant past, helping assess its predictability.
Association between chemerin, omentin-1 and risk of heart failure in the population-based EPIC-Potsdam study
Authors: Menzel Juliane , di Giuseppe Romina , Biemann Ronald , Wittenbecher Clemens , Aleksandrova Krasimira , Eichelmann Fabian , Fritsche Andreas , Schulze Matthias B. , Boeing Heiner , Isermann Berend , Weikert Cornelia
Published: October 2017

The adipokines chemerin and omentin-1 have been suggested to influence cardiovascular function. The study aimed to investigate the longitudinal association between chemerin, omentin-1 concentrations and risk of incident heart failure (HF), respectively. We conducted a case-cohort study nested within the European Prospective Investigation into Cancer and Nutrition (EPIC)-Potsdam cohort (n = 27548) including a randomly drawn subsample and all incident HF cases during a mean follow-up of 8.2 ± 1.5 years. A total of 212 incident HF cases and 2168 individuals free of HF cases were included in the study. After multivariable adjustment for established cardiovascular risk factors chemerin was strongly associated with risk of HF (HR per doubling chemerin: 4.91; 95%-CI: 2.57–9.39; p < 0.0001). Omentin-1 was not significantly related to HF risk in the overall study population. However, the association between omentin-1 and HF risk was modified by prevalent coronary heart disease (CHD), showing that the shape of the association was linear in participants without prevalent CHD (HR doubling omentin-1: 2.11; 95%-CI: 1.36–3.27; p linear = 0.0009) and U-shaped in participants with pre-existing CHD (p non-linear = 0.006). Our study provides first evidence for a strong positive association between chemerin and risk of HF. The association between the adipokine omentin-1 and risk of HF may differ according to pre-existing CHD.
Sulforaphane reactivates cellular antioxidant defense by inducing Nrf2/ARE/Prdx6 activity during aging and oxidative stress
Authors: Kubo Eri , Chhunchha Bhavana , Singh Prerna , Sasaki Hiroshi , Singh Dhirendra P.
Published: October 2017

Upon oxidative stress and aging, Nrf2 (NFE2-related factor2) triggers antioxidant defense genes to defends against homeostatic failure. Using human(h) or rat(r) lens epithelial cells (LECs) and aging human lenses, we showed that a progressive increase in oxidative load during aging was linked to a decline in Prdx6 expression. DNA binding experiments using gel-shift and ChIP assays demonstrated a progressive reduction in Nrf2/ARE binding (−357/−349) of Prdx6 promoter. The promoter (−918) with ARE showed a marked reduction in young vs aged hLECs, which was directly correlated to decreased Nrf2/ARE binding. A Nrf2 activator, Sulforaphane (SFN), augmented Prdx6, catalase and GSTπ expression in dose-dependent fashion, and halted Nrf2 dysregulation of these antioxidants. SFN reinforced Nrf2/DNA binding and increased promoter activities by enhancing expression and facilitating Nrf2 translocalization in nucleus. Conversely, promoter mutated at ARE site did not respond to SFN, validating the SFN-mediated restoration of Nrf2/ARE signaling. Furthermore, SFN rescued cells from UVB-induced toxicity in dose-dependent fashion, which was consistent with SFN’s dose-dependent activation of Nrf2/ARE interaction. Importantly, knockdown of Prdx6 revealed that Prdx6 expression was prerequisite for SFN-mediated cytoprotection. Collectively, our results suggest that loss of Prdx6 caused by dysregulation of ARE/Nrf2 can be attenuated through a SFN, to combat diseases associated with aging.
Optical properties of functionalized nanodiamonds
Authors: Pichot V. , Muller O. , Seve A. , Yvon A. , Merlat L. , Spitzer D.
Published: October 2017

Detonation nanodiamonds exhibit strong nonlinear optical properties depending on their electronic properties. In the present paper, the nanodiamond functional groups are chemically modified to obtain nanodiamonds with primary amines on their surface. The optical properties of such nanodiamonds placed in water suspensions are studied and compared with the one of classical detonation nanodiamonds. Transmission, scattering and Z-scan experiments are performed for two different wavelengths (532 nm and 1064 nm). A lower threshold for optical limiting associated to more pronounce non-linear optical effects is detected at the wavelength of 1064 nm compared to the one at 532 nm. This effect may be due to a stronger nonlinear backscattering behavior at 1064 nm. Moreover, a striking result obtained from the Z-scan experiments reveals a completely different behavior of the functionalized nanodiamonds for both wavelengths. This result is discussed in regard to the electronic properties of the material and possible charge transfer.
Conformal QED in two-dimensional topological insulators
Authors: Menezes Natália , Palumbo Giandomenico , Morais Smith Cristiane
Published: October 2017

It has been shown that local four-fermion interactions on the edges of two-dimensional time-reversal-invariant topological insulators give rise to a new non-Fermi-liquid phase, called helical Luttinger liquid (HLL). Here, we provide a first-principle derivation of this HLL based on the gauge-theory approach. We start by considering massless Dirac fermions confined on the one-dimensional boundary of the topological insulator and interacting through a three-dimensional quantum dynamical electromagnetic field. Within these assumptions, through a dimensional-reduction procedure, we derive the effective 1 + 1-dimensional interacting fermionic theory and reveal its underlying gauge theory. In the low-energy regime, the gauge theory that describes the edge states is given by a conformal quantum electrodynamics (CQED), which can be mapped exactly into a HLL with a Luttinger parameter and a renormalized Fermi velocity that depend on the value of the fine-structure constant α.
Regulatory Compliant Tissue-Engineered Human Corneal Endothelial Grafts Restore Corneal Function of Rabbits with Bullous Keratopathy
Authors: Peh Gary S. L. , Ang Heng-Pei , Lwin Chan N. , Adnan Khadijah , George Benjamin L. , Seah Xin-Yi , Lin Shu-Jun , Bhogal Maninder , Liu Yu-Chi , Tan Donald T. , Mehta Jodhbir S.
Published: October 2017

Corneal transplantation is the only treatment available to restore vision for individuals with blindness due to corneal endothelial dysfunction. However, severe shortage of available donor corneas remains a global challenge. Functional regulatory compliant tissue-engineered corneal endothelial graft substitute can alleviate this reliance on cadaveric corneal graft material. Here, isolated primary human corneal endothelial cells (CEnCs) propagated using a dual media approach refined towards regulatory compliance showed expression of markers indicative of the human corneal endothelium, and can be tissue-engineered onto thin corneal stromal carriers. Both cellular function and clinical adaptability was demonstrated in a pre-clinical rabbit model of bullous keratopathy using a tissue-engineered endothelial keratoplasty (TE-EK) approach, adapted from routine endothelial keratoplasty procedure for corneal transplantation in human patients. Cornea thickness of rabbits receiving TE-EK graft gradually reduced over the first two weeks, and completely recovered to a thickness of approximately 400 µm by the third week of transplantation, whereas corneas of control rabbits remained significantly thicker over 1,000 µm (p < 0.05) throughout the course of the study. This study showed convincing evidence of the adaptability of the propagated CEnCs and their functionality via a TE-EK approach, which holds great promises in translating the use of cultured CEnCs into the clinic.
Correction: Corrigendum: A whole-cell tumor vaccine modified to express fibroblast activation protein induces antitumor immunity against both tumor cells and cancer-associated fibroblasts
Authors: Chen Meihua , Xiang Rong , Wen Yuan , Xu Guangchao , Wang Chunting , Luo Shuntao , Yin Tao , Wei Xiawei , Shao Bin , Liu Ning , Guo Fuchun , Li Meng , Zhang Shuang , Li Minmin , Ren Kexing , Wang Yongsheng , Wei Yuquan
Published: October 2017

Scientific Reports 5: Article number: 14421; published online: 23 September 2015; updated: 20 October 2017. In the Supplementary Information of our Article panels are duplicated in Figure S2. The panel for B16F10 in spleen is duplicated as the panel for pVector-B16F10 in spleen. The panel for n.s. in kidney is duplicated as the panel for B16F10 in kidney.
Correction: Corrigendum: A Short-Snouted, Middle Triassic Phytosaur and its Implications for the Morphological Evolution and Biogeography of Phytosauria
Authors: Stocker Michelle R. , Zhao Li-Jun , Nesbitt Sterling J. , Wu Xiao-Chun , Li Chun
Published: October 2017

Scientific Reports 7: Article number: 46028; published online: 10 April 2017; updated: 20 October 2017. The Supplementary Information file originally published with this Article, contained errors in the Supplementary Figure S6. The taxon ‘Parasuchus hislopi’ was accidentally inserted twice and ‘Smilosuchus lithodendrorum’ was inadvertently transposed with Smilosuchus adamanensis’.
Correction: Corrigendum: Attenuation of Na/K-ATPase Mediated Oxidant Amplification with pNaKtide Ameliorates Experimental Uremic Cardiomyopathy
Authors: Liu Jiang , Tian Jiang , Chaudhry Muhammad , Maxwell Kyle , Yan Yanling , Wang Xiaoliang , Shah Preeya T. , Khawaja Asad A. , Martin Rebecca , Robinette Tylor J. , El-Hamdani Adee , Dodrill Michael W. , Sodhi Komal , Drummond Christopher A. , Haller Steven T. , Kennedy David J. , Abraham Nader G. , Xie Zijian , Shapiro Joseph I.
Published: October 2017

Scientific Reports 6: Article number: 34592; published online: 04 October 2016; updated: 20 October 2017. The Acknowledgements section in this Article is incomplete. “This work was supported by NIH grants HL109015 (to J.I.S. and Z.X.), HL071556 (to J.I.S.) and HL105649 (to J.T., Z.X. and J.I.S.) as well as HL55601 and HL34300 (to N.
Heteromultimetallic catalysis for sustainable organic syntheses
Authors: Lorion Mélanie M. , Maindan Karan , Kapdi Anant R. , Ackermann Lutz
Published: October 2017

Fully complementary bimetallic catalysis has been identified as an increasingly powerful tool for molecular transformations, which was largely inspired by early examples of sequential catalytic transformations.
Rational design of a molecularly imprinted polymer for dinotefuran: theoretical and experimental studies aimed at the development of an efficient adsorbent for microextraction by packed sorbent
Authors: Silva Camilla Fonseca , Borges Keyller Bastos , do Nascimento Clebio Soares
Published: October 2017

In this work, we studied theoretically the formation process of a molecularly imprinted polymer (MIP) for dinotefuran (DNF), by testing distinct functional monomers (FM) in various solvents through density functional theory calculations.
Bonding-induced emission of silyl-protected copper nanoclusters for luminescence turn-on detection of trace water in organic solvents
Authors: Zhao Meizhi , Feng Hui , Zhang Xiaoxiao , Ao Hang , Qian Zhaosheng
Published: October 2017

Luminescence turn-on detection of trace water in organic solvents via bonding-induced emission of silyl-protected copper nanoclusters was achieved.
Novel magnesium-seamed organic nanocapsules with hierarchical structural complexity
Authors: Zhang Chen , Patil Rahul S. , Barnes Charles L. , Atwood Jerry L.
Published: October 2017

Novel magnesium-seamed organic nanocapsules with hierarchical structural complexity are prepared via endohedral and exterior functionalization.
1,2,4-Triazole-aided native chemical ligation between peptide-N-acyl-N′-methyl-benzimidazolinone and cysteinyl peptide
Authors: Sakamoto Ken , Tsuda Shugo , Nishio Hideki , Yoshiya Taku
Published: October 2017

Novel thiol-additive-free NCL using easy-to-prepare peptide-MeNbz and 1,2,4-triazole can be readily combined with one-pot desulfurization and Cys-modification.
Raman microspectroscopy and multivariate data analysis: optical differentiation of aqueousd- andl-tryptophan solutions
Authors: Koch H. , Polepil S. , Eisen K. , Will S.
Published: October 2017

The combination of Raman spectroscopy as a sensitive and selective optical measurement technique and multivariate data analysis forms a powerful tool for probing intermolecular interactions between enantiomers.
Thermodynamic foundations of applications of ab initio methods for determination of the adsorbate equilibria: hydrogen at the GaN(0001) surface
Authors: Kempisty Pawel , Strąk Paweł , Sakowski Konrad , Kangawa Yoshihiro , Krukowski Stanisław
Published: October 2017

This paper describes the equilibrium between vapor and the adsorbed layer at the surface in terms of pressure and temperature.
S-shaped velocity deformation induced by ionic hydration in aqueous salt solution flow
Authors: Fan Wen , Chen Jige , Lei Xiaoling , Fang Haiping
Published: October 2017

An S-shaped flow velocity profile is induced with deformation linearly dependent upon the energy density of the ionic hydration shell.
An accidental resonance mediated predissociation pathway of water molecules excited to the electronic C̃ state
Authors: He Zhigang , Yang Dongyuan , Chen Zhichao , Yuan Kaijun , Dai Dongxu , Wu Guorong , Yang Xueming
Published: October 2017

Accidental resonance enhances the predissociation of the C̃(010) state of H2O.
In situ neutron diffraction study of the formation of Ho2Ge2O7 pyrochlore at high temperature and pressure
Authors: Playford Helen Y. , Bull Craig L. , Tucker Matthew G. , Funnell Nicholas P. , Ridley Christopher J. , Marshall Kenneth P. , Walton Richard I.
Published: October 2017

The formation of the spin-ice pyrochlore Ho2Ge2O7 by two different high temperature, high pressure routes has been explored using in situ neutron diffraction.
Design and understanding of encapsulated perovskite solar cells to withstand temperature cycling
Authors: Cheacharoen Rongrong , Rolston Nicholas , Harwood Duncan , Bush Kevin A. , Dauskardt Reinhold H. , McGehee Michael D.
Published: October 2017

Perovskite solar cells retain their performance with temperature cycling using a compliant, ethylene vinyl acetate encapsulant.
Emerging investigator series: development and application of polymeric electrospun nanofiber mats as equilibrium-passive sampler media for organic compounds
Authors: Qian Jiajie , Jennings Brandon , Cwiertny David M. , Martinez Andres
Published: October 2017

We fabricated a suite of polymeric electrospun nanofiber mats (ENMs) and investigated their performance as next-generation passive sampler media for environmental monitoring of organic compounds.
Time-dependent bacterial transcriptional response to CuO nanoparticles differs from that of Cu2+and provides insights into CuO nanoparticle toxicity mechanisms
Authors: Moore Joe D. , Avellan Astrid , Noack Clinton W. , Guo Yisong , Lowry Gregory V. , Gregory Kelvin B.
Published: October 2017

Hyperspectral imaging and gene expression demonstrate nanoparticle-specific induction of a membrane damage response.
Solvent- and base-free synthesis of wax esters from fatty acid methyl esters by consecutive one-pot, two-step catalysis
Authors: Nguyen D. H. , Raffa G. , Morin Y. , Desset S. , Capet F. , Nardello-Rataj V. , Dumeignil F. , Gauvin R. M.
Published: October 2017

Wax esters were produced from fatty acid methyl esters using a catalytic one-pot, two-step sequence under solvent- and base-free conditions.
An interaction network approach to study the correlation between endocrine disrupting chemicals and breast cancer
Authors: Polo Andrea , Nittoli Chiara , Crispo Anna , Langastro Teresa , Cocco Stefania , Severino Lorella , De Laurentiis Michelino , Ciliberto Gennaro , Montella Maurizio , Budillon Alfredo , Costantini Susan
Published: October 2017

Linking between the interaction networks of proteins modulated by either environmental EDCs and mycotoxins in breast cancer.
The effect of alkylthio side chains in oligothiophene-based donor materials for organic solar cells
Authors: Zou Yan , Wu Yue , Yang Hang , Dong Yingying , Cui Chaohua , Li Yongfang
Published: October 2017

The engineering of alkylthio side chains in the molecular conjugated backbone of small molecules is in favor of achieving a linear molecular backbone conformation, slightly red-shifting the absorption spectrum, and down-shifting the HOMO energy level of the resulting molecule.
The potential use of glucose oxidase-imprinted polymer-coated electrodes for biofuel cells
Authors: Lee Mei-Hwa , Thomas James L. , Shih Ching-Ping , Lin Chang-Chih , Lin Shi-Hsin , Chen Wen-Janq , Lin Hung-Yin
Published: October 2017

Enzymatic biofuel cells using molecularly imprinted polymer coated electrodes.
Chemical conversion of zinc–zinc phosphate composite coating on TC4 by galvanic coupling
Authors: Wang Ling-ling , Xu Wen-hua , Xiao Gui-yong , Jiang Cong-cong , Zheng Yong-zhen , Lu Yu-peng
Published: October 2017

Galvanic coupling was introduced into chemical conversion on TC4, which endowed the coating with better performance due to double protection.
4-Bis(4-aminophenoxy)phenoxy derivitized phthalocyanine conjugated to metallic nanoparticles: searching for enhanced optical limiting materials
Authors: Nwaji Njemuwa , Mack John , Nyokong Tebello
Published: October 2017

Amino derivative phthalocyanine linked to metallic nanoparticles showed enhanced photophysical and nonlinear optical response.
A highly sensitive and fast responsive naphthalimide-based fluorescent probe for Cu2+ and its application
Authors: Zhang Beibei , Qin Fengyun , Niu Huawei , Liu Yao , Zhang Di , Ye Yong
Published: October 2017

The response of the probe L to Cu2+ is reversible and very fast (20 s). L has a low detection limit of 49 nM and was used for imaging of Cu2+ in MCF-7 cells with satisfying results. The sensor L can be analyzed with a molecular logic gate.
An investigation of ligand effects on the visible light-induced formation of porphyrin–iron(iv)-oxo intermediates
Authors: Kwong Ka Wai , Patel Dharmesh , Malone Jonathan , Lee Ngo Fung , Kash Benjamin , Zhang Rui
Published: October 2017

Depending on the structure of the porphyrin ligands, the visible light photolysis of porphyrin–iron(iii) bromates produced iron(iv)-oxo radical cations or iron(iv)-oxo porphyrins, permitting direct kinetic studies of their oxidation reactions.
Unexpected self-assembly, photoluminescence behavior, and film-forming properties of polysiloxane-based imidazolium ionic liquids prepared by one-pot thiol–ene reaction
Authors: Zuo Yujing , Gou Zhiming , Li Zhaoyue , Qi Jinwan , Feng Shengyu
Published: October 2017

The synthesis of a series of polysiloxane-based ionic liquids (PNLs) is reported via straightforward thiol–ene reaction with high yield using three kinds of imidazolium ionic liquid monomers.
Hexafluoroisopropanol mediated benign synthesis of 2H-pyrido[1,2-a]pyrimidin-2-ones by using a domino protocol
Authors: Alsharif Zakeyah , Ali Mohamad Akbar , Alkhattabi Hessa , Jones Derika , Delancey Evan , Ravikumar P. C. , Alam Mohammad A.
Published: October 2017

A domino strategy has been used for the synthesis of 2H-pyrido[1,2-a]pyrimidin-2-ones.
High-performance wearable strain sensors based on fragmented carbonized melamine sponges for human motion detection
Authors: Fang Xiaoliang , Tan Jianpin , Gao Yang , Lu Yongfeng , Xuan Fuzhen
Published: October 2017

Strain sensors based on fragmented carbonized melamine sponges can detect various large and subtle human body motions.
Discovery of novel BET inhibitors by drug repurposing of nitroxoline and its analogues
Authors: Jiang Hao , Xing Jing , Wang Chen , Zhang Hao , Yue Liyan , Wan Xiaozhe , Chen Wei , Ding Hong , Xie Yiqian , Tao Hongru , Chen Zhifeng , Jiang Hualiang , Chen Kaixian , Chen Shijie , Zheng Mingyue , Zhang Yuanyuan , Luo Cheng
Published: October 2017

The BET family of bromodomain-containing proteins (BRDs) is believed to be a promising drug target for therapeutic intervention in a number of diseases.
Hybridization of metal–organic frameworks and task-specific ionic liquids: fundamentals and challenges
Authors: Luo Qun-xing , An Bo-wen , Ji Min , Zhang Jie
Published: October 2017

This critical review presents the fundamentals, challenges, and outlooks in MTHMs according to state-of-the-art progress and first-hand experience.
10 gram-scale synthesis of a chiral oxazoline iminopyridine ligand and its applications
Authors: Chen Jianhui , Xi Tuo , Lu Zhan
Published: October 2017

This method reports on the preparation of a chiral oxazoline iminopyridine (OIP) ligand and its applications on a scale of 10 grams.
Crystal structure transformation and step-by-step thermal decomposition behavior of dihydroxylammonium 5,5′-bistetrazole-1,1′-diolate
Authors: Jia Jianhui , Liu Yu , Huang Shiliang , Xu Jinjiang , Li Shichun , Zhang Haobin , Cao Xiong
Published: October 2017

The crystal structure transformation and step-by-step thermal decomposition behavior of dihydroxylammonium 5,5′-bistetrazole-1,1′-diolate (TKX-50) under thermal stimulation were studied.
High mechanical properties of epoxy networks with dangling chains and tunable microphase separation structure
Authors: Huang Yizhou , Tian Yazhou , Li Yuanyuan , Tan Xiaocun , Li Qing , Cheng Jue , Zhang Junying
Published: October 2017

The microphase separation was related to the compatibility and rigidity of the backbone.
Mesoporous TiO2 hierarchical structures: preparation and efficacy in solar cells
Authors: Hwang Dae-Kue , Kim Jeong-Hwa , Kim Kang-Pil , Sung Shi-Joon
Published: October 2017

We investigated an electrospray-based method to manufacture photoelectrodes for dye-sensitized solar cells (DSSCs).
S-Allylmercaptocysteine induces G2/M phase arrest and apoptosis via ROS-mediated p38 and JNK signaling pathway in human colon cancer cells in vitro and in vivo
Authors: Zhu Xiaosong , Jiang Xiaoyan , Duan Chonggang , Li Ang , Sun Yueyue , Qi Qiuchen , Liu Yan , Li Siying , Zhao Zhongxi
Published: October 2017

SAMC inhibits colon cancer cell growth through the reactive oxygen species-dependent pathway.
Highly thermally conductive graphene-based electrodes for supercapacitors with excellent heat dissipation ability
Authors: Zhao Bo , Fu Xian-Zhu , Sun Rong , Wong Ching-Ping
Published: October 2017

The highly thermally conductive graphene-based electrodes for supercapacitors exhibit great heat dissipation ability as well as excellent cycling performance and rate capacity.
Humidity-responsive actuators from integrating liquid crystal networks in an orienting scaffold
Authors: Ryabchun Alexander , Lancia Federico , Nguindjel Anne-Déborah , Katsonis Nathalie
Published: October 2017

Integrating liquid crystal networks in an anisotropic porous scaffold allows enhancing their mechanical performance and promotes their alignment. By combining this approach with humidity-responsive liquid crystals and gradients in cross-linking density, we demonstrate soft yet tough actuators that curl, wind or twist in response to humidity.
Correction: Metal-functionalized covalent organic frameworks as precursors of supercapacitive porous N-doped graphene
Authors: Romero Jorge , Rodriguez-San-Miguel David , Ribera Antonio , Mas-Ballesté Rubén , Otero Toribio F. , Manet Ilse , Liscio Fabiola , Abellán Gonzalo , Zamora Felix , Coronado Eugenio
Published: October 2017

Correction for ‘Metal-functionalized covalent organic frameworks as precursors of supercapacitive porous N-doped graphene’ by Jorge Romero et al., J. Mater. Chem. A, 2017, 5, 4343–4351.
Trace eyeblink conditioning is associated with changes in synaptophysin immunoreactivity in the cerebellar interpositus nucleus in guinea pigs
Authors: Li Rui , Li Qi , Chu Xiao-Lei , Tao Tao , Li Lan , He Cheng-Qi , Gao Fang-You
Published: October 2017

Synaptic plasticity plays a role during trace eyeblink conditioning (TEBC). Synaptophysin (Syn) is a major integral transmembrane protein, located particularly in the synaptic vesicles, and is considered a molecular marker of synapses. In addition, Syn immunoreactivity is an important indicator of synaptic plasticity. In the present study, we used immunohistochemical techniques to assess changes in Syn expression in the cerebellar interpositus nucleus (IN) of guinea pigs exposed to TEBC and pseudoconditioning. Additionally, we analyzed the relationship between Syn immunoreactivity and the percentage of trace-conditioned responses. Guinea pigs underwent trace conditioning or pseudoconditioning. Following two, six, or ten sessions, they were perfused and the cerebellum was removed for Syn immunohistochemical evaluation. After sessions 6 and 10, a significant increase in conditioned response (CR) percentage was observed in the trace-conditioned group, with the CR percentage reaching the learning criteria following session 10. Besides, for trace-conditioned animals, the Syn expression in IN was found significantly up-regulated after session 10 compared with pseudoconditioned ones. Our data suggest that the increase in Syn expression links to synaptic plasticity changes in the cerebellar IN and provides a histological substrate in the IN relating to TEBC training. The changing trend of Syn immunoreactivity in the IN is associated with CR percentage.
Rapid expansion of international new ventures across institutional distance
Authors: Deng Ziliang , Jean Ruey-Jer “Bryan” , Sinkovics Rudolf R
Published: October 2017

Rapid export expansion into institutionally distant locations has become more possible in the era of digital economy. Will such rapid expansion bring desirable outcome to firms? In a context of international new ventures (INVs) from emerging markets, we reconceptualize export expansion speed as the pace of exporting across institutional distance over a certain period of time. We then examine the relationship between rapid export expansion across institutional distance and overall firm performance. We incorporate directionality into export expansion and hypothesize the relationship to be positive when INVs export upwardly to more open countries, yet the relationship to be negative when INVs export downwardly to less open countries. We also hypothesize that the degree of market liberalization in subnational regions of origin of the INVs moderates the above speed–performance relationships. Instrumental variable models based on data of Chinese indigenous INVs during 2000–2009 support these hypotheses. This study both zooms in and zooms out the analytical lens along the location-related institutional axis, examines the joint effect of institutions involved in supranational directions and subnational origins on firm performance, and advances institutional theory.
Comprehensive description of the electro-optic effects in strained silicon waveguides
Authors: Damas Pedro , Berciano Mathias , Marcaud Guillaume , Alonso Ramos Carlos , Marris-Morini Delphine , Cassan Eric , Vivien Laurent
Published: October 2017

We present a novel and comprehensive analysis method that considers both the plasma-dispersion effect and the strain-induced Pockels effect to faithfully describe the electro-optic effects taking place in a strained silicon waveguide under an applied voltage. The change in carrier distribution arising from the application of a voltage leads to a redistribution of the electrostatic field which deeply affects the strain-induced Pockels effect. By simulating the strain gradient distribution inside the waveguide together with the free carrier concentration in silicon, we were able to describe that the effective index change due to the Pockels effect in strained silicon waveguides and the applied voltage have a nonlinear relationship.
Neutral beam and ICP etching of HKMG MOS capacitors: Observations and a plasma-induced damage model
Authors: Kuo Tai-Chen , Shih Tzu-Lang , Su Yin-Hsien , Lee Wen-Hsi , Current Michael Ira , Samukawa Seiji
Published: October 2017

In this study, TiN/HfO2/Si metal-oxide-semiconductor (MOS) capacitors were etched by a neutral beam etching technique under two contrasting conditions. The configurations of neutral beam etching technique were specially designed to demonstrate a “damage-free” condition or to approximate “reactive-ion-etching-like” conditions to verify the effect of plasma-induced damage on electrical characteristics of MOS capacitors. The results show that by neutral beam etching (NBE), the interface state density (Dit) and the oxide trapped charge (Qot) were lower than routine plasma etching. Furthermore, the decrease in capacitor size does not lead to an increase in leakage current density, indicating less plasma induced side-wall damage. We present a plasma-induced gate stack damage model which we demonstrate by using these two different etching configurations. These results show that NBE is effective in preventing plasma-induced damage at the high-k/Si interface and on the high-k oxide sidewall and thus improve the electrical performance of the gate structure.
Effect of pinning particles on grain boundary motion from interface random walk
Authors: Chen Dengke , Ghoneim Tarek , Kulkarni Yashashree
Published: October 2017

Impurities can dramatically influence grain boundary migration, thereby impacting material properties. In this letter, we present a theoretical model for grain boundary motion in the presence of embedded particles using the interface random walk approach. Based on the fluctuation-dissipation relation, we derive an analytical expression relating the grain boundary fluctuations to the boundary mobility and key parameters governing the drag effect of the particles. In addition to predicting the modified boundary mobility due to pinning particles, the model provides a way to estimate the force acting on the particle-boundary interface from atomistic simulations. The theory facilitates an enriched analysis of atomistic simulations of a grain boundary with embedded particles, revealing that a pinned grain boundary exhibits a response akin to tethered Brownian motion.
Reduction of on-resistance and current crowding in quasi-vertical GaN power diodes
Authors: Zhang Yuhao , Sun Min , Piedra Daniel , Hennig Jonas , Dadgar Armin , Palacios Tomás
Published: October 2017

This paper studies the key parameters affecting on-resistance and current crowding in quasi-vertical GaN power devices by experiment and simulation. The current distribution in the drift region, n−-GaN, was found to be mainly determined by the sheet resistance of the current spreading layer, n+-GaN. The actual on-resistance of the drift region significantly depends on this current distribution rather than the intrinsic resistivity of the drift layer. As a result, the total specific on-resistance of quasi-vertical diodes shows a strong correlation with the device area and sheet resistance of the current spreading layer. By reducing the sheet resistance of the current spreading layer, the specific on-resistance of quasi-vertical GaN-on-Si power diodes has been reduced from ∼10 mΩ·cm2 to below 1 mΩ·cm2. Design space of the specific on-resistance at different breakdown voltage levels has also been revealed in optimized quasi-vertical GaN power diodes.
Confined ion energy >200 keV and increased fusion yield in a DPF with monolithic tungsten electrodes and pre-ionization
Authors: Lerner Eric J. , Hassan Syed M. , Karamitsos Ivana , Von Roessel Fred
Published: October 2017

To reduce impurities in the dense plasma focus FF-1 device, we used monolithic tungsten electrodes with pre-ionization. With this new set-up, we demonstrated a three-fold reduction of impurities by mass and a ten-fold reduction by ion number. FF-1 produced a 50% increase in fusion yield over our previous copper electrodes, both for a single shot and for a mean of ten consecutive shots with the same conditions. These results represent a doubling of fusion yield as compared with any other plasma focus device with the same 60 kJ energy input. In addition, FF-1 produced a new single-shot record of 240 ± 20 keV for mean ion energy, a record for any confined fusion plasma, using any device, and a 50% improvement in ten-shot mean ion energy. With a deuterium-nitrogen mix and corona-discharge pre-ionization, we were also able to reduce the standard deviation in the fusion yield to about 15%, a four-fold reduction over the copper-electrode results. We intend to further reduce impurities with new experiments using microwave treatment of tungsten electrodes, followed by the use of beryllium electrodes.
High efficiency carbon nanotube thread antennas
Authors: Amram Bengio E. , Senic Damir , Taylor Lauren W. , Tsentalovich Dmitri E. , Chen Peiyu , Holloway Christopher L. , Babakhani Aydin , Long Christian J. , Novotny David R. , Booth James C. , Orloff Nathan D. , Pasquali Matteo
Published: October 2017

Although previous research has explored the underlying theory of high-frequency behavior of carbon nanotubes (CNTs) and CNT bundles for antennas, there is a gap in the literature for direct experimental measurements of radiation efficiency. These measurements are crucial for any practical application of CNT materials in wireless communication. In this letter, we report a measurement technique to accurately characterize the radiation efficiency of λ/4 monopole antennas made from the CNT thread. We measure the highest absolute values of radiation efficiency for CNT antennas of any type, matching that of copper wire. To capture the weight savings, we propose a specific radiation efficiency metric and show that these CNT antennas exceed copper's performance by over an order of magnitude at 1 GHz and 2.4 GHz. We also report direct experimental observation that, contrary to metals, the radiation efficiency of the CNT thread improves significantly at higher frequencies. These results pave the way for practical applications of CNT thread antennas, particularly in the aerospace and wearable electronics industries where weight saving is a priority.
Impact of organic linking and terminal groups on the mechanical properties of self-assembly based low-k dielectrics
Authors: Vanstreels K. , Krishtab M. , Garcia Gonzalez L. , Armini S.
Published: October 2017

The impact of terminal and linking organic groups on the mechanical stability of self-assembly based porous ultralow-k dielectrics was investigated by nanoindentation and four-point bending tests in conjunction with quantitative FTIR analysis. Using a set of six porous low-k dielectric films functionalized with alkyl- and aryl-based groups, we demonstrated that both elastic and fracture properties can be sensitive to the type of embedded linking or terminal groups. Based on the obtained correlations between the material composition and the mechanical properties, two approaches for improvement of fracture toughness in low-k dielectrics are proposed.
Ion aggregation in high salt solutions. VII. The effect of cations on the structures of ion aggregates and water hydrogen-bonding network
Authors: Choi Jun-Ho , Choi Hyung Ran , Jeon Jonggu , Cho Minhaeng
Published: October 2017

Ions in high salt solutions have a strong propensity to form polydisperse ion aggregates with broad size and shape distributions. In a series of previous comparative investigations using femtosecond IR pump-probe spectroscopy, molecular dynamics simulation, and graph theoretical analysis, we have shown that there exists a morphological difference in the structures of ion aggregates formed in various salt solutions. As salt concentration increases, the ions in high salt solutions form either cluster-like structures excluding water molecules or network-like structures entwined with water hydrogen-bonding networks. Interestingly, such morphological characteristics of the ion aggregates have been found to be in correlation with the solubility limits of salts. An important question that still remains unexplored is why certain salts with different cations have notably different solubility limits in water. Here, carrying out a series of molecular dynamics simulations of aqueous salt solutions and analyzing the distributions and connectivity patterns of ion aggregates with a spectral graph analysis method, we establish the relationship between the salt solubility and the ion aggregate morphology with a special emphasis on the cationic effects on water structures and ion aggregation. We anticipate that the understanding of large scale ion aggregate structures revealed in this study will be critical for elucidating the specific ion effects on the solubility and conformational stability of co-solute molecules such as proteins in water.
Single-active-electron analysis of laser-polarization effects on atomic/molecular multiphoton excitation
Authors: Kanno Manabu , Inada Nobuyoshi , Kono Hirohiko
Published: October 2017

We theoretically explore the effects of optical ellipticity on single-active-electron multiphoton excitation in atoms and (nearly) spherical molecules irradiated by intense polarized laser fields. This work was motivated by the experimental and theoretical studies of Hertel et al. [Phys. Rev. Lett. 102, 023003 (2009) and Phys. Rev. A 79, 053414 (2009)], who reported pronounced changes in the near-infrared-induced ion yields of xenon and C60 as a function of ellipticity (in particular, yield reduction for circular polarization) at low light intensities and derived a perturbative cross section formula to describe such polarization effects by assuming that the excited-state energies and radial transition electric dipole moments of the system are independent of the azimuthal quantum number l. First, by reformulating the N-photon absorption cross section of a single active electron, we prove that their assumptions reduce the network of optically allowed transition pathways into what we call the “Pascal triangle” consisting of (N + 1) (N + 2)/2 states only. Next, nonperturbative analytical and numerical solutions of the time-dependent Schrödinger equation for a simple model of two-photon excitation are presented not only in the low-intensity regime but also in the high-intensity regime. The results show that the determining factor of ellipticity-dependent multiphoton excitation probability is transition moment magnitudes and that the detailed energetic structure of the system also becomes important at high intensities. The experimentally observed flattening of the ion yields of xenon and C60 with increasing intensity can be explained without a saturation effect, which was previously deemed to be responsible for it. We also argue the applicability range of the cross section formula by Hertel et al. and the identity of the “doorway state” for ionization of C60.
Low temperature synthesis of highly oriented p-type Si1-xGex (x: 0–1) on an insulator by Al-induced layer exchange
Authors: Toko K. , Kusano K. , Nakata M. , Suemasu T.
Published: October 2017

A composition tunable Si1-xGex alloy has a wide range of applications, including in electronic and photonic devices. We investigate the Al-induced layer exchange (ALILE) growth of amorphous Si1-xGex on an insulator. The ALILE allowed Si1-xGex to be large grained (> 50 μm) and highly (111)-oriented (> 95%) over the whole composition range by controlling the growth temperature (≤ 400 °C). From a comparison with conventional solid-phase crystallization, we determined that such characteristics of the ALILE arose from the low activation energy of nucleation and the high frequency factor of lateral growth. The Si1-xGex layers were highly p-type doped, whereas the process temperatures were low, thanks to the electrically activated Al atoms with the amount of solid solubility limit. The electrical conductivities approached those of bulk single crystals within one order of magnitude. The resulting Si1-xGex layer on an insulator is useful not only for advanced SiGe-based devices but also for virtual substrates, allowing other materials to be integrated on three-dimensional integrated circuits, glass, and even a plastic substrate.
Switched ratiometric lock-in amplifier enabling sub-ppm measurements in a wide frequency range
Authors: Gervasoni G. , Carminati M. , Ferrari G.
Published: October 2017

Lock-in amplifiers (LIAs) are extensively used to perform high-resolution measurements. Ideally, when using LIAs, it would be possible to measure a minimum signal variation limited by the instrument input equivalent noise at the operating frequency and the chosen filtering bandwidth. Instead, digital LIAs show an unforeseen 1/f noise at the instrument demodulated output, proportional to the signal amplitude that poses a fundamental limit to the minimum detectable signal variation using the lock-in technique. In particular, the typical resolution limit of fast operating LIAs (>1 MHz) is of tens of ppm, orders of magnitude worse than the expected value. A detailed analysis shows that the additional noise is due to slow fluctuations of the signal gain from the generation stage to the acquisition one, mainly due to the digital-to-analog and analog-to-digital converters. To compensate them, a switched ratiometric technique based on two analog-to-digital converters alternately acquiring the signal coming from the device under test and the stimulus signal has been conceived. A field-programmabale gate array-based LIA working up to 10 MHz and implementing the technique has been realized, and results demonstrate a resolution improvement of more than an order of magnitude (from tens of ppm down to sub-ppm values) compared to standard implementations working up to similar frequencies. The technique is generally applicable without requiring calibration nor ad hoc experimental arrangements.
Internal stress and opto-electronic properties of ZnO thin films deposited by reactive sputtering in various oxygen partial pressures
Authors: Tuyaerts Romain , Poncelet Olivier , Raskin Jean-Pierre , Proost Joris
Published: October 2017

In this article, we propose ZnO thin films as a suitable material for piezoresistors in transparent and flexible electronics. ZnO thin films have been deposited by DC reactive magnetron sputtering at room temperature at various oxygen partial pressures. All the films have a wurtzite structure with a strong (0002) texture measured by XRD and are almost stoichiometric as measured by inductively coupled plasma optical emission spectroscopy. The effect of oxygen concentration on grain growth has been studied by in-situ multi-beam optical stress sensor, showing internal stress going from 350 MPa to −1.1 GPa. The transition between tensile and compressive stress corresponds to the transition between metallic and oxidized mode of reactive sputtering. This transition also induces a large variation in optical properties—from absorbent to transparent, and in the resistivity—from 4×10−2Ω.cm to insulating. Finally, the piezoresistance of the thin film has been studied and showed a gauge factor (ΔR/R)/ε comprised between −5.8 and −8.5.
Luminescence of crystals excited by a runaway electron beam and by excilamp radiation with a peak wavelength of 222 nm
Authors: Sorokin D. A. , Burachenko A. G. , Beloplotov D. V. , Tarasenko V. F. , Baksht E. Kh. , Lipatov E. I. , Lomaev M. I.
Published: October 2017

This paper presents research data on cathodoluminescence, photoluminescence, and Cherenkov radiation at 200–800 nm excited in crystals with different refractive indices by a subnanosecond runaway electron beam and by KrCl excilamp radiation with a peak wavelength of 222 nm. The data include spectral and amplitude-time characteristics measured with a resolution of up to ∼100 ps for natural and synthetic diamonds of type IIa, sapphire, CsI, ZnS, CaF2, ZrO2, Ga2O3, CaCO3, CdS, and ZnSe. The research suggests that cathodoluminescence and photoluminescence should be accounted for in Cherenkov-type detectors of runaway electrons. The results can be useful for detecting high-energy electrons in tokamaks.
Multiple exciton generation in chiral carbon nanotubes: Density functional theory based computation
Authors: Kryjevski Andrei , Mihaylov Deyan , Kilina Svetlana , Kilin Dmitri
Published: October 2017

We use a Boltzmann transport equation (BE) to study time evolution of a photo-excited state in a nanoparticle including phonon-mediated exciton relaxation and the multiple exciton generation (MEG) processes, such as exciton-to-biexciton multiplication and biexciton-to-exciton recombination. BE collision integrals are computed using Kadanoff-Baym-Keldysh many-body perturbation theory based on density functional theory simulations, including exciton effects. We compute internal quantum efficiency (QE), which is the number of excitons generated from an absorbed photon in the course of the relaxation. We apply this approach to chiral single-wall carbon nanotubes (SWCNTs), such as (6,2) and (6,5). We predict efficient MEG in the (6,2) and (6,5) SWCNTs within the solar spectrum range starting at the 2Eg energy threshold and with QE reaching ∼1.6 at about 3Eg, where Eg is the electronic gap.
Development of a spectro-electrochemical cell for soft X-ray photon-in photon-out spectroscopy
Authors: Ishihara Tomoko , Tokushima Takashi , Horikawa Yuka , Kato Masaru , Yagi Ichizo
Published: October 2017

We developed a spectro-electrochemical cell for X-ray absorption and X-ray emission spectroscopy, which are element-specific methods to study local electronic structures in the soft X-ray region. In the usual electrochemical measurement setup, the electrode is placed in solution, and the surface/interface region of the electrode is not normally accessible by soft X-rays that have low penetration depth in liquids. To realize soft X-ray observation of electrochemical reactions, a 15-nm-thick Pt layer was deposited on a 150-nm-thick film window with an adhesive 3-nm-thick Ti layer for use as both the working electrode and the separator window between vacuum and a sample liquid under atmospheric pressure. The designed three-electrode electrochemical cell consists of a Pt film on a SiC window, a platinized Pt wire, and a commercial Ag|AgCl electrode as the working, counter, and reference electrodes, respectively. The functionality of the cell was tested by cyclic voltammetry and X-ray absorption and emission spectroscopy. As a demonstration, the electroplating of Pb on the Pt/SiC membrane window was measured by X-ray absorption and real-time monitoring of fluorescence intensity at the O 1s excitation.