bluuebunny/crossref_metadata_2025 huggingface dataset:
Induction of GADD45α protects M17 neuroblastoma cells against MPP*
Authors: Wang Xiao‐Feng , Zeng Qing‐gan , Zeng Yan , Man Rong‐Yong , Lu Bing‐Xun , Luo Yi‐Feng
Published: December 2014

Growth arrest and DNA‐damage‐inducible protein 45α (GADD45α) is an important member of the family of growth arrest and DNA damage‐inducible (GADD) proteins. The expression patterns and possible roles of GADD45α in Parkinson's disease (PD) are so far less understood. In this study, we found that 1‐methyl‐4‐phenylpyridinium (MPP+) treatment up‐regulates the expression of GADD45α in both a time‐dependent manner and a dose‐dependent manner in human dopamine neuroblastoma M17 cells. The up‐regulation of GADD45α was abolished by pretreatment with the c‐Jun N‐terminal kinases (JNK) inhibitor SP600125 but not the p38 specific inhibitor SB203580. Further study revealed that c‐Jun silencing abolished the effects of MPP+ on the expression of GADD45α. Important, ChIP studies verified the ability of c‐Jun to bind to the GADD45 promoter. In addition, we found that inhibition of GADD45α by small RNA interference exacerbates the impaired cell viability, LDH release, and apoptosis induced by MPP+. Correspondingly, silence of GADD45 exacerbated Caspase‐3 activation induced by MPP+. These data suggested a neuroprotective effect of GADD45α against MPP+ neurotoxicity. © 2014 IUBMB Life, 66(11):786–792, 2014
Galectin‐1 Triggers Epithelial‐Mesenchymal Transition in Human Hepatocellular Carcinoma Cells
Authors: Bacigalupo María L. , Manzi Malena , Espelt María V. , Gentilini Lucas D. , Compagno Daniel , Laderach Diego J. , Wolfenstein‐Todel Carlota , Rabinovich Gabriel A. , Troncoso María F.
Published: December 2014

Galectin‐1 (Gal1), a β‐galactoside‐binding protein abundantly expressed in tumor microenvironments, is associated with the development of metastasis in hepatocellular carcinomas (HCC). However, the precise roles of Gal1 in HCC cell invasiveness and dissemination are uncertain. Here, we investigated whether Gal1 mediate epithelial‐mesenchymal transition (EMT) in HCC cells, a key process during cancer progression. We used the well‐differentiated and low invasive HepG2 cells and performed ‘gain‐of‐function' and ‘loss‐function' experiments by transfecting cells with Gal1 cDNA constructs or by siRNA strategies, respectively. Epithelial and mesenchymal markers expression, changes in apico‐basal polarity, independent‐anchorage growth, and activation of specific signaling pathways were studied using Western blot, fluorescence microscopy, soft‐agar assays, and FOP/TOP flash reporter system. Gal1 up‐regulation in HepG2 cells induced down‐regulation of the adherens junction protein E‐cadherin and increased expression of the transcription factor Snail, one of the main inducers of EMT in HCC. Enhanced Gal1 expression facilitated the transition from epithelial cell morphology towards a fibroblastoid phenotype and favored up‐regulation of the mesenchymal marker vimentin in HCC cells. Cells overexpressing Gal1 showed enhanced anchorage‐independent growth and loss of apico‐basal polarity. Remarkably, Gal1 promoted Akt activation, β‐catenin nuclear translocation, TCF4/LEF1 transcriptional activity and increased cyclin D1 and c‐Myc expression, suggesting activation of the Wnt pathway. Furthermore, Gal1 overexpression induced E‐cadherin downregulation through a PI3K/Akt‐dependent mechanism. Our results provide the first evidence of a role of Gal1 as an inducer of EMT in HCC cells, with critical implications in HCC metastasis. J. Cell. Physiol. 230: 1298–1309, 2015. © 2014 Wiley Periodicals, Inc., A Wiley Company
Humid Bonding with a Water‐Soluble Adhesive Inspired by Mussels and Sandcastle Worms
Authors: Li Ailei , Jia Mingchen , Mu Youbing , Jiang Wei , Wan Xiaobo
Published: December 2014

Inspired by mussels and sandcastle worms, a water‐soluble adhesive is prepared by grafting catechol and phosphoric acid functionalities to the polyoxetane backbone, which achieves improved adhesion in humid environment. The adhesive is characterized by 1H and 31P NMR spectroscopy and size‐exclusive chromatography. The influence of the content ratio of catechol and different phosphoric acid groups and the Fe3+ ions as the crosslinker on the outcome of the adhesive properties is investigated. When the molar ratio of Fe3+ to catechol and PO4 is 1/1 and 0.7/1, respectively, the best bonding strength of 0.35 MPa is achieved for the adhesive containing 5 mol% catechol and 26 mol% bis‐phosphoric acid groups under humid conditions. It is found out that Fe3+ interacts not only with the catechol, but also with the bis‐phosphoric acid groups, which accounts for its performance in humid conditions.

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The Understanding of Pain by Older Adults Who Consider Themselves to Have Aged Successfully
Authors: Collis David , Waterfield Jackie
Published: December 2014

Objectives

Despite an ageing population and an increased prevalence of chronic pain, the relationship between chronic pain and the concept of successful ageing is unclear. The aim of the present research was to explore older people's views on past and present experiences of pain, and its management, and how these experiences relate to their perceptions of successful ageing.

Methods

Semi‐structured interviews with six participants, aged 75 years or older, who considered themselves to have aged successfully, explored what this concept meant to them and their experiences of pain. Data analysis used methods drawn from grounded theory. The themes reported in this article are ‘understanding of pain’ and ‘perceptions of ageing’.

Results

None of the participants recalled painful experiences that were not attributable to physical trauma. They believed that pain is part of life and a natural consequence of the ageing process. While some accepted this with little resistance, others felt frustration at what they considered a dismissive attitude towards older people experiencing pain from healthcare practitioners. The concept of successful ageing was previously unfamiliar to participants, and their conceptualization of ageing derived from comparing themselves with their peers.

Conclusions

The findings of the present study suggest that predictable experiences of pain as one ages may contribute to an acceptance of pain as a biomedical certainty, a belief reinforced both by health professionals and society. However, one may have chronic pain and yet consider oneself to have aged successfully, and it should therefore be recognized that there is a distinction between having pain and having a problem with pain. Copyright © 2014 John Wiley & Sons, Ltd.
“Zum Wohl der Menschheit”
Authors: Männig Detlef
Published: December 2014

100 Jahre nach dem erstmaligen Einsatz von Chemiewaffen im Ersten Weltkrieg sind chemische Kampfstoffe heute weltweit geächtet. Das seit dem Jahr 1997 geltende Chemiewaffenübereinkommen wurde zur Erfolgsgeschichte.
Wenn Nanogramm das Aroma verändern
Authors: Schmarr Hans‐Georg , Slabizki Petra , Legrum Charlotte , Langen Johannes
Published: December 2014

Oft sind es nur Spuren von Substanzen, die den Charakter eines Weines ausmachen. Diese unter der Menge an flüchtigen Substanzen in einem Weinaroma herauszufinden und zu quantifizieren, erfordert mehrdimensionale chromatographische Trennmethoden und kriminalistischen Spürsinn.
Moral Identity in Friendships between Gay, Lesbian, and Bisexual Students and Straight Students in College
Authors: Ueno Koji , Gentile Haley
Published: December 2014

People construct moral identities for being a supportive affiliate of stigmatized groups. To extend past research that focused on such identities within formal organizations, this study seeks to identify the process of moral identity construction in a personal setting—friendships between gay, lesbian, and bisexual (GLB) people and straight people. Analyzing data from in‐depth interviews with college students, we show that straight students claim moral worth by emphasizing their deliberate decisions to develop and sustain friendships with GLB people and by highlighting how the friendships led them to personal enlightenment and political engagement. GLB students, as a stigmatized group, also claim moral worth by emphasizing their ability to transcend the community boundary and to be accepted in the larger society. Students make such claims as they strategically link these aspects of cross‐orientation friendships to existing moral discourses in the larger society and draw on resources available in the organizational and life course contexts.
Gravity current propagation up a valley
Authors: Jones Catherine S. , Cenedese Claudia , Chassignet Eric P. , Linden P. F. , Sutherland Bruce R.
Published: December 2014

The advance of the front of a dense gravity current propagating in a rectangular channel and V-shaped valley both horizontally and up a shallow slope is examined through theory, full-depth lock–release laboratory experiments and hydrostatic numerical simulations. Consistent with theory, experiments and simulations show that the front speed is relatively faster in the valley than in the channel. The front speed measured shortly after release from the lock is 5–22 % smaller than theory, with greater discrepancy found in upsloping V-shaped valleys. By contrast, the simulated speed is approximately 6 % larger than theory, showing no dependence on slope for rise angles up to ${\it\theta}=8^{\circ }$. Unlike gravity currents in a channel, the current head is observed in experiments to be more turbulent when propagating in a V-shaped valley. The turbulence is presumably enhanced due to the lateral flows down the sloping sides of the valley. As a consequence, lateral momentum transport contributes to the observed lower initial speeds. A Wentzel–Kramers–Brillouin like theory predicting the deceleration of the current as it runs upslope agrees remarkably well with simulations and with most experiments, within errors.
How International Organizations Support Democratization: Preventing Authoritarian Reversals or Promoting consolidation?
Authors: Poast Paul , Urpelainen Johannes
Published: December 2014

Democratization in the developing world is, according to Samuel Huntington, “an important—perhaps the most important—global political development of the late twentieth century.” While scholars of comparative politics have explored the domestic political economy of democratic transitions, they, along with scholars of international relations, also recognize that international actors, particularly international organizations (IOs), are crucial for successful political transformation.
Customer dissatisfaction among older consumers: a mixed-methods approach
Authors: CAMERON MICHAEL P. , RICHARDSON MARGARET , SIAMEJA SIALUPAPU
Published: December 2014

Worldwide, populations are ageing and consequently so are the consumer profiles for most organisations. Understanding how best to ensure satisfaction in interactions with older customers, patients, members of organisations, and so on is therefore increasingly important. This paper examines two research questions: (a) How satisfied or dissatisfied are older people with their customer service experience, and what are the factors associated with dissatisfaction? and (b) What prompts older people to want to change service providers? The research questions are addressed using a mixed-methods approach – quantitative analysis of observation logs, supported by illustrative quotes from focus groups. We find that on the whole older people are generally satisfied with their interactions with organisations, although a substantial minority of interactions lead to dissatisfaction or lower-than-expected satisfaction. Dissatisfaction with interactions is mostly associated with impersonal communications, including interactions that are not conducted face to face, and those that are one-off interactions rather than repeated interactions. Media and communications firms prompted the greatest levels of dissatisfaction among older consumers. Dissatisfied older consumers from our sample are more than 12 times more likely to report an intention to switch providers than satisfied consumers. This highlights the potential costs to organisations of poor customer interactions with older people.
Design and locomotion analysis of a novel deformable mobile robot with worm-like, self-crossing and rolling motion
Authors: Tian Yaobin , Yao Yan-An , Ding Wan , Xun Zhiyuan
Published: December 2014

This paper presents a novel deformable mobile robot with five degrees of freedom (DOFs). The robot contains two equivalent expandable triangular platforms connected by three equivalent chains. Each platform is a regular triangle with a single DOF. Each chain consists of two links and three joints (one spherical joint at the middle of a chain, and one revolute joint at each end of the chain). Through kinematic and locomotion mode analysis, the robot exhibits three motion modes: worm-like, self-crossing, and rolling modes. The worm-like and self-crossing modes can be used for narrow passages (e.g., pipelines, holes, and caves). The rolling mode has three different directions at the initial state. By switching between these, the robot can operate on rough ground. To verify the locomotion modes and functionality of the robot, the results of a series of experiments performed on a manufactured prototype are reported.
How to measure mood in nutrition research
Authors: Hammersley Richard , Reid Marie , Atkin Stephen L.
Published: December 2014

Mood is widely assessed in nutrition research, usually with rating scales. A core assumption is that positive mood reinforces ingestion, so it is important to measure mood well. Four relevant theoretical issues are reviewed: (i) the distinction between protracted and transient mood; (ii) the distinction between mood and emotion; (iii) the phenomenology of mood as an unstable tint to consciousness rather than a distinct state of consciousness; (iv) moods can be caused by social and cognitive processes as well as physiological ones. Consequently, mood is difficult to measure and mood rating is easily influenced by non-nutritive aspects of feeding, the psychological, social and physical environment where feeding occurs, and the nature of the rating system employed. Some of the difficulties are illustrated by reviewing experiments looking at the impact of food on mood. The mood-rating systems in common use in nutrition research are then reviewed, the requirements of a better mood-rating system are described, and guidelines are provided for a considered choice of mood-rating system including that assessment should: have two main dimensions; be brief; balance simplicity and comprehensiveness; be easy to use repeatedly. Also mood should be assessed only under conditions where cognitive biases have been considered and controlled.
We Must Create Beings with Moral Standing Superior to Our Own
Authors: RAKIĆ VOJIN
Published: December 2014

Several lines of reasoning have been employed to both approve and disapprove two of Nicholas Agar’s positions: his argument that the creation of postpersons (based on moral status enhancement) is imaginable and possible and his inductive argument disfavoring the creation of postpersons. This article discusses a number of these lines of reasoning, arguing that

1)

The creation of postpersons is imaginable if they are envisaged as morally enhanced beings.

2)

The creation of postpersons is justified, subject to the condition that we create morally enhanced postpersons.

The reason given for the first point is that it is possible to imagine postpersons who are morally enhanced, provided that we consider moral enhancement as an augmented inclination to act in line with how we believe we ought to act. There are two reasons offered for the second point: the first indicates probability, and the second offers proof. That is, if we assume that the higher moral status of postpersons implies their enhanced morality, we can conclude, inductively, that (morally enhanced) postpersons will not be inclined to annihilate mere persons. For if mere persons have moral inhibitions against obliterating some species of a lower moral status than their own, morally enhanced postpersons will be even less likely to do the same to mere persons. In fact, they might consider it their moral duty to preserve those beings who enabled them to come into existence. Moreover, even if morally enhanced postpersons decide to annihilate mere persons, we can conclude, deductively, that such a decision is by necessity a morally superior stance to the wish of mere persons (i.e., morally unenhanced persons) to continue to exist.
Performance of PET post-consume bottle fiber into a concrete matrix
Authors: Herrera-Ramirez J.M. , Baldenebro-Lopez F.J. , Gomez-Esparza C.D. , Castorena-Gonzalez J.H. , Velazquez-Dimas J.I. , Antunez-Flores W. , Ledezma-Sillas J.E. , Martinez-Sanchez R.
Published: December 2014

Extended abstract of a paper presented at Microscopy and Microanalysis 2013 in Indianapolis, Indiana, USA, August 4 – August 8, 2013.
THE FINITE FOURIER TRANSFORM OF CLASSICAL POLYNOMIALS
Authors: DIXIT ATUL , JIU LIN , MOLL VICTOR H. , VIGNAT CHRISTOPHE
Published: December 2014

The finite Fourier transform of a family of orthogonal polynomials is the usual transform of these polynomials extended by$0$outside their natural domain of orthogonality. Explicit expressions are given for the Legendre, Jacobi, Gegenbauer and Chebyshev families.
ON DIFFERENTIAL CHARACTERISTIC CLASSES
Authors: HO MAN-HO
Published: December 2014

In this paper we give explicit formulas for differential characteristic classes of principal$G$-bundles with connections and prove their expected properties. In particular, we obtain explicit formulas for differential Chern classes, differential Pontryagin classes and the differential Euler class. Furthermore, we show that the differential Chern class is the unique natural transformation from (Simons–Sullivan) differential$K$-theory to (Cheeger–Simons) differential characters that is compatible with curvature and characteristic class. We also give the explicit formula for the differential Chern class on Freed–Lott differential$K$-theory. Finally, we discuss the odd differential Chern classes.
The homeobox gene DLX4 promotes generation of human induced pluripotent stem cells
Authors: Tamaoki Naritaka , Takahashi Kazutoshi , Aoki Hitomi , Iida Kazuki , Kawaguchi Tomoko , Hatakeyama Daijirou , Inden Masatoshi , Chosa Naoyuki , Ishisaki Akira , Kunisada Takahiro , Shibata Toshiyuki , Goshima Naoki , Yamanaka Shinya , Tezuka Ken-ichi
Published: December 2014

The reprogramming of somatic cells into induced pluripotent stem cells (iPSCs) by defined transcription factors has been a well-established technique and will provide an invaluable resource for regenerative medicine. However, the low reprogramming efficiency of human iPSC is still a limitation for clinical application. Here we showed that the reprogramming potential of human dental pulp cells (DPCs) obtained from immature teeth is much higher than those of mature teeth DPCs. Furthermore, immature teeth DPCs can be reprogrammed by OCT3/4 and SOX2, conversely these two factors are insufficient to convert mature teeth DPCs to pluripotent states. Using a gene expression profiles between these two DPC groups, we identified a new transcript factor, distal-less homeobox 4 (DLX4), which was highly expressed in immature teeth DPCs and significantly promoted human iPSC generation in combination with OCT3/4, SOX2 and KLF4. We further show that activation of TGF-β signaling suppresses the expression of DLX4 in DPCs and impairs the iPSC generation of DPCs. Our findings indicate that DLX4 can functionally replace c-MYC and supports efficient reprogramming of immature teeth DPCs.
Genetic algorithms coupled with quantum mechanics for refinement of force fields for RNA simulation: a case study of glycosidic torsions in the canonical ribonucleosides
Authors: Kato Rodrigo B. , Silva Frederico T. , Pappa Gisele L. , Belchior Jadson C.
Published: December 2014

We report the use of genetic algorithms (GA) as a method to refine force field parameters in order to determine RNA energy.
Universality in surface mixing rule of adsorption strength for small adsorbates on binary transition metal alloys
Authors: Ko Jeonghyun , Kwon Hyunguk , Kang Hyejin , Kim Byung-Kook , Han Jeong Woo
Published: December 2014

Understanding the adsorption phenomena of small adsorbates involved in surface reactions on transition metals is important because their adsorption strength can be a descriptor for predicting the catalytic activity.
Retracted Article: Monodisperse CuB23nanoparticles grown on graphene as highly efficient catalysts for unactivated alkyl halide Heck coupling and levulinic acid hydrogenation
Authors: Fu Shi Yan , Li Yuan Zhi , Chu Wei , Li Chun , Tong Dong Ge
Published: December 2014

Monodisperse CuB23nanoparticles grown on graphene exert exceedingly high activity towards unactivated alkyl halide Heck coupling and levulinic acid hydrogenation.
Large scale patterning of hydrogel microarrays using capillary pinning
Authors: Gumuscu Burcu , Bomer Johan G. , van den Berg Albert , Eijkel Jan C. T.
Published: December 2014

Capillary barriers provide a simple and elegant means of autonomous fluid-flow control in microfluidic systems.
Highly efficient stabilisation of meta-ethynylpyridine polymers with amide side chains in water by coordination of rare-earth metals
Authors: Makida Hiroki , Abe Hajime , Inouye Masahiko
Published: December 2014

An amphiphilic meta-ethynylpyridine polymer with chiral amide side chains coordinated with rare-earth metal salts, especially strongly with Sc(iii), to stabilise its helical structure with CD enhancement.
Poly(4-methyl-1-pentene)/alkylated graphene oxide nanocomposites: the emergence of a new crystal structure
Authors: Xu Li-yang , Yan Huai-wen , Gong Lei , Yin Bo , Yang Ming-bo
Published: December 2014

Modified graphene oxide (GO) not only offers a wrinkled structure but may also transform the crystal structure, giving it a potential application in high performance polymer/filler composites.
Quinine catalysed asymmetric Michael additions in a sustainable solvent
Authors: Castro-Osma José A. , Comerford James W. , Heath Samantha , Jones Oliver , Morcillo Maria , North Michael
Published: December 2014

Diethyl carbonate is shown to be a suitable, sustainable solvent in which to carry out quinine catalysed asymmetric Michael additions of malononitriles to enones.
Diindeno[1,2-g:1′,2′-s]rubicene: all-carbon non-fullerene electron acceptor for efficient bulk-heterojunction organic solar cells with high open-circuit voltage
Authors: Chen Hung-Yang , Golder Jan , Yeh Shih-Chieh , Lin Chiao-Wen , Chen Chao-Tsen , Chen Chin-Ti
Published: December 2014

An all carbon non-fullerene electron acceptor material based on diindeno[1,2-g:1′,2′-s]rubicene (DIR) was readily synthesized and processed for bulk-heterojunction organic solar cells.
Plasmonic GaInP solar cells with improved energy conversion efficiency
Authors: Zhang Qian , Liu Duo , Lin Guanjun , Zuo Zhiyuan , Lin Xiaoyu , Zhao Dongfang , Jia Ran , Gao Naikun , Xu Xiangang
Published: December 2014

Schematic diagram of Ag nanoparticles decorated on GaInP solar cells and the improved photocurrent densities at different wavelengths.
A facile solution-based approach to a photocatalytic active branched one-dimensional TiO2array
Authors: Wu Jin-Ming , Yin Jia-Xing
Published: December 2014

Branched one-dimensional TiO2array with enhanced photocatalytic activity was fabricatedviaa facile solution-based strategy.
Computational modelling of the enantioselectivity in the asymmetric 1,4-addition reaction catalyzed by a Rh complex of a S-chiral disulfoxide
Authors: Li You-Gui , Li Li , Yang Ming-Yue , Qin Hua-Li , Kantchev Eric Assen B.
Published: December 2014

Computational chemistry is a powerful tool for understanding chiral catalysis and can also aid future catalyst design.
Unprecedented catalyst-free lignin dearomatization with hydrogen peroxide and dimethyl carbonate
Authors: Wiermans Lotte , Schumacher Hannah , Klaaßen Christian-Marvin , Domínguez de María Pablo
Published: December 2014

By dissolving lignin in dimethyl carbonate and adding hydrogen peroxide, a catalyst-free lignin dearomatization is observed. Full dearomatized gels or solid fibers partly dearomatized can be achieved.
A recyclable, fluorescent, and colorimetric sensor for fluoride anion in water using a crosslinked polymer functionalized with hydroxyl quinolinium
Authors: Tang Qian , Nie Hong-Mei , Gong Cheng-Bin , Liu Hua-Dong , Xiao Kun
Published: December 2014

A crosslinked polymer-based recyclable, fluorescent, and colorimetric sensor for F− in water.
The optimization of electric properties of multilayered BNT–BT–ST/BCST thin films by configuration
Authors: Li Wei , Li Peng , Zeng Huarong , Hao Jigong , Zhai Jiwei
Published: December 2014

The 0.755Bi0.5Na0.5TiO3–0.065BaTiO3–0.18SrTiO3/Ba0.98Ca0.02Ti0.96Sn0.04O3 (BNT–BT–ST/BCST) multilayered thin films, consisting of BNT–BT–ST layers and BCST layers, were prepared by using the sol–gel processing technique.
Novel wood-based all-solid-state flexible supercapacitors fabricated with a natural porous wood slice and polypyrrole
Authors: Lv Shaoyi , Fu Feng , Wang Siqun , Huang Jingda , Hu La
Published: December 2014

A simple dipping-and-polymerization method to prepare an interesting electrode material consisting of PPy-coated wood transverse section slice (WTSS), and fabricated an eco-friendly wood-based solid-state flexible supercapacitors.
Enhanced water retention and proton conductivity of proton exchange membranes by incorporating hollow polymer microspheres grafted with sulfonated polystyrene brushes
Authors: Zhang Wei , Zhang Bei , He Guangwei , Liu Bin , Jiang Zhongyi , Yang Xinlin , Li Chenxi
Published: December 2014

The paper describes the synthesis of hollow polymer microspheres with sulfonated polystyrene brushes and investigation of the enhanced water retention and proton conductivity of proton exchange membranes.
Enhanced mechanical and thermal properties of epoxy with hyperbranched polyester grafted perylene diimide
Authors: Pan Lulu , Lu Shaorong , Xiao Xiane , He Zihai , Zeng Cen , Gao Jian , Yu Jinhong
Published: December 2014

The mechanical and thermal properties of epoxy were significantly enhanced modified by H20-g-PDI.
Experimental observation of induced stochastic transitions in a multiwall potential of an rf-SQUID loop
Authors: Turutanov O. G. , Lyakhno V. U. , Shnyrkov V. I.
Published: December 2014

Experimental observation of a weak low-frequency harmonic signal in a point (superconductor-constriction-superconductor, ScS) contact superconducting quantum interference device (rf-SQUID loop), being amplified due to the stochastic transitions between two or more metastable states of the loop, under the influence of applied noise flux of varying intensity (the effect of stochastic resonance, SR). In addition to the usual SR effect found in a bi-stable system with Gaussian noise, there were observed transitions between several metastable states of the multiwell SQUID loop potential, due to the influence of binary noise, which can be interpreted as a kind of noise “spectroscopy” of the loop's metastable states, with varying values of trapped magnetic flux.
Magnetic properties of the quantum Shastry–Sutherland model with spin S = 1/2
Authors: Slavin V. V. , Krivchikov A. A.
Published: December 2014

Magnetization dependence on the external magnetic field was studied in a system with the Shastry–Sutherland lattice using exact diagonalization method at zero temperature within the xxz-model with spin S = 1/2. It was found that contrary to the classical Heisenberg model, the magnetization plateaus corresponding to m* = m/msat = 1/4, 1/3, and 1/2 (here msat is the saturation magnetization) exist even in the case of isotropic exchange interactions. The effect of exchange interaction on the width of the plateaus was studied. It was shown that depending on the ratio of exchange constants, there exist three regions corresponding to different types of the behavior of the system: the regions of a Neel-like antiferromagnet, a “dimer” antiferromagnet, and an intermediate region where the unique properties of Shastry–Sutherland lattices are most pronounced. The boundaries of these regions were also determined.
Intervalence charge transfer luminescence: The anomalous luminescence of cerium-doped Cs2LiLuCl6 elpasolite
Authors: Seijo Luis , Barandiarán Zoila
Published: December 2014

The existence of intervalence charge transfer (IVCT) luminescence is reported. It is shown that the so called anomalous luminescence of Ce-doped elpasolite Cs2LiLuCl6, which is characterized mainly by a very large Stokes shift and a very large band width, corresponds to an IVCT emission that takes place in Ce3+–Ce4+ pairs, from the 5deg orbital of Ce3+ to 4f orbitals of Ce4+. Its Stokes shift is the sum of the large reorganization energies of the Ce4+ and Ce3+ centers formed after the fixed-nuclei electron transfer and it is equal to the energy of the IVCT absorption commonly found in mixed-valence compounds, which is predicted to exist in this material and to be slightly larger than 10 000 cm−1. The large band width is the consequence of the large offset between the minima of the Ce3+–Ce4+ and Ce4+–Ce3+ pairs along the electron transfer reaction coordinate. This offset is approximately \documentclass[12pt]{minimal}\begin{document}$2\sqrt{3}$\end{document}23 times the difference of Ce–Cl equilibrium distances in the Ce3+ and Ce4+ centers. It is shown that the energies of the peaks and the widths of IVCT absorption and emission bands can be calculated ab initio with reasonable accuracy from diabatic energy surfaces of the ground and excited states and that these can be obtained, in turn, from independent calculations on the donor and acceptor active centers. We obtained the energies of the Ce3+ and Ce4+ active centers of Ce-doped Cs2LiLuCl6 by means of state-of-the-art wave-function-theory spin-orbit coupling relativistic calculations on the donor cluster (CeCl6Li6Cs8)11+ and the acceptor cluster (CeCl6Li6Cs8)12+ embedded in a quantum mechanical embedding potential of the host. The calculations provide interpretations of unexplained experimental observations as due to higher energy IVCT absorptions, and allow to reinterpret others. The existence of another IVCT emission of lower energy, at around 14 000-16 000 cm−1 less than the 5dt2g emission, is also predicted.
On stability of water and heavy-water nanoclusters in a nitrogen cryomatrix
Authors: Drobyshev A. , Aldiyarov A. , Katpaeva K. , Korshikov E. , Kurnosov V. , Shinbayeva A.
Published: December 2014

Earlier studies of the properties of cryocondensed films of diluted solutions of ethanol in nitrogen have shown that a slight increase in the temperature of solid nitrogen, long before its sublimation, leads to changes in the vibrational spectrum of ethanol. The present work is a continuation of these studies and is focused on exploring the properties of thin films of cryovacuum condensates of dilute solutions of water and heavy water in nitrogen. The measurements were carried out in the temperature range from 12 to 40 K; the pressure in the vacuum chamber was below 5 × 10−8 Torr. The concentration of water and heavy water in nitrogen was varied in the range from 0.5% to 3%. Based on the analysis of the vibrational spectra, it is suggested that the structure of the two-component film is a system of polyaggregates. An increase in the temperature of the matrix leads to the transformation of these polyaggregates into more stable states, as indicated by the changes in the fine structure of the bands. The presence of the absorption bands with the frequencies corresponding to the water monomers and dimers in a nitrogen matrix can be due to the fact that a fraction of the water molecules constituting polyaggregates might not be connected through hydrogen bonds with the neighboring molecules, forming broken chains. Thus, a population of quasi-free molecules with the corresponding absorption bands is formed. It is assumed that these unbound quasi-free molecules are mainly located in the subsurface layer of the clusters.
Optimizations of spin-exchange relaxation-free magnetometer based on potassium and rubidium hybrid optical pumping
Authors: Fang Jiancheng , Wang Tao , Zhang Hong , Li Yang , Zou Sheng
Published: December 2014

The hybrid optical pumping atomic magnetometers have not realized its theoretical sensitivity, the optimization is critical for optimal performance. The optimizations proposed in this paper are suitable for hybrid optical pumping atomic magnetometer, which contains two alkali species. To optimize the parameters, the dynamic equations of spin evolution with two alkali species were solved, whose steady-state solution is used to optimize the parameters. The demand of the power of the pump beam is large for hybrid optical pumping. Moreover, the sensitivity of the hybrid optical pumping magnetometer increases with the increase of the power density of the pump beam. The density ratio between the two alkali species is especially important for hybrid optical pumping magnetometer. A simple expression for optimizing the density ratio is proposed in this paper, which can help to determine the mole faction of the alkali atoms in fabricating the hybrid cell before the cell is sealed. The spin-exchange rate between the two alkali species is proportional to the saturated density of the alkali vapor, which is highly dependent on the temperature of the cell. Consequently, the sensitivity of the hybrid optical pumping magnetometer is dependent on the temperature of the cell. We proposed the thermal optimization of the hybrid cell for a hybrid optical pumping magnetometer, which can improve the sensitivity especially when the power of the pump beam is low. With these optimizations, a sensitivity of approximately 5 fT/Hz1/2 is achieved with gradiometer arrangement.
Magnetic anisotropy in Ta/CoFeB/MgO investigated by x-ray magnetic circular dichroism and first-principles calculation
Authors: Kanai Shun , Tsujikawa Masahito , Miura Yoshio , Shirai Masafumi , Matsukura Fumihiro , Ohno Hideo
Published: December 2014

We study the spin and orbital magnetic moments in Ta/Co0.4Fe0.4B0.2/MgO by x-ray magnetic circular dichroism measurements as well as first-principles calculations, in order to clarify the origin of the perpendicular magnetic anisotropy. Both experimental and theoretical results show that orbital magnetic moment of Fe is more anisotropic than that of Co with respect to the magnetization direction. The anisotropy is larger for thinner CoFeB, indicating that Fe atoms at the interface with MgO contribute more than Co to the observed perpendicular magnetic anisotropy.
On the kinetic barriers of graphene homo-epitaxy
Authors: Zhang Wei , Yu Xinke , Cahyadi Erica , Xie Ya-Hong , Ratsch Christian
Published: December 2014

The diffusion processes and kinetic barriers of individual carbon adatoms and clusters on graphene surfaces are investigated to provide fundamental understanding of the physics governing epitaxial growth of multilayer graphene. It is found that individual carbon adatoms form bonds with the underlying graphene whereas the interaction between graphene and carbon clusters, consisting of 6 atoms or more, is very weak being van der Waals in nature. Therefore, small carbon clusters are quite mobile on the graphene surfaces and the diffusion barrier is negligibly small (∼6 meV). This suggests the feasibility of high-quality graphene epitaxial growth at very low growth temperatures with small carbon clusters (e.g., hexagons) as carbon source. We propose that the growth mode is totally different from 3-dimensional bulk materials with the surface mobility of carbon hexagons being the highest over graphene surfaces that gradually decreases with further increase in cluster size.
Phase-amplitude coupling characteristics in directly modulated quantum dot lasers
Authors: Wang C. , Osiński M. , Even J. , Grillot F.
Published: December 2014

We present a semi-analytical model for studying the phase-amplitude coupling (α-factor) in quantum dot (QD) semiconductor lasers, which takes into account the influence of carrier populations in the excited state and in the two-dimensional carrier reservoir on the refractive index change. Calculations of the α-factor based on the amplified spontaneous emission method and on the “FM/AM” technique are both investigated. It is shown that the α-factor of a QD laser strongly depends on the energy separation between the ground state and the off-resonant states. Through band structure engineering, the α-factor can be reduced by enlarging this energy separation.
Effects of potassium doping on solution processed kesterite Cu2ZnSnS4 thin film solar cells
Authors: Tong Zhengfu , Yan Chang , Su Zhenghua , Zeng Fangqin , Yang Jia , Li Yi , Jiang Liangxing , Lai Yanqing , Liu Fangyang
Published: December 2014

Alkaline metals doping is one of the approaches for achieving high efficiency Cu(In,Ga)Se2 (CIGS) solar cell. Recently, potassium doping helps to break the record efficiency of CIGS solar cell doped with sodium. In this paper, we have investigated how incorporation of potassium can influence the properties of Cu2ZnSnS4 (CZTS) thin film and the performance of resulting solar cell. Our results showed that K doping can enhance the (112) preferred orientation, increase the grain size and reduce the second phase ZnS of the CZTS thin films. After K doping, despite of some drop of Voc for CZTS thin film solar cells, the Rs is decreased and the Jsc is improved markedly, and the solar cell efficiency is boosted.
Large scale electromechanical transistor with application in mass sensing
Authors: Jin Leisheng , Li Lijie
Published: December 2014

Nanomechanical transistor (NMT) has evolved from the single electron transistor, a device that operates by shuttling electrons with a self-excited central conductor. The unfavoured aspects of the NMT are the complexity of the fabrication process and its signal processing unit, which could potentially be overcome by designing much larger devices. This paper reports a new design of large scale electromechanical transistor (LSEMT), still taking advantage of the principle of shuttling electrons. However, because of the large size, nonlinear electrostatic forces induced by the transistor itself are not sufficient to drive the mechanical member into vibration—an external force has to be used. In this paper, a LSEMT device is modelled, and its new application in mass sensing is postulated using two coupled mechanical cantilevers, with one of them being embedded in the transistor. The sensor is capable of detecting added mass using the eigenstate shifts method by reading the change of electrical current from the transistor, which has much higher sensitivity than conventional eigenfrequency shift approach used in classical cantilever based mass sensors. Numerical simulations are conducted to investigate the performance of the mass sensor.
Low-resistivity bulk silicon prepared by hot-pressing boron- and phosphorus-hyperdoped silicon nanocrystals
Authors: Luan Qingbin , Ni Zhenyi , Koura Setsuko , Zhu Tiejun , Yang Deren , Pi Xiaodong
Published: December 2014

Technologically important low-resistivity bulk Si has been usually produced by the traditional Czochralski growth method. We now explore a novel method to obtain low-resistivity bulk Si by hot-pressing B- and P-hyperdoped Si nanocrystals (NCs). In this work bulk Si with the resistivity as low as ∼ 0.8 (40) mΩ•cm has been produced by hot pressing P (B)-hyperdoped Si NCs. The dopant type is found to make a difference for the sintering of Si NCs during the hot pressing. Bulk Si hot-pressed from P-hyperdoped Si NCs is more compact than that hot-pressed from B-hyperdoped Si NCs when the hot-pressing temperature is the same. This leads to the fact that P is more effectively activated to produce free carriers than B in the hot-pressed bulk Si. Compared with the dopant concentration, the hot-pressing temperature more significantly affects the structural and electrical properties of hot-pressed bulk Si. With the increase of the hot-pressing temperature the density of hot-pressed bulk Si increases. The highest carrier concentration (lowest resistivity) of bulk Si hot-pressed from B- or P-hyperdoped Si NCs is obtained at the highest hot-pressing temperature of 1050 °C. The mobility of carriers in the hot-pressed bulk Si is low (≤  ∼ 30 cm-2V-1s-1) mainly due to the scattering of carriers induced by structural defects such as pores.
Nitrogen partitioning, energy use efficiency and isotopic fractionation measurements from cows differing in genetic merit fed low-quality pasture in late lactation
Authors: Cheng L. , Woodward S. L. , Dewhurst R. J. , Zhou H. , Edwards G. R.
Published: December 2014

The study was carried out to evaluate energy and nitrogen (N) use efficiencies of high and low breeding worth (BW) cow groups relative to N isotopic fractionation (Δ15N). Eight high- and eight low-BW cows (mean BW index = 198 and 57, respectively) in late lactation were used to conduct an N balance study with all cows fed autumn pasture. Individual cow pasture DM intake, N intake and N outputs of milk, urine and faeces were quantified. Plasma sample from each cow was harvested. Feed, plasma, faeces, urine and milk samples were measured for δ15N and calculated for Δ15N. Urea N in milk and plasma, and urinary excretion of purine derivatives were also measured. The metabolisable energy (ME) intake, milk energy output, and energy and N use efficiencies of high-BW cows were greater on average than low-BW cows. Conversely, the ratios of urinary N excretion to faecal N excretion and urinary N excretion to N intake were greater for low-BW cows than high-BW cows. There was no effect of BW groups on manure N output, apparent N digestibility, retained N, purine derivatives excretion or ratio of purine derivatives excretion to ME intake. No relationships were found between N and energy efficiencies and δ15N measurements. Regression analysis with individual cow measurement showed plasma δ15N – feed δ15N was negatively correlated with DM intake. N use efficiency was positively correlated with BW. High genetic merit cows are more efficient in N and energy use than lower genetic merit cows when fed low quality pasture in late lactation. Plasma δ15N – feed δ15N was proved to be a potential indicator of DM intake for individual cows when identical feed was offered. BW may be used to predict N use efficiency for individual cows.
Effects of different doses of sodium monensin on rumen papillae and tissue histology of feedlot Nellore cattle
Authors: Pereira Murillo C. S. , Carrara Tássia V. B. , da Silva Juliana , Pinto Ana Carolina J. , Vicari Daniel V. F. , Pereira Flavia T. V. , Arrigoni Mário D. B. , Millen Danilo D.
Published: December 2014

The experiment was designed to determine the effects of different doses of sodium monensin (MON) on rumen papillae and tissue histology of feedlot Nellore cattle. The experiment was designed as a completely randomised block, replicated 12 times, in which 60 20-month-old yearling Nellore bulls (402.52 ± 33.0 kg) were fed in individual pens for 84 days according to the following doses of MON expressed in ppm (on a dry-matter basis): 0, 9, 18, 27 and 36. The adaptation program consisted of ad libitum feeding of two adaptation diets over a period of 14 days, with concentrate level increasing from 68% to 84% of diet dry matter. Orthogonal contrasts were used to assess linear, quadratic, cubic and quartic relationships between doses of MON and the dependent variable. No significant (P > 0.10) MON effect was observed for number of papillae, mean papillae area, papillae area as a percentage of absorptive surface and rumenitis incidence. However, as the dose of MON increased, the absorptive surface area, papillae surface area and mitotic index were affected (P < 0.05) cubically, in which animals fed 9 and 36 ppm presented larger absorptive surface area and greater number of cells in mitosis. Thus, based on the results, feeding of MON affected rumen papillae and tissue histology of feedlot Nellore cattle. The doses of 9 or 36 ppm of MON should be considered as the most feasible options, because they promote better development of rumen epithelium.
Epigenetics, embryo quality and developmental potential
Authors: Beaujean Nathalie
Published: December 2014

It is very important for embryologists to understand how parental inherited genomes are reprogrammed after fertilisation in order to obtain good-quality embryos that will sustain further development. In mammals, it is now well established that important epigenetic modifications occur after fertilisation. Although gametes carry special epigenetic signatures, they should attain embryo-specific signatures, some of which are crucial for the production of healthy embryos. Indeed, it appears that proper establishment of different epigenetic modifications and subsequent scaffolding of the chromatin are crucial steps during the first cleavages. This ‘reprogramming’ is promoted by the intimate contact between the parental inherited genomes and the oocyte cytoplasm after fusion of the gametes. This review introduces two main epigenetic players, namely histone post-translational modifications and DNA methylation, and highlights their importance during early embryonic development.
Reproductive performance: at the cross-road of genetics, technologies and environment
Authors: Vaiman Daniel
Published: December 2014

Sexual reproduction depends on a negotiation between the sexes at the level of the cells (gametes), tissue (trophectoderm of the blastocyst and endometrium in the uterus) and organisms (to allow sexual intercourse). This review evaluates new questions linked to sexual reproduction in the biosphere in the context of the 21st century, in light of current knowledge in genetics and epigenetics. It presents the challenge of ‘forcing reproductive efficiency’ using ineffective gametes, or despite other fertility problems, through medically assisted reproduction and presents the reproductive challenge of high production farm animals, which are in a situation of chronically negative energy balance. It also analyses the situation created by the release of endocrine disruptors into the environment and discusses the possible transgenerational consequences of environmental modifications linked to these compounds.
Exploring the function of long non-coding RNA in the development of bovine early embryos
Authors: Caballero Julieta , Gilbert Isabelle , Fournier Eric , Gagné Dominic , Scantland Sara , Macaulay Angus , Robert Claude
Published: December 2014

Now recognised as part of the cellular transcriptome, the function of long non-coding (lnc) RNA remains unclear. Previously, we found that some lncRNA molecules in bovine embryos are highly responsive to culture conditions. In view of a recent demonstration that lncRNA may play a role in regulating important functions, such as maintenance of pluripotency, modification of epigenetic marks and activation of transcription, we sought evidence of its involvement in embryogenesis. Among the numerous catalogued lncRNA molecules found in oocytes and early embryos of cattle, three candidates chosen for further characterisation were found unexpectedly in the cytoplasmic compartment rather than in the nucleus. Transcriptomic survey of subcellular fractions found these candidates also associated with polyribosomes and one of them spanning transzonal projections between cumulus cells and the oocyte. Knocking down this transcript in matured oocytes increased developmental rates, leading to larger blastocysts. Transcriptome and methylome analyses of these blastocysts showed concordant data for a subset of four genes, including at least one known to be important for blastocyst survival. Functional characterisation of the roles played by lncRNA in supporting early development remains elusive. Our results suggest that some lncRNAs play a role in translation control of target mRNA. This would be important for managing the maternal reserves within which is embedded the embryonic program, especially before embryonic genome activation.