bluuebunny/crossref_metadata_2025_split huggingface dataset:
Universal method for the synthesis of arbitrary polarization states radiated by a nanoantenna
Authors: Rodríguez‐Fortuño Francisco J. , Puerto Daniel , Griol Amadeu , Bellieres Laurent , Martí Javier , Martínez Alejandro 
Published: February 2014

AbstractOptical nanoantennas efficiently convert confined optical energy into free‐space radiation. The polarization of the emitted radiation depends mainly on nanoantenna shape, so it becomes extremely difficult to manipulate it unless the nanostructure is physically altered. Here, a simple way is demonstrated to synthetize the polarization of the radiation emitted by a single nanoantenna so that every point on the Poincaré sphere becomes attainable. The nanoantenna consists of a single scatterer created on a dielectric waveguide and fed from its both sides so that the polarization of the emitted optical radiation is controlled by the amplitude and phase of the feeding signals. The nanoantenna is created on a silicon chip using standard top‐down nanofabrication tools, but the method is universal and can be applied to other materials, wavelengths and technologies. This work will open the way towards the synthesis and control of arbitrary polarization states in nano‐optics.
The lubrication effect of hyaluronic acid and chondroitin sulfate on the natural temporomandibular cartilage under torsional fretting wear
Authors: Wu Ting‐ting , Gan Xue‐qi , Cai Zhen‐bing , Zhu Min‐hao , Qiao Meng‐ting , Yu Hai‐yang 
Published: February 2014

ABSTRACTThe aim of this study is to investigate the lubrication of hyaluronic acid (HA) and chondroitin sulfate (CS) on the condylar cartilage of the temporomandibular joint. The wear behaviour of bovine condyle cartilage was explored against a zirconia ball with different lubrications under torsional fretting mode. The worn cartilage morphologies were observed using scanning electron microscopy and hemotoxylin and eosin staining. The results indicated that HA or CS could significantly lower the friction torque and dissipated energy of fretting interface and reduce the damage of the articular cartilage surface compared to the control (phosphate‐buffered saline). The mixture (HA and CS) could provide better protection for the cartilage layer. Absence of good lubrication in overloading torsional fretting process caused excessive cartilage wear. High concentration and high molecular weight HA or CS acted as good boundary lubricants, and the lubrication effect of their mixture was better due to their synergistic function. Copyright © 2014 John Wiley & Sons, Ltd.
Layer‐by‐Layer Coated PLA Nanoparticles with Oppositely Charged β‐Cyclodextrin Polymer for Controlled Delivery of Lipophilic Molecules
Authors: El Fagui Amani , Wintgens Véronique , Gaillet Christine , Dubot Pierre , Amiel Catherine 
Published: February 2014

The preparation of novel nanoparticles is described, which consist of a poly(lactic acid) (PLA) core obtained by the nanoprecipitation method with a shell made of oppositely charged β‐cyclodextrin polymer (poly‐β‐CD) assembled using the layer‐by‐layer technique. Characterization of these nanoparticles is accomplished through dynamic light scattering, ζ‐potential measurements, X‐ray photoelectron spectroscopy and electron microscopy. The release of a loaded lipophilic molecule, benzophenone (BP), is mainly controlled by diffusion of BP and by its host–guest interaction with the β‐CD cavities of the adsorbed poly‐β‐CD. Increasing the number of poly‐β‐CD layers results in a better control of the release through the partition equilibrium between free BP and BP included in the cavities inside the multilayers.
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High‐Tg and low‐dielectric epoxy thermosets based on a propargyl ether‐containing phosphinated benzoxazine
Authors: Lin Ching Hsuan , Huang Chu Ming , Wong Tung I. , Chang Hou Chien , Juang Tzong Yuan , Su Wen Chiung 
Published: February 2014

ABSTRACTA propargyl ether‐containing benzoxazine (4) was prepared from a potassium carbonate‐catalyzed nucleophilic substitution of propargyl bromide and a phenolic OH‐containing benzoxazine (3), which was prepared from 1‐(4‐hydroxyphenyl)‐1‐(4‐aminophenyl)‐1‐(6‐oxido‐6H ‐dibenz <c,e><1,2> oxaphosphorin‐6‐yl)ethane (1) by a three‐step procedure. The curing reactions of (4) were monitored by IR and DSC. A reaction mechanism was proposed based on the observation. Benzoxazines (3) and (4) were applied as epoxy curing agents. The microstructure and the structure‐property relationship of the resulting thermosets are discussed. The double‐strand structure in (4)‐cured epoxy thermosets afforded higher crosslinking density, and led to higher thermal properties. In addition, the (4)‐cured epoxy thermosets possess half the amount of highly polar hydroxyl groups than those of the (3)‐cured epoxy thermosets, resulting in a lower dielectric constant, dissipation factor, and water absorption. © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2014, 52, 1359–1367
Influence of the electrostatic interactions on thermophysical properties of polyimides: Molecular‐dynamics simulations
Authors: Falkovich Stanislav G. , Lyulin Sergey V. , Nazarychev Victor M. , Larin Sergey V. , Gurtovenko Andrey A. , Lukasheva Natalia V. , Lyulin Alexey V. 
Published: February 2014

ABSTRACTRevealing the way of how modification of the chemical structure of a polymer affects its macroscopic physical properties offers an opportunity to develop novel polymer materials with pre‐defined characteristics. To address this problem two thermoplastic polyimides, ULTEM™ and EXTEM™, were simulated with small difference in chemical structures of monomer units, namely, the phenyl ring in ULTEM™ was replaced by the diphenylsulphone group in EXTEM™. It is shown that such a small modification results in a drastic difference of the thermal properties: the glass transition temperature of EXTEM™ is higher than that of ULTEM™. Our molecular‐dynamics simulations clearly demonstrated that it is the electrostatic interactions that are responsible for the observed difference in thermal properties of ULTEM™ and EXTEM™: large partial charges of the sulphone group in the EXTEM™ lead to strong dipole–dipole intra‐ and intermolecular interactions and correspondingly to an elevated glass transition temperature. © 2014 Wiley Periodicals, Inc. J. Polym. Sci. Part B: Polym. Phys. 2014, 52, 640–646
Stochastic stability and stabilization of discrete‐time singular Markovian jump systems with partially unknown transition probabilities
Authors: Wang Jianhua , Zhang Qingling , Yan Xing‐Gang , Zhai Ding 
Published: February 2014

SummaryThis paper considers the stochastic stability and stabilization of discrete‐time singular Markovian jump systems with partially unknown transition probabilities. Firstly, a set of necessary and sufficient conditions for the stochastic stability is proposed in terms of LMIs, then a set of sufficient conditions is proposed for the design of a state feedback controller to guarantee that the corresponding closed‐loop systems are regular, causal, and stochastically stable by employing the LMI technique. Finally, some examples are provided to demonstrate the effectiveness of the proposed approaches. Copyright © 2014 John Wiley & Sons, Ltd.
Machine learning methods in chemoinformatics
Authors: Mitchell John B. O. 
Published: February 2014

Machine learning algorithms are generally developed in computer science or adjacent disciplines and find their way into chemical modeling by a process of diffusion. Though particular machine learning methods are popular in chemoinformatics and quantitative structure–activity relationships (QSAR), many others exist in the technical literature. This discussion is methods‐based and focused on some algorithms that chemoinformatics researchers frequently use. It makes no claim to be exhaustive. We concentrate on methods for supervised learning, predicting the unknown property values of a test set of instances, usually molecules, based on the known values for a training set. Particularly relevant approaches include Artificial Neural Networks, Random Forest, Support Vector Machine, k‐Nearest Neighbors and naïve Bayes classifiers. WIREs Comput Mol Sci 2014, 4:468–481.This article is categorized under:

Computer and Information Science > Chemoinformatics
Alignment and dataset identification of linked data in Semantic Web
Authors: Gunaratna Kalpa , Lalithsena Sarasi , Sheth Amit 
Published: February 2014

The Linked Open Data (LOD) cloud has gained significant attention in the Semantic Web community over the past few years. With rapid expansion in size and diversity, it consists of over 800 interlinked datasets with over 60 billion triples. These datasets encapsulate structured data and knowledge spanning over varied domains such as entertainment, life sciences, publications, geography, and government. Applications can take advantage of this by using the knowledge distributed over the interconnected datasets, which is not realistic to find in a single place elsewhere. However, two of the key obstacles in using the LOD cloud are the limited support for data integration tasks over concepts, instances, and properties, and relevant data source selection for querying over multiple datasets. We review, in brief, some of the important and interesting technical approaches found in the literature that address these two issues. We observe that the general purpose alignment techniques developed outside the LOD context fall short in meeting the heterogeneous data representation of LOD. Therefore, an LOD‐specific review of these techniques (especially for alignment) is important to the community. The topics covered and discussed in this article fall under two broad categories, namely alignment techniques for LOD datasets and relevant data source selection in the context of query processing over LOD datasets.This article is categorized under:

Algorithmic Development > Spatial and Temporal Data Mining
Technologies > Structure Discovery and Clustering
Plasmonic antennas and zero‐mode waveguides to enhance single molecule fluorescence detection and fluorescence correlation spectroscopy toward physiological concentrations
Authors: Punj Deep , Ghenuche Petru , Moparthi Satish Babu , de Torres Juan , Grigoriev Victor , Rigneault Hervé , Wenger Jérôme 
Published: February 2014

Single‐molecule approaches to biology offer a powerful new vision to elucidate the mechanisms that underpin the functioning of living cells. However, conventional optical single molecule spectroscopy techniques such as Förster fluorescence resonance energy transfer (FRET) or fluorescence correlation spectroscopy (FCS) are limited by diffraction to the nanomolar concentration range, far below the physiological micromolar concentration range where most biological reaction occur. To breach the diffraction limit, zero‐mode waveguides (ZMW) and plasmonic antennas exploit the surface plasmon resonances to confine and enhance light down to the nanometer scale. The ability of plasmonics to achieve extreme light concentration unlocks an enormous potential to enhance fluorescence detection, FRET, and FCS. Single molecule spectroscopy techniques greatly benefit from ZMW and plasmonic antennas to enter a new dimension of molecular concentration reaching physiological conditions. The application of nano‐optics to biological problems with FRET and FCS is an emerging and exciting field, and is promising to reveal new insights on biological functions and dynamics.This article is categorized under:

Diagnostic Tools > Biosensing
Diagnostic Tools > Diagnostic Nanodevices
Nanotechnology Approaches to Biology > Nanoscale Systems in Biology
Synthesis, Characterization, and X‐ray Crystal Structures of Ru3(CO)9(dppm)AsPh3 and Ru3(CO)9(dpam)PPh3 Complexes
Authors: Bin Shawkataly Omar , Khan Imthyaz Ahmed , Syaida Sirat Siti , Fun Hoong‐Kun , Mustaqim Rosli Mohd 
Published: February 2014

Abstract Clusters Ru3(CO)10(dppm) and Ru3(CO)10(dpam) on reaction with AsPh3 and PPh3 in refluxing n‐hexane afford trisubstituted clusters Ru3(CO)9(dppm)AsPh3 and Ru3(CO)9(dpam)PPh3, respectively. These two trisubstituted clusters are characterized by spectroscopic and single‐crystal X‐ray diffraction. Ru3(CO)9(dppm)AsPh3 and Ru3(CO)9(dpam)PPh3 show a triangle of ruthenium atoms, in which the bidentate and monodentate group 15 ligands occupy equatorial position and all the carbonyl units are terminally bonded. The Ru–Ru distances in Ru3(CO)9(dppm)AsPh3 are 2.8461(7) Å, 2.8495(7) Å, and 2.8930(6) Å, with the longest distance cis to the monodentate AsPh3 ligand. For Ru3(CO)9(dpam)PPh3, the Ru–Ru distances are 2.8652(2) Å, 2.8809(2) Å, and 2.8560(2) Å with the longest distance also cis to the monodenatate PPh3 ligand.
New Mn2‐based Heusler Compounds
Authors: Kreiner Guido , Kalache Adel , Hausdorf Steffen , Alijani Vajiheh , Qian Jin‐Feng , Shan Guangcun , Burkhardt Ulrich , Ouardi Siham , Felser Claudia 
Published: February 2014

AbstractMn2‐based Heusler compounds have attracted a great deal of interest as half‐metallic ferri‐ and ferromagnets and as materials for spintronic applications. In this paper, we report the synthesis, crystal structure, and disorder type of the new Heusler compounds Mn2RuGe, Mn2RhGa, and the redetermination of the crystal structure of Mn2RuSn. They crystallize cubic with L21b structure type in Fm$\bar{3}$m, which is an inverse Heusler structure with a transition metal disorder of the type (Mn0.5,Y0.5)2MnZ (Y = Ru or Rh and Z = Ge, Ga or Sn). It is shown that an inverse Heusler structure can generally gain stability through the configurational part of the entropy of mixing at elevated temperatures without loosing too much enthalpy in the configurational part of the enthalpy of mixing owing to a special bond arrangement in the inverse type structure. The enthalpy of formation of transition‐metal‐based Heusler compounds and Al, Ga, and Ge as the main group metals obtained from DFT calculations and experimental data are used to confirm Burch's rule, which predicts the stability of transition‐metal‐based inverse Heusler compounds. Alloying tendencies as manifested in binary phase diagrams and the enthalpies obtained from the Miedema model are correlated with the stability of Heusler compounds. Burch's rule is in excellent agreement with the current available experimental data. The DFT data and general alloying tendencies show that deviations are expected from this rule. Miedema's model allows the estimation of the enthalpy of formation for the transition‐ and main group metal‐based Heusler compounds, except for those having period 6 elements and Pd.
Point mutation of the xylose reductase (XR) gene reduces xylitol accumulation and increases citric acid production in Aspergillus carbonarius
Authors: Weyda István , Lübeck Mette , Ahring Birgitte K , Lübeck Peter S 
Published: February 2014

Abstract
Aspergillus carbonarius accumulates xylitol when it grows on d-xylose. In fungi, d-xylose is reduced to xylitol by the NAD(P)H-dependent xylose reductase (XR). Xylitol is then further oxidized by the NAD+-dependent xylitol dehydrogenase (XDH). The cofactor impairment between the XR and XDH can lead to the accumulation of xylitol under oxygen-limiting conditions. Most of the XRs are NADPH dependent and contain a conserved Ile-Pro-Lys-Ser motif. The only known naturally occurring NADH-dependent XR (from Candida parapsilosis) carries an arginine residue instead of the lysine in this motif. In order to overcome xylitol accumulation in A. carbonarius a Lys-274 to Arg point mutation was introduced into the XR with the aim of changing the specificity toward NADH. The effect of the genetic engineering was examined in fermentation for citric acid production and xylitol accumulation by using d-xylose as the sole carbon source. Fermentation with the mutant strain showed a 2.8-fold reduction in xylitol accumulation and 4.5-fold increase in citric acid production compared to the wild-type strain. The fact that the mutant strain shows decreased xylitol levels is assumed to be associated with the capability of the mutated XR to use the NADH generated by the XDH, thus preventing the inhibition of XDH by the high levels of NADH and ensuring the flux of xylose through the pathway. This work shows that enhanced production of citric acid can be achieved using xylose as the sole carbon source by reducing accumulation of other by-products, such as xylitol.
Changes in the glacier extent and surface elevation along the Ningchan and Shuiguan river source, eastern Qilian Mountains, China
Authors: Cao Bo , Pan Baotian , Wang Jie , Shangguan Donghui , Wen Zhenling , Qi Wentao , Cui Hang , Lu Yaoyang 
Published: February 2014

AbstractWe investigate the changes at nine glaciers in the Ningchan and Shuiguan river source, eastern Qilian Mountains, between 1972 and 2010. According to analysis of topographic maps and multispectral satellite data, all nine glaciers in the study area have retreated, by a maximum of 250 ± 57.4 m and a minimum of 91 ± 57.4 m. The total glacier area decreased by 1.20 km2, corresponding to 9.9% of the glacierized area in 1972. Comparing the two DEMs generated from the topographic maps and Real-Time Kinematic GPS data, the mean glacier thinning rate was 0.64 m yr− 1 between 1972 and 2010. The most significant thinning generally occurred on the termini. The ice-volume loss was about 106.8 ± 46.7 × 10− 3 km3 (equal to 90.8 ± 39.7 × 10− 3 km3 w.e.), which suggested a mean water discharge of 0.1 ± 0.05 m3/s during 1972–2010. Based on analysis of meteorological data, the summer temperature (June–August) tends to increase over a similar time period. The consistency of temperature increase and glacier shrinkage allows us to suggest that air temperature plays an important role in glacier changes in this region.
Cape Verdean and Mozambican Women's Literature: Liberating the National and Seizing the Intimate
Authors: P. B. Rodrigues Isabel , Sheldon Kathleen 
Published: February 2014

Abstract:In Mozambique and Cape Verde, writing in Portuguese by African women has directly engaged political reconstruction by denouncing colonial oppression and embracing national freedom. This article addresses the recent history of Lusophone African women's fiction, which has been pivotal in inscribing the intimate arena of sexuality and motherhood into power relations and has also revealed ways in which the domain of violence intersects with private lives. By focusing on two novels that exemplify this trend, this article demonstrates links between the political and the intimate. It also shows how Lusophone African authors contribute to healing social conflict through their narratives, and draws some conclusions about gender relations in the Lusophone African experience and across the continent.
Deploying Development to Counter Terrorism: Post-9/11 Transformation of U.S. Foreign Aid to Africa
Authors: Miles William F. S. 
Published: February 2014

Abstract:Since September 11, 2001, the aid component of American foreign policy toward Africa has undergone a significant evolution: U.S. security has come to rival development as an increasingly explicit rationale. Development programming and project implementation now contain a security dimension that is underpinned by Pentagon strategists working through AFRICOM as much as by USAID officers partnering with the State Department. This article argues that given the potential of terrorism for undermining development in Africa itself, soft counterterrorism should be envisioned as a strategic developmental defense activity. Making use of unpublished country risk assessments and the author's participant observation during USAID field mission consultancies in the Sahel, as well as the scholarly literature and relevant policy documents of the Bush and Obama administrations, this article explores the new agenda and grassroots dynamics of development projects as tools for terrorism prevention. It contends that policy and institutional responses to 9/11 have resulted in a greater convergence of operational goals among U.S. government agencies that in the past, at least according to publicly stated goals, had pursued distinctly different missions in Africa. Normative implications of this change are mixed. Because of differing expectations with respect to separation of powers, African public opinion, paradoxically, may be more sympathetic to U.S. military engagement with civilians for developmental purposes than American public opinion is.
The Local Politics of Ethiopia's Green Revolution in South Wollo
Authors: Adem Teferi Abate 
Published: February 2014

Abstract:This article argues that Ethiopia's agricultural extension program, which received more government funding and donor support than other similar programs in Africa, reinforced the rural presence and authoritarian powers of the ruling party while largely failing to improve smallholder agriculture. The principal reason for this outcome has to do with the systematic entanglement of the Green Revolution package delivery system with the immediate goal of guaranteeing the party's political security. In one Amharic-speaking community that provided ethnographic information for this article, overzealous party leaders rewarded supporters at the expense of imagined opponents. This distortion, coupled with a culturally embedded concept of success (defined as upward mobility), caused pervasive fear, insecurity, suspicion, and rivalry among farmers. Not surprisingly, this insecurity has a deleterious effect on hardworking farmers. The article suggests that any meaningful attempt at improving the program must recognize the centrality of politics, especially at the community and household levels, where parochial interests interface with cultural expectations.
Disability Rights Activism in Kenya, 1959–1964: History from Below
Authors: Gebrekidan Fikru Negash 
Published: February 2014

Abstract:This article examines the early history of disability rights activism in Kenya. The transitional years from colonialism to independence were a period of great expectations. For persons with disabilities in particular, decolonization held additional possibilities and potential. National independence promised not just majority rule but also an all-inclusive citizenship and the commitment to social justice. Among the visually impaired of Kenya, such collective aspirations led to the birth of the Kenya Union of the Blind in 1959. In 1964, after years of futile correspondence with government officials, the Union organized a street march to the prime minister's office to attract attention to its grievances. The result was a government panel, the Mwendwa Committee for the Care and Rehabilitation of the Disabled, whose published report became the blueprint for social and rehabilitation programs. The government possessed limited resources, and the reforms that ensued were long overdue. Yet the sociohistorical dynamics behind the march are of particular significance. From the social historian's point of view, they affirm not only the historical agency of persons with disabilities, but also the need to recast and broaden the scope of African social history.