bluuebunny/crossref_metadata_2025 huggingface dataset:
Epigenetics and Oncology
Authors: Mummaneni Padmaja , Shord Stacy S.
Published: March 2014

Epigenetic modifications play a critical role in the development of pediatric and adult cancers, contributing to the cumulative changes observed as normal cells undergo malignant transformation. These modifications have been studied to develop epigenome‐targeted therapies and new diagnostic tools. The U.S. Food and Drug Administration has approved four epigenome‐targeted anticancer drugs. Two are drugs that inhibit DNA methyltransferases: azacitidine and decitabine, and two are drugs that inhibit histone deacetylases: vorinostat and romidepsin. These initial successes demonstrate the potential effectiveness of epigenome‐targeted therapies as monotherapy in hematologic malignancies, but newer studies are focused on combination therapy in many cancers. Epigenetic modifications have also been used to evaluate potential biomarkers to diagnose patients with cancer, identify patient populations likely to respond to specific anticancer therapies, and select reasonable dosages for investigational anticancer drugs, as observed with other newer targeted anticancer drugs. Although much has been learned about the relationship between the epigenome and cancer, many questions remain unanswered at this time. The next step is to continue to translate emerging epigenetic knowledge into anticancer drug development. In this review, we discuss the role of epigenetic modifications in the development of cancer and anticancer drug resistance, and we describe the progress and challenges associated with developing epigenome‐targeted anticancer drugs and diagnostic tools that identify epigenetic modifications.
Rheological behaviour of some amphiphilic β‐cyclodextrin‐based azo aromatic polyurethanes in N,N‐dimethylformamide solutions
Authors: Filip Daniela , Vlad Stelian
Published: March 2014

Amphiphilic β‐cyclodextrin‐based azo aromatic poly(ether urethane)s with different soft segment lengths have been synthesized and characterized. Hydrogen bonding in these systems was demonstrated by Fourier transform infrared spectroscopy analysis (carbonyl stretching region). A rheological study was performed on solutions of the synthesized poly(ether urethane)s in N,N‐dimethylformamide at various concentrations and temperatures by employing parallel plate geometry, and a comparative evaluation of the influence of the structural components on the viscometric responses was performed. The rheological behaviour was found to be strongly dependent on the chemical composition of the synthesized polyurethanes which promotes self‐assembly and structuring in solution. Hard segment content and polymer concentration influence pseudoplastic shear‐thinning flow behaviour. The rheology can be interpreted in terms of hydrophobic associations and chain entanglements and a hydrogen bonding network occurring in solution. The start‐up flow of the polymer solutions is determined by the lifetime of the associative polymer segments. Shear stress plateaux indicative of ‘shear banding’ behaviour explained by the structuring of the polymer solutions at increased temperatures were obtained. The studied amphiphilic polyurethane solutions are thermoresponsive systems exhibiting viscosity increase with increasing temperature contrary to the usual Arrhenius thermo‐thinning behaviour. At constant shear rate viscosity was found to increase with increasing temperature due to thermo‐association. © 2014 Society of Chemical Industry
Ultrahigh‐Density Plasmonic‐Nanoparticle‐Sensitized Semiconductor Photocatalysts Profit from Cooperative Light Harvesting and Charge Separation Processes: Experiments, Simulations, and Multifunctional Plasmonics
Authors: Yang Tung‐Han , Huang Li‐De , Pan Ming‐Yang , Harn Yeu‐Wei , Chen Miao‐Chun , Lin Chun‐Cheng , Wei Pei‐Kuen , Wu Jenn‐Ming
Published: March 2014

Here, a controlled synthesis of remarkable 3D photocatalysts is presented that is composed of ultrahigh‐density unaggregated plasmonic Au nanoparticles (AuNPs) chemically bound to vertically aligned ZnO nanorod arrays (ZNA) through bifunctional molecular linkers. Experimental probes and electromagnetic simulations of electron transfer and localized plasmonic coupling processes are exploited to gain insight into the underlying light‐irradiation‐induced interactions in the 3D ZNA–AuNPs photocatalysts. Highly dense AuNPs on ZNA surfaces act as sinks for the storage of UV‐generated electrons, which promote the separation of charge carriers and create numerous photocatalytic reaction centers. Furthermore, 3D finite‐difference time domain simulation indicates that significant visible light confinement and enhancement around the ZNA–AuNPs interfacial plasmon “hot spots” contribute to efficient conversion of light energy to electron‐hole pairs. Significantly, in comparison with the bare ZNA, the 10‐nm‐sized AuNPs‐decorated ZNA exhibits 10.6‐fold enhanced photoreaction rate in the entire UV–vis region. Moreover, various novel hybrid structures based on the plasmonic AuNPs and diverse nanostructures (films, powdered nanorods, mesoporous, and nanotubes) or functional materials (multiferroic BiFeO3, CuInGaSe2 absorber layers, and photoactive TiO2) are successfully constructed using the present synthesis methodology. It may stimulate the progress in materials science toward the synthesis of multifunctional plasmonic heterostructures or devices.
Investigation of the transition phases from amorphous silicon‐based multilayers to silicon nanostructures by in situ X‐ray diffraction
Authors: Agbo Solomon , Calta Pavel , Sutta Pavol , Vavrunkova Veronika , Netrvalova Marie , Prusakova Lucie
Published: March 2014

We report the investigation of the formation phases of silicon nanostructures obtained from thermal annealing of hydrogenated amorphous silicon (a‐Si:H)‐based multilayers using in situ X‐ray diffractometry, XRD. The multilayers composed of alternating layers of a‐Si:H and silicon oxide were deposited on [100]‐oriented crystalline silicon substrates using a plasma‐enhanced chemical vapor deposition. Our results indicate that crystallization only starts after hydrogen effusion at a 500 °C annealing temperature, independent of the a‐Si:H sublayer thickness. Hydrogen effusion results in the reordering of the silicon structure from the tetragonal to the diamond structure, while the films maintain their amorphous medium‐range order. The onset of crystallization and phase separation occur at different annealing temperatures depending on the a‐Si:H sublayer thickness. The fraction of the crystallized nanostructure are found to also depend on the a‐Si:H sublayer thickness. Phase separation and formation of silicon nanostructures is observed by the shift of the SiO stretching vibration to higher wave numbers in the Fourier transform infrared (FTIR) absorption spectra. The different crystallization phases as observed with in situ XRD will be corroborated by measurements from Raman and FTIR spectroscopies. The crystallite size obtained from XRD compares well with that obtained from transmission electron microscopy.
Quantum interference in HgTe structures
Authors: Gornyi I. V. , Kachorovskii V. Yu. , Mirlin A. D. , Ostrovsky P. M.
Published: March 2014

We study quantum transport in HgTe/HgCdTe quantum wells under the condition that the chemical potential is located outside of the band gap. We first analyze symmetry properties of the effective Bernevig–Hughes–Zhang Hamiltonian and the relevant symmetry‐breaking perturbations. Based on this analysis, we overview possible patterns of symmetry breaking that govern the quantum interference (weak localization or weak antilocalization) correction to the conductivity in two‐dimensional HgTe/HgCdTe samples. Further, we perform a microscopic calculation of the quantum correction beyond the diffusion approximation. Finally, the interference correction and the low‐field magnetoresistance in a quasi‐one‐dimensional geometry are analyzed.
Theoretical study of charge separation at the rutile–anatase interface
Authors: Kullgren Jolla , Huy Huynh Anh , Aradi Bálint , Frauenheim Thomas , Deák Peter
Published: March 2014

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Mixed phase TiO2 powders are very effective in photo‐catalysis. It is assumed that this efficiency is connected to the separation of photogenerated mobile electrons and holes between rutile and anatase, controlled by the offsets between their valence and conduction bands. The actual alignment is, however, debated. Our high level electronic structure calculations suggest that, at typical rutile/anatase interfaces, the band edges of rutile lie higher in energy than those of anatase. This conclusion is reached by taking into account the generic alignment of the bulk band structures and the specific structure of the interface. The latter has been obtained by simulated annealing, using approximate quantum mechanical molecular dynamics on models of the rutile(100)/anatase(100) and of the rutile(110)/anatase(101) interface. Our results are corroborated by photoelectron spectroscopy of actual rutile/anatase interfaces in the literature. The predicted band offsets would lead to accumulation of mobile electrons in anatase and mobile holes in rutile, with the process being also supported by electron self‐trapping in rutile and hole self‐trapping in anatase. We show, however, that interface defects, like the oxygen vacancy, may provide a recombination channel. Such effects may explain the variation in the suggested direction of charge transfer in many experiments.

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The rutile(100)/anatase(100) interface. Titanium atoms are drawn with gray and oxygen with red circles. The black arrows show the preferred direction in the charge transfer of photogenerated electrons and holes.

(© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Green tea (Camellia sinensis) alleviates arsenic‐induced damages to DNA and intestinal tissues in rat and in situ intestinal loop by reinforcing antioxidant system
Authors: Acharyya Nirmallya , Sajed Ali Sk. , Deb Bimal , Chattopadhyay Sandip , Maiti Smarajit
Published: March 2014

This study elucidates the protective role of Green tea (Camellia sinensis or CS) against arsenic‐induced mutagenic DNA‐breakage/intestinal (small) damages in female rats. Intestinal epithelial cells receive ingested arsenic initially. Though, the possibility of damages in this tissue is immense and the therapeutic strategies against this damage are of great concern, reports on either issue are scanty. Our earlier study on arsenic‐exposed human unveils a link between carcinogenesis and mutagenic DNA damage. Here, we demonstrate that supplementation of CS‐extract (10 mg/mL water) with NaAsO2 (0.6 ppm)/100 g b.w. for 28 days to rats offered a significant protection against arsenic‐induced oxidative damages to DNA and intestinal (small) tissues by buttressing antioxidant systems. Necrotic and apoptotic damages and their CS‐protection are shown in DNA‐fragmentation, comet‐assay, and histoarchitecture (hematoxylin and eosin and periodic acid‐schiff staining) results. Only arsenic exposure significantly decreased intestinal superoxide dismutase, catalase activities, and level of soluble thiol with a concomitant increase in malondialdehyde/conjugated dienes. Alteration of serum necrotic marker lactate dehydrogenase and the metabolic inflammatory marker c‐reactive protein also indicate the impairment may be occurring at transcription and/or cellular signal transduction level. In addition, in situ incubation in rat intestinal loop filled for 24 h with NaAsO2 alone (250 µM) or with aqueous CS‐extract (250 mg/mL) suggests that small intestinal epithelial cells are significantly protected by CS against arsenic‐associated necrotic/mutagenic damages, which is observed in DNA‐breakage studies. In conclusion, besides intensifying endogenous antioxidant system, CS polyphenols also offer a direct role on free radical scavenging activity that is associated to the protection from mutagenic DNA‐breakages and prevention of tissue necrosis/carcinogenesis generated by arsenic. © 2014 Wiley Periodicals, Inc. Environ Toxicol 30: 1033–1044, 2015.
Grassland birds and dairy farms in the northeastern United States
Authors: Perlut Noah G.
Published: March 2014

Although grassland birds are declining throughout their North American range, and these declines are associated with agricultural land conversion or intensification, no broad‐scale market‐based conservation plan has been enacted. This gap is especially apparent in the northeastern United States, where remnant grassland habitat is predominantly on privately owned agricultural lands. However, in this region, dairy cow‐based agriculture has also declined significantly. I explored the relationship between grassland‐bird declines and dairy cow‐based agriculture from 1966 to 2007. The declining number of dairy farms and increasing human population best explained variation in population trends for 4 of 6 grassland‐bird species. Bird population trends were not explained by the total amount of corn acres, number of pasture–grazing farms, or the average farm size. I suggest a long‐term conservation method using “buy local” campaigns where the local community supports a spatially linked network of cow‐based farms, in part because these farms support grassland birds. © 2014 The Wildlife Society.
Scaling arguments for the fluxes in turbulent miscible fountains
Authors: Burridge H. C. , Hunt G. R.
Published: March 2014

For established axisymmetric turbulent miscible Boussinesq fountains in quiescent uniform environments, expressions are developed for the fluxes of volume, momentum and buoyancy at the outflow from the fountain: the outflow referring to the counterflow at the horizontal plane of the source. The fluxes are expressed in terms of the fountain source conditions and two dimensionless functions of the source Froude number, ${\rm Fr}_{0}$: a radial function (relating a horizontal scale of the outflow to the source radius) and a volume flux function (relating the outflow and source volume fluxes). The forms taken by these two functions at low ${\rm Fr}_{0}$ and high ${\rm Fr}_{0}$ are deduced, thereby providing the outflow fluxes and outflow Froude number solely in terms of the source conditions. For high ${\rm Fr}_{0}$, the outflow Froude number, ${\rm Fr}_{out}$, is shown to be invariant, indicating (by analogy with plumes for which the ‘far-field’ Froude number is invariant with source Froude number) that the outflow may be regarded as ‘far-field’ since the fluxes within the fountain have adjusted to attain a balance which is independent of the source conditions. Based on ${\rm Fr}_{out}$, the fluxes in the plume that forms beyond the fountain outflow are deduced. Finally, from the results of previously published studies, we show that the scalings deduced for fountains are valid for $0.0025 \lesssim {\rm Fr}_{0} \lesssim 1.0 $ for low ${\rm Fr}_{0}$ and $ {\rm Fr}_{0} \gtrsim 3.0 $ for high ${\rm Fr}_{0}$.
Later Wittgenstein's Anti-Philosophical Therapy
Authors: Jacquette Dale
Published: March 2014

The object of this essay is to discuss Ludwig Wittgenstein's remarks inPhilosophical Investigationsand elsewhere in the posthumously published writings concerning the role of therapy in relation to philosophy. Wittgenstein's reflections seem to suggest that there is a kind of philosophy or mode of investigation targeting the philosophical grammar of language uses that gratuitously give rise to philosophical problems, and produce in many thinkers philosophical anxieties for which the proper therapy is intended to offer relief. Two possible objectives of later Wittgensteinian therapy are proposed, for subjectivepsychologicalversus objectivesemanticsymptoms of ailments that a therapy might address for the sake of relieving philosophical anxieties. The psychological in its most plausible form is rejected, leaving only the semantic. Semantic therapy in the sense defined and developed is more general and long-lasting, and more in the spirit of Wittgenstein's project on a variety of levels. A semantic approach treats language rather than the thinking, language-using subject as the patient needing therapy, and directs its attention to the treatment of problems in language and the conceptual framework a language game use expresses in its philosophical grammar, rather than to soothing unhappy or socially ill-adjusted individual psychologies.
Crystallographic structure of LiFe1−xMnxPO4 solid solutions studied by neutron powder diffraction
Authors: Li X.Y. , Zhang B. , Zhang Z.G. , He L.H. , Li H. , Huang X.J. , Wang F.W.
Published: March 2014

High-resolution neutron powder diffraction (NPD) data were recorded on a series of cathode material LiFe1−xMnxPO4 (x = 0, 0.2, 0.5, 0.8, and 1.0) solid solutions using the HRPD machine at SINQ/PSI, Switzerland. Ab initio crystal structure solution via program FOX indicates demonstrably that the space group of LiFePO4 is Pnma with Li1+ occupying octahedral (4a) sites and Fe2+ octahedral (4c) sites, respectively, in the olivine structure. Rietveld refinement (program FullProf suite version July-2011), complementary with X-ray diffraction data, shows that Fe2+ may partially (about 2%) distribute over Li1+ sites. NPD data for LiFe1−xMnxPO4 (x = 0, 0.2, 0.5, 0.8, and 1.0) reveal that the Mn2+ replaces Fe2+ at the octahedral (4c) sites. The cell parameters a, b, and c increase linearly and the interatomic distances (in Å) of Li–O(2) and Li–O(1) increase, while the interatomic distances (in Å) of Li–O(3) decrease on the addition of Mn, respectively, partially explaining a higher potential plateau of ~4.1 eV in LiMnPO4 compared to ~3.5 eV in LiFePO4.
C–H···O and C–H···X (X = Cl/Br) hydrogen bond tuned supramolecular assembly: a combined X-ray powder diffraction and Hirshfeld surface analysis
Authors: Hazra Dipak K. , Ghosh Soumen , Chatterjee Paramita , Ghosh Somnath , Mukherjee Monika , Mukherjee Alok K.
Published: March 2014

Crystal structures of N-(2-chlorophenyl) acetamide (1) and phenyl (2-bromomethyl) benzoate (2) have been determined from laboratory X-ray powder diffraction data. In addition to intermolecular N–H···O and C–H···O hydrogen bonds, the crystal packing in (1) and (2) exhibits weak C–H···Cl/Br interactions, which facilitate formation of three-dimensional architectures. Hirshfeld surface analysis of compounds (1), (2), and a few related chloro- and bromo-phenyl derivatives retrieved from the CSD indicates that 83–97% of Hirshfeld surface areas in this class of compounds are due to H···H, H···π, H···O, and H···Cl/Br contacts.
The distribution and conservation of Gurney’s Pitta Pitta gurneyi in Myanmar
Authors: DONALD PAUL F. , HLA HTIN , WIN LAY , AUNG THIRI DAWEI , MOSES SAW , ZAW SAO MYO , AG TIN TUN , OO KYAW NAING , EAMES JONATHAN C.
Published: March 2014

Following a recent assessment of the distribution and habitat use of Gurney’s Pitta in Myanmar (Burma), further extensive surveys were undertaken in 2010, 2011 and 2012. These have extended the species’ known altitudinal limit to between 250 m and 300 m asl and its latitudinal limit to above 12.5°N, around 80 km north of the northernmost historical record, although the species was recorded far less frequently at higher altitudes and latitudes. Birds were recorded in a range of forested habitats, from intact primary forest to secondary and bamboo forest, with no significant difference between major forest types in the likelihood of occurrence. Niche envelope modelling (MaxEnt) suggested a total range size in Myanmar of 3,379 km2, and did not identify any potentially suitable areas in adjacent parts of Thailand. The species’ preference for warmer, wetter areas on flat ground, conditions ideal for growing oil palm and rubber, suggest that its distribution is likely to contract in the near future. The entire range of Gurney’s Pitta in Myanmar falls within the part of the country most suitable for commercial oil palm production, although the projected yields within its range are low to moderate. Field surveys found evidence of rapid recent deforestation and high levels of hunting and trapping in many parts of the region. The species’ range in Myanmar does not overlap with any protected areas. The protection of southern Myanmar’s biodiversity will require substantial investment by foreign conservation interests, sympathetic land-use planning and the strengthening of environment legislation. Protection of extensive tracts of lowland forest within the range of Gurney’s Pitta, particularly the proposed Lenya National Park and the adjacent Ngawun and Htaung Pru Reserve Forests, is urgently needed. Conserving these areas will also protect populations of other globally threatened bird and mammal species.
Realizability interpretation of PA by iterated limiting PCA
Authors: AKAMA YOHJI
Published: March 2014

For any partial combinatory algebra (PCA for short) $\mathcal{A}$, the class of $\mathcal{A}$-representable partial functions from $\mathbb{N}$ to $\mathcal{A}$ quotiented by the filter of cofinite sets of $\mathbb{N}$ is a PCA such that the representable partial functions are exactly the limiting partial functions of $\mathcal{A}$-representable partial functions (Akama 2004). The n-times iteration of this construction results in a PCA that represents any n-iterated limiting partial recursive function, and the inductive limit of the PCAs over all n is a PCA that represents any arithmetical partial function. Kleene's realizability interpretation over the former PCA interprets the logical principles of double negation elimination for Σ0n-formulae, and over the latter PCA, it interprets Peano's arithmetic (PA for short). A hierarchy of logical systems between Heyting's arithmetic (HA for short) and PA is used to discuss the prenex normal form theorem, relativised independence-of-premise schemes, and the statement ‘PA is an unbounded extension of HA’.
H1foo is essential forin vitromeiotic maturation of bovine oocytes
Authors: Yun Yan , An Peng , Ning Jing , Zhao Gui-Ming , Yang Wen-Lin , Lei An-Min
Published: March 2014

Oocyte-specific linker histone, H1foo, is localized on the oocyte chromosomes during the process of meiotic maturation, and is essential for mouse oocyte maturation. Bovine H1foo has been identified, and its expression profile throughout oocyte maturation and early embryo development has been established. However, it has not been confirmed if H1foo is indispensable during bovine oocyte maturation. Effective siRNAs against H1foo were screened in HeLa cells, and then siRNA was microinjected into bovine oocytes to down-regulate H1foo expression. H1foo overexpression was achieved via mRNA injection. Reverse transcription polymerase chain reaction (RT-PCR) results indicated that H1foo was up-regulated by 200% and down-regulated by 70%. Based on the first polar body extrusion (PB1E) rate, H1foo overexpression apparently promoted meiotic progression. The knockdown of H1foo significantly impaired bovine oocyte maturation compared with H1foo overexpression and control groups (H1foo overexpression = 88.7%, H1foo siRNA = 41.2%, control = 71.2%;P< 0.05). This decrease can be rescued by co-injection of a modified H1foo mRNA that has escaped from the siRNA target. However, the H1e (somatic linker histone) overexpression had no effect on PB1E rate when compared with the control group. Therefore we concluded that H1foo is essential for bovine oocyte maturation and its overexpression stimulates the process.
Small- and large-signal modeling of InP HBTs in transferred-substrate technology
Authors: Johansen Tom K. , Rudolph Matthias , Jensen Thomas , Kraemer Tomas , Weimann Nils , Schnieder Frank , Krozer Viktor , Heinrich Wolfgang
Published: March 2014

In this paper, the small- and large-signal modeling of InP heterojunction bipolar transistors (HBTs) in transferred substrate (TS) technology is investigated. The small-signal equivalent circuit parameters for TS-HBTs in two-terminal and three-terminal configurations are determined by employing a direct parameter extraction methodology dedicated to III–V based HBTs. It is shown that the modeling of measured S-parameters can be improved in the millimeter-wave frequency range by augmenting the small-signal model with a description of AC current crowding. The extracted elements of the small-signal model structure are employed as a starting point for the extraction of a large-signal model. The developed large-signal model for the TS-HBTs accurately predicts the DC over temperature and small-signal performance over bias as well as the large-signal performance at millimeter-wave frequencies.
Comparative analysis of radial and axial power output in relativistic magnetron and effect of dielectric side-walls introduced in the resonator on dominant operating mode
Authors: Saxena Ayush , Barakade Raju , Singh Navdeep M. , Patel Ankur
Published: March 2014

A comparative analysis of radiated power in relativistic magnetron is done using particle-in-cell simulations performed on Magic3d code developed by ATK Mission Systems. The Resonator with dielectric side-walls (DSW) is compared with no-side wall (NSW) configuration having same input parameters and resonator dimensions. Observations and comments have been made on the output power, obtained both axially and radially, taking into consideration π as well as 2π modes of operation for both configurations. The DSW assist in π-mode operation at 3.3 GHz and delivers radial peak power output of ~2.5 GW, which is more than ~1.5 GW, the radial peak power for the NSW case. The NSW case operates in dominant 2π mode (radially) at 5.68 GHz with axial power radiated at dominant π-mode frequency. The electron kinetic energies and their distribution in the cavity are discussed together with the dynamic behavior of particles, which result in spokes formation.
The serine protease prostasin regulates hepatic insulin sensitivity by modulating TLR4 signalling
Authors: Uchimura Kohei , Hayata Manabu , Mizumoto Teruhiko , Miyasato Yoshikazu , Kakizoe Yutaka , Morinaga Jun , Onoue Tomoaki , Yamazoe Rika , Ueda Miki , Adachi Masataka , Miyoshi Taku , Shiraishi Naoki , Ogawa Wataru , Fukuda Kazuki , Kondo Tatsuya , Matsumura Takeshi , Araki Eiichi , Tomita Kimio , Kitamura Kenichiro
Published: March 2014

The effects of high-fat diet (HFD) and postprandial endotoxemia on the development of type 2 diabetes are not fully understood. Here we show that the serine protease prostasin (PRSS8) regulates hepatic insulin sensitivity by modulating Toll-like receptor 4 (TLR4)-mediated signalling. HFD triggers the suppression of PRSS8 expression by inducing endoplasmic reticulum (ER) stress and increases the TLR4 level in the liver. PRSS8 releases the ectodomain of TLR4 by cleaving it, which results in a reduction in the full-length form and reduces the activation of TLR4. Liver-specific PRSS8 knockout (LKO) mice develop insulin resistance associated with the increase in hepatic TLR4. Restoration of PRSS8 expression in livers of HFD, LKO and db/db mice decreases the TLR4 level and ameliorates insulin resistance. These results identify a novel physiological role for PRSS8 in the liver and provide new insight into the development of diabetes resulting from HFD or metabolic endotoxemia.
In situ growth of a MoSe2/Mo counter electrode for high efficiency dye-sensitized solar cells
Authors: Chen Haijie , Xie Yian , Cui Houlei , Zhao Wei , Zhu Xiaolong , Wang Yaoming , Lü Xujie , Huang Fuqiang
Published: March 2014

A facile and economical MoSe2/Mo structure was in situ prepared to replace the currently preferred expensive Pt and FTO counter electrode (CE) in dye-sensitized solar cells.
Network formation in graphene oxide composites with surface grafted PNIPAM chains in aqueous solution characterized by rheological experiments
Authors: GhavamiNejad Amin , Hashmi Saud , Joh Han-Ik , Lee Sungho , Lee Youn-Sik , Vatankhah-Varnoosfaderani Mohammad , Stadler Florian J.
Published: March 2014

PolyN-isopropyl acrylamide (PNI) radically polymerized in aqueous solution in the presence of graphene oxide (GO) can significantly change the properties of the resulting solution from a regular polymer solution to a soft solid with a GO content of only 0.176 wt% (3 wt% with respect to PNI).
High hydrostatic pressure treatment provides persimmon good characteristics to formulate milk-based beverages with enhanced functionality
Authors: Hernández-Carrión M. , Tárrega A. , Hernando I. , Fiszman S. M. , Quiles A.
Published: March 2014

High hydrostatic pressure (HHP) treatment encourages the release of carotenoids from the plant material matrix and increases their extractability compared to pasteurization. HHP-treated persimmon could be used to formulate milk-based beverages with high carotenoid content.
Hemostatic polymers: the concept, state of the art and perspectives
Authors: di Lena Fabio
Published: March 2014

This article presents a critical overview of the most significant developments in the use of polymers as hemostatic agents.
Unexpected explanation for the enigmatic acid-catalysed reactivity of [Fe4S4X4]2− clusters
Authors: Alwaaly Ahmed , Dance Ian , Henderson Richard A.
Published: March 2014

DFT calculations reveal that protonation of μ3-S in [Fe4S4X4]2− (and other FeS clusters) breaks an Fe–S bond, creating an under-coordinated Fe which is the reactive site of substitution.
Pharmaceutical co-crystals – are we there yet?
Authors: Blagden N. , Coles S. J. , Berry D. J.
Published: March 2014

Progression from drug to co-crystal to medicine.
On the role of DMSO-O(lone pair)⋯π(arene), DMSO-S(lone pair)⋯π(arene) and SO⋯π(arene) interactions in the crystal structures of dimethyl sulphoxide (DMSO) solvates
Authors: Zukerman-Schpector Julio , Tiekink Edward R. T.
Published: March 2014

DMSO-O(lone pair)⋯π(arene), DMSO-S(lone pair)⋯π(arene) and SO⋯π(arene) interactions are found in DMSO solvates.
Synergistic contributions by decreasing overpotential and enhancing charge-transfer in α-Fe2O3/Mn3O4/graphene catalysts with heterostructures for photocatalytic water oxidation
Authors: Yin Shunli , Wang Xiaomei , Mou Zhigang , Wu Yijie , Huang Hui , Zhu Mingshan , Du Yukou , Yang Ping
Published: March 2014

Proposed mechanism of oxygen evolution from α-Fe2O3/Mn3O4-1/rGO-3 photocatalyst.
Synthesis of poly(ethylene furandicarboxylate) polyester using monomers derived from renewable resources: thermal behavior comparison with PET and PEN
Authors: Papageorgiou George Z. , Tsanaktsis Vasilios , Bikiaris Dimitrios N.
Published: March 2014

Poly(ethylene-2,5-furandicarboxylate) (PEF) is a new polyester that can be prepared from monomers derived from renewable resources and its crystallization behavior was studied for the first time.
The first ruthenium-silsesquioxyl complexes – synthesis, structure and mechanistic implications in silylative coupling
Authors: Żak Patrycja , Kubicki Maciej , Marciniec Bogdan , Rogalski Szymon , Pietraszuk Cezary , Frąckowiak Dawid
Published: March 2014

The first ruthenium-silsesquioxyl complexes have been synthesised and characterized. The complexes obtained were proved to be intermediates in the catalytic cycle of silylative coupling of olefins with vinylsilsesquioxane.
Speciation of organometals using a synchronizing GC-EIMS and GC-ICPMS system for simultaneous detection
Authors: D'Ulivo Lucia , Yang Lu , Feng Yong-Lai , Murimboh John , Mester Zoltán
Published: March 2014

Accurate quantitation and characterization of organometals are successfully achieved by splitting the gas chromatography (GC) flow to both an electron ionization mass spectrometer (EIMS) and an inductively coupled plasma mass spectrometer (ICPMS).
Formation of elongated fascicle-inspired 3D tissues consisting of high-density, aligned cells using sacrificial outer molding
Authors: Neal Devin , Sakar Mahmut Selman , Ong Lee-Ling S. , Harry Asada H.
Published: March 2014

Fascicle-inspired tissue strips were generated having high (~100 s) length to diameter ratios using a novel external sacrificial molding method. High levels of alignment, 3D cell distribution, and cell density are demonstrated.
A protecting group free and scalable approach towards total synthesis of (−)-venlafaxine
Authors: Chavan Subhash P. , Pawar Kailash P. , Garai Sumanta
Published: March 2014

A protecting group free asymmetric total synthesis of (−)-venlafaxine is reported. The strategy employs Sharpless epoxidation and regio-selective epoxide ring opening by an in situ generated Gilman reagent as key steps. This paper reports a 53% overall yield in 6 steps for total synthesis of (−)-venlafaxine.
Efficient Cu2ZnSnS4solar cells spray coated from a hydro-alcoholic colloid synthesized by instantaneous reaction
Authors: Larramona Gerardo , Bourdais Stéphane , Jacob Alain , Choné Christophe , Muto Takuma , Cuccaro Yan , Delatouche Bruno , Moisan Camille , Péré Daniel , Dennler Gilles
Published: March 2014

A fast simple preparation based on spraying a Cu–Zn–Sn–S colloid and a sequentially annealing in N2and H2S yields compact, continuous layers with grain size of micron order.
Synthesis of ZnO@ZnS–Bi2S3 core–shell nanorod grown on reduced graphene oxide sheets and its enhanced photocatalytic performance
Authors: Xitao Wang , Rong Lv , Kang Wang
Published: March 2014

The successful synthesis of ZnO@ZnS–Bi2S3 core–shell nanorods anchored on RGO sheets and the important roles played by Bi2S3 on photo absorption and photocatalytic activity are described.
Investigation of the magnetic properties of insulating thin films using the longitudinal spin Seebeck effect
Authors: Kehlberger A. , Jakob G. , Onbasli M. C. , H. Kim D. , Ross C. A. , Kläui M.
Published: March 2014

The longitudinal spin Seebeck effect is used as a detector for the magnetic properties and switching characteristics of magnetic thin insulating films. We use a 300 nm and a 20 nm thick Yttrium Iron Garnet (YIG, Y3Fe5O12) film prepared by pulsed laser deposition and afterwards coated by platinum for the detection of the thermally excited magnons by the inverse spin Hall effect. The inverse spin Hall signals reveal a magnetic uniaxial anisotropy along the direction of the platinum stripe in the thicker film. For the thin film we find a more isotropic behavior, which is complementarily observed using the magnetoresistance occurring at the platinum/YIG interface. We explain our results on the basis of x-ray diffraction data, which reveal a miscut of the substrate and film surface and an expansion of the YIG lattice. Both findings favor a growth-induced magnetic anisotropy that we observe.
Lattice-engineered Si1-xGex-buffer on Si(001) for GaP integration
Authors: Skibitzki Oliver , Paszuk Agnieszka , Hatami Fariba , Zaumseil Peter , Yamamoto Yuji , Andreas Schubert Markus , Trampert Achim , Tillack Bernd , Ted Masselink W. , Hannappel Thomas , Schroeder Thomas
Published: March 2014

We report a detailed structure and defect characterization study on gallium phosphide (GaP) layers integrated on silicon (Si) (001) via silicon-germanium (SiGe) buffer layers. The presented approach uses an almost fully relaxed SiGe buffer heterostructure of only 400 nm thickness whose in-plane lattice constant is matched to GaP—not at room but at GaP deposition temperature. Single crystalline, pseudomorphic 270 nm thick GaP is successfully grown by metalorganic chemical vapour deposition on a 400 nm Si0.85Ge0.15/Si(001) heterosystem, but carries a 0.08% tensile strain after cooling down to room temperature due to the bigger thermal expansion coefficient of GaP with respect to Si. Transmission electron microscopy (TEM) studies confirm the absence of misfit dislocations in the pseudomorphic GaP film but growth defects (e.g., stacking faults, microtwins, etc.) especially at the GaP/SiGe interface region are detected. We interpret these growth defects as a residue of the initial 3D island coalescence phase of the GaP film on the SiGe buffer. TEM-energy-dispersive x-ray spectroscopy studies reveal that these defects are often correlated with stoichiometric inhomogeneities in the GaP film. Time-of-flight Secondary ion mass spectrometry detects sharp heterointerfaces between GaP and SiGe films with a minor level of Ga diffusion into the SiGe buffer.
Multi-scale coarse-graining of non-conservative interactions in molecular liquids
Authors: Izvekov Sergei , Rice Betsy M.
Published: March 2014

A new bottom-up procedure for constructing non-conservative (dissipative and stochastic) interactions for dissipative particle dynamics (DPD) models is described and applied to perform hierarchical coarse-graining of a polar molecular liquid (nitromethane). The distant-dependent radial and shear frictions in functional-free form are derived consistently with a chosen form for conservative interactions by matching two-body force-velocity and three-body velocity-velocity correlations along the microscopic trajectories of the centroids of Voronoi cells (clusters), which represent the dissipative particles within the DPD description. The Voronoi tessellation is achieved by application of the K-means clustering algorithm at regular time intervals. Consistently with a notion of many-body DPD, the conservative interactions are determined through the multi-scale coarse-graining (MS-CG) method, which naturally implements a pairwise decomposition of the microscopic free energy. A hierarchy of MS-CG/DPD models starting with one molecule per Voronoi cell and up to 64 molecules per cell is derived. The radial contribution to the friction appears to be dominant for all models. As the Voronoi cell sizes increase, the dissipative forces rapidly become confined to the first coordination shell. For Voronoi cells of two and more molecules the time dependence of the velocity autocorrelation function becomes monotonic and well reproduced by the respective MS-CG/DPD models. A comparative analysis of force and velocity correlations in the atomistic and CG ensembles indicates Markovian behavior with as low as two molecules per dissipative particle. The models with one and two molecules per Voronoi cell yield transport properties (diffusion and shear viscosity) that are in good agreement with the atomistic data. The coarser models produce slower dynamics that can be appreciably attributed to unaccounted dissipation introduced by regular Voronoi re-partitioning as well as by larger numerical errors in mapping out the dissipative forces. The framework presented herein can be used to develop computational models of real liquids which are capable of bridging the atomistic and mesoscopic scales.
Plasmon resonance enhancement of Faraday rotation of liquid phase epitaxy grown garnet films populated with gold nanoparticles on the film surfaces
Authors: Lang G. S. , Bowen D. , Krafft C. , Mayergoyz I. D.
Published: March 2014

Enhancement of the Faraday rotation of rare-earth iron garnet thin films offers the promise for development of compact and higher performance polarization dependent optical devices. Faraday rotation enhancement has been achieved utilizing strong localized electric fields induced by the excitation of plasmon resonances in gold nanoparticles deposited on garnet films. This paper presents experimental results that reveal strong Faraday rotation enhancement in bismuth-doped garnet films with gold nanoparticles of various dimensions and separations deposited on the epitaxial films. Stronger enhancements can be obtained by increasing the height and relative spacing between the nanoparticles formed on the garnet film surfaces.
Conformal holonomy in MacDowell-Mansouri gravity
Authors: Reid James A. , Wang Charles H.-T.
Published: March 2014

The MacDowell-Mansouri formulation of general relativity is based on a gauge theory whose gauge algebra depends on the sign of the cosmological constant. In this article, we show that the gauge algebra is uniquely determined by the conformal structure of spacetime itself. Specifically, we show that in vacuum: the spacetime conformal holonomy algebra coincides with the MacDowell-Mansouri gauge algebra for both signs of the cosmological constant, in both Lorentzian and Euclidean metric signatures.
Application of micro solid immersion lens as probe for near-field scanning microscopy
Authors: Assafrao A. C. , Kumar N. , Wachters A. J. H. , Pereira S. F. , Urbach H. P. , Brun M. , Olivier Segolene
Published: March 2014

We present an experimental and theoretical study of the immersing properties of a micron-sized solid immersion lens (μ-SIL) and evaluate its capabilities of functioning as a near-field probe. It was found that the μ-SIL reduces an impinging focused spot by a factor of approximately its refractive index, similarly to a macroscopic solid immersion lens. This reduced immersed spot is used to investigate the visibility of a periodic grating structure. Results show an improvement in the visibility by approximately 30% when compared to confocal microscopy, demonstrating the potential application of these tiny micro-lenses as a near-field probe in scanning microscopy and other high-resolution optical systems.
Solvent polarity and nanoscale morphology in bulk heterojunction organic solar cells: A case study
Authors: Thomas Ajith , Elsa Tom Anju , Rao Arun D. , Varman K. Arul , Ranjith K. , Vinayakan R. , Ramamurthy Praveen C. , Ison V. V.
Published: March 2014

Organic bulk heterojunction solar cells were fabricated under identical experimental conditions, except by varying the solvent polarity used for spin coating the active layer components and their performance was evaluated systematically. Results showed that presence of nitrobenzene-chlorobenzene composition governs the morphology of active layer formed, which is due to the tuning of solvent polarity as well as the resulting solubility of the P3HT:PCBM blend. Trace amount of nitrobenzene favoured the formation of better organised P3HT domains, as evident from conductive AFM, tapping mode AFM and surface, and cross-sectional SEM analysis. The higher interfacial surface area thus generated produced cells with high efficiency. But, an increase in the nitrobenzene composition leads to a decrease in cell performance, which is due to the formation of an active layer with larger size polymer domain networks with poor charge separation possibility.
Microstructure evolution of hot-deformed Nd-Fe-B anisotropic magnets
Authors: Liu J. , Sepehri-Amin H. , Ohkubo T. , Hioki K. , Hattori A. , Hono K.
Published: March 2014

The microstructural evolution of hot-deformed Nd-Fe-B magnets in each stage of hot-deformation process was studied using transmission electron microscopy and three dimensional atom probe (3DAP). The anisotropic growth of initially isotropic grains in rapidly solidified alloy occurs by annealing without pressing. 3DAP analyses showed a higher concentration of rare-earth elements in the intergranular phase parallel to the flat surface of platelet shaped Nd2Fe14B grains compared to that in the intergranular phase at the side of platelets.
Performance of magnetorheological fluids beyond the chain based shear limit
Authors: Sherman Stephen G. , Wereley Norman M.
Published: March 2014

Magnetorheological (MR) fluids consist of magnetizable particles suspended in a carrier fluid, and upon application of a magnetic field, the particles form chains, and the so-called MR effect occurs, causing the fluid to develop a yield stress. However, calculations have shown that as the Mason number rises, the maximum stable chain length falls, and above a critical Mason number, no stable chains can form in the fluid, implying an upper limit on the existence of the MR effect. Using a standard simulation model for MR fluids, we find a significant reduction in fluid stress at the predicted Mason numbers for low volume fraction fluids.
Nonlinear simulations to optimize magnetic nanoparticle hyperthermia
Authors: Reeves Daniel B. , Weaver John B.
Published: March 2014

Magnetic nanoparticle hyperthermia is an attractive emerging cancer treatment, but the acting microscopic energy deposition mechanisms are not well understood and optimization suffers. We describe several approximate forms for the characteristic time of Néel rotations with varying properties and external influences. We then present stochastic simulations that show agreement between the approximate expressions and the micromagnetic model. The simulations show nonlinear imaginary responses and associated relaxational hysteresis due to the field and frequency dependencies of the magnetization. This suggests that efficient heating is possible by matching fields to particles instead of resorting to maximizing the power of the applied magnetic fields.
Flipping water molecules at insulator/solution interface using an externally applied weak electric field
Authors: Kondo Takahiro , Ito Tsuyohito
Published: March 2014

Effects of an externally applied electric field on orientation polarization of the water molecules at an insulator–solution interface were studied using sum-frequency generation (SFG) spectroscopy. Orientation of water molecules that have a structure causing a signal at ∼3100 cm–1 in the SFG spectra are strongly affected by an applied electric field. Moreover, the water dipole flips when an electric field is applied in the opposite direction of the electric field generated from the surface charge of a solid insulator (calcium fluoride). The required electric field is extremely low compared to that expected by the zeta potential, implying that the structure of the SFG signal is formed not on the calcium fluoride surface, where the electric field is expected to be the strongest, but further from the interface.
Strain rate and adhesive energy dependent viscoplastic damage modeling for nanoparticulate composites: Molecular dynamics and micromechanical simulations
Authors: Yang B. J. , Shin H. , Kim H. , Lee H. K.
Published: March 2014

A viscoplastic damage model based on molecular dynamics (MD) and micromechanics is proposed to predict the rate-dependent inelastic behavior of nanoparticle-reinforced polymer composites. The constitutive equation is developed by combining the solution of the elastic problem and Laplace-transformed superposition principle. The MD simulation is then conducted to derive the interfacial adhesive energy of nanocomposites (silica/nylon-6), and the MD results are applied to the viscoplastic damage model. Influences of the strain rate sensitivity and the interfacial debonding damage on nanocomposites are discussed, and predictions from the proposed approach are compared with experimental measurements to elucidate the potential of the formulation.
Mechanism of direct current electrical charge conduction in p-toluenesulfonate doped polypyrrole/carbon composites
Authors: Kumar Amit , Singh Rajiv K. , Singh Hari K. , Srivastava Pankaj , Singh Ramadhar
Published: March 2014

Polypyrrole/carbon (PPy/C) composites have been synthesized using varying concentration of p-toluenesulfonate (pTS) dopant by surface initiated in-situ chemical oxidative polymerization. The synthesis and influence of pTS on the structure of the PPy/C composites are confirmed by Fourier transform infrared studies and the morphological features have been examined by scanning electron microscopy. X-ray photoelectron spectroscopy, employed to examine the surface composition and doping level of these composites, confirms the anionic doping into the polymer backbone. Electron spin resonance measurement has been carried out on these samples to identify the nature of the charge carriers and their concentration at different doping levels. The dc electrical conductivity of these composites has been measured in the temperature range ∼10–305 K. The observed results have been analyzed in the framework of existing theoretical models. Different Mott's parameters, such as characteristic temperature (T0), density of states at the Fermi level {N(EF)}, average hopping distance (R), and average hopping energy (W), evaluated from dc conductivity data supports the applicability of Mott's three dimensional variable range hopping mechanism in this system.