bluuebunny/crossref_metadata_2025 huggingface dataset:
Female rule in lemurs is ancestral and hormonally mediated
Authors: Petty Joseph M. A. , Drea Christine M.
Published: May 2015

Female social dominance (FSD) over males is unusual in mammals, yet characterizes most Malagasy lemurs, which represent almost 30% of all primates. Despite its prevalence in this suborder, both the evolutionary trajectory and proximate mechanism of FSD remain unclear. Potentially associated with FSD is a suite of behavioural, physiological and morphological traits in females that implicates (as a putative mechanism) ‘masculinization’ via androgen exposure; however, relative to conspecific males, female lemurs curiously show little evidence of raised androgen concentrations. By observing mixed‐sex pairs of related Eulemur species, we identified two key study groups ‐‐ one comprised of species expressing FSD and increased female scent marking, the other comprised of species (from a recently evolved clade) showing equal status between the sexes and the more traditional pattern of sexually dimorphic behaviour. Comparing females from these two groups, we show that FSD is associated with more masculine androgen profiles. Based on the widespread prevalence of male‐like features in female lemurs and a current phylogeny, we suggest that relaxation of hormonally mediated FSD emerged only recently and that female masculinization may be the ancestral lemur condition, an idea that could revolutionize our understanding of the ancient socioecology and evolution of primate social systems.
Structure-based discovery of the first non-covalent inhibitors of Leishmania major tryparedoxin peroxidase by high throughput docking
Authors: Brindisi Margherita , Brogi Simone , Relitti Nicola , Vallone Alessandra , Butini Stefania , Gemma Sandra , Novellino Ettore , Colotti Gianni , Angiulli Gabriella , Di Chiaro Francesco , Fiorillo Annarita , Ilari Andrea , Campiani Giuseppe
Published: May 2015

Leishmaniasis is a neglected vector-born disease caused by a protozoan of the genus Leishmania and affecting more than 1.300.000 people worldwide. The couple tryparedoxin/tryparedoxin peroxidase is essential for parasite survival in the host since it neutralizes the hydrogen peroxide produced by macrophages during the infection. Herein we report a study aimed at discovering the first class of compounds able to non-covalently inhibit tryparedoxin peroxidase. We have solved the high-resolution structure of Tryparedoxin peroxidase I from Leishmania major (LmTXNPx) in the reduced state and in fully folded conformation. A first series of compounds able to inhibit LmTXNPx was identified by means of the high throughput docking technique. The inhibitory activity of these compounds was validated by a Horseradish peroxidase-based enzymatic assay and their affinity for LmTXNPx calculated by surface plasmon resonance experiments. On the basis of these results, the analysis of the enzyme-inhibitor docked models allowed us to rationally design and synthesize a series of N,N-disubstituted 3-aminomethyl quinolones. These compounds showed an inhibitory potency against LmTXNPx in the micromolar range. Among them, compound 12 represents the first non-covalent LmTXNPx inhibitor reported to date and could pave the way to the discovery of a new class of drugs against leishmaniasis.
Single-cell evaluation of red blood cell bio-mechanical and nano-structural alterations upon chemically induced oxidative stress
Authors: Sinha Ameya , Chu Trang T. T. , Dao Ming , Chandramohanadas Rajesh
Published: May 2015

Erythroid cells, specifically red blood cells (RBCs), are constantly exposed to highly reactive radicals during cellular gaseous exchange. Such exposure often exceeds the cells' innate anti-oxidant defense systems, leading to progressive damage and eventual senescence. One of the contributing factors to this process are alterations to hemoglobin conformation and globin binding to red cell cytoskeleton. However, in addition to the aforementioned changes, it is possible that oxidative damage induces critical changes to the erythrocyte cytoskeleton and corresponding bio-mechanical and nano-structural properties of the red cell membrane. To quantitatively characterize how oxidative damage accounts for such changes, we employed single-cell manipulation techniques such as micropipette aspiration and atomic force microscopy (AFM) on RBCs. These investigations demonstrated visible morphological changes upon chemically induced oxidative damage (using hydrogen peroxide, diamide, primaquine bisphosphate and cumene hydroperoxide). Our results provide previously unavailable observations on remarkable changes in red cell cytoskeletal architecture and membrane stiffness due to oxidative damage. Furthermore, we also demonstrate that a pathogen that infects human blood cells, Plasmodium falciparum was unable to penetrate through the oxidant-exposed RBCs that have damaged cytoskeleton and stiffer membranes. This indicates the importance of bio-physical factors pertinent to aged RBCs and it's relevance to malaria infectivity.
In Vitro Study of Surface Modified Poly(ethylene glycol)-Impregnated Sintered Bovine Bone Scaffolds on Human Fibroblast Cells
Authors: Pramanik Sumit , Ataollahi Forough , Pingguan-Murphy Belinda , Oshkour Azim Ataollahi , Osman Noor Azuan Abu
Published: May 2015

Scaffold design from xenogeneic bone has the potential for tissue engineering (TE). However, major difficulties impede this potential, such as the wide range of properties in natural bone. In this study, sintered cortical bones from different parts of a bovine-femur impregnated with biodegradable poly(ethylene glycol) (PEG) binder by liquid phase adsorption were investigated. Flexural mechanical properties of the PEG-treated scaffolds showed that the scaffold is stiffer and stronger at a sintering condition of 1000°C compared with 900°C.In vitrocytotoxicity of the scaffolds evaluated by Alamar Blue assay and microscopic tests on human fibroblast cells is better at 1000°C compared with that at 900°C. Furthermore,in vitrobiocompatibility and flexural property of scaffolds derived from different parts of a femur depend on morphology and heat-treatment condition. Therefore, the fabricated scaffolds from the distal and proximal parts at 1000°C are potential candidates for hard and soft TE applications, respectively.
Layer-selective half-metallicity in bilayer graphene nanoribbons
Authors: Jeon Gi Wan , Lee Kyu Won , Lee Cheol Eui
Published: May 2015

Half-metallicity recently predicted in the zigzag-edge graphene nanoribbons (ZGNRs) and the hydrogenated carbon nanotubes (CNTs) enables fully spin-polarized electric currents, providing a basis for carbon-based spintronics. In both carbon systems, the half-metallicity arises from the edge-localized electron states under an electric field, lowering the critical electric field Dc for the half-metallicity being an issue in recent works on ZGNRs. A properly chosen direction of the electric field alone has been predicted to significantly reduce Dc in the hydrogenated CNTs, which in this work turned out to be the case in narrow bilayer ZGNRs (biZGNRs). Here, our simple model based on the electrostatic potential difference between the edges predicts that for wide biZGNRs of width greater than ~2.0 nm (10 zigzag carbon chains), only one layer of the biZGNRs becomes half-metallic leaving the other layer insulating as confirmed by our density functional theory (DFT) calculations. The electric field-induced switching of the spin-polarized current path is believed to open a new route to graphene-based spintronics applications.
Unfolding grain size effects in barium titanate ferroelectric ceramics
Authors: Tan Yongqiang , Zhang Jialiang , Wu Yanqing , Wang Chunlei , Koval Vladimir , Shi Baogui , Ye Haitao , McKinnon Ruth , Viola Giuseppe , Yan Haixue
Published: May 2015

Grain size effects on the physical properties of polycrystalline ferroelectrics have been extensively studied for decades; however there are still major controversies regarding the dependence of the piezoelectric and ferroelectric properties on the grain size. Dense BaTiO3 ceramics with different grain sizes were fabricated by either conventional sintering or spark plasma sintering using micro- and nano-sized powders. The results show that the grain size effect on the dielectric permittivity is nearly independent of the sintering method and starting powder used. A peak in the permittivity is observed in all the ceramics with a grain size near 1 μm and can be attributed to a maximum domain wall density and mobility. The piezoelectric coefficient d33 and remnant polarization Pr show diverse grain size effects depending on the particle size of the starting powder and sintering temperature. This suggests that besides domain wall density, other factors such as back fields and point defects, which influence the domain wall mobility, could be responsible for the different grain size dependence observed in the dielectric and piezoelectric/ferroelectric properties. In cases where point defects are not the dominant contributor, the piezoelectric constant d33 and the remnant polarization Pr increase with increasing grain size.
Soret Fishnet Metalens Antenna
Authors: Orazbayev Bakhtiyar , Beruete Miguel , Pacheco-Peña Víctor , Crespo Gonzalo , Teniente Jorge , Navarro-Cía Miguel
Published: May 2015

At the expense of frequency narrowing, binary amplitude-only diffractive optical elements emulate refractive lenses without the need of large profiles. Unfortunately, they also present larger Fresnel reflection loss than conventional lenses. This is usually tackled by implementing unattractive cumbersome designs. Here we demonstrate that simplicity is not at odds with performance and we show how the fishnet metamaterial can improve the radiation pattern of a Soret lens. The building block of this advanced Soret lens is the fishnet metamaterial operating in the near-zero refractive index regime with one of the edge layers designed with alternating opaque and transparent concentric rings made of subwavelength holes. The hybrid Soret fishnet metalens retains all the merits of classical Soret lenses such as low profile, low cost and ease of manufacturing. It is designed for the W-band of the millimeter-waves range with a subwavelength focal length FL = 1.58 mm (0.5λ0) aiming at a compact antenna or radar systems. The focal properties of the lens along with its radiation characteristics in a lens antenna configuration have been studied numerically and confirmed experimentally, showing a gain improvement of ~2 dB with respect to a fishnet Soret lens without the fishnet metamaterial.
Metastatic breast cancer cells in lymph nodes increase nodal collagen density
Authors: Rizwan Asif , Bulte Camille , Kalaichelvan Anusha , Cheng Menglin , Krishnamachary Balaji , Bhujwalla Zaver M. , Jiang Lu , Glunde Kristine
Published: May 2015

The most life-threatening aspect of breast cancer is the occurrence of metastatic disease. The tumor draining lymph nodes typically are the first sites of metastasis in breast cancer. Collagen I fibers and the extracellular matrix have been implicated in breast cancer to form avenues for metastasis. In this study, we have investigated extracellular matrix molecules such as collagen I fibers in the lymph nodes of mice bearing orthotopic human breast cancer xenografts. The lymph nodes in mice with metastatic MDA-MB-231 and SUM159 tumor xenografts and tumor xenografts grown from circulating tumor cell lines displayed an increased collagen I density compared to mice with no tumor and mice with non-metastatic T-47D and MCF-7 tumor xenografts. These results suggest that cancer cells that have metastasized to the lymph nodes can modify the extracellular matrix components of these lymph nodes. Clinically, collagen density in the lymph nodes may be a good marker for identifying lymph nodes that have been invaded by breast cancer cells.
Derivation and characterization of human embryonic stem cells on human amnion epithelial cells
Authors: Lai Dongmei , Wang Yongwei , Sun Jian , Chen Yifei , Li Ting , Wu Yi , Guo Lihe , Wei Chunsheng
Published: May 2015

Culture conditions that support the growth of undifferentiated human embryonic stem cells (hESCs) have already been established using primary human amnion epithelial cells (hAECs) as an alternative to traditional mitotically inactivated mouse embryonic fibroblasts (MEFs). In the present work, inner cell masses (ICM) were isolated from frozen embryos obtained as donations from couples undergoing in vitro fertilization (IVF) treatment and four new hESC lines were derived using hAECs as feeder cells. This feeder system was able to support continuous growth of what were, according to their domed shape and markers, undifferentiated naïve-like hESCs. Their pluripotent potential were also demonstrated by embryoid bodies developing to the expected three germ layers in vitro and the productions of teratoma in vivo. The cell lines retained their karyotypic integrity for over 35 passages. Transmission electron microscopy (TEM) indicated that these newly derived hESCs consisted mostly of undifferentiated cells with large nuclei and scanty cytoplasm. The new hESCs cultured on hAECs showed distinct undifferentiated characteristics in comparison to hESCs of the same passage maintained on MEFs. This type of optimized culture system may provide a useful platform for establishing clinical-grade hESCs and assessing the undifferentiated potential of hESCs.
A novel and rapid method for obtaining high titre intact prion strains from mammalian brain
Authors: Wenborn Adam , Terry Cassandra , Gros Nathalie , Joiner Susan , D’Castro Laura , Panico Silvia , Sells Jessica , Cronier Sabrina , Linehan Jacqueline M. , Brandner Sebastian , Saibil Helen R. , Collinge John , Wadsworth Jonathan D. F.
Published: May 2015

Mammalian prions exist as multiple strains which produce characteristic and highly reproducible phenotypes in defined hosts. How this strain diversity is encoded by a protein-only agent remains one of the most interesting and challenging questions in biology with wide relevance to understanding other diseases involving the aggregation or polymerisation of misfolded host proteins. Progress in understanding mammalian prion strains has however been severely limited by the complexity and variability of the methods used for their isolation from infected tissue and no high resolution structures have yet been reported. Using high-throughput cell-based prion bioassay to re-examine prion purification from first principles we now report the isolation of prion strains to exceptional levels of purity from small quantities of infected brain and demonstrate faithful retention of biological and biochemical strain properties. The method’s effectiveness and simplicity should facilitate its wide application and expedite structural studies of prions.
Evaluation of the analytical performances of a valve-based droplet direct injection system by inductively coupled plasma-atomic emission spectrometry
Authors: Shigeta Kaori , Kaburaki Yuki , Iwai Takahiro , Miyahara Hidekazu , Okino Akitoshi
Published: May 2015

We evaluated the analytical performances of a new sample introduction system using a magnetic valve type dispenser, which can generate a large variety of droplet sizes for stable injection of cell suspension.
Facile synthesis and optical properties of pure and Ni2+, Co2+, Bi3+, Sb3+substituted Cu3SnS4
Authors: Gusain Meenakshi , Rawat Pooja , Nagarajan Rajamani
Published: May 2015

Reacting thiourea precursors of the respective metals in ethyleneglycol for few hours, orthorhombic Cu3SnS4and Ni2+, Co2+and Sb3+substituted quaternary compositions has been synthesised and characterized thoroughly.
A one-piece lateral flow impedimetric test strip for label-free clenbuterol detection
Authors: Shi ZhuanZhuan , Tian YunLi , Wu XiaoShuai , Li ChangMing , Yu Ling
Published: May 2015

A one-piece lateral flow impedance strip was developed for detection of clenbuterol hydrochloride, a restricted food additive.
Sensitive and simple sonoluminescence detection of melamine via aggregation of Au nanoparticles
Authors: Liu Jing , Feng Shaohong , Shi Yun , Lyu Jitong , Lv Jiagen
Published: May 2015

A novel nano-material-sonoluminescence design is proposed by converting the melamine responsive aggregation of Au nanoparticles into sonoluminescence signals for sensitive detection of melamine.
Graphene oxide nanocapsules within silanized hydrogels suitable for electrochemical pseudocapacitors
Authors: Kataky R. , Hadden J. H. L. , Coleman K. S. , Ntola C. N. M. , Chowdhury M. , Duckworth A. R. , Dobson B. P. , Campos R. , Pyner S. , Shenton F.
Published: May 2015

Graphene oxide rolls up into nanocapsules within silanized hydrogel pores affording a redox biocompatible material.
Correction: Strongly correlated plexcitonics: evolution of the Fano resonance in the presence of Kondo correlations
Authors: Goker A.
Published: May 2015

Correction for ‘Strongly correlated plexcitonics: evolution of the Fano resonance in the presence of Kondo correlations’ by A. Goker et al., Phys. Chem. Chem. Phys., 2015, 17, 11569–11576.
CdS-decorated triptycene-based polymer: durable photocatalysts for hydrogen production under visible-light irradiation
Authors: Liang Qian , Jiang Guiyuan , Zhao Zhen , Li Zhongyu , MacLachlan Mark J.
Published: May 2015

Nanocomposites formed by CdS with porous triptycene-based polymers are effective catalysts for photocatalytic hydrogen production.
Graphene oxide coated coordination polymer nanobelt composite material: a new type of visible light active and highly efficient photocatalyst for Cr(vi) reduction
Authors: Shi Gui-Mei , Zhang Bin , Xu Xin-Xin , Fu Yan-Hong
Published: May 2015

GO/CPNB was fabricated successfully, which displays excellent photocatalytic activity in visible light. Furthermore, the influence of GO on photocatalytic activity is discussed.
2-(2′-Pyridyl)-4,6-diphenylphosphinine versus 2-(2′-pyridyl)-4,6-diphenylpyridine: synthesis and characterization of novel Cr0, Mo0 and W0 carbonyl complexes containing chelating P,N and N,N ligands
Authors: de Krom Iris , Lutz Martin , Müller Christian
Published: May 2015

Replacing nitrogen by phosphorus in otherwise similar structures changes the properties of the resulting compounds significantly due to the electronic differences that exist between these heteroatoms.
Ambivalent binding between a radical-based pincer ligand and iron
Authors: Harriman Katie L. M. , Leitch Alicea A. , Stoian Sebastian A. , Habib Fatemah , Kneebone Jared L. , Gorelsky Serge I. , Korobkov Ilia , Desgreniers Serge , Neidig Michael L. , Hill Stephen , Murugesu Muralee , Brusso Jaclyn L.
Published: May 2015

An inherently redox active pincer-type ligand, 3,5-bis(2-pyridyl)-1,2,4,6-thiatriazinyl (Py2TTA˙), was employed to isolate Fe(Py2TTA)Cl2.
Sensitive high resolution ion microprobe – stable isotope (SHRIMP-SI) analysis of water in silicate glasses and nominally anhydrous reference minerals
Authors: Turner Michael , Ireland Trevor , Hermann Joerg , Holden Peter , Padrón-Navarta José Alberto , Hauri Erik H. , Turner Simon
Published: May 2015

Water concentrations in geological reference materials are evaluated with the new SHRIMP SI ion microprobe.
Band edge engineering of TiO2@DNA nanohybrids and implications for capacitive energy storage devices
Authors: Imani Roghayeh , Pazoki Meysam , Tiwari Ashutosh , Boschloo G. , Turner Anthony P. F. , Kralj-Iglič V. , Iglič Aleš
Published: May 2015

Novel TiO2@oligonucleotide (TiO2@DNA) nanohybrid electrodes comprising of covalently encoded DNA with mesoporous TiO2microbeads using dopamine as a linker show potential application in supercapacitors.
Regioselective Suzuki couplings of non-symmetric dibromobenzenes: alkenes as regiochemical control elements
Authors: Zhao Peng , Young Marshall D. , Beaudry Christopher M.
Published: May 2015

The regioselective Suzuki coupling of dibromobenzenes has been investigated. The regiochemistry is high when one bromine atom is proximal to an alkene.
Direct access to site-specifically phosphorylated-lysine peptides from a solid-support
Authors: Bertran-Vicente Jordi , Schümann Michael , Schmieder Peter , Krause Eberhard , Hackenberger Christian P. R.
Published: May 2015

A new synthetic approach is described for the first direct synthesis of site-specifically phosphorylated Lys peptides from solid-supported azido-peptides.
Photocatalytic water disinfection by simple and low-cost monolithic and heterojunction ceramic wafers
Authors: Makwana Neel M. , Hazael Rachael , McMillan Paul F. , Darr Jawwad A.
Published: May 2015

In this work, the photocatalytic disinfection of Escherichia coli (E. coli) using dual layer ceramic wafers, prepared by a simple and low-cost technique, was investigated. Heterojunction wafers were prepared by pressing TiO2 and WO3 powders together into 2 layers within a single, self-supported monolith. Data modelling showed that the heterojunction wafers were able to sustain the formation of charged species (after an initial “charging” period). In comparison, a wafer made from pure TiO2 showed a less desirable bacterial inactivation profile in that the rate decreased with time (after being faster initially). The more favourable kinetics of the dual layer system was due to superior electron–hole vectorial charge separation and an accumulation of charges beyond the initial illumination period. The results demonstrate the potential for developing simplified photocatalytic devices for rapid water disinfection.
Extension of three-dimensional activity cliff information through systematic mapping of active analogs
Authors: Hu Ye , Furtmann Norbert , Bajorath Jürgen
Published: May 2015

Shown is a superposition of two analogs (green and orange) on crystallographic ligands (magenta and cyan) forming a three-dimensional activity cliff (MMP stands for Matched Molecular Pair).
Binder free and free-standing electrospun membrane architecture for sensitive and selective non-enzymatic glucose sensors
Authors: Raj kumar T. , Babu K. Justice , Yoo Dong Jin , Kim Ae Rhan , Gnana kumar G.
Published: May 2015

Novel free standing and binder free non-enzymatic electrochemical sensors were fabricated usingin situgrown copper (Cu) nanoparticles on polyvinylidenefluoride-co-hexafluoropropylene (PVdF-HFP) nanofibers.
Nanomedicines for targeted delivery of etoposide to non-small cell lung cancer using transferrin functionalized nanoparticles
Authors: Pooja Deep , Kulhari Hitesh , Tunki Lakshmi , Chinde Srinivas , Kuncha Madhusudana , Grover Paramjit , Rachamalla Shyam S. , Sistla Ramakrishna
Published: May 2015

Tf-conjugated solid lipid nanoparticles were designed for selectively targeting etoposide to human non-small cell lung cancer resulting in sustained drug release, improved plasma concentrations and accumulation of etoposide in targeted lung tissues.
Palladium-catalyzed Heck coupling of arylhydrazines via C–NHNH2bond activation
Authors: Liu Jin-Biao , Chen Fu-Jiao , Liu Na , Hu Jiang
Published: May 2015

A novel palladium-catalyzed Heck coupling reaction of arylhydrazines with olefins is described, which affords various styrenes with high efficiency. This transformation proceeds through a C–NHNH2bond activation under mild conditions.
Gold loaded titanium dioxide–carbon nanotube composites as active photocatalysts for cyclohexane oxidation at ambient conditions
Authors: Mohamed Mohamed Mokhtar
Published: May 2015

Photocatalytic oxidation of neat cyclohexane with H2O2 was carried out using several types of gold modified materials including titania nanotubes, reduced graphene oxide and titania nanotube–multiwalled carbon nanotube composites under UV irradiation.
On stereocomplexed polylactide materials as support for PAMAM dendrimers: synthesis and properties
Authors: Gardella Lorenza , Basso Andrea , Prato Mirko , Monticelli Orietta
Published: May 2015

Synthesis of a PLA-based system capable of supporting dendritic/star-like molecules, combining the properties of the stereocomplex PLA matrix with those of PAMAM dendrimers.
A turn-on fluorescent pyrene-based chemosensor for Cu(ii) with live cell application
Authors: Venkatesan Parthiban , Wu Shu-Pao
Published: May 2015

A pyrene-based fluorescent sensor (PHP) was synthesized for Cu(ii) detection.
Mitigation mechanism of Cd-contaminated soils by different levels of exogenous low-molecular-weight organic acids and Phytolacca americana
Authors: Liu Huan , Liu Yun-guo , Zeng Guang-ming , Xie Jie-li , Zheng Bo-hong , Tan Xiao-fei , Wang Da-fei , Sun Zhi-chao , Nie Jian , Jiang Zheng-jiang , Gan Chao , Liu Wei , Wang Shu-fan
Published: May 2015

Phytolacca americana L. (pokeweed) is a promising plant for phytoremediation of cadmium (Cd)-contaminated soil, with its large biomass and fast growth rate.
Thermally stable polyimide nanocomposite films from electrospun BaTiO3 fibers for high-density energy storage capacitors
Authors: Wu Yun-Hui , Zha Jun-Wei , Yao Zhi-Qiang , Sun Fang , Li Robert K. Y. , Dang Zhi-Min
Published: May 2015

PI composite films with electrospun BT fibers were fabricated using the in situ dispersion polymerization method. The microstructures, thermal and dielectric properties of the BT fibers and composite films were investigated.
Low temperature direct bonding of silica glass via wet chemical surface activation
Authors: Mai Chengle , Li Mingyu , Yang Shihua
Published: May 2015

A silica glass chip with a ∼200 μm rectangular channel was bonded through low temperature chemical surface activation direct bonding.
Polyhedral oligomeric silsesquioxane containing gel polymer electrolyte based on a PMMA matrix
Authors: Huang Yun , Gong Sheng-Dong , Huang Rui , Cao Hai-Jun , Lin Yuan-Hua , Yang Man , Li Xing
Published: May 2015

A polyhedral oligomeric silsesquioxane (POSS) nano-cage can endow gel polymer electrolyte (GPE) with similar properties as can be accomplished with other inorganic nanoparticles; the organic substituents at the cage corners of POSS are more compatible with GPEs.
A 3-D metal–organic framework with a rutile topology network, right- or left- handed helical chains and tunable UV-to-visible photoluminescence
Authors: Zhou Wei-Wei , Zhao Wang , Wang Feng-Wu , Fang Wen-Yan , Liu Dao-Fu , Wei Yi-Jun , Xu Mai , Zhao Xing , Liang Xian
Published: May 2015

A solvothermally synthesized 3-D Cd(ii) metal–organic framework with rutile topology was found containing right- or left- handed helices in its structure, and emitting tunable UV-to-visible photoluminescence.
Stability-indicating chromatographic determination of hydroquinone in combination with tretinoin and fluocinolone acetonide in pharmaceutical formulations with a photodegradation kinetic study
Authors: Abbas Samah S. , Elghobashy Mohamed R. , Bebawy Lories I. , Shokry Rafeek F.
Published: May 2015

Stability indicating HPLC and TLC-densitometric methods for the determination of hydroquinone, tretinoin, fluocinolone acetonide, their degradation products and preservatives.
K2S2O8/I2promoted syntheses of α-thio-β-dicarbonyl compounds via oxidative C–S coupling reactions under transition metal-free and solvent-free conditions
Authors: Liu Yi-Wei , Badsara Satpal Singh , Liu Yi-Chen , Lee Chin-Fa
Published: May 2015

K2S2O8/I2promoted C–S coupling reaction of β-diketone with disulfide has been described. The resulting α-thio-β-diketones compounds were obtained in good to excellent yields.
An unusual magnetic response in a π-stacked 66-dia net structure of [4 + 2] copper(ii) cubane
Authors: Das Mithun , Shaw Bikash Kumar , Ghosh Biswa Nath , Rissanen Kari , Saha Shyamal Kumar , Chattopadhyay Shouvik
Published: May 2015

Unusual hysteresis loops with coercivity maximum (∼2000 Oe) at 20 K are observed in a copper(ii) cubane. The apparent anomaly appears due to variation of intercubane π⋯π stacking with thermal energy.
Shape-controlled synthesis and lithium storage properties of SnO2 nonspherical hollow structures
Authors: Wang Yong , Ding Panshuang , Su Xiaowen
Published: May 2015

SnO2 hollow structures, such as peanuts, capsules and pseudocubes, have been controlled-synthesized by using SiO2 colloids with different shapes as templates, and show enhanced lithium storage performances.
Regioselective thioacetylation of chitosan end-groups for nanoparticle gene delivery systems
Authors: Pickenhahn V. D. , Darras V. , Dziopa F. , Biniecki K. , De Crescenzo G. , Lavertu M. , Buschmann M. D.
Published: May 2015

We present a novel, aqueous thiol-based conjugation strategy that constitutes an alternative to the oxime-click pathway for generating a reactive end-group on chitosan (CS), which could also be applicable to other polymers.
Stöber-like method to synthesize ultralight, porous, stretchable Fe2O3/graphene aerogels for excellent performance in photo-Fenton reaction and electrochemical capacitors
Authors: Qiu Bocheng , Xing Mingyang , Zhang Jinlong
Published: May 2015

The highly compressible Fe2O3/GAs synthesized via the Stöber-like method exhibit an outstanding performance in the photo-Fenton reaction and in electrochemical capacitors.
3D Fe3O4 nanocrystals decorating carbon nanotubes to tune electromagnetic properties and enhance microwave absorption capacity
Authors: Chen Yi-Hua , Huang Zi-Han , Lu Ming-Ming , Cao Wen-Qiang , Yuan Jie , Zhang De-Qing , Cao Mao-Sheng
Published: May 2015

3D Fe3O4-MWCNTs, a novel nanostructure, exhibited excellent microwave absorption due to the synergy of dielectric loss and magnetic loss and the enhancement effect of multiple interfaces.
“Breathing” unimolecular micelles based on a novel star-like amphiphilic hybrid copolymer
Authors: Fan Xiaoshan , Wang Zhuo , He Chaobin
Published: May 2015

Novel unimolecular micelles that possess a pH-induced “breathing” feature are presented in this paper.
Efficient naturalistic approach to image contrast enhancement
Authors: Chen Qiqiang , Wan Yi
Published: May 2015

Contrast enhancement is an important step in many image processing and analysis applications. Although the idea of enhancing image contrast is simple, most published mechanisms of letting computers do so automatically tend to be complex or not so intuitive, and the performance is generally not consistent across different image shooting conditions. A new naturalistic approach to this problem that directly mimics what a human artist would do for contrast enhancement is proposed. The goal is to make every non‐noise detail easily perceivable by a normal human. Specifically, the gradient/contrast and local background are computed for each pixel and then linearly mapped to an objective point in the gradient–background plane. Then, a cross‐bilateral filter is used to smooth the two linear map parameter images. A moving local window is used to obtain the local noise level for each pixel, which is used to determine whether the pixel should be enhanced. The proposed approach is easy to implement and leads to superior results compared with typical state‐of‐the‐art methods, as confirmed by experimental results.
High-resolution (e, 2e + ion) study of electron-impact ionization and fragmentation of methane
Authors: Ren Xueguang , Pflüger Thomas , Weyland Marvin , Baek Woon Yong , Rabus Hans , Ullrich Joachim , Dorn Alexander
Published: May 2015

The ionization and fragmentation of methane induced by low-energy (E0 = 66 eV) electron-impact is investigated using a reaction microscope. The momentum vectors of all three charged final state particles, two outgoing electrons, and one fragment ion, are detected in coincidence. Compared to the earlier study [Xu et al., J. Chem. Phys. 138, 134307 (2013)], considerable improvements to the instrumental mass and energy resolutions have been achieved. The fragment products CH4+, CH3+, CH2+, CH+, and C+ are clearly resolved. The binding energy resolution of ΔE = 2.0 eV is a factor of three better than in the earlier measurements. The fragmentation channels are investigated by measuring the ion kinetic energy distributions and the binding energy spectra. While being mostly in consistence with existing photoionization studies the results show differences including missing fragmentation channels and previously unseen channels.
Surface coupling effects on the capacitance of thin insulating films
Authors: Jamali Tayeb , Farahani S. Vasheghani , Jannesar Mona , Palasantzas George , Jafari G. R.
Published: May 2015

A general form for the surface roughness effects on the capacitance of a capacitor is proposed. We state that a capacitor with two uncoupled rough surfaces could be treated as two capacitors in series which have been divided from the mother capacitor by a slit. This is in contrast to the case where the two rough surfaces are coupled. When the rough surfaces are coupled, the type of coupling decides the modification of the capacitance in comparison to the uncoupled case. It is shown that if the coupling between the two surfaces of the capacitor is positive (negative), the capacitance is less (higher) than the case of two uncoupled rough plates. Also, we state that when the correlation length and the roughness exponent are small, the coupling effect is not negligible.
Angular magnetoresistance in semiconducting undoped amorphous carbon thin films
Authors: Sagar Rizwan Ur Rehman , Saleemi Awais Siddique , Zhang Xiaozhong
Published: May 2015

Thin films of undoped amorphous carbon thin film were fabricated by using Chemical Vapor Deposition and their structure was investigated by using High Resolution Transmission Electron Microscopy and Raman Spectroscopy. Angular magnetoresistance (MR) has been observed for the first time in these undoped amorphous carbon thin films in temperature range of 2 ∼ 40 K. The maximum magnitude of angular MR was in the range of 9.5% ∼ 1.5% in 2 ∼ 40 K. The origin of this angular MR was also discussed.
Magnetotransport study of nanocrystalline and polycrystalline manganites La0.8Sr0.2MnO3 in high magnetic fields
Authors: Pękała M. , Pękała K. , Drozd V.
Published: May 2015

Comparative study of magnetotransport and magnetic properties in strong magnetic fields up to 47 T is reported for nanocrystalline and polycrystalline mixed valence manganites La0.8Sr0.2MnO3. The low temperature resistivity enhancement observed only in nanocrystalline manganite is ascribed to the electrostatic blockade of charge carriers between the fine grains/crystallites. Small polaron model is found to describe the high temperature conductivity both in poly- and nanocrystalline manganites. The quantitative analysis supplies the low temperature blocking energy barrier and polaron activation energy. An evolution of resistivity with temperature and magnetic field reveals the intrinsic and extrinsic contributions to large negative magnetoresistance effect. The magnetoresistance is found to be correlated with a squared magnetization.
Quantum dynamics of 16O + 36O2 and 18O + 32O2 exchange reactions
Authors: Rajagopala Rao T. , Guillon G. , Mahapatra S. , Honvault P.
Published: May 2015

We present quantum dynamical investigations of 16O + 36O2 and 18O + 32O2 exchange reactions using a time-independent quantum mechanical method and an accurate global potential energy surface of ozone [Dawes et al., J. Chem. Phys. 135, 081102 (2011)]. Initial state-selected integral cross sections, rate constants, and Boltzmann averaged thermal rate constants are obtained and compared with earlier experimental and theoretical results. The computed thermal rate constants for the oxygen exchange reactions exhibit a negative temperature dependence, as found experimentally. They are in better agreement with the experiments than the previous studies on the same reactions.
Air nonlinear dynamics initiated by ultra-intense lambda-cubic terahertz pulses
Authors: Shalaby Mostafa , Hauri Christoph P.
Published: May 2015

We report on the measurement of the instantaneous Kerr nonlinearity and the retarded alignment of air molecules CO2, N2, and O2 triggered by an intense, lambda-cubic terahertz pulse, a diffraction- and transform-limited single-cycle pulse. The strong-field, impulsive low-frequency excitation (3.9 THz) leads to field-free alignment dynamics of these molecules thanks to the terahertz-induced transient dipole moments in the otherwise non-polar molecules. The strong coupling to the terahertz electric transient results in the excitation of coherent large amplitude long-living rotational states at room temperature and ambient pressure. Beyond fundamental investigations of nonlinear properties in gases, our results suggest a route towards field-free molecular alignment at laser intensity well below the ionization threshold.
The time resolved measurement of ultrashort terahertz-band electric fields without an ultrashort probe
Authors: Walsh D. A. , Snedden E. W. , Jamison S. P.
Published: May 2015

The time-resolved detection of ultrashort pulsed THz-band electric field temporal profiles without an ultrashort laser probe is demonstrated. A non-linear interaction between a narrow-bandwidth optical probe and the THz pulse transposes the THz spectral intensity and phase information to the optical region, thereby generating an optical pulse whose temporal electric field envelope replicates the temporal profile of the real THz electric field. This optical envelope is characterised via an autocorrelation based FROG (frequency resolved optical gating) measurement, hence revealing the THz temporal profile. The combination of a narrow-bandwidth, long duration, optical probe, and self-referenced FROG makes the technique inherently immune to timing jitter between the optical probe and THz pulse and may find particular application where the THz field is not initially generated via ultrashort laser methods, such as the measurement of longitudinal electron bunch profiles in particle accelerators.
Supersonic laser-induced jetting of aluminum micro-droplets
Authors: Zenou M. , Sa'ar A. , Kotler Z.
Published: May 2015

The droplet velocity and the incubation time of pure aluminum micro-droplets, printed using the method of sub-nanosecond laser induced forward transfer, have been measured indicating the formation of supersonic laser-induced jetting. The incubation time and the droplet velocity were extracted by measuring a transient electrical signal associated with droplet landing on the surface of the acceptor substrate. This technique has been exploited for studying small volume droplets, in the range of 10–100 femto-litters for which supersonic velocities were measured. The results suggest elastic propagation of the droplets across the donor-to-acceptor gap, a nonlinear deposition dynamics on the surface of the acceptor and overall efficient energy transfer from the laser beam to the droplets.
Thermal conductivity, electrical conductivity, and thermoelectric properties of CdTe and Cd0.8Zn0.2Te crystals between room temperature and 780oC
Authors: Su Ching-Hua
Published: May 2015

The thermal conductivity, electrical conductivity, and Seebeck coefficient of a vapor-grown CdTe and two melt-grown Cd0.8Zn0.2Te crystals, including In-doped CZT-30 and un-doped CZT-34 samples, were measured from room temperature to 780oC. The measured thermal conductivity of CdTe was higher than the two CdZnTe samples in the low temperature range and the three sets of data merged together at temperature above 750oC. The measured electrical conductivities of CdTe and CZT-30 were close to be intrinsic from 190oC to 780oC. The CZT-34 sample showed higher electrical conductivity value at 290oC and merged with the data of CZT-30 at temperatures above 650oC. The measured Seebeck coefficients for all three samples showed high positive values, between 0.9 and 1.1mV/K, in the intermediate temperature range between 350 and 550oC and, as temperature increased, decreased slowly and converted to n-type. The Figure of Merit for the thermoelectric application, zT, calculated for the three samples were orders of magnitude lower than the state-of-the-art p-type thermoelectric materials mainly due to the low values of the electrical conductivity. A rough estimate was made on the hole concentration needed to improve the value of zT for CdTe to 1.0 at 500oC. A simple interpolation and extrapolation of the present data gives the value of zT for the n-type intrinsic CdTe to be 1.2±0.4 at 1050oC.
Mapping the likelihood of koalas across New South Wales for use in Private Native Forestry: developing a simple, species distribution model that deals with opportunistic data
Authors: Predavec Martin , Lunney Daniel , Shannon Ian , Scotts Dave , Turbill John , Faulkner Bill
Published: May 2015

In Private Native Forestry in New South Wales, species-specific provisions in the code of practice are triggered by the presence of koalas (Phascolarctos cinereus), based on existing database records in the Atlas of NSW Wildlife. Whereas Species Distribution Modelling allows questions to be posed regarding the distribution of a species, and how it relates to environmental variables and threats, the key question, in many management situations, is whether or not a species is, or has been, present at a particular location, rather than the overall predicted distribution of the species. This is particularly the case for such a high-profile species as the koala. In this project, we developed a simple distribution model for the koala in New South Wales based on the proportion of koala records from within a suite of mammal records in 10 km × 10 km cells. This provides a measure of the likelihood of koalas being present. At the same time it allows deficiencies in the data to be highlighted, and recommendations made for further survey. This model and map will allow the potential for more robust and transparent decisions to be made regarding koala protection in areas proposed for private native forestry.
The reproductive biology of the introduced root holoparasite Orobanche ramosa subsp. mutelii (Orobanchaceae) in South Australia
Authors: Prider Jane
Published: May 2015

An understanding of the timing and constraints on seed production is necessary for the successful control of many invasive plant species. In the present study, we investigated the reproductive traits of the annual root holoparasite, Orobanche ramosa L. subsp. mutelii (F.W.Shultz) Cout. (branched broomrape), which occurs in the western Murray mallee area of South Australia. Flowering stems emerge above the ground from early September. Each flower spike has from 2 to 24 flowers and the first flower opens on the base 8 days after emergence and senesces 6 days later. An additional flower opens acropetally every 1–2 days. The species is autogamous and self-pollination can occur before anthesis. Mature seeds were observed from 9–10 days after flower senescence and capsules dehisced 12 days later. Although each plant is in flower only for an average of 20 days, in large populations or multi-branched plants, the flowering period extends over several weeks, with a peak in mid-October. Seed production in sampled populations was highly variable, ranging from 1000 to over 200 000 per plant. Large plants with several branching stems produced the most seeds, although capsules produced per stem and seeds per capsule were also variable. There is a brief window of opportunity for control of O. ramosa subsp. mutelii after it emerges above the soil surface and before it sets seed. Weedy root parasites such as Orobanche ramosa can have devastating impacts on host crops, but are difficult to control because most growth occurs underground. We identified key characters that contribute to the success of this introduced plant, including self-pollination, rapid maturation of the reproductive stages and high seed output. Vigilance is required so that plants can be controlled before they set seed.
Kinetic Method Analysis of the Effect of cis- and trans-Hydroxylation on the Proton Affinity of Proline
Authors: Kanchi Vinod , Shin Joong-Won
Published: May 2015

Proton affinities of proline and hydroxyproline were measured using the Cooks’ kinetic method. The measurements show that hydroxylation increases the proton affinity, which is consistent with X3LYP computation results. This work supports findings from a previous study (S. Mezzache et al., Rapid Commun. Mass Spectrom. 2005, 19, 2279) that modification of proline increases its proton affinity, but it does not provide compelling evidence for the prediction in the same study that proton affinity of the molecule is substantially influenced by intramolecular interactions involving the proton. PBE1PBE calculations suggest that isotropic polarizability rather than intramolecular hydrogen-bonding interactions provides a more suitable diagnosis for trends in proton affinity changes associated with modifications.
Nematicidal Activities of Diamides with Diphenylacetylene Scaffold Against Meloidogyne Incognita
Authors: Li Jiling , Zhang Zhicheng , Xu Xiaoyong , Shao Xusheng , Li Zhong
Published: May 2015

With the goal of searching for new potential nematicides with high activity and low toxicity, new molecules are needed as potential prototypes for the synthesis of new nematicidal compounds. A series of novel diamides based on diphenylacetylene scaffold were designed and synthesised. The conformation of the amide was restricted through the ten-membered H-bonded ring. Their structures were characterised by 1H NMR, 13C NMR, 19F NMR, and high-resolution mass spectrometry. The preliminary bioassays evaluated against Meloidogyne Incognita indicated that most of the title compounds were endowed with moderate-to-good activities at the concentration of 25 mg L–1. In particular, compounds 9a, 9c, 9g, 9h, 9k, and 9l displayed >50 % nematicidal activity at 5 mg L–1. It is possible that the novel diamides with diphenylacetylene scaffold, which possess good nematicidal activities, provide distinct nematicidal chemotypes that can be used as leads for further optimisation.
Association of a region of bovine chromosome 1 (BTA1) with age at puberty in Angus bulls
Authors: Fernández María E. , Prando Alberto , Rogberg-Muñoz Andrés , Peral-García Pilar , Baldo Andrés , Giovambattista Guillermo , Lirón Juan P.
Published: May 2015

Age at puberty is an important component of reproductive performance in cattle, so it is important to identify genes that contribute to the regulation of the onset of puberty and polymorphisms that explain differences between bulls. In a previous study, we found putative associations between age at puberty in Angus bulls and single-nucleotide polymorphisms (SNPs) in Chromosomes 1 and X. In the present work we aimed to confirm these findings in a larger sample of Angus bulls (n = 276). Four SNPs located in these regions were genotyped using SEQUENOM technology and the genotypes obtained were tested for association with age at puberty. The results showed that SNPs rs135953349 and rs110604205 on BTA1 were still significantly associated with age of puberty estimated at progressive sperm motility of 10% (P < 0.05). The association previously found on Chromosome X could not be confirmed. Analysis of the bovine genome revealed that the associated region (99.17–99.99 Mb) contained four predicted loci: myelodysplasia syndrome 1 (MDS1) and ecotropic virus integration site 1 (EVI1) complex locus (MECOM), eGF-like and EMI domain-containing 1 pseudogene-like (LOC100337483), microRNA mir-551b (MIR551B) and mCG140927-like (LOC100139843). The results obtained could contribute to the understanding of puberty regulation and could be useful for further identification and annotation of gene function in the context of reproduction.