bluuebunny/crossref_metadata_2025 huggingface dataset:
A Glutathione Derivative with Chelating and in vitro Neuroprotective Activities: Synthesis, Physicochemical Properties, and Biological Evaluation
Authors: Cacciatore Ivana , Cornacchia Catia , Fornasari Erika , Baldassarre Leonardo , Pinnen Francesco , Sozio Piera , Di Stefano Antonio , Marinelli Lisa , Dean Annalisa , Fulle Stefania , Di Filippo Ester Sara , La Rovere Rita Maria Laura , Patruno Antonia , Ferrone Alessio , Di Marco Valerio
Published: October 2013

Metal‐ion dysregulation and oxidative stress have been linked to the progressive neurological decline associated with neurodegenerative disorders such as Alzheimer’s and Parkinson’s diseases. Herein we report the synthesis and chelating, antioxidant, and in vitro neuroprotective activities of a novel derivative of glutathione, GS(HQ)H, endowed with an 8‐hydroxyquinoline group as a metal‐chelating moiety. In vitro results showed that GS(HQ)H may be stable enough to be absorbed unmodified and arrive intact to the blood–brain barrier, that it may be able to remove CuII and ZnII from the Aβ peptide without causing any copper or zinc depletion in vivo, and that it protects SHSY‐5Y human neuroblastoma cells against H2O2‐ and 6‐OHDA‐induced damage. Together, these findings suggest that GS(HQ)H could be a potential neuroprotective agent for the treatment of neurodegenerative diseases in which a lack of metal homeostasis has been reported as a key factor.
Synthesis and Biological Evaluation of Imidazopyridine–Oxindole Conjugates as Microtubule‐Targeting Agents
Authors: Kamal Ahmed , Reddy Vangala Santhosh , Karnewar Santosh , Chourasiya Sumit S. , Shaik Anver Basha , Kumar G. Bharath , Kishor Chandan , Reddy M. Kashi , Narasimha Rao M. P. , Nagabhushana Ananthamurthy , Ramakrishna Kallaganti V. S. , Addlagatta Anthony , Kotamraju Srigiridhar
Published: October 2013

A library of imidazopyridine–oxindole conjugates was synthesised and investigated for anticancer activity against various human cancer cell lines. Some of the tested compounds, such as 10 a, 10 e, 10 f, and 10 k, exhibited promising antiproliferative activity with GI50 values ranging from 0.17 to 9.31 μM. Flow cytometric analysis showed that MCF‐7 cells treated by these compounds arrested in the G2/M phase of the cell cycle in a concentration‐dependent manner. More particularly, compound 10 f displayed a remarkable inhibitory effect on tubulin polymerisation. All the compounds depolarised mitochondrial membrane potential and caused apoptosis. These results are further supported by the decreased phosphorylation of Akt at Ser473. Studies on embryonic development revealed that the lead compounds 10 f and 10 k caused delay in the development of zebra fish embryos. Docking of compound 10 f with tubulin protein suggested that the imidazo[1,2‐a]pyridine moiety occupies the colchicine binding site of tubulin.
Effect of annealing treatment on the mechanical properties and corrosion behaviors of 01570 aluminum alloy
Authors: Wang X. H. , Wang J. H. , Song J. , Fu C. W.
Published: October 2013

01570 aluminum alloy was cold rolled and annealed at different temperatures, and their microstructure, mechanical properties, pitting and stress corrosion cracking (SCC) behaviors were observed and determined by scanning electron microscopy (SEM), transmission electron microscopy (TEM), immersion test, slow strain rate tensile (SSRT), and constant loading tests. The results reveal that the dislocations within the grains of alloy 01570 are transformed from dislocation tangles to dislocation walls and subgrains as the treatment varies from the cold rolled temper to the annealed tempers; at the same time, the tensile strength and SCC resistance of alloy 01570 are increased and the elongation is decreased, whereas the corrosion rate is negligibly influenced by the annealing treatments. Therefore, the annealed at 300 °C temper can be selected as the optimum heat treatment for the practical application of alloy 01570.
Effect of carbonation process on the passivating products of zinc in Ca(OH)2 saturated solution
Authors: Roventi G. , Bellezze T. , Barbaresi E. , Fratesi R.
Published: October 2013

The effect of carbonation process on the passivating layer of zinc in Ca(OH)2 saturated solution was studied. The investigation was performed by means of corrosion potential, corrosion current density, and impedance measurements. To analyze the changes in the passivating layer, X‐ray diffraction, Raman spectroscopy and scanning electron microscopy (SEM) were utilized. The results obtained indicate that the layer of calcium hydroxyzincate (Ca[Zn(OH)3]2 · 2H2O) (CHZ), which determines the passivity state of zinc both in Ca(OH)2 saturated solution and in concrete, is destroyed by the carbonation process, in agreement with previous results obtained for galvanized steel embedded in concrete. X‐ray diffractometry and Raman spectroscopy showed that CHZ reaction with CO2 leads to the formation of Zn5(CO3)2(OH)6 (hydrozincite) and CaCO3 (calcite). SEM observation confirms the deep transformation in the passivating layer caused by carbonation. Corrosion potential and corrosion current density measurements show that zinc maintains its passive state also after carbonation. However, impedance measurements indicate that hydrozincite has lower passivating properties than calcium hydroxyzincate in the carbonated solution.
Potential change and corrosion behavior of two AlMgSi alloys with different Si content under MgCl2 drops in 33% relative humidity
Authors: Li J.‐F. , Tan X.
Published: October 2013

The Volta potential change and corrosion behaviors of alloys Al‐0.63Mg‐0.28Si and Al‐0.52Mg‐0.63Si under MgCl2 drops with the initial concentration of 0.1–1.0 M in environments with relative humidity (RH) 33% were studied using a Kelvin probe (KP). For the alloy Al‐0.63Mg‐0.28Si, the Volta potential curve was mainly featured with many potential transients in the form of a sudden drop followed by an immediate recovery along the potential baseline at a higher potential value of −0.35 to −0.5 VSHE, which were associated with initiation and repassivation of metastable pits with diameter less than 3 μm. For the alloy Al‐0.52Mg‐0.63Si containing excess Si particles, the potential curve was featured with potential change in the form of slow increase followed by a sudden drop along the potential baseline at a lower potential value of about −0.7 VSHE. The sudden potential drop and stabilizing at the lower potential level were associated with corrosion initiation and growth, respectively. In the case of lower initial concentration and higher Si content leading to excess Si particles, the corrosion rating was higher. However, the excess Si particles showed a greater impact than the initial concentration.
Laboratory corrosion testing of coatings and substrates simulating coal combustion under a low NOx burner atmosphere
Authors: Agüero A. , Gutiérrez M. , Muelas R. , Plana D. , Román A. , Hernández M.
Published: October 2013

It is certainly a difficult task to evaluate new materials and coatings to be used for boilers in power plants, as conditions are extremely complex, comprising a highly erosive environment, high temperature, highly corrosive gases, and reactive deposits. In particular, early catastrophic failures, as well as higher degradation rates have been observed on different power plant boiler components when operating under atmospheres containing low levels of oxygen. These atmospheres are typical of low NOx burners, and can be more corrosive than normal oxidizing conditions. The presence of a sulfidizing atmosphere as well as ash deposits present in boilers, are in part responsible of this accelerated damage. In this work, testing under a low oxygen atmosphere has been carried out on T22 and P92 uncoated and coated specimens. The atmosphere was equal to that measured in a Spanish coal‐fired power plant (ENDESA, Compostilla, León) and the test temperature was 580 °C. Tested coatings were slurry applied aluminides, as well as two HVOF sprayed coatings including a commercially deposited Cr2C3NiCr, and a newly developed Cr2O3‐Cr composite coating. The specimens were covered with ash (taken from the plant) prior to testing. After testing, the uncoated substrates exhibited high thickness oxides with some sulfide inclusions whereas all tested coatings were very protective. Exposed samples of T22 tubes employed in the Compostilla power plants were analyzed and compared with the corresponding specimens tested in the laboratory. In both cases, the scales contained Fe3O4 and FeS but the sulfide content was significantly higher in the scale formed in the plant. Moreover, ash particles were found embedded in the both scales.
Highly transparent and flexible field electron emitters based on hybrid carbon nanostructure
Authors: Ghosh Debasish , Ghosh Pradip , Noda Takuto , Hayashi Yasuhiko , Tanemura Masaki
Published: October 2013

We demonstrate a unique strategy to fabricate highly transparent and flexible field electron emitters (FEEs) based on combined carbon nanostructures, i.e., conical nanocarbon structures (CNCSs) and single‐walled carbon nanotubes (SWNTs). The combined structure was prepared by spray coating of 1,2‐dichloroethane (DCE) dispersed SWNTs onto neon ion (Ne+) irradiation induced CNCSs on nafion substrate. The field emission (FE) property of SWCNTs on both flat nafion and CNCSs surfaces increased with increasing the SWCNTs amount. The best FE result was attained for the highest amount of SWCNTs on the CNCSs substrate. This kind of collective structures is found to be effective emitters on transparent and flexible ion‐irradiated nafion substrate. Moreover, the combined carbon nanostructures showed improved transparency and emission performance compared to the individual nanostructures. The FE properties of 0.5 ml SWCNTs solution on CNCSs surfaces were equal to those of 1.5 ml SWCNTs solution on flat nafion surface. The hybrid structure based emitters (CNCSs and SWCNTs) produced by this method are lower‐cost cathode materials than hybrid structures of SWCNTs and flat nafion. Thus the combined nanostructures of SWCNTs/CNCSs might have huge prospects for the fabrication of efficient transparent and flexible FEEs and their broad application in next‐generation portable display devices. (© 2013 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Genetic Polymorphisms in the APOA1 Gene and their Relationship with Serum HDL Cholesterol Levels
Authors: Bandarian Fatemeh , Hedayati Mehdi , Daneshpour Maryam Sadat , Naseri Mohsen , Azizi Fereidoun
Published: September 2013

Low high density lipoprotein cholesterol (HDL‐C) is a known risk factor of coronary artery disease. Apolipoprotein A1 (APOA1) is the most abundant component of HDL‐C. This study aimed at identifying sequence variations (rare and common) in the APOA1 gene and its association with serum HDL‐C levels. This study was conducted from April 2012 to February 2013 on 79 Tehranians (participants of Tehran Lipid and Glucose Study) with extremely low HDL‐C (within the 5th percentile) and 63 individuals with extremely high HDL‐C (within the 95th percentile) levels. After DNA amplification by PCR, DNA sequencing of all three exons and 700 bps of promoter region of the APOA1 gene was performed. Sequence results were analyzed and interpreted using the appropriate software and variants were identified. After sequencing 42 common and rare variants were identified, 11 of which were known variants and the others had been unreported so far. Of the exonic variants, 11 were missense, 6 were synonymous and 1 was nonsense. There was a significant association between serum HDL‐C and variant of rs2070665 as well as variants Chr.11:116707788, Chr.11:116708059, Chr.11:116708036, Chr.11:116707729, rs201148448, Chr.11:116707018, Chr.11:116707801, Chr.11:116708530, Chr.11:116708088, rs121912724 and Chr.11:116706966 (p < 0.001). Variants Chr.11:116707018, rs121912724 and 2070665 were independent predictors of the HDL‐C level (p < 0.001). SNP Chr.11:116707018 was the strongest predictor of the HDL‐C level (OR 7.527, p < 0.001). This study identified 42 variants in APOA1 gene, 31 of which were new variants. Three variants of rs2070665, rs121912724 and Chr.11:116707018 could predict the HDL‐C level independently. Variant rs2070665 was protective against low‐HDL‐C levels while variants rs121912724 and Chr.11:116707018 were risk factors for that in our population.
The Effect of Capacity, Rotational Speed and Storage on Crystallization and Rheological Properties of Puff Pastry Butter
Authors: Rønholt S. , Kirkensgaard J. J. K. , Høyer K. F. , Mortensen K. , Knudsen J. C.
Published: September 2013

In the margarine and butter industry, sustainable and more efficient refrigerants, such as CO2, are introduced to industrial scraped surface heat exchangers, allowing an increased capacity compared to conventional use of NH3. The effect of such changes in capacity and a varied rotational speed was studied in relation to the structural behavior of puff pastry butter during 4 weeks of isothermal storage at 20 °C. The physical properties of the fat crystal network were studied in detail at several length scales by combining X‐ray diffraction with differential scanning calorimetry, confocal laser scanning microscopy, LR‐NMR and rheology. Our data shows that a high capacity combined with high rotational speed decreases the brittleness of puff pastry butter after 7 days of storage. This effect is, however, diminished after 28 days of storage. Likewise, changes in capacity and rotational speed are shown to induce no microstructural and polymorphic differences after 28 days of storage. However, the degree of work softening is related to the manufacturing conditions: a high capacity and a high rotational speed increase the ability of the puff pastry butter to resist structural breakdown during working. With this being the only observed difference; a wide operational window exists on an industrial level to produce puff pastry butter with similar structural behavior.
Gaston Bachelard et Albert Flocon. La rencontre d'un philosophe avec un graveur
Authors: Rheinberger Hans-Jörg
Published: October 2013

Cet article porte sur la collaboration entre le philosophe des sciences Gaston Bachelard et le graveur sur cuivre Albert Flocon durant la première décennie suivant la Seconde Guerre mondiale. De leurs échanges résultèrent plusieurs ouvrages dont le contenu est analysé ici.
Some Remarks on the Internal Consistency of Online Consumer Reviews
Authors: Schindler Diana , Decker Reinhold
Published: September 2013

In recent years, online consumer reviews (OCRs) have developed into a popular topic of qualitative and quantitative marketing research. Depending on the platform they arise from, OCRs can be composed of an overall star rating, explicit pros and cons, free text comments and a recommendation indicator. This paper examines whether these components provide consistent information regarding the evaluated product. Insights about the internal consistency of this form of electronic word-of-mouth (eWOM) can be useful in consumer-oriented marketing strategies, complaint management as well as product development and improvement. By using a regression analysis framework the correlative relationships between star rating and recommendation are studied, as well as the effects that posted advantages and disadvantages, stated either explicitly or implicitly, have on these two types of product evaluations. The available results clearly support the view of OCRs as a consistent database for marketing research concerning eWOM. However, they also show that a combined consideration of all components can remarkably increase the information obtainable from this data source.
Who Caucuses? An Experimental Approach to Institutional Design and Electoral Participation
Authors: Karpowitz Christopher F. , Pope Jeremy C.
Published: September 2013

During the 2008 presidential campaign, the question of mass participation in primaries and caucuses became unusually salient, with a close Democratic race calling special attention to these often overlooked procedural elements of America's democratic system. This study adds a new element to scholarship on institutional design and citizen participation by way of a survey-based experiment conducted in the midst of the 2008 campaign. The results show that institutional choices are not neutral. Nominating candidates through caucuses rather than primaries not only reduces the number of participants, but also significantly affects the ideological composition of the electorate. Caucuses produce a more ideologically consistent electorate than do primaries, because policy centrists appear to avoid caucuses. This experimental finding is strongly buttressed by the observational data on Obama and Clinton voters.
Intervention and colonial-modernity: decolonising the Italy/Ethiopia conflict through Psalms 68:31
Authors: SHILLIAM ROBBIE
Published: September 2013

In this article I utilise the editors' conceptual frame of sovereignty/intervention/transnational social forces to argue that the relationship that ensues between these phenomena has to be understood in colonial-modern – rather than modern – terms. I thereby argue that intervention is a distinctive technology of colonial-modern rule, specifically, one that erects and polices the difference between sovereign and quasi-sovereign entities via a standard of civilisation. Additionally, I argue that transnational social forces struggle – cognitively, socially, and politically – over the upholding or refuting of this standard; and in this struggle, some might even defend particular sovereign entities against colonial interventions. I demonstrate my argument by explicating the global colonial context of the Italy/Ethiopia conflict in 1935–6, the nadir of the interwar crisis. I ‘decolonise’ received interpretations of the conflict through the heuristic of two differing catechisms of Psalms 68:31 proffered at the time: one, invoking a civilising mission of Africans; the other, invoking a project of self-liberation by Africans.
Determinants of child malnutrition in rural and urban Ecuadorian highlands
Authors: Ortiz Johana , Van Camp John , Wijaya Sylviana , Donoso Silvana , Huybregts Lieven
Published: September 2013

Objective

To identify and compare the sociodemographic determinants of stunting, wasting and overweight among infants of urban and rural areas in the Ecuadorian highlands.

Design

Cross-sectional study.

Setting

Nabon (rural) and Cuenca (urban) cantons, Azuay Province, Ecuador.

Subjects

A total of 703 children aged 0–24 months and their caregivers (227 rural and 476 urban) recruited during the period from June to September 2008.

Results

Stunting prevalence was significantly higher in the rural area (37·4 %v. 17·7 %;P< 0·001) while wasting (7·1 %) and overweight (17·1 %) prevalence were more similar between areas. Determinants of stunting for the pooled sample were male gender (OR = 1·43; 95 % CI 1·06, 1·92;P= 0·02), preterm delivery (OR = 1·65; 95 % CI 1·14, 2·38;P= 0·008), child's age (OR = 1·04; 95 % CI 1·01, 1·07;P= 0·011), maternal education (OR = 0·95; 95 % CI 0·92, 0·99;P= 0·025) and facility-based delivery (OR = 0·57; 95 % CI 0·45, 0·74;P< 0·001). The latter was also a determinant of overweight (OR = 0·39; 95 % CI 0·25, 0·62;P< 0·001). Rural determinants of stunting were maternal height (OR = 0·004; 95 % CI 0·00004, 0·39;P= 0·018), diarrhoea prevalence (OR = 2·18; 95 % CI 1·13, 4·21;P= 0·02), socio-economic status (OR = 0·79; 95 % CI 0·64, 0·98;P= 0·030) and child's age (OR = 1·07; 95 % CI 1·02, 1·11;P= 0·005). Urban determinants were: maternal BMI for stunting (OR = 0·91; 95 % CI 0·84, 0·99;P= 0·027), cough prevalence (OR = 0·57; 95 % CI 0·34, 0·96;P= 0·036) and facility-based delivery (OR = 0·25; 95 % CI 0·09, 0·73;P= 0·011) for overweight, and hygiene for wasting (OR = 0·57; 95 % CI 0·36, 0·89;P= 0·013).

Conclusions

Infant malnutrition was associated with different sociodemographic determinants between urban and rural areas in the Ecuadorian highlands, a finding which contributes to prioritize the determinants to be assessed in nutritional interventions.
THE PARTIAL-ISOMETRIC CROSSED PRODUCTS BY SEMIGROUPS OF ENDOMORPHISMS AS FULL CORNERS
Authors: ADJI SRIWULAN , ZAHMATKESH SAEID
Published: September 2013

Suppose that ${\Gamma }^{+ } $ is the positive cone of a totally ordered abelian group $\Gamma $, and $(A, {\Gamma }^{+ } , \alpha )$ is a system consisting of a ${C}^{\ast } $-algebra $A$, an action $\alpha $ of ${\Gamma }^{+ } $ by extendible endomorphisms of $A$. We prove that the partial-isometric crossed product $A\hspace{0.167em} { \mathop{\times }\nolimits}_{\alpha }^{\mathrm{piso} } \hspace{0.167em} {\Gamma }^{+ } $ is a full corner in the subalgebra of $\L ({\ell }^{2} ({\Gamma }^{+ } , A))$, and that if $\alpha $ is an action by automorphisms of $A$, then it is the isometric crossed product $({B}_{{\Gamma }^{+ } } \otimes A)\hspace{0.167em} {\mathop{\times }\nolimits }^{\mathrm{iso} } \hspace{0.167em} {\Gamma }^{+ } $, which is therefore a full corner in the usual crossed product of system by a group of automorphisms. We use these realizations to identify the ideal of $A\hspace{0.167em} { \mathop{\times }\nolimits}_{\alpha }^{\mathrm{piso} } \hspace{0.167em} {\Gamma }^{+ } $ such that the quotient is the isometric crossed product $A\hspace{0.167em} { \mathop{\times }\nolimits}_{\alpha }^{\mathrm{iso} } \hspace{0.167em} {\Gamma }^{+ } $.
Nuclear targeting of dystroglycan promotes the expression of androgen regulated transcription factors in prostate cancer
Authors: Mathew G. , Mitchell A. , Down J. M. , Jacobs L. A. , Hamdy F. C. , Eaton C. , Rosario D. J. , Cross S. S. , Winder S. J.
Published: September 2013

Dystroglycan is frequently lost in adenocarcinoma, but the mechanisms and consequences are poorly understood. We report an analysis of β-dystroglycan in prostate cancer in human tissue samples and in LNCaP cells in vitro. There is progressive loss of β-dystroglycan immunoreactivity from basal and lateral surfaces of prostate epithelia which correlates significantly with increasing Gleason grade. In about half of matched bone metastases there is significant dystroglycan re-expression. In tumour tissue and in LNCaP cells there is also a tyrosine phosphorylation-dependent translocation of β-dystroglycan to the nucleus. Analysis of gene expression data by microarray, reveals that nuclear targeting of β-dystroglycan in LNCaP cells alters the transcription of relatively few genes, the most unregulated being the transcription factor ETV1. These data suggest that proteolysis, tyrosine phosphorylation and translocation of dystroglycan to the nucleus resulting in altered gene transcription could be important mechanisms in the progression of prostate cancer.
Medium-term Outcomes of Cemented Prostheses and Cementless Modular Prostheses in Revision Total Hip Arthroplasty
Authors: Wang Long , Lei Pengfei , Xie Jie , Li Kanghua , Dai Zixun , Hu Yihe
Published: September 2013

There is an increasing trend towards cementless modular femoral prostheses for revision hip replacement surgery, especially in patients with severe proximal femoral bone defects. However, for minor femoral bone defects, the benefit of cementless modular is not clear. We designed a retrospective cross-sectional study to compare outcomes of the two femoral implant designs. There were no significant differences in terms of visual analog pain scores, Harris hip scores, femoral bone restoration, stem subsidence, leg length correction, or overall complication rate. Three femoral reoperations (11%) occurred in the cemented group and two (9%) in the cementless modular group. One femoral stem re-revised (4%) in the cemented group due to recurrent deep infection. Five-year survival for femoral reoperation was 88.2% for patients with the cemented implant and 91.3% for cementless group. Both groups had good clinical and radiological outcomes for femoral revision in patients with minor femoral bone defects during medium-term follow-up.
Bottom-Up Catalytic Approach towards Nitrogen-Enriched Mesoporous Carbons/Sulfur Composites for Superior Li-S Cathodes
Authors: Sun Fugen , Wang Jitong , Chen Huichao , Qiao Wenming , Ling Licheng , Long Donghui
Published: October 2013

We demonstrate a sustainable and efficient approach to produce high performance sulfur/carbon composite cathodes via a bottom-up catalytic approach. The selective oxidation of H2S by a nitrogen-enriched mesoporous carbon catalyst can produce elemental sulfur as a by-product which in-situ deposit onto the carbon framework. Due to the metal-free catalytic characteristic and high catalytic selectivity, the resulting sulfur/carbon composites have almost no impurities that thus can be used as cathode materials with compromising battery performance. The layer-by-layer sulfur deposition allows atomic sulfur binding strongly with carbon framework, providing efficient immobilization of sulfur. The nitrogen atoms doped on the carbon framework can increase the surface interactions with polysulfides, leading to the improvement in the trapping of polysulfides. Thus, the composites exhibit a reversible capacity of 939 mAh g−1 after 100 cycles at 0.2 C and an excellent rate capability of 527 mAh g−1 at 5 C after 70 cycles.
Multiple spectra of electron spin resonance in chiral molecule-based magnets networked by a single chiral ligand
Authors: Mito M. , Nagano T. , Tsuruta K. , Deguchi H. , Takagi S. , Kishine J. , Yoshida Y. , Inoue K.
Published: October 2013

A molecule-based magnet [Cr(CN)6][Mn(R/S)-pnH(H2O)](H2O) (termed R/S-GN) is a chiral crystal without an inversion center and mirror reflection, and its structural network is constructed using a chiral ligand diaminopropane (R/S)-pn. In S-GN, multiple spectra of ESR were observed below the magnetic ordering temperature by Morgunov et al. [Phys. Rev. B 77, 184419 (2008)]. They concluded that the phenomenon at the high field side occurred because the incommensurate magnetic structure resulted in a length-controllable superlattice of domain walls (the so-called chiral soliton lattice, CSL) under a dc magnetic field H applied perpendicular to the magnetic chiral axis. However, there multiple spectra were observed even for H nearly parallel to the chiral axis, a-axis, and their interpretation is unreasonable. Thus, we conducted an X-band electron spin resonance (ESR) measurement of R-GN under conditions similar to those of their experiment and performed Fourier spectrum analyses for the data of R-GN as an approach of physical characterization. By using two Lorentz spectra, the main ESR spectra for H // a were reproduced, and furthermore two prominent periodic modes were found by spectrum analyses based on Fourier transform. Two characteristic periods, p1 and p2 (<p1), are related by p1 = 2p2, and the temperature dependence of the multiplicity can be physically characterized with those of p1 and p2. The unique spectra observed below the magnetic ordering temperature are due not to hyperfine structure but magnetic fine structure, and it certainly originates from the existence of plural nonequivalent magnetic sites. Thus, it is unreasonable to consider CSL to explain the multiple ESR spectra observed independently of the field direction, whereas the observed complex spectra appeal wealthy scientific potentiality in chiral crystals.
Low-energy inverse photoemission spectroscopy using a high-resolution grating spectrometer in the near ultraviolet range
Authors: Yoshida Hiroyuki
Published: October 2013

An inverse photoemission spectroscopy (IPES) apparatus using a Czerny-Turner grating spectrometer is demonstrated. Previous IPES instruments based on grating spectrometers used a concave grating and operated in the vacuum ultraviolet range. The reflectance of such gratings is lower than 20% and the aberration cannot be finely corrected leading to an energy resolution of up to 0.1 eV. In the present study, employing the low energy IPES regime [H. Yoshida, Chem. Phys. Lett. 539–540, 180 (2012)], incident electrons with a kinetic energy below 5 eV are used, while photon emission in the range of between 250 and 370 nm is analyzed with a 10-cm Czerny-Turner grating spectrometer. The signal intensity is at least 30 times higher than the previous apparatus. The resolution of photon detection is set at 0.07 eV though the ultimate resolution is one order of magnitude higher. The experiment is performed both by sweeping the electron energy (isochromat mode) and by simultaneously analyzing the photon of whole wavelength range (tunable photon energy mode).
Reproducing continuous radio blackout using glow discharge plasma
Authors: Xie Kai , Li Xiaoping , Liu Donglin , Shao Mingxu , Zhang Hanlu
Published: October 2013

A novel plasma generator is described that offers large-scale, continuous, non-magnetized plasma with a 30-cm-diameter hollow structure, which provides a path for an electromagnetic wave. The plasma is excited by a low-pressure glow discharge, with varying electron densities ranging from 109 to 2.5 × 1011 cm−3. An electromagnetic wave propagation experiment reproduced a continuous radio blackout in UHF-, L-, and S-bands. The results are consistent with theoretical expectations. The proposed method is suitable in simulating a plasma sheath, and in researching communications, navigation, electromagnetic mitigations, and antenna compensation in plasma sheaths.
Impact of a binary Ga2Se3 precursor on ternary CuGaSe2 thin-film and solar cell device properties
Authors: Ishizuka Shogo , Yamada Akimasa , Fons Paul J. , Shibata Hajime , Niki Shigeru
Published: October 2013

CuGaSe2 (CGS) thin-films grown by the three-stage coevaporation process using various Se-fluxes during each growth stage exhibited distinctive properties different from those grown with a constant Se-flux during all three stages. CGS grain size, growth orientation, and the depletion width in solar cell devices were found to depend strongly on the Ga2Se3 precursor formed during the first stage, whereas photo-absorption spectra and device parameters were largely determined by the Se-flux used during the second and third stages when the CGS film near-surface region was formed. A certified efficiency exceeding 10% demonstrated for a ternary CGS solar cell is also reported.
A microfluidic device for simultaneous measurement of viscosity and flow rate of blood in a complex fluidic network
Authors: Jun Kang Yang , Yeom Eunseop , Lee Sang-Joon
Published: October 2013

Blood viscosity has been considered as one of important biophysical parameters for effectively monitoring variations in physiological and pathological conditions of circulatory disorders. Standard previous methods make it difficult to evaluate variations of blood viscosity under cardiopulmonary bypass procedures or hemodialysis. In this study, we proposed a unique microfluidic device for simultaneously measuring viscosity and flow rate of whole blood circulating in a complex fluidic network including a rat, a reservoir, a pinch valve, and a peristaltic pump. To demonstrate the proposed method, a twin-shaped microfluidic device, which is composed of two half-circular chambers, two side channels with multiple indicating channels, and one bridge channel, was carefully designed. Based on the microfluidic device, three sequential flow controls were applied to identify viscosity and flow rate of blood, with label-free and sensorless detection. The half-circular chamber was employed to achieve mechanical membrane compliance for flow stabilization in the microfluidic device. To quantify the effect of flow stabilization on flow fluctuations, a formula of pulsation index (PI) was analytically derived using a discrete fluidic circuit model. Using the PI formula, the time constant contributed by the half-circular chamber is estimated to be 8 s. Furthermore, flow fluctuations resulting from the peristaltic pumps are completely removed, especially under periodic flow conditions within short periods (T < 10 s). For performance demonstrations, the proposed method was applied to evaluate blood viscosity with respect to varying flow rate conditions [(a) known blood flow rate via a syringe pump, (b) unknown blood flow rate via a peristaltic pump]. As a result, the flow rate and viscosity of blood can be simultaneously measured with satisfactory accuracy. In addition, the proposed method was successfully applied to identify the viscosity of rat blood, which circulates in a complex fluidic network. These observations confirm that the proposed method can be used for simultaneous measurement of viscosity and flow rate of whole blood circulating in the complex fluid network, with sensorless and label-free detection. Furthermore, the proposed method will be used in evaluating variations in the viscosity of human blood during cardiopulmonary bypass procedures or hemodialysis.
Transport characteristics and colossal dielectric response of cadmium sulfide nanoparticles
Authors: Ahmad Mushtaq , Rafiq M. A. , Hasan M. M.
Published: October 2013

We report here the synthesis of ∼20 nm sized cadmium sulfide (CdS) nanoparticles via conventional solid state reaction at low temperature ∼200 °C and ambient pressure. X-ray diffraction and high resolution transmission electron microscopy analysis confirmed the synthesis of hexagonal phased nanoparticles. Impedance and electrical modulus investigations were carried out in the frequency range 20 Hz to 2 MHz and at temperature from 300 K to 400 K, which show the presence of bulk, grain boundary, and sub-grain boundary phases in CdS nanoparticles. Overlapped large polaron tunneling was the observed mechanism of charge carriers in used temperature range. The presence of colossal dielectric constant in the system is attributed to the Maxwell-Wagner type polarization. High and temperature dependent dielectric constants make the CdS nanoparticles efficient material to be used in capacitive energy storage devices.
Controlling intensity and phase of terahertz radiation with an optically thin liquid crystal-loaded metamaterial
Authors: Buchnev O. , Wallauer J. , Walther M. , Kaczmarek M. , Zheludev N. I. , Fedotov V. A.
Published: October 2013

We experimentally demonstrate intensity and phase modulation of terahertz radiation using an actively controlled large-area planar metamaterial (metafilm) hybridized with a 12 μm thick layer of a liquid crystal. Active control was introduced through in-plane electrical switching of the liquid crystal, which enabled to achieve a reversible single-pass absolute transmission change of 20% and a phase change of 40° at only 20 V.
Electrical tunability of soft parametric resonance by hot electrons in graphene
Authors: Sekwao Samwel , Leburton Jean-Pierre
Published: October 2013

We show that the onset of soft parametric resonance (SPR) at ω=ηωF, where ωF=eFovf/ℏωOP for hot carriers interacting with optic phonons ℏωOP in graphene is independent of temperature, whereas η ∼ 0.56 is practically independent of the DC field Fo, which makes SPR tunable over a sizeable range of Fo. Our model based on the linearization of the time-dependent Boltzmann transport equation (BTE) predicts a secondary resonance at ω∼ωF, emerging from a weak shoulder in the ac current at T = 300 K, when the temperature decreases to T = 77 K and lower. The two resonances behave differently as scattering at low energy strengthens.
Retention of resistance states in ferroelectric tunnel memristors
Authors: Kim D. J. , Lu H. , Ryu S. , Lee S. , Bark C. W. , Eom C. B. , Gruverman A.
Published: October 2013

Resistive properties of Co/BaTiO3/La2/3Sr1/3MnO3 ferroelectric tunnel junctions on (110) NdGaO3 substrates are investigated. A notable characteristic of these junctions is the memristive behavior—a dependence of resistance on amplitude and duration of a writing pulse, which is attributed to field-induced charge accumulation at the Co/BaTiO3 interface. It is found that retention of the resistance states depends on the thickness of the ferroelectric barrier: the junctions with the thinnest 4-unit-cell-thick BaTiO3 barrier exhibit significant relaxation of the low resistance state while the junctions with thicker barriers exhibit stable resistance. It is proposed that, in a thinner barrier, a larger depolarizing field triggers a faster dissipation of the accumulated charges, resulting in a recovery of interfacial tunnel barrier height and gradual transition from a low to a high resistance state.
Structure of intermediate shocks in collisionless anisotropic Hall-magnetohydrodynamics plasma models
Authors: Sánchez-Arriaga G.
Published: October 2013

The existence of discontinuities within the double-adiabatic Hall-magnetohydrodynamics (MHD) model is discussed. These solutions are transitional layers where some of the plasma properties change from one equilibrium state to another. Under the assumption of traveling wave solutions with velocity C and propagation angle θ with respect to the ambient magnetic field, the Hall-MHD model reduces to a dynamical system and the waves are heteroclinic orbits joining two different fixed points. The analysis of the fixed points rules out the existence of rotational discontinuities. Simple considerations about the Hamiltonian nature of the system show that, unlike dissipative models, the intermediate shock waves are organized in branches in parameter space, i.e., they occur if a given relationship between θ and C is satisfied. Electron-polarized (ion-polarized) shock waves exhibit, in addition to a reversal of the magnetic field component tangential to the shock front, a maximum (minimum) of the magnetic field amplitude. The jumps of the magnetic field and the relative specific volume between the downstream and the upstream states as a function of the plasma properties are presented. The organization in parameter space of localized structures including in the model the influence of finite Larmor radius is discussed.
Electrostatic waves in carbon nanotubes with an axial magnetic field
Authors: Abdikian Alireza , Bagheri Mehran
Published: October 2013

Based on a linearized hydrodynamic model and within the quasi-static approximation, the dispersion relation of electrostatic waves propagating through single-walled carbon nanotubes subject to an axial magnetic field is theoretically explored. In the classical limit, we obtain two main possible waves which in turn are divided into two branches, a low-frequency acoustical and a high-frequency optical plasmon branch. In the quantum case, we have found that the dispersion relation is substantially modified when the electron wavelength becomes large enough compared to the propagation wavelength of the electrostatic waves in the quantum plasma. We also show that the axial magnetic field manifest itself on the perturbed electron density through the quantum term and gives rise to the propagation of the electrostatic waves within the quantum plasma. As a result, the effect of the magnetic field is pronounced in the plasma dispersion relations in such a way that their curves approach to zero when the magnetic field is weak; and for the strong magnetic field, they asymptotically meet the constant lines.
ZnO nanoparticle-protein interaction: Corona formation with associated unfolding
Authors: Bhunia A. K. , Samanta P. K. , Saha S. , Kamilya T.
Published: October 2013

The interaction as well as the formation of bioconjugate of Bovine Serum Albumin (BSA) and Zinc Oxide nanoparticles (ZnO NPs) is investigated. The surface binding along with reorganization of BSA on the surface of ZnO NPs forms stable “hard corona.” The time constants for surface binding and reorganization are found to be 1.10 min and 70.68 min, respectively. The close proximity binding of BSA with ZnO NPs via tryptophan is responsible for bioconjugate formation. Fibrillar aggregated structure of BSA is observed due to conformational change of BSA in interaction with ZnO NPs.
Highly enhanced ultraviolet photosensitivity and recovery speed in electrospun Ni-doped SnO2 nanobelts
Authors: Huang Siya , Matsubara Kohei , Cheng Jing , Li Heping , Pan Wei
Published: October 2013

Precisely controlled Ni-doped SnO2 (NSO) nanobelt arrays are synthesized and assembled via electrospinning. In comparison to pristine SnO2 nanobelts, enhanced photosensitivity (∼103) as well as recovery speed (∼1 s) is obtained in NSO nanobelts. The mechanism is clarified by the compensation effect of acceptor impurity Ni, which not only promotes the oxygen-surface interaction but also introduces trapping centers in SnO2 matrix. The reduced grain size (∼4 nm) along with increased depletion layer thickness also benefits the photosensitivity of NSO nanobelts. These improved photoresponse properties make the NSO nanobelt a promising candidate for high-performance ultraviolet detectors.
Memory device application of wide-channel in-plane gate transistors with type-II GaAsSb-capped InAs quantum dots
Authors: Liao Yu-An , Chao Yi-Kai , Chang Shu-Wei , Chang Wen-Hao , Chyi Jen-Inn , Lin Shih-Yen
Published: October 2013

We demonstrate room-temperature electron charging/discharging phenomena of InAs quantum dots using wide-channel in-plane gate transistors. The device based on type-II GaAsSb-capped InAs quantum dots exhibits both the longer charging and discharging times than those of the type-I counterpart with GaAs capping layers. The slow charge relaxation of GaAsSb-capped InAs quantum dots and simple architecture of in-plane gate transistors reveal the potential of this device architecture for practical memory applications.
Strain-induced self-assembly of Ge nanodashes, nanodumbbells, and dot chains on Si(001)
Authors: Zhang J. J. , Schmidt O. G.
Published: October 2013

We investigate the growth of self-assembled Ge nanostructures on top of embedded Ge nanowires on Si(001) substrates. Ge nanostructures, such as nanodashes, nanodumbbells, and dot chains are observed simply by tuning the growth temperature and thickness of the Si spacer between the Ge layers. The self-assembly process is governed by the surface strain fields generated by the embedded Ge nanowires and is well-described by our theoretical calculations. The catalyst-free and horizontal growth of such Ge nanostructures directly on Si(001) is attractive for investigating exotic transport properties through Si/Ge-based quantum devices.
Structure-induced negatively skewed X-ray diffraction pattern of carbon onions
Authors: Siklitskaya Alexandra , Yastrebov Sergey , Smith Roger
Published: October 2013

The idea is discussed that a gradual change of intershell separation in carbon onions may introduce a negative skewness into the most intense X-ray diffraction band. As an example, the experimental X-ray diffraction pattern of carbon onions is analysed using a weighted Lorentzian X-ray profile broadening model for each intershell separation contributing to the profile. The dependence of the mean radius for carbon onion shells on the intershell spacing between the adjacent shells is derived from the model analysis. Comparison with the internal distribution of atomic density in carbon onions measured with high resolution transmission electron microscopy is discussed.
Coupling parameter series expansion for fluid with square-well plus repulsive-square-barrier potential
Authors: Zhou Shiqi , Solana J. R.
Published: October 2013

Monte Carlo simulations in the canonical ensemble are performed for fluid with potential consisting of a square-well plus a square-barrier to obtain thermodynamic properties such as pressure, excess energy, constant volume excess heat capacity, and excess chemical potential, and structural property such as radial distribution function. The simulations cover a wide density range for the fluid phase, several temperatures, and different combinations of the parameters defining the potential. These simulation data have been used to test performances of a coupling parameter series expansion (CPSE) recently proposed by one of the authors [S. Zhou, Phys. Rev. E 74, 031119 (2006)], and a traditional 2nd-order high temperature series expansion (HTSE) based on a macroscopic compressibility approximation (MAC) used with confidence since its introduction in 1967. It is found that (i) the MCA-based 2nd-order HTSE unexpectedly and depressingly fails for most situations investigated, and the present simulation results can serve well as strict criteria for testing liquid state theories. (ii) The CPSE perturbation scheme is shown to be capable of predicting very accurately most of the thermodynamic properties simulated, but the most appropriate level of truncating the CPSE differs and depends on the range of the potential to be calculated; in particular, the shorter the potential range is, the higher the most appropriate truncating level can be, and along with rising of the potential range the performance of the CPSE perturbation scheme will decrease at higher truncating level. (iii) The CPSE perturbation scheme can calculate satisfactorily bulk fluid rdf, and such calculations can be done for all fluid states of the whole phase diagram. (iv) The CPSE is a convergent series at higher temperatures, but show attribute of asymptotic series at lower temperatures, and as a result, the surest asymptotic value occurs at lower-order truncation.
Activity patterns and roosting of the eastern blossom-bat (Syconycteris australis)
Authors: Drury Rebecca L. , Geiser Fritz
Published: September 2013

We quantified activity patterns, foraging times and roost selection in the eastern blossom-bat (Syconycteris australis) (body mass 17.6 g) in coastal northern New South Wales in winter using radio-telemetry. Bats roosted either in rainforest near their foraging site of flowering coast banksia (Banksia integrifolia) and commuted only 0.3 ± 0.1 km (n = 8), whereas others roosted 2.0 ± 0.2 km (n = 4) away in wet sclerophyll forest. Most bats roosted in rainforest foliage, but in the wet sclerophyll forest cabbage palm leaves (Livistonia australis) were preferred roosts, which likely reflects behavioural thermoregulation by bats. Foraging commenced 44 ± 22 min after sunset in rainforest-roosting bats, whereas bats that roosted further away and likely flew over canopies/open ground to reach their foraging site left later, especially a female roosting with her likely young (~4 h after sunset). Bats returned to their roosts 64 ± 12 min before sunrise. Our study shows that S. australis is capable of commuting considerable distances between appropriate roost and foraging sites when nectar is abundant. Bats appear to vary foraging times appropriately to minimise exposure to predators and to undertake parental care.
Chemical composition of cuticular waxes during fruit development of Pingguoli pear and their potential role on early events of Alternaria alternata infection
Authors: Li Yongcai , Yin Yan , Chen Songjiang , Bi Yang , Ge Yonghong
Published: September 2013

To elucidate the role of fruit wax in fungal infection, changes in chemical composition of wax during fruit development of Pingguoli pear, and their role in Alternaria alternata infection were studied. Results showed that wax content increased during fruit development. Fruit harvested 130 days after full bloom (DAFB) had a peak wax content that was eight times higher than from fruit at 100 DAFB. There were differences in the relative chain-length distribution of wax classes during development. Alkanes were major components during early development, whereas alkanes and triterpenoids predominated during late development. Results of in vitro tests showed that conidial germination and mycelial growth of A. alternata could be inhibited by wax extracted from the fruit surface at different developmental stages. These results shed new light on the chemical basis for wax involvement in fungal infection.