bluuebunny/crossref_metadata_2025 huggingface dataset:
Cr/4H‐SiC Schottky contacts investigated by electrical and photoelectron spectroscopy techniques
Authors: Koliakoudakis C. , Dontas J. , Karakalos S. , Kayambaki M. , Ladas S. , Konstantinidis G. , Zekentes K. , Kennou S.
Published: October 2008

Cr/4H‐SiC Schottky contacts were investigated by standard electrical measurements and photoelectron spectroscopy. XPS (X‐ray Photoelectron Spectroscopy) measurements were performed during the in‐situ formation of the metal‐semiconductor interface formation as well as after several annealing steps of the Cr/4H‐SiC contact. A barrier height of 1.2 eV was determined from XPS measurements. The electrical measurements have showed the necessity of thermal annealing at 600 °C to obtain best performance (ΦB = 1.05 eV from C‐V measurements and 0.94 eV from I‐V measurements with ideality factor n = 1.08). (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
First‐principles study of the structural and electronic properties of the α modification of zinc diphosphide
Authors: Fan Chao‐Lei , Cheng Xin‐Lu , Zhang Hong
Published: October 2008

First‐principles calculations are carried out to investigate the structural and electronic properties of the α modification of zinc diphosphide (α‐ZnP2). We use the conjugate gradient (CG) minimization method, in which both the local density approximation (LDA) and the generalized gradient approximation (GGA) as implemented in the SIESTA code are employed. The ground state properties such as the lattice parameters, bulk modulus, pressure derivative of the bulk modulus at zero pressure, bond lengths and bond angles are determined and compared with the available experimental data. The energy band structure and electron density of states (DOS) of α‐ZnP2 are also presented. By analyzing the electronic band structure, a band gap of 1.91 eV is obtained. Based on the study of properties of α‐ZnP2 at high pressure, it is found that the structural and electronic properties of α‐ZnP2 at high pressure are quite stable. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
First‐principles study on the boron antimony compound
Authors: Cui Shouxin , Feng Wenxia , Hu Haiquan , Feng Zhenbao
Published: October 2008

The structural, electronic, elastic and optical properties of the boron antimony (BSb) compound are investigated by first‐principles pseudopotential method. The calculations show the structural phase transition from the zincblende (ZB) to the rocksalt (RS) structures at the transition pressure of 56 GPa and with a volume reduction of 13%. The ground‐state, electronic and optical properties, i.e. the lattice constant, elastic constants, band structure, reflectivity and the refractive index, are calculated using the plane‐wave pseudopotential method within the density functional theory. We discuss our results and compare them with other theoretical studies. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Enhanced Raman scattering in grooved silicon matrix
Authors: Mamichev D. A. , Timoshenko V. Yu. , Zoteyev A. V. , Golovan L. A. , Krutkova E. Yu. , Laktyunkin A. V. , Kashkarov P. K. , Astrova E. V. , Perova T. S.
Published: October 2008

Multiple enhancement of the Stokes Raman scattering in grooved silicon structures, which consist of sequences of voids (grooves) and crystalline Si walls, was observed under excitation with wavelength close to the Si wall width of ∼1 μm. The results obtained are interpreted as a manifestation of the partial light localization within the grooved structures, which increases the effective volume of the medium interacting with excitation light. Based on this effect, we conclude that grooved silicon structures can act as a matrix for increasing the Raman scattering efficiency of different substances embedded into the grooves. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Direct determination of intrinsic Inx Ga1–xP (x = 0.49) band‐gap deformation potentials by cathodoluminescence piezo‐spectroscopy
Authors: Porporati Alessandro Alan , Furukawa Naohide , Zhu Wenliang , Pezzotti Giuseppe
Published: October 2008

We determined to a degree of precision the complete set of three deformation potentials of zinc‐blende‐like (intrinsic) Inx Ga1–x P (x = 0.49) and found that their variation with chemical composition does not follow a linear rule‐of‐mixture between values of InP and GaP, as usually assumed in the published literature. Measurements were made according to a microscopic cathodoluminescence piezo‐spectroscopic (CL/ PS) procedure, previously calibrated for paradigm materials, which deformation potentials are known according to macroscopic calibration calibration procedures. The procedure followed in this study allowed us to obtain the desired deformation potential values directly on a thin film (i.e., without the need of a bulk sample), by exploiting the high spatial resolution of the electron probe. Microscopic strain fields were used, which were preliminary introduced by a pyramidal indentation print on the surface of the epitaxially grown film. The methodology enabled accurate deformation potential assessments in small material volumes for both tensile and compressive stress fields. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Cluster perturbation study of 1D electron–hole Hubbard model
Authors: Asano Kenichi , Nishida Takuto , Ogawa Tetsuo
Published: October 2008

We studied the quarter‐filled electron–hole Hubbard model of one dimension using the cluster perturbation method. We found that the ground states of this system are always insulating as long as the electron–hole attractive interaction has a finite value. The calculated density of states for the electron and hole is significantly renormalized by the interaction, and show energy gaps at the Fermi energy. These gaps are induced by the excitonic mechanism at U > U ′ and by the biexcitonic one at U < U ′, where U (> 0) denotes the electron–electron and hole–hole repulsive interaction, and U ′(< 0) denotes the electron–hole attractive interaction. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Comparative study of excitonic structures and luminescence properties of Bi4Ge3O12 and Bi12GeO20
Authors: Itoh Minoru , Katagiri Tsuyoshi , Mitani Hiroyuki , Fujita Masami , Usuki Yoshiyuki
Published: October 2008

Measurements of reflection, emission‐excitation, luminescence decay kinetics, and X‐ray photoelectron of Bi4Ge3O12 and Bi12GeO20 crystals have been performed, in addition to relativistic molecular orbital calculations. Both materials consist of the same elements but form different crystal structures. Based on the obtained results, the excitonic reflection structures and luminescence properties of Bi4Ge3O12 and Bi12GeO20 are discussed in comparison with each other. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Optical evaluation of electron and hole g ‐factors in single quantum dots
Authors: Kaji R. , Yamada K. , Sasakura H. , Adachi S.
Published: October 2008

Precise optical evaluation of electron and hole g ‐factors in single InAlAs quantum dot was performed by using the optical pumping of nuclear magnetic field and its bistable behavior. The measurement is based on the fact that the induced nuclear field is effective only on electrons and can compensate the external magnetic field. The experimental results indicate that the effective electron g ‐factor can change in large magnitude including the sign in a controllable manner. Therefore, the method will be useful for the spin manipulation experiments such as photon‐spin qubit conversion. In addition, the in‐plane electron and hole g ‐factors were measured in Voigt geometry. This is the first report of individual g ‐factors of electron and hole in single InAlAs/AlGaAs quantum dots, which have been reported so far by only a few studies about the exciton g ‐factor. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Excitons in a perfect quasi‐1D organic quantum wire, an isolated polydiacetylene chain
Authors: Legrand Laurent , Choueiry Antoine Al , Holcman Jérémy , Enderlin Alexandre , Melet Romain , Barisien Thierry , Voliotis Valia , Grousson Roger , Schott Michel
Published: October 2008

The exciton in single luminescent polydiacetylene (PDA) chains dispersed in their single crystal monomer matrix is studied. As reported these quantum wires have the properties of a perfect quasi‐1D semiconducting system.

The macroscopic spatial coherence of a single exciton state on a chain as a function of temperature is investigated using an interference experiment. The interference pattern contrast decreasing with increasing temperature is non zero up to 30 K.

Experiments developed in order to observe the regime of formation of the stationary coherent exciton state are described. Within the time resolution of the experiment, it is concluded that the formation of this state is faster than ∼5 picoseconds which confirms the assumption of a transient regime.

Finally the first steps of the manipulation of phase locked excitonic wave‐packets on a PDA wire are discussed. The experimental results measured in a weak exciton‐photon coupling regime are compared to simulations obtained through the Bloch optical equations in the framework of a three‐levels model. A direct estimate of the coherence time of the vibronic state photocreated in the present non resonant scheme is derived. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Negative linear thermal expansion of oblique‐angle (monoclinic and triclinic) crystals as a common case
Authors: Filatov Stanislav K.
Published: October 2008

The traditional principle of the mid‐twentieth century that ‘stronger chemical bonds imply a weaker thermal expansion' appeared to be valid for cubic crystals but failed to explain many cases of real high anisotropic thermal expansion of non‐cubic crystals. In particular, the discovery, a quarter of a century ago, of the frequent occurrence of negative linear thermal expansion in monoclinic and triclinic crystals was unexpected. For this reason, it is necessary to consider an additional principle of thermal expansion (symmetrical rearrangement of a crystal structure with temperature). According to both principles, the value of thermal expansion is dictated by the strength of chemical bonds, and the anisotropy of thermal expansion is determined mainly by the tendency of crystal symmetry to increase upon heating, etc. The last 25 years have proved to be a test and development period of thermal expansion theory. The principles mentioned above are considered in the light of their present‐day advancements. This allows us to achieve a better understanding of real thermal expansion. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Gas management through thick macroporous and mesoporousmacroporous membranes
Authors: Desplobain S. , Gautier G. , Gharbage N. , Ventura L. , Roy M.
Published: October 2008

Among all the potential applications of porous silicon, gas or liquid management through membranes is a key point in various micro‐system applications. In this paper, we compare the hydrogen flow through two different porous silicon structures. The first one is a 240 µm thick macroporous silicon membrane with pore diameters between 2 and 3 µm. The second one is a combination of a macroporous layer surmounted by a mesoporous one (average pore diameters of 10 nm). We present also a new method achieving the pore opening on the whole backside surface of the sample. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Thick microporous silicon isolation layers for integrated RF inductors
Authors: Gautier G. , Leduc P. , Semai J. , Ventura L.
Published: October 2008

In this paper, we present processes to etch high thickness porous silicon layers for RF device applications. Indeed, on‐chip inductors realized on bulk silicon suffer from mediocre Q‐factor values mainly because of electrical losses into the substrate and capacitive coupling with the silicon appearing beyond 1 GHz. We present a detailed study of etching parameters such as the current density or the HF concentration in HF: H2O:acetic acid based electrolytes. In addition, we propose a prospective study of integrated copper inductor performances on porous silicon substrates in the range of 100 MHz to 10 GHz. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
The effect of crystallization technology and gate insulator deposition method on the performance and reliability of polysilicon TFTs
Authors: Moschou Despina C. , Kontogiannopoulos Giannis P. , Kouvatsos Dimitrios N. , Voutsas Apostolos T.
Published: October 2008

Polysilicon TFTs were fabricated using solid phase crystallization (SPC) and also two different excimer laser annealing techniques (ELA) for polysilicon crystallization. Moreover, we tried two different gate oxide deposition methods, using PECVD or TEOS LPCVD. Comparing the characteristics of the fabricated TFTs, we were able to probe the effects of the polysilicon crystallization techniques and the gate oxide deposition methods on TFT performance and reliability. This way, an optimization of the TFT fabrication procedure could be possible. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Investigation of top gate electrode options for high‐k gate dielectric MOS capacitors
Authors: Moschou D. C. , Verrelli E. , Kouvatsos D. N. , Normand P. , Tsoukalas D. , Speliotis A. , Bayiati P. , Niarchos D.
Published: October 2008

Capacitors with a high‐k HfO2film as gate dielectric were fabricated, using three different variations for the top gate electrode. This way it was possible to acquire important information on which kind of gate material should be used in combination with HfO2as a gate insulator for optimum performance of possible low temperature applications, such as high‐k TFTs. The variations of gate electrode were e‐gun evaporated Al, sputtered W and CVD polysilicon followed by ion implantation and annealing. The capacitors were then characterized with capacitance‐voltage measurements and current‐voltage measurements. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Porous anodic alumina thin films on Si: interface characterization
Authors: Gianneta V. , Nassiopoulou A. G. , Krontiras C. A. , Georga S. N.
Published: October 2008

Porous anodic alumina (PAA) thin films (thickness ∼ 50nm) were fabricated on Si by anodization of thin Al films under constant voltage of 20 V in sulphuric acid aqueous solution. The films exhibit cylindrical vertical pores of diameter ∼ 13–15 nm, arranged in hexagonal close packed structure. Electrochemical oxidation of the Si substrate through PAA, used as masking layer with openings in the pores, resulted in the formation of SiO2 dots at each pore tip. Two different kinds of films, namely with or without SiO2 dots at pore tips, were fabricated. In order to characterize the electrical quality of the interface of PAA thin films with Si, C‐V and G‐V measurements were performed on Metal‐Insulator‐Semiconductor (MIS) structures with Al metallization. The measurements were carried out in the voltage range +1.0 V to –3.0 V in steps of 0.05 V and in the frequency range 1 MHz to 100 Hz. The typical form of C‐V and G‐V curves of a MIS structure was obtained. In order to determine the interface trap density Dit, C‐f and G‐f measurements were performed as a function of the applied gate voltage in the depletion region. Dit was evaluated following the Conductance Method (E. H. Nicollian, and J. R. Brews, MOS Physics and Technology (J. Wiley & Sons, New York, 1982), p. 222 [1]). Both types of samples exhibit values of Dit in the order of 1011 eV–1cm–2. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Evaluation of a gas flow sensor implemented on organic substrate
Authors: Petropoulos A. , Kaltsas G. , Speliotis T. , Nassiopoulou A.G.
Published: October 2008

In this paper we present results of the evaluation of a thermal gas flow sensor device implemented on a printed circuit board (PCB) substrate by a combination of PCB and MEMs technologies. The device consists of 3 parallel Pt strip resistors in direct electrical contact to patterned copper tracks of the PCB. For planarization purposes, the Pt strips reside on a thick polymer layer (SU8). The central resistor plays the role of a heater and the two other resistors, situated symmetrically on both sides of the heater, are temperature dependent sensing elements. The three main advantages of this specific sensor are: the low thermal conductivity of the substrate materials (FR4 and SU8, with thermal conductivity ∼0.2 W(m·K)) which permits high sensitivity at low power, its robustness compared to suspended membrane sensors and its simple fabrication process. The sensor can operate in both hot wire and calorimetric modes. The sensor was mounted inside a 1.5m long tube with 25 mm2 cross sectional area and was evaluated in nitrogen flow up to 100 SLPM, which corresponds to Reynolds numbers up to 25.000. The sensor signal in both the calorimetric and the hot‐wire modes is a monotonous function of the flow rate. A very high sensitivity is obtained in the calorimetric mode at very low flow rates (<0.05SLPM), while the sensor signal in the hot‐wire mode appears to be a linear function of the flow rate throughout the entire measurement region. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
FeNi alloys electroplated into porous (n‐type) silicon
Authors: Ouir S. , Sam S. , Fortas G. , Gabouze N. , Beldjilali K. , Tighilt F.
Published: October 2008

We report here a study on the electrodeposition of FeNi alloys into porous silicon (PS) made in n‐type Si substrate. The electrodeposited thin films were characterized by scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS) and X‐ray diffraction (XRD). The results show that the morphology, composition and structure of the deposited FeNi alloys are strongly dependent on the deposition conditions. A tubular structure of the FeNi alloys can be obtained with a chemical composition of (80%) Ni (20%) Fe. Finally, SEM characterization shows that a good filling of pores with FeNi alloy is achieved. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Nanowire manipulation on surfaces through electrostatic self‐assembly and magnetic interactions
Authors: Bellino Martín G. , Calvo Ernesto J. , Gordillo Gabriel J.
Published: October 2008

A method for fabricating aligned nanowire arrays on surfaces is shown. Gold and segmented Au/Ni/Au nanowires of high aspect ratio have been prepared by template electrosynthesis, and functionalized with charged short alkanethiols that can be ionized in aqueous solutions. Different distributions of funtionalized nanowires could be obtained on large surfaces from nanowire aqueous suspensions, avoiding aggregation due to electrical repulsion. Due to the high magnetic anisotropy of segmented Au/Ni/Au nanowires chaining of aligned nanowires could be obtained by applying a low magnetic field. While electrostatics favours side wire interactions due to the high aspect ratio, concurrent electrostatics and applied magnetic field yields end‐to‐end interaction and linear alignment without bifunctionalization. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Antinociceptive peripheral effect ofAchillea millefoliumL. andArtemisia vulgarisL.: both plants known popularly by brand names of analgesic drugs
Authors: Pires Júlia Movilla , Mendes Fúlvio R. , Negri Giuseppina , Duarte‐Almeida Joaquim M. , Carlini Elisaldo A.
Published: October 2008

The hydroalcohol extracts ofAchillea millefoliumL. (AM) andArtemisia vulgarisL. (AV), both belonging to the Asteraceae family, were evaluated by the hot plate, writhing, formalin and intestinal transit tests in an attempt to confirm their folk use as analgesic, antiinflammatory and antispasmodic agents. AM 500 and 1000 mg/kg significantly inhibited abdominal contortions by 65% and 23%, respectively, whereas AV 500 and 1000 mg/kg inhibited them by 48% and 59%, respectively. None of the extracts produced differences in the intestinal transit in mice, nor in the response time in the hot plate or in the immediate or late responses in the formalin test. In HPLC/DAD analyses ‘fingerprint’, monitored at 360 and 270 nm, both hydroalcohol extracts showed the same flavonoid glycoside as a principal constituent, which was identified as rutin. A high content of caffeic acid derivatives were also found in both extracts. The main differences were observed at 240 nm: AM had a higher content of rutin, while in AV the hydroxybenzoic acid derivative was the major component. Copyright © 2008 John Wiley & Sons, Ltd.
Antiobesity effect of ginsenoside Rg3 involves the AMPK and PPAR‐γ signal pathways
Authors: Hwang Jin‐Taek , Lee Myoung‐Su , Kim Hyun‐Jin , Sung Mi‐Jeong , Kim Hye Young , Kim Myung Sunny , Kwon Dae Young
Published: October 2008

Ginsenosides, the active component of ginseng, exerts antidiabetic and anticancer effects. This study investigated the molecular basis of ginsenoside Rg3, a red ginseng rich constituent, focusing on its ability to inhibit adipocyte differentiation in 3T3‐L1 cells. The data show that ginsenoside Rg3 was effective in the inhibition of adipocyte differentiation. This inhibitory effect of ginsenoside Rg3 on adipocyte differentiation was accompanied by PPAR‐γ inhibition in rosiglitazone‐treated cells. The study also tested whether AMP‐activated protein kinase (AMPK) activation was involved in the inhibitory effects of ginsenoside Rg3. AMPK plays a role in maintaining health in the context of diseases such as type 2 diabetes, obesity and cancer. AMPK was reported to control nutritional and hormonal signal modulating. Rg3 significantly and time‐dependently activated AMPK. Taken together, these results suggest that the antiobesity effect of red ginseng rich constituent, ginsenoside Rg3, involves the AMPK signaling pathway and PPAR‐γ inhibition. Copyright © 2008 John Wiley & Sons, Ltd.
Improving effects of the mushroom Yamabushitake (Hericium erinaceus) on mild cognitive impairment: a double‐blind placebo‐controlled clinical trial
Authors: Mori Koichiro , Inatomi Satoshi , Ouchi Kenzi , Azumi Yoshihito , Tuchida Takashi
Published: October 2008

A double‐blind, parallel‐group, placebo‐controlled trial was performed on 50‐ to 80‐year‐old Japanese men and women diagnosed with mild cognitive impairment in order to examine the efficacy of oral administration of Yamabushitake (Hericium erinaceus), an edible mushroom, for improving cognitive impairment, using a cognitive function scale based on the Revised Hasegawa Dementia Scale (HDS‐R). After 2 weeks of preliminary examination, 30 subjects were randomized into two 15‐person groups, one of which was given Yamabushitake and the other given a placebo. The subjects of the Yamabushitake group took four 250 mg tablets containing 96% of Yamabushitake dry powder three times a day for 16 weeks. After termination of the intake, the subjects were observed for the next 4 weeks. At weeks 8, 12 and 16 of the trial, the Yamabushitake group showed significantly increased scores on the cognitive function scale compared with the placebo group. The Yamabushitake group's scores increased with the duration of intake, but at week 4 after the termination of the 16 weeks intake, the scores decreased significantly. Laboratory tests showed no adverse effect of Yamabushitake. The results obtained in this study suggest that Yamabushitake is effective in improving mild cognitive impairment. Copyright © 2008 John Wiley & Sons, Ltd.
Characterization of Mixtures Part 1: Prediction of Infinite‐Dilution Activity Coefficients Using Neural Network‐Based QSPR Models
Authors: Ajmani Subhash , Rogers Stephen C. , Barley Mark H. , Burgess Andrew N. , Livingstone David J.
Published: October 2008

The major problem in building QSAR/QSPR models for mixtures lies in their characterization. It has been shown that it is possible to construct QSPR models for the density of binary liquid mixtures using simple mole fraction weighted physicochemical descriptors. Such parameters are unsatisfactory; however, from the point of view of interpretation of the resultant models. In this paper, an alternative mechanism‐based approach to the characterization of mixtures has been investigated. It has been shown that while it is not possible to build significant linear models using these descriptors, it has been possible to construct satisfactory artificial neural network models. The performance of these models and the importance of the individual descriptors are discussed.
Identification of Novel CDK2 Inhibitors by QSAR and Virtual Screening Procedures
Authors: Babu Padavala Ajay , Smiles Dondapati Jesse , Narasu Mangamoori Laxmi , Srinivas Kolli
Published: October 2008

Quantitative Structure–Activity Relationship (QSAR) studies were carried out on a set of 46 imidazo[1,2‐a]pyridines, imidazo[1,2‐b]pyridazines and 2,4‐bis anilino pyrimidines, and nitroso‐6‐aminopyrimidine and 2,6‐diaminopyrimidine inhibitors of CDK2 (Cyclin‐dependent Kinase2) using a multiple regression procedure. The activity contributions of these compounds were determined from regression equation and the validation procedures such as external set cross‐validation r2, (R2cv,ext) and the regression of observed activities against predicted activities and vice versa for validation set were described to analyze the predictive ability of the QSAR model. An accurate and reliable QSAR model involving five descriptors was chosen based on the FIT Kubinyi function which defines the statistical quality of the model. The proposed model due to its high predictive ability was utilized to screen similar repertoire of compounds reported in the literature, and the biological activities are estimated. The screening study clearly demonstrated that the strategy presented shall be used as an alternative to the time‐consuming experiments as the model tolerated a variety of structural modifications signifying its potential for drug design studies.
Surface modification of polyester by oxygen‐ and nitrogen‐plasma treatment
Authors: Vesel Alenka , Junkar Ita , Cvelbar Uros , Kovac Janez , Mozetic Miran
Published: October 2008

In this paper, we present a study on the surface modification of polyethyleneterephthalate (PET) polymer by plasma treatment. The samples were treated by nitrogen and oxygen plasma for different time periods between 3 and 90 s. The plasma was created by a radio frequency (RF) generator. The gas pressure was fixed at 75 Pa and the discharge power was set to 200 W. The samples were treated in the glow region, where the electrons temperature was about 4 eV, the positive ions density was about 2 × 1015 m−3, and the neutral atom density was about 4 × 1021 m−3 for oxygen and 1 × 1021 m−3 for nitrogen. The changes in surface morphology were observed by using atomic force microscopy (AFM). Surface wettability was determined by water contact angle measurements while the chemical composition of the surface was analyzed using XPS. The stability of functional groups on the polymer surface treated with plasma was monitored by XPS and wettability measurements in different time intervals. The oxygen‐plasma‐treated samples showed much more pronounced changes in the surface topography compared to those treated by nitrogen plasma. The contact angle of a water drop decreased from 75° for the untreated sample to 20° for oxygen and 25° for nitrogen‐plasma‐treated samples for 3 s. It kept decreasing with treatment time for both plasmas and reached about 10° for nitrogen plasma after 1 min of plasma treatment. For oxygen plasma, however, the contact angle kept decreasing even after a minute of plasma treatment and eventually fell below a few degrees. We found that the water contact angle increased linearly with the O/C ratio or N/C ratio in the case of oxygen or nitrogen plasma, respectively. Ageing effects of the plasma‐treated surface were more pronounced in the first 3 days; however, the surface hydrophilicity was rather stable later. Copyright © 2008 John Wiley & Sons, Ltd.
Newly developed high spatial resolution X‐ray microscope equipped with carbon nanotube field emission cathode
Authors: Yabushita Ryosuke , Hata Koichi
Published: October 2008

An X‐ray microscope equipped with a multiwalled carbon nanotube (MWCNT) cathode was developed. This system has ordinary scanning electron microscopy functions available for the precise adjustment of focusing conditions including astigmatism and an alignment of an electron beam. Owing to the adoption of a transmission type, X‐ray images with high magnification can be easily obtained. The diameter of an electron probe, which is one of the factors limiting a spatial resolution of X‐ray microscopes, was estimated to be ca 50 nm from a resolution of obtained SEM images. X‐ray images were taken as a demonstration of the X‐ray microscope and clear images with a resolution higher than 700 nm were successfully obtained. Copyright © 2008 John Wiley & Sons, Ltd.
Nanostructured black cobalt coatings for solar absorbers
Authors: Abdel Hamid Z. , Abdel Aal A. , Schmuki P.
Published: October 2008

Nanocrystalline black cobalt electrically deposited onto a steel substrate from aqueous solution was investigated. The influence of electrolyte composition and operating parameters on the appearance and optical properties of the coat was studied. The deposition conditions that ensure the highest solar absorptance were optimized. The chemical composition of fabricated thin films before and after annealing at 400 °C was determined by energy dispersive X‐ray analysis (EDS) and XPS technique. The crystal structure analysis showed that the bulk composition of the films was mainly cobalt oxide. The surface analysis reveals that the topmost surface layers of the films are made of different cobalt compounds confirming the multivalence state of Co on the surface with an oxidation state of ≥ + 2. Scanning electron microscope (SEM) observation indicated that the surface morphology was changed from dendritic structure to lamellar at higher current density. The black cobalt film showed soft magnetic characteristicsand excellent optical properties to transform solar energy into thermal energy. Copyright © 2008 John Wiley & Sons, Ltd.
A New Bio‐Inspired Route to Metal‐Nanoparticle‐Based Heterogeneous Catalysts
Authors: Debecker Damien P. , Faure Chrystel , Meyre Marie‐Edith , Derré Alain , Gaigneaux Eric M.
Published: October 2008

Onion‐type multilamellar vesicles are made of concentric bilayers of organic surfactant and are mainly known for their potential applications in biotechnology. They can be used as microreactors for the spontaneous and controlled production of metal nanoparticles. This process does not require any thermal treatment and, hence, it is also attractive for material sciences such as heterogeneous catalysis. In this paper, silver‐nanoparticle‐based catalysts are prepared by transferring onion‐grown silver nanoparticles onto inorganic supports. The resulting materials are active in the total oxidation of benzene, attesting that this novel bio‐inspired concept is promising in inorganic catalysis.
Nanostructured Surfaces and Assemblies as SERS Media
Authors: Ko Hyunhyub , Singamaneni Srikanth , Tsukruk Vladimir V.
Published: October 2008

Metallic nanostructures attract much interest as an efficient media for surface‐enhanced Raman scattering (SERS). Significant progress has been made on the synthesis of metal nanoparticles with various shapes, composition, and controlled plasmonic properties, all critical for an efficient SERS response. For practical applications, efficient strategies of assembling metal nanoparticles into organized nanostructures are paramount for the fabrication of reproducible, stable, and highly active SERS substrates. Recent progress in the synthesis of novel plasmonic nanoparticles, fabrication of highly ordered one‐, two‐, and three‐dimensional SERS substrates, and some applications of corresponding SERS effects are discussed.

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Rod‐Shaped Nanocrystals Elicit Neuronal Activity In Vivo
Authors: Malvindi Maria Ada , Carbone Luigi , Quarta Alessandra , Tino Angela , Manna Liberato , Pellegrino Teresa , Tortiglione Claudia
Published: October 2008

The development of novel nanomaterials has raised great interest in efforts to evaluate their effect on biological systems, ranging from single cells to whole animals. In particular, there exists an open question regarding whether nanoparticles per se can elicit biological responses, which could interfere with the phenomena they are intended to measure. Here it is reported that challenging the small cnidaria Hydra vulgaris in vivo with rod‐shaped semiconductor nanoparticles, also known as quantum rods (QRs), results in an unexpected tentacle‐writhing behavior, which is Ca2+ dependent and relies on the presence of tentacle neurons. Due to the absence of surface functionalization of the QRs with specific ligands, and considering that spherical nanoparticles with same composition as the QRs fail to induce any in vivo behavior on the same experimental model, it is suggested that unique shape‐tunable electrical properties of the QRs may account for the neuronal stimulation. This model system may represent a widely applicable tool for screening neuronal response to nanoparticles in vivo.
Mesocrystals: A New Class of Solid Materials
Authors: Zhou Lei , O'Brien Paul
Published: October 2008

Possible types of, and formation mechanisms for, mesocrystals are summarized. Mesocrystals are a new class of solid materials, which can be regarded as assemblies of crystallographically oriented nanocrystals. Mesocrystals have high crystallinity as well as high porosity, making them promising substitutes for single‐crystalline and/or porous polycrystalline materials in many applications such as catalysis, sensing, and solar‐energy conversion.
Turkish grade 10 students' and science teachers' conceptions of nature of science: A national study
Authors: Dogan Nihal , Abd‐El‐Khalick Fouad
Published: October 2008

This study aimed to assess grade 10 Turkish students' and science teachers' conceptions of nature of science (NOS) and whether these conceptions were related to selected variables. These variables included participants' gender, geographical region, and the socioeconomic status (SES) of their city and region; teacher disciplinary background, years of teaching experience, graduate degree, and type of teacher training program; and student household SES and parents' educational level. A stratified sampling approach was used to generate a representative national sample comprising 2,087 students and 378 science teachers. After establishing their validity in the Turkish context, participants were administered a questionnaire comprising 14 modified “Views on Science‐Technology‐Society” (VOSTS) items to assess their views of certain aspects of NOS. A total of 2,020 students (97%) and 362 teachers (96%) completed the questionnaire. Participant responses were categorized as “naïve,” “have merit,” or “informed,” and the frequency distributions for these responses were compared for various groupings of participants. The majority of participants held naïve views of a majority of the target NOS aspects. Teacher views were mostly similar to those of their students. Teacher and student views of some NOS aspects were related to some of the target variables. These included teacher graduate degree and geographical region, and student household SES, parent education, and SES of their city and geographical region. The relationship between student NOS views and enhanced economic and educational capitals of their households, as well as the SES status of their cities and geographical regions point to significant cultural (specifically Western) and intellectual underpinnings of understandings about NOS. © 2008 Wiley Periodicals, Inc. J Res Sci Teach 45: 1083–1112, 2008
Pup development and maternal behavior in captive Key Largo woodrats (Neotoma floridana smalli)
Authors: Alligood Christina A. , Wheaton Catharine J. , Forde Holly M. , Smith Kathleen N. , Daneault Andre J. , Carlson Robert C. , Savage Anne
Published: October 2008

This study describes the first systematic observations of maternal behavior and pup development of captive Key Largo woodrats (Neotoma floridana smalli) during the first 30 days of life. Data were collected on six litters of pups born to four dams between December 2006 and July 2007. Gestations for the six litters averaged 38 days and all dams exhibited adequate maternal care postpartum. Key Largo woodrat maternal and pup behavior was generally consistent with behavior observed in other woodrat species. We observed greater pup independence from the dam and a marked change in social interactions between days 13–22. No sex differences in pup development or maternal care were observed. Activity budgets were consistent across dams and across days within the observation period. Although dams spent much of their time inactive with pups attached to their teats, the average percent of intervals with at least one pup observed attached decreased steadily during the 30‐day observation period. Attachment of pups to the dams' teats did not interfere with dams' ability to forage. Feeding with pups attached and feeding following active detachment of pups were both common. Dams were observed to actively detach pups by performing a circular turning motion. This information has application for the future management of this endangered species in captivity and in the wild. Zoo Biol 27:394–405, 2008. © 2008 Wiley‐Liss, Inc.
N‐terminal region of α‐synuclein is essential for the fatty acid‐induced oligomerization of the molecules
Authors: Karube Hiroki , Sakamoto Masahiro , Arawaka Shigeki , Hara Susumu , Sato Hiroyasu , Ren Chang-Hong , Goto Saori , Koyama Shingo , Wada Manabu , Kawanami Toru , Kurita Keiji , Kato Takeo
Published: October 2008

Exposure of α‐synuclein (αS), a major component of Lewy bodies in Parkinson's disease, to polyunsaturated fatty acids (PUFAs) triggers the formation of soluble αS oligomers. Here, we demonstrate that PUFA binds recombinant αS protein through its N‐terminal region (residues 2–60). In HEK293 cells, αS mutants lacking the N‐terminal region failed to form oligomers in the presence of PUFA. The PUFA‐induced αS oligomerization was accelerated by C‐terminal truncation or Ser129 phosphorylation of αS; however, this effect was abolished by deletion of the N‐terminus. The results indicate that the N‐terminus of αS is essential for the PUFA‐induced αS oligomerization.
Effects of α‐tocopherol (vitamin E) on the stability and lipid dynamics of model membranes mimicking the lipid composition of plant chloroplast membranes
Authors: Hincha Dirk K.
Published: October 2008

Tocopherol (vitamin E) is widely recognized as a cellular antioxidant. It is essential for human and animal health, but only synthesized in photosynthetic organisms, where it is localized in chloroplast membranes. While many studies have investigated non‐antioxidative effects of tocopherol on phospholipid membranes, nothing is known about its effects on membranes containing chloroplast glycolipids. Here, liposomes resembling plant chloroplast membranes were used to investigate the effects of α‐tocopherol on vesicle stability during freezing and on lipid dynamics. α‐Tocopherol had a pronounced influence on membrane dynamics and showed strong interactions in its effects on membrane stability during freezing with the cryoprotectant sucrose. α‐Tocopherol showed maximal effects at low concentrations (around 2 mol%), close to its contents in chloroplast membranes.
Beyond fit and attitude: The effect of emotional attachment on consumer responses to brand extensions
Authors: Fedorikhin Alexander , Park C. Whan , Thomson Matthew
Published: October 2008

In two studies employing fictitious and real brands, this paper shows that brand attachment goes beyond attitude and fit in determining consumers' behavioral reactions to brand extensions such as purchase intentions, willingness to pay, word‐of‐mouth, and forgiveness. The effect is pronounced at high and moderate, but not low levels of fit. The paper also shows that attachment has an impact on the extent to which the extension is categorized as a member of the parent brand family, which partially mediates attachment's effects.
Effect of recombinant human thyroid stimulating hormone on serum thyroxin and thyroid scintigraphy in euthyroid cats
Authors: van Hoek Ingrid M. , Peremans Kathelijne , Vandermeulen Eva , Duchateau Luc , Gommeren Kris , Daminet Sylvie
Published: October 2008

This study investigated the thyroidal response to administration of recombinant human thyroid stimulating hormone (rhTSH) by means of serum total thyroxine (TT4) concentration and pertechnetate uptake by the thyroid gland in six healthy euthyroid spayed female cats. A pertechnetate scan was performed on day 1 to calculate thyroid/salivary gland (T/S) uptake ratio. On day 3, 25 μg rhTSH was injected intravenously. Six hours later the thyroid scan was repeated as on day 1. Blood was drawn for serum TT4 measurement prior to injection of rhTSH and performance of the pertechnetate scan. Statistically significant differences in mean serum TT4 concentration, T/S uptake ratio before and 6 h after rhTSH administration and T/S uptake ratio between left and right lobes were noted. We can conclude that 25 μg rhTSH increases pertechnetate uptake in the thyroid glands of cats, this should be taken into account when thyroid scintigraphy after rhTSH administration is interpreted.
The Last Day of a Fortified Classic Maya Center: Archaeological Investigations at Aguateca, Guatemala
Authors: Inomata Takeshi
Published: October 2008

Archaeological investigations at Aguateca, Guatemala, by the Petexbatun Regional Archaeological Project have provided clues to the intriguing sequence of the downfall of this Maya center. The earliest substantial occupation at Aguateca dates to the Late Preclassic period. After very little presence during the Early Classic period, Aguateca rapidly grew into a densely occupied center, probably at the beginning of the eighth century a.d. Migration from other areas may have contributed to this rapid population growth. In the late eighth century, extensive defensive walls were constructed, most likely as a response to intensified warfare. Despite this defensive effort, Aguateca was finally attacked and brought down by enemies probably at the beginning of the ninth century. The center appears to have been almost completely abandoned soon after this event. This reconstructed sequence confirms other evidence of the Petexbatun Project that intensified warfare played an important role in the Classic Maya collapse.
Belastungserleben und Bewältigungsstrategien bei pflegenden Angehörigen von demenziell erkrankten türkischen Migranten/-innen
Authors: Küçük Filiz
Published: October 2008

Dieser Beitrag stellt die Teilergebnisse einer qualitativen Studie zum Erleben von pflegenden Angehörigen demenziell erkrankter türkischer Migranten/-innen in Berlin vor. Mittels problemzentrierter Interviews mit sieben pflegenden (Enkel-)Töchtern und Söhnen wurden Daten zum Belastungserleben und zu den Bewältigungsstrategien in der Pflegesituation erhoben und mit der strukturierenden Inhaltsanalyse ausgewertet. Die Aussagen der fünf befragten Frauen und der zwei befragten Männer zeigen, dass Schuldgefühle, fehlende Anerkennung im bzw. fehlende Unterstützung durch das familiäre Umfeld als psychische Belastungen empfunden werden. Ebenso wirken sich zunehmende soziale Isolation und stärkere Beeinträchtigungen der Privatsphäre negativ auf das Belastungserleben aus. Entlastungs- bzw. Bewältigungsstrategien sind das Wissen über die Krankheit und ihre Symptome, Sozialkontakte und Gespräche, der Glaube, die innere und äußere Distanzierung sowie die Artikulation und das Ausleben von Emotionen ( Piechotta 2007, S. 2 ).
Antidementiva aus der Sicht von Pflegekräften
Authors: Schramm Kai , Fleischmann Ulrich M.
Published: October 2008

Die Wirksamkeit von Antidementiva, wie AChE-Inhibitoren oder NMDA-Rezeptorantagonisten zur Behandlung der Alzheimer-Demenz ist anhand zahlreicher Studien belegt. Ihr Einsatz wird zur symptomatischen Behandlung von Hirnleistungsstörungen in einschlägigen Therapieleitlinien ausdrücklich empfohlen. Das ärztliche Verschreibungsverhalten wird bis heute diesen Leitlinien nicht gerecht. Mehrere unabhängige Studien legen nahe, dass der überwiegende Teil der Demenzpatienten in Deutschland unterversorgt ist. Etwa 40 %, d. h. ca. 270 000 der Alterspatienten mit Alzheimer-Demenz werden in Deutschland derzeit in Einrichtungen der stationären Altenpflege versorgt. Nach Hallauer, Bienstein, Lehr & Rönsch (2005 ) stellen in diesen Einrichtungen fast ausschließlich Pflegekräfte den Kontakt zu den behandelnden Ärzten her. Ihnen kommt damit eine Schlüsselfunktion in der gesamten medizinischen Versorgung einschließlich der antidementiven Behandlung der Heimbewohner zu. Kenntnisse über Antidementiva bei Pflegekräften und positive Annahmen zu deren Wirksamkeit können als eine Grundvoraussetzung gelten, im Falle demenzieller Veränderungen Kontakt zu den behandelnden Ärzten aufzunehmen und eine entsprechende antidementive Behandlung zu ermöglichen. Um herauszufinden, welche Bedeutung Pflegekräfte einer antidementiven Behandlung zusprechen, wurden ihr Wissensstand und ihre Wirksamkeitsvermutungen hinsichtlich Antidementiva erhoben. Die bei 53 examinierten Pflegekräften gewonnenen Ergebnisse machen deutlich, dass eine insgesamt positive Auffassung zu einer medikamentösen antidementiven Behandlung vorherrscht, wenngleich deutliche Wissensdefizite zum Einsatz moderner Antidementiva bestehen. Einschlägige Fortbildungen und kontinuierlich eingesetzte Pflegeassessments werden als Ansätze vorgeschlagen, um die antidementive Versorgung Demenzkranker im Heimbereich zu verbessern.
Assessment of Individual Differences in Implicit Cognition
Authors: Schnabel Konrad , Asendorpf Jens B. , Greenwald Anthony G.
Published: October 2008

This review discusses basic features of Implicit Association Tests (IATs) that are relevant in order to estimate their suitability of IATs for the valid assessment of individual differences. We start with a description of the essential characteristics of the procedures of IATs and also refer to theoretical accounts for IAT effects. Then, we provide an overview of research on the psychometric properties of IATs including their reliability and incremental validity for the prediction of behavior over and above explicit measures. Finally, we describe some alternatives to IAT measures and offer an outlook for future research.
Response Interference as a Mechanism Underlying Implicit Measures
Authors: Gawronski Bertram , Deutsch Roland , LeBel Etienne P. , Peters Kurt R.
Published: October 2008

Over the last decade, implicit measures of mental associations (e.g., Implicit Association Test, sequential priming) have become increasingly popular in many areas of psychological research. Even though successful applications provide preliminary support for the validity of these measures, their underlying mechanisms are still controversial. The present article addresses the role of a particular mechanism that is hypothesized to mediate the influence of activated associations on task performance in many implicit measures: response interference (RI). Based on a review of relevant evidence, we argue that RI effects in implicit measures depend on participants attention to association-relevant stimulus features, which in turn can influence the reliability and the construct validity of these measures. Drawing on a moderated-mediation model (MMM) of task performance in RI paradigms, we provide several suggestions on how to address these problems in research using implicit measures.