bluuebunny/crossref_metadata_2025 huggingface dataset:
Water uptake and dye sorption studies of chemically crosslinked highly swollen novel ternary acrylamide‐based hydrogels including citraconic acid and sodium acrylate
Authors: Üzüm Ömer Barış , Durukan H. Berna , Kundakci Semiha , Karadağ Erdener
Published: December 2007

Highly swollen hydrogels made by the polymerization of acrylamide (AAm) with some anionic monomers such as citraconic acid (CITA) and sodium acrylate (SA) were investigated as a function of composition to find materials with swelling and dye sorption properties. Highly swollen AAm/CITA/SA or AAm/SA/CITA hydrogels were prepared by free radical solution polymerization in aqueous solutions of AAm with CITA and SA as co‐monomers and two multifunctional crosslinkers such as ethylene glycol dimethacrylate (EGDMA) and 1,4‐butanediol dimethacrylate (BDMA). Swelling experiments were performed in water at 25°C, gravimetrically. Chemically crosslinked AAm/CITA/SA or AAm/SA/CITA hydrogels were used in experiments on sorption of water‐soluble monovalent cationic dye such as “Nil blue” (Basic Blue 12; BB 12). Equilibrium percentage swelling values of AAm/CITA/SA or AAm/SA/CITA hydrogels were calculated in the range of 1797–22,098%. Some swelling kinetic parameters were found. Diffusion behavior of water was investigated. Water diffusion into the hydrogels was found to be non‐Fickian in character. For sorption of cationic dye, BB 12 into the hydrogels was studied by batch sorption technique at 25°C. AAm/CITA/SA or AAm/SA/CITA hydrogels in the dye solutions showed coloration, whereas AAm hydrogel did not show sorption of any dye from the solution. The sorption capacity of AAm/CITA/SA or AAm/SA/CITA hydrogels was investigated. At the end of the experiments, 21.70–78.91% BB 12 adsorptions were determined. Copyright © 2007 John Wiley & Sons, Ltd.
Synthesis and characterization of (hydroxypropyl)cellulose/TiO2 nanocomposite films
Authors: Halamus Tomasz , Wojciechowski Piotr , Bobowska Izabela
Published: December 2007

A new method of synthesis of TiO2 nanoparticles as well as preparation of the organic–inorganic hybrid nanocomposite films of (hydroxypropyl)cellulose (HPC)/TiO2 is presented. At the first stage, the oxotitanium hydrogel phase was obtained by the mineralization of (tetra‐isopropyl)orthotitanate (TIPT) modified by the methacrylic acid (MAA) in 15 wt% solution of H2O2 at room temperature and subsequent annealing at the temperature of 85°C. The crystallization of the nanoparticles of TiO2 was conducted at the oxotitanium hydrogel phase at temperatures around 120°C in the closed vessel. Nanocomposite hybrid films were prepared by the casting method from a solution of HPC and TiO2 nanoparticles in the water. The films of nanocomposite with 10 µm thickness are transparent to visible light and have a lower glass transition temperature compared with HPC in the bulk. This shift of the glass transition is interpreted in terms of packing density of HPC in the interface of HPC nanocomposite with TiO2. The X‐ray diffraction pattern of the nanocomposite film suggests a lower amount of mesomorphic phase of HPC in the composite compared with HPC in the bulk. Copyright © 2007 John Wiley & Sons, Ltd.
Octafunctional cubic silsesquioxane (CSSQ)/poly(methyl methacrylate) nanocomposites: Synthesis by atom transfer radical polymerization at mild conditions and the influence of CSSQ on nanocomposites
Authors: Hussain Hazrat , Mya Khine Yi , Xiao Yang , He Chaobin
Published: December 2007

Organic/inorganic hybrid star‐like nanocomposites from two different octafunctional cubic silsesquioxane (CSSQ) nano‐cage cores and poly(methyl methacrylate) (PMMA) were synthesized using atom transfer radical polymerization (ATRP) at mild conditions, in which octafunctional octakis(3‐hydroxypropyldimethylsiloxy)octasilsesquioxane (OHPS) and octa(aminophenyl)silsesquioxane (OAPS) nano‐cages were used as ATRP initiators. The polymerization was carried out at 50 °C in acetonitrile/water mixture. 1H‐NMR and GPC were employed to characterize the obtained nanocomposites. GPC data revealed that the resulting nanocomposites exhibit unimodal and narrow molecular weight distributions indicating well‐controlled synthesis and well‐defined hybrid nanocomposites with star architecture. The influence of CSSQ nano‐cages on the thermal property of nanocomposites was investigated using differential scanning calorimetry and thermal gravimetric analysis (TGA). It was observed that the nanocomposites exhibit significantly higher glass transition temperature compared with its linear counterpart because of slow relaxation caused by the star‐like architecture. TGA study, however, did not reveal any significant improvement in thermal stability of nanocomposites as compared with linear PMMA. Finally, field emission scanning electron microscopy images of fractured surfaces of nanocomposite sample films showed well dispersed CSSQ nano‐cages in PMMA matrix without phase separation. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 766–776, 2008
Poly(vinyltriethoxysilane) modified MWCNT/polyimide nanocomposites—Preparation, morphological, mechanical, and electrical properties
Authors: Yuen Siu‐Ming , Ma Chen‐Chi M. , Chiang Chin‐Lung , Teng Chih‐Chun , Yu Yi‐Hsiuan
Published: December 2007

Multi‐walled carbon nanotube (MWCNT) modified by vinyltriethoxysilane (VTES) via free radical reaction has been prepared (poly (vinyltriethoxysilane) modified MWCNTs, PVTES‐MWCNT). Precursor of polyimide, polyamic acid has been synthesized by reacting 4,4′‐oxydianiline with 3,3′,4,4′‐benzophenone tetracarboxylic dianhydride. PVTES‐MWCNT were then mixed with polyamic acid and heated to 300 °C to form CNT/polyimide composite. During the imidization processes, the silanes on CNT surface reacted with each other and may be connected together by covalent bond (SiOSi). The PVTES‐MWCNT was analyzed by Fourier transform infrared and X‐ray photoelectron spectroscopy. The PVTES‐MWCNT/polyimide composites were analyzed by CP/MAS solid state 29Si nuclear magnetic resonance (NMR) spectroscopy. Morphological properties of the PVTES‐MWCNT/polyimide composites were investigated by scanning electron microscope and transmission electron microscope. Electrical conductivity increased dramatically comparing to the unmodified MWCNT/polyimide composites. Mechanical properties of nanocomposite were enhanced significantly by PVTES‐MWCNT. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 803–816, 2008
Synthesis, self‐assembly and recognition properties of biomimetic star‐shaped poly(ε‐caprolactone)‐b‐glycopolymer block copolymers
Authors: Dai Xiao‐Hui , Dong Chang‐Ming
Published: December 2007

Biomimetic star‐shaped poly(ε‐caprolactone)‐b‐poly(gluconamidoethyl methacrylate) block copolymers (SPCL‐PGAMA) were synthesized from the atom transfer radical polymerization (ATRP) of unprotected GAMA glycomonomer using a tetra(2‐bromo‐2‐methylpropionyl)‐terminated star‐shaped poly(ε‐caprolactone) (SPCL‐Br) as a macroinitiator in NMP solution at room temperature. The block length of PGAMA glycopolymer within as‐synthesized SPCL‐PGAMA copolymers could be adjusted linearly by controlling the molar ratio of GAMA glycomonomer to SPCL‐Br macroinitiator, and the molecular weight distribution was reasonably narrow. The degree of crystallization of PCL block within copolymers decreased with the increasing block length ratio of outer PGAMA to inner PCL. Moreover, the self‐assembly properties of the SPCL‐PGAMA copolymers were investigated by NMR, UV‐vis, DLS, and TEM, respectively. The self‐assembled glucose‐installed aggregates changed from spherical micelles to worm‐like aggregates, then to vesicles with the decreasing weight fraction of hydrophilic PGAMA block. Furthermore, the biomolecular binding of SPCL‐PGAMA with Concanavalin A (Con A) was studied by means of UV‐vis, fluorescence spectroscopy, and DLS, which demonstrated that these SPCL‐PGAMA copolymers had specific recognition with Con A. Consequently, this will not only provide biomimetic star‐shaped SPCL‐PGAMA block copolymers for targeted drug delivery, but also improve the compatibility and drug release properties of PCL‐based biomaterials for hydrophilic peptide drugs. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 817–829, 2008
Formation of poly(ethylene phosphates) in polycondensation of H3PO4 with ethylene glycol. Kinetic and mechanistic study
Authors: Pretula Julia , Kaluzynski Krzysztof , Wisniewski Blazej , Szymanski Ryszard , Loontjens Ton , Penczek Stanislaw
Published: December 2007

Conditions of synthesis of poly(ethylene phosphates) in reaction of H3PO4 with HOCH2CH2OH (EG), the actual path of polycondensation, and structure of the obtained polymers (mostly oligomers) and kinetics of reaction are described. Preliminary kinetic information, based on the comparison of the MALDI‐TOF‐ms and 31P{1H} NMR spectra as a function of conversion is given as well. Because of the dealkylation process fragments derived from di‐ and triethylene glycols are also present in the repeating units. Structures of the end groups (CH2CH2OH or OP(O)(OH)2) depend on the starting ratio of [EG]0/[H3PO4]0, although even at the excess of EG the acidic end groups prevail because of the dealkylation process. In MALDI‐TOF‐ms products with Pn equal up to 21 have been observed. The average polymerization degrees (Pn) are lower and have been calculated from the proportion of the end groups. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 830–843, 2008
The effect of group cohesion on rehabilitation outcome in cancer survivors
Authors: May Anne M. , Duivenvoorden Hugo J. , Korstjens Irene , van Weert Ellen , Hoekstra‐Weebers Josette E. H. M. , van den Borne Bart , Mesters Ilse , van der Schans Cees P. , Ros Wynand J. G.
Published: December 2007

Objective: Group‐based physical training interventions have been shown to be effective in increasing quality of life in cancer survivors. Until now, however, the impact of cohesion within the group on intervention outcome has not been investigated.

Methods: We examined self‐reported individual group cohesion ratings collected in the first half of a 12‐week rehabilitation programme for cancer survivors (N=132). Four dimensions of group cohesion were measured, i.e. the bond with the group as whole, the bond with other members, cooperation within the group and the instrumental value. Quality of life, physical functioning and fatigue were assessed before and after the intervention using the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire‐C30. Linear multiple multivariate regression analysis was conducted to explore the relationship between group cohesion and intervention outcome.

Results: The relationship between group cohesion and outcome was significantly modified by gender. Higher ratings of cooperation within the group predicted better post‐intervention quality of life and physical functioning and less fatigue in men, and better quality of life and physical functioning in women. Additionally, women who reported a stronger bond with other members showed a lower quality of life after the intervention. No relationship was found between the instrumental value and the outcome variables.

Conclusion: Some dimensions of group cohesion seem to be associated with intervention outcome. The underlying mechanisms need to be unravelled. Copyright © 2007 John Wiley & Sons, Ltd.
Using temperature and state transitions to forecast wind speed
Authors: Reikard Gordon
Published: December 2007

A major issue in forecasting wind speed is non‐linear variability. The probability distribution of wind speed series shows heavy tails, while there are frequent state transitions, in which wind speed changes by large magnitudes, over relatively short time periods. These so‐called large ramp events are one of the critical issues currently facing the wind energy community. Two forecasting algorithms are analyzed here. The first is a regression on lags, including temperature as a causal factor, with time‐varying parameters. The second augments the first using state transition terms. The main innovation in state transition models is that the cumulative density function from regressions on the states is used as a right‐hand side variable in the regressions for wind speed. These two methods are tested against a persistence forecast and several non‐linear models, using eight hourly wind speed series. On average, these two models produce the best results. The state transition model improves slightly over the regression. However, the improvement achieved by both models relative to the persistence forecast is fairly small. These results argue that there are limits to the accuracy that can be achieved in forecasting wind speed data. Copyright © 2007 John Wiley & Sons, Ltd.
Induction of trophinin in human endometrial surface epithelia by CGβ and IL‐1β
Authors: Sugihara Kazuhiro , Kabir-Salmani Maryam , Byrne James , Wolf Don P. , Lessey Bruce , Iwashita Mitsutoshi , Aoki Daisuke , Nakayama Jun , Fukuda Michiko N.
Published: December 2007

During embryo implantation, trophinin mediates cell adhesion by homophilic binding at the apical surfaces of trophectoderm and endometrium. Trophinin is expressed on the human endometrial epithelia in rare occasions. We developed hCG‐coated agarose beads that mimic the physical and physiological features of an implantation‐stage human blastocyst. When hCG‐coated beads were applied to human endometrial epithelial cells in the presence of IL‐1β, endometrial cells acquired strong trophinin expression and the ability for apical cell adhesion with trophinin‐expressing human trophoblastic cells. These results provide a mechanism for trophinin‐mediated adhesion of human blastocyst to endometrium by a spatially and temporally restricted paracrine effect of hCG derived from the blastocyst.
Arabidopsis HY5 protein functions as a DNA‐binding tag for purification and functional immobilization of proteins on agarose/DNA microplate
Authors: Sawasaki Tatsuya , Kamura Nami , Matsunaga Satoko , Saeki Mihoro , Tsuchimochi Masateru , Morishita Ryo , Endo Yaeta
Published: December 2007

Protein microarray is considered to be one of the key analytical tools for high‐throughput protein function analysis. Here, we report that the Arabidopsis HY5 functions as a novel DNA‐binding tag (DBtag) for proteins. We also demonstrate that the DBtagged proteins could be immobilized and purified on a newly designed agarose/DNA microplate. Furthermore, we show three applications using the microarray: (1) detection of autophosphorylation activity of DBtagged human protein kinases and inhibition of their activity by staurosporine, (2) specific cleavage of DBtagged proteins by a virus protease and caspase 3, and (3) detection of a protein–protein interaction between the DBtagged UBE2N and UBE2v1. Thus, this method may facilitate rapid functional analysis of a wide range of proteins.
The xanthophyll cycle pool size controls the kinetics of non‐photochemical quenching in Arabidopsis thaliana
Authors: Johnson Matthew P. , Davison Paul A. , Ruban Alexander V. , Horton Peter
Published: December 2007

Arabidopsis plants overexpressing β‐carotene hydroxylase 1 accumulate over double the amount of zeaxanthin present in wild‐type plants. The final amplitude of non‐photochemical quenching (NPQ) was found to be the same in these plants, but the kinetics were different. The formation and relaxation of NPQ consistently correlated with the de‐epoxidation state of the xanthophyll cycle pool and not the amount of zeaxanthin. These data indicate that zeaxanthin and violaxanthin antagonistically regulate the switch between the light harvesting and photoprotective modes of the light harvesting system and show that control of the xanthophyll cycle pool size is necessary to optimize the kinetics of NPQ.
Dignity and Rank
Authors: Waldron Jeremy
Published: December 2007

This paper considers the meaning conveyed by the term “dignity” in human rights discourse. It considers various ambiguities associated with the term (e.g. Does it describe the content or the ground of certain rights?) as well as alternative accounts of the kind of meaning that “dignity” has (descriptive or evaluative, technical or ordinary language). The second part of the paper argues that the distinctive contribution that “dignity” makes to human rights discourse is associated, paradoxically, with the idea of rank: once associated with hierarchical differentiations of rank and status, “dignity” now conveys the idea that all human persons belong to the same rank and that, that rank is a very high one indeed, in many ways as high as what were formerly regarded as ranks of nobility.
The Specificity of Money
Authors: Ingham Geoffrey
Published: December 2007

In “Laundering ‘money’: on the need for conceptual clarity within the sociology of money”, (Archives Européennes de Sociologie, XLVI, 3 (2005), pp. 387–411, Nigel Dodd tells us that recent work has added further complications to an existing “conceptual muddle” in the sociology of money, and advances a claim to have made matters clearer (Dodd 2005a). The “muddle” is identified in the work of Cohen (2004), Hart (2000), Zelizer (1994, 2000), and in my own book The Nature of Money (Ingham 2004). In the same year, Dodd advanced the same critique – at times verbatim, in Economy and Society (Dodd 2005b), where, subsequently, I responded to what I take to be the misunderstanding and misrepresentation of my work (Ingham 2006). Here, I will briefly reiterate these objections, focusing mainly on the uncertainty, ambiguity, and consequent incoherence, of Dodd's attempt to identify the specific nature of money. On the one hand, he asserts that “any attempt to build a coherent theoretical conception of money is bound to fail” (p. 387). But, on the other, Dodd also argues that that “greater conceptual clarity can be brought to bear” by making a distinction between the monetary medium and money's denomination (p. 406). Leaving aside for a moment the fact that such a distinction has been commonplace in monetary theory at least since Plato and Aristotle (see Schumpeter 1994 [1954]), Dodd appears to be unsure, on rather curious intellectual grounds, about the usefulness of his claim to have provided conceptual clarity.
Modélisation analytique de l'action
Authors: Gurov Boris
Published: December 2007

Today confronting Pareto versus Weber is commonplace. For the majority of contemporary researchers, validating one of the two theoritical constructs means ipso facto rejecting the other. The present paper attempts to prove the lack of scientific ground. The Weberian and Parsonian approaches operate at two different levels. They should be put to work jointly in a sequential manner, Pareto first, Weber thereafter.
GENDER INEQUALITY INCREASES WOMEN’S RISK OF HIV INFECTION IN MOSHI, TANZANIA
Authors: SA ZHIHONG , LARSEN ULLA
Published: December 2007

This study examined the hypothesis that multiple dimensions of gender inequality increase women’s risk for HIV infection using a population-based survey of 1418 women aged 20 to 44 in Moshi, Tanzania. Three forms of HIV exposures were assessed reflecting gender power imbalance: economic exposures (age difference between partners and partner’s contributions to children’s expenses), physical exposures (coerced first sex and intimate partner violence) and social exposures (ever had problems conceiving). Behavioural risk factors included number of sexual partners for women in the last three years, partner had other wives or girlfriends, non-use of condom and alcohol use at least once a week in the last 12 months. Multivariate logistic regression analysis showed that a woman had a significantly elevated risk for HIV if she had a partner more than 10 years older (OR=2·5), her partner made low financial contributions to children’s expenses (OR=1·7), or she experienced coerced first sex before age 18 years (OR=2·0) even after taking into account the effects of risk behaviour factors. The association between ever had problem conceiving and HIV infection was explained away by risk behaviour factors. The findings lend support to the hypothesis that economic deprivation and experience of sexual violence increase women’s vulnerability to HIV, providing further evidence for extending the behavioural approach to HIV interventions to incorporate women’s economic empowerment, elimination of gender-based violence and promotion of changing attitudes and behaviours among men.
Virulence factors in brucellosis: implications for aetiopathogenesis and treatment
Authors: Fugier Emilie , Pappas Georgios , Gorvel Jean-Pierre
Published: December 2007

Brucellaspecies are responsible for the global zoonotic disease brucellosis. These intracellular pathogens express a set of factors – including lipopolysaccharides, virulence regulator proteins and phosphatidylcholine – to ensure their full virulence. Some virulence factors are essential for invasion of the host cell, whereas others are crucial to avoid elimination by the host. They allowBrucellaspp. to survive and proliferate within its replicative vacuole and enable the bacteria to escape detection by the host immune system. Several strategies have been used to develop animal vaccines against brucellosis, but no adequate vaccine yet exists to cure the disease in humans. This is probably due to the complicated pathophysiology of humanBrucellaspp. infection, which is different than in animal models. Here we reviewBrucellaspp. virulence factors and how they control bacterial trafficking within the host cell.
Overexpression of Mitochondrial Hsp70/Hsp75 Protects Astrocytes against Ischemic Injury in vitro
Authors: Voloboueva Ludmila A , Duan Melissa , Ouyang YiBing , Emery John F , Stoy Christian , Giffard Rona G
Published: December 2007

Mitochondrial heat shock protein 70 (mtHsp70/Hsp75/Grp75/mortalin/TRAP-1/PBP74) is an essential mitochondrial chaperone and a member of the heat shock protein 70 (HSP70) family. Although many studies have shown the protective properties of overexpression of the cytosolic inducible member of the HSP70 family, Hsp72, few studies have investigated the protective potential of Hsp75 against ischemic injury. Mitochondria are one of the primary targets of ischemic injury in astrocytes. In this study, we analyzed the effects of Hsp75 overexpression on cellular levels of reactive oxygen species (ROS), mitochondrial membrane potential, ATP levels, and viability during the ischemia-like conditions of oxygen-glucose deprivation (OGD) or glucose deprivation (GD) in primary astrocytic cultures. We show that Hsp75 overexpression decreases ROS production and preserves mitochondrial membrane potential during GD, and preserves ATP levels and cell viability during OGD. These findings indicate that Hsp75 can provide protection against ischemia-like in vitro injury and suggest that it should be further studied as a potential candidate for protection against ischemic injury.
RNA silencing movement in plants
Authors: Kalantidis Kriton , Schumacher Heiko Tobias , Alexiadis Tasos , Helm Jutta Maria
Published: December 2007

Higher eukaryotes have developed a mechanism of sequence‐specific RNA degradation which is known as RNA silencing. In plants and some animals, similar to the nematode Caenorhabditis elegans, RNA silencing is a non‐cell‐autonomous event. Hence, silencing initiation in one or a few cells leads progressively to the sequence‐specific suppression of homologous sequences in neighbouring cells in an RNA‐mediated fashion. Spreading of silencing in plants occurs through plasmodesmata and results from a cell‐to‐cell movement of a short‐range silencing signal, most probably 21‐nt siRNAs (short interfering RNAs) that are produced by one of the plant Dicer enzymes. In addition, silencing spreads systemically through the phloem system of the plants, which also translocates metabolites from source to sink tissues. Unlike the short‐range silencing signal, there is little known about the mediators of systemic silencing. Recent studies have revealed various and sometimes surprising genetic elements of the short‐range silencing spread pathway, elucidating several aspects of the processes involved. In this review we attempt to clarify commonalities and differences between the individual silencing pathways of RNA silencing spread in plants.
Caspase‐3‐truncated type 1 inositol 1,4,5‐trisphosphate receptor enhances intracellular Ca2+ leak and disturbs Ca2+ signalling
Authors: Verbert Leen , Lee Bora , Kocks Sarah L. , Assefa Zerihun , Parys Jan B. , Missiaen Ludwig , Callewaert Geert , Fissore Rafael A. , De Smedt Humbert , Bultynck Geert
Published: December 2007

Background information. The IP3R (inositol 1,4,5‐trisphosphate receptor) is a tetrameric channel that accounts for a large part of the intracellular Ca2+ release in virtually all cell types. We have previously demonstrated that caspase‐3‐mediated cleavage of IP3R1 during cell death generates a C‐terminal fragment of 95 kDa comprising the complete channel domain. Expression of this truncated IP3R increases the cellular sensitivity to apoptotic stimuli, and it was postulated to be a constitutively active channel.

Results. In the present study, we demonstrate that expression of the caspase‐3‐cleaved C‐terminus of IP3R1 increased the rate of thapsigargin‐mediated Ca2+ leak and decreased the rate of Ca2+ uptake into the ER (endoplasmic reticulum), although it was not sufficient by itself to deplete intracellular Ca2+ stores. We detected the truncated IP3R1 in different cell types after a challenge with apoptotic stimuli, as well as in aged mouse oocytes. Injection of mRNA corresponding to the truncated IP3R1 blocked sperm factor‐induced Ca2+ oscillations and induced an apoptotic phenotype.

Conclusions. In the present study, we show that caspase‐3‐mediated truncation of IP3R1 enhanced the Ca2+ leak from the ER. We suggest a model in which, in normal conditions, the increased Ca2+ leak is largely compensated by enhanced Ca2+‐uptake activity, whereas in situations where the cellular metabolism is compromised, as occurring in aging oocytes, the Ca2+ leak acts as a feed‐forward mechanism to divert the cell into apoptosis.
Simulation of the photodeactivation of formamide in the nO-π∗ and π-π∗ states: An ab initio on-the-fly surface-hopping dynamics study
Authors: Antol Ivana , Eckert-Maksić Mirjana , Barbatti Mario , Lischka Hans
Published: December 2007

The short-time photodynamics (1ps) of formamide in its low-lying singlet excited nO-π* and π-π* states have been investigated by the direct trajectory surface-hopping method based on multiconfigurational ab initio calculations. The simulations showed that in both states, the primary deactivation process is C–N bond dissociation. In the ground state, the energy is transferred to (a) translational motion of the HCO and NH2 fragments, (b) additional C–H dissociation from the vibrationally hot HCO fragment, or (c) formation of NH3 and CO. In addition to the C–N dissociation pathway, C–O bond fission is found to be an additional primary deactivation path in the π-π* dynamics. From fractional occupations of trajectories, lifetimes of formamide were estimated: τ(S1)=441fs and τ(S2)=66fs.
Multidimensional Franck-Condon simulations of photodetachment spectra for the formate-water cluster anion: Investigating H atom transfer along the HCOOH+OH reaction coordinate
Authors: Guo Jingwei , Pugliesi Igor , Müller-Dethlefs Klaus , Dessent Caroline E. H.
Published: December 2007

A new multidimensional Franck-Condon (FC) simulation methodology was applied to an anionic-neutral cluster transition for the first time to investigate the use of photodetachment spectroscopy of the HCOO−∙H2O anion as a means to study the HCOO∙H2O and HCOOH∙OH neutral clusters. For the HCOO−∙H2O to HCOO∙H2O transition, vibrationally resolved simulated spectra were obtained across the threshold detachment region, indicating that photodetachment spectroscopy of the respective anionic cluster should provide detailed structural information on the bifurcated HCOO∙H2O neutral cluster. The simulations predict that the photodetachment spectra should display prominent progressions of both the intermolecular stretch and the in-plane OCO bending mode. In contrast, for the HCOO−∙H2O to HCOOH∙OH transition, the vibronic FC simulations resulted in transitions with negligible intensities, despite the fact that the geometries of the respective anionic and neutral systems were similar. The low FC intensities were traced to the large off-diagonal elements of the Duschinsky matrix for this transition, which arise due to the considerable differences in the vibrational wave functions following hydrogen transfer.
Microscale friction phenomena in oscillatory sliding contacts
Authors: Timpe S. J. , Komvopoulos K. , Dugger M. T.
Published: December 2007

Microscale friction phenomena encountered in oscillatory sliding contacts were examined with a special reciprocating surface micromachine. Variations in static and dynamic friction forces were tracked in situ throughout testing under controlled loading and environmental conditions. Stick-slip surface interactions emerged at high numbers of sliding cycles. An unexpected binary friction behavior occurred as sliding transitioned between two-body and three-body conditions due to the formation of fine wear particles. The dominant friction mechanisms arising at the asperity scale are interpreted in the context of temporal evolutions of the static and dynamic friction forces and the decrease of the static and dynamic operational safety factors with accumulating sliding cycles. An important finding is that oscillating microdevices tend to fail in static friction mode rather than in dynamic friction mode. The results of this study illustrate the important role of microscale stick-slip phenomena in high-speed oscillatory microcontacts and the need for developing dynamic friction theories applicable at the microscale.
Photon-trap spectroscopy of mass-selected ions in an ion trap: Optical absorption and magneto-optical effects
Authors: Terasaki Akira , Majima Takuya , Kondow Tamotsu
Published: December 2007

A novel experimental technique has been developed to observe a trace of optical absorption of free mass-selected ions. The technique combines a linear radio-frequency ion trap with a high-finesse optical cavity to perform cavity ring-down spectroscopy (photon-trap spectroscopy for generality), where the storage lifetime of photons in the cavity provides a sensitivity high enough to probe the trapped ions. Absorption spectra of the manganese ion Mn+ are presented, showing hyperfine structures for the P2,3,47←S37 transitions in the ultraviolet range. Implementation of a solenoidal magnet allows us to observe the Zeeman splitting and the Faraday rotation as well.
Effect of fluid compressibility on the flow caused by a sudden impulse applied to a sphere immersed in a viscous fluid
Authors: Felderhof B. U.
Published: December 2007

The flow of a viscous compressible fluid about a sphere suddenly set in motion by an applied impulse is studied on the basis of linearized hydrodynamic equations. Mixed slip-stick boundary conditions are assumed to hold at the surface of the sphere. An analytic expression for the flow pattern is presented for an idealized fluid in which the damping of sound waves is neglected. The time dependence of the pressure part and the viscous part of the fluid momentum is investigated. It is shown that at long times, one-third of the imparted momentum resides in the pressure part.
Electrical characteristics of organic perylene single-crystal-based field-effect transistors
Authors: Lee Jin-Woo , Kang Han-Saem , Kim Min-Ki , Kim Kihyun , Cho Mi-Yeon , Kwon Young-Wan , Joo Jinsoo , Kim Jae-Il , Hong Chang-Seop
Published: December 2007

We report on the fabrication of organic field-effect transistors (OFETs) using perylene single crystal as the active material and their electrical characteristics. Perylene single crystals were directly grown from perylene powder in a furnace using a relatively short growth time of 1–3 h. The crystalline structure of the perylene single crystals was characterized by means of a single-crystal x-ray diffractometer. In order to place the perylene single crystal onto the Au electrodes of the field-effect transistor, a polymethlymethacrylate thin layer was spin-coated on top of the crystal surface. The OFETs fabricated using the perylene single crystal showed a typical p-type operating mode. The field-effect mobility of the perylene crystal based OFETs was measured to be ∼9.62×10−4 cm2/V s at room temperature. The anisotropy of the mobility implying the existence of different mobilities when applying currents in different directions was observed for the OFETs, and the existence of traps in the perylene crystal was found through the measurements of the temperature-dependent mobility at various operating drain voltages.
Experimental evidence of end effects in magneto-electric laminate composites
Authors: Chang Chia-Ming , Carman Gregory P.
Published: December 2007

This paper experimentally and theoretically studies the magneto-electric (M-E) responses of layered magnetostrictive and piezoelectric composites. A total of three different piezoelectric volume fractions of 0.17, 0.29, and 0.44 were prepared to investigate the strain variation in the sample and the effective M-E voltage coefficient α¯ as a function of bias magnetic field Hbias. Analytical modeling involving uniform strain, shear lag only, and shear lag plus demagnetization was performed and compared with experimental measurements. The results demonstrate that the uniform strain theory significantly overestimates the measured strain and α¯ values. This discrepancy is physically attributed to shear lag and demagnetizing effects. The analytical models involving shear lag and demagnetizing effects agree with the experimental results well within 5%.
Phase stability in nanocrystalline metals: A thermodynamic consideration
Authors: Qin W. , Nagase T. , Umakoshi Y.
Published: December 2007

The mechanism of structural transition in nanocrystalline metals was studied from a thermodynamic point of view. Crystal lattice distortion and interfacial effect were found to be the reasons for structural instability. Nanocrystalline Fe samples prepared by the milling method and by the crystallization method were used for analyses and comparison. The contributions of lattice distortion and interfacial energy to thermodynamics were calculated using the quasiharmonic Debye approximation and the Gibbs-Thomson equation, respectively. By examining the change in Gibbs free energy and considering the effect of negative stress of grain boundaries on the crystal volume change in structural transition, we calculated the critical grain size of fcc-Fe formation. Results show that relative to the crystallized nanocrystalline state, it is more likely that the fcc Fe forms in the milled nanocrystalline state. Whether or not the phase transition occurs in nanocrystalline materials is closely related to the preparation technology, the grain-boundary structure, and the grain size.
Stability of core-shell nanoparticles formed in a dielectric medium
Authors: Mohan Sabitha , Jose Gin
Published: December 2007

We report the time evolution of declustering phenomenon of metal nanoclusters of size less than 2nm grown in a glassy medium. The clusters are found to be of core shell in structure and the shell formation is inevitable and accompanied by the clusters of such smaller size. Clusters having two different size distributions are grown during the aging period of the sample showing surface plasmon resonant (SPR) absorptions peaked at the wavelengths ∼460 and ∼600nm. We explain the formation of secondary clusters and the cluster decay process based on the SPR of silver clusters formed in an ion-exchanged silicate glass using a generalized Mie scattering theory and a supporting thermodynamic description.
Enhanced magnetism in Fe-doped TiO2 anatase nanorods
Authors: Ding Y. , Han W.-Q. , Lewis L. H.
Published: December 2007

Simultaneous high-Curie temperature (TC) ferromagnetism and enhanced temperature-independent paramagnetism (χTIP) is quantified in TiO2 anatase nanorods doped with nominal 0.5 at % Fe synthesized by a hydrothermal route. The nanorod dimensions are 8–35 nm in width and several hundred nanometers in length and possess an Fe concentration of 0.3–1.0 at %; no evidence of pure iron nanoparticles is detected. Magnetometry shows ferromagnetism at low fields that transitions to paramagnetism at higher fields with an enhanced temperature-independent susceptibility >100 times that of pure bulk anatase TiO2. The enhanced magnetism is tentatively attributed to the defect structure of the nanorods.
In
As
∕
Al
Sb
quantum cascade lasers emitting at 2.75–2.97μm
Authors: Devenson J. , Cathabard O. , Teissier R. , Baranov A. N.
Published: December 2007

Quantum cascade lasers emitting at wavelengths as short as 2.75μm at 80K and 2.97μm near room temperature are demonstrated. Despite the small band gap of InAs, the laser performances are not affected by interband absorption. No effect of the L valley in InAs on quantum cascade laser performances is observed at 80K in these devices.
Bright upconversion white light emission in transparent glass ceramic embedding Tm3+∕Er3+∕Yb3+:β-YF3 nanocrystals
Authors: Chen Daqin , Wang Yuansheng , Zheng Kelu , Guo Tailiang , Yu Yunlong , Huang Ping
Published: December 2007

Intense red (Er3+:F9∕24→I15∕24, Tm3+:G41→F43), green (Er3+:H11∕22, S3∕24→I15∕24), and blue (Tm3+:D21→F43, G41→H63) upconversion emissions were simultaneously generated in the transparent glass ceramics containing Tm3+∕Er3+∕Yb3+:β-YF3 nanocrystals under single 976nm laser excitation. It was demonstrated that Tm3+ behaves as the sensitizer for red luminescence of Er3+ and Er3+ as the quenching center for blue, red, and near-infrared upconversion emissions of Tm3+. Various colors of the luminescence, including perfect and bright white light with CIE-X=0.310 and CIE-Y=0.358, can be easily tuned by adjusting the concentrations of the rare earth ions in the material.
Terahertz sensing method for protein detection using a thin metallic mesh
Authors: Yoshida H. , Ogawa Y. , Kawai Y. , Hayashi S. , Hayashi A. , Otani C. , Kato E. , Miyamaru F. , Kawase K.
Published: December 2007

A label-free biological sensor, which is based on the resonant transmission phenomenon of a thin metallic mesh, is proposed in the terahertz wave region. By using this sensor, we demonstrate the highly sensitive detection of small amounts of protein horseradish peroxidase. For quantitative investigation of the sensitivity of our sensor, horseradish peroxidase was printed on the metallic mesh surface by using a commercial available printer. A distinct shift of the transmission dip frequency is observed for 500pg∕mm2 (11fmol) of horseradish peroxidase printed on the metallic mesh, indicating the significantly high sensitivity of our sensor.
Nonpolar m-plane thin film GaN and InGaN∕GaN light-emitting diodes on LiAlO2(100) substrates
Authors: Liu B. , Zhang R. , Xie Z. L. , Liu C. X. , Kong J. Y. , Yao J. , Liu Q. J. , Zhang Z. , Fu D. Y. , Xiu X. Q. , Lu H. , Chen P. , Han P. , Gu S. L. , Shi Y. , Zheng Y. D. , Zhou J. , Zhou S. M.
Published: December 2007

The nonpolar m-plane (11¯00) thin film GaN and InGaN∕GaN light-emitting diodes (LEDs) grown by metal-organic chemical vapor deposition on LiAlO2 (100) substrates are reported. The LEDs emit green light with output power of 80μW under a direct current of 20mA for a 400×400μm2 device. The current versus voltage (I-V) characteristic of the diode shows soft rectifying properties caused by defects and impurities in the p-n junction. The electroluminescence peak wavelength dependence on injection current, for currents in excess of 20mA, saturates at 515–516nm. This proves the absence of polarization fields in the active region present in c-plane structures. The light output intensity versus current (L-I) characteristic of the diode exhibits a superlinear relation at low injection current caused by nonradiative centers providing a shunt path and a linear light emission zone at high current level when these centers are saturated.
Effect of photon irradiation on structure of yttria-doped zirconia thin films grown on semiconductor substrates
Authors: Tsuchiya Masaru , Ramanathan Shriram
Published: December 2007

Structural changes and atomic-scale interfacial phenomena induced by room temperature ultraviolet (UV) irradiation on yttria-doped zirconia (YDZ) thin films grown on semiconductor substrates have been investigated in detail. Interfacial layer formation, film densification, and changes in crystallinity were observed in films grown on Si, while there was minimal difference in films grown on Ge. No significant grain growth and phase transformation were observed, suggesting that cation related kinetics remains unperturbed under UV exposure. The formation of interfacial layers thicker than room temperature self-limiting thickness suggests that effective local field for oxygen vacancies inside the YDZ film was affected by photon illumination.
CLC Cl
−
/H
+
transporters constrained by covalent cross-linking
Authors: Nguitragool Wang , Miller Christopher
Published: December 2007

CLC Cl
−
/H
+
exchangers are homodimers with Cl
−
-binding and H
+
-coupling residues contained within each subunit. It is not known whether the transport mechanism requires conformational rearrangement between subunits or whether each subunit operates as a separate exchanger. We designed various cysteine substitution mutants on a cysteine-less background of CLC-ec1, a bacterial CLC exchanger of known structure, with the aim of covalently linking the subunits. The constructs were cross-linked in air or with exogenous oxidant, and the cross-linked proteins were reconstituted to assess their function. In addition to conventional disulfides, a cysteine–lysine cross-bridge was formed with I
2
as an oxidant. The constructs, all of which contained one, two, or four cross-bridges, were functionally active and kinetically competent with respect to Cl
−
turnover rate, Cl
−
/H
+
exchange stoichiometry, and H
+
pumping driven by a Cl
−
gradient. These results imply that large quaternary rearrangements, such as those known to occur for “common gating” in CLC channels, are not necessary for the ion transport cycle and that it is therefore likely that the transport mechanism is carried out by the subunits working individually, as with “fast gating” of the CLC channels.
ZFIQ: a software package for zebrafish biology
Authors: Liu Tianming , Nie Jingxin , Li Gang , Guo Lei , Wong Stephen T. C.
Published: December 2007

Summary: Rapid development, transparency and small size are the outstanding features of zebrafish that make it as an increasingly important vertebrate system for developmental biology, functional genomics, disease modeling and drug discovery. Zebrafish has been regarded as ideal animal specie for studying the relationship between genotype and phenotype, for pathway analysis and systems biology. However, the tremendous amount of data generated from large numbers of embryos has led to the bottleneck of data analysis and modeling. The zebrafish image quantitator (ZFIQ) software provides streamlined data processing and analysis capability for developmental biology and disease modeling using zebrafish model.

Availability: ZFIQ is available for download at http://www.cbi-platform.net

Contact:  STWong@tmhs.org

Supplementary information: Additional documentation for this software package is referred to http://www.cbi-platform.net/document.htm. Application examples of this software are referred to http://www.cbi-platform.net/download.htm
Mucuna pruriens Reduces Stress and Improves the Quality of Semen in Infertile Men
Authors: Shukla Kamla Kant , Mahdi Abbas Ali , Ahmad Mohammad Kaleem , Jaiswar Shyam Pyari , Shankwar Satya Narain , Tiwari Sarvada Chandra
Published: December 2007

The present investigation was undertaken to assess the role of Mucuna pruriens in infertile men who were under psychological stress. Study included 60 subjects who were undergoing infertility screening and were found to be suffering from psychological stress, assessed on the basis of a questionnaire and elevated serum cortisol levels. Age‐matched 60 healthy men having normal semen parameters and who had previously initiated at least one pregnancy were included as controls. Infertile subjects were administered with M. pruriens seed powder (5 g day−1) orally. For carrying out morphological and biochemical analysis, semen samples were collected twice, first before starting treatment and second after 3 months of treatment. The results demonstrated decreased sperm count and motility in subjects who were under psychological stress. Moreover, serum cortisol and seminal plasma lipid peroxide levels were also found elevated along with decreased seminal plasma glutathione (GSH) and ascorbic acid contents and reduced superoxide dismutase (SOD) and catalase activity. Treatment with M. pruriens significantly ameliorated psychological stress and seminal plasma lipid peroxide levels along with improved sperm count and motility. Treatment also restored the levels of SOD, catalase, GSH and ascorbic acid in seminal plasma of infertile men. On the basis of results of the present study, it may be concluded that M. pruriens not only reactivates the anti‐oxidant defense system of infertile men but it also helps in the management of stress and improves semen quality.
Aspects of the reproductive biology of skates (Chondrichthyes: Rajiformes: Rajoidei) from southern Africa
Authors: Ebert David A. , Compagno Leonard J. V. , Cowley Paul D.
Published: December 2007

Ebert, D. A., Compagno, L. J. V., and Cowley, P. D. 2008. Aspects of the reproductive biology of skates (Chondrichthyes: Rajiformes: Rajoidei) from southern Africa. – ICES Journal of Marine Science, 65: 81–102. New information is presented on the reproductive biology of 22 southern African skate species. Sex ratios for most species were relatively even. Sexual dimorphic differences in disc shape were evident in all species, but the total length (LT) to disc width (D) relationship was significantly different in only three species, and the LT to weight (W) relationship significant in just five species. Sexual dimorphism relative to maximum total length (LTmax) was absent in all but the two largest species. Males and females of the same species grow to a similar LTmax except those whose LTmax is >1.5 m LT. Size at first and 50% (LT50) sexual maturity was approximately the same for both sexes in all but the two largest species. First maturity occurred at >60% of LTmax for all species for which sufficient data were available, and most (n = 18) matured at >75% LTmax. The large size at maturity relative to LTmax suggests that growth slows or is partially suspended following sexual maturity. The egg cases of 15 species are described, and a key to their identification is presented. Egg cases in utero were observed throughout the year suggesting that most species reproduce year-round.