bluuebunny/crossref_metadata_2025 huggingface dataset:
Surface Properties of Mesophase‐Forming Fluorinated Bicycloacrylate/Polysiloxane Methacrylate Copolymers
Authors: Martinelli Elisa , Glisenti Antonella , Gallot Bernard , Galli Giancarlo
Published: September 2009

Novel random copolymers were synthesized by free‐radical polymerization of a bicycloacrylate monomer carrying a fluorocarbon chain side group (BAF10) with a methacrylate monomer having a polysiloxane side graft (SiMA). The copolymers with higher contents of BAF10 gave rise to a well‐ordered smectic bilayer mesophase. The surface structure of the derived polymer films was investigated by measurements of the contact angle with several interrogating liquids and X‐ray photoelectron spectroscopy (XPS) at different photoemission angles. The values of the contact angles were used to evaluate the film surface tension, following different additive‐component and equation‐of‐state methods. The low surface energies found were attributed to the pronounced hydrophobicity and oleophobicity of the outermost surface caused by the preferential segregation of the fluorocarbon chains to the polymer–air interface.

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Click Chemistry Approach to Rhodamine B‐Capped Polyrotaxanes and their Unique Fluorescence Properties
Authors: Wu Jiayan , Gao Chao
Published: September 2009

A fluorescent polyrotaxane (PR) made from the diazido‐poly(ethylene glycol) (N3‐PEG‐N3) axis, α‐cyclodextrins, and alkyne‐functionalized rhodamine B (RhB‐alk) stoppers via Cu(I)‐catalyzed azide–alkyne click chemistry is reported. A nanowire‐like morphology of the prepared fluorescent PRs was visualized by atomic force microscopy. The fluorescence emission intensities of RhB‐capped PEG (RhB‐PEG‐RhB) and the PR were much higher than that of neat RhB or RhB‐alk with the same concentration of RhB fluorophore in both dimethylsulfoxide and alkaline aqueous solutions. Fluorescence lifetimes were detected as 3.59, 3.31, 2.99, and 2.99 ns for neat RhB, RhB‐alk, RhB‐PEG‐RhB, and the PR, respectively. The PRs with unique fluorescence properties might have further applications in the fields of biomedicine and bionanotechnology.

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Magnetic resonance spectroscopy shows an inverse correlation between intramyocellular lipid content in human calf muscle and local glycogen synthesis rate
Authors: van der Graaf Marinette , Tack Cees J. , de Haan Jacco H. , Klomp Dennis W. J. , Heerschap Arend
Published: September 2009

Intramyocellular lipid (IMCL) content of skeletal muscle, as measured with 1H MRS, is inversely correlated with insulin sensitivity as determined by whole body glucose uptake. The latter, however, does not necessarily represent the actual glucose uptake in the corresponding skeletal muscle. In this study, we examined whether IMCL content in human calf muscle correlated with local glucose uptake assessed by measurement of glycogen synthesis rate within the same muscle compartment. We studied 20 subjects belonging to four subgroups of five persons each: young lean, elderly lean, young obese and elderly obese. IMCL content in the soleus and gastrocnemius muscle was determined using 1H MR spectroscopic imaging and local glycogen synthesis rate in the calf muscle was measured by 13C MRS during a euglycaemic hyperinsulinaemic clamp with 20% w/v 30% 13C‐1‐labelled glucose infusion. Significantly higher IMCL contents were found in elderly (soleus: p < 0.0001 and gastrocnemius: p < 0.01) and obese subjects (p < 0.01 for both muscles). Local glycogen synthesis rate decreased significantly with obesity (p < 0.01). The principal finding of this study was that the mean IMCL content of the soleus and gastrocnemius muscles was indeed inversely correlated with the local glycogen synthesis rate in the calf muscle (rs = −0.50, p < 0.05), with a very similar dependency as the inverse correlation between mean IMCL content and total body glucose uptake (rs = −0.54, p < 0.05). We conclude that IMCL content of the soleus and gastrocnemius muscles reflects a measure for local insulin resistance within the same muscle compartment as determined by glycogen synthesis rate. Although the inverse correlation suggests that insulin sensitivity is affected by the local amount of fat present, it remains to be determined if this is a cause or a consequence. Copyright © 2009 John Wiley & Sons, Ltd.
Crystallization behavior and thermal property of biodegradable poly(3‐hydroxybutyrate)/multi‐walled carbon nanotubes nanocomposite
Authors: Xu Changling , Qiu Zhaobin
Published: September 2009

Biodegradable poly(3‐hydroxybutyrate) (PHB)/functionalized multi‐walled carbon nanotubes (f‐MWNTs) nanocomposite was prepared in this work by solution casting method at 2 wt% f‐MWNTs loading. Scanning electron microscopy and transmission electron microscopy observations indicate a homogeneous distribution of f‐MWNTs in the PHB matrix. Nonisothermal melt crystallization, overall isothermal melt crystallization kinetics, and crystalline morphology of neat PHB and the PHB/f‐MWNTs nanocomposite were studied in detail. It is found that the presence of f‐MWNTs enhances the crystallization of PHB during nonisothermal and isothermal melt crystallization processes in the nanocomposite due to the heterogeneous nucleation effect of f‐MWNTs. Moreover, the incorporation of a small quantity of f‐MWNTs apparently improves the thermal stability of the PHB/f‐MWNTs nanocomposite with respect to neat PHB. Two methods are employed to study the activation energies of thermal degradation for both the neat PHB and the PHB/f‐MWNTs nanocomposite. The activation energy of thermal degradation of the PHB/f‐MWNTs nanocomposite is higher than that of neat PHB. Copyright © 2009 John Wiley & Sons, Ltd.
Deep‐red emissive conjugated poly(2,6‐BODIPY‐ethynylene)s bearing alkyl side chains
Authors: Donuru Venkat R. , Vegesna Giri K. , Velayudham Singaravelu , Meng Ge , Liu Haiying
Published: September 2009

Novel deep‐red emissive poly(2,6‐BODIPY‐ethynylene)s bearing dodecyl side chains (polymersA,B, andC) have been prepared by palladium‐catalyzed Sonogashira polymerization of 2,6‐diiodo‐functionalized BODIPY monomers with 2,6‐diethynyl‐functionalized BODIPY monomers. These polymers emit in the deep‐red region with emission maxima at up to 690 nm, and exhibit significant red shifts (up to 166 and 179 nm) of both absorption and emission maxima compared with their parent BODIPY dyes due to significant extension of π‐conjugation. These polymers possess good thermal stability with decomposition temperature between 270 and 360 °C. The polymers exhibit a little larger Stokes shifts and shorter lifetime than their corresponding BODIPY dyes. The solid state thin films of polymersA,B, andCemit in near‐infrared region between 723 and 743 nm, and show significantly red shifts (up to 57 nm) in absorption and emission maxima relative to their polymer solution. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 5354–5366, 2009
Development of synthetic double helical polymers and oligomers
Authors: Furusho Yoshio , Yashima Eiji
Published: September 2009

There is growing interest in the design and synthesis of artificial helical polymers and oligomers, in connection with biological importance as well as development of novel chiral materials. Since the discovery of the helical structure of isotactic polypropylene, a significant advancement has been achieved for synthetic polymers and oligomers with a single helical conformation for about half a century. In contrast, the chemistry of double helical counterparts is still premature. This short review highlights the recent advances in the synthesis, structures, and functions of double helical polymers and oligomers, featuring an important role of supramolecular chemistry in the design and synthesis of double helices. Although the artificial double helices reported to date are still limited in number, recent advancement of supramolecular chemistry provides plenty of structural motifs for new designs. Therefore, artificial double helices hold great promise as a new class of compounds. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 5195–5207, 2009
Ferroelectric behavior and structural change of poly(trimethylene terephthalate) induced by external electric field
Authors: Matsuda Yasuhiro , Nakano Gaku , Tasaka Shigeru
Published: September 2009

The ferroelectric behavior and structural change induced by the external electric field were observed for poly(trimethylene terephthalate) (PTT), which has nonpolar crystalline structure with carbonyl groups aligned antiparallel to each other. The displacement‐electric field hysteresis curves of PTT films showed hysteresis above 140 °C, which indicated the polarization reversal of PTT. The pyroelectric constant and thermally stimulated depolarization current suggest the depolarization of the polar structure of PTT induced by the external electric field above 150 °C. An endothermic peak caused by the depolarization was also observed in the differential scanning calorimetry for the PTT film poled at 30 MV/m. The change of the crystalline structure and the orientation of carbonyl groups induced by the electric filed were investigated by X‐ray diffraction patterns and infrared spectra. © 2009 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 47: 1991–1996, 2009
Mechanical Spectral Hole Burning in polymer solutions
Authors: Qin Qian , Doen Hiroko , McKenna Gregory B.
Published: September 2009

Mechanical Spectral Hole Burning (MSHB) was previously developed to investigate dynamic heterogeneity for polymeric materials, which exhibit relatively weak dielectric responses. In our previous work, MSHB was applied to a densely entangled block copolymer and successfully distinguishes the heterogeneous from the homogeneous states. Here, a series of polystyrene (PS) solutions was chosen to further investigate the effect of different types of heterogeneity on mechanical spectral hole burning. The three types of heterogeneity of interest include the entanglement spacing, the entanglement density (or number of entanglements per chain), and chain end density. The heterogeneity was varied by changing either solution concentration or molecular weight of the PS. Different types of dynamics from close to the Rouse regime into the terminal region were also examined. Our results are consistent with a heterogeneous dynamics over the time scales from close to Rouse regime into the rubbery plateau regime and the rubbery plateau‐to‐terminal flow transition regime. Terminal relaxation dynamics, on the other hand, were found to be homogeneous for the PS/diethyl phthalate solutions investigated. The results also indicate the hole properties are dominated by the type of dynamics rather than the length scale of heterogeneity. © 2009 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 47: 2047–2062, 2009
Adhesion of Ti and TiC Coatings on PMMA Subject to Plasma Treatment: Effect of Intermediate Layers of Al2O3 and TiO2 Deposited by Atomic Layer Deposition
Authors: Kääriäinen Tommi O. , Cameron David C. , Tanttari Mari
Published: September 2009

Magnetron sputtered metal and metal compound films generally show very poor adhesion to PMMA; this limits the use of the polymer for components which are wear or scratch resistant or have a decorative finish. We have shown that adhesion could be significantly improved by a duplex process where a nanometer‐scale thickness adhesion layer of TiO2 or Al2O3 was deposited by low temperature atomic layer deposition (ALD) prior to magnetron sputtering. The metal precursors used for TiO2 and Al2O3 were TDMAT and TMA, respectively, and ozone was used as a source of oxygen in both processes. This process was followed by deposition of the metal/metal carbide layer using pulsed DC reactive magnetron sputtering. With the presence of the ALD adhesion layer, the pull‐off adhesion strength increased with its thickness until a point where the failure mechanism was due to cohesive disruption of the substrate material itself. It has been shown that the ALD deposited layers protect the PMMA against plasma damage during the sputtering process by blocking both direct ion damage and disruption of the polymer structure by ultra‐violet radiation.

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Study on the Thermal Stability of Ti(C,O,N) Decorative Coatings
Authors: Moura Cacilda , Cunha Luís , Chappé Jean Marie , Vaz Filipe
Published: September 2009

This work reports on the study of thermal stability of dark decorative Ti(C,O,N) thin films produced by reactive magnetron sputtering, from a pure titanium target, using acetylene and an oxygen and nitrogen mixture as reactive gases. The thermal resistance and evolution of structural and physical properties were studied by performing annealing experiments at three different temperatures: 800, 900 and 1 000 °C. In order to study the effect of the thermal treatments on the properties of the films, mainly the physical ones (where surface colourations will deserve particular importance), X‐ray diffraction (XRD) and Raman spectroscopy (RS) were used. The optical properties of the films were obtained by reflectance experiments, in visible region, and the colour of the films is expressed in the CIE 1976 L*a*b* colour space.
Influence of Al Content on the Properties of MgO Grown by Reactive Magnetron Sputtering
Authors: Saraiva Marta , Chen Hong , Leroy Wouter P. , Mahieu Stijn , Jehanathan Neerushana , Lebedev Oleg , Georgieva Violeta , Persoons Rosita , Depla Diederik
Published: September 2009

In the present work, reactive magnetron sputtering in DC mode was used to grow complex oxide thin films, starting from two separate pure metal targets. A series of coatings was produced with a stoichiometry of the film ranging from MgO, over MgxAlyOz to Al2O3. The surface energy, crystallinity, hardness, refractive index, and surface roughness were investigated. A relationship between all properties studied and the Mg content of the samples was found. A critical compositional region for the Mg–Al–O system where all properties exhibit a change was noticed.
Prolongation of off‐cycle interval by finasteride is not associated with survival improvement in intermittent androgen deprivation therapy in LNCaP tumor model
Authors: Wang Yujuan , Gupta Shubham , Hua Vi , Ramos‐Garcia Raquel , Shevrin Daniel , Jovanovic Borko D. , Nelson Joel B. , Wang Zhou
Published: September 2009

BACKGROUND

We have previously reported that finasteride administration in intermittent androgen deprivation therapy (IADT) can improve survival of nude mice bearing LNCaP xenograft tumors when the duration of off‐cycle in IADT was fixed. A recent retrospective study showed that addition of finasteride doubled the duration of the off‐cycle, without changing progression to castration resistance. In view of the above difference, we attempted to investigate the relationship of 5α‐reductase inhibition with the off‐cycle interval and overall survival in a murine model.

METHODS

Subcutaneous LNCaP tumors were established in nude mice (Balb/C‐Nu). After the tumors reached a size of 0.5 cm in diameter, the mice were castrated and followed up for 2 weeks after which they were randomized to continuous androgen deprivation (CAD), CAD plus finasteride, IADT, and IADT plus finasteride. The off‐cycle was discontinued when the tumor volume was doubled. Subsequent cycles were carried out similarly.

RESULTS

Use of finasteride during the off‐cycle of IADT doubled the first off‐cycle duration. However, prolongation of the off‐cycle by finasteride did not translate into an increase in overall survival.

CONCLUSIONS

The survival advantage of IADT + finasteride over IADT that we previously reported was lost when the off‐cycle prolongation by finasteride was allowed. Maximum possible lengthening of the off‐cycle by 5α‐reductase inhibition is not associated with survival improvement in this animal model. Prostate 70: 147–154, 2010. ©2009 Wiley‐Liss, Inc.
Preparation of lithium indium oxide via a rheological phase route and its electrochemical characteristics in LiOH and Li2SO4 solutions
Authors: Zhang Guo‐Qing , Zhang Sheng‐Tao , Wu Xing‐Fa
Published: September 2009

Submicrometer‐sized lithium indium oxide (LiInO2) powder via a rheological phase method using trilithium citrate tetra hydrate (C6H5Li3O7 · 4H2O) and indium oxide (In2O3) has been prepared in this work for the first time. The optimal pyrolyzing temperature range to prepare crystalline LiInO2 is between 650 and 900 °C, which was confirmed by thermal gravimetric and differential thermogravimetric analysis of the precursor and X‐ray diffraction analysis. The pure phase LiInO2 sample obtained has a uniform particle morphology and submicrosize, which was observed by scanning electron microscopy. The electrochemical studies show that a new pair of cathodic and anodic peaks at 0.23 and 0.38 V (vs. saturated calomel electrode) was obviously observed from the cyclic voltammetry curve of LiInO2 in 1 M LiOH solution, indicating a battery characteristic of the material in this electrolyte. While in 1 M Li2SO4 solution, the sample presents a supercapacitive characteristic within the same potential range. The reasons for different electrochemical behaviors in these two electrolytes can be attributed to the fact that the reaction of lithium ion insertion/extraction into/out of a LiInO2 electrode takes place in the bulk material in LiOH electrolyte solution, whereas it takes place on the electrode/electrolyte interface for Li2SO4 electrolyte case.
In‐plane gate transistors implanted with different channel geometries by focussed ion beam in positive mode pattern definition technique
Authors: Draghici Mihai , Diaconescu Dorina , Melnikov Alexander , Wieck Andreas D.
Published: September 2009

In‐plane gate (IPG) transistors with various channel geometries have been fabricated by focus ion beam implantation technique in positive pattern definition mode on GaAs/AlxGa1−xAs heterostructures. Both n‐ and p‐type channel transistors were obtained for either n‐ or p‐doped heterostructures, by implantation of the channel or the gate regions with the complementary dopant type to compensate the initial doping. The current–voltage characteristics showed that the channel can be fully controlled by a gate bias, i.e., it can be completely depleted or enhanced, but two gates are needed to control the channel. Different channel geometries were studied, the most efficient being the “Z‐shaped” one. The n‐type channel IPG transistors present source–drain currents of few hundreds of microamperes, which is two to three orders of magnitudes higher than that for the p‐type channel ones.
Structural and optical properties of electron‐beam evaporated Al2O3‐doped V2O5 thin films for various applications
Authors: Ali H. M. , Hakeem A. M. Abdel
Published: September 2009

The solid‐state reaction method was used to prepare tablets of (V2O5)100−x (Al2O3)x with x = 5, 10, 15, 20 wt. %. Thin films of Al2O3‐doped V2O5 were deposited onto glass substrates using an electron‐beam evaporation technique. The influence of doping and annealing temperature on the structural and optical characteristics has been investigated in detail. Optical properties of the films were studied extensively in the wavelength range 200–2500 nm from the measurements of the optical transmittance (T) and optical reflectance (R). It was observed that the optical properties such as transmittance, reflectance, optical bandgap, and refractive index of (V2O5)100−x (Al2O3)x films were strongly affected by the ratio of Al2O3 and the temperature of annealing.
Dielectric and ac conductivity studies in as‐grown Ga2Te3 crystals with the defect zinc‐blende structure
Authors: Seki Y. , Kusakabe M. , Kashida S.
Published: September 2009

Ga2Te3 crystallizes in the zinc‐blende structure where one‐third of the cation sites are vacant. The dielectric properties of as‐grown Ga2Te3 crystals have been studied in the frequency range from 102 to 109 Hz. Below room temperature, the dielectric constant is around 20 and almost independent of temperature. The ac conductivity is found to obey a power law σac ∼ ωs, with s ∼ 1 indicating that the conduction is due to hopping of localized charge carriers. Above room temperature the dielectric constant shows an S‐shaped step‐like increase up to a very large value around 104. The relaxation is found to be of thermal activated Debye type, the relaxation time changes as $\tau = \tau _0 \,{\rm exp}(E_\tau /kT)$ ($E_\tau \approx 0.27\,{\rm eV}$). The activation energy of the relaxation nearly coincides with that deduced from conductivity. These results are analyzed using the Maxwell Wagner model and the space charge model.
Distributed model predictive control for constrained linear systems
Authors: Ding Baocang , Xie Lihua , Cai Wenjian
Published: September 2009

We address the distributed model predictive control (MPC) for a set of linear local systems with decoupled dynamics and a coupled global cost function. By the decomposition of the global cost function, the distributed control problem is converted to the MPC for each local system associated with a cost involving neighboring system states and inputs. For each local controller, the infinite horizon control moves are parameterized as N free control moves followed by a single state feedback law. An interacting compatibility condition is derived, disassembled and incorporated into the design of each local control so as to achieve the stability of the global closed‐loop system. Each local system exchanges with its neighbors the current states and the previous optimal control strategies. The global closed‐loop system is shown to be exponentially stable provided that all the local optimizers are feasible at the initial time. Copyright © 2009 John Wiley & Sons, Ltd.
Random majority percolation
Authors: Balister Paul , Bollobás Béla , Johnson J. Robert , Walters Mark
Published: September 2009

We shall consider the discrete time synchronous random majority‐vote cellular automata on the n by n torus, in which every vertex is in one of two states and, at each time step t, every vertex goes into the state the majority of its neighbors had at time t ‐ 1 with a small chance p of error independently of all other events. We shall show that, if n is fixed and p is sufficiently small, then the process spends almost half of its time in each of two configurations. Further more, we show that the expected time for it to reach one of these configurations from the other is Θ(1/pn+1) despite the actual time spent in transit being O(1/p3). Unusually, it appears difficult to obtain any results for this regime by simulation. © 2009 Wiley Periodicals, Inc. Random Struct. Alg., 2010
On predictive routing of security contexts in an all‐IP network
Authors: Kim Hahnsang , Shin Kang G.
Published: September 2009

While mobile nodes (MNs) undergo handovers across inter‐wireless access networks, their security contexts must be propagated for secure re‐establishment of on‐going application sessions, such as those in secure mobile internet protocol (IP), authentication, authorization, and accounting (AAA) services. Routing security contextsviaan IP network either on‐demand or based on MNs' mobility prediction, imposes new challenging requirements of securecross‐handoverservices and security context management. In this paper, we present acontext router(CXR) that manages security contexts in an all‐IP network, providing seamless and secure handover services for the mobile users that carry multimedia‐access devices. A CXR is responsible for (1) monitoring of MNs' cross‐handover, (2) analysis of MNs' movement patterns, and (3) routing of security contexts ahead of MNs' arrival at relevant access points. The predictive routing reduces the delay in the underlying security association that would otherwise fetch an involved security context from a remote server. The predictive routing of security contexts is performed based on statistical learning of MNs' movement pattern, gauging (dis)similarities between the patterns obtainedviadistance measurements. The CXR has been evaluated with a prototypical implementation based on an MN mobility model on a grid. Our evaluation results support the predictive routing mechanism's improvement in seamless and secure cross‐handover services by a factor of 2.5. Also, the prediction mechanism is shown to outperform the Kalman filter‐based method [13] as a Kalman Fiter‐based mechanism up to 1.5 and 3.6 times regarding prediction accuracy and computation performance, respectively. Copyright © 2009 John Wiley & Sons, Ltd.
Randomization by minimization for unbalanced treatment allocation
Authors: Han Baoguang , Enas Nathan H. , McEntegart Damian
Published: September 2009

Minimization is a dynamic randomization technique that has been widely used in clinical trials for achieving a balance of prognostic factors across treatment groups, but most often it has been used in the setting of equal treatment allocations. Although unequal treatment allocation is frequently encountered in clinical trials, an appropriate minimization procedure for such trials has not been published. The purpose of this paper is to present novel strategies for applying minimization methodology to such clinical trials. Two minimization techniques are proposed and compared by probability calculation and simulation studies. In the first method, called naïve minimization, probability assignment is based on a simple modification of the original minimization algorithm, which does not account for unequal allocation ratios. In the second method, called biased‐coin minimization (BCM), probability assignment is based on allocation ratios and optimized to achieve an ‘unbiased’ target allocation ratio. The performance of the two methods is investigated in various trial settings including different number of treatments, prognostic factors and sample sizes. The relative merits of the different distance metrics are also explored. On the basis of the results, we conclude that BCM is the preferable method for randomization in clinical trials involving unequal treatment allocations. The choice of different distance metrics slightly affects the performance of the minimization and may be optimized according to the specific feature of trials. Copyright © 2009 John Wiley & Sons, Ltd.
Modeling the spread of infectious disease using genetic information within a marked branching process
Authors: Leman Scotland C. , Levy Foster , Walker Elaine S.
Published: September 2009

Accurate assessment of disease dynamics requires a quantification of many unknown parameters governing disease transmission processes. While infection control strategies within hospital settings are stringent, some disease will be propagated due to human interactions (patient‐to‐patient or patient‐to‐caregiver‐to‐patient). In order to understand infectious transmission rates within the hospital, it is necessary to isolate the amount of disease that is endemic to the outside environment. While discerning the origins of disease is difficult when using ordinary spatio‐temporal data (locations and time of disease detection), genotypes that are common to pathogens, with common sources, aid in distinguishing nosocomial infections from independent arrivals of the disease. The purpose of this study was to demonstrate a Bayesian modeling procedure for identifying nosocomial infections, and quantify the rate of these transmissions. We will demonstrate our method using a 10‐year history of Morexella catarhallis. Results will show the degree to which pathogen‐specific, genotypic information impacts inferences about the nosocomial rate of infection. Published in 2009 by John Wiley & Sons, Ltd.
Nanostructured Silicon Anodes for Lithium Ion Rechargeable Batteries
Authors: Teki Ranganath , Datta Moni K. , Krishnan Rahul , Parker Thomas C. , Lu Toh‐Ming , Kumta Prashant N. , Koratkar Nikhil
Published: September 2009

Rechargeable lithium ion batteries are integral to today's information‐rich, mobile society. Currently they are one of the most popular types of battery used in portable electronics because of their high energy density and flexible design. Despite their increasing use at the present time, there is great continued commercial interest in developing new and improved electrode materials for lithium ion batteries that would lead to dramatically higher energy capacity and longer cycle life. Silicon is one of the most promising anode materials because it has the highest known theoretical charge capacity and is the second most abundant element on earth. However, silicon anodes have limited applications because of the huge volume change associated with the insertion and extraction of lithium. This causes cracking and pulverization of the anode, which leads to a loss of electrical contact and eventual fading of capacity. Nanostructured silicon anodes, as compared to the previously tested silicon film anodes, can help overcome the above issues. As arrays of silicon nanowires or nanorods, which help accommodate the volume changes, or as nanoscale compliant layers, which increase the stress resilience of silicon films, nanoengineered silicon anodes show potential to enable a new generation of lithium ion batteries with significantly higher reversible charge capacity and longer cycle life.
Effect of prenatal auditory stimulation on numerical synaptic density and mean synaptic height in the posthatch Day 1 chick hippocampus
Authors: Chaudhury Sraboni , Nag Tapas Chandra , Wadhwa Shashi
Published: September 2009

Previous studies on prenatal auditory stimulation by species‐specific sound or sitar music showed enhanced morphological and biochemical changes in chick hippocampus, which plays an important role in learning and memory. Changes in the efficiency of synapses, synaptic morphology and de novo synapse formation affects learning and memory. Therefore, in the present study, we set out to investigate the mean synaptic density and mean synaptic height at posthatch Day 1 in dorsal and ventral part of chick hippocampus following prenatal auditory stimulation. Fertilized 0 day eggs of domestic chick incubated under normal conditions were exposed to patterned sounds of species‐specific and sitar music at 65 dB levels for 15 min/h round the clock (frequency range: 100–6300 Hz) from embryonic Day 10 till hatching. The synapses identified under transmission electron microscope were estimated for their numerical density by physical disector method and also the mean synaptic height calculated. Our results demonstrate a significant increase in mean synaptic density with no alterations in the mean synaptic height following both types of auditory stimulation in the dorsal as well as ventral part of the hippocampus. The observed increase in mean synaptic density suggests enhanced synaptic substrate to strengthen hippocampal function. Synapse 63:152–159, 2009. © 2008 Wiley‐Liss, Inc.
Synthesis and Crystal Structure of Mercury(II) Metal Crown Ether with N‐Heterocyclic Carbene Linkage
Authors: Wan Xiangjian , Xu Fengbo , Zang Zhengzhi , Song Haibin
Published: September 2009

The mercury(II) metal crown ether (2a) was obtained in high yield by reaction of the carbene precursor 1,2‐bis[N‐(1‐naphthylmethylene)imidazoliumethoxy]benzene dihexafluorophosphate (1) and Hg(OAc)2. Addition of NaI to the acetone solution of 2a resulted in precipitation of pale yellow solid 2b. The structures of 2a and 2b were determined by single‐crystal X‐ray diffractometry. Both molecules display a helical conformation with a torsional cycle. The mercury atom in complex 2a is tricoordinated by two intramolecular carbene carbon atoms and an acetate oxygen atom. The mercury atom in complex 2b is tetracoordinated by two intramolecular carbene carbon atoms and two cis‐iodine atoms.
2‐Organoselenomethyl‐1H‐benzimidazole Complexes of Copper(II) and Copper(I)
Authors: Leboschka Markus , Sieger Monika , Sarkar Biprajit , Heck Jürgen , Niemeyer Mark , Bubrin Denis , Lissner Falk , Schleid Thomas , Záliš Stanislav , Su Cheng‐Yong , Kaim Wolfgang
Published: September 2009

Structurally characterized 2‐methylselenomethyl‐1H‐benzimidazole (msbi) is shown to form complexes in 2:1 ratio with copper(II). Whereas the central cation [Cu(msbi)2Cl]+ = 1+ in [Cu(msbi)2Cl]Cl·2MeOH crystallizes in an approximately mixed square‐pyramidal/trigonal‐bipyramidal structure (τ = 0.52) with the second and third row atoms chlorine and selenium in the equatorial plane, the related [Cu(msbi)2(MeOH)](BF4)2 = [2](BF4)2 exhibits a closer to square‐pyramidal arrangement with τ = 0.36 for that complex dication 22+. In both cases, the Cu–N bonds are short at about 1.94 Å, whereas the Cu–Se distances vary between 2.62 Å for 1+ and ca. 2.54 Å for 22+. Slight differences between the Jahn–Teller influenced species 1+ and 22+ are also apparent from absorption and EPR spectra. Since copper(I) complexes of msbi suitable for crystal structure analysis could not be obtained, the related 1‐methyl‐2‐phenylselenomethyl‐1H‐benzimidazole (mpsbi) was prepared and used to obtain [Cu(mpsbi)2](X) = [3](X) (X = BF4 or PF6). The copper(I) ion in the corresponding cation 3+ shows a DFT‐reproduced distorted tetrahedral configuration with an N–CuI–N angle at 146.7(3)°, less straightened than the ca. 170° in similar CuI complexes with thioether‐1H‐benzimidazole ligands. A copper(I) compound [Cu(psbi)2][Cu(psbi)(psbi‐H+)](PF6) = [4][4′](PF6) with another related ligand, 2‐phenylselenomethyl‐1H‐benzimidazole (psbi), was crystallized in partially benzimidazole‐deprotonated acetonitrile solvate form, showing short Cu–N bonds of 1.898(5) Å, an N–CuI–N angle of 157.5(3)°, a Se···Se interaction at 3.6237(3) Å, and a very small Se–Cu–Se angle of 78.23(4)°. The different responses resulting from thioether and selenoether coordination to copper in the complexes at hand are being discussed.
Synthesis, Structures, and Spectroscopic Properties of Three Polynuclear Complexes from Nickel(II) Precursor with a 14‐membered Tetraaza Macrocyclic Ligand
Authors: Zhang Rui‐Hong , Wang Qing‐Lun , Huang Jin , Yang Fan , Yang Guang‐Ming
Published: September 2009

Based on the complex ligand NiL (H2L = 3,12‐dichloro‐8‐methyl‐5‐phenyl‐5,6,7,8,9,10,15,18‐octahydro‐6,9,15,18‐tetraaza‐dibenzocyclotetradecene‐16,17‐dione), a dinuclear complex [(NiL)Cu(phen)(EtOH)](ClO4)2·EtOH·0.5H2O (1) and two tetranuclear complexes (NiL)3Co(ClO4)2 (2) and (NiL)3Cu(ClO4)2 (3) were prepared. The crystal structures of 1–3 were determined. EPR spectra of complex 1 and 3 were simulated.
New CF3 Substituted Phosphorus‐Tellurium Heterocycles
Authors: Lux Karin , Schön Oliver , Karaghiosoff Konstantin
Published: September 2009

The reaction of trifluormethyl dichlorophosphine (CF3PCl2) with sodium telluride Na2Te or bis(trimethylsilyl) telluride (Me3Si)2Te results in the formation of four new phosphorus tellurium heterocycles (1–4) with the electron withdrawing CF3 substituent bonded to phosphorus. The telluratriphosphetane (CF3P)3Te (1), telluratetraphospholane (CF3P)4Te (2), telluradiphosphirane (CF3P)2Te (3) and ditelluratriphospholane (CF3P)3Te2 (4) are characterized by multinuclear (31P, 19F and 125Te) NMR spectroscopy. A full analysis of the 19F NMR spectrum of telluratriphosphetane (CF3P)3Te is presented. The new heterocycles are remarkably stable in solution and eliminate only slowly tellurium to form cyclophosphines (CF3P)n (n = 3–5).
Die Reaktion von mer‐[ScCl3(H2O)3] mit Pyridin. Kristallstruktur von [Sc2Cl4(μ‐OH)2(Py)4]·4Py
Authors: Massa Werner , Agarwal Seema , Grabe Norman , Dehnicke Kurt
Published: September 2009

mer‐[ScCl3(H2O)3] (1) was prepared from aqueous solutions of scandium trichloride by evaporation and subsequent treatment with thionyl chloride at room temperature. The IR spectrum of 1 is in accordance with the meridional arrangement of the chlorido and aqua ligands. Its reaction with excess pyridine yields [Sc2Cl4(μ‐OH)2(py)4]·4py (2·4py), which is characterized by X‐ray diffraction: Space group I2/a, Z = 8, lattice dimensions at 193(2) K: a = 2051.3(2), b = 1056.3(7), c = 4389.4(5) pm, β = 102.967(12)°, R1 = 0.0584. The molecular structure of 2 consists of distorted octahedrally coordinated scandium atoms, which are connected by μ‐OH groups to form planar Sc2O2 four‐membered rings. The coordination of the scandium atoms is completed by two chlorine ligands and by the nitrogen atoms of the pyridine molecules, the latter being in trans‐positions to one another., Experiments to use 2 as possible catalyst for ring‐opening polymerization of ϵ‐caprolactone (ROP) without co‐catalysts were not successful.
Vascular Endothelial Growth Factor: An Essential Component of Angiogenesis and Fracture Healing
Authors: Beamer Brandon , Hettrich Carolyn , Lane Joseph
Published: September 2009

Fractures require adequate stability and blood supply to heal. The vascular supply to long bones is compromised in a fracture, and the ability to heal hinges on the ability of new blood vessels to proliferate from surrounding vessels in a process known as angiogenesis. This process is largely driven by the growth factor, vascular endothelial growth factor (VEGF), whose levels are increased locally and systemically during fracture healing. VEGF is involved in many steps throughout the fracture healing cascade, from initially being concentrated in fracture hematoma, to the promotion of bone turnover during the final remodeling phase. This article reviews the current literature surrounding the role of VEGF and other growth factors in reestablishing vascular supply to fractured bone, as well as medications and surgical techniques that may inhibit this process.
Detection and Quantification of Free Glycerol in Virgin Olive Oil by 31P‐NMR Spectroscopy
Authors: Hatzakis Emmanuel , Agiomyrgianaki Alexia , Dais Photis
Published: September 2009

31P‐Nuclear magnetic resonance (NMR) spectroscopy was employed to detect and quantify free glycerol in virgin olive oils originating from various regions of Greece. This analytical method was based on the derivatization of the hydroxyl groups of glycerol with the tagging reagent 2‐chloro‐4,4,5,5‐tetramethyldioxaphospholane, and identification of the phosphitylated compound on the basis of 31P chemical shifts. Quantification of glycerol in olive oils was accomplished by integration of the appropriate signals in the 31P NMR spectrum and the use of the phosphitylated cyclohexanol as internal standard. A linear correlation was observed between the glycerol content and 1,3‐diacylglycerols and free acidity indicating that glycerol is the final product of the partial hydrolysis of triacylglycerols.
Adiponectin Receptor-1 C-Terminal Fragment (CTF) in Plasma: Putative Biomarker for Diabetes
Authors: Pugia Michael J. , Franke Deanna D. H. , Barnes Sean L. , Zercher Amy , Brock David , Foltz Mary , Valdes Roland , Jortani Saeed A.
Published: September 2009

Introduction

Polypeptide fragments from cell surface receptors when found in plasma may be indicators of receptor regulation in disease conditions. It is known that subjects with diabetes have significantly lower plasma concentrations of adiponectin, a hormone released by adipose tissue, compared with nondiabetic controls. This hormone interacts with cell surface receptors in muscle (AdipoR1) and liver (AdipoR2).

Methods

We analyzed the relative distribution of specific fragments of AdipoR1 in healthy and diabetic individuals using an immunoaffinity mass spectrometry approach. We used antibodies raised against AdipoR1 immobilized on pre-activated protein chip surfaces to determine the molecular weights of bound polypeptide fragments using immunomass spectrometry (immuno-MS).

Results

Initially, immuno-MS analyses using a polyclonal antibody revealed two peaks (m/z 3,902 and 7,812) in plasma from normal, healthy individuals (n = 5) that were not present in the plasma of diabetics (n = 5). To confirm the detection of these fragments, a monoclonal antibody was developed against the last 25 amino acids of the AdipoR1 C-terminal fragment (CTF). Using the immuno-MS method, the monoclonal antibody detected the AdipoR1 CTF (m/z 3475) in all healthy controls (n = 10), but did not detect these fragments in the diabetic patients (n = 10).

Discussion

These preliminary observations suggest that the plasma levels of this receptor fragment may serve as an indicator of diabetic condition.
Sonographic pleural fluid volume estimation in cats
Authors: Shimali Jerry , Cripps Peter J , Newitt Anna L.M.
Published: September 2009

The aims of this study were to evaluate whether a recently published study used to objectively monitor pleural fluid volumes in dogs could be successfully employed in cats and secondly to assess its accuracy. Eleven feline cadavers were selected. Using the trans-sternal view employed in dogs, linear measurements from the pleural surface of the midline of the sternebra at the centre of the heart to the furthest ventro-lateral point of both right and left lung edges were recorded. Isotonic saline was injected using ultrasound guidance into both right and left pleural spaces and the measurements were repeated using standard increments until 400 ml total volume was reached. The mean measurement increased in a linear relationship with the cube root of fluid volume for all cats individually. An equation was produced to predict the volume of fluid from the mean linear measurement for all cats combined:

Volume=[-3.75+2.41(mean)]3 (P<0.001) but variability in the slope of the curve for individual cats limited the accuracy of the combined equation. Equations were derived to predict the constant and slope of the curve for individual cats using the thoracic measurements made, but the residual diagnostic graphs demonstrated considerable variability. As in dogs, good correlation was found between the ultrasonographic measurement and fluid volume within individual cats. An accurate equation to predict absolute pleural fluid volume was not identified. Further analysis with reference to thoracic measurements did not increase accuracy. In conclusion, this study does provide a method of estimating absolute pleural fluid volume in cats, which may be clinical useful for pleural fluid volume monitoring but this is yet to be validated in live cats.
Successful surgical treatment of a prostatic biphasic tumour (sarcomatoid carcinoma) in a cat
Authors: Zambelli Daniele , Cunto Marco , Raccagni Ramona , Merlo Barbara , Morini Maria , Bettini Giuliano
Published: September 2009

A 12-year-old, neutered male, mixed-breed, domestic cat was presented for dysuria and haematuria accompanied by recurrent dyschezia and constipation. At rectal digital examination a non-painful, globose and relatively immobile mass was detected at the pelvic brim, ventral to the rectum. Abdominal ultrasound showed the prostate replaced by a mass with a regular shape but patchy/non-uniform echogenicity. A prostatectomy followed by prepubic urethrostomy was performed. At histopathology the tumour was composed of epithelial ducts and acini with malignant features, surrounded by proliferating cellular stroma with mitoses and nuclear atypia; an immunohistochemical panel confirmed the biphasic nature of the tumour proliferation. The diagnosis was non-infiltrating malignant mixed tumour, resembling human sarcomatoid carcinoma of the prostate. Two years after surgery the animal has not shown any health problems. To the author's knowledge, this is the first reported case of prostatic tumour with a positive follow-up after surgical treatment in cat.
Prospective evaluation of tissue plasminogen activator in 11 cats with arterial thromboembolism
Authors: Welch Kristin M , Rozanski Elizabeth A , Freeman Lisa M , Rush John E.
Published: September 2009

The purpose of this study was to evaluate the clinical response and side effects of tissue plasminogen activator (tPA) for the treatment of feline arterial thromboembolism (ATE). Previous reports of conservative and thrombolytic therapy were used to provide a historical control group of cats with ATE. The study was terminated due to a high frequency of adverse outcomes. tPA was administered to 11 cats with clinical signs of ATE for a median duration of 4.0 h (range 2–12 h) prior to treatment. Pulses were restored in 40% of limbs within 4 h and 53% within 24 h. Motor function was restored to 33% of limbs within 24 h. Adverse effects were seen in 11/11 cats following administration of tPA including azotemia ( n=5), neurological signs ( n=5), cardiac arrhythmias ( n=5), hyperkalemia ( n=4), acidosis ( n=2) and sudden death in one cat. Ultimately, three cats (27%) were discharged alive from the hospital. While signs compatible with thrombolysis were noted in many cats following tPA administration, a high rate of side effects and low rate of hospital discharge were noted in this study.
On the swimming of a flexible body in a vortex street
Authors: ALBEN SILAS
Published: September 2009

We formulate a new theoretical model for the swimming of a flexible body in a vortex street. We consider the class of periodic travelling-wave body motions, in the limit of small amplitude. We calculate the output power provided to the body by thrust forces, and the input power done against pressure forces, as functions of the aspect ratio and strength of the vortex street. We then formulate two optimization problems. In the first, we determine the body wave which provides maximum output power for fixed amplitude. We find a closed-form solution with a transition from power law to exponential decay of output power as the vortex street widens. In the second problem, we incorporate internal viscoelasticity to the swimming body and compute its contribution to the input power. We find the body wave which maximizes efficiency for a given output power. The body shape and resulting efficiency are found in closed form and simple approximate formulas are given. We find that efficiency scales as the inverse of the damping parameter. Finally, we compare our results with previous experiments and simulations. We find agreement in some aspects and disagreement in others. We give physical interpretations for agreements and disagreements in terms of the phase between the body wave and vortex street.
Conserving the oldest historic sites in the Antarctic: the challenges in managing the sealing sites in the South Shetland Islands
Authors: Pearson Michael , Stehberg Ruben , Zarankín Andrés , Senatore M. Ximena , Gatica Carolina
Published: September 2009

The fur seal population of the South Shetland Islands, Antarctica, was intensively hunted by sealers from the discovery of the islands in 1819 to the early 1820s, by which time the seal numbers were so depleted that sealing became uneconomic. Sealing was revived for both fur seals and elephant seals at several periods later in the century. Sealers were put ashore in gangs and built makeshift shelters in which to live, and also occupied caves. Many of these have been identified on the various islands of the South Shetlands, and a number have been excavated. The paper addresses some of the management issues facing the conservation of these sites, which include accelerating tourism, disturbance by scientific researchers, disturbance by animal activity, burial or erosion by drifting sand, and climate change.
The tragedy at Kapp Thordsen, Spitsbergen, 1872–1873. Could lead poisoning have been the cause?
Authors: Kjær Kjell-G. , Aasebø Ulf , Hultgreen Tora
Published: September 2009

A group of 17 Norwegian sealers died in Svenskhuset, the Swedish House at Kapp Thordsen, Spitsbergen during the winter and spring of 1872–1873. The Swedish House was built by a mining company, but was left deserted as there were poor prospects for mining in the area. The house was well stocked with food, fuel and hunting gear. The death of these men has been a mystery for 135 years although the usual interpretation has been that they died from scurvy. In an effort to challenge this historical diagnosis, the authors applied for permission to open the graves to sample the bone for lead analysis, and, if possible, to examine the skeletons for evidence of scurvy. This was granted. No objective signs of scurvy were found. The level of lead in bone, however, was very high, indicating that lead poisoning very probably played a part in the tragedy. This article reveals the historical facts behind the tragedy, the excavation of the sealers’ graves in 2008, and presents a discussion of the medical evidence.