bluuebunny/crossref_metadata_2025 huggingface dataset:
A novel electromagnetism‐assisted imprinting technology to replicate microstructures onto a large‐area curved surface using a flexible magnetic mold
Authors: Weng Y.‐J. , Weng Y.‐C. , Yang S.‐Y. , Wong J.‐L.
Published: November 2008

Replication of microstructures from a mold onto a curved surface is difficult. The conformal contact between the mold and the substrate has to be ensured. The present study proposes an innovative mechanism, which employs an electromagnetic disk to provide magnetic force and a PDMS flexible mold with a layer compounded magnetic powder. This mechanism provides not only the gradual contact from center to edge to avoid air entrapment but also conformal contact between the mold and the substrate during the imprinting operation. A system based on this electromagnetic soft imprinting technology has been implemented, and imprinting to replicate microstructures from the mold onto a curved surface has been carried out. The results reveal that the PDMS magnetic mold and the electromagnetic disk‐controlled magnetic force can successfully perform the imprinting and accurately replicate the microstructures onto the large‐area, curved surface glass. The PDMS flexible magnetic mold incorporated with the magnetic disk can be employed to achieve the conformal contact between the mold and the substrate. In addition, due to the low surface free energy of the PDMS, the de‐molding without sticking can be easily accomplished. Copyright © 2008 John Wiley & Sons, Ltd.
pH sensitive microporous polypropylene membrane prepared through ozone induced surface grafting
Authors: Li Weihong , Liu Pengbo , Zou Huawei , Fan Ping , Xu Wen
Published: November 2008

Peroxide was introduced onto the microporous polypropylene (PP) membrane through ozone treatment. The acrylic acid monomer was further grafted onto the membrane by peroxide initiation. The effects of different ozone treatment and grafting conditions on the structure, tensile properties, graft yield of the membrane, and the water permeability of the grafted membrane were studied in this paper. The experimental results show that with the increase of ozone treatment time and the raising of ozone treatment temperature, more carbonyl groups (CO) and peroxide were introduced onto the microporous PP membrane. However, excessive ozone treatment made the mechanical properties of the membrane deteriorate, which means the ozone treatment time should be restricted within an appropriate range. With the increase of grafting time, concentration of acrylic acid and the raising of grafting temperature, the graft yield of microporous PP membrane increased. The graft yield could be controlled by altering these reaction conditions. After grafting, the amount of the pores in the microporous PP membrane decreased and the pore size became smaller. The water flux through the grafted membranes decreased dramatically when pH value varied from 3 to 6 because the conformation of the PAA varied significantly with the change of pH value of the contacting solution. Copyright © 2008 John Wiley & Sons, Ltd.
Characterization of complexation of PVP copolymer with DNA
Authors: Zhang Lifen , Liang Yong , Meng Lingzhi , Wang Chang
Published: November 2008

Interactions of amphiphilic copolymer poly(N‐vinylpyrrolidone‐co‐N‐t‐Boc‐ tryptophanamido‐N′‐methacrylthiourea) [P(NVP‐co‐TrpAMT)] and poly(N‐vinylpyrrlidone) (PVP) with DNA were studied with the aim to understand the difference in their complexation efficiencies when considered as a potential non‐viral delivery vector. Fluorescence spectroscopy, ethidium bromide (EB) quenching, ζ potential measurement, and agarose gel electrophoresis were all carried out in Tris‐HCl (pH 7.4) solution to assess the degree of interaction between the (co)polymers P(NVP‐co‐TrpAMT) and DNA. All of these measurements show that the high affinity of the copolymer for DNA can be demonstrated. We also found that P(NVP‐co‐TrpAMT)‐I (PVP/PTrpAMT molar ratio was 100:2.88) exhibited a high DNA cleavage activity and induced the supercoiled form of the plasmid cleavage in the nicked and linear forms.

Moreover, P(NVP‐co‐TrpAMT)‐I exhibited stronger affinity for DNA than PVP and P(NVP‐co‐TrpAMT)‐II (PVP/PTrpAMT molar ratio of 100:6.35). This phenomenon is believed to be related to the structure of TrpAMT and the hydrophobic nature of the copolymer. P(NVP‐co‐TrpAMT)‐II with higher hydrophobic segments creates a strong hydrophobic interaction and induces a steric barrier which hinders their complexation with DNA. The study reveals important information about the inner mechanisms involved in the interaction of the PVP copolymer with DNA, which aids in the design of novel efficient non‐ionic gene carriers. Copyright © 2008 John Wiley & Sons, Ltd.
High performance toughened cyanate ester resin with low injection temperature for RTM process
Authors: He Shaobo , Liang Guozheng , Yan Hongxia , Wang Jinhe , Yang Lianli
Published: November 2008

A high‐performance modified cyanate resin system with low injection temperature for fabricating advanced composites via resin transfer molding (RTM) was developed, which was made of bisphenol A dicyanate ester (BADCy) and diallyl phthalate (DAP). The processing characteristics, mechanical, and thermal properties of the resin were studied, and the effect of the content of DAP on the processing and performance parameters was discussed. The results show that the processing properties of the modified cyanate system are dependent on the content of DAP. All the formulations studied in this paper have good processing characteristics; their injection temperatures are between 30 and 40°C and the pot life is about 20 hr at 50°C. The cured resins exhibited good thermal stability, excellent toughness, and good hot–wet resistance, suggesting that the toughened cyanate resin is a potential high‐performance RTM matrix for advanced composites. Copyright © 2008 John Wiley & Sons, Ltd.
Reinforcement of compatibilized NR/NBR blends by fly ash particles and precipitated silica
Authors: Kantala C. , Wimolmala E. , Sirisinha C. , Sombatsompop N.
Published: November 2008

Effects of precipitated silica (PSi) and silica from fly ash (FA) particles (FASi) on the cure and mechanical properties before and after thermal and oil aging of natural rubber (NR) and acrylonitrile–butadiene rubber (NBR) blends with and without chloroprene rubber (CR) or epoxidized NR (ENR) as a compatibilizer have been reported in this paper. The experimental results suggested that the scorch and cure times decreased with the addition of silica and the compound viscosity increased on increasing the silica content. The mechanical properties for PSi filled NR/NBR vulcanizates were greater than those for FASi filled NR/NBR vulcanizates in all cases. The PSi could be used for reinforcing the NR/NBR vulcanizates while the silica from FA was regarded as a semi‐reinforcing and/or extending filler. The incorporation of CR or ENR enhanced the mechanical properties of the NR/NBR vulcanizates, the ENR being more effective and compatible with the blend. The mechanical properties of the NR/NBR vulcanizates were improved by post‐curing effect from thermal aging but deteriorated by the oil aging. Copyright © 2008 John Wiley & Sons, Ltd.
Diaminobisbenzothiazole chain extended polyurethanes as a novel class of thermoplastic polyurethane elastomers with improved thermal stability and electrical insulation properties
Authors: Yeganeh Hamid , Ghaffari Mehdi , Jangi Abolfazl
Published: November 2008

This work was devoted to the development of a new class of modified polyurethane as an electrical insulating material. For this purpose, NCO‐terminated urethane prepolymers at different NCO contents were prepared and chain extended by 6,6′‐oxybis(2‐aminobenzothiazole) (ABT) to produce thermoplastic polyurethane elastomers. All of the polymers were characterized by FTIR and 1HNMR spectroscopies and examined for their thermal, mechanical, and electrical properties. The dynamic mechanical measurements results showed two glass transitions indicating phase separation. A considerable improvement in the thermal and electrical properties in comparison to common polyurethanes was detected for these polymers. The level of enhancement in the measured properties was related to the polyol molecular weight, hard segment content, and consequently the amount of the introduced urea and benzothiazole moieties. These findings indicated the improved high service temperature performance of these materials as electrical insulator for metallic surfaces. Copyright © 2008 John Wiley & Sons, Ltd.
Robust method of manufacturing rubber waste‐based water repellent surfaces
Authors: Bormashenko Edward , Goldshtein Vadim , Barayev Reuven , Stein Tamir , Whyman Gene , Pogreb Roman , Barkay Zahava , Aurbach Doron
Published: November 2008

A novel method of rubber waste recycling is presented. Shredded rubber is processed into a biomimetic superhydrophobic material demonstrating high apparent contact angles (APCAs). Wetting properties of the obtained surfaces are reported. The presented method of rubber waste processing is robust, inexpensive and promises a good potential for building industry. Copyright © 2008 John Wiley & Sons, Ltd.
Dynamic characteristics of plug‐assist thermoforming process
Authors: Hosseini H. , Berdyshev B.V. , Mehrabani‐Zeinabad A.
Published: November 2008

Plug‐assist thermoforming is a well‐known technique in polymer processing because of its interesting features. The dynamic value of driving‐force for the stretching process is determined based on equilibrium equation. This amount of force is required for applying to a plug to stretch a sheet. It is used for calculation of the required theoretical work and power of a plug‐assist thermoforming process. By using a nonlinear viscoelastic rheological model in the proposed mathematical model, its validity was examined by performing experimental tests on ABS sheets. POLYM. ENG. SCI., 2009. © 2008 Society of Plastics Engineers
Evolution of rheological properties and morphology development during crosslinking of polyolefin elastomers and their TPV blends with polypropylene
Authors: Li Zuning , Kontopoulou Marianna
Published: November 2008

This work investigates the evolution of the rheological properties of elastomeric dynamically vulcanized ethylene‐α‐olefin copolymers (ECs) and their blends with polypropylene (PP), during peroxide initiated crosslinking. Rheological techniques are used in conjunction with gel content measurements to determine the onset of gelation during static crosslinking. The complex viscosity and moduli follow power‐law dependence with respect to frequency at the gel point. The relaxation exponent and corresponding values of tan δ at the gel point are determined from the complex viscosity versus frequency curves and used as criteria for the determination of the instance of gelation. The evolution of morphology of thermoplastic vulcanizate (TPV) blends consisting of EC and PP during dynamic crosslinking is discussed in the context of the evolving rheological properties of the matrix and the dispersed phase that take place upon peroxide modification. TPVs having the crosslinked EC as the matrix present a very fine morphology, whereas the blends containing crosslinked EC particles, present a coarser morphology. POLYM. ENG. SCI., 2009. © 2008 Society of Plastics Engineers
Accelerated controlled radical polymerization of methacrylates
Authors: Ansong Omari E , Jansen Susan , Wei Yen , Pomrink Gregory , Lu Hui , Patel Alpa , Li Shuxi
Published: November 2008

BACKGROUND: Nitroxide adducts 1,1‐ditertbutyl‐1‐(1‐methyl‐1‐cyanoethoxy)‐amine (AIBN/DBN), 1,1‐ditertbutyl‐1‐(benzoylperoxy)‐amine (BPO/DBN) and 2,2,6,6,‐tetramethyl‐4‐oxo‐1‐(1‐methyl‐1‐cyanoethoxy)‐piperidine (AIBN/4‐OXO‐TEMPO) were prepared and evaluated as stabilized unimolecular initiators for controlled radical polymerization of methacrylate monomers using sulfuric acid as an accelerating additive. Their effectiveness was evaluated from polymerization rates, molecular weight control and dispersity (D) of the polymers. Thermal stabilities of the polymers were also examined. The monomers used were methyl methacrylate, triethylene glycol dimethacrylate (TEGDMA) and ethoxylated bisphenol A dimethacrylate (EBPADMA).

RESULTS: Polymerization was accomplished at 70 and 130 °C in 5 min to 144 h. The value of D of poly(methyl methacrylate) (PMMA) was 1.05–1.22. The glass transition temperature (Tg) for PMMA was 122–127 °C. The activity of the chain ends was established by chain extension and controlled polymerization was established by plotting Mn versus monomer conversion. First‐order kinetics in monomer consumption was established and an electron paramagnetic resonance study was conducted. Decomposition temperature (Td) for PMMA was 360–380 °C, for poly(TEGDMA) was 300–380 °C and for poly(EBPADMA) was 360–440 °C. Photoinitiation without additive yielded no polymer. Thermal initiation by AIBN/4‐OXO‐TEMPO was the fastest.

CONCLUSIONS: The initiators are applicable in low‐temperature additive‐enhanced controlled polymerization of methacylates and dimethacrylates, producing polymers with excellent attributes and a low value of D. Copyright © 2008 Society of Chemical Industry
Hydrolyzed polyacrylonitrile‐blend‐soy protein hydrogel fibers: a study of structure and dynamic pH response
Authors: Yu Liwei , Gu Lixia
Published: November 2008

BACKGROUND: The introduction of protein into polyacrylonitrile artificial muscle systems has been shown to be a good way to achieve quicker and better responses. This research work mainly focused on the structure and dynamic pH response of hybrid hydrolyzed polyacrylonitirile‐blend‐soy protein (H‐PAN/SP) hydrogel fibers.

RESULTS: The micro‐morphology and swelling/shrinking kinetics of H‐PAN/SP hydrogel fibers were investigated using scanning electron microscopy and elongation/contraction experiments with different fiber diameters, concentration of crosslinker and temperature. The results revealed good consistency between Tanaka–Fillmore theory and the surface morphology of the multi‐porous microstructures of the fibers. In addition, the crosslinking density and temperature had a great impact on the pH response of the hydrogel fibers, consistent with Flory–Huggins theory. Hydrogel fibers with a high content of soy protein showed an excellent and stable pH response.

CONCLUSION: Studies of dynamic elongation and contraction behavior assist in the understanding and control of the pH response of H‐PAN/SP hydrogel fibers. Copyright © 2008 Society of Chemical Industry
Emulsion copolymerization of styrene and sodium styrene sulfonate: kinetics, monomer reactivity ratios and copolymer properties
Authors: Arunbabu Dhamodaran , Sanga Zomuan , Seenimeera Kamal Mohamed , Jana Tushar
Published: November 2008

BACKGROUND: The synthesis of poly[styrene‐co‐(sodium styrene sulfonate)], poly(S‐co‐NaSS), with a high loading of sulfonate groups is of current interest owing to its potential use in numerous areas. A series of these copolymers with various sulfonate loads were synthesized using the emulsion polymerization technique with a study of the copolymerization kinetics, monomer reactivity ratio and copolymer properties.

RESULTS: The copolymerization kinetics are significantly enhanced with an increase of NaSS feed in the polymerization. Monomer reactivity ratios were determined from NMR data by employing the Fineman–Ross and Kelen–Tüdös methods. Styrene (r1) and NaSS (r2) reactivity ratios are 0.5 and 10, respectively. The colloidal particle size of the copolymers depends upon the NaSS composition. The thermal stability of the copolymers is greatly enhanced with higher NaSS content in the copolymer backbone. Higher glass transition temperatures are observed for the copolymers with higher NaSS content.

CONCLUSION: The reactivity ratio values suggest that styrene prefers to form copolymers whereas NaSS produces homopolymers. It is also found that styrene copolymerization with NaSS is only twice as fast as homopolymerization. In contrast, NaSS homopolymerization is ten times faster than NaSS copolymerization with styrene. The NaSS content in the copolymer backbone affects the thermal stability and the glass transition of the copolymers. Copyright © 2008 Society of Chemical Industry
Poly(hydroxyether of bisphenol A) ‐alt‐polydimethylsiloxane: a novel thermally crosslinkable alternating block copolymer
Authors: Wang Lei , Gong Wei , Zheng Sixun
Published: November 2008

BACKGROUND: An important strategy for making polymer materials with combined properties is to prepare block copolymers consisting of well‐defined blocks via facile approaches.

RESULTS: Poly(hydroxyether of bisphenol A)‐block‐polydimethylsiloxane alternating block copolymers (PH‐alt‐PDMS) were synthesized via Mannich polycondensation involving phenolic hydroxyl‐terminated poly(hydroxyether of bisphenol A), diaminopropyl‐terminated polydimethylsiloxane and formaldehyde. The polymerization was carried out via the formation of benzoxazine ring linkages between poly(hydroxyether of bisphenol A) and polydimethylsiloxane blocks. Differential scanning calorimetry and small‐angle X‐ray scattering show that the alternating block copolymers are microphase‐separated. Compared to poly(hydroxyether of bisphenol A), the copolymers displayed enhanced surface hydrophobicity (dewettability). In addition, subsequent crosslinking can occur upon heating the copolymers to elevated temperatures owing to the existence of benzoxazine linkages in the microdomains of hard segments.

CONCLUSION: PH‐alt‐PDMS alternating block copolymers were successfully obtained. The subsequent self‐crosslinking of the PH‐alt‐PDMS alternating block copolymers could lead to these polymer materials having potential applications. Copyright © 2008 Society of Chemical Industry
Inclusion of ionization states of ligands in affinity calculations
Authors: Donnini Serena , Villa Alessandra , Groenhof Gerrit , Mark Alan E. , Wierenga Rik K. , Juffer André H.
Published: November 2008

When estimating binding affinities of a ligand, which can exists in multiple forms, for a target molecule, one must consider all possible competing equilibria. Here, a method is presented that estimates the contribution of the protonation equilibria of a ligand in solution to the measured or calculated binding affinity. The method yields a correction to binding constants that are based on the total concentration of inhibitor (the sum of all ionized forms of the inhibitor in solution) to account for the complexed form of the inhibitor only. The method is applied to the calculation of the difference in binding affinity of two inhibitors, 2‐phosphoglycolate (PGA) and its phoshonate analog 3‐phosphonopropionate (3PP), for the glycolytic enzyme triosephosphate isomerase. Both inhibitors have three titrating sites and exist in solution as a mixture of different forms. In this case the form that actually binds to the enzyme is present at relative low concentrations. The contributions of the alternative forms to the difference in binding energies is estimated by means of molecular dynamics simulations and corrections. The inhibitors undergo a pKa shift upon binding that is estimated by ab initio calculations. An interesting finding is that the affinity difference of the two inhibitors is not due to different interactions in the active site of the enzyme, but rather due to the difference in the solvation properties of the inhibitors. Protein 2009. © 2008 Wiley‐Liss, Inc.
Geometric characteristics of hydrogen bonds involving sulfur atoms in proteins
Authors: Zhou Peng , Tian Feifei , Lv Fenglin , Shang Zhicai
Published: November 2008

Sulfur atoms have been known to participate in hydrogen bonds (H‐bonds) and these sulfur‐containing H‐bonds (SCHBs) are suggested to play important roles in certain biological processes. This study aims to comprehensively characterize all the SCHBs in 500 high‐resolution protein structures (≤1.8 Å). We categorized SCHBs into six types according to donor/acceptor behaviors and used explicit hydrogen approach to distinguish SCHBs from those of nonhydrogen bonding interactions. It is revealed that sulfur atom is a very poor H‐bond acceptor, but a moderately good H‐bond donor. In α‐helix, considerable SCHBs were found between the sulphydryl group of cysteine residue i and the carbonyl oxygen of residue i‐4, and these SCHBs exert effects in stabilizing helices. Although for other SCHBs, they possess no specific secondary structural preference, their geometric characteristics in proteins and in free small compounds are significantly distinct, indicating the protein SCHBs are geometrically distorted. Interestingly, sulfur atom in the disulfide bond tends to form bifurcated H‐bond whereas in cysteine‐cysteine pairs prefer to form dual H‐bond. These special H‐bonds remarkably boost the interaction between H‐bond donor and acceptor. By oxidation/reduction manner, the mutual transformation between the dual H‐bonds and disulfide bonds for cysteine‐cysteine pairs can accurately adjust the structural stability and biological function of proteins in different environments. Furthermore, few loose H‐bonds were observed to form between the sulphydryl groups and aromatic rings, and in these cases the donor H is almost over against the rim rather than the center of the aromatic ring. Proteins 2009. © 2008 Wiley‐Liss, Inc.
Comparisons of experimental and computed protein anisotropic temperature factors
Authors: Yang Lei , Song Guang , Jernigan Robert L.
Published: November 2008

Because of its appealing simplicity, the anisotropic network model (ANM) has been widely accepted and applied to study many molecular motion problems: such as ribosome motions, the molecular mechanisms of GroEL‐GroES function, allosteric changes in hemoglobin, motor‐protein motions, and conformational changes in general. However, the validity of the ANM has not been closely examined. In this work, we use ANM to predict the anisotropic temperature factors of proteins obtained from X‐ray and NMR data. The rich, directional anisotropic temperature factor data available for hundreds of proteins in the protein data bank are used as validation data to closely test the ANM model. The significance of this work is that it presents a timely, important evaluation of the model, shows the extent of its accuracy in reproducing experimental anisotropic temperature factors, and suggests ways to improve the model. An improved model will help us better understand the internal dynamics of proteins, which in turn can greatly expand the usefulness of the models, which has already been demonstrated in many applications. Proteins 2009. © 2008 Wiley‐Liss, Inc.
The dynamics of heat lows over flat terrain
Authors: Spengler Thomas , Smith Roger K.
Published: November 2008

The numerical model for a heat low developed by Rácz and Smith is extended to include a representation of radiative heating and cooling. The model is run with a higher horizontal resolution than the original version and is used to investigate additional dynamical aspects of the structure and evolution of a heat low over a subcontinental‐ or continental‐scale circular island surrounded by sea. Of particular interest is the diurnal and day‐to‐day evolution of the upper‐ and lower‐level circulations and the degree of balance that exists in these. The heat low is surmounted by an anticyclone, the development of which is closely tied to the outflow branch of the sea breeze. The anticyclone has a much smaller diurnal variation than the heat low and, unlike the heat low is largely in balance, except in the region affected by the upward‐propagating gravity wave induced by the inland‐penetrating sea breeze. There is a strong analogy to certain aspects of tropical cyclones, which have a warm core, a shallow unbalanced boundary layer, and which are surmounted also by an anticyclone. Principles governing the absolute angular momentum budget are the same as those relating to the tropical cyclones and to the zonal‐mean flow over Antarctica. Implications of these principles for obtaining a realistic steady state in long‐term integrations of axisymmetric models are discussed. Copyright © 2008 Royal Meteorological Society
Structural Parameter Characterization and Bioactivity Simulation Based on Peptide Sequence
Authors: Shu Mao , Mei Hu , Yang Shanbin , Liao Limin , Li Zhiliang
Published: November 2008

In this paper, a new set of descriptors, Hydrophobic, Electronic, Steric, and Hydrogen (HESH) (principal components scores vectors of the HESH bond contribution properties), were derived from Principal Component Analysis (PCA) on the collected 171 physicochemical properties of 20 coded amino acids. By applying HESH descriptors to Quantitative Structure–Activity Relationship (QSAR) study on three peptides including 58 Angiotensin‐Converting Enzyme (ACE) inhibitors, 48 bitter‐tasting dipeptides, and 20 thromboplastin inhibitors, we get three excellent Partial Least Squares (PLS) models, with the squared multiple correlation coefficients (R$\rm{ _{{\rm{cum}}}^{\rm{2}} }$), cross‐validation (R$\rm{ _{{\rm{cum}}}^{\rm{2}} }$), and Root Mean Square Error (RMSE) of 0.877, 0.838, and 0.361 for ACE inhibitors, 0.926,0.865, and 0.172 for bitter‐tasting dipeptides and 0.996, 0.865, and 0.115 for thromboplastin inhibitors. These results were superior to many other reported researches. It showed that HESH may be a useful structural expression method for the study on QSAR of peptide.
Linear Free Energy Relationship Correlation of The Distribution of Solutes Between Water And Cetytrimethylammonium Bromide (CTAB) Micelles
Authors: Sprunger Laura M. , Gibbs Jennifer , Acree William E. , Abraham Michael H.
Published: November 2008

Data have been assembled from the published literature on the water‐to‐micellar Cetyltrimethylammonium Bromide (CTAB) partition coefficient data for more than 60 compounds, and on the Micellar Electrokinetic Chromatographic (MEKC) retention factors for more than 50 compounds measured on a CTAB pseudostationary phase. In total more than 200 experimental data have been compiled. The water‐to‐micellar CTAB partition coefficients and MEKC retention factor data from three separate studies have been combined into a single database and correlated with the Abraham model. The derived correlation described the 200 experimental values to within a standard deviation of 0.175 log units. Also, the previously derived Abraham model correlation for water‐to‐micellar Sodium Dodecylsulfate (SDS) was updated to include MEKC retention factor data from the five recent experimental studies. The new repression correlation for SDS is based on 706 experimental values. Principal component analysis showed that water‐to‐micellar surfactant partition systems are good models for non‐polar and polar narcotic toxicities of organic compounds toward fish, water fleas, and other aquatic organisms.
Toward a cross‐layer monitoring process for mobilead hocnetworks
Authors: Rachedi Abderrezak , Benslimane Abderrahim
Published: November 2008

The intrusion detection system (IDS) for mobilead hocnetworks (MANET) consists in monitoring the nodes' behavior, in order to detect the malicious activity of nodes. Many existing solutions deal with the problem at each layer separately. But new kinds of misbehavior attacks are cross‐layer attacks. And such smart misbehaviors cannot be detected at the level of one layer. In this paper, we propose a new cross‐layer approach based on physical, MAC, and routing layers for a monitoring mechanism. A new analytical model is proposed to illustrate the parameters' effect on these different layers. The impact of the signal to noise ratio (SNR) and the distance between monitor and monitored nodes are clearly introduced. Moreover, the difference between the carrier sense, the interference range, and the transmission range is taken into account in our model. The proposed model improves the evaluation of the nodes' cooperation and reduces the risk of having any false positive rate. The analytical study and simulation results illustrate our purpose. In addition, with the simulations' results, we illustrate the impact of the distance between monitor and monitored nodes on the monitoring mechanism. Finally, we show that our cross‐layer mechanism has a lower false positive rate than the classical Watchdog mechanism in different network's parameters such as the nodes' density, the speed mobility, and the different traffic loads. Copyright © 2008 John Wiley & Sons, Ltd.
Integrating fingerprint with cryptosystem for internet‐based live pay‐TV system
Authors: Hou Shuhui , Uehara Tetsutaro , Satoh Takashi , Morimura Yoshitaka , Minoh Michihiko
Published: November 2008

In the last few years, live pay‐TV systemviathe Internet has come to be established with the development of broadband network. To develop such a system, a mechanism for content protection is required. In this paper, a new architecture integrating fingerprint with cryptosystem is proposed to protect digital contents (image and video) from unauthorized viewing and illegal redistribution. Then, a scheme integrating anti‐collusion code and Home Page public‐key cryptosystem (PKC) is described. Such a scheme is shown feasible and realistic for implementing with respect to computation/transmission cost. Copyright © 2008 John Wiley & Sons, Ltd.
Mie and Bragg Plasmons in Subwavelength Silver Semi‐Shells
Authors: Maaroof Abbas I. , Cortie Michael B. , Harris Nadine , Wieczorek Lech
Published: November 2008

2D arrays of silver semi‐shells of 100 and 200 nm diameter display complex reflection and transmission spectra in the visible and near‐IR. Here these spectral features are deconstructed and it is demonstrated that they result from the coupling of incident light into a delocalized Bragg plasmon, and the latter's induction of localized Mie plasmons in the arrays. These phenomena permit the excitation of transverse dipolar plasmon resonances in the semi‐shells despite an ostensibly unfavorable orientation with respect to normally incident light. The resulting spectral feature in the mid‐visible is strong and tunable.
Single‐Walled Carbon‐Nanotube Networks on Large‐Area Glass Substrate by the Dip‐Coating Method
Authors: Jang Eui Yun , Kang Tae June , Im Hyeoung Wook , Kim Dae Weon , Kim Yong Hyup
Published: November 2008

Highly uniform and large‐area single‐walled carbon‐nanotube (SWNT) networks are realized by the dip‐coating method, which is based on fundamental fluid‐dynamic phenomena such as capillary condensation and surface tension. The changes in the polarity and hydration properties of the substrate affect the morphology of the SWNT networks and result in nonlinear growth of the networks in the repetitive dip‐coating process. The density and the thickness of the SWNT networks are controlled by processing variables including number of dip coatings, concentration of SWNT colloidal solution, and withdrawal velocity. The networks have uniform sheet resistances and high optical transmittance in the visible wavelength range.
Room‐Temperature Synthetic Pathways to Barium Titanate Nanocrystals
Authors: Beier Christopher W. , Cuevas Marie A. , Brutchey Richard L.
Published: November 2008

Novel room‐temperature pathways to BaTiO3nanocrystals have been recently developed, which stand in contrast to traditional high‐temperature methods. Peptide‐assisted, bio‐facilitated routes have been developed for low‐temperature nanocrystal growth, in addition to two low‐temperature routes completely independent of biomolecules. These innovative methods lay the groundwork for the facile production of nanoscale BaTiO3in economical and energy‐efficient ways.
Postexposure prophylaxis following sexual exposure to HIV
Authors: Shanmuga Sundaram Sangeetha , Mani Reena
Published: November 2008

Postexposure prophylaxis following sexual exposure to HIV should be prescribed on a case‐by‐case basis. The authors explain how to assess the risk from what is known about the source and exposure, and consider the benefits and challenges of this treatment. Copyright © 2008 Wiley Interface Ltd
A randomized study to assess two different techniques of aspiration while performing transabdominal chorionic villus sampling
Authors: Battagliarin G. , Lanna M. , Coviello D. , Tassis B. , Quarenghi A. , Nicolini U.
Published: November 2008

Objective

The technique used to perform transabdominal chorionic villus sampling (CVS) is not standardized, but aspiration of villi is generally obtained by discontinuous vacuum created in a syringe, manually or by a hand‐grip device. We evaluated the feasibility of a new method of performing CVS which employs a 4‐mL Vacutainer® connected to the needle, producing a continuous negative pressure.

Methods

Two hundred pregnant women, whose gestational age ranged from 10 + 2 to 16 + 2 (mean, 12 + 1) weeks, entered the randomized study, which was powered to detect with 90% probability the absence of any difference in the size of chorionic samples obtained by using a 20‐mL syringe with the vacuum obtained by a hand‐grip device (Group 1) or by a vacutainer (Group 2). Four operators with different levels of experience performed all the procedures, which were done transabdominally using a freehand technique with a 20‐gauge needle under ultrasound guidance.

Results

Maternal age, body mass index, gestational age and the way the needle was inserted within the chorion were similar in the two groups. The median amount of villi sampled was 20 mg, with no differences between the two groups. The rate of fetal loss was 1.7%. All losses occurred in women of Group 1 who had only one needle insertion. A second needle insertion was required more frequently while using the vacutainer.

Conclusion

This new technique for performing transabdominal CVS uses a readily available device and is as effective as traditional sampling systems to aspirate villi. It has the advantage of being a one‐operator procedure. Copyright © 2008 ISUOG. Published by John Wiley & Sons, Ltd.
Reactivity of [(Ph2Si)2O3]4[Al(OH)]4 and [(Ph2Si)2O3]4[Al(OLi)]4 towards NaOEt and LiOH. Synthesis of New Twelve‐membered Alumopolysiloxane Rings
Authors: Veith Michael , Smail Hakima , Huch Volker
Published: November 2008

The reaction between [(Ph2Si)2O3]4[Al(OH)]4 (1) or [(Ph2Si)2O3]4[Al(OLi)]4 (2) with sodium ethoxide, or lithium hydroxide in presence of CuI·H2O leads to the formation of new alumopolysiloxane compounds. Indeed, transformations of 1 under the partial incorporation of the reactants are found giving rise to new heteroleptic inorganic macrocycles. The molecular structure of [(Ph2Si)2O3]4[Al(ONa)]2[Al(OH)(NaOEt)]2·2Et2O (3) and [(Ph2Si)2O3]4[Al(OLi)]2[Al(OH)(LiOH)]2·2Et2O·2THF (4) have been determined by single‐X‐ray diffraction analysis. Both alumosiloxanes 3 and 4 are constituted by a twelve‐membered ring.
Three New Thioantimonates(V): Solvothermal Syntheses and Crystal Structures of [M(chxn)3]3(SbS4)2·4H2O (M = Ni, Co) and [Co(dien)2][Co(tren)SbS4]2·4H2O
Authors: Engelke Lars , Näther Christian , Leisner Phillipp , Bensch Wolfgang
Published: November 2008

The three new thioantimonates(V) [Ni(chxn)3]3(SbS4)2·4H2O (I), [Co(chxn)3]3(SbS4)2·4H2O (II) (chxn is trans‐1,2‐diaminocyclohexane) and [Co(dien)2][Co(tren)SbS4]2·4H2O (III) (dien is diethylenetriamine and tren is tris(2‐aminoethyl)amine) were synthesized under solvothermal conditions. Compounds I and II are isostructural crystallizing in space group C2/c. The structures are composed of isolated [M(chxn)3]2+ complexes (M = Ni, Co), [SbS4]3− anions and crystal water molecules. Short S···N/S···O/O···O separations indicate hydrogen bonding interactions between the different constituents. Compound III crystallizes in space group $P{\bar 1}$ and is composed of [Co(dien)2]2+ and [Co(tren)SbS4]− anions and crystal water molecules. In the cationic complex the Co2+ ion is in an octahedral environment of two dien ligands whereas in [Co(tren)SbS4]− the Co2+ ion is in a trigonal bipyramidal coordination of four N atoms of tren and one S atom of the [SbS4]3− anion, i.e., two different coordination polyhedra around Co2+ coexist in this compound. Like in the former compounds an extended hydrogen bonding network connects the complexes and the water molecules into a three‐dimensional network.
Relativité et réalité Nottale, Simondon et le réalisme des relations
Authors: Barthélémy Jean-Hugues , Bontems Vincent
Published: November 2008

L'épuisement de la querelle du réalisme en physique, qui est la conséquence épistémologique de la divergence inexplicable entre mécanique quantique et physique relativiste, manifeste la nécessité d'un dépassement de l'opposition traditionnelle entre réalisme et antiréalisme. La Théorie de la Relativité d'Échelle de Laurent Nottale, dans la mesure où elle vise à réunifier microphysique et macrophysique grâce aux concepts d'espace-temps fractal et de dépendance d'échelle, opère le dépassement de cette opposition en postulant la valeur d'être des relations physiques. L'exigence d'un réalisme des relations en physique confirme ainsi les intuitions de la philosophie de l'individuation de Gilbert Simondon, qui jugeait nécessaire d'accorder à la relation une valeur ontologique pour fonder la «synthèse grandiose de la relativité et des quanta ».
Relativité d'échelle et morphogenèse
Authors: Norrale Laurent
Published: November 2008

La théorie de la relativité d'échelle se propose de généraliser les lois de la mécanique à un mouvement continu mais non-différentiable. Cela implique trois conséquences au moins: a) l'espace-temps et donc ses géodésiques deviennent fractals; b) il existe une infinité de géodésiques entre deux points, ce qui conduit à une description non-déterministe; c) le concept de vitesse se dédouble, ce qu'on traduit par un formalisme complexe. L'équation fondamentale de la dynamique s'intègre alors sous forme d'une équation de Schrôdinger, dont les solutions définissent des densités de probabilité qui peuvent s'interpréter en termes de morphologies naturellement hiérarchisées. Cette approche théorique conduit également à proposer des généralisations aux lois invariantes d'échelle, susceptibles d'applications dans des domaines autres que la physique.
Process algebraic modelling of attentional capture and human electrophysiology in interactive systems
Authors: Su Li , Bowman Howard , Barnard Philip , Wyble Brad
Published: November 2008

Previous research has developed a formal methods-based (cognitive-level) model of the Interacting Cognitive Subsystems central engine, with which we have simulated attentional capture in the context of Barnard’s key-distractor Attentional Blink task. This model captures core aspects of the allocation of human attention over time and as such should be applicable across a range of practical settings when human attentional limitations come into play. In addition, this model simulates human electrophysiological data, such as electroencephalogram recordings, which can be compared to real electrophysiological data recorded from human participants. We have used this model to evaluate the performance trade-offs that would arise from varying key parameters and applying either a constructive or a reactive approach to improving interactive systems in a stimulus rich environment. A strength of formal methods is that they are abstract and the resulting specifications of the operator are general purpose, ensuring that our findings are broadly applicable. Thus, we argue that new modelling techniques from computer science can also be employed in computational modelling of the mind. These would complement existing techniques, being specifically targeted at psychological level modelling, in which it is advantageous to directly represent the distribution of control.
Lower annual fecundity in long-distance migrants than in less migratory birds of temperate Europe
Authors: Bruderer Bruno , Salewski Volker
Published: November 2008

We use widely supported handbook data on annual fecundity (clutch size × annual number of normal broods) to obtain indications related to the relative costs of long-distance migration compared to lower levels of migratoriness. Our examples show that the yearly production of eggs in congeneric passerines of similar size from temperate Europe is lower in long-distance migrants than in their less migratory relatives. The same tendency shows up in a more heterogeneous sample of non-passerines. In most passerines and in one among five pairs of non-passerines, this is due to longer breeding periods allowing a higher number of clutches in the less migratory species in spite of a tendency towards larger clutches in the passerine long-distance migrants. If both migratory types have only one clutch (as in one species pair of the passerines and in four non-passerine pairs) the trend towards larger clutches was reversed between the two types. The higher fecundity of the less migratory species suggests that wintering under harsh conditions may be more expensive than trans-Sahara migration among similar species. In keeping with this result, Ortolan and Rock Buntings (Emberiza hortulana and E. cia) breeding syntopically (and, in the 1980s, still in relatively stable populations) in an inner Alpine valley provide a well-studied example illustrating the high longevity of the migrants compared to the relatively short life span of the residents.
Pharmacokinetics of tetrahydrobiopterin following oral loadings with three single dosages in patients with phenylketonuria
Authors: Gramer G. , Garbade S. F. , Blau N. , Lindner M.
Published: November 2008

Background:

Tetrahydrobiopterin (BH4) loading has been performed for many years in patients detected by newborn screening for hyperphenylalaninaemia (HPA) to distinguish BH4 cofactor synthesis or recycling defects from phenylalanine hydroxylase (PAH)‐deficient HPA. Previous studies have shown that the pharmacokinetics of BH4 shows high intra‐individual and inter‐individual variability.

Methods:

Seventeen adult patients with PAH‐deficient HPA were classified in one of three phenotypic groups (mild, moderate, classical PKU) according to their response to a standardized protein loading test. Genotype information was available for all participants. In a randomized controlled double‐blind design, BH4 loadings in single oral dosages of 10, 20 and 30 mg BH4/kg body weight (bw) were performed to assess BH4 responsiveness. As part of this study, levels of BH4 metabolites in dried blood spots were studied to provide information on the pharmacokinetics of BH4 following oral administration.

Results:

Levels of biopterin and pterin (B + P) increased significantly with increasing BH4 dose (p < 0.0001). Maximum B + P levels were reached 4 hours after application of BH4. There was no significant difference in BH4 pharmacokinetics between the three phenotypic groups of PKU. Male and female patients showed different levels of BH4 metabolites following 10 mg BH4/kg bw, but not following 20 and 30 mg BH4/kg bw. There was no relationship between age of patients and BH4 pharmacokinetics. There was no correlation between B + P levels and decrease in Phe level (p = 0.69).

Conclusion:

BH4 pharmacokinetics are variable between patients regarding absolute levels of BH4 metabolites reached after BH4 loading, but are similar regarding the interval to individual maximum B + P levels. Levels of B + P increase significantly with increasing BH4 doses. There is no correlation between B + P levels and decrease in Phe level.
International cooperation in the expansion of a newborn screening programme in Lebanon: a possible model for other programmes
Authors: Khneisser I. , Adib S. M. , Megarbane A. , Lukacs Z.
Published: November 2008

Tandem mass spectrometry (MS/MS) is rapidly gaining support, even in less‐developed nations, as the method of choice for the newborn screening of metabolic disorders, although difficulties in acquiring this technology may at times be major obstacles in several Middle East and North Africa (MENA) countries. In Lebanon, international cooperation allowed this acquisition at the Newborn Screening Laboratory (NSL) of the Saint Joseph University (USJ) in the capital city of Beirut. NSL is currently screening up to 20% of all newborns in Lebanon. The expansion was made possible through initial collaboration with the Metabolic Laboratory at the Hamburg University Medical Center (HUMC) and subsequently with other centres. During phase I of the expansion (2006–2007), blood spots were shipped to HUMC with rapid couriers twice a week and electronic reports were sent back generally within 4 days after shipment. Positive cases were recalled to NSL and new specimens were sent back for confirmation at HUMC. During that first phase, the Beirut staff received training at the HUMC and in other centres. Phase II was a transitory period of 4 months during which machines were installed in Beirut and working procedures were adopted and documented. The activity has now entered a consolidation phase (Phase III) in which all measurements are exclusively performed in Beirut while HUMC acts as a backup centre. International cooperation remains crucial for periodic quality assurance procedures, and for supporting the transformation of the USJ‐NSL into a training centre able to transfer MS/MS technology to the MENA region.
Hypoxanthine‐guanine phosphoribosylotransferase deficiency—The spectrum of Polish mutations
Authors: Jurecka A. , Popowska E. , Tylki‐Szymanska A. , Kubalska J. , Ciara E. , Krumina Z. , Sykut‐Cegielska J. , Pronicka E.
Published: November 2008

Hypoxanthine‐guanine phosphoribosyltransferase (HPRT; EC 2.4.2.8) deficiency (OMIM 308000) is an inborn error of purine metabolism. The defect causes three overlapping clinical syndromes: Lesch–Nyhan disease (LND; OMIM 300322), HPRT‐related hyperuricaemia with neurologic dysfunction (HRND) and hyperuricaemia alone (HRH; OMIM 300322). During the period 1977–2007, 18 patients belonging to 12 Polish families and one Latvian family with HPRT deficiency have been identified. The majority of patients had a typical LND phenotype, three patients were classified as HRH and one patient as an intermediate phenotype (HRND). Genetic analysis revealed 12 different HPRT1 mutations, five of them being unique. In two typical Lesch–Nyhan families a novel single‐base substitution, c.220T>G (p.Phe74Val), and a deletion of seven nucleotides, c.395_401del7 (p.Ile132LysfsX3), were found. Another novel single‐base substitution, c.295T>G (p.Phe99Val), was identified in a patient with severe partial deficiency of HPRT with neurological dysfunction. In patients belonging to the HRH group, two transitions were detected: c.481G>A (p.Ala161Thr) and c.526C>T (p.Pro176Ser). Other mutations identified in Polish patients, c.131A>G (p.Asp44Gly), c.222C>A (p.Phe74Leu), c.385–1G>A (p.Asn129_Glu134del), c.482C>A (p.Ala161Glu), c.508C>T (p.Arg170Ter) and c.569G>A (p.Gly190Glu), have been reported previously in unrelated patients and are located within one of the clusters of hot spots of the HPRT1 gene (exons 3, 7 and 8). Patients with partial phenotypes presented mutations predicted to permit some degree of residual enzyme function (single‐base substitutions). All mutations, except c.508C>T (p.Arg170Ter), were found in single families only, indicating the lack of any common mutation causing HPRT deficiency in Poland.
Thermosensitive Nanocables Prepared by Surface-Initiated Atom Transfer Radical Polymerization
Authors: Wei Qingshan , Zhou Wenbo , Ji Jian , Shen Jiacong
Published: November 2008

Thermosensitive nanocables consisting of Au nanowire cores and poly(N-isopropylacrylamide) sheaths (denoted as Au/PNIPAAm) were synthesized by surface-initiated atom transfer radical polymerization (SI-ATRP). The formation of PNIPAAm sheath was verified by Fourier transform infrared (FTIR) and hydrogen nuclear magnetic resonance (1H NMR) spectroscopy. Transmission electron microscope (TEM) results confirmed the core/shell structure of nanohybrids. The thickness and density of PNIPAAm sheaths can be adjusted by controlling the amount of cross-linker during the polymerization. Signature temperature response was observed from Au/cross-linked-PNIPAAm nanocables. Such smart nanocables show immense potentials as building blocks for novel thermosensitive nanodevices in future.