bluuebunny/crossref_metadata_2025 huggingface dataset:
CCN family 2/connective tissue growth factor (CCN2/CTGF) promotes osteoclastogenesis via induction of and interaction with dendritic cell–specific transmembrane protein (DC-STAMP)
Authors: Nishida Takashi , Emura Kenji , Kubota Satoshi , Lyons Karen M , Takigawa Masaharu
Published: August 2010

CCN family 2/connective tissue growth factor (CCN2/CTGF) promotes endochondral ossification. However, the role of CCN2 in the replacement of hypertrophic cartilage with bone is still unclear. The phenotype of Ccn2 null mice, having an expanded hypertrophic zone, indicates that the resorption of the cartilage extracellular matrix is impaired therein. Therefore, we analyzed the role of CCN2 in osteoclastogenesis because cartilage extracellular matrix is resorbed mainly by osteoclasts during endochondral ossification. Expression of the Ccn2 gene was upregulated in mouse macrophage cell line RAW264.7 on day 6 after treatment of glutathione S transferase (GST) fusion mouse receptor activator of NF-κB ligand (GST-RANKL), and a combination of recombinant CCN2 (rCCN2) and GST-RANKL significantly enhanced tartrate-resistant acid phosphatase (TRACP)–positive multinucleated cell formation compared with GST-RANKL alone. Therefore, we suspected the involvement of CCN2 in cell-cell fusion during osteoclastogenesis. To clarify the mechanism, we performed real-time PCR analysis of gene expression, coimmunoprecipitation analysis, and solid-phase binding assay of CCN2 and dendritic cell–specific transmembrane protein (DC-STAMP), which is involved in cell-cell fusion. The results showed that CCN2 induced and interacted with DC-STAMP. Furthermore, GST-RANKL–induced osteoclastogenesis was impaired in fetal liver cells from Ccn2 null mice, and the impaired osteoclast formation was rescued by the addition of exogenous rCCN2 or the forced expression of DC-STAMP by a retroviral vector. These results suggest that CCN2 expressed during osteoclastogenesis promotes osteoclast formation via induction of and interaction with DC-STAMP. © 2011 American Society for Bone and Mineral Research.
A comparison of client preferences for intervention empirical support versus common therapy variables
Authors: Swift Joshua K. , Callahan Jennifer L.
Published: August 2010

Client preferences have been identified as an essential part of evidence‐based practice in psychology. Further, client preferences have been found to play an important role in determining premature termination and therapy outcomes. However, our current understanding of this client variable is limited because of the methodologies that have previously been used to assess these preferences. In this study, 57 adult clients from a university‐based psychology department clinic completed an instrument weighing preferences for intervention specific empirical support against preferences for 4 other common factor variables. These clients were found to discount a significant amount of intervention empirical support to ensure the following: (a) a satisfactory therapeutic relationship could be developed, (b) their therapist would be empathetic and accepting, (c) their therapist would have a greater level of experience, and (d) they, as clients, would do more of the talking during sessions. These findings suggest that clients prefer treatment decisions to be based on variables other than intervention empirical support alone. Recommendations are made for assessing and including client preferences to provide more individually tailored interventions. © 2010 Wiley Periodicals, Inc. J Clin Psychol 66:1–15, 2010.
The clinical utility of a brief measure of perceived burdensomeness and thwarted belongingness for the detection of suicidal military personnel
Authors: Bryan Craig J.
Published: August 2010

Perceived burdensomeness (PB) and thwarted belongingness (TB) are important indicators of suicide risk; however, limited research has investigated applicability to military populations, and no efforts have been initiated to translate these constructs into easily implemented clinical tools. The current study examined the structure and validity of a brief self‐report survey of PB and TB, the 10‐item Interpersonal Needs Questionnaire (INQ‐10), among a sample of 219 deployed military personnel. Factor analysis confirmed that PB and TB are distinct, and are correlated with psychiatric symptomatology. Receiver operating characteristic analyses indicated the most useful cutoff scores were PB=1 and TB=3.2. Both scales significantly improved the ability to rule‐in and rule‐out current suicide ideation among deployed service members. © 2010 Wiley Periodicals, Inc. J Clin Psychol 67:981–992, 2011.
Mediator toxicity and dual effect of glucose on the lifespan for current generation by Cyanobacterium Synechocystis PCC 6714 based photoelectrochemical cells
Authors: Xie Xuan‐Hui , Li Erin Lin , Kang Tang Zi
Published: August 2010

BACKGROUND: The capability of cyanobacteria to convert carbon dioxide into carbohydrates offers a promising carbon‐neutral energy solution. Unfortunately, the lifespan of cyanobacteria based photoelectrochemical cells is poor because discharge current drops to zero within days. The primary factor that limits lifespan was believed to be the toxicity of an artificial mediator that extracts electrons from cyanoacteria to electrode. It is critical to experimentally identify the true limiting factor such that we could prolong the lifespan for practical use.

RESULTS: Systematic tests on cell physiology and current discharge were performed in autotrophic and heterotrophic conditions. Contrary to previous belief, results for cell viability, chlorophyll content and growth curve of Cyanobacterium Synechocystis PCC 6714 under continuous vitamin K3‐mediated current discharge did not exhibit any toxic effect. The role of glucose was then investigated. Surprisingly, discharge current dropped to zero although there was significant intracellular glycogen (2.5 × 10−10 mg cell−1). Further tests of current response to the addition of exogenous glucose suggest the regulatory role of glucose on cyanobacterial metabolism that is relevant to current generation. Furthermore, current generation in the light and dark conditions corroborates glucose as energy reserve.

CONCLUSION: It is not mediator toxicity but the regulatory effect of glucose on the metabolism of cyanobacteria that limits the lifespan for current generation. Glucose functions in a dual role as energy reserve and regulatory molecule to modulate cyanobacterial metabolism related to current generation. Copyright © 2010 Society of Chemical Industry
Effect of PEG4000 on cellulase catalysis in the lignocellulose saccharification processes
Authors: Zhang Yuqing , Zhang Yuefeng , Tang Linru
Published: August 2010

BACKGROUND: Lignocellulose is a large source of biomass. However, the conversion ratio of lignocellulose into fermentable sugars is quite low, and the saccharification process requires lots of enzyme. In order to improve biocatalysis efficiency of cellulase for lignocellulose, poly ethylene glycol (PEG4000) is added to the above process. The effect of the order of addition of PEG4000 and cellulase on lignocellulose saccharification processes, and the interaction between PEG4000 and eocellobiohydrolase I (CBH I) were investigated by DNS, UV absorption spectra and Fourier transform infrared (FTIR) spectroscopy.

RESULTS: Results show that different orders of addition of PEG4000 and cellulase have a strong influence on the saccharification process, and both orders of addition can improve the saccharification rate. In particular, the addition of PEG4000 before cellulase can reduce wasteful cellulase adsorption on the lignin, and the saccharification rate of lignocellulose can be significantly improved. Without corn stover (substrate) in the saccharification process, examinations by UV absorption spectra and FTIR demonstrate that the interactions between PEG4000 and CBH I are hydrogen bonds and hydrophobic interaction. In addition, it is found that the activity of CBH I is decreased with increasing interaction time and the amount of the PEG4000 added in the saccharification process.

CONCLUSION: The addition of PEG4000 before cellulase to lignocellulose saccharification processes is a reasonable way to improve the saccharification rate of lignocellulose. Copyright © 2010 Society of Chemical Industry
Respiratory mucosal immunization with adenovirus gene transfer vector induces helper CD4 T cell‐independent protective immunity
Authors: Mu Jingyu , Jeyanathan Mangalakumari , Shaler Christopher R. , Horvath Carly , Damjanovic Daniela , Zganiacz Anna , Kugathasan Kapilan , McCormick Sarah , Xing Zhou
Published: August 2010

Background

Virus‐vectored vaccine is a powerful activator of CD8 T cell‐mediated immunity and is especially amenable to respiratory mucosal immunization, offering hopes for use in humans with diminished helper CD4 T cell function. However, whether virus‐mediated mucosal immunization can produce immune protective CD8 T cells without the CD4 T cell help remains to be investigated.

Methods

We used a replication‐deficient adenovirus vector expressing an Mycobacterium tuberculosis antigen Ag85A for intranasal vaccination and evaluated its effect on CD8 T cell activation and protection in mice depleted of CD4 T cells.

Results

Intranasal vaccination of CD4 T cell‐depleted mice led to suboptimal generation of Ag‐specific tetramer+ or interferon (IFN)‐γ‐producing CD8 T cells in the lung and spleen but this was observed mainly at the early time after vaccination. Reduced CD8 T cell priming was also accompanied by decreased CD8 T cell responses (CTL). Nevertheless, the ratio of Ag‐specific CD8 T cells to IFN‐γ‐producing CD8 T cells in CD4 T cell‐depleted hosts remained comparable to that in CD4 T cell‐competent hosts. Furthermore, the ‘unhelped’ CD8 T cells also displayed a similar immune phenotype as the ‘helped’ counterparts. The animals with ‘unhelped’ CD8 T cells were as well‐protected from pulmonary M. tuberculosis challenge as those with ‘helped’ CD8 T cells in the absence of CD4 T cells.

Conclusions

The data obtained in the present study suggest that the fully immune protective CD8 T cells can still be generated by respiratory mucosal viral‐mediated immunization without CD4 T cells and that CD8 T cells, ‘helped’ or ‘unhelped’, can confer significant protection against pulmonary tuberculosis independent of CD4 T cells. Copyright © 2010 John Wiley & Sons, Ltd.
Limb development in the gekkonid lizard gonatodes albogularis: A reconsideration of homology in the lizard carpus and tarsus
Authors: Leal Francisca , Tarazona Oscar A. , Ramírez‐Pinilla Martha Patricia
Published: August 2010

Despite the attention squamate lizards have received in the study of digit and limb loss, little is known about limb morphogenesis in pentadactyl lizards. Recent developmental studies have provided a basis for understanding lizard autopodial element homology based on developmental and comparative anatomy. In addition, the composition and identity of some carpal and tarsal elements of lizard limbs, and reptiles in general, have been the theme of discussions about their homology compared to non‐squamate Lepidosauromorpha and basal Amniota. The study of additional embryonic material from different lizard families may improve our understanding of squamate limb evolution. Here, we analyze limb morphogenesis in the gekkonid lizard Gonatodes albogularis describing patterns of chondrogenesis and ossification from early stages of embryonic development to hatchlings. Our results are in general agreement with previous developmental studies, but we also show that limb development in squamates probably involves more chondrogenic elements for carpal and tarsal morphogenesis, as previously recognized on the grounds of comparative anatomy. We provide evidence for the transitory presence of distal carpale 1 and intermedium in the carpus and tibiale, intermedium, distal centralia, and distal tarsale 2 in the tarsus. Hence, we demonstrate that some elements that were believed to be lost in squamate evolution are conserved as transitory elements during limb development. However, these elements do not represent just phylogenetic burden but may be important for the morphogenesis of the lizard autopodium. J. Morphol., 2010. © 2010 Wiley‐Liss, Inc.
Retention mechanism of the multifunctional solute on columns with different coverage densities using highly aqueous reversed‐phase conditions
Authors: Bocian Szymon , Buszewski Bogusław
Published: August 2010

A series of 11 homemade octadecyl bonded phases with different coverage densities were tested to determine the influence of the stationary phase on the retention in highly aqueous mobile phases. The concentrations of the organic modifiers (methanol and ACN) were in the range of 0–20%v/v. The coverage density of bonded ligands and the presence of the end‐capping have strong influence on the solute retention. Amoxicillin (AMO) was chosen as the test compound. Dual properties of AMO, which contain hydrophobic skeleton and polar groups (amino, hydroxyl and carbonyl), cause irregular changes of the retention over the stationary phase hydrophobicity and silanol activity at given mobile phase composition. Presented data show that application of non‐standard low coverage density C18 phases allow to determine AMO in the RPLC condition with high retention.
Application of ultrasound‐assisted matrix solid‐phase dispersion extraction to the HPLC confirmatory determination of cephalosporin residues in milk
Authors: Karageorgou Eftichia G. , Samanidou Victoria F.
Published: August 2010

Ultrasound‐assisted matrix solid‐phase dispersion (MSPD) was applied to isolate eight cephalosporins (cefadroxil, cefaclor, cephalexin, cefotaxime, cefazolin, cefuroxime, cefoperazone and ceftiofur) from milk. Multi‐residue analysis was subsequently performed by HPLC‐diode array detection. Extraction yield by matrix solid‐phase dispersion using Nexus sorbent was higher than various investigated SPE protocols. Three analytical columns, two conventional silica based and one monolithic, were compared based on resolution, peak shape and retention time. The optimum method using Chromolith RP‐18e (100×4.6 mm) achieved separation in less than 16 min. Method validation was performed according to the European Union Decision 2002/657/EC, determining linearity, selectivity, stability, decision limit, detection capability, accuracy and precision. RSD values observed were lower than 15.3%. Recovery rates of examined antimicrobials from milk ranged from 93.8 to 101.9% for cefadroxil, from 94.7 to 103.6% for cefaclor, from 93.4 to 106.6% for cephalexine, from 104.1 to 115.3% for cefotaxime, from 97.1 to 105.6% for cefazolin, from 97.4 to 108.6% for cefuroxime, from 98.8 to 103.4% for cefoperazone and from 95.5 to 103.6% for ceftiofur. Correlation coefficients ranged from 0.9926 to 0.9999. CCb values were in the range from 103.5 to 112.3 μg/kg for analytes with a maximum residue limit of 100 μg/kg and from 54.4 to 56.3 μg/kg for those with a maximum residue limit of 50 μg/kg.
Unexpected enantioseparation of mandelic acids and their derivatives on 1,2,3‐triazolo‐linked quinine tert‐butyl carbamate anion exchange‐type chiral stationary phase
Authors: Kacprzak Karol , Maier Norbert , Lindner Wolfgang
Published: August 2010

Replacement of the flexible thioether linker for the novel, rigid 1,2,3‐triazole spacer group in the course of immobilization of quinine tert‐butyl carbamate onto a silica surface led to a chiral stationary phase (CSP) with enhanced enantioselectivity for the resolution of mandelic acid and derivatives thereof. These new CSPs allowed efficient resolution of a wide set of mandelic acids with α‐values between 1.08 and 1.68. The high loadability of these chiral ion exchange type CSPs allows preparative separation in the milligram range on an analytical column of 100×4 mm id in a single run as it was demonstrated for 4‐trifluoromethylmandelic, 2‐naphthylglycolic and 3,4‐methylenedioxymandelic acids. The chiral recognition process has been studied using a library of 25 diverse racemic probes. A tentative model suggests that the rigid 1,2,3‐triazole group takes part in the formation of an enantioselective‐binding pocket of the entire and immobilized selector moiety of the CSP. The primary interaction site is given by the ionizable quinuclidine group of the Cinchona alkaloid supported by possible π–π stabilization effects within the selector–selectand complex.
Calcium Phosphate Mineralization beneath a Polycationic Monolayer at the Air–Water Interface
Authors: Junginger Mathias , Kita‐Tokarczyk Katarzyna , Schuster Thomas , Reiche Jürgen , Schacher Felix , Müller Axel H. E. , Cölfen Helmut , Taubert Andreas
Published: August 2010

The self‐assembly of the amphiphilic block copolymer poly(n‐butyl methacrylate)‐block‐poly[2‐(dimethylamino)ethyl methacrylate] at the air–water interface has been investigated at different pH values. Similar to Rehfeldt et al. (J. Phys. Chem. B 2006, 110, 9171), the subphase pH strongly affects the monolayer properties. The formation of calcium phosphate beneath the monolayer can be tuned by the subphase pH and hence the monolayer charge. After 12 h of mineralization at pH 5, the polymer monolayers are still transparent, but transmission electron microscopy (TEM) shows that very thin calcium phosphate fibers form, which aggregate into cotton ball‐like features with diameters of 20 to 50 nm. In contrast, after 12 h of mineralization at pH 8, the polymer film is very slightly turbid and TEM shows dense aggregates with sizes between 200 and 700 nm. The formation of calcium phosphate is further confirmed by Raman and energy dispersive X‐ray spectroscopy. The calcium phosphate architectures can be assigned to the monolayer charge, which is high at low pH and low at high pH. The study demonstrates that the effects of polycations should not be ignored if attempting to understand the colloid chemistry of biomimetic mineralization. It also shows that basic block copolymers are useful complementary systems to the much more commonly studied acidic block copolymer templates.

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Electrochemical behavior of NiPSiC composite coatings: Effect of heat treatment and SiC particle incorporation
Authors: Malfatti C. F. , Ferreira J. Z. , Oliveira C. T. , Rieder E. S. , Bonino J.‐P.
Published: August 2010

This paper describes the effects of heat treatment and of SiC particle incorporation on the electrochemical behavior and physical structure of NiP (17 at% P) composite coatings. The deposits were obtained by electrodeposition with various contents of SiC particles in the plating bath and heat treated at 420 °C. The physical structure was investigated by inductively coupled plasma atomic emission spectrometry (ICP‐AES), X‐ray diffraction (XRD), and scanning electron microscopy (SEM – image analysis). The electrochemical behavior of the resultant composite coatings was determined by chronopotentiometry, electrochemical impedance spectroscopy, and potentiodynamic measurements in 0.6 M NaCl solution at pH 6. Heat treatment showed a positive effect on the electrochemical behavior of NiP coatings, shifting the open circuit potential toward less active potentials. The incorporation of SiC particles inhibited pit nucleation on the NiP composite coating, with or without post‐heat treatment. However, heat treatment in the NiPSiC seemed to induce cracks in the metallic matrix, initiating at the SiC particles, possibly caused by the contraction in the metallic matrix. The cracked structure promoted localized corrosion, while coatings without heat treatment resulted in a general and uniform corrosion.
Corrosion study of copper in the presence of benzotriazole and its hydroxy derivative
Authors: Finšgar M. , Milošev I.
Published: August 2010

The inhibitory properties of benzotriazole (BTAH) and its hydroxy derivative, 1‐hydroxy‐benzotriazole (BTAOH) on copper corrosion, were compared in 3% NaCl solution using cyclic voltammetry (CV), immersion tests, profilometry and scanning electron microscopy (SEM) combined with energy dispersive spectroscopy (EDX). CV experiments showed rapid interaction of both inhibitors with a Cu surface, but only at high concentrations. Immersion tests under stationary conditions showed that BTAOH offered corrosion protection only at concentration of 10 mM. Moreover, it was not effective under stirring conditions at any of the concentrations investigated. In contrast, BTAH exhibited good corrosion inhibition ability in all immersion tests. BTAOH, at up to 1 mM, increased the surface roughness of Cu more than 3% NaCl solution alone, but a significant reduction of surface roughening was observed when BTAH was present. Porous cross‐linked acicular structures and star‐like structures were observed using SEM/EDX in the case of BTAOH treatment. When Cu was treated with BTAH, roundish surface structures composed of bent plates with toothed‐like edges, acicular structures and non‐porous few hundred nm thick plates were observed.
Ten‐year results of galvanic sacrificial anodes in steel reinforced concrete
Authors: Sergi G.
Published: August 2010

Zinc sacrificial anodes have been included in patch repairs to steel reinforced concrete structural elements suffering from corrosion since the mid‐1990s. A number of these anode‐containing repairs have been monitored with time. One of the first monitored sites was of a locally repaired cross beam of a bridge structure in Leicester, UK, which has now completed 10 years since its original repair and anode installation. This paper reviews the performance of the anodes installed at the Leicester site in terms of anode current output and steel reinforcement polarisation and corrosion rate over the period. It also presents results of analysis of recovered anodes exposed for 10 years which still show electrolyte continuity, uniform consumption of the zinc and coherent encasing mortar. The knowledge gained from the 10 year results has enabled the development of new, higher current output anodes, which are now trialled in this and other sites.
Lab and field investigations on localized corrosion of casing
Authors: Ren C. Q. , Wang X. , Liu L. , Yang H. E. , Xian N.
Published: August 2010

The corrosion of casing was investigated in the laboratory and oilfield by series methods of EIS, SEM, EDS, well logging, and field coupon test. Data reveal the middle vertical profile along the casing is greatly threatened by localized form rather than generalized corrosion. The pit initiates in the micro‐pore of the corrosion scale on the surface of the steel. The development of pitting depends on the water type classified by geochemist. The calcium chloride water shows highest acceleration to pitting due to the two orders of magnitude higher concentration of chloride ion by comparing sodium sulfate and sodium bicarbonate water types. The element analysis and microstructure observation were used to further describe the pit propagation. It is proposed to get a better understanding of the corrosion damage of casing in the petroleum industry.
Lifetime Assessment of Load‐Bearing Polymer Glasses: The Influence of Physical Ageing
Authors: Visser Hendrikus A. , Bor Ton C. , Wolters Mannes , Wismans Joris G. F. , Govaert Leon E.
Published: August 2010

The timescale at which ductile failure occurs in loaded glassy polymers can be successfully predicted using the engineering approach presented in a previous publication. In this paper the influence of progressive physical ageing on the plastic deformation behaviour of unplasticised poly(vinyl chloride) (uPVC) is characterised and incorporated in the existing approach. With the modification it is possible to quantitatively predict long‐term failures which show a so‐called endurance limit. The predictions are compared with failure data of uPVC specimens which were subjected to constant or dynamic loads. In dynamic loading conditions a second type of failure mode was observed: fatigue crack growth. A brief study on the influence of the frequency and stress ratio of the applied stress signal shows that crack growth failure is not expected to occur within experimentally reasonable timescales for constant loading conditions.

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Compatibilization and Properties of EVA Copolymers Containing Surface‐Functionalized Cellulose Microfibers
Authors: Pracella Mariano , Haque M. Minhaz‐Ul , Alvarez Vera
Published: August 2010

Cellulose microfibers were modified with two different bi‐functional monomers. Composites of EVA copolymer with modified and unmodified cellulose were prepared by melt mixing. The samples were analyzed by SEM, XRD, FT‐IR, DSC, TGA, DMTA and tensile mechanical tests. SEM showed that the presence of reactive groups on cellulose surface enhanced the compatibility, improving the fiber/matrix interfacial adhesion. FT‐IR disclosed the occurrence of chemical reactions between the functionalized cellulose and polymer chains. The incorporation of fibers affected the crystallization behaviour and crystallinity of the polymer matrix. Composites with GMA modified cellulose displayed better compatibility, higher thermal and mechanical properties.

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Finite groups with some given systems of Xm‐semipermutable subgroups
Authors: Guo Wenbin , Shum K. P. , Skiba A. N.
Published: August 2010

Let X be a nonempty subset of a group G. We call a subgroup A of G an Xm‐semipermutable subgroup of G if A has a minimal supplement T in G such that for every maximal subgroup M of any Hall subgroup T1 of T there exists an element x ∈ X such that AMx = MxA. In this paper, we study the structure of finite groups with some given systems of Xm‐semipermutable subgroups (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Smoothing arithmetic error terms: the case of the Euler φ function
Authors: Kaczorowski Jerzy , Wiertelak Kazimierz
Published: August 2010

In many cases known methods of detecting oscillations of arithmetic error terms involve certain smoothing pro‐cedures. Usually an application of the smoothing operator does not change significantly the order of magnitude of the error under consideration. This is so for instance in the case of the classical error terms known in the prime number theory. The main purpose of this paper is to show that the situation for primes is not general. Considering the error term in the asymptotic formula for the Euler totient function we show that just one application of an integral smoothing operator changes situation dramatically: the order of magnitude of drops from x to √x (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Time‐Resolved Small‐Angle Neutron Scattering as a Tool for Studying Controlled Release from Liposomes using Polymer‐Enzyme Conjugates
Authors: Ferguson Elaine L. , De Luca Edoardo , Heenan Richard K. , King Stephen M. , Griffiths Peter C.
Published: August 2010

The action of phospholipase A2 (PLA2) on 1,2‐dipalmitoyl‐sn‐glycero‐3‐phosphocholine (DPPC) liposomes (vesicles) – an integral component in the polymer enzyme liposome therapy (PELT) mechanism (R. Duncan et al., J. Controlled Release 2001, 74, 135) for the controlled delivery of poorly soluble therapeutic molecules within liposomes – may be “masked” by conjugation to the biodegradable polymer dextrin and subsequently regenerated by the endogenous enzyme α‐amylase that degrades the dextrin; that is, incorporating the so‐called polymer‐unmasked‐masked protein therapy (PUMPT) approach (R. Duncan, et al. Biomacromolecules 2008, 9, 1146). Small‐angle neutron scattering (SANS) has been used to quantify the detailed structure of DPPC liposomes and any perturbation in that structure induced by the presence of PLA2 in native, “masked” (dextrin–PLA2 conjugate) and an in situ α‐amylase‐unmasked form. A time‐dependent degradation of the vesicular structure was observed for the two active PLA2 cases, but not for the masked case. This study demonstrates that the PLA2‐induced hydrolysis of the DPPC – and the associated rupture of the liposome and the release of the enclosed material – may be controlled through masking with dextrin. Accordingly, the viability of using such a combinatorial nanomedicine approach as a general route for the controlled delivery of poorly soluble therapeutic molecules is shown.

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RIS Model of the Helix‐Kink Conformation of Erythro Diisotactic Polynobornene
Authors: Chung Won J. , Henderson Clifford L. , Ludovice Peter J.
Published: August 2010

Computer simulations reveal the unique conformation of or erythro diisotactic polynorbornene, a polymer with numerous important applications in microelectronics. While previous simulations suggested that this polymer adopts a helix‐kink morphology, the results presented herein indicate that the reversal of the helix symmetry is the origin of such kinks which cause a transition from a rigid‐rod conformation to a random coil with increasing molecular weight. An RIS model was developed that accurately predicts the unique conformation of this polymer. This model predicts a rigid‐rod helical conformation that eventually transitions to a random coil at a degree of polymerization of approximately 500.

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Kinetics and Modeling of Melt Polycondensation for Synthesis of Poly[(butylene succinate)‐co‐(butylene terephthalate)], 1 – Esterification
Authors: Hu Lixia , Wu Linbo , Song Fangchao , Li Bo‐Geng
Published: August 2010

The kinetics of the tetrabutyl titanate‐catalyzed homogeneous succinic acid/1,4‐butylenediol (BDO) and heterogeneous terephthalic acid/BDO esterifications were investigated experimentally and theoretically. A unified kinetic model considering two main esterifications as well as one reversible polycondensation and two THF‐forming side reactions has been developed for the two esterification systems. The model agrees well with the experimental results. The effects of reaction temperature, diol/diacid ratio, catalyst amount, and heterogeneity on the esterification kinetics are simulated and discussed.

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Fetal sex determination using circulating cell‐free fetal DNA (ccffDNA) at 11 to 13 weeks of gestation
Authors: Akolekar Ranjit , Farkas Daniel H. , VanAgtmael Anna L. , Bombard Allan T. , Nicolaides Kypros H.
Published: August 2010

Objective

To examine the performance of a mass spectrometry‐based detection platform using three Y‐chromosome sequences for fetal sex determination from circulating cell‐free fetal DNA (ccffDNA) in maternal blood in the first trimester of pregnancy.

Methods

We extracted ccffDNA for the determination of fetal sex from stored maternal plasma obtained at 11 to 13 weeks' gestation from singleton pregnancies with documented fetal gender. Mass spectrometry was used to examine 236 specimens for the presence of three Y‐chromosome sequences (SRY, DBY and TTTY2). The sample was classified as male, female or inconclusive depending on the detection of three, one/none and two sequences, respectively.

Results

Three (1.3%) of the 236 cases were classified as invalid due to the absence of a well‐defined spectral peak for TGIF and 22 (9.3%) were reported as inconclusive. In the 211 cases with a valid result, the fetal sex was correctly identified in 90 of 91 male babies and 119 of 120 female babies giving an accuracy of 99.1% and sensitivity and specificity for prediction of male fetuses of 98.9 and 99.2%, respectively.

Conclusion

Fetal sex determination can be accurately determined from maternal ccffDNA in the first trimester of pregnancy using mass spectrometry analysis. Copyright © 2010 John Wiley & Sons, Ltd.
Sixteen years of prenatal consultations for the N370S/N370S Gaucher disease genotype: What have we learned?
Authors: Eitan Yael , Abrahamov Ayala , Phillips Mici , Elstein Deborah , Zimran Ari
Published: August 2010

Objective

Although prenatal diagnosis and genotyping are available for Gaucher disease, genetic counseling for an affected child's parents reflects the inability to predict disease course with certainty. The purpose of this survey is to ascertain disease status of children identified by prenatal screening.

Methods

All carrier couples for glucocerebrosidase mutations who were counseled at our large Gaucher Clinic were included; none had genotyped the fetus. Medical status of children was assessed by questionnaires and data were collected from clinic charts and/or telephone contact with the parents.

Results

Of 34 children born, 1 died in utero, 5 fetuses (N370S/N370S) aborted. Of 21 genotyped N370S/N370S, 7 children had Gaucher‐like symptoms/signs but for only one child (two symptoms) were these ascribable to Gaucher disease; four children had non‐Gaucher symptoms/signs.

Conclusion

Of 21 children whose parents pursued prenatal counseling for Gaucher disease and were found to have the N370S/N370S genotype, none has presented with severe disease with follow‐up of 15 years. The Israeli experience shows that Gaucher disease N370S screening does not identify children requiring treatment, but rather leads to termination of asymptomatic fetuses; this may lead to reconsideration of guidelines regarding Gaucher screening. Copyright © 2010 John Wiley & Sons, Ltd.
The effect of fetal gender in predicting Down syndrome using long bone ultrasonographic measurements
Authors: Goetzinger Katherine R. , Dicke Jeffrey M. , Gray Diana L. , Stamilio David M. , Macones George A. , Odibo Anthony O.
Published: August 2010

Objective

To determine if fetal gender affects the screening efficiency of short femur and humerus lengths in the prediction of trisomy 21.

Methods

Retrospective cohort study of 62 111 patients presenting for ultrasound from 1990 to 2006. Short humerus and femur lengths were defined using (1) biparietal diameter (BPD) to femur/humerus length (FL/HL) ratios > 1.5 standard deviations above the mean, (2) the observed to expected (O/E) ratio of femur length ≤0.91 or humerus length ≤0.89, and (3) femur and humerus lengths < 5th percentile. The sensitivity, specificity, and likelihood ratios were calculated for the association of short FL/HL and trisomy 21 stratified by gender.

Results

Both BPD/long bone ratios as well as O/E ratios demonstrated a statistically significant higher specificity for the detection of trisomy 21 in female fetuses. This difference was most clinically significant when using the O/E ratio, which yielded a specificity of 82.6% in males and 90.6% in females for short femur, and 69.7% in males and 77.9% in females for short humerus, when these markers were evaluated as isolated findings.

Conclusion

Gender‐specific differences in the effectiveness of both short femur and humerus lengths for the prediction of trisomy 21 may exist, but their presence and magnitude are largely dependent on the formula used. Copyright © 2010 John Wiley & Sons, Ltd.
Bowel dilation as a predictor of adverse outcome in isolated fetal gastroschisis
Authors: Garcia L. , Brizot M. , Liao A. , Silva M. M. , Tannuri A. C. , Zugaib M.
Published: August 2010

Objectives

This study was designed to evaluate bowel diameter as a predictor of adverse outcome in isolated fetal gastroschisis.

Methods

Retrospective study involving 94 singleton pregnancies. Ultrasound measurements of herniated bowel transverse diameter (BTD) were performed up to 3 weeks before delivery. Adverse outcome was intrauterine/neonatal death and/or bowel complications.

Results

Last BTD was recorded at 35.6 ± 1.6 weeks and mean interval to delivery was 6.2 ± 5.0 days. Intrauterine/neonatal death occurred in 10 (10.6%) cases; bowel complications were observed in 8 (8.5%). BTD ≥ 15, ≥ 20, ≥ 25, and ≥ 30 mm were found in 87, 46, 13, and 4% of pregnancies with a favorable outcome, respectively. BTD ≥ 25 mm sensitivity was 38%, and positive and negative predictive values were 38 and 87%. For BTD ≥ 30 mm, the values were 19, 50, and 85%. Observed/expected BTD ROC curve showed an area of 0.67, best cut‐off value at 1.39; prediction values were similar to those for BTD ≥ 25 mm. Bowel dilatation was also significantly associated with lower rate of primary surgical closure, longer period to full oral feeding, and prolonged hospital stay.

Conclusions

Bowel dilatation demonstrated up to 3 weeks before delivery is a predictor of intestinal complications and is associated with lower rate of primary surgical closure, longer period to achieve full oral feeding, and hospital stay. Copyright © 2010 John Wiley & Sons, Ltd.
Insecticide resistance in field populations of Bemisia tabaci (Hemiptera: Aleyrodidae) in West Africa
Authors: Houndété Thomas A , Kétoh Guillaume K , Hema Omer SA , Brévault Thierry , Glitho Isabelle A , Martin Thibaud
Published: August 2010

BACKGROUND: The tobacco whitefly, Bemisia tabaci Gennadius (Hemiptera: Aleyrodidae), has developed a high degree of resistance to several chemical classes of insecticides throughout the world. To evaluate the resistance status in West Africa, eight insecticides from different chemical families were tested using the leaf‐dip method on four field populations collected from cotton in Benin, Togo and Burkina Faso.

RESULTS: Some field populations showed a significant loss of susceptibility to pyrethroids such as deltamethrin [resistance ratio (RR) 3–5] and bifenthrin (RR 4–36), to organophosphates (OPs) such as dimethoate (RR 8–15) and chlorpyrifos (RR 5–7) and to neonicotinoids such as acetamiprid (RR 7–8) and thiamethoxam (RR 3–7). Bemisia tabaci was also resistant to pymetrozine (RR 3–18) and to endosulfan (RR 14–30).

CONCLUSION: The resistance of B. tabaci to pyrethroids and OPs is certainly due to their systematic use in cotton treatments for more than 30 years. Acetamiprid has been recently introduced for the control of whiteflies. Unfortunately, B. tabaci populations from Burkina Faso seem to be already resistant. Because cross‐resistance between these compounds has never been observed elsewhere, resistance to neonicotinoids could be due to the presence of an invasive B. tabaci biotype recently detected in the region. Copyright © 2010 Society of Chemical Industry
Effects of six selected orchard insecticides on Neoseiulus fallacis (Acari: Phytoseiidae) in the laboratory
Authors: Bostanian Noubar J , Hardman John M , Thistlewood Howard A , Racette Gaétan
Published: August 2010

BACKGROUND: Neoseiulus fallacis (Garman) is a key predator of tetranychid mites in integrated pest management (IPM) programs across Canada. This study identified compounds that would be recommended for tier‐II field evaluations in an IPM program.

RESULTS: The overall egg mortality caused by the six insecticides was negligible as it extended from 0 to 12.1%. Imidacloprid was classified as toxic to adults. The label rate was 7.73‐fold the LC50. Thiamethoxam was classified as moderately toxic to adults, and its label rate was 2.87‐fold the LC50. Acetamiprid and spinosad were classified as marginally toxic, and their label rates were respectively 0.99‐ and 0.45‐fold the LC50 for adults. Thiacloprid and methoxyfenozide were virtually innocuous to adults.

CONCLUSION: Methoxyfenozide was totally harmless to all stages of N. fallacis, and it would be included in IPM programs immediately. Acetamiprid, spinosad and thiacloprid had varying degrees of mild toxicity to at least one growth stage of the predator. Therefore, they were recommended for tier‐II field testing according to their label claims. Imidacloprid and thiamethoxam were toxic to moderately toxic to adults and had significant adverse effects on fecundity. Therefore, they would be field evaluated only if alternatives were unavailable. Copyright 2010 Crown in the right of Canada. Published by JohnWiley & Sons, Ltd
Density change during the manufacturing process of PU–PE open cell auxetic foams
Authors: Bianchi M. , Frontoni S. , Scarpa F. , Smith C. W.
Published: August 2010

This paper describes a modified manufacturing route involving a large change in density in auxetic negative Poisson's ratio (NPR) foams. Density change of auxetic foams after manufacturing is a common feature for this porous material. Samples of open cell PU–PE (i.e. the combination of polyurethane–polyethylene) foams with NPR are produced from two similar native materials using both the classical and the novel custom manufacturing methods. In the classical manufacturing route the cooling process is typically carried out with the foam in a confined state. Conversely, in the new manufacturing process it was substituted with a release process. Samples were subjected to both tensile and compressive loading, as well as density measurements. A thorough mechanical characterisation of the foams is described, linking the mechanical properties with their change in density after conversion into auxetic.
Auxetic fibre networks and their composites
Authors: Jayanty Sharmila , Crowe Jason , Berhan Lesley
Published: August 2010

The growing interest in the field of negative Poisson's ratio materials is motivated by the attractive mechanical properties of these materials and the potential enhancements that might be derived from replacing a positive Poisson's ratio component with its auxetic counterpart. In this paper we report on preliminary results of an ongoing experimental study to test the hypothesis that an auxetic composite can be produced by embedding an auxetic fibre network within a conventional (positive Poisson's ratio) matrix. First we present results of tensile tests performed on samples of compressed mats of sintered stainless steel fibres which are known to have a negative Poisson's ratio out‐of‐plane. Next we present results of mechanical tests and imaging studies on composite samples made by infusing the stainless steel mats with a polymer. Finally we report on the auxetic behaviour observed in some polymer nanocomposites with a high loading of carbon nanofibers. We conjecture that the embedded nanofibers form an effective network and, like the stainless steel mats, the compression of the samples during fabrication renders the embedded networks auxetic. The compliance of the polymer matrix relative to the nanofiber network results in an auxetic composite. The results demonstrate the feasibility of the approach and the potential for developing new auxetic composites with auxetic fibre networks as the reinforcing phase.
Viscoelastic, dielectric, and thermal properties of BaTiO3‐3%KNbO3
Authors: Dong Liang , Stone Donald S. , Lakes Roderic S.
Published: August 2010

Viscoelastic behavior (modulus and damping) of polycrystalline 3%KNbO3‐BaTiO3 has been studied in torsion and bending via broadband viscoelastic spectroscopy (BVS) over a range of temperature passing through both the orthorhombic‐to‐tetragonal and tetragonal‐to‐cubic phase transformations. Softening in bulk modulus and minima in Poisson's ratio as well as peaks in mechanical damping, dielectric constant, and heat capacity vs. temperature were observed in the vicinity of the transformations. Viscoelastic response vs. temperature was sharper than dielectric or thermal response. Transition temperatures of both transformations shifted to lower temperatures in comparison to pure BaTiO3. Damping peaks vs. temperature were wider (5 °C) than in pure BaTiO3 (less than 1 °C) and of smaller magnitude. Broadening of response is attributed to material heterogeneity on a fine scale.
Kinetics of SH‐ssDNA immobilization on gold coated cantilevers under electrochemical control
Authors: Arroyo‐Hernández María , Martín‐González Marisol , Costa‐Krämer José Luis
Published: August 2010

Controlling electrochemical parameters (setting the bias voltage and monitoring the current) during immobilization of thiolated single stranded DNA (SH‐ssDNA) on gold coated cantilevers allows tailoring the reaction kinetics. In particular, the immobilization time can be reduced more than 40 times when compared with conventional passive immobilization (cantilever electrically floated during the process). Besides the kinetics, the surface stress induced during the immobilization process can be also controlled and maximized. The combination of an electrochemically monitored immobilization with in‐situ profile measurements provides a powerful tool to optimize DNA immobilization and increase the nanomechanical response. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Supramolecular organization of chiral molecules on metallic surfaces: D‐alaninol on Cu(100) as a case study
Authors: Gori Paola , Contini Giorgio , Prosperi Tommaso , Zema Nicola , Ronci Fabio , Colonna Stefano , Cricenti Antonio , Turchini Stefano , Catone Daniele , Aschi Massimiliano , Palma Amedeo
Published: August 2010

The adsorption configuration of a chiral amino alcohol, Dalaninol, on Cu(100) is studied with DFT ab‐initio calculations. We address the case of the formation of a self‐assembled monolayer that is experimentally found when depositing the molecule at room temperature. Preliminary calculations are performed for a cluster of four isolated molecules in gas phase, both at the MP2 and GGA‐DFT level. Further results deal with the adsorption on the copper surface. STM images of two candidates structures are simulated and compared with experiments (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Mobility gaps in disordered graphene‐based materials: an ab initio ‐based tight‐binding approach to mesoscopic transport
Authors: Biel Blanca , Cresti Alessandro , Avriller Rémi , Dubois Simon , López‐Bezanilla Alejandro , Triozon François , Blase X. , Charlier Jean‐Christophe , Roche Stephan
Published: August 2010

As is common knowledge, armchair graphene nanoribbons (aGNRs) share many electronic features with carbon nanotubes (CNTs). Nevertheless, crucial differences emerge when disorder comes into play. It is thus instructive, both from a theoretical and a technological perspective, to analyze the impact of possible types of disorder on the transport properties of these graphene‐based materials.

Here we report such a comparative study between CNTs and GNRs, which points out the similarities and differences emerging as a consequence of doping by substitutional boron and nitrogen impurities. The role of edge defects (absent in CNTs) is also contrasted with chemical doping disorder. All disorder models have been derived from accurate ab initio calculations of the electronic structures (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
High‐temperature stability of suspended single‐layer graphene
Authors: Kim Kwanpyo , Regan William , Geng Baisong , Alemán Benjamín , Kessler B. M. , Wang Feng , Crommie M. F. , Zettl A.
Published: August 2010

We report in situ Joule heating on suspended single‐layer graphene in a transmission electron microscope (TEM). Thermally‐driven degradation of pre‐deposited nanoparticles on the membrane is monitored and used for local temperature estimation. By extrapolating the Joule heating power and temperature relation, we find that the suspended single‐layer graphene has exceptional thermal stability up to at least 2600 K. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
High critical oxygen concentration in microcrystalline silicon solar cells
Authors: Merdzhanova Tsvetelina , Woerdenweber Jan , Beyer Wolfhard , Zastrow Uwe , Stiebig Helmut , Gordijn Aad
Published: August 2010

For microcrystalline silicon based p–i–n solar cells the effect of deposition conditions on the critical oxygen concentration was investigated. All solar cells were prepared by 13.56 MHz plasma‐enhanced chemical vapour deposition. The critical oxygen concentration defines the lowest oxygen concentration in the intrinsic absorber layer causing a deterioration of the solar cell performance. For intentional contamination of ∼1.2–1.3 µm thick i‐layers, the oxygen was inserted by a controllable leak at the process gases supply line, i.e. by a gas pipe leak. For µc‐Si:H deposited at a discharge power of 0.53 W/cm2 we find a critical oxygen concentration of 1–2 × 1019 cm–3 in agreement with values commonly reported in literature. However, changing the deposition conditions, we find that the critical oxygen concentration in µc‐Si:H cells is not fixed. At reduced power of 0.20 W/cm2 a much higher value for the critical oxygen concentration of 1 × 1020 cm–3 is observed. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)