bluuebunny/crossref_metadata_2025_split huggingface dataset:
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

AbstractDespite 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

AbstractA 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

AbstractUltrasound‐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

AbstractReplacement 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

AbstractThe 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

AbstractThis 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

AbstractThe 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

AbstractZinc 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

AbstractThe 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

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

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

AbstractLet 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

AbstractIn 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

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

AbstractComputer 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.magnified image
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

AbstractThe 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.magnified image
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

AbstractObjectiveTo 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.MethodsWe 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.ResultsThree (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.ConclusionFetal 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

AbstractObjectiveAlthough 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.MethodsAll 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.ResultsOf 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.ConclusionOf 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.