bluuebunny/crossref_metadata_2025_split huggingface dataset:
Stability studies of stationary phases from poly(methyltetradecylsiloxane) sorbed and immobilized onto metalized and unmodified silicas
Authors: Faria Anizio M. , Tonhi Edivan , Collins Kenneth E. , Collins Carol H. 
Published: May 2007

AbstractStationary phases for RP‐HPLC were prepared from metalized (titanized and zirconized) and unmodified silica particles using sorbed and immobilized poly(methyltetradecylsiloxane) (PMTDS). Different immobilization procedures, such as gamma irradiation and thermal treatments, were used for the preparation of the immobilized PMTDS phases. The stabilities of these stationary phases were evaluated by passing alkaline (pH 10) mobile phase through 60 mm×3.9 mm columns of the different phases, with periodic tests to evaluate chromatographic performance. The results show that higher stabilities were obtained with stationary phases based on PMTDS immobilized on zirconized silica, these phases being 50% more stable than their titanized silica counterparts and 400% more stable than those based on unmodified silica. These supports provide higher chemical stability to the laboratory‐made stationary phases, when compared with chemically bonded silica‐based phases.
Automated semipreparative purification with mass spectrometric fraction collection trigger: Modeling and experimental evaluation of a setup employing passive splitting
Authors: Steiner Frank , Mahsunah Anis , Arnold Frank , Piecha Thomas , Huber Christian G. 
Published: May 2007

AbstractA semipreparative HPLC setup was evaluated for automated fractionation with both photometric‐ and mass spectrometric trigger. The goals of the work were to systematically study and optimize the flow‐splitting setup for mass‐directed purifications by mathematical modeling and experimental verification. The system comprised a passive splitting device with make‐up flow capability, which directed a small fraction of the column effluent to the mass spectrometer and the remainder to the fraction collector. Tubing lengths and diameters of the splitter as well as make‐up flow rates were varied in order to address and optimize peak dispersion, delay times between mass detector and fraction collector, and mass spectrometric signal quality. A paraben standard mixture was analyzed and purified on both microparticulate and monolithic columns with 10 mm inner diameter and at typical flow rates of 5–10 mL/min. Fraction purities and recoveries close to 100% were achieved. The system allowed mass‐triggered fractionations on a 1 mg scale at flow rates of 10 mL/min in combination with monolithic columns in less than 2 min. Finally, the system was successfully applied to the fully automated isolation of milligram quantities of degradation products in a pharmaceutical preparation to successfully allow for structure elucidation with NMR spectroscopy.
A notion of selective ultrafilter corresponding to topological Ramsey spaces
Authors: Mijares José G. 
Published: May 2007

AbstractWe introduce the relation of almost‐reduction in an arbitrary topological Ramsey space ℛ as a generalization of the relation of almost‐inclusion on ℕ[∞]. This leads us to a type of ultrafilter 𝒰 ⊆ ℛ which corresponds to the well‐known notion of selective ultrafilter on ℕ. The relationship turns out to be rather exact in the sense that it permits us to lift several well‐known facts about selective ultrafilters on ℕ and the Ellentuck space ℕ[∞] to the ultrafilter 𝒰 and the Ramsey space ℛ. For example, we prove that the open coloring axiom holds on L (ℝ)[𝒰], extending therefore the result from [3] which gives the same conclusion for the Ramsey space ℕ[∞]. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Bases, spanning sets, and the axiom of choice
Authors: Howard Paul 
Published: May 2007

AbstractTwo theorems are proved: First that the statement“there exists a field F such that for every vector space over F, every generating set contains a basis”implies the axiom of choice. This generalizes theorems of Halpern, Blass, and Keremedis. Secondly, we prove that the assertion that every vector space over ℤ2 has a basis implies that every well‐ordered collection of two‐element sets has a choice function. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
A note on stable sets, groups, and theories with NIP
Authors: Onshuus Alf , Peterzil Ya'acov 
Published: May 2007

AbstractLetMbe an arbitrary structure. Then we say that anM‐formulaφ(x)defines a stable set inMif every formulaφ(x) ∧α(x,y) is stable. We prove: IfGis anM‐definable group and every definable stable subset ofGhasU‐rank at mostn(the samenfor all sets), thenGhas a maximal connected stable normal subgroupHsuch thatG/His purely unstable. The assumptions hold for example ifMis interpretable in an o‐minimal structure.More generally, anM‐definable setXisweakly stableif theM‐induced structure onXis stable. We observe that, by results of Shelah, every weakly stable set in theories with NIP is stable. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
A note on the decidability of exponential terms
Authors: D'Aquino Paola , Terzo Giuseppina 
Published: May 2007

AbstractIn this paper we prove, modulo Schanuel's Conjecture, that there are algorithms which decide if two exponential polynomials in π are equal in ℝ and if two exponential polynomials in π and i coincide in ℂ. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Novel Morphologies Produced by Active Shear Rotation during Injection Molding
Authors: Silva Cristina A. , Viana Júlio C. , Cunha António M. 
Published: May 2007

AbstractA special mold with mechanically driven mold surface motions (rotation and axial) was developed allowing the imposition of different molding sequences, thus enlarging the possibilities of controlling the thermomechanical environment, and consequently the manipulation of the developed morphology. In this work, centre gated discs were injection molded with distinct rotation velocities of the mold surface. The moldings were characterized by several structure sensitive techniques. The imposition of a mold surface rotation has a marked effect on the morphology of the moldings, with novel molding morphologies being developed: a laminated skin–core structure featuring a dual shish‐kebab structure differently oriented relatively to the flow direction, one in each of the skin layer.magnified image
Poly(vinyl alcohol)/Clay‐Based Nanocomposite Hydrogels: Swelling Behavior and Characterization
Authors: Paranhos Caio M. , Soares Bluma G. , Oliveira Renata N. , Pessan Luiz A. 
Published: May 2007

AbstractPolymer/clay composite hydrogels were prepared based on PVA hydrogels containing 3–10 wt.‐% MOM. Their microstructure and morphology were studied by FT‐IR, WAXS and SEM, whereas the interactions between MOM and PVA were evaluated by thermal analyses. The swelling ratios for the PVA/MOM hydrogels decrease with increasing MOM content. WAXS results indicate that MOM was intercalates, and DSC results show a strong interaction between PVA and MOM. This interaction results in a stable network, which is confirmed by the elastic modulus and the thermal decomposition behavior of the hydrogels. Therefore, MOM acts as a co‐crosslinker, improving the stability of the network.magnified image
The minmax multidimensional knapsack problem with application to a chance‐constrained problem
Authors: Kress Moshe , Penn Michal , Polukarov Maria 
Published: May 2007

AbstractIn this paper we present a new combinatorial problem, called minmax multidimensional knapsack problem (MKP), motivated by a military logistics problem. The logistics problem is a two‐period, two‐level, chance‐constrained problem with recourse. We show that the MKP is NP‐hard and develop a practically efficient combinatorial algorithm for solving it. We also show that under some reasonable assumptions regarding the operational setting of the logistics problem, the chance‐constrained optimization problem is decomposable into a series of MKPs that are solved separately. © 2007 Wiley Periodicals, Inc. Naval Research Logistics, 2007
A case of Os odontoideum in the palaeopathological record
Authors: Curate F. 
Published: May 2007

AbstractOs odontoideum is an uncommon abnormality of the second cervical vertebra, the aetiology of which is contentious. Whether congenital or acquired, the condition often results in atlantoaxial instability and subsequent compression of cervical cord or vertebrobasilar vessels. The bioarchaeological study of a medieval sample from the Christian necropolis of Cacela Velha (Algarve, southern Portugal) provided the opportunity to describe one of the first cases of this rare anomaly ever reported in the palaeopathological record. Copyright © 2007 John Wiley & Sons, Ltd.
Diagnostic criteria for developmental dislocation of the hip in human skeletal remains
Authors: Mitchell P. D. , Redfern R. C. 
Published: May 2007

AbstractDislocation is the most severe form of developmental dysplasia of the hip (DDH). It significantly impairs hip function in the young, and may lead to debilitating early‐onset osteoarthritis in adults. To our knowledge no thorough study of a large skeletal population has ever been undertaken to determine the wide range of diagnostic criteria for this condition in pathological specimens. To identify these criteria we have analysed the cases of developmental dislocation from a large series of 6000 individuals (6580 hips) from the medieval cemetery at Spitalfields in London, UK. We describe the changes at the true acetabulum, and have created a four‐stage classification of the false acetabulum. The skeletal response to the altered biomechanics and limb shortening that occurs in developmental dislocation is described in the pelvis, lower limb and spine. This includes asymmetric growth in childhood, and asymmetric degenerative change in adulthood. We conclude with a discussion of the clinical literature on developmental dislocation of the hip that will aid palaeopathologists to estimate the symptoms that an excavated individual may have experienced during their lifetime. Copyright © 2007 John Wiley & Sons, Ltd.
1‐allyloxy‐2‐hydroxy‐propyl‐starch: Synthesis and characterization
Authors: Huijbrechts Annemarie A. M. L. , Huang Junrong , Schols Henk A. , van Lagen Barend , Visser Gerben M. , Boeriu Carmen G. , Sudhölter Ernst J. R. 
Published: May 2007

AbstractNew reactive unsaturated starch derivatives, 1‐allyloxy‐2‐hydroxy‐propyl‐starches (AHP‐starches), were synthesized by the reaction of waxy maize starch (WMS) and amylose‐enriched maize starch (AEMS) with allyl glycidyl ether in a heterogeneous alkaline suspension containing NaOH and Na2SO4. The degree of substitution (DS) was determined by 1H NMR spectroscopy, and a DS of 0.20 ± 0.01 was found for both AHP‐WMS and AHP‐AEMS, respectively. The AHP derivatives of WMS and AEMS were further characterized with 1H and 13C NMR. It was shown that the AHP substitution was located on the C‐6 hydroxyl group of the glucose residues in the starch. The substitution pattern of the AHP groups along the polymer chain was randomly clustered, as determined by enzymatic digestion using pullulanase, α‐amylase, and amyloglucosidase, followed by matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry analysis of the digestion products. With X‐ray diffraction and scanning electron microscopy, no changes in the granular morphology and crystallinity between the unmodified starches and AHP‐starches were detected. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 2734–2744, 2007
Frontal polymerization with monofunctional and difunctional ionic liquid monomers
Authors: Jiménez Zulma , Pojman John A. 
Published: May 2007

AbstractFor the first time, we studied frontal polymerization with ionic liquid monomers. We synthesized a series of compounds from the neutralization reaction between trialkylamines (tributylamine, trihexylamine, trioctylamine, and (2‐dimethylamino)ethyl methacrylate) and acrylic or methacrylic acid. For the ionic liquids prepared from the unreactive amines, frontal polymerization could not be achieved without the addition of a diacrylate. With the addition of a diacrylate, the front velocities were slower than for dodecyl acrylate (with the diacrylate), a compound of comparable molecular weight. Monomers prepared from the (2‐dimethylamino)ethyl methacrylate could support frontal polymerization alone but the front velocities were lower than dodecyl (meth)acrylate. These results are contrasted with recent results of Jiménez et al. for room temperature kinetics. Finally, the polymers prepared were comparable to those prepared by batch curing at 75 °C except for the monomethacrylate ionic liquid, which lost some tertiary amine by dissociation and evaporation. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 2745–2754, 2007
Towards a TTOP ground temperature model for mountainous terrain in central‐eastern Norway
Authors: Juliussen Håvard , Humlum Ole 
Published: May 2007

AbstractThe lack of simple mountain permafrost distribution models taking snow depth and site‐specific factors into consideration led us to test the regional Canadian temperature at the top of the permafrost or at the bottom of the seasonally frozen layer (TTOP)‐model in mountain terrain in central‐eastern Norway. The TTOP‐model uses seasonal n‐factors (nt and nf) and air temperature to model the mean annual ground‐surface temperature (MAGST), and a ratio of thawed to frozen thermal conductivity to model the average TTOP.This study presents 28 and 36 values of nt and nf, respectively. The potential incoming solar radiation, derived in a Geographical Information System (GIS), was used to parameterise nt, and average snow depth was used to parameterise nf. Due to limited information on the subsurface component of the model, only MAGST was modelled. The model was run for the 1961–90 normal period, the Little Ice Age and the year 2050. The model was evaluated against existing model predictions based on bottom temperature of winter snow (BTS) and geophysical soundings. Finally, critical values of snow depth, potential incoming solar radiation and thermal conductivity ratio that constrain negative MAGST and thus permafrost were determined. Copyright © 2007 John Wiley & Sons, Ltd.
The Effect of Transient Conditions on an Equilibrium Permafrost‐climate Model. Dan Riseborough. Permafrost and Periglacial Processes Vol. 18 No. 1 2007, pages 21–32.
Authors: Riseborough Dan 
Published: May 2007

AbstractThe original article to which this Erratum refers was published in Permafrost and Periglacial Processes 18(1) 2007, 21–32. Copyright © 2007 John Wiley & Sons, Ltd.
Recognition and management of actinic keratoses in primary care
Authors: Cerio Rino 
Published: May 2007

AbstractActinic keratoses are areas of abnormal epidermal growth that usually form on sun‐exposed skin, and may lead to carcinomas if left untreated. Here, Professor Cerio discusses the clinical features of actinic keratoses and describes the various treatment options. Copyright © 2007 Wiley Interface Ltd
High‐efficiency AlGaN based UV emitters grown on high‐crystalline‐quality AlGaN using grooved AlN layer on sapphire substrate
Authors: Iida K. , Watanabe H. , Takeda K. , Nagai T. , Sumii T. , Nagamatsu K. , Kawashima T. , Balakrishnan K. , Iwaya M. , Kamiyama S. , Amano H. , Akasaki I. , Bandoh A. 
Published: May 2007

AbstractCrack‐free and low‐dislocation‐density AlGaN was successfully grown on grooved AlN layer. UV light‐emitting diodes (LEDs) with a peak wavelength of 330 nm on these AlGaN films were fabricated. The efficiency of the UV LEDs is found to be strongly affected by the crystalline quality of the underlying AlN. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
One‐step lateral growth for reduction in defect density of a ‐plane GaN on r ‐sapphire substrate and its application in light emitters
Authors: Iida D. , Miura A. , Okadome Y. , Tsuchiya Y. , Kawashima T. , Nagai T. , Iwaya M. , Kamiyama S. , Amano H. , Akasaki I. 
Published: May 2007

AbstractLow defect density a ‐plane GaN films were successfully grown by sidewall epitaxial lateral overgrowth (SELO) technology. Using this technology, a ‐plane GaN films with atomically flat surface were grown. The threading dislocation and stacking fault densities in the overgrown regions were lower than 106 cm−2 and 103 cm−1, respectively. We also fabricated and characterized a ‐plane‐GaN‐based LEDs using SELO technology. The light output power of a blue‐green LED was shown to monotonically increase with decreasing of threading dislocation density. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Characterization of the DNA‐assisted purification of single‐walled carbon nanotubes
Authors: Sánchez‐Pomales G. , Santiago‐Rodríguez L. , Rivera‐Vélez N. E. , Cabrera C. R. 
Published: May 2007

AbstractCarbon nanotubes (CNTs) possess outstanding structural, mechanical, and electronic properties. Nevertheless, to achieve their full potential, many problems still need to be solved, including the development of an easy purification procedure, the design of functionalization chemistries that result in increased solubility of the CNTs without altering their properties, and the development of a simple route for the attachment of aligned CNTs on solid substrates. DNA offers a solution to the previous challenges. Recently, DNA‐functionalized single‐walled carbon nanotubes (SWNTs) have been prepared by our group and attached on gold by the self‐assembling technique [1, 2]. We therefore decided to perform an in‐depth study of the DNA‐assisted functionalization of SWNTs, which leads to their purification. The results showed a decrease in the SWNTs impurities after functionalization with DNA and demonstrated that the method used is a straightforward and time‐effective route for the purification of SWNTs at room temperature. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Transparent carbon nanotube field emission devices for display and lamp
Authors: Cho Yousuk , Lee Sunhee , An Myungchan , Kim Dojin 
Published: May 2007

AbstractA new, simple method to fabricate transparent carbon nanotube field emission devices is developed. The highly graphitized, single wall carbon nanotubes (SWNTs) are attached to an Sn/ITO glass by the arc discharge method. Post‐heat treatments of the sample below the deformation temperature of soda‐lime glass form a Sn–SWNT composite, and the nanotubes form good mechanical adhesion and electrical contact with the substrates. When the composite is oxidized in air below 400 °C, the Sn particles change to a transparent oxide form. The emission current density of the heat‐treated SWNT–Sn composite is about 1 mA/cm2 at an electric field of 3 V/μm. The emission current density of the SWNT–SnOx composite is similar. However, at a higher oxidation temperature, the emitter shows more stable emission property and longer life time. The transparency of the emitter can be useful in the design of emitter devices. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Production of colloidal gold nanoparticles by picosecond laser ablation in liquids
Authors: Giorgetti E. , Giusti A. , Laza S. C. , Marsili P. , Giammanco F. 
Published: May 2007

AbstractWe produced gold nanoparticles in water by picosecond laser ablation at 532 nm and 1064 nm. We used the amino‐terminated dendrimer PAMAM G5 as stabilizing agent. At 532 nm, the production process exhibits a threshold that is about 10 times lower than at 1064 nm and rapidly saturates. The fast saturation is due to single photon absorption of the ablating beam and a possible further energy loss due to photofragmentation of existing nanoparticles. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Simple route for intermatrix synthesis of polymer stabilized core‐shell metal nanoparticles for sensor applications
Authors: Muraviev D. N. , Macanás J. , Esplandiu M. J. , Farre M. , Muñoz M. , Alegret S. 
Published: May 2007

AbstractIn this paper we report the novel simple route for the inter‐matrix synthesis and characterization of Polymer Stabilized Metal Nanoparticles (PSMNPs) with core‐shell structure. The proposed approach is based on the use of functionalized polymeric membranes (FPM) as a nanoreactor for both to synthesize and to characterize the composition and morphology of PSMNPs. The desired functionalization is achieved by the chemical grafting of the desired functional groups (sulphonic in our case) to the polymeric matrix. The proposed approach is illustrated by the results obtained by studying the intermatrix synthesis of Pt@Cu‐core‐shell PSMNPs of different compositions in sulfonated poly(ether ether ketone) (SPEEK) membranes. The electrochemical response of amperometric sensors prepared by using SPEEK‐Pt@Cu‐PSMNP nanocomposite membranes as a sensing element has been shown to increase with the loading of the shell‐forming metal (Pt). The presence of Pt@Cu‐PSMNC inside the membrane not only substantially improves the electric conductivity of the polymer, but also testifies to manifestation of clearly pronounced strong electrocatalytic activity of Pt@Cu‐PSMNC towards analyte under study (H2O2). (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Ultra high sensitive detection of mechanical resonances of nanowires by field emission microscopy
Authors: Perisanu S. , Vincent P. , Ayari A. , Choueib M. , Guillot D. , Bechelany M. , Cornu D. , Miele P. , Purcell S. T. 
Published: May 2007

AbstractWe present here highly sensitive measurements of nanowire mechanical resonances by analyzing Field Emission Microscopy (FEM) images from the nanowires while they are excited by sinusoidally time‐varying voltages. Numerical analysis of the image blurring during frequency sweeps through resonances are shown to allow detection with ≃100× higher sensitivity as compared to our previous measurements where they were detected by the changes in the total field emission (FE) current. Furthermore since FEM approximately measures the end angle of the nanowire, this detection is more sensitive to higher resonance modes which in general have much smaller amplitudes. Observation of the mechanical response of SiC nanowires in FEM shows that they almost always present non linear mechanical behavior with large hysteresis and abrupt jump effects in their frequency response that are related to the large applied electric field. We approach the linear regime by reducing the excitation voltage and by using the sensitive image detection method. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Localized quantum spin reversal by spin injection in a spin quantum dot: A model calculation
Authors: Kokado Satoshi , Ueda Kazumasa , Harigaya Kikuo , Sakuma Akimasa 
Published: May 2007

AbstractWe theoretically study the reversal of localized quantum spin induced by spin injection in a spin quantum dot, where the dot has a localized quantum spin and it is connected to the left and the right electrodes. We consider a situation in which up spins are sequentially injected from the left electrode into the dot, and an exchange interaction acts between the injected spins and the localized spin. When the right electrode interface has energy levels of conduction electrons with only down spin, we obtain the reversal time of localized spin and the time dependence of the expectation value of localized spin, using a simple approach based on the time dependent Schrödinger equation. It is also shown that a system with the nonmagnetic right electrode interface exhibits the spin reversal or nonreversal depending on the exchange interaction. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)