bluuebunny/crossref_metadata_2025_split huggingface dataset:
Environmental risk factors for multiple sclerosis. Part II: Noninfectious factors
Authors: Ascherio Alberto , Munger Kassandra L. 
Published: May 2007

AbstractAs discussed in Part I of this review, the geographic distribution of multiple sclerosis (MS) and the change in risk among migrants provide compelling evidence for the existence of strong environmental determinants of MS, where “environmental” is broadly defined to include differences in diet and other behaviors. As we did for infections, we focus here primarily on those factors that may contribute to explain the geographic variations in MS prevalence and the change in risk among migrants. Among these, sunlight exposure emerges as being the most likely candidate. Because the effects of sun exposure may be mediated by vitamin D, we also examine the evidence linking vitamin D intake or status to MS risk. Furthermore, we review the evidence on cigarette smoking, which cannot explain the geographic variations in MS risk, but may contribute to the recently reported increases in the female/male ratio in MS incidence. Other proposed risk factors for MS are mentioned only briefly; although we recognize that some of these might be genuine, evidence is usually sparse and unpersuasive. Ann Neurol 2007
PAMAM Dendrimers as Anchors for the Preparation of Electrocatalytically Active Ultrathin Metallic Films
Authors: Raghu Subash C. , Berchmans Sheela , Phani Kanala L. , Yegnaraman Venkatraman 
Published: May 2007

AbstractThis paper describes the formation of catalytically active thin films of Pt, Pt/Au, and Pt/Ru on gold substrates stabilized by amine‐terminated polyamidoamine (PAMAM) dendrimers. A monolayer of dendrimer is initially self‐assembled on the gold substrate, which serves as a template for the growth of catalytically active thin films. As dendrimers contain tens to hundreds of functional groups at the periphery, the aggregate strength of the multidentate interactions with the gold substrate leads to the formation of robust films. The films were found to exhibit high catalytic activity for the oxidation of small hydrocarbons such as methanol. Such films offer versatility and scope for the design of effective electrocatalysts, especially in the context of microfuel cells and “dendrichips”; hence, they could find applications in the fields of sensors, fuel cells, and waste‐water treatment.
Factors affecting outcome following endoscopic thoracic sympathectomy
Authors: Jaffer U , Weedon K , Cameron A E P 
Published: May 2007

Abstract

Background
Endoscopic thoracic sympathectomy (ETS) is an effective treatment for palmar hyperhidrosis and has been extended to craniofacial symptoms such as blushing and facial sweating. Adverse effects, including compensatory sweating, may cause patients to regret surgery. Such adverse events are currently unpredictable. This study investigated whether age, sex or bodyweight influenced the outcome.

Methods
A total of 110 patients who had bilateral ETS for palmar hyperhidrosis or facial symptoms (blushing or sweating) were asked to complete a questionnaire before and after surgery regarding physical and emotional symptoms, and overall satisfaction.

Results
Seventy-nine useable questionnaires were obtained. A decrease (an improvement) in physical symptom score was found in all patients; the median (interquartile range) change was − 15 (−9 to − 18) for facial symptoms and − 8 (−6·75 to − 9) for palmar symptoms. Similarly, there was an improvement in emotional symptom score of − 16 (−8 to − 28) for facial symptoms and − 13 (−7·25 to − 18·5) for palmar symptoms. More compensatory sweating was noted in those treated for facial symptoms (P = 0·007). There was no influence of age, sex or body mass index on outcome.

Conclusion
ETS is an effective treatment for palmar and facial symptoms. Side-effects may be worse in patients treated for facial symptoms.
A Mass Spectrometric Investigation of Native and Oxidatively Inactivated Chloroperoxidase
Authors: Grey Carl Elovson , Hedström Martin , Adlercreutz Patrick 
Published: May 2007

AbstractThe enzyme chloroperoxidase (CPO) found in Caldariomyces fumago is able to catalyze several stereoselective oxidation reactions by using a clean oxidant, usually hydrogen peroxide (H2O2), without the need for expensive cofactor generation. CPO’s lack of operational stability, however, is a major limitation for its commercial use. In the present study, a capillary‐LC on‐line trypsin‐digestion system combined with reversed‐phase chromatography and mass spectrometric detection was optimized for studying the primary sequence of CPO. Samples containing native CPO, CPO treated with H2O2, and CPO oxidatively inactivated by the use of indole and H2O2 were analyzed and compared. Three oxidized peptides were found in the samples treated with H2O2. Two additional oxidized peptides were found in the CPO samples that were completely inactivated, one of which contained an oxidized cysteine residue, Cys50, which is an essential amino acid due to its function as the axial ligand to the iron in the heme—the prosthetic group in CPO. In addition, the heme group was absent in the inactivated samples but was readily detected in other samples.
Enantioselective Alkynylation of Ketones Promoted by β‐Sulfonamide Alcohol‐Titanium Complexes
Authors: Ni Ming , Zhou Yi‐Feng , Chen Chao , Xu Jiang‐Ke , Wang Rui 
Published: May 2007

AbstractA readily available β‐sulfonamide alcohol‐titanium complex was found to be effective on promoting the asymmetric addition reaction of an alkynylzinc reagent to unactivated simple ketones under very mild conditions. And the corresponding chiral tertiary propargylic alcohols were obtained with enantiomeric excesses of up to 86%, which provided a simple, practical and inexpensive method to generate chiral tertiary propargylic alcohols.
Nonlinear optical media in photonic crystal waveguides: Intrinsic localized modes and device applications
Authors: McGurn A. R. 
Published: May 2007

AbstractA review is given of some of the properties of photonic crystal waveguides containing or interacting with nonlinear optical media including discussions of potential device applications. An introduction is given to photonic crystals, photonic crystal waveguide technologies, the properties of Kerr nonlinear dielectric media, the properties of new types of excitations in these systems known as intrinsic localized modes, and optical bistability. Device designs for switches, waveguide couplers, interferometers, transistors, photonic crystal receivers and transmitters, and photonic crystal sensors are reviewed. © 2007 Wiley Periodicals, Inc. Complexity 12: 18–32, 2007
Repeating earthquakes, episodic tremor and slip: Emerging patterns in complex earthquake cycles?
Authors: Chen Wang‐Ping , Brudzinski Michael R. 
Published: May 2007

AbstractThe lack of regularity in earthquake cycles continues to be a confounding issue in earthquake science. Lately, observations of episodic nonvolcanic tremor and slip (ETS) along a few well‐instrumented tectonic plate boundaries are intriguing: these features recur together with predictable time intervals. Data now trace recurring ETS back to 1990 and no significant earthquake ever followed an ETS episode. This observation and the fact that stress drops associated with episodic slips are low, only on the order of 0.01 MPa, suggests that repeated ETS has little cumulative effects in priming the fault for the next large earthquake. Another known regularity in seismic activity is the so‐called repeating earthquakes that rupture the same patch of fault repetitively. Current hypotheses for repeating earthquakes point to the interaction of continual, aseismic fault slip with locked, seismogenic patches of the fault. Interestingly, ETS also recur near where the transition between brittle faulting and plastic flow is expected, although it is not clear how and why regularities in space and time are interconnected. New data show that ETS recurs throughout the entire length of the Cascadia subduction zone, thus ruling out any special, local factors as necessary conditions for ETS. Recurrence intervals of ETS vary along the Cascadia. Such variations are not governed by the rate of plate motion that ultimately drives the earthquake process, but they do coincide with variations in the geology of the overriding plate that can influence the rheology along the plate interface. To this end, we call attention to the Portevin‐Le Chatelier effect (PLC, or jerky flow) as a potential analog to the earthquake process. The dynamics of the PLC has been extensively studied and shows many intriguing features as the system goes from chaotic to self‐organized critical regimes as strain rate increases. In particular, the PLC exhibits not only stick‐slip behavior (stress serration) over time but also spatial interactions over extended regions—features that are necessary to account for complex spatio‐temporal variations associated with earthquake activities. © 2007 Wiley Periodicals, Inc. Complexity 12: 33–43, 2007
Low‐Temperature PECVD of Transparent SiOxCyHz Thin Films
Authors: Barreca D. , Gasparotto A. , Maccato C. , Maragno C. , Tondello E. , Rossetto G. 
Published: May 2007

AbstractHybrid organic/inorganic SiOxCyHz thin films are prepared on Cu, Si(100), and SiO2 substrates by plasma‐enhanced (PE)CVD using tetramethoxysilane (TMOS) as the precursor compound. Depositions are performed from Ar plasmas at temperatures as low as 60 °C, avoiding the use of oxidizing reagents in view of possible film application as protective coatings against substrate oxidation. In situ monitoring of deposition processes is performed using laser reflection interferometry (LRI), which provides valuable information on the growth rate as a function of the adopted synthesis conditions. The obtained film thickness values are confirmed by scanning electron microscopy (SEM), which is also used to investigate the film morphology and its adhesion to the substrate. The chemical structure and composition are investigated in detail by a combined use of energy dispersive X‐ray spectroscopy (EDX), Fourier transform infrared (FTIR) spectroscopy, and X‐ray photoelectron spectroscopy (XPS). Glancing incidence X‐ray diffraction (GIXRD) and UV‐vis spectroscopy are used for the study of the structural and optical properties of the system. Finally, nanoindentation measurements permit the evaluation of the hardness of the synthesized coatings. Amorphous layers with a silica‐like network incorporating covalently bonded methyl and methoxy groups are obtained under very mild synthesis conditions. Furthermore, the coatings are characterized by good substrate conformal coverage and remarkable optical transparency.
Incubation Effects upon Polycrystalline Silicon on Glass Deposited by Hot‐Wire CVD
Authors: Lien S.‐Y. , Mao H.‐Y. , Wu B.‐R. , Horng R.‐H. , Wuu D.‐S . 
Published: May 2007

AbstractA growth mechanism diagnosis for high‐rate, polycrystalline silicon deposition using hot‐wire CVD is explored in this article. The effects of various deposition parameters on the Si film growth are investigated by Raman spectroscopy and transmission electron microscopy (TEM) measurements, with special attention paid to the crystalline and amorphous phases. It is found that the H2/SiH4 ratio and substrate temperature (Ts) are the essential process parameters in determining the crystalline phase and the incubation thickness of the as‐deposited Si film. Under low hydrogen dilution conditions, an amorphous incubation layer was formed and degraded the crystalline fraction of the Si film. The incubation thickness prior to the nucleation decreases with the increase of the hydrogen dilution ratio. Under higher H2/SiH4 ratios (≥50), the amorphous phase deposited on the substrate could be etched selectively by the atomic hydrogen. As a consequence, nucleation of small crystallite occurs directly on the substrate. At low substrate temperatures, the deposition process shows the disadvantages of small grain size and low crystallinity. The poly‐Si film can be deposited from the seed layer under high Ts conditions (>350 °C) where the Si appears singly crystallized at the initial stage and then grows epitaxially.
Giardia lamblia infection diagnosed by endoscopic ultrasound‐guided fine‐needle aspiration
Authors: Carter J. Elliot , Nelson John J. , Eves Matthew , Boudreaux Carole 
Published: May 2007

AbstractThe protozoan Giardia lamblia is a major cause of gastrointestinal disease worldwide. We report the case of a 59‐yr‐old male who presented to his primary care physician with complaints of abdominal pain and weight loss. Imaging studies revealed a liver mass and a pancreatic head mass. Biopsy of the liver mass proved to be benign, and endoscopic ultrasound‐guided fine‐needle aspiration of the mass in the head of the pancreas showed no evidence of malignancy; however, numerous pear‐shaped, binucleated, flagellated organisms morphologically consistent with trophozoites of Giardia lamblia were identified in the specimen. With the increasing use of endoscopic ultrasound‐guided fine‐needle aspiration for sampling of gastrointestinal, hepatobiliary, and pancreatic lesions, cytopathologists examining such specimens will need to be familiar with the diagnostic characteristics of this protozoal parasite. Diagn. Cytopathol. 2007;35:363–365. © 2007 Wiley‐Liss, Inc.
Germ‐line and rearranged Tcrd transcription distinguish bona fide NK cells and NK‐like γδ T cells
Authors: Stewart Charles A. , Walzer Thierry , Robbins Scott H. , Malissen Bernard , Vivier Eric , Prinz Immo 
Published: May 2007

AbstractNK cells and γδ T cells are distinct subsets of lymphocytes that contextually share multiple phenotypic and functional characteristics. However, the acquisition and the extent of these similarities remain poorly understood. Here, using T cell receptor δ locus‐histone 2B‐enhanced GFP (Tcrd‐H2BEGFP) reporter mice, we show that germ‐line transcription of Tcrd occurs in all maturing NK cells. We also describe a population of mouse NK‐like cells that are indistinguishable from “bona fide” NK cells using standard protocols. Requirements for V(D)J recombination and a functional thymus, along with very low‐level expression of surface TCRγδ but high intracellular CD3, define these cells as γδ T cells. “NK‐like γδ T cells” are CD127+, have a memory‐activated phenotype, express multiple NK cell receptors and readily produce interferon‐γ in response to IL‐12/IL‐18 stimulation. The close phenotypic resemblance between NK cells and NK‐like γδ T cells is a source of experimental ambiguity in studies bridging NK and T cell biology, such as those on thymic NK cell development. Instead, it ascribes chronic TCRγδ engagement as a means of acquiring NK‐like function.See accompanying commentary: at http://dx.doi.org/10.1002/eji.200737418
Ligand Exchange Processes on Solvated Lithium Cations: Complexation by Cryptands in Acetone as Solvent
Authors: Pasgreta Ewa , Puchta Ralph , Zahl Achim , van Eldik Rudi 
Published: May 2007

AbstractKinetic studies on Li+ exchange between the cryptands C222 and C221 and acetone as solvent were performed as a function of ligand‐to‐metal ratio, temperature and pressure using 7Li NMR spectroscopy. Temperature and pressure dependence measurements were performed in the presence of an excess of Li+. The rate and activation parameters for the exchange process are: C222: k298 = (1.7 ± 0.5) × 103 s–1, ΔH# = 24 ± 1 kJ mol–1 and ΔS# = –105 ± 4 J K–1 mol–1; C221: k298 = 2.24 ± 0.09 s–1, ΔH# = 29 ± 2 kJ mol–1 and ΔS# = –141 ±5 J K–1 mol–1. The influence of pressure on the exchange rate is insignificant for both ligands, such that the activation volume is around zero within the experimental error limits. The reported activation parameters suggest that the exchange of Li+ between solvated and chelated ions follows an associative interchange mechanism.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)
Facile Formation of Hexacyclic [Al3O2Cl] Aluminum and Alkoxide‐Bridged Titanium Complexes: Reactions of AlMe3 with [Ti(L)Cl2] [L = 2,2′‐Methylenebis(6‐tert‐butyl‐4‐methylphenolato)]
Authors: Zhang Dao 
Published: May 2007

AbstractThe titanium dichloride complex [(L)TiCl2] [L = 2,2′‐methylenebis(6‐tert‐butyl‐4‐methylphenolato)] (1) reacted with trimethylaluminum (AlMe3) in a 1:2 ratio to give a trimetallic aluminum complex of the composition [(L)(AlMe2)3(μ‐Cl)] (2) with a symmetric six‐membered ring [Al3(μ2‐O)2(μ2‐Cl)] and a four‐coordinate aluminum center in the solid state. The reaction of 1 equiv. AlMe3 gave [(L)TiMeCl] (3), which could absorb O2 gas to afford the oxygen‐insertion product [{(L)TiCl}2(μ‐OMe)2] (4) with a five‐coordinate metal center. Upon reaction of H2L with AlMe3, the binuclear, four‐coordinate adduct [{(L)AlMe}2] (5) was formed. Complex 4 supported on MgCl2 and activated with aluminum alkyls reveals high catalytic activity for ethylene polymerization to produce polymers with molecular weight distributions of ca. 3.1. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)
Coordinated 1,3‐Diyne Diols as Organometallic Building Blocks for Large Macrocycles Containing Oxygen and Unsaturated Donor Units
Authors: Hope‐Weeks Louisa J. , Mays Martin J. , Solan Gregory A. 
Published: May 2007

AbstractThe acid‐catalysed reaction of [{Co2(CO)6(μ‐η2‐HOCH2C2‐)}2] (1a) with a range of alkyl diols has been examined as means of preparing large crown‐type macrocycles (up to twenty eight‐membered) containing at least one coordinated 1,3‐diyne unit, multiple oxygen atoms and a variety of soft donor units. Thus, interaction of 1a with HOCH2(CH2)nCH2OH, allows access to the monomeric cyclised complexes [{Co2(CO)6}2{cyclo‐μ‐η2:μ‐η2‐CH2C2C2CH2OCH2(CH2)nCH2O}] (3a: n = 2, 3b: n = 3, 3c: n = 4) along with the dimeric cyclised species [{Co2(CO)6}2{cyclo‐μ‐η2:μ‐η2‐CH2C2C2CH2OCH2(CH2)nCH2O}]2 (4a: n = 2, 4b: n = 3, 4c: n = 4). Introduction of additional oxygen donor atoms into the macrocycle can be achieved by reaction of 1a with the glycols, HO(CH2CH2O)nH, to afford exclusively monomeric [{Co2(CO)6}2{cyclo‐μ‐η2:μ‐η2‐CH2C2C2CH2O(CH2CH2O)n}] (5a: n = 3, 5b: n = 4). On the other hand, treatment of 1a with the 1,3‐diyne‐linked alkyl diols, HOCR2C≡CC≡CCR2OH, furnishes the more rigid monomeric [{Co2(CO)6}2{cyclo‐μ‐η2:μ‐η2‐CH2C2C2CH2OCR2C2C2CR2O}] [6a: R = H, 6b: R = Me] and dimeric macrocycles [{Co2(CO)6}2{cyclo‐μ‐η2:μ‐η2‐CH2C2C2CH2OCR2C2C2CR2O}]2 [7a: R = H, 7b: R = Me], whereas the use of the alkynyl‐ or aryl‐linked alkyl diols, HOCH2(L)CH2OH, affords the unsymmetrical dimeric [{Co2(CO)6}2{cyclo‐μ‐η2:μ‐η2‐CH2C2C2CH2}2O{OCH2(L)CH2O}] [8a: L = –C≡C–, 8b: L = 1,4‐C6H4] and symmetrical dimeric species [{Co2(CO)6}2{cyclo‐μ‐η2:μ‐η2‐CH2C2C2CH2OCH2(L)CH2O}]2 [9a: L = –C≡C–, 9b: L = 1,4‐C6H4]. Also isolated as a by‐product from all the above reactions is the self‐dimerised macrocycle [{Co2(CO)6}2{cyclo‐μ‐η2:μ‐η2‐CH2C2C2CH2O}]2 (2) which can itself be synthesised more directly by treating 1a with catalytic quantities of HBF4·OEt2. Single crystal X‐ray diffraction studies have been performed on 2, 3a, 5a, 7a, 8a, 8b and 9a. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)
Electrophoretic chip for high‐fidelity fractionation of double‐stranded DNA
Authors: Sun Kai , Li Zheyu , Ueno Kosei , Juodkazis Saulius , Noji Sumihare , Misawa Hiroaki 
Published: May 2007

AbstractWe report the high fidelity, on‐chip fractionation of selected segments from an electrophoretic flow of separated fragments. dsDNA fragments (10–330 base pairs (bp)) were initially separated using a 6.5 cm long channel with an electric field strength of 150 V/cm. As an example of the fractionation process, a target fragment of 20 bp was selected and extracted from the separation channel. The extraction was confirmed and evaluated by fluorescence imaging. High resolution and extraction fidelity were achieved by introducing new procedures for (i) extraction channel‐blocking and (ii) segment transfer with cleaning. These procedures are necessary for the development of a practical, fully automated multitarget fractionation electrophoretic chip. A kind of CCD image processing method was introduced to monitor, control, and evaluate the procedure of fractionation. The resolution limits of the separation and extraction are discussed.
True moving bed electrophoresis using stepped electric field gradients
Authors: Thome Brian M. , Ivory Cornelius F. 
Published: May 2007

AbstractTrue moving bed electrophoresis has been shown to be an effective technique for the bench‐scale separation of enantiomers, and it is desired to increase the maximum possible throughput attainable with the process by using electric field gradients. Homatropine enantiomer separations were performed and results using a stepped electric field gradient were compared to those using a traditional non‐gradient separation. In order to accomplish this, a newly designed stator was constructed for use with the Vortex‐Stabilized Electrophoresis Apparatus that has three sets of electrode housings, one set at both ends and one in the middle of the chamber. There were several problems related to the membranes used at the middle electrode. The dialysis membranes were permeable to the homatropine enantiomers, and while a switch to anion exchange membranes prevented the permeation of the homatropine, this caused a pH shift that interrupted binding to the hydroxypropyl‐ß‐cyclodextrin chiral selector. These problems prevented any meaningful data from being collected using homatropine enantiomers, and due to this, a proof of concept study was conducted using two bovine proteins. The separations using fluorescein‐labeled BSA and bovine hemoglobin showed that a 63% increase in the maximum processing rate was attainable. The maximum throughput using the non‐gradient process was 30.6 mg/h and the maximum was 50.0 mg/h using an electric field gradient that was 10% lower than the non‐gradient field in section II and 10% higher in section III.
Seismic structural demands taking accuracy of response estimation into account
Authors: Mori Yasuhiro , Maruyama Yutaka 
Published: May 2007

AbstractPredictors of seismic structural demands (such as inter‐storey drift angles) that are less time consuming than nonlinear dynamic analysis (NDA) have proven useful for structural performance assessment and for design. Several techniques have been proposed using the results of a nonlinear static pushover analysis. These techniques often use the maximum response computed via NDA of the inelastic oscillator that is ‘equivalent’ to the original frame. In practice, it is desirable to estimate the response approximately via a simpler method such as an equivalent linearization technique and uniform hazard spectra at the site. In reliability‐based seismic performance assessment and design of a structure, it is necessary to consider the level of accuracy of the techniques used in the assessment. A simple technique is proposed in this paper to estimate the r‐year return period value of the inter‐storey drift angle of a moment‐resisting steel frame using a single uniform hazard spectrum of the r‐year return period displacement of an elastic oscillator. The structural demand is estimated using the safety factors evaluated taking the variability in the seismic hazard, accuracy of the techniques for estimating structural response, and the structural performance level into account. The accuracy of the technique is investigated relative to the structural demand estimated more directly from the probability distributions of the seismic hazard. Copyright © 2007 John Wiley & Sons, Ltd.