bluuebunny/crossref_metadata_2025 huggingface dataset:
Structure and properties of tecto-gallosilicates II. Sodium chloride, bromide and iodide sodalites
Authors: Gesing Thorsten M.
Published: May 2007

The crystal structures of the gallosilicate sodalites Na8[GaSiO4]6Cl2, Na8[GaSiO4]6Br2 and Na8[GaSiO4]6I2 were refined from X-ray powder data in the space group P-43n: a = 894.70 pm, V = 0.7162 nm3, R
WP = 0.066, R
P = 0.050, R
I = 0.011, a = 900.83 pm, V = 0.73102 nm3, R
WP = 0.066, R
P = 0.051, R
I = 0.016 and a = 908.36 pm, V = 0.74951 nm3, R
WP = 0.050, R
P = 0.036, R
I = 0.013 for 4000 data points and 14 variable positional parameters in each case for the chloride, bromide and iodide compound, respectively. The gallium and silicon atoms on the tetrahedral framework positions are totally ordered, the halide anions were found at the centre of the sodalite cage coordinated by four sodium atoms. The recorded infrared and Raman spectra show absorption bands typical for the sodalite structure, but indicate also clearly the difference between chloride, bromide and iodide incorporation in the sodalite cage by different absorption band in the FIR range. Heating X-ray investigations show the expected increases of lattice parameters for all three sodalites with increasing temperature and no phase transition was detected. But for the freshly prepared bromide sample a different nearly linear increase of the lattice parameter was observed up to 770 K and above 870 K with an invariant behaviour between these temperatures. The tilt and T—O—T angle as well as the interatomic Si—O and Ga—O distances show an expected temperature dependent behaviour as found by Rietveld calculations of the high-temperature X-ray data. The angles in the tetragonal distorted SiO4 tetrahedra show values comparable to those found in alumosilicate sodalites but seem to be temperature dependent. Additionally, the corresponding GaO4 angles indicate a disappearance of the tetragonal tetrahedron distortion around the temperature where the discontinuity was observed for the lattice parameter. The GaO4 tetragonal tetrahedron distortion is close to zero during the formation of the framework which leads to different distortion direction. This different distortion direction could be relaxed by heating the sample or a self relaxing occurs within several months at room temperature.
The conformation cis of N-acetyl-N-methyl-α,β-dehydroalanine N′-methylamide and saturated analogues
Authors: Siodlak Dawid , Macedowska-Capiga Agnieszka , Ejsmont Krzysztof , Zaleski Jacek , Rzeszotarska Barbara
Published: May 2007

A series of three homologous amino acids derivatives: N-acetyl-N-methyl-α,β–dehydroalanine N′-methylamide (1), N-acetyl-N-methyl-L-alanine N′-methylamide (2), and N-acetyl-N-methyl-DL-alanine N′-methylamide have been synthesised. The racemic species undergoes spontaneous separation into L and D-enantiomers. From these two chiral forms, the structure of L-enantiomer (3) was analysed. The molecules of 1 – 3 adopt the cis arrangement of the N-terminal amide bond. The molecular conformations are similar for 1 (φ, ψ = 94.6(1)°, −1.7(1)°) and 3 (φ, ψ = 111.5(1)°, −23.8(1)°), and also 2 (φ, ψ = −114.8(2)°, 29.5(2)°), if inversion through the chiral C2 carbon is considered. They are stabilised by intramolecular N—H…N hydrogen bond. In the case of 1, the π—electron conjugation resulting from the planar arrangement of the C2—C21 double bond and C-terminal amide group is another stabilising force of this conformation. Thus, the N-methyldehydroalanine residue should promotes trans-cis isomerisation to a greater extend than the saturated analogue. The compounds 1 – 3 reveal similar associative pattern and form centrosymmetric dimers linked by the intermolecular N—H…O hydrogen bonds.
No need for reconsidering the definition …
Authors: Janssen Ted
Published: May 2007

When in the seventies and eighties materials were analysed which did not show lattice periodicity but were very similar to the then known crystals the IUCr decided to extend the definition of ‘crystal’. This resulted in the well known definition which is a bit vague but points to a spectrum with essentially Bragg peaks. By being a bit vague one could also include crystals with defects and finite sizes. Of course, it was well known that there are other notions of order. …
Thoughts on “crystal”
Authors: Senechal Marjorie
Published: May 2007

What is a crystal? The Commission on Aperiodic Crystals, in a recent report, listed three statements “that each by itself might characterize the crystalline state”:(1) a solid with an essentially discrete diffraction diagram;(2) a solid with an atomic structure with long range order;(3) a solid with an atomic structure that can be obtained as a section of an n-dimensional periodic structure (n = 3, 4, …). The report noted that “advantages of and problems with each of these definitions were discussed.”…
Die Fragmente des Phaethon -Dramas von Euripides im Spiegel von Goethes Rekonstruktion
Authors: Adorjáni Zsolt
Published: May 2007

This paper aims to
reexamine the arguments concerning the three main problems of the fragmentary
Euripidean tragedy
Phaethon
, i.e. what character and conflict lies
behind Phaethon's excessive reluctance to the marriage; who the mysterious
bride is; and finally, what kind of exodos fits in the dramatic context on the
basis of the fragmentary textual evidence. In my discussion Goethe's
reconstruction is dealt with closely; moreover, the poet's suggestions prove to
be valuable not only artistically, but philologically as well. Some personal
bias of his treatment nevertheless hints at a new articulation of the
Phaethontic character in the Euphorion-episode of
FaustII
and a general
reevaluation of the hybris-drama.
Catullus 115. 4: tot moda possideat
Authors: Olszaniec Włodzimierz
Published: May 2007

This note suggests an
emendation of Catullus 115.4:
qui uno in saltu tot commoda possideat
.
Guiding principles for future developments in transport
Authors: Lyons G. , Marsden G. , Beecroft M. , Chatterjee K.
Published: May 2007

Transport policy in the UK has been the focus of much deliberation and reformulation in recent years. While a ten year £180 billion spending plan is now in place this does not, nor should it, preclude the ongoing debate over transport's future and the principles with which it should be shaped. This paper presents a set of such principles which has been produced by the Transport Visions Network. The Network is a virtual community of some 250 young professionals that is exploring the future of transport in the twenty-first century. Having taken a long-term view in its deliberations, the Network has conceived twelve principles relating to the topics of: accessibility; mobility; costs; environment; trip type; health and safety; electronic communication; land use; reliability; social participation; stakeholders; and information.
Nonvolatile Memory Elements Based on Organic Materials
Authors: Scott J. C. , Bozano L. D.
Published: May 2007

Many organic electronic devices exhibit switching behavior, and have therefore been proposed as the basis for a nonvolatile memory (NVM) technology. This Review summarizes the materials that have been used in switching devices, and describes the variety of device behavior observed in their charge–voltage (capacitive) or current–voltage (resistive) response. A critical summary of the proposed charge‐transport mechanisms for resistive switching is given, focusing particularly on the role of filamentary conduction and of deliberately introduced or accidental nanoparticles. The reported device parameters (on–off ratio, on‐state current, switching time, retention time, cycling endurance, and rectification) are compared with those that would be necessary for a viable memory technology.
Environmental risk factors for multiple sclerosis. Part II: Noninfectious factors
Authors: Ascherio Alberto , Munger Kassandra L.
Published: May 2007

As 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

This 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

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

The 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

A 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

A 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

The 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

Hybrid 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

A 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

The 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

NK 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

Kinetic 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

The 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

The 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

We 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

True 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

Predictors 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.
Loss of distal 11q is associated with DNA repair deficiency and reduced sensitivity to ionizing radiation in head and neck squamous cell carcinoma
Authors: Parikh Rahul A. , White Jason S. , Huang Xin , Schoppy David W. , Baysal Bora E. , Baskaran Rajasekaran , Bakkenist Christopher J. , Saunders William S. , Hsu Lih‐Ching , Romkes Marjorie , Gollin Susanne M.
Published: May 2007

About 45% of head and neck squamous cell carcinomas (HNSCC) are characterized by amplification of chromosomal band 11q13. This amplification occurs by a breakage‐fusion‐bridge (BFB) cycle mechanism. The first step in the BFB cycle involves breakage and loss of distal 11q, from FRA11F (11q14.2) to 11qter. Consequently, numerous genes, including three critical genes involved in the DNA damage response pathway, MRE11A, ATM, and H2AFX are lost in the step preceding 11q13 amplification. We hypothesized that this partial loss of genes on distal 11q may lead to a diminished DNA damage response in HNSCC. Characterization of HNSCC using fluorescence in situ hybridization (FISH) revealed concurrent partial loss of MRE11A, ATM, and H2AFX in all four cell lines with 11q13 amplification and in four of seven cell lines without 11q13 amplification. Quantitative microsatellite analysis and loss of heterozygosity studies confirmed the distal 11q loss. FISH evaluation of a small series of HNSCC, ovarian, and breast cancers confirmed the presence of 11q loss in at least 60% of these tumors. All cell lines with distal 11q loss exhibited a diminished DNA damage response, as measured by a decrease in the size and number of γ‐H2AX foci and increased chromosomal instability following treatment with ionizing radiation. In conclusion, loss of distal 11q results in a defective DNA damage response in HNSCC. Distal 11q loss was also unexpectedly associated with reduced sensitivity to ionizing radiation. Although the literature attributes the poor prognosis in HNSCC to 11q13 gene amplification, our results suggest that distal 11q deletions may be an equally significant factor. © 2007 Wiley‐Liss, Inc.
Discounting and health benefits
Authors: Parsonage Michael , Neuburger Henry
Published: May 2007

This paper argues that non‐monetary health benefits should not be discounted at the same rate as variables expressed in monetary terms. It argues instead that the appropriate discount rate should be at or close to zero. It explores the various influences of rising income, age and pure time preference on the relative value of current and future health states. It examines various arguments advanced to justify the current practice of discounting health benefits at the same rate as monetary costs. These include uncertainty and delay. The article concludes with an analysis of the likely impact of adopting a zero discount rate on the ranking of health interventions.
Fairness and feasibility in national health care systems
Authors: Pauly Mark V.
Published: May 2007

The issue of National Health Care reform has been discussed from many different perspectives. One of the most fundamental justifications for such reform is based on the notion of horizontal equity. The motivation for equity in medical services use contrasts with the the seeming lack of concern for equity in financing. Proposed policy remedies often involve transfers through taxation, though the effects of government taxation often reduce the efficiency of publicly financed health insurance. Further, the effects of heterogeneous preferences complicate the assessment of optimal medical service consumption levels. Ethical justification aside, this paper addresses the notion of fairness in the provision of medical care from an economic perspective. It suggests policies which might be most suitable in achieving such a goal. A paradoxical result of these considerations of fairness is that unequal insurance coverage is requisite to ensure more equal utilization of medical services by the population. The concept of fairness is then developed into a bottom up system of equity in the medical market.
Quality assurance in Canada: What are the health professions doing?
Authors: Kushner Carol
Published: May 2007

Although quality assurance (QA) programming in Canada is still at an early stage of development, health professionals are increasingly being called upon to substantiate the value of the services they provide. A body of research showing wide variations in the rates of service provision and significant amounts of inappropriate care have convinced many policy makers about the need to improve quality in the Canadian health system. Recent and severe economic pressures on provincial government funders could foster a more rational approach to resource allocation, including the consideration that better quality care is more efficient care.

The bulk of health care in Canada is delivered in the private offices of practitioners, where quality assurance programming is relatively undeveloped. Although some licensing organizations do conduct proactive routine audits of their members' practices, a national survey, based on self‐report, indicated that most of these programmes do not conform to recommendations found in the quality assurance literature.

Although there have been some new initiatives in Canadian QA, it remains to be seen how these will influence the evolution of quality assurance programming conducted by Canada's health professions.
Management of human resources in health care: The Canadian experience
Authors: Adams Orvill
Published: May 2007

Each of Canada's ten provinces has a publicly administered system of health insurance, funded by provincial and federal taxes, that is accessible to all citizens and covers all medically necessary services provided by physicians and hospitals. Canadians spend an estimated 9.2 percent of their gross national product on health care (about 2.8 percentage points below US spending), of which three quarters is public‐sector spending. According to the Organization for Economic Cooperation and Development, Canada's health status is equal to or better than that of the United States, despite lower per capita health spending.

About seven percent of the Canadian labour force works in health care, and attempts to introduce coordinated planning of human resources in health care have not as yet proceeded far. The predominant policy issue here is the supply and the role of physicians. It has been argued that entrenching within the system the fee‐for‐service method of paying physicians has created a disincentive to the delegation of responsibility to health personnel other than doctors.

It is also argued that introduction of government‐run health insurance provided the opportunity for human resource planning, but that the decision by governments to act only as the payer resulted in ad‐hoc planning approaches.

However, governments' concern over health care costs has led to a more direct role by them in the planning of the human resources in health. They are re‐examining the autonomy and jurisdictional rights of the professions that deliver health care to Canadians.
Are increases in cigarette taxation regressive?
Authors: Borren Pim , Sutton Matthew
Published: May 2007

Using the latest published data from Tobacco Advisory Council surveys, this paper re‐evaluates the question of whether or not increases in cigarette taxation are regressive in the United Kingdom. The extended data set shows no evidence of increasing price‐elasticity by social class as found in a major previous study. To the contrary, there appears to be no clear pattern in the price responsiveness of smoking behaviour across different social classes. Increases in cigarette taxation, while reducing smoking levels in all groups, fall most heavily on men and women in the lowest social class. Men and women in social class five can expect to pay eight and eleven times more of a tax increase respectively, than their social class one counterparts. Taken as a proportion of relative incomes, the regressive nature of increases in cigarette taxation is even more pronounced.
Equity and efficiency in Italian health care
Authors: Paci Pierella , Wagstaff Adam
Published: May 2007

Health care finance and provision in Italy is unusual by international standards: public financing relies heavily on both general taxation and social insurance, and although the vast majority of expenditure is publicly financed, the majority of care is provided by the private sector. The system suffers, however, from a chronic failure to control expenditures and its record on perinatal and infant mortality is poor. Hospitals in Italy have a low bed‐occupancy rate by international standards and the per diem system of reimbursing private hospitals encourages unduly long stays. Costs per inpatient day are high by international standards, but costs per admission are close to the OECD average. Ambulatory care costs are extremely low, but this appears to be due to the fact that GPs see so many patients that their role is inevitably mainly administrative. Consumption of medicines is extremely high, but because the cost per item is low, expenditure per capita is not unduly high. Despite the emphasis on social insurance, the financing system appears to be progressive. There is evidence of inequalities in health in Italy, and some evidence that health care is not provided equally to those in the same degree of need.
Recruitment methods for screening programmes: The price of high compliance
Authors: Torgerson D. J. , Donaldson C. , Garton M. J. , Reid D. M. , Russell I. T.
Published: May 2007

High population compliance is seen as a prerequisite for an equitable screening service. To achieve high compliance fixed appointments are usually advocated. However, the costs of achieving high compliance have not previously been described. To assess the costs of achieving high compliance we have used a randomised trial of two common appointment methods: 800 women aged 45‐49 living within 20 miles of Aberdeen were selected at random from the Community Health Index. They were randomly assigned to receive one of two letters—one offering a fixed appointment, the other inviting them to telephone to make an appointment.

For a defined population fixed appointments achieved high compliance but only by reducing the opportunities for screening; for every 100 women screened, 110 additional women were denied the opportunity of a screening test. In contrast the open letters of invitation achieved efficiency by increasing the number of women screened with given resources within a larger population. Thus for screening services with fixed budgets, high compliance is achieved only by screening fewer people.
Trends in the structure, productivity, effectiveness and unit costs of the hospital and community health services workforce in England: 1979–1991
Authors: Cutler Peter
Published: May 2007

In this paper it is shown that there have been significant structural changes in the composition of the Hospital and Community Health Services (HCHS) workforce over the 1980s. The number of doctors, nurses and other medical professionals has grown at the expense of support staff such as ancillaries and maintenance workers. The number of agency and contract staff has risen rapidly, partly offsetting the loss of directly‐employed support staff.

Changes in the workforce have been compared with changes in activity, as measured by the cost‐weighted activity index. According to this measure labour productivity has grown by a compound rate of 1.9% annually. Adjusting the labour force index for the wage bill of each group reveals productivity growth of 1.5%. The effectiveness of treatment, as proxied by the decline in avoidable perinatal mortality, has grown by 3.4% annually.

Unit labour costs have fallen over the period at an average annual rate of 0.3%. The trend conceals wide fluctuations, with labour costs falling slowly during the first half of the decade, and rising strongly during the second half. Medical professionals benefited disproportionately from wage increases in comparison with other HCHS groups during the mid to late 1980s.
Income transfers and the labour market participation of disabled individuals in the UK
Authors: O'Donnell Owen
Published: May 2007

Data from the OPCS Disability Survey are used to model the labour force participation of disabled individuals. The model is an endogenous switching regression and estimation is by the two stage probit procedure. The estimates are used to simulate the impact of Disability Working Allowance, introduced in April 1992, on the participation rate of the disabled population.
Generalizability of valuations on health states collected with the EuroQolc‐questionnaire
Authors: Essink‐Bot Marie‐Louise , Stouthard Marlies E. A. , Bonsel Gouke J.
Published: May 2007

Problem: Non‐response and non‐usable response were found in population surveys on valuation of health states. If non‐response is selective regarding valuations, then generalization of the resulting values to the whole survey population is not permitted. This could limit the use of empirical utility values in resource allocation in health care.

Methods: Response behaviour of a sample of 1400 from the Dutch general population to the mailed EuroQolc‐questionnaire was analyzed by four methods. I. Phoning resolute non‐respondents; II. comparison of zip code characteristics of respondents and non‐respondents (because individual data on background characteristics were not available for the non‐respondents); III. analysis of response over time (wave‐analysis); IV: comparison of background variables of successful (less than two valuations missing) and unsuccessful respondents, combined with analysis of the effect of these background variables on valuations.

Results: No indications for selective non‐response were found, although the phenomenon appeared hard to investigate. The successful response came from a slightly younger and better educated subsample. However, a general influence of age and educational level on valuations could not be shown. This finding is consistent with the literature.

Conclusion: Although the existence of selective non‐response cannot be excluded, its relevance can be considered to be small. This finding is encouraging for the use of empirical utility values in allocative decisions.
A cost function analysis of residential services for adults with a learning disability
Authors: Shiell Alan , Pettipher Catherine , Raynes Norma , Wright Ken
Published: May 2007

Successive UK governments have pursued a policy of community care for people with learning disabilities which, in the past ten years, has led to a marked change in the nature of residential provision. Research evidence on the costs and quality of alternative forms of community provision is inconclusive and contradictory. It is therefore timely to consider whether or not community residential facilities have delivered the expected quality of service at appropriate cost. The paper presents the results of a cost function analysis of a random stratified sample of staffed community facilities in England excluding London.

Both costs and quality of care were found to vary greatly amongst community residential facilities. The most important factors explaining differences in cost were case‐mix factors relating to client age, dependency and length of stay. Facility characteristics such as the type of building, the internal layout and the structural quality were not significant. Quality of service measures such as the extent to which care‐regimes were client orientated and made use of local community services were positively and significantly associated with costs. Type of provider had no impact on costs independent of differences in case‐mix and quality of care with the exception of the private for profit sector which appeared less expensive than other agencies.

The shortcomings of the methods and implications of these findings for policy makers are discussed.
Have procompetitive changes altered hospital provision of indigent care?
Authors: Campbell Ellen S. , Ahern Melissa W.
Published: May 2007

In the past decade alone there have been numerous changes in the financial and competitive environment of hospitals in the United States. Some examples include the advent of Medicare's Prospective Payment System, growth in managed care options, relaxation of states' Certificate of Need (CON) regulations, and court cases questioning the tax‐exempt status of nonprofit hospitals. In this paper we attempt to reveal how hospitals alter their provision of care to the poor in a more cost conscious and competitive environment. Using hospital data from the State of California for the fiscal years ending in 1983 and 1987, estimates explaining uncompensated care commitments are presented. In particular, this study illustrates how hospitals under different ownership control varied their provision of uncompensated care over the period studied on average and by profitability level. Other factors, such as hospital location, teaching status, medicare patient load, and contractual adjustments, are also included in the analysis. A number of interesting trends are detected. Moreover, the results are found to be compatible with a quid pro quo hypothesis which states that hospital regulators reward large uncompensated care providers with profitable CON licenses.