bluuebunny/crossref_metadata_2025 huggingface dataset:
Thienopyrazine‐Based Low‐Bandgap Poly(heteroaryleneethynylene)s for Photovoltaic Devices
Authors: Ashraf Raja Shahid , Shahid Munazza , Klemm Elisabeth , Al‐Ibrahim Maher , Sensfuss Steffi
Published: August 2006

Summary: Low‐bandgap π‐conjugated polymers that consist of alkyl thiophene/alkoxy phenylene and 2,3‐diphenylthieno[3,4‐b]pyrazine units have been prepared in high yields by a Sonogashira polycondensation. The copolymers are characterized by NMR, IR, UV, GPC, and elemental analysis. Thin films of the polymers P1, P2, and P3 exhibit an optical bandgap of ≈1.57–1.60 eV. Under simulated AM 1.5 conditions P2/PCBM devices on polyester foil provide a short circuit current of ISC = 10.72 mA · cm−2, an open circuit voltage of Voc = 0.67 V, and a power conversion efficiency of 2.37%.

Schematic of the photovoltaic device made from the polymers synthesized here.

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Schematic of the photovoltaic device made from the polymers synthesized here.
Delamination of Organically Modified Layered Filler via Solid‐State Processing
Authors: Saito Tomotaka , Okamoto Masami , Hiroi Ryoichi , Yamamoto Minoru , Shiroi Takashi
Published: August 2006

Summary: Solid‐state processing for the preparation of poly(p‐phenylenesulfide) (PPS‐) based nano‐composites having finely dispersed layered fillers was conducted. The mixture of PPS and organically modified layered filler (OMLF) (95/5 wt./wt.) was subjected to the processing using thermostated hot‐press at 150 °C, below Tm of PPS (i.e., PPS is still at the solid‐state), and applying pressures of 33 MPa for 30 s. The mixture exhibited disorder and delaminated layer structure with the thickness of 10–20 nm into the PPS matrix. In contrast, a nano‐composite prepared by melt compounding at 300 °C for 3 min showed large stacked silicate layers in the PPS matrix. The processing led to delamination of the silicate layers and attained the discrete dispersion.

TEM bright field image and FFT spectrum of a solid‐state processed PPS nano‐composite.

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TEM bright field image and FFT spectrum of a solid‐state processed PPS nano‐composite.
Spinocerebellar ataxia type 1, 2, and 3 and restless legs syndrome: Striatal dopamine D2 receptor status investigated by [11C]raclopride positron emission tomography
Authors: Reimold Matthias , Globas Christoph , Gleichmann Marc , Schulze Michael , Gerloff Christian , Bares Roland , Machulla H.‐J. , Bürk Katrin
Published: August 2006

In spinocerebellar ataxias (SCAs), up to 30% of patients complain of restless legs syndrome (RLS). In primary RLS, a putative role of the dopaminergic system has been postulated. To assess dopaminergic function in SCA1, 2, and 3, dopamine D2 receptor binding potential (BP) was assessed by [11C]raclopride positron emission tomography in 10 SCA patients, 4 of whom suffered from RLS as demonstrated by polysomnography. BP was compared to 9 age‐matched control subjects. In 2 SCA patients, striatal BP was clearly reduced (<2 SD below the mean of controls). However, there were no significant group differences between SCA and controls, largely owing to a significantly higher variance of striatal BP in SCA. BP was negatively correlated with disease duration. The fit suggests an increased BP in early stages, followed by a moderate decline in all quantified regions (caudate, dorsal putamen, ventral striatum) presumably reflecting a progressive loss of D2 receptors. RLS in SCA was not accompanied by a significant reduction of D2 receptor availability in the striatum. This missing correlation may point to an extrastriatal origin of RLS. © 2006 Movement Disorder Society
Time of loss of employment in Parkinson's disease
Authors: Schrag Anette , Banks Pauline
Published: August 2006

We examined time to loss of employment in two U.K.‐based studies of 151 and 308 patients with Parkinson's disease (PD) with onset age before 65 years. Fifty‐two percent and 57% of patients had retired early due to PD, 18% and 5% of patients were unemployed, and 8% and 11% were part‐time–employed. Mean age of retirement was 55.8 years compared to an average retirement age of 62 years in the U.K. population. Mean time to loss of employment was 4.9 years, ranging from a mean of 6.7 years in those with onset before age 45 to 1.7 years in those with onset after age 56, but the range was large (0–17 years). After censoring for those still working and those retiring at a normal retirement age, survival analysis revealed that 46% had stopped working after a disease duration of 5 years and 82% after 10 years with a median survival to loss of employment of 6.0 (95% CI: 5.4–6.6) years. Age of onset correlated negatively with time to loss of employment (r = −0.6; P < 0.001). There were no differences between sexes, rural vs. urban living, types of work, those living alone or with a partner, and those with and without children in their household. We conclude that Parkinson's disease leads to loss of employment on average within less than 10 years of disease onset. However, the variability of time to loss of employment is large, indicating that other factors than onset age and disease duration influence loss of patients' employment. © 2006 Movement Disorder Society
Joint and skeletal deformities in Parkinson's disease, multiple system atrophy, and progressive supranuclear palsy
Authors: Ashour Ramsey , Jankovic Joseph
Published: August 2006

The objective of this study is to characterize clinical features of joint and skeletal deformities in Parkinson's disease (PD), multiple system atrophy (MSA), and progressive supranuclear palsy (PSP). Clinical information including age, gender, presence of deformity, initial symptom side, neuropsychological and motor features, family history, and treatment with levodopa/dopamine agonists was collected on consecutive patients with PD, MSA, and PSP evaluated at the Movement Disorders Clinic at Baylor College of Medicine. In this series of 202 patients, 36.1% had deformities of the limbs, neck, or trunk, including 33.5% of PD, 68.4% of MSA, and 26.3% of PSP patients. “Striatal” hand and foot deformities were present in 13.4%, involuntary trunk flexion in 12.9%, anterocollis in 9.4%, and scoliosis in 8.4% of all patients. Patients with these joint and skeletal deformities had higher mean Unified Parkinson's Disease Rating Scale scores (57.4 vs. 46.6; P < 0.01) and were more often treated with levodopa (69.9% vs. 50.4%; P < 0.01) than patients without deformity, independent of disease duration. Patients with striatal deformity were younger than patients without deformity (mean 60.4 vs. 68.6 years; P < 0.01), and they tended to have an earlier age of onset of initial parkinsonian symptoms (mean 54.7 vs. 62.5 years; P < 0.01). Furthermore, the side of striatal deformity correlated with the side of initial parkinsonian symptoms in all patients (100%) with striatal hand and in 83.3% of patients with striatal foot. Joint and skeletal deformities are common and frequently under‐recognized features of PD, MSA, and PSP that often cause marked functional disability independent of other motor symptoms. © 2006 Movement Disorder Society
Open‐label pilot study of levetiracetam (Keppra) for the treatment of chorea in Huntington's disease
Authors: Zesiewicz Theresa A. , Sullivan Kelly L. , Hauser Robert A. , Sanchez‐Ramos Juan
Published: August 2006

The objective of this study is to evaluate the tolerability and preliminary efficacy of levetiracetam (LEV) in reducing chorea in Huntington's disease (HD) patients in a prospective open‐label pilot study. Nine HD patients with chorea were treated with LEV in doses up to 3,000 mg/day for up to 48 days. The primary endpoint measure was the Unified Huntington's Disease Rating Scale (UHDRS) chorea subscore. The mean dose (±SD) of LEV at endpoint was 2,583.3 ± 1,020.6 mg/day. Mean UHDRS chorea score decreased from 12.6 ± 3.0 at baseline to 6.7 ± 4.3 at endpoint (P = 0.01). There was no significant change in UHDRS total motor scores (38.8 ± 11.4 at baseline and 33.6 ± 26.7 at endpoint; P = 0.24). Somnolence contributed to a 33% drop‐out rate, and 3 patients developed Parkinsonism. Results of this open label study suggest that LEV may be efficacious in reducing chorea in HD patients. © 2006 Movement Disorder Society
Case–control study of UCHL1 S18Y variant in Parkinson's disease
Authors: Tan Eng‐King , Puong Kim‐Yoong , Fook‐Chong Stephanie , Chua Eva , Shen Hui , Yuen Yih , Pavanni Ratnagopal , Wong Meng‐Cheong , Puvan Kathiravelu , Zhao Yi
Published: August 2006

A recent meta‐analysis observed a greater significant inverse association of the ubiquitin carboxy‐terminal hydrolase L1 (UCHL1) S18Y variant with Parkinson's disease (PD) for Asian (predominantly Japanese) populations compared with Caucasian populations. We performed an independent case–control study in 335 PD and 341 control subjects with data from a Chinese population to investigate the age‐of‐onset effect of the UCHL1 variant in PD. The Y/Y and Y/S genotypes were less frequent in the PD young‐onset group than in controls and the frequency of the Y alleles was higher in young controls compared to young‐onset PD (age at examination ≤ 65 years; P = 0.003). Multivariate analysis revealed the Y/Y genotype was significantly lower (P = 0.008) in the young‐onset PD (Y/Y vs. S/S: odds ratio [OR]: 0.42; 95% confidence interval [CI]: 0.24, 0.74; S/Y vs. S/S: OR: 0.66, 95% CI: 0.41, 1.08) compared with controls, but this difference was not seen for the late‐onset PD. Kaplan–Meier analysis carried out on PD subjects demonstrated that the Y/Y genotype was associated with a later onset of PD than Y/S plus S/S genotypes (P = 0.05). We provided an independent confirmation of the protective effect of the UCHL1 S18Y variant (Y/Y genotype) against PD in young Chinese subjects. Further functional studies of the S18Y variant in both cell and animal models will be of interest. © 2006 Movement Disorder Society
Cloprostenol, a prostaglandin F2α analog, induces hypoxia in rat placenta: BOLD contrast MRI
Authors: Girsh Eliezer , Plaks Vicki , Gilad Assaf A. , Nevo Nava , Schechtman Edna , Neeman Michal , Dekel Nava
Published: August 2006

Blood oxygen level dependent (BOLD) contrast was used to monitor hypoxia induced by cloprostenol, a prostaglandin F2α (PGF2α) analog, in the rat embryo‐placental unit (EPU). It is shown that administration of cloprostenol (0.025 mg/rat) at mid‐gestation (day 16) reduced EPU oxygenation, as detected by BOLD contrast MRI, in correlation with induction of vascular endothelial growth factor (VEGF) gene (Vegfa) expression in the corresponding placenta (r = 0.56, p = 0.03). Elevated VEGF mRNA expression in response to cloprostenol treatment was also observed at early gestation (day 9) in the forming placenta (p = 0.04) and uterus (p = 0.03). Cloprostenol increased the expression levels of endothelin‐1 (ET‐1) gene (Edn1) (p = 0.03) and its corresponding peptide (p = 0.02) in the forming placenta, as well as the expression of the endothelin receptor type A (ETA) gene (Ednra) in both the forming placenta (p = 0.009) and the uterus (p = 0.01). The levels of the endothelin receptor type B (ETB) gene (Ednrb) were not affected in response to cloprostenol, but a significant elevation in the expression level of this receptor was observed in the uterus at mid‐ and late gestation (day 22) (p = 0.04 and 0.01 respectively), suggesting a role for ETB in the vasodilatory status of the pregnant uterus. It is suggested that PGF2α induces uteroplacental vasoconstriction in the rat, and that ET‐1 may take part in mediating this effect, probably via activation of ETA receptor. The uteroplacental vasoconstriction induces hypoxia, as manifested by significant changes in BOLD MRI and by upregulation of VEGF. Copyright © 2006 John Wiley & Sons, Ltd.
NMR study of the cooperative behavior of thermotropic model polypeptides
Authors: Kurková Dana , Kříž Jaroslav , Rodríguez‐Cabello José Carlos , Arias Francisco Javier
Published: August 2006

Using 1H and 13C 1D and 2D NMR spectra, relaxation and PFG NMR measurements, the structural changes of two genetically engineered, and thus unimolecular, elastin‐like polypentapeptides [(GVGVP)2‐(GEGVP)‐(GVGVP)2]n, n = 9 and 15, in D2O and H2O solutions and at two concentrations (5 and 0.5% wt), were studied in the temperature interval 288–330 K, i.e. below, at and above their inverse temperature transition (ITT). According to the extent of extreme signal broadening, the rigidity of both polymers increases at and above ITT. The process of polymer stiffening proceeds primarily from the polymer backbone and is accompanied by coiling of the polymer and aggregation. It is distinctly more effective in the polymer with higher molecular weight, as well as at higher concentration, which indicates intra‐ and intermolecular cooperativity of the process. According to the measured NHCH dihedral angles and chemical shifts, the conformation of the visible part of both polypeptides does not significantly differ from random coil conformation both below and above the transition temperatures. However, this could be due to fast averaging of more definite conformations. Tighter coiling of the NMR‐visible part of the polymer during thermal transition is indicated by a decrease of its hydrodynamic radius, derived from the self‐diffusion coefficient measured by PFG NMR. Lower values of HOD T1 relaxation time and lower slope of its increase compared to those of HOD in pure D2O suggest a remaining interaction of the polymer with water above ITT. Copyright © 2006 Society of Chemical Industry
Plasmonen als Lichttransporter: Nanooptik
Authors: Aussenegg Franz , Ditlbacher Harald
Published: August 2006

Metallische Nanopartikel, Nanodrähte oder Filme können Licht in Oberflächen‐Plasmonen einfangen. Dieses Phänomen spielt sich im optischen Nahfeld und im Subwellenlängenbereich ab. Dabei entsteht ein hybrider, optoelektronischer Anregungszustand aus Licht und oszillierenden Leitungselektronen. Metallische Nanopartikel können zum Beispiel als “Hilfsantennen” die Fluoreszenz von Biomolekülen erheblich verstärken. Das ist für Fluoreszenzsensoren interessant. Experimente zeigen, dass metallische Nanodrähte in Oberflächen‐Plasmonen Licht transportieren können. Auf zweidimensionalen, strukturierten Metallfilmen wurden Bauelemente bis hin zum Interferometer für Plasmonen erfolgreich demonstriert. Das junge Feld der Plasmonik könnte wichtige Beiträge zu einer zukünftigen Nanooptik liefern.
Der Blick ins Gehirn: Bildgebende Verfahren in der Gehirnforschung
Authors: Pietrzyk Uwe , Khodaverdi Maryam
Published: August 2006

Moderne bildgebende Verfahren ermöglichen Untersuchungen am menschlichen Gehirn, ohne es in seinen Funktionen zu stören oder zu verletzten. Sie erzeugen hoch aufgelöste Abbildungen, die Medizinern die Möglichkeit geben, Krankheiten zu diagnostizieren und chirurgische Eingriffe zu planen. Aber auch die Funktion und Struktur des Gehirns lässt sich mit der Bildgebung erforschen. Die Physiker stellen dazu immer sensitivere und genauere Hilfsmittel zur Verfügung.
Ludwig Boltzmann als Experimentalphysiker: Frühe Bestätigung der Maxwell‐Theorie
Authors: Rumpf Klemens , Granitzer Petra
Published: August 2006

Am Beispiel von Boltzmanns Experimenten zur Bestätigung der Maxwell‐Theorie wird dessen hervorragende Begabung auch als Experimentalphysiker deutlich. Die dargestellten Arbeiten fanden etwa 15 Jahre vor den Hertzschen Experimenten statt, zu einem Zeitpunkt also, als die noch junge Maxwell‐Theorie dringend experimenteller Bestätigung bedurfte. Boltzmann konnte mit seinen experimentellen Untersuchungen eine direkte Konsequenz der Maxwellschen elektromagnetischen Theorie, die so genannte Maxwell‐Relation, bestätigen. Seine Experimente stellten nicht nur lange Zeit den stärksten Beleg für die Richtigkeit der Maxwellschen Lichttheorie dar, sondern waren eine experimentelle Spitzenleistung an der Grenze des damals Möglichen. Besonders Boltzmanns Bestimmung der Dielektrizitätskonstanten von Gasen fand noch Jahrzehnte später Erwähnung in namhaften Lehrbüchern.
Was ist ein Proton?
Authors: Ziegler Thomas
Published: August 2006

Eine Gruppe am Jefferson Lab in den USA hat kürzlich neue Experimente zur Untersuchung der Protonstruktur durchgeführt. Dabei konzentrierten sich die Physiker auf die Frage nach der Existenz von Strange‐Quarks im Proton. Das Ergebnis war überraschend und lässt die Diskussion darüber, was ein Proton wirklich ist, erneut aufflammen.
Meilenstein in der Physik der B‐Mesonen
Authors: Ziegler Thomas
Published: August 2006

In Japan hat die Belle‐Kollaboration am KEK einen wichtigen Durchbruch erzielt. Zum ersten Mal wurde der sehr seltene, rein leptonische Zerfall eines B‐Mesons beobachtet. Er bietet die Möglichkeit, andere wichtige Größen der Elementarteilchenphysik, wie die Masse des Higgs‐Teilchens, besser vorhersagen und verstehen zu können.
Ein Phasenkontrast‐Mikroskop für Neutronen
Authors: Pfeiffer Franz
Published: August 2006

Phasenkontrast mit sichtbarem Licht ist ein unentbehrliches Hilfsmittel der modernen Mikroskopie. Einem Forscherteam am schweizerischen Paul Scherrer Institut (PSI) ist es nun gelungen, ein entsprechendes Abbildungsverfahren auch für Neutronenstrahlen zu entwickeln. So können quantenmechanische Wechselwirkungen von Neutronen mit Materie in Form von zwei‐ und dreidimensionalen Bildern sichtbar gemacht werden.
Fragwürdiges beim Millikan‐Versuch
Authors: Heering Peter
Published: August 2006

Robert A. Millikan erhielt 1923 als erster amerikanischer Physiker den Nobelpreis für Physik. Geehrt wurde er für seine Präzisionsmessungen zum Photoeffekt und zur experimentellen Bestimmung der elektrischen Elementarladung. Millikans Experimente zur Elementarladung sind auch heute noch ein Standardthema im schulischen Physikunterricht, gleichzeitig werfen sie aber eine Reihe von wissenschaftstheoretischen und ethisch relevanten Fragen auf.
Das Universum® in Bremen
Authors: Althans Svenja , Haller Kerstin , Wolff Tobias
Published: August 2006

Im Universum® Science Center Bremen tauchen die Besucher mit allen Sinnen in die Welt wissenschaftlicher Phänomene ein. Auf drei Expeditionen durch die Gebiete Mensch, Erde, Kosmos wird jeder Besucher zum Forscher, kann ausprobieren und experimentieren. Die konkreten Erfahrungen bilden dabei die Basis für nachhaltiges Lernen naturwissenschaftlicher Zusammenhänge.
Das Schmoren der Tripelhelix
Authors: Vilgis Thomas
Published: August 2006

Schmoren ist eine der beliebtesten Methoden, geschmackvolles Fleisch auf den Tisch zu zaubern, ob als Gulasch oder als klassischen Sauerbraten. Garzeiten von mehr als zwei Stunden sind keine Seltenheit. Der Grund dafür liegt in der Biophysik des durchwachsenen Schmorfleisches. Das Bindegewebe Kollagen muss zuerst in Gelatine umgewandelt werden, damit es dem Genuss keinen Widerstand mehr bietet.
Thermodynamic analysis of the reaction‐induced phase separation of solutions of random copolymers of methyl methacrylate and N,N‐dimethylacrylamide in the precursors of a polythiourethane network
Authors: Soulé E. R. , Jaffrennou B. , Méchin F. , Pascault J. P. , Borrajo J. , Williams R. J. J.
Published: August 2006

Poly(methyl methacrylate) and random copolymers of methyl methacrylate (MMA) and N,N‐dimethylacrylamide (DMA) containing 7.5, 15, or 20 wt % DMA were dissolved in a stoichiometric mixture of m‐xylylene diisocyanate and 4‐mercaptomethyl‐3,6‐dithia‐1,8‐octanedithiol, precursors of a polythiourethane network. Phase separation, which took place during polymerizations at 60, 90, and 120 °C, exhibited a lower critical solution temperature behavior. The cloud‐point conversions, which were determined by the iodometric titration of free thiol groups of samples chilled in ice at the cloud point, increased with the weight fraction of DMA in the random copolymer. This could be used to control the cloud‐point conversion and determine the characteristic size of the dispersed domains. A thermodynamic analysis was performed with the Flory–Huggins equation, taking into account the polydispersities of both the thermoplastic and thermoset polymers and using an interaction parameter depending on the temperature and on the three binary interaction energies. A reasonable fitting of the experimental curves was obtained with negative values for the interaction energies of the MMA–thermoset and DMA–thermoset pairs and with a positive value for the MMA–DMA pair. © 2006 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 44: 2821–2827, 2006
Generalized modeling of enzyme–ligand interactions using proteochemometrics and local protein substructures
Authors: Strömbergsson Helena , Kryshtafovych Andriy , Prusis Peteris , Fidelis Krzysztof , Wikberg Jarl E. S. , Komorowski Jan , Hvidsten Torgeir R.
Published: August 2006

Modeling and understanding protein–ligand interactions is one of the most important goals in computational drug discovery. To this end, proteochemometrics uses structural and chemical descriptors from several proteins and several ligands to induce interaction‐models. Here, we present a new and generalized approach in which proteins varying greatly in terms of sequence and structure are represented by a library of local substructures. Using linear regression and rule‐based learning, we combine such local substructures with chemical descriptors from the ligands to model binding affinity for a training set of hydrolase and lyase enzymes. We evaluate the predictive performance of these models using cross validation and sets of unseen ligand with unknown three‐dimensional structure. The models are shown to generalize by outperforming models using descriptors from only proteins or only ligands, or models using global structure similarities rather than local similarities. Thus, we demonstrate that this approach is capable of describing dependencies between local structural properties and ligands in otherwise dissimilar protein structures. These dependencies are often, but not always, associated with local substructures that are in contact with the ligands. Finally, we show that strongly bound enzyme–ligand complexes require the presence of particular local substructures, while weakly bound complexes may be described by the absence of certain properties. The results demonstrate that the alignment‐independent approach using local substructures is capable of describing protein–ligand interaction for largely different proteins and hence opens up for proteochemometrics‐analysis of the interaction‐space of entire proteomes. Current approaches are limited to families of closely related proteins. families of closely related proteins. Proteins 2006. © 2006 Wiley‐Liss, Inc.
Multifrequency magnetic resonance and blocking behavior of FexPt1–x nanoparticles
Authors: Antoniak C. , Lindner J. , Salgueiriño‐Maceira V. , Farle M.
Published: August 2006

Multifrequency ferromagnetic resonance well above the blocking temperature was used to determine the composition dependent g ‐factor in wet‐chemically synthesized Fex Pt1–x nanoparticles with mean diameters around 3 nm. The magnetic relaxation process in these experiments is found to be non‐Gilbert like. To obtain the blocking temperature and the effective anisotropy, zero‐field‐cooled magnetometry data are simulated using a model of non‐interacting particles. In this simulation, the temperature dependence of the effective anisotropy has to be taken into account for accurate results. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Optical characterization of CuIn3Se5, CuGa3Se5 and CuGa5Se8 crystals by spectroscopic ellipsometry
Authors: León M. , Serna R. , Levcenko S. , Nateprov A. , Nicorici A. , Merino J. M. , Arushanov E.
Published: August 2006

The ellipsometric spectra of CuIn3Se5, CuGa3Se5 and CuGa5Se8 ordered vacancy compounds (OVC) have been studied in the spectral range from 0.8 to 4.4 eV. The structures observed in the measured spectra were analyzed by fitting the second derivative of the experimental spectrum to analytical line shapes. The energies corresponding to different electronic transitions were determined. The lowest direct gap (E 0) is characterized by 3‐dimensional critical points, while higher energy structures are characterized by 2D critical points. Optical constants related to dielectric function, such as the complex refractive index n *(ω ), extinction coefficient k (ω ), absorption coefficient α (ω ), and normal‐incidence reflectivity R (ω ), of studied OVC were determined. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
The structural representation and properties of mutually incommensurate composite crystal (BiS)xTS2 (T = Ti, V, Nb and Ta)
Authors: Gotoh Y. , Fujihisa H. , Takeya S. , Yamaguchi I.
Published: August 2006

The structural representation of mutually incommensurate composite crystal, (BiS)x TS2 (T = Ti, V, Nb and Ta), with layered substructures has been described by superspace group approach. The incommensurate composite structures of (BiS)x TS2 have been successfully characterized by the single‐crystal X‐ray‐diffraction method. Temperature dependences of in‐plane electrical resistivity of single composite crystals of (BiS)x TS2 have been obtained by a standard d.c. four probe method in the range of 1.7–300 K. It has been found that the electronic transport properties of (BiS)x TS2 compounds show metallic behavior below room temperature. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Donor‐acceptor pair recombination luminescence from Cu2ZnSnS4 bulk single crystals
Authors: Tanaka K. , Miyamoto Y. , Uchiki H. , Nakazawa K. , Araki H.
Published: August 2006

Photoluminescence from Cu2ZnSnS4 bulk single crystals was studied as a function of temperature and excitation power density. The bulk single crystals showed a broad luminescence between 1.1 and 1.45 eV. The peak energy of the photoluminescence was shifted to higher energy side when the excitation power density was increased. The origon of the photoluminescence was attributed to donor–acceptor pair recombination with an activation energy of 48 meV. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Electronic structure and exchange constants in magnetic semiconductor digital alloys: chemical and band‐gap effects
Authors: Picozzi S. , Ležaić M. , Blügel S.
Published: August 2006

First‐principles simulations have been performed for [001]‐ordered Mn/Ge and Mn/GaAs “digital alloys”, focusing on the effects of (i) a larger band‐gap and (ii) a different semiconducting host on the electronic structure of the magnetic semiconductors of interest. Our results for the exchange constants in Mn/Ge, evaluated using a frozen‐magnon scheme, show that a larger band‐gap tends to give a stronger nearest‐neighbor ferromagnetic coupling and an overall enhanced in‐plane ferromagnetic coupling even for longer‐ranged coupling constants. As for the chemical effects on the exchange constants, we show that Mn/GaAs shows a smaller nearest‐neighbor ferromagnetic coupling than Mn/Ge, but exchange constants for higher Mn–Mn distance show an overall increased ferromagnetic behavior in Mn/GaAs. As a result, from the magnetic‐coupling point of view, the two systems behave on average rather similarly. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Electronic structure of ternary thallium chalcogenide compounds
Authors: Kashida S. , Yanadori Y. , Otaki Y. , Seki Y. , Panich A. M.
Published: August 2006

The electronic structures of the ternary thallium chalcogenide compounds, TlGaSe2 and TlGaS2 are studied, using the linear muffin‐tin orbital (LMTO) method. The calculated band dispersion shows that both compounds are indirect gap semiconductors. For both compounds, the top of the valence bands is located at Γ. For TlGaSe2, the bottom of the conduction band is located along the Z(0, 0, –5)–L(0.5, 0.5, –0.5) line. For TlGaS2, the bottom of the conduction band is located along the Γ–Y(0, 1, 0) line. An inspection of the LMTO wave functions shows that the valence band top has the character of Tl:6s–Se:4p or S:3p antibonding state, while the conduction band bottom has the character of Tl:6p–Se:4p or S:3p antibonding state. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Microstructures and MR effects of transparent ferromagnetic chemically prepared Fe–Zn–O films
Authors: Shinagawa T. , Izaki M. , Inui H. , Murase K. , Awakura Y.
Published: August 2006

Transparent ferromagnetic Fe–Zn–O films with an entire oxide system were prepared by chemical bath depositions followed by heat treatment. The Fe–Zn–O film was composed of two phases, where spinel‐type iron oxide particles of 20 nm in diameter were embedded in a wurtzite zinc oxide film with 240 nm thickness. The electrical properties evaluated by a Hall effects measuring system revealed that the film is an n‐type semiconductor with a resistivity of 2.6 Ω cm. The Fe–Zn–O film exhibited magnetic hysteresis at room temperature, and magnetic moment of 0.5μ B/Fe and coercive force of 172.5 Oe were observed. A negative magnetoresistance effect, probably due to a spin‐dependent scattering of carrier electrons, of about −0.35% in a 5 kOe magnetic field was detected at room temperature. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Local structure in (MnS)2x(CuInS2)1–x alloys
Authors: Pietnoczka A. , Bacewicz R. , Schorr S.
Published: August 2006

Local structure around Mn atoms in (MnS)2x (CuInS2)1–x alloys for x ≤ 0.09 has been determined using near‐edge and extended X‐ray absorption fine structure (XANES and EXAFS) measured at the Mn K‐edge. We found that for the Mn concentration up to 9 at% Mn atoms substitute preferentially for indium in the chalcopyrite lattice. The Mn–S bond length is 2.43 ± 0.015 Å, and is about 2% shorter than the In–S bond length. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Electronic structures of Fe3–xVxSi probed by photoemission spectroscopy
Authors: Cui Y. T. , Kimura A. , Miyamoto K. , Sakamoto K. , Xie T. , Qiao S. , Nakatake M. , Shimada K. , Taniguchi M. , Fujimori S.‐I. , Saitoh Y. , Kobayashi K. , Kanomata T. , Nashima O.
Published: August 2006

The electronic structures of the Heusler type compounds Fe3–x Vx Si in the concentration range between x = 0 and x = 1 have been probed by photoemission spectroscopy (PES). The observed shift of Si 2p core‐ level and the main valence band structres indicates a chemical potential shift to higher energy with increasing x . It is also clarified that the density of state at Fermi edge is owing to the collaboration of V 3d and Fe 3d derived states. Besides the decrease of the spectral intensity near Fermi edge with increasing x suggests the formation of pseudo gap at large x . (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Electronic and optical properties of zinc blende and complex crystal structured solids
Authors: Verma A. S. , Bhardwaj S. R.
Published: August 2006

The dielectric description of ionicity developed by Phillips and Van Vechten has been successfully employed in a wide range of semi‐conductors and insulators. However, the applicability of this Phillips and Van Vechten (PV) dielectric analysis has been limited to only the simple AN B8–N compounds, which contain only one type of bond. Levine has extended the theory of PV to multi bond and complex crystals. Levine's theory of ionicity has been used to calculate the various bond parameters for the chalcopyrites. In this paper a simple method based on the product of ionic charge and nearest‐neighbor distance of solids, is proposed for the calculation of ionic gap (E c), average energy gap (E g), crystal ionicity (f i) and dielectric constant (ϵ) of zinc blende (AIIBVI and AIIIBV) and chalcopyrite (AIBIII$ \rm C ^{\rm VI}_{2} $ and AIIBIV$ \rm C ^{\rm V}_{2} $) semiconductors. We find the ionic gap (E c) and average energy gap (E g) are inversely related to product of ionic charge and nearest‐neighbor distance. Our evaluated values are in excellent agreement with the values reported by different researchers. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Description of high‐spin restricted open‐shell molecules with the Piris natural orbital functional
Authors: Leiva P. , Piris M.
Published: August 2006

The Piris natural orbital functional (PNOF) based on a new approach for the two‐electron cumulant is considered for the case of high‐spin restricted open‐shell systems. The theory is applied to the calculation of molecular energies, dipole moments, vertical ionization potentials (IP), and electron affinities (EA) of 10 open‐shell molecules. Vertical values of IP and EA were used to evaluate the hardness. It was observed that the results obtained using the PNOF method are comparable to the corresponding results obtained using CCSD(T) in the case of energies and dipole moments. Best agreement between theory and experiment is achieved by PNOF for EA and hardness values. The calculated PNOF values for the mentioned properties are in good agreement with the available experimental data, considering the basis sets used (6–31 ++G**). © 2006 Wiley Periodicals, Inc. Int J Quantum Chem, 2007
Computational approach to the blood–aluminum problem?
Authors: Exley Christopher , Beardmore James , Rugg Gordon
Published: August 2006

Aluminum has no known function in biota and, when biologically available, is inimical to life. A key to understanding its potential toxicity in humans is its transport in blood. A consensus of opinion has identified the binding of aluminum by the iron‐transport protein transferrin as the preeminent factor in the transport of aluminum in blood, although this idea has emanated from in vitro analysis of isolated blood and has never been tested in vivo. We have highlighted what we believe to be inadequacies of our present understanding of aluminum transport in blood, and we have proposed the application of computational methods to test rigorously what we have coined “the blood‐aluminum problem.” © 2006 Wiley Periodicals, Inc. Int J Quantum Chem, 2007
The design of simulation studies in medical statistics
Authors: Burton Andrea , Altman Douglas G. , Royston Patrick , Holder Roger L.
Published: August 2006

Simulation studies use computer intensive procedures to assess the performance of a variety of statistical methods in relation to a known truth. Such evaluation cannot be achieved with studies of real data alone. Designing high‐quality simulations that reflect the complex situations seen in practice, such as in prognostic factors studies, is not a simple process. Unfortunately, very few published simulation studies provide sufficient details to allow readers to understand fully all the processes required to design a simulation study. When planning a simulation study, it is recommended that a detailed protocol be produced, giving full details of how the study will be performed, analysed and reported. This paper details the important considerations necessary when designing any simulation study, including defining specific objectives of the study, determining the procedures for generating the data sets and the number of simulations to perform. A checklist highlighting the important considerations when designing a simulation study is provided. A small review of the literature identifies the current practices within published simulation studies. Copyright © 2006 John Wiley & Sons, Ltd.
Infant mice with glutaric acidaemia type I have increased vulnerability to 3‐nitropropionic acid toxicity
Authors: Bjugstad K. B. , Crnic L. S. , Goodman S. I. , Freed C. R.
Published: August 2006

Glutaric acidaemia type I (GA I) is an inborn error of metabolism caused by a deficiency of glutaryl‐CoA dehydrogenase (GCDH) and is characterized clinically by striatal degeneration that almost always occurs in early childhood. A murine knockout model of GA I has the organic aciduria seen in the human disorder, but this model does not develop striatal degeneration spontaneously. 3‐Nitropropionic acid (3NP), a succinic dehydrogenase inhibitor with specificity for the striatum, was investigated as a potential initiator of striatal degeneration in GCDH‐deficient mice. This study shows that GCDH‐deficient mouse pups are more susceptible to 3NP than their wild‐type littermates, and that all mouse pups are more sensitive to 3NP as infants than as adolescents and adults. Increased sensitivity to 3NP early in life may model the developmental window for the striatal damage observed in human GA I.
Sleep disturbances in aspartylglucosaminuria (AGU): A questionnaire study
Authors: Lindblom Niki , Kivinen Satu , Heiskala Hannu , Laakso Maija‐Liisa , Kaski Markus
Published: August 2006

Sleep disturbances are common in many progressive metabolic encephalopathies. The possible presence of disturbed sleep–wake behaviour in the lysosomal storage disorder aspartylglucosaminuria, has not been previously studied, however. The sleep–wake behaviour of 81 patients with aspartylglucosaminuria (AGU, age 3–55 years, median 22 years; 42 female and 39 male) and 49 controls (age 2–57 years, median 18 years; 25 female and 24 male) was assessed through a postal survey. A slightly modified version of the validated Basic Nordic Sleep Questionnaire was used. Fifty‐eight per cent of the AGU patients were reported to suffer daily from a sleep‐related problem (controls 31%, p < 0.01). In AGU adults (age >17 years) and children (age ≤17 years), the corresponding figures were 52% and 61%, respectively (control children 22%, p < 0.05 and control adults 38%, p = 0.06). In AGU children, settling difficulties were reported to occur significantly more commonly than in control children. Children with AGU were also reported to snore more often than were the controls. Adults with this disorder were found to suffer from severely fragmented night‐time sleep, which was experienced as highly distressing by the parents and other caregivers. A long night sleep period was reported to be common in the ageing AGU patients (AGU 9.5 ± 1.7 vs controls 7.2 ± 1.0 h, mean ± SD, p < 0.001). Parents and caregivers also often complained about disturbing movements during sleep in AGU patients. In conclusion, both children and adults with aspartylglucosaminuria were reported to display several types of sleep disturbances significantly more commonly than healthy controls.
Direct Measurement of Nonlinear Properties of Bipartite Quantum States
Authors: Bovino F. A. , Castagnoli G. , Ekert A. , Alves C. Moura , Horodecki P. , Sergienko A. V.
Published: August 2006

Nonlinear properties of quantum states, such as entropy or entanglement, quantify important physical resources and are frequently used in quantum information science. They are usually calculated from a full description of a quantum state, even though they depend only on a small number of parameters that specify the state. Here we extract a nonlocal and a nonlinear quantity, namely the Renyi entropy, from local measurements on two pairs of polarization entangled photons. We also introduce a "phase marking" technique which allows to select uncorrupted outcomes even with nondeterministic sources of entangled photons. We use our experimental data to demonstrate the violation of entropic inequalities. They are examples of a nonlinear entanglement witness and their power exceeds all linear tests for quantum entanglement based on all possible Bell-CHSH inequalities.
Media Reviews
Authors: Van Hoover Cheri
Published: August 2006

Editor's Note: The challenges faced by the midwife in our modern world seem to be of constantly increasing intensity and complexity. Our society's reliance on technology influences the choices women make regarding their lives and bodies. Midwives find themselves being with women in the face of skyrocketing cesarean section rates, surging popularity of epidural anesthesia, widespread use of mood‐altering medications, and acceptance of cosmetic procedures as gynecologic office routines. These trends can sometimes seem overwhelming to health care providers whose professional identity is rooted in dedication to helping women discover their own strength and make healthy choices and whose philosophical orientation is toward the preservation of normalcy.

In this issue of the Journal we offer three reviews, which we hope will help remind us who we are, where we come from, and what we have to offer to the women we serve. The wise voice of Justine Siegemund speaks across the centuries directly to our hearts about her life, her struggles, and her dedication to our profession. We discover a nearly forgotten cadre of colleagues, the highly educated Japanese–American midwives who practiced in the United States from 1880 to 1950. And finally, we are given a gift of practical skills that we can use in our daily work, even as we acknowledge the facts of birth as it currently exists in the United States. These powerful books help us to realize that we cannot create the world to our desires in this or any other age, but we can persevere and serve and continue to make a difference for the future, just as our sisters did for us in the past.
Perioperative Nursing Core Curriculum
Authors: Lampkins Gwendolyn T.
Published: August 2006

Perioperative Nursing Core Curriculum Edited by Rosemary Ann Roth 1995, 380 pp $35 paperback
Work and Role Redesign: Tools and Techniques for the Health Care Setting
Authors: Walker Nathalie F.
Published: August 2006

Work and Role Redesign: Tools and Techniques for the Health Care Setting By Ruth B Hanson, Betty Sayers 1995, 232 pp $39 AHA members, $49 nonmembers, paperback
The Effect of Humorous and Musical Distraction on Preoperative Anxiety
Authors: Gaberson Kathleen B.
Published: August 2006

This study investigated the effect of humorous and musical distraction on preoperative anxiety among 46 patients scheduled for same day, elective, nondiagnostic surgery. Preoperative anxiety was measured with a horizontal visual analog scale after treatment group subjects listened to either a humorous audiotape or a tranquil music audiotape for 20 minutes and control group subjects received no intervention. Results show no significant difference between the group anxiety means. This study provides no evidence that humor or music decreases preoperative anxiety, but it also shows no evidence that perioperative nurses should avoid using humor or music as nursing interventions. AORN J 62 (Nov 1995) 784‐791.
Implementing Differentiated Nursing Practice
Authors: Taylor Kelly M.
Published: August 2006

Implementing Differentiated Nursing Practice By JoEllen Goertz Koerner, Kathryn Linda Karpiuk 1994, 256 pp $49 hardcover
Developing Critical Pathways for the Operating Room
Authors: Wieczorek Patricia
Published: August 2006

Case management and managed care systems are emerging in the 1990s as ways to deliver quality, cost‐effective patient care. The essential tool of managed care systems is a critical pathway, which is developed through the collaboration of health care team members. The critical pathway is an abbreviated version of the patient's hospital course according to his or her medical diagnosis or case type and it allows health care team members to continually evaluate the patient's care. It has helped team members at Johns Hopkins Hospital, Baltimore, identify more effective and cost‐efficient ways to deliver patient care. AORN J 62 (Dec 1995) 925‐929.
Perioperative Nurses' Involvement on Nursing Ethics Committees
Authors: Schroeter Kathryn
Published: August 2006

Ethics issues in health care are evolving constantly; however, perioperative nurses often feel unprepared or unqualified to deal with aspects of ethical decision making. Through involvement as members of a nursing ethics committee, perioperative nurses can obtain the knowledge and skills necessary to assist patients and peers in ethical decision making. Participation on nursing ethics committees improves perioperative nurses' levels of moral reasoning, enhances their ethical decision‐making and patient advocacy skills, and increases their professional satisfaction. AORN J 64 (Oct 1996) 588–596.
Outcomes of Effective Management Practice
Authors: Clayton Judith L.
Published: August 2006

Outcomes of Effective Management Practice Edited by Kathleen Kelly 1996, 256 pp $39.95 hardcover
Pediatric Fibromatosis Requiring Mandibular Resection and Reconstruction
Authors: Steuer Katie
Published: August 2006

Fibromatosis is the nonmalignant proliferation of fibroblasts that aggressively invade adjacent tissues. The cause of this abundant growth is unknown. When fibromatosis develops in the mandible or adjoining tissues, its aggressive growth can compress the trachea and cause death. Resection is the treatment of choice. Mandibular reconstruction is performed to prevent displacement of the remaining mandibular segment or segments and consequent difficulties in eating and speaking. Perioperative nurses who care for children with oral or paraoral fibromatoses must understand the special physical and psychological needs of these patients to effectively plan their care. AORN J 62 (Aug 1995) 212‐226.
Evaluating a Revised Self‐efficacy Scale for Preoperative Patients
Authors: Oetker‐Black Sharon L. , Kauth Charistine
Published: August 2006

Nurses conduct preoperative teaching to help patients cope with the adversities of surgery. Self‐efficacy can predict an individual's behavior in aversive situations (eg, surgery); therefore, assessing patients' self‐efficacy is one way perioperative nurses can plan patient care and help patients through the surgical experience. This study expands on the results of a previous evaluation of a preoperative selfefficacy scale. The content and face validity of the revised 15‐item scale used in this study were assessed before the instrument was administered to preoperative patients. Evidence supports the validity of the multidimensional instrument. Internal consistency estimates >.84 support the subscales' reliability. AORN J 62 (Aug 1995) 244‐250.
25 Stupid Things Nurses do to Self Destruct
Authors: Garrett Caroline K.
Published: August 2006

25 Stupid Things Nurses do to Self Destruct By Teresa Allen Joan Brady Laura Gasparis Vonfrolio 1994, 157 pp $19.95 paperback
The PDR Family Guide to Women's Health and Prescription Drugs
Authors: Hudepohl Deborah J.
Published: August 2006

The PDR Family Guide to Women's Health and Prescription Drugs Edited by David W. Sifton 1994, 891 pp $25.95 paperback
Outcomes Research on One Continuing Education Activity
Authors: Brazen Linda
Published: August 2006

Outcomes evaluation research on continuing education (CE) is virtually unexplored in the perioperative and general nursing literature. This outcomes evaluation research study explored whether participants changed their practice behaviors after participation in a one‐day CE activity (eg, used knowledge gained, consistently performed new skills, integrated new values into their practices). One hundred seventy‐one attendees participated. Data analysis revealed that behaviors and practices did change as a result of attending the CE activity. Participants reported that the organizations, settings, or departments in which they were employed and their peers were challenges to their use of CE in practice. AORN J 62 (July 1995) 92–100.
Women's Health and Development
Authors: Berry Jean
Published: August 2006

Women's Health and Development By Beverly J. McElmurry et al 1993, 303 pp $47.50 hardcover
The Post Anesthesia Care Unit
Authors: Cox Jeri M.
Published: August 2006

The Post Anesthesia Care Unit, third ed By Cecil B. Drain 1994, 640 $45 hardcover
Reconceptualizing Organizational Commitment
Authors: Gaberson Kathleen B.
Published: August 2006

Reconceptualizing Organizational Commitment, G. Tumulty, I.E. Jernigan G. Kohut, Journal of Nursing Administration, Vol 25, January 1995, 61–65
Implementing a Parent‐Present Induction Program
Authors: LaRosa‐Nash Patricia A. , Murphy Jane M. , Wade Loretta A. , Clasby Laura L.
Published: August 2006

One of the greatest fears of children undergoing surgery is separation from their parents. Children for whom preoperative sedation is contraindicated often endure the distress of this separation and the beginning of anesthesia surrounded by masked strangers. Those who receive sedation often experience the invasiveness of a medication administered rectally or intramuscularly or the insertion of an IV line. Until recently, the doors to the operating room remained closed to family members. Like other hospitals throughout the country, however, Children's Hospital in Boston has responded to the concerns of parents and staff members by implementing a parent‐present anesthesia induction program. As a result, the surgical experience for many children and families has changed significantly for the better. AORN J 61 (March 1995) 526–531.