bluuebunny/crossref_metadata_2025 huggingface dataset:
A film of patients with movement disorders made in Queen Square, London in the Mid‐1920s by Samuel Alexander Kinnier Wilson
Authors: Reynolds E. H. , Healy D. G. , Lees A. J.
Published: March 2011

Background:

Through Edward Reynolds' collaboration with Samuel Alexander Kinnier Wilson's (SAKW) son, James, on Babylonian neurology and psychiatry, and his contact with James' nephew, Jim, grandson of SAKW, a remarkable film of patients with movement disorders, made by SAKW in the mid‐1920s, has come to light.

Methods/Results:

The 20‐min silent film with captions by SAKW includes patients with senile tremor, Parkinson's disease and postencephalitic parkinsonism, hemiballismus, Huntington's chorea, Sydenham's chorea, hysterical palsy and tremor, multiple sclerosis, and progressive lenticular degeneration. Most of the patients are filmed in the square outside the National Hospital. The British Film Institute dates the film to 1924 and the captions to 1925. The case records of 6 of the 14 patients, who were admitted to the National Hospital, Queen Square, under the care of Dr. SAKW have been identified and summarized.

Discussion:

SAKW may have been stimulated and facilitated to make this film through his personal contact with Charlie Chaplin with whom he stayed at his Californian estate, probably in the summer of 1924. The first films of neurological patients were made in Europe and USA at the beginning of the 20th century, although most have perished. This may be one of the oldest examples from UK. It is also notable for the inclusion of Wilson's disease and a brief shot of SAKW himself. © 2011 Movement Disorder Society
Interleaved variable density sampling with a constrained parallel imaging reconstruction for dynamic contrast‐enhanced MR angiography
Authors: Wang Kang , Busse Reed F. , Holmes James H. , Beatty Philip J. , Brittain Jean H. , Francois Christopher J. , Reeder Scott B. , Du Jiang , Korosec Frank R.
Published: March 2011

For MR applications such as contrast‐enhanced MR angiography, it is desirable to achieve simultaneously high spatial and temporal resolution. The current clinical standard uses view‐sharing methods combined with parallel imaging; however, this approach still provides limited spatial and temporal resolution. To improve on the clinical standard, we present an interleaved variable density (IVD) sampling method that pseudorandomly undersamples each individual frame of a 3D Cartesian ky–kz plane combined with parallel imaging acceleration. From this dataset, time‐resolved images are reconstructed with a method that combines parallel imaging with a multiplicative constraint. Total acceleration factors on the order of 20 are achieved for contrast‐enhanced MR angiography of the lower extremities, and improvements in temporal fidelity of the depiction of the contrast bolus passage are demonstrated relative to the clinical standard. Magn Reson Med, 2011. © 2011 Wiley‐Liss, Inc.
Assessment of radiofrequency self‐heating around a metallic wire with MR T1‐based thermometry
Authors: Detti V. , Grenier D. , Perrin E. , Beuf O.
Published: March 2011

Heat produced by a magnetic resonance (MR) imaging sequence in the vicinity of a conductive wire (pacemaker, electrodes, or catheter), is a subject of interest for the assessment of patient safety during imaging. For this purpose, the measurement of temperature rises during an MR imaging sequence using MR T1‐based thermometry provides several advantages, mainly in its ability to retrieve in situ real‐time thermal maps. Recent studies investigated the heat produced by an independent radiofrequency pulse, assessing MR imaging sequence heating using a specific MR thermometry sequence. This study focuses on self‐heating for which the radiofrequency pulses used for measuring temperature create the heat. An experimental design was set up to evaluate T1‐based thermometry self‐heating using a coupled/decoupled wire and to compare it with a reference temperature gathered by an optical fiber device. For the tested experimental set up, T1‐based thermometry is in fairly good agreement with optical fiber reference temperature. Magn Reson Med, 2011. © 2011 Wiley‐Liss, Inc.
Arterial input functions determined from MR signal magnitude and phase for quantitative dynamic contrast‐enhanced MRI in the human pelvis
Authors: Cron Greg O. , Foottit Claire , Yankeelov Thomas E. , Avruch Leonard I. , Schweitzer Mark E. , Cameron Ian
Published: March 2011

Dynamic contrast‐enhanced (DCE) MRI is often used to measure the transfer constant (Ktrans) and distribution volume (ve) in pelvic tumors. For optimal accuracy and reproducibility, one must quantify the arterial input function (AIF). Unfortunately, this is challenging due to inflow and signal saturation. A potential solution is to use MR signal phase (ϕ), which is relatively unaffected by these factors. We hypothesized that phase‐derived AIFs (AIFϕ) would provide more reproducible Ktrans and ve values than magnitude‐derived AIFs (AIF|S|). We tested this in 27 prostate dynamic contrast‐enhanced MRI studies (echo time = 2.56 ms, temporal resolution = 13.5 s), using muscle as a standard. AIFϕ peak amplitude varied much less as a function of measurement location (inferior–superior) than AIF|S| (5.6 ± 0.6 mM vs. 2.6 ± 1.5 mM), likely as a result of ϕ inflow insensitivity. However, our main hypothesis was not confirmed. The best AIF|S| provided similar reproducibility versus AIFϕ (interpatient muscle Ktrans = 0.039 ± 0.021 min−1 vs. 0.037 ± 0.025 min−1, ve = 0.090 ± 0.041 vs. 0.062 ± 0.022, respectively). Magn Reson Med, 2011. © 2011 Wiley‐Liss, Inc.
Test‐retest reliability and reproducibility of short‐echo‐time spectroscopic imaging of human brain at 3T
Authors: Gasparovic Charles , Bedrick Edward J. , Mayer Andrew R. , Yeo Ronald A. , Chen HongJi , Damaraju Eswar , Calhoun Vince D. , Jung Rex E.
Published: March 2011

A1H magnetic resonance spectroscopic imaging study at 3T and short echo time was conducted to evaluate both the reproducibility, as measured by the interscan coefficient of variation (CV), and test‐retest reliability, as measured by the intraclass correlation coefficient (ICC), of measurements of glutamate (Glu), combined glutamate and glutamine (Glx), myo‐inositol (mI),N‐acetylaspartate, creatine, and choline in 21 healthy subjects. The effect of partial volume correction on these measures and the relationship of reproducibility and reliability to data quality were also examined. A1H magnetic resonance spectroscopic imaging slice was prescribed above the lateral ventricles and single repeat scans were performed within 30 min to minimize physiologic variability. Interscan CVs based on all the voxels varied from 0.05 to 0.07 forN‐acetylaspartate, creatine, and choline to 0.10–0.13 for mI, Glu, and Glx. Findings on the reproducibility of gray and white matter estimates ofN‐acetylaspartate, creatine, and choline are consistent with previous studies using longer echo times, with CVs in the range of 0.02–0.04 and ICC in the range of 0.65–0.90. CVs for Glu, Glx, and mI are much lower than reported in previous studies at 1.5T, while white matter mI (CV = 0.04, ICC = 0.93) and gray matter Glx (CV = 0.04, ICC = 0.68) demonstrated both high reproducibility and test‐retest reliability. Magn Reson Med, 2011. © 2011 Wiley‐Liss, Inc.
Approximate deflection of rigidly framed earth retaining structures due to an unknown earth pressure distribution
Authors: Iskander Magued , Dimond Andrew J. , Aboumoussa Walid , Masood Farah
Published: March 2011

A simple and reliable method for predicting the relationship between lateral displacement and earth pressure for rigidly framed earth retaining structures (RFERS) was developed. Closed‐form equations were derived such that if one value of displacement or pressure is known (or assumed) the other can be computed for hydrostatic, seismic, uniform, and semi‐elliptical earth pressure distributions. Additionally, the general form of the equations can be used to predict the magnitude of the lateral force even if the shape of the earth pressure is unknown, with a reasonable degree of accuracy. The expressions for deflection were derived by treating the structure as an equivalent cantilever beam and calibrating the resulting expression using the finite element method (FEM). A parametric FEM analysis, of 42 000 different RFERS configurations, was performed to calibrate the expressions, using multivariate non‐linear regression between the derived expressions and FEM. A Weibull statistical analysis was performed for each equation and determined that the equations had better than 80% probability to yield deflections that are within 25% of the value computed using FEM. Furthermore, there is a 98% certainty that each equation will yield a deflection that is within 50% of that computed using FEM. Copyright © 2011 John Wiley & Sons, Ltd.
Implementation of an algorithm for general material behavior of steel taking interaction between plasticity and transformation‐induced plasticity into account
Authors: Wolff Michael , Böhm Michael , Mahnken Rolf , Suhr Bettina
Published: March 2011

In this article a semi‐implicit algorithm (predictor–corrector approach) for incorporating the interaction between plasticity and transformation‐induced plasticity (TRIP) in steel is developed. Contrary to the usual elasto‐plasticity, the underlying model of material behavior of steel is far more complex. The interaction between plasticity and TRIP requires extensions of algorithms developed in Doghri (Int. J. Numer. Meth. Engng 1993; 36:3915–3932) and in Mahnken (Commun. Numer. Meth. Engng 1999; 15:745–754). A particular feature of the algorithm is that the inner iteration can be reduced to a single scalar equation. Numerical examples illustrate the algorithm's capabilities. Copyright © 2011 John Wiley & Sons, Ltd.
3D NURBS‐enhanced finite element method (NEFEM)
Authors: Sevilla Ruben , Fernández‐Méndez Sonia , Huerta Antonio
Published: March 2011

This paper presents the extension of the recently proposed NURBS‐enhanced finite element method (NEFEM) to 3D domains. NEFEM is able to exactly represent the geometry of the computational domain by means of its CAD boundary representation with non‐uniform rational B‐splines (NURBS) surfaces. Specific strategies for interpolation and numerical integration are presented for those elements affected by the NURBS boundary representation. For elements not intersecting the boundary, a standard finite element rationale is used, preserving the efficiency of the classical FEM. In 3D NEFEM special attention must be paid to geometric issues that are easily treated in the 2D implementation. Several numerical examples show the performance and benefits of NEFEM compared with standard isoparametric or cartesian finite elements. NEFEM is a powerful strategy to efficiently treat curved boundaries and it avoids excessive mesh refinement to capture small geometric features. Copyright © 2011 John Wiley & Sons, Ltd.
Perturbation and stability analysis of strong form collocation with reproducing kernel approximation
Authors: Hu Hsin‐Yun , Chen Jiun‐Shyan , Chi Sheng‐Wei
Published: March 2011

Solving partial differential equations using strong form collocation with nonlocal approximation functions such as orthogonal polynomials and radial basis functions offers an exponential convergence, but with the cost of a dense and ill‐conditioned linear system. In this work, the local approximation functions based on reproducing kernel approximation are introduced for strong form collocation method, called the reproducing kernel collocation method (RKCM). We perform the perturbation and stability analysis of RKCM, and estimate the condition numbers of the discrete equation. Our stability analyses, validated with numerical tests, show that this approach yields a well‐conditioned and stable linear system similar to that in the finite element method. We also introduce an effective condition number where the properties of both matrix and right‐hand side vector of a linear system are taken into consideration in the measure of conditioning. We first derive the effective condition number of the linear systems resulting from RKCM, and show that using the effective condition number offers a tighter estimation of stability of a linear system. The mathematical analysis also suggests that the effective condition number of RKPM does not grow with model refinement. The numerical results are also presented to validate the mathematical analysis. Copyright © 2011 John Wiley & Sons, Ltd.
OLED technology: also the ultimate lighting solution?
Authors: Visser Peter
Published: March 2011

The interest for OLEDs (Organic Light Emitting Diodes) has grown since SONY sold out its first two shipments of the XEL‐1: an 11 inch TV with an OLED screen of only 3 mm thickness. With its superior contrast ratio, vivid colors, speed and huge viewing angle this is indeed the ultimate TV solution. But OLED technology has much more potential: it can also be applied for lighting purposes. In this article the potential and status of OLED technology for lighting applications is reviewed.
Next Generation Light Sources for Biomedical Applications
Authors: Clowes John
Published: March 2011

Lasers are increasingly important components within biological imaging and analysis systems. Applications range from flow cytometry to confocal and multi‐photon microscopy. However, many commercial imaging systems are still limited in performance by the availability of suitable laser sources‐limited in the availability of wavelengths and in the size, cost, power and reliability of conventional laser technologies. Ultrafast fibre lasers offer turnkey, compact and reliable solutions for next generation biomedical imaging systems.
Mehrdimensionale Objekterfassung mittels PMD­Sensorik
Authors: Hagebeuker Bianca
Published: March 2011

Klassische optisch empfindliche Sensoren detektieren nur Helligkeitsinformationen und liefern damit nur ein projiziertes Abbild der Umgebung, d. h. die räumliche Information geht verloren. PMD­Sensoren dagegen registrieren inhärent das konventionelle Helligkeitsbild pixelweise mit der Tiefeninformation der betrachteten Szene. Ähnlich einem Laserradar bestimmt ein PMD­Pixel die Entfernung über das TOF­Verfahren (TOF, engl.: time­of­flight), d. h. die Echolaufzeit eines ausgesandten Lichtsignals zur Objektoberfläche und zurück wird gemessen.
EUV Sources for Lithographic Applications
Authors: Schriever Guido , Zink Peter
Published: March 2011

Semiconductor device manufacturing is currently using excimer lasers as the light source for lithographic structuring. The wavelength of these ArF lasers is 193 nm and the high volume manufacturing of structures with 45 nm has started already. To further shrink the structure size to 32 nm and beyond, a reduction of the used wavelength is required for physical reasons. The next technology will be the extreme ultraviolet (EUV) lithography using light with 13.5 nm wavelength. Efficient optical elements like multi layer optics were developed in the last years using improvements in thin film technology on large area substrates with roughness in the sub­nanometer range. Sources for such light are plasma based sources in which the plasmas are generated either by electrical gas discharges or by pulsed laser radiation. In this paper we describe the discharge produced plasma (DPP) sources only because of their advantages concerning efficiency, simplicity, reliability and maturity.
Calcium Fluoride Crystals
Authors: Maushake Peter
Published: March 2011

The performance of microchips continues to double about every 18 months. The incredible progress that is being made in lithography and many other areas of technology owes a lot to calcium fluoride crystals. Low solubility and wide transmission make calcium fluoride extremely useful for a variety of different applications, including microlithography, mirror substrates for UV laser systems, windows, lenses and prisms for UV and IR applications.
Optical Fiber Technology
Authors: Paschotta Rüdiger
Published: March 2011

Optical fibers have a very broad range of applications, where they serve many purposes, such as simply transporting light from a source to some other device, transmitting optically encoded data, sensing temperature or strain in some environment, or generating and amplifying laser light. This article gives an introduction into both the basic physical principles and different types of fibers.
Der enttarnte Terrorist
Authors: May Torsten , Meyer Hans Georg
Published: March 2011

Wieviel sicherer wären unsere Flugreisen, wenn die Kontrollbeamten wirklich alle versteckten Bedrohungen finden könnten, die potentielle Terroristen mit an Bord eines Flugzeugs schmuggeln wollen. Auf einem Terahertzbild könnte man Verdächtigen buchstäblich unter die Kleidung schauen. Doch bislang gab es noch keine Technologie, eine THz‐Videokamera zu bauen. Jenaer Forscher aus dem Institut für Photonische Technologien könnten das jetzt ändern.
Mikroskopie jenseits der Beugungsgrenze
Authors: Hell Stefan
Published: March 2011

In einer Festveranstaltung am 23. November 2006 in Berlin wurde der „10. Deutsche Zukunftspreis ‐ Preis des Bundespräsidenten für Technik und Innovation”︁ vergeben. Aus vier nominierten Teams wurde Stefan Hell, Direktor am Max‐Planck‐Institut für biophysikalische Chemie und Leiter der Abteilung Nano‐Biophotonik, ausgewählt und für seine bahnbrechenden Ideen zur Verbesserung der Lichtmikroskopie ausgezeichnet. Andreas Thoß sprach für Optik & Photonik mit dem Preisträger über die Hintergründe dieser Erfindung.
Industrielle Bildverarbeitung für automatisierte Produktionen
Authors: Modrich Kai‐Udo
Published: March 2011

Die industrielle Bildverarbeitung (IBV) hat sich in vielen Branchen zu einem festen Standbein entwickelt. Sie unterstützt den Menschen bei der Triade aus „Sehen — Erkennen — Verstehen”︁, die in vielen Bereichen die Grundlage für zielgerichtetes Handeln und erfolgreiches Wirtschaften bildet. Bei hoch entwickelten Fertigungstechnologien wie auch bei hohen Personalkosten sind Produktionsanlagen nur mit einem hohen Grad an Automatisierung wirtschaftlich zu betreiben. Daher sind im industriellen Bereich effiziente Automatisierungslösungen unabdingbar.
Interlaced goes Digital
Authors: Lewerendt Ingo
Published: March 2011

Totgesagte leben länger. Warum Interlaced‐Sensoren weiterhin beliebt sind und wie sie jetzt dank neuen Kameras von Allied Vision Technologies mit digitalem Interface kombiniert werden können.
Nanostrukturen für die Optik
Authors: Klenke Martin
Published: March 2011

Nanomaterialien sind bislang bekannt für ihre mechanischen (Lotuseffekt) oder elektrischen (Festplatte) Eigenschaften. Eine neue Idee erlaubt jetzt auch die gezielte Nutzung der optischen Eigenschaften von Nanomaterialien. Dabei geht es darum, Nanostrukturen auf ein Substrat oder ein anderes optisches Element aufzubringen und ihre wellenoptischen Eigenschaften so zu gestalten, dass sich ein definierter diffraktiver Effekt ergibt.
Chirp Managed Lasers
Authors: Fan Frank , Mahgerefteh Daniel
Published: March 2011

High‐performance optical transmitters based on external modulator technologies have been used in 10 Gbps telecommunication systems for all applications that extend beyond a few kilometers. Such externally modulated transmitters require a continuous wave (CW) laser to provide the light source and a modulator to encode the digital data into the intensity of the light. Now, a new technology may eliminate the external modulators.
Plastic Optics Enable LED Lighting Revolution
Authors: Kuntze Tomi
Published: March 2011

Only some years ago LEDs were predominantly used as tiny marker lamps in electronic devices. The recent rapid development in semiconductor and packaging technologies has quickly turned LEDs into powerful lighting components, capable of replacing existing light sources, such as bulbs, halogen lamps or even highly efficient fluorescent tubes.
Precision Injection Molding
Authors: Mayer Ralf
Published: March 2011

Whether it is a cellphone camera or a head‐up display — polymer optics is at the heart of many high tech devices and the market demand for such precision optical components is growing year by year. The main application fields are in the automotive industry, in the medical field (disposable optics), in sensor and information technology. Beside lightweight and economic advantages, polymer optics enables completely new solutions in optics. The key to all this is precision manufacturing.
Optical Design using Fresnel Lenses
Authors: Davis Arthur , Kühnlenz Frank
Published: March 2011

The Fresnel lens can be used in a wide variety of applications. The basic principles of the Fresnel lens are reviewed and some practical examples are described. There are definite advantages and tradeoffs that should be considered when deciding if a Fresnel lens is the appropriate component to use in a design. Some basic optimization rules are presented which may facilitate a first order design or feasibility study.
Der Vormarsch der strahlenden Halbleiter
Authors: Löfken Jan Oliver
Published: March 2011

Leuchtdioden haben Signalleuchten und Taschenlampen schon erobert — jetzt setzen sie zum Sprung an auf Frontscheinwerfer, Projektoren und die Beleuchtung von Häusern und Innenräumen
Rapid lamina propria retraction and zipper‐like constriction of the epithelium preserves the epithelial lining in human small intestine exposed to ischaemia–reperfusion
Authors: Grootjans Joep , Thuijls Geertje , Derikx Joep PM , van Dam Ronald M , Dejong Cornelis HC , Buurman Wim A
Published: March 2011

To ensure a sufficient barrier between a host and noxious luminal content, the intestinal epithelium must be equipped with efficient mechanisms to limit damage to the epithelial lining. Using a human model, we were able to investigate these mechanisms in the human gut exposed to ischaemia–reperfusion (IR) over the time course of 150 min. In 10 patients a part of jejunum, to be removed for surgical reasons, was selectively exposed to IR. Control tissue was collected, as well as tissue exposed to 30 min of ischaemia with 0, 30 or 120 min of reperfusion. Haematoxylin/eosin staining demonstrated the appearance of subepithelial spaces following 30 min of ischaemia, while the epithelial lining remained intact at this stage. Western blot for myosin light chain kinase (MLCK) revealed a significant increase in protein levels after ischaemia (p < 0.01), and selective staining of MLCK and phosphorylated MLC (pMLC) in lamina propria muscle fibres indicated that appearance of subepithelial spaces was a consequence of active villus contraction. Early during reperfusion, accumulation of pMLC was observed exclusively at the basal side of enterocytes that had lost contact with the collagen‐IV‐positive basement membrane. These epithelial sheets were pulled together like a zipper, even before these cells were shed. This constriction, verified by increased F‐actin and pMLC double staining, accounted for a 45% reduction in virtual wound surface (p < 0.001) at 30 min of reperfusion. In addition, these mechanisms were involved in resealing remaining small epithelial defects, resulting in a fully restored epithelial lining within 120 min of reperfusion. In conclusion, we show in a human in vivo model that the human jejunum has the ability to preserve the epithelial lining during intestinal IR by rapid lamina propria contraction and zipper‐like constriction of epithelial cells that are to be shed into the lumen. These newly described phenomena limit exposure to noxious luminal content. Copyright © 2011 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Minimal residual disease detected prior to hematopoietic cell transplantation
Authors: Foster Jennifer H. , Hawkins Douglas S. , Loken Michael R. , Wells Denise A. , Thomson Blythe
Published: March 2011

Previous studies to evaluate minimal disease in acute lymphoblastic leukemia (ALL) after treatment have relied on the diagnostic specimen to develop patient‐specific analytical probes. The diagnostic specimen is often not available in a tertiary setting; therefore, we evaluated the use of flow cytometry (FCM) using a “difference from normal” approach to detect residual disease prior to myeloablative allogeneic hematopoietic cell transplantation (HCT). Among 116 pediatric patients with ALL who were in morphological remission at time of transplant, we found that those patients who had detectable residual disease by FCM prior to HCT experienced significantly inferior outcome. Pediatr Blood Cancer 2011;57:163–165. © 2011 Wiley‐Liss, Inc.
New computerized fetal heart rate analysis for surveillance of intrauterine growth restriction
Authors: Huhn E. A. , Lobmaier S. , Fischer T. , Schneider R. , Bauer A. , Schneider K. T. , Schmidt G.
Published: March 2011

Objective

Decreased fetal heart rate variability is associated with higher perinatal morbidity and mortality in intrauterine growth restriction (IUGR). This study used a new method [phase‐rectified signal averaging (PRSA)] to calculate acceleration‐ and deceleration‐related fluctuations of the fetal heart rate.

Method

Cardiotocograms from 74 growth‐restricted and 161 normal fetuses were included. Both groups were matched for gestational age. The transformed PRSA signal was quantified by the acceleration‐related parameter‐averaged acceleration capacity (AAC) and compared to the standard short‐term variation (STV). Mann‐Whitney test and receiver operator characteristic (ROC) curves were used for statistical analysis.

Results

For AAC, the median values of the IUGR group and control group were 1.97 bpm [interquartile range (IQR): 1.66–2.23] and 2.49 bpm (IQR: 2.24–2.72), respectively. For STV, these values were 5.44 ms (IQR: 4.49–7.38) and 7.79 ms (IQR: 6.35–9.66), respectively. The area under the ROC curve was 81.4% for AAC and 70.5% for STV.

Conclusion

The results of AAC are in both groups comparable to STV. Longitudinal studies are needed to investigate the association of AAC with the clinical outcome of the newborn. Copyright © 2011 John Wiley & Sons, Ltd.
Accuracy of prenatal diagnosis and prediction of lethality for fetal skeletal dysplasias
Authors: Yeh Peter , Saeed Ferha , Paramasivam Gowrishankar , Wyatt‐Ashmead Josephine , Kumar Sailesh
Published: March 2011

Objectives

We reviewed all cases with fetal skeletal dysplasia and correlated the accuracy of prenatal diagnoses with the final post‐mortem, radiological, or molecular diagnoses. The accuracy of prenatal prediction of lethality was also reviewed.

Methods

All cases of fetal skeletal dysplasia referred between October 2002 and August 2010 were reviewed. Perinatal outcome, the accuracy of prenatal diagnosis, and prediction of lethality were ascertained. Lethality was suspected when significant thoracic narrowing, severe micromelia, multiple fractures, or long bone bowing was present.

Results

There were 40 cases of skeletal dysplasia. Thirty‐nine (97.5%) were singletons and one (2.5%) was a dichorionic twin pregnancy. Twenty‐eight (70%) pregnancies were terminated, five (12.5%) were stillborn, and only seven (17.5%) cases were live born. A final diagnosis was established in 28 (70%) cases. In 29 cases with a presumptive prenatal diagnosis, this was confirmed in 23 (79.3%) cases postnatally. Lethality was predicted with 100% certainty.

Conclusion

We report higher prenatal/postnatal concordance rates in this series. A precise prenatal diagnosis is frequently difficult and often inaccurate. Prediction of lethality is much easier and often possible with accuracy. Parents need to be aware that the outcome of many skeletal dysplasias is poor. Copyright © 2011 John Wiley & Sons, Ltd.
Viscoelasticity of concentrated polyacrylonitrile solutions: effects of solution composition and temperature
Authors: Tan Lianjiang , Wan Ajun , Pan Ding
Published: March 2011

The effects of solution composition and temperature on the viscoelasticity of concentrated polyacrylonitrile (PAN) solutions were studied using a variety of rheological measurements, such as steady‐state shearing, dynamic stress sweep and transient rheological tests. The first normal stress difference N1 and the shear stress τ were found to increase with decreasing temperature and increasing PAN concentration and water content in the solutions. The crossover point of N1 and τ, denoting the equal contribution of viscosity and elasticity to the viscoelasticity of the solutions, moved to lower shear rates at lower temperature, higher PAN concentration and higher water content. The values of the relaxation time (λ) were larger at 70 °C than at 40 °C. In addition, the changes of λ with PAN concentration and water content were different at the two temperatures, ascribed to the different states of the solutions. The PAN solutions were in the linear viscoelastic regime in the temperature range 40–70 °C when the shear stress was below 300 Pa. The creep compliance recovery rate decreased with increasing temperature, but increased with increasing PAN concentration and water content. Thixotropic tests showed that the thixotropy of the solutions was also affected by the solution composition and temperature. Gelation was found to influence the way the solution composition and temperature affected the viscoelastic properties of the PAN solutions. Copyright © 2011 Society of Chemical Industry
Dual glassy relaxations in physically aged semi‐crystalline poly(L‐lactic acid)
Authors: Shieh Yeong‐Tarng , Jho Jia‐Cing , Wang Tzong‐Liu , Yang Chien‐Hsin , Su Chean‐Cheng
Published: March 2011

Semi‐crystalline poly(L‐lactic acid) (PLLA) was physically aged below the glass transition temperature for various times to investigate its amorphous phase behavior. During a differential scanning calorimetry heating scan, dual enthalpy recovery endotherms were found to appear in the glass transition region of PLLA, aged at 52 °C, of a particular degree of crystallinity (Xc) within a definite range. Below the lower Xc limit, only the low endotherm corresponding to the free amorphous phase was observed; above the upper Xc limit, only the high endotherm corresponding to the constrained amorphous phase was observed. Dual tan δ peaks in dynamic mechanical analysis confirmed the coexistence of the dual amorphous phases. Both lower and upper limits of the Xc range increased with an increase in isothermal crystallization temperature from the melt. Long‐term physical aging at 52 °C, which did not affect Xc, allowed the evolution of the free amorphous phase to the constrained amorphous phase in PLLA with Xc within the definite range. The effects of physical aging at various temperatures on the enthalpy recovery endotherms were also investigated. Copyright © 2011 Society of Chemical Industry
Progress with epitaxy wrap‐through crystalline silicon thin‐film solar cells
Authors: Mitchell Emily J. , Brinkmann Nils , Reber Stefan
Published: March 2011

Wafer‐Equivalents are thin‐film solar cells that use a low‐cost silicon substrate to epitaxially grow a high‐quality crystalline silicon active layer. The epitaxy wrap‐through (EpiWT) cell is a back‐contact version of the Wafer‐Equivalent that aims to increase currents and gain other benefits of back contacts. The EpiWT cell can be made in a symmetrically interdigitated configuration with 50% back emitter coverage, or using an isolation layer to lower the back emitter coverage to ∼10%, which will theoretically increase voltages. The epitaxial deposition through via holes in the substrate depends on many factors, including the sealing of the deposition chamber, and produces various thicknesses and geometrical forms of the layers in the holes. An extended process has been developed to incorporate a passivated selective emitter and the first batch has been fabricated. The best result was an efficiency of 13.2% with ∼22 µm base layer thickness. The results are limited most by the fill factors at this stage, e.g. 75% for this cell, which is due to a processing difficulty encountered with screen‐printing in via holes. A new isolation layer was tested and successfully implemented for the low back‐emitter configuration. Comparable voltages and currents were achieved but the fill factors were lower than for the 50% back emitter cells, resulting in a best efficiency of 11.2%. Copyright © 2011 John Wiley & Sons, Ltd.
Optimization of SiN AR coating for Si solar cells and modules through quantitative assessment of optical and efficiency loss mechanism
Authors: Kang Moon Hee , Ryu Kyungsun , Upadhyaya Ajay , Rohatgi Ajeet
Published: March 2011

Plasma‐enhanced chemical vapor deposition (PECVD) SiN films are widely used as antireflection (AR) coating for silicon solar cells and particularly for multi‐crystalline solar cells for hydrogen passivation of bulk defects. In this paper, the detailed optical properties of various SiN films and their effect on silicon solar cell efficiency in air and under glass is evaluated by a combination of Monte‐Carlo geometrical ray tracing program, Sunrays, and a device modeling program PC1D. Maximum module power under glass and ethylene vinyl acetate (EVA) encapsulation is used as the figure of merit for optimizing the index and thickness of the SiN films. Simulations are categorized by surface morphology (planar or textured) and ambient (air or glass). SiN films with refractive index (n) in the range of 2.03–2.42 are used for this study. It is found that although n = 2.03 is not the optimum index in terms of reflectance under glass (n = 1.5), it produces maximum cell or module efficiency under glass. This is because n = 2.03 film produces much higher cell efficiency (17.9%) in air, therefore, even after a significant optical encapsulation loss of 0.8% in absolute efficiency, the cell efficiency remains highest (17.1%) under glass. In contrast SiN film with an index of 2.4 produces only 0.5% air to glass efficiency loss but due to the low starting efficiency of 17% in air; the final cell efficiency under glass is only 16.5%. In addition, texturing provides a larger window of thickness around the optimum without affecting the optical performance. Similar analysis done for planar cells indicate that optimum index for highest module power is 2.20. This is because reflection is much higher in planar cells, therefore higher index can be tolerated before loss due to absorption in SiN exceeds the gain in reflectance under glass. Copyright © 2011 John Wiley & Sons, Ltd.
Der einäugige Riese. Das European Extremely Large Telescope
Authors: Kissler‐Patig Markus
Published: March 2011

Das European Extremely Large Telescope (E‐ELT) wird mit einem Primärspiegel von 42 m Durchmesser das größte Teleskop werden, das die Menschheit je gebaut hat. Diese europäische Großforschungsanlage wird bis zum Ende des Jahrzehnts in der Atacama‐Wüste im Norden Chiles errichtet. Innovativ ist die komplette Regelung der Optiken, inklusive der Echtzeitkompensation der Turbulenzen der Erdatmosphäre. Mit 1200 m2 Lichtsammelfläche und der 16‐fachen Winkelauflösung des Weltraumteleskops Hubble wird das E‐ELT ein Teleskop der Superlative. Neben einer Vielfalt von Forschungsprojekten ist das Hauptziel des E‐ELT die Charakterisierung der Atmosphären von Exoplaneten.
Ein Außenseiter als Atomist
Authors: Loos Andreas
Published: March 2011

Woraus besteht Luft? Wie viele Atome Sauerstoff und Wasserstoff ergeben ein Wassermolekül? Fragen dieser Art sind heute Schulstoff, im ausgehenden 18. Jahrhundert waren sie Zündstoff. Dutzende Chemiker, Physiker und Amateure konkurrierten mit ihren Theorien.
Lichtsammelkomplexe in der Küche
Authors: Vilgis Thomas
Published: March 2011

Gemüsefarbstoffe gelten unter Ernährungsexperten als kleine Gesundheitswunder. Auch in der Biophysik spielen die elektronenreichen Moleküle eine ganz besondere Rolle, denn sie sind Teil des Fotosyntheseapparats. Der beschert der Pflanze ihr Wachsen und Gedeihen, indem er über Elektronen Lichtenergie in chemische Reaktionen umwandelt. Auch in der Küche lässt sich mit dem grünen Farbstoff Chlorophyll bestens experimentieren.
Dreidimensionale Abbildung magnetischer Domänen
Authors: Manke Ingo , Kardjilov Nikolay , Strobl Markus , Banhart John
Published: March 2011

Magnetische Domänen bilden die Grundlage für das Verständnis vieler magnetischer Phänomene und der Eigenschaften magnetischer Materialien. Ihre Existenz hat Pierre‐Ernest Weiss bereits 1907 vorhergesagt, weshalb sie als Weiss‐Bezirke bezeichnet werden. Mittlerweile gibt es zwar mehrere Verfahren zur Visualisierung magnetischer Domänen. Sie sind jedoch alle auf die zweidimensionale Abbildung, zumeist an Oberflächen oder in dünnen Schichten, beschränkt. Am Zentrum für Materialien und Energie Berlin (HZB) hat unsere Gruppe eine Methode entwickelt, mit der sich das gesamte Netzwerk magnetischer Domänen sowie auch einzelne individuelle Domänenformen im Inneren von magnetischen Materialien dreidimensional abbilden lassen.
Identification of differentially expressed proteins in blood plasma of control and cigarette smoke‐exposed mice by 2‐D DIGE/MS
Authors: Tewari Arun K. , Popova‐Butler Alexandra , El‐Mahdy Mohamed A. , Zweier Jay L.
Published: March 2011

Cigarette smoke exposure is known to induce obstructive lung disease and several cardiovascular disease states in humans and also in animal models. Smoking leads to oxidative stress and inflammation that are important in triggering pulmonary and cardiovascular disease. The objective of the current study was to quantify differences in expression levels of plasma proteins of cigarette smoke ‐exposed and control mice, at the time of disease onset, and identify these proteins for use as potential biomarkers of the onset of smoking‐induced disease. We utilized 2‐D DIGE/MS to characterize these proteomic changes. 2‐D DIGE of plasma samples identified 11 differentially expressed proteins in cigarette smoke ‐exposed mice. From these 11 proteins, 9 were downregulated and 2 were upregulated. The proteins identified are involved in vascular function, coagulation, metabolism and immune function. Among these, the alterations in fibrinogen (2.2‐fold decrease), α‐1‐antitrypsin (1.8‐fold increase) and arginase (4.5‐fold decrease) are of particular interest since these have been directly linked to cardiovascular and lung pathology. Differences in expression levels of these proteins were also confirmed by immunoblotting. Thus, we observe that chronic cigarette smoke exposure in mice leads to prominent changes in the protein expression profile of blood plasma and these changes in turn can potentially serve as markers predictive of the onset and progression of cardiovascular and pulmonary disease.
Protein expression profiling in the zebrafish (Danio rerio) embryos exposed to the microcystin‐LR
Authors: Li Guangyu , Chen Jun , Xie Ping , Jiang Yan , Wu Laiyan , Zhang Xuezhen
Published: March 2011

Microcystin‐leucine‐arginine (MCLR) is the most toxic and the most commonly encountered variant of microcystins (MCs) in aquatic environment, and it has the potential for developmental toxicity. A number of previous studies have described the developing toxicity of MCLR based on conventional toxicological indices. However, the molecular mechanisms by which it expresses its toxicity during the early development remain largely unknown. To further our understanding of mechanisms of action and identify the potential protein biomarkers for MCLR exposure, a proteomic analysis was performed on developing zebrafish embryos exposed to 0.5 mg/L MCLR until 96 hours post‐fertilization. 2‐DE combined with MS was employed to detect and identify the protein profiles. Results showed that 75 spots from the 0.5 mg/L MCLR condition showed a significant increase or decrease in abundance compared with the control. In total, 40 proteins were identified. These proteins were mainly included in process related to oxidative stress, energetic metabolism, and the cytoskeleton assembly. MCLR exposure also affects the expression of the subunits of protein phosphatases 2A. Furthermore, the proteomic and transcriptional analysis of nine proteins was determined by Western blot and quantitative real‐time PCR due to their correlation with the known MCLR toxic mechanisms. The consistent and discrepant results between protein and mRNA levels indicated complicated regulatory mechanisms of gene expression in response to MCLR exposure.
Interaction of water‐soluble triphenylphosphines with β‐cyclodextrin: a quantum chemistry study
Authors: Sayede Adlane , Ferreira Michel , Bricout Hervé , Tilloy Sébastien , Monflier Eric
Published: March 2011

The interaction of β‐cyclodextrin (β‐CD) with meta‐trisulfonated triphenylphosphine derivatives bearing one or two methyl (or methoxy) groups on the aromatic rings has been investigated by PM3 calculations. The results show that phosphine molecules interact with β‐CD having either an unsubstituted sulfophenyl group or a substituted sulfophenyl group at the para and/or meta‐position. The presence of one methyl or methoxy group in the ortho‐position on each aromatic ring prevents the formation of an inclusion complex between meta‐trisulfonated triphenylphosphine derivatives and β‐CD. The deeply included phosphines in the β‐CD cavity show significant van der Waals interactions with β‐CD. These interactions are at the origin of the high association constants between these molecules and β‐CD. Phosphines exhibiting small association constants interact with β‐CD by forming H‐bonds and weak (or null) van der Waals interactions. Copyright © 2011 John Wiley & Sons, Ltd.
Consistent truncations with massive modes and holography
Authors: Cassani D. , Dall'Agata G. , Faedo A.F.
Published: March 2011

We review the basic features of some recently found consistent Kaluza–Klein truncations including massive modes. We emphasize the general ideas underlying the reduction procedure, then we focus on type IIB supergravity on 5‐dimensional manifolds admitting a Sasaki–Einstein structure, which leads to half‐maximal gauged supergravity in five dimensions. Finally, we comment on the holographic picture of consistency.
Dynamical gauge fields in holographic superconductors
Authors: Silva P.J.
Published: March 2011

Holographic superconductors have been studied so far in the absence of dynamical electromagnetic fields, namely in the limit in which they coincide with holographic superfluids. It is possible, however, to introduce dynamical gauge fields if a Neumann‐type boundary condition is imposed on the AdS‐boundary. In 3 + 1 dimensions, the dual theory is a 2 + 1 dimensional CFT whose spectrum contains a massless gauge field, signaling the emergence of a gauge symmetry. We study the impact of a dynamical gauge field in vortex configurations where it is known to significantly affect the energetics and phase transitions.
Instabilities and doubly spinning black holes
Authors: Astefanesei D. , Rodriguez M.J. , Theisen S.
Published: March 2011

Ultra‐spinning black holes in higher dimensions have qualitatively similar thermodynamical properties to the black strings/p‐branes– they exhibit a black membrane‐like phase. In these notes we will explore which doubly spinning black holes and black rings show this black membrane‐like phase and pinpoint the threshold of these regimes. For the same cases we will study the thermodynamical instabilities in the grand canonical ensemble and compute the zeros of the Hessian of the Gibbs potential. Comparing our results, we will show that the thresholds of the black membrane phase and the thermal instability do not necessarily coincide.
Electronic energy levels of RbCdBr3 crystal
Authors: Demirbilek R. , Bozdoğan A. Çelik , Çalışkan M. , Özen G.
Published: March 2011

The RbCdBr3 crystal that consists of edge shared [CdBr6]4− octahedrons was grown by using the Bridgman growth technique and its electronic energy levels are investigated by measuring the excitation and the emission spectra. An energy level diagram for electronic energy levels of RbCdBr3‐crystal is constructed by using the observed excitation spectra and symmetry considerations.
Self‐diffusion in silicon – Change of a paradigm
Authors: Seeger Alfred
Published: March 2011

Diffusion processes play a key role in the fabrication of semiconductor devices. For a long time the underlying mechanisms were thought to be analogous to those in metals, based on vacancies as thc dominant lattice defects in thermal equilibrium. From the mid‐sixties onwards it became clear that this picture is invalid for Si, where strongly relaxed self‐interstitials are dominant and responsible for self‐ and Group‐III‐ diffusion. Inter alia, this change of a paradigm led to novel concepts and to the quantitative explanation of the diffusion of so‐called hybrids such as Au, Pt, and Zn in Si by the so‐called kick‐out mechanism.
Image instability during the electrical measurement in scanning electron microscope
Authors: Kumagai Kazuhiro , Yao Yuanzhao , Chen Jun , Sekiguchi Takashi
Published: March 2011

During electrical measurements in a scanning electron microscope (SEM), secondary electron (SE) images often become dark or the image contrast becomes weaker. We have revealed that this phenomenon originates in the negative charging of the insulating part in an electric circuit. This charging can be caused by stray electrons, even if the insulator is not directly irradiated. The electrostatic field owing to this charge deflects SEs and reduces the intensity of detected electrons. We have demonstrated this effect by observing systematic shifts of the field of view of SE detector, which appears in SE images. This explanation is supported by a calculation of electron trajectories in the electrostatic field in the SEM chamber. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
CL and dark field TEM analysis of composition change at interfaces in InGaP/GaAs junctions grown by MOCVD
Authors: Frigeri C. , Shakhmin A. A. , Vinokurov D. A. , Zamoryanskaya M. V.
Published: March 2011

Dark field transmission electron microscopy by using both the (200) two beam diffraction mode and the high angle annular dark field (HAADF) method has been used to check the presence and composition of unwanted layer(s), that had formed at the place of the nominal 10 nm thick GaAs QW grown on top of the InGaP barrier in MOCVD InGaP/GaAs samples, and whose existence was suggested by cathodoluminescence. It is shown that the nominal 10 nm GaAs QW has been replaced by 2 layers: a thin one made of In0,15Ga0,85As0,80P0.20 closer to InGaP followed by a second one made of either GaAs0.91P0.09or In0,05Ga0,95As0,84P0.16. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Time‐resolved cathodoluminescence on polychromatic light emitting (In,Ga)N quantum wells grown on (11‐22) GaN facets
Authors: Corfdir Pierre , Simeonov Dobri , Feltin Eric , Carlin Jean‐François , Lefebvre Pierre , Grandjean Nicolas , Deveaud‐Plédran Benoît , Ganière Jean‐Daniel
Published: March 2011

We present a low‐temperature time‐resolved cathodoluminescence study on (In,Ga)N/GaN quantum wells grown on the (11‐22) facets of non‐coalesced ELO‐GaN. Taking advantage of the quantum confined Stark effect, such structures have been proposed as promising monolithic white light emitters. Here, we show that in order to achieve solar‐like white light emission from this kind of structure, one has to pay attention on the respective evolutions of radiative and non‐radiative QW exciton decay times along the (11‐22) facets (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Cathodoluminescence study of individual ZnO nanorods
Authors: Gruzintsev A. N. , Red'kin A. N. , Yakimov E. E. , Yakimov E. B.
Published: March 2011

Investigations of individual ZnO nanorod cathodoluminescence (CL) spectra and of low energy electron beam irradiation effect on their optical properties were carried out. The spatially inhomogeneous distribution in the CL emission excitation was observed in some nanorods. The dependence of CL spectra on the nanorod size was revealed. It was shown that the defect‐related luminescence is practically absent in these samples. It was observed that the CL intensity of nanorods increased after a short irradiation time with low energy electron beam and then started to decrease (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)