bluuebunny/crossref_metadata_2025 huggingface dataset:
Photoacoustic microscopy
Authors: Yao Junjie , Wang Lihong V.
Published: January 2013

Photoacoustic microscopy (PAM) is a hybrid in vivo imaging technique that acoustically detects optical contrast via the photoacoustic effect. Unlike pure optical microscopic techniques, PAM takes advantage of the weak acoustic scattering in tissue and thus breaks through the optical diffusion limit (∼1 mm in soft tissue). With its excellent scalability, PAM can provide high‐resolution images at desired maximum imaging depths up to a few millimeters. Compared with backscattering‐based confocal microscopy and optical coherence tomography, PAM provides absorption contrast instead of scattering contrast. Furthermore, PAM can image more molecules, endogenous or exogenous, at their absorbing wavelengths than fluorescence‐based methods, such as wide‐field, confocal, and multi‐photon microscopy. Most importantly, PAM can simultaneously image anatomical, functional, molecular, flow dynamic and metabolic contrasts in vivo. Focusing on state‐of‐the‐art developments in PAM, this Review discusses the key features of PAM implementations and their applications in biomedical studies.
High Intensity Focused Ultrasound Triggered Shape Memory and Drug Release from Biodegradable Polyurethane
Authors: Han Jianjun , Fei Guoxia , Li Guo , Xia Hesheng
Published: January 2013

A shape memory biodegradable polyurethane composite is prepared and shape recovery and simultaneous release of embedded copper sulfate are realized by high intensity focused ultrasound (HIFU). The composite shows an excellent HIFU‐controlled shape recovery performance, wherein temporal and spatial control can be realized by switching the HIFU on/off or selecting the place where the ultrasound is focused. The composite shows an excellent HIFU switchable drug release function. The release process of a model payload can be tuned by adjusting the HIFU intensity and time. The shape memory polyurethane shows a rapid enzymatic biodegradation rate. This polyurethane composite has potential applications in minimally invasive interventional therapy devices.

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Compressed Exponential Response Function Arising From a Continuous Distribution of Gaussian Decays – Distribution Characteristics
Authors: Hansen Eddy W. , Gong Xiaoliang , Chen Qun
Published: January 2013

A compressed exponential function (CEF) is shown to be represented by a distribution of Gaussian functions. The properties and characteristics of the distribution are detailed and discussed, and are illustrated with reference to the change in the NMR spectroscopy proton Hahn echo relaxation response that takes place in a composite material (prepared by melt compounding a mixture of graphite nanoparticles and pyromellitic anhydride modified polypropylene carbonate (PPC)) during aging at 90 °C. The results show that both the width and the average value of the spin‐spin relaxation rate distribution decrease during aging, suggesting that the molecular motion becomes less constrained and less heterogeneous.

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On the negative squares of a class of self‐adjoint extensions in Krein spaces
Authors: Behrndt Jussi , Luger Annemarie , Trunk Carsten
Published: January 2013

A description of all exit space extensions with finitely many negative squares of a symmetric operator of defect one is given via Krein's formula. As one of the main results an exact characterization of the number of negative squares in terms of a fixed canonical extension and the behaviour of a function τ (that determines the exit space extension in Krein's formula) at zero and at infinity is obtained. To this end the class of matrix valued \documentclass{article}\usepackage{amssymb}\begin{document}\pagestyle{empty}$\mathcal {D}_\kappa ^{n\times n}$\end{document}‐functions is introduced and, in particular, the properties of the inverse of a certain \documentclass{article}\usepackage{amssymb}\begin{document}\pagestyle{empty}$\mathcal {D}_\kappa ^{2\times 2}$\end{document}‐function which is closely connected with the spectral properties of the exit space extensions with finitely many negative squares is investigated in detail. Among the main tools here are the analytic characterization of the degree of non‐positivity of generalized poles of matrix valued generalized Nevanlinna functions and some extensions of recent factorization results.
Precision Biopolymers from Protein Precursors for Biomedical Applications
Authors: Kuan Seah Ling , Wu Yuzhou , Weil Tanja
Published: January 2013

The synthesis of biohybrid materials with tailored functional properties represents a topic of emerging interest. Combining proteins as natural, macromolecular building blocks, and synthetic polymers opens access to giant brush‐like biopolymers of high structural definition. The properties of these precision polypeptide copolymers can be tailored through various chemical modifications along their polypeptide backbone, which expands the repertoire of known protein‐based materials to address biomedical applications.

 In this article, the synthetic strategies for the design of precision biopolymers from proteins through amino acid specific conjugation reagents are highlighted and the different functionalization strategies, their characterization, and applications are discussed.
Water‐Soluble Fluorescent Probes Based on Dendronized Polyfluorenes for Cell Imaging
Authors: Bai Libin , Li Wei , Chen Jingtian , Bo Fuli , Gao Baoxiang , Liu Hongmei , Li Jingjing , Wu Yonggang , Ba Xinwu
Published: January 2013

Novel water‐soluble dendronized fluorescent polyfluorenes (DFPFs) are prepared from hydrophilic monomers and hydrophobic comonomers. Incomplete energy transfer is found to result in a two‐color emission of the DFPFs at around 410 and 650 nm. The incomplete energy transfer can be attributed to the poor compatibility between the fluorene and benzothiadiazole units. Polyethylene oxide (PEO) encapsulation of the DFPFs shows over 90% cell viability, indicating good biocompatibility. These DFPFs show differential cellular uptake. P1 with fewer PEO chains exhibits limited cellular membrane uptake and low brightness in cells. By contrast, P3 with more PEO chains is efficiently internalized by cells and accumulated in the cytoplasm. A strong fluorescence from whole cells is also observed.
Modular Establishment of a Diketopyrrolopyrrole‐Based Polymer Library via Pd‐Catalyzed Direct C–H (Hetero)arylation: a Highly Efficient Approach to Discover Low‐Bandgap Polymers
Authors: Guo Qiang , Dong Jiaxing , Wan Danyang , Wu Di , You Jingsong
Published: January 2013

A concise, highly efficient palladium‐catalyzed direct C–H (hetero)arylation is developed to modularly assemble a diketopyrrolopyrrole (DTDPP)‐based polymer library to screen low‐bandgap and near‐infrared (NIR) absorbing materials. The DTDPP‐based copolymers P1 and P2 with an alternating donor–acceptor–donor–acceptor (D–A–D–A) sequence and the homopolymer P9 exhibit planarity and excellent π‐conjugation, which lead to low bandgaps (down to 1.22 eV) as well as strong and broad NIR absorption bands (up to 1000 nm).
Anticancer activity of fish oils against human lung cancer is associated with changes in formation of PGE2 and PGE3 and alteration of Akt phosphorylation
Authors: Yang Peiying , Cartwright Carrie , Chan Diana , Ding Jibin , Felix Edward , Pan Yong , Pang Jihai , Rhea Patrea , Block Keith , Fischer Susan M. , Newman Robert A.
Published: January 2013

The beneficial effects of omega‐3 fatty acids are believed to be due in part to selective alteration of arachidonate metabolism that involves cyclooxygenase (COX) enzymes. Here we investigated the effect of eicosapentaenoic acid (EPA) on the proliferation of human non‐small cell lung cancer A549 (COX‐2 over‐expressing) and H1299 (COX‐2 null) cells as well as their xenograft models. While EPA inhibited 50% of proliferation of A549 cells at 6.05 µM, almost 80 µM of EPA was needed to reach similar levels of inhibition of H1299 cells. The formation of prostaglandin (PG)E3 in A549 cells was almost threefold higher than that of H1299 cells when these cells were treated with EPA (25 µM). Intriguingly, when COX‐2 expression was reduced by siRNA or shRNA in A549 cells, the antiproliferative activity of EPA was reduced substantially compared to that of control siRNA or shRNA transfected A549 cells. In line with this, dietary menhaden oil significantly inhibited the growth of A549 tumors by reducing tumor weight by 58.8 ± 7.4%. In contrast, a similar diet did not suppress the development of H1299 xenograft. Interestingly, the ratio of PGE3 to PGE2 in A549 was about 0.16 versus only 0.06 in H1299 xenograft tissues. Furthermore, PGE2 up‐regulated expression of pAkt, whereas PGE3 downregulated expression of pAkt in A549 cells. Taken together, the results of our study suggest that the ability of EPA to generate PGE3 through the COX‐2 enzyme might be critical for EPA‐mediated tumor growth inhibition which is at least partly due to down‐regulation of Akt phosphorylation by PGE3. © 2013 Wiley Periodicals, Inc.
Infinitely many solutions to elliptic systems with critical exponents and Hardy potentials
Authors: Wang Li
Published: January 2013

In this paper, we consider the following elliptic systems with critical Sobolev growth and Hardy potentials:
urn:x-wiley:01704214:media:mma2705:mma2705-math-0001
where N ≥ 3, η > 0, λ1,λ2 ∈ [0,ΛN), and is the best Hardy constant. is the critical Sobolev exponent. a1, a2, b1, and b2 are positive parameters, and α,β > 1 satisfy 2 < α + β < 2*. h(x) ≢ 0, h(x) ≥ 0, , , and with . By means of the concentration–compactness principle and R. Kajikiya's new version of symmetric mountain pass lemma, we obtain infinitely many solutions that tend to zero. Copyright © 2013 John Wiley & Sons, Ltd.
Global weak solutions for a periodic two‐component μ‐Camassa–Holm system
Authors: Zhang Ying
Published: January 2013

In this paper, we consider the global existence of weak solutions for a two‐component μ‐Camassa–Holm system in the periodic setting. Global existence for strong solutions to the system with smooth approximate initial value is derived. Then, we show that the limit of approximate solutions is a global‐in‐time weak solution of the two‐component μ‐Camassa–Holm system. Copyright © 2013 John Wiley & Sons, Ltd.
Heat transfer in granular materials: effects of nonlinear heat conduction and viscous dissipation
Authors: Yang Hyunjin , Aubry Nadine , Massoudi Mehrdad
Published: January 2013

In this paper, we study the heat transfer in a one‐dimensional fully developed flow of granular materials down a heated inclined plane. For the heat flux vector, we use a recently derived constitutive equation that reflects the dependence of the heat flux vector on the temperature gradient, the density gradient, and the velocity gradient in an appropriate frame invariant formulation. We use two different boundary conditions at the inclined surface: a constant temperature boundary condition and an adiabatic condition. A parametric study is performed to examine the effects of the material dimensionless parameters. The derived governing equations are coupled nonlinear second‐order ordinary differential equations, which are solved numerically, and the results are shown for the temperature, volume fraction, and velocity profiles. Copyright © 2013 John Wiley & Sons, Ltd.
Exercise in neuromuscular disease
Authors: Anziska Yaacov , Sternberg Alex
Published: January 2013

In this review, we present an overview of the role of exercise in neuromuscular disease (NMD). We demonstrate that despite the different pathologies in NMDs, exercise is beneficial, whether aerobic/endurance or strength/resistive training, and we explore whether this benefit has a similar mechanism to that of healthy subjects. We discuss further areas for study, incorporating imaginative and novel approaches to training and its assessment in NMD. We conclude by suggesting ways to improve future trials by avoiding previous methodological flaws and drawbacks in this field. Muscle Nerve, 2013
Asymmetric sensory ganglionopathy: A case series
Authors: Marquez‐Infante Celedonio , Murphy Sinéad M. , Mathew Liberty , Alsanousi Ali , Lunn Michael P. , Brandner Sebastian , Yousry Tarek A. , Blake Julian , Reilly Mary M.
Published: January 2013

Introduction

Sensory ganglionopathies are uncommon but potentially very disabling. They have heterogeneous etiologies including autoimmune, paraneoplastic, toxic, and inflammatory although many remain idiopathic despite intensive investigation. Asymmetric sensory loss is relatively common at the onset, but with time, symptoms usually spread to involve all limbs symmetrically.

Methods

We report 6 patients with a persistent strikingly asymmetrical sensory ganglionopathy with acute or subacute onset and slow progression.

Results

Peripheral nerve biopsies in 5 patients showed axonal loss without significant inflammation; a dorsal root ganglion biopsy in 1 patient showed neuronal loss and inflammatory infiltrate. Four patients received immunomodulatory treatment, but overall the response to treatment was poor.

Conclusions

Asymmetrical sensory ganglionopathies may have an inflammatory basis. Immunomodulatory therapy may be considered early in the disease course, although in this series there was a limited response to treatment. Muscle Nerve, 2013
Dynamic sonographic measurements at the carpal tunnel inlet: Reliability and reference values in healthy wrists
Authors: Filius Anika , Korstanje Jan‐Wiebe H. , Selles Ruud W. , Hovius Steven E.R. , Slijper Harm P.
Published: January 2013

Introduction: Reliability and reference values are not well‐established for most dynamic sonographic measurements of the median nerve (MN) and flexor tendons that may be used for diagnosing carpal tunnel syndrome (CTS). Methods: Wrists of 20 healthy participants were imaged using ultrasound. Cines of the carpal tunnel inlet were acquired during hand motion. Based on shape and displacement measurements, intra‐ and interrater reliability and reference values were calculated. Results: Intraclass correlation coefficients (ICCs) for measurements of the MN and most flexor tendons were ≥0.51 for shape parameters and ≥0.71 for displacement parameters. During motion, the MN flattened with ulnar movement, tendons became more circular, and flexor tendons of corresponding fingers moved toward each other. Conclusion: Shape and displacement measurements of the MN and most flexor tendons had reliability results ranging from moderate to excellent. The reference values may be useful for the diagnosis of CTS. Muscle Nerve 48: 525–531, 2013
Why short stature is beneficial in duchenne muscular dystrophy
Authors: Bodor Marko , Mcdonald Craig M.
Published: January 2013

Introduction

Duchenne muscular dystrophy (DMD) is caused by a genetic defect resulting in absent dystrophin, yet children are able to walk when small and young but lose this ability as they grow. The mdx mouse has absent dystrophin yet does not exhibit significant disability.

Methods

Allometric modeling of linearly increasing load per muscle fiber and stress on the sarcolemma with growth and exponential decline associated with loss of muscle fibers correlated with case studies and animal models of DMD.

Results

Smaller species or breeds are predictably less affected than large as follows: mdx mice < small golden retriever muscular dystrophy (GRMD) dogs < large GRMD dogs < humans. Case reports of combined growth hormone and dystrophin deficiency show a relatively benign course of disease.

Conclusions

Future therapeutic trials in DMD might include specific growth inhibitors in combination with standard of care treatments to delay the clinical onset and reduce the severity of disease and disability. Muscle Nerve 48: 336–342, 2013
A general degree hybrid equilibrium finite element for Kirchhoff plates
Authors: Moitinho de Almeida J.P. , Maunder E.A.W.
Published: January 2013

We present a family of hybrid equilibrium finite elements for the quasistatic linear elastic analysis of plates governed by Kirchhoff theory. The moments are approximated by self‐balanced polynomial fields of general degree, and in order to impose strong codiffusivity, the normal boundary rotations are approximated with complete polynomials of the same degree, whereas the transverse deflections use polynomials one degree lower. Furthermore, it is also necessary to include an independent approximation of the vertex translations. We show that the triangular form of this element is stable, that is, free from spurious kinematic modes, and the formulation that we present allows these elements to be used as a standard displacement element. Examples of computed values and convergence of the solutions are presented, which demonstrate the performance of these elements. Copyright © 2013 John Wiley & Sons, Ltd.
Developmental Changes in the Composition of Five Anthraquinones from Rheum palmatum as Quantified by 1H‐NMR
Authors: Wang Zhi‐Wei , Wang Jun‐Song , Yang Ming‐Hua , Luo Jian‐Guang , Kong Ling‐Yi
Published: January 2013

Introduction

Rheum palmatum is an important traditional Chinese medicine featuring anthraquinones with several activities. Generally, rhein, emodin, aloe‐emodin, physcion and chrysophanol are used as chemical markers for the quality control of rhubarb products.

Objective

To develop a simple protocol for the quantification of rhein, emodin, aloe‐emodin, physcion and chrysophanol in R. palmatum collected at different developmental stages.

Methods

1H‐NMR spectra were measured on samples dissolved in acetone‐d6, quantification was carried out using the signals of H‐4 of rhein (δH 8.36), H‐7 of emodin (δH 6.68), CH2OH of aloe‐emodin (δH 4.81), OCH3 of physcion (δH 4.02) and CH3 of chrysophanol (δH 2.50), which were well separated from other signals. Quantitative analysis was based on the relative ratio of the intensity of each compound to the known amount of internal standard maleic acid.

Results

The quantitative 1H‐NMR (qHNMR) method developed showed good precision, trueness, linearity, repeatability and stability for the quantification of rhein, emodin, aloe‐emodin, physcion and chrysophanol. This method was applied successfully to explore the seasonal variations of the five major anthraquinones in R. palmatum, and provided quantitative results in reasonable agreement with those obtained by the HPLC–UV method.

Conclusion

Compared with the conventional HPLC‐based methods, the qHNMR analysis is rapid, reference‐free and convenient with less sample pre‐treatment. This technique should be a feasible choice for the quality control of R. palmatum. Copyright © 2013 John Wiley & Sons, Ltd.
New technologies in insulin delivery
Authors: Taylor MJ , Sahota TS
Published: January 2013

The electronic age is bringing advances in the treatment of diabetes, and this is important because the complications of diabetes remain despite the availability of effective therapeutic tools such as insulin. These developments focus on the need to deliver accurately timed and sized doses for predicted blood glucose levels.

In this review, blood monitoring methods are discussed since, although the chemistry remains based on the enzymic oxidation of glucose, the display, storage and manipulation of data have transformed recently to engage with smartphone users. Continuous glucose monitoring sensing (CGMS) types are described along with an appreciation of the shortcomings of sensor technology. The discussion includes responses to other barriers to CGMS use for reducing the HbA1c value safely so that hypoglycaemia can be avoided. The newer pumps and the emergence of the minimalised patch pumps and patch pens are described. This includes the moves to attract more type 2 users to pump use, addresses the perceived obtrusiveness noted by younger users, and reviews the obstacles to rolling out pump use more widely in the UK. Penultimately, after reference to islet implants, the combination of the continuous sensing and conventional pump strategies to form a closed loop system is described, including a summary of the electronic algorithms and the clinical performance of systems in research settings. The review closes with an explanation of how other closed loop systems have been developed including the peritoneal Medtronic and the DiaPort and a smart gel, non‐electronic design. Copyright © 2013 John Wiley & Sons.
Review of 3D topological insulator thin‐film growth by molecular beam epitaxy and potential applications
Authors: He Liang , Kou Xufeng , Wang Kang L.
Published: January 2013

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Thin films of V–VI compound semiconductors (Bi2Se3, Bi2Te3 and Sb2Te3) have been synthesized recently as three‐dimensional topological insulators (TIs). Although these materials have been used as thermoelectric materials for many years, for future studies and applications of the topological surface states, a major bottleneck remains the lack of high‐quality bulk materials that have very few defects and the Fermi level can be moved to inside the bulk bandgap. In this paper, we review the use of molecular beam epitaxy (MBE) technique to achieve high‐quality TI materials. Furthermore, the use of layered growth in MBE affords us the fabrication of heterostructures, such as quantum wells and superlattices. Thus, it may further enable additional studies and applications, similar to those of conventional semiconductor heterostructures but with the novel properties of TI. We explore the growth mechanism, providing a detail discussion on the growth parameters of thin‐film synthesis by MBE. Then we discuss more complex cases, such as functional doping, heterostructures and superlattices. Potential new properties in such quantum structures are discussed. Finally, we give an outlook on this material system for both fundamental studies and applications. (© 2013 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Sample size determination for testing equality in Poisson frequency data under an AB/BA crossover trial
Authors: Lui Kung‐Jong
Published: January 2013

Assuming that the frequency of occurrence follows the Poisson distribution, we develop sample size calculation procedures for testing equality based on an exact test procedure and an asymptotic test procedure under an AB/BA crossover design. We employ Monte Carlo simulation to demonstrate the use of these sample size formulae and evaluate the accuracy of sample size calculation formula derived from the asymptotic test procedure with respect to power in a variety of situations. We note that when both the relative treatment effect of interest and the underlying intraclass correlation between frequencies within patients are large, the sample size calculation based on the asymptotic test procedure can lose accuracy. In this case, the sample size calculation procedure based on the exact test is recommended. On the other hand, if the relative treatment effect of interest is small, the minimum required number of patients per group will be large, and the asymptotic test procedure will be valid for use. In this case, we may consider use of the sample size calculation formula derived from the asymptotic test procedure to reduce the number of patients needed for the exact test procedure. We include an example regarding a double‐blind randomized crossover trial comparing salmeterol with a placebo in exacerbations of asthma to illustrate the practical use of these sample size formulae. Copyright © 2013 John Wiley & Sons, Ltd.
A stochastic parametrization for deep convection using cellular automata
Authors: Bengtsson Lisa , Steinheimer Martin , Bechtold Peter , Geleyn Jean‐François
Published: January 2013

A cellular automaton (CA) is introduced to the deep convection parametrization of the high‐resolution limited‐area model Aire Limitée Adaptation/Application de la Recherche à l'Opérationnel (ALARO). The self‐organizational characteristics of the CA allow for lateral communication between adjacent numerical weather prediction (NWP) model grid boxes and add additional memory to the deep convection scheme. The CA acts in two horizontal dimensions, with finer grid spacing than the NWP model. It is randomly seeded in regions where convective available potential energy (CAPE) exceeds a threshold value. Both deterministic and probabilistic rules, coupled to the large‐scale wind, are explored to evolve the CA in time. Case studies indicate that the scheme has the potential to organize cells along convective squall lines and enhance advective effects. An ensemble of forecasts using the present CA scheme demonstrated an ensemble spread in the resolved wind field in regions where deep convection is large. Such a spread represents the uncertainty due to subgrid variability of deep convection and could be an interesting addition to an ensemble prediction system.
Combining computer models to account for mass loss in stellar evolution
Authors: Stein Nathan M. , van Dyk David A. , von Hippel Ted , DeGennaro Steven , Jeffery Elizabeth J. , Jefferys William H.
Published: January 2013

Intricate computer models can be used to describe complex physical processes in astronomy such as the evolution of stars. Like a sampling distribution, these models typically predict observed quantities as a function of a number of unknown parameters. Including them as components of a statistical model, however, leads to significant modeling, inferential, and computational challenges. In this article, we tackle these challenges in the study of the mass loss that stars experience as they age. We have developed a new Bayesian technique for inferring the so‐called initial–final mass relation (IFMR), the relationship between the initial mass of a Sun‐like star and its final mass as a white dwarf. Our model incorporates several separate computer models for various phases of stellar evolution. We bridge these computer models with a parameterized IFMR in order to embed them into a statistical model. This strategy allows us to apply the full force of powerful statistical tools to build, fit, check, and improve the statistical models and their computer model components. In contrast to traditional techniques for inferring the IFMR, which tend to be quite ad hoc, we can estimate the uncertainty in our fit and ensure that our model components are internally coherent. We analyze data from three star clusters: NGC 2477, theHyades, and M35 (NGC 2168). The results from NGC 2477 and M35 suggest different conclusions about the IFMR in the mid‐ to high‐mass range, raising questions for further astronomical work. We also compare the results from two different models for the primary hydrogen‐burning stage of stellar evolution. We show through simulations that misspecification at this stage of modeling can sometimes have a severe effect on inferred white dwarf masses. Nonetheless, when working with observed data, our inferences are not particularly sensitive to the choice of model for this stage of evolution. © 2013 Wiley Periodicals, Inc. Statistical Analysis and Data Mining 6: 34–52, 2013
Periodicity detection in irregularly sampled light curves by robust regression and outlier detection
Authors: Thieler Anita Monika , Backes Michael , Fried Roland , Rhode Wolfgang
Published: January 2013

An important task in astroparticle physics is the detection of periodicities in irregularly sampled time series, called light curves. Many periodogram methods for light curves may be characterized as fitting periodic models using least squares regression. We generalize this approach and allow robust regression and weighted regression. This gives a unified concept which includes further methods proposed in the literature, allows to create new methods and take additional information about measurement accuracies into account. We compare all these methods using simulated data. We observe that if the quality of the measurement accuracies is dubious, they should be ignored, and that robust methods can be helpful if the light curve contains outliers. Finally, we propose a new way to determine valid periods by robust fitting of a distribution to the periodogram and outlier detection. In our simulations, this leads to better detection rates for periodic fluctuations with unexpected shape and less wrong detections in light curves of pure red and white noise. © 2013 Wiley Periodicals, Inc. Statistical Analysis and Data Mining 6: 73–89, 2013
Annealing of silver nanolayers sputtered on polytetrafluoroethylene
Authors: Siegel J. , Juřík P. , Kolská Z. , Švorčík V.
Published: January 2013

Silver nanolayers sputtered on polytetrafluoroethylene and their changes induced by post‐deposition annealing at 100–300 °C are studied. Changes in surface morphology and roughness are examined by atomic force microscopy and by measurement of electrical sheet resistance by two‐point technique. Chemical composition was determined by X‐ray photoelectron spectroscopy (XPS) and electrokinetic analysis in dependence on the gold layer thickness. The annealing at 300 °C leads to significant rearrangement of the silver layer, and the transition threshold increases to 35 nm. The presence of oxidized structures on silver‐coated samples is observed in XPS spectra and by electrokinetic analysis, too. Annealing of pristine and silver‐coated poly(tetrafluoroethylene) at 300 °C results in significant change of the sample surface morphology and chemistry. There is observed formation of isolated silver islands on the surface, which could be connected with silver melting. Later, the silver agglomeration takes place. Copyright © 2013 John Wiley & Sons, Ltd.
A note on the catch‐up time method for estimating lead or sojourn time in prostate cancer screening
Authors: Draisma Gerrit , van Rosmalen Joost
Published: January 2013

Models of cancer screening assume that cancers are detectable by screening before being diagnosed clinically through symptoms. The duration of this preclinical phase is called sojourn time, and it determines how much diagnosis might be advanced in time by the screening test (lead time). In the catch‐up time method, mean sojourn time or lead time are estimated as the time needed for cumulative incidence in an unscreened population to catch up with the detection rate (prevalence) at a first screening test. The method has been proposed as a substitute of the prevalence/incidence ratio in the case of prostate cancer where incidence cannot be treated as a constant. A model is proposed to justify this estimator. It is shown that this model is different from classic Markov‐type models developed for breast cancer screening. In both models, the catch‐up time method results in biased estimates of mean sojourn time. Copyright © 2013 John Wiley & Sons, Ltd.
Impact of cord entanglement on perinatal outcome of monoamniotic twins: a systematic review of the literature
Authors: Rossi A. C. , Prefumo F.
Published: January 2013

Objective

To review the current literature concerning perinatal outcome of monoamniotic pregnancies with cord entanglement.

Methods

A search in PubMed, EMBASE and MEDLINE for articles published between January 2000 and December 2011 was performed, using the following keywords: monoamniotic/monochorionic pregnancy(ies); twins; cord entanglement; fetal ultrasound/surveillance. Inclusion criteria for the study were: monoamniotic twins with documented cord entanglement at delivery, and perinatal outcome reported as proportional rates. Exclusion criteria were: higher‐order multiple pregnancy; selective feticide; presence of twin reversed arterial perfusion sequence; conjoined twins; fewer than four cases in the series; and non‐English language publication. Survival rates were stratified for method of prenatal management, sonographic diagnosis of cord entanglement and delivery mode. A meta‐analysis was also performed using data from articles that stratified outcome according to the presence or absence of cord entanglement at birth. Comparison between neonates with cord entanglement and controls was deemed significant if the 95% CI of the pooled odds ratios did not encompass 1. MOOSE (Meta‐analysis Of Observational Studies in Epidemiology) guidelines were followed.

Results

Nine articles met the inclusion criteria for this review, including a total of 114 monoamniotic twin sets (228 fetuses) with cord entanglement. The overall survival rate was 202/228 (88.6%). Perinatal mortality occurred in 26 (11.4%) fetuses; of these, 17 (65%) died in utero and nine (35%) died at birth. Five neonatal deaths occurred as a result of prematurity, two were related to structural abnormalities and two were caused by cord entanglement. Sonographic visualization of cord entanglement did not improve outcome. Four articles were included in the meta‐analysis, with no significant difference in mortality between controls (n = 66 fetuses) and twins with cord entanglement (n = 82 fetuses), and higher morbidity in controls.

Conclusions

Cord entanglement does not contribute to prenatal morbidity and mortality in monoamniotic twin pregnancies.
Re: Vaginal progesterone, cerclage or cervical pessary for preventing preterm birth in asymptomatic singleton pregnant women with history of preterm birth and a sonographic short cervix. Z. Alfirevic, J. Owen, E. Carreras Moratonas, A. N. Sharp, J. M. Szychowski, M. Goya. Ultrasound Obstet Gynecol 2013; 41: 146–151
Authors: Makrydimas G.
Published: January 2013

Linked Comment: Ultrasound Obstet Gynecol 2013:41:146–151
Atomistic simulations of nucleosomes
Authors: Biswas Mithun , Langowski Jörg , Bishop Thomas C.
Published: January 2013

Nearly a dozen all‐atom molecular dynamics (MD) simulations of the nucleosome have been performed. Collectively, these simulations provide insights into the structure and dynamics of the biomolecular complex that serves as the fundamental folding unit of chromatin. Nucleosomes contain 146 base pairs of DNA wrapped in a left‐handed superhelix around a core of eight histones. This review provides a survey of what has been learned about DNA, histones, and solvent interactions based on all‐atom MD studies of the nucleosome. The longest simulations to date are on the order of 100 nanoseconds. On this time scale, nucleosomes are quite stable. DNA kinks, the histone tails, solvent, and ions are highly dynamic and can be readily investigated using equilibrium dynamics methods. Steered MD is required to observe large‐scale structural changes. The need for explicit solvent techniques is underscored by the inability of continuum solvent methods to properly describe the ion‐nucleosome radial distribution functions. The atomistic techniques reviewed here are deemed necessary for exploration of the near infinite variations in atomic composition that exists even in the canonical nucleosome octamer. Continued development of these nascent simulation efforts will enable experimentalists to utilize rational design strategies in their efforts to investigate nucleosomes and chromatin. © 2013 John Wiley & Sons, Ltd.

This article is categorized under:

Molecular and Statistical Mechanics > Molecular Dynamics and Monte-Carlo Methods
Four Coordination Polymers Constructed from 3, 5‐Bis‐oxy­acetate‐benzoic Acid and N‐donor Ligands
Authors: Tong Ying , Jiang Xian‐Rong , Feng Yun‐Long
Published: January 2013

Four coordination polymers, [M3(boaba)2(4, 4′‐bipy)2(H2O)8] [M = Co (1), Ni (2), Mn (3)] and [Cu3(boaba)2(bimb)3]·4H2O (4) [H3boaba = 3, 5‐bis‐oxyacetate‐benzoic acid, 4, 4′‐bipy = 4, 4′‐bipyridine, bimb = 1, 4‐bis(imidazol‐1′‐yl)butane], were hydrothermally synthesized and characterized by single‐crystal X‐ray diffraction, IR spectroscopy, and TG analyses. Compounds 1–3 are isostructural and crystallize in the triclinic P$\bar{1}$ space group. Their structures can be considered constructed from two‐dimensional layers, which consist of two neighboring 1D ladder chains and are further linked by intermolecular O–H···O hydrogen bonds into a 3D supramolecular network. Compound 4 is a 3D (3, 4, 4)‐connected topology network.
SO(9) supergravity in two dimensions
Authors: Ortiz Thomas , Samtleben Henning
Published: January 2013

Abstract

We present maximal supergravity in two dimensions with gauge group SO(9). The construction is based on selecting the proper embedding of the gauge group into the infinite-dimensional symmetry group of the ungauged theory. The bosonic part of the Lagrangian is given by a (dilaton-)gravity coupled non-linear gauged σ-model with Wess-Zumino term. We give explicit expressions for the fermionic sector, the Yukawa couplings and the scalar potential which supports a half-supersymmetric domain wall solution. The theory is expected to describe the low-energy effective action upon reduction on the D0-brane near-horizon warped AdS
2 ×S
8 geometry, dual to the supersymmetric (BFSS) matrix quantum mechanics.
Identification of the 1PL Model with Guessing Parameter: Parametric and Semi-parametric Results
Authors: San Martín Ernesto , Rolin Jean-Marie , Castro Luis M.
Published: January 2013

In this paper, we study the identification of a particular case of the 3PL model, namely when the discrimination parameters are all constant and equal to 1. We term this model, 1PL-G model. The identification analysis is performed under three different specifications. The first specification considers the abilities as unknown parameters. It is proved that the item parameters and the abilities are identified if a difficulty parameter and a guessing parameter are fixed at zero. The second specification assumes that the abilities are mutually independent and identically distributed according to a distribution known up to the scale parameter. It is shown that the item parameters and the scale parameter are identified if a guessing parameter is fixed at zero. The third specification corresponds to a semi-parametric 1PL-G model, where the distribution G generating the abilities is a parameter of interest. It is not only shown that, after fixing a difficulty parameter and a guessing parameter at zero, the item parameters are identified, but also that under those restrictions the distribution G is not identified. It is finally shown that, after introducing two identification restrictions, either on the distribution G or on the item parameters, the distribution G and the item parameters are identified provided an infinite quantity of items is available.
The effects of patellar tendon advancement on the immature proximal tibia
Authors: Patthanacharoenphon Cameron , Maples Dayle L. , Saad Christina , Forness Michael J. , Halanski Matthew A.
Published: January 2013

Purpose

The aim of this study is to examine the short-term effects of patellar tendon advancement on the proximal tibial slope in the skeletally immature patient.

Methods

A retrospective, non-randomized, comparative cohort design was used. Koshino indices and tibial slopes were assessed pre-operatively and post-operatively and compared with age- and sex-matched controls.

Results

Nine children with 17 patellar tendon advancements were analyzed for changes in Koshino indices. Of these 17 tibiae, radiographs on changes in tibial slope were available for 16 tibiae which were also compared with controls. Children aged <11 years had a greater initial posterior tibial slope (69.8° ± 3.5°) than age-matched controls (80.3° ± 2.7°). A decrease in posterior slope was seen in these younger patients (average change 10.3° ± 4.8°) at an average of 1.6 years of follow-up. Of the nine apophyses in children aged <11 years of age, seven had undergone premature closure.

Conclusion

Patellar tendon advancement appears to have an unreported effect on the proximal tibial growth in the young patient (<11 years old). These patients appear to be susceptible to apophyseal closure, resulting in subsequent loss of posterior tibial slope. Surgeons should be aware of this effect and monitor younger patients with radiographs if performing this procedure.
Mersey deanery ophthalmology trainees’ views of the objective assessment of
surgical and technical skills (OSATS) workplace-based assessment tool
Authors: Tsagkataki Myrto , Anshoo Choudhary Anshoo
Published: January 2013

Objective assessment of surgical and technical skills (OSATS) workplace-based
assessment tool is now mandatory during ophthalmology speciality training in the United
Kingdom. The opinions of those undergoing this assessment have not been formally sought.
This study evaluated the views of ophthalmology trainees on OSATS assessment as applied
to cataract surgery. A questionnaire was circulated to 34 ophthalmology speciality
trainees of the Mersey deanery. A total of 28 responses were received. The most positive
aspects of the process identified were feedback, learning and opportunity for reflective
practice. The most negative aspects were time constraints, assessor’s availability and
case selection. Of the trainees, 93 % mentioned that no previous agreed action was taken
into consideration when filling in subsequent forms and their performance was not
discussed in their annual summative assessment. This study highlights important aspects
of trainees’ perceptions of OSATS. Trainees appreciate the formative aspects of OSATS
assessment. Some problems came to light, which can be resolved by specification of
standards, training of assessors, and commitment from both trainers and trainees.
Changes are needed to allow demonstration of surgical progression with time. The issues
identified here will be relevant to other specialities as well. A larger survey would be
beneficial.
Recovery from chronic fatigue syndrome after treatments given in the PACE trial
Authors: White P. D. , Goldsmith K. , Johnson A. L. , Chalder T. , Sharpe M.
Published: January 2013

Background

A multi-centre, four-arm trial (the PACE trial) found that rehabilitative cognitive behaviour therapy (CBT) and graded exercise therapy (GET) were more effective treatments for chronic fatigue syndrome (CFS) than specialist medical care (SMC) alone, when each was added to SMC, and more effective than adaptive pacing therapy (APT) when added to SMC. In this study we compared how many participants recovered after each treatment.

Method

We defined recovery operationally using multiple criteria, and compared the proportions of participants meeting each individual criterion along with two composite criteria, defined as (a) recovery in the context of the trial and (b) clinical recovery from the current episode of the illness, however defined, 52 weeks after randomization. We used logistic regression modelling to compare treatments.

Results

The percentages (number/total) meeting trial criteria for recovery were 22% (32/143) after CBT, 22% (32/143) after GET, 8% (12/149) after APT and 7% (11/150) after SMC. Similar proportions met criteria for clinical recovery. The odds ratio (OR) for trial recovery after CBT was 3.36 [95% confidence interval (CI) 1.64–6.88] and for GET 3.38 (95% CI 1.65–6.93), when compared to APT, and after CBT 3.69 (95% CI 1.77–7.69) and GET 3.71 (95% CI 1.78–7.74), when compared to SMC (pvalues ⩽0.001 for all comparisons). There was no significant difference between APT and SMC. Similar proportions recovered in trial subgroups meeting different definitions of the illness.

Conclusions

This study confirms that recovery from CFS is possible, and that CBT and GET are the therapies most likely to lead to recovery.
The Illusion of Mirrors: Velázquez's Las Meninas
Authors: Altmann Simon
Published: January 2013

There have been dozens of interpretations of Las Meninas but most critics assume that either the Royal couple, or their portrait in the Velazquez's large canvas shown in the picture, is actually reflected on a back mirror. I shall provide evidence, however, to support the view that this mirror never existed. And there is no evidence whatsoever that the double portrait was ever painted. In view of these facts I shall make a new proposal about the way the picture was painted and about the painter's intentions. I shall show evidence that the king was adamant that he did not want his portrait painted, since he did not want to show his age (he was more than double the age of his queen). It is thus reasonable to assume that Velázquez, in order to assuage the King's qualms, created the mirror, thus allowing him to produce a very diffuse picture of the royal couple, where no evidence of aging could possibly be discerned.
Elite Perceptions of the Judiciary in East Central and South East Europe
Authors: Grødeland Åse B. , Aasland Aadne
Published: January 2013

This article challenges the notion that the EU accession process has reduced the scope for informal practice in the judiciary in post-communist states. Elite survey data suggest that such practice is widespread – although primarily used in response to transition, informal practice has to some extent been carried over from communism and is largely used out of habit. Efforts to reduce the negative impact of informal practice in the judiciary should therefore not only seek to enhance its independence and capacity, but also address (1) public attitudes towards the law and the judiciary as such; (2) the coping strategies applied when interacting with the judiciary; and (3) the judges’ and prosecutors’ responses to such strategies.
Russians as Asiatics: Memory about the Present
Authors: Shlapentokh Dmitry
Published: January 2013

History as recorded very often follows the desire of political pragmatists. Nineteenth-century French views of Russia are a good example. France was in conflict with Russia through most of that century. As racism grew across Europe, French historians presented Russians as brutish Asiatics and a mortal threat to civilized Europe. The Russo-French alliance in 1894 changed these views, but the stereotypes continued to hibernate in the collective subconscious of the West to be resurrected in times of political expediency.
Rap1 and Canoe/afadin are essential for establishment of apical–basal polarity in theDrosophilaembryo
Authors: Choi Wangsun , Harris Nathan J. , Sumigray Kaelyn D. , Peifer Mark
Published: January 2013

The establishment and maintenance of apical–basal cell polarity is critical for assembling epithelia and maintaining organ architecture. Drosophila embryos provide a superb model. In the current view, apically positioned Bazooka/Par3 is the initial polarity cue as cells form during cellularization. Bazooka then helps to position both adherens junctions and atypical protein kinase C (aPKC). Although a polarized cytoskeleton is critical for Bazooka positioning, proteins mediating this remained unknown. We found that the small GTPase Rap1 and the actin-junctional linker Canoe/afadin are essential for polarity establishment, as both adherens junctions and Bazooka are mispositioned in their absence. Rap1 and Canoe do not simply organize the cytoskeleton, as actin and microtubules become properly polarized in their absence. Canoe can recruit Bazooka when ectopically expressed, but they do not obligatorily colocalize. Rap1 and Canoe play continuing roles in Bazooka localization during gastrulation, but other polarity cues partially restore apical Bazooka in the absence of Rap1 or Canoe. We next tested the current linear model for polarity establishment. Both Bazooka and aPKC regulate Canoe localization despite being “downstream” of Canoe. Further, Rap1, Bazooka, and aPKC, but not Canoe, regulate columnar cell shape. These data reshape our view, suggesting that polarity establishment is regulated by a protein network rather than a linear pathway.