bluuebunny/crossref_metadata_2025 huggingface dataset:
Chemistry at the Edge of Graphene
Authors: Bellunato Amedeo , Arjmandi Tash Hadi , Cesa Yanina , Schneider Grégory F.
Published: December 2015

The selective functionalization of graphene edges is driven by the chemical reactivity of its carbon atoms. The chemical reactivity of an edge, as an interruption of the honeycomb lattice of graphene, differs from the relative inertness of the basal plane. In fact, the unsaturation of the pzorbitals and the break of the π conjugation on an edge increase the energy of the electrons at the edge sites, leading to specific chemical reactivity and electronic properties. Given the relevance of the chemistry at the edges in many aspects of graphene, the present Review investigates the processes and mechanisms that drive the chemical functionalization of graphene at the edges. Emphasis is given to the selective chemical functionalization of graphene edges from theoretical and experimental perspectives, with a particular focus on the characterization tools available to investigate the chemistry of graphene at the edge.
Oxygen Reduction on Ag(100) in Alkaline Solutions—A Theoretical Study
Authors: Goduljan Aleksej , de Campos Pinto Leandro Moreira , Juarez Fernanda , Santos Elizabeth , Schmickler Wolfgang
Published: December 2015

Silver is much more reactive to oxygen than gold; nevertheless, in alkaline solutions, the rates of oxygen reduction on both metals are similar. To explain this phenomenon, the first, rate‐determining step of oxygen reduction on Ag(100) is determined by a combination of DFT, molecular dynamics, and electrocatalysis theory. In vacuum, oxygen is adsorbed on Ag(100), but in the electrochemical environment, the adsorption energy is offset by the loss of hydration energy as the molecule approaches the surface. As a result, the first electron transfer should take place in an outer‐sphere mode. Previously, the same mechanism for oxygen reduction on Au(100) has been predicted, and these calculations have been repeated by using a more advanced version of the electrocatalysis theory discussed herein to confirm previous conclusions. The theoretical results compare well with experimental data.
Revisiting the maximum power transfer for linear n‐ports with uncoupled loads and applications to power systems
Authors: Bhaya Amit , Herrera Edwin Alejandro , Diene Oumar
Published: December 2015

This paper revisits three classical results of circuit theory: the Thévenin theorem, the maximum power transfer theorem, and Bode's bilinear theorem, as well as its multilinear generalization due to Lin. Combining these results, it proposes a new measurement‐based approach that provides a practical new version of the ‘maximum’ power transfer theorem for n‐ports terminated with uncoupled loads, in the sense that it allows a functional algebraic description of the entire power hypersurface as a function of the chosen port parameters. This is more useful than merely computing port parameters for maximum power transfer, because the power hypersurface can be used along with constraints on port parameters, such as voltages, to find their values for optimal viable power transfer. An example of maximum power transfer to two chosen load buses is given for the IEEE‐30 bus system, with voltage constraints, in order to show applicability to practical cases. Copyright © 2015 John Wiley & Sons, Ltd.
Molecular and structural transition mechanisms in long‐term volume overload
Authors: Mohamed Belal A. , Schnelle Moritz , Khadjeh Sara , Lbik Dawid , Herwig Melissa , Linke Wolfgang A. , Hasenfuss Gerd , Toischer Karl
Published: December 2015

Aim

We have previously reported that early phase (1 week) of experimental volume overload (VO) has an adaptive phenotype while wall stress‐matched pressure overload (PO) is maladaptive. Here we investigate the transition from adaptation to heart failure (HF) in long‐term VO.

Methods and results

FVB/N wild‐type mice were subjected to VO induced by aortocaval shunt, and were followed by serial echocardiography until in vivo left ventricular ejection fraction was below <50% (135 ± 35 days). Heart failure was evident from increased lung and liver weight and increased mortality compared with sham. Maladaptive remodelling resulted in significantly reduced sarcomeric titin phosphorylation (causing increased sarcomeric stiffness), whereas interstitial fibrosis was not increased. This was paralleled by re‐expression of the fetal gene program, activation of calcium/calmodulin‐dependent protein kinase II (CaMKII), decreased protein kinase B (Akt) phosphorylation, high oxidative stress, and increased apoptosis. Consistently, development of HF and mortality were significantly aggravated in Akt‐deficient mice.

Conclusion

Transition to HF in VO is associated with decreased Akt and increased CaMKII signalling pathways together with increased oxidative stress and apoptosis. Lack of interstitial fibrosis together with sarcomeric titin hypophosphorylation indicates an increased stiffness at the sarcomeric but not matrix level in VO‐induced HF (in contrast to PO). Transition to HF may result from myocyte loss and myocyte dysfunction owing to increased stiffness.
Surgical management of oropharyngeal squamous cell carcinoma: Survival and functional outcomes
Authors: Kumar Bhavna , Cipolla Michael J. , Old Matthew O. , Brown Nicole V. , Kang Stephen Y. , Dziegielewski Peter T. , Durmus Kasim , Ozer Enver , Agrawal Amit , Carrau Ricardo L. , Schuller David E. , Leon Marino E. , Pan Quintin , Kumar Pawan , Wood Valerie , Burgers Jessica , Wakely Paul E. , Teknos Theodoros N.
Published: December 2015

Background

The purpose of this study was to further define the impact of primary surgery in the management of oropharyngeal squamous cell carcinoma (SCC).

Methods

Two hundred ninety‐six patients with oropharyngeal SCC treated with primary surgery were included. Multivariable analysis and recursive partitioning analysis (RPA) identified predictors of survival and gastrostomy tube presence.

Results

Multivariable analysis identified that HPV negativity (p = .0002), presence of extranodal extension (p = .0025), and advanced T classification (p = .0081) were independent predictors of survival. For HPV‐positive patients, surgical approach (p = .0111) and margin status (p = .0287) were significant predictors of survival. For HPV‐negative patients, extranodal extension (p = .0021) and advanced T classification (p = .0342) were significant predictors of survival. Smoking status and advanced neck disease did not impact survival, and the addition of adjuvant chemotherapy did not confer survival benefit in HPV‐positive or HPV‐negative subgroups.

Conclusion

Independent predictors of survival are unique in patients with oropharyngeal SCC treated with primary surgery. © 2015 Wiley Periodicals, Inc. Head Neck 38: E1794–E1802, 2016
Relationship between swallow‐specific quality of life and fiber‐optic endoscopic evaluation of swallowing findings in patients with head and neck cancer
Authors: Florie Michelle , Baijens Laura , Kremer Bernd , Kross Kenneth , Lacko Martin , Verhees Femke , Winkens Bjorn
Published: December 2015

Background

The purpose of this study was to determine the relationship between swallow‐specific quality of life (QOL) using the MD Anderson Dysphagia Inventory (MDADI) and the swallowing function using a standardized fiber‐optic endoscopic evaluation of swallowing (FEES) protocol in patients with dysphagia with head and neck cancer.

Methods

Sixty‐three patients with dysphagia and head and neck cancer were enrolled in the study. Patients completed the MDADI questionnaire and underwent a standardized FEES examination. Ordinal FEES variables were measured. Descriptive statistics and 1‐way analysis of variance tests were carried out.

Results

For all FEES variables, the observer agreement level was sufficient (kappa ≥0.7).These preliminary results show statistically significant mean differences of MDADI subscales between the ordinal scale levels for several FEES variables.

Conclusion

The MDADI questionnaire can be used to assess the impact of dysphagia on the patients' health‐related QOL. Despite clear trends, it remains unclear if the MDADI questionnaire can be used as an indicator for the severity of oropharyngeal dysphagia. © 2015 Wiley Periodicals, Inc. Head Neck 38: E1848–E1856, 2016
International publication trends in the Journal of Applied Behavior Analysis: 2000–2014
Authors: Martin Neil T. , Nosik Melissa R. , Carr James E.
Published: December 2015

Dymond, Clarke, Dunlap, and Steiner's (2000) analysis of international publication trends in the Journal of Applied Behavior Analysis (JABA) from 1970 to 1999 revealed low numbers of publications from outside North America, leading the authors to express concern about the lack of international involvement in applied behavior analysis. They suggested that a future review would be necessary to evaluate any changes in international authorship in the journal. As a follow‐up, we analyzed non‐U.S. publication trends in the most recent 15 years of JABA and found similar results. We discuss potential reasons for the relative paucity of international authors and suggest potential strategies for increasing non‐U.S. contributions to the advancement of behavior analysis.
Systematic evaluation of the biological variance within the Raman based colorectal tissue diagnostics
Authors: Vogler Nadine , Bocklitz Thomas , Subhi Salah Firas , Schmidt Carsten , Bräuer Rolf , Cui Tiantian , Mireskandari Masoud , Greten Florian R. , Schmitt Michael , Stallmach Andreas , Petersen Iver , Popp Jürgen
Published: December 2015

Being among the most common cancers worldwide screening and early diagnosis of colorectal cancer is of high interest for the health system, the patients and for research. Raman microspectroscopy as a label‐free, non‐invasive and non‐destructive technique is a promising tool for an early diagnosis. However, to ensure a reliable diagnosis specially designed statistical analysis workflows are required. Several statistical approaches have been introduced leading to varying results in the overall accuracy, sensitivity and specificity. In this study a systematic evaluation of different statistical analysis approaches has been performed using a colon cancer mouse model with genotypic identical individuals. Based on the inter‐individual Raman spectral variances a measure for the biological variance can be estimated. By applying a leave‐one‐individual‐out cross‐validation a clinically relevant discrimination of healthy tissue versus adenoma and carcinoma with an accuracy of 95% is shown. Furthermore, the transfer of a model from tissue to biopsy specimen is demonstrated.

magnified image
Effects of an electric field on interaction of aromatic systems
Authors: Youn Il Seung , Cho Woo Jong , Kim Kwang S.
Published: December 2015

The effect of uniform external electric field on the interactions between small aromatic compounds and an argon atom is investigated using post‐HF (MP2, SCS‐MP2, and CCSD(T)) and density functional (PBE0‐D3, PBE0‐TS, and vdW‐DF2) methods. The electric field effect is quantified by the difference of interaction energy calculated in the presence and absence of the electric field. All the post‐HF methods describe electric field effects accurately although the interaction energy itself is overestimated by MP2. The electric field effect is explained by classical electrostatic models, where the permanent dipole moment from mutual polarization mainly determines its sign. The size of π‐conjugated system does not have significant effect on the electric field dependence. We found out that PBE0‐based methods give reasonable interaction energies and electric field response in every case, while vdW‐DF2 sometimes shows spurious artifact owing to its sensitivity toward the real space electron density. © 2015 Wiley Periodicals, Inc.
Effective protein conformational sampling based on predicted torsion angles
Authors: Yang Yuedong , Zhou Yaoqi
Published: December 2015

Protein structure prediction is a long‐standing problem in molecular biology. Due to lack of an accurate energy function, it is often difficult to know whether the sampling algorithm or the energy function is the most important factor for failure of locating near‐native conformations of proteins. This article examines the size dependence of sampling effectiveness by using a perfect “energy function”: the root‐mean‐squared distance from the target native structure. Using protein targets up to 460 residues from critical assessment of structure prediction techniques (CASP11, 2014), we show that the accuracy of near native structures sampled is relatively independent of protein sizes but strongly depends on the errors of predicted torsion angles. Even with 40% out‐of‐range angle prediction, 2 Å or less near‐native conformation can be sampled. The result supports that the poor energy function is one of the bottlenecks of structure prediction and predicted torsion angles are useful for overcoming the bottleneck by restricting the sampling space in the absence of a perfect energy function. © 2015 Wiley Periodicals, Inc.
Engineers at Play: Games as Teaching Tools for Undergraduate Engineering Students
Authors: Bodnar Cheryl A. , Anastasio Daniel , Enszer Joshua A. , Burkey Daniel D.
Published: December 2015

Background

Many students may not respond strongly to instruction that they do not perceive as engaging. One pedagogical approach to help engage students involves the use of games. Educational games can provide students with a motivating and stimulating environment while providing them with immediate feedback to promote learning.

Purpose

This systematic review examines research focused on the implementation of games to teach undergraduate engineering students; it summarizes prevailing features and cites examples from a variety of engineering disciplines.

Scope/Method

The systematic review was conducted through a detailed search of Science Direct journals and the Scopus, Web of Science, Compendex/Inspec, and ERIC Education Research Abstract databases using terms pertinent to games in engineering education. A total of 191 papers was included after application of the inclusion/exclusion criteria. After screening those to determine if assessment of student learning outcomes was performed, 62 papers were found suitable for more detailed analysis.

Conclusions

Research on the implementation of games in undergraduate engineering classrooms has shown that, despite diverse forms of assessment applied, there is a general trend that both student learning and attitudes are improved by game‐based activities. However, since only a relatively small subset of the literature demonstrates a systematic, validated approach in assessment, significant opportunities remain for future research.
Preparing Engineers for the Workplace through Service Learning: Perceptions of EPICS Alumni
Authors: Huff James L. , Zoltowski Carla B. , Oakes William C.
Published: December 2015

Background

Service‐learning programs that emphasize engineering design have been posited to bolster the professional preparedness of engineering alumni. However, we know little about how such programs actually prepare engineers for the workplace. Nor does prior literature fully explain how characteristics of these programs affect professional preparation.

Purpose

This study investigates how alumni perceive the impact of one service‐learning program, Engineering Projects in Community Service (EPICS), in preparing them for the workplace. We seek to provide empirical and theoretical foundations about how this program affected the alumni's perceptions of how they were prepared for professional practice.

Design/Method

This investigation was an embedded, sequential mixed‐methods study, which began by administering a survey to 523 participants. On the basis of survey responses, we interviewed 27 participants and conducted a thematic analysis of transcripts to describe how participants related their EPICS experiences to the workplace.

Results

The findings describe how alumni perceived the role of EPICS in preparing them for the workplace. The thematic analysis reveals how alumni perceived the nature of their preparation through three themes: EPICS was a bridge from education to practice, EPICS provided a means for gaining workplace experience, and EPICS developed a variety of professional skills.

Conclusions

Grounded in alumni perspectives, this study demonstrates a strong link between participating in service‐learning activities and navigating the complexity of the workplace. Finally, we identify three key characteristics of EPICS that are transferable to other institutions.
Spectral engineering of coupled open‐access microcavities
Authors: Flatten L.C. , Trichet A.A.P. , Smith J.M.
Published: December 2015

Open‐access microcavities are emerging as a new approach to confine and engineer light at mode volumes down to the λ3 regime. They offer direct access to a highly confined electromagnetic field while maintaining tunability of the system and flexibility for coupling to a range of matter systems. This article presents a study of coupled cavities, for which the substrates are produced using Focused Ion Beam milling. Based on experimental and theoretical investigation the engineering of the coupling between two microcavities with radius of curvature of 6 m is demonstrated. Details are provided by studying the evolution of spectral, spatial and polarisation properties through the transition from isolated to coupled cavities. Normal mode splittings up to 20 meV are observed for total mode volumes around . This work is of importance for future development of lab‐on‐a‐chip sensors and photonic open‐access devices ranging from polariton systems to quantum simulators.

image
Aqueous Solutions of Poly[2‐(N‐morpholino)ethyl methacrylate]: Learning about Macromolecular Aggregation Processes from a Peculiar Three‐Step Thermoresponsive Behavior
Authors: Eggers Steffen , Fischer Birgit , Abetz Volker
Published: December 2015

Aqueous solutions of narrowly distributed poly[2‐(N‐morpholino)ethyl methacrylate], a biocompatible multiple stimuli‐responsive polymer, show a peculiar three‐step aggregation behavior upon heating, an effect which has hitherto barely been reported for other polymers. The phenomenon is discussed in terms of mesoglobule formation (first step) as well as by an unusual distinct disruption of hydrophobic hydration (second step) and hydrogen bonding to the hydrophilic aggregate surface (third step). Macroscopic precipitation only takes place after the third step, a behavior which resembles the denaturation and limited aggregation of proteins. Furthermore, the influence of different anions along the Hofmeister series is investigated, identifying salting‐out (kosmotropic) and salting‐in (chaotropic) effects. As an experimental tool to monitor the thermally induced aggregate growth, dynamic light scattering is used. The reported findings might lead to a more detailed understanding of both aggregation behavior of (biological) macromolecules and mechanistic processes involved in thermoresponsivity and salt‐responsivity of water soluble polymers.

image
Gradual Precipitation to Fabricate PLLA Materials with High Porosity and Tunable Strength Formed by High Crystalline Nanosheets
Authors: Yin Guangzhong , Zhao Donglin , Zhang Lianwei , Feng Jianyu , Ren Ye , Chen Guangxin , Zhou Zheng , Li Qifang
Published: December 2015

In this study, a facile method about generating porous poly (l‐lactide) (PLLA) materials with uniform morphology by gradual precipitation is reported. By adjusting the solvents, concentrations of polymer solution, and drying process, petal‐like PLLA nanosheets can be conveniently obtained, which can further form porous materials with tunable porosities (85–92%). X‐ray diffraction affirms that α‐form crystals of PLLA with high crystallinity (51.66% according to differential scanning calorimetry) can be obtained. Mechanical test shows that the compression modulus is tunable with values ranging from 1.76 to 19.98 MPa. Notably, because of its high porosity, interconnected pore structure, and tunable mechanical properties, these versatile porous materials are especially fit for being utilized in polymer scaffold field.

image
One‐Pot Preparation of Organic–Inorganic Composite Microspheres Comprising Silica Nanoparticles and End‐Functionalized Polymers
Authors: Satoh Hiroki , Yabu Hiroshi
Published: December 2015

Colloidal assemblies of inorganic nanoparticles dispersed in liquid media hold particular promise for the creation of a unique class of functional materials with innovative applications. In the present report, “compound‐eye”‐like core–shell and Janus‐type silica and amino‐terminated 1,2‐polybutadiene (PB‐NH2) and polystyrene (PS) composite microspheres are successfully prepared by simply mixing an aqueous dispersion of silica particles into a tetrahydrofran (THF) solution of PB‐NH2, and PB‐NH2 and PS blends, followed by evaporation of the THF. This co‐precipitation process provides a new approach for producing organic–inorganic composite particles without the need for surface modification of the inorganic nanoparticles.

image
Spectrality of certain self‐affine measures on the generalized spatial Sierpinski gasket
Authors: Wang Qi , Li Jian‐Lin
Published: December 2015

The self‐affine measure corresponding to a upper or lower triangle expanding matrix M and the digit set in the space is supported on the generalized spatial Sierpinski gasket, where are the standard basis of unit column vectors in . We consider in this paper the existence of orthogonal exponentials on the Hilbert space , i.e., the spectrality of . Such a property is directly connected with the entries of M and is not completely determined. For this generalized spatial Sierpinski gasket, we present a method to deal with the spectrality or non‐spectrality of . As an application, the spectral property of a class of such self‐affine measures are clarified. The results here generalize the corresponding results in a simple manner.
MMP20, KLK4, and MMP20/KLK4 double null mice define roles for matrix proteases during dental enamel formation
Authors: Hu Yuanyuan , Smith Charles E. , Richardson Amelia S , Bartlett John D. , Hu Jan C.C. , Simmer James P.
Published: December 2015

Matrix metalloproteinase 20 (MMP20) and kallikrein‐related peptidase 4 (KLK4) are secreted proteinases that are essential for proper dental enamel formation. We characterized and compared enamel formed in wild‐type, Mmp20−/−, Klk4−/−, Mmp20+/−Klk4+/−, and Mmp20−/−Klk4−/− mice using dissecting and light microscopy, backscattered scanning electron microscopy (bSEM), SEM, microcomputed tomography (μCT), and energy‐dispersive X‐ray analysis (EDX). Following eruption, fractures were observed on Mmp20−/−, Klk4−/−, Mmp20+/−Klk4+/−, and Mmp20−/−Klk4−/− molars. Failure of the enamel in the Mmp20+/−Klk4+/− molars was unexpected and suggested that digenic effects could contribute to the etiology of amelogenesis imperfecta in humans. Micro‐CT analyses of hemimandibles demonstrated significantly reduced high‐density enamel volume in the Mmp20−/− and Klk4−/− mice relative to the wild‐type, which was further reduced in Mmp20−/−Klk4−/− mice. bSEM images of 7‐week Mmp20−/− and Mmp20−/−Klk4−/− mandibular incisors showed rough, pitted enamel surfaces with numerous indentations and protruding nodules. The Mmp20+/− and Mmp20+/−Klk4+/− incisors showed prominent, evenly spaced, horizontal ridges that were more distinct in Mmp20+/−Klk4+/− incisors relative to Mmp20+/− incisors due to the darkening of the valleys between the ridges. In cross sections, the Mmp20−/− and Mmp20−/−Klk4−/− exhibited three distinct layers. The outer layer exhibited a disturbed elemental composition and an irregular enamel surface covered with nodules. The Mmp20 null enamel was apparently unable to withstand the sheer forces associated with eruption and separated from dentin during development. Cells invaded the cracks and interposed between the dentin and enamel layers. MMP20 and KLK4 serve overlapping and complementary functions to harden enamel by removing protein, but MMP20 potentially serves multiple additional functions necessary for the adherence of enamel to dentin, the release of intercellular protein stores into the enamel matrix, the retreat of ameloblasts to facilitate thickening of the enamel layer, and the timely transition of ameloblasts to maturation.
Obesity and hyperglycemia lead to impaired post‐ischemic recovery after permanent ischemia in mice
Authors: Tulsulkar Jatin , Nada Shadia E. , Slotterbeck Brandon D. , McInerney Marcia F. , Shah Zahoor A.
Published: December 2015

Objective

Obesity‐induced diabetes has increased over the years and has become one of the risk factors for stroke. We investigated the influence of diet‐induced obesity and hyperglycemia on permanent distal middle cerebral artery occlusion (pMCAO)‐induced ischemic stroke in mice.

Methods

Male C57/Bl6 mice were treated with a high‐fat/high‐carbohydrate diet [HFCD/obese and hyperglycemia (O/H)] or a normal diet (control) for 3.5 months, subjected to pMCAO, and sacrificed after 7 days.

Results

Infarct volume analysis showed no differences between the O/H and control group, whereas neurological deficits were significantly higher in the O/H group compared to the control group. Sirtuin (Sirt1) was overexpressed and NADPH oxidase was reduced in the O/H group. O/H mice had significantly lower expression of Wnt and glycogen synthase kinase 3 α and β, a key component in the Wnt signaling pathway. Translocation of apoptosis inducing factor (AIF) to the nucleus was observed in both the O/H and control groups, but O/H mice showed a higher expression of AIF in the nucleus.

Conclusions

These data suggest that impaired Wnt signaling and active apoptosis result in reduced post‐stroke recovery in obese and hyperglycemic mice.
Nucleolipids of Canonical Purine ß‐d‐Ribo‐Nucleosides: Synthesis and Cytostatic/Cytotoxic Activities Toward Human and Rat Glioblastoma Cells
Authors: Knies Christine , Hammerbacher Katharina , Bonaterra Gabriel A. , Kinscherf Ralf , Rosemeyer Helmut
Published: December 2015

We report on the synthesis of two series of canonical purine ß‐d‐ribonucleoside nucleolipids derived from inosine and adenosine, which have been characterized by elemental analyses, electrospray ionization mass spectrometry (ESI MS) as well as by 1H and 13C NMR, and pH‐dependent UV/Vis spectroscopy. A selection of the novel nucleolipids with different lipophilic moieties were first tested on their cytotoxic effect toward human macrophages. Compounds without a significant inhibitory effect on the viability of the macrophages were tested on their cytostatic/cytotoxic effect toward human astrocytoma/oligodendroglioma GOS‐3 cells as well as against the rat malignant neuroectodermal BT4Ca cell line. In order to additionally investigate the potential molecular mechanisms involved in the cytotoxic effects of the derivatives on GOS‐3 or BT4Ca cells, we evaluated the induction of apoptosis and observed the particular activity of the nucleolipid ethyl 3‐{4‐hydroxymethyl‐2‐methyl‐6‐[6‐oxo‐1‐(3,7,11‐trimethyl‐dodeca‐2,6,10‐trienyl)‐1,6‐dihydro‐purin‐9‐yl]‐tetrahydro‐furo[3,4‐d][1,3]dioxol‐2‐yl}propionate (8 c) toward both human and rat glioblastoma cell lines in vitro.
Psychosocial Assessment as a Standard of Care in Pediatric Cancer
Authors: Kazak Anne E. , Abrams Annah N. , Banks Jaime , Christofferson Jennifer , DiDonato Stephen , Grootenhuis Martha A. , Kabour Marianne , Madan‐Swain Avi , Patel Sunita K. , Zadeh Sima , Kupst Mary Jo
Published: December 2015

This paper presents the evidence for a standard of care for psychosocial assessment in pediatric cancer. An interdisciplinary group of investigators utilized EBSCO, PubMed, PsycINFO, Ovid, and Google Scholar search databases, focusing on five areas: youth/family psychosocial adjustment, family resources, family/social support, previous history/premorbid functioning, and family structure/function. Descriptive quantitative studies, systematic reviews, and meta‐analyses (n = 149) were reviewed and evaluated using grading of recommendations, assessment development, and evaluation (GRADE) criteria. There is high quality evidence to support a strong recommendation for multifaceted, systematic assessments of psychosocial health care needs of youth with cancer and their families as a standard of care in pediatric oncology. Pediatr Blood Cancer © 2015 Wiley Periodicals, Inc.
Thermoelectric efficiency in the linear transport regime
Authors: Eltschka Christopher , Thierschmann Holger , Buhmann Hartmut , Siewert Jens
Published: December 2015

Improving the efficiency of thermoelectric devices is a long‐term goal in thermoelectricity research. Deeper insight into the meaning of the related quantities, in particular the figure of merit is instrumental for progress in this direction. Here, we study the regime of linear transport where entirely general statements can be made for the electronic part of the thermoelectric efficiency. These results essentially do not depend on the type of device, its layout, or the involved transport mechanisms. For two‐terminal devices, where charge and heat currents flow along the same path, we find a particularly simple and intuitive expression for the figure of merit . In multi‐terminal devices with different paths for the currents, the thermoelectric efficiency does not admit such a simple interpretation. Nonetheless, nontrivial device‐independent statements can be made about the efficiency. As a practical example, we consider the heat‐to‐current converter Sánchez and Büttiker, Phys. Rev. B 83, 085428 (2011) ().
Thermomigration and Soret effect in NaxCoO2 as thermoelectric material: Preparation and characterization of sodium cobaltate thin films
Authors: Schneider Christian , Schichtel Patrick , Mogwitz Boris , Straubinger Rainer , Beyer Andreas , Rohnke Marcus , Volz Kerstin , Janek Jürgen
Published: December 2015

Sodium cobaltate (NaxCoO2, NCO) is a model type thermoelectric material for high temperature applications, which is representative for the class of non‐stoichiometric and mixed ion‐electron conducting thermoelectrics (e.g., Cu2 – xSe). The present study deals with the kinetic instability of the originally homogeneous chemical composition when a temperature gradient is applied – a common situation in thermoelectric materials with a mobile component (element), but rarely considered in thermoelectric materials research so far. In order to investigate a well reproducible system, highly epitaxial thin films of NaxCoO2 with an atmosphere protective capping layer of alumina are prepared via pulsed laser deposition on sapphire (001) and lanthanum aluminate (111). A self‐designed non‐isothermal set‐up allows the precise determination of the heat of transport for mobile sodium as 8.3 kJ mol−1 and, therefore, the quantification of thermodiffusion (i.e., the Ludwig‐Soret effect in the stationary state). The experiments also allow to estimate the chemical diffusion coefficient of sodium at 422 K as about  = 5 × 10−4 cm2 s−1.
Surface‐oxide‐controlled InAlN/GaN MOS‐HEMTs with water vapor
Authors: Ozaki Shiro , Makiyama Kozo , Ohki Toshihiro , Kamada Yoichi , Sato Masaru , Niida Yoshitaka , Okamoto Naoya , Joshin Kazukiyo
Published: December 2015

We have investigated the effect of oxidant sources on the performance of InAlN/GaN metal–oxide–semiconductor high electron mobility transistors (MOS‐HEMTs). We clarified that the surface‐oxide of InAlN comprises aluminum oxide (Al2O3) and indium oxide (In2O3) when using conventional oxygen (O2) plasma, and In2O3 causes the gate leakage and current collapse of InAlN/GaN MOS‐HEMTs due to its narrow bandgap and electron traps, such as oxygen vacancies. Then, we proposed water (H2O) vapor oxidation to decrease In2O3 for the surface‐oxide by focusing on the thermal stability of intermediate hydroxide. Aluminum hydroxide [Al(OH)x] is thermally stable because it changes into Al2O3 at 300 °C. On the other hand, indium hydroxide [In(OH)x] is thermally unstable because it desorbs at 150 °C. Therefore, Al2O3 was selectively increased when using 300 °C H2O vapor because of In(OH)x desorption, and the gate leakage and current collapse were successfully reduced due to the decrease in In2O3. We concluded from these results that a key role in improving the performance of InAlN/GaN MOS‐HEMTs is decreasing In2O3 for the surface‐oxide.
III‐nitride‐based waveguides for ultrafast all‐optical signal processing at 1.55 μm
Authors: Monteagudo‐Lerma Laura , Naranjo Fernando B. , Valdueza‐Felip Sirona , Jiménez‐Rodríguez Marco , Monroy Eva , Postigo Pablo A. , Corredera Pedro , González‐Herráez Miguel
Published: December 2015

We present an overview of the recently developed III‐nitride‐based optical waveguides for application in ultrafast signal processing at telecom wavelengths. We focus on different active and passive optical devices for further implementation within all‐optical integrated circuits. Optical waveguides based on GaN/AlN quantum dots have been demonstrated to act as saturable absorbers requiring ∼3 pJ of input pulse energy to reach +3 dB transmittance contrast for TM‐polarized light. On the contrary, sputtered‐InN‐based devices show −3 dB transmittance contrast associated to two‐photon absorption for input pulse energies of ∼1 pJ, making them suitable to act as highly‐efficient reverse saturable absorbers. Finally, the passive optical nature of waveguides based on sputtered AlN at 1.55 μm makes them suitable for further connections between different III‐nitride‐based active devices.
Internal quantum efficiency and carrier injection efficiency of c‐plane, and InGaN/GaN‐based light‐emitting diodes
Authors: Wang Junjun , Meisch Tobias , Heinz Dominik , Zeller Raphael , Scholz Ferdinand
Published: December 2015

The electroluminescence (EL) output power of c‐plane InGaN/GaN‐based light‐emitting diodes (LEDs) is much higher than that of semipolar and LEDs at the same operation current. In order to elucidate the reasons for this behavior, we have fitted the pulsed EL data by the well‐known ABC model to extract the internal quantum efficiency (IQE) and the carrier injection efficiency (CIE) to clarify which parameter weighs more for the poor EL output power of the semipolar LEDs. The CIE shows large differences, 78%, 4%, and 4% for the c‐plane, and LEDs, respectively, whereas the IQE values are fairly the same for all three structures. The fit of resonant photoluminescence (PL) data at room temperature confirms the similar IQE values for all three structures. The CIE was increased from 4% to 10% for the planar LED with better electrical conductivity of the p‐GaN layer.
Effect of Ultra Fast Cooling on the Alloy Cost Reduction of the X80 Pipeline Steel
Authors: Zhou Feng , Wu Kaiming M. , Zhang Cong , Isayev Oleg , Hodgson Peter D.
Published: December 2015

The microstructures and mechanical properties of X80 pipeline steels produced by both novel ultra fast cooling and conventional‐accelerated continuous cooling modes are investigated. Results showed that different levels of Mo addition had a remarkable effect on the microstructures and mechanical properties of the investigated pipeline steels. The proeutectoid ferrite and pearlite formation is inhibited in the high‐Mo steel and acicular ferrite is obtained over a wide range of cooling rates, whereas the dominant acicular ferrite microstructure can only be obtained when the cooling rates reach up to 5 C s−1. Very similar microstructures and mechanical properties are obtained in the low‐Mo steel produced with ultra fast cooling and in the high‐Mo steel produced by the conventional‐accelerated continuous cooling. It was proved by simulation and industrial trials that high‐strength low‐alloy steels such as pipeline steels, can be produced using the novel ultra fast cooling which also reduce alloy cost.
Teratoma: from spontaneous tumors to the pluripotency/malignancy assay
Authors: Bulic‐Jakus Floriana , Katusic Bojanac Ana , Juric‐Lekic Gordana , Vlahovic Maja , Sincic Nino
Published: December 2015

A teratoma is a benign tumor containing a mixture of differentiated tissues and organotypic derivatives of the three germ layers, while a teratocarcinoma also contains embryonal carcinoma cells (EC cells). Experimental teratomas and teratocarcinomas have been derived from early mammalian embryos transplanted into the adult animal (ectopic sites). In the rat, the pluripotency of the transplanted epiblast was demonstrated and a quantifiable restriction of developmental potential persisted after subsequent transplantation of chemically defined cultivated postimplantation embryos. The rat is nonpermissive for teratocarcinoma development and rat pluripotent cell lines have been established only recently. Transplantation of mouse embryos, epiblast, or embryonic stem cells (mESCs) gave rise to teratocarcinomas. The pluripotency of reprogrammed human cells has been tested by a ‘gold standard’ trilaminar teratoma assay in immunocompromised mice in vivo. Human pluripotent stem cells proposed for use in regenerative medicine such as human embryonic stem cell (hESC), human nuclear‐transfer/therapeutic cloning embryonic stem cell (NT‐ESC), or human induced pluripotent stem cell (hiPSC) lines, once differentiated in vitro to the desired cell type, should be again tested in a long‐term animal teratoma assay to exclude their malignancy. Such an approach led to a recently implemented human therapy with retinal pigmented epithelium. For greater biosafety, the teratoma assay should be standardized and complemented by assessments of mutations/epimutations, RNA/protein expression, and possible immunogenicity of autologous pluripotent cells. Furthermore, the standardized teratoma assay should be directed more to the assessment of EC/malignant cell features than of differentiated tissues, especially after a unique case of human therapy with neural stem cells was found to lead to malignancy. WIREs Dev Biol 2016, 5:186–209. doi: 10.1002/wdev.219

This article is categorized under:

Adult Stem Cells, Tissue Renewal, and Regeneration > Methods and Principles

Adult Stem Cells, Tissue Renewal, and Regeneration > Stem Cells and Disease

Comparative Development and Evolution > Model Systems
Controlling the properties of surface acoustic waves using graphene
Authors: Bandhu Lokeshwar , Nash Geoffrey R.
Published: December 2015

Surface acoustic waves (SAWs) are elastic waves that propagate on the surface of a solid, much like waves on the ocean, with SAW devices used widely in communication and sensing. The ability to dynamically control the properties of SAWs would allow the creation of devices with improved performance or new functionality. However, so far it has proved extremely difficult to develop a practical way of achieving this control. In this paper we demonstrate voltage control of SAWs in a hybrid graphene-lithium niobate device. The velocity shift of the SAWs was measured as the conductivity of the graphene was modulated using an ion-gel gate, with a 0.1% velocity shift achieved for a bias of approximately 1 V. This velocity shift is comparable to that previously achieved in much more complicated hybrid semiconductor devices, and optimization of this approach could therefore lead to a practical, cost-effective voltage-controlled velocity shifter. In addition, the piezoelectric fields associated with the SAW can also be used to trap and transport the charge carriers within the graphene. Uniquely to graphene, we show that the acoustoelectric current in the same device can be reversed, and switched off, using the gate voltage.
Reciprocal relations between body satisfaction and self‐esteem: A large 13‐year prospective study of adolescents☆
Authors: Wichstrøm Lars , von Soest Tilmann
Published: December 2015

Previous research has demonstrated that body satisfaction and self‐esteem are highly correlated in adolescence, but reasons are poorly understood. We tested three explanations: (i) the two constructs are actually one; (ii) the correlation is explained by a third factor; (iii) there are prospective relationships between body satisfaction and self‐esteem. A population based sample of Norwegian adolescents (n = 3251) was examined four times over a 13‐year period. Confirmatory factor analysis showed that body satisfaction and self‐esteem were separate constructs and the correlation between them was not attenuated when adjusting for 3rd variables. Autoregressive cross‐lagged analysis showed reciprocal relations between body satisfaction and self‐esteem. The prospective relationship between body satisfaction during adolescence and self‐esteem in late adolescence and emerging adulthood was stronger than at later stages.
Parabolic equations and the bounded slope condition
Authors: Duzaar Frank , Marcellini Paolo , Signoriello Stefano , Bögelein Verena
Published: December 2015

In this paper we establish the existence of Lipschitz-continuous solutions to the Cauchy Dirichlet problem of evolutionary partial differential equations

\begin{cases}
\partial _{t}u−\mathrm{div}\:Df(Du) = 0 &\text{in }\mathrm{\Omega }_{T}\text{,} \\
u = u_{o} &\text{on }\partial _{\mathcal{P}}\mathrm{\Omega }_{T}\text{.}
\end{cases}

The only assumptions needed are the convexity of the generating function

f:\mathbb{R}^{n}\rightarrow \mathbb{R}

, and the classical bounded slope condition on the initial and the lateral boundary datum

u_{o} \in W^{1,\infty }(\mathrm{\Omega })

. We emphasize that no growth conditions are assumed on

f

and that – an example which does not enter in the elliptic case

– u_{o}

could be any Lipschitz initial and boundary datum, vanishing at the boundary

∂Ω

, and the boundary may contain flat parts, for instance

Ω

could be a rectangle in

\mathbb{R}^{n}

.
Cerebrospinal fluid ratios with Aβ42 predict preclinical brain β‐amyloid accumulation
Authors: Racine Annie M. , Koscik Rebecca L. , Nicholas Christopher R. , Clark Lindsay R. , Okonkwo Ozioma C. , Oh Jennifer M. , Hillmer Ansel T. , Murali Dhanabalan , Barnhart Todd E. , Betthauser Tobey J. , Gallagher Catherine L. , Rowley Howard A. , Dowling N. Maritza , Asthana Sanjay , Bendlin Barbara B. , Blennow Kaj , Zetterberg Henrik , Carlsson Cynthia M. , Christian Bradley T. , Johnson Sterling C.
Published: December 2015

Introduction

Biomarkers are urgently needed for the critical yet understudied preclinical stage of Alzheimer's disease (AD).

Methods

Cerebrospinal fluid (CSF) collection, [C‐11]Pittsburgh compound B (PiB) amyloid imaging, and magnetic resonance imaging were acquired in 104 cognitively healthy adults enriched with risk for sporadic AD. Image‐derived cerebral β‐amyloid (Aβ) burden, measured concurrently and longitudinally, was regressed on CSF measures of Aβ, neural injury, and inflammation, as well as ratios with Aβ42. Linear mixed‐effects regression was used to model the effect of the CSF measures that predicted longitudinal brain amyloid accumulation on longitudinal cognitive decline, measured by memory test scores.

Results

At baseline, Aβ42/Aβ40 and all CSF ratios to Aβ42 were associated with PiB binding in AD‐vulnerable regions. Longitudinally, Aβ42/Aβ40 and ratios of total tau (t‐tau), phosphorylated‐tau (p‐tau), neurofilament light protein, and monocyte chemoattractant protein‐1 to Aβ42 were associated with increased Aβ deposition over 2 years, predominantly in lateral parietal and temporal cortex. However, these CSF ratios were not significantly associated with cognitive decline, and the effect seems to be largely driven by Aβ42 in the denominator.

Discussion

These results corroborate previous findings that t‐tau/Aβ42 and p‐tau/Aβ42 are the strongest candidate biomarkers during the preclinical time frame. They support a framework in which neural injury and amyloid deposition are likely occurring simultaneously. It may be that neurodegenerative processes influence progressive amyloid accumulation, even in the preclinical time frame. CSF biomarkers for nonspecific axonal injury and inflammation may provide more information at more advanced stages of the preclinical time course.
Gastrointestinal stromal tumor of rectum diagnosed by three-dimensional anorectal ultrasound
Authors: Ratin Raphael Ferreira , Melão Suelen , dos Reis Lima Doryane Maria , Sagae Univaldo Etsuo , Kurachi Gustavo
Published: December 2015

Gastrointestinal stromal tumors (GIST) are relatively rare lesions of mesenchymal origin, being more frequent in the stomach and small intestine. These are clinically asymptomatic lesions, and in advanced stages may present with nausea, vomiting, bleeding, abdominal pain, a palpable mass, and even intestinal obstruction. The only effective treatment consists of a complete tumor resection. We report two cases of GIST located in the distal rectum and evaluated with three-dimensional anorectal ultrasonography, a procedure of great value in identifying the size of the lesion, its involvement toward nearby structures and lymph node invasion.
A review of experimental models in colorectal carcinogenesis
Authors: Machado Vanessa Foresto , Feitosa Marley Ribeiro , da Rocha Jose Joaquim Ribeiro , Féres Omar
Published: December 2015

Colorectal cancer is the leading cause of malignancy of the gastrointestinal tract. A better understanding of the molecular and cellular changes that lead to the disease is necessary to develop early diagnosis and optimal treatment modalities. Rodent models are rapid, reproducible and exhibit an adenoma-carcinoma sequence similar to that found in humans. The objective of this manuscript is to review the most common chemical carcinogens used to induce experimental tumors and the usual methods of evaluation.
Receptor tyrosine kinase gene expression profiles of Ewing sarcomas reveal ROR1 as a potential therapeutic target in metastatic disease
Authors: Potratz Jenny , Tillmanns Amelie , Berning Philipp , Korsching Eberhard , Schaefer Christiane , Lechtape Birgit , Schleithoff Carolin , Unland Rebekka , Schäfer Karl-Ludwig , Müller-Tidow Carsten , Jürgens Heribert , Dirksen Uta
Published: December 2015

Receptor tyrosine kinases (RTKs) have provided molecular targets for the development of novel, prognosis‐improving agents in many cancers; however, resistances to these therapies occur. On the cellular level, one resistance mechanism is attributed to functional RTK redundancies and compensatory cross‐signaling, leading to perception of RTKs as signaling and target networks. To provide a basis for better exploitation of this network in Ewing sarcoma, we generated comprehensive qPCR gene expression profiles of RTKs in Ewing sarcoma cell lines and 21 untreated primary tumors. Key findings confirm broad‐spectrum RTK expressions with potential for signaling redundancy. Profile analyses with regard to patient risk‐group further revealed several individual RTKs of interest. Among them, VEGFR3 and TIE1 showed high‐level expressions and also were suggestive of poor prognosis in localized tumors; underscoring the relevance of angiogenic signaling pathways and tumor‐stroma interactions in Ewing sarcoma. Of note, compared to localized disease, tumors derived from metastatic disease were marked by global high‐level RTK expressions. Nine individual RTKs were significantly over‐expressed, suggesting contributions to molecular mechanisms of metastasis. Of these, ROR1 is being pursued as therapeutic target in leukemias and carcinomas, but un‐characterized in sarcomas. We demonstrate expression of ROR1 and its putative ligand Wnt5a in Ewing sarcomas, and of an active ROR1 protein variant in cell lines. ROR1 silencing impaired cell migration in vitro. Therefore, ROR1 calls for further evaluation as a therapeutic target in metastatic Ewing sarcoma; and described as a pseudo‐kinase with several isoforms, underlines these additional complexities arising in our understanding of RTK signaling networks.