bluuebunny/crossref_metadata_2025 huggingface dataset:
Endocrine Imbalance Associated With Proteome Changes in Diabetes
Authors: Khairallah Ahmed , Farag Abo‐Alela , Johar Dina , Bernstein Larry
Published: April 2017

The dynamics of cellular metabolism involves rapid interactions between proteins and nucleic acids, proteins and proteins, and signaling. These involve the interactions with respect to the sulfur bond, noncovalent electrostatic interactions, protein structure stabilization and protein‐ligand binding, weak electrostatic interactions in proteins, oxygen radicals that initiate a change in conformation and a chain of events. We review a development in molecular medicine that is a very promising work in progress. We also review the current and future research methods involving mitochondria. Long‐term effects of diabetes include glycation of proteins, for example, glycohemoglobin (HbA1c), increased risk of cardiovascular diseases, atherosclerosis, retinopathy, nephropathy, and neurological dysfunctions. Tissues are exposed to significant quantities of highly reactive chemical species including nitric oxide •NO and reactive oxygen species ROS over months to years, to an extent generated by mitochondrial activities. The reactions of •NO can be broadly discussed with reference to three main processes which control their fate in biological systems: (1) diffusion and intra‐cellular consumption; (2) autooxidation to form nitrous anhydride N2O3; and (3) reaction with superoxide O2•‐ to form peroxynitrite ONOO–. Reactive nitrogen species produced by macrophages and neutrophils in the interstitial space, with emphasis on •NO, N2O3, ONOO–, and nitrogen dioxide radicals •NO2 generate protein and DNA damage. Serum thiol (‐SH) groups act as an important extracellular scavenger of peroxides and are therefore helpful in protecting the surrounding tissues. The events described here are a homeostatic endocrine imbalance that is associated with proteostasis. The advances we have seen in untangling this web of interactions are sure to continue at a breathtaking pace. J. Cell. Biochem. 118: 3569–3576, 2017. © 2017 Wiley Periodicals, Inc.
Deletion of a Distal RANKL Gene Enhancer Delays Progression of Atherosclerotic Plaque Calcification in Hypercholesterolemic Mice
Authors: Shamsuzzaman Sohel , Onal Melda , St John Hillary C. , Pike J. Wesley
Published: April 2017

Receptor activator of NF‐κB ligand (RANKL) is a TNF‐like cytokine which mediates diverse physiological functions including bone remodeling and immune regulation. RANKL has been identified in atherosclerotic lesions; however, its role in atherosclerotic plaque development remains elusive. An enhancer located 75 kb upstream of the murine Rankl gene's transcription start site designated D5 is important for its calciotropic hormone‐ and cytokine‐mediated expression. Here, we determined the impact of RANKL levels in atherosclerotic plaque development in the D5 enhancer‐null (D5−/−) mice in an atherogenic Apoe−/− background fed a high‐fat diet (HFD). Rankl mRNA transcripts were increased in aortic arches and thoracic aortae of Apoe−/− mice; however, this increase was blunted in Apoe−/−;D5−/− mice. Similarly, higher Rankl transcripts were identified in splenic T lymphocytes in Apoe−/− mice, and their levels were reduced in Apoe−/−;D5−/− mice. When analyzed by micro‐computed tomography (µCT), atherosclerotic plaque calcification was identified in six out of eight Apoe−/− mice, whereas only one out of eight Apoe−/−;D5−/− mice developed plaque calcification after 12 weeks of HFD. However, following 18 weeks of HFD challenge, all of Apoe−/− and Apoe−/−;D5−/− animals developed atherosclerotic plaque calcification. Likewise, atherosclerotic lesion sizes were site‐specifically reduced in the aortic arch of Apoe−/−;D5−/− mice at initial stage of atherosclerosis and this effect was diminished as atherosclerosis proceeded to a more advanced stage. Our data suggest that deletion of the RANKL D5 enhancer delays the progression of atherosclerotic plaque development and plaque calcification in hypercholesterolemic mice. This work provides important insight into RANKL's regulatory role in atherosclerosis. J. Cell. Biochem. 118: 4240–4253, 2017. © 2017 Wiley Periodicals, Inc.
A rapid solvent accessible surface area estimator for coarse grained molecular simulations
Authors: Wei Shuai , Brooks Charles L. , Frank Aaron T.
Published: April 2017

The rapid and accurate calculation of solvent accessible surface area (SASA) is extremely useful in the energetic analysis of biomolecules. For example, SASA models can be used to estimate the transfer free energy associated with biophysical processes, and when combined with coarse‐grained simulations, can be particularly useful for accounting for solvation effects within the framework of implicit solvent models. In such cases, a fast and accurate, residue‐wise SASA predictor is highly desirable. Here, we develop a predictive model that estimates SASAs based on
‐only protein structures. Through an extensive comparison between this method and a comparable method, POPS‐R, we demonstrate that our new method, Protein‐C
Solvent Accessibilities or PCASA, shows better performance, especially for unfolded conformations of proteins. We anticipate that this model will be quite useful in the efficient inclusion of SASA‐based solvent free energy estimations in coarse‐grained protein folding simulations. PCASA is made freely available to the academic community at https://github.com/atfrank/PCASA. © 2017 Wiley Periodicals, Inc.
Are induced fit protein conformational changes caused by ligand‐binding predictable? A molecular dynamics investigation
Authors: Gao Cen , Desaphy Jeremy , Vieth Michal
Published: April 2017

In this work, the ability of molecular dynamics simulations (MD) to prospectively predict regions of ligand binding sites that could undergo induced fit effects was investigated. Conventional MD was run on 39 apo structures (no ligand), and the resulting trajectories were compared to a set of 147 holo X‐ray structures (ligand‐bound). It was observed from the simulations, in the absence of the ligands, that structures exhibiting large residue conformational changes indicated higher likelihood of induced fit effects. Nevertheless, the simulation results did not perform better than using the normalized crystallographic structural factors as predictors of active‐site rigid residues (87% predictive power) and mobile residues (47% predictive power). While the simulations could not produce full active sites conformations similar to holo‐like states, it was found that the simulations could reproduce bound state conformations of individual residues. These results suggest potential issues in the use of unligated simulation frames directly for drug design applications such as ligand docking, and an overall caution in the use of protein flexibility in docking protocols should be emphasized. © 2017 Wiley Periodicals, Inc.
Modeling and Simulation of Pivotal Clinical Trials Using Linked Models for Multiple Endpoints in Chronic Obstructive Pulmonary Disease With Roflumilast
Authors: Facius Axel , Krause Andreas , Claret Laurent , Bruno Rene , Lahu Gezim
Published: April 2017

Roflumilast is a selective phosphodiesterase 4 inhibitor (PDE4i) for the treatment of severe chronic obstructive pulmonary disease (COPD). In 2 large phase 3 trials in a broader population of COPD patients (BY217/M2‐111, ClinicalTrials.gov: NCT00076089 and BY217/M2‐112, ClinicalTrials.gov: NCT00430729), treatment with roflumilast reduced the rate of exacerbations; however, the reduction did not reach statistical significance. Two linked dose‐response models for the primary (annualized COPD exacerbation counts) and secondary (change from baseline in forced expiratory volume in 1 second [FEV1]) end points were therefore developed to characterize and quantify effect sizes and the patient characteristics influencing them. The models showed that disease severity and bronchitis, particularly the severity of bronchitis expressed in cough‐and‐sputum scores, were good predictors of exacerbation rates and differential benefit of roflumilast in exacerbation reduction. The models were used to support the rational design of 2 phase 3 randomized, placebo‐controlled clinical trials (BY217/M2‐124, ClinicalTrials.gov: NCT00297102 and BY217/M2‐125, ClinicalTrials.gov: NCT00297115) by identifying the most appropriate patient population using clinical trial simulations. Model predictions for both end points were found to be highly accurate — as confirmed by the results from these trials, which led to the approval of roflumilast as the first oral PDE4i for the treatment of COPD in patients associated with chronic bronchitis and a history of exacerbations.
Cardiac troponin T and fast skeletal muscle denervation in ageing
Authors: Xu Zherong , Feng Xin , Dong Juan , Wang Zhong‐Min , Lee Jingyun , Furdui Cristina , Files Daniel Clark , Beavers Kristen M. , Kritchevsky Stephen , Milligan Carolanne , Jin Jian‐Ping , Delbono Osvaldo , Zhang Tan
Published: April 2017

Background

Ageing skeletal muscle undergoes chronic denervation, and the neuromuscular junction (NMJ), the key structure that connects motor neuron nerves with muscle cells, shows increased defects with ageing. Previous studies in various species have shown that with ageing, type II fast‐twitch skeletal muscle fibres show more atrophy and NMJ deterioration than type I slow‐twitch fibres. However, how this process is regulated is largely unknown. A better understanding of the mechanisms regulating skeletal muscle fibre‐type specific denervation at the NMJ could be critical to identifying novel treatments for sarcopenia. Cardiac troponin T (cTnT), the heart muscle‐specific isoform of TnT, is a key component of the mechanisms of muscle contraction. It is expressed in skeletal muscle during early development, after acute sciatic nerve denervation, in various neuromuscular diseases and possibly in ageing muscle. Yet the subcellular localization and function of cTnT in skeletal muscle is largely unknown.

Methods

Studies were carried out on isolated skeletal muscles from mice, vervet monkeys, and humans. Immunoblotting, immunoprecipitation, and mass spectrometry were used to analyse protein expression, real‐time reverse transcription polymerase chain reaction was used to measure gene expression, immunofluorescence staining was performed for subcellular distribution assay of proteins, and electromyographic recording was used to analyse neurotransmission at the NMJ.

Results

Levels of cTnT expression in skeletal muscle increased with ageing in mice. In addition, cTnT was highly enriched at the NMJ region—but mainly in the fast‐twitch, not the slow‐twitch, muscle of old mice. We further found that the protein kinase A (PKA) RIα subunit was largely removed from, while PKA RIIα and RIIβ are enriched at, the NMJ—again, preferentially in fast‐twitch but not slow‐twitch muscle in old mice. Knocking down cTnT in fast skeletal muscle of old mice: (i) increased PKA RIα and reduced PKA RIIα at the NMJ; (ii) decreased the levels of gene expression of muscle denervation markers; and (iii) enhanced neurotransmission efficiency at NMJ.

Conclusions

Cardiac troponin T at the NMJ region contributes to NMJ functional decline with ageing mainly in the fast‐twitch skeletal muscle through interfering with PKA signalling. This knowledge could inform useful targets for prevention and therapy of age‐related decline in muscle function.
An updated synthesis of [11C]carfentanil for positron emission tomography (PET) imaging of the μ‐opioid receptor
Authors: Blecha Joseph E. , Henderson Bradford D. , Hockley Brian G. , VanBrocklin Henry F. , Zubieta Jon‐Kar , DaSilva Alexandre F. , Kilbourn Michael R. , Koeppe Robert A. , Scott Peter J.H. , Shao Xia
Published: April 2017

[11C]Carfentanil ([11C]CFN) is a selective radiotracer for in vivo positron emission tomography imaging studies of the μ‐opioid system that, in our laboratories, is synthesized by methylation of the corresponding carboxylate precursor with [11C]MeOTf, and purified using a C2 solid‐phase extraction cartridge. Changes in the commercial availability of common C2 cartridges have necessitated future proofing the synthesis of [11C]CFN to maintain reliable delivery of the radiotracer for clinical imaging studies. An updated synthesis of [11C]CFN is reported that replaces a now obsolete purification cartridge with a new commercially available version and also substitutes the organic solvents used in traditional production methods with ethanol.
Intravoxel incoherent motion MRI for the differentiation of benign, intermediate, and malignant solid soft‐tissue tumors
Authors: Wu Haijun , Zhang Shuixing , Liang Changhong , Liu Hui , Liu Yanhui , Mei Yingjie , Liu Hongjun , Liu Zaiyi , Xu Fangping
Published: April 2017

Purpose

To determine the diagnostic potential of apparent diffusion coefficient (ADC) and intravoxel incoherent motion (IVIM)‐derived parameters for the differentiation of benign, intermediate, and malignant solid soft‐tissue tumors.

Materials and Methods

The Institutional Review Board approved this prospective study, and informed consent was obtained. IVIM imaging was performed in 64 patients including 44 benign, 6 intermediate, and 14 malignant solid soft‐tissue tumors at 1.5T. The IVIM parameters of the soft‐tissue tumors were assessed using the Kruskal–Wallis test. The diagnostic performance of the parameters was evaluated using receiver operating characteristic (ROC) analysis.

Results

The ADC and true diffusion coefficient (D) values of malignancies (1.28 ± 0.31, 1.06 ± 0.23 [×10−3 mm2/sec]) were significantly lower than those of intermediate (1.49 ± 0.54, 1.30 ± 0.50 [×10−3 mm2/sec]), or benign soft‐tissue tumors (1.62 ± 0.37, 1.36 ± 0.33 [×10−3 mm2/sec]) (P = 0.007 and P = 0.009, respectively). In the differential diagnosis of malignancies from benign tumors, ADC demonstrated the highest area under the curve (Az) value (Az = 0.793). The perfusion fraction (f) values of intermediate soft‐tissue tumors (8.41 ± 2.73) were significantly different from those of benign and malignant tumors (14.70 ± 5.37 [P = 0.002]; 14.44 ± 5.31 [P = 0.021]). f showed the highest Az value in differentiating intermediate from benign, and malignant soft‐tissue tumors (Az = 0.90, and Az = 0.833, respectively). The pseudodiffusion coefficient (D*) values of malignant soft‐tissue tumors (144.40 ± 24.88 [×10−3 mm2/sec]) were significantly higher than those of benign tumors (124.96 ± 26.24 [×10−3 mm2/sec]) (P = 0.019).

Conclusion

IVIM imaging may be helpful for differentiating benign, intermediate, and malignant solid soft‐tissue tumors.

Level of Evidence: 1

Technical Efficacy: Stage 2

J. Magn. Reson. Imaging 2017;46:1611–1618.
Raman optical activity of humanα‐synuclein in intrinsically disordered, micelle‐boundα‐helical, molten globule and oligomericβ‐sheet state
Authors: Mensch Carl , Konijnenberg Albert , Van Elzen Roos , Lambeir Anne‐Marie , Sobott Frank , Johannessen Christian
Published: April 2017

Alpha‐synuclein (α‐syn) is a 140 residue protein that plays a central role in Parkinson's disease and other neurological disorders. The precise function and pathological properties ofα‐syn remain however poorly understood. Whileα‐syn is considered to be a flexible and disordered protein under native conditions, its ability to adopt a variety of conformational ensembles depending on the environment is considered to be related to its pathology. Raman optical activity (ROA) is a chiroptical spectroscopic technique that is uniquely sensitive to the secondary structure of proteins in solution and was used here for the first time to study the different conformational ensembles ofα‐syn. In this paper, the Raman and ROA spectral characteristics of these different conformations ofα‐syn are investigated. We show that Raman and ROA spectroscopy are sensitive enough not only to detect transitions from a disordered to anα‐helical or aβ‐sheet rich ensemble but also to differentiate between theα‐helical forms of wild‐type and C‐terminal truncatedα‐syn 107. Using increasing concentrations of fluorinated alcohols, we induce the aggregation pathway ofα‐syn and identify a molten globule intermediate structure andβ‐sheet rich oligomers. Taken together, these results demonstrate the power of Raman and ROA spectroscopies for the structural elucidation of proteins that are challenging to characterise. Copyright © 2017 John Wiley & Sons, Ltd.
European cowpea landraces for a more sustainable agriculture system and novel foods
Authors: Carvalho Márcia , Bebeli Penelope J , Pereira Graça , Castro Isaura , Egea‐Gilabert Catalina , Matos Manuela , Lazaridi Efstathia , Duarte Isabel , Lino‐Neto Teresa , Ntatsi Georgia , Rodrigues Miguel , Savvas Dimitrios , Rosa Eduardo , Carnide Valdemar
Published: April 2017

BACKGROUND

Genetic diversity is fundamental to breeding programs and consequently has an important role in obtaining new varieties. To properly use the genetic diversity present in germplasm collections, a good knowledge of the agro‐morphological traits of each accession is needed. The aim of this study was to explore the production capacity of 24 cowpea landraces from southern Europe, through phenotypic characterization and evaluation in three different locations in Greece and Portugal.

RESULTS

Most qualitative parameters tested showed a high stability among the three locations. A wide difference was observed among the three locations with respect to number of days to flowering, ranging from 55 to 99 days. Quantitative traits showed a higher genotype × environment than genetic variance component. In general, an inverse relationship between σ2ge/σ2g ratio (where σ2ge is genotype × genotype interaction and σ2g is genotype impact) and heritability value was observed. Principal component analysis was able to group accessions based on their origin. The first two principal components explained 97.52% of variation, being the number of seeds per plant, plant height and seed protein content, the traits which contributed most to variability.

CONCLUSION

The results show that sufficient variation exists in different traits within landraces in the studied cowpea germplasm to pursue a breeding program. However, the quantitative traits showed a higher genotype × environment component. © 2017 Society of Chemical Industry
Study on Crosslinked Structure and Thermal Properties of Polymer Networks Based on Tung Oil and PVA with Different Catalytic Systems
Authors: Jianprasert Apichaya , Monvisade Pathavuth , Yamaguchi Masayuki
Published: April 2017

This work focuses on the effect of different catalytic systems on network structures and thermal properties of the polymer networks from poly(vinyl alcohol) (PVA) and Tung oil. The polymer networks based on Tung oil and PVA using potassium persulfate (KPS) as a thermal catalyst or KPS and sodium thiosulfate as a redox catalyst were performed at 60 °C and 80 °C. FTIR results confirmed that Tung oil could be crosslinked by both catalysts. Moreover, at 60 °C, it can be seen that the crosslinking reaction with the redox catalyst could occur better than with the thermal catalyst. To prove the crosslinking reaction of PVA in the polymer networks, water resistance of the polymer networks was also investigated. It was found that the PVA was successfully crosslinked by thermal catalyst but was not by redox catalyst. Besides, from this result, it could be suggested that, in the redox system, structure of the polymer networks was mainly formed by Tung oil. From DMA results, Tg of PVA with the thermal catalyst is higher than that with the redox catalyst because of the network formation of PVA in thermal catalytic system. While the Tg of Tung oil in the polymer networks with the redox catalyst is higher than that with the thermal catalyst. This is reasonable because the crosslinking reaction of Tung oil with the redox catalyst could easily occur better than with the thermal catalyst. Altogether, crosslink structure of Tung oil exhibited major influence on properties of PVA/Tung oil polymer network.
Unreactive Gel Networks as Versatile Confined Spaces for Enhanced Photoinduced Processes
Authors: Häring Marleen , Abramov Alex , Díaz Díaz David
Published: April 2017

Gel materials have been recognized as promising confined media to enhance photoinduced reactions of reactants that are physically embedded in the gel network. In particular, stimuli‐responsive supramolecular self‐assembled gels that are unreactive to light irradiation constitute versatile materials to enhance both unimolecular and bimolecular photoinduced processes (in comparison to those carried out in solution) such as dimerization, isomerization and redox reactions, including multistep mechanisms.
A Comparison of How Well Two Different Models of Thermo‐Setting Polymers Predict Their Thermo‐Mechanical Aspects
Authors: Lowe Chris , Taylor Ambrose
Published: April 2017

The output from a molecular model of a polyester melamine thermoset coating, generated using techniques developed for modelling biological systems, that attempts to predict the performance of free films in a tensile test, is compared to empirical results and the out‐put from a phenomenological model. The latter was constructed using standard equations used by engineers to predict the behaviour of polymers under various conditions from a set of parameters measured by Dynamic Mechanical Analysis. Both come close to predicting reality but a more rapid change in intermolecular forces with temperature, for the first model, would help it to achieve more accurate predictions. Associating some of the parameters of the phenomenological model with molecular mass and chain length may help improve the second model.
Hemichoreo‐hemibalism as a Manifestation of Central Nervous System Chronic Graft‐versus‐Host Disease
Authors: Enriquez‐Marulanda Alejandro , Sierra‐Ruiz Melibea , Jaramillo Francisco Javier , Escobar Luis Alberto , Granados Ana María , Rodríguez‐Rojas Lisa Ximena , Lees Andrew J. , Orozco Jorge Luis
Published: April 2017

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Bridging Type 2 Diabetes and Alzheimer's Disease: Assembling the Puzzle Pieces in the Quest for the Molecules With Therapeutic and Preventive Potential
Authors: de Matos Ana Marta , de Macedo Maria Paula , Rauter Amélia Pilar
Published: April 2017

Type 2 diabetes (T2D) and Alzheimer's disease (AD) are two age‐related amyloid diseases that affect millions of people worldwide. Broadly supported by epidemiological data, the higher incidence of AD among type 2 diabetic patients led to the recognition of T2D as a tangible risk factor for the development of AD. Indeed, there is now growing evidence on brain structural and functional abnormalities arising from brain insulin resistance and deficiency, ultimately highlighting the need for new approaches capable of preventing the development of AD in type 2 diabetic patients. This review provides an update on overlapping pathophysiological mechanisms and pathways in T2D and AD, such as amyloidogenic events, oxidative stress, endothelial dysfunction, aberrant enzymatic activity, and even shared genetic background. These events will be presented as puzzle pieces put together, thus establishing potential therapeutic targets for drug discovery and development against T2D and diabetes‐induced cognitive decline—a heavyweight contributor to the increasing incidence of dementia in developed countries. Hoping to pave the way in this direction, we will present some of the most promising and well‐studied drug leads with potential against both pathologies, including their respective bioactivity reports, mechanisms of action, and structure–activity relationships.
Assessment of TRMM data for precipitation measurement in Bangladesh
Authors: Tarek Mehedi Hasan , Hassan Adil , Bhattacharjee Joy , Choudhury Sayedul Hasan , Badruzzaman Abu Borhan Md.
Published: April 2017

Application of the Tropical Rainfall Measuring Mission (TRMM) can be an efficient method for precipitation measurement in Bangladesh. The TRMM was a joint US−Japan space programme used to measure tropical rainfall with spatial and temporal distribution. This study analyses the reliability of TRMM data by comparing them with the rain gauge data of Bangladesh Meteorological Department at 35 different locations. The comparison is made for the data from 1998 to 2010. Extensive analyses were performed on the basis of different temporal scales (daily, monthly, seasonal and yearly). Both datasets were compared for average, peak and total values. The correlation co‐efficient and bias of TRMM rainfall data with respect to rain gauge values were also determined. However, the rainfall products are also compared at the two most extreme elevation stations to observe the influence of station topography (if any). Results show that TRMM rainfall data closely match with rain gauge data for average values on an annual basis, and the correlation co‐efficient is found to be greater than 0.90. However, significant deviation is found for daily peak rainfall values. Again, a seasonal comparison shows that the TRMM data outputs match with station data except during the dry season. The rainfall data at the highest and lowest elevations show that the TRMM data follow a similar trend to the station data but they underestimate the value to some extent, especially during the wet season. Finally, it is inferred that the TRMM data are reliable in estimating the average rainfall in Bangladesh for hydrological analyses of watersheds.
Generative Topographic Mapping of Conformational Space
Authors: Horvath Dragos , Baskin Igor , Marcou Gilles , Varnek Alexandre
Published: April 2017

Herein, Generative Topographic Mapping (GTM) was challenged to produce planar projections of the high‐dimensional conformational space of complex molecules (the 1LE1 peptide). GTM is a probability‐based mapping strategy, and its capacity to support property prediction models serves to objectively assess map quality (in terms of regression statistics). The properties to predict were total, non‐bonded and contact energies, surface area and fingerprint darkness. Map building and selection was controlled by a previously introduced evolutionary strategy allowed to choose the best‐suited conformational descriptors, options including classical terms and novel atom‐centric autocorrellograms. The latter condensate interatomic distance patterns into descriptors of rather low dimensionality, yet precise enough to differentiate between close favorable contacts and atom clashes. A subset of 20 K conformers of the 1LE1 peptide, randomly selected from a pool of 2 M geometries (generated by the S4MPLE tool) was employed for map building and cross‐validation of property regression models. The GTM build‐up challenge reached robust three‐fold cross‐validated determination coefficients of Q2=0.7…0.8, for all modeled properties. Mapping of the full 2 M conformer set produced intuitive and information‐rich property landscapes. Functional and folding subspaces appear as well‐separated zones, even though RMSD with respect to the PDB structure was never used as a selection criterion of the maps.
Free‐breathing liver fat quantification using a multiecho 3D stack‐of‐radial technique
Authors: Armstrong Tess , Dregely Isabel , Stemmer Alto , Han Fei , Natsuaki Yutaka , Sung Kyunghyun , Wu Holden H.
Published: April 2017

Purpose

The diagnostic gold standard for nonalcoholic fatty liver disease is an invasive biopsy. Noninvasive Cartesian MRI fat quantification remains limited to a breath‐hold (BH). In this work, a novel free‐breathing 3D stack‐of‐radial (FB radial) liver fat quantification technique is developed and evaluated in a preliminary study.

Methods

Phantoms and healthy subjects (n = 11) were imaged at 3 Tesla. The proton‐density fat fraction (PDFF) determined using FB radial (with and without scan acceleration) was compared to BH single‐voxel MR spectroscopy (SVS) and BH 3D Cartesian MRI using linear regression (correlation coefficient ρ and concordance coefficient ρc) and Bland‐Altman analysis.

Results

In phantoms, PDFF showed significant correlation (ρ > 0.998, ρc > 0.995) and absolute mean differences < 2.2% between FB radial and BH SVS, as well as significant correlation (ρ > 0.999, ρc > 0.998) and absolute mean differences < 0.6% between FB radial and BH Cartesian. In the liver and abdomen, PDFF showed significant correlation (ρ > 0.986, ρc > 0.985) and absolute mean differences < 1% between FB radial and BH SVS, as well as significant correlation (ρ > 0.996, ρc > 0.995) and absolute mean differences < 0.9% between FB radial and BH Cartesian.

Conclusion

Accurate 3D liver fat quantification can be performed in 1 to 2 min using a novel FB radial technique. Magn Reson Med 79:370–382, 2018. © 2017 International Society for Magnetic Resonance in Medicine.
Frequency response as a surrogate eigenvalue problem in topology optimization
Authors: Andreassen Erik , Ferrari Federico , Sigmund Ole , Diaz Alejandro R.
Published: April 2017

This article discusses the use of frequency response surrogates for eigenvalue optimization problems in topology optimization that may be used to avoid solving the eigenvalue problem. The motivation is to avoid complications that arise from multiple eigenvalues and the computational complexity associated with computation of eigenvalues in very large problems. Copyright © 2017 John Wiley & Sons, Ltd.
Note: Engineering of crosslinked poly(isothiouronium methylstyrene) microparticles of narrow size distribution for antibacterial applications
Authors: Cohen Sarit , Laitman Inna , Tennenbaum Tammy Lublin , Natan Michal , Banin Ehud , Margel Shlomo
Published: April 2017

The article from this special issue was previously published in Polymers for Advanced Technologies, Volume 28, Issue 2, 2017. For completeness we are including the title page of the article below. The full text of the article can be read in Issue 28:2 on Wiley Online Library: http://onlinelibrary.wiley.com/doi/10.1002/pat.3873/full
Improvement in treatment abandonment in pediatric patients with cancer in Guatemala
Authors: Alvarez Elysia , Seppa Midori , Rivas Silvia , Fuentes Lucia , Valverde Patricia , Antillón‐Klussmann Federico , Castellanos Mauricio , Sweet‐Cordero E. Alejandro , Messacar Kevin , Kurap John , Bustamante Marisol , Howard Scott C. , Efron Bradley , Luna‐Fineman Sandra
Published: April 2017

Background

Treatment refusal and abandonment are major causes of treatment failure for children with cancer in low‐ and middle‐income countries (LMICs), like Guatemala. This study identified risk factors for and described the intervention that decreased abandonment.

Methods

This was a retrospective study of Guatemalan children (0–18 years) with cancer treated at the Unidad Nacional de Oncología Pediátrica (UNOP), 2001–2008, using the Pediatric Oncology Network Database. Treatment refusal was a failure to begin treatment and treatment abandonment was a lapse of 4 weeks or longer in treatment. The impact of medicina integral, a multidisciplinary psychosocial intervention team at UNOP was evaluated. Cox proportional hazards analysis identified the effect of demographic and clinical factors on abandonment. Kaplan–Meier analysis estimated the survival.

Results

Of 1,789 patients, 21% refused or abandoned treatment. Abandonment decreased from 27% in 2001 to 7% in 2008 following the implementation of medicina integral. Factors associated with increased risk of refusal and abandonment: greater distance to the centre (P < 0.001), younger age (P = 0.017) and earlier year of diagnosis (P < 0.001). Indigenous race/ethnicity (P = 0.002) was associated with increased risk of abandonment alone. Abandonment correlated with decreased overall survival: 0.57 ± 0.02 (survival ± standard error) for those who completed therapy versus 0.06 ± 0.02 for those who abandoned treatment (P < 0.001) at 8.3 years.

Conclusion

This study identified distance, age, year of diagnosis and indigenous race/ethnicity as risk factors for abandonment. A multidisciplinary intervention reduced abandonment and can be replicated in other LMICs.
A simple imaging‐based technique for quantifying haze and transmittance of materials
Authors: Busato Stephan , Perevedentsev Aleksandr
Published: April 2017

We present a simple technique for measuring haze and transmittance of materials that uses inexpensive and virtually ubiquitous hardware, and is based on photographic imaging of at least partially transparent samples backlit through a “knife‐edge” array mask. Its performance is tested for a series of injection‐molded polyethylene plaques containing a varied fraction of a clarifying agent, as well as commercially available ASTM D1003 haze standards. The results show excellent agreement with those obtained using a conventional haze meter adhering to the ASTM D1003 standard and, moreover, are specifically indicative of the overall contact haze—a desirable feature for characterization of, for instance, commodity plastics for packaging applications. Notably, the quantification of haze is based explicitly on the reduction of perceived image quality of objects viewed through a material sample and, hence, quantifies haze in a more practically useful way compared with the, arguably, more arbitrary ASTM definition. The demonstrated technique can be further used to extract more sophisticated, local information on the microstructure and optical properties, which cannot be obtained with a conventional haze meter. Its potential for being standardized, as well as additional modifications that can enable improved performance, are also discussed. POLYM. ENG. SCI., 58:345–352, 2018. © 2017 Society of Plastics Engineers
Tailoring polymers through interplay of ligands within precatalysts: 8‐(Nitro/benzhydryl‐arylimino)‐7,7‐dimethyl‐5,6‐dihydroquinolylnickel halides in ethylene polymerization
Authors: Huang Chuanbing , Zeng Yanning , Flisak Zygmunt , Zhao Zhijuan , Liang Tongling , Sun Wen‐Hua
Published: April 2017

A series of 8‐(nitro/benzhydryl‐substituted arylimino)‐7,7‐dimethyl‐5,6‐dihydroquinolines and the corresponding nickel halide complexes were synthesized and characterized. Molecular structures of representative nickel complexes were determined by single crystal X‐ray diffraction, showing the dinuclear dimers with distorted square‐pyramidal geometry around the nickel center. The binding energies determined by X‐ray photoelectron spectroscopy (XPS) indicate the effective coordination between the sp2‐nitrogen and nickel atoms as well as the influence of both the halogen ligands and the substituents within dihydroquinolines on the strength of the NiN bond. Ethylene polymerization with the nickel precatalysts in presence of either methylaluminoxane or diethylaluminum chloride was explored in detail. For the complexes containing the nitro substituent within the organic ligand, the catalytic activity is inversely proportional to the electron density around the nickel core determined by XPS; such phenomenon is consistent with the conclusion of the computational study stating that the activity of precatalysts is correlated with the net charge on the metal center. In the polymerization process, unimodal and branched polyethylenes containing vinyl or vinylene groups were obtained. The nickel precatalysts bearing bulky benzhydryl within the organic ligand as well as bromide rather than chloride attached to the nickel atom produce polymers with relatively large amount of vinylene groups. © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2017, 55, 2071–2083
Dependence of electrical performance on structural organization in polymer field effect transistors
Authors: Bittle Emily G. , Ro Hyun Wook , Snyder Chad R. , Engmann Sebastian , Kline R. Joseph , Zhang Xinran , Jurchescu Oana D. , DeLongchamp Dean M. , Gundlach David J.
Published: April 2017

Organic semiconductors (OSCs) are strong contenders for use in printed, flexible electronics. Although organic electronic materials have been studied for many years, the physics of charge transport is still under investigation. This is in part due to variability resulting from the large variety of molecules that can be synthesized and inconsistency in electrical characterization due to device and processing conditions. Molecular ordering in OSCs is known to alter the charge transport characteristics and attention to long range and short range ordering provides clues as to the nature of transport pathways. Here, we study ordered regioregular poly(3‐hexylthiophene‐2,5‐diyl) films carefully prepared to obtain a set of three samples with incrementally increasing order on identical transistor architectures. Ordering was characterized using a variety of short and long range techniques to probe the coherence and number of crystallites formed during processing, and the correlation between these different measures of order are quantified. We observe three changes in transistor behavior that show a shift from non‐ideal to more textbook‐like characteristics with increasing order: reduction of the contact resistance, shift to field‐independent mobility, and a shift from a diode‐like (S‐shaped) to linear response at low lateral fields. © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2017, 55, 1063–1074
Theoretical study on the translocation of partially charged polymers through nanopore
Authors: Wu Fan , Yang Xiao , Luo Meng‐Bo
Published: April 2017

The translocation time τ of partially charged polymers through a neutral nanopore is calculated using Fokker–Planck equation with adsorbing–adsorbing boundary conditions. For the polymer with one charged monomer, we find that τ is dependent on the position of the charged monomer and on the magnitude of the driving force f inside the nanopore. When the charge is located at the front half of the polymer chain, τ is larger than that of neutral polymer and increases with f. When the charge is located at the back half, it is smaller than that of the neutral polymer and decreases with increasing f. We have also studied the behavior of a symmetrical polymer with two like charges located symmetrically in the chain and that of an asymmetrical polymer with two unlike charges. Moreover, we have calculated the translocation time for a general condition of polymer with two randomly distributed charges. All results show that τ is dependent on the positions of charges in the polymer chain and on the magnitude of the driving force. The results can be explained qualitatively by the free‐energy landscape of polymer translocation. © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2017, 55, 1017–1025
Structural rearrangement and stiffening of hydrophobically modified supramolecular hydrogels during thermal annealing
Authors: Wang Chao , Wiener Clinton G. , Yang Yiming , Weiss R. A. , Vogt Bryan D.
Published: April 2017

Dynamic crosslinks formed by thermoreversible associations provide an energy dissipation mechanism to toughen hydrogels. However, the details of the organization of these crosslinks impact the hydrogel properties through constraints on the network chain conformation. The physical crosslinks generated by hydrophobic association of the 2‐(N‐ethylperfluorooctane‐sulfonamido)ethyl methacrylate (FOSM) groups in a random copolymer ofN,N‐dimethylacrylamide (DMA) and FOSM provide a simple system to investigate how the hydrogel structure (as determined from small angle neutron scattering impacts the mechanical properties of the hydrogel. The initial hydration of the copolymer at 25 °C leads to a kinetically trapped structure with large‐scale heterogeneities. Heating the hydrogel at 60 °C, which is above the glass transition temperature for the FOSM domains, allows the hydrogel structure to rearrange to reduce the density of network defects and the structural heterogeneities. That effectively increases the crosslink density of the network, which stiffens the hydrogel and decreases the swelling at equilibrium at 25 °C. The processing history determines how the hydrophobes aggregate to form the physically crosslinked network, whose structure defines the mechanical properties of these hydrogels. © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys.2017,55, 1036–1044
Robust state estimation for wireless sensor networks with data‐driven communication
Authors: Liu Huabo , Wang Dongqing
Published: April 2017

Robust state estimation problem for wireless sensor networks composed of multiple remote sensor nodes and a fusion node is investigated subject to a limitation on the communication rate. An analytical robust fusion estimator based on a data‐driven transmission strategy is derived to save the sensor energy consumption and reduce the network traffic congestion. The conditions guaranteeing the uniform boundedness of estimation errors of the robust fusion estimator are investigated. Numerical simulations are provided to show the effectiveness of the proposed approach. Copyright © 2017 John Wiley & Sons, Ltd.
Facile Large‐Scale Synthesis of Nanoscale Fayalite, α‐Fe2SiO4
Authors: Chang Qiang , Zhang Chenghua , Liu Chengwei , Li Ke , Yun Yifeng , Cheruvathur Ajin V. , Yang Yong , Li Yongwang
Published: April 2017

Fayalite has been found various applications in many fields. However, it is scarce in Earth's crust. Most of the preparation methods reported earlier are slightly rigorous or complicated and mainly used for preparing large crystal or single crystal fayalite. Because of the potential applications in the field of functional materials and catalysis, nanoscale fayalite would be interesting and attractive. Herein we designed a new method to synthesize nanoscale α‐Fe2SiO4 via a H2‐assisted gas‐solid reaction. We have used three different approaches based on the above method. The highly dispersed precursor, which was prepared by a continuous co‐precipitation method, was heated to a phase‐transition temperature (∼600 °C) under H2 atmosphere to synthesize nanoscale α‐Fe2SiO4. The fayalites were characterized by XAD, XAS and FT‐IR. Comparing with the earlier reported methods, our method largely reduces the reaction temperature, and facilitates large scale synthesis of nanoscale fayalite. It is found that the well distribution of Fe−O and Si−O domains in a nanometer scale plays an important role in the preparation.
Measuring Self‐Association of Pt Complexes by 195Pt NMR
Authors: Suleymanova Alfiya F. , Eltsov Oleg S. , Kozhevnikov Dmitry N. , Lantushenko Anastasia O. , Evstigneev Maxim P. , Kozhevnikov Valery N.
Published: April 2017

A highly soluble neutral cyclometallated Pt complex of C N N type was prepared and its self‐aggregation in CDCl3 solution was studied by NMR dilution method. It was shown that 195Pt NMR can be used to quantify aggregation and therefore be potentially applied to many other Pt complexes. Two‐dimensional HMBC 1H‐195Pt technique increases sensitivity of experiment and allowed recording 195Pt chemical shift values at concentration as low as 1 mM and it was observed that opposite to shielding of aromatic protons, Pt nucleus is deshielded upon increase of concentration.
Interorganizational Imitation and Acquisitions of High‐tech Ventures
Authors: Ozmel Umit , Reuer Jeffrey J. , Wu Cheng‐Wei
Published: April 2017

Research summary: This article shows that there is a positive association between the changes in the number of prior acquisitions or the changes in the prominence of prior acquirers within the focal venture's subfield and the venture's likelihood to be acquired. Results are in line with the existence of frequency‐ and trait‐based imitation in acquisitions targeting tech ventures. More importantly, these positive associations are more pronounced when (a) exogenous technological uncertainty within the venture's subfield increases and (b) there are significant differences between the focal venture's and acquirer's technological resources. Our findings are in accord with the suggestion that uncertainty in the technology domain is an important boundary condition in moderating the extent of imitation in technology acquisitions. We also discuss alternative explanations and implications.

Managerial summary: The findings of this article suggest that when deciding whether or not to acquire a technology venture (i.e., startup company in a high‐tech industry), managers infer information by observing other acquisitions in the venture's subfield to make assessments about the underlying value of the potential targets. We also find that receiving some informational cues from previous acquisitions would be more useful when there is high technological uncertainty in the potential target's subfield about which technologies will be dominant, and when the potential acquirer and the tech venture operate in dissimilar technological areas. This article shows that imitation can be one way to deal with decision‐making under uncertainty when making acquisition decisions in high‐tech environments. Copyright © 2017 John Wiley & Sons, Ltd.
Systems‐of‐systems modeling using a comprehensive viewpoint‐based SysML profile
Authors: Mori Marco , Ceccarelli Andrea , Lollini Paolo , Frömel Bernhard , Brancati Francesco , Bondavalli Andrea
Published: April 2017

In recent years, more and more efforts have been devoted in supporting the design of systems‐of‐systems (SoS). Designing such systems is a multidisciplinary problem which involves considering emergent phenomena, assuring the achievement of dependability/security requirements, guaranteeing system responsiveness, and supporting dynamicity/evolution and multicriticality of provided services. A first step towards a viable design approach is to provide a conceptual model of SoS which captures SoS concepts, and their interrelationships aiming at enhancing the understandability of SoS to stakeholders and providing the basis for further automated analysis. In this context, the AMADEOS European project is bringing together researchers and practitioners to provide the support to design SoS starting from the definition of a domain specific ontology serving as a vocabulary for SoS. Our contribution consists in the modeling of the key SoS concepts and relationships defined in AMADEOS adopting a systems modeling language visual modeling language. We propose a systems modeling language profile for SoS, and we show its applicability in a Smart Grid scenario. We show how to use the profile in a model‐driven engineering process to support different types of analyses, and we discuss how to integrate the profile in a user‐friendly model‐driven engineering tool for SoS rapid modeling, validation, code‐generation, and simulation.
Effects of Bainitic Phase on Mechanical Properties of Bainite−Aided Multiphase Steels
Authors: Apimonton Chanakarn , Sungthong Chaninee , Luksanayam Siwaphan , Suranuntchai Surasak , Uthaisangsuk Vitoon
Published: April 2017

Advanced high strength steels play an important role in the automotive industry. However, they still show inferior formability such as low stretch−flangeability. Therefore, in this work, various heat treatment processes are performed for generating multiphase steels with enhanced mechanical and forming behavior. The bainitic phase with different amounts is included in dual phase (DP) steels by controlling oil−quenching temperatures. In other steels, varying bainitic transformation temperatures are applied. Microstructures and phase fractions of the investigated multiphase (MP) steels are characterized by optical and scanning electron microscope. Tensile test, hole expansion test, and micro−hardness measurement are carried out for the steel sheets. It is found that increased oil temperature leads to larger amount of bainite occurred in the DP steels. The bainite−aided DP steels exhibit lower strength, but considerably higher elongation, improved hole expansion ratio, and larger damage tolerance value. In case of MP steels with retained austenite, increasing the bainitic transformation temperature causes ferrite in the steels to be replaced by bainite and retained austenite with various amounts. It seems that the MP steels with higher bainitic phase fraction show deteriorated edge–flangeability and fracture resistance.