bluuebunny/crossref_metadata_2025 huggingface dataset:
Synthesis of 1,1′‐ and 2,2′‐Bicarbazole Alkaloids by Iron(III)‐Catalyzed Oxidative Coupling of 2‐ and 1‐Hydroxycarbazoles
Authors: Brütting Christian , Fritsche Raphael F. , Kutz Sebastian K. , Börger Carsten , Schmidt Arndt W. , Kataeva Olga , Knölker Hans‐Joachim
Published: October 2017

We describe the synthesis of 1,1′‐ and 2,2′‐bicarbazoles by oxidative homocoupling of 2‐ and 1‐hydroxycarbazoles. The oxidative coupling using catalytic amounts of F16PcFe can be applied to both groups of substrates. Although F16PcFe generally provides the best yields for the synthesis of 1,1′‐bicarbazoles, di‐tert‐butyl peroxide affords better results for the 2,2′‐bicarbazoles. In our study, we have achieved the first syntheses of the biscarbalexines A–C, bisglybomine B, 2,2′‐dihydroxy‐7,7′‐dimethoxy‐3,3′‐dimethyl‐1,1′‐bicarbazole, bispyrayafoline C, and bisisomahanine. The iron‐catalyzed coupling of koenigine led to an improved synthesis of 8,8′′‐biskoenigine and afforded an unprecedented decacylic product. Oxidative coupling of 1‐hydroxycarbazoles led to bisclausenol, and to the first total syntheses of bismurrayafoline B and D.
Numerical Modelling of Braiding and Meandering Instabilities in Gravity‐Driven Liquid Rivulets
Authors: Sebastia‐Saez Daniel , Reina Tomas Ramirez , Arellano‐Garcia Harvey
Published: October 2017

Rivulet instabilities appear in many engineering applications. In absorption equipment, they affect the interface area available for mass transfer, and thus, reducing the efficiency. Here, computational fluid dynamics are used to reproduce the meanders and braids in rivulets flowing down an inclined channel. Fast oscillations of the meander (f = 5.6 Hz) are observed at low flow rates. At greater flow rates, an analysis of the transversal velocity in the retraction waves shows the effect of the surface tension, which causes the braiding phenomenon, and thus, the reduction in gas‐liquid interface area.
Improved survival of patients with melanoma brain metastases in the era of targeted BRAF and immune checkpoint therapies
Authors: Sloot Sarah , Chen Yian A. , Zhao Xiuhua , Weber Jamie L. , Benedict Jacob J. , Mulé James J. , Smalley Keiran S. , Weber Jeffrey S. , Zager Jonathan S. , Forsyth Peter A. , Sondak Vernon K. , Gibney Geoffrey T.
Published: October 2017

BACKGROUND

The development of brain metastases is common for systemic treatment failure in patients with melanoma and has been associated with a poor prognosis. Recent advances with BRAF and immune checkpoint therapies have led to improved patient survival. Herein, the authors evaluated the risk of de novo brain metastases and survival among patients with melanoma brain metastases (MBM) since the introduction of more effective therapies.

METHODS

Patients with unresectable AJCC stage III/IV melanoma who received first‐line systemic therapy at Moffitt Cancer Center between 2000 and 2012 were identified. Data were collected regarding patient characteristics, stage of disease, systemic therapies, MBM status/management, and overall survival (OS). The risk of de novo MBM was calculated using a generalized estimating equation model and survival comparisons were performed using Kaplan‐Meier and Cox proportional analyses.

RESULTS

A total of 610 patients were included, 243 of whom were diagnosed with MBM (40%). Patients with MBM were younger, with a lower frequency of regional metastasis. No significant differences were noted with regard to sex, BRAF status, or therapeutic class. The risk of de novo MBM was found to be similar among patients treated with chemotherapy, biochemotherapy, BRAF‐targeted therapy, ipilimumab, and anti‐programmed cell death protein 1/programmed death‐ligand 1 regimens. The median OS of patients with MBM was significantly shorter when determined from the time of first regional/distant metastasis but not when determined from the time of first systemic therapy. The median OS from the time of MBM diagnosis was 7.5 months, 8.5 months, and 22.7 months, respectively, for patients diagnosed from 2000 to 2008, 2009 to 2010, and 2011 to the time of last follow‐up (P = .002).

CONCLUSIONS

Brain metastases remain a common source of systemic treatment failure. The OS for patients with MBM has improved significantly. Further research into MBM prevention is needed. Cancer 2018;124:297‐305. © 2017 American Cancer Society.
Encapsulating Co2P@C Core–Shell Nanoparticles in a Porous Carbon Sandwich as Dual‐Doped Electrocatalyst for Hydrogen Evolution
Authors: Yang Yuanyuan , Liang Xiongyi , Li Feng , Li Shuwen , Li Xinzhe , Ng Siu‐Pang , Wu Chi‐Man Lawrence , Li Rong
Published: October 2017

A highly efficient and pH‐universal hydrogen evolution reaction (HER) electrocatalyst with a sandwich‐architecture constructed using zero‐dimensional N‐ and P‐dual‐doped core–shell Co2P@C nanoparticles embedded into a 3 D porous carbon sandwich (Co2P@N,P‐C/CG) was synthesized through a facile two‐step hydrothermal carbonization and pyrolysis method. The interfacial electron transfer rate and the number of active sites increased owing to the synergistic effect between the N,P‐dual‐doped Co2P@C core–shell and sandwich‐nanostructured substrates. The presence of a high surface area and large pore sizes improved the mass‐transfer dynamics. This nanohybrid showed remarkable electrocatalytic activity toward the HER in a wide pH range with good stability. The computational study and experiments revealed that the carbon atoms close to the N and P dopants on the shell of Co2P@N,P‐C were effective active sites for HER catalysis and that both Co2P and the N,P dopants gave rise to an optimized binding free energy of H on the active sites.
Comparison of two photographic methodologies for collecting and analyzing the condition of coral reef ecosystems
Authors: Bryant D. E. P. , Rodriguez‐Ramirez A. , Phinn S. , González‐Rivero M. , Brown K. T. , Neal B. P. , Hoegh‐Guldberg O. , Dove S.
Published: October 2017

Coral reefs are declining rapidly in response to unprecedented rates of environmental change. Rapid and scalable measurements of how benthic ecosystems are responding to these changes are critically important. Recent technological developments associated with the XL Catlin Seaview Survey have begun to provide high‐resolution 1‐m2 photographic quadrats of ~1.8–2 km of coral reefs at 10 m depth by using a semi‐autonomous image collection SeaView II camera system (SVII). The rapid collection of images by SVII can result in images being taken at a variable distance (1–2 m) from the substrate as well as having natural light variability between images captured. This variability can affect the quality of taxonomic resolution archived from photographic quadrats captured by SVII. Conventional approaches for taking photographic quadrats of coral reefs involve taking images from a fixed distance with the use of artificial light. These methods often provide images that enable high taxonomic resolution, but are typically used to cover areas of 50–150 m. Here, we select key metrics associated with coral reef condition from a functional perspective to contrast how much is lost in terms of association and agreement from image annotations using SVII images (1‐m2 photoquadrats) compared to conventional methods, capturing 0.5‐m2 photoquadrats using a digital single lens reflex camera from a fixed height of 0.5 m above the benthos. Comparisons were made over the same 50‐m linear transects at 15 sites in the Maldives. Photoquadrats were manually analyzed using an online image annotation tool and image repository called coral net with 25 randomly placed dots per 0.5 m2 of a quadrat. Our results reveal high levels of correlation and agreement between methods when measuring the abundance of hard corals as a functional group and individual labels, which make up hard corals as a functional group. These results demonstrate the two methods are comparable when measuring functional groups and coral communities on coral reefs. Therefore, involving rapid semi‐automated technologies that maximize data collection for monitoring coral reefs does not necessarily imply that taxonomic resolution is compromised. This insight has important ramifications for detecting important changes in coral reef condition, such as a decline in coral cover or shifts in benthic community composition.
Two Sustainability Epistemologies in the Marketization of a Natural Resource
Authors: Säwe Filippa , Hultman Johan
Published: October 2017

The normative implications of sustainable development mean that different understandings of how sustainability should be achieved will either facilitate or put at risk different values associated with economic, environmental and social aspects of sustainability. By a qualitative analysis of Swedish fishery legislation documents, we analyse and outline the consequences of two different and competing sustainability epistemologies: a top‐down system understanding and a bottom‐up experiential understanding. To define these two epistemologies, the case study adopts discourse analysis on one fishery law and one fishery regulation proposal, and the remittance answers to these documents. We demonstrate how a top‐down system approach shapes social reality according to its own logic of efficiency, and that pre‐defined principles of economic optimization prevail over social experience and continuity. We conclude that qualitative analysis holds promise to expand the understanding of the premises and consequences of alternative environmental governance trajectories due to its ability to uncover social constructions of meaning. Copyright © 2017 John Wiley & Sons, Ltd and ERP Environment
Enantioselective 1,3‐Dipolar Cycloaddition Reactions of C‐Carboxy Ketonitrones and Enals with MacMillan Catalysts: Evidence of a Nonconcerted Mechanism
Authors: Ben Ayed Kawther , Laurent Mathieu Y. , Martel Arnaud , Selim Khalid B. , Abid Souhir , Dujardin Gilles
Published: October 2017

Highly diastereo‐ and enantioselective 1,3‐dipolar cycloadditions between functional ketonitrones and β‐substituted enals are promoted by MacMillan imidazolidinium organocatalysts. A study of the reaction scope shows that high selectivities are conserved if the N‐protecting group or the ester function is varied. However, the reaction is sensitive to steric interactions with the C substituent of the nitrone. In all cases, the reaction proceeds with high exo selectivity. In most cases, a third diastereomer, incompatible with a concerted mechanism, was also observed, albeit in minute amounts. DFT calculations suggest that the cycloaddition proceeds in a nonconcerted fashion by an initial oxa‐Michael‐type addition of the nitrone to the double bond followed by a cyclization. This mechanism explains the formation of the observed minor diastereomers. In addition, the diastereo‐ and enantioselectivities of the reaction were shown to be intermediately thermodynamically controlled, and the diastereomeric ratio is modulated by the kinetics of iminium hydrolysis.
Population impacts of free‐ranging domestic cats on mainland vertebrates
Authors: Loss Scott R , Marra Peter P
Published: October 2017

Domestic cats (Felis catus) have contributed to at least 63 vertebrate extinctions, pose a major hazard to threatened vertebrates worldwide, and transmit multiple zoonotic diseases. On continents and large islands (collectively termed “mainlands”), cats are responsible for very high mortality of vertebrates. Nevertheless, cat population management is traditionally contentious and usually involves proving that cats reduce prey population sizes. We synthesize the available evidence of the negative effects of cats on mainland vertebrates. More than a dozen observational studies, as well as experimental research, provide unequivocal evidence that cats are capable of affecting multiple population‐level processes among mainland vertebrates. In addition to predation, cats affect vertebrate populations through disease and fear‐related effects, and they reduce population sizes, suppress vertebrate population sizes below their respective carrying capacities, and alter demographic processes such as source–sink dynamics. Policy discussions should shift from requiring “proof of impact” to a precautionary approach that emphasizes evidence‐driven management to reduce further impacts from outdoor cats.
A numerical study on the feasibility of evaluating CO2injection wellbore integrity through casing deformation monitoring
Authors: Li Yurong , Nygaard Runar
Published: October 2017

Distributed sensing technologies have been increasingly used for downhole monitoring in the oil field in recent years. A casing deformation monitoring system based on distributed strain sensors has been developed and proposed for wellbore integrity monitoring. However, due to the lack of field data on casing deformation induced by various exploration and development activities, the relationship between casing deformation and wellbore integrity remains unclear. To study the feasibility of evaluating short‐term CO2injection wellbore integrity through casing deformation monitoring, a staged finite element analysis is conducted for an existing well in the Weyburn field to study the relationship between casing deformation and wellbore integrity during CO2injection. The model is generated with HypermeshTMand the analysis is conducted with AbaqusTM. The staged finite element model applies loads and materials in multiple steps to replicate the actual drilling process. The wellbore stress, casing strain, and interface gap distance change at the surface casing shoe and production casing shoe are calculated. A parametric study is also conducted to study the effect of various parameters on CO2injection wellbore integrity in the Weyburn field. The result shows that the casing deformation can be correlated to the wellbore integrity by cement expansion/shrinkage through its effect on the interface gap distance change and the stress difference between wellbore components induced by CO2injection. © 2017 Society of Chemical Industry and John Wiley & Sons, Ltd.
Dendrites, deep learning, and sequences in the hippocampus
Authors: Bhalla Upinder S.
Published: October 2017

The hippocampus places us both in time and space. It does so over remarkably large spans: milliseconds to years, and centimeters to kilometers. This works for sensory representations, for memory, and for behavioral context. How does it fit in such wide ranges of time and space scales, and keep order among the many dimensions of stimulus context? A key organizing principle for a wide sweep of scales and stimulus dimensions is that of order in time, or sequences. Sequences of neuronal activity are ubiquitous in sensory processing, in motor control, in planning actions, and in memory. Against this strong evidence for the phenomenon, there are currently more models than definite experiments about how the brain generates ordered activity. The flip side of sequence generation is discrimination. Discrimination of sequences has been extensively studied at the behavioral, systems, and modeling level, but again physiological mechanisms are fewer. It is against this backdrop that I discuss two recent developments in neural sequence computation, that at face value share little beyond the label “neural.” These are dendritic sequence discrimination, and deep learning. One derives from channel physiology and molecular signaling, the other from applied neural network theory ‐ apparently extreme ends of the spectrum of neural circuit detail. I suggest that each of these topics has deep lessons about the possible mechanisms, scales, and capabilities of hippocampal sequence computation.
GenIce: Hydrogen‐Disordered Ice Generator
Authors: Matsumoto Masakazu , Yagasaki Takuma , Tanaka Hideki
Published: October 2017

GenIce is an efficient and user‐friendly tool to generate hydrogen‐disordered ice structures. It makes ice and clathrate hydrate structures in various file formats. More than 100 kinds of structures are preset. Users can install their own crystal structures, guest molecules, and file formats as plugins. The algorithm certifies that the generated structures are completely randomized hydrogen‐disordered networks obeying the ice rule with zero net polarization. © 2017 The Authors. Journal of Computational Chemistry Published by Wiley Periodicals, Inc.
Information on Gas‐Phase Diatomic Molecules from Magnetically Induced Current Densities
Authors: Alvarez‐Thon Luis , Mammino Liliana
Published: October 2017

Magnetically induced current densities are different for different types of chemical bonds, and may help highlight some of their characteristics and stress their main differences. The present work considers magnetically induced current densities in the bonds of diatomic molecules bonded by covalent bonds as well as the gas phase molecules of 1:1 ionic compounds, comparing the current strength values and visualizing current density maps. The results show clear‐cut differences for the different types of bonds (non‐polar covalent, polar covalent, and ionic), and can also be related to the extent of the covalent or ionic character of a bond. For ionic compounds, the results also show relevant differences depending on the charges of the ions and on their electron configuration (including significant effects from the presence of d electrons in the outer shell of the ions). The article presents and analyses the results in detail. It is concluded that the magnetically induced current densities contribute to the description and interpretation of chemical bonding in diatomic molecules. © 2017 Wiley Periodicals, Inc.
Headwaters to oceans: Ecological and biogeochemical contrasts across the aquatic continuum
Authors: Xenopoulos Marguerite A. , Downing John A. , Kumar M. Dileep , Menden‐Deuer Susanne , Voss Maren
Published: October 2017

While the disciplines of oceanography and limnology often operate in isolate, freshwater, estuarine, and marine ecosystems are intricately linked. The emphasis of this special issue for Limnology and Oceanography is on the aquatic continuum and the connectivity between aquatic ecosystems from headwater streams and inland waters, to coastal and marine systems. Changes in the transport and transformation of elements as well as ecological functions occur along this aquatic continuum. Assemblages of organisms change in a way that reflects the ecological and biogeochemical conditions of the aquatic gradient. Here, we highlight research progress in limnology and oceanography across the aquatic continuum and at the interfaces of headwaters to oceans. Contributions explored nutrient and carbon dynamics which included release, transportation, transformation, and stoichiometry from freshwaters to marine. The special issue also explored food web continua, including functional changes, biodiversity gradients, and photosynthesis and respiration comparisons among ecosystems at different points in the continuum. Rapid improvements in biomolecular techniques, use of long‐term datasets, applications of novel statistical methods, and improved upscaling methods can transform the way aquatic scientists are describing biological organisms and communities from freshwaters to oceans. One important conclusion is the recognition that anthropogenic activities such as invasive species and nutrient pollution trigger challenge the current concepts of aquatic continua including the river continuum concept, the land to ocean continuum, river to estuary systems, and the submarine groundwater discharge. Both limnologists and oceanographers have much to gain from exchanging information with one another, especially in light of global change.
Benthic N pathways in illuminated and bioturbated sediments studied with network analysis
Authors: Magri M. , Benelli S. , Bondavalli C. , Bartoli M. , Christian R. R. , Bodini A.
Published: October 2017

The regulation of benthic nitrogen (N) cycling by multiple interactions among bacteria, macrofauna, and primary producers is poorly understood. We hypothesized that a biodiverse benthic system should better exploit the benthic N‐availability and retain N than a simpler one. Retention occurs by avoiding losses both to the water column via increased recycling and to the atmosphere via decreased N2 fluxes and by limiting energy‐costly processes as N‐fixation. We also hypothesized that primary producer‐bacterial competition is reduced in the presence of macrofauna due to mobilization of refractory N pools. To this purpose, the effects of two bioturbators (the detritivorous Sparganophilus tamesis and the filter‐feeding Corbicula spp.) and two primary producer growth forms (the rooted macrophyte Vallisneria spiralis and microphytobenthos) on benthic N cycling were studied. An array of N‐processes were measured along a complexity gradient (from bare sediments to all combinations of the above mentioned organisms), and experimental outcomes were analyzed via ecological network analysis (ENA). This suite of algorithms, applied to the microscale, revealed differential partitioning of N fluxes among bare sediments (highest denitrification rates), sediments with macrofauna (highest recycling), and sediments with rooted plants (highest N‐fixation). N2 losses and inputs were significantly reduced when all components were represented, and N requirements by primary producers were to a large extent supported by the activity of macrofauna. Ecological interactions in biodiverse benthic systems promoted an efficient exploitation of sedimentary N pools, increased the coupling between recycling and uptake, and maximized N use efficiency at the expenses of losses and imports.
Water absorption and mold susceptibility of wood flour/polypropylene composites modified with silane‐wax emulsions
Authors: Chen Yu , Guo Xi , Peng Yao , Cao Jinzhen
Published: October 2017

Wood plastic composites can absorb water in exterior applications due to the hygroscopicity of wood flour (WF). The cycle of adsorption and desorption process causes damage to the interfacial bonding between WF and polymer matrix, which benefits the fungal attack. In this study, WF was, respectively, immersed with silane, wax emulsion, and their compound systems for modification at different concentrations (1, 2, and 4%, respectively). Then, the modified WF was mixed with polypropylene (PP) to produce WF/PP composites at mass ratio of 6:4. The water absorption and mold susceptibility of the composites against Aspergillus niger were investigated. The results showed that silane can improve the interfacial adhesion between WF and PP. The water uptake of WF/PP composites treated with 4% silane decreased by 6% compared with the control, and the average mold growth rating decreased from level 4 (mold covering of 75–100%) to level 1 (mold covering of 0–25%). The strong hydrophobicity of wax had a negative effect on the interfacial adhesion of the composites. Thus, composites modified with wax and silane‐wax compounds showed higher water uptake than the control. However, the mold resistance of composites was improved in these groups. POLYM. COMPOS., 40:141–148, 2019. © 2017 Society of Plastics Engineers
Using probability of drug use as independent variable in a register‐based pharmacoepidemiological cause‐effect study—An application of the reverse waiting time distribution
Authors: Hallas Jesper , Pottegård Anton , Støvring Henrik
Published: October 2017

Background

In register‐based pharmacoepidemiological studies, each day of follow‐up is usually categorized either as exposed or unexposed. However, there is an underlying continuous probability of exposure, and by insisting on a dichotomy, researchers unwillingly force a nondifferential misclassification into their analyses. We have recently developed a model whereby probability of exposure can be modeled, and we tested this on an empirical case of nonsteroidal anti‐inflammatory drug (NSAID)‐induced upper gastrointestinal bleeding (UGIB).

Methods

We used a case‐controls data set, consisting of 3568 cases of severe UGIB and 35 552 matched controls. Exposure to NSAID was based on 3 different conventional dichotomous measures. In addition, we tested 3 probabilistic exposure measures, a simple univariate backward‐recurrence model, a “full” multivariable model, and a “reduced” multivariable model. Odds ratios (ORs) and 95% confidence intervals for the association between NSAID use and UGIB were calculated by conditional logistic regression, while adjusting for preselected confounders.

Results

Compared to the conventional dichotomous exposure measures, the probabilistic exposure measures generated adjusted ORs in the upper range (4.37‐4.75) while at the same time having the most narrow confidence intervals (ratio between upper and lower confidence limit, 1.46‐1.50). Some ORs generated by conventional measures were higher than the probabilistic ORs, but only when the assumed period of intake was unrealistically short.

Conclusion

The pattern of high ORs and narrow confidence intervals in probabilistic exposure measures is compatible with less nondifferential misclassification of exposure than in a dichotomous exposure model. Probabilistic exposure measures appear to be an attractive alternative to conventional exposure measures.
The effects of processing parameters on the morphology of PLA/PEG melt electrospun fibers
Authors: Nazari Tayebe , Garmabi Hamid
Published: October 2017

Electrospinning of a polymer melt is an ideal technique to produce highly porous nanofibrous or microfibrous scaffolds appropriate for biomedical applications. In recent decades, melt electrospinning has been known as an eco‐friendly procedure as it eliminates the cytotoxic effects of the solvents used in solution electrospinning. In this work, the effects of spinning conditions such as temperature, applied voltage, nozzle to collector distance and collector type as well as polyethylene glycol (PEG) concentration on the diameter of melt electrospun polylactic acid (PLA)/PEG fibers were studied. The thermal stability of PLA/PEG blends was monitored through TGA and rheometry. Morphological investigations were carried out via optical and scanning electron microscopy. Based on the results, blends were almost stable over the temperature range of melt electrospinning (170 − 230 °C) and a short spinning time of 5 min. To obtain non‐woven meshes with uniform fiber morphologies, experimental parameters were optimized using ANOVA. While increasing the temperature, applied voltage and PEG content resulted in thinner fibers, PEG concentration was the most influential factor on the fiber diameter. In addition, a nozzle to collector distance of 10 cm was found to be the most suitable for preparing uniform non‐woven PLA/PEG meshes. At higher PEG concentrations, alterations in the collector distance did not affect the uniformity of fibers, although at lower distances vigorous bending instabilities due to polarity augmentation and viscosity reduction resulted in curly fibrous meshes. Finally, the finest and submicron scale fibers were obtained through melt electrospinning of PLA/PEG (70/30) blend collected on a metallic frame. © 2017 Society of Chemical Industry
Pharmacokinetics and Pharmacodynamics of Meloxicam in East Asian Populations: The Role of Ethnicity on Drug Response
Authors: Aoyama Takahiko , Ishida Yoshimasa , Kaneko Masato , Miyamoto Aoi , Saito Yoshiro , Tohkin Masahiro , Kawai Shinichi , Matsumoto Yoshiaki
Published: October 2017

We aimed to reanalyze the differences in the pharmacokinetics (PKs) of meloxicam in East Asian populations based on a population approach using previously published data and to investigate the factors found in population PK analysis that affect the pharmacodynamics (PDs) of meloxicam. Population PK analysis was performed in 119 healthy male subjects (30 Japanese, 30 Chinese, 29 Korean, and 30 white) under strictly controlled trial conditions with regulated meals and a single lot of the drug. We found that CYP2C9 genotype and lean body mass were statistically significant predictors of clearance and volume of distribution, respectively. A statistical significant difference in the PK parameters between ethnic groups could not be identified. Simulations using PK/PD models showed that CYP2C9 genotype is the factor that affects the PDs of meloxicam. The genetic polymorphisms highlighted in this study would be beneficial for conducting clinical trials in East Asians with similar genetic backgrounds.
Engineering Magnetic and Tunneling Magnetoresistance Properties of CoxFe3−xO4 Nanorods
Authors: Mitra Arijit , Mohapatra Jeotikanta , Sharma Himanshu , Aslam Mohammed
Published: October 2017

A simple cation exchange reaction has been adapted to produce the CoxFe3−xO4 nanorods with different concentration of Co. The substitution of Fe2+ with Co2+ ions increase the magnetocrystalline anisotropy and coercivity of pristine superparamagnetic Fe3O4 nanorods. Atomic concentration of 5–11% of Co2+ in Fe3O4 nanorods renders coercivity of 300–460 Oe at room temperature and 2200–4050 Oe at 10 K. Hydrocarbon long‐chain amine (oleylamine) functionalized nanorod assemblies form a multiple tunnel junction, where organic amine monolayers act as insulating tunnel barriers. CoxFe3−xO4 nanorods show a magnetoresistance switching behavior at room temperature and the switching field is consistent with the magnetic coercivity. A 14–15% TMR is recorded at room temperature in CoxFe3−xO4 nanorod assemblies, which increases to 23–26% at 150 K at a magnetic field of ±2 T. The calculated spin polarization for Co0.33Fe2.67O4 nanorods at room temperature is 52%. A similar spin polarization and TMR as Fe3O4 in Co‐doped Fe3O4 nanorod assemblies is obtained. Thus, controlled doping of Co ions engineers the coercivity and remanence of the “super‐paramagnetic” Fe3O4 without hindering their TMR performances, which could be very useful for memory devices.
Design of 3D Graphene‐Oxide Spheres and Their Derived Hierarchical Porous Structures for High Performance Supercapacitors
Authors: Li Zhuangnan , Gadipelli Srinivas , Yang Yuchen , Guo Zhengxiao
Published: October 2017

Graphene‐oxide (GO) based porous structures are highly desirable for supercapacitors, as the charge storage and transfer can be enhanced by advancement in the synthesis. An effective route is presented of, first, synthesis of three‐dimensional (3D) assembly of GO sheets in a spherical architecture (GOS) by flash‐freezing of GO dispersion, and then development of hierarchical porous graphene (HPG) networks by facile thermal‐shock reduction of GOS. This leads to a superior gravimetric specific capacitance of ≈306 F g−1 at 1.0 A g−1, with a capacitance retention of 93% after 10 000 cycles. The values represent a significant capacitance enhancement by 30–50% compared with the GO powder equivalent, and are among the highest reported for GO‐based structures from different chemical reduction routes. Furthermore, a solid‐state flexible supercapacitor is fabricated by constructing the HPG with polymer gel electrolyte, exhibiting an excellent areal specific capacitance of ≈220 mF cm−2 at 1.0 mA cm−2 with exceptional cyclic stability. The work reveals a facile but efficient synthesis approach of GO‐based materials to enhance the capacitive energy storage.
The Complex Relationship Between Home and School Literacy: A Blurred Boundary Between Formal and Informal English Literacy Practices of Greek Teenagers
Authors: Rothoni Anastasia
Published: October 2017

This article reports on findings of an ethnographically oriented multiple case study research study on teenagers’ everyday literacy practices in English as a foreign language in contemporary Greece. Drawing on new literacy studies, discourse analysis, and ethnography, the study extended over a period of 18 months and employed multiple data collection tools (interviews, field notes, literacy diaries, in‐home observations, documents, photographs) to provide an emic account of the literacy practices in English of 15 teenagers from varied backgrounds living in Athens, Greece. Contrary to conventional understandings of home and school as mutually exclusive domains and of teenagers’ literacy practices across these spaces as disconnected and mismatched, the findings presented in this article suggest that young people's English literacy practices are constituted by flows between formal and informal sites and thus cannot be easily disentangled into separable school and home practices. Overall, the article foregrounds a more subtle understanding of the relationship between school and out‐of‐school literacy and illustrates the need to move beyond traditional understandings of English language literacy as a static set of cognitive skills exclusively encountered and acquired in bounded contexts—predominantly educational ones.
Word maturity indices with latent semantic analysis: why, when, and where is Procrustes rotation applied?
Authors: Jorge‐Botana Guillermo , Olmos Ricardo , Luzón José M.
Published: October 2017

The aim of this paper is to describe and explain one useful computational methodology to model the semantic development of word representation: Word maturity. In particular, the methodology is based on the longitudinal word monitoring created by Kirylev and Landauer using latent semantic analysis for the representation of lexical units. The paper is divided into two parts. First, the steps required to model the development of the meaning of words are explained in detail. We describe the technical and theoretical aspects of each step. Second, we provide a simple example of application of this methodology with some simple tools that can be used by applied researchers. This paper can serve as a user‐friendly guide for researchers interested in modeling changes in the semantic representations of words. Some current aspects of the technique and future directions are also discussed. WIREs Cogn Sci 2018, 9:e1457. doi: 10.1002/wcs.1457

This article is categorized under:

Computer Science > Natural Language Processing

Linguistics > Language Acquisition

Psychology > Development and Aging
The Clinical Implications of Liver Resection Margin Size in Patients with Hepatocellular Carcinoma in Terms of Positron Emission Tomography Positivity
Authors: Park Jae Hyun , Kim Dong Hwi , Kim Sung Hoon , Kim Moon Young , Baik Soon Koo , Hong In Su
Published: October 2017

Background

The positivity of positron emission tomography (PET) in hepatocellular carcinoma (HCC) correlates with aggressive tumor factors and poor survival. Adequate resection margin size is still a topic of debate. We analyzed the clinical implications of resection margin size in patients with HCC in terms of PET positivity.

Methods

We retrospectively reviewed the medical records of 92 patients who underwent liver resection from March 2012 to October 2015. We investigated prognostic factors for recurrence and survival. We analyzed the correlation of resection margin size and PET positivity. Resection margins were classified as less than 1 cm and more than 1 cm.

Results

Twenty six (31.3%) patients had PET‐positive HCC. Multivariate analysis showed PET, satellite nodules, microvessel invasion, and multicentric occurrence were significant prognostic factors for HCC recurrence. Multivariate analysis also showed satellite nodules and microscopic portal vein invasion were significant prognostic factors for overall survival (OS). Resection margin size did not affect disease‐free survival (DFS) (p = 0.681) or OS (p = 0.301) in patients with PET‐negative HCC, but showed a difference in DFS [<1 cm at 11 months vs. ≥1 cm at 41 months (p = 0.188)] and OS [<1 cm at 28 months vs. ≥1 cm at 48 months (p < 0.001)] in patients with PET‐positive HCC.

Conclusions

PET has low sensitivity for HCC. However, it is useful to predict treatment outcomes after liver resection or liver transplantation for HCC. Although the extent of liver resection must be decided based on liver function, a resection margin size >1 cm may improve DFS and OS in patients with PET‐positive HCC.
Effects of Timing of Appendectomy on the Risks of Perforation and Postoperative Complications of Acute Appendicitis
Authors: Kim Jong Wan , Shin Dong Woo , Kim Doo Jin , Kim Jeong Yeon , Park Sung Gil , Park Jun Ho
Published: October 2017

Background

It is generally believed that appendectomy should be performed immediately to prevent perforation and complications. Therefore, our objectives were to investigate the effect of timing of appendectomy on the incidence of perforation and complications.

Methods

We retrospectively reviewed the medical records of patients who underwent laparoscopic appendectomy between January 2014 and June 2015. The time from symptom onset to appendectomy was categorized into three periods: time from symptom onset to hospital admission (symptomatic time), time from admission to appendectomy (hospitalization time), and time from symptom onset to appendectomy [symptomatic period + hospitalization period (overall time)]. Multivariable analyses were performed to identify independent factors associated with perforation and complications.

Results

A total of 1753 patients were included in the present study. Perforation occurred in 28.2% of patients, and postoperative complications occurred in 10.0% of patients. Multivariable analysis showed that BT > 38 °C (P = 0.006), WBC count >13,000 cells/µl (P = 0.02), neutrophil ratio >80% (P < 0.001), and symptomatic time >24 h (P < 0.001) were independent factors of appendiceal perforation, while the neutrophil ratio >80% (P < 0.001) and symptomatic time >48 h (P = 0.003) were independently associated with complications.

Conclusions

The present study showed that the symptomatic time and overall time were significantly associated with perforation and complications, whereas hospitalization time was not associated with either perforation or complications.
Clinical Outcome, Social Impact and Patient Expectation: a Purposive Sampling Pilot Evaluation of Patients in Benin Seven Years After Surgery
Authors: White Michelle C. , Randall Kirsten , Avara Esther , Mullis Jenny , Parker Gary , Shrime Mark G.
Published: October 2017

Background

Access to affordable and timely surgery is not equitable around the world. Five billion people lack access, and while non‐governmental organizations (NGOs) help to meet this need, long‐term surgical outcomes, social impact or patient experience is rarely reported.

Method

In 2016, Mercy Ships, a surgical NGO, undertook an evaluation of patients who had received surgery seven years earlier with Mercy Ships in 2009 in Benin. Using purposive sampling, patients who had received maxillofacial, plastics or orthopedic surgery were invited to attend a surgical evaluation day. In this pilot study, we used semi‐structured interviews and questionnaire responses to assess patient expectation, surgical and social outcome.

Results

Our results show that seven years after surgery 35% of patients report surgery‐related pain and 18% had sought further care for a clinical complication of their condition. However, 73% of patients report gaining social benefit from surgery, and overall patient satisfaction was 89%, despite 35% of patients saying that they were unclear what to expect after surgery indicating a mismatch of doctor/patient expectations and failure of the consent process.

Conclusion

In conclusion, our pilot study shows that NGO surgery in Benin provided positive social impact associated with complication rates comparable to high‐income countries when assessed seven years later. Key areas for further study in LMICs are: evaluation and treatment of chronic pain, consent and access to further care.
Mesh Versus Patch Repair for Epigastric and Umbilical Hernia (MORPHEUS Trial); One‐Year Results of a Randomized Controlled Trial
Authors: Ponten J. E. H. , Leenders B. J. M. , Leclercq W. K. G. , Lettinga T. , Heemskerk J. , Konsten J. L. M. , Castelijns P. S. S. , Nienhuijs S. W.
Published: October 2017

Design

This trial is a randomized controlled, patient‐blinded, multicentre, superiority trial.

Methods

All patients ≥18 years with a single, symptomatic and primary umbilical or epigastric hernia (<2 fingers) qualified for participation in the study. Flat polypropylene mesh repair was compared to patch repair (PROCEED® Ventral Patch) (PVP). The objective of this trial was to identify a superior method for umbilical and epigastric hernia repair in terms of complication rates.

Results

A total of 352 patients were randomized in this trial; 348 patients received the intervention (n = 177 PVP vs. n = 171 mesh). No peri‐operative complications occurred. PVP placement was significantly faster compared to mesh placement (30 min, SD 11 vs. 35 min, SD 11) and was scored as an easier procedure. At 1‐month follow‐up, 76 patients suffered any kind of complication. There was no significant difference in the proportion of complications (24.9% for PVP and 18.7% for mesh, p = 0.195). A significant difference was seen in re‐operation rate within 1 month, significantly less early re‐operations in the mesh group (0.0 vs. 2.8%, p = 0.027). After 1‐year follow‐up, no significant differences are seen in recurrence rates (n = 13, 7.8% PVP vs. n = 5, 3.3% mesh, p = 0.08).

Conclusions

Both mesh and PVP had a comparable amount of reported complications. There was a significantly higher incidence of early re‐operations due to early complications in the PVP group. No differences were seen in infection rates and the need for antibiotic treatment. No significant difference was seen in the recurrence rates.

Registration

This trial was registered in the Dutch Trail Registry (NTR) NTR2514NL33995.060.10. [12].
Long‐term impact of intensive lifestyle intervention on cognitive function assessed with the National Institutes of Health Toolbox: The Look AHEAD study
Authors: Hayden Kathleen M. , Baker Laura D. , Bray George , Carvajal Raymond , Demos‐McDermott Kathryn , Hergenroeder Andrea L. , Hill James O. , Horton Edward , Jakicic John M. , Johnson Karen C. , Neiberg Rebecca H. , Rapp Stephen R. , Wadden Thomas A. , Miller Michael E. ,   Look AHEAD Movement and Memory and Look AHEAD Brain MRI Ancillary Study Groups
Published: October 2017

Introduction

This study sought to determine whether 10 years of assignment to intensive lifestyle intervention (ILI) relative to diabetes support and education leads to better cognition. We examine intervention effects overall and among clinical subgroups, and report correlations between computer‐administered and interviewer‐administered cognitive batteries.

Methods

The Action for Health in Diabetes (Look AHEAD) was a 16‐site randomized controlled trial with overweight/obese individuals (aged 45–76) who had type 2 diabetes. The NIH Toolbox Cognition Battery tests developed to measure cognition across the lifespan were used to evaluate cognition. Results were compared with standard paper‐and‐pencil tests. The Toolbox and paper‐and‐pencil tests were administered an average of 10.9 years after randomization to 1002 participants.

Results

Toolbox measures significantly correlated with interviewer‐administered measures, with the strongest correlations between the Toolbox Fluid Cognition Composite and Trails B (r = −0.64, P < .0001) and Digit Symbol Coding (r = 0.63, P < .0001), and between the Toolbox Dimensional Change Card Sort (r = 0.55, P < .0001) and the Digit Symbol Coding test. Overall, ILI and diabetes support and education groups had similar adjusted mean cognitive outcomes (P > .05 for all). Subgroup analyses identified different intervention effects within baseline body mass index groups for Picture Sequence Memory (P = .01), within baseline cardiovascular disease groups for Picture Vocabulary (P = .01) and Fluid Cognition Composite (P = .02) measures, and within baseline age groups for Picture Vocabulary (P = .02).

Discussion

Correlations between Toolbox and interviewer‐administered outcomes provide a measure of internal validity. Findings suggest no overall effect of the intervention on cognition and that an ILI resulting in weight loss may have negative implications for cognition in individuals aged ≥60, with previous history of cardiovascular disease, and those with body mass index ≥40.
Disruptions to the cerebellar GABAergic system in juvenile guinea pigs following preterm birth
Authors: Shaw Julia C. , Palliser Hannah K. , Dyson Rebecca M. , Berry Mary J. , Hirst Jonathan J.
Published: October 2017

Background

Children that are born preterm are at an increased risk of developing cognitive problems and behavioural disorders, such as attention deficit hyperactivity disorder (ADHD). There is increasing interest in the role of the cerebellum in these processes and the potential involvement of GABAergic pathways in neurodevelopmental disorders. We propose that preterm birth, and the associated loss of the trophic intrauterine environment, alters the development of the cerebellum, contributing to ongoing neurobehavioral disorders.

Methods

Guinea pigs were delivered preterm (GA62) or spontaneously at term (GA69), and tissues collected at corrected postnatal day (PND) 28. Neurodevelopmental and GABAergic markers myelin basic protein (MBP), neuronal nuclei (NeuN), calbindin (Purkinje cells), and GAD67 (GABA synthesis enzyme) were analysed in cerebellar lobules IX and X by immunohistochemistry. Protein expression of GAD67 and GAT1 (GABA transporter enzyme) were quantified by western blot, whilst neurosteroid‐sensitive GABAA receptor subunits were measured by RT‐PCR.

Results

MBP immunostaining was increased in lobule IX of preterm males, and reduced in lobule X of preterm females when compared to their term counterparts. GAD67 staining was decreased in lobule IX and X of the preterm males, but only in lobule X of the preterm females compared to term cohorts for each sex. Internal granule cell layer width of lobule X was decreased in preterm cohorts of both sexes compared to terms. There were no differences between gestational age groups for NeuN staining, GAD67 and GAT1 protein expression as measured by western blotting, or GABAA receptor subunits as measured by RT‐PCR between preterm and term for either sex.

Conclusions

The present findings suggest that components of the cerebellar GABAergic system of the ex‐preterm cerebellum are disrupted. The higher expression of myelin in the preterm males may be due to a deficit in axonal pruning, whereas females have a deficit in myelination at 28 corrected days of age. Together these ongoing alterations may contribute to the neurodevelopmental and behavioural disorders observed in those born preterm.
Acute appendicitis mimicking acute scrotum: a rare complication of a common abdominal inflammatory disease
Authors: Buzatti Kelly Cristine de Lacerda Rodrigues , Gonçalves Marcus Vinícius Capanema , Silva Rodrigo Gomes da , Rodrigues Beatriz Deoti e Silva
Published: October 2017

Introduction Acute appendicitis is the most common surgical disease of the abdomen in clinical practice, affecting mainly young adults. It has a wide variety of clinical presentations, due to the anatomical variation of the cecal appendix. Its presentation as acute scrotum and scrotal abscess is quite rare and atypical, occurring mainly in young male patients with patent processus vaginalis.

Case presentation An 18-years-old male patient attended the emergency unit complaining of diffuse abdominal pain, fever and hyporexia for four days followed by inflammatory signs in the scrotum. He was taken to the operation room after diagnosis of scrotal and abdominal sepsis. During scrotum exploration, pus was found inside the right hemiscrotum coming down from the groin and communicating with the abdominal cavity. The laparotomy found perforated appendicitis and peritonitis leading to the scrotal abscess. The abscess was drained, appendectomy was performed and the scrotal and abdominal cavity were washed with saline solution. Despite postoperative complications such as pneumonia and intra-abdominal abscess, the reported patient recovered and was discharged in the 44th postoperative day.

Conclusion Acute appendicitis can mimic acute scrotum and surgeons must have a high index of suspicion of this complication for diagnosing. This unusual clinical presentation may be challenging and can delay the diagnosis leading to perforated peritonitis.