bluuebunny/crossref_metadata_2025 huggingface dataset:
Fabrication of periodical Ag–Au compound nanostructure films with controllable Ag nanoparticle aggregate patterns: a study on surface‐enhanced Raman scattering
Authors: Ruan Weidong , Cui Yinqiu , Lin Feng , Zhou Tieli , Hui Ge , Wang Ye , Chen Yufeng , Lu Fei , Guo Jie , Zhao Bing
Published: June 2015

The Ag–Au compound nanostructure films with controllable patterns of Ag nanoparticle (NP) aggregates were fabricated. A strategy of two‐step synthesis was employed toward the target products. Firstly, the precursor Au NP (17 nm) films were synthesized as templates. Secondly, the Ag NPs (45 nm) were deposited on the precursor films. Three types of Ag NP aggregates were obtained including discrete Ag NPs (discrete type), necklace‐like Ag NP aggregates (necklace type), and huddle‐like Ag NP aggregates (huddle type). The surface‐enhanced Raman scattering (SERS) property was studied on these nanostructures by using the probing molecule of rhodamine 6G under the excitation laser of 514.5 nm. Interestingly, the different types of samples showed different enhancement abilities. A statistical method was employed to assess the enhancement. The relative enhancement factor for each Ag NP was estimated quantitatively under the ratio of 1 : 25 : 18 for the discrete‐type, necklace‐type, and huddle‐type samples at the given concentration of 10−8 mol/l. This research shows that the enhancement ability of each Ag NP is dependent on the aggregate morphology. Moreover, the different enhancement abilities displayed different limit detection concentrations up to 10−8, 10−11, and 10−9 mol/l, separately. The understanding of the relationship between the defined nanostructures and the SERS enhancement is very meaningful for the design of new SERS substrates with better performance. Copyright © 2015 John Wiley & Sons, Ltd.
Do formalin fixation and freeze‐thaw affect near‐infrared Raman spectroscopy of cartilaginous tissue? A preliminary ex vivo analysis of native human articular cartilage
Authors: Takahashi Yasuhito , Shishido Takaaki , Yamamoto Kengo , Sawaji Yasunobu , Nishida Jun , Pezzotti Giuseppe
Published: June 2015

Near‐infrared (NIR) Raman microprobe spectroscopy has been applied to the non‐invasive characterization of the biochemical structure of extracellular matrix in articular cartilage, a step forward along the path of in vivo diagnostic application of chondropathy. In most studies handling ex vivo cartilage specimens, formalin fixation or freeze‐thaw treatments have been applied in order to stabilize tissue and cell constituents prior to spectroscopic measurements. However, these pre‐processing manipulations might significantly affect certain target bands of the cartilage spectra, thus introducing biases in the characterizations, and potentially leading to data misinterpretation. In this study, we evaluated how formalin fixing and freeze‐thaw processes affect Raman spectra from human femur cartilage. Healthy cartilage specimens were fixed/stored either in a 10% neutral buffered formalin solution or in a deep freezer set at −80 °C. The results of this study show that formalin fixation significantly affects the NIR Raman spectra of cartilage specimens due to concurrent formalin absorption and water dehydration within both collagen and glycosaminoglycan macromolecules. Water dehydration was also confirmed in the amide I structure in the frozen‐thawed specimen, but to a much lesser extent. Furthermore, soaking the tissues in phosphate‐buffered saline solution minimized the storage‐induced Raman artifacts, but its immersion had limited effectiveness in formalin‐fixed specimens, predominantly due to an overlap of signals from the formalin liquid (i.e. emitting at 1046 and 1492 cm−1). Therefore, to provide a highly accurate biochemical evaluation of extracellular matrix using NIR Raman spectroscopy, freeze‐thaw processes are more suitable for ex vivo samples of human cartilage than formalin fixation. Copyright © 2015 John Wiley & Sons, Ltd.
Effects of 2D wedge design as a wayfinding facilitator in a 3D virtual environment
Authors: Chen Chien‐Hsiung , Chen Shih‐Chieh
Published: June 2015

The purpose of this study is to investigate users' wayfinding task performance and subjective preference in a three‐dimensional (3D) virtual environment. The research variables are interaction mode (touch sensitive vs body movement modes), viewing perspective [first‐person perspective (1PP) versus third‐person perspective (3PP)], and gender (man versus woman). Three difficult levels of tasks were conducted, i.e., A, A‐P, and A‐A types. The experiment is 2 × 2 × 2 between‐subject design. Participants needed to complete three wayfinding tasks and fill out subjective preference questionnaires regarding task fluency, satisfaction, system usability scale, and NASA Task Load Index (NASA‐TLX). Fifty‐six participants (28 men and 28 women) were invited using convenient sampling method. The results are as follows: (1) Participants adopting touch‐sensitive mode performed better than body movement mode. (2) Participants using touch‐sensitive mode could have better task fluency and higher SUS score, and with less effort and frustration. (3) Participants adopting 3PP had better wayfinding task performance than first‐person perspective. They also had higher system usability scale score and spent less effort for having wider viewing perspective. (4) The gender variable only showed significant effect in A‐P type of wayfinding task. Men performed better than women. It is concluded that adopting touch‐sensitive interaction and 3PP designs can better facilitate users' wayfinding tasks.
Preparation and characterization of erythromycin molecularly imprinted polymers based on distillation–precipitation polymerization
Authors: Liu Jiang , Li Le , Tang Hui , Zhao Feilang , Ye Bang‐Ce , Li Yingchun , Yao Jun
Published: June 2015

Erythromycin‐imprinted polymers with excellent recognition properties were prepared by an innovative strategy called distillation–precipitation polymerization. The interaction between erythromycin and methacrylic acid was studied by ultraviolet absorption spectroscopy, and the as‐prepared materials were characterized by Fourier‐transform infrared spectroscopy and scanning electron microscopy. Moreover, their binding performances were evaluated in detail by static, kinetic and selective sorption tests. It was found that the molecularly imprinted polymers afforded good morphology, monodispersity, and high adsorption capacity when the fraction of the monomers was 7 vol% in the whole reaction system, and the adsorption data for imprinted polymers correlated well with the Langmuir model. The maximum capacity of the imprinted and the non‐imprinted polymers for adsorbing erythromycin is 44.03 and 19.95 mg/g, respectively. The kinetic studies revealed that the adsorption process fitted a pseudo‐second‐order kinetic model. Furthermore, the imprinted polymers display higher affinity toward erythromycin, compared with its analogue roxithromycin.
Alloy 800H under supercritical water conditions: a flow reactor study of corrosion and hydrogen evolution
Authors: Choudhry K. I. , Svishchev I. M. , Orlovskaya L.
Published: June 2015

Hydrogen evolution and corrosion rates for an Alloy 800H flow‐through reactor operating under supercritical water conditions were determined. Experiments were performed in the temperature range of 650 to 750 °C both with deoxygenated feed water, with an O2 concentration of less than 10 μg L−1 (ppb), and with a high oxygen concentration of around 20 mg L−1 (ppm). Effective rate constants for hydrogen evolution during the corrosion of an Alloy 800H were calculated to be 2.52×10−11, 2.88×10−11 and 4.30×10−11 mol cm−2 s−1, for the reactor temperatures of 650, 700 and 750 °C, respectively.
Effects of Ce on inclusions and corrosion resistance of low‐nickel austenite stainless steel
Authors: Cai G.‐J. , Li C.‐S.
Published: June 2015

Effects of Ce on the corrosion resistance of low‐nickel austenite stainless steel containing Ce from 0.005 to 0.022 wt% were investigated in 3.5 wt% NaCl solution, 5 wt% H2SO4 solution, 1 mol/L NaHCO3 and 0.5 mol/L Na2CO3 solution. The results demonstrate that addition of Ce to low‐nickel austenite stainless steel forms multi‐phase inclusions containing CeAlO3 and Ce2O2S that can prevent corrosion. Ce addition to steels increases the corrosion resistance owing to metamorphic inclusions and the improvement of electrode potential in the matrix. The pitting corrosion originates from the defects of passive film or inclusions and then continues to expand, deteriorating the pitting corrosion resistance. The EIS measurements indicate that the steels with Ce addition exhibit higher Rp values than that without Ce, which demonstrates the relative resistance to corrosion is accompanied by an increasing Ce addition. AISI 202 stainless steel with 0.016 wt% Ce addition in the mass fraction has the best corrosion resistance.
Novel concepts on the growth of corrosion fatigue small and short cracks
Authors: Lukaszewicz M. , Zhou S. , Turnbull A.
Published: June 2015

Corrosion fatigue small, short and long crack growth rates have been determined for a 12Cr steam turbine steel in aerated 300 ppb Cl‐ + 300 ppb SO42‐ solution and in air at 90 °C. The crack growth rate for short and long cracks was monitored by direct current potential drop (DCPD) and for the small cracks by combining high resolution optical microscopy and DCPD. Comparison of the fatigue growth rate demonstrated that in solution the short crack growth rate was remarkably enhanced in comparison to long cracks, when the crack size is smaller than 250 μm. This enhancement was attributed to the electrochemical crack size effect associated with greater anodic polarisation of the short crack in such low conductivity solution. However, such enhanced growth was not observed for small cracks, which was rationalised on the basis of additional contribution of current from the pit limiting crack‐tip polarisation.
Dysarthria and Stutter as Presenting Symptoms of Late‐Onset Tay‐Sachs Disease in Three Siblings
Authors: Grim Kristina K. , Phillips Gregory D. , Renner David R.
Published: June 2015

Late‐onset Tay‐Sachs disease (LOTS) is a rare autosomal‐recessive genetic disorder caused by insufficient activity of the lysosomal enzyme, beta‐hexosaminidase A, resulting in intracellular accumulation of gangliosides in the central nervous system. Clinical manifestations can include unsteadiness in gait, muscle weakness, cognitive dysfunction, psychiatric disturbance, and dysarthric speech. The variable presentation of these symptoms, combined with the late onset of the disease, often results in misdiagnosis. We present video of 3 sibling cases of LOTS in which a dysarthric stutter was the sole presenting symptom in order to better characterize the phenotype of this disease.
Real‐time distortion correction of spiral and echo planar images using the gradient system impulse response function
Authors: Campbell‐Washburn Adrienne E. , Xue Hui , Lederman Robert J. , Faranesh Anthony Z. , Hansen Michael S.
Published: June 2015

Purpose

MRI‐guided interventions demand high frame rate imaging, making fast imaging techniques such as spiral imaging and echo planar imaging (EPI) appealing. In this study, we implemented a real‐time distortion correction framework to enable the use of these fast acquisitions for interventional MRI.

Methods

Distortions caused by gradient waveform inaccuracies were corrected using the gradient impulse response function (GIRF), which was measured by standard equipment and saved as a calibration file on the host computer. This file was used at runtime to calculate the predicted k‐space trajectories for image reconstruction. Additionally, the off‐resonance reconstruction frequency was modified in real time to interactively deblur spiral images.

Results

Real‐time distortion correction for arbitrary image orientations was achieved in phantoms and healthy human volunteers. The GIRF‐predicted k‐space trajectories matched measured k‐space trajectories closely for spiral imaging. Spiral and EPI image distortion was visibly improved using the GIRF‐predicted trajectories. The GIRF calibration file showed no systematic drift in 4 months and was demonstrated to correct distortions after 30 min of continuous scanning despite gradient heating. Interactive off‐resonance reconstruction was used to sharpen anatomical boundaries during continuous imaging.

Conclusions

This real‐time distortion correction framework will enable the use of these high frame rate imaging methods for MRI‐guided interventions. Magn Reson Med 75:2278–2285, 2016. © 2015 Wiley Periodicals, Inc.
On contrast mechanisms in p‐space imaging
Authors: Straub Sina , Ladd Mark E. , Wetscherek Andreas , Laun Frederik B.
Published: June 2015

Purpose

The effects of microstructure on susceptibility mapping have recently received increasing attention. In this work, the capability of p‐space imaging to resolve subvoxel structure and susceptibility is assessed.

Methods

In a simulation study, the p‐space contrast of axon bundles comprised of hollow cylinders is investigated. Various axon and susceptibility distributions are considered and compared with the corresponding case of a voxel with homogeneous substructure of the order of the voxel size.

Results

MR signal behavior for p‐space imaging of a voxel containing axon bundles and a voxel containing homogeneous substructure are nearly identical.

Conclusion

p‐Space imaging resolves subvoxel structure of the order of the voxel size. Due to dephasing effects, strong susceptibility variations alter p‐space contrast. However, p‐space contrast is not directly linked to the susceptibility of the axon compartment. Magn Reson Med 75:2526–2533, 2016. © 2015 Wiley Periodicals, Inc.
Direct dynamic measurement of intracellular and extracellular lactate in small‐volume cell suspensions with 13C hyperpolarised NMR
Authors: Breukels Vincent , Jansen Kees (C.) F. J. , van Heijster Frits H. A. , Capozzi Andrea , van Bentum P. Jan M. , Schalken Jack A. , Comment Arnaud , Scheenen Tom W. J.
Published: June 2015

Hyperpolarised (HP) 13C NMR allows enzymatic activity to be probed in real time in live biological systems. The use of in vitro models gives excellent control of the cellular environment, crucial in the understanding of enzyme kinetics. The increased conversion of pyruvate to lactate in cancer cells has been well studied with HP 13C NMR. Unfortunately, the equally important metabolic step of lactate transport out of the cell remains undetected, because intracellular and extracellular lactate are measured as a single resonance. Furthermore, typical experiments must be performed using tens of millions of cells, a large amount which can lead to a costly and sometimes highly challenging growing procedure. We present a relatively simple set‐up that requires as little as two million cells with the spectral resolution to separate the intracellular and extracellular lactate resonances. The set‐up is tested with suspensions of prostate cancer carcinoma cells (PC3) in combination with HP [1‐13C]pyruvate. We obtained reproducible pyruvate to lactate label fluxes of 1.2 and 1.7 nmol/s per million cells at 2.5 and 5.0 mM pyruvate concentrations. The existence of a 3‐Hz chemical shift difference between intracellular and extracellular lactate enabled us to determine the lactate transport rates in PC3. We deduced a lactate export rate of 0.3 s−1 and observed a decrease in lactate transport on addition of the lactate transport inhibitor α‐cyano‐4‐hydroxycinnamic acid. Copyright © 2015 John Wiley & Sons, Ltd.
Augmented AMG‐shifted Laplacian preconditioners for indefinite Helmholtz problems
Authors: Tsuji P. , Tuminaro R.
Published: June 2015

Discrete representations of the Helmholtz operator generally give rise to extremely difficult linear systems from an iterative solver perspective. This is due in part to the large oscillatory near null space of the linear system. Typical iterative methods do not effectively reduce error components in the subspace associated with this near null space. Traditional coarse grids used within multilevel solvers also cannot capture these components because of their oscillatory nature. While the shifted Laplacian is a popular method allowing multigrid preconditioners to achieve improved convergence, it is still unsatisfactory for higher‐frequency problems. This paper analyzes the shifted Laplacian through polynomial smoothers to show its effect on the spectrum of the discrete Helmholtz operator. This analysis reveals desirable features of the shifted Laplacian preconditioners as well as limitations. Shifted Laplacian techniques are first extended to smoothed aggregation algebraic multigrid. Motivated by analysis, we propose augmenting the algebraic multigrid shifted Laplacian with a two‐grid error correction step. This additional step consists of the generalized minimal residual iterations applied to a projected version of the unshifted equations on a single auxiliary coarse grid. Results indicate that augmentation can improve the convergence significantly and can reduce the overall solve time on two‐dimensional and three‐dimensional problems. Copyright © 2015 John Wiley & Sons, Ltd.
Chemical structure characteristics of wood/lignin composites during mold pressing
Authors: Li Dong‐Li , Ge Sheng‐Bo , Peng Wan‐Xi , Wu Qing‐Ding , Wu Jian‐Guo
Published: June 2015

To reuse lignin polymers from bioethanol biorefinery plants, wood/lignin composites (WLC) were modified by mold pressing, processed, and analyzed using X‐ray diffractometry, Fourier transform‐infrared spectroscopy, thermogravimetric analysis, and thermal desorption‐gas chromatography‐mass spectrometry. With increased temperature and time, cellulose, hemicellulose, and lignin increased the thermal degradation reaction and generated many extracts. Comprehensive analysis of the analytical results suggested that mold pressing at 160°C or 220°C for 20 min was optimal for WLC preparation. However, care should be taken as the volatiles included acetic acid, phenol and its derivatives, and benzene and its derivatives, which are toxic. POLYM. COMPOS., 38:955–965, 2017. © 2015 Society of Plastics Engineers
Effect of reinforcement on the barrier and dielectric properties of epoxidized natural rubber–graphene nanocomposites
Authors: Yaragalla Srinivasarao , Chandran C. Sarath , Kalarikkal Nandakumar , Subban R.H.Y. , Chan Chin Han , Thomas Sabu
Published: June 2015

The influence of epoxidation level of natural rubber (i.e., ENR25, ENR50) on the dielectric and oxygen gas barrier properties of thermally reduced graphene oxide (GR) and graphite (GT) (with 2%·w/w) filled nanocomposites are investigated here. GR, GT filled epoxidized natural rubber (ENR) nanocomposites were fabricated by mechanical mixing using environment friendly two‐roll mill mixing method. Raman spectroscopy and Fourier transform infrared spectroscopy studies were carried out to investigate the extent of chemical interactions between GR and ENR. Morphological studies were done using transmission electron microscopy to evaluate the distribution of GR and GT in the ENR. The improved gas barrier and dielectric properties of GT‐ENR and GR–ENR composites synthesized by a novel green ecofriendly method is correlated with the chemical interactions among GT, GR, and ENR. POLYM. ENG. SCI., 55:2439–2447, 2015. © 2015 Society of Plastics Engineers
Substituent effect of N‐aryl‐N′‐pyridyl ureas as thermal latent initiators on ring‐opening polymerization of epoxide
Authors: Makiuchi Naoyuki , Sudo Atsushi , Endo Takeshi
Published: June 2015

A series of N‐aryl‐N′‐pyridyl ureas were synthesized by the reactions of 4‐aminopyridine (4AP) with the corresponding isocyanates such as phenyl isocyanate, 4‐methylphenyl isocyanate, 4‐methoxyphenyl isocyanate, 4‐chlorophenyl isocyanate, 4‐(trifluoromethyl)phenyl isocyanate, and 4‐nitrophenyl isocyanate. Bulk polymerization of diglycidyl ether of bisphenol A (DGEBA) in the presence of the ureas as initiators was evaluated by differential scanning calorimetry (DSC) at a heating rate of 10 °C/min. The resulting DSC profiles indicated exothermic peaks above 140 °C, while the DSC profile measured for a formulation composed of DGEBA and pristine 4AP indicated an exothermic peak at around 120 °C, implying that the derivation of 4AP into the corresponding ureas is a useful strategy to achieve thermal latency. The peak top temperatures were correlated with the electron density of the aromatic ring of the ureas, that is, as the electron‐withdrawing nature of the substituent on the aromatic ring became larger, the peak increases. © 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2015, 53, 2569–2574
A facile method to synthesize high‐molecular‐weight biobased polyesters from 2,5‐furandicarboxylic acid and long‐chain diols
Authors: Tsanaktsis Vasilios , Papageorgiou George Z. , Bikiaris Dimitrios N.
Published: June 2015

In this study, biobased furan dicarboxylate polyesters have been prepared using 2,5‐furandicarboxylic acid (FDCA) and diols with high number of methylene groups (long‐chain diols), namely, 8, 9, 10, and 12. Because of the high boiling points of these diols, a modified procedure of the well‐known melt polycondensation was applied in this work. According to this, the dimethyl ester of FDCA (DMFD) reacted in the first transesterification stage with the corresponding diols forming bis‐hydroxy‐alkylene furan dicarboxylates (BHFD). In the second stage, the BHFD reacted with DMFD again at temperatures of 150–170 °C (for 4–5 h), and in the final stage, the temperature was raised to 210–230 °C (vacuum was applied for 2–3 h). The molecular weight of the polyesters and the content of oligomers, as was verified by gel permeation chromatography analysis, depend on the polycondensation time and temperature. The chemical structure of the polyesters was verified from 1H NMR spectroscopy. All the polymers were found to be semicrystalline, with melting temperatures from 69 to 140 °C depending on the diol used. In addition, the mechanical properties also varied with the type of diol. The higher values were observed for poly(octylene 2,5‐furanoate), whereas the lowest values were observed for poly(dodecylene 2,5‐furanoate) with the higher number of methylene groups in its repeating unit. © 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2015, 53, 2617–2632
Strategic Lifestyle Management in Later Life: Swedish Lifestyle Movers in Malta Seeking the ‘Best of Both Worlds’
Authors: Åkerlund Ulrika
Published: June 2015

In affluent societies, an active choice of lifestyle is increasingly becoming an option. With increased possibilities for mobility, opportunities to lead a good life can be accessed across global space. However, lifestyle management is largely directed and constrained by structural frameworks, and movers have to allocate resources and experience in order to manoeuvre structures and make optimal lifestyle choices. This paper explores how residential mobility may be used as a resource to gain access to opportunities. Based on thematic analysis of in‐depth interviews, this is performed by exploring the experiences of Swedish lifestyle movers in Malta, in their tailoring of mobility practices that allow them to enjoy opportunities for the good life in both countries. The research questions that have guided this study are as follows: (a) What does the good life comprise? (b) How are structural frameworks surrounding opportunities for lifestyle management perceived by movers? and (c) In what ways do movers actively tailor their mobility practices to achieve the good life? The results show that movers are highly engaged in tailoring their access to opportunities through place fixity, such as permanent residency and social integration, and through routinised and timed mobility practices. Copyright © 2015 John Wiley & Sons, Ltd.
Thermal imaging using polymer nanocomposite temperature sensors
Authors: Sauerbrunn Elizabeth , Chen Ying , Didion Jeffrey , Yu Miao , Smela Elisabeth , Bruck Hugh A.
Published: June 2015

Sensing temperature distributions over an area is of interest for many applications, and it is currently performed using sensors that are attached to the structure. In this work a conductive “smart paint”, made from latex and exfoliated graphite, is introduced for temperature sensing. This provides, as an alternative to manual fixation, the ability to integrate sensors during fabrication because the approach is amenable to additive manufacturing technologies such as 3D printing. We demonstrate that calibration of the spray‐coatable polymer/carbon composite thin film sensors allows accurate temperature measurement over an area. We further demonstrate continuous, distributed temperature sensing by employing electrical impedance tomography to reconstruct a thermal image from measurements at the perimeter of the sensing region.
Study of the correlation between hydrogenated amorphous silicon microstructure and crystalline silicon surface passivation in heterojunction solar cells
Authors: Guo Wanwu , Zhang Liping , Meng Fanying , Bao Jian , Wang Dongliang , Liu Jinning , Feng Zhiqiang , Verlinden Pierre J. , Liu Zhengxin
Published: June 2015

The properties of hydrogenated amorphous silicon (a‐Si:H) thin layers were studied by spectroscopic ellipsometry (SE) and Fourier transform infrared spectroscopy (FTIR) measurements to determine their effects on the surface passivation of crystalline silicon (c‐Si) in heterojunction solar cells. It was demonstrated that the high bulk quality of a‐Si:H layers with denser structures was not sufficient for the passivation of c‐Si surfaces in Silicon Heterojunction (SHJ) solar cells, in which the passivation performance is strongly governed by the total hydrogen content (CH) as a‐Si:H layers are ultra‐thin. High effective carrier lifetime and implied open‐circuit voltage (Voc,im), as well as low surface recombination velocity, were obtained at the appropriate CH values, and the optimal windows of CH and of the hydrogen content in the Si–H2 configuration (C2) were determined to be 5.0 ∼ 8.5 and 2.9 ∼ 6.8 at.%, respectively. For CH values higher than 8.5 at.%, the passivation effect was degraded due to the deteriorated bulk properties of the a‐Si:H layers. However, Voc,im decreased when CH was lower than 5.0 at.% because the number of H atoms was insufficient to saturate the dangling bonds at the a‐Si:H/c‐Si interface even though the a‐Si:H layers had dense microstructures.
Designing a study to evaluate the benefit of a biomarker for selecting patient treatment
Authors: Janes Holly , Brown Marshall D. , Pepe Margaret S.
Published: June 2015

Biomarkers that predict the efficacy of treatment can potentially improve clinical outcomes and decrease medical costs by allowing treatment to be provided only to those most likely to benefit. We consider the design of a randomized clinical trial in which one objective is to evaluate a treatment selection marker. The marker may be measured prospectively or retrospectively using samples collected at baseline. We describe and contrast criteria around which the trial can be designed. An existing approach focuses on determining if there is a statistical interaction between the marker and treatment. We propose three alternative approaches based on estimating clinically relevant measures of improvement in outcomes with use of the marker. Importantly, our approaches accommodate the common scenario in which the marker‐based rule for recommending treatment is developed with data from the trial. Sample sizes are calculated for powering a trial to assess these criteria in the context of adjuvant chemotherapy for the treatment of estrogen‐receptor‐positive, node‐positive breast cancer. In this example, we find that larger sample sizes are generally required for assessing clinical impact than for simply evaluating if there is a statistical interaction between marker and treatment. We also find that retrospectively selecting a case‐control subset of subjects for marker evaluation can lead to large efficiency gains, especially if cases and controls are matched on treatment assignment. Copyright © 2015 John Wiley & Sons, Ltd.
Exact optimum coin bias in Efron's randomization procedure
Authors: Antognini Alessandro Baldi , Rosenberger William F. , Wang Yang , Zagoraiou Maroussa
Published: June 2015

Efron's biased coin design is a restricted randomization procedure that has very favorable balancing properties, yet it isfully randomized, in that subjects are always randomized to one of two treatments with a probability less than 1. The parameter of interest is the biaspof the coin, which can range from 0.5 to 1. In this note, we propose a compound optimization strategy that selectspbased on a subjected weighting of the relative importance of the two fundamental criteria of interest for restricted randomization mechanisms, namely balance between the treatment assignments and allocation randomness. We use exact and asymptotic distributional properties of Efron's coin to find the optimalpunder compound criteria involving imbalance variability, expected imbalance, selection bias, and accidental bias, for both small/moderate trials and large samples. Copyright © 2015 John Wiley & Sons, Ltd.
Minutaside A, new α‐amylase inhibitor flavonol glucoside from Tagetes minuta: Antidiabetic, antioxidant, and molecular modeling studies
Authors: Ibrahim Sabrin R.M. , Mohamed Gamal A. , Abdel‐Latif Mohamed M. M. , El‐Messery Shahenda M. , Al Musayeib Nawal M. , Shehata Ibrahim A.
Published: June 2015

Investigation of the EtOAc fraction of Tagetes minuta L. (Asteraceae) aerial parts has afforded a new flavonol glucoside, minutaside A (quercetagetin 6‐O‐(6‐O‐hexanoyl)‐β‐D‐glucopyranoside) (1), together with four known flavonoids: axillarin 7‐O‐β‐D‐glucopyranoside (2), quercetagetin 3,7‐dimethoxy‐6‐O‐β‐D‐glucopyranoside (3), quercetagetin 7‐methoxy‐6‐O‐β‐D‐glucopyranoside (4), and quercetagetin 6‐O‐β‐D‐glucopyranoside (5). Their structures were established by multiple spectroscopic methods in addition to HRESIMS (high‐resolution electrospray ionisation mass spectra) and comparison with literature data. The antioxidant and anti‐diabetic activities of the isolated flavonoids were evaluated using 2,2‐diphenyl‐1‐picrylhydrazyl (DPPH) and α‐amylase inhibition assays. Compounds 1 and 5 showed significant antioxidant activity (84.1 and 83.0% at a 20 μM dose, respectively). Compounds 1, 4, and 5 exhibited strong α‐amylase inhibitory activity compared with acarbose (a reference α‐amylase inhibitor). However, 2 and 3 showed moderate activity. Molecular modeling studies of 1–5 that included docking, flexible alignment, and surface mapping were performed to evaluate their recognition profile α‐amylase receptor. In docking simulations, 5 displayed a binding mode similar to that of acarbose in the active site of α‐amylase enzyme.
The elegance of energy balance: Insight from circuit‐level manipulations
Authors: Webber Emily S. , Bonci Antonello , Krashes Michael J.
Published: June 2015

Mechanisms of energy balance were first examined using very powerful neuroscience techniques such as lesions and electrical stimulation. This early work identified the hypothalamus as a key structure involved in hunger and feeding; however, neural resolution of cell‐defined populations contributing to appetite regulation remained elusive. Recent innovations in neuroscience have produced constructs that allow for a high degree of specificity in loss‐ and gain‐of‐function manipulations in molecularly circumscribed neural subsets as well as monosynaptic circuit mapping and in vivo neurophysiology. These complimentary techniques have provided researchers an unprecedented amount of empirical agility. As a result, cell populations in two subregions of the hypothalamus have emerged as key players in the physiological control of feeding behavior. The arcuate nucleus of the hypothalamus and the paraventricular nucleus of the hypothalamus contain neural populations that have a direct role in the promotion of hunger and satiety. These include neurons that express agouti‐related peptide, pro‐opiomelanocortin, single‐minded homolog 1 protein, and the melanocortin‐4 receptor. This review focuses on how these neural subsets communicate with one another, link up to build elaborate networks, and ultimately contribute to alterations in food intake. The continuing advancement of neuroscience tools, as well as a multimodal integration of findings, will be critical in illuminating an exhaustive and clinically relevant hunger circuit. Synapse 69:461–474, 2015. © 2015 Wiley Periodicals, Inc. This article is a U.S. Government work and is in the public domain in the USA. Synapse published by Wiley Periodicals, Inc.
Engineering structure and function using thermoresponsive biopolymers
Authors: Pastuszka Martha K. , MacKay J. Andrew
Published: June 2015

Self‐assembly enables exquisite control at the smallest scale and generates order among macromolecular‐building blocks that remain too small to be manipulated individually. Environmental cues, such as heating, can trigger the organization of these materials from individual molecules to multipartixcle assemblies with a variety of compositions and functions. Synthetic as well as biological polymers have been engineered for these purposes; however, biological strategies can offer unparalleled control over the composition of these macromolecular‐building blocks. Biologic polymers are macromolecules composed of monomeric units that can be precisely tailored at the genetic level; furthermore, they can often utilize endogenous biodegradation pathways, which may enhance their potential clinical applications.DNA(nucleotides), polysaccharides (carbohydrates), and proteins (amino acids) have all been engineered to self‐assemble into nanostructures in response to a change in temperature. This focus article reviews the growing body of literature exploring temperature‐dependent nano‐assembly of these biological macromolecules, summarizes some of their physical properties, and discusses future directions.WIREs Nanomed Nanobiotechnol2015, 8:123–138. doi: 10.1002/wnan.1350

This article is categorized under:

Biology-Inspired Nanomaterials > Nucleic Acid-Based Structures

Nanotechnology Approaches to Biology > Nanoscale Systems in Biology

Biology-Inspired Nanomaterials > Peptide-Based Structures
Novel transporters from Kluyveromyces marxianus and Pichia guilliermondii expressed in Saccharomyces cerevisiae enable growth on l‐arabinose and d‐xylose
Authors: Knoshaug Eric P. , Vidgren Virve , Magalhães Frederico , Jarvis Eric E. , Franden Mary Ann , Zhang Min , Singh Arjun
Published: June 2015

Genes encoding l‐arabinose transporters in Kluyveromyces marxianus and Pichia guilliermondii were identified by functional complementation of Saccharomyces cerevisiae whose growth on l‐arabinose was dependent on a functioning l‐arabinose transporter, or by screening a differential display library, respectively. These transporters also transport d‐xylose and were designated KmAXT1 (arabinose–xylose transporter) and PgAXT1, respectively. Transport assays using l‐arabinose showed that KmAxt1p has Km 263 mm and Vmax 57 nm/mg/min, and PgAxt1p has Km 0.13 mm and Vmax 18 nm/mg/min. Glucose, galactose and xylose significantly inhibit l‐arabinose transport by both transporters. Transport assays using d‐xylose showed that KmAxt1p has Km 27 mm and Vmax 3.8 nm/mg/min, and PgAxt1p has Km 65 mm and Vmax 8.7 nm/mg/min. Neither transporter is capable of recovering growth on glucose or galactose in a S. cerevisiae strain deleted for hexose and galactose transporters. Transport kinetics of S. cerevisiae Gal2p showed Km 371 mm and Vmax 341 nm/mg/min for l‐arabinose, and Km 25 mm and Vmax 76 nm/mg/min for galactose. Due to the ability of Gal2p and these two newly characterized transporters to transport both l‐arabinose and d‐xylose, one scenario for the complete usage of biomass‐derived pentose sugars would require only the low‐affinity, high‐throughput transporter Gal2p and one additional high‐affinity general pentose transporter, rather than dedicated d‐xylose or l‐arabinose transporters. Additionally, alignment of these transporters with other characterized pentose transporters provides potential targets for substrate recognition engineering. Accession Nos: KmAXT1: GZ791039; PgAXT1: GZ791040 Copyright © 2015 John Wiley & Sons, Ltd.
Long‐Term Outcome After Resection of Huge Hepatocellular Carcinoma ≥10 cm: Single‐Institution Experience with 471 Patients
Authors: Hwang Shin , Lee Young‐Joo , Kim Ki‐Hun , Ahn Chul‐Soo , Moon Deok‐Bog , Ha Tae‐Yong , Song Gi‐Won , Jung Dong‐Hwan , Lee Sung‐Gyu
Published: June 2015

Background

Tumor recurrence is very common after resection of huge hepatocellular carcinoma (HCC). This study intended to evaluate early recurrence and long‐term outcomes in patients with huge HCC ≥ 10 cm after primary resection and treatment of recurrence.

Methods

Recurrence and survival outcomes were retrospectively evaluated in 471 patients with huge HCCs who underwent resection between January 2000 and April 2012.

Results

Mean tumor diameter was 13.6 ± 3.1 cm, with 93 % of patients having single tumors. Anatomic and R0 resection rates were 91.1 and 89.4 %, respectively. Perioperative mortality rate was 1.7 %. Tumor recurrence and patient survival rates were 62.2 and 69.2 % at 1 year and 76.0 and 35.5 % at 5 years, respectively. Of patients with recurrence, 92.5 % received specific treatment. Median patient survival period after initial intrahepatic recurrence was 16 months. Tumor volume did not affect recurrence or survival outcomes. Independent risk factors for tumor recurrence and patient survival were serum alpha‐fetoprotein ≥100 ng/mL, hypermetabolic uptake on positron emission tomography, satellite nodules, and microvascular invasion. These four factors were used to develop a risk prediction model, in which 1‐year HCC recurrence rates in patients with 0, 1, 2, 3, and 4 risk factors were 18.7, 30.3, 58.7, 79.0, and 92.1 %, respectively, and their 1‐year patient survival rates were 100, 97.0, 75.5, 63.9, and 42.1 %, respectively.

Conclusions

In patients with huge HCCs, hepatic resection with active recurrence treatment resulted in improved long‐term survival. Our 4‐factor risk prediction model appears to contribute to quantitative postoperative risk estimation for early HCC recurrence and patient survival in patients with HCC ≥ 10 cm.
Unexploited Thapsia garganica, Orlaya maritima, and Retama raetam Seeds: Potential Sources of Unsaturated Fatty Acid and Natural Antioxidants
Authors: Tlili Nizar , Mejri Houda , Lajnef Houda Ben , Feriani Anouer , Khaldi Abdelhamid , Nasri Nizar
Published: June 2015

Total lipid contents, fatty acid compositions, phenolic profiles and antioxidants activities of seeds from Thapsia garganica, Orlaya maritima, and Retama raetam were investigated. The oil values were more than 26 %, except seeds of R. raetam (ca. 3 %). Unsaturated fatty acids accounted for the majority of the fatty acids (more than 75 %). Oleic and linoleic acid were the predominant fatty acids. Total phenolic compounds (24–104 mg GAE g−1 DR), total flavonoids (4–102 mg QE g−1g DR), total tannins (28–85 mg GAE g−1 DR) and condensed tannins (0.62–131 mg CE g−1 DR) were also determined. The antioxidant activities using different assays were evaluated. The predominant detected classes were the phenolic acids (42–85 %) and the flavonoids (11–48 %). The major phenolic acids were caffeic, trans‐4‐hydroxy‐3‐methoxycinnamic, p‐coumaric, and gallic acid. The predominant flavonoids were quercetin, luteolin, naringin, apigenin, and kaempferol. This study brings attention to the medicinal importance of these species as a source of oil and antioxidant molecules.
Outcome of Antenatally Diagnosed Cardiac Rhabdomyoma: Case Series from a Tertiary Fetal Medicine Center in India
Authors: Ghaisas Sushrut Dilip , Seshadri Suresh , Suresh Beena
Published: June 2015

The aim of this case series is to review our institution’s experience with fetal cardiac rhabdomyoma, to document the clinical outcome and the incidence of associated tuberous sclerosis (TS) in these babies after birth. Eight cases with fetal cardiac rhabdomyoma were studied over a period of three years and the perinatal outcome was obtained. Out of these eight cases diagnosed antenatally, seven pregnancies continued till term and one woman opted for termination of pregnancy. There was one early neonatal death and of the six living, five developed TS with cutaneous and neurological manifestations. This association is similar with other larger multicentric studies and meta-analysis. Fetal cardiac rhabdomyoma is strongly associated with the development of TS in postnatal life, and the couples should be counseled regarding this association.
Sexual risk at first coitus: Does alcohol make a difference?
Authors: Livingston Jennifer A. , Testa Maria , Windle Michael , Bay‐Cheng Laina Y.
Published: June 2015

This study examines whether use of alcohol at first coitus is associated with increased sexual risk for young women. First coitus is the focus of the investigation because it is a memorable, formative experience that has implications for subsequent sexual health. A community sample of young women ages 18–19 years (N = 227) completed retrospective interviews. Characteristics and perceptions of the first coital event were examined using chi squares and one‐way multivariate analysis of variance (MANOVA) to determine if there were differences based on alcohol‐involvement. Alcohol‐involved first coitus events occurred in social settings with risky partners, were rated less positively, and were non‐consensual relative to those that did not involve alcohol. Alcohol use was not related to condom use. Alcohol‐involvement was associated with subsequent pairing of alcohol with sex and incapacitated rape. Adolescent alcohol use occurs in contexts that increases young women's sexual risk through exposure to risky partners.
Robotic‐Assisted Thoracic Surgery for Early‐Stage Lung Cancer: A Review
Authors: Brooks Paula
Published: June 2015

This review evaluates the benefits and disadvantages associated with the use of robotic‐assisted technology in performing lobectomies in patients with early‐stage lung cancer. The author conducted a literature search of Ovid®, MEDLINE®, PubMed®, and CINAHL® for articles published from 2005 to 2013. Search criteria included key terms such as robot, robotic, robotic‐assisted lobectomy, and lung cancer. Of 922 articles, the author included a total of 12 research‐based published studies in the analysis and incorporated the findings into an evidence table. Results showed that robotic‐assisted lobectomies are feasible safe procedures for patients with stage 1A or 1B lung cancer; however, there is a steep learning curve and long‐term randomized studies evaluating robotic‐assisted lobectomy and conventional posterolateral thoracotomy or video‐assisted thoracic lobectomy are needed. For patient safety, perioperative nurses should be aware of the length of time and experience required to perform these procedures, the costs, techniques, benefits, and disadvantages.
Can Efficient Smoke Evacuation Limit Aerosolization of Bacteria?
Authors: Schultz Leonard
Published: June 2015

Preventing surgical site infections requires knowledge of the sources of wound contamination. One possible source of wound contamination is bacteria aerosolized in diathermy plume (ie, surgical smoke). This study used an experimental model of porcine tissue embedded with Serratia marcescens to determine the extent of viable bacteria present in surgical plume. The results showed that only blended current electrosurgery, not laser plume or coagulation electrosurgery, contains viable bacteria. Further, the study revealed that placing a suction device near the electrosurgical site reduced the number of aerosolized viable bacteria. Therefore, evacuating the electrosurgical plume may help reduce contamination of the surgical wound. Nurses may wish to advocate for the use of air suction devices as one way to protect patients from surgical site infections.
Cognitive behavioural therapy for depression: systematic review of imaging studies
Authors: Franklin George , Carson Alan J , Welch Killian A.
Published: June 2015

Objective

Although cognitive behavioural therapy (CBT) has been shown to be an effective treatment for depression, the biological mechanisms underpinning it are less clear. This review examines if it is associated with changes identifiable with current brain imaging technologies.

Methods

To better understand the mechanisms by which CBT exerts its effects, we undertook a systematic review of studies examining brain imaging changes associated with CBT treatment of depression.

Results

Ten studies were identified, five applying functional magnetic resonance imaging, three positron emission tomography, one single photon emission computer tomography, and one magnetic resonance spectroscopy. No studies used structural MRI. Eight studies included a comparator group; in only one of these studies was there randomised allocation to another treatment. CBT-associated changes were most commonly observed in the anterior cingulate cortex (ACC), posterior cingulate, ventromedial prefrontal cortex/orbitofrontal cortex (VMPFC/OFC) and amygdala/hippocampus.

Discussion

The evidence, such as it is, suggests resting state activity in the dorsal ACC is decreased by CBT. It has previously been suggested that treatment with CBT may result in increased efficiency of a putative ‘dorsal cognitive circuit’, important in cognitive control and effortful regulation of emotion. It is speculated this results in an increased capacity for ‘top-down’ emotion regulation, which is employed when skills taught in CBT are engaged. Though changes in activity of the dorsal ACC could be seen as in-keeping with this model, the data are currently insufficient to make definitive statements about how CBT exerts its effects. Data do support the contention that CBT is associated with biological brain changes detectable with current imaging technologies.
Katherine of Aragon and the Veil
Authors: HADWIN J. F.
Published: June 2015

According to several distinguished historians Katherine of Aragon could have averted the Henrician reformation by accepting Cardinal Campeggio's suggestion that she take vows of religion and enter a nunnery, thus facilitating her husband's remarriage. Here it is argued that, even if Katherine had agreed, the fulfilment of such a project would pose serious problems. Once he recognised the enormity of what the legate intended, Henry rapidly lost interest: his craving for an undisputed succession could hardly have been satisfied by adding a second potentially contentious papal bull to that which had allowed his first marriage.
The Prodigal Son: Pope Gregory XVI and a Wayward Priest
Authors: KORTEN CHRISTOPHER
Published: June 2015

This article deals with the evolving attitude of Mauro Cappellari (later Pope Gregory XVI) towards the extraordinary case of a capricious priest, Calogerá Biondi, caught up in an illicit marital affair in Constantinople. Given the fragile state of the Armenian Catholic Church in the Ottoman Empire in the 1820s, and the potential firestorm that could be set off if the couple's story came to light, Cappellari lobbied the Curia to release Biondi from his spiritual obligations and countenance the marriage. Once elected pope in 1831, he would overrule his predecessor's decision that denied them this union. Cappellari's pragmatic approach to this case stands in stark contrast to the overwhelming perception of him within the historiography as sternly doctrinaire.