bluuebunny/crossref_metadata_2025 huggingface dataset:
Fluorescence Modulation in Tribranched Switchable [4]Rotaxanes
Authors: Zhang Ji‐Na , Li Hong , Zhou Wei , Yu Shi‐Lin , Qu Da‐Hui , Tian He
Published: November 2013

Two novel tribranched [4]rotaxanes with a 1,3,5‐triphenylene core and three rotaxane arms have been designed, synthesized, and characterized by 1H and 13C NMR spectroscopies and HR‐ESI mass spectrometry. [4]Rotaxanes 1 and 2 each possess the same three‐armed skeleton. Each arm incorporates two distinguishable binding sites for a dibenzo[24]crown‐8 ring, namely a dibenzylammonium site and an N‐methyltriazolium site, and is terminated by a 4‐morpholino‐naphthalimide fluorophore as a stopper. [4]Rotaxane 1 has three di‐ferrocene‐functionalized dibenzo[24]crown‐8 rings whereas 2 has three simple dibenzo[24]crown‐8 rings interlocked with the thread component. Uniform shuttling motions of the three macrocycles in both 1 and 2 can be driven by external acid–base stimuli, which were confirmed by 1H NMR spectroscopy. However, [4]rotaxanes 1 and 2 show distinct modes of fluorescence modulation in response to external acid–base stimuli. [4]Rotaxane 1 exhibits a remarkable fluorescence decrease in response to the addition of 1,8‐diazabicyclo[5.4.0]undec‐7‐ene (DBU) as a base, which can displace the ferrocene‐functionalized macrocycle from the dibenzylammonium station to the N‐methyltriazolium station. In contrast, the fluorescence intensity of [4]rotaxane 2 showed an enhancement with the addition of DBU. Time‐resolved fluorescence measurements have been performed. The different photoinduced electron‐transfer processes responsible for the fluorescence changes in the two molecular systems are discussed. Topological structures of this kind have significant potential for the design and construction of large and complex assemblies with controllable functions.
Synthesis and Biological Evaluation of Benzo[b]furans as Inhibitors of Tubulin Polymerization and Inducers of Apoptosis
Authors: Kamal Ahmed , Reddy N. V. Subba , Nayak V. Lakshma , Reddy V. Saidi , Prasad B. , Nimbarte Vijaykumar D. , Srinivasulu Vunnam , Vishnuvardhan M. V. P. S. , Reddy C. Suresh
Published: November 2013

A series of benzo[b]furans was synthesized with modification at the 5‐position of the benzene ring by introducing C‐linked substituents (aryl, alkenyl, alkynyl, etc.). These compounds were evaluated for their antiproliferative activities, inhibition of tubulin polymerization, and cell‐cycle effects. Some compounds in this series displayed excellent activity in the nanomolar range against lung cancer (A549) and renal cell carcinoma (ACHN) cancer cell lines. (6‐Methoxy‐5‐((4‐methoxyphenyl)ethynyl)‐3‐methylbenzofuran‐2‐yl)(3,4,5‐trimethoxyphenyl)methanone (26) and (E)‐3‐(6‐methoxy‐3‐methyl‐2‐(1‐(3,4,5‐trimethoxyphenyl)vinyl)benzofuran‐5‐yl)prop‐2‐en‐1‐ol (36) showed significant activity in the A549 cell line, with IC50 values of 0.08 and 0.06 μM, respectively. G2/M cell‐cycle arrest and subsequent apoptosis was observed in the A549 cell line after treatment with these compounds. The most active compound in this series, 36, also inhibited tubulin polymerization with a value similar to that of combretastatin A‐4 (1.95 and 1.86 μM, respectively). Furthermore, detailed biological studies such as Hoechst 33258 staining, DNA fragmentation and caspase‐3 assays, and western blot analyses with the pro‐apoptotic protein Bax and the anti‐apoptotic protein Bcl‐2 also suggested that these compounds induce cell death by apoptosis. Molecular docking studies indicated that compound 36 interacts and binds efficiently with the tubulin protein.
Synthesis and Characterization of Glycol Chitosan DNA Nanoparticles for Retinal Gene Delivery
Authors: Mitra Rajendra N. , Han Zongchao , Merwin Miles , Al Taai Muhammed , Conley Shannon M. , Naash Muna I.
Published: November 2013

Given the number of monogenic ocular diseases and the number of non‐monogenic degenerative ocular diseases for which gene therapy is considered as a treatment, the development of effective therapeutic delivery strategies for DNA is a critical research goal. In this work, nonviral nanoparticles (NPs) composed of glycol chitosan (GCS) and plasmid DNA (pDNA) were generated, characterized, and evaluated. These particles are stable, do not aggregate in saline, are resistant to DNases, and have a hydrodynamic diameter of approximately 250 nm. Furthermore, the plasmid in these NPs was shown to maintain its proper conformation and can be released and expressed inside the cell. To determine whether these NPs would be suitable for intraocular use, pDNA carrying the ubiquitously expressed CBA‐eGFP expression cassette was compacted and subretinally injected into adult wild‐type albino mice. At day 14 post‐injection (PI), substantial green fluorescent protein (GFP) expression was observed exclusively in the retinal pigment epithelium (RPE) in eyes treated with GCS NPs but not in those treated with uncompacted pDNA or vehicle (saline). No signs of gross retinal toxicity were observed, and at 30 days PI, there was no difference in electroretinogram function between GCS NP‐, pDNA‐, or vehicle‐treated eyes. These results suggest that with further development, GCS NPs could be a useful addition to the available repertoire of genetic therapies for the treatment of RPE‐associated diseases.
Analyzing Sector‐Specific CSR Reporting: Social and Environmental Disclosure to Investors in the Chemicals and Banking and Insurance Industry
Authors: Lock Irina , Seele Peter
Published: November 2013

This paper aims to deepen the understanding of corporate social responsibility (CSR) reporting practices toward stakeholder group investors. Quantitative content analysis was applied to 437 articles of CSR reports from the chemicals, and banking and insurance industries in Germany and Switzerland. The results were benchmarked to the Sarasin sustainability rating's weighting of social and environmental industry risks. It was found that the chemicals industry's CSR reports meet the benchmark, whereas those from the banking and insurance industry do not (RQ1). Swiss chemicals producers perform well in reporting on their specific industry risks, while German companies mirror the sector‐specific risks in the banking and insurance industry (RQ2). The results thus indicate the appropriateness of investor‐specific reporting and suggest – in line with GRI and the European Union – further standardization in order to level the playing field of CSR in Europe. Copyright © 2013 John Wiley & Sons, Ltd and ERP Environment
Dynamic occupancy models for analyzing species' range dynamics across large geographic scales
Authors: Bled Florent , Nichols James D. , Altwegg Res
Published: November 2013

Large‐scale biodiversity data are needed to predict species' responses to global change and to address basic questions in macroecology. While such data are increasingly becoming available, their analysis is challenging because of the typically large heterogeneity in spatial sampling intensity and the need to account for observation processes. Two further challenges are accounting for spatial effects that are not explained by covariates, and drawing inference on dynamics at these large spatial scales. We developed dynamic occupancy models to analyze large‐scale atlas data. In addition to occupancy, these models estimate local colonization and persistence probabilities. We accounted for spatial autocorrelation using conditional autoregressive models and autologistic models. We fitted the models to detection/nondetection data collected on a quarter‐degree grid across southern Africa during two atlas projects, using the hadeda ibis (Bostrychia hagedash) as an example. The model accurately reproduced the range expansion between the first (SABAP1: 1987–1992) and second (SABAP2: 2007–2012) Southern African Bird Atlas Project into the drier parts of interior South Africa. Grid cells occupied duringSABAP1 generally remained occupied, but colonization of unoccupied grid cells was strongly dependent on the number of occupied grid cells in the neighborhood. The detection probability strongly varied across space due to variation in effort, observer identity, seasonality, and unexplained spatial effects. We present a flexible hierarchical approach for analyzing grid‐based atlas data using dynamical occupancy models. Our model is similar to a species' distribution model obtained using generalized additive models but has a number of advantages. Our model accounts for the heterogeneous sampling process, spatial correlation, and perhaps most importantly, allows us to examine dynamic aspects of species ranges.
Efficient pretreatment for bioethanol production from water hyacinth (eichhornia crassipes) involving naturally isolated and recombinant enzymes and its recovery
Authors: Das Saprativ P. , Ravindran Rajeev , Ghosh Arabinda , Deka Deepmoni , Das Debasish , Jawed Mohammad , Fontes Carlos M.G.A. , Goyal Arun
Published: November 2013

Simultaneous saccharification and fermentation (SSF) experiments involving water hyacinth (Eichhornia crassipes), an abundantly available renewable bioresource, using hydrolytic enzymes, and fermentative microbes were investigated. Water hyacinth containing 30.01 (%, w/w) cellulose, 44.49 (%, w/w) hemicellulose, and 20.04 (%, w/w) lignin was subjected to three different pretreatments, namely, wet oxidation, phosphoric acid (H3PO4)‐acetone, and ammonia fiber explosion (AFEX). Hydrolytic enzymes, namely, recombinant Clostridium thermocellum cellulase (GH5) and hemicellulase (GH43), Trichoderma reesei and Bacillus subtilis AS3 cellulases were employed separately for saccharification. Saccharomyces cerevisiae and Candida shehatae were used for fermentation. The AFEX pretreated 1% (w/v) water hyacinth along with recombinant cellulase (GH5)‐hemicellulase (GH43) consortium gave the highest ethanol titer of 1.52 g/L as compared with wet oxidation (1.23 g/L) and phosphoric acid‐acetone pretreatments (1.31 g/L). The best SSF combination with 5% (w/v) substrate at shake flask contributed an ethanol titer and yield of 7.83 g/L, 0.266 (g of ethanol/g of substrate) and its scale up at bioreactor level resulted in significantly higher ethanol titer and yield of 14.39 g/L and 0.489 (g/g), respectively. 93.0 (%, v/v) ethanol from bioreactor was recovered by rotary evaporator with 20.4% purification efficiency. © 2013 American Institute of Chemical Engineers Environ Prog, 33: 1396–1404, 2014
Continuous biohydrogen and biomethane production from whey permeate in a two‐stage fermentation process
Authors: Kisielewska M. , Wysocka I. , Rynkiewicz M.R.
Published: November 2013

This study focuses on the exploitation of the two‐stage continuous fermentation process for biohydrogen and biomethane production from whey permeate. Mesophilic fermentative biohydrogen production was investigated at a constant hydraulic retention time (HRT) of 24 h and organic loading rates (OLRs) of 20, 25, 30, and 35 kg COD/m3·d. The hydrogenogenic reactor was successfully operated at OLR of 30 kg COD/m3·d when the proportion of hydrogen in biogas, volumetric productionrsquo rate of hydrogen, and hydrogen yield reached the maximum values of 44.6 ± 0.8%, 5.26 ± 0.15 L H2/d, and 4.19 mol H2/kg CODremoved, respectively. The effluent from hydrogenogenic reactor was further digested to biogas in the second reactor operated at a HRT of 3 d and variable OLR in the range of 0.9–1.9 kg COD/m3·d. Maximum biogas production rate, volumetric production rate of methane and methane yield were 16.90 ± 0.6 L/d, 11.95 ± 0.6 L CH4/d, and 0.12 m3 CH4/kg CODadded. The total chemical oxygen demand elimination from whey permeate reached 98% in a two‐stage process. © 2013 American Institute of Chemical Engineers Environ Prog, 33: 1411–1418, 2014
Light‐controlled astrocytes promote human mesenchymal stem cells toward neuronal differentiation and improve the neurological deficit in stroke rats
Authors: Tu Jie , Yang Fan , Wan Jun , Liu Yunhui , Zhang Jie , Wu Bifeng , Liu Yafeng , Zeng Shaoqun , Wang Liping
Published: November 2013

Astrocytes are key components of the central nervous system (CNS) and release factors to support neural stem cell proliferation, differentiation, and migration. Adenosine 5'‐triphosphate (ATP) is one of the key factors released upon activation of astrocytes that regulates the neural stem cell's function. However, it is not clear whether ATP derived from the depolarized astrocytes plays a vital role in promoting the neuronal differentiation of mesenchymal stem cells (MSCs) in vitro and in vivo. Herein, for the first time, we co‐cultured MSCs with light‐stimulated‐channelrhodopsin‐2 (ChR2)‐astrocytes, and observed that the neuronal differentiation of MSCs was enhanced by expressing more neuronal markers, Tuj1 and NeuN. The ChR2‐astrocyte‐conditioned medium also stimulated MSCs differentiating into neuronal lineage cells by expressing more Tuj1 and Pax6, which was blocked by the P2X receptor antagonist, TNP‐ATP. Then we found that light‐depolarization of astrocytes significantly increased ATP accumulation in their bathing medium without impairing the cell membrane. We further found that ATP up‐regulated the Tuj1, Pax6, FZD8 and β‐catenin mRNA levels of MSCs, which could be reversed by application of TNP‐ATP. Together these in vitro data provided convergent evidence that ATP from light‐depolarized‐astrocytes activated the wnt/β‐catenin signaling of MSCs through binding to the P2X receptors, and promoted the neuronal differentiation of MSCs. Finally but importantly, our study also demonstrated in stroke rats that light‐controlled astrocytes stimulated endogenous ATP release into the ischemic area to influence the transplanted MSCs, resulting in promoting the MSCs towards neuronal differentiation and improvements of neurological deficit. GLIA 2013;62:106–121
Extranodal marginal zone lymphoma of mucosa‐associated lymphoid tissue of the salivary glands: A population‐based study from 1994 to 2009
Authors: Vazquez Alejandro , Khan Mohemmed N. , Sanghvi Saurin , Patel Neal R. , Caputo Joseph L. , Baredes Soly , Eloy Jean Anderson
Published: November 2013

Background

Extranodal marginal zone lymphoma of mucosa‐associated lymphoid tissue (MALT lymphoma) arising from the salivary glands is rare.

Methods

Five hundred seven cases were available for frequency/incidence analysis, and 712 for relative survival and regression analysis in the Surveillance Epidemiology and End Results (SEER) database.

Results

Of the total patients, 72.98% were women, 80.47% were white, and 74.75% were ≥50 years old. The parotid gland was involved in 80.87% of cases. Ann Arbor stage at diagnosis was 53.85% IE, 18.54% IIE, and 10.06% IIIE/IV. Overall, 15‐year relative survival was 78.40%. Relative survival was worst among blacks and those with advanced‐stage disease. No difference was noted between those treated with surgery, radiation, or both. Statistically significant poor prognosticators included black race (hazard ratio [HR], 2.3961; 95% confidence interval [CI], 1.54–3.72; p = .0001) and stage IIIE/IV (HR, 2.3677; 95%CI, 1.36–4.11; p = .0022).

Conclusion

Early‐stage salivary gland MALT lymphoma disease may be amenable to unimodality treatment. Even patients with advanced disease have relatively high survivals. © 2014 Wiley Periodicals, Inc. Head Neck 37: 18–22, 2015
Impact of nodal ratio on survival in recurrent nasopharyngeal carcinoma
Authors: Chan Richie Chiu‐Lung , Chan Jimmy Yu Wai
Published: November 2013

Background

The purpose of this study was to investigate if nodal ratio has a prognostic role in the survival of patients with recurrent nasopharyngeal carcinoma (NPC) in the neck.

Methods

Patients with recurrent NPC in the neck who were treated in Queen Mary Hospital from 2000 to 2011 were identified. Clinical data, pathological results, and survival outcome were analyzed.

Results

Only nodal ratio remained as a statistically significant predictor in multivariate analysis for nodal recurrence (p = .045) and nodal recurrence‐free survival (p = .010). All other predictors lost significance when compared with each other and with nodal ratio. Nodal ratio was also a significant predictor for overall survival (OS) in univariate analysis (p = .001) but lost its significance in multivariate analysis. The cutoff points 10% and 15% effectively stratified the patients into 3 risk groups (p = .02).

Conclusion

In patients with NPC with neck recurrence, nodal ratio (the ratio of positive nodes to the total number of nodes examined) is a strong predictor of further nodal recurrence and nodal recurrence‐free survival. Nodal ratio also impacts the OS but loses its significance in multivariate analysis, including concurrent local recurrence. Stratification of patients into low, medium, and high‐risk groups according to nodal ratio may have a potential role in guiding therapeutic decision‐making. Therefore, further exploration in this area is warranted. © 2014 Wiley Periodicals, Inc. Head Neck 37: 12–17, 2015
Distillation technology – still young and full of breakthrough opportunities
Authors: Kiss Anton A.
Published: November 2013

Throughout history, distillation has been the most widespread separation method. However, despite its simplicity and flexibility, distillation still remains very energy inefficient. Novel distillation concepts based on process intensification, can deliver major benefits, not just in terms of significantly lower energy use, but also in reducing capital investment and improving eco‐efficiency. While very likely to remain the separation technology of choice for the next decades, there is no doubt that distillation technology needs to make radical changes in order to meet the demands of the energy‐conscious modern society. This article aims to show that in spite of its long age, distillation technology is still young and full of breakthrough opportunities. Moreover, it provides a broad overview of the recent developments in distillation based on process intensification principles, for example heat pump assisted distillation (e.g. vapor compression or compression–resorption), heat‐integrated distillation column, membrane distillation, HiGee distillation, cyclic distillation, thermally coupled distillation systems (Petlyuk), dividing‐wall column, and reactive distillation. These developments as well as the future perspectives of distillation are discussed in the context of changes towards a more energy efficient and sustainable chemical process industry. Several key examples are also included to illustrate the astonishing potential of these new distillation concepts to significantly reduce the capital and operating cost at industrial scale. © 2013 Society of Chemical Industry
Estimation of aortic pulse pressure using fourier velocity encoded M‐mode MR
Authors: Taviani Valentina , Hickson Stacey S. , Hardy Christopher J. , Patterson Andrew J. , Young Victoria E. , McEniery Carmel M. , Wilkinson Ian B. , Gillard Jonathan H. , Graves Martin J.
Published: November 2013

Purpose

To use a simplified hemodynamic model and Fourier‐encoded velocity data to measure pulse pressure (PP) in the descending aorta.

Materials and Methods

A one‐dimensional, cylindrically localized pulse sequence with Fourier velocity encoding (FVE) was used to obtain time‐dependent velocity distributions along the descending aorta. Numerical evaluation of a simplified hemodynamic model, based on a cross‐sectionally averaged form of the mass conservation equation, allowed estimation of the average pressure waveform and PP along 6‐cm‐long segments located within the descending aorta. Magnetic resonance (MR)‐derived pressures were compared against applanation tonometry (AT) performed in healthy subjects (n = 18) and intravascular pressure measurements (IVPM) obtained in patients (n = 4) undergoing diagnostic cardiac angiography and then found to be either normal or with clinically insignificant coronary artery disease.

Results

The root mean square (RMS) error between MR‐ and AP‐derived pressure waveforms was 11.7 ± 5.8%. With respect to IVPM, the RMS error ranged from 4.2% to 14.7%. In terms of pulse pressures, there was good agreement with both AT (bias = 0.99 mmHg; 95% limits of agreement (LOA) = [−5.0 to 7.0 mmHg]; range = 12.0 mmHg) and IVPM (bias = −1.82 mmHg; 95% LOA = [−7.2 to 3.5 mmHg]; range = 10.7 mmHg).

Conclusion

FVE M‐mode and numerical evaluation of a simplified flow model can be used to estimate central pulse pressures noninvasively and accurately with respect to well‐established gold standards. J. Magn. Reson. Imaging 2014;39:85–93. © 2013 Wiley Periodicals, Inc.
Sclerosed hemangioma of the liver: Concordance of MRI features with histologic characteristics
Authors: Ridge Carole A. , Shia Jinru , Gerst Scott R. , Do Richard K.G.
Published: November 2013

Purpose

To correlate the MRI features of sclerosed hemangiomas with histologic appearance.

Materials and Methods

A medical record search identified patients with sclerosed hemangioma who underwent MRI and biopsy/resection from January 2000 to March 2012 for this retrospective institutional review board approved study. Two radiologists independently performed image analysis. A pathologist evaluated lesion histologic characteristics.

Results

Twelve patients (median age 65; range 41–78 years) were included; 7/12 patients had typical hemangiomas which were also analyzed. Sclerosed hemangiomas were less often moderately T2 hyperintense (5/11 45%; compared with 7/7, 100%; P = 0.0377) and demonstrated moderate arterial phase enhancement less frequently (4/12, 33% compared with 7/7, 100%; P = 0.0128) than typical hemangiomas. Markedly sclerosed hemangiomas (N = 7) exhibited the least “typical” findings, including mild T2 hyperintensity (5/7; 71%), absent arterial phase enhancement (4/7; 57%), mild portal venous phase enhancement (6/7; 86%), and absent centripetal fill‐in (6/7; 86%). Arterial phase hyperenhancement occurred more often in mild/moderately sclerosed hemangiomas (3/5; 60%) compared with markedly sclerosed hemangiomas (1/7; 14%).

Conclusion

Sclerosed hemangiomas exhibit MRI features that appear to correspond with the degree of sclerosis. These features coupled with the presence of other typical hemangiomas may aid in prospectively diagnosing sclerosed hemangioma. J. Magn. Reson. Imaging 2014;39:812–818. © 2013 Wiley Periodicals, Inc.
White matter segmentation based on a skeletonized atlas: Effects on diffusion tensor imaging studies of regions of interest
Authors: Zhang Shengwei , Arfanakis Konstantinos
Published: November 2013

Purpose

To compare the influence of conventional and skeletonized atlas‐based white matter (WM) segmentation on diffusion tensor imaging (DTI) region‐of‐interest (ROI) investigations.

Materials and Methods

A conventional WM atlas was skeletonized by thinning the corresponding fractional anisotropy (FA) map and labels. The conventional and skeletonized versions of the atlas were used for WM segmentation. The percentage of non‐WM voxels assigned to WM labels, as well as statistical summaries of tensor‐derived quantities, were compared between segmentation approaches. The ability to detect small differences in diffusion properties across groups of subjects was also compared between segmentation approaches.

Results

Skeletonized segmentation resulted in significantly lower non‐WM percentage (P < 0.05), higher mean FA and lower trace (P < 0.05) in most WM labels, and mainly lower standard deviation of FA and trace in labels neighboring the ventricles. In terms of maximizing the ability to detect intergroup DTI differences, skeletonized segmentation was superior in the corpus callosum, but the optimal approach varied for other WM labels.

Conclusion

Conventional and skeletonized atlas‐based segmentation probe different portions of brain tissue and lead to different statistical summaries of diffusion characteristics in WM labels. Careful selection of segmentation approach is required for DTI investigations of WM ROIs. J. Magn. Reson. Imaging 2014;l40:1189–1198. © 2013 Wiley Periodicals, Inc.
Quantification of left ventricular dyssynchrony in patients with systolic dysfunction: A comparison of circumferential strain MR‐tagging metrics
Authors: El Ghannudi Soraya , Germain Philippe , Jeung Mi‐Young , Breton Elodie , Croisille Pierre , Durand Emmanuel , Roy Catherine , Gangi Afshin
Published: November 2013

Purpose

To define which circumferential strain MR‐tagging metrics of left intraventricular dyssynchrony better identifies patients with systolic dysfunction against control subjects.

Materials and Methods

One hundred fifty subjects were studied: (i) controls with ejection fraction (EF) > 55% (n = 84), (ii) patients with EF ≤ 55% not eligible for cardiac resynchronization therapy (CRT) (n = 52), and (iii) patients eligible for CRT according to the ESC guidelines (n = 14). Tagging cine MR‐based circumferential filtered strain curves were extracted. Six dyssynchrony indices were studied: standard deviation (SD) of peak strain (SD_Ecc_ES), SD of time‐to‐peak (SD_TTP), strain delay index (LIM), regional variance vector (RVV), circumferential uniformity ratio estimate (CURE), and uniformity of strain TTP (US_TTP).

Results

All metrics show significant differences between the three groups (ANOVA, P < 10−4) and are correlated with EF. Significantly higher AUC values of ROC curves between patients with normal vs. decreased EF were obtained with SD_TTP (0.998) and CURE (0.995). Agreement among different methods was fair to good (kappa 0.32 to 0.89). Interobserver variability was best for CURE (1.2%) and US_TTP (0.8%) while more than 3‐times larger for other metrics.

Conclusion

SD_TTP and CURE are the most discriminant dyssynchrony metrics for systolic dysfunction. However, taking into account the method's variability argues in favor of indices of uniformity of the strain, ie, CURE and US_TTP.J. Magn. Reson. Imaging 2014;40:1238–1246. © 2013 Wiley Periodicals, Inc.
MRI‐guided high‐intensity focused ultrasound ablation of bone: Evaluation of acute findings with MR and CT imaging in a swine model
Authors: Bucknor Matthew D. , Rieke Viola , Do Loi , Majumdar Sharmila , Link Thomas M. , Saeed Maythem
Published: November 2013

Purpose

To evaluate hyperacute (<1 hour) changes on magnetic resonance (MR) and computed tomography (CT) imaging following MR‐guided high‐intensity focused ultrasound (MRgHIFU) in a swine bone model as a function of sonication number and energy.

Materials and Methods

Experimental procedures received approval from the local Institutional Animal Care and Use Committee. MRgHIFU was used to create distal and proximal ablations in the right femur of eight pigs. Each target was dosed with four or six sonications within similar volumes. The energy dosed to the distal target was higher (419 ± 19 J) than the proximal target (324 ± 17 J). The targeted femur and contralateral control were imaged before and after ablation using MR at 3T. Qualitative changes in signal on T1‐weighted, T2‐weighted, and T1‐weighted postcontrast images were assessed. Ablation dimensions were calculated from postcontrast MRI. The 64‐slice CT images were also obtained before and after ablation and qualitative changes were assessed.

Results

MRgHIFU bone ablation size measured on average 8.5 × 21.1 × 16.2 mm (transverse × craniocaudal × anteroposterior). Interestingly, within similar prescribed volumes, increasing the number of sonications from 4 to 6 increased the depth of the intramedullary hypoenhanced zone from 2.9 mm to 6.5 mm (P < 0.001). There was no difference in the appearance of low versus high energy ablations. CT imaging did not show structural abnormalities.

Conclusion

The number of MRgHIFU focal sonications can be used to increase the depth of treatment within the targeted bone. Unlike CT, T2‐weighted and contrast‐enhanced MR demonstrated the hyperacute structural changes in the femur and surrounding soft tissue.J. Magn. Reson. Imaging 2014;40:1174–1180 © 2013 Wiley Periodicals, Inc.
Characterization of N‐Boc/Fmoc/Z‐N′‐formyl‐gem‐diaminoalkyl derivatives using electrospray ionization multi‐stage mass spectrometry
Authors: Verardo Giancarlo , Gorassini Andrea
Published: November 2013

N‐Boc/Fmoc/Z‐N′‐formyl‐gem‐diaminoalkyl derivatives, intermediates particularly useful in the synthesis of partially modified retro‐inverso peptides, have been characterized by both positive and negative ion electrospray ionization (ESI) ion‐trap multi‐stage mass spectrometry (MSn). The MS2 collision induced dissociation (CID) spectra of the sodium adduct of the formamides derived from the corresponding N‐Fmoc/Z‐amino acids, dipeptide and tripeptide acids show the [M + Na‐NH2CHO]+ ion, arising from the loss of formamide, as the base peak. Differently, the MS2 CID spectra of [M + Na]+ ion of all the N‐Boc derivatives yield the abundant [M + Na‐C4H8]+ and [M + Na‐Boc + H]+ ions because of the loss of isobutylene and CO2 from the Boc protecting function. Useful information on the type of amino acids and their sequence in the N‐protected dipeptidyl and tripeptidyl‐N′‐formamides is provided by MS2 and subsequent MSn experiments on the respective precursor ions. The negative ion ESI mass spectra of these oligomers show, in addition to [M‐H]−, [M + HCOO]− and [M + Cl]− ions, the presence of in‐source CID fragment ions deriving from the involvement of the N‐protecting group. Furthermore, MSn spectra of [M + Cl]− ion of N‐protected dipeptide and tripeptide derivatives show characteristic fragmentations that are useful for determining the nature of the C‐terminal gem‐diamino residue. The present paper represents an initial attempt to study the ESI‐MS behavior of these important intermediates and lays the groundwork for structural‐based studies on more complex partially modified retro‐inverso peptides. Copyright © 2013 John Wiley & Sons, Ltd.
Detection and identification of the designer benzodiazepine flubromazepam and preliminary data on its metabolism and pharmacokinetics
Authors: Moosmann Bjoern , Huppertz Laura M. , Hutter Melanie , Buchwald Armin , Ferlaino Sascha , Auwärter Volker
Published: November 2013

The appearance of pyrazolam in Internet shops selling ‘research chemicals’ in 2012 marked the beginning of designer benzodiazepines being sold as recreational drugs or ‘self medication’. With recent changes in national narcotics laws in many countries, where two uncontrolled benzodiazepines (phenazepam and etizolam), which were marketed by pharmaceutical companies in some countries, were scheduled, clandestine laboratories seem to turn to poorly characterized research drug candidates as legal substitutes. Following the appearance of pyrazolam, it comes with no surprise that recently, flubromazepam (7‐bromo‐5‐(2‐fluorophenyl)‐1,3‐dihydro‐2H‐1,4‐benzodiazepin‐2‐one), a second designer benzodiazepine, was offered on the market. In this article, this new compound was characterized using nuclear magnetic resonance, gas chromatography‐mass spectrometry (GC–MS), liquid chromatography–mass spectrometry (LC–MS/MS) and liquid chromatography quadrupole time‐of‐flight MS (LC–Q–ToF–MS). Additionally, a study was carried out, in which one of the authors consumed 4 mg of flubromazepam to gain preliminary data on the pharmacokinetic properties and the metabolism of this compound. For this purpose, serum as well as urine samples were collected for up to 31 days post‐ingestion and analyzed applying LC–MS/MS and LC–Q‐ToF‐MS techniques. On the basis of this study, flubromazepam appears to have an extremely long elimination half‐life of more than 100 h. One monohydroxylated compound and the debrominated compound could be identified as the predominant metabolites, the first allowing a detection of a consumption for up to 28 days post‐ingestion when analyzing urine samples in our case. Additionally, various immunochemical assays were evaluated, showing that the cross‐reactivity of the used assay seems not to be sufficient for safe detection of the applied dose in urine samples, bearing the risk that it could be misused in drug‐withdrawal settings or in other circumstances requiring regular drug testing. Furthermore, it may be used in drug‐facilitated crimes without being detected. Copyright © 2013 John Wiley & Sons, Ltd.
Structural motifs in primary oxidation products of palmitoyl‐arachidonoyl‐phosphatidylcholines by LC‐MS/MS
Authors: Reis A. , Domingues P. , Domingues M. R. M.
Published: November 2013

Oxidative modifications to phospholipids (OxPL) play a major role in modulating signaling events in inflammation and infection, and complete understanding on the induced biological effects can only be understood based on knowledge of the oxidative motifs present.

Specific neutral losses observed in tandem mass spectrometry data (LC‐MS/MS) of primary peroxidation products in oxidized palmitoyl‐arachidonoyl‐phosphatidylcholines (OxPAPC) provide information on the prevailing structural motifs regarding the oxidized acyl carbon chain, the nature of oxidized group and the site of carbon oxidation. The higher hydrophobicity of hydroperoxides compared to di‐hydroxy derivatives under reverse‐phase conditions together with specific fragmentation patterns enabled the identification of 12 structurally different OxPAPC structural (di‐hydroxy and hydroperoxide derivatives) and positional isomers as well as the presence of poly‐hydroxy together with isoprostanes derivatives.

The fragmentation patterns described in quadrupole time‐of‐flight and linear ion trap instruments complement the m/z value and retention time parameters in the identification of oxidative composition in OxPAPC products becoming a valuable tool for the exploratory screening of oxidized phosphatidylcholines in OxPAPC extracts, distinction of native and modified PC isobaric structures in complex samples contributing to the increased understanding of redox lipidomics in inflammation and infection. Copyright © 2013 John Wiley & Sons, Ltd.
Identification of wild collected mosquito vectors of diseases using gas chromatography–mass spectrometry in Jazan Province, Saudi Arabia
Authors: Al Ahmed Azzam M. , Badjah‐Hadj‐Ahmed Ahmed‐Yacine , Al Othman Zeid A. , Sallam Mohamed F.
Published: November 2013

Thirty‐three species of mosquitoes have been reported from the Kingdom of Saudi Arabia. Several of these mosquitoes, Anopheles gambiae Giles s.l., Anopheles stephensi Liston, Culex pipiens Linnaeus, Culex quinquefasciatus Say, Culex tritaeniorhynchus Giles, Stegomyia aegypti (Linnaeus) and Aedimorphus vexans arabiensis (Patton) are known vectors of human and animal diseases. In this study, the cuticular hydrocarbon profiles of eight mosquito species using gas chromatography–mass spectrometry were analyzed. Wild collected fourth‐instar larvae were reared, and single, newly emerged, unfed adult females were used for the analysis. A total of 146–160 peaks were detected from the cuticular extracts by gas chromatography. Repeated analysis of variance (ANOVA) and Tukey HSD Post Hoc test was used to test for quantitative differences in relative hydrocarbon quantity. In addition, a linear regression model was applied using Enter method to determine the diagnostic peaks for the eight mosquito specimens. The ANOVA test indicated that relative peaks were significant (P < 0.05) when selected pairs of peaks were compared. Also, seven compounds showed qualitative differences among the five mosquito vectors tested. The classes of constituents present were n‐alkanes, monomethylalkanes, dimethylalkanes, trimethylalkanes, alkenes, branched aromatic hydrocarbons, aldehydes and esters. These compounds have a carbon chain length ranging from 8 to 18 carbons. The most abundant compound in all adult mosquito specimens was n‐hexylacrylate [retention time (RT) 6.73 min], which was not detected in Cx. pipiens. In Cx. pipiens, the most abundant peak was benzaldehyde (RT 2.98 min). Gas chromatography–mass spectrometry is a suitable method to identify adult mosquitoes, especially from focal areas of public health concern such as Jazan Province, Saudi Arabia. This method allows a wide range of adult collected material to be identified with high accuracy. Copyright © 2013 John Wiley & Sons, Ltd.
Quality of life in head and neck cancer patients: Impact of HPV and primary treatment modality
Authors: Maxwell Jessica H. , Mehta Vikas , Wang Hong , Cunningham Diana , Duvvuri Umamaheswar , Kim Seungwon , Johnson Jonas , Ferris Robert L.
Published: November 2013

Objectives/Hypothesis

To determine posttreatment quality of life (QOL) in head and neck cancer patients, stratifying by human papillomavirus (HPV)/p16 status and primary treatment modality.

Study Design

Retrospective study.

Methods

One hundred and seventy‐seven patients (N = 177) with head and neck squamous cell carcinoma and known HPV/p16 status were included. All patients completed at least one baseline or posttreatment University of Washington QOL survey. QOL scores were averaged and compared across patients, stratifying by HPV/p16 status and primary treatment modality (surgical vs. nonsurgical). In the analysis, p16 was used as a surrogate marker for HPV.

Results

Of the 177 patients, 80 (45.2%) were p16‐positive and 49.7% of subsites were oropharyngeal. Nearly 60% (105/177) of patients underwent primary surgery, 26.7% (28/105) of patients with transoral robotic or laser techniques. The remainder 40.7% of patients underwent primary radiation and/or chemotherapy. Overall, QOL scores were better for p16‐positive patients compared to p16‐negative patients at baseline (P = 0.008), at 6 months posttreatment (P = 0.034), and at greater than 1 year posttreatment (P = 0.013). P16‐positive patients had better QOL scores in speech (P = 0.0009), chewing (P = 0.0004), and swallowing (P = 0.021) after 1 year posttreatment compared to p16‐negative patients. Primary treatment modality did not affect overall QOL or any of the 12 QOL categories in p16‐positive patients at any time point. At over 1 year posttreatment, QOL was at or above baseline in both p16‐positive treatment groups.

Conclusion

The p16‐positive patients had better baseline and posttreatment overall QOL compared to p16‐negative patients. The overall and category specific QOL scores for p16‐positive patients were not affected by primary treatment modality.

Level of Evidence

4. Laryngoscope, 124:1592–1597, 2014
Interrater reliability of sleep videofluoroscopy for airway obstruction in obstructive sleep apnea
Authors: Kim Dong‐Kyu , Lee Woo‐Hyun , Lee Chul Hee , Rhee Chae Seo , Kim Jeong‐Whun
Published: November 2013

Objectives/Hypothesis

Sleep videofluoroscopy (SVF) has been introduced to identify upper airway obstruction. This study was aimed to determine the interrater reliability of SVF in patients with obstructive sleep apnea (OSA).

Study Design

A retrospective analysis.

Methods

On the basis of apnea‐hypopnea index in full‐night attended polysomnography, 374 consecutive OSA patients who underwent SVF were enrolled in this study. The SVF was evaluated by three independent reviewers. Interrater reliabilities were assessed by evaluating agreement of the obstructive anatomic structures (soft palate, tongue base, tonsils, and epiglottis) and airway levels (velopharynx, oropharynx, and hypopharynx) between the reviewers.

Results

In a comparison between an unblinded and a blinded well‐experienced sleep surgeons, the interrater reliability for the presence of obstruction was the highest for the soft palate at the level of the velopharynx (Cohen's kappa value, 0.919) and the lowest for the soft palate at the level of the oropharynx (Cohen's kappa value, 0.757). In a blind comparison between a well‐experienced and less‐experienced sleep surgeons, the interrater reliability for the presence of obstruction was also the highest for the soft palate at the level of the velopharynx (Cohen's kappa value, 0.938) and the lowest for the palatine tonsils at the level of the oropharynx (Cohen's kappa value, 0.635).

Conclusion

This study showed that SVF was a diagnostic modality that can be used to evaluate upper airway obstruction without significant interrater disagreements.

Level of Evidence

4. Laryngoscope, 124:1267–1271, 2014
A Clustering‐based Methodology for Discontinuous Pareto Frontier Representation
Authors: Padmanabhan Dhanesh
Published: November 2013

This paper presents a methodology for capturing complex trade‐off relationships among objective functions and the underlying design principles through Pareto frontier representations, for Multi‐Objective Optimization problems in complex engineering design processes. The methodology provides engineers a way to quickly assess achievability of target values on objective functions (referred to as f‐feasibility), and propose design solutions that meet or exceed these targets. Obtaining Pareto frontier representations can be challenging for cases when there are discontinuities in the Pareto frontiers and when the trade‐off relationships vary across these discontinuities. The proposed methodology addresses this issue by first identifying discontinuities in the Pareto frontier through a clustering procedure, and then obtaining functional approximations of the trade‐off relationships for each of the discontinuous portion of the Pareto frontier. A two‐stage approach for clustering is employed. In the first stage, a DBSCAN clustering technique is used to classify disjoint Pareto sets in the objective space (f‐space) into different groups. In the second stage, a frequent set mining algorithm named ECLAT and a subsequent filtering procedure are used to extract design constraint combinations that are active (binding) within each of these groups to form subgroups. Approximations are obtained for each of the subgroups using a constrained least squares technique, which are then combined to obtain an overall equation for assessing f‐feasibility of any arbitrary point in objective space. In the two implementation studies, it is observed that the two‐stage approach for clustering is highly effective in yielding good quality Pareto frontier representations and f‐feasibility assessments. Copyright © 2013 John Wiley & Sons, Ltd.
Morphology, thermal, and mechanical properties of poly(butylene succinate) reinforced with halloysite nanotube
Authors: Wu Wei , Cao Xianwu , Luo Jun , He Guangjian , Zhang Yijun
Published: November 2013

Poly(butylene succinate) (PBS)/halloysite nanotube (HNT) nanocomposites were fabricated by melt compounding. The morphology of the nanocomposites was studied by scanning electron microscopy and the results showed that the HNT dispersed uniformly in the PBS matrix. The thermogravimetric analysis results showed that the addition of HNT decreased the decomposition temperature and activation energy, and thus accelerated the thermal degradation of PBS. The differential scanning calorimetry analysis indicated that HNT could serve as nucleating agent for the PBS, and thus increased its crystallization temperature and crystallinity. However, it was demonstrated by the X‐ray diffractometry spectra that the incorporation of HNT did not affect the crystal form of PBS. Mechanical tests in flexure, tension, and notched Izod impact demonstrated that the strength and modulus of nanocomposites were increased by the addition of HNT without significant loss of ductility. POLYM. COMPOS., 35:847–855, 2014. © 2013 Society of Plastics Engineers
Particle configuration and properties of poly(vinyl chloride)/halloysite nanotubes nanocomposites via in situ suspension polymerization
Authors: Liu Cong , Luo Yuanfang , Jia Zhixin , Li Shuangquan , Huang Dong , Jia Demin
Published: November 2013

Poly(vinyl chloride) (PVC)/halloysite nanotubes (HNTs) nanocomposites were synthesized by in situ suspension polymerization of vinyl chloride (VC) in the presence of HNTs. The microstructure, mean particle size, and cold plasticizer absorption (CPA) of these resins and the rheological property, mechanical properties and thermal properties of PVC/HNTs nanocomposites were investigated. The results show that the mean particle size, the degree of porosity, and the CPA of PVC resins decrease with the addition of HNTs. The plasticization time and the equilibrium torque of PVC/HNTs nanocomposites are found to be longer and higher than that for the neat PVC. HNTs are uniformly distributed in the PVC matrix and effective in toughening and stiffening PVC nanocomposites when the addition of HNTs is 4.0 wt% or less. The glass transition temperatures of the PVC/HNTs nanocomposites were nearly identical to that of pure PVC. POLYM. COMPOS., 35:856–863, 2014. © 2013 Society of Plastics Engineers
Enhancing the device performance of a blue light‐emitting copolymer using CdSe/ZnS quantum dots
Authors: Mucur Selin Pıravadılı , Lenkeit Daniel , Kanelidis Ioannis , San Sait Eren , Holder Elisabeth , Tekin Emine
Published: November 2013

An alternating triarylamine‐functionalized fluorene‐based copolymer synthesized using a Suzuki–Miyaura cross‐coupling procedure is used as blue emitting layer in polymer light‐emitting diodes (PLEDs). Subsequently, the effects of CdSe/ZnS quantum dots (QDs) on the optoelectronic properties of the copolymer are investigated. Therefore, CdSe/ZnS QDs are embedded into the copolymer matrix and hybrid PLEDs are fabricated. The devices comprised of CdSe/ZnS QDs reveal enhanced performances, yielding about 3.4 times more luminous efficiency than that of the device without QDs. Further enhancement is achieved by using electron transport layer; the luminous efficiency rose from 0.065 to 1.740 cd A−1 for the hybrid PLEDs, corresponding to a superb 27‐fold intensification of the efficiency. © 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2014, 52, 147–156
Energetic Residues from the Detonation of IMX‐104 Insensitive Munitions
Authors: Walsh Michael R. , Walsh Marianne E. , Ramsey Charles A. , Thiboutot Sonia , Ampleman Guy , Diaz Emmanuela , Zufelt Jon E.
Published: November 2013

The development of insensitive munitions by NATO countries is an ongoing effort. Less‐sensitive ingredients in both explosives and propellants will ensure the protection of deployed troops against an unwanted reaction to an external stimulus on the munitions stockpile. In the US Army, current efforts are directed towards the development of melt cast insensitive explosive formulations. Various formulations, mainly based on DNAN and NTO, have been developed and are now being fielded. Our research goal is to measure the deposition rate of energetics compounds from various insensitive munitions detonation scenarios. Our hypothesis is that the relative insensitiveness of these formulations leads to slightly higher deposition rates than conventional explosive formulations. This paper describes detonation residues research on mortar rounds containing IMX‐104 explosive. Analyses indicate that high‐order detonation residues are slightly greater for this formulation than for conventional munitions. However, blow‐in‐place detonations (BIPs) resulted in much higher residues deposition, indicating that a larger donor charge is required for efficient detonation. The highly soluble compound NTO was particularly problematic, with BIP deposition approaching 95 % of the original load. Toxicological studies of NTO are not finalized, leaving considerable uncertainty regarding the feasibility of approving these rounds for distribution.
Electric control of magnetism in a multiferroic metal–organic framework
Authors: Tian Ying , Cong Junzhuang , Shen Shipeng , Chai Yisheng , Yan Liqin , Wang Shouguo , Sun Young
Published: November 2013

Electric control of magnetism is demonstrated in a multiferroic metal–organic framework with a perovskite structure. A moderate electric field of a few kV/cm applied during the cooling process is able to cause a large (more than 50%) change of the magnetization at low temperature. This significant magnetoelectric effect is ascribed to the electric field manipulation of orientation of hydrogen bonds that modify the superexchange interaction between metal ions.

magnified image

Electric‐field cooling causes a large change in the magnetization of a multiferroic MOF.

(© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)