bluuebunny/crossref_metadata_2025 huggingface dataset:
Examining the association between late‐life depressive symptoms, cognitive function, and brain volumes in the context of cognitive reserve
Authors: O'Shea Deirdre M. , Fieo Robert A. , Hamilton Jamie L. , Zahodne Laura B. , Manly Jennifer J. , Stern Yaakov
Published: August 2014

Objective

The present study aimed to investigate whether cognitive reserve moderated the association between depressive symptoms and cognition, as well as brain volumes in a sample of older adults.

Methods

Non‐demented participants (n = 3484) were selected from the Washington Heights/Hamilton Heights Inwood Columbia Aging Project (Northern Manhattan). A subsample of these participants without dementia (n = 703), who had brain imaging data, was also selected for a separate analysis. Depressive symptomatology was assessed with the 10‐item Center for Epidemiologic Studies Depression Scale. Reading level and years of education were used as measures of cognitive reserve. Four distinct cognitive composite scores were calculated: executive function, memory, visual–spatial, and language.

Results

Multiple regression analysis revealed interaction effects between both measures of cognitive reserve and depressive symptoms on all the cognitive outcome measures except for visual–spatial ability. Those with greater reserve showed greater cognitive decrements than those with lower levels of reserve as depressive symptoms increased. A borderline interaction effect was revealed between reading level and depressive symptoms on total brain volumes. Those with lower reading scores showed greater volume loss as depressive symptoms increased than those with higher reading scores.

Conclusions

Our findings indicate that the association between late‐life depressive symptoms and core aspects of cognition varies depending on one's level of cognitive reserve. Those that had greater levels of education and/or reading ability showed a greater decrease in memory, executive, and language performances as depressive symptoms increased than those with lower years of education and reading ability. Copyright © 2014 John Wiley & Sons, Ltd.
First Diastereoselective PasseriniSmiles and UgiSmiles Reactions Using Chiral Aldehydes
Authors: Radha Krishna Palakodety , Dayaker Gandrath , Venkata Ramana D. , Kunde Ramesh
Published: August 2014

A diastereoselective O/N‐arylative Passerini/Ugi reaction of chiral aldehydes with commercially available isocyanides affording O‐aryl amides and N‐aryl amides, respectively, as products in moderate to good yields, together with de values, is reported.
Ethenolate Transfer Reactions: A Facile Synthesis of Vinyl Esters
Authors: Kaliyaperumal Appaye Srinivasan , Pandurang Nikumbh Satish , Reddy Govindapur Rajeshwar , Banerjee Shyamapada , Bhalerao Dinesh S. , Syam Kumar Unniaran K.
Published: August 2014

A simple and efficient metal‐free ethenolate transfer reaction has been elaborated in moderate‐to‐high yields from vinyl acetate. This reaction was accomplished by generation of potassium ethenolate, which was then reacted with homo and mixed anhydrides of aliphatic, aryl and heteroaryl acids, to yield the corresponding vinyl esters. The utility of thus generated vinyl esters was then probed by carrying out intramolecular Heck reactions to give isobenzofuran‐1(3H)‐one derivatives in excellent yields.
A New Megastigmane Glucoside and Three New Flavonoid Glycosides from Spiraea prunifolia var. simpliciflora
Authors: Hye Yean Min , Sun Kim Ju , Sik Kang Sam , Shik Kim Yeong
Published: August 2014

A new megastigmane glucoside, simplicifloranoside (1), and three new flavonol glycosides, prunifolianosides A–C (2–4, resp.), were isolated from the aerial parts of Spiraea prunifolia var. simpliciflora. In addition, fifteen known compounds, including five phenolic acids, three lignans, four flavonoids, one eugenol glycoside, and two alkyl‐primeverosides, were also identified. Their structures were elucidated on the basis of detailed spectroscopic analyses and acid hydrolysis.
Labdane Diterpenoids from the Roots of Amomum maximum and Their Cytotoxic Evaluation
Authors: Luo Jian‐Guang , Yin Hong , Fan Bo‐Yi , Kong Ling‐Yi
Published: August 2014

A rare labdane diterpene γ‐lactam, 1, and two new labdane diterpenoids, 2 and 3, along with two known diterpenes, 4 and 5, were isolated from the roots of Amomum maximum. Their structures were established on the basis of spectroscopic data. All of the isolates were evaluated for their cytotoxic activities, and compound 3 was found to exhibit an inhibitory activity against MG‐63 cell lines with an IC50 value of 3.3±0.8 μg/ml.
Synthesis of 3‐(ω‐Hydroxyalkoxy)isobenzofuran‐1(3H)‐ones by Trifluoroacetic Acid‐Mediated Lactonization of tert‐Butyl 2‐(1,3‐Dioxol‐2‐yl)‐ or 2‐(1,3‐Dioxan‐2‐yl)benzoates
Authors: Kobayashi Kazuhiro , Kuroda Minami
Published: August 2014

An efficient two‐step method for the preparation of 3‐(2‐hydroxyethoxy)‐ or 3‐(3‐hydroxypropoxy)isobenzofuran‐1(3H)‐ones 3 has been developed. Thus, the reaction of 1‐(1,3‐dioxol‐2‐yl)‐ or 1‐(1,3‐dioxan‐2‐yl)‐2‐lithiobenzenes, generated in situ by the treatment of 1‐bromo‐2‐(1,3‐dioxol‐2‐yl)‐ or 1‐bromo‐2‐(1,3‐dioxan‐2‐yl)benzenes 1 with BuLi in THF at −78°, with (Boc)2O afforded tert‐butyl 2‐(1,3‐dioxol‐2‐yl)‐ or 2‐(1,3‐dioxan‐2‐yl)benzoates 2, which can subsequently undergo facile lactonization on treatment with CF3COOH (TFA) in CH2Cl2 at 0° to give the desired products in reasonable yields.
Dye‐Labeled Cα‐Tetrasubstituted α‐Amino Acids
Authors: Dobmeier Michael , Maity Prantik , König Burkhard
Published: August 2014

We report the synthesis of pyrene‐ and carboxyfluorescein labeled Cα‐tetrasubstituted amino acids (TAAs). The fluorescent dye can be coupled to the TAA before or after its incorporation into a peptide sequence using a Suzuki‐type CC bond formation.
Oligonucleotide Analogues with Integrated Bases and Backbone (ONIB). Part 31
Authors: Schulze‐Adams Martina , Touboul David , Bernet Bruno , Vasella Andrea
Published: August 2014

The self‐complementary guanosine‐ and cytidine‐derived aminomethylene‐linked C*[n]G dinucleoside 9 was synthesized by reductive amination of aldehyde 3 with an iminophosphorane derived from azide 7. Deacylation of 9 gave the isopropylidene‐protected dinucleoside 10. The sequence‐isomeric G*[n]C dinucleoside 11 was similarly prepared from aldehyde 8 and azide 5, and deacylated to 12. The association of 10 and 12 in CHCl3 or in CHCl3/DMSO mixtures, and the structure of the associates were studied by 1H‐NMR, ESI‐MS, CD, and vapor pressure osmometry (VPO). Broad 1H‐NMR signals of dinucleosides 10 and 12 evidence an equilibrium between duplexes and quadruplexes (Hoogsteen base pairing between the WatsonCrick base‐paired duplexes). The quadruplex dominates for the G*[n]C dinucleoside 12 between −50° and room temperature. The sequence‐isomeric C*[n]G 10 forms mostly only a cyclic duplex in CDCl3 and in CDCl3/(D6)DMSO 9 : 1.
Methylation of Bone SOST, Its mRNA, and Serum Sclerostin Levels Correlate Strongly With Fracture Risk in Postmenopausal Women
Authors: Reppe Sjur , Noer Agate , Grimholt Runa M , Halldórsson Bjarni V , Medina-Gomez Carolina , Gautvik Vigdis T , Olstad Ole Kristoffer , Berg Jens Petter , Datta Harish , Estrada Karol , Hofman Albert , Uitterlinden André G , Rivadeneira Fernando , Lyle Robert , Collas Philippe , Gautvik Kaare M
Published: August 2014

Inhibition of sclerostin, a glycoprotein secreted by osteocytes, offers a new therapeutic paradigm for treatment of osteoporosis (OP) through its critical role as Wnt/catenin signaling regulator. This study describes the epigenetic regulation of SOST expression in bone biopsies of postmenopausal women. We correlated serum sclerostin to bone mineral density (BMD), fractures, and bone remodeling parameters, and related these findings to epigenetic and genetic disease mechanisms. Serum sclerostin and bone remodeling biomarkers were measured in two postmenopausal groups: healthy (BMD T-score > –1) and established OP (BMD T-score < –2.5, with at least one low-energy fracture). Bone specimens were used to analyze SOST mRNAs, single nucleotide polymorphisms (SNPs), and DNA methylation changes. The SOST gene promoter region showed increased CpG methylation in OP patients (n = 4) compared to age and body mass index (BMI) balanced controls (n = 4) (80.5% versus 63.2%, p = 0.0001) with replication in independent cohorts (n = 27 and n = 36, respectively). Serum sclerostin and bone SOST mRNA expression correlated positively with age-adjusted and BMI-adjusted total hip BMD (r = 0.47 and r = 0.43, respectively; both p < 0.0005), and inversely to serum bone turnover markers. Five SNPs, one of which replicates in an independent population-based genomewide association study (GWAS), showed association with serum sclerostin or SOST mRNA levels under an additive model (p = 0.0016 to 0.0079). Genetic and epigenetic changes in SOST influence its bone mRNA expression and serum sclerostin levels in postmenopausal women. The observations suggest that increased SOST promoter methylation seen in OP is a compensatory counteracting mechanism, which lowers serum sclerostin concentrations and reduces inhibition of Wnt signaling in an attempt to promote bone formation. © 2014 American Society for Bone and Mineral Research.
Semiframes with Block Size Three and Odd Group Size
Authors: Cao H. , Fan J. , Xu D.
Published: August 2014

A ‐semiframe of type is a ‐GDD of type , , in which the collection of blocks can be written as a disjoint union where is partitioned into parallel classes of and is partitioned into holey parallel classes, each holey parallel class being a partition of for some . A ‐SF is a ‐semiframe of type in which there are p parallel classes in and d holey parallel classes with respect to . In this paper, we shall show that there exists a (3, 1)‐SF for any if and only if , , , and .
Peptic ulcer as a risk factor for postherpetic neuralgia in adult patients with herpes zoster
Authors: Chen Jen‐Yin , Lan Kuo‐Mao , Sheu Ming‐Jen , Tseng Su‐Feng , Weng Shih‐Feng , Hu Miao‐Lin
Published: August 2014

Postherpetic neuralgia is the most common complication of herpes zoster. Identifying predictors for postherpetic neuralgia may help physicians screen herpes zoster patients at risk of postherpetic neuralgia and undertake preventive strategies. Peptic ulcer has been linked to immunological dysfunctions and malnutrition, both of which are predictors of postherpetic neuralgia. The aim of this retrospective case‐control study was to determine whether adult herpes zoster patients with peptic ulcer were at greater risk of postherpetic neuralgia. Adult zoster patients without postherpetic neuralgia and postherpetic neuralgia patients were automatically selected from a medical center's electronic database using herpes zoster/postherpetic neuralgia ICD‐9 codes supported with inclusion and exclusion criteria. Consequently, medical record review was performed to validate the diagnostic codes and all pertaining data including peptic ulcer, Helicobacter pylori (H. pylori) infection and ulcerogenic medications. Because no standard pain intensity measurement exists, opioid usage was used as a proxy measurement for moderate to severe pain. In total, 410 zoster patients without postherpetic neuralgia and 115 postherpetic neuralgia patients were included. Multivariate logistic regressions identified 60 years of age and older, peptic ulcer and greater acute herpetic pain as independent predictors for postherpetic neuralgia. Among etiologies of peptic ulcer, H. pylori infection and usage of non‐selective nonsteroidal anti‐inflammatory drugs were significantly associated with the increased risk of postherpetic neuralgia; conversely, other etiologies were not significantly associated with the postherpetic neuralgia risk. In conclusion, 60 years of age and older, peptic ulcer and greater acute herpetic pain are independent predictors for postherpetic neuralgia in adult herpes zoster patients. J. Med. Virol. 87:222–229, 2015. © 2014 Wiley Periodicals, Inc.
Liquid chromatography with mass spectrometry method based two‐step precursor ion scanning for the structural elucidation of flavonoids
Authors: Li Yong , Pang Tao , Shi Junli , Lu Xiuping , Deng Jianhua , Lin Qian
Published: August 2014

Plant flavonoids are very important secondary metabolites for insect and virus control of their host plant and are potent nutrients for humans. To be able to understand the bioavailability and functions of plant flavonoids, it is necessary to reveal their exact chemical structures. Liquid chromatography with tandem mass spectrometry is a powerful approach for structural elucidation of metabolites. In this report, a two‐step precursor ion scanning based liquid chromatography with tandem mass spectrometry method was developed for the structural elucidation of plant flavonoids. The established method consists of the two‐step precursor ions scanning for possible flavonoids extraction, MS2 fragment spectra acquisition and comparison with an online database, liquid chromatography retention rules correction, and commercial standards verification. The developed method was used for the structure elucidation of flavonoids in flowers and leaves of tobacco (Nicotiana tabacum), and 17 flavonoids were identified in the tobacco variety Yunyan 97. Nine of the 17 identified flavonoids were considered to be found in tobacco flowers or/and leaves for the first time based on the available references. This method was proved to be very effective and can be used for the identification of flavonoids in other plants.
Changes in site of obstruction in obstructive sleep apnea patients according to sleep position: A DISE study
Authors: Lee Chul H. , Kim Dong K. , Kim So Y. , Rhee Chae‐Seo , Won Tae‐Bin
Published: August 2014

Objectives/Hypothesis

This study aimed to evaluate changes in obstruction site in obstructive sleep apnea (OSA) patients according to sleep position.

Study Design

Prospective case series.

Methods

Eighty‐five patients who had undergone level 1 sleep study and drug‐induced sleep endoscopy in the supine and lateral positions were included. Obstruction sites were classified as soft palate (SP), tongue base (TB), lateral wall (LW), and larynx (LX). Subgroup analysis was performed according to lateral apnea‐hypopnea index (AHI): those with an AHI of ≥ 10 (lateral obstructors, LO) and those with an AHI of < 10 (lateral nonobstructors, LNO).

Results

Prevalence in obstruction site of SP, TB, and LX decreased significantly after change from supine to lateral position (P < 0.05). However, the prevalence of LW obstruction was not affected by position change. LW collapse in moderate OSA decreased (from 66.7% to 35.9%) after change to lateral sleep, whereas it persisted in severe OSA patients (81.6%–89.5%). In the lateral position, persistent obstruction at the LW was observed more frequently in the LO group compared to the LNO group (83.3% vs. 33.3%).

Conclusion

When sleep posture is changed from supine to lateral, obstruction due to structures such as tongue base and larynx improves dramatically. Obstruction in lateral position is mostly due to obstruction at the oropharyngeal LWs. Therefore, position dependency is mostly determined by LW collapsibility. Evaluating the changes of the upper airway according to sleep position can further characterize the upper airway collapsibility and can be used for tailored treatment planning.

Level of Evidence

4. Laryngoscope, 125:248–254, 2015
Non‐ablative fractional laser provides long‐term improvement of mature burn scars–A randomized controlled trial with histological assessment
Authors: Taudorf Elisabeth H. , Danielsen Patricia L. , Paulsen Ida F. , Togsverd‐Bo Katrine , Dierickx Christine , Paasch Uwe , Haedersdal Merete
Published: August 2014

Background and Objectives

Non‐ablative fractional laser‐treatment is evolving for burn scars. The objective of this study was to evaluate clinical and histological long‐term outcome of 1,540 nm fractional Erbium: Glass laser, targeting superficial, and deep components of mature burn scars.

Materials & Methods

Side‐by‐side scar‐areas were randomized to untreated control or three monthly non‐ablative fractional laser‐treatments using superficial and extra‐deep handpieces. Patient follow‐up were at 1, 3, and 6 months. Primary outcome was improvement in overall scar‐appearance on a modified‐Patient‐and‐Observer‐Scar‐Assessment‐Scale (mPOSAS, 1 = “normal skin”, 10 = “worst imaginable scar”). Secondary outcomes included histology, patient satisfaction (0–10), patient‐assessed improvement, and safety.

Results

Study was completed by 17 of 20 randomized patients with normotrophic (n = 11), hypertrophic (n = 5) or atrophic (n = 1) scars. Scar‐appearance improved from laser‐treatments (P < 0.001 vs. untreated) and histology at 6 months supported collagen‐remodeling. Improvement appeared continuously during the post‐operative period (mPOSAS baseline: 7 [5–8], 6 months: 4 [3–5] P = < 0.001). At 6 months, patients were satisfied with treatment (6 [3–9]) and 82% reported improved scar‐texture. Treatments caused mild to moderate pain (4 [2–7]). Adverse effects decreased during follow‐up and at final assessment, discrete erythema, hyperpigmentation or imprints from laser‐grid were present in 11 patients. No patients experienced worsening of scar‐appearance.

Conclusions

Combined superficial and deep non‐ablative fractional laser‐treatments induce long‐term clinical and histological improvement of mature burn scars. Lasers Surg. Med. 47:141–147, 2015. © 2014 Wiley Periodicals, Inc.
Catalytic Precision Polymerization: Rare Earth Metal‐Mediated Synthesis of Homopolymers, Block Copolymers, and Polymer Brushes
Authors: Soller Benedikt S. , Zhang Ning , Rieger Bernhard
Published: August 2014

Recent studies have shown that rare earth metal‐mediated group transfer polymerization (REM‐GTP) can be applied to a variety of polar monomers, besides the classic (meth)­acrylates or (meth)acrylamides, giving access to new polymeric materials. This article highlights progress in this new field and gives a current overview of the initiation and propagation of vinylphosphonates, the extension to Michael‐type nitrogen‐coordinating monomers, and application to block copolymers, statistical copolymers, and 2D and 3D structures. Based on molecular understanding and high‐precision synthesis, REM‐GTP represents a versatile method for the preparation of new materials.

image
Probing signal phase in direct visualization of short transverse relaxation time component (ViSTa)
Authors: Kim Daeun , Lee Hyo Min , Oh Se‐Hong , Lee Jongho
Published: August 2014

Purpose

To demonstrate the phase evolutions of direct visualization of short transverse relaxation time component (ViSTa) matches with those of myelin water.

Method

Myelin water imaging (MWI) measures short transverse signals and has been suggested as a biomarker for myelin. Recently, a new approach, ViSTa, has been proposed to acquire short T2* signals by suppressing long T1 signals. This method does not require any ill‐conditioned data processing and therefore provides high‐quality images. In this study, the phase of the ViSTa signal was compared with the phase of myelin water simulated by the magnetic susceptibility model of hollow cylinder.

Results

The phase evolutions of the ViSTa signal were similar to the simulated myelin water phase evolutions. When fiber orientation was perpendicular relative to the main magnetic field, both the ViSTa and the simulated myelin water phase showed large positive frequency shifts, whereas the gradient echo phase showed a slightly negative frequency shift. Additionally, the myelin water phase map generated using diffusion tensor imaging (DTI) information revealed a good match with the ViSTa phase image.

Conclusion

The results of this study support the origin of ViSTa signal as myelin water. ViSTa phase may potentially provide sensitivity to demyelination. Magn Reson Med 74:499–505, 2015. © 2014 Wiley Periodicals, Inc.
Optimal diffusion weighting for in vivo cardiac diffusion tensor imaging
Authors: Scott Andrew D. , Ferreira Pedro F. A. D. C. , Nielles‐Vallespin Sonia , Gatehouse Peter , McGill Laura‐Ann , Kilner Philip , Pennell Dudley J. , Firmin David N.
Published: August 2014

Purpose

To investigate the influence of the diffusion weighting on in vivo cardiac diffusion tensor imaging (cDTI) and obtain optimal parameters.

Methods

Ten subjects were scanned using stimulated echo acquisition mode echo planar imaging with six b‐values, from 50 to 950 s·mm−2, plus b = 15 s·mm−2 reference. The relationship between b‐value and both signal loss and signal‐to‐noise ratio measures was investigated. Mean diffusivity, fractional anisotropy, and helical angle maps were calculated using all possible b‐value pairs to investigate the effects of diffusion weighting on the main and reference data.

Results

Signal decay at low b‐values was dominated by processes with high apparent diffusion coefficients, most likely microvascular perfusion. This effect could be avoided by diffusion weighting of the reference images. Parameter maps were improved with increased b‐value until the diffusion‐weighted signal approached the noise floor. For the protocol used in this study, b = 750 s·mm−2 combined with 150 s·mm−2 diffusion weighting of the reference images proved optimal.

Conclusion

Mean diffusivity, fractional anisotropy, and helical angle from cDTI are influenced by the b‐value of the main and reference data. Using optimal values improves parameter maps and avoids microvascular perfusion effects. This optimized protocol should provide greater sensitivity to pathological changes in parameter maps. Magn Reson Med 74:420–430, 2015. © 2014 Wiley Periodicals, Inc.
Comprehensive RF safety concept for parallel transmission MR
Authors: Graesslin Ingmar , Vernickel Peter , Börnert Peter , Nehrke Kay , Mens Giel , Harvey Paul , Katscher Ulrich
Published: August 2014

Purpose

The goal of this study is to increase patient safety in parallel transmission (pTx) MRI systems. A major concern in these systems is radiofrequency‐induced tissue heating, which can be avoided by specific absorption rate (SAR) prediction and SAR monitoring before and during the scan.

Methods

In this novel comprehensive safety concept, the SAR is predicted prior to the scan based on precalculated fields obtained from electromagnetic simulations on different body models. The radiofrequency fields and the global and local SAR are supervised in real time during the scan. This concept is integrated into a 3 T pTx MR scanner and validated experimentally.

Results

Phantom and in vivo experiments successfully validated the basic feasibility of the real‐time SAR supervision concept. Supervising the SAR minimizes SAR overestimation. Monitoring the radiofrequency fields allows the detection of unsafe radiofrequency situations for the patient, which a SAR supervision system alone cannot detect.

Conclusion

This study demonstrates safe scanning in a pTx system. This new safety concept is also applicable for field strengths above 3 T and represents an important step toward safe operation of pTx systems. Magn Reson Med 74:589–598, 2015. © 2014 Wiley Periodicals, Inc.
Assessment of lung function in asthma and COPD using hyperpolarized 129Xe chemical shift saturation recovery spectroscopy and dissolved‐phase MRI
Authors: Qing Kun , Mugler John P. , Altes Talissa A. , Jiang Yun , Mata Jaime F. , Miller G. Wilson , Ruset Iulian C. , Hersman F. William , Ruppert Kai
Published: August 2014

Magnetic‐resonance spectroscopy and imaging using hyperpolarized xenon‐129 show great potential for evaluation of the most important function of the human lung ‐‐ gas exchange. In particular, chemical shift saturation recovery (CSSR) xenon‐129 spectroscopy provides important physiological information for the lung as a whole by characterizing the dynamic process of gas exchange, while dissolved‐phase (DP) xenon‐129 imaging captures the time‐averaged regional distribution of gas uptake by lung tissue and blood. Herein, we present recent advances in assessing lung function using CSSR spectroscopy and DP imaging in a total of 45 subjects (23 healthy, 13 chronic obstructive pulmonary disease (COPD) and 9 asthma). From CSSR acquisitions, the COPD subjects showed red blood cell to tissue–plasma (RBC‐to‐TP) ratios below the average for the healthy subjects (p < 0.001), but significantly higher septal wall thicknesses as compared with the healthy subjects (p < 0.005); the RBC‐to‐TP ratios for the asthmatic subjects fell outside two standard deviations (either higher or lower) from the mean of the healthy subjects, although there was no statistically significant difference for the average ratio of the study group as a whole. Similarly, from the 3D DP imaging acquisitions, we found that all the ratios (TP to gas phase (GP), RBC to GP, RBC to TP) measured in the COPD subjects were lower than those from the healthy subjects (p < 0.05 for all ratios), while these ratios in the asthmatic subjects differed considerably between subjects. Despite having been performed at different lung inflation levels, the RBC‐to‐TP ratios measured by CSSR and 3D DP imaging were fairly consistent with each other, with a mean difference of 0.037 (ratios from 3D DP imaging larger). In ten subjects the RBC‐to‐GP ratios obtained from the 3D DP imaging acquisitions were also highly correlated with their diffusing capacity of the lung for carbon monoxide per unit alveolar volume ratios measured by pulmonary function testing (R = 0.91). Copyright © 2014 John Wiley & Sons, Ltd.
Incorporation effect of enzymatic hydrolysis lignin on the mechanical and rheological properties of the resulting wood flour/high‐density polyethylene composites
Authors: Liu Tian , Wang Qingwen , Xie Yanjun , Fu Qiliang
Published: August 2014

Enzymatic hydrolysis lignin (EHL) from ethanol production was used as an additive to incorporate in the wood flour/high‐density polyethylene (HDPE) composite during the melt extrusion, and the incorporating effects on the mechanical and rheological properties of the resulting composites were investigated. The addition of EHL caused an improvement in both the tensile strength and impact strength, and a reduction in the complex viscosity of the composites as evidenced by the rotational rheometry, which suggests an increased flowability of the composite melt due to incorporation of EHL. The water absorption and swelling of the composites decreased with increasing EHL content during water immersion test. The scanning electron microscopy micrographs of EHL incorporated wood flour/high‐density polyethylene composites showed a homogeneous dispersion of wood flour and EHL in the HDPE matrix. POLYM. COMPOS., 37:379–384, 2016. © 2014 Society of Plastics Engineers
Integration of biobased functionalized feedstock and plastisol in epoxy resin matrix toward developing structural jute biocomposites with enhanced impact strength and moisture resistance properties
Authors: Bhosale Subhash Hanmant , Singh Vismay Vinodkumar , Rangasai Madoor Comandore , Bandyopadhyay‐Ghosh Sanchita , Ghosh Subrata Bandhu
Published: August 2014

Epoxy resin matrix based on diglycidyl ether of bisphenol A (DGEBA) was modified with addition of epoxidized soybean oil (ESBO). Structural jute composites prepared with ESBO modified DGEBA resin showed a decrease in tensile strengths, owing to reduced cross linking density. Percentage elongation of the samples increased with addition of ESBO. An optimized composition was identified, at which the composite showed increase in tensile strength, modulus and elongation. Interestingly, impact strengths increased initially with incorporation of ESBO, but with further increase in ESBO, impact strengths decreased. Structural Jute composites were also prepared by incorporating polyvinyl (chloride) (PVC) plastisol into the modified matrix which showed an increase in both tensile and impact strengths. Fourier transform infrared spectroscopy (FT‐IR) analysis indicated the curing state of the composites. The spectrum peaks became increasingly stronger in the OH band with increasing ESBO quantities. This could be attributed to the hydrophilic nature of ESBO, a result that was well supported by the moisture absorption test. Although, water uptake capacity of ESBO/DGEBA modified matrix composites recorded increasing trend with increased ESBO content, with inclusion of plastisol, the water uptake values dropped. Composite with DGEBA/ESBO/plastisol modified matrix actually recorded water uptake capacity comparable to composite with neat DGEBA, possibly owing to improved interfacial adhesion and hydrophobic nature of PVC plastisol. POLYM. COMPOS., 37:391–397, 2016. © 2014 Society of Plastics Engineers
Light absorption and many‐particle electron–phonon interactions in intermediate band quantum well solar cells
Authors: Milde Frank , Weber Carsten , Knorr Andreas
Published: August 2014

The carrier dynamics under solar excitation in the third generation AlAs‐Ga0.27In0.73As quantum well solar cell on an InP substrate is theoretically investigated. The quantum well shows a significantly higher carrier occupation compared with that of a pure bulk sample. Furthermore, the influence of carrier scattering via the interaction with a bath of longitudinal optical phonons stemming from the substrate is taken into account, showing strong intraband and interband relaxation of the carrier distribution toward the lowest subband states. Copyright © 2014 John Wiley & Sons, Ltd.
Temperature effect on template polymerization of methacrylic acid using stereocomplex formation on quartz crystal microbalance substrates
Authors: Ajiro Hiroharu , Ueyama Tatsuaki , Akashi Mitsuru
Published: August 2014

The radical polymerization of methacrylic acid (MAA) at 0, 20, 40, and 70 °C was achieved in porous isotactic (it‐) poly(methyl methacrylate) (PMMA) films on quartz crystal microbalance (QCM) substrates, which were prepared by layer‐by‐layer assembled stereocomplex films of it‐PMMA and syndiotactic (st‐) poly(methacrylic acid) (PMAA), followed by the subsequent extraction of st‐PMAA. The MAA polymerization yields increased from 35 to 75%, as the polymerization temperature increased from 0 to 70 °C. Furthermore, infrared spectroscopy revealed that a higher polymerization temperature is necessary to form it‐PMMA/st‐PMAA stereocomplexes via stereoregular polymerization manner that resemble native it‐PMMA/st‐PMAA stereocomplexes. X‐ray diffraction pattern of porous it‐PMMA were also investigated for reaction fields. © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2014, 52, 3032–3036
Photo‐induced thiol‐ene polysulfide‐crosslinked materials with tunable thermal and mechanical properties
Authors: An So Young , Lee Dong Geun , Hwang Ji Won , Kim Kyung Nam , Nam Joon Hyun , Jung Hyun Wook , Noh Seung Man , Oh Jung Kwon
Published: August 2014

Photo‐induced thiol‐ene crosslinked polymeric networks have been extensively explored in constructing a variety of new materials with enhanced mechanical properties for optical, biomedical, and sensing applications. Toward the broad applications, however, tunable mechanical properties are greatly desired. Here, an effective approach utilizing high‐molecular‐weight methacrylate copolymers having pendant thiol and vinyl groups (MCPsh and MCPenes) to modulate thermal and mechanical properties of photo‐induced thiol‐ene crosslinked materials is reported. The MCP copolymers are synthesized by an industrially friendly polymerization method, followed by post‐modification including either a facile coupling reaction or reductive cleavage. Upon UV irradiation, thiol‐ene reactive blends of MCPsh and MCPenes yield highly crosslinked materials through the formation of flexible sulfide linkages. These polysulfide‐crosslinked materials based on rigid MCP backbones exhibit enhanced mechanical properties. Further, their thermal and mechanical properties are tuned by modulating monomer compositions of MCPs as well as varying numbers of pendant SH or vinyl groups (i.e., extent of crosslinking densities). This approach is versatile and effective for development of high performance polymeric materials. © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2014, 52, 3060–3068
Fluorescent PMMA/MEH‐PPV electrospun nanofibers: Investigation of morphology, solvent, and surfactant effect
Authors: Roque Aline P. , Mercante Luiza A. , Scagion Vanessa P. , Oliveira Juliano E. , Mattoso Luiz H. C. , De Boni Leonardo , Mendonca Cleber R. , Correa Daniel S.
Published: August 2014

Electrospinning is a powerful technique to produce nanofibers of tunable diameter and morphology for medicine and biotechnological applications. By doping electrospun nanofibers with inorganic and organic compounds, new functionalities can be provided for technological applications. Herein, we report a study on the morphology and optical properties of electrospun nanofibers based on the conjugated polymer poly[2‐methoxy‐5‐(2‐ethylhexyloxy)‐1,4‐phenylenevinylene] (MEH‐PPV) and poly(methylmethacrylate) (PMMA). Initially, we investigate the influence of the solvent, surfactant, and the polymer concentration on electrospinning of PMMA. After determining the best conditions, 0.1% MEH‐PPV was added to obtain fluorescent nanofibers. The optical characterizations display the successful impregnation of MEH‐PPV into the PMMA fibers without phase separation and the preservation of fluorescent property after fiber electrospinning. The obtained results show the ability of the electrospinning approach to obtain fluorescent PMMA/MEH‐PPV nanofibers with potential for optical devices applications. © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2014, 52, 1388–1394
A randomized trial comparing live and telemedicine deliveries of an imagery‐based behavioral intervention for breast cancer survivors: reducing symptoms and barriers to care
Authors: Freeman Lyn W. , White Rebecca , Ratcliff Chelsea G. , Sutton Sue , Stewart Mary , Palmer J. Lynn , Link Judith , Cohen Lorenzo
Published: August 2014

Objective

This multi‐site randomized trial evaluates the quality of life (QOL) benefits of an imagery‐based group intervention titled ‘Envision the Rhythms of Life’(ERL).

Methods

Breast cancer survivors >6 weeks post‐treatment were randomized to attend five weekly 4‐h group sessions at a community center with therapist present (live delivery (LD), n = 48), therapist streamed via telemedicine (telemedicine delivery (TD), n = 23), or to a waitlist control (WL) group (n = 47). Weekly individual phone calls to encourage at‐home practice began at session one and continued until the 3‐month follow‐up. Seven self‐report measures of QOL were examined at baseline, 1‐month and 3‐month post‐treatments including health‐related and breast cancer‐specific QOL, fatigue, cognitive function, spirituality, distress, and sleep.

Results

The Bonferroni method was used to correct for multiple comparisons, and alpha was adjusted to 0.01. Linear multilevel modeling analyses revealed less fatigue, cognitive dysfunction, and sleep disturbance for LD and TD compared with WL across the follow‐up (p's < 0.01). Changes in fatigue, cognitive dysfunction, sleep disturbance, and health‐related and breast cancer‐related QOL were clinically significant. There were no differences between LD and TD.

Conclusions

Both the live and telemedicine delivered ERL intervention resulted in improvements in multiple QOL domains for breast cancer survivors compared with WL. Further, there were no significant differences between LD and TD, suggesting telemedicine delivered ERL intervention may represent an effective and viable option for cancer survivors in remote areas. Copyright © 2014 John Wiley & Sons, Ltd.
Semiconducting Polymer Nanoparticles as Fluorescent Probes for Biological Imaging and Sensing
Authors: Chan Yang‐Hsiang , Wu Pei‐Jing
Published: August 2014

In recent years, semiconducting polymer nanoparticles have emerged as a new class of extraordinarily bright fluorescent probes. These polymer nanoparticles, which are primarily composed of π‐conjugated polymers, exhibit a variety of outstanding features, including exceptional fluorescence brightness, fast radiative rate, good photostability, facile surface functionalization, and low cytotoxicity. These advantageous characteristics make polymer nanoparticles highly promising for applications in biological imaging and sensing. This progress report highlights recent advances in the synthesis, characterization, and applications as bio‐labels or sensors of these highly emissive organic nanoparticles.
On the IEEE 802.11i security: a denial‐of‐service perspective
Authors: Singh Rajeev , Sharma Teek Parval
Published: August 2014

The IEEE 802.11i standard provides authentication and security at the Medium Access Control layer in wireless local area networks (WLANs). It involves an authentication process followed by a four‐way handshake to evolve a key for securing data sessions. The standard suffers under denial‐of‐service (DoS) attacks. These attacks often block the ongoing communication process and deprive services to the legitimate users. These are easy to conduct while maintaining anonymity of the attackers. It hence becomes imperative to learn about the attacks and their solutions in IEEE 802.11i‐protected WLANs so that future research proposals and solutions to mitigate the attack may develop. The paper presents a review of DoS attacks and existing solutions pertaining to the IEEE 802.11i security standard. Copyright © 2014 John Wiley & Sons, Ltd.
ReDD: recommendation‐based data dissemination in privacy‐preserving mobile social networks
Authors: Chen Le , Lu Rongxing , AlHarbi Khalid , Lin Xiaodong , Cao Zhenfu
Published: August 2014

Mobile social network (MSN), which is built upon popular smart phone devices and enables mobile users with similar interests to connect with one another, has received considerable attention in recent years. A common phenomenon that makes the MSN vivid today is mobile users often like to share attractive things to their friends in MSN. In this paper, based on this common phenomenon, we propose an efficient recommendation‐based data dissemination (ReDD) protocol for MSN, which can efficiently disseminate high‐quality messages in a privacy‐preserving way. Specifically, in the proposed ReDD protocol, each mobile user, based on both his or her own view and his or her friends' recommendations, will form his or her personal estimation on the quality of a message. Only if the estimation of quality reaches a threshold, the message will be disseminated. In this way, high‐quality messages can be widely spread in the network and occupy more network resources than low‐quality ones. In order to check the validity of friends' recommendations, ReDD also employs an efficient anonymous authentication technique, which ensures that only the friends of a user can verify recommendations made by the user. Detailed security analysis demonstrates that ReDD can effectively resist various attacks launched by attackers and ensure identity privacy of nodes, confidentiality of shared keys and integrity of data packets. In addition, extensive simulations are also conducted to evaluate the performance of ReDD in terms of the number of active nodes and the average active time, and the simulation results show that high‐quality messages can be disseminated widely and efficiently, while low‐quality ones will be eliminated shortly to avoid occupying network resources. Copyright © 2014 John Wiley & Sons, Ltd.
A new secure and efficient scheme for network mobility management
Authors: Smaoui Salima , Obaidat Mohammad S. , Zarai Faouzi , Hsiao K. F.
Published: August 2014

In order to separate a host's identity from its location on the Internet, the Host Identity Protocol (HIP) was developed by the Internet Engineering Task Force as a mobility management solution. HIP provides a solid basis to enable secured mobility and multihoming features. Several extensions and proposals have been introduced in recent publications to improve the micro‐mobility features of HIP. Moreover, many other publications have dealt with the efficiency of Network Mobility (NEMO) management with HIP. However, the HIP‐based micro‐mobility management solutions adapted to NEMO scenario do not cover all security aspects requirements and still suffer from security flaws. Therefore, in this paper, a number of potential threats in the typical HIP with Rendez Vous Server are identified. A new secure and efficient scheme for network mobility management is also proposed to overcome the outlined ones. The proposed solution ensures strong authentication between network entities, reduces Denial of Service attacks, secures against Domain Name Server spoofing, reply, and eavesdropping attacks, and ensures end‐to‐end confidentiality and integrity protection. To analyze the security properties of the proposed scheme, we have performed automated formal specification and evaluation with the help of both the Automated Validation of Internet Security Protocols and Applications and the Security Protocol Animator, which have proved that authentication and confidentiality goals are achieved. Hence, the scheme is effective when an intruder is present. Copyright © 2014 John Wiley & Sons, Ltd.
Innovation as system intervention
Authors: Hatchuel A. , Agrell P. , Van Gigch J. P.
Published: August 2014

In a world of high technology, it is paramount to gain a thorough understanding of the factors and forces that shape and stimulate innovation. Herein, innovation is characterized as a process of organizational intervention where rationality is valued more for its process than for its results. An interactive dialectical process of learning leads to innovative solutions through the reconceptualization of models and of organizational logics. The roles of metamodeling and of metaknowledge in innovation are also outlined.
The ABL/W4 methodology for system modelling
Authors: Jaworski W. M. , Ficocelli L. , O'Mara K. S.
Published: August 2014

This paper presents an environment and a methodology for system modelling. The environment provides a powerful, language independent, infrastructure for the transformation of problems to programs. The methodology is designed to account for the representational distortions found throughout the various phases of problem refinement and resolution. It is thus useful within the software lifecycle and can form the infrastructure for the development of Expert Systems.
A transformational model of economies from late to post industrial periods
Authors: Auger Pierre
Published: August 2014

A model of a set of interacting sectors is proposed. Dynamic equations governing the motions of sectoral productions are chosen. A supplementary equation establishing equilibrium of the national budget is obtained. The contradictory effects of technical change on the economic system are studied, as this change destroys employment by replacing men with machines and computers and also creates new sectors and employment. The paper studies a particular case of an economic system in which technical change globally destroys employment. Stimulation of the economic system can be done either by inducement to consumption or by inducement to production. In order to maintain total consumption and production, the paper shows that it is necessary to increase the purchase power of consumers and to create new sectors absorbing a lot of working hours per production unit. To obtain this, good quality products needing a lot of working hours must gradually replace all identical factory products needing less and less working hours.
Investigating the Reading Practices of EFL Yemeni Students Using the Learning by Design Framework
Authors: Bhooth Abdullah Mohammad , Azman Hazita , Ismail Kemboja
Published: August 2014

This article investigates the reading practices of 45 EFL Yemeni students using the learning by design framework. The framework organizes the teaching and learning of literacy into four processes: experiencing, conceptualising, analysing, and applying. Quantitative and qualitative methods were used to collect data on a sample of students studying English as a foreign language at a university in Yemen. The researchers collected quantitative data through a questionnaire and gathered qualitative data using semistructured interviews guided by the research objectives. The findings reveal that the use of reading practices by this group of students was underdeveloped in all four processes. Findings also reveal that vocabulary difficulties, complex sentence structures, and inability to use reading strategies are some of the serious challenges faced by Yemeni students when reading in English. These findings suggest that the reading practices and reading abilities of Yemeni students are still limited, even at the tertiary level, in terms of meeting the multiliterate requirements for reading effectively in a multimodal world.
The RNAissance family: SR proteins as multifaceted regulators of gene expression
Authors: Howard Jonathan M. , Sanford Jeremy R.
Published: August 2014

Serine and arginine‐rich (SR) proteins play multiple roles in the eukaryotic gene expression pathway. Initially described as constitutive and alternative splicing factors, now it is clear that SR proteins are key determinants of exon identity and function as molecular adaptors, linking the pre‐messenger RNA (pre‐mRNA) to the splicing machinery. In addition, now SR proteins are implicated in many aspects of mRNA and noncoding RNA (ncRNA) processing well beyond splicing. These unexpected roles, including RNA transcription, export, translation, and decay, may prove to be the rule rather than the exception. To simply define, this family of RNA‐binding proteins as splicing factors belies the broader roles of SR proteins in post‐transcriptional gene expression. WIREs RNA 2015, 6:93–110. doi: 10.1002/wrna.1260

This article is categorized under:

RNA Interactions with Proteins and Other Molecules > Protein–RNA Recognition

RNA Interactions with Proteins and Other Molecules > Protein–RNA Interactions: Functional Implications

RNA Processing > Splicing Mechanisms

RNA Processing > Splicing Regulation/Alternative Splicing
Food Additives Reducing Volatility of Antioxidants at Frying Temperature
Authors: Hwang Hong‐Sik , Winkler‐Moser Jill K.
Published: August 2014

At frying temperature, antioxidants are lost not only by reaction with radicals formed by oil oxidation but also by decomposition and evaporation before they are able to exert antioxidant activity. In this study, it was hypothesized that an additive that can bind or interact with an antioxidant could reduce volatility of the antioxidant at frying temperature. Three synthetic antioxidants, tert‐butylhydroquinone (TBHQ), butylated hydroxyanisole (BHA) and butylated hydroxytoluene (BHT), which have relatively high volatility, were used as antioxidants in this study to examine the hypothesis. Thermogravimetric analysis (TGA) experiments showed that all 22 additives tested in this study effectively reduced volatility of the antioxidants. An NMR study showed that signals of BHT shifted by addition of an additive, evidencing the interaction between the two substances in the chloroform solution. To examine the effect of these interactions on antioxidant activity, heating tests were conducted with soybean oil (SBO) containing 200 ppm antioxidants at 180 °C. Oxidation was monitored with 1H NMR for loss of olefinic protons and bisallylic protons in SBO and with gel permeation chromatography (GPC) for polymerized triacylglycerols (PTAG). Improved antioxidant activity of the antioxidants were observed when combined with several additives tested in this study, and HPLC analysis showed that the antioxidants were effectively reserved by the additives in SBO during the heating process. The concentrations of the antioxidants retained in SBO were relatively well correlated with the antioxidant activity.