bluuebunny/crossref_metadata_2025 huggingface dataset:
Synthesis of pH‐responsive polyethylene terephthalate track‐etched membranes by grafting hydroxyethyl‐methacrylate using atom‐transfer radical polymerization method
Authors: Pan Kai , Ren Ruimin , Liang Bin , Li Li , Li Haizhu , Cao Bing
Published: May 2014

pH‐responsive polyethylene terephthalate (PET) track‐etched membranes were synthesized by grafting 2‐hydroxyethyl‐methacrylate (HEMA) on the surface of the membrane via atom transfer radical polymerization. The controllability of grafting polymerization of HEMA on membrane surface is systematically investigated. The pH‐responsive characteristics of PET‐g‐poly(2‐hydroxyethyl‐methacrylate) (PHEMA) gating membranes with different grafted PHEMA chain lengths are measured by tracking the permeation of water solution with different pH values. The results show that the grafting polymerization is controllable, and the permeation of grafted membranes is affected by the grafted PHEMA chain lengths on the surface of membrane. The results also demonstrate that the grafted PET membranes exhibit reversible pH‐response permeation to environmental pH values. Desired pH‐responsive membranes are obtained by controlling the grafted PHEMA chain lengths via atom transfer radical polymerization method. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40912.
Electrical percolation behavior and electromagnetic shielding effectiveness of polyimide nanocomposites filled with carbon nanofibers
Authors: Nayak Lalatendu , Chaki Tapan K. , Khastgir Dipak
Published: May 2014

The objective of present study is to prepare conductive polyimide (PI)–carbon nanofibers (CNFs) composite at very low percolation threshold. The combined advantage of in situ polymerization of PI in the presence of highly graphitized CNFs and continuous probe type sonication throughout the polymerization provide electrically conductive PI composites with a significantly lower percolation threshold than previously reported. The electrical conductivity and electromagnetic interference shielding effectiveness (EMI SE) of the nanocomposite with different weight percentages of CNFs (0.25–5 wt %) were investigated at room temperature. The measurement of EMI SE was carried out using thin film of composites in a frequency range of 8.2–12.4 GHz (X‐band). The direct current conductivity of composites follows the percolation scaling law with a very low percolation threshold (CNF, 0.5 wt %). The electrical conductivity of the PI composite increases by more than 10 decades of magnitude, from 5.8 × 10−16 to 2.03 × 10−6 mho cm−1 owing to the addition of 0.5 wt % of CNF. An increase in dielectric permittivity and decrease in alternating current impedance with increasing concentration of CNF are observed. The conduction mechanism in composites is explained in the light of power law‐dependent current (I)–voltage (V) characteristics. The composite of 0.07‐mm thickness shows EMI SE of above 12 decibel (dB) at 5 wt % of CNF loading. The experimental data suggest that the prepared composites can be used for the dissipation of electrostatic charge and EMI shielding purpose. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40914.
Factors influencing student performance on the carpal bone test as a preliminary evaluation of anatomical knowledge retention
Authors: Meyer Amanda J. , Armson Anthony , Losco C. Dominique , Losco Barrett , Walker Bruce F.
Published: May 2014

It has been demonstrated that a positive correlation exists between clinical knowledge and retained concepts in basic sciences. Studies have demonstrated a modest attrition of anatomy knowledge over time, which may be influenced by students' perceived importance of the basic sciences and the learning styles adopted. The aims of this study were to: (1) conduct a cross‐sectional evaluation of the retention of anatomical knowledge in preclinical (second‐year) and clinical (fifth‐year) chiropractic students at Murdoch University; and (2) examine students' perceptions of factors that may influence their anatomy knowledge retention. Second‐ and fifth‐year chiropractic students at Murdoch University were invited to participate in the study. Ninety‐one students voluntarily participated. The Carpal Bone Test, previously utilized to determine the retention of anatomical knowledge, was utilized to determine the extent to which participants retained gross anatomy knowledge. Participants also completed a questionnaire specifically designed to identify the factors that may have influenced their retention of gross anatomy knowledge. A two‐sided Pearson chi‐square test of association was used to ascertain statistically significant differences in carpal bone retention and students' responses between the two cohorts. Seventy percent of the fifth‐year (clinical) chiropractic students correctly identified all eight carpal bones compared to only six percent of second‐year chiropractic students. The majority of participants in both cohorts believed that gross anatomy knowledge is of clinical importance. The use of mnemonics and the clinical application of anatomy knowledge were identified as factors that significantly influenced participants' gross anatomy knowledge retention within this study. Anat Sci Educ 8: 133–139. © 2014 American Association of Anatomists.
SPC methods for nonstationary correlated count data with application to network surveillance
Authors: Fu Yingzhuo , Jeske Daniel R.
Published: May 2014

Network surveillance methods are becoming increasingly important as the ability to monitor a wide variety of data is rapidly expanding. Network traffic metrics are usually correlated count data that display a nonstationary pattern in their mean structures. We propose to model traffic counts using a generalized linear mixed model to capture these features. We then develop three tracking statistics proposed for anomaly detection. Two of the statistics are derived variants of a Bartlett‐type likelihood ratio, which itself is not computationally tractable. The first of these variants is based on an approximation to the integrated likelihood while the second is based on the concept of h‐likelihood. We also consider a tracking statistic that is an exponentially weighted moving average. We compare the properties of the three tracking statistics from the point of view of FAR and detection power and contrast the proposed tracking statistics with current literature. Our comparisons show that the two generalized likelihood ratio variants are preferred choices as statistical process control tools for network surveillance. Computational aspects of the three procedures are also discussed. While our application focus is network surveillance, our proposed methods apply to other applications that have similar data characteristics. Copyright © 2014 John Wiley & Sons, Ltd.
Characterization and cancer cell targeted imaging properties of human antivascular endothelial growth factor monoclonal antibody conjugated CdTe/ZnS quantum dots
Authors: Pang Lili , Xu Jian , Shu Chang , Guo Jin , Ma Xiaona , Liu Yu , Zhong Wenying
Published: May 2014

High luminescence quantum yield water‐soluble CdTe/ZnS core/shell quantum dots (QDs) stabilized with thioglycolic acid were synthesized. QDs were chemically coupled to fully humanized antivascular endothelial growth factor165 monoclonal antibodies to produce fluorescent probes. These probes can be used to assay the biological affinity of the antibody. The properties of QDs conjugated to an antibody were characterized by ultraviolet and visible spectrophotometry, fluorescent spectrophotometry, sodium dodecyl sulfate–polyacrylamide gel electrophoresis, transmission electron microscopy and fluorescence microscopy. Cell‐targeted imaging was performed in human breast cancer cell lines. The cytotoxicity of bare QDs and fluorescent probes was evaluated in the MCF‐7 cells with an MTT viability assay. The results proved that CdTe/ZnS QD–monoclonal antibody nanoprobes had been successfully prepared with excellent spectral properties in target detections. Surface modification by ZnS shell could mitigate the cytotoxicity of cadmium‐based QDs. The therapeutic effects of antivascular endothelial growth factor antibodies towards cultured human cancer cells were confirmed by MTT assay. Copyright © 2014 John Wiley & Sons, Ltd.
Influence of body mass index on mortality after surgery for perforated peptic ulcer
Authors: Buck D L , Møller M H
Published: May 2014

Background

Body mass index (BMI) is a strong predictor of mortality in the general population. In spite of the medical hazards of obesity, a protective effect on mortality has been suggested in surgical patients: the obesity paradox. The aim of the present nationwide cohort study was to examine the association between BMI and mortality in patients treated surgically for perforated peptic ulcer (PPU).

Methods

This was a national prospective cohort study of all Danish patients treated surgically for PPU between 1 February 2003 and 31 August 2009, for whom BMI was registered. Non-surgically treated patients and those with malignant ulcers were excluded. The primary outcome measure was 90-day mortality. The association between BMI and mortality was calculated as crude and adjusted relative risks (RRs) with 95 per cent confidence intervals (c.i.).

Results

Of 2668 patients who underwent surgical treatment for PPU, 1699 (63·7 per cent) had BMI recorded. Median age was 69·4 (range 17·6–100·9) years and 53·7 per cent of the patients were women. Some 1126 patients (66·3 per cent) had at least one of six co-morbid diseases; 728 (42·8 per cent) had an American Society of Anesthesiologists grade of III or more. A total of 471 patients (27·7 per cent) died within 90 days of surgery. Being underweight was associated with a more than twofold increased risk of death following surgery for PPU (adjusted RR 2·26, 95 per cent c.i. 1·37 to 3·71). No statistically significant association was found between obesity and mortality.

Conclusion

Being underweight was associated with increased mortality in patients with PPU, whereas being overweight or obese was neither protective nor an adverse prognostic factor.
Trends in surgery for screen-detected and interval breast cancers in a national screening programme
Authors: Nederend J , Duijm L E M , Louwman M W J , Roumen R M H , Jansen F H , Voogd A C
Published: May 2014

Background

This population-based study aimed to evaluate trends in surgical approach for screen-detected cancer versus interval breast cancer, and to determine the factors associated with positive resection margins.

Methods

Screening mammograms of women aged 50–75 years, who underwent biennial screening in a Dutch breast-screening region between 1997 and 2011, were included. Patient and tumour characteristics were compared between women who underwent mastectomy or breast-conserving surgery (BCS) for screen-detected or interval cancer, and women with a negative or positive resection margin after BCS.

Results

Some 417 013 consecutive screening mammograms were included. A total of 2224 screen-detected and 825 interval cancers were diagnosed. The BCS rate remained stable (mean 6·1 per 1000 screened women; P = 0·099), whereas mastectomy rates increased significantly during the study from 0·9 (1997–1998) to 1·9 (2009–2010) per 1000 screened women (P < 0·001). The proportion of positive resection margins for invasive cancer was 19·6 and 7·6 per cent in 1997–1998 and 2009–2010 respectively (P < 0·001), with significant variation between hospitals. Dense breasts, preoperative magnetic resonance imaging, microcalcifications, architectural distortion, tumour size over 20 mm, axillary lymph node metastasis and treating hospital were independent risk factors for mastectomy. Interval cancer, image-guided tumour localization, microcalcifications, breast parenchyma asymmetry, tumour size greater than 20 mm, lobular tumour histology, low tumour grade, extensive invasive component and treating hospital were independent risk factors for positive resection margins.

Conclusion

Mastectomy rates doubled during a 14-year period of screening mammography and the proportion of positive resection margins decreased, with variation among hospitals. The latter observation stresses the importance of quality control programmes for hospitals treating women with breast cancer.
Screening of allergic components mediated by H1R in homoharringtonine injection through H1R/CMC‐HPLC/MS
Authors: Guo Ying , Han Shengli , Cao Jingjing , Liu Qi , Zhang Tao
Published: May 2014

It has been reported that the histamine H1 receptor (H1R) gene is up‐regulated in patients with allergic rhinitis and H1R expression level strongly correlates with the severity of allergy symptoms. Drugs for therapy should avoid allergy symptoms, especially for patients with over‐expressed H1R. Therefore, screening of the components which could induce H1R activation is urgently needed for drug safety evaluation. Homoharringtonine injection is a preparation for acute nonlymphocytic leukemia, which is approved by China Food and Drug Administration (CFDA) and US Food and Drug Administration. However, severely adverse reactions often occur with intravenous injection of the preparation. In present study, an H1R/CMC model was applied for capturing membrane retained components which could induce H1R activation. Retention components were enriched and analyzed by H1R/CMC‐HPLC/MS. Homoharringtonine was recognized, separated and identified in homoharringtonine injection. Ca2+ flux assay and p‐IP3R expression founded that homoharringtonine retained by the H1R/CMC model increased phosphorylation of IP3R and promoted cytosolic free Ca2+ elevation in a dose‐dependent manner which further verified the activity of homoharringtonine in activating the H1R. In conclusion, homoharringtonine was screened and identified as a potential allergic factor. This provides an indication that a patient with over‐expressed H1R should be aware of possible allergic reaction when applying homoharringtonine injection. Copyright © 2014 John Wiley & Sons, Ltd.
An LC‐MS/MS method for the simultaneous determination and pharmacokinetic studies of bergenin, chlorogenic acid and four flavonoids in rat plasma after oral administration of a QingGanSanJie decotion extract
Authors: Zhao Liang , Qian Xian , Li Wuhong , Lv Lei , Zhang Hai , Chai Yifeng , Zhang Guoqing
Published: May 2014

A rapid, simple and sensitive, liquid chromatography–tandem mass spectrometry (LC‐MS/MS) method was developed and validated for simultaneous determination of bergenin, chlorogenic acid and four flavonoids in a QingGanSanJie preparation in rat plasma. Puerarin was selected as the internal standard (IS). Plasma samples were precipitated with methanol and separated with a reverse phase Agilent Poroshell 120 EC‐C18 column using a gradient mobile phase of methanol–water containing 0.1% formic acid (v/v). A triple quadruple mass spectrometer was used for quantification (limit of detection 0.36–5.55 ng/mL). Intra‐day and inter‐day precisions were within 15% and the average extraction recoveries ranged from 85 to 115% for each analyte. The method allowed simultaneous quantification for the first time of the pharmacokinetics of bergenin, chlorogenic acid and four flavonoids after intragastric administration of a QingGanSanJie extract in Sprague–Dawley rats. It was found that bergenin and chlorogenic acid had typical extravascular administration concentration–time curves; flavonoids had a bimodal distribution improving bioavailability and extending the pharmacodynamics period. Copyright © 2014 John Wiley & Sons, Ltd.
Liquid chromatography mass spectrometry simultaneous determination of vindoline and catharanthine in rat plasma and its application to a pharmacokinetic study
Authors: Lin Chongliang , Cai Jinzhang , Yang Xuezhi , Hu Lufeng , Lin Guanyang
Published: May 2014

Vinblastine and vincristine, both of which are bisindole alkaloids derived from vindoline and catharanthine, have been used for cancer chemotherapy; their monomeric precursor molecules are vindoline and catharanthine. A simple and selective liquid chromatography mass spectrometry method for simultaneous determination of vindoline and catharanthine in rat plasma was developed. Chromatographic separation was achieved on a C18 (2.1 × 50 mm, 3.5 µm) column with acetonitrile–0.1% formic acid in water as mobile phase with gradient elution. The flow rate was set at 0.4 mL/min. An electrospray ionization source was applied and operated in positive ion mode; selective ion monitoring mode was used for quantification. Mean recoveries were in the range of 87.3–92.6% for vindoline in rat plasma and 88.5–96.5% for catharanthine. Matrix effects for vindoline and catharanthine were measured to be between 95.3 and 104.7%. Coefficients of variation of intra‐day and inter‐day precision were both <15%. The accuracy of the method ranged from 93.8 to 108.1%. The method was successfully applied in a pharmacokinetic study of vindoline and catharanthine in rats. The bioavailability of vindoline and catharanthine were 5.4 and 4.7%, respectively. Copyright © 2014 John Wiley & Sons, Ltd.
Enhanced conjugation of Candida rugosa lipase onto multiwalled carbon nanotubes using reverse micelles as attachment medium and application in nonaqueous biocatalysis
Authors: Raghavendra Tripti , Vahora Uzma , Shah Amita R. , Madamwar Datta
Published: May 2014

Three liquid phases (viz. aqueous, nonaqueous, and reverse micelles) were scrutinized as medium for attachment of the enzyme Candida rugosa lipase (CRL) onto multiwalled carbon nanotubes (CNTs). The nanotubes were functionalized to attain carboxyl and amino groups on their surfaces before enzyme conjugation. Transmission electron microscopy and Fourier transformation infrared spectroscopic studies were used for characterization of the nanotubes during the course of functionalization. High enzyme loadings associated with the functionalized CNTs were observed when reverse micelles were used as the attachment medium. In addition, high activity in terms of ester synthesis in organic solvents was also observed while using those preparations. The nanobioconjugates prepared using reverse micelles were found to be highly sturdy and exhibited appreciable operational stability of around 95 ± 3% at 20th cycle (in case of carboxylated nanotubes) and 90 ± 5% at 10th cycle (in case of aminated nanotubes) for esterification. This shows the potential application of reverse micelles as the attachment medium for surface active enzymes such as CRL onto CNTs. © 2014 American Institute of Chemical Engineers Biotechnol. Prog., 30:828–836, 2014
Real‐time depth‐of‐field rendering using single‐layer composition
Authors: Fang Xiaoxin , Sheng Bin , Wu Wen , Fan Zengzhi , Ma Lizhuang
Published: May 2014

In this paper, we propose a single‐layer post‐processing method for real‐time depth‐of‐field rendering that uses single‐layer composition. In the proposed method, blurring is achieved by gathering background pixels and scattering foreground pixels. Major artifacts in post‐filtering techniques such as intensity leakage and blurring discontinuity are reduced by using two different blurring functions and the controllable parameter in the gathering process. The method can be entirely implemented in GPU parallelization to achieve the real‐time performance required for virtual reality. The results of comparisons of our method with recent post‐processing methods in terms of rendering quality and rendering performance indicate that our method generates realistic natural images and is also the fastest in terms of frames per second. Copyright © 2014 John Wiley & Sons, Ltd.
Understanding Photochirogenesis: Solvent Effects on Circular Dichroism and Anisotropy Spectroscopy
Authors: Bredehöft Jan Hendrik , Jones Nykola C. , Meinert Cornelia , Evans Amanda C. , Hoffmann Søren V. , Meierhenrich Uwe J.
Published: May 2014

The basic units that constitute essential biopolymers (proteins and nucleic acids) are enantiomerically biased. Proteins are constructed from L‐amino acids and nucleic acids possess a backbone composed exclusively of D‐sugars. Photochirogenesis has been postulated to be the source of this homochirality of biomolecules: Asymmetric photochemical reactions were catalyzed by circularly polarized light (cpl) in interstellar environments and generated the first chiral prebiotic precursors. Enantiomers absorb cpl differently and this difference can dictate the kinetics of asymmetric photochemical reactions. These differences in absorption can be studied using circular dichroism (CD) and anisotropy spectroscopy. Rather than measuring the CD spectrum alone, the anisotropy factor g is recorded (CD divided by absorption). This factor g is directly related to the maximum achievable enantiomeric excess. We now report on the substantial influence of solvent and molecular surroundings on CD and anisotropy spectroscopy. This shows for the first time that CD and anisotropy signals depend just as much on the molecular surroundings of a molecule as on the nature of the molecule itself. CD and g spectra of amino acids in different solvents and in the solid state are presented here and the influence of these different surroundings on the spectra is discussed. Chirality 26:373–378, 2014. © 2014 Wiley Periodicals, Inc.
The impact of significant input of fine sediment on benthic fauna at tributary junctions: a case study of the Bermejo–Paraguay River confluence, Argentina
Authors: Blettler Martín C. M. , Amsler Mario L. , Ezcurra de Drago Inés , Espinola Luis A. , Eberle Eliana , Paira Aldo , Best James L. , Parsons Daniel R. , Drago Edmundo E.
Published: May 2014

This study examines the morphological features, suspended sediment inputs and hydraulic conditions within a large river in association with ecological patterns before and after a tributary confluence. In order to examine these effects, the macroinvertebrate distributions from three reaches of the Paraguay and Bermejo Rivers (Paraguay–Argentina) are investigated. The Bermejo River is a tributary that supplies significant quantities of fine sediment to the Paraguay River, primarily in suspension. Two reaches were examined on the Paraguay River, upstream and downstream of the Bermejo River junction, with the third study reach located on the Bermejo River, upstream of the confluence with the Paraguay River. The results provide clear evidence that a significantly increased loading of fine sediment at a river confluence has effects on the distribution and potential movement of benthic invertebrates in the lotic environment by representing physical barriers at affected sites. These effects may be important at both local and regional scales, and such increases in suspended sediment (especially associated with anthropogenic change) may thus pose a major threat to ecosystem integrity that has been historically underestimated. Copyright © 2014 John Wiley & Sons, Ltd.
Evidence for microbial activity in British and Irish Ordovician pillow lavas
Authors: Parnell John , Hole Malcolm , Boyce Adrian J.
Published: May 2014

Pyrite is consistently found in modern seafloor vesicular basalts and has a sulphur isotopic composition consistent with microbial activity. We present S isotope data from pyrite in Ordovician pillow lavas at localities across the British Isles, which yield a range of δ34S compositions consistent with two components of sulphur: groundmass pyrite (~0 ± 4‰) and 32S‐enriched pyrite in the vesicles (−8‰ to −27‰). The latter are recorded from vesicular lavas in four different terranes, representing different settings at the margins of the Iapetus Ocean. Whereas a component of magmatic sulphate is recognized in the groundmass values, the isotopically light data in the vesicles are consistent with microbial reduction of seawater sulphate in sub‐seafloor lavas. This is consistent with modern examples and indicates considerable longevity for this sub‐seafloor microbial habitat. Copyright © 2014 John Wiley & Sons, Ltd.
Parents' Emotion‐Related Beliefs, Behaviours, and Skills Predict Children's Recognition of Emotion
Authors: Castro Vanessa L. , Halberstadt Amy G. , Lozada Fantasy T. , Craig Ashley B.
Published: May 2014

Children who are able to recognize others' emotions are successful in a variety of socioemotional domains, yet we know little about how school‐aged children's abilities develop, particularly in the family context. We hypothesized that children develop emotion recognition skill as a function of parents' own emotion‐related beliefs, behaviours, and skills. We examined parents' beliefs about the value of emotion and guidance of children's emotion, parents' emotion labelling and teaching behaviours, and parents' skill in recognizing children's emotions in relation to their school‐aged children's emotion recognition skills. Sixty‐nine parent–child dyads completed questionnaires, participated in dyadic laboratory tasks, and identified their own emotions and emotions felt by the other participant from videotaped segments. Regression analyses indicate that parents' beliefs, behaviours, and skills together account for 37% of the variance in child emotion recognition ability, even after controlling for parent and child expressive clarity. The findings suggest the importance of the family milieu in the development of children's emotion recognition skill in middle childhood and add to accumulating evidence suggesting important age‐related shifts in the relation between parental emotion socialization and child emotional development. Copyright © 2014 John Wiley & Sons, Ltd.
Gamma delta T cells in non‐immune patients during primary schistosomal infection
Authors: Schwartz Eli , Rosenthal Etti , Bank Ilan
Published: May 2014

The mevalonate pathway is critical for the survival of Schistosoma. γδ T cells, a small subset of peripheral blood (PB) T cells, recognize low molecular weight phosphorylated antigens in the mevalonate pathway, which drive their expansion to exert protective and immunoregulatory effects. To evaluate their role in schistosomiasis, we measured γδ T cells in the PB of non‐immune travelers who contracted Schistosoma hematobium or Schistosoma mansoni in Africa. The maximal level of γδ T‐cells following infection was 5.78 ± 2.19% of the total T cells, versus 3.72 ± 3.15% in 16 healthy controls [P = 0.09] with no difference between S. hematobium and S. mansoni in this regard. However, among the nine patients in the cohort who presented with acute schistosomiasis syndrome (AS), the level (3.5 ± 1.9%) was significantly lower than in those who did not (8.6 ± 6.4%, P < 0.05), both before and after therapy. Furthermore, γδ T cells increased significantly in response to praziquantel therapy. In a patient with marked expansion of γδ T cells, most expressed the Vδ2 gene segment, a hallmark of cells responding to cognate antigens in the mevalonate pathways of the parasite or the human host. These results suggest an immunoregulatory role of antigen responsive γδ T cells in the clinical manifestations of early schistosomal infection.
MIXED‐FREQUENCY STRUCTURAL MODELS: IDENTIFICATION, ESTIMATION, AND POLICY ANALYSIS
Authors: Foroni Claudia , Marcellino Massimiliano
Published: May 2014

The mismatch between the timescale of DSGE (dynamic stochastic general equilibrium) models and the data used in their estimation translates into identification problems, estimation bias, and distortions in policy analysis. We propose an estimation strategy based on mixed‐frequency data to alleviate these shortcomings. The virtues of our approach are explored for two monetary policy models. Copyright © 2014 John Wiley & Sons, Ltd.
Enhancement of adhesion and promotion of osteogenic differentiation of human adipose stem cells by poled electroactive poly(vinylidene fluoride)
Authors: Pärssinen Jenita , Hammarén Henrik , Rahikainen Rolle , Sencadas Vitor , Ribeiro Clarisse , Vanhatupa Sari , Miettinen Susanna , Lanceros‐Méndez Senentxu , Hytönen Vesa P.
Published: May 2014

Poly(vinylidene fluoride) (PVDF) is a biocompatible material with excellent electroactive properties. Nonelectroactive α‐PVDF and electroactive β‐PVDF were used to investigate the substrate polarization and polarity influence on the focal adhesion (FA) size and number as well as on human adipose stem cells (hASCs) differentiation. hASCs were cultured on different PVDF surfaces adsorbed with fibronectin and FA size and number, total adhesion area, cell size, cell aspect ratio and FA density were estimated using cells expressing vinculin fused to enhanced green fluorescent protein. Osteogenic differentiation was also determined using a quantitative alkaline phosphatase assay. The surface charge of the poled PVDF films (positive or negative) influenced the hydrophobicity of the samples, leading to variations in the conformation of adsorbed extracellular matrix proteins, which ultimately modulated the stem cell adhesion on the films and induced their osteogenic differentiation. © 2014 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 103A: 919–928, 2015.
Facile synthesis and in situ magnetization of carbon‐decorated lignocellulose fiber for highly efficient removal of methylene blue
Authors: Li Meng , Wang Shi , Luo Wenjun , Xia Hua , Gao Qiang , Zhou Chenggang
Published: May 2014

BACKGROUND

Magnetic adsorption is currently a popular way to remove chemical pollutants from water. The present work reported highly efficient removal of methylene blue (MB) by magnetically retrievable carbon‐decorated lignocellulose fiber (mC@LCF).

RESULTS

Carbon‐decorated lignocellulose fiber (C@LCF) was successfully synthesized via the hydrothermal carbonization process using a low‐cost and environment‐friendly lignocellulose fiber (LCF) as raw material. Further, the C@LCF was in situ magnetized by simply adding it and magnetic nanoparticle (MNP) into methylene blue (MB) solution taking advantage of the spontaneous behavior of MNP adherence to the surface of C@LCF. During this period, MB was efficiently removed, and the maximum removal capacity was 232.3 mg g−1 at 303.15 K. Kinetic and thermodynamic investigations as well as isotherm analysis were also undertaken. Reusability of mC@LCF was evaluated, and results showed that removal of MB exceeded 90% after seven consecutive cycles.

CONCLUSIONS

The mC@LCF has obvious advantages including ease of production, low production costs, environmental friendliness, magnetic retrievability, and high efficiency for MB adsorption. Thus mC@LCF is a promising adsorbent for the purification of dye‐containing wastewater. © 2014 Society of Chemical Industry
A User Evaluation Study: Do Participants' Personal Notes Help Us to Summarise Meetings?
Authors: Bothin Antje , Clough Paul
Published: May 2014

We describe a novel user evaluation study on the value of people's personal meeting notes for a question‐answering task involving meeting data taken from the Augmented Multiparty Interaction (AMI) corpus. A survey on task perceptions and note‐taking strategies in meetings was also conducted. The results suggest that written notes taken by multiple meeting participants contain the majority of the most informative meeting information and are thus likely to support information systems that employ automatic meeting understanding and summarisation. The users were able to achieve 79% and 76% accuracy in the task with handwritten and typed notes respectively as information source. Contrary to that, they scored 36% accuracy only using short extracts from the meeting speech and 98% correctness using abstractive human model summaries. The survey showed that people are generally very experienced with attending meetings and note‐taking and usually record the most important meeting events in a concise way. This provides evidence for the fact that personal notes are suitable as keywords and indices into a meeting recording. In general, task results correlated positively with perceived success. Users liked well‐structured abstractive human reference summaries but found meeting speech extracts difficult to work with. However, they also disliked the appearance of the notes, in particular the fact that the handwritten ones were hard to read. This emphasises the need for the development of innovative handwriting recognition methods and user interfaces that employ new presentation techniques, for example, key area highlighting. Meeting participants would also benefit from corporate training for better communication and note‐taking skills. Copyright © 2014 John Wiley & Sons, Ltd.
Investigation of Ageing Mechanisms in Thermoplastic Polyurethanes by Means of IR and Raman Spectroscopy
Authors: Bruckmoser Katharina , Resch Katharina
Published: May 2014

Within the present study FTIR and Raman spectroscopy are evaluated as to specific strengths in terms of analysing deterioration in TPU induced by UV radiation or thermal load. A conventional ester based TPU grade formulated from 4,4‘‐methylene diphenyl diisocyanate, 1,4‐butanediol and polycaprolactone was investigated. Exposure to UV was done in a Suntest CPS+ at different exposure times. Thermal treatment was done in an air circulation oven at 180 °C and different exposure times. Exposed samples were characterized as to changes in molecular structure with complementary methods ATR and Raman spectroscopy. To establish interrelationships between structural changes and macroscopic material characteristics UV/Vis/NIR spectroscopy and DSC were applied.

UV/Vis/NIR spectroscopy clearly indicated yellowing, and thus an increase in absorption in the visible wavelength range, of TPU after exposure to UV or to thermal load. Yellowing correlated well with formation of chromophoric groups detected by ATR and Raman spectroscopy. ATR spectroscopy turned out to be very sensitive in detection of changes in chemical structure induced by UV radiation. Raman spectroscopy was found to be very sensitive in detection of changes in chemical structure induced by thermal load. No distinct effect of UV exposure on morphology of TPU was ascertained. In contrast, a strong effect of thermal treatment on (para)crystalline morphology was observed.
On the existence of a solution of a second‐order singular initial value problem
Authors: Aslanov Afgan
Published: May 2014

In this paper, we consider a class of second‐order initial value problems. We extend the family of second‐order initial value problems for which the existence and uniqueness of a solution is known. To handle the singularity, we introduce the more general Caratheodory type of restrictions. The solvability results of the Emden–Fowler type of equations is established as a special case.Copyright © 2014 John Wiley & Sons, Ltd.
Oxygen‐induced frequency shifts in hyperoxia: a significant component of BOLD signal
Authors: Song Youngkyu , Cho Gyunggoo , Chun Song‐I , Baek Jin Hee , Cho HyungJoon , Kim Young Ro , Park Sung Bin , Kim Jeong Kon
Published: May 2014

In comparison to the well‐documented significance of intravascular deoxyhemoglobin (deoxyHgb), the effects of dissolved oxygen on the blood‐oxygen‐level‐dependent (BOLD) signal have not been widely reported. Based on the fact that the prolonged inspiration of high oxygen fraction gas can result in up to a sixfold increase of the baseline tissue oxygenation, the current study focused on the influence of dissolved oxygen on the BOLD signal during hyperoxia. As results, our in vitro study revealed that the r1 and r2 (relaxivities) of the oxygen‐treated serum were 0.22 mM−1 · s−1and 0.19 mM−1 · s−1, respectively. In an in vivo experiment, hyperoxic respiration induced negative BOLD contrast (i.e. signal decrease) in 18–42% of measured brain regions, voxels with accompanying significant decreases in both the T2* (−12.1% to −19.4%) and T1 (−5.8% to −3.3%) relaxation times. In contrast, the T2* relaxation time significantly increased (11.2% to 14.0%) for the voxels displaying positive BOLD contrast (in 41–50% of the measured brain), which reflected a hyperoxygenation‐induced reduction in tissue deoxyHgb concentration. These data imply that hyperoxia‐driven BOLD signal changes are primarily determined by the counteracting effects of extravascular oxygen and intravascular deoxyHgb. Oxygen‐induced magnetic susceptibility was further demonstrated by the study of 1 min hypoxia, which induced BOLD signal changes opposite to those under hyperoxia. Vasoconstriction was more common in voxels with negative BOLD contrast than in voxels with positive contrast (% change of blood volume, −9.8% to −12.8% versus 2.0% to 2.2%), which further suggests that negative BOLD contrast is mainly evoked by an increase in extravascular oxygen concentration. Conclusively, frequency shifts, which are induced by the accumulation of oxygen molecules and associated magnetic field inhomogeneity, are a significant source of the negative BOLD contrast during hyperoxia. Copyright © 2014 John Wiley & Sons, Ltd.
Effect of vapor‐grown carbon nanofibers and in situ hydrolyzed silica on the mechanical and shape memory properties of water‐borne epoxy composites
Authors: Dong Yubing , Ni Qing‐Qing
Published: May 2014

Vapor‐grown carbon nanofiber (VGCNF)/water‐borne epoxy (WEP) and SiO2/WEP composites were successfully synthesized via freeze drying and hot‐press molding. VGCNFs were mixed directly with a WEP emulsion, while SiO2 was synthesized by in situ hydrolysis of TEOS solution (3‐triethoxysilylpropylamine (KH550): tetraethoxysilane (TEOS): absolute ethanol = 1:5:20, w/w/w) dispersed in the WEP emulsion. WEP composites were obtained from these mixtures by freeze drying and compressing under a pressure of 10 MPa at 120°C for 2 h. The morphology and mechanical properties of the WEP composites were investigated by transmission electron microscopy, scanning electron microscopy, dynamic mechanical analysis and tensile testing. The shape memory (SM) properties of the WEP composites were evaluated by fold‐deploy SM testing. The effects of filler content and recovery temperature on the SM properties were revealed through systematic variation. The results confirmed that VGCNF and in situ hydrolyzed SiO2 were homogenously dispersed and incorporated into the WEP matrices. Thus, significant improvements in the mechanical and SM properties of the composites were achieved. POLYM. COMPOS., 36:1712–1720, 2015. © 2014 Society of Plastics Engineers
Intensity–voltage low‐energy electron microscopy for functional materials characterization
Authors: Flege Jan Ingo , Krasovskii Eugene E.
Published: May 2014

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Dynamic I (V)‐LEEM, i.e., the continuous recording of low‐energy electron microscopy (LEEM) images upon cycling the electron kinetic energy, enables time‐resolved characterization of surface structure on the nanometer scale. When combined with state‐of‐the‐art theoretical calculations, detailed information on geometric and electronic structure as well as chemical composition can be gained. Here, we present a contemporary review of the experimental and theoretical methodology and provide a survey of the application of I (V)‐LEEM to the study of functional materials, particularly focusing on structural phenomena in oxide heteroepitaxy and chemical redox reactions.

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Time‐dependent intensity–voltage curves demonstrate the transformation from the (1 × 1)‐O adlayer phase to RuO2(110) during Ru(0001) oxidation on the nanometer scale.

(© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Surface analysis of diblock copolymer films by TOF‐SIMS in combination with AFM
Authors: Lee Jihye , Shin Kwanwoo , Lee Kang‐Bong , Lee Yeonhee
Published: May 2014

For block copolymers, the chemical difference between the two blocks will result in a preferential segregation of one of the blocks to the interface, but the phase separation is only on a microscopic scale, forming micro‐domain structures due to the influence of inter‐segment linkages, which restricts the extent to which the phases can separate. In this study, we report the characterization of the morphology from the lower disorder–order transition diblock copolymer, polystyrene‐b‐poly(2‐ethyl hexyl acrylate) (PS‐PEHA) where the PS blocks are perdeuterated, using surface techniques. The molecular surface composition and microscopic morphology for the diblock copolymers were obtained by time‐of‐flight secondary ion mass spectrometry (TOF‐SIMS) and atomic force microscopy (AFM). TOF‐SIMS depth profiles of diblock copolymers showed consistently regular alternative patterns with a constant period that was the same size as the lamellar spacing structure, as determined by AFM images. Structural characterization of dPS‐PEHA thin films by TOF‐SIMS and AFM was also performed for different molecular weights and film thickness. Copyright © 2014 John Wiley & Sons, Ltd.
Influence of sputter power on structural and electrical properties of TiO2 films for Al/TiO2/Si gate capacitors
Authors: Chandra Sekhar M. , Nanda Kumar Reddy N. , Venkata Rao B. , Mohan Rao G. , Uthanna S.
Published: May 2014

Titanium dioxide (TiO2) thin films were deposited onto p‐Si substrates held at room temperature by reactive Direct Current (DC) magnetron sputtering at various sputter powers in the range 80–200 W. The as‐deposited TiO2 films were annealed at a temperature of 1023 K. The post‐annealed films were characterized for crystallographic structure, chemical binding configuration, surface morphology and optical absorption. The electrical and dielectric properties of Al/TiO2/p‐Si structure were determined from the capacitance–voltage and current–voltage characteristics. X‐ray diffraction studies confirmed that the as‐deposited films were amorphous in nature. After post‐annealing at 1023 K, the films formed at lower powers exhibited anatase phase, where as those deposited at sputter powers >160 W showed the mixed anatase and rutile phases of TiO2. The surface morphology of the films varied significantly with the increase of sputter power. The electrical and dielectric properties on the air‐annealed Al/TiO2/p‐Si structures were studied. The effect of sputter power on the electrical and dielectric characteristics of the structure of Al/TiO2/p‐Si (metal‐insulator‐semiconductor) was systematically investigated. Copyright © 2014 John Wiley & Sons, Ltd.
Topography and field effects in the inner side of microvia hole using ToF‐SIMS
Authors: Lee Jae Cheol , Kyoung Yong Koo , Song In Yong , Lee Jae Woo , Shin Young Sik , Kim Jin Seok , Iida Shin‐ichi
Published: May 2014

We have developed a simple and powerful method, which is called ‘angled sample holder method’, to characterize a topographic structured sample such as microsized via hole of ball grid array using time‐of‐flight SIMS. The diameter of via holes was 100 µm and the depth was 70 µm. To remove the shaded area by incidence primary ion beam and to extract secondary ions from the bottom of a via hole, several types of angled sample holders with compensation steering plate were applied on the basis of simulation results using SIMION code. And the analyses using angled sample holder method enabled us to characterize the bottom and side wall of a via hole in clear. Copyright © 2014 John Wiley & Sons, Ltd.
Habitat relationships of great gray owl prey in meadows of the Sierra Nevada Mountains
Authors: Kalinowski Ryan S. , Johnson Matthew D. , Rich Adam C.
Published: May 2014

Annual productivity of great gray owls (Strix nebulosa) in California, USA, is thought to be largely dependent on vole (Microtus spp.) and pocket gopher (Thomomys spp.; hereafter, gopher) abundance, yet factors influencing these prey populations have not been thoroughly investigated. The abundance of voles and gophers has been influenced by vegetation and cattle grazing in other regions; and many meadows are grazed within the breeding range of great gray owls in the Sierra Nevada Mountains of California. We evaluated the influence of vegetation and cattle grazing on great gray owl foraging habitat by quantifying vole abundance, gopher abundance, and vegetation features in grazed and ungrazed meadows in 2010 and 2011. We found that vole presence was positively associated with sward height and corn lily (Veratrum californicum) dominance; vole abundance was weakly negatively associated with cattle grazing. Gopher abundance was negatively associated with site wetness, and weakly positively associated with stem density, the frequency of forb presence, cattle grazing, and the dominance of corn lily. To efficiently manage vegetation and cattle grazing to benefit great gray owl prey, we suggest prioritizing habitat for voles in wet meadows because gophers were not likely to be abundant in wet sites. Particularly in areas with moist soils, we recommend maintaining sward height commensurate with the habitat relationships of voles found in this study; >290 mm where corn lily is not dominant and 125 mm where it is. Sustaining sward height for voles should benefit great gray owls and other meadow or forest edge carnivores. © 2014 The Wildlife Society.
Genetic effects of living in a highly polluted environment: the case of the silversideBasilichthys microlepidotus(Jenyns) (Teleostei: atherinopsidae) in the Maipo River basin, central Chile
Authors: Vega‐Retter Caren , Muñoz‐Rojas Pablo , Vila Irma , Copaja Sylvia , Véliz David
Published: May 2014

Freshwater systems are one of the environments most impacted by human activity, with pollution being a highly important factor. In Chile, several rivers exhibit varied levels of pollution, one of which is the Maipo River basin where the city of Santiago is located. The silversideBasilichthys microlepidotus(Jenyns) is an endemic fish species that inhabits this basin, thus we hypothesized that pollution has affected gene diversity and migration in populations ofB. microlepidotusfrom the Maipo River basin. The aim of this study was to identify the population structure ofB. microlepidotusin this basin and to determine if the populations of the silverside inhabiting polluted sites present differences in gene diversity and gene flow compared to populations inhabiting non‐polluted areas. Using the variability of eight microsatellites, five populations of silverside were detected; three inhabiting non‐polluted sites and two inhabiting polluted sites. From this, it was inferred thatB. microlepidotushas been able to tolerate pollution in the Maipo River basin. No differences in gene diversity or migration were detected between polluted and non‐polluted sites but comparison with historical estimation revealed an increase in the current migration rate when all the data from the basin were compared. A reduction in current effective population size was also observed when compared to historical values, and this is probably due to river degradation. Despite the disappearance of other fish species recorded at this basin, our results suggest thatB. microepidotusis tolerant to pollution, thus indicating that native species respond differently to this environmental factor.
Rise of New Centres of Power in Eurasia: Implications for Turkish Foreign Policy
Authors: Erşen Emre
Published: May 2014

The emergence of new centres of power in Eurasia has entailed a re-reading of Zbigniew Brzezinski's book which drew an analogy between the Eurasian supercontinent and a grand chessboard. Following the global financial crisis of the last few years, countries like China, Russia and India have started to project greater global political and economic influence. Eventually, Eurasia has become a geopolitical symbol signifying a multipolar world order unlike fifteen years ago when Brzezinski wrote his book in a world dominated by the US superpower. The changes in the geopolitical meaning of Eurasia have also been very important for Turkey for a number of reasons. First, it is a country that is strategically located at the meeting point of Europe and Asia. Second, its economy has grown at an impressive rate throughout the 2000s turning it into a rising Eurasian power. Third, its multi-dimensional foreign policy approach in the last decade has enabled it to develop closer relations with the Eurasian states.