bluuebunny/crossref_metadata_2025 huggingface dataset:
Carotenoid bioaccessibility from nine raw carotenoid‐storing fruits and vegetables using an in vitro model
Authors: Jeffery Jennifer L , Turner Nancy D , King Stephen R
Published: July 2012

BACKGROUND: Many techniques exist for processing fruits and vegetables. The impact of these processes on nutritional qualities of the food can be considerable, however. Given the benefits of eating raw foods, nutrient sources need to be identified that deliver substantial benefit without cooking. In this study a survey of carotenoid bioaccessibility was carried out in order to additionally evaluate the impact of their distinctive storage structures (chromoplasts) on bioaccessibility.

RESULTS: Per cent carotenoid bioaccessibility varied among the nine raw, whole fruits and vegetables evaluated, with values of 1–39% for lycopene, 18–20% for α‐carotene, 7–49% for β‐carotene, 9–59% for lutein, 4–22% for violaxanthin and 47–96% for phytoene. Per 100 g of food, grapefruit and watermelon imparted the most lycopene (69 and 64 µg respectively), carrot the most α‐carotene (559 µg), β‐carotene (1078 µg), lutein (91 µg) and phytoene (23 mg) and mango the most violaxanthin (177 µg). Digestive stability averaged over 80%, except for the xanthophylls, which exhibited a wider and lower range of stabilities.

CONCLUSION: These data identify raw food sources for carotenoid bioaccessibilities comparable to those of other foods accomplished by substantial processing. The information presented here also has application in identifying appropriate plant‐breeding goals and optimal sources for commercial carotenoid isolations. Copyright © 2012 Society of Chemical Industry
Patient reasoning in palliative surgical oncology
Authors: Collins Lindsey K. , Goodwin Julia A. , Spencer Horace J. , Guevara Caesar , Ferrell Betty , McSweeney Jean , Badgwell Brian D.
Published: July 2012

Background

The purpose of this study was to determine the patient reasoning behind treatment choice after palliative surgical consultation.

Methods

Patients undergoing palliative surgical consultation were prospectively enrolled in this observational cohort study (11/2009–5/2011) and administered an open‐ended questionnaire asking for their reasoning in choosing their treatment strategy.

Results

Of 98 patients enrolled, 54 were treated non‐operatively and 44 with surgery. Patient responses indicating their reason for treatment selection were categorized into (1) quality of life or symptom relief, (2) unclear or response not related to treatment strategy, (3) increase length of life, (4) treat the cancer, (5) concerns over surgical complications, (6) doctor's recommendation, (7) religious reasons for treatment choice, and (8) for family. The most frequently cited reason for treatment selection was symptom relief or quality of life improvement in 46 patients. Thirty‐eight patients cited their doctor's recommendation while 20 patients selected their treatment to increase length of life or treat their cancer. Only 2 patients cited concerns over surgical complications as their reason for choosing their treatment strategy.

Conclusions

The most common reasons for treatment selection in palliative surgical consultation include symptom relief or improvement in quality of life and the doctor's recommendation with few patients listing concerns over surgical morbidity. J. Surg. Oncol. 2013;107:372–375. © 2012 Wiley Periodicals, Inc.
Proximal tibial resections and reconstructions: Clinical outcome of 225 patients
Authors: Mavrogenis Andreas F. , Pala Elisa , Angelini Andrea , Ferraro Andrea , Ruggieri Pietro
Published: July 2012

Background

Previous studies reported variable outcome of proximal tibial resections and reconstructions. Therefore, we evaluated the survival, Musculoskeletal Tumor Society (MSTS) function, and complications of patients and reconstructions in this location.

Materials and Methods

We reviewed the files of 225 patients with proximal tibial tumors treated with proximal tibial resection, fixed or rotating hinge megaprosthetic reconstruction and extensor mechanism reattachment using sutures, mechanical clamping, artificial ligaments, and/or gastrocnemius flap from 1985 to 2010 (mean follow‐up, 90 months; median, 56; range, 2–294). Survival of patients and reconstructions, type of hinge, extensor mechanism reconstruction, MSTS function, and complications were analyzed.

Results

Survival of patients with sarcomas was 68% and 62% at 5 and 10 years. Survival of megaprosthetic reconstructions was 82% and 78% at 5 and 10 years, without any difference between fixed and rotating hinge megaprostheses. MSTS function was significantly better in univariate and multivariate analysis for rotating compared to fixed hinge megaprostheses, without any difference between the types of extensor mechanism reconstructions. Most common complications were infection (12%), aseptic loosening (6%), and extensor mechanism rupture (3%).

Conclusions

Rotating hinge proximal tibia megaprosthetic reconstructions have better function compared to fixed hinge, regardless of the type of extensor mechanism reconstruction. J. Surg. Oncol. 2013;107:335–342. © 2012 Wiley Periodicals, Inc.
New validated high‐performance liquid chromatographic method for simultaneous analysis of ten flavonoid aglycones in plant extracts using a C18 fused‐core column and acetonitrile–tetrahydrofuran gradient
Authors: Olszewska Monika A.
Published: July 2012

An HPLC method of high resolution has been developed and validated for the simultaneous determination of ten prominent flavonoid aglycones in plant materials using a fused‐core C18‐silica column (Ascentis® Express, 4.6 mm × 150 mm, 2.7 μm). The separation was accomplished with an acetonitrile‐tetrahydrofuran gradient elution at a flow rate of 1 mL/min and temperature of 30°C. UV spectrophotometric detection was employed at 370 nm for flavonols (quercetin [QU], myricetin [MY], isorhamnetin [IS], kaempferol [KA], sexangularetin [SX], and limocitrin [LM]) and 340 nm for flavones (apigenin [AP], acacetin [AC], chrysoeriol [CH], and luteolin [LU]). The high resolution of critical pairs QU/LU (10.50), QU/CH (3.40), AP/CH (2.51), SX/LM (2.30), and IS/KA (2.70) was achieved within 30.3 min. The observed column back pressure was less than 4300 psi, thus acceptable for conventional HPLC equipment. The method was sensitive enough having LODs of 0.115–0.525 ng and good linearity (r > 0.9999) over the test range. The precision values, expressed as RSD values, were <7.5%, and the accuracy was in the range of 95.3–100.2% for all analytes except MY (73.8%). The method was successfully employed for the determination of flavonoids in several medicinal plants, such as Ginkgo biloba, Betula pendula, and a variety of Sorbus species.
Exploring the Moderating Effects of Value Offerings Between Market Orientation and Performance in Tourism Industry
Authors: Chen Ching‐Fu , Myagmarsuren Odonchimeg
Published: July 2012

Market orientation as a business strategy has recently been adopted in the travel and tourism industry, as well as other industries, to enhance performance. Value offerings have also emerged as a new research interest within the strategic marketing domain. Based on the theory of strategy–environment fit, this study investigates the relationship between market orientation (i.e. customer and competitor orientations) and performance, and the moderating role of value offerings (i.e. service emphasis and price emphasis), using a sample of 132 Taiwanese travel agencies. The research results obtained from hierarchical regression analyses indicate that only both customer and competitor orientations, but not value offerings, have positive and direct effects on performance. However, the results show that one dimension of value offerings, i.e. service emphasis, has a moderating role in the market orientation‐performance relationship. The managerial implications of these results are also discussed. Copyright © 2012 John Wiley & Sons, Ltd.
High‐Performance Pristine Graphene/Epoxy Composites With Enhanced Mechanical and Electrical Properties
Authors: Wajid Ahmed S. , Ahmed H. S. Tanvir , Das Sriya , Irin Fahmida , Jankowski Alan F. , Green Micah J.
Published: July 2012

High‐strength conductive pristine graphene/epoxy composites are prepared by two simple processing methods – freeze dry/mixing and solution processing. PVP‐stabilized graphene is aggregation‐resistant and allows for excellent dispersion in both the resin and final composite, as confirmed by optical microscopy and SEM images. The superior dispersion quality results in excellent nanofiller/matrix load transfer, with a 38% increase in strength and a 37% improvement in modulus for 0.46 vol% graphene loading. The composites have a very low electrical percolation threshold of 0.088 vol%. Despite the effectiveness of both methods, the freeze‐drying method is more promising and versatile enough to be used for graphene dispersion in a wide range of other composite precursors.

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A 28/56 GHz dual‐band CMOS VCO using reversely tunable LC source degeneration and the push–push technique
Authors: Lin Yo‐Sheng , Yu Po‐Wei
Published: July 2012

A 28/56 GHz dual‐band voltage‐controlled oscillator (VCO) using reversely tunable LC source‐degeneration and the push–push technique is demonstrated in a standard 0.13 μm CMOS process. The reversely tunable LC source degeneration is made by adding two reversely tunable LC tanks, which use varactors as the needed capacitors, to the source terminals of the cross‐coupled transistor pair of the VCO. Compared with the traditional cross‐coupled transistor pair, the proposed one significantly decreases the equivalent parallel capacitance (CEQ). This in turn results in the increase of both the operation frequency and the tuning range of the VCO. The VCO core draws 10.48 mA current from a 0.9 V power supply, that is, it only consumes 9.43 mW. The VCO achieves a tuning range of 27.7–28.7 GHz at the fundamental port and a tuning range of 55.176–58.124 GHz at the push–push port. In addition, at the fundamental port, the VCO achieves a low phase noise of −120.46 dBc/Hz at 1‐MHz offset from 28.19 GHz. The corresponding figure‐of‐merit is −199.7 dBc/Hz, one of the best results ever reported for a K‐band or Ka‐band CMOS VCO. The circuit occupies a chip area of 0.724 × 0.681 mm2, that is, 0.493 mm2, including the test pads. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:2272–2278, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.27046
Wideband multilayer directional coupler with tight coupling and high directivity
Authors: Djordjević Antonije R. , Napijalo Veljko M. , Olćan Dragan I. , Zajić Alenka G.
Published: July 2012

A novel, wideband, symmetrical, printed directional coupler is described, which has tight coupling and high directivity. The coupler consists of four interconnected strips printed in two layers. The dimensions of the strips are optimized to minimize the dispersion of propagating modes. Design data are provided for some typical practical cases. The theoretical results are verified experimentally. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:2261–2267, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.27051
Investigation of radiation patterns of longitudinally oriented slot antenna array for imaging radar applications
Authors: Kang Woong , Lee Seokjae , Kim Kangwook
Published: July 2012

A longitudinally oriented slot antenna array for imaging radar applications is designed and its performance was investigated. When constructing a two‐dimensional physical array to image a target, arranging the antenna in a longitudinal direction can be problematic due to the limited space for antennas. Hence, when arranging slot elements in a longitudinal direction, the proposed antenna array is designed such that two slot elements share a single slot arm, which achieves proper element spacing. In this letter, as a proof‐of‐concept, a two‐port longitudinally oriented slot antenna array is designed. The initial array shows radiation pattern distortion, which can have a negative effect on radar sensing. Several geometric modifications to correct the distorted radiation pattern are then introduced and the performance after modifications is measured. The results show that the modified antenna array structure can be useful in imaging radar applications. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:2408–2412, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.27055
Linearly polarized elliptical microstrip antenna with improved polarization purity and bandwidth characteristics
Authors: Kumar Chandrakanta , Guha Debatosh
Published: July 2012

Elliptical microstrip patch, etched on a grounded PTFE substrate, has been examined here for the first time as a linearly polarized (LP) antenna. All earlier investigations dealt with only circularly polarized design. Inherent shortcoming of poor polarization purity has been alleviated using the newly developed approach of using defected ground structure. Apart from a design guideline, a comprehensive study using a set of prototypes with different eccentricity values has been provided. Possibility of using elliptical patch as a new LP radiating element with improved features relative to an identical circular microstrip has been documented for the first time. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:2309–2314, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.27056
Design of a novel ultrawideband antenna with dual band‐notched characteristics
Authors: Chen Bin , Wang An‐Guo , Zhao Guo‐Huang
Published: July 2012

A simple printed ultrawideband (UWB) antenna with reconfigurable band‐rejected characteristics is proposed. The antenna was fabricated on an FR‐4 epoxy substrate and has a volume of 40.0 × 32.0 × 1.0 mm3. The simulated and measured results show that the antenna has nearly omnidirectional patterns, stable gain, and an available impedance bandwidth of 9.38 GHz which covers 2.34–11.72 GHz. By etching two slots in the radiator, band‐ notched features centered at 3.5 and 5.5GHz are achieved. With adding two microelectromechanical system switches across slots, the band‐rejected characteristics can be reconfigurable and the proposed antenna is capable of operating among none or single or dual band‐notched modes. Meanwhile, to discuss the mechanisms of the band‐rejected properties, the conceptual equivalent circuit models are presented. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:2401–2405, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.27061
Band‐notched UWB planar monopole antenna using slotted conductor‐backed plane
Authors: Moradhesari Amin , Moosazadeh Mahdi , Esmati Zahra
Published: July 2012

In this letter, a planar antenna with band‐notched characteristic is designed for ultrawideband application.Distinctive features of this antenna in comparison with the other reported antennas are the compact dimensions and omnidirectional radiation across the whole band of operation using slotted conductor‐backed plane. The ground plane is located at the bottom layer, which also includes a Γ‐shaped conductor‐backed plane used to widen the impedance bandwidth. Also, band‐notched characteristic is achieved by a Γ‐shaped form inside the slotted conductor‐backed plane. The measured results of the manufactured (18 × 18 mm2) antenna on 0.8‐mm FR4 substrate show that the antenna operates with VSWR less than 2 over the frequency band from 3.05 to 12.9 GHz, except a frequency notched band of 3.3–4.3 GHz. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:2237–2241, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.27063
Experimental analysis on the response of long period grating to refractive indices higher and lower than that of fiber cladding
Authors: Libish T. M. , Bobby M. C. , Linesh J. , Nampoori V. P. N. , Radhakrishnan P.
Published: July 2012

The response of the long period grating (LPG) to refractive indices greater than and less than that of cladding is studied by monitoring the wave length shift and amplitude changes of the attenuation bands. The fundamental principle of analysis is the sensitive dependence of the resonance peaks of an LPG on the changes in the refractive index of the medium surrounding the cladding surface of the grating. An LPG with grating period 550 μm written into the core of a hydrogen loaded standard telecommunication fiber (SMF‐28e) is used to carry out the experimental study. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:2356–2360, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.27068
Highly integrated, two‐in‐one, metal‐plate PIFA for 2.4‐GHz module applications
Authors: Su Saou‐Wen , Lee Cheng‐Tse
Published: July 2012

A novel, two‐in‐one, planar inverted‐F antenna (PIFA) having two signal feeding ports to operate in the 2.4 band for wireless module applications is proposed. The PIFA was of a symmetrical structure and can be fully integrated into the printed circuit board (PCB) of the module by through‐hole soldering. The design was comprised of two sub‐antennas of identical size and had two shorting portions linked by a horizontal strip. This structure allows the antenna to be stamped from one metal plate only at low cost and surface mountable as a dual‐in‐line package (DIP) component with four leads. Further, by incorporating a decoupling, neutralization line shunted at around the two shorting portions, the antenna port isolation less than −20 dB over the 2.4 GHz band can be achieved. The radiating strip of the PIFA mainly extended along the edge of the PCB, and the neutralization line in this study occupied very little board space. Details of the design prototypes are described and discussed in the article. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:2433–2438, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.27071
A novel inconsistency condition for 2‐port vector network analyzer calibration
Authors: Shoaib Nosherwan
Published: July 2012

An inconsistency condition for 2‐port vector network analyzer (VNA) calibration is presented.This inconsistency condition discussed the use of Reciprocal device and Line or Thru for calibration of 2‐port VNA. Mathematical analysis is carried out. The experimental results are compared with well known calibration algorithms like Thru‐Short‐Delay, Thru‐Reflect‐Line, Short‐Open‐Load‐ Reciprocal, and Thru‐Short‐Match. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:2372–2375, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.27072
Dual‐band CMOS voltage‐controlled oscillator with comparable outpower at both bands
Authors: Jang Sheng‐Lyang , Tu Do Anh , Chang Chia‐Wei , Huang Jhin‐Fang
Published: July 2012

A low phase noise dual‐band voltage‐controlled oscillator (VCO) is proposed to achieve large voltage swings at both high‐frequency and low‐frequency bands. The VCO consists of a dual‐resonance LC resonator and a cross‐coupled switching transistor pair. The dual‐resonance LC resonator comprises a parallel‐tuned LC resonator and a series‐resonant resonator. The proposed VCO has been implemented with the TSMC 0.18‐μm 1P6M CMOS technology and the core power consumption is 1.99 mW at the DC drain‐source bias of 0.51 V. The VCO can generate differential signals in the frequency range of 8.19–8.77 GHz and 3.38–3.84 and it also has comparable high output voltage swings at both low‐ and high‐frequency bands. The die area of the dual‐band VCO is 0.47 × 0.748 mm2. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:2349–2352, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.27097
Reconstruction of the scattering support of dielectric objects from near field data
Authors: Gragnani Gian Luigi , Mendez Maurizio Diaz
Published: July 2012

A method for reconstructing the convex scattering support of dielectric objects from near field data is presented.Two different strategies for solving the problem are discussed. The usual reconstruction of the convex scattering support is extended introducing a fast near field to far field transformation based on the analytical expression of an equivalent source in a circular domain. Results of both single and multiview approaches are shown. To evaluate the reconstruction capabilities, some quality parameters are introduced. Single view results could be subjected to detriment at some specific angles of propagation of the incident field, and this is related both to the angle of propagation and to the presence of sharp corners in the object. Multiview results always enclose the dielectric scatterers inside a scattering support smaller than the original investigation domain. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:2314–2321, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.27098
Erratum: Periodic substrate structure suppresses spurious response in coupled line filters
Authors: Saeidi Chiya , van der Weide Daniel
Published: July 2012

Originally published Microwave Opt Technol Lett 54: 2175–2178, 2012. @ 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54: 2446, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.27101(Original article DOI 10.1002/mop.26999)
Selective lighting up of segments around Gly, Ala and Ser/Thr in proteins
Authors: Chakraborty Swagata , A. L. Susmitha , Hosur Ramakrishna V.
Published: July 2012

Direct detection of 13C nucleus can be used as a valuable alternative where 1H detection poses a challenge due to relaxation effects, chemical exchange and poor chemical shift dispersion. In this context, we have designed a suite of 2D 13Cα‐detected hNCA experiments that provide sequential correlations of 13Cα with 15N on one hand and efficient spectroscopic labeling of certain groups of residues, namely, Gly, Ala, Ser and Thr, on the other. These residues act as checkpoints in the sequential walk, which in turn offer new possibilities of backbone assignment of small proteins from a set of 2D experiments, thereby providing great economy in terms of spectrometer time. The direct identification of peptide segments around Gly, Ala, Ser and Thr residues along a protein chain will be highly valuable for deriving important information on sites of ligand binding, phosphorylation, inhibitor/substrate binding, understanding protein folding pathways, comprehending local conformational dynamics etc. without having to obtain complete sequence‐specific assignments, which can be time consuming and at times formidable, especially in large proteins. We have illustratively demonstrated the multifaceted applications of these variants of 2D experiments on ubiquitin and M‐crystallin. We foresee that these 2D hNCA experiments will provide economic and efficient strategies for studying the structure and function of proteins. Copyright © 2012 John Wiley & Sons, Ltd.
Lipid suppression in CSI with spatial priors and highly undersampled peripheral k‐space
Authors: Bilgic Berkin , Gagoski Borjan , Kok Trina , Adalsteinsson Elfar
Published: July 2012

Mapping 1H brain metabolites using chemical shift imaging is hampered by the presence of subcutaneous lipid signals, which contaminate the metabolites by ringing due to limited spatial resolution. Even though chemical shift imaging at spatial resolution high enough to mitigate the lipid artifacts is infeasible due to signal‐to‐noise constraints on the metabolites, the lipid signals have orders of magnitude of higher concentration, which enables the collection of high‐resolution lipid maps with adequate signal‐to‐noise. The previously proposed dual‐density approach exploits this high signal‐to‐noise property of the lipid layer to suppress truncation artifacts using high‐resolution lipid maps. Another recent approach for lipid suppression makes use of the fact that metabolite and lipid spectra are approximately orthogonal, and seeks sparse metabolite spectra when projected onto lipid‐basis functions. This work combines and extends the dual‐density approach and the lipid‐basis penalty, while estimating the high‐resolution lipid image from 2‐average k‐space data to incur minimal increase on the scan time. Further, we exploit the spectral‐spatial sparsity of the lipid ring and propose to estimate it from substantially undersampled (acceleration R = 10 in the peripheral k‐space) 2‐average in vivo data using compressed sensing and still obtain improved lipid suppression relative to using dual‐density or lipid‐basis penalty alone. Magn Reson Med, 2013. © 2012 Wiley Periodicals, Inc.
Tolerant identification with Euclidean balls
Authors: Junnila Ville , Laihonen Tero , Parreau Aline
Published: July 2012

The concept of identifying codes was introduced by Karpovsky, Chakrabarty and Levitin in 1998. The identifying codes can be applied, for example, to sensor networks. In this article, we consider as sensors the set
\documentclass{article}\usepackage{mathrsfs, amsmath, amssymb}\pagestyle{empty}\begin{document} $\mathbb{Z}^2$ \end{document}
where one sensor can check its neighbors within Euclidean distance r. We construct tolerant identifying codes in this network that are robust against some changes in the neighborhood monitored by each sensor. We give bounds for the smallest density of a tolerant identifying code for general values of r. We also provide infinite families of values r with optimal such codes and study the case of small values of r. © 2012 Wiley Periodicals, Inc. NETWORKS, 2013
Immune markers of disease severity and treatment response in pediatric acquired aplastic anemia
Authors: Sutton Kathryn S. , Shereck Evan B. , Nemecek Eneida R. , Kurre Peter
Published: July 2012

Background

To investigate the immune status among pediatric patients with aplastic anemia (AA) and explore PNH‐status, T‐regulatory and NK‐cell frequency as potential markers of clinical response.

Methods

Data were retrospectively analyzed from twenty‐six patients diagnosed with AA. PNH populations, T‐ and NK‐subsets were determined via flow cytometry.

Results

At diagnosis, 9/23 patients with severe AA (SAA) versus 1/3 with moderate AA (MAA) were PNHpos. Among PNHpos patients treated with ATG based immunosuppression, 2/6 had a complete response (CR), while 4/6 had a partial response (PR), similarly 2/6 PNHneg patients had a CR and 4/6 had a PR. Lymphocyte subset immunophenotyping revealed that T‐regulatory cells represented 7.2% of total lymphocytes at diagnosis. Their frequency varied with disease severity (5.5% for SAA and 14.1% for MAA) and response (8.9% for CR and 1.5% for PR), generally increasing following therapy with IST (14.6%). The NK cell frequency was not substantially different based on disease severity or response.

Conclusions

Neither PNH cell populations, nor NK cell frequency corresponded with disease severity or response. T‐regulatory cell frequency, although not statistically significant given the small sample size, corresponded with both severity and response, indicating potential utility as a prognostic tool. Pediatr Blood Cancer 2013; 60: 455–460. © 2012 Wiley Periodicals, Inc.
In situ encapsulation of hydrogel in ultrafine fibers by suspension electrospinning
Authors: Han Fengxuan , Zhang Hong , Zhao Jin , Zhao Yunhui , Yuan Xiaoyan
Published: July 2012

Composite ultrafine fibers of hydrogel/polylactide copolymer were successfully electrospun from water‐in‐oil suspensions. Effects of the suspension composition on the morphology and microstructure of the obtained fibers were investigated, including both aqueous phase and oily phase, that is, hydrogel (chitosan or gelatin), polylactide copolymers [poly(ethylene glycol)‐b‐poly (L‐lactide‐co‐caprolactone) (PELCL) or poly(L‐lactide‐co‐glycolide) (PLGA)], organic solvents and surfactants. Scanning electron micrographs showed that mixed solvents of chloroform and N,N‐dimethyl formamide or 2,2,2‐trifluoroethanol were preferred to form beads‐free ultrafine fibers with diameter in the range of 230–470 nm. With ethyl acetate as organic solvent, compared with chitosan hydrogel/PELCL composite fibers, chitosan hydrogel/PLGA fibers showed narrower distribution of diameter in 230–590 nm. Different hydrogel and surfactants used in this experiment had slight effects on the morphology of the obtained fibers, whereas transmission electron micrographs exhibited chitosan and gelatin hydrogel could be in situ encapsulated in the fibers discontinuously. This method may promise a new aqueous reservoir for encapsulation and controlled release of bioactive agents. POLYM. ENG. SCI., 2012. © 2012 Society of Plastics Engineers
Synthesis of new organic semiconductors based on poly(2‐anilinoethanol) doped with different acids and investigation of their electro‐optical properties
Authors: Ahlatcıoğlu E. , Şenkal B.F. , Yakuphanoğlu F. , Mansour Sh.A.
Published: July 2012

The polyaniline (PANI) was synthesized using different dopant acids (iminodiacetic, methanesulfonic, phosphoric, and boron trifuoride) using oxidative polymerization method. These obtained new polymers were characterized by using spectrophotometric methods such as FTIR, UV–vis. The calculated value of the optical energy gap for the doped investigated polymer was reached to 3.70 eV for PANI‐OH doped by boron trifuoride. The conductivity of the polymers was also investigated. The direct current (dc) conductivity as a function of temperature for the doped polymers has been studied. The results show increase in the conductivity with increase in temperature. Also, the value of dc conductivity at room temperature was found to be greater than that of the undoped PANI by nearly one to four orders of magnitude with respect to the used dopant acid. POLYM. ENG. SCI., 2013. © 2012 Society of Plastics Engineers
Investigation of the effect of hydrolysis products of postconsumer polyethylene terephthalate bottles on the properties of alkyd resins
Authors: Tuna Ö. , Bal A. , Güçlü G.
Published: July 2012

Hydrolysis of waste polyethylene terephthalate (PET) flakes obtained from grinding postconsumer bottles was carried out at 200–230°C and molar ratios of PET/H2O were taken as 1/5; 1/10; 1/20. The reaction products, when extracted with boiling water, yielded a water soluble crystallizable fraction (WSCF) and a water insoluble fraction (WIF). These fractions were characterized by acid and hydroxyl value determinations and DSC analysis. WSCF and WIF were used for preparation of alkyd resins. Five long oil alkyd resins were prepared from phthalic anhydride (PA) (reference alkyd resin) or hydrolysis products of the waste PET (PET‐based alkyd resin), pentaerithrithol (PE), soybean oil fatty acid (SOFA), and ethylene glycol (EG). Film properties and thermal degradation stabilities of these alkyd resins were investigated. Drying time, hardness, alkaline resistance, and thermal oxidative degradation resistance of the PET‐based alkyd resins are better than these properties of reference resin. The results show that hydrolysis products of waste PET obtained from postconsumer bottles are suitable for manufacturing of alkyd resins. POLYM. ENG. SCI., 2013. © 2012 Society of Plastics Engineers
A one‐pot method to prepare transparent poly(methyl methacrylate)/montmorillonite nanocomposites using imidazolium‐based ionic liquids
Authors: Xu Hong , Tong Fangfang , Yu Jian , Wen Lixiong , Zhang Jun , He Jiasong
Published: July 2012

Poly(methyl methacrylate) (PMMA)/montmorillonite (MMT) nanocomposites were prepared by a new one‐pot technique, where the hydrophilic Na‐MMT layers were decorated with hydrophobic 1‐dodecyl‐3‐methylimidazolium hexafluorophosphate (C12mimPF6) ionic liquid in situ during melt blending with PMMA and intercalation of polymer chains took place subsequently. The in situ modification and intercalation of Na‐MMT were confirmed using X‐ray diffraction and transmission electron microscopy. The combination of the compatible C12mimPF6 with PMMA and the good dispersion of MMT layers at the nanoscale rendered the resultant PMMA/MMT nanocomposites with improved optical transparency, thermal stability and mechanical properties. Copyright © 2012 Society of Chemical Industry
Preparation of ‘click’ hydrogels from polyaspartamide derivatives
Authors: Huynh Ngoc‐Thach , Jeon Young‐Sil , Zrinyi Miklos , Kim Ji‐Heung
Published: July 2012

Lately, copper‐assisted azide–alkyne cycloaddition (CuAAC) has become a very interesting tool for synthesizing biocompatible polymer‐based materials such as hydrogels or microgels, which can be used as biomaterials for tissue engineering and drug delivery. Novel poly(2‐hydroxyethyl aspartamide)s (PHEAs) functionalized with pendent acetylene or azide groups were prepared from polysuccinimide, which is the thermal polycondensation product of aspartic acid, through successful ring‐opening reactions using propargylamine, 1‐azido‐2‐aminoethane and ethanolamine. The composition of the prepared copolymers was analyzed using 1H NMR spectroscopy. Clickable PHEA derivatives were crosslinked by mixing together in water with a catalyst system of Cu(I) and N, N, N′, N′, N″‐pentamethyldiethylenetriamine, a type of Huisgen's 1,3‐dipolar azide‐alkyne cycloaddition. The reaction of the polymers resulted in a chemoselective coupling between alkynyl and azido functional groups with multiple formation of triazole crosslinks to give hydrogels. The triazole linkages in the hydrogels are highly stable and may also play a role in swelling behavior. PHEA‐based hydrogels were also obtained by the crosslinking of azide‐ or alkyne‐modified PHEA with a small‐molecule crosslinker. The hydrogels prepared using these two methods were characterized by their degree of swelling and the morphology of the hydrogels was confirmed using scanning electron microscopy. The approach we describe here presents a promising alternative to common chemical hydrogel preparation techniques, and these hydrogels seem to possess structures having potential for a variety of industrial and biomedical applications. © 2012 Society of Chemical Industry
Dynamics of salivary proteins and metabolites during extreme endurance sports – a case study
Authors: Zauber Henrik , Mosler Stephan , Heßberg Andreas von , Schulze Waltraud X.
Published: July 2012

As noninvasively accessible body fluid, saliva is of growing interest in diagnostics. To exemplify the diagnostic potential of saliva, we used a mass spectrometry‐based approach to gain insights into adaptive physiological processes underlying long‐lasting endurance work load in a case study. Saliva was collected from male and female athlete at four diurnal time points throughout a 1060 km nonstop cycling event. Total sampling time covered 180 h comprising 62 h of endurance cycling as well as reference samples taken over 3 days before the event, and over 2 days after. Altogether, 1405 proteins and 62 metabolites were identified in these saliva samples, of which 203 could be quantified across the majority of the sampling time points. Many proteins show clear diurnal abundance patterns in saliva. In many cases, these patterns were disturbed and altered by the long‐term endurance stress. During the stress phase, metabolites of energy mobilization, such as creatinine and glucose were of high abundance, as well as metabolites with antioxidant functions. Lysozyme, amylase, and proteins with redox‐regulatory function showed significant increase in average abundance during work phase compared to rest or recovery phase. The recovery phase was characterized by an increased abundance of immunoglobulins. Our work exemplifies the application of high‐throughput technologies to understand adaptive processes in human physiology.
New ladder‐type conjugated polymer with broad absorption, high thermal stability, and low band gap
Authors: Wang Shitao , Hong Wei , Ren Shendong , Li Jie , Wang Mao , Gao Xike , Li Hongxiang
Published: July 2012

New ladder‐type π‐conjugated polymer poly{6‐alkyl‐pyrrolo[3,2‐b:4,5‐b′]bis‐[1,4]benzothiazine} (PPBBTZ) was synthesized through a simple method. PPBBTZ showed good solubility in organic solvents (such as chloroform, tetrahydrofuran, chlorobenzene, o‐dichlorobenzene) and high thermal stability (decomposition temperatures up to 323 °C and 299 °C in nitrogen and air, respectively). The highest occupied molecular orbital and lowest unoccupied molecular orbital energy level estimated from electrochemistry result and absorption spectrum were −5.46 and −3.81 eV, respectively, with a band gap of 1.65 eV. More interestingly, PPBBTZ displayed broad absorption from ultraviolet to visible light regions (200–750 nm). These properties suggested PPBBTZ was a good candidate in opto‐electronics. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012
Plasma Deposition of PEO‐Like Coatings with Aerosol‐Assisted Dielectric Barrier Discharges
Authors: Da Ponte Gabriella , Sardella Eloisa , Fanelli Fiorenza , d'Agostino Riccardo , Gristina Roberto , Favia Pietro
Published: July 2012

In this paper, we describe the deposition of PEO‐like coatings using dielectric barrier discharges (DBDs) fed with aerosols of the TEGDME organic precursor in helium. By properly tuning plasma parameters such as aerosol/carrier flow ratio, frequency of the electric field applied and input power, the deposition process could be modulated to obtain coatings with variable PEO character, from 50% (cell adhesive) to 70% (nonfouling), which are interesting for surface modification of biomaterials and biomedical devices.

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Multistate approaches in computational protein design
Authors: Davey James A. , Chica Roberto A.
Published: July 2012

Computational protein design (CPD) is a useful tool for protein engineers. It has been successfully applied towards the creation of proteins with increased thermostability, improved binding affinity, novel enzymatic activity, and altered ligand specificity. Traditionally, CPD calculations search and rank sequences using a single fixed protein backbone template in an approach referred to as single‐state design (SSD). While SSD has enjoyed considerable success, certain design objectives require the explicit consideration of multiple conformational and/or chemical states. Cases where a “multistate” approach may be advantageous over the SSD approach include designing conformational changes into proteins, using native ensembles to mimic backbone flexibility, and designing ligand or oligomeric association specificities. These design objectives can be efficiently tackled using multistate design (MSD), an emerging methodology in CPD that considers any number of protein conformational or chemical states as inputs instead of a single protein backbone template, as in SSD. In this review article, recent examples of the successful design of a desired property into proteins using MSD are described. These studies employing MSD are divided into two categories—those that utilized multiple conformational states, and those that utilized multiple chemical states. In addition, the scoring of competing states during negative design is discussed as a current challenge for MSD.
Effect of distribution and concentration of topically applied neonicotinoid insecticides in buffalograss, Buchloe dactyloides, leaf tissues on the differential mortality of Blissus occiduus under field conditions
Authors: Stamm Mitchell D , Heng‐Moss Tiffany M , Baxendale Frederick P , Siegfried Blair D , Gaussoin Roch E , Snow Daniel D , Cassada David A
Published: July 2012

BACKGROUND: Neonicotinoid insecticides are generally efficacious against many turfgrass pests, including several important phloem‐feeding insects. However, inconsistencies in control of western chinch bugs, Blissus occiduus, have been documented in field efficacy studies. This research investigated the efficacy of three neonicotinoid insecticides (clothianidin, imidacloprid and thiamethoxam) against B. occiduus in buffalograss under field conditions and detected statistically significant differences in B. occiduus numbers among treatments. A subsequent study documented the relative quantity and degradation rate of these insecticides in buffalograss systemic leaf tissues, using HPLC.

RESULTS: Neonicotinoid insecticides initially provided significant reductions in B. occiduus numbers, but mortality diminished over the course of the field studies. Furthermore, while all three neonicotinoids were present in the assayed buffalograss leaf tissues, imidacloprid concentrations were significantly higher than those of clothianidin and thiamethoxam. Over the course of the 28 day study, thiamethoxam concentrations declined 700‐fold, whereas imidacloprid and clothianidin declined only 70‐fold and 60‐fold respectively.

CONCLUSIONS: Field studies continued to verify inconsistencies in B. occiduus control with neonicotinoid insecticides. This is the first study to document the relative concentrations of topically applied neonicotinoid insecticides in buffalograss systemic leaf tissues. Copyright © 2012 Society of Chemical Industry
Genetic engineering of plant volatile terpenoids: effects on a herbivore, a predator and a parasitoid
Authors: Kos Martine , Houshyani Benyamin , Overeem Aart‐Jan , Bouwmeester Harro J , Weldegergis Berhane T , van Loon Joop JA , Dicke Marcel , Vet Louise EM
Published: July 2012

BACKGROUND: Most insect‐resistant transgenic crops employ toxins to control pests. A novel approach is to enhance the effectiveness of natural enemies by genetic engineering of the biosynthesis of volatile organic compounds (VOCs). Before the commercialisation of such transgenic plants can be pursued, detailed fundamental studies of their effects on herbivores and their natural enemies are necessary. The linalool/nerolidol synthase gene FaNES1 was constitutively expressed from strawberry in three Arabidopsis thaliana accessions, and the behaviour of the aphid Brevicoryne brassicae L., the parasitoid Diaeretiella rapae McIntosh and the predator Episyrphus balteatus de Geer was studied.

RESULTS: Transgenic FaNES1‐expressing plants emitted (E)‐nerolidol and larger amounts of (E)‐DMNT and linalool. Brevicoryne brassicae was repelled by the transgenic lines of two of the accessions, whereas its performance was not affected. Diaeretiella rapae preferred aphid‐infested transgenic plants over aphid‐infested wild‐type plants for two of the accessions. In contrast, female E. balteatus predators did not differentiate between aphid‐infested transgenic or wild‐type plants.

CONCLUSION: The results indicate that the genetic engineering of plants to modify their emission of VOCs holds considerable promise for facilitating biological control of herbivores. Validation for crop plants is a necessary next step to assess the usefulness of modified volatile emission in integrated pest management. Copyright © 2012 Society of Chemical Industry
Scanning tunneling microscopy and density functional theory combined studies of rutile TiO2(1 1 0) surface chemistry: Watch surface processes at the atomic scale
Authors: Zhang Wenhua , Li Zhenyu , Wang Bing , Yang Jinlong
Published: July 2012

TiO2 has attracted great interest in chemical and physical sciences, partially due to its potential applications in catalysis. This article provides a brief review on recent progresses of joint scanning tunneling microscopy and density functional theory investigations on the electronic structure of reduced rutile TiO2(1 1 0) surface and the adsorption and reaction of oxygen, carbon monoxide, carbon dioxide, methanol, and ethanol on the surface. © 2012 Wiley Periodicals, Inc.
The analysis of polarization effects on the interelectronic separations in the atoms and molecules of the G1 test set
Authors: Proud Adam J. , Walker Michael P. , Pearson Jason K.
Published: July 2012

We have calculated the differences between kinetic, nuclear attraction, and two‐electron energies as well as the position intracules, P(u), for 56 molecules and 17 atoms contained in the G1 test set, using basis sets differing in their degree of polarization. The calculations were performed using an unrestricted Hartree–Fock wave function that was expanded using the 6‐31G, 6‐31G(d,p), 6‐31G(3d,3p), 6‐31G(3df,3pd), 6‐311G, 6‐311G(d,p), 6‐311G(3d,3p), 6‐311G(3df,3pd), 6‐311++G, 6‐311++G(d,p), 6‐311++G(3d,3p), and 6‐311++G(3df,3pd) basis sets. In addition to these Pople basis sets, the Dunning's cc‐pVDZ and cc‐pVTZ bases as well as the non‐polarized portions of these basis sets were used. We observe a consistent contraction of electron pairs (as measured by the distribution in P(u)) as the number of polarization functions is increased beyond zero in molecular systems. This contraction is related to an increase in the electron density in the internuclear bonding regions of molecules as the wave functions are polarized. We note that the increased flexibility in the polarized basis set allows for a more accurate description of the chemical bond and is energetically favorable due to an increased level of attraction to the nuclei (despite the obvious increase in electronic repulsion energy). Because of the increase in electron density in internal regions of the molecule (at the expense of electron density depletions in outer regions), the probability of observing electrons closer together (i.e., at smaller u) increases due to the relationship between P(u) and its Coulomb component, J(u). © 2012 Wiley Periodicals, Inc.
Recursion relations for the three‐electron subsidiary integral W (l, m, n; α, β, γ)
Authors: Li Chun , Wang Liming , Yan Zong‐Chao
Published: July 2012

The subsidiary integral W (l, m, n; α, β, γ) is a key integral that appears in the variational calculation of a three‐electron atomic system using Hylleraas coordinates. For the case where the ratio α/(α + β + γ) ∼ 1, an important special situation that may occur in the evaluation of the Bethe logarithm, existing approaches for calculating the W integral become impractical due to the problem of slow convergence. In this article, we present a computationally efficient and numerical stable method, in which the W integral can be expressed in terms of either a finite series or a finite recursion relation. Numerical tests are given. © 2012 Wiley Periodicals, Inc.
Stability and robustness of large platoons of vehicles with double‐integrator models and nearest neighbor interaction
Authors: Hao He , Barooah Prabir
Published: July 2012

We study the stability and robustness of a large platoon of vehicles, where each vehicle is modeled as a double integrator, for two decentralized control architectures: predecessor following and symmetric bidirectional. In the predecessor‐following architecture, the control action on each agent only depends on the information from its immediate front neighbor, whereas in the symmetric bidirectional architecture, it depends equally on the information from both its immediate front neighbor and back neighbor. We prove asymptotic stability of the formation for a class of nonlinear controllers with sector nonlinearity, with the linear controller as a special case. We show that the convergence rate of the predecessor‐following architecture is much faster than that of the symmetric bidirectional architecture. However, the predecessor‐following architecture suffers high algebraic growth of initial errors. We also establish scaling laws (with N) of certain H ∞  norms of the formation that measure its robustness to external disturbances for the linear case. It is shown that the robustness performance grows geometrically in N for predecessor‐following architecture but only polynomially in N for symmetric‐bidirectional architecture. Extensive numerical simulations are conducted to verify the predictions for the linear case and empirically estimate the corresponding performance metrics for a saturation‐type nonlinear controller. On the basis of the analytical and numerical results, it is seen that the symmetric bidirectional architecture outperforms the predecessor‐following architecture in all measures of performance. Within the predecessor‐following architecture, the nonlinear controller is seen to perform better in general than the linear one. A number of design guidelines are provided on the basis of these conclusions. Copyright © 2012 John Wiley & Sons, Ltd.