bluuebunny/crossref_metadata_2025_split huggingface dataset:
Cole Parameter Estimation from the Modulus of the Electrical Bioimpeadance for Assessment of Body Composition. A Full Spectroscopy Approach
Authors: Buendia R. , Gil-Pita R. , Seoane F. 
Published: October 2011

Abstract
Activities around applications of Electrical Bioimpedance Spectroscopy (EBIS) have proliferated in the past decade significantly. Most of these activities have been focused in the analysis of the EBIS measurements, which eventually might enable novel applications. In Body Composition Assessment (BCA), the most common analysis approach currently used in EBIS is based on the Cole function, which most often requires curve fitting. One of the most implemented approaches for obtaining the Cole parameters is performed in the impedance plane through the geometrical properties that the Cole function exhibit in such domain as depressed semi-circle. To fit the measured impedance data to a semi-circle in the impedance plane, obtaining the Cole parameters in an indirect and sequential manner has several drawbacks. Applying a Non-Linear Least Square (NLLS) iterative fitting on the spectroscopy measurement, obtains the Cole parameters considering the frequency information contained in the measurement. In this work, from experimental total right side EBIS measurements, the BCA parameters have been obtained to assess the amount and distribution of whole body fluids. The values for the BCA parameters have been obtained using values for the Cole parameters estimated with both approaches: circular fitting on the impedance plane and NLLS impedance-only fitting. The comparison of the values obtained for the BCA parameters with both methods confirms that the NLLS impedance-only is an effective alternative as Cole parameter estimation method in BCA from EBIS measurements. Using the modulus of the Cole function as the model for the fitting would eliminate the need for performing phase detection in the acquisition process, simplifying the hardware specifications of the measurement instrumentation when implementing a bioimpedance spectrometer.
High‐Energy Al/CuO Nanocomposites Obtained by DNA‐Directed Assembly
Authors: Séverac Fabrice , Alphonse Pierre , Estève Alain , Bancaud Aurélien , Rossi Carole 
Published: October 2011

AbstractOver the next few years, it is expected that new, energetic, multifunctional materials will be engineered. There is a need for new methods to assemble such materials from manufactured nanopowders. In this article, we demonstrate a DNA‐directed assembly procedure to produce highly energetic nanocomposites by assembling Al and CuO nanoparticles into micrometer‐sized particles of an Al/CuO nanocomposite, which has exquisite energetic performance in comparison with its physically mixed Al/CuO counterparts. Using 80 nm Al nanoparticles, the heat of reaction and the onset temperature are 1.8 kJ g−1 and 410 °C, respectively. This experimental achievement relies on the development of simple and reliable protocols to disperse and sort metallic and metal oxide nanopowders in aqueous solution and the establishment of specific DNA surface‐modification processes for Al and CuO nanoparticles. Overall, our work, which shows that DNA can be used as a structural material to assemble Al/Al, CuO/CuO and Al/CuO composite materials, opens a route for molecular engineering of the material on the nanoscale.
Bioceramics: From Bone Regeneration to Cancer Nanomedicine
Authors: Vallet‐Regí María , Ruiz‐Hernández Eduardo 
Published: October 2011

AbstractResearch on biomaterials has been growing in the last few years due to the clinical needs in organs and tissues replacement and regeneration. In addition, cancer nanomedicine has recently appeared as an effective means to combine nanotechnology developments towards a clinical application. Ceramic materials are suitable candidates to be used in the manufacturing of bone‐like scaffolds. Bioceramic materials may also be designed to deliver biologically active substances aimed at repairing, maintaining, restoring or improving the function of organs and tissues in the organism. Several materials such as calcium phosphates, glasses and glass ceramics able to load and subsequently release in a controlled fashion drugs, hormones, growth factors, peptides or nucleic acids have been developed. In particular, to prevent post surgical infections bioceramics may be surface modified and loaded with certain antibiotics, thus preventing the formation of bacterial biofilms. Remarkably, mesoporous bioactive glasses have shown excellent characteristics as drug carrying bone regeneration materials. These bioceramics are not only osteoconductive and osteoproductive, but also osteoinductive, and have therefore been proposed as ideal components for the fabrication of scaffolds for bone tissue engineering. A recent promising development of bioceramic materials is related to the design of magnetic mediators against tumors. Magnetic composites are suitable thermoseeds for cancer treatment by hyperthermia. Moreover, magnetic nanomaterials offer a wide range of possibilities for diagnosis and therapy. These nanoparticles may be conjugated with therapeutic agents and heat the surrounding tissue under the action of alternating magnetic fields, enabling hyperthermia of cancer as an effective adjunct to chemotherapy regimens.
Heterogeneous and homogeneous reactions of pyrolysis vapors from pine wood
Authors: Hoekstra Elly , Westerhof Roel J. M. , Brilman Wim , Van Swaaij Wim P.M. , Kersten Sascha R. A. , Hogendoorn Kees J. A. , Windt Michael 
Published: October 2011

AbstractTo maximize oil yields in the fast pyrolysis of biomass it is generally accepted that vapors need to be rapidly quenched. The influence of the heterogeneous and homogeneous vapor‐phase reactions on yields and oil composition were studied using a fluidized‐bed reactor. Even high concentrations of mineral low char (till 55 vol %) appeared not to be catalytically active. However, the presence of minerals, either in biomass or added, does influence the yields, especially by the occurrence of vapor‐phase charring/polymerization reactions. Contradictory, in the absence of minerals, homogeneous vapor‐phase cracking reactions were dominant over polymerization/charring reactions (400–550°C, 1–15 s). With increasing vapor residence time, the oil yield reached an asymptotic value, which decreased with temperature. At a vapor temperature of 400°C no decrease in oil yield was observed, but dedicated analysis showed that homogeneous vapor to vapor reactions had occurred. © 2011 American Institute of Chemical Engineers AIChE J, 2012
Endoscopic verification of the sphenoid sinus
Authors: Orlandi Richard R. , Smith Brett , Shah Lubdha , Wiggins Richard H. 
Published: October 2011

AbstractBackground:Differentiating between posterior ethmoid and sphenoid sinuses can be difficult endoscopically. Anatomic relationships should guide surgery, irrespective of the ability to verify them with image guidance. The authors sought to verify an anatomic landmark found to be useful during endoscopic sinus surgery: the ability to see the sphenoid floor with a 0‐degree nasal endoscope.Methods:The angle formed by a nasal endoscope placed at the sphenoid ostium and the mucosa of the sphenoid floor was measured in 93 consecutive sphenoid sinuses radiologically. Angles of view of 3 common endoscopes were directly measured and compared to the radiologic measurements.Results:The angle to the most inferior aerated portion of the sphenoid sinus averaged 113.6 degrees with a range of 77 to 145 degrees. The angle of view of the 3 endoscopes was found to be 38.1 degrees, 46.7 degrees, and 44.4 degrees. With these angles of view, the most inferior aerated portion of 100% of the radiologically assessed sinuses could not be seen with these endoscopes.Conclusion:Inability to see the mucosa of the floor of the sphenoid sinus with a 0‐degree nasal endoscope appears to be a reliable finding. Individual variations that may affect this finding such as hypoplasia or severe mucosal edema should be identified preoperatively on imaging. In their absence, the inability to see the floor of an entered sinus with a 0‐degree nasal endoscope provides another reliable clue to the position of the sphenoid sinus during endoscopic sinus surgery. © 2011 ARS‐AAOA, LLC.
Isothermal and nonisothermal crystallization kinetics of poly(ϵ‐caprolactone)
Authors: Dhanvijay Prarthana U. , Shertukde Vikrant V. , Kalkar Arun K. 
Published: October 2011

AbstractWith increasing environmental awareness, evaluating the potential of biopolymers as a substitute for traditional materials has been of great interest. Crystallization kinetics provides fundamental knowledge required for evaluation, playing vital role in determining the final properties of the product. In this study, the isothermal and nonisothermal crystallization kinetics of poly(ϵ‐caprolactone) (PCL) were investigated with the help of various models. The Avrami model best described the isothermal crystallization kinetics, suggesting three‐dimensional spherulitic growth, which was in agreement with the morphology studies; whereas the Liu model fit well under nonisothermal crystallization conditions. The failure of the Kissinger model to determine the activation energy was overcome with the Friedman model. The kinetic crystallizability determined by the Ziabacki model indicated a higher crystallization ability of PCL at lower cooling rates. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Functionalization of wool with L‐cysteine: Process characterization and assessment of antimicrobial activity and cytotoxicity
Authors: Gouveia Isabel C. , Sá Daniela , Henriques Mariana 
Published: October 2011

AbstractThis investigation reports a new biotechnological process that uses L‐cysteine (L‐Cys) which provides a permanent, nontoxic and effective antimicrobial effect over wool‐based materials. This process is simple and carried out via widespread exhausting methods. Typically, wool fabrics are incubated with L‐Cys for 50 min at 60°C in a pH 4.8 acetate buffer solution 25 mM, under mild agitation to give a good absorption rate. The minimal inhibitory concentration (MIC) of L‐Cys was evaluated by the NCCLS M07‐A6 standard method, and the results showed a good antibacterial activity against S. aureus and K. pneumoniae within the range of 6.0 × 10−3 − 4.8 × 10−2 g/mL [MIC 0.6% (w/v)] and 6.0 × 10−3 − 4.8 × 10−2 g/mL [MIC 0.6% (w/v)], respectively. In addition, the antimicrobial activity of the functionalized wool was assessed by the international standard JIS 1902‐2002 showing a good inhibition of bacterial growth for an L‐Cys concentration of 1% over the weight of fabric, both against Staphylococcus aureus and Klebsiella pneumoniae. Moreover, the biocidal mechanism was found to be related with the increase of sulfhydryl's groups onto wool fibers, which were quantified by the Ellman's reagent (5,5′‐Dithio‐bis(2‐nitrobenzoic acid) method. The new process is easy to perform, non toxic, preserve wool quality and is a novel biomimetic approach that uses antimicrobial amino acids and may open new avenues for the design of biomedical textiles with a broad range of applications in healthcare. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Electrical conductivity and electric modulus of stable Kevlar® fiber loaded HAF/NBR rubber composite
Authors: Salam M. H. Abd‐El , Ismail A. M. 
Published: October 2011

AbstractDC, AC conductivities and dielectric properties of high abrasion furnace carbon black (HAF)/acrylonitrile butadiene rubber (NBR) composite have been studied with varying the aramide Stable Kevlar® fiber content, temperature, and frequency. Generally, the electrical conductivity was decreased with increasing Stable Kevlar® fiber content, which was confirmed by the positron annihilation lifetime spectroscopy. Negative temperature coefficient of conductivity (NTCC) behavior between 353 and 413 K was detected, except for the composite containing 10 phr Kevlar which showed positive temperature coefficient of conductivity (PTCC) behavior above 383 K. These NTCC and PTCC behaviors were further manifested by differential scanning calorimetry (DSC). For the composite with 10 phr Kevlar, the interfacial polarization between the fibers and the polymeric composite can be ascribed to Maxwell‐Wagner‐Sillars mechanism. The (MWS) relaxation disappeared for higher fibers content. The analysis of the electric modulus in the frequency range from 1 kHz to 1 MHz shows that the interfacial relaxation obeys Cole–Davison distribution of relaxation times. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Development of bacterial cellulose nanowhiskers reinforced EVOH composites by electrospinning
Authors: Martínez‐Sanz Marta , Olsson Richard T. , Lopez‐Rubio Amparo , Lagaron Jose M. 
Published: October 2011

AbstractIn the current study, hybrid electrospun ethylene vinyl alcohol (EVOH) fibers reinforced with bacterial cellulose nanowhiskers (BCNW) were developed and characterized. Additionally, electrospinning was suggested as a method for the incorporation of well‐dispersed BCNW into an EVOH matrix by melt compounding. With the aim of maximizing the BCNW's loading in the electrospun fibers, an optimized method was applied for generating fibers from solutions containing up to 40 wt % BCNW. As demonstrated by FTIR spectroscopy, it was possible to incorporate BCNW concentrations up to ∼ 24 wt %, although a complete incorporation of the nanofiller into the fibers was only achieved with solutions containing up to 20 wt % of the filler, DSC analyses suggested that the incorporation of the nanofiller reduced the crystallinity of the as‐obtained EVOH fibers and produced an increase in the glass transition temperature of these during the second heating run. Thermogravimetric analyses showed that even though EVOH protects the nanowhiskers from thermal degradation, the electrospun hybrid fibers present a relatively lower thermal stability than the pure EVOH fibers. FTIR analyses of the samples subjected to different thermal treatments confirmed that the stiffening effect observed by DSC only occurs after melting of the EVOH phase and is cooperative with a partial acid chemical development in the BCNW, which promotes strong chemical interactions between the polymeric matrix and the nanofiller. Finally, the hybrid electrospun fibers were incorporated into pure EVOH by melt compounding to produce composite films. This methodology showed higher stability and dispersion of the BCNW than direct addition of the freeze‐dried nanofiller to EVOH. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Preparation and characterization of dense cellulose film for membrane application
Authors: Ichwan Muhammad , Son Tae‐Won 
Published: October 2011

AbstractRegenerated cellulose films were prepared with environmentally friendly process by utilized N‐methylmorpholine‐N‐oxide (NMMO)‐Cellulose system. To prepare a dense cellulose film for membrane application, some parameter process which influence porous forming such as cellulose DP, cellulose concentration, addition NMMO in coagulation bath, coagulation bath temperature, and drying condition were investigated. We resumed that the porosity and pore size of cellulose membrane decrease with lower cellulose DP, higher cellulose concentration, addition of NMMO in coagulation bath, applying room temperature in coagulation bath and drying, and applying vacuum on drying process resulted in membranes with porosity in range of 24–41% and pore size 13.4–20.2 nm. The main factor for controlling porosity and pore size of dense cellulose membrane was coagulation process condition especially addition of NMMO into coagulation bath. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Influence of the geometric factors of the experimental device used in suspension polymerization on the properties of poly(styrene‐co‐divinylbenzene) microparticles
Authors: Rodrigo Raúl , Toro Claudio A. , Cuellar Jorge 
Published: October 2011

AbstractThe prediction of the final particle size for reactive systems such as the reactions of suspension polymerization is a complex matter. Thus, the preparation of very small microparticles is specially challenging, probably because of the coalescence of the polymeric beads taking place during the later stages of the polymerization. In this work, very small gel‐type styrene‐co‐divinylbenzene beads were synthesized by using a previously determined set of experimental synthesis conditions in which the stabilization of the dispersion of the monomeric droplets was ensured, and, under these conditions, the factors related to the geometry of the experimental device were modified to determine their actual effect on the final size of the microparticles. From the experimental results, a very simple and useful model was obtained that was able to predict the final size of the microparticles as a function of the values of the geometric factors of the reactor. This model indicates that the most influential factors in the final size of the microparticles are the liquid depth inside the reactor and the stirrer diameter; thus, an increase in the liquid depth produces larger particles, and, conversely, the particle size decreases when using larger stirrer diameters. Additionally, the model permits the design of polymerization experiments aimed at obtaining microparticles with a diameter smaller than 50 μm. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Application of a novel halogen‐free intumescent flame retardant for acrylonitrile‐butadiene‐styrene
Authors: Yi Liu , JiangSong Yi , XuFu Cai 
Published: October 2011

AbstractA novel intumescent flame retardant (IFR), containing ammonium polyphosphate (APP) and poly(tetramethylene terephthalamide) (PA4T), was prepared to flame‐retard acrylonitrile‐butadiene‐styrene (ABS). The flame retardation of the IFR/ABS composite was characterized by limiting oxygen index (LOI) and UL‐94 test. Thermogravimetric analysis (TGA) and TGA coupled with Fourier transform infrared spectroscopy (TG‐FTIR) were carried out to study the thermal degradation behavior of the composite and look for the mechanism of the flame‐retarded action. The morphology of the char obtained after combustion of the composite was studied by scanning electron microscopy (SEM). It has been found the intumescent flame retardant showed good flame retardancy, with the LOI value of the PA4T/APP/ABS (7.5/22.5/70) system increasing from 18.5 to 30% and passing UL‐94 V‐1 rating. Meanwhile, the TGA and TG‐FTIR work indicated that PA4T could be effective as a carbonization agent and there was some reaction between PA4T and APP, leading to some crosslinked and high temperature stable material formed, which probably effectively promoted the flame retardancy of ABS. Moreover, it was revealed that uniform and compact intumescent char layer was formed after combustion of the intumescent flame‐retarded ABS composite. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
In situ synthesis and characterization of ZnS/epoxy nanocomposites via gas‐liquid state reaction method
Authors: Ding Ke Hong , Wang Gen Lin , Zhang Ming 
Published: October 2011

AbstractIn this article, the ZnS/epoxy nanocomposites were successfully prepared by the reaction of zinc acetate and H2S gas via a simple step. Epoxy resin acted as the matrix for the formation of ZnS nanoparticles (10–20 nm) in the reaction system and kept them from agglomerating. The structure, composition, and mechanical properties of the resultant products were successfully investigated by powder X‐ray diffraction, transmission electron microscope, field emission scanning electron microscope, energy dispersive X‐ray fluorescence, and universal testing machine. Meanwhile, by employing differential scanning calorimetry (DSC) we had studied, under nonisothermal condition, the kinetic analysis of the cure reaction which was performed using two classic models: Kissinger and Flynn‐Wall‐Ozawa. The activation energy of curing reaction was 74.63 kJ/mol and 77.57 kJ/mol, respectively, by Kissinger's and Flynn‐Wall‐Ozawa's methods. The possible mechanism of preparation of ZnS/epoxy composites was discussed in this article. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Genome analyses substantiate male mutation bias in many species
Authors: Wilson Sayres Melissa A. , Makova Kateryna D. 
Published: October 2011

AbstractIn many species the mutation rate is higher in males than in females, a phenomenon denoted as male mutation bias. This is often observed in animals where males produce many more sperm than females produce eggs, and is thought to result from differences in the number of replication‐associated mutations accumulated in each sex. Thus, studies of male mutation bias have the capacity to reveal information about the replication‐dependent or replication‐independent nature of different mutations. The availability of whole genome sequences for many species, as well as for multiple individuals within a species, has opened the door to studying factors, both sequence‐specific and those acting on the genome globally, that affect differences in mutation rates between males and females. Here, we assess the advantages that genomic sequences provide for studies of male mutation bias and general mutation mechanisms, discuss major challenges left unresolved, and speculate about the direction of future studies.
Oxidative stress and thyroid impairment after gibberellic acid treatment in pregnant and lactating rats and their offspring
Authors: Troudi Afef , Amara Ibtissem Ben , Samet Amira Mahjoubi , Fetoui Hamadi , Soudani Nejla , Guermazi Fadhel , Boudawara Tahia , Zeghal Najiba 
Published: October 2011

AbstractGibberellic acid (GA3) has been worldwide used in agriculture as a plant growth regulator. The purpose of this study is to assess the effects of GA3 on the morphology and the thyroid hormone levels in adult rats and their suckling pups. Animals were given daily 200 ppm GA3 in drinking water from the 14th day of pregnancy until day 14 after delivery. Compared with a control group, GA3‐treated mothers and pups showed an increase in body and thyroid weights, a decrease in plasma FT4 and FT3 levels, which were more pronounced in pups than in their mothers. Thyroid iodine content was also decreased in pups. These biochemical modifications corresponded histologically; the majority of follicles had cubical epithelial cells, which surrounded empty vesicular cavities. Toxicity was objectified by a significant increase in plasma malondialdehyde, protein carbonyls, and advanced oxidation protein products levels in GA3‐treated dams and their suckling pups; while, the activities of superoxide dismutase, catalase, and glutathione peroxidase were decreased in plasma of both dams and their pups. Moreover, a significant decline was observed in plasma glutathione, nonprotein thiols, and vitamin C levels. We conclude that GA3 treatment affects thyroid function and plasma antioxidant status in adult rats and their progeny.