bluuebunny/crossref_metadata_2025_split huggingface dataset:
Clan, language, and migration history has shaped genetic diversity in Haida and Tlingit populations from Southeast Alaska
Authors: Schurr Theodore G. , Dulik Matthew C. , Owings Amanda C. , Zhadanov Sergey I. , Gaieski Jill B. , Vilar Miguel G. , Ramos Judy , Moss Mary Beth , Natkong Francis ,   The Genographic Consortium
Published: May 2012

AbstractThe linguistically distinctive Haida and Tlingit tribes of Southeast Alaska are known for their rich material culture, complex social organization, and elaborate ritual practices. However, much less is known about these tribes from a population genetic perspective. For this reason, we analyzed mtDNA and Y‐chromosome variation in Haida and Tlingit populations to elucidate several key issues pertaining to the history of this region. These included the genetic relationships of Haida and Tlingit to other indigenous groups in Alaska and Canada; the relationship between linguistic and genetic data for populations assigned to the Na‐Dene linguistic family, specifically, the inclusion of Haida with Athapaskan, Eyak, and Tlingit in the language family; the possible influence of matrilineal clan structure on patterns of genetic variation in Haida and Tlingit populations; and the impact of European entry into the region on the genetic diversity of these indigenous communities. Our analysis indicates that, while sharing a “northern” genetic profile, the Haida and the Tlingit are genetically distinctive from each other. In addition, Tlingit groups themselves differ across their geographic range, in part due to interactions of Tlingit tribes with Athapaskan and Eyak groups to the north. The data also reveal a strong influence of maternal clan identity on mtDNA variation in these groups, as well as the significant influence of non‐native males on Y‐chromosome diversity. These results yield new details about the histories of the Haida and Tlingit tribes in this region. Am J Phys Anthropol 148:422–435, 2012. © 2012 Wiley Periodicals, Inc.
Chronic rhinosinusitis symptoms and computed tomography staging: improved correlation by incorporating radiographic density
Authors: Sedaghat Ahmad R. , Bhattacharyya Neil 
Published: May 2012

AbstractBackground:Traditional methods for staging of chronic rhinosinusitis (CRS) by computed tomography (CT) have not proven to be predictive of subjective reports of patients' symptoms. An objective measure of CRS severity that correlates well with patients' symptoms, particularly if available from CT data, would be a valuable tool in assessment of disease status and outcomes after surgery.Methods:Retrospective chart review of CRS patients with symptom data from the Rhinosinusitis Symptom Inventory (RSI) and objective data from a sinus CT scan. CRS disease severity on CT imaging was measured according to the traditional Lund‐Mackay scoring, as well as by raw measures of the densities of sinus opacities (in Hounsfield units [HU]) and density‐weighted Lund‐Mackay scoring. These data were related to symptom severity scores using a multivariate regression model.Results:There was no significant correlation between either raw density values of sinus opacities or weighted Lund‐Mackay scores with facial or total symptom scores. Oropharyngeal symptoms scores were negatively correlated with the sum of “average HU” values (p = 0.036, β = −1.120) but were positively correlated with the sum of “maximum HU” values (p = 0.047, β = 1.221). There was a significant negative correlation between the systemic symptoms score and mean of “average HU” values (p = 0.010, β = −0.272). Finally, there was a positive correlation between “maximum HU” value‐weighted Lund‐Mackay score with nasal symptom scores (p = 0.016, β = 0.241), systemic symptom scores (p = 0.008, β = 0.605), and total symptom scores (p = 0.078, β = 0.179).Conclusion:Incorporation of radiographic characteristics of sinus opacification with Lund‐Mackay scores offers greater predictive power of patients' subjective symptom severity. © 2012 ARS‐AAOA, LLC.
Effect of steroid‐releasing sinus implants on postoperative medical and surgical interventions: an efficacy meta‐analysis
Authors: Han Joseph K. , Marple Bradley F. , Smith Timothy L. , Murr Andrew H. , Lanier Brent J. , Stambaugh James W. , Mugglin Andrew S. 
Published: May 2012

AbstractBackground:Endoscopic sinus surgery (ESS) for chronic rhinosinusitis (CRS) can be compromised by postoperative inflammation, polyposis, and adhesions, often requiring subsequent interventions. A bioabsorbable, steroid‐releasing sinus implant has been studied in 2 prospective, randomized clinical trials for its ability to preserve sinus patency and reduce medical and surgical interventions after ESS in patients with CRS. The objective of this study was to perform a meta‐analysis of the efficacy results from the 2 trials.Methods:The 2 prospective, randomized, double‐blinded, multicenter trials enrolled a total of 143 patients utilizing an intrapatient control design. Postoperative day 30 videos were obtained for each patient, randomly ordered, and presented to an independent panel of 3 otolaryngologists for grading of efficacy endpoints. The need for postoperative interventions, formation of polyposis, and adhesions were assessed. Results from the 2 studies were then pooled.Results:Implants were successfully placed in all 286 ethmoid sinuses. According to the grading done by the panel, drug‐releasing implants reduced postoperative interventions by 35% (p = 0.0008), lysis of adhesions by 51% (p = 0.0016), and oral steroid need by 40% (p = 0.0023), compared to controls. The relative reduction in frank polyposis was 46% (p < 0.0001).Conclusion:Early postoperative healing is a predictor of longer‐term success after sinus surgery. Evaluation of postoperative outcomes by a blinded independent panel demonstrates that steroid‐releasing implants that provide a sustained release of corticosteroid improve surgical outcomes by reducing frank polyp formation, sinus adhesions, and middle turbinate lateralization. Steroid‐releasing implants reduce the need for surgical intervention, and the need for oral steroid treatment. © 2012 ARS‐AAOA, LLC.
Emodin voltammetric sensor based on molecularly imprinted polymer membrane‐modified electrode using a multiple hydrogen bonds strategy
Authors: Yu Zerong , Yang Jiajian , Zhong Jinfeng , Wu Suqin , Xu Zhiguang , Tang Youwen 
Published: May 2012

AbstractSimilar to those in complementary nucleotides' base pairs, we present a novel molecularly imprinted electrochemical sensor for emodin, constructed using a multiple hydrogen bonds strategy. We obtained the sensor by in situ photopolymerization, using allobarbital as a new functional monomer. We optimized the conditions of membrane imprinting and the composition of adsorption solvent. This artificial receptor exhibits high selectivity for the template in comparison with closely related analogs, aloin A and simetryne. The sensor was successfully applied in determination of emodin levels in one of the traditional Chinese medicines, the content of emodin in Sanhuang tablets detected using the voltammetric sensor and high performance liquid chromatography (HPLC) were 0.249 ± 0.009 (mg/tablet) and 0.246 ± 0.007 (mg/tablet), respectively. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Water‐soluble star polymers with a phthalocyanine as the core and poly(ethylene glycol) chains as branches
Authors: Mineo Placido , Alicata Rossana , Micali Norberto , Villari Valentina , Scamporrino Emilio 
Published: May 2012

AbstractUncharged water‐soluble phthalocyanines (Pc's) and some metallophthalocyanines (Me‐Pc's) were prepared by means of a chemical modification of a commercial Pc or by a cyclic tetramerization reaction starting from 4‐nitrophthalonitrile derivatives. The necessary hydrophilicity for the water solubility of these Pc derivatives was achieved by the binding of eight 9‐methoxytriethyleneoxy branches on peripheral Pc positions or, alternatively, four or eight linear poly(ethylene glycol) methyl ether (PEGME; weight‐average molar mass = 350 or 750 g/mol) units. The chemical structure of these products was characterized by 1H‐NMR and matrix‐assisted laser desorption/ionization–time ‐of ‐flight mass spectrometric analysis. Finally, their solutions were examined by ultraviolet–visible and luminescence spectroscopy and dynamic light scattering experiments. All of the samples were water soluble, although the formation of small aggregates was ascertained by dynamic light scattering measurements. Furthermore, a lower scattered light intensity was measured for Pc derivatives with longer PEGME branches, which, probably playing a more negative role in the self‐assembly process, hindered the aggregation phenomenon. Preliminary data on their sensing ability are also reported. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Solid‐state graft polymerization of styrene in spherical polypropylene particles in the presence of montmorillonite
Authors: Fu Zhisheng , Sun Fangli , Fan Zhiqiang 
Published: May 2012

AbstractIn this work, cetyltrimethyl ammonium bromide and methacryloyloxyethyhrimethyl ammonium chloride were used to prepare organophilic montmorillonite (O‐MMT). Then, polypropylene (PP)–clay nanocomposites were prepared by the in situ grafting polymerization of styrene (St)‐containing O‐MMT onto PP with tert‐butyl perbenzoate as an initiator in the solid state. Fourier transform infrared spectroscopy, gel permeation chromatography, transmission electron microscopy, and X‐ray diffraction were applied to study the structure of the layered silicate and modified PP. The surfaces of the composites and, thus, the distribution of the clay in the PP matrix were characterized by scanning electron microscopy. The rheology and mechanical properties were studied and are discussed. According to the characterization results, OMMT and St were already grafted onto the PP main chain. Also, the intercalated structure of montmorillonite could be stabilized, and a stable exfoliated structure could be attained. Namely, intercalated PP/OMMT nanocomposites were obtained. The rheological results clearly show that these PP/OMMT nanocomposites had long‐chain‐branched structures. The peroxide modification of PP had minor effects on the tensile and bending strengths of the modified PP; however, this modification resulted in a significant reduction in the impact strength. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Copolymerization of potassium chloroacetate and potassium N‐chloroacetyl‐6‐aminohexanoate
Authors: Murase Sara Keiko , Franco Lourdes , Rodríguez‐Galán Alfonso , Puiggalí Jordi 
Published: May 2012

AbstractThe polymerization kinetics of potassium chloroacetate (MGL), potassium N‐chloroacetyl‐6‐aminohexanoate (MEA), and their mixtures was studied by Fourier transform infrared spectroscopy. The bulk polycondensation reaction was faster for MEA than for MGL but kinetic differences in the selected temperature range (110–130°C) were not large enough to make unfeasible copolymerization of both monomers. A decrease in the activation energy was deduced for the polycondensation of monomer mixtures with respect to that determined for the homopolymerization reaction of the predominant neat monomer. differential scanning calorimetry data also showed significant differences in the exothermic polycondensation peaks that suggested an effective copolymerization reaction and favored the kinetic process over the corresponding homopolymerization. The resulting new poly(ester amide)s were characterized by spectroscopy and thermal analysis. 1H NMR spectra of samples with high MEA content revealed the existence of hetero‐sequences whose ratio was slightly lower than that expected for a random polymerization of the two monomers. Samples with high molecular weights were only attained when the MGL molar ratio in the monomer mixture was lower than 65%. Calorimetric data showed that all samples were thermally stable and became amorphous for intermediate compositions. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Synthesis, effectiveness, and working mechanism of humic acid‐{sodium 2‐acrylamido‐2‐methylpropane sulfonate‐co‐N,N‐dimethyl acrylamide‐co‐acrylic acid} graft copolymer as high‐temperature fluid loss additive in oil well cementing
Authors: Salami Oyewole Taye , Plank Johann 
Published: May 2012

AbstractMonomers of 2‐acrylamido‐2‐methylpropane sulfonic acid (AMPS®), N,N–dimethyl acrylamide (NNDMA) and acrylic acid (AA) were grafted on humic acid as backbone by aqueous free radical copolymerization in such a manner that a graft copolymer possessing lateral terpolymer chains was obtained. Molar ratios between AMPS®, NNDMA, and AA were found to be 1 : 1.54 : 0.02 and the ratio between backbone and graft chain was 20 : 80 wt %. The synthesized fluid loss additive (FLA) was characterized by size exclusion chromatography (SEC), charge titration, and Brookfield viscometry. Thermogravimetric and SEC analysis revealed stretched backbone worm architecture for the polymer whereby humic acid constitutes the backbone decorated with lateral graft chains. Grafting was confirmed by SEC data (Rg) and by ineffectiveness of a blend of AMPS®‐NNDMA‐AA copolymer with humic acid. Their performance as high temperature FLA was studied at 150°C by measuring static filtration properties of oil well cement slurries containing 35% bwoc of silica fume and 1.2% bwoc AMPS®‐co‐itaconic acid retarder. At this temperature, 1.0% bwoc graft copolymer achieves API fluid loss value of 40 mL, thus confirming high effectiveness. The graft copolymer viscosifies cement slurries less than other common synthetic FLAs. The working mechanism of the graft copolymer was found to rely on adsorption onto surface of hydrating cement, as was evidenced by adsorption and zeta potential measurements. Adsorption is hardly affected by temperature and results in constriction of the filter cake pores. The study provides insight into performance of cement additives under the harsh conditions of high temperature and high pressure. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Preparation of polyester polyols from unsaturated fatty acid
Authors: Junming Xu , Jianchun Jiang , Jing Li 
Published: May 2012

AbstractOleic acid is a typical unsaturated fatty acid that is found widely in vegetable oils. The objective of this investigation was to produce a new type of oleic‐based polyol from oleic acid. Possible advantages of this approach include the production of high‐performance polyurethane materials from renewable resources and value‐added research for oleic acid. Oleic‐based polyols were synthesized by a three‐step process consisting of epoxidation and ring‐opening reaction, followed by esterification. The synthesized polyols appeared as a viscous liquid at room temperature with hydroxyl numbers from 307 to 425 mg KOH/g. Preparation of polyurethane foams using oleic‐based polyols and isocyanate was studied. An environmentally friendly blowing agent, HCFC‐141b, together with a small amount of water, was used. The synthesized foams were characterized by FTIR, SEM, and TG/DSC. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Effects of processing and functionalization methods on nylon‐6,6 nanocomposites with Helical‐ribbon carbon nanofibers
Authors: Rodriguez‐Pastor I. , Varela‐Rizo H. , Bortz D. R. , Montes de Oca G. , Guinea I. , Martin‐Gullon I. 
Published: May 2012

AbstractHelical‐ribbon carbon nanofiber‐based nylon‐6,6 nanocomposites were obtained by three processing methods: in situ polymerization, solvent processing through coagulation, and melt compounding. Composites were produced with pristine carbon nanofibers and four functionalization treatments, HNO3, O3, air/NH3, and ethylenediamine, which form sets of two liquid/gas phase treatments and two acidic/basic treatments. Dispersion was monitored at the microscale by optical microscopy, showing clear differences depending on processing and functionalization methods. The best dispersion was obtained by solvent processing, whereas the most appropriate functionalizations were obtained by air/NH3 and ethylenediamine treatments. It was observed that lower aspect ratio CNFs and stronger CNF‐matrix interaction increased crystallization temperature. Percolation was not detected in the melt‐compounded composites while network formation was observed at concentrations of 2 wt % in the solvent and in situ processing methods, where a high‐aspect ratio was critical for performance. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Biodegradation of Phormium tenax/poly(lactic acid) composites
Authors: Fortunati E. , Puglia D. , Santulli C. , Sarasini F. , Kenny J. M. 
Published: May 2012

AbstractThe disintegration patterns of composites produced by a melt compounding process using 0, 20, 30, and 40 wt % of Phormium tenax fibers in poly(lactic acid) (PLA) matrix were studied for a period of 40 days in composting conditions. The characterization of PLA and PLA/phormium composites included disintegration measurements, differential scanning calorimetry, FTIR analysis, thermogravimetric analysis, and scanning electron microscopy. The two controlling factors for disintegrability appeared to be the crystallinity of PLA and phormium fiber content: in general, the matrix tends to disintegrate completely before the 40 days and also phormium fibers undergo a substantial degradation during this period of time. Measurements taken at 10, 20, 30, and 40 days confirm that the disintegration process progresses steadily, though most of it takes place between 20 and 30 days. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Controlled release of nonionic compounds from poly(lactic acid)/cellulose nanocrystal nanocomposite fibers
Authors: Xiang Chunhui , Taylor Alan G. , Hinestroza Juan P. , Frey Margaret W. 
Published: May 2012

AbstractPoly(lactic acid)(PLA)/cellulose nanocrystal nanocomposite fibers were prepared by electrospinning at elevated temperature. Columbia Blue, a nonionic hydrophobic dye with a molecular weight and partition coefficient that mimics a systemic agrichemical, was incorporated into the fibers as a model compound. The release of Columbia Blue into water displayed little burst release. Diffusion‐controlled release of Columbia Blue was significantly influenced by the hydrophobicity of the electrospun PLA nanocomposite fibers and followed Fickian diffusion kinetics. The release of Columbia Blue by degradation‐controlled mechanism followed zero‐order, time‐independent Case II kinetics (n = 1.0). Increasing cellulose nanocrystal content in the fibers increased the fiber degradation rate and the Columbia Blue release rate. The plasticizing effect of Columbia Blue on the thermal properties of the electrospun nanocomposite fibers showed the miscibility of Columbia Blue inside the electrospun nanocomposite fibers. A greenhouse trial confirmed the anticipated trends of higher pesticide dosage causing higher whitefly mortality percentage. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2013
Shape memory properties of polycaprolactone‐based polyurethanes prepared by reactive extrusion
Authors: Weng Shengguang , Xia Zhean , Chen Jianding , Gong Luanluan 
Published: May 2012

AbstractThe shape memory properties of polycaprolactone‐based polyurethanes (PCLUs) synthesized via a novel route of reactive extrusion were investigated in terms of the deformation amplitude, temperature, and rate by differential scanning calorimetry (DSC), dynamic mechanical analyzer, and polarized optical microscopy (POM). DSC analysis shows that the crystalline melting temperature and crystallinity of PCLU increased monotonically with increasing the average polymerization degree
$ ( \overline {DPn}) $
of poly(ε‐caprolactone) (PCL) block. The retract force increased with increasing the temperature and reached the maximum (6–7 MPa) within 45–55°C. Furthermore, a modified model with two recovery stages was postulated to elucidate the shape memory process, which is visually presented by POM analysis. The two stages of tensile and compressive recovery are distinguished by the inflexion temperature, within 43–48°C and 64–66°C, respectively. The shape fixity is about 60–70% and can be improved to 100% by choosing proper deformation temperature. The tensile deformation recovery ratio was 80–98% due to the water absorption, whereas the compressive deformation recovery ratio was almost 100%. Besides, recovery tests show that the lowest recovery temperature ranged from 24 to 47°C was influenced by the deformation temperature, rate and the PCL block
$ ( \overline {DPn}) $. Thus, the shape memory properties can be adjusted according to different purposes. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Preparation of methacrylic acid‐grafted chitin using cerium (IV) ion and its application in adsorbing paraquat
Authors: Hsu Shih‐Tong , Lin Wen‐Churng , Hsiao Wen‐Feng , Lee Cheng‐Chieh , Pan Ting‐Chung , Wang Tzu‐Ta , Huang Yu‐Miao 
Published: May 2012

AbstractChitin‐grafted‐poly(methacrylic acid) (chi‐g‐PMAA) was synthesized and characterized as an adsorbent of paraquat. Chi‐g‐PMAA copolymers were prepared using various concentrations of ammonium cerium(IV) nitrate (Ce+4) to determine the optimal concentration of Ce+4. Grafting was verified by differential scanning calorimeter thermograms, FTIR, and solid‐state 13C‐NMR spectra. A representative chi‐g‐PMAA copolymer was neutralized to a sodium salt (chi‐g‐PMANa) and used to adsorb paraquat. The adsorption equilibrium data are strongly related to both the Langmuir and the Freundlich isotherms. The maximal adsorption capacity is 147.0 mg/g‐adsorbent. This value exceeds those of Fuller's earth and activated carbon, which are the most common binding agents that are currently used for paraquat. The results suggest that chi‐g‐PMANa has potential as a paraquat adsorbent. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Rectorite powder modified by butadiene‐styrene‐vinyl pyridine rubber: Structure and its dispersion in styrene‐butadiene rubber
Authors: Wang Lei , Wang Yi‐Qing , Zhang Li‐Qun , Wu You‐Ping 
Published: May 2012

AbstractRectorite (REC) powders modified by butadiene‐styrene‐vinyl pyridine rubber (VPR) were prepared by spray drying, designated as REC‐VPRs. X‐ray diffraction (XRD), Scanning electron microscope (SEM), and transmission electron microscopy (TEM) analyses showed that in the REC‐VPRs, VPR did not intercalate into the intergallery of layers. However, compared with REC, the layers of REC‐VPRs had more wrinkles and piled loosely. To strengthen the interfacial interaction between VPR and REC, a REC‐VPR was treated by volatilized hydrochloric acid, resulting in the formation of ion bonds between REC and VPR, according to Fourier transform infrared spectra measurements. XRD analyses revealed that the intercalated structure emerged in acid treated REC‐VPR filled styrene‐butadiene rubber (SBR). However, the better dispersion was observed for the SBR composite filled with REC‐VPR without acid treatment, indicating that a proper interfacial interaction between REC and VPR is the key to improve the dispersion of REC layers in SBR. Acid treatment did not improve the tensile and tear strengths of the SBR composite filled with REC‐VPR. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci., 2013