bluuebunny/crossref_metadata_2025_split huggingface dataset:
Thermal degradation of poly(3‐hydroxybutyrate) and poly(3‐hydroxybutyrate‐co‐3‐hydroxyvalerate) in drying treatment
Authors: Chen Yun , Chou I‐Ning , Tsai Ya‐Hui , Wu Ho‐Shing 
Published: June 2013

ABSTRACTThis study examines the isothermal treatment of poly(3‐hydroxybutyrate) (PHB) and poly(3‐hydroxybutyrate‐co‐3‐hydroxyvalerate) (PHBV) powders and films. The PHB and PHBV crystallinities were determined using X‐ray diffractometry, and shown to increase with temperature (130–150°C) and then decreased from 55% to 45% at 180°C. The crystal morphology of crystal planes (101) and (111) became sharp at a high temperature. The weight average molecular weight (Mw) of PHB decreased from 1,028,000 to 41,800 g/mol when heated at 180°C for 30 min. The molecular weight of PHB decreased more rapidly than that of PHBV with time. No peak signal was observed in gel permeation chromatography after heating at 150°C because the solubility of PHB changed with crystallinity. The thermal behaviors of PHB and PHBV were analyzed by differential scanning calorimetry and thermogravimetric analysis. The roughness, contact angle, and surface morphology of PHB and PHBV films were also measured to determine the surface properties. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 3659–3667, 2013
Cyclic alkyl ketene oligomers
Authors: Yoshida Yutaka , Isogai Akira 
Published: June 2013

ABSTRACTTwo alkyl ketene oligomers (AKOs) with almost 100% purities were prepared in high yields of 80–90% from palmitic acid chloride and alkyl ketene dimer (prepared from palmitic acid chloride) in the presence of amine promoters. Two AKOs thus obtained had quite similar molecular weights (1000–10,000), carbon/hydrogen contents, X‐ray diffraction patterns, solution‐state 13C‐NMR spectra, and water‐contact angles. However, two AKOs had different size‐exclusion chromatograms, differential scanning calorimetric curves, FTIR spectra, and solution‐state 13C‐NMR spectra for 13C‐labeled AKOs. Based on the 13C‐NMR spectra of 13C‐unlabeled AKOs, AKOs are likely to have cyclic structures, thus having the limited molecular weights of <10,000. The results of FTIR spectra and 13C‐NMR spectra of 13C‐labeled AKOs indicated that three different repeating units were linked with various molar ratios and various connection patterns and combinations, constituting the cyclic AKOs. As a result, 13C‐NMR spectra of 13C‐labeled AKOs showed quite a number of carbon signals due to various 13CO and 13CC structures present in AKOs. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 3668–3673, 2013
Synthesis and properties of a novel superabsorbent polymer composite from microwave irradiated waste material cultured Auricularia auricula and poly (acrylic acid‐co‐acrylamide)
Authors: Cheng Zhiqiang , Li Junfeng , Yan Juntao , Kang Lijuan , Ru Xin , Liu Mengzhu 
Published: June 2013

ABSTRACTA novel superabsorbent polymer composite was successfully synthesized from waste material cultured Auricularia auricula (WMCAA) and poly (acrylic acid‐co‐acrylamide) (P(AA‐co‐AM)) using microwave irradiation. Optimal synthesis conditions were determined by investigating the water absorbency of the superabsorbent composite. The effects associated with weight ratios of WMCAA, acrylamide (AM) monomers, initiators, and acrylic acid (AA) crosslinkers, as well as the degree of neutralization of AA were examined. The maximum water absorbencies were found to be 1548 g/g (distilled water) and 72 g/g (0.9% NaCl solution). Fourier transform infrared spectroscopy (FTIR) was applied to determine the molecular structure of the superabsorbent composite, and scanning electron microscopy (SEM) was used to demonstrate the characteristic compact and porous structure of the material. Further studies conducted via transmission electron microscopy (TEM) revealed the formation of a novel interpenetrating polymer network structure. Thermogravimetry/differential thermal (TG/DTG) analysis demonstrated improved thermal stability in the composite material compared with WMCAA. Additionally, high water absorption rates observed in the polymer during the swelling process indicated first‐order kinetics. The water absorption and adsorption of the superabsorbent composite were studied in a variety of fertilizer solutions, revealing an indirect relationship between water absorbing ability and fertilizer concentration. Conversely, a direct relationship was observed between absorbed fertilizer and fertilizer concentration. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 3674–3681, 2013
Robust Stabilization of Ship Course Via Convex Optimization
Authors: Yu Jiafeng , Yan Zhibin , Wang Jian , Li Qinsheng 
Published: June 2013

AbstractFor ship course control, this paper presents a novel nonlinear controller design method using the sum of squares (SOS) technique combined with the dual of Lyapunov's stability theorem based on density function. Varying load condition and ship speed are seen as uncertainty, so the robust nonlinear controller is designed based on the suggested method. Simulations are performed by taking an ocean‐going ship model as example.
Determination of the stress biomarker corticosterone in serum of tumor‐bearing mice by surrogate‐based liquid chromatography–tandem mass spectrometry
Authors: Kang Lei , Jiang Tao , Ge Xinxing , Peng Liang , Xie Ying , Luan Xin , Li Huafang , Rong Zhengxing , Qi Hong , Chen Hongzhuan 
Published: June 2013

ABSTRACTA simple, robust and specific liquid chromatography tandem mass spectrometry (LC‐MS/MS) method was developed and validated to determine the concentration of corticosterone (Cort) which is usually regarded as a stress biomarker in mouse serum. Since Cort is an endogenous hormone, a ‘surrogate analyte’ strategy was adopted using the stable isotope‐deuterated corticosterone as a surrogate of the authentic analyte to generate the calibration curve. With telmisartan as the internal standard, the analytes were extracted with methanol, ethanol and acetone (1:1:1, v/v/v) and separated on a XTerra C18 (2.1 × 50 mm, 3.5 µm) column using a mobile phase consisting of 0.2% formic acid in water–methanol (30:70, v/v). Detection was performed in multiple reaction monitoring mode with an electrospray ionization source operated in positive ion mode. The standard curves were linear (r2 > 0.999) over the dynamic range of 8.60–430 ng/mL, with a lower limit of quantification of 8.60 ng/mL. The intra‐ and inter‐assay precisions were less than 15.0% of the relative standard deviation. This method was further used for analysis of serum samples from C57B/L tumor‐bearing mice before and after the treatment of fluoxetine. Validation of the assay and its application to the analysis demonstrated that the method was applicable to determine meaningful changes in Cort concentrations in serum samples of the tumor‐bearing mice for the stress status evaluation. Copyright © 2013 John Wiley & Sons, Ltd.
Planar Chiral Iridium Complexes with the Δ‐TRISPHAT Anion: Toward the First Enantiopure o‐Quinone Methide π‐Complex
Authors: Moussa Jamal , Chamoreau Lise Marie , Amouri Hani 
Published: June 2013

ABSTRACTWe describe the resolution of a planar chiral cationic iridium complex [Cp*Ir(η5‐2‐methyl‐oxodienyl)][OT f] (2) following the counterion strategy, where anion metathesis by Δ‐TRISPHAT generates the two diastereomers (pR, pS)‐[Cp*Ir(η5‐2‐methyl‐oxodienyl)][Δ‐TRISPHAT] (3a, 3a'). Upon fractional crystallization both compounds were separated as confirmed by 1H nuclear magnetic resonance (NMR) and circular dichroism studies recorded in solution. The latter represents the key‐complex precursors for the enantioselective synthesis of metallated o‐quinone methide complexes (4a, 4a'). Chirality 25:449–454, 2013. © 2013 Wiley Periodicals, Inc.
Iron Nanoparticles Supported on Graphene Oxide: A Robust, Magnetically Separable Heterogeneous Catalyst for the Oxidative Cyanation of Tertiary Amines
Authors: Verma Deepak , Verma Sanny , Sinha Anil K. , Jain Suman L. 
Published: June 2013

AbstractWell‐dispersed iron nanoparticles supported on chemically derived graphene oxide containing uniform distribution of iron nanoparticles (FeNPs) throughout the surface was synthesized and was used as a heterogeneous catalyst for oxidative cyanation of tertiary amines to the corresponding α‐aminonitriles in high to excellent yields using hydrogen peroxide with sodium cyanide in acetic acid. After the reaction the catalyst could easily be separated by the influence of an external magnet and reused for several runs without any significant change in the catalytic activity and without leaching of the metal during the reaction.
Interpersonal Factors Associated with Depression in Adolescents: Are These Consistent with Theories Underpinning Interpersonal Psychotherapy?
Authors: O'Shea Gabrielle , Spence Susan H. , Donovan Caroline L. 
Published: June 2013

The aim of this study was to investigate whether depressed adolescents differed from non‐depressed adolescents in terms of constructs consistent with those that are proposed to underpin interpersonal psychotherapy. In particular, it was hypothesized that compared with non‐depressed adolescents, depressed adolescents would demonstrate a greater number of negative life events associated with interpersonal loss and major life transitions, a more insecure attachment style and poorer communication skills, interpersonal relationships and social support. Thirty‐one clinically diagnosed depressed adolescents were matched with 31 non‐depressed adolescents on age, gender and socio‐economic status. The 62 participants were aged between 12 and 19 years and comprised 18 male and 44 female adolescents. On a self‐report questionnaire, depressed adolescents reported a greater number of negative interpersonal life events, a less secure attachment style and scored higher on all insecure attachment styles compared with the non‐depressed adolescents. In addition, depressed adolescents demonstrated lower levels of social skill (on both adolescent and parent report), a poorer quality of relationship with parents (on both adolescent and parent report) and lower social competence (adolescent report only). Parents of depressed adolescents also reported more negative parental attitudes and behaviours towards their adolescent compared with parents of non‐depressed adolescents. Thus, the results of this study are consistent with the constructs underlying interpersonal psychotherapy and suggest their usefulness in the assessment, conceptualization and treatment of adolescent depression. Clinical implications are discussed. Copyright © 2013 John Wiley & Sons, Ltd.Key Practitioner MessageIssues relating to interpersonal stress and loss, poor interpersonal relationships, insecure attachment style, and poor social skills are evident among depressed adolescents in comparison with their non‐depressed peers.Although it is not clear whether these factors are causal in the development of depression or if they reflect a consequence or concomitant of the disorder, it is important that clinicians consider these variables in the case formulation.Interpersonal psychotherapy addresses these variables through a focus on handling interpersonal conflicts, role transitions and interpersonal losses, and building social support and social skills.
Modeling implications of food resource aggregation on animal migration phenology
Authors: Bailleul Frédéric , Grimm Volker , Chion Clément , Hammill Mike 
Published: June 2013

AbstractThe distribution of poikilotherms is determined by the thermal structure of the marine environment that they are exposed to. Recent research has indicated that changes in migration phenology of beluga whales in the Arctic are triggered by changes in the thermal structure of the marine environment in their summering area. If sea temperatures reflect the spatial distribution of food resources, then changes in the thermal regime will affect how homogeneous or clumped food is distributed. We explore, by individual‐based modelling, the hypothesis that changes in migration phenology are not necessarily or exclusively triggered by changes in food abundance, but also by changes in the spatial aggregation of food. We found that the level of food aggregation can significantly affect the relationship between the timing of the start of migration to the winter grounds and the total prey capture of individuals. Our approach strongly indicates that changes in the spatial distribution of food resources should be considered for understanding and quantitatively predicting changes in the phenology of animal migration.
Enantioselective Synthesis of Succinimides by Michael Addition of Aldehydes to Maleimides Organocatalyzed by Chiral Primary Amine‐Guanidines
Authors: Avila Angel , Chinchilla Rafael , Gómez‐Bengoa Enrique , Nájera Carmen 
Published: June 2013

AbstractThe monoguanylation of (1S,2S)‐ and (1R,2R)‐cyclohexane‐1,2‐diamine affords chiral primary amine‐guanidines that are used as chiral organocatalysts in the enantioselective Michael addition of aldehydes, particularly α,α‐disubstituted aldehydes, to maleimides. The reaction is carried out in the presence of imidazole, as an additive, in aqueous N,N‐dimethylformamide, as the solvent, and affords the corresponding enantioenriched succinimides in high or quantitative yields with enantioselectivities up to 96 % ee. Theoretical calculations (DFT and M06–2X) suggest a different hydrogen‐bonding coordination pattern between the maleimide (C=O) and the catalyst (NH groups) is responsible for the enantioinduction switch that is observed when the reaction is carried out using primary amine‐guanidines versus primary amine‐thioureas as the organocatalysts.
The Effect of Lewis Acids on the Cycloaddition of 3,3,6‐Trimethylcyclohex‐5‐ene‐1,2,4‐trione: Hydrogen Transfer versus Cycloaddition with Cyclopentadiene
Authors: Eddy Nicholas A. , Richardson Jay J. , Fenteany Gabriel 
Published: June 2013

AbstractExposure of 3,3,6‐trimethylcyclohex‐5‐ene‐1,2,4‐trione to catalytic amounts of Lewis acids revealed two disparate reactions in the presence of cyclopentadiene. The expected cycloaddition was found to be reversible for the title compound, and transfer hydrogenation was the preferred pathway over long periods of time. Other tested substrates were able to undergo facile cycloaddition with considerable yields and without the parallel reduction.
Communicating geomorphology: global challenges for the twenty‐first century
Authors: Gregory Kenneth J. , Lane Stuart N. , Lewin John , Ashworth Philip J. , Downs Peter W. , Kirkby Michael J. , Viles Heather A. 
Published: June 2013

ABSTRACTThe British Society for Geomorphology (BSG), established as the British Geomorphological Research Group (BGRG) in 1960, is considering how best to represent geomorphology and geomorphologists in the light of recent changes in the nature of communication. These changes provide the BSG and other academic societies with challenges and opportunities. Seven drivers of communication change are outlined: the changing position of geomorphology in higher education, the nature of academic interaction, the means of communication available, a transformation in the nature of geomorphological research, changes in funding support, the government role in resource allocation, and developments in quantifying international research impact. Challenges arising from changing communications are identified as occurring beyond the ‘academy’, in the nature of publication within the ‘academy’, and associated with meetings of the ‘academy’. Although national societies now have to contemplate significantly different purposes to provide for their members than in the twentieth century, there are opportunities available that cannot be fulfilled by international organizations alone. Copyright © 2013 John Wiley & Sons, Ltd.
Promoter hypermethylation of CDKN2A, MGMT, MLH1, and DAPK genes in laryngeal squamous cell carcinoma and their associations with clinical profiles of the patients
Authors: Pierini Stefano , Jordanov Stanislav H. , Mitkova Atanaska V. , Chalakov Ivan J. , Melnicharov Mincho B. , Kunev Kuncho V. , Mitev Vanio I. , Kaneva Radka P. , Goranova Teodora E. 
Published: June 2013

AbstractBackgroundLaryngeal squamous cell carcinoma (laryngeal SCC) is a frequently occurring cancer of the head and neck area. Epigenetic changes of tumor‐related genes contribute to its genesis and progression.MethodsWe assessed promoter methylation status of the selected genes (CDKN2A, MGMT, MLH1, and DAPK) using methylation‐sensitive high resolution melting (MS‐HRM) in 100 patients with laryngeal SCC and studied the correlations with clinical characteristics.ResultsThe prevalence of promoter methylation in MGMT, CDKN2A, MLH1, and DAPK was 59 of 97 (60.8%), 46 of 97 (47.4%), 45 of 97 (46.4%), and 41 of 97 patients (42.3%), respectively. Significantly increased methylation of CDKN2A was observed in heavy smokers. Epigenetic inactivation of CDKN2A and MLH1 were found to be associated with lymph node involvement. An inverse correlation was present between MLH1 methylation and alcohol consumption.ConclusionOur results strongly suggest that deregulation of p16‐associated, and MLH1‐associated pathways, because of promoter hypermethylation, is associated with increased cancer cell migration, tumor invasiveness, and, thus, aggressive phenotype. © 2013 Wiley Periodicals, Inc. Head Neck 36: 1103–1108, 2014
Unusual case of Cowden‐like syndrome, neck paraganglioma, and pituitary adenoma
Authors: Efstathiadou Zoe A. , Sapranidis Michail , Anagnostis Panagiotis , Kita Marina D. 
Published: June 2013

BackgroundPituitary tumors, paragangliomas, and Cowden syndrome do not usually occur together.MethodsThe synchronous presentation of papillary thyroid carcinoma and neck paraganglioma was revealed in a 43‐year‐old woman who had been diagnosed with a microprolactinoma one decade before and now presented with a constellation of characteristics that are components of Cowden syndrome, specifically macrocephaly, multiple skin papules, fibrocystic mammary disease, and uterine leiomyofibroma.ResultsGermline mutation analysis of phosphatase and tensin homolog (PTEN), succinate dehydrogenase subunit B (SDHB), succinate dehydrogenase subunit C (SDHC), and succinate dehydrogenase subunit D (SDHD) was performed with revelation of 3 polymorphic sites in introns 1, 4, and 8 of the PTEN gene and 1 polymorphic site in exon 1 of the SDHB gene, but absence of known pathogenic mutations.ConclusionThe coexistence of Cowden‐like syndrome, neck paraganglioma, and pituitary adenoma is described for the first time, and could represent a novel genetic syndrome with an as yet unidentified common genetic basis. © 2013 Wiley Periodicals, Inc. Head Neck 36: E12–E16, 2014
Psychosocial functioning and vascular endothelial growth factor in patients with head and neck cancer
Authors: Fang Carolyn Y. , Egleston Brian L. , Ridge John A. , Lango Miriam N. , Bovbjerg Dana H. , Studts Jamie L. , Burtness Barbara A. , Einarson Margret B. , Klein–Szanto Andres J. P. 
Published: June 2013

AbstractBackgroundPsychosocial functioning is associated with vascular endothelial growth factor (VEGF) in various patient populations. This study examined whether psychosocial functioning in patients with head and neck squamous cell carcinoma (HNSCC) is associated with tumor VEGF expression, a protein that stimulates angiogenesis and is associated with poor prognosis.MethodsForty‐two newly diagnosed patients completed assessments of psychosocial functioning (ie, depressive symptoms, perceived stress, anxiety, social support) before surgery. Tumor samples were obtained for VEGF analysis and human papillomavirus (HPV)‐typing.ResultsPoorer psychosocial functioning was associated with greater VEGF expression controlling for disease stage (odds ratio [OR], 4.55; 95% confidence interval [CI], 1.72–12.0; p < .01). When examined by HPV status, the association between psychosocial functioning and VEGF remained significant among patients who were HPV negative (OR, 5.50; 95% CI, 1.68–17.3; p < .01), but not among patients who were HPV positive.ConclusionThese findings inform our understanding of the biobehavioral pathways that may contribute to poor outcomes in non‐HPV‐associated HNSCCs. © 2013 Wiley Periodicals, Inc. Head Neck 36: 1113–1119, 2014
MicroRNA‐23a modulates tumor necrosis factor‐alpha‐induced osteoblasts apoptosis by directly targeting fas
Authors: Dong Jun , Cui Xingang , Jiang Zhensong , Sun Jianmin 
Published: June 2013

ABSTRACTTumor necrosis factor (TNF)‐alpha is a key cytokine regulator of bone and mediates inflammatory bone loss. The molecular signaling that regulates bone loss downstream of TNF‐alpha is poorly defined. Recent studies implicated an important role of microRNAs (miRNAs) in TNF‐alpha‐mediated bone metabolism, including osteoblasts differentiation, osteoclasts differentiation and apoptosis. However, there are very few studies on the complex regulation of miRNAs during TNF‐alpha‐induced osteoblasts apoptosis. In the present study, the clonal murine osteoblastic cell line, MC3T3‐E1, was used. We screened for differentially expressed miRNAs during TNF‐alpha induced MC3T3‐E1 cell apoptosis and identified microRNA‐23a as a potential inhibitor of apoptosis. To delineate the role of microRNA‐23a in apoptosis, we respectively silenced and overexpressed microRNA‐23a in MC3T3‐E1 cells. We found that microRNA‐23a depletion significantly enhances TNF‐alpha‐induced MC3T3‐E1 cell apoptosis and over‐expressing microRNA‐23a remarkably attenuates this phenomenon. Mechanistic studies showed that microRNA‐23a inhibits Fas expression through a microRNA‐23a‐binding site within the 3′‐untranslational region of Fas. The post‐transcriptional repression of Fas was further confirmed by luciferase reporter assay. These results showed that microRNA‐23a, an important protecting factor, plays a significant role in the process of TNF‐alpha induced MC3T3‐E1 cell apoptosis, by regulating Fas expression. J. Cell. Biochem. 114: 2738–2745, 2013. © 2013 Wiley Periodicals, Inc.
Chemiluminescence of Colloidal MnO2 with Luminol and Determination of Polyhydroxyl Compounds
Authors: Li Yinhuan , Yang Yun 
Published: June 2013

AbstractThe reaction between luminol and colloidal MnO2 (prepared by chemical reduction of KMnO4 with Na2S2O3 under neutral aqueous condition) produced an intense chemiluminescence (CL) emission in alkaline medium. The CL reaction conditions were carefully optimized and the CL reaction mechanism was thoroughly discussed. Manganese(III) was suggested to be involved in the reaction and 3‐aminophthalate anion was the luminophor. Moreover, the effects of 23 compounds on the colloidal MnO2‐luminol CL system were investigated to explore its possible analytical applications. Polyhydroxyl compounds were observed to inhibit the signal significantly, whereas sulfhydryl compounds enhance it slightly. The analytical figures for five polyhydroxyl compounds, namely ascorbic acid, rutin, pyrogallol, quercetin, and L‐adrenaline, were presented. As a preliminary application, the method was applied to the determination of rutin in pharmaceutical formulations.