bluuebunny/crossref_metadata_2025_split huggingface dataset:
The flame retardant group‐synergistic‐effect of a phosphaphenanthrene and triazine double‐group compound in epoxy resin
Authors: Qian Lijun , Qiu Yong , Liu Jing , Xin Fei , Chen Yajun 
Published: September 2013

ABSTRACTA flame retardant tri‐(phosphaphenanthrene‐(hydroxyl‐methylene)‐phenoxyl)‐1, 3, 5‐triazine (Trif‐DOPO) and its control samples are incorporated into diglycidyl ether of bisphenol‐A (DGEBA) and 4, 4′‐diamino‐diphenyl sulfone (DDS) to prepare flame retardant thermosets, respectively. According to the results of limited oxygen index (LOI), UL94 vertical burning test and cone calorimeter test, the Trif‐DOPO/DGEBA/DDS thermoset with 1.2 wt % phosphorus possesses the LOI value of 36% and UL94 V‐0 flammability rating, and Trif‐DOPO can decrease the peak of heat release rate (pk‐HRR) and reduce the total heat release (THR) of thermosets. All these prove better flame retardant performance of Trif‐DOPO than that of 9,10‐dihydro‐9‐oxa‐10‐phosphaphenanthrene‐10‐oxide(DOPO). The residue photos of thermosets after cone calorimetry test disclose that Trif‐DOPO can promote the formation of thick and tough melting char layer for combined action of the flame retardant groups of Trif‐DOPO. The results from thermo gravimetric analysis (TGA) and pyrolysis‐gas chromatography‐mass spectrometry(Py‐GC/MS) show that the groups in Trif‐DOPO can be decomposed and produce PO2 fragments, phosphaphenanthrene and phenoxy fragments, which can jointly quench the free radical chain reaction during combustion. Therefore, the excellent flame retardancy of Trif‐DOPO is attributed to its flame retardant group‐synergic‐effect. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 39709.
Preparation and characteristic of a sodium alginate/carboxymethylated bacterial cellulose composite with a crosslinking semi‐interpenetrating network
Authors: Lin Qinghua , Zheng Yudong , Ren Lingling , Wu Jian , Wang Hong , An Jiaxin , Fan Wei 
Published: September 2013

ABSTRACTA novel ionic crosslinking sodium alginate (SA)/carboxymethylated bacterial cellulose (CM‐BC) composite with a semi‐interpenetrating polymer network (semi‐IPN) structure was developed in this study. The composite was prepared through the blending of an SA gel with CM‐BC then crosslinking by Ca2+ followed by a freeze‐drying process. Scanning electron microscopy showed the composite matrix organized in a three‐dimensional network of CM‐BC interpenetrated against SA molecular chains with a quantity of calcium alginate microspheres upon the surface. The swelling ratios of the composite were enhanced by 183, 198, and 212% with the supplementation of CM‐BC weight fractions of 25, 50, and 75%, respectively; the swelling ratios changed with changing pH. The tensile modulus, tensile strength, and elongation at break of SA were enhanced by 165, 152, and 188%, respectively, with the addition of 50 wt % CM‐BC. This study demonstrated that the semi‐IPN structure dramatically changed the swelling and mechanical properties of the composite, and the semi‐IPN will be a promising candidate for biomedical applications such as wound dressings and skin tissue engineering. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 39848.
Stable carbon and nitrogen isotopes as indicators of sedentism and territoriality in late Holocene South Australia
Authors: Pate F. Donald , Owen Timothy D. 
Published: September 2013

AbstractPrevious research has presented hypotheses concerning the presence of widespread Aboriginal sedentism in coastal and riverine South Australia during the past 5000 years. These hypotheses were based on biological distance data (metric and non‐metric), isotopic analyses at the inland Roonka Flat site and the emergence of large, well‐defined cemeteries throughout the region. Stable carbon and nitrogen isotope data for a large burial population at the Swanport archaeological site in the lower Murray River Basin of South Australia, near the coastal river mouth, provide additional evidence for the presence of hunter–gatherer sedentism and territoriality during the late Holocene. Stable isotope research provides a powerful method to examine subsistence‐settlement systems and social relations in prehistoric populations.
A Caged, Destabilized, Free Radical Intermediate in the Q‐Cycle
Authors: Vennam Preethi R. , Fisher Nicholas , Krzyaniak Matthew D. , Kramer David M. , Bowman Michael K. 
Published: September 2013

AbstractThe Rieske/cytochrome b complexes, also known as cytochrome bc complexes, catalyze a unique oxidant‐induced reduction reaction at their quinol oxidase (Qo) sites, in which substrate hydroquinone reduces two distinct electron transfer chains, one through a series of high‐potential electron carriers, the second through low‐potential cytochrome b. This reaction is a critical step in energy storage by the Q‐cycle. The semiquinone intermediate in this reaction can reduce O2 to produce deleterious superoxide. It is yet unknown how the enzyme controls this reaction, though numerous models have been proposed. In previous work, we trapped a Q‐cycle semiquinone anion intermediate, termed SQo, in bacterial cytochrome bc1 by rapid freeze‐quenching. In this work, we apply pulsed‐EPR techniques to determine the location and properties of SQo in the mitochondrial complex. In contrast to semiquinone intermediates in other enzymes, SQo is not thermodynamically stabilized, and can even be destabilized with respect to solution. It is trapped in Qo at a site that is distinct from previously described inhibitor‐binding sites, yet sufficiently close to cytochrome bL to allow rapid electron transfer. The binding site and EPR analyses show that SQo is not stabilized by hydrogen bonds to proteins. The formation of SQo involves “stripping” of both substrate ‐OH protons during the initial oxidation step, as well as conformational changes of the semiquinone and Qo proteins. The resulting charged radical is kinetically trapped, rather than thermodynamically stabilized (as in most enzymatic semiquinone species), conserving redox energy to drive electron transfer to cytochrome bL while minimizing certain Q‐cycle bypass reactions, including oxidation of prereduced cytochrome b and reduction of O2.
Cooperative Catalysis: Combining an Achiral Metal Catalyst with a Chiral Brønsted Acid Enables Highly Enantioselective Hydrogenation of Imines
Authors: Tang Weijun , Johnston Steven , Li Chaoqun , Iggo Jonathan A. , Bacsa John , Xiao Jianliang 
Published: September 2013

AbstractAsymmetric hydrogenation of imines leads directly to chiral amines, one of the most important structural units in chemical products, from pharmaceuticals to materials. However, highly effective catalysts are rare. This article reveals that combining an achiral pentamethylcyclopentadienyl (Cp*)–iridium complex with a chiral phosphoric acid affords a catalyst that allows for highly enantioselective hydrogenation of imines derived from aryl ketones, as well as those derived from aliphatic ones, with ee values varying from 81 to 98 %. A range of achiral iridium complexes containing diamine ligands were examined, for which the ligands were shown to have a profound effect on the reaction rate, enantioselectivity and catalyst deactivation. The chiral phosphoric acid is no less important, inducing enantioselection in the hydrogenation. The induction occurs, however, at the expense of the reaction rate.
Concealed Cyclotrimeric Polymorph of Lithium 2,2,6,6‐Tetramethylpiperidide Unconcealed: X‐Ray Crystallographic and NMR Spectroscopic Studies
Authors: Hevia Eva , Kennedy Alan R. , Mulvey Robert E. , Ramsay Donna L. , Robertson Stuart D. 
Published: September 2013

AbstractLithium 2,2,6,6‐tetramethylpiperidide (LiTMP), one of the most important polar organometallic reagents both in its own right and as a key component of ate compositions, has long been known for its classic cyclotetrameric (LiTMP)4 solid‐state structure. Made by a new approach through transmetalation of Zn(TMP)2 with tBuLi in n‐hexane solution, a crystalline polymorph of LiTMP has been uncovered. X‐ray crystallographic studies at 123(2) K revealed this polymorph crystallises in the hexagonal space group P63/m and exhibited a discrete cyclotrimeric (C3h) structure with a strictly planar (LiN)3 ring containing three symmetrically equivalent TMP chair‐shaped ligands. The molecular structure of (LiTMP)4 was redetermined at 123(2) K, because its original crystallographic characterisation was done at ambient temperature. This improved redetermination confirmed a monoclinic C2/c space group with the planar (LiN)4 ring possessing pseudo (non‐crystallographic) C4h symmetry. Investigation of both metalation and transmetalation routes to LiTMP under different conditions established that polymorph formation did not depend on the route employed but rather the temperature of crystallisation. Low‐temperature (freezer at −35 °C) cooling of the reaction solution favoured (LiTMP)3; whereas high‐temperature (bench) storage favoured (LiTMP)4. Routine 1H and 13C NMR spectroscopic studies in a variety of solvents showed that (LiTMP)3 and (LiTMP)4 exist in equilibrium, whereas 1H DOSY NMR studies gave diffusion coefficient results consistent with their relative sizes.
Synthesis and Structure of Organobismuth Chlorides and Triflates Containing (C,E)‐Chelating Ligands (E=O, S) and Their Catalytic Application in the Allylation of Aldehydes with Tetraallyltin
Authors: Tan Nianyuan , Chen Yi , Zhou Yongbo , Au Chak‐Tong , Yin Shuang‐Feng 
Published: September 2013

AbstractFour air‐stable hypervalent organobismuth compounds with (C,O)‐ or (C,S)‐chelating ligands, namely, R2BiCl (R=2‐(MeECH2)C6H4; E=O (3), S (4)), [2‐(MeOCH2)C6H4]2BiOTf (5), and [{2‐(MeSCH2)C6H4}2Bi][OTf] (6; OTf=triflate) were successfully synthesized. The structures of compounds 3–6 were determined by single‐crystal X‐ray diffraction. Compound 6 comprises the [2‐(MeSCH2)C6H4]2Bi+ cation and the OTf− anion. Compounds 5 exhibited good catalytic efficiency and reusability for the allylation reaction of different aldehydes with tetraallyltin in methanol to give the corresponding homoallylic alcohols in excellent yields.
Long‐term metapopulation study of the Glanville fritillary butterfly (Melitaea cinxia): survey methods, data management, and long‐term population trends
Authors: Ojanen Sami P. , Nieminen Marko , Meyke Evgeniy , Pöyry Juha , Hanski Ilkka 
Published: September 2013

AbstractLong‐term observational studies conducted at large (regional) spatial scales contribute to better understanding of landscape effects on population and evolutionary dynamics, including the conditions that affect long‐term viability of species, but large‐scale studies are expensive and logistically challenging to keep running for a long time. Here, we describe the long‐term metapopulation study of the Glanville fritillary butterfly (Melitaea cinxia) that has been conducted since 1991 in a large network of 4000 habitat patches (dry meadows) within a study area of 50 by 70 km in the Åland Islands in Finland. We explain how the landscape structure has been described, including definition, delimitation, and mapping of the habitat patches; methods of field survey, including the logistics, cost, and reliability of the survey; and data management using the EarthCape biodiversity platform. We describe the long‐term metapopulation dynamics of the Glanville fritillary based on the survey. There has been no long‐term change in the overall size of the metapopulation, but the level of spatial synchrony and hence the amplitude of fluctuations in year‐to‐year metapopulation dynamics have increased over the years, possibly due to increasing frequency of exceptional weather conditions. We discuss the added value of large‐scale and long‐term population studies, but also emphasize the need to integrate more targeted experimental studies in the context of long‐term observational studies. For instance, in the case of the Glanville fritillary project, the long‐term study has produced an opportunity to sample individuals for experiments from local populations with a known demographic history. These studies have demonstrated striking differences in dispersal rate and other life‐history traits of individuals from newly established local populations (the offspring of colonizers) versus individuals from old, established local populations. The long‐term observational study has stimulated the development of metapopulation models and provided an opportunity to test model predictions. This combination of empirical studies and modeling has facilitated the study of key phenomena in spatial dynamics, such as extinction threshold and extinction debt.
A Synthetic Approach to Tetrasubstituted Alkenes: Using β‐Carbonyl Benzothiazol‐2‐yl Sulfones as Electrophiles
Authors: Ou Song , Cao Chun‐Ru , Jiang Min , Liu Jin‐Tao 
Published: September 2013

AbstractA novel olefination method based on the modified Julia olefination reaction was developed. The reactions of β‐carbonyl benzothiazol‐2‐yl sulfones with a series of alkynyllithiums and TMSCN gave the corresponding β‐alkoxy sulfone intermediates, which underwent facile Smiles rearrangement and spontaneous elimination to yield tetrasubstituted enynes and cyanoalkenes, respectively.
Physical Activity Correlates in Persons with Binge Eating Disorder: A Systematic Review
Authors: Vancampfort Davy , Vanderlinden Johan , Stubbs Brendon , Soundy Andrew , Pieters Guido , Hert Marc De , Probst Michel 
Published: September 2013

AbstractUnderstanding the factors that influence physical activity in persons with binge eating disorders can aid the design of more effective interventions. In order to address this, the present paper provides a systematic quantitative review of the correlates of physical activity in people with binge eating disorder. We searched PsycINFO, PubMed and PEDro from inception until June 2013. Keywords included ‘binge eating’ with ‘physical activity’ or ‘exercise’, or ‘physical inactivity’ or ‘sedentary’. Nine papers involving 636 (489 women) persons with binge eating disorders and evaluating 24 correlates were included. No consistent physical activity correlates were reported in four or more studies. The only significant correlate with lower physical activity participation reported in more than one study was a negative body attitude. Further research is required to address this current gap in literature. Copyright © 2013 John Wiley & Sons, Ltd and Eating Disorders Association.
Si‐Doped B12N12 Nanocage as an Adsorbent for Dissociation of N2O to N2 Molecule
Authors: Baei Mohammad T. 
Published: September 2013

ABSTRACTAdsorption of N2O molecule by using density functional theory calculations at the B3LYP/6–31G* level onto pristine and Si‐doped B12N12 nanocage in terms of energetic, geometric, and electronic properties was investigated. The results of calculations showed that the N2O molecule is physically adsorbed on the pristine and Si‐doped B12N12 (SiN) models, releasing energies in the range of –1.13 to –2.02 kcal mol−1. It was found that the electronic properties of the models have not changed significantly upon the N2O adsorption. On the other hand, the adsorption energy of N2O on the Si‐doped B12N12 (SiB model) was about –67.20 kcal mol−1and the natural bond orbital charge of 0.58|e| is transferred from the nanocage to the N2O molecule. In the configuration, the O atom of N2O molecule is bonded to the Si atom of the nanocage, so that an N2 molecule escapes from the wall of the nanocage. The results showed that the SiB model can be an adsorbent for dissociation of the N2O molecule.
A high resolution multi‐view 3D display using switchable liquid crystal lens
Authors: Yang Yingbao , Koito Takeo , Takasaki Naoyuki 
Published: September 2013

AbstractA 4.4‐inch 2D/3D switchable full high definition (FHD) six‐view 3D display with 3D resolution greater than 170 ppi has been accomplished. In addition to adopting low temperature polysilicon technology (LTPS), which is most suitable for high resolution displays, a new RGBW pixel arrangement using four‐square sub‐pixels has been devised. In 2D, a resolution greater than 500 ppi, accompanied with high luminance, has been achieved. A new liquid crystal lens (LCL) has been exploited for 2D/3D switching. By employing a special multielectrode structure and dedicated manufacturing process, an optical focal ratio less than 20%, which is essential for low 3D cross talk for a six‐view 3D display, has been attained by adopting the LCL. In the vertical direction of the display, there is no cross talk increase when the viewing position is changed because of the new pixel structure. The strong focal strength of the LCL combined with a revised high‐density multi‐view design give rise to a wide 3D viewing angle greater than 20 degrees in the horizontal direction and minimum cross talk less than 10%.
Extranodal metastasis is a powerful prognostic factor in patients with adenocarcinoma of the esophagogastric junction
Authors: Zhang Hong‐Dian , Tang Peng , Duan Xiao‐Feng , Chen Chuan‐Gui , Ma Zhao , Gao Yong‐Yin , Zhang Hua , Yu Zhen‐Tao 
Published: September 2013

AbstractBackground and ObjectivesThe purpose of this study is to estimate the effect of extranodal metastasis (EM) on recurrence and survival in patients with adenocarcinoma of the esophagogastric junction (AEG) after curative resection.MethodsClinical data from 284 node‐positive AEG patients who underwent curative resection were reviewed. Univariate and multivariate analyses were conducted to elucidate the effect of EM on recurrence‐free survival (RFS) and overall survival (OS).ResultsEM was detected in 70 (24.6%) of the 284 cases. It had a significant correlation with tumor size, Lauren type, histopathological grading, depth of tumor invasion, number of metastatic nodes, lymph node ratio, and TNM stage. The 5‐year RFS and OS rates were 22.2% and 24.3%, respectively. Patients with EM had a significantly decreased RFS (16 vs. 36 months, P < 0.001) and OS (23 vs. 41 months, P < 0.001) compared with those without EM. Multivariate analyses identified EM as an independent prognostic factor (P = 0.003 and 0.001, respectively).ConclusionThe presence of EM increases recurrence probability and reduces OS probability of AEG patients with lymph node metastasis. EM is a powerful prognostic factor reflecting a particularly aggressive biological behavior. Better understanding of EM status can help clinicians with regard to treatment decision and prognosis evaluation. J. Surg. Oncol. 2013; 108:542–549. © 2013 Wiley Periodicals, Inc.
The cytoplasmic PASC domain of the sensor kinase DcuS of Escherichia coli: role in signal transduction, dimer formation, and DctA interaction
Authors: Monzel Christian , Degreif‐Dünnwald Pia , Gröpper Christina , Griesinger Christian , Unden Gottfried 
Published: September 2013

AbstractThe cytoplasmic PASC domain of the fumarate responsive sensor kinase DcuS of Escherichia coli links the transmembrane to the kinase domain. PASC is also required for interaction with the transporter DctA serving as a cosensor of DcuS. Earlier studies suggested that PASC functions as a hinge and transmits the signal to the kinase. Reorganizing the PASC dimer interaction and, independently, removal of DctA, converts DcuS to the constitutive ON state (active without fumarate stimulation). ON mutants were categorized with respect to these two biophysical interactions and the functional state of DcuS: type I‐ON mutations grossly reorganize the homodimer, and decrease interaction with DctA. Type IIA‐ON mutations create the ON state without grossly reorganizing the homodimer, whereas interaction with DctA is decreased. The type IIB‐ON mutations were neither in PASC/PASC, nor in DctA/DcuS interaction affected, similar to fumarate activated wild‐typic DcuS. OFF mutations never affected dimer stability. The ON mutations provide novel mechanistic insight: PASC dimerization is essential to silence the kinase. Reorganizing the homodimer and its interaction with DctA activate the kinase. The study suggests a novel ON homo‐dimer conformation (type IIB) and an OFF conformation for PASC. Type IIB‐ON corresponds to the fumarate induced wild‐type conformation, representing an interesting target for structural biology.
Role of mitogen‐activated protein kinases and Mcl‐1 in apoptosis induction by withaferin A in human breast cancer cells
Authors: Hahm Eun‐Ryeong , Lee Joomin , Singh Shivendra V. 
Published: September 2013

AbstractWithaferin A (WA), a bioactive constituent of Ayurvedic medicine plant Withania somnifera, is a potent apoptosis inducer in cancer cells but the mechanism of cell death induction is not fully characterized. The present study was undertaken to determine the role of mitogen‐activated protein kinases (MAPK), including c‐jun NH2‐terminal kinase (JNK), extracellular signal‐regulated kinase (ERK), and p38 MAPK, and anti‐apoptotic protein myeloid cell leukemia‐1 (Mcl‐1) in regulation of WA‐induced apoptosis using human breast cancer cells. Exposure of MCF‐7 (estrogen responsive) and SUM159 (triple negative) human breast cancer cells to WA resulted in increased phosphorylation of ERK, JNK, and p38 MAPK, but these effects were relatively more pronounced in the former cell line than in SUM159. Overexpression of manganese‐superoxide dismutase conferred partial protection against WA‐mediated hyperphosphorylation of ERK, but not JNK or p38 MAPK. Cell death resulting from WA treatment in MCF‐7 cells was significantly augmented by pharmacological inhibition of ERK and p38 MAPK. Interestingly, the WA‐induced apoptosis in MCF‐7 cells was partially but significantly blocked in the presence of a JNK‐specific inhibitor. Pharmacological inhibition of ERK or JNK had no effect on WA‐induced apoptosis in SUM159 cells. The WA‐treated cells exhibited induction of long and short forms of Mcl‐1. RNA interference of Mcl‐1 alone triggered apoptosis. Furthermore, the WA‐induced cell death in MCF‐7 cells was modestly but significantly augmented by knockdown of the Mcl‐1 protein. These observations indicate that: MAPK have cell line‐specific role in cell death by WA, and Mcl‐1 induction confers modest protection against WA‐induced apoptosis. © 2013 Wiley Periodicals, Inc.
Zwischen Protein und Membran
Authors: Silva Daniel Varón 
Published: September 2013

AbstractSpezielle Glykolipide verankern eukaryotische Proteine an der äußeren Zellmembran. Bislang ist jedoch wenig über die Funktionen dieser Glykosylphosphatidylinositole bekannt. Erkenntnisse über ihre biologischen Eigenschaften lassen sich mit synthetischen Molekülen gewinnen.
FTIR‐Spektroskopie im Ultrahochvakuum: Messung an TiO2‐Pulver
Authors: Stammer Xia , Heißler Stefan 
Published: September 2013

AbstractDie Zahl der Defektstellen auf der Rutiloberfläche ist maßgebendes Kriterium für deren katalytische Aktivität. Um diese zu bestimmen, gibt es ein neues Ultrahochvakuum‐FT‐IR‐Spektrometer. So lassen sich nun IR‐Spektren für Pulverpartikel unmittelbar mit IR‐Daten für einkristalline Referenzsysteme vergleichen.
Symposium statt Seminar — Bioanorganik im Masterstudium
Authors: Zbikowski Frauke 
Published: September 2013

AbstractAn der Universität Gießen organisieren Masterstudenten im Bioanorganik‐Modul ein Symposium für Oberstufenschüler mit Experimentalvorträgen. Christian Würtele, der dieses Modul entwickelt hat, erhielt dafür den Hessischen Hochschulpreis für Exzellenz in der Lehre. Inzwischen hat sich die neuartige Lehrform in Gießen etabliert und findet jährlich im Sommersemester statt.