bluuebunny/crossref_metadata_2025_split huggingface dataset:
Determination of the Absolute Configuration of Perylene Quinone‐Derived Mycotoxins by Measurement and Calculation of Electronic Circular Dichroism Spectra and Specific Rotations
Authors: Podlech Joachim , Fleck Stefanie C. , Metzler Manfred , Bürck Jochen , Ulrich Anne S. 
Published: July 2014

AbstractAltertoxins I–III, alterlosins I and II, alteichin (alterperylenol), stemphyltoxins I–IV, stemphyperylenol, stemphytriol, 7‐epi‐8‐hydroxyaltertoxin I, and 6‐epi‐stemphytriol are mycotoxins derived from perylene quinone, for which the absolute configuration was not known. Electronic circular dichroism (ECD) spectra were calculated for these compounds and compared with measured spectra of altertoxins I–III, alteichin, and stemphyltoxin III and with reported Cotton effects. Specific rotations were calculated and compared with reported specific rotations. The absolute configuration of all the toxins, except for stemphyltoxin IV, could thus be determined. The validity of the assignment was high whenever reported ECD data were available for comparison, and the validity was lower when the assignment was based only on the comparison of calculated and reported specific rotations. ECD spectra are intrinsically different for toxins with a biphenyl substructure and for toxins derived from dihydroanthracene.
ZSM‐5 Zeolite Nanosheets with Improved Catalytic Activity Synthesized Using a New Class of Structure‐Directing Agents
Authors: Kore Rajkumar , Srivastava Rajendra , Satpati Biswarup 
Published: July 2014

AbstractA new series of multiquaternary ammonium structure‐directing agents, based on 1,4‐diazabicyclo[2.2.2]octane, was prepared. ZSM‐5 zeolites with nanosheet morphology (10 nm crystal thickness) were synthesized under hydrothermal conditions using multiquaternary ammonium surfactants as the zeolite structure‐generating agents. Both wide‐angle and small‐angle diffraction patterns were obtained using only a suitable structure‐directing agent under a specific zeolite synthesis composition. A mechanism of zeolite formation is proposed based on the results obtained from various physicochemical characterizations. ZSM‐5 materials were investigated in catalytic reactions requiring medium to strong acidity, which are important for the synthesis of a wide range of industrially important fine and specialty chemicals. The catalytic activity of ZSM‐5 materials was compared with that of the conventional ZSM‐5 and amorphous mesoporous aluminosilicate Al‐MCM‐41. The synthesis strategy of the present investigation using the new series of structure‐directing agents could be extended for the synthesis of other related zeolites or other porous materials in the future. Zeolite with a structural feature as small as the size of a unit cell (5–10 nm) with hierarchically ordered porous structure would be very promising for catalysis.
para‐Quinodimethane‐Bridged Perylene Dimers and Pericondensed Quaterrylenes: The Effect of the Fusion Mode on the Ground States and Physical Properties
Authors: Das Soumyajit , Lee Sangsu , Son Minjung , Zhu Xiaojian , Zhang Wenhua , Zheng Bin , Hu Pan , Zeng Zebing , Sun Zhe , Zeng Wangdong , Li Run‐Wei , Huang Kuo‐Wei , Ding Jun , Kim Dongho , Wu Jishan 
Published: July 2014

AbstractPolycyclic hydrocarbon compounds with a singlet biradical ground state show unique physical properties and promising material applications; therefore, it is important to understand the fundamental structure/biradical character/physical properties relationships. In this study, para‐quinodimethane (p‐QDM)‐bridged quinoidal perylene dimers 4 and 5 with different fusion modes and their corresponding aromatic counterparts, the pericondensed quaterrylenes 6 and 7, were synthesized. Their ground‐state electronic structures and physical properties were studied by using various experiments assisted with DFT calculations. The proaromatic p‐QDM‐bridged perylene monoimide dimer 4 has a singlet biradical ground state with a small singlet/triplet energy gap (−2.97 kcal mol−1), whereas the antiaromatic s‐indacene‐bridged N‐annulated perylene dimer 5 exists as a closed‐shell quinoid with an obvious intramolecular charge‐transfer character. Both of these dimers showed shorter singlet excited‐state lifetimes, larger two‐photon‐absorption cross sections, and smaller energy gaps than the corresponding aromatic quaterrylene derivatives 6 and 7, respectively. Our studies revealed how the fusion mode and aromaticity affect the ground state and, consequently, the photophysical properties and electronic properties of a series of extended polycyclic hydrocarbon compounds.
Metalation of Polyamine Dendrimers with Ethynylcobalticenium for the Construction of Mono‐ and Heterobimetallic Polycationic Metallodendrimers
Authors: Wang Yanlan , Rapakousiou Amalia , Ruiz Jaime , Astruc Didier 
Published: July 2014

AbstractThe introduction of robust redox groups at the periphery of common amine‐terminated dendrimers is of interest in the design of dendritic nanobatteries, sensors, and redox catalysts. Here we are applying the recently discovered uncatalyzed hydroamination of ethynylcobalticenium, a mild “green” reaction that quantitatively yields trans‐enamines without the formation of any byproduct, to functionalize dendrimers that are terminated with primary or secondary amino groups. Poly(amido amine) (PAMAM) dendrimers terminated by primary amino groups and arene‐centered dendrimers terminated by secondary amino groups yield dendrimers that contain up to 81 trans‐enamine‐cobalticenium termini using this reaction. The hydroamination reaction was also conducted with dendrimers that contained ferrocenylmethylamino groups, which yielded dendrimers that contained both ferrocenyl and cobalticenium termini. The size of the dendrimers was investigated using both dynamic light scattering and diffusion‐ordered spectroscopy (DOSY) 1H NMR spectroscopy, and the number of electrons involved in heterogeneous multielectron transfers at electrodes was searched by cyclic voltammetry. The latter works well up to the 27‐branch dendrimer, whereas the 81‐dendrimer yielded a result in an excess amount (110 electrons) owing to adsorption onto the cathode that becomes all the more significant as the metallodendrimer size increases.
Double Metal Ions Competitively Control the Guest‐Sensing Process: A Facile Approach to Stimuli‐Responsive Supramolecular Gels
Authors: Lin Qi , Sun Bin , Yang Qing‐Ping , Fu Yong‐Peng , Zhu Xin , Wei Tai‐Bao , Zhang You‐Ming 
Published: July 2014

AbstractA facile approach to the design of stimuli‐responsive supramolecular gels (SRSGs) termed double‐metal‐ion competitive coordination control is reported. By this means, the fluorescence signals and guest‐selective responsiveness of the SRSGs are controlled by the competitive coordination of two different metal ions with the gelators and the target guest. To demonstrate this approach, a gelator G2 based on multiple self‐assembly driving forces was synthesized. G2 could form Ca2+‐coordinated metallogel CaG with strong aggregation‐induced emission (AIE). Doping of CaG with Cu2+ results in AIE quenching of CaG and formation of Ca2+‐ and Cu2+‐based metallogel CaCuG. CaCuG could fluorescently detect CN− with specific selectivity through the competitive coordination of CN− with the Cu2+ and the coordination of Ca2+ with G2 again. This approach may open up routes to novel stimuli‐responsive supramolecular materials.
Direct Anisotropic Growth of CdS Nanocrystals in Thermotropic Liquid Crystal Templates for Heterojunction Optoelectronics
Authors: Yuan Kai , Chen Lie , Chen Yiwang 
Published: July 2014

AbstractThe direct growth of CdS nanocrystals in functional solid‐state thermotropic liquid crystal (LC) small molecules and a conjugated LC polymer by in situ thermal decomposition of a single‐source cadmium xanthate precursor to fabricate LC/CdS hybrid nanocomposites is described. The influence of thermal annealing temperature of the LC/CdS precursors upon the nanomorphology, photophysics, and optoelectronic properties of the LC/CdS nanocomposites is systematically studied. Steady‐state PL and ultrafast emission dynamics studies show that the charge‐transfer rates are strongly dependent on the thermal annealing temperature. Notably, annealing at liquid‐crystal state temperature promotes a more organized nanomorphology of the LC/CdS nanocomposites with improved photophysics and optoelectronic properties. The results confirm that thermotropic LCs can be ideal candidates as organization templates for the control of organic/inorganic hybrid nanocomposites at the nanoscale level. The results also demonstrate that in situ growth of semiconducting nanocrystals in thermotropic LCs is a versatile route to hybrid organic/inorganic nanocomposites and optoelectronic devices.
Label‐free Electrochemiluminescent Enantioselective Sensor for Distinguishing between Chiral Metallosupramolecular Complexes
Authors: Wu Li , Zhao Chuanqi , Ren Jinsong , Qu Xiaogang 
Published: July 2014

AbstractChiral molecular recognition of DNA is important for rational drug design and for developing structural probes of DNA conformation. Developing a convenient and inexpensive assay for sensitive and selective identification of DNA‐specific binding compounds with rapid, easy manipulation is in ever‐increasing demand. Here, we present a “turn‐on” and label‐free electrochemiluminescent (ECL) biosensor for distinguishing chiral metallosupramolecular complexes based on DNA three‐way junction formation selectively induced by the analyte. The fabricated ECL sensor shows excellent performance in the chiral discrimination of two enantiomers with an enantioselective recognition ratio of up to 4.4. More importantly, as a “turn‐on” detection system, the ECL chiral sensor does not suffer from false positives and limited signal range of “signal‐off” systems. Therefore, this concept may provide a new insight into the design of efficient sensors for distinguishing chiral molecules and for investigating the interactions between DNA and small molecules.
Radiotherapy for benign head and neck paragangliomas: A 45‐year experience
Authors: Gilbo Philip , Morris Christopher G. , Amdur Robert J. , Werning John W. , Dziegielewski Peter T. , Kirwan Jessica , Mendenhall William M. 
Published: July 2014

BACKGROUNDParagangliomas of the head and neck are rare, slow‐growing, generally benign tumors of neuroendocrine cells associated with the peripheral nervous system that commonly involve the carotid body, jugular bulb, vagal ganglia, and temporal bone. Treatment options include surgery, radiotherapy (RT), stereotactic radiosurgery (SRS), and observation. This article briefly reviews our 45‐year institutional experience treating this neoplasm with RT.METHODSFrom January 1968 through March 2011, 131 patients with 156 benign paragangliomas of the temporal bone, carotid body, jugular bulb, or glomus vagale were treated with RT at a median dose of 45 Gy in 25 fractions. The mean and median follow‐up times were 11.5 years and 8.7 years, respectively.RESULTSFive tumors (3.2%) recurred locally after RT, all within 10 years of treatment. The overall local control rates at 5 and 10 years were 99% and 96%, respectively. The cause‐specific survival rates at 5 and 10 years were 98% and 97%, respectively. The distant‐metastasis free survival rates at 5 and 10 years were 99% and 99%, respectively. The overall survival rates at 5 and 10 years were 91% and 72%, respectively. There were no severe complications.CONCLUSIONRT for benign head and neck paragangliomas is a safe and efficacious treatment associated with minimal morbidity. Surgery is reserved for patients in good health whose risk of associated morbidity is low. SRS may be suitable for patients with skull base tumors <3 cm where RT is logistically unsuitable. Observation is a reasonable option for asymptomatic patients with a limited life expectancy. Cancer 2014;120:3738–3743. © 2014 American Cancer Society.
Effect of total dose and fraction size on survival of patients with locally recurrent nasopharyngeal carcinoma treated with intensity‐modulated radiotherapy: A phase 2, single‐center, randomized controlled trial
Authors: Tian Yun‐ming , Zhao Chong , Guo Ying , Huang Ying , Huang Shao‐Min , Deng Xiao‐Wu , Lin Cheng‐Guang , Lu Tai‐xiang , Han Fei 
Published: July 2014

BACKGROUNDThe optimal model of total dose and fraction size for patients with locally recurrent nasopharyngeal carcinoma treated with intensity‐modulated radiotherapy (IMRT) remains unclear. The authors designed a randomized phase 2 clinical trial to investigate the efficacy of 2 different models, with the objective of determining an optimal model.METHODSBetween January 2003 and December 2007, a total of 117 patients with locally recurrent nonmetastatic nasopharyngeal carcinoma were randomized to 2 different models of total dose and fraction size: group A (59 patients) received 60 gray in 27 fractions and group B (58 patients) received 68 gray in 34 fractions. Both groups received 5 daily fractions per week. All patients received IMRT alone.RESULTSThe median follow‐up was 25.0 months. The 5‐year overall survival in group A was higher than that in group B (44.2% vs 30.3%; P =.06), and the local failure‐free survival in group A was slightly lower than that in group B (63.7% vs 71.0%; P =.41). Severe late complications were the main cause of death. The incidences of mucosal necrosis and massive hemorrhage in patients in group B were significantly higher than those among patients in group A at 50.8% versus 28.8% (P =.02) and 31.0% versus 18.6% (P =.12), respectively. Tumor volume (P<.01) and model of total dose and fraction size (P =.03) were found to be significant factors for mucosal necrosis and massive hemorrhage.CONCLUSIONSAppropriately decreasing the total dose and increasing the fraction size can achieve local control similar to that achieved with a higher dose after IMRT; furthermore, it can improve overall survival by significantly reducing the incidence of severe late complications including mucosal necrosis and massive hemorrhage. Cancer 2014;120:3502–3509. © 2014 American Cancer Society.
Effects of Oil on Aqueous Foams: Electrical Conductivity of Foamed Emulsions
Authors: Yan Yong‐Li , Shan Cheng , Wang Yao , Deng Qiang 
Published: July 2014

AbstractThree‐phase foams containing dispersed oils (also called foamed emulsion) are usually encountered in such areas as enhanced oil recovery, food foams, and in foams containing antifoams. The presence of oil causes these complex fluids to exhibit extraordinary properties in contrast to aqueous foams. We experimentally investigated, for the first time, the conductive properties of the foamed emulsions and found that the electrical conductivity increases monotonically with the volumetric liquid fraction, presenting a linear relationship. Combined with the analysis on the foaming capacity and microstructure of this complex fluid, the conductive mechanism is revealed. In these foamed emulsions, the whole conductive network is comprised of two levels of structural hierarchy, which displays a different mechanism from those of the conventional aqueous foams. The lamella of emulsions is taken as primary electrical channel, whereas the secondary electrical channel occurs in the lamella between two bubbles. This conductive behaviour is attributed to the microstructure properties of the foamed emulsions. We believe that such findings are potentially important for a better understanding of the fundamentals of these tri‐phase dispersion systems.
Spectroscopic and Computational Characterizations of Alkaline‐Earth‐ and Heavy‐Metal‐Exchanged Natrolites
Authors: Liu Dan , Chen Xin , Ma Yanming , Liu Zhenxian , Vogt Thomas , Lee Yongjae 
Published: July 2014

AbstractInvited for this month’s cover features the collaboration between four different research groups at Yonsei University, Jilin University, Geophysical Laboratory, and the NanoCentre of the University of South Carolina. The image shows the framework of the small pore zeolite natrolite made up of alternating SiO4 and AlO4 tetrahedral 4‐rings and helical 8‐rings, which can accommodate, by structural relaxations, diverse alkali, alkaline‐earth as well as some heavy metals as charge‐balancing extra‐framework cations (EFC). Systematic structural changes have now been linked to the spectroscopic data. Read the full text of the article at 10.1002/cplu.201402114
Compositional Insights and Valorization Pathways for Carbonaceous Material Deposited During Bio‐Oil Thermal Treatment
Authors: Ochoa Aitor , Aramburu Borja , Ibáñez María , Valle Beatriz , Bilbao Javier , Gayubo Ana G. , Castaño Pedro 
Published: July 2014

AbstractThis work analyses the composition, morphology, and thermal behavior of the carbonaceous materials deposited during the thermal treatment of bio‐oil (thermal pyrolytic lignin—TPL). The bio‐oil was obtained by flash pyrolysis of lignocellulosic biomass (pine sawdust), and the TPLs were obtained in the 400–700 °C range. The TPLs were characterized by performing elemental analysis; 13C NMR, Raman, FTIR, and X‐ray photoelectron spectroscopy; SEM; and temperature‐programmed oxidation analyzed by differential thermogravimetry and differential scanning calorimetry. The results are compared to a commercial lignin (CL). The TPLs have lower oxygen and hydrogen contents and a greater aromaticity and structural order than the CL material. Based on these features, different valorization routes are proposed: the TPL obtained at 500 °C is suitable for use as a fuel, and the TPL obtained at 700 °C has a suitable morphology and composition for use as an adsorbent or catalyst support.
Stage‐dependent responses to emergent habitat heterogeneity: consequences for a predatory insect population in a coffee agroecosystem
Authors: Liere Heidi , Perfecto Ivette , Vandermeer John 
Published: July 2014

AbstractInteractions among members of biological communities can create spatial patterns that effectively generate habitat heterogeneity for other members in the community, and this heterogeneity might be crucial for their persistence. For example, stage‐dependent vulnerability of a predatory lady beetle to aggression of the ant, Azteca instabilis, creates two habitat types that are utilized differently by the immature and adult life stages of the beetle. Due to a mutualistic association between A. instabilis and the hemipteran Coccus viridis – which is A. orbigera main prey in the area – only plants around ant nests have high C. viridis populations. Here, we report on a series of surveys at three different scales aimed at detecting how the presence and clustered distribution of ant nests affect the distribution of the different life stages of this predatory lady beetle in a coffee farm in Chiapas, Mexico. Both beetle adults and larvae were more abundant in areas with ant nests, but adults were restricted to the peripheries of highest ant activity and outside the reach of coffee bushes containing the highest densities of lady beetle larvae. The abundance of adult beetles located around trees with ants increased with the size of the ant nest clusters but the relationship is not significant for larvae. Thus, we suggest that A. orbigera undergoes an ontogenetic niche shift, not through shifting prey species, but through stage‐specific vulnerability differences against a competitor that renders areas of abundant prey populations inaccessible for adults but not for larvae. Together with evidence presented elsewhere, this study shows how an important predator is not only dependent on the existence of two qualitatively distinct habitat types, but also on the spatial distribution of these habitats. We suggest that this dependency arises due to the different responses that the predator's life stages have to this emergent spatial pattern.
Blood parasite infection differentially relates to carotenoid‐based plumage and bill color in the American goldfinch
Authors: Lumpkin David C. , Murphy Troy G. , Tarvin Keith A. 
Published: July 2014

AbstractMale and female American goldfinches (Spinus tristis) express condition‐dependent carotenoid‐based plumage and bill coloration. Plumage color is relatively static, as pigments incorporated into feathers during the spring molt cannot be mobilized thereafter. In contrast, bill color is dynamic, reflecting changes in condition over short time periods. Previous studies have shown that male and female ornaments, though similar in expression, are differentially related to measures of immunocompetence, suggesting that the relationship between ornamentation and parasite infection may differ between the sexes. In this study, we evaluate the relationship between condition‐dependent ornamentation (plumage and bill color) and blood parasite infection in male and female American goldfinches. We captured goldfinches after completion of the pre‐alternate molt and prior to the onset of nesting and assessed prevalence of Trypanosoma parasites via blood smears. Plumage color strongly predicted trypanosome infection: Birds with more colorful plumage were less likely to present infections. In contrast, we detected no relationship between infection and bill color, which in other studies has been shown to dynamically reflect current condition. Sex did not affect the relationship between infection status and either ornament. Together, these results suggest that physiological pathways linking carotenoid ornamentation and infection may vary even within a single species.
Enzymatic degumming: Degumming efficiency versus yield increase
Authors: Sampaio Klicia A. , Zyaykina Nadezhda , Wozniak Bogumila , Tsukamoto Junko , Greyt Wim De , Stevens Christian V. 
Published: July 2014

Enzymatic degumming trials were performed on crude extracted soybean (SBO) and rapeseed oils (RSO) with a microbial phospholipase A1 (Lecitase Ultra®). We obtained a degummed oil with a phosphorus content < 10 mg/kg when applying an enzyme dosage of 30 mg/kg and (feedstock dependent) a contact time of 10–120 min. While a good degumming efficiency can already be obtained after a relative short reaction time, it was observed that a longer reaction time (1–2 h) is required for complete degradation of the phospholipids (PL), which results in a yield increase. We demonstrated that Lecitase Ultra® has no specificity for a given PL, but that the rate of conversion depends on the PL composition of the crude oil. After 60 min, 80% of phosphatidyl ethanolamine (PE) was degraded to its lyso‐form while only 40% of phosphatidyl inositol (PI) was converted in the same time interval. The formation of glycerophospholipids (GPL) was only observed after 60 min reaction.Practical applications: Practical advantages and disadvantages of the use of Lecithase Ultra for enzymatic degumming of oils is described, focusing on soybean oil and rapeseed oil. The information will be valuable and important for the oil refining industry.Degumming of soybean and rapeseed oils with phospholipase A1 (Lecithase Ultra) was performed and it was demonstrated that there is no specificity for a given phospholipid. However, the conversion rate depends on the phospholipid composition of the crude oils.
Convenient Access to Carbohydrate–BODIPY Hybrids by Two Complementary Methods Involving One‐Pot Assembly of “Clickable” BODIPY Dyes
Authors: Martinez‐Gonzalez Mayra R. , Urías‐Benavides Arlette , Alvarado‐Martínez Enrique , Lopez J. Cristobal , Gómez Ana M. , del Rio Mayca , Garcia Inmaculada , Costela Angel , Bañuelos Jorge , Arbeloa Teresa , Lopez Arbeloa Iñigo , Peña‐Cabrera Eduardo 
Published: July 2014

AbstractTwo complementary one‐pot, three component synthetic strategies based on copper(I)‐catalyzed azide–alkyne cycloadditions (CuAAC) have been developed, which allow the efficient assembly of glycosyl‐derived alkynes or azides with highly fluorescent boron–dipyrromethene (BODIPY) cores containing azido or alkyne moieties, respectively. The resulting carbohydrate–BODIPY derivatives display excellent photophysical and laser properties that relate to the spacer (amino group or aromatic ring) employed in each of the synthetic protocols.