bluuebunny/crossref_metadata_2025_split huggingface dataset:
Pinene: reichlich vorhandene und erneuerbare Bausteine für eine Vielzahl an nachhaltigen Polymeren
Authors: Winnacker Malte 
Published: May 2018

AbstractPinene – eine Gruppe von Monoterpenen, die eine Doppelbindung enthalten – sind sehr nützliche und erneuerbare Monomerbausteine für eine Vielzahl an nachhaltigen Polymeren und Materialien. Ihre Verfügbarkeit von hauptsächlich nicht‐essbaren Pflanzenteilen sowie die Leichtigkeit ihrer Isolierung machen diese Moleküle einzigartig innerhalb der Vielfalt an Biomasse, die für neue Materialien nutzbar gemacht werden kann. Dementsprechend wird ihre Verwendung für die Synthese von biobasierten Polymeren intensiv untersucht, wobei hier insbesondere in den vergangenen 2–3 Jahren starke Fortschritte erzielt wurden. Direkte kationische oder radikalische Polymerisationen über die Doppelbindungen der Pinene sowie die Polymerisation nach weiterer Funktionalisierung können eine Vielzahl an nachhaltigen Polymeren mit zahlreichen Anwendungsmöglichkeiten ergeben, was in diesem Kurzaufsatz zusammengefasst ist.
Copper‐Mediated Polymerization without External Deoxygenation or Oxygen Scavengers
Authors: Liarou Evelina , Whitfield Richard , Anastasaki Athina , Engelis Nikolaos G. , Jones Glen R. , Velonia Kelly , Haddleton David M. 
Published: May 2018

AbstractAs a method for overcoming the challenge of rigorous deoxygenation in copper‐mediated controlled radical polymerization processes [e.g., atom‐transfer radical polymerization (ATRP)], reported here is a simple Cu0‐RDRP (RDRP=reversible deactivation radical polymerization) system in the absence of external additives (e.g., reducing agents, enzymes etc.). By simply adjusting the headspace of the reaction vessel, a wide range of monomers, namely acrylates, methacrylates, acrylamides, and styrene, can be polymerized in a controlled manner to yield polymers with low dispersities, near‐quantitative conversions, and high end‐group fidelity. Significantly, this approach is scalable (ca. 125 g), tolerant to elevated temperatures, compatible with both organic and aqueous media, and does not rely on external stimuli which may limit the monomer pool. The robustness and versatility of this methodology is further demonstrated by the applicability to other copper‐mediated techniques, including conventional ATRP and light‐mediated approaches.
The Effect of the Active‐Site Structure on the Activity of Copper Mordenite in the Aerobic and Anaerobic Conversion of Methane into Methanol
Authors: Sushkevich Vitaly L. , Palagin Dennis , van Bokhoven Jeroen A. 
Published: May 2018

AbstractSamples of the zeolite mordenite with different Si/Al ratios were used to synthesize materials with monomeric and oligomeric copper sites that are active in the direct conversion of methane into methanol. A comparison of two reactivation protocols with oxygen (aerobic oxidation) and water (anaerobic oxidation), respectively, revealed that such copper–oxo species possess different reactivity towards methane and water. We show for the first time that oligomeric copper species exhibit high activity under both aerobic and anaerobic activation conditions, whereas monomeric copper sites produce methanol only in aerobic processes.
Supramolecularly Catalyzed Polymerization: From Consecutive Dimerization to Polymerization
Authors: Tang Xiaoyan , Huang Zehuan , Chen Hao , Kang Yuetong , Xu Jiang‐Fei , Zhang Xi 
Published: May 2018

AbstractHerein, we propose a new method for promoting covalent polymerization by supramolecular catalysts. To this end, we employed cucurbit[8]uril (CB[8]) as a supramolecular catalyst, and successfully prepared polyelectrolytes in an aqueous solution by taking advantage of the CB[8]‐enhanced photodimerization of Brooker merocyanine moieties. Interestingly, 10 mol % CB[8] is enough to effectively catalyze this polymerization, because CB[8] can be spontaneously replaced by terminal groups from photodimerized products. In addition, the molecular weights of the obtained polyelectrolytes can be varied by the irradiation time or the monomer. By combining supramolecular catalysis and polymer chemistry, this line of research may enrich the methodology of polymerization and open up new horizons for supramolecular polymer chemistry.
Two Bacterial Diterpene Synthases from Allokutzneria albata Produce Bonnadiene, Phomopsene, and Allokutznerene
Authors: Lauterbach Lukas , Rinkel Jan , Dickschat Jeroen S. 
Published: May 2018

AbstractTwo diterpene synthases from Allokutzneria albata were studied for their products, resulting in the identification of the new compound bonnadiene from the first enzyme. Although phylogenetically unrelated to fungal phomopsene synthase, the second enzyme produced a mixture of phomopsene and a biosynthetically linked new compound, allokutznerene, as well as spiroviolene. Both enzymes were subjected to in‐depth mechanistic studies involving isotopic labelling experiments, metal‐cofactor variation, and site‐directed mutagenesis. Oxidation products of phomopsene and allokutznerene are also discussed.
Synthesis and properties of phthalonitrile terminated polyaryl ether nitrile containing fluorene group
Authors: Wang Guangxing , Guo Ying , Li Zheng , Xu Shuangshuang , Han Yue , Luo Zhenhua , Ye Li , Zhou Heng , Zhao Tong 
Published: May 2018

ABSTRACTA series of phthalonitrile terminated polyaryl ether nitrile oligomers containing fluorene group (BPPENs) were synthesized and cured in the presence of bis[4‐(4‐aminophenoxy)phenyl]sulfone. Additionally, the quartz fiber reinforced composites were prepared by hot‐pressing process. The structure of oligomers was characterized by 1H‐NMR and GPC. The curing behavior of BPPENs was studied by DSC, IR, and rheological tests in detail. Thermal stability and mechanical properties were also investigated. The results showed that the oligomers showed excellent solubility. BPPENs could be dissolved in common solvents at ambient temperature. TGA and DMA results showed that the cured polymer and composites possessed excellent thermal properties with high residual weight of 72.4% at 1000 °C and 5% thermal degradation temperature (T5%) of 548 °C under inert atmosphere. The bending strength of quartz fiber reinforced composites was about 500 MPa, exhibiting good mechanical property. The products could be used as high performance polymers or a modifier for heat‐resistant resins. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46606.
Development and characterization of collagen/gelatin films and gels incorporated with pequi oil
Authors: Horn Marilia M. , Martins Virginia C. A. , Fernandes Yasmin O. M. , Vulcani Valcinir A. S. , Plepis Ana Maria G. 
Published: May 2018

ABSTRACTNatural compounds, such as pequi oil, could be added to collagen/gelatin mixtures to improve its properties. Gels characterized by rheological analysis indicated modifications in entanglement network of the mixtures after pequi oil addition. Films processed by casting were analyzed by mechanical and thermal properties, contact angle, and scanning electron microscopy (SEM). The pequi oil addition reduced the contact angle values due to the addition of carboxyl groups found in the palmitic and oleic acid chains of pequi oil. The rough characteristic observed by SEM images was a result of a good homogenization process after oil incorporation. In addition, pequi oil addition decreased the tensile forces and elongation of the films and increased the thermal stability possibly due to lower inter‐ and intra‐molecules interactions. The results suggested a good compatibility between pequi oil and biopolymers and the potential application of this natural compound to increase the wound healing process. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46627.
Antiarthritic Effects of Sorafenib in Rats with Adjuvant‐Induced Arthritis
Authors: Wang Zhen‐Zhen , Liu Fei , Gong Yong‐Fang , Huang Tian‐Yu , Zhang Xiao‐Ming , Huang Xue‐Ying 
Published: May 2018

ABSTRACTRheumatoid arthritis (RA) is a chronic inflammatory disease affecting the synovial membrane of joints. In this study, we aimed to investigate whether sorafenib exerts antiarthritic effects on RA in vivo. Adjuvant arthritis (AA) was induced (day 0) in male Sprague–Dawley rats by intradermal injection of 0.1 mL of complete Freund's complete adjuvant into the left hind paw. Sorafenib (10, 20, or 40 mg/kg/day) was administered intragastrically from day 10 to 24. Body weight, paw volume, synovial inflammation, and tumor necrosis factor alpha (TNF‐α), interleukin‐1β (IL‐1β), IL‐10, and IL‐17 serum levels were detected. In addition, microvascular density (MVD) and the expression of vascular endothelial growth factor receptor 2 (VEGFR‐2) and fibroblast growth factor receptor 1 (FGFR‐1) in synovial tissues were analyzed. Our data revealed that sorafenib administration led to significant body weight gain in AA rats but suppressed paw swelling, synovial hyperplasia, and inflammatory infiltration. Furthermore, it decreased TNF‐α, IL‐1β, and IL‐17 serum levels and upregulated IL‐10. MVD and VEGFR‐2 and FGFR‐1 expression in synovial tissues were significantly reduced. Thus, this study shows that sorafenib exerts anti‐arthritic effects in AA rats and therefore has potential in RA treatment. Anat Rec, 301:1519–1526, 2018. © 2018 Wiley Periodicals, Inc.
Design of Single‐Site Photocatalysts by Using Metal–Organic Frameworks as a Matrix
Authors: Wen Meicheng , Mori Kohsuke , Kuwahara Yasutaka , An Taicheng , Yamashita Hiromi 
Published: May 2018

AbstractSingle‐site photocatalysts generally display excellent photocatalytic activity and considerably high stability compared with homogeneous catalytic systems. A rational structural design of single‐site photocatalysts with isolated, uniform, and spatially separated active sites in a given solid is of prime importance to achieve high photocatalytic activity. Intense attention has been focused on the design and fabrication of single‐site photocatalysts by using porous materials as a platform. Metal–organic frameworks (MOFs) have great potential in the design and fabrication of single‐site photocatalysts due to their remarkable porosity, ultrahigh surface area, extraordinary tailorability, and significant diversity. MOFs can provide an abundant number of binding sites to anchor active sites, which results in a significant enhancement in photocatalytic performance. In this focus review, the development of single‐site MOF photocatalysts that perform important and challenging chemical redox reactions, such as photocatalytic H2 production, photocatalytic CO2 conversion, and organic transformations, is summarized thoroughly. Successful strategies for the construction of single‐site MOF photocatalysts are summarized and major challenges in their practical applications are noted.
Honeycomb‐Patterned Polyimide Film as a Versatile Coating for High‐Performance Dielectric Material
Authors: Ma Yingyi , Xu Le , Wu Zijian , Zhang Wenlong , Zhang Mingyan , He Zhenfeng 
Published: May 2018

AbstractA honeycomb‐patterned porous film was conveniently prepared by means of the microemulsion method and then used as an effective coating for improving the dielectric properties and water resistance of polyimide (PI) film while maintaining its mechanical properties. The dielectric properties could be regulated by tuning the structure of the porous film through controlling its formation conditions. When suitable conditions were used, the prepared composite PI film exhibited a significant reduction of 28.3 % in its dielectric constant and 9.48–54.99 % in dielectric loss accompanied by an extremely low water uptake of 0.62 % relative to the 2.47 % of flat PI film. The composite PI film also displayed excellent durability under moist conditions, as the dielectric constant was still below 2.4 after exposure to 75 % relative humidity for more than 12 h. This provides a novel method to improve and control the dielectric properties of materials. It also suggests that this film is a suitable candidate for coating dielectric materials in high‐humidity environments.
Verankerungsverhalten textiler Bewehrungen in dünnen Betonbauteilen
Authors: Bielak Jan , Spelter Arne , Will Norbert , Claßen Martin 
Published: May 2018

AbstractDie Frage der sicheren und sinnvollen Verankerung von textiler Bewehrung im Beton beschäftigt nicht nur Anwender des innovativen Verbundwerkstoffs Carbonbeton. Auch in der Forschung sind für die Thematik des Verbunds und der Verankerung wesentliche Fragen nicht abschließend geklärt. Bisher existiert kein Bemessungsmodell für die Verankerung oder Übergreifung, welches bei der derzeit verfügbaren Bandbreite textiler Bewehrungen mit weicher bis steifer Tränkung gleichermaßen gültig ist. Die unterschiedlichen Versagensmechanismen des Verbunds, die aus den Charakteristika der Materialien resultieren, werden selten klar unterschieden. Dieser Artikel verdeutlicht die Auswirkungen des Formschlusses auf das Verankerungsverhalten am Beispiel einer textilen Bewehrung mit steifer Tränkung und ordnet Ergebnisse von experimentellen Untersuchungen in die bisherige Forschung ein. Hierzu wird ein Prüfaufbau für einen Auszugversuch vorgestellt, welcher auch zur Abschätzung des Verankerungsverhaltens in Praxisprojekten und zur Qualitätskontrolle in der Produktion genutzt werden kann.
A Designed Enzyme Promotes Selective Post‐translational Acylation
Authors: Gosavi Pallavi M. , Jayachandran Megha , Rempillo Joel J. L. , Zozulia Oleksii , Makhlynets Olga V. , Korendovych Ivan V. 
Published: May 2018

AbstractA computationally designed, allosterically regulated catalyst (CaM M144H) produced by substituting a single residue in calmodulin, a non‐enzymatic protein, is capable of efficient and site selective post‐translational acylation of lysines in peptides with highly diverse sequences. Calmodulin′s binding partners are involved in regulating a large number of cellular processes; this new chemical‐biology tool will help to identify them and provide structural insight into their interactions with calmodulin.
Synthesis of Azo Dyes from Mesoionic Carbenes and Nitrous Oxide
Authors: Eymann Léonard Y. M. , Scopelliti Rosario , Tirani Farzaneh Fadaei , Severin Kay 
Published: May 2018

AbstractCovalent adducts of imidazole‐based mesoionic carbenes and nitrous oxide (N2O, “laughing gas”) can be converted into azo dyes by reaction with arenes in the presence of AlCl3 or HCl. The azo coupling can be achieved with electron‐rich aromatic compounds such as mesitylene, trimethoxybenzene, azulene, or dibenzo‐18‐crown‐6. The latter coupling reaction allows for the easy preparation of a colorimetric sensor for potassium or sodium ions. As a putative intermediate of the reaction with acid, we were able to isolate and structurally characterize a rare diazohydroxide. Using imidazolium compounds with two N2O groups, it was possible to prepare amine‐substituted azo dyes or dyes with two azoarene groups attached to the heterocycle. A triazole‐based mesoionic carbene was also found to form a stable covalent adduct with N2O. The adduct could be used to prepare novel azo triazolium dyes in good yields.
Small molecule targeting of the actin associating protein tropomyosin Tpm3.1 increases neuroblastoma cell response to inhibition of Rac‐mediated multicellular invasion
Authors: Mitchell Camilla B. , Stehn Justine R. , O'Neill Geraldine M. 
Published: May 2018

AbstractThe migration and invasion of cells through tissues in the body is facilitated by a dynamic actin cytoskeleton. The actin‐associating protein, tropomyosin Tpm3.1 has emerged to play important roles in cell migration and invasion. To date, investigations have focused on single cell migration and invasion where Tpm3.1 expression is inversely associated with Rac GTPase‐mediated cell invasion. While single cell and collective cell invasion have many features in common, collective invasion is additionally impacted by cell–cell adhesion, and the role of Tpm3.1 in collective invasion has not been established. In the present study we have modelled multicellular invasion using neuroblastoma spheroids embedded in 3D collagen and analysed the function of Tpm3.1 using recently established compounds that target the Tpm3.1 C‐terminus. The major findings from our study reveal that combined Rac inhibition and Tpm3.1 targeting result in greater inhibition of multicellular invasion than either treatment alone. Together, the data suggest that Tpm3.1 disruption sensitises neuroblastoma cells to inhibition of Rac‐mediated multicellular invasion.
Multispectral Live‐Cell Imaging
Authors: Cohen Sarah , Valm Alex M. , Lippincott‐Schwartz Jennifer 
Published: May 2018

AbstractFluorescent proteins and vital dyes are invaluable tools for studying dynamic processes within living cells. However, the ability to distinguish more than a few different fluorescent reporters in a single sample is limited by the spectral overlap of available fluorophores. Here, we present a protocol for imaging live cells labeled with six fluorophores simultaneously. A confocal microscope with a spectral detector is used to acquire images, and linear unmixing algorithms are applied to identify the fluorophores present in each pixel of the image. We describe the application of this method to visualize the dynamics of six different organelles, and to quantify the contacts between organelles. However, this method can be used to image any molecule amenable to tagging with a fluorescent probe. Thus, multispectral live‐cell imaging is a powerful tool for systems‐level analysis of cellular organization and dynamics. © 2018 by John Wiley & Sons, Inc.
Exploring attentional biases towards facial expressions of pain in men and women
Authors: Keogh E. , Cheng F. , Wang S. 
Published: May 2018

AbstractBackgroundInterpersonal factors may help explain why men and women differ in their perception and expression of pain. Whilst the focus is often on the person in pain, how observers respond to those in pain is important. This study explored whether male–female differences exist in the way observers attend to expressions of pain in others.MethodsFifty‐three adults (26 females) completed a visual dot‐probe task, to measure selective attentional biases to facial expressions of pain and fear. Expression pairs (e.g. pain/neutral) were displayed by either the same male or female actor, and in two different viewing duration conditions: 150 and 1250 ms. Dot‐probes appeared in either a congruent or incongruent location to the target expression.ResultsNo evidence was found for sex‐related attentional biases towards pain or fear. However, when examining congruency and incongruency indexes separately, differences emerged. The congruency index analysis indicated that in the 150‐ms presentation condition, both men and women were slower during congruent female pain/neutral trials when compared to neutral/neutral trials, and relatively faster at responding during congruent male pain/neutral trials.ConclusionsThere is utility in exploring the attentional processes involved in the decoding of pain‐related expressions to understand the influence of sex and gender differences in pain. Although male–female differences were found, this was most clearly related to the actor. Our results point to an early attentional mechanism that orients attention away from female expressions of pain. Future consideration of sex‐ and gender‐related contextual factors in attentional processing is warranted.SignificanceSex‐related factors seem to affect how observers view the pain of others. Our results point to an early attentional mechanism that orients the attention of observers away from female expressions of pain.
Optimization of artemisinin extraction from Artemisia annua L. with supercritical carbon dioxide + ethanol using response surface methodology
Authors: Ciftci Ozan Nazim , Cahyadi Jessica , Guigard Selma E. , Saldaña Marleny D. A. 
Published: May 2018

AbstractMalaria is a high priority life‐threatening public health concern in developing countries, and therefore there is a growing interest to obtain artemisinin for the production of artemisinin‐based combination therapy products. In this study, artemisinin was extracted from the Artemisia annua L. plant using supercritical carbon dioxide (SC‐CO2) modified with ethanol. Response surface methodology based on central composite rotatable design was employed to investigate and optimize the extraction conditions of pressure (9.9–30 MPa), temperature (33–67°C), and co‐solvent (ethanol, 0–12.6 wt.%). Optimum SC‐CO2 extraction conditions were found to be 30 MPa and 33°C without ethanol. Under optimized conditions, the predicted artemisinin yield was 1.09% whereas the experimental value was 0.71 ± 0.07%. Soxhlet extraction with hexane resulted in higher artemisinin yields and there was no significant difference in the purity of the extracts obtained with SC‐CO2 and Soxhlet extractions. Results indicated that SC‐CO2 and SC‐CO2+ethanol extraction is a promising alternative for the extraction of artemisinin to eliminate the use of organic solvents, such as hexane, and produce extracts that can be used for the production of antimalarial products.
Performance of Oxygen Carriers with Different Porosities in Chemical Looping Water‐Splitting
Authors: Qiu Yu , Zeng DeWang , Chen Chao , Zeng JiMin , Zhang Shuai , Xiao Rui 
Published: May 2018

AbstractChemical looping is a novel process for clean energy conversion with CO2 capture. However, sintering of oxygen carriers is one of the important issues that hinders the development of chemical looping technology. Here we applied an air‐liquid foam templated sol‐gel method to produce anti‐sintering materials. By virtue of tunable sol precursors, we obtained a series of materials with different porous characteristics and found these initial textures could significantly affect the activity and stability of the materials in chemical looping. In the first cycle, materials with larger exposed surface had better reactivity. However, small pore closure and particle shrinkage occurred in the subsequent cycles. All of these factors contributed to the unstable nature of the materials, and the results suggested materials derived from templated sol solutions with more large pores were more robust during chemical looping. For other clean energy applications, we also hope the explored method can be extended to produce more materials with high reactivity and stability.
Web‐based thyroid imaging reporting and data system: Malignancy risk of atypia of undetermined significance or follicular lesion of undetermined significance thyroid nodules calculated by a combination of ultrasonography features and biopsy results
Authors: Choi Young Jun , Baek Jung Hwan , Shin Jung Hee , Shim Woo Hyun , Kim Seon‐Ok , Lee Won‐Hong , Song Dong Eun , Kim Tae Yong , Chung Ki‐Wook , Lee Jeong Hyun 
Published: May 2018

AbstractBackgroundThe purpose of this study was to construct a web‐based predictive model using ultrasound characteristics and subcategorized biopsy results for thyroid nodules of atypia of undetermined significance/follicular lesion of undetermined significance (AUS/FLUS) to stratify the risk of malignancy.MethodsData included 672 thyroid nodules from 656 patients from a historical cohort. We analyzed ultrasound images of thyroid nodules and biopsy results according to nuclear atypia and architectural atypia. Multivariate logistic regression analysis was performed to predict whether nodules were diagnosed as malignant or benign.ResultsThe ultrasound features, including spiculated margin, marked hypoechogenicity, calcifications, biopsy results, and cytologic atypia, showed significant differences between groups. A 13‐point risk scoring system was developed, and the area under the curve (AUC) of the receiver operating characteristic (ROC) curve of the development and validation sets were 0.837 and 0.830, respectively (http://www.gap.kr/thyroidnodule_b3.php).ConclusionWe devised a web‐based predictive model using the combined information of ultrasound characteristics and biopsy results for AUS/FLUS thyroid nodules to stratify the malignant risk.