bluuebunny/crossref_metadata_2025_split huggingface dataset:
Pd nanoparticles immobilized on magnetic chitosan as a novel reusable catalyst for green Heck and Suzuki cross‐coupling reaction: In water at room temperature
Authors: Hajipour Abdol R. , Sadeghi Ali R. , Khorsandi Zahra 
Published: October 2017

A novel type of magnetically responsive chitosan nanocomposite was successfully synthesized as a green and high powerful palladium‐based heterogeneous catalyst and its efficiency in Heck and Suzuki cross‐coupling was evaluated. This catalyst promote a large library of functional substrates of these reactions under mild and sustainable conditions (water or ethanol as solvent, at room temperature, in significantly short reaction time (20 minutes)) and stand as recyclable, metal scavenging catalytic systems.
Facile synthesis of silicone‐toughened unsaturated polyester by hydroxyl‐terminated silicone copolycondensation
Authors: Xu Dawei , Wu Dingcai , Yu Tongbai , Fu Ruowen 
Published: October 2017

ABSTRACTA facile method is developed to synthesize silicone‐toughened unsaturated polyester (SUP‐M) by monomer copolymerization of anhydrides and diols with hydroxyl‐terminated silicone. The structures and molecular weights of the SUP‐M resins were characterized by Fourier transform infrared spectroscopy and gel permeation chromatography, respectively. The gelation time and mechanical properties, including impact strength, flexural strength, and tensile strength, were investigated. The fracture behaviors were studied by scanning electron microscopy, and their glass‐transition temperature and storage modulus were measured by dynamic mechanical analysis. The experimental results showed that the impact strength of SUP‐M can be obviously improved through copolymerization with a small amount of silicone without decreasing its mechanical properties. The impact strength, flexural strength, and tensile strength of SUP‐M‐0.5 are as high as 12.5 KJ m−2, 131 MPa, and 59 MPa, which are increased by 76.1%, 21.2%, and 6.7%, respectively, compared with those of unsaturated polyester. Impacts on SUP‐M with low silicone content produce a large number of evenly and regularly distributed continuous narrow crack bands combined with many evenly distributed branching crazes, which are of great benefit in absorbing a large amount of impact energy. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 45562.
Working mechanism of post‐acting polycarboxylate superplasticizers containing acrylate segments
Authors: Zhang Liran , Kong Xiangming , Xing Feng , Dong Biqin , Wang Fang 
Published: October 2017

ABSTRACTAcrylate‐containing polycarboxylate superplasticizers were synthesized by copolymerizing acrylic acid, α‐methallyl‐ω‐methoxy poly(ethylene glycol) ether, and acrylic esters [hydroxyethyl acrylate (HEA) or hydroxypropyl acrylate (HPA)]. Their dispersing effects and fluidity‐retaining capabilities were evaluated by spread tests of cement pastes. The temperature sensitivity of the performance was especially focused upon. It was found by Fourier transform infrared spectroscopy and specific anionic charge density measurements that the ester groups in the acrylate‐containing copolymers hydrolyze in alkaline conditions, and thus additional RCOO− groups are continuously produced. The gradual production of RCOO− leads to increasing charge density and hence increasing adsorption of the polymer on the cement surface. The hydrolysis of HEA units is slightly faster than of HPA units in the corresponding copolymers. By this mechanism, a post‐acting, or delayed, dispersing effect is realized. Such post‐acting polymers alone or formulated with normal polycarboxylate superplasticizer can be used achieve a long fluidity retention of fresh concrete, especially under elevated temperatures. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 45753.
Optimization of material formulation and processing parameters in relation to mechanical properties of bioepoxy/clay nanocomposites using Taguchi design of experiments
Authors: Salam H. , Dong Y. , Davies I. J. , Pramanik A. 
Published: October 2017

ABSTRACTThis article aims to study the effects of material formulation and processing parameters on mechanical properties of bioepoxy/clay nanocomposites based on epoxidized soybean oil (ESO) via Taguchi design of experiments (DoEs). A mixed‐level DoE with an L16 orthogonal array was constructed to achieve maximum levels of tensile strength, tensile modulus, and impact strength for corresponding bionanocomposites. Pareto analysis of variance (ANOVA) was used to identify significant factors and preferred formulations in the manufacture of bioepoxy/clay nanocomposites. The ESO content was found to have the most significant effect with regards to bionanocomposite mechanical properties with contribution percentages of 66.63, 72.96, and 40.14% for their tensile strength, tensile modulus, and impact strength, respectively. With regards to material processing parameters, mechanical mixing speed was identified as a critical factor to achieve optimal tensile and impact properties. Nonetheless, the results also indicated clay content to be a significant factor for tensile strength, whereas curing agent type was vital for the improvement of tensile modulus and impact strength. Clay type and sonication time were also found to be significant factors for impact strength. In contrast to this, manufacturing parameters such as mechanical mixing temperature, mixing time, and sonication frequency were considered to be non‐significant factors due to their low cumulative contribution percentages of <10%. Finally, experimental confirmation tests based on the preferred combination of factors demonstrated good agreement with statistically predicted results. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 45769.
Laccase‐mediated grafting of polyphenols onto cationized cotton fibers to impart UV protection and antioxidant activities
Authors: Kim Suyeon , Lee Hyunkyung , Kim Juhea , Oliveira Fernando , Souto Pedro , Kim Hyerim , Nakamatsu Javier 
Published: October 2017

ABSTRACTEnzyme‐mediated in situ functionalization of cotton fibers was studied using laccase. Caffeic acid and morin were used as reactive phenolic substrates for laccase and further employed to the modification of fiber surfaces. Laccase‐mediated oxidation and polymerization reactions of caffeic acid were monitored by ultraviolet–visible spectroscopy. During the wetting process, initial cationization of fiber surfaces using poly(diallyldimethylammonium chloride) followed by enzymatic treatment with phenolic substrates resulted ineffective polymer grafting evidenced by high color stability. Changes of fiber surface properties by polymer grafting, such as morphology and hydrophilicity/hydrophobicity, were tested using scanning electron microscopy and gravimetric absorption tests. An acceptable level of color resistance to washing stress was obtained on caffeic acid treated samples, and a high level of rubbing resistance was obtained on samples treated with both caffeic acid and morin. Regarding the ultraviolet protection test, the cationized and enzymatically functionalized samples showed a very good protection grade (ultraviolet protection factor = 25). Finally, the antioxidant activity test of the modified fibers presented an improvement for radical scavenging potential due to the phenolic compounds incorporated to cotton fibers by laccase‐mediated catalysis. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 45801.
The microencapsulation of calcium chloride hexahydrate as a phase‐change material by using the hybrid coupler of organoalkoxysilanes
Authors: Yang Jeong Min , Kim Jeong Soo 
Published: October 2017

ABSTRACTA novel method of microencapsulation for inorganic salt hydrates as phase‐change material (PCM), which is essential for their broad application, was pursued by combining sol–gel process with interfacial polymerization. Calcium chloride hexahydrate (CCH), chosen as a representative PCM of salt hydrates, was used as a core material, and organoalkoxysilane was applied to provide hybrid properties of mediating the hydrophilic core and hydrophobic shell material. The Fourier transform infrared spectra and SEM images confirmed that the siloxane and polyurea shell material successfully capsulated the CCH core. Fine morphology of microcapsules was further investigated with SEM, and it presented almost‐spherical shape and a well‐defined core–shell structure. Thermogravimetric analysis indicated that microcapsules containing CCH have sufficient thermal stability, which usually degraded in four steps. Differential scanning calorimeter investigation confirmed additionally that the microencapsulated CCH absorbs thermal energy with phase change during the melt process but undergo a severe super cooling phenomenon in the crystallizing process. In addition, the durability test was conducted to evaluate the siloxane polymer and polyurea as a shell material, protecting CCH from leaking. The effect of pH and the ratio of ingredients were studied in terms of encapsulation possibility and performance of core PCM, which include morphology of core–shell particles and essential thermal properties as a PCM. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 45821.
Evidence of compatibility and thermal stability improvement of poly(propylene carbonate) and polyoxymethylene blends
Authors: Calderón Bárbara A. , Sobkowicz Margaret J. 
Published: October 2017

ABSTRACTPoly(propylene carbonate) (PPC) is a promising new sustainable polymer produced from carbon dioxide. PPC has inferior thermal stability which could be enhanced by synergistic blending with other polymers. Blends of PPC and the engineering thermoplastic polyoxymethylene are produced by melt compounding in various weight ratios. The compatibility of the blends is investigated using thermogravimetric analysis (TGA), differential scanning calorimetry, Fourier transform infrared spectroscopy (FTIR), density measurements, and scanning electron microscopy (SEM). TGA reveals that thermal stability of the blends increases dramatically in comparison to the neat PPC. A small shift in the glass transition temperature demonstrates the immiscibility of the blends but also indicates some compatibility, attributed to potential dipole–dipole interactions which are also corroborated with the FTIR results. A deviation of the rule of mixtures for density is found for some of the blends. SEM analysis of the blends shows two phase morphology; however, the interfacial adhesion appeared to be enhanced with increasing PPC content. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 45823.
Construction of tissue‐engineered lymphatic vessel using human adipose derived stem cells differentiated lymphatic endothelial like cells and decellularized arterial scaffold: A preliminary study
Authors: Yang Yi , Yang Jian‐Tao , Chen Xiao‐Hu , Qin Ben‐Gang , Li Fu‐Gui , Chen Yun‐Xian , Gu Li‐Qiang , Zhu Jia‐Kai , Li Ping 
Published: October 2017

AbstractWe have previously demonstrated that human adipose‐derived stem cells (hADSCs) can be differentiated into lymphatic endothelial like cells. The purpose of this study was to investigate the feasibility of utilizing the induced lymphatic endothelial like cells and decellularized arterial scaffold to construct the tissue‐engineered lymphatic vessel.The hADSCs were isolated from adipose tissue in healthy adults and were characterized the multilineage differentiation potential. Decellularized arterial scaffold was prepared using the Triton x‐100 method. ADSCs were differentiated into lymphatic‐like endothelial cells, and the induced cells were then seeded onto the decellularized arterial scaffold to engineer the lymphatic vessel. The histological analyses were performed to examine the endothelialized construct.The decellularized arterial scaffold was successfully obtained and was able to maintain its vessel morphology. The isolated ADSCs can be differentiated into osteocytes and adipocytes. After seeding onto the scaffold, the seeded cells attached and grew well on the decellularized arterial scaffold.Our preliminary results demonstrated that the induced lymphatic endothelial like cells combined with decellularized arterial scaffold could be utilized to successfully engineer the lymphatic vessel. Our findings may be helpful for the development of tissue‐engineering of the lymphatic graft.
Raumkonditionierung durch Sandwichfertigteildecken mit integrierten Phasenwechselmaterialien
Authors: Bilgin Deniz , Carrigan Svenja , Friedrich Thomas , Kornadt Oliver 
Published: October 2017

AbstractIn diesem Beitrag wird über die Entwicklung und Erprobung einer neuartigen Raumkonditionierung unter Verwendung von Phasenwechselmaterialien (PCM) berichtet. Das Prinzip besteht darin, überschüssige Wärme im Gebäudeinneren durch ein Umluftsystem in makroverkapseltes PCM, welches in die Sandwichdecke integriert ist, zu speichern. Das PCM erhöht die Wärmespeicherfähigkeit des Bauteils im relevanten Temperaturbereich um mehr als das 10‐fache und reduziert weitgehend vollständig ein Ansteigen der Bauteiltemperatur über die Temperatur des Phasenübergangs des PCM. Einer Überhitzung des Raums wird dadurch ganz beträchtlich entgegengewirkt. Die hier vorgestellten Ergebnisse umfangreicher Laborversuche belegen die grundsätzliche Funk tionsfähigkeit des Systems hinsichtlich Verarbeitbarkeit, Zyklenstabilität des verwendeten PCMs und Absenkung der Lufttemperatur. Es konnte gezeigt werden, dass in einem zyklischen Tag‐Nachtbetrieb eine Reduktion der Lufttemperatur von 2 Kelvin erreicht werden könnte.
Zerstörungsfreie Prüfung von Schutzbauteilen mit dem Impakt‐Echo‐Verfahren
Authors: Zircher Tobias , Schulz Tobias 
Published: October 2017

AbstractMilitärische Einrichtungen der deutschen Bundeswehr stellen bei Einsätzen in einem Konfliktgebiet ein mögliches Ziel für Angriffe dar. Aus diesem Grund kommt der Sicherung von Infrastruktur mittels massiver Schutzbauteile eine hohe Bedeutung zu. Als Grundlage für die Entwicklung von Ingenieurmodellen zur Bemessung der Bauteile für Einwirkungen mit hohen Belastungsgeschwindigkeiten wurden Kontaktdetonationsversuche an Probekörpern, die aus Normal‐ und Stahlfaserbeton hergestellt sind, durchgeführt. Der durch die Kontaktdetonation erzeugte Schädigungsverlauf im Bauteil ist mittels zerstörungsfreier Prüfung untersucht worden. Ziel der Untersuchung war es, die Eignung des Impakt‐Echo(IE)‐Verfahrens für dieses besondere Anwendungsgebiet zu überprüfen. Die Untersuchungen zeigten, dass das IE‐Verfahren zur Bestimmung der Größe des geschädigten Bereichs geeignet war, aber nicht zur Detektion der exakten Schadenstiefe an jedem einzelnen Messpunkt. In der Zukunft werden noch weitere Untersuchungen mit zerstörungsfreien Prüfgeräten wie beispielsweise dem Georadar durchgeführt.
Abschätzung der Rissausbreitung in Stahlbetonbauteilen
Authors: Meinhardt Marcel 
Published: October 2017

AbstractDie Rissbildung in Beton ist ein komplexes Phänomen, welches durch äußere Lasten und Zwang hervorgerufen werden kann und somit das Last‐Verformungs‐Verhalten von Stahlbeton beeinflusst, sobald die Zugfestigkeit überschritten wird. Folglich ist es bedeutsam vorherzusagen, wo Risse auftreten und wie sie sich ausbreiten.Dieser Artikel gibt einen kurzen Überblick über die im Labor für Konstruktiven Ingenieurbau an der Universität der Bundeswehr München durchgeführten Experimente an Stahlbetonscheiben und ‐platten sowie über die wesentlichen Ergebnisse derselben. Anschließend wird auf die aktuelle Forschung des Autors eingegangen. Um ein besseres Verständnis zur Spannungsverteilung in der direkten Umgebung der Längs‐ und Querbewehrung zu erlangen, wird ein kleiner vereinfachter Ausschnitt einer Stahlbetonplatte in dem Finite‐Elemente‐Programm ANSYS modelliert. Ziel war es, die Möglichkeiten und Grenzen der Extended Finite Element Method (XFEM), welche in ANSYS zur Rissfortschrittsanalyse implementiert ist, zu evaluieren sowie den Ort der Rissinitiierung und die Rissausbreitung zu untersuchen.
Verbund von Beton und Bewehrungsstahl bei hochdynamischer Beanspruchung
Authors: Michal Mathias 
Published: October 2017

AbstractBei dem Entwurf von Bauwerken wie Botschaften, militärischen Einrichtungen und Kernkraftwerken sind neben den planmäßigen auch außergewöhnliche Beanspruchungen wie Explosion und Impakt zu berücksichtigen. Diese Einwirkungen führen zu großen Verzerrungsraten in den betroffenen Baustoffen. Es ist bekannt, dass sich die mechanischen Eigenschaften von Stahl und Beton ebenso wie ihr Verbundverhalten mit der Belastungsgeschwindigkeit verändern. Die Kenntnis des ratenabhängigen Verbundverhaltens von Stahl und Beton ist die Voraussetzung für die nichtlineare Analyse von Stahlbetonbauteilen bei hochdynamischen Beanspruchungen, wenn Systemreserven durch plastische Lastumlagerungen ausgenutzt werden sollen, die Dichtigkeit gegen Flüssigkeiten oder Gase gewährleistet sein muss und Anforderungen an die Begrenzung der Rissbreite bestehen oder die auftretende Verformung begrenzt werden muss. Um das komplexe Zusammenwirken von Stahl und Beton bei hohen Belastungsgeschwindigkeiten zu erfassen, wurden geeignete experimentelle Methoden entwickelt. Auf Grundlage der Versuchsergebnisse werden Modelle vorgeschlagen, mit denen der Einfluss der Zeit auf den Verbund beschrieben werden kann.
Developing students’ mathematical and computational knowledge to investigate mooring line in ocean engineering
Authors: Zhou Xiang‐Lian , Wang Jian‐Hua , Zhang Lu‐Lu , Zhang Jun 
Published: October 2017

AbstractThe rapid development of fast, powerful, and affordable computer technology has provided educators options to introduce innovations in teaching and learning process. The purpose of this study is to investigate the effect of computational simulations on students' understanding of marine mooring line tension in ocean engineering course. Instructional strategies need to incorporate mathematical and computational knowledge into their practice project so that students can use its core concepts to solve interdisciplinary problems. By writing students own Matlab program, students will demonstrate the effect of mathematical and computational tools on the analysis of ocean structural dynamics. The effectiveness of instructional methods by investigating learning gains, instructional effect, and student perceptions about the course are evaluated. Through the teaching practice, students significantly increase their understanding of ocean engineering concepts.
Metabolic characteristics of programmed cell death‐ligand 1‐expressing lung cancer on 18F‐fluorodeoxyglucose positron emission tomography/computed tomography
Authors: Takada Kazuki , Toyokawa Gouji , Okamoto Tatsuro , Baba Shingo , Kozuma Yuka , Matsubara Taichi , Haratake Naoki , Akamine Takaki , Takamori Shinkichi , Katsura Masakazu , Shoji Fumihiro , Honda Hiroshi , Oda Yoshinao , Maehara Yoshihiko 
Published: October 2017

AbstractProgrammed cell death‐1 (PD‐1) and programmed cell death‐ligand 1 (PD‐L1) have been identified as novel targets of immunotherapy of lung cancer. In present study, we evaluated the metabolic characteristics of lung cancer by using 18F‐fluorodeoxyglucose positron emission tomography/computed tomography (18F‐FDG PET/CT) with regard to PD‐L1 protein expression. PD‐L1 protein expression was evaluated by immunohistochemistry with the antibody clone SP142 in 579 surgically resected primary lung cancer patients. Cases with less than 5% tumor membrane staining were considered negative. We examined the association between the frequency of PD‐L1 protein expression and the maximum standardized uptake value (SUVmax) in preoperative 18F‐FDG PET/CT. The cut‐off values for SUVmax were determined by receiver operating characteristic curve analyses. The SUVmax was significantly higher in nonsmall cell lung cancer (NSCLC) patients with PD‐L1 protein expression compared with those without PD‐L1 protein expression (P < 0.0001). However, there was no correlation between SUVmax and PD‐L1 protein expression in patients with neuroendocrine tumors (P = 0.6545). Multivariate analysis revealed that smoking, the presence of pleural invasion, and high SUVmax were independent predictors of PD‐L1 positivity. PD‐L1‐expressing NSCLC had a high glucose metabolism. The SUVmax in preoperative 18F‐FDG PET/CT was a predictor of PD‐L1 protein expression in patients with NSCLC.
Dynamic changes of urine proteome in a Walker 256 tumor‐bearing rat model
Authors: Wu Jianqiang , Guo Zhengguang , Gao Youhe 
Published: October 2017

AbstractDespite advances in cancer treatments, early diagnosis of cancer is still the most promising way to improve outcomes. Without homeostatic control, urine reflects systemic changes in the body and can potentially be used for early detection of cancer. In this study, a tumor‐bearing rat model was established by subcutaneous injection of Walker 256 cells. Urine samples from tumor‐bearing rats were collected at five time points during cancer development. Dynamic urine proteomes were profiled using liquid chromatography coupled with tandem mass spectrometry (LC‐MS/MS). Several urine proteins that changed at multiple time points were selected as candidate cancer biomarkers and were further validated by multiple reaction monitoring (MRM) analysis. It was found that the urinary protein patterns changed significantly with cancer development in a tumor‐bearing rat model. A total of 10 urinary proteins (HPT, APOA4, CO4, B2MG, A1AG, CATC, VCAM1, CALB1, CSPG4, and VTDB) changed significantly even before a tumor mass was palpable, and these early changes in urine could also be identified with differential abundance at late stages of cancer. Our results indicate that urine proteins could enable early detection of cancer at an early onset of tumor growth and monitoring of cancer progression.
Simultaneous IR‐Spectroscopic Observation of α‐Synuclein, Lipids, and Solvent Reveals an Alternative Membrane‐Induced Oligomerization Pathway
Authors: Fallah Mohammad A. , Gerding Hanne R. , Scheibe Christian , Drescher Malte , Karreman Christiaan , Schildknecht Stefan , Leist Marcel , Hauser Karin 
Published: October 2017

AbstractThe intrinsically disordered protein α‐synuclein (αS), a known pathogenic factor for Parkinson's disease, can adopt defined secondary structures when interacting with membranes or during fibrillation. The αS–lipid interaction and the implications of this process for aggregation and damage to membranes are still poorly understood. Therefore, we established a label‐free infrared (IR) spectroscopic approach to allow simultaneous monitoring of αS conformation and membrane integrity. IR showed its unique sensitivity for identifying distinct β‐structured aggregates. A comparative study of wild‐type αS and the naturally occurring splicing variant αS Δexon3 yielded new insights into the membrane's capability for altering aggregation pathways.
AGT Activity Towards Intrastrand Crosslinked DNA is Modulated by the Alkylene Linker
Authors: O'Flaherty Derek K. , Wilds Christopher J. 
Published: October 2017

AbstractDNA oligomers containing dimethylene and trimethylene intrastrand crosslinks (IaCLs) between the O4 and O6 atoms of neighboring thymidine (T) and 2′‐deoxyguanosine (dG) residues were prepared by solid‐phase synthesis. UV thermal denaturation (Tm) experiments revealed that these IaCLs had a destabilizing effect on the DNA duplex relative to the control. Circular dichroism spectroscopy suggested these IaCLs induced minimal structural distortions. Susceptibility to dealkylation by reaction with variousO6‐alkylguanine DNA alkyltransferases (AGTs) from human andEscherichia coliwas evaluated. It was revealed that only human AGT displayed activity towards the IaCL DNA, with reduced efficiency as the IaCL shortened (from four to two methylene linkages). Changing the site of attachment of the ethylene linkage at the 5′‐end of the IaCL to the N3 atom of T had minimal influence on duplex stability and structure, and was refractory to AGT activity.