bluuebunny/crossref_metadata_2025_split huggingface dataset:
Influence of sulfenamide accelerators on cure kinetics and properties of natural rubber foam
Authors: Charoeythornkhajhornchai Pollawat , Samthong Chavakorn , Somwangthanaroj Anongnat 
Published: January 2017

ABSTRACTThe effect of types of sulfenamide accelerator, i.e., 2‐morpholinothiobenzotiazole (MBS), N‐t‐butylbenzothiazole‐2‐sulfenamide (TBBS), and N‐cyclohexyl benzothiazole‐2‐sulfenamide (CBS) on the cure kinetics and properties of natural rubber foam was studied. It has been found that the natural rubber compound with CBS accelerator shows the fastest sulfur vulcanization rate and the lowest activation energy (Ea) because CBS accelerator produces higher level of basicity of amine species than other sulfenamide accelerators, further forming a complex structure with zinc ion as ligand in sulfur vulcanization. Because of the fastest cure rate of CBS accelerator, natural rubber foam with CBS accelerator shows the smallest bubble size and narrowest bubble size distribution. Moreover, it exhibits the lowest cell density, thermal conductivity and thermal expansion coefficient, as well as the highest compression set as a result of fast crosslink reaction. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 44822.
Optically active tyrosine‐containing poly(N‐propargylamides): Synthesis, helical conformation, and infrared emissivity study
Authors: Bu Xiaohai , Zhang Zewu , Hang Zusheng , Huang Ying , Zhou Yuming 
Published: January 2017

ABSTRACTNovel optically active and racemic poly(N‐propargylamides) bearing tyrosine pendants (LPT, DPT, and RPT) were synthesized and characterized. The polymers possessed moderate molecular weights and were thoroughly soluble in common organic solvents. The secondary structure of these three polymers in chloroform was studied and the results indicated that LPT and DPT could adopt helical structures with predominantly one‐handed screw sense according to their intense Cotton effect and large specific rotation values, while RPT adopted random coiled polymer chain. The amide groups could form amide‐amide hydrogen bonds to engender the twist of dihedral angle and the strong steric repulsion of phenol groups might have the opposite effect on the helix. The helical structure of the optically active polymers were conclusively constructed and stabilized by the optimization of intra‐ and intermolecular hydrogen bonding and steric repulsion of the side chains. Moreover, the infrared emissivity values of LPT and DPT at 30 °C were 0.682 and 0.671, which were much lower than RPT. LPT and DPT also showed superior heat resistance due to their unique helical conformation. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 44824.
Thermal degradation of urea‐formaldehyde cellulose composites filled with aluminum particles: Kinetic approach to mechanisms
Authors: Azeem Arshad Muhammad , Maaroufi AbdelKrim , Benavente Rosario , Pinto Gabriel 
Published: January 2017

ABSTRACTThis article reports a study on structural characterization and thermal degradation kinetics of insulating/conducting urea‐formaldehyde cellulose (UFC) composites filled with aluminum particles. Structural characterization of UFC/Al composites carried out by SEM, XRD, and FTIR analyses reveals that composites are fairly homogenous, and the interactions between UFC and aluminum in UFC/Al composites are more probably physical in nature. Measurements of inherent thermal stabilities, probing reaction complexity, and thermal degradation kinetics of UFC and UFC/Al composites have been undertaken by thermogravimetric (TG)/differential thermogravimetric (DTG) analyses under nonisothermal conditions. The integral procedure decompositions temperature (IPDT) elucidates significant thermal stability of UFC, and higher aluminum contents in composites are capable of enhancing the thermal stability of UFC resin. TG/DTG analyses suggest highly complicated thermal degradation profiles of UFC and UFC/Al composites, which consist of various parallel/consecutive reactions. Generalized linear integral isoconversional method has been employed to determine the activation energies of thermal degradation processes. Substantial variations in activation energies of UFC and UFC/Al composites with the advancement of reaction verify their multi‐step reaction pathways. Advanced reaction model determination methodology with the help of a novel kinetic function F(α,T) reveals that the multi‐step thermal degradation of UFC goes to completion by principally following intricate nucleation/growth mechanisms. It is also found that aluminum more likely participates in the thermal degradation of resin and tends to alter its reaction mechanism. Detailed interpretations of the obtained kinetic parameters are given, and their probable physical significances are discussed. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 44826.
Renewably sourced phenolic resins from lignin bio‐oil
Authors: Vithanage Anushka E. , Chowdhury Emtias , Alejo Luz D. , Pomeroy Paige C. , DeSisto William J. , Frederick Brian G. , Gramlich William M. 
Published: January 2017

ABSTRACTTraditional lignin pyrolysis generates a bio‐oil with a complex mixture of alkyl‐functionalized guaiacol and syringol monomers that have limited utility to completely replace phenol in resins. In this work, formate assisted fast pyrolysis (FAsP) of lignin yielded a bio‐oil consisting of alkylated phenol compounds, due to deoxyhydrogenation, that was used to synthesize phenol/formaldehyde resins. A solvent extraction method was developed to concentrate the phenolics in the extract to yield a phenol rich monomer mixture. Phenolic resins were synthesized using phenol (phenol resin), FAsP bio‐oil (oil resin), and an extract mimic (mimic resin) that was prepared to resemble the extract after further purification. All three phenolic sources could synthesize novolac resins with reactive sites remaining for subsequent resin curing. Differential scanning calorimetry and thermogravimetric analysis of the three resins revealed similar thermal and decomposition behavior of phenol and the mimic resins, while the oil resin was less stable. Resins were cured with hexamethylenetetramine and the mimic resin demonstrated improved curing energies compared to the oil resin. The adhesive strength of the mimic resin was found to be superior to that of the oil resins. These results confirmed that extracting a mixture of substituted aromatics from FAsP bio‐oil could synthesize resins with properties similar to those from phenol and improved over the parent bio‐oil. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 44827.
Impact of fillers and counterface topography on wear behavior of PTFE polymers for ultrasonic motor
Authors: Wang Qihua , Song Fuzhi , Zhang Xinrui , Zhao Gai , Wang Tingmei 
Published: January 2017

ABSTRACTAimed to study the effects of reinforcing or functional fillers on mechanical and tribological properties of PTFE‐based friction materials of ultrasonic motor, carbon fibers reinforced PTFE composites modified with different functional fillers with differences in dimension, size, and hardness are fabricated. The tribological performances of PTFE‐based friction materials are comparatively investigated under different sliding velocities and normal loads on different surface morphologies, respectively. The experimental results reveal that nano‐SiO2 shows excellent performance in improving friction stabilities and wear resistance in different operating conditions. It is believed the silica‐based tribofilms, higher deformation resistance, and bearing capacity play a key role in improving friction stabilities. Furthermore, the results also show that the surface topography plays an important role in wear properties. The lower wear rate (sliding against with the disordered surface) is believed to be attributed to wear debris easy‐store characteristic of the topography, which promotes transfer films formation and decreases the wear rate effectively. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 44835.
Effectively enhancing cytotoxic and apoptotic effects of alpha‐momorcharin by integrating a heparin‐binding peptide
Authors: Tan Meng‐Jie , Cao Xue‐Wei , Li Peng‐Fei , Zhai Yi‐Zhou , Zhou Yu , Liu Ye‐Jun , Zhao Jian , Wang Fu‐Jun 
Published: January 2017

AbstractAlpha‐momorcharin (α‐MMC), a type I ribosome‐inactivating protein, has attracted a great deal of attention because of its antitumor activity. However, the cytotoxicity of α‐MMC is limited due to insufficient cellular internalization in cancer cells. To enhance the cytotoxicity of α‐MMC, a heparin‐binding domain derived from heparin‐binding epidermal growth factor (named heparin‐binding peptide [HBP]) was used as a cell‐penetrating peptide and fused to the C‐terminus of α‐MMC. This novel α‐MMC‐HBP fusion protein was expressed and purified with a Ni2+‐resin. The N‐glycosidase activity and DNase activity assay indicated that the introduction of HBP did not interfere with the intrinsic bioactivities of α‐MMC. HBP was able to efficiently carry α‐MMC into the tested cancer cells and significantly enhance the cytotoxic effects of α‐MMC in a dose‐dependent manner. This enhanced cytotoxic ability occurred due to the higher level of cell apoptosis induced by α‐MMC‐HBP, which was demonstrated in western blot analysis in which α‐MMC‐HBP triggered caspase 8, caspase 9, casapase 3, and PARP more intensely than α‐MMC alone. α‐MMC‐HBP led to an upregulation of cleaved PARP and an increase in the Bax/Bcl‐2 ratio. Our study provided a new practical way to greatly improve the antitumor activity of α‐MMC, which could significantly expand the pharmaceutical applications of α‐MMC.
Simultaneous detection of three sex steroid hormone classes using a novel yeast‐based biosensor
Authors: Chamas Alexandre , Pham Ha Thi Minh , Jähne Martin , Hettwer Karina , Uhlig Steffen , Simon Kirsten , Einspanier Almuth , Baronian Kim , Kunze Gotthard 
Published: January 2017

ABSTRACTA biosensor detecting estrogens, progestogens, and androgens in complex samples and in a single step is described. Three Arxula adeninivorans yeast strains were created, each strain producing a different recombinant human hormone receptor and a different fluorescent reporter protein. These strains were then mixed to create G1212/YRC102‐hHR‐fluo, the biological component of the biosensor. During incubation with G1212/YRC102‐hHR‐fluo, hormones present in a sample bind to their target receptor, which leads to the production of a specific fluorescent protein. Three fluorescence scans of the yeast suspension determine which fluorescence protein has been produced, thus revealing which hormone receptor (estrogen, progesterone, and androgen) has been activated by the hormones or hormone mimics present in the sample. The biosensor has similar sensitivities to the existing A. adeninivorans cell‐based assays. The detection of the three hormone classes in one single experiment reduces the labor and time required to assay for the three hormone classes. The biosensor was also trialed with animal serum samples for the detection of progestogens, androgens, and estrogens and gave results that correlated well with ELISA analysis in case of progestogens. These results highlight the potential usefulness of the biosensor for comprehensive determination of hormone status in samples from veterinary origin. Biotechnol. Bioeng. 2017;114: 1539–1549. © 2017 Wiley Periodicals, Inc.
Randomized clinical trial of preoperative oral versus intravenous iron in anaemic patients with colorectal cancer
Authors: Keeler B D , Simpson J A , Ng O , Padmanabhan H , Brookes M J , Acheson A G , Banerjea A , Walter C , Maxwell-Armstrong C , Williams J , Scholefield J , Abercrombie J , Robinson M , Vitish-Sharma P , Bhandal N , Gornall C , Petsas A , Ward K , Pyke S , Johnson P , Cripps H , Williams G , Green M E , Rankin J , Pinkney T , Iqbal T , Ward D , Tselepis C , Narewal M , Futaba K , Ghods-Ghorbani M , Lund J , Theophilidou E , Peacock O , Longman R , Francis N , Spurdle K , Miskovic D , Moriarty C 
Published: January 2017

Abstract

Background
Treatment of preoperative anaemia is recommended as part of patient blood management, aiming to minimize perioperative allogeneic red blood cell transfusion. No clear evidence exists outlining which treatment modality should be used in patients with colorectal cancer. The study aimed to compare the efficacy of preoperative intravenous and oral iron in reducing blood transfusion use in anaemic patients undergoing elective colorectal cancer surgery.

Methods
Anaemic patients with non-metastatic colorectal adenocarcinoma were recruited at least 2 weeks before surgery and randomized to receive oral (ferrous sulphate) or intravenous (ferric carboxymaltose) iron. Perioperative changes in haemoglobin, ferritin, transferrin saturation and blood transfusion use were recorded until postoperative outpatient review.

Results
Some 116 patients were included in the study. There was no difference in blood transfusion use from recruitment to trial completion in terms of either volume of blood administered (P = 0·841) or number of patients transfused (P = 0·470). Despite this, increases in haemoglobin after treatment were higher with intravenous iron (median 1·55 (i.q.r. 0·93–2·58) versus 0·50 (−0·13 to 1·33) g/dl; P &lt; 0·001), which was associated with fewer anaemic patients at the time of surgery (75 versus 90 per cent; P = 0·048). Haemoglobin levels were thus higher at surgery after treatment with intravenous than with oral iron (mean 11·9 (95 per cent c.i. 11·5 to 12·3) versus 11·0 (10·6 to 11·4) g/dl respectively; P = 0·002), as were ferritin (P &lt; 0·001) and transferrin saturation (P &lt; 0·001) levels.

Conclusion
Intravenous iron did not reduce the blood transfusion requirement but was more effective than oral iron at treating preoperative anaemia and iron deficiency in patients undergoing colorectal cancer surgery.
RNA Protection is Effectively Achieved by Pullulan Film Formation
Authors: Hsieh Ping‐Yao , Monsur Ali M. , Tram Kha , Jahanshahi‐Anbuhi Sana , Brown Christine L. , Brennan John D. , Filipe Carlos D. M. , Li Yingfu 
Published: January 2017

AbstractRNA is a functionally versatile polymer but suffers from susceptibility to spontaneous and RNase‐catalyzed degradation. This vulnerability makes it difficult to preserve RNA for extended periods of time, thus limiting its use in various contexts, including practical applications as functional nucleic acids. Here we present a simple method to preserve RNA by pullulan (a complex sugar produced by Aureobasidium pullulans fungus) film formation. This strategy can markedly suppress both spontaneous and RNase degradation. Importantly, the pullulan film readily dissolves in aqueous solution, thus allowing retrieval of fully functional RNA species. In order to illustrate the advantage of this protective method in a practical application, we engineered a simple paper sensor containing a bacteria‐detecting RNA‐cleaving DNAzyme. This detection capability of the device was unchanged after storage at room temperature for six months.
Successful evacuation of large perirenal hematoma after extracorporeal shock wave lithotripsy (ESWL) ‐ step 1 of the IDEAL recommendations of surgical innovation
Authors: Hallmann Steffen , Petersein Jan , Ruttloff Jürgen , Ecke Thorsten H. 
Published: January 2017

Key Clinical MessageLarger perirenal hematomas after extracorporeal shock wave lithotripsy (ESWL) are sometimes related to the loss of renal function due to compression of the normal renal tissue. After computed tomography‐guided drainage and locally applied urokinase, the hematoma was fractionally evacuated. This procedure is a save and fast way to recover normal renal function.
Electrochemical Infilling of CuInSe2 within TiO2 Nanotube Layers and Subsequent Photoelectrochemical Studies
Authors: Das Sayantan , Sopha Hanna , Krbal Milos , Zazpe Raul , Podzemna Veronika , Prikryl Jan , Macak Jan M. 
Published: January 2017

AbstractAnodic self‐organized TiO2 nanotube layers (with different aspect ratios) were electrochemically infilled with CuInSe2 nanocrystals with the aim to prepare heterostructures with a photoelectrochemical response in the visible light. The resulting heterostructure assembly was confirmed by field‐emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), and X‐ray diffraction (XRD). High incident photon‐to‐electron conversion efficiency values exceeding 55% were obtained in the visible‐light region. The resulting heterostructures show promise as a candidate for solid‐state solar cells.
Enhanced Urea Activity of Oxidation on Nickel‐Deposited Tin Dendrites
Authors: Singh Ramesh Kumar , Subramanian Palaniappan , Schechter Alex 
Published: January 2017

AbstractUrea oxidation has gained tremendous research interest, owing to its application in direct urea fuel cells and urea electrolyzers. In this work, the electrochemical oxidation of urea on a Ni/Sn dendrites catalyst is investigated. Ni and Ni/Sn dendrites are synthesized through electrodeposition on porous Toray© carbon paper. The prepared catalysts were characterized by scanning electron microscopy, X‐ray diffraction, and inductively coupled plasma−optical emission spectroscopy. The Ni/Sn dendrites oxidized 0.33 M urea in alkaline solution at an onset potential of 0.34 V vs. Ag/AgCl with a current density of 44 mA cm−2@0.55 V, which is higher than that of electrodeposited Ni/TC (31 mA cm−2 @0.55 V). In situ Raman spectroscopic measurements indicate that urea oxidation on Ni/Sn dendrites is initiated by Ni(III)OOH species. Electrochemical impedance spectroscopy patterns of Ni/Sn dendrites in the presence of urea displayed a single depressed semicircle at potentials of 325 mV and two semicircles above 325 mV with a decreased total charge‐transfer resistance. The Ni/Sn dendrites electrode shows lower resistance at the tested potentials, indicative of faster urea oxidation kinetics.
α‐Aminoxy Peptoids: A Unique Peptoid Backbone with a Preference for cis‐Amide Bonds
Authors: Krieger Viktoria , Ciglia Emanuele , Thoma Roland , Vasylyeva Vera , Frieg Benedikt , de Sousa Amadeu Nader , Kurz Thomas , Janiak Christoph , Gohlke Holger , Hansen Finn K. 
Published: January 2017

Abstractα‐Peptoids, or N‐substituted glycine oligomers, are an important class of peptidomimetic foldamers with proteolytic stability. Nevertheless, the presence of cis/trans‐amide bond conformers, which contribute to the high flexibility of α‐peptoids, is considered as a major drawback. A modified peptoid backbone with an improved control of the amide bond geometry could therefore help to overcome this limitation. Herein, we have performed the first thorough analysis of the folding propensities of α‐aminoxy peptoids (or N‐substituted 2‐aminoxyacetic acid oligomers). To this end, the amide bond geometry and the conformational properties of a series of model α‐aminoxy peptoids were investigated by using 1D and 2D NMR experiments, X‐ray crystallography, natural bond orbital (NBO) analysis, circular dichroism (CD) spectroscopy, and molecular dynamics (MD) simulations revealing a unique preference for cis‐amide bonds even in the absence of cis‐directing side chains. The conformational analysis based on the MD simulations revealed that α‐aminoxy peptoids can adopt helical conformations that can mimic the spatial arrangement of peptide side chains in a canonical α‐helix. Given their ease of synthesis and conformational properties, α‐aminoxy peptoids represent a new member of the peptoid family capable of controlling the amide isomerism while maintaining the potential for side‐chain diversity.
Active Site Mapping of Xylan‐Deconstructing Enzymes with Arabinoxylan Oligosaccharides Produced by Automated Glycan Assembly
Authors: Senf Deborah , Ruprecht Colin , de Kruijff Goswinus H. M. , Simonetti Sebastian O. , Schuhmacher Frank , Seeberger Peter H. , Pfrengle Fabian 
Published: January 2017

AbstractXylan‐degrading enzymes are crucial for the deconstruction of hemicellulosic biomass, making the hydrolysis products available for various industrial applications such as the production of biofuel. To determine the substrate specificities of these enzymes, we prepared a collection of complex xylan oligosaccharides by automated glycan assembly. Seven differentially protected building blocks provided the basis for the modular assembly of 2‐substituted, 3‐substituted, and 2‐/3‐substituted arabino‐ and glucuronoxylan oligosaccharides. Elongation of the xylan backbone relied on iterative additions of C4‐fluorenylmethoxylcarbonyl (Fmoc) protected xylose building blocks to a linker‐functionalized resin. Arabinofuranose and glucuronic acid residues have been selectively attached to the backbone using fully orthogonal 2‐(methyl)naphthyl (Nap) and 2‐(azidomethyl)benzoyl (Azmb) protecting groups at the C2 and C3 hydroxyls of the xylose building blocks. The arabinoxylan oligosaccharides are excellent tools to map the active site of glycosyl hydrolases involved in xylan deconstruction. The substrate specificities of several xylanases and arabinofuranosidases were determined by analyzing the digestion products after incubation of the oligosaccharides with glycosyl hydrolases.
Thermogravimetric characterization of ex situ polymethacrylate (EDMA‐co‐GMA) monoliths
Authors: Acquah Caleb , Danquah Michael K. , Moy Charles K. S. , Anwar Mahmood , Ongkudon Clarence M. 
Published: January 2017

AbstractThe thermo‐molecular mechanisms associated with free radical synthesis of polymethacrylate monoliths offer an effective pathway to tune their pore characteristics. In this work, thermogravimetric analyses were used for ex situ characterization of polymethacrylate monoliths synthesised from ethylene glycol dimethacrylate (EDMA) and glycidyl methacrylate (GMA). Apparent activation energies of the polymeric monoliths were determined by using Ozawa‐Flynn‐Wall (OFW) and Kissinger‐Akahira‐Sunose (KAS) isoconversional methods. The number of degradation stages for the polymers were observed to be as follows: homopolymeric GMA and EDMA (2 degradation stages each) and polymeric EDMA‐co‐GMA monoliths (3 degradation stages). The relationship between apparent activation energy and extent of conversion showed that the degradation of monoliths is based on a complex multi‐step reaction rather than a single reaction model. Kinetic parameters showed that an increase in the composition of EDMA and GMA above 20 % significantly enhances the thermal stability of polymeric EDMA‐co‐GMA monoliths under elevated non‐isothermal conditions. E40/G60 and E60/G40 monoliths were identified as the most thermally stable monoliths from the kinetic analyses.
Platinum Overgrowth on Gold Multipod Nanoparticles: Investigation of Synergistic Catalytic Effects in a Bimetallic Nanosystem
Authors: Moon Youngseo , Mai Hien Duy , Yoo Hyojong 
Published: January 2017

AbstractHighly ordered heteronanostructures can be synthesized by overgrowth of a secondary material on the as‐prepared seed nanocrystal. The unique morphology of seed nanocrystals directs the shape of the secondary structure, which is exploited to develop structure‐controlled composite nanomaterials. Herein, we report a facile and controllable synthetic strategy toward noble star‐shaped bimetallic nanostructures. Gold multipod nanoparticle (GMN) core–platinum shell nanoparticles (GMN@Pt NPs) are successfully synthesized through the overgrowth of Pt on the surface of GMN seeds. Due to the structural uniqueness of GMNs, GMN@Pt NPs show bimetallic core–shell geometries, which have surface roughness and star‐shaped multi‐branches with sharp edges and tips. The island nucleation and growth of individual Pt particles to form a shell provide larger surface areas and plenty of defects on the bimetallic nanocrystals. GMN@Pt NPs with optimized Pt shells show much higher catalytic activities in 4‐nitrophenol reduction and ethanol electrooxidation than those of GMNs or Pt nanoparticles, mainly due to the synergistic effects of the bicomponent nanosystem.