bluuebunny/crossref_metadata_2025_split huggingface dataset:
Tailor‐Made Ruthenium‐Triphos Catalysts for the Selective Homogeneous Hydrogenation of Lactams
Authors: Meuresch Markus , Westhues Stefan , Leitner Walter , Klankermayer Jürgen 
Published: December 2015

AbstractThe development of a tailored tridentate ligand enabled the synthesis of a molecular ruthenium‐triphos catalyst, eliminating dimerization as the major deactivation pathway. The novel catalyst design showed strongly increased performance and facilitated the hydrogenation of highly challenging lactam substrates with unprecedented activity and selectivity.
Iron‐Catalyzed Intramolecular C(sp2)−H Amination
Authors: Alt Isabel T. , Plietker Bernd 
Published: December 2015

AbstractThe nucleophilic iron complex Bu4N[Fe(CO)3(NO)] (TBA[Fe]) catalyzes the direct intramolecular C−H amination of α‐azidobiaryls and (azidoaryl)alkenes into the corresponding carbazoles and indoles, respectively, under mild conditions and with low catalyst loadings. These features and the broad functional‐group tolerance render this method a particularly attractive alternative to established noble‐metal‐based procedures.
Flame‐retardant and thermal degradation mechanism of low‐density polyethylene modified with aluminum hypophosphite and microencapsulated red phosphorus
Authors: Wang De Kang , He Hui , Yu Peng 
Published: December 2015

ABSTRACTAluminum hypophosphite (AHP), a novel flame retardant, was used to improve the flame retardancy of low‐density polyethylene (LDPE) with microencapsulated red phosphorus (MRP). The synergistic effect between MRP and AHP was investigated by the limiting oxygen index (LOI), vertical burning test (UL‐94), and thermogravimetric analysis. When the contents of MRP and AHP were 10 and 30 phr, the LOI of LDPE/10MRP/30AHP composite was 25.5%, and it passed the UL‐94 V‐0 rating (the number before “MRP” and “AHP” is the loading of MRP and AHP, In LDPE/10MRP/30AHP, the content of the LDPE, MRP and AHP is 100phr, 10phr and 30phr, where phr refers to parts per hundreds of resin). The results of cone calorimetry testing show that the heat release rate of the composites was significantly reduced, and the strength of the char layer improved when the loading of AHP increased. The thermal stability of the LDPE/10MRP/30AHP composite was enhanced. The structure of the char was investigated by Fourier transform infrared spectrometry and scanning electron microscopy/energy‐dispersive spectrometry. The results indicate that AHP promoted the formation of stable char. This research provided a good way to prepare flame‐retardant materials with a halogen‐free flame retardant and contributed to environmental protection. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 43225.
Rapid fabrication of poly(ε‐caprolactone) nanofibers using needleless alternating current electrospinning
Authors: Lawson Caitlin , Stanishevsky Andrei , Sivan Manikandan , Pokorny Pavel , Lukáš David 
Published: December 2015

ABSTRACTPoly(ε‐caprolactone) (PCL) biopolymer nanofibers and micro‐fibers have been fabricated for the first time at the rates up to 14.0 g per hour using a needleless and collectorless alternating current electrospinning technique. By combining the ac‐voltage, “green” low toxicity glacial acetic acid (AA) as the solvent and sodium acetate (NaAc) as an additive, beadless PCL fibers with diameters tunable from 150 nm to 2000 nm, varying surface morphology and degree of self‐bundling are obtained. In this new approach, the addition of NaAc plays a crucial role in improving the spinnability of PCL solution and fiber morphology. NaAc reveals the concentration‐dependent effect on charge transfer and rheological properties of the PCL/AA precursor, which results in broader ranges of spinnable PCL concentrations and ac‐voltages suitable for rapid manufacturing of PCL‐based fibers. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 43232.
Diluent selection forNylon 11 andNylon 12 thermally induced phase separation systems
Authors: Funk Caleb V. , Koreltz Michael S. , Billovits Gerald F. 
Published: December 2015

ABSTRACTNylon 11 and Nylon 12 are commercially important polymers due to their unique combination of mechanical strength, chemical resistance, and processability. Products have been prepared from these polymers via thermally induced phase separation (TIPS) for many years. Nevertheless, known diluents for Nylon 11 and 12 pose specific processing problems, and it would be desirable to find a diluent that allows low processing temperatures, has a high flash point, is inexpensive, and exhibits low toxicity. This work investigated a variety of alternative diluents not previously documented in the literature. A fundamental study was also performed to determine which factors are important in selecting a diluent for preparing Nylon liquid–liquid TIPS membranes. The information gathered in this study, including phase diagrams for all feasible systems investigated, will be important in shaping future formulation work for Nylon use in microporous membranes. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci.2016,133, 43237.
Syndiotactic polypropylene nanofibers obtained from solution electrospinning process at ambient temperature
Authors: Maeda Tomoki , Takaesu Keita , Hotta Atsushi 
Published: December 2015

ABSTRACTFabrication of semicrystalline syndiotactic polypropylene (sPP) nanofibers by solution electrospinning was studied. It was found that sPP nanofibers with an average diameter of 230 nm were successfully fabricated via solution electrospinning with methylcyclohexane as solvent at room temperature (25°C). The obtained diameter was significantly thinner than the minimum diameter of 350 nm of PP fibers that were reported previously. It was also found that increasing viscosity of the sPP solution, which was customarily a useful way of fabricating noncrystalline thin fibers, was found ineffectual in producing thinner semicrystalline sPP fibers in our experiments. In fact, a careful selection of solvent by considering the evaporation rate and the specific viscosity could effectively lead to the fabrication of thinner sPP fibers by imposing proper elongation and preventing the sPP solution from gelation. The results could be applied to other semicrystalline polyolefins with similar gelation characteristics analogous to sPP to produce thinner nanofibers. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 43238.
Mechanical and thermal properties of modified kaolin clay/unsaturated polyester nanocomposites
Authors: George Manoj , Kochimoolayil George Elias , Jayadas Narakathra Haridas 
Published: December 2015

ABSTRACTThe improvement in thermal and mechanical properties of Nanocomposites prepared with unsaturated polyester (UP) as polymer matrix and various loadings of amino‐modified nano kaolinite clay as filler has been studied. Mechanical stirring and ultrasonication resulted in better dispersion of the clay. For curing polyester resin, cobalt naphthenate was used as accelerator and MEKP as initiator. Dynamic Mechanical Analysis (DMA) was carried out to find storage and loss modulus. Thermal stability was found through thermogravimetric analysis and the evaluation of structure and morphology of the nanocomposites were done through XRD, SEM, and TEM. Nanocomposite with 3 phr of amino modified clay has shown higher storage modulus and an improved thermal stability of UP/clay nanocomposites has been established. Tensile strength and toughness of the composite have been found to achieve maximum values at 1 phr of clay and the storage modulus has had an improvement of 38% compared to neat UPR. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 43245.
Quantitative measurement of physisorbed silane on a silica particle surface treated with silane coupling agents by thermogravimetric analysis
Authors: Yamazaki Ryota , Karyu Nozomi , Noda Masayo , Fujii Syuji , Nakamura Yoshinobu 
Published: December 2015

ABSTRACTWe investigated a new method for estimating the amount of silanes physisorbed on a silica particle surface treated with silane coupling agents from a weight loss curve measured by thermogravimetric (TG) analysis. The silica particles were treated with 3‐glycidoxypropyl trimethoxysilane (GPTMS) or 3‐mercaptopropyl trimethoxysilane (MrPTMS) with both dry and wet treatment methods. In the TG curve for silica particles treated with GPTMS, the weight decreased in three steps: 100–170°C (first step), 170–250°C (second step), and 250–400°C (third step). The weight loss in the first step decreased with heating or acetone washing to remove the physisorbed molecules as the posttreatment. The three weight losses were found to be based on physisorbed monomeric silanes (first step), physisorbed polycondensed silanes (second step), and chemisorbed silanes (third step), respectively. The amount of physisorbed silanes on the silane‐treated layer could be estimated from the TG curve without solvent washing to remove the physisorbed molecules. The amounts obtained were almost equal to those measured from a comparison of the weight losses for the treated particles before and after acetone washing. A similar tendency was observed for MrPTMS‐treated silica. Thus, the amount of physisorbed silanes in silane‐coupling‐agent‐treated silica particles was successfully estimated from the TG measurements. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 43256.
Apoferritin‐templated biosynthesis of manganese nanoparticles and investigation of direct electron transfer of MnNPs–HsAFr at modified glassy carbon electrode
Authors: Rafipour Ronak , Kashanian Soheila , Hashemi Sadegh , Omidfar Kobra , Ezzati Nazhad Dolatabadi Jafar 
Published: December 2015

AbstractManganese nanoparticles (MnNPs) were created within horse spleen apoferritin (HsAFr) cavity nanotemplates. Transmission electron microscopy revealed the particle size to be 6 nm. Intrinsic fluorescence data showed that the mineralization acted as a quencher of the HsAFr fluorescence, and extrinsic fluorescence data revealed that the hydrophobic binding site at the surface of HsAFr was not changed. Finally, the MnNP‐HsAFr was immobilized onto multiwalled carbon nanotubes entrapped into chitosan (CS) matrices by through sequential 1‐ethyl‐3‐(3‐dimethylaminopropyl) carbodiimide–N‐hydroxysuccinimide and glutaraldehyde coupling. The MnNPs–HsAFr immobilized on CNT‐CS/GC electrode was characterized by cyclic voltammetry. This charge transfer coefficient (α) and the exchange current (i0) of MnNPs–HsAFr immobilized on modified electrode in 0.1 M phosphate solution (pH 7.5) were found to be 0.57 and 0.48 μA, respectively.
Effect of age on survival in patients undergoing resection of hepatocellular carcinoma
Authors: Cucchetti A , Sposito C , Pinna A D , Citterio D , Ercolani G , Flores M , Cescon M , Mazzaferro V 
Published: December 2015

Abstract

Background
The benefit of surgical intervention for cancer should be estimated in relation to the life expectancy of the general population. The aim of this study was to provide a measure of relative survival after hepatectomy for hepatocellular carcinoma (HCC).

Methods
Consecutive patients with liver cirrhosis and HCC who underwent hepatectomy were divided into age quartiles for analysis. Short- and mid-term survival rates were used to estimate survival until death for all patients, in relation to age and other co-variables. Years of life lost (YLL) were estimated using a reference cohort, derived from the general population matched for sex, age and year of diagnosis.

Results
Some 919 patients were included in the study. The following age quartiles were identified: less than 60 years (229 patients), 60–66 years (230), 67–70 years (231) and over 70 years (229). Postoperative mortality rates were similar between age quartiles, as were survival rates up to 3 years (P = 0·404). A statistically significant reduction in 5–10-year survival rates was observed with ageing (P = 0·001). Relative survival calculation showed that the youngest age quartile (less than 60 years) experienced the longest entire postoperative lifespan (15·6 years) but also the greatest number of YLL (11·0 years). Patients aged over 70 years had the shortest entire postoperative lifespan (6·4 years) but also the smallest number of YLL (3·7 years).

Conclusion
Although survival after liver resection for HCC is shortest in elderly patients, relative survival estimates suggest that hepatectomy can be of benefit in these patients, with a small loss of the entire individual lifespan.
A quantitative determination of fluorochloridone in rat plasma by UPLC‐MS/MS method: application to a pharmacokinetic study
Authors: Liu Shihong , Shi Jingmin , Fan Junpei , Sun Jie , Zhang Suhui , Hu Yue , Wei Li , Wu Chunhua , Chang Xiuli , Tang Liming , Zhou Zhijun 
Published: December 2015

AbstractA precise, high‐throughput and sensitive ultra‐performance liquid chromatography–tandem mass spectrometry (UPLC‐MS/MS) method has been developed for the determination of fluorochloridone (FLC) in rat plasma. The extraction of analytes from plasma samples was carried out by protein precipitation procedure using acetonitrile prior to UPLC‐MS/MS analysis. Verapamil was proved as a proper internal standard (IS) among many candidates. The chromatographic separation based on UPLC was well optimized. Multiple reaction monitoring in positive electrospray ionization was used with the optimized MS transitions at: m/z 312.0 → 292.0 for FLC and m/z 456.4 → 165.2 for IS. This method was well validated with good linear response (r2 > 0.998) observed over the investigated range of 3–3000 ng/mL and with satisfactory stability. This method was also characterized with adequate intra‐ and inter‐day precision and accuracy (within 12%) in the quality control samples, and with high selectivity and less matrix effect observed. Total running time was only 1.5 min. This method has been successfully applied to a pilot FLC pharmacokinetic study after oral administration. Copyright © 2016 John Wiley & Sons, Ltd.
In vitro and in vivo metabolism studies of dimethazine
Authors: Geldof Lore , Tudela Eva , Lootens Leen , van Lysebeth Jasper , Meuleman Phillip , Leroux‐Roels Geert , van Eenoo Peter , Deventer Koen 
Published: December 2015

AbstractThe use of anabolic steroids is prohibited in sports. Effective control is done by monitoring their metabolites in urine samples collected from athletes. Ethical objections however restrict the use of designer steroids in human administration studies. To overcome these problems alternative in vitro and in vivo models were developed to identify metabolites and to assure a fast response by anti‐doping laboratories to evolutions on the steroid market. In this study human liver microsomes and an uPA+/+‐SCID chimeric mouse model were used to elucidate the metabolism of a steroid product called ‘Xtreme DMZ’. This product contains the designer steroid dimethazine (DMZ), which consists of two methasterone molecules linked by an azine group. In the performed stability study, degradation from dimethazine to methasterone was observed. By a combination of LC‐High Resolution Mass Spectrometry (HRMS) and GC‐MS(/MS) analysis methasterone and six other dimethazine metabolites (M1–M6), which are all methasterone metabolites, could be detected besides the parent compound in both models. The phase II metabolism of dimethazine was also investigated in the mouse urine samples. Only metabolites M1 and M2 were exclusively detected in the glucuro‐conjugated fraction; all other compounds were also found in the free fraction. For effective control of DMZ misuse in doping control samples, screening for methasterone and methasterone metabolites should be sufficient. Copyright © 2016 John Wiley & Sons, Ltd.
GeoTest—A system for the automatic evaluation of geometry‐based problems
Authors: Gergelitsová Šárka , Holan Tomáš 
Published: December 2015

ABSTRACTThis paper presents the design of a system for the assignment and evaluation of tasks in the area of geometry. The goal of this design is to help teachers specify and test/verify the initial level of knowledge and abilities required from students entering the relevant course. This design has been used for the implementation of GeoTest, a web based application using the GeoGebra dynamic geometry software. GeoTest has been in use by more than 100 teachers and 5,000 students at universities and secondary and elementary schools during the last 4 years. The feedback received from teachers confirms the usability of the application and its positive acceptance by teachers as well as students. © 2015 Wiley Periodicals, Inc. Comput Appl Eng Educ 24:297–304, 2016; View this article online at wileyonlinelibrary.com/journal/cae; DOI 10.1002/cae.21712
Distal bile duct carcinomas and pancreatic ductal adenocarcinomas: postulating a common tumor entity
Authors: Schmuck Rosa B. , de Carvalho‐Fischer Cynthia V. , Neumann Christopher , Pratschke Johann , Bahra Marcus 
Published: December 2015

AbstractThe set definition of distal cholangiocarcinomas and adenocarcinomas of the pancreatic head is challenged by their close anatomical relation, similar growth pattern, and corresponding therapeutic outcome. They show a mutual development during embryologic organ formation and share phenotypic characteristics. This review will highlight the similarities with regard to the common origin of their primary organs, histopathological similarities, and modern clinical management. Thus, we propose to subsume those entities under a common superfamily.
Toluene Dioxygenase‐Catalysed Oxidation of Benzyl Azide to Benzonitrile: Mechanistic Insights for an Unprecedented Enzymatic Transformation
Authors: Vila María Agustina , Pazos Mariana , Iglesias César , Veiga Nicolás , Seoane Gustavo , Carrera Ignacio 
Published: December 2015

AbstractEnzymatic dioxygenation of benzyl azide by toluene dioxygenase (TDO) produces significant amounts of the cis‐cyclohexadienediol derived from benzonitrile, along with the expected azido diols. We demonstrate that TDO catalyses the oxidation of benzyl azide to benzonitrile, which is further dioxygenated to produce the observed cis‐diol. A proposed mechanism for this transformation involves initial benzylic monooxygenation followed by a nitrene‐mediated rearrangement to form an oxime, which is further dehydrated to afford the nitrile. To the best of our knowledge, this is the first report of enzymatic oxidation of an alkyl azide to a nitrile. In addition, the described oxime‐dehydration activity has not been reported for Rieske dioxygenases.
Efficient Photocatalytic Oxygen Production over Nitrogen‐Doped Sr4Nb2O9 under Visible‐Light Irradiation
Authors: Wu Fangfang , Lv Meilin , Sun Xiaoqin , Xie Yinghao , Chen Hongmei , Ni Shuang , Liu Gang , Xu Xiaoxiang 
Published: December 2015

AbstractPhotocatalytic water splitting is an appealing process for solar energy conversions yet it is often limited by the slow oxidation of water to oxygen half‐reaction. Here we performed an investigation on N‐doped Sr4Nb2O9 as a water oxidation photocatalyst. Our results show that N doping is an effective approach to improve the visible‐light response of Sr4Nb2O9. Efficient photocatalytic oxygen production was observed after N doping, and the highest production rate of ∼27 μmol h−1 under visible‐light irradiation corresponds to an apparent quantum efficiency of ∼0.31 %. Clear anodic photocurrent can be generated under visible‐light illumination, and the flat‐band potential was determined to be ∼−1.25 V vs. Ag/AgCl at pH 7. Theoretical calculations reveal that N doping introduces additional valence bands and is responsible for the visible‐light response. Variations in light absorption and photo‐oxidation performance can be controlled by modifying these valence band positions using different nitridation temperatures.
Simple Continuous High‐Pressure Hydrogen Production and Separation System from Formic Acid under Mild Temperatures
Authors: Iguchi Masayuki , Himeda Yuichiro , Manaka Yuichi , Matsuoka Koichi , Kawanami Hajime 
Published: December 2015

AbstractA simple and continuous high‐pressure (>120 MPa) hydrogen production system was developed by the selective decomposition of formic acid at 80 °C using an iridium complex as a catalyst, with a view to its application in future hydrogen fuel filling stations. The system is devoid of any compressing system. The described method can provide high‐pressure H2 with 85 % purity after applying an effective gas–liquid separation process to separate the generated gas obtained from the decomposition of formic acid (H2/CO2=1:1). The efficiency of the catalyst lies with its high turnover frequency (1800 h−1 at 40 MPa) to produce high‐pressure H2 with a good lifetime of >40 h. Interestingly, only very low levels carbon monoxide (less than 6 vol ppm) were detected in the generated gas, even at 120 MPa.
Low‐Temperature Preferential Oxidation of Carbon Monoxide on Pt3Ni Alloy Nanoparticle Catalyst with Engineered Surface
Authors: Hwang Sang Youp , Yurchekfrodl Eric , Zhang Changlin , Peng Zhenmeng 
Published: December 2015

AbstractThe front cover artwork for Issue 01/2016 is provided by the catalysis research group at the University of Akron (USA). The image shows an octahedral Pt3Ni alloy nanoparticle catalyst that benefits from unique surface geometry and electronic structure. This catalyst exhibits high activity and selectivity for the preferential oxidation of carbon monoxide in hydrogen. See the Communication itself at http://dx.doi.org/10.1002/cctc.201500783.
Reduction Process of Tetraplatin in the Presence of Deoxyguanosine Monophosphate (dGMP): A Computational DFT Study
Authors: Šebesta Filip , Burda Jaroslav V. 
Published: December 2015

AbstractThe reduction mechanism of [PtIV(dach)Cl4] (dach=diaminocyclohexyl) in the presence of dGMP was studied. The first step is substitution of a chloro ligand by dGMP, followed by nucleophilic attack of a phosphate or sugar oxygen atom to the C8‐position of guanine. Subsequent reduction forms the [PtII(dach)Cl2] complex. The whole process is completed by a hydrolysis. Two different pathways for the substitution reaction were examined: a direct associative and a Basolo–Pearson autocatalytic mechanism. All the explored structures were optimized at the B3LYP‐D3/6‐31G(d) level and by using the COSMO solvation model with Klamt's radii. Single‐point energetics was determined at the B3LYP‐GD3BJ/6‐311++G(2df,2pd)/PCM/scaled‐UAKS level. Activation barriers were used for an estimation of the rate constants and these were compared with experimental values. It was found that the rate‐determining step is the nucleophilic attack with a slightly faster performance in the 3′‐dGMP branch than in the case of 5′‐dGMP with activation barriers of 21.1 and 20.4 kcal mol−1(experimental: 23.8 and 23.2 kcal mol−1). The reduction reaction is connected with an electron flow from guanine. The product of the reduction reaction is a chelate structure, which dissociates within the last reaction step, that is, a hydrolysis reaction. The whole redox process (substitution, reduction, and hydrolysis) is exergonic by 34 and 28 kcal mol−1for 5′‐dGMP and 3′‐dGMP, respectively.
A Highly Energetic N‐Rich Metal–Organic Framework as a New High‐Energy‐Density Material
Authors: Zhang Huabin , Zhang Mingjian , Lin Ping , Malgras Victor , Tang Jing , Alshehri Saad M. , Yamauchi Yusuke , Du Shaowu , Zhang Jian 
Published: December 2015

AbstractMetal–organic framework (MOF)‐based energetic material [Cu3(MA)2(N3)3] (1; MA=melamine) was synthesized and structurally characterized (47.55 % N). The structural analysis revealed the existence of unusual multiwalled tubular channels and interweaving of single and double helical units in 1. The standard molar enthalpy of formation was found to be 1788.73 kJ mol−1, which is the highest value among previously reported MOF‐based energetic materials. The calculated detonation properties showed that 1 can be used as a potential explosive. Sensitivity tests revealed that 1 is insensitive and thus can function as a high‐energy‐density material with a favorable level of safety.