bluuebunny/crossref_metadata_2025_split huggingface dataset:
A model of devolatilization behavior in lignite pyrolysis with solid heat carriers
Authors: Li Fang‐zhou , Feng Jie , Li Xiao‐hong , Li Wen‐ying , Wang Jin 
Published: March 2019

AbstractTo elucidate the influence of the process conditions on pyrolytic products, the interactions between transport phenomena and pyrolysis kinetics are quantitatively analyzed at the level of a single coal particle. A comprehensive mathematical model is formulated to predict intraparticle multiphysics and devolatilization behaviors; the model contains two correlative one‐dimensional unsteady heat conservation equations and ternary mass conservation equations in conjunction with the simplified dusty‐gas model. Moreover, a multistep kinetic model of coal devolatilization is adopted to predict the generating rates of the lumped pyrolytic products. Validation of the model against experimental and literature data showed that can predict the transient temperature profiles of a coal particle and the yields of volatiles. Finally, the effects of the main process conditions on the intra‐ and extra‐temperature history of lignite during pyrolysis with solid heat carriers are analyzed. The interactions between physical transport and the pyrolysis reaction are also examined.
Leptospiraspp., rotavirus, norovirus, and hepatitis E virus surveillance in a wild invasive golden‐headed lion tamarin (Leontopithecus chrysomelas; Kuhl, 1820) population from an urban park in Niterói, Rio de Janeiro, Brazil
Authors: Molina Camila V. , Heinemann Marcos B. , Kierulff Cecilia , Pissinatti Alcides , da Silva Tiago F. , de Freitas Danilo G. , de Souza Gisele O. , Miotto Bruno A. , Cortez Adriana , Semensato Beatriz de P. , Moreno Luisa Z. , Catão‐Dias José L. , Bueno Marina G. 
Published: March 2019

AbstractThe world currently faces severe biodiversity losses caused by anthropogenic activities such as deforestation, pollution, the introduction of exotic species, habitat fragmentation, and climate changes. Disease ecology in altered environments is still poorly understood. The golden‐headed lion tamarin (GHLT,Leontopithecus chrysomelas) is an endangered species that became invasive in an urban park in Niterói, Rio de Janeiro, Brazil. The initially few invasive GHLT individuals became hundreds, adapted to living in proximity to humans and domestic animals. These GHLTs were captured as part of a conservation project; some animals were translocated to Bahia and some were kept in captivity. This study tested 593 GHLT forLeptospiraserology; 100 and 95 GHLT for polymerase chain reaction (PCR) toLeptospiraand hepatitis E virus genotype 3 (HEV‐3), respectively, and 101 familiar groups for PCR to viruses (rotavirus A, norovirus GI and GII, and HEV‐3). One animal had antibodies forLeptospiraserovar Shermani and another for serovar Hebdomadis. One saprophyticLeptospirawas found by the 16S PCR and sequencing. Viruses were not detected in samples tested. Findings suggest that the epidemiological importance of such pathogens in this GHLT population is either low or nonexistent. These data are important to understand the local disease ecology, as well as monitoring a translocation project, and to contribute data for species conservation.
Blockade der ClpXP‐vermittelten Proteolyse mit maßgeschneiderten Peptid‐Phenylestern durch den ungewöhnlichen Zerfall in eine Heptamer‐Hexamer‐Anordnung
Authors: Lakemeyer Markus , Bertosin Eva , Möller Friederike , Balogh Dóra , Strasser Ralf , Dietz Hendrik , Sieber Stephan A. 
Published: March 2019

AbstractDer proteolytische ClpXP‐Komplex ist essenziell für die bakterielle Homöostase und Pathogenese. Aufgrund seiner konformativen Flexibilität ist die Entwicklung wirksamer ClpXP‐Inhibitoren eine große Herausforderung, und neue Ansätze werden dringend benötigt, um die komplexe Enzymregulation zu verstehen. Aminosäurebasierte Phenylester werden hier als molekulare Sonden für die Untersuchung der Aktivität und Oligomerisierung des ClpXP‐Komplexes von S. aureus vorgestellt. Die systematische Untersuchung von (R)‐ und (S)‐Aminosäuren offenbarte Verbindungen, die die ClpXP‐vermittelte Proteolyse entweder inhibieren oder aber stimulieren. Die substöchiometrische Bindung der Sonden arretiert ClpXP in einer zuvor unbekannten Heptamer‐Hexamer‐Anordnung, in der die beiden heptameren ClpP‐Ringe voneinander dissoziiert vorliegen. Zugleich steigt die Affinität von ClpX und ClpP, was eine Inhibition beider Enzyme zur Folge hat. Diese konformative Arretierung ist vorteilhaft für eine konsolidierte Hemmung von ClpXP und ermöglicht die Untersuchung der Oligomerisierung des Komplexes während des Katalysezyklus.
Tailored Peptide Phenyl Esters Block ClpXP Proteolysis by an Unusual Breakdown into a Heptamer–Hexamer Assembly
Authors: Lakemeyer Markus , Bertosin Eva , Möller Friederike , Balogh Dóra , Strasser Ralf , Dietz Hendrik , Sieber Stephan A. 
Published: March 2019

AbstractThe proteolytic complex ClpXP is fundamental to bacterial homeostasis and pathogenesis. Because of its conformational flexibility, the development of potent ClpXP inhibitors is challenging, and novel tools to decipher its intricate regulation are urgently needed. Herein, we present amino acid based phenyl esters as molecular probes to study the activity and oligomerization of the ClpXP complex of S. aureus. Systematic screening of (R)‐ and (S)‐amino acids led to compounds showing potent inhibition, as well as stimulation of ClpXP‐mediated proteolysis. Substoichiometric binding of probes arrested ClpXP in an unprecedented heptamer–hexamer assembly, in which the two heptameric ClpP rings are dissociated from each other. At the same time, the affinity between ClpX and ClpP increased, leading to inhibition of both enzymes. This conformational arrest is beneficial for the consolidated shutdown of ClpXP, as well as for the study of the oligomeric state during its catalytic cycle.
New palladium (II) complexes containing phosphine‐nitrogen ligands and their use as catalysts in aminocarbonylation reaction
Authors: Aranda Braulio , Moya Sergio A. , Vega Andres , Valdebenito Gonzalo , Ramirez‐Lopez Sofia , Aguirre Pedro 
Published: March 2019

Aminocarbonylation of aryl halides, homogeneously catalysed by palladium, is an efficient method that can be employed for obtaining amides for pharmaceutical and synthetic applications.In this work, palladium (II) complexes containing P^N ligands were studied as catalysts in the aminocarbonylation of iodobenzene in the presence of diethylamine. Two types of systems were used: a palladium (II) complex formed in situ; and one prepared prior to the catalytic reaction. In general, the palladium complexes studied achieved high conversions in an average reaction time of less than 2 hr, which is less than that for the standard system (Pd (II)/PPh3) used. The pre‐synthesized complexes were faster than their in situ counterparts, as the latter require an induction time to form the Pd/P^N species. The structure and electronic properties of the ligand P^N can influence both the activity and the selectivity of the reaction, stabilizing the acyl‐palladium intermediates formed in a better manner.
Synthesis, reactivity and preliminary biological activity of iron(0) complexes with cyclopentadienone and amino‐appended N‐heterocyclic carbene ligands
Authors: Cingolani Andrea , Zanotti Valerio , Zacchini Stefano , Massi Massimiliano , Simpson Peter V. , Maheshkumar Desai Nima , Casari Ilaria , Falasca Marco , Rigamonti Luca , Mazzoni Rita 
Published: March 2019

Neutral and cationic cyclopentadienone (CpO) N‐heterocyclic carbene (NHC) bis‐carbonyl iron(0) complexes bearing, appended to the NHC ligand, either a terminal amino group on the lateral chain, [Fe(η4‐CpO)(CO)2(κC‐NHC(CH2)nNH2)] with n = 2 (2a) and 3 (2b), or a cationic NMe3+ fragment, [Fe(η4‐CpO)(CO)2(κC‐NHC(CH2)2NMe3)](I) (3), were prepared and characterized in terms of their structure, stability and reactivity. The photochemical properties of 2a and 2b were examined both in organic solvents and in water, revealing the photoactivated release of one CO ligand followed by the formation of the chelated complex [Fe(η4‐CpO)(CO)(κ2C,N‐NHC(CH2)2NH2)] (4), whose molecular structure was confirmed by single crystal X‐ray diffraction studies. This metallacyclization occurs only in the case of 2a, with the ethylene spacer between NHC ring and NH2 group in the lateral chain, allowing the formation of a stable 6‐membered ring. On the other hand, 2b undergoes decomposition upon irradiation. The reactivity in aqueous solutions revealed the chemical speciation of the complexes at different pH and especially under physiological conditions (phosphate buffer solution at pH 7.4 and 37 °C). The lack of data on the biological properties of iron(0) complexes prompted us to preliminarily investigate their cytotoxicity against model cancer cells (AsPC‐1 and HPAF‐II), along with a determination of their lipophilicity.
Nano NiO/AlMCM‐41, a green synergistic, highly efficient and recyclable catalyst for the reduction of nitrophenols
Authors: Derikvand Zohreh , Rahmati Fatemeh , Azadbakht Azadeh 
Published: March 2019

Highly ordered mesoporous molecular sieves AlMCM‐41 and a new NiO/AlMCM‐41 nanocomposite were synthesized using a sol–gel method. Fourier transform infrared (FT‐IR) spectroscopy, X‐ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), energy dispersive X‐ray spectroscopy (EDX), and N2 adsorption desorption analyses were used to examine the structure, morphology, size and phase composition of the synthesized NiO/AlMCM‐41 nanocomposites. AlMCM‐41 embedded with NiO nanoparticles was subsequently prepared using different nickel loadings in a direct synthetic route. The results show the successful deposition of NiO nanoparticles onto the framework of AlMCM‐41. AlMCM‐41 provides enormous benefits such as environmentally safe, economic viability and porosity when used as support for NiO nanoparticles. The excellent catalytic activities of AlMCM‐41 and NiO/AlMCM‐41 were investigated for the reduction of nitrophenols (4‐NP, 2‐NP) to aminophenols (4‐AP, 2‐AP) in water at ambient temperature. The best observed performance of reduction of NP with 100% conversion into analogous amino derivatives occurred within 6 min with an estimated rate constant of 0.46 min−1. The efficiency of reduction was observed to increase as a function of NiO enrichment. The NiO/AlMCM‐41 nanocomposite could be recycled and reused up to five times without noticeable change in its structure and activity. These properties make NiO/AlMCM‐41 nanocomposite an ideal platform to study various heterogeneous catalytic processes which can have application in purification, catalysis, sensing devices, and green chemistry.
Effect of nano silicon dioxide on the structure and properties of FeCl3‐doped polyvinyl alcohol photopolymer film
Authors: Xue Runping , Mao Jianzhao , Zhao Hong , Yang Chen , Gao Huihui , Xu Jianjun , Jiang Mengjin 
Published: March 2019

ABSTRACTThe polyvinyl alcohol (PVA) photopolymer films (PFs) were prepared based on iron(III) trichloride as the photosensitizer and PVA as the polymer matrix (Fe(III)‐PVA). The nano silicon dioxide (nano‐SiO2) was mixed with the resin in proportions of 0.5, 1.0, 2.0, and 5.0 wt %, respectively. The iodine gallium lamp (350–450 nm) was used as a UV curing light source. The effects of nano‐SiO2 on the structures and properties of Fe(III)‐PVA PFs were studied by scanning electron microscopy(SEM) analysis, ultraviolet–visible absorption spectroscopy(UV/Vis), X‐ray diffraction (XRD), dynamic thermomechanical analysis(DMA), gel content test, tensile strength test, and Shore hardness test. The Fe(III)‐PVA PFs with the content of 1.0 wt %‐nano‐SiO2 exhibits the highest gel content and tensile strength. The Fe(III)‐PVA PFs with the content of 2.0 wt % nano‐SiO2 exhibits the highest Shore hardness. Photolithographic patterning of the Fe(III)‐PVA PFs using a UV source has been carried out, which leads to a good contrast behavior after development in an aqueous media when the content of nano‐SiO2 was lower than 2.0 wt %. After evaluating the structure, performance, and development results, the Fe(III)‐PVA PFs with the content of 1.0 wt % nano‐SiO2 exhibits the best overall properties. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 47702.
New relaxed stabilization conditions for discrete‐time Takagi–Sugeno fuzzy control systems
Authors: Kong Lei , Yuan Jingqi 
Published: March 2019

AbstractThis paper develops relaxed stabilization conditions for discrete‐time Takagi–Sugeno fuzzy control systems based on the extended nonquadratic Lyapunov function, the nonparallel distributed compensation law, and the convexity of the fuzzy blending coefficients. Three new main results are proposed to further reduce the conservatism by fully exploring the slack matrix technique and introducing new slack matrices and extra collection matrices. The new stabilization conditions are gradually less and less conservative, and more advantageous than the existing results by overall consideration of the conservatism and the computational efforts. A well‐known numerical case and a practical case are carried out to demonstrate the effectiveness of the proposed stabilization conditions.
Design and evaluation of a three‐dimensional virtual laboratory on vector operations
Authors: Salinas Isabel , Giménez Marcos H. , Cuenca‐Gotor Vanesa P. , Seiz‐Ortiz Rafael , Monsoriu Juan A. 
Published: March 2019

AbstractIn Physics, many quantities are vectors, and their use requires typical operations such as addition, subtraction, scalar multiplication, scalar product (dot product), vector product (cross product), and scalar triple product. This is a very basic topic in all General Physics courses for Engineering degrees. However, we have detected that some students lack a deep understanding of vector operations and their properties. In this study, we present a virtual laboratory (developed using the tool “Easy Java Simulations”) for the study and understanding of these topics. The user can introduce the components of the input vectors and gets a three‐dimensional representation, which can be scaled and rotated for better visualization. Any of the aforementioned operations can be selected, and the result is shown both numerically and graphically. The user can also modify any represented vector. In this way, the virtual lab provides a real‐time visualization of how the change affects the result. The possibility of limiting the changes to either magnitude or direction is also included. The efficiency of the virtual laboratory has been tested analyzing the results obtained in two groups of students (virtual laboratory vs traditional resources). A satisfaction survey has been also carried out.
Selenoglycosides as Lectin Ligands:77Se‐Edited CPMG‐HSQMBC NMR Spectroscopy To Monitor Biomedically Relevant Interactions
Authors: Raics Mária , Timári István , Diercks Tammo , Szilágyi László , Gabius Hans‐Joachim , Kövér Katalin E. 
Published: March 2019

AbstractThe fundamental importance of protein–glycan recognition calls for specific and sensitive high‐resolution techniques for their detailed analysis. After the introduction of19F NMR spectroscopy to study the recognition of fluorinated glycans, a new77Se NMR spectroscopy method is presented for complementary studies of selenoglycans with optimised resolution and sensitivity, in which direct NMR spectroscopy detection on77Se is replaced by its indirect observation in a 2D1H,77Se HSQMBC spectrum. In contrast to OH/F substitution, O/Se exchange allows the glycosidic bond to be targeted. As an example, selenodigalactoside recognition by three human galectins and a plant toxin is readily indicated by signal attenuation and line broadening in the 2D1H,77Se HSQMBC spectrum, in which CPMG‐INEPT long‐range transfer ensures maximal detection sensitivity, clean signal phases, and reliable ligand ranking. By monitoring competitive displacement of a selenated spy ligand, the selective77Se NMR spectroscopy approach may also be used to screen non‐selenated compounds. Finally,1H,77Se CPMG‐INEPT transfer allows further NMR sensors of molecular interaction to be combined with the specificity and resolution of77Se NMR spectroscopy.
Clinical characteristics and genetic analysis of gene mutations in a Chinese pedigree with Peutz‐Jeghers syndrome
Authors: Qiu Yudian , Xuan Tao , Yin Mujun , Gao Zhidong , Guo Peng , Chen Xi , Ye Yingjiang , Shen Zhanlong 
Published: March 2019

Key Clinical MessageThe genome‐wide sequencing information of PJS is still lacking. Our result demonstrates that c.862+2T>C variant on STK11 as an important foundation of molecular mechanism in this familial PJS. Variants in KDR and MLL3 may play important roles in the initiation and development of this familial PJS polyps.
Synthesis, Crystal Structure, and Selected Properties of [Au(S2CNH2)2]SCN: A Precursor for Gold Macro‐Needles Consisting of Gold Nanoparticles Glued by Graphitic Carbon Nitride
Authors: Teske Christoph Ludwig , Hansen Anna‐Lena , Weihrich Richard , Kienle Lorenz , Kamp Marius , van der Zwan Kasper Pieter , Senker Jürgen , Dosche Carsten , Wittstock Gunther , Bensch Wolfgang 
Published: March 2019

AbstractA new preparation route is developed for the synthesis of needle‐like crystals of [Au(S2CNH2)2]SCN, which avoids disproportionation of the AuI salt used as a starting material. In the crystal structure, the two crystallographically independent AuIII centers are in a square‐planar environment of two S2CNH2 ligands. The Hirshfeld surface analysis reveals the presence of noncovalent intermolecular S⋅⋅⋅S interactions, which are essential for the spatial arrangement of the molecules. Density functional theory (DFT) calculations including dispersion and damping corrections result in a unit cell volume very close to the value determined experimentally. Thermal decomposition in an inert atmosphere generates black needles with lengths of up to 500 μm. X‐ray powder diffraction and pair distribution function analyses demonstrate that the needles are composed of nanosized crystals with a volume‐weighted average domain size of 20(1) nm. According to results of X‐ray photoemission experiments, the black needles are covered by a nitrogen‐rich carbon nitride with composition near (CN)2N. 13C solid‐state NMR investigations indicate that two different carbon species are present, with signals corresponding well to heptazine units as in melon and triazine units as in poly(triazin imide) type compounds. Scanning transmission electron microscopy tomography evidences that the needles are composed of slightly elongated nanoparticles.
Polar‐Covalent Bonding Beyond the Zintl Picture in Intermetallic Rare‐Earth Germanides
Authors: Freccero Riccardo , Solokha Pavlo , De Negri Serena , Saccone Adriana , Grin Yuri , Wagner Frank R. 
Published: March 2019

AbstractA comparative chemical bonding analysis for the germanides La2MGe6(M=Li, Mg, Al, Zn, Cu, Ag, Pd) and Y2PdGe6is presented, together with the crystal structure determination forM=Li, Mg, Cu, Ag. The studied compounds adopt the two closely related structure typesoS72‐Ce2(Ga0.1Ge0.9)7andmS36‐La2AlGe6, containing zigzag chains and corrugated layers of Ge atoms bridged byMspecies, with La/Y atoms located in the biggest cavities. Chemical bonding was studied by means of the quantum chemical position‐space techniques QTAIM (quantum theory of atoms in molecules), ELI‐D (electron localizability indicator), and their basin intersections. The new penultimate shell correction (PSC0) method was introduced to adapt the ELI‐D valence electron count to that expected from the periodic table of the elements. It plays a decisive role to balance the Ge−La polar‐covalent interactions against the Ge−Mones. In spite of covalently bonded Ge partial structures formally obeying the Zintl electron count forM=Mg2+, Zn2+, all the compounds reveal noticeable deviations from the conceptual 8−Npicture due to significant polar‐covalent interactions of Ge with La andM ≠Li, Mg atoms. ForM=Li, Mg a formulation as a germanolanthanateM[La2Ge6] is appropriate. Moreover, the relative Laplacian of ELI‐D was discovered to reveal a chemically useful fine structure of the ELI‐D distribution being related to polyatomic bonding features. With the aid of this new tool, a consistent picture of La/Y−Minteractions for the title compounds was extracted.
Photoinduced C(sp3)−N Bond Cleavage Leading to the Stereoselective Syntheses of Alkenes
Authors: Yang Ze‐Kun , Xu Ning‐Xin , Wang Chao , Uchiyama Masanobu 
Published: March 2019

AbstractHerein we report a versatile Mizoroki–Heck‐type photoinduced C(sp3)−N bond cleavage reaction. Under visible‐light irradiation (455 nm, blue LEDs) at room temperature, alkyl Katritzky salts react smoothly with alkenes in a 1:1 molar ratio in the presence of 1.0 mol % of commercially available photoredox catalyst without the need for any base, affording the corresponding alkyl‐substituted alkenes in good yields with broad functional‐group compatibility. Notably, the E/Z‐selectivity of the alkene products can be controlled by an appropriate choice of photoredox catalyst.
Configurationally Stable Platinahelicene Enantiomers for Efficient Circularly Polarized Phosphorescent Organic Light‐Emitting Diodes
Authors: Yan Zhi‐Ping , Luo Xu‐Feng , Liu Wei‐Qiang , Wu Zheng‐Guang , Liang Xiao , Liao Kang , Wang Yi , Zheng You‐Xuan , Zhou Liang , Zuo Jing‐Lin , Pan Yi , Zhang Hongjie 
Published: March 2019

AbstractChiral materials with circularly polarized luminescence (CPL) are potentially applicable for 3D displays. In this study, by decorating the pyridinyl‐helicene ligands with ‐CF3 and ‐F groups, the platinahelicene enantiomers featured superior configurational stability, as well as high sublimation yield (>90 %) and clear CPPL properties, with dissymmetry factors (|gPL|) of approximately 3.7×10−3 in solution and about 4.1×10−3 in doped film. The evaporated circularly polarized phosphorescent organic light‐emitting diodes (CP‐PhOLEDs) with two enantiomers as emitters exhibited symmetric CPEL signals with |gEL| of (1.1–1.6)×10−3 and decent device performances, achieving a maximum brightness of 11 590 cd m−2, a maximum external quantum efficiency up to 18.81 %, which are the highest values among the reported devices based on chiral phosphorescent PtII complexes. To suppress the effect of reverse CPEL signal from the cathode reflection, the further implementation of semitransparent aluminum/silver cathode successfully boosts up the |gEL| by over three times to 5.1×10−3.
Mn‐Catalyzed Selective Double and Mono‐N‐Formylation and N‐Methylation of Amines by using CO2
Authors: Huang Zijun , Jiang Xiaolin , Zhou Shaofang , Yang Peiju , Du Chen‐Xia , Li Yuehui 
Published: March 2019

AbstractFunctionalization of amines by using CO2 is of fundamental importance considering the abundance of amines and CO2. In this context, the catalytic formylation and methylation of amines represent convenient and successful protocols for selective CO2 utilization as a C1 building block. This study represents the first example of selective catalytic double N‐formylation of aryl amines by using a dinuclear Mn complex in the presence of phenylsilane. This robust system also allows for selective formylation and methylation of amines under a range of conditions.