bluuebunny/crossref_metadata_2025_split huggingface dataset:
Enantio‐ and Diastereoselective Synthesis of Homopropargyl Amines by Copper‐Catalyzed Coupling of Imines, 1,3‐Enynes, and Diborons
Authors: Manna Srimanta , Dherbassy Quentin , Perry Gregory J. P. , Procter David J. 
Published: January 2020

AbstractAn efficient, enantio‐ and diastereoselective, copper‐catalyzed coupling of imines, 1,3‐enynes, and diborons is reported. The process shows broad substrate scope and delivers complex, chiral homopropargyl amines; useful building blocks on the way to biologically‐relevant compounds. In particular, functionalized homopropargyl amines bearing up to three contiguous stereocenters can be prepared in a single step.
Funktionelle Inhibition der krebsrelevanten Interaktion von Survivin und Histon H3 mit einem Guanidiniumcarbonylpyrrol‐Liganden
Authors: Vallet Cecilia , Aschmann Dennis , Beuck Christine , Killa Matthias , Meiners Annika , Mertel Marcel , Ehlers Martin , Bayer Peter , Schmuck Carsten , Giese Michael , Knauer Shirley K. 
Published: January 2020

AbstractDas Protein Survivin ist bei den meisten Krebsarten überexprimiert und gilt als einer der Hauptakteure der Krebsentstehung. Wir haben einen supramolekularen Ansatz genutzt, um Survivin als Wirkstoff‐Ziel zu adressieren, indem wir die Protein‐Protein‐Interaktion von Survivin und seinem funktionell relevanten Bindungspartner Histon H3 inhibieren. Ligand L1 basiert auf dem Guanidiniumcarbonylpyrrol‐Kation und dient als hochspezifischer Anionenbinder. Durch NMR‐Titrationen konnte die Bindung von L1 an die Histon H3‐Bindungsstelle von Survivin bestätigt werden. Die Hemmung der Survivin‐Histon‐H3‐Interaktion und folglich eine Verringerung der Proliferation von Krebszellen wurde durch mikroskopische und zelluläre Assays nachgewiesen.
Lösemittel‐induzierter Halbleiter‐Metall‐Übergang: Planare [Bi1−]‐Zickzack‐Ketten im metallischen KBi⋅NH3 im Vergleich zu [Bi1−]‐Helices im halbleitenden KBi
Authors: Mayer Kerstin , Dums Jasmin V. , Benda Christian B. , Klein Wilhelm , Fässler Thomas F. 
Published: January 2020

AbstractDas polymere Anion
[Bi]− in KBi⋅NH3 (1) besteht aus planaren Zickzack‐Ketten mit zweifach verknüpften Bi‐Atomen und zeigt metallische Eigenschaften, im Gegensatz dazu besitzt die bekannte Verbindung KBi helikale Ketten aus Bi‐Atomen und ist halbleitend. Die Isomerisierung der Bi‐Atom‐Kette wird durch ein zusätzliches Lösemittelmolekül hervorgerufen. In dieser neuartigen Schichtstruktur sind ungeladene
[KBi]‐Schichten durch eingelagerte NH3‐Moleküle getrennt. Wir interpretieren diese Schichten als Strukturausschnitt des iso(valenz)elektronisch CaSi, dessen metallische Eigenschaften von der Planarität der Si‐Zickzack‐Ketten stammen. Quantenchemische Rechnungen unterstützen diese Sichtweise, da sie ein anisotropes metallisches Verhalten entlang der Bi‐Kette aufzeigen. Eine Delokalisierung von Elektronen wird auch in dem neuen ringförmigen Anion [Bi6]4− beobachtet, das in der Verbindung K2[K([18]Krone‐6)]2[Bi6]⋅9 NH3 (2) vorliegt. Zweifach verknüpfte Bi‐Atome bilden einen Sechsring mit Sesselkonformation. Obwohl [Bi6]4− eine lokalisierte Doppelbindung besitzen sollte, wird eine Elektronendelokalisierung analog zu den leichteren homologen [P6]4− und [As6]4− beobachtet. Beide Verbindungen wurden durch Einkristall‐Röntgenstrukturanalyse charakterisiert.
Cyclophane‐Type Chlorin Dimers from Dynamic Covalent Chemistry of 2,18‐Porphyrinyl Dicyanomethyl Diradicals
Authors: Adinarayana B. , Kato Kenichi , Shimizu Daiki , Tanaka Takayuki , Furukawa Ko , Osuka Atsuhiro 
Published: January 2020

Abstract2,18‐Bis(dicyanomethyl)‐substituted NiII porphyrin 8 and ZnII porphyrin 11 were prepared and subjected to oxidation with PbO2 in CH2Cl2 at 298 K to give cyclophane‐type chlorin dimers (9)2 and (12)2 as a consequence of double recombination of biradicals 9 and 12, respectively. Dimer (9)2 takes a syn‐conformation of two distorted NiII chlorins but (12)2 takes an anti‐conformation of relatively planar ZnII chlorins. At 298 K, dimer (9)2 is stable and its 1H NMR spectrum is sharp but becomes broad at high temperature, while the 1H NMR spectrum of (12)2 is considerably broad even at 298 K but becomes sharper at low temperature. These results indicate that the chlorin dimers dissociate to radical species, but the activation barrier of the dissociation of (12)2 is much less than that of (9)2. The involvement of diradicals in dynamic covalent chemistry has been suggested by thermal scrambling of hetero dimer (16)2 to give homo dimers (9)2 and (15)2.
Cobalt‐Catalyzed Regio‐ and Stereoselective Hydroboration of Allenes
Authors: Li Can , Yang Zheng , Wang Lei , Guo Yinlong , Huang Zheng , Ma Shengming 
Published: January 2020

AbstractAn efficient pincer‐ligand‐based cobalt‐complex‐catalyzed allene hydroboration affording Z‐allylic boronates is described. The reaction demonstrates an excellent regio‐ as well as Z‐stereoselectivity and a wide substrate scope that tolerates many functional groups. Based on solvent‐assisted electrospray ionization mass spectrometry (SAESI‐MS) studies, a rationale for the cobalt‐catalyzed hydroboration involving the highly selective insertion of an allene into the Co−H bond to form Z‐allylic cobalt intermediates is proposed.
Solvate‐Induced Semiconductor to Metal Transition: Flat [Bi1−] Zigzag Chains in Metallic KBi⋅NH3 versus [Bi1−] Helices in Semiconducting KBi
Authors: Mayer Kerstin , Dums Jasmin V. , Benda Christian B. , Klein Wilhelm , Fässler Thomas F. 
Published: January 2020

AbstractPolymeric
[Bi]− in KBi⋅NH3 has planar zigzag chains with two‐connected Bi atoms and metallic properties, whereas KBi, which has helical chains of Bi atoms, is semiconducting. The isomerization of the Bi chain is induced by solvate molecules. In the novel layered solvate structure uncharged
[KBi] layers are separated by intercalated NH3 molecules. These layers are a structural excerpt of the iso(valence)electronic CaSi, whose metallic properties arise from the planarity of the zigzag chain of Si atoms. Computational studies support this view, they show an anisotropic metallic behavior along the Bi chain. Electron delocalization is also found in the new cyclic anion [Bi6]4− isolated in K2[K(18‐crown‐6)]2[Bi6]⋅9 NH3. Although [Bi6]4− should exhibit one localized double bond, electron delocalization is observed in analogy to the lighter homologues [P6]4− and [As6]4−. Both compounds were characterized by single‐crystal X‐ray structure determination.
Experiences and lessons learned as a Chair of anatomy—An 18‐year journey
Authors: Bertram John F. 
Published: January 2020

AbstractIn 1998, I was appointed Chair of the Department of Anatomy at Monash University in Melbourne, Australia. On commencing as Chair, I had three main goals: (a) to maintain and extend the high quality of anatomy teaching in the medical program; (b) to introduce significantly more developmental biology, cell biology, and neuroscience into our existing Bachelor of Science major in human anatomy; and (c) to establish an active research program in the department. Over the next 18 years, I worked with staff and students at all levels of the university to turn this vision into a reality, with the Monash Department of Anatomy and Developmental Biology now arguably the top ranked anatomy department in Australia. During my tenure, countless challenges were faced and while some errors were made, and a good number of goals were never realized the general outcome was a vibrant scholarly environment where that rich nexus of research and teaching was realized. This personal account provides some insights into that 18‐year journey, which I hope may prove useful for current and future Chairs of anatomy. For me personally, it was definitely a journey worth taking.
Nonlinear model order reduction with low rank tensor approximation
Authors: Yang Junman , Jiang Yao‐Lin , Xu Kang‐Li 
Published: January 2020

AbstractIn this article, two methods of model order reduction based on the low rank approximation of tensor are introduced for the large scale nonlinear problem. We first introduce some definitions and results on tensor extended from matrix theory. Then we show how the general nonlinear system can be converted into the low rank form we treated in this research. We put the model order reduction of it in two frameworks, that is, polynomial framework and moment‐matching framework. In these two frameworks we construct the algorithms correspondingly, and analyze properties of these algorithms, including the preservation of stability, and moment‐matching properties. Next the priorities of these algorithms are presented. Finally we setup several numerical experiments to validate the effectiveness of the algorithms.
Infinite time linear quadratic stackelberg game problem for unknown stochastic discrete‐time systems via adaptive dynamic programming approach
Authors: Liu Xikui , Liu Ruirui , Li Yan 
Published: January 2020

AbstractIn this paper, we propose an adaptive dynamic programming (ADP) approach to solve the infinite horizon linear quadratic (LQ) Stackelberg game problem for unknown stochastic discrete‐time systems with multiple decision makers. Firstly, the stochastic LQ Stackelberg game problem is converted into the deterministic problem by system transformation. Next, a value iteration ADP approach is put forword and the convergence is given. Thirdly, in order to implement the iterative method, back propagation neural network (BPNN) is chosen to design model network, critic network and action network to approximate the unknown systems, objective functions and Stackelberg strategies. Finally, simulation results show that the algorithm is effective.
Transport model calculations of deuteron production in relativistic hadron and heavy‐ion collisions
Authors: Bleicher Marcus , Hillmann Paula , Reichert Tom , Steinheimer Jan , Sombun Sukanya , Herold Christoph , Limphirat Ayut , Yan Yupeng 
Published: January 2020

AbstractThe production of deuterons and heavy clusters such as triton and helium (or even hypertriton) has gained increased attention during the last years. This attention was mainly stimulated by the recent hypertriton data and has led to the question of whether cluster production is driven by coalescence of its constituents or by thermal emission of the cluster itself. Here, we explore the cluster production by coalescence using the Ultra‐relativistic Quantum Molecular Dynamics model and a phase–space coalescence model. We explore deuteron production over a wide range of reactions and energies from GeV to TeV. Overall, we observe that coalescence leads to an excellent description of the deuteron yields and momentum distributions.
Pion mass modification in a weak magnetic field
Authors: Ayala Alejandro , Farias Ricardo Luciano Sonego , Hernández‐Ortiz Saul , Hernández Luis Alberto , Manreza‐Paret Daryel , Zamora Renato 
Published: January 2020

AbstractWe use the linear sigma model coupled to quarks with an explicit symmetry breaking term, to compute the one‐loop magnetic modification of the neutral pion mass, in the weak field approximation. The self‐energy, the effective, and the meson self‐coupling are computed at one‐loop order. We obtain a decreasing behavior for the neutral pion mass as the magnetic field increases. This result is in good agreement both with other effective models and lattice quantum chromodynamics (QCD) results.
Novel surface plasmon resonance biosensor that uses full‐length Det7 phage tail protein for rapid and selective detection of Salmonella enterica serovar Typhimurium
Authors: Hyeon Seok Hywan , Lim Woon Ki , Shin Hae Ja 
Published: January 2020

AbstractWe report a novel surface plasmon resonance (SPR) biosensor that uses the full‐length Det7 phage tail protein (Det7T) to rapidly and selectively detect Salmonella enterica serovar Typhimurium (S. Typhimurium). Det7T, which was obtained using recombinant protein expression and purification in Escherichia coli, demonstrated a size of ∼75 kDa upon SDS‐PAGE and was homotrimeric in its native structure. Microagglutination and transmission electron microscopy (TEM) data revealed that the protein specifically bound to the host, S. Typhimurium, but not to nonhost E. coli K‐12 cells. The observed protein agglutination occurred over a concentration range of 0.8–24.6 µg/mL. The Det7T proteins were immobilized on gold‐coated surfaces using amine‐coupling to generate a novel Det7T‐functionalized SPR biosensor, wherein the specific binding of these proteins with bacteria was detected by SPR. We observed rapid detection of (∼20 Min) and typical binding kinetics with S. Typhimurium in the range of 5 × 104–5 × 107 CFU/mL, but not with E. coli at any tested concentration, indicating that the sensor exhibited recognition specificity. Similar binding was observed with 10% apple juice spiked with S. Typhimurium, suggesting that this strategy provides promise for the rapid, real‐time, and selective monitoring of target microorganisms in the environment, and thus has great potential for supporting health by enabling early disease prevention.
Synthesis and photophysical studies on a new fluorescent phenothiazine‐based derivative
Authors: Al‐Zahrani Fatimah A.M. , Abu Mellah Khloud , El‐Shishtawy Reda M. , Al‐Soliemy Amerah M. , Asiri Abdullah M. 
Published: January 2020

AbstractA new typical phenothiazine compound functionalized with thienyl‐indandione derivative (PTZTID) was synthesized and characterized using spectral analysis (ultraviolet–visible (UV–vis) light, infrared (IR), 1H nuclear magnetic resonance (NMR) and 13C NMR tools). The UV–vis absorption spectra of the PTZTID solution in 1,4‐dioxane showed two absorption bands attributed to localized aromatic π–π* transitions of conjugated aromatic moieties and intramolecular charge transfer with the characteristics of a π–π* transition. The fluorescence spectra exhibited a maximum emission wavelength at 580 nm. The effect of concentration on photophysical properties took the form of a minor hypsochromic shift, which was attributed to some extent to the occurrence of H‐type aggregation of the PTZTID derivative. Binary solvent effects on the spectroscopic behaviour of PTZTID were measured at different H2O/1,4‐dioxane ratios. Similarly, when increasing the water content, a hypsochromic shift was observed that resulted from H‐type aggregation. Furthermore, geometry and electronic configurations of PTZTID were studied at density functional theory /B3LYP level and indicated that the compound had a nonplanar (butterfly structure).
Characterization of a Tryptophan 6‐Halogenase from Streptomyces albus and Its Regioselectivity Determinants
Authors: Lee Jeongchan , Kim Joonwon , Kim Hyun , Kim Eun‐Jung , Jeong Hee‐Jin , Choi Kwon‐Young , Kim Byung‐Gee 
Published: January 2020

AbstractTryptophan halogenases are found in diverse organisms and catalyze regiospecific halogenation. They play an important role in the biosynthesis of halogenated indole alkaloids, which are biologically active and of therapeutic importance. Here, a tryptophan 6‐halogenase (SatH) from Streptomyces albus was characterized by using a whole‐cell reaction system in Escherichia coli. SatH showed substrate specificity for chloride and bromide ions, leading to regiospecific halogenation at the C6‐position of l‐tryptophan. In addition, SatH exhibited higher performance in bromination than that of previously reported tryptophan halogenases in the whole‐cell reaction system. Through structure‐based protein mutagenesis, it has been revealed that two consecutive residues, A78/V79 in SatH and G77/I78 in PyrH, are key determinants in the regioselectivity difference between tryptophan 6‐ and 5‐halogenases. Substituting the AV with GI residues switched the regioselectivity of SatH by moving the orientation of tryptophan. These data contribute to an understanding of the key residues that determine the regioselectivity of tryptophan halogenases.
Design and Expeditious Synthesis of Quinoline‐Pyrene‐Based Ratiometric Fluorescent Probes for Targeting Lysosomal pH
Authors: Hande Pankaj E. , Mishra Manjari , Ali Fariyad , Kapoor Shobhna , Datta Anindya , Gharpure Santosh J. 
Published: January 2020

AbstractIntracellular pH plays a significant role in many pathological and physiological processes. A series of quinoline‐pyrene probes were synthesized in one‐step fashion through an oxonium‐ion‐triggered alkyne carboamination sequence involving C−C, C−O and C−N bond formation for intracellular pH sensing. The quinoline‐pyrenes showed significant red shifts at low pH. Fluorescence lifetime decay measurements of the probes showed decreases in lifetime at pH 4. The probes showed excellent selectivity in the presence of various potential interfering agents such as amino acids and cations/anions. Furthermore, the probes were found to show completely reversible emission behaviour in the window between pH 4 and 7. A morpholine‐substituted quinoline‐pyrene probe efficiently stained lysosomes with high Pearson correlation coefficients (0.86) with Lysotracker Deep Red DND‐99 as a reference. A co‐localization study of the probe with Lysotracker DND‐99 showed selective intracellular targeting and a shift in fluorescence emission due to acidic lysosomal pH.
Mild Homogeneous Synthesis of Gold Nanoparticles through the Epoxide Route: Kinetics, Mechanisms, and Related One‐Pot Composites
Authors: Oestreicher Víctor , Huck‐Iriart Cristián , Soler‐Illia Galo , Angelomé Paula C. , Jobbágy Matías 
Published: January 2020

AbstractA new one‐pot homogeneous methodology at room temperature to obtain Au nanoparticles (AuNP) on the basis of the epoxide route is presented. The proposed method takes advantage of the homogenous generation of OH− moieties driven by epoxide ring‐opening, mediated by chloride nucleophilic attack. Once reached alkaline conditions, the reducing medium allows the quantitative formation of AuNP under well‐defined kinetic control. A stabilizing agent, such as polyvinylpyrrolidone (PVP) or cetyltrimethylammonium chloride (CTAC), is required to maintain the AuNP stable. Meanwhile their presence dramatically affects the reduction kinetics and pathway, as demonstrated by the evolution of the UV/Vis spectra, small‐angle X‐ray scattering (SAXS) patterns, and pH value along the reaction. In the presence of PVP nanogold spheroids are obtained following a similar reduction mechanism as that observed for control experiments in the absence of PVP. However, if CTAC is employed a stable complex with AuIII is formed, leading to a different reaction pathway and resulting in ellipsoidal‐like shaped AuNP. Moreover, the proposed methodology allows stabilize the growing AuNP, by coupling their formation with nonalkoxidic sol–gel reactions, leading to nanocomposite gels with embedded metallic nanoparticles. The epoxide route thus offers a versatile scenario for the one‐pot preparation of new metal nanoparticles–inorganic/hybrid matrices nanocomposites with valuable optical properties.
A Phosphate‐Based Silver–Bipyridine 1D Coordination Polymer with Crystallized Phosphoric Acid as Superprotonic Conductor
Authors: Pal Arun , Pal Shyam Chand , Otsubo Kazuya , Lim Dae‐Woon , Chand Santanu , Kitagawa Hiroshi , Das Madhab C. 
Published: January 2020

AbstractPhosphate‐based silver–bipyridine (Ag‐bpy) 1D coordination polymer {[{Ag(4,4′‐bpy)}2{Ag(4,4′‐bpy)(H2PO4)}]⋅2 H2PO4⋅H3PO4⋅5 H2O}n (1) with free phosphoric acid (H3PO4), its conjugate base (H2PO4−) and water molecules in its lattice was synthesized by room‐temperature crystallization and the hydrothermal method. An XRD study showed that coordinated H2PO4−, lattice H2PO4− anions, free H3PO4 and lattice water molecules are interconnected by H‐bonding interactions, forming an infinitely extended 2D H‐bonded network that facilitates proton transfer. This material exhibits a high proton conductivity of 3.3×10−3 S cm−1 at 80 °C and 95 % relative humidity (RH). Furthermore, synthesis of this material from commercially available starting materials in water can be easily scaled up, and it is highly stable under extreme conditions of conductivity measurements. This report inaugurates the usage and design principle of proton‐conducting frameworks based on crystallized phosphoric acid and phosphate.
An Enantiopure Propeller‐Like Trityl‐Brominated Radical: Bringing Together a High Racemization Barrier and an Efficient Circularly Polarized Luminescent Magnetic Emitter
Authors: Mayorga‐Burrezo Paula , Jiménez Vicente G. , Blasi Davide , Parella Teodor , Ratera Imma , Campaña Araceli G. , Veciana Jaume 
Published: January 2020

AbstractA new persistent organic free radical has been synthetized with Br atoms occupying the ortho‐ and para‐positions of a trityl core. After the isolation of its two propeller‐like atropisomers, Plus (P) and minus (M), their absolute configurations were assigned by a combination of theoretical and experimental data. Remarkably, no hints of racemization were observed up to 60 °C for more than two hours, due to the higher steric hindrance imposed by the bulky Br atoms. Therefore, when compared to its chlorinated homologue (t1/2=18 s at 60 °C), an outstanding stability against racemization was achieved. A circularly polarized luminescence (CPL) response of both enantiomers was detected. This free radical shows a satisfactory luminescent dissymmetry factor (|glum(592 nm)|≈0.7×10−3) despite its pure organic nature and low luminescence quantum yield (LQY). Improved organic magnetic CPL emitters derived from the reported structure can be envisaged thanks to the wide possibilities that Br atoms at para‐positions offer for further functionalization.
Effect of Food on the Pharmacokinetics of Quizartinib
Authors: Li Jianke , Holmes Melissa , Kankam Martin , Trone Denise , Mendell Jeanne , Gammon Guy 
Published: January 2020

AbstractQuizartinib is an oral, highly potent, and selective type II FMS‐like tyrosine kinase 3 inhibitor in development for acute myeloid leukemia. This parallel‐group study evaluated potential food effects on quizartinib absorption in healthy subjects who received a single 30‐mg dose after overnight fasting (n = 34) or a high‐fat, high‐calorie meal (n = 30). Blood samples were collected through 504 hours after dosing, and pharmacokinetic parameters calculated were maximum observed concentration (Cmax) and area under plasma concentration–time curve from time 0 to last quantifiable concentration (AUClast) and from time 0 to infinity (AUCinf). Mean quizartinib pharmacokinetic profiles were similar under fasted and fed conditions. The geometric least squares means ratios (%) for fed/fasted and associated 90% confidence intervals (CIs) for Cmax, AUClast, and AUCinf were 91.58 (82.15‐102.08), 105.39 (90.79‐122.35), and 108.39 (91.54‐128.34), respectively. The 90%CI for the ratio fell within the 80% to 125% limits for Cmax and AUClast, with 90%CI for AUCinf slightly outside the limits (ie, 128%). Food delayed quizartinib time to Cmax by 2 hours. All adverse events were either mild or moderate; no discontinuations due to adverse events occurred. Based on these results, quizartinib can be administered without regard to food.