bluuebunny/crossref_metadata_2025_split huggingface dataset:
Opportunities to address lung cancer disparities among African Americans
Authors: Coughlin Steven S. , Matthews‐Juarez Patricia , Juarez Paul D. , Melton Courtnee E. , King Mario 
Published: September 2014

AbstractRace and socioeconomic status are well known to influence lung cancer incidence and mortality patterns in the U.S. Lung cancer incidence and mortality rates are higher among blacks than whites. In this article we review opportunities to address disparities in lung cancer incidence, mortality, and survivorship among African Americans. First, we summarize recent advances in the early detection and treatment of lung cancer. Then we consider black‐white disparities in lung cancer treatment including factors that may contribute to such disparities; the literature on smoking cessation interventions for patients with or without a lung cancer diagnosis; and the important roles played by cultural competency, patient trust in their physician, and health literacy in addressing lung cancer disparities, including the need for culturally competent lung cancer patient navigators. Intervention efforts should focus on providing appropriate quality treatment for lung cancer and educating African Americans about the value of having these treatments in order to reduce these disparities. Culturally competent, patient navigation programs are needed that support lung cancer patients, especially socioeconomically disadvantaged patients, from the point of diagnosis to the initiation and completion of treatment, including cancer staging.
A Membrane‐Bound Prenyltransferase Catalyzes the O‐Prenylation of 1,6‐Dihydroxyphenazine in the Marine Bacterium Streptomyces sp. CNQ‐509
Authors: Zeyhle Philipp , Bauer Judith S. , Steimle Marco , Leipoldt Franziska , Rösch Manuela , Kalinowski Jörn , Gross Harald , Heide Lutz 
Published: September 2014

AbstractStreptomyces sp. CNQ‐509 produces the rare O‐prenylated phenazines marinophenazines A and B. To identify the enzyme catalyzing the O‐prenyl transfer in marinophenazine biosynthesis, we sequenced the genome of S. sp. CNQ‐509. This led to the identification of two genomic loci harboring putative phenazine biosynthesis genes. The first locus contains orthologues for all seven genes involved in phenazine‐1‐carboxylic acid biosynthesis in pseudomonads. The second locus contains two known phenazine biosynthesis genes and a putative prenyltransferase gene termed cnqPT1. cnqPT1 codes for a membrane protein with sequence similarity to the prenyltransferase UbiA of ubiquinone biosynthesis. The enzyme CnqPT1 was identified as a 1,6‐dihydroxyphenazine geranyltransferase, which catalyzes the CO bond formation between C‐1 of the geranyl moiety and O‐6 of the phenazine scaffold. CnqPT1 is the first example of a prenyltransferase catalyzing O‐prenyl transfer to a phenazine.
De novo acute myeloid leukemia with monocytoid blasts and erythrophagocytosis
Authors: Blieden Clifford , Fan Yao‐Shan , Chapman Jennifer Rose , Vega Francisco 
Published: September 2014

Key Clinical MessageAcute myeloid leukemia (AML) with t(8:16) is an infrequent acute leukemia subtype. It can occur de novo or more frequently therapy‐related. The presence of blasts with monocytoid morphology and erythrophagocytosis suggest the presence of the t(8;16).
One‐Step Approach to 2,5‐Diformylfuran from Fructose by Proton‐ and Vanadium‐Containing Graphitic Carbon Nitride
Authors: Chen Jinzhu , Guo Yuanyuan , Chen Jiayi , Song Lu , Chen Limin 
Published: September 2014

Abstract5‐Hydroxymethylfurfural (HMF) was selectively synthesized from fructose by using protonated graphitic carbon nitride [g‐C3N4(H+)] as a solid acid. With g‐C3N4 as the same precursor material, 2,5‐diformylfuran (DFF) was efficiently obtained from aerobic oxidation of HMF by using vanadium‐doped g‐C3N4 (V–g‐C3N4) as an environmentally benign heterogeneous catalyst with atmospheric pressure of molecular oxygen as the oxidant. In addition, a combination of g‐C3N4(H+) and V–g‐C3N4 successfully afforded the direct synthesis of DFF from fructose through g‐C3N4(H+)‐promoted fructose dehydration and V–g‐C3N4‐catalyzed successively aerobic oxidation of HMF to DFF in a one‐pot and two‐step process. Moreover, a bifunctional catalyst made of protonated V–g‐C3N4 [V–g‐C3N4(H+)] allowed one‐pot as well as one‐step direct transformation of fructose into DFF. Under optimized conditions, 80 % yield of HMF and 82 % yield of DFF were obtained from g‐C3N4(H+)‐promoted fructose dehydration and V–g‐C3N4‐catalyzed HMF oxidation, respectively. Stepwise addition of g‐C3N4(H+) and V–g‐C3N4 in the one‐pot process improved the DFF yield up to 63 % from fructose. In contrast, V–g‐C3N4(H+)‐catalyzed direct one‐step transformation of fructose into DFF led to a DFF yield of 45 %. The research highlights a one‐step approach to DFF from fructose with functional g‐C3N4 catalyst.
Supramolecular Complexation of Biological Phosphates with an Acyclic Triazolium‐Linked Anthracenyl‐1,3‐Diconjugate of Calix[4]Arene: Synthesis, Characterization, Spectroscopy, Microscopy, and Computational Studies
Authors: Sreenivasu Mummidivarapu V. V. , Kumar Hinge Vijaya , Samanta Kushal , Yarramala Deepthi S. , Pulla Rao Chebrolu 
Published: September 2014

AbstractA triazolium‐anthracenyl calix[4]arene conjugate (L) was synthesized by methylating the precursor triazole derivative and then characterized. The potential of the cationic L to differentiate nucleoside triphosphates (NTPs) from their mono‐ and diphosphates was demonstrated. Due to its unique combination of arms with the calix‐platform, a fluorescence enhancement was observed for L with all the NTPs, whereas there is no report with such enhancement being exhibited in case of all the NTPs. This has been supported by the aggregation of L observed from microscopy. Selectivity of L towards NTPs over other phosphates was a result of specific weak interactions, namely, ion–ion, hydrogen bonding and π⋅⋅⋅π, present in the 1:2 complex of L and NTPs (based on ESI MS), which were absent in their congener‐phosphates as delineated by NMR and computational studies. Thus, L stands as a unique receptor for NTPs.
Diamine‐Catalyzed Addition of ZnEt2 to PhC(O)CF3: Two Mechanisms and Autocatalytic Asymmetric Enhancement
Authors: Calvillo‐Barahona Mercedes , Casares Juan A. , Cordovilla Carlos , Genov Miroslav N. , Martínez‐Ilarduya Jesús M. , Espinet Pablo 
Published: September 2014

AbstractNMR spectroscopic studies of the catalytic addition reaction of ZnEt2 to PhC(O)CF3 in the presence of three very efficient catalysts [TMEDA, tBuBOX, and L; where L is a chiral diamine synthesized from optically pure (R,R)‐1,2‐diphenylethylenediamine and (S)‐2,2′‐bis‐(bromomethyl)‐1,1′‐binaphthalene] reveal large differences in their behavior. For the ligands TMEDA and tBuBOX, the catalysis shows no unusual features and proceeds via [(NN)Zn(Et){OC(CF3)(Et)Ph}]. For NNL, the observation of autocatalytic asymmetric enhancement during the catalysis, and unusual inverse concentration dependence on the reaction rate, indicate the participation of an additional novel catalytic cycle that goes through a dinuclear intermediate containing one ZnEt2 and one ZnEt fragment connected by NN and OR bridges. Interestingly, the 19F NMR signals of the main product of the reaction ([Zn(Et){OC*(CF3)(Et)Ph}]2) allowed us to assess the enantioselectivity of the processes in situ without the assistance of chiral chromatography.
Base‐Catalyzed Intramolecular Hydroamination of Cyclohexa‐2,5‐dienes: Insights into the Mechanism through DFT Calculations and Application to the Total Synthesis of epi‐Elwesine
Authors: Rousseau Géraldine , Lebeuf Raphaël , Schenk Kurt , Castet Frédéric , Robert Frédéric , Landais Yannick 
Published: September 2014

AbstractThe base‐catalyzed intramolecular hydroamination of 1‐ethylaminocyclohexa‐2,5‐dienes is described. The transformation proceeds through isomerization of the cyclohexa‐1,4‐dienyl fragment into the corresponding conjugated 1,3‐diene prior to the hydroamination step. Attaching a chiral glycinol ether auxiliary on the amino group allows the protonation to occur with complete diastereocontrol. The resulting lithium amide then adds onto the 1,3‐dienyl moiety, affording the desired fused pyrrolidine ring along with the corresponding lithium allylic anion. Protonation of the latter then proceeds with high regiocontrol to favor the resulting allylic amines. In contrast, when the reaction was performed on primary amines, fused pyrrolidines bearing a homoallylic amino group were obtained. The stereochemical course of the process and determination of the reaction pathways were established based on calculations performed at the DFT level. Finally, application of the methodology to the enantioselective synthesis of (+)‐epi‐elwesine, a crinane alkaloid, is described.
Mechanistic Insights into RNA Transphosphorylation from Kinetic Isotope Effects and Linear Free Energy Relationships of Model Reactions
Authors: Chen Haoyuan , Giese Timothy J. , Huang Ming , Wong Kin‐Yiu , Harris Michael E. , York Darrin M. 
Published: September 2014

AbstractPhosphoryl transfer reactions are ubiquitous in biology and the understanding of the mechanisms whereby these reactions are catalyzed by protein and RNA enzymes is central to reveal design principles for new therapeutics. Two of the most powerful experimental probes of chemical mechanism involve the analysis of linear free energy relations (LFERs) and the measurement of kinetic isotope effects (KIEs). These experimental data report directly on differences in bonding between the ground state and the rate‐controlling transition state, which is the most critical point along the reaction free energy pathway. However, interpretation of LFER and KIE data in terms of transition‐state structure and bonding optimally requires the use of theoretical models. In this work, we apply density‐functional calculations to determine KIEs for a series of phosphoryl transfer reactions of direct relevance to the 2′‐O‐transphosphorylation that leads to cleavage of the phosphodiester backbone of RNA. We first examine a well‐studied series of phosphate and phosphorothioate mono‐, di‐ and triesters that are useful as mechanistic probes and for which KIEs have been measured. Close agreement is demonstrated between the calculated and measured KIEs, establishing the reliability of our quantum model calculations. Next, we examine a series of RNA transesterification model reactions with a wide range of leaving groups in order to provide a direct connection between observed Brønsted coefficients and KIEs with the structure and bonding in the transition state. These relations can be used for prediction or to aid in the interpretation of experimental data for similar non‐enzymatic and enzymatic reactions. Finally, we apply these relations to RNA phosphoryl transfer catalyzed by ribonuclease A, and demonstrate the reaction coordinate–KIE correlation is reasonably preserved. A prediction of the secondary deuterium KIE in this reaction is also provided. These results demonstrate the utility of building up knowledge of mechanism through the systematic study of model systems to provide insight into more complex biological systems such as phosphoryl transfer enzymes and ribozymes.
Understanding the Mechanisms of Unusually Fast HH, CH, and CC Bond Reductive Eliminations from Gold(III) Complexes
Authors: Nijamudheen A. , Karmakar Sharmistha , Datta Ayan 
Published: September 2014

AbstractCarbon–carbon bond reductive elimination from gold(III) complexes are known to be very slow and require high temperatures. Recently, Toste and co‐workers have demonstrated extremely rapid CC reductive elimination from cis‐[AuPPh3(4‐F‐C6H4)2Cl] even at low temperatures. We have performed DFT calculations to understand the mechanistic pathway for these novel reductive elimination reactions. Direct dynamics calculations inclusive of quantum mechanical tunneling showed significant contribution of heavy‐atom tunneling (>25 %) at the experimental reaction temperatures. In the absence of any competing side reactions, such as phosphine exchange/dissociation, the complex cis‐[Au(PPh3)2(4‐F‐C6H4)2]+ was shown to undergo ultrafast reductive elimination. Calculations also revealed very facile, concerted mechanisms for HH, CH, and CC bond reductive elimination from a range of neutral and cationic gold(III) centers, except for the coupling of sp3 carbon atoms. Metal–carbon bond strengths in the transition states that originate from attractive orbital interactions control the feasibility of a concerted reductive elimination mechanism. Calculations for the formation of methane from complex cis‐[AuPPh3(H)CH3]+ predict that at −52 °C, about 82 % of the reaction occurs by hydrogen‐atom tunneling. Tunneling leads to subtle effects on the reaction rates, such as large primary kinetic isotope effects (KIE) and a strong violation of the rule of the geometric mean of the primary and secondary KIEs.
Hexameric MnII Dendrimer as MRI Contrast Agent
Authors: Zhu Jiang , Gale Eric M. , Atanasova Iliyana , Rietz Tyson A. , Caravan Peter 
Published: September 2014

AbstractA MnII chelating dendrimer was prepared as a contrast agent for MRI applications. The dendrimer comprises six tyrosine‐derived [Mn(EDTA)(H2O)]2− moieties coupled to a cyclotriphosphazene core. Variable temperature 17O NMR spectroscopy revealed a single water co‐ligand per MnII that undergoes fast water exchange (kex=(3.0±0.1)×108 s−1 at 37 °C). The 37 °C per MnII relaxivity ranged from 8.2 to 3.8 mM−1 s−1 from 0.47 to 11.7 T, and is sixfold higher on a per molecule basis. From this field dependence a rotational correlation time was estimated as 0.45(±0.02) ns. The imaging and pharmacokinetic properties of the dendrimer were compared to clinically used [Gd(DTPA)(H2O)]2− in mice at 4.7 T. On first pass, the higher per ion relaxivity of the dendrimer resulted in twofold greater blood signal than for [Gd(DTPA)(H2O)]2−. Blood clearance was fast and elimination occurred through both the renal and hepatobiliary routes. This MnII containing dendrimer represents a potential alternative to Gd‐based contrast agents, especially in patients with chronic kidney disease where the use of current Gd‐based agents may be contraindicated.
Reverse Micelle Synthesis of Colloidal Nickel–Manganese Layered Double Hydroxide Nanosheets and Their Pseudocapacitive Properties
Authors: Sim Hwansu , Jo Changshin , Yu Taekyung , Lim Eunho , Yoon Songhun , Lee Jung Heon , Yoo Jibeom , Lee Jinwoo , Lim Byungkwon 
Published: September 2014

AbstractColloidal nanosheets of nickel–manganese layered double hydroxides (LDHs) have been synthesized in high yields through a facile reverse micelle method with xylene as an oil phase and oleylamine as a surfactant. Electron microscopy studies of the product revealed the formation of colloidal nanoplatelets with sizes of 50–150 nm, and X‐ray diffraction, energy dispersive X‐ray spectroscopy, and X‐ray photoelectron spectroscopy studies showed that the Ni–Mn LDH nanosheets had a hydrotalcite‐like structure with a formula of [Ni3Mn(OH)8](Cl−)⋅n H2O. We found that the presence of both Ni and Mn precursors was required for the growth of Ni‐Mn LDH nanosheets. As pseudocapacitors, the Ni–Mn LDH nanosheets exhibited much higher specific capacitance than unitary nickel hydroxides and manganese oxides.
Homo‐ and Heteroleptic Bismuth(III/V) Thiolates from N‐Heterocyclic Thiones: Synthesis, Structure and Anti‐Microbial Activity
Authors: Luqman Ahmad , Blair Victoria L. , Brammananth Rajini , Crellin Paul K. , Coppel Ross L. , Andrews Philip C. 
Published: September 2014

AbstractHomo‐ and heteroleptic bismuth thiolato complexes have been synthesised and characterised from biologically relevant tetrazole‐, imidazole‐, thiadiazole‐ and thiazole‐based heterocyclic thiones (thiols): 1‐methyl‐1H‐tetrazole‐5‐thiol (1‐MMTZ(H)); 4‐methyl‐4H‐1,2,4‐triazole‐3‐thiol (4‐MTT(H)); 1‐methyl‐1H‐imidazole‐2‐thiol (2‐MMI(H)); 5‐methyl‐1,3,4‐thiadiazole‐2‐thiol (5‐MMTD(H)); 1,3,4‐thiadiazole‐2‐dithiol (2,5‐DMTD(H)2); and 4‐(4‐bromophenyl)thiazole‐2‐thiol (4‐BrMTD(H)). Reaction of BiPh3 with 1‐MMTZ(H) produced the rare BiV thiolato complex [BiPh(1‐MMTZ)4], which undergoes reduction in DMSO to give [BiPh(1‐MMTZ)2{(1‐MMTZ(H)}2]. Reactions with PhBiCl2 or BiPh3 generally produced monophenylbismuth thiolates, [BiPh(SR)2]. The crystal structures of [BiPh(1‐MMTZ)2{1‐MMTZ(H)}2], [BiPh(5‐MMTD)2], [BiPh{2,5‐DMTD(H)}2(Me2CO)] and [Bi(4‐BrMTD)3] were obtained. Evaluation of the bactericidal properties against M. smegmatis, S. aureus, MRSA, VRE, E. faecalis and E. coli showed complexes containing the anionic ligands 1‐ MMTZ, 4‐MTT and 4‐BrMTD to be most effective. The dithiolato dithione complexes [BiPh(4‐MTT)2{4‐MTT(H)}2] and [BiPh(1‐MMTZ)2{1‐MMTZ(H)}2] were most effective against all the bacteria: MICs 0.34 μM for [BiPh(4‐MTT)2{4‐MTT(H)}2] against VRE, and 1.33 μM for [BiPh(1‐MMTZ)2{1‐MMTZ(H)}2] against M. smegmatis and S. aureus. Tris‐thiolato BiIII complexes were least effective overall. All complexes showed little or no toxicity towards mammalian COS‐7 cells at 20 μg mL−1.
Rhodium(III)‐Catalyzed N‐Nitroso‐Directed CH Addition to Ethyl 2‐Oxoacetate for Cycloaddition/Fragmentation Synthesis of Indazoles
Authors: Chen Jinsen , Chen Pei , Song Chao , Zhu Jin 
Published: September 2014

AbstractRhIII‐catalyzed N‐nitroso‐directed CH addition to ethyl 2‐oxoacetate allows subsequent construction of indazoles, a privileged heterocycle scaffold in synthetic chemistry, through the exploitation of reactivity between the directing group and installed group. The formal [2+2] cycloaddition/fragmentation reaction pathway identified herein, a unique reactivity pattern hitherto elusive for the N‐nitroso group, emphasizes the importance of forward reactivity analysis in the development of useful CH functionalization‐based synthetic tools. The synthetic utility of the protocol is demonstrated with the synthesis of a tricyclic‐fused ring system. The diversity of covalent linkages available for the nitroso group should enable the extension of the genre of reactivity reported herein to the synthesis of other types of heterocycles.
Total Synthesis of the Anti‐inflammatory and Pro‐resolving Lipid Mediator MaR1n−3 DPA Utilizing an sp3–sp3 Negishi Cross‐Coupling Reaction
Authors: Tungen Jørn Eivind , Aursnes Marius , Dalli Jesmond , Arnardottir Hildur , Serhan Charles Nicholas , Hansen Trond Vidar 
Published: September 2014

AbstractThe first total synthesis of the lipid mediator MaR1n−3 DPA (5) has been achieved in 12 % overall yield over 11 steps. The stereoselective preparation of 5 was based on a Pd‐catalyzed sp3–sp3 Negishi cross‐coupling reaction and a stereocontrolled Evans–Nagao acetate aldol reaction. LC‐MS/MS results with synthetic material matched the biologically produced 5. This novel lipid mediator displayed potent pro‐resolving properties stimulating macrophage efferocytosis of apoptotic neutrophils.
Photoresponsive DNA Nanocapsule Having an Open/Close System for Capture and Release of Nanomaterials
Authors: Takenaka Tomohiro , Endo Masayuki , Suzuki Yuki , Yang Yangyang , Emura Tomoko , Hidaka Kumi , Kato Takayuki , Miyata Tomoko , Namba Keiichi , Sugiyama Hiroshi 
Published: September 2014

AbstractA photofunctionalized square bipyramidal DNA nanocapsule (NC) was designed and prepared for the creation of a nanomaterial carrier. Photocontrollable open/close system and toehold system were introduced into the NC for the inclusion and release of a gold nanoparticle (AuNP) by photoirradiation and strand displacement. The reversible open and closed states were examined by gel electrophoresis and atomic force microscopy (AFM), and the open behavior was directly observed by high‐speed AFM. The encapsulation of the DNA‐modified AuNP within the NC was carried out by hybridization of a specific DNA strand (capture strand), and the release of the AuNP was examined by addition of toehold‐containing complementary DNA strand (release strand). The release of the AuNP from the NC was achieved by the opening of the NC and subsequent strand displacement.
Ultrasound‐facilitated particle breakage: Estimation of kinetic parameters using population balance modelling
Authors: Bari Atul H. , Pandit Aniruddha B. 
Published: September 2014

AbstractUltrasound‐facilitated particle breakage has been proven to be a good technique for size reduction. However, because of the difficulties associated with the solution of population balance equation (PBE), there has been little attention on the estimation of kinetics of this process. In this paper an attempt has been made to develop a generic approach for solving PBE with a given particle size distribution (PSD) data to estimate the breakage kinetics. For this purpose, discretization technique along with gPROMS parameter estimation tool was used. This method was found to be a comprehensive method for the estimation of breakage kinetics in general and was subsequently used for the estimation of ultrasound‐facilitated breakage kinetics, using a simple model system. Potassium nitrate (KNO3) particles suspended in toluene was used as model system, and the effect of induced power on breakage strength was studied. The data obtained were used for the estimation of specific breakage rate with different particle size distribution function. The distribution function, for which simulated PSD was found to match with the experimental PSD, was considered for deriving energy‐size reduction law.
Demineralization of glucose solutions by electrodialysis: Influence of the ionic composition on the mass transfer and process performances
Authors: Galier Sylvain , Balmann Hélène Roux‐de 
Published: September 2014

AbstractThe aim of the present work was to investigate the influence of the ionic composition on the demineralization of a saccharide solution containing glucose. Experiments were carried out in order to evaluate the influence of the ionic composition on the solvent and solutes fluxes (glucose and electrolytes) through the membrane under different conditions (ionic compositions: NaCl, Na2SO4 and CaCl2; with or without current). From diffusion experiments (without current), it was shown that the glucose diffusion flux decreases for increasing ion hydration. These results are in agreement with those obtained in a previous work showing that the transfer modification reflects changes in the membrane properties associated with the hydration of its counter‐ion which is likely linked to swelling mechanisms at a microscopic scale.From the experiments carried out in normal ED conditions (with current) an additional convective contribution was pointed out. This kind of result is rather scarce in the literature. The glucose flux was then the sum of two contributions: diffusion and convection, due to the electro‐osmotic flux which is proportional to the electrical current. The contribution of the glucose convection flux on the overall glucose transfer was ranged between 70 and 90 % according to the electrolyte nature (NaCl, Na2SO4 and CaCl2) and the electric current (150 or 300 A m−2). The variation of the convective flux has been further correlated to the hydration of the ions. Indeed increasing convection fluxes were obtained for decreasing anion (or cation) hydration. It was shown that the saccharide transfer increases in presence of salts and that this increase was correlated to the saccharide dehydration in presence of electrolyte. Finally, the solvent, ions and glucose fluxes were used to calculate the glucose loss factor versus the demineralization factor to evaluate the influence of the electrolyte nature on the demineralization process performances. It was observed that, for a fixed demineralization factor, the glucose loss factor (comprised between 4 and 5 % for a demineralization factor of 90 %) increased with the ion hydration due to the higher contribution of the glucose convection flux.