bluuebunny/crossref_metadata_2025_split huggingface dataset:
(−)‐Tarchonanthuslactone: Design of New Analogues, Evaluation of their Antiproliferative Activity on Cancer Cell Lines, and Preliminary Mechanistic Studies
Authors: Toneto Novaes Luiz Fernando , Martins Avila Carolina , Pelizzaro‐Rocha Karin Juliane , Vendramini‐Costa Débora Barbosa , Pereira Dias Marina , Barbosa Trivella Daniela Barreto , Ernesto de Carvalho João , Ferreira‐Halder Carmen Veríssima , Pilli Ronaldo Aloise 
Published: August 2015

AbstractNatural products containing the α,β‐unsaturated δ‐lactone skeleton have been shown to possess a variety of biological activities. The natural product (−)‐tarchonanthuslactone (1) possessing this privileged scaffold is a popular synthetic target, but its biological activity remains underexplored. Herein, the total syntheses of dihydropyran‐2‐ones modeled on the structure of 1 were undertaken. These compounds were obtained in overall yields of 17–21 % based on the Keck asymmetric allylation reaction and were evaluated in vitro against eight different cultured human tumor cell lines. We further conducted initial investigation into the mechanism of action of selected analogues. Dihydropyran‐2‐one 8 [(S,E)‐(6‐oxo‐3,6‐dihydro‐2H‐pyran‐2‐yl)methyl 3‐(3,4‐dihydroxyphenyl)acrylate], a simplified analogue of (−)‐tarchonanthuslactone (1) bearing an additional electrophilic site and a catechol system, was the most cytotoxic and selective compound against six of the eight cancer cell lines analyzed, including the pancreatic cancer cell line. Preliminary studies on the mechanism of action of compound 8 on pancreatic cancer demonstrated that apoptotic cell death takes place mediated by an increase in the level of reactive oxygen species. It appears as though compound 8, possessing two Michael acceptors and a catechol system, may be a promising scaffold for the selective killing of cancer cells, and thus, it deserves further investigation to determine its potential for cancer therapy.
LASSBio‐1829 Hydrochloride: Development of a New Orally Active N‐Acylhydrazone IKK2 Inhibitor with Anti‐inflammatory Properties
Authors: Guedes Isabella A. , Freitas Rosana H. C. N. , Cordeiro Natália M. , Nascimento Thaís S. do , Valerio Tayna S. , Fernandes Patrícia D. , Dardenne Laurent E. , Fraga Carlos A. M. 
Published: August 2015

AbstractInhibitor of nuclear factor κB kinase 2 (IKK2) is suggested to be a potential target for the development of novel anti‐inflammatory and anticancer drugs. In this work, we applied structure‐based drug design to improve the potency of the inhibitor (E)‐N′‐(4‐nitrobenzylidene)‐2‐naphthohydrazide (LASSBio‐1524, 1 a: IC50=20 μm). The molecular model built for IKK2 together with the docking methodology employed were able to provide important and consistent information with respect to the structural and chemical inhibitor characteristics that may confer potency to IKK2 inhibitors, providing important guidelines for the development of a new N‐acylhydrazone (NAH) derivative. (E)‐N′‐(4‐(1H‐pyrrolo[2,3‐b]pyridin‐4‐yl)benzylidene)‐2‐naphthohydrazide hydrochloride (LASSBio‐1829 hydrochloride, 10) is a 7‐azaindole NAH able to inhibit IKK2 with an IC50 value of 3.8 μm. LASSBio‐1829 hydrochloride was found to be active in several pharmacological inflammation tests in vivo, showing its potential as an anti‐inflammatory prototype.
Triphilic Ionic‐Liquid Mixtures: Fluorinated and Non‐fluorinated Aprotic Ionic‐Liquid Mixtures
Authors: Hollóczki Oldamur , Macchiagodena Marina , Weber Henry , Thomas Martin , Brehm Martin , Stark Annegret , Russina Olga , Triolo Alessandro , Kirchner Barbara 
Published: August 2015

AbstractWe present here the possibility of forming triphilic mixtures from alkyl‐ and fluoroalkylimidazolium ionic liquids, thus, macroscopically homogeneous mixtures for which instead of the often observed two domains—polar and nonpolar—three stable microphases are present: polar, lipophilic, and fluorous ones. The fluorinated side chains of the cations indeed self‐associate and form domains that are segregated from those of the polar and alkyl domains. To enable miscibility, despite the generally preferred macroscopic separation between fluorous and alkyl moieties, the importance of strong hydrogen bonding is shown. As the long‐range structure in the alkyl and fluoroalkyl domains is dependent on the composition of the liquid, we propose that the heterogeneous, triphilic structure can be easily tuned by the molar ratio of the components. We believe that further development may allow the design of switchable, smart liquids that change their properties in a predictable way according to their composition or even their environment.
Theoretical Insights into the Tuning of Metal Binding Sites of Paddlewheels in rht‐Metal–Organic Frameworks
Authors: Pham Tony , Forrest Katherine A. , Gao Wen‐Yang , Ma Shengqian , Space Brian 
Published: August 2015

AbstractTheoretical investigations of CO2 sorption are performed in four members of the highly tunable rht‐metal–organic framework (MOF) platform. rht‐MOFs contain two Cu2+ ions that comprise the metal paddlewheels and both are in chemically distinct environments. Indeed, one type of Cu2+ ion faces toward the center of the linker whereas the other type faces away from the center of the linker. Electronic structure calculations on the series of rht‐MOFs demonstrate that one of the Cu2+ ions has a consistently higher charge magnitude relative to the other. As a consequence, the Cu2+ ion with the higher partial positive charge acts as the favored sorbate binding site at initial loading as revealed by grand canonical Monte Carlo (GCMC) simulations that include many‐body polarization. It was found that the charge distribution about the copper paddlewheels is dependent on the type of functional groups present on the linker. This study demonstrates how the binding site about the metal paddlewheels in the rht‐MOF platform can be controlled by changing the functionality on the organic ligand.
Three‐Dimensionally Controllable Synthesis of Multichannel Silica Nanotubes and Their Application as Dual Drug Carriers
Authors: Wang Haiqing , Xiong Cuirong , Li Zheng , Kong Yan , Chen Jin , Wang Jun 
Published: August 2015

AbstractThree‐dimensionally controllable multichannel silica nanotubes (MC‐SNTs) have been constructed. Quaternary ammonium type (CnH2n+1(CH3)3N+) surfactants were used as structure‐directing agents (SDAs) in basic ammonia. A low concentration of block copolymer HO(CH2CH2O)20[CH2CH(CH3)O]70(CH2CH2O)20H (P123) was employed as an additive. The length, diameter, and pore size of MC‐SNTs can be finely controlled in the range of 50 nm to 5 μm, 50 nm to 350 nm, and 2 nm to 3 nm by changing the molar ratio of P123 and SDA, the concentration of ammonia, and the length of carbon chain of SDAs, respectively. Observations based on transmission electron microscopy confirmed the role of P123 and ammonia in the self‐assembly of micelles of SDA. Compared with the one‐pot method reported previously, the aspect ratios (ARs; length/diameter) of obtained MC‐SNTs were tunable in a wide range of approximately 1 to 100. The tunable MC‐SNTs were used as dual drug‐delivery carriers for anticancer drug doxorubicin (Dox) and anti‐inflammatory drug ibuprofen (Ibu). Results of release behavior and toxicity to cancer cells of Dox–Ibu‐loaded MC‐SNTs with different ARs revealed that Dox and Ibu were successfully codelivered and did not interfere with each other. The produced MC‐SNTs with larger AR values of showed advantages in the amount of accumulated dual drugs, the duration time of release, and inhibition of the growth of HeLa cells.
Photostable, Oxygen‐Sensitive Optical Probe Based on a Homonuclear Terbium(III) Complex Covalently Bound to Functionalized Polydimethylsiloxane
Authors: Gaspar Rafael D. L. , Monteiro Jorge H. S. K. , Raimundo Ivo M. , Mazali Italo O. , Sigoli Fernando A. 
Published: August 2015

AbstractA new oxygen‐sensitive optical probe based on the [Tb(3,5‐dcba)3]⋅1/2 H2O (3,5‐dcba=3,5‐dichlorobenzoate) complex, which is chemically attached to a phosphine‐oxide‐functionalized polydimethylsiloxane is presented. The hybrid material shows green emission and transparency in the visible range. The optically sensitive probe is photostable under excitation at 350 nm and shows the highest oxygen sensitivity, I0/I100 equal to 8.9 at 1 atm, among probes based on homonuclear lanthanide compounds. Furthermore its reversibility is demonstrated after several cycles ranging from 100 % N2 to 100 % O2 with response time of 8.5 s (N2→O2) and recovery time of 49.5 s (O2→N2).
Anion Binding Inside a Bambus[6]uril Macrocycle in Chloroform
Authors: Havel Vaclav , Sindelar Vladimir 
Published: August 2015

AbstractBambus[6]urils are a class of neutral anion receptors with outstanding binding properties in various solvents. The host–guest associations of bambusurils in aqueous environments have been investigated in detail, but their behavior in nonpolar solvents has not yet been reported. This paper presents isothermal calorimetry and 1H NMR data on the binding of dodecabenzylbambus[6]uril (Bn12BU[6]) to seventeen anions in chloroform. Under these conditions, anion inclusion in the macrocycle appears to be enthalpy‐driven, yielding complexes with stability constants of up to 1010 m−1. Perchlorate was optimally sized for inclusion in Bn12BU[6], while larger anions exhibited significantly lower affinity for the macrocycle. In addition, complexes of bambusuril and anions can be differentiated by NMR analysis based on the unique chemical shifts of characteristic peaks in their spectra. This finding was used to perform quantitative and qualitative analysis of multiple anion mixtures.
A Highly Efficient Heterogenized Iridium Complex for the Catalytic Hydrogenation of Carbon Dioxide to Formate
Authors: Park Kwangho , Gunasekar Gunniya Hariyanandam , Prakash Natarajan , Jung Kwang‐Deog , Yoon Sungho 
Published: August 2015

AbstractA heterogenized catalyst on a highly porous covalent triazine framework was synthesized and characterized to have a coordination environment similar to that of its homogeneous counterpart. The catalyst efficiently converted CO2 into formate through hydrogenation with a turnover number of 5000 after 2 h and an initial turnover frequency of up to 5300 h−1; both of these values are the highest reported to date for a heterogeneous catalyst, which makes it attractive toward industrial application. Furthermore, the synthesized catalyst was found to be stable in air and was recycled by simple filtration without significant loss of catalytic activity.
Endothelial progenitor cells, defined by the simultaneous surface expression of VEGFR2 and CD133, are not detectable in healthy peripheral and cord blood
Authors: Lanuti Paola , Rotta Gianluca , Almici Camillo , Avvisati Giuseppe , Budillon Alfredo , Doretto Paolo , Malara Natalia , Marini Mirella , Neva Arabella , Simeone Pasquale , Di Gennaro Elena , Leone Alessandra , Falda Alessandra , Tozzoli Renato , Gregorj Chiara , Di Cerbo Melania , Trunzo Valentina , Mollace Vincenzo , Marchisio Marco , Miscia Sebastiano 
Published: August 2015

AbstractCirculating endothelial cells (CEC) and their progenitors (EPC) are restricted subpopulations of peripheral blood (PB), cord blood (CB), and bone marrow (BM) cells, involved in the endothelial homeostasis maintenance. Both CEC and EPC are thought to represent potential biomarkers in several clinical conditions involving endothelial turnover/remodeling. Although different flow cytometry methods for CEC and EPC characterization have been published so far, none of them have reached consistent conclusions, therefore consensus guidelines with respect to CEC and EPC identification and quantification need to be established. Here, we have carried out an in depth investigation of CEC and EPC phenotypes in healthy PB, CB and BM samples, by optimizing a reliable polychromatic flow cytometry (PFC) panel. Results showed that the brightness of CD34 expression on healthy PB and CB circulating cells represents a key benchmark for the identification of CEC (CD45neg/CD34bright/CD146pos) respect to the hematopoietic stem cell (HSC) compartment (CD45dim/CD34pos/CD146neg). This approach, combined with a dual‐platform counting technique, allowed a sharp CEC enumeration in healthy PB (n = 38), and resulting in consistent CEC counts with previously reported data (median = 11.7 cells/ml). In parallel, by using rigorous PFC conditions, CD34pos/CD45dim/CD133pos/VEGFR2pos EPC were not found in any healthy PB or CB sample, since VEGFR2 expression was never detectable on the surface of CD34pos/CD45dim/CD133pos cells. Notably, the putative EPC phenotype was observed in all analyzed BM samples (n = 12), and the expression of CD146 and VEGFR2, on BM cells, was not restricted to the CD34bright compartment, but also appeared on the HSC surface. Altogether, our findings suggest that the previously reported EPC antigen profile, defined by the simultaneous expression of VEGFR2 and CD133 on the surface of CD45dim/CD34pos cells, should be carefully re‐evaluated and further studies should be conducted to redefine EPC features in order to translate CEC and EPC characterization into clinical practice. © 2015 International Society for Advancement of Cytometry
Lack of evolution in a leaf beetle that lives on two contrasting host plants
Authors: Gould Katherine , Wilson Paul 
Published: August 2015

AbstractThe interactions between plant‐eating insects and their hosts have shaped both the insects and the plants, driving evolution of plant defenses and insect specialization. The leaf beetle Trirhabda eriodictyonis (Chrysomelidae) lives on two shrubs with differing defenses: Eriodictyon crassifolium has hairy leaves, whereas E. trichocalyx has resinous leaves. We tested whether these beetles have differentiated onto the two host plants, and if not, whether the beetles prefer the better host plant and prefer mates who are from that host plant. In feeding tests, adult beetles strongly preferred eating E. trichocalyx regardless of which host they came from. In addition, females laid more eggs if they ate E. trichocalyx than E. crassifolium. So, E. trichocalyx is generally the better host. However, beetle mate preference was not in line with food choice. Males did not prefer to mate with females from E. trichocalyx. Females from E. crassifolium did prefer males from E. trichocalyx over males from E. crassifolium, but did not lay more eggs as a result of these matings. We conclude that the beetle populations we studied have not differentiated based on their host plants and may not have even adapted to the better host. Although to humans these host plant defenses differ dramatically, signs that they have caused evolution in the beetles are lacking. The case of T. eriodictyonis stands counter to many other studies that have seen the differentiation of ecotypes and/or adaptive coordination of an herbivore's life cycle based on host plant differences.
Trade‐offs in the evolution of bumblebee colony and body size: a comparative analysis
Authors: Cueva del Castillo Raúl , Sanabria‐Urbán Salomón , Serrano‐Meneses Martín Alejandro 
Published: August 2015

AbstractTrade‐offs between life‐history traits – such as fecundity and survival – have been demonstrated in several studies. In eusocial insects, the number of organisms and their body sizes can affect the fitness of the colony. Large‐than‐average body sizes as well as more individuals can improve a colony's thermoregulation, foraging efficiency, and fecundity. However, in bumblebees, large colonies and large body sizes depend largely on high temperatures and a large amount of food resources. Bumblebee taxa can be found in temperate and tropical regions of the world and differ markedly in their colony sizes and body sizes. Variation in colony size and body size may be explained by the costs and benefits associated with the evolutionary history of each species in a particular environment. In this study, we explored the effect of temperature and precipitation (the latter was used as an indirect indicator of food availability) on the colony and body size of twenty‐one bumblebee taxa. A comparative analysis controlling for phylogenetic effects as well as for the body size of queens, workers, and males in bumblebee taxa from temperate and tropical regions indicated that both temperature and precipitation affect colony and body size. We found a negative association between colony size and the rainiest trimester, and a positive association between the colony size and the warmest month of the year. In addition, male bumblebees tend to evolve larger body sizes in places where the rain occurs mostly in the summer and the overall temperature is warmer. Moreover, we found a negative relationship between colony size and body sizes of queens, workers, and males, suggesting potential trade‐offs in the evolution of bumblebee colony and body size.
Interspecific variation in the phenology of advertisement calling in a temperate Australian frog community
Authors: Heard Geoffrey W. , Canessa Stefano , Parris Kirsten M. 
Published: August 2015

AbstractSpatial and temporal partitioning of resources underlies the coexistence of species with similar niches. In communities of frogs and toads, the phenology of advertisement calling provides insights into temporal partitioning of reproductive effort and its implications for community dynamics. This study assessed the phenology of advertisement calling in an anuran community from Melbourne, in southern Australia. We collated data from 1432 surveys of 253 sites and used logistic regression to quantify seasonality in the nightly probability of calling and the influence of meteorological variables on this probability for six species of frogs. We found limited overlap in the predicted seasonal peaks of calling among these species. Those shown to have overlapping calling peaks are unlikely to be in direct competition, due to differences in larval ecology (Crinia signifera and Litoria ewingii) or differences in calling behavior and acoustics (Limnodynastes dumerilii and Litoria raniformis). In contrast, closely related and ecologically similar species (Crinia signfera and Crinia parinsignifera; Litoria ewingii and Litoria verreauxii) appear to have staggered seasonal peaks of calling. In combination with interspecific variation in the meteorological correlates of calling, these results may be indicative of temporal partitioning of reproductive activity to facilitate coexistence, as has been reported for tropical and temperate anurans from other parts of the globe.
The ‘Policy Mix’ for Sustainable Urban Transition: The city district of Hammarby Sjöstad in Stockholm
Authors: Mahzouni Arian 
Published: August 2015

AbstractThis paper analyses the policy mix for urban transition by drawing on insights from studies in institutions and path dependence. It sheds new light on the role of institutions and actors in creating a policy mix for sustainable city districts, which has not been systematically addressed in the current debate on policy mix. The interaction and trade‐offs between policy instruments for energy efficiency in buildings in the city district of Hammarby Sjöstad are analysed historically. The key findings are that long periods of increasing returns in existing technological systems and the institutions that have supported them have created different types of ‘lock‐ins’ (behavioural, policy and industry). A systemic approach to developing a framework for policy mix analysis is necessary to address the relationship between various ‘lock‐ins’. © 2015 The Authors. Environmental Policy and Governance published by ERP Environment and John Wiley & Sons Ltd
Calix[6]arene Functionalized at Four Bridges: Conformation and Intramolecular Guest Exchange
Authors: Leader Avia , Itzhak Norbert , Bogoslavsky Benny , Biali Silvio E. 
Published: August 2015

AbstractReaction of the tert‐butoxycarbonyl derivative of p‐tert‐butylcalix[6]arene (2) with excess NBS under irradiation yields a calixarene with four bromomethine bridges as the major product (3). On the basis of the number of signals in the NMR spectrum, to the product was assigned a 1,2,4,5‐substitution pattern. X‐ray crystallography indicates that the product possesses the rct2 configuration and crystallized as a mixture of two conformers. The major form in the crystal exists in a 1,2,3‐alternate conformation where a single tert‐butoxycarbonyl group is self‐included in the cavity and all bromines are located at equatorial positions. A rotational barrier of 18.4 kcal mol–1 was measured for the intramolecular guest exchange rotational process that involves the mutual exchange between the unique self‐included Boc group and the Boc group on the opposite ring (Boc = tert‐butoxycarbonyl).
Assessment of global linear stability analysis using a time‐stepping approach for compressible flows
Authors: Ohmichi Y. , Suzuki K. 
Published: August 2015

SummaryGlobal linear stability analysis combined with computational fluid dynamics (CFD) is considered useful for understanding the physics of fluid flows. However, the numerical techniques of global linear stability analysis for compressible flows have not been well established in comparison with those for incompressible flows. In this study, we develop and assess a set of appropriate numerical techniques required to conduct a global linear stability analysis for compressible flows. For the eigensystem analysis, the Arnoldi method combined with time integration is in effect to preserve the memory (RAM) size of the computer. The compact difference scheme is used for the CFD analysis from the viewpoints of computing accurate global modes and saving memory by reducing the number of grid points to obtain the necessary spatial resolution. To assess the proposed method, two‐dimensional compressible flow problems, including regularized cavity flow, flow around a square cylinder, and the compressible mixing layer, are analyzed, and it is confirmed that the proposed method can obtain accurate mode shapes, growth rate, and frequency of the corresponding global modes. In addition, influences and an appropriate formulation of the outflow boundary conditions are investigated. Results reveal that the outflow boundary causes spurious unstable modes in the global linear stability analysis, and the radiation and outflow boundary condition and the extension of the computational domain with grid stretching keep the spurious unstable modes to a minimum. Copyright © 2015 John Wiley & Sons, Ltd.