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G protein-coupled receptors (GPCRs) are an ancient family of signal transducers that are both abundant and consequential in metazoan endocrinology. The evolutionary history and function of the GPCRs of the decapod superfamilies of gonadotropin-releasing hormone (GnRH) are yet to be fully elucidated. As part of which, the use of traditional phylogenetics and the recycling of a diminutive set of mis-annotated databases has proven insufficient. To address this, we have collated and revised eight existing and three novel GPCR repertoires for GnRH of decapod species. We developed a novel bioinformatic workflow that included clustering analysis to capture likely GnRH receptor-like proteins, followed by phylogenetic analysis of the seven transmembrane-spanning domains. A high degree of conservation of the sequences and topology of the domains and motifs allowed the identification of species-specific variation (up to ~70%, especially in the extracellular loops) that is thought to be influential to ligand-binding and function. Given the key functional role of the DRY motif across GPCRs, the classification of receptors based on the variation of this motif can be universally applied to resolve cryptic GPCR families, as was achieved in this work. Our results contribute to the resolution of the evolutionary history of invertebrate GnRH receptors and inform the design of bioassays in their deorphanization and functional annotation. [ABSTRACT FROM AUTHOR]

Organometallic η6-arene ruthenium(II) complexes with 3-chloro-6-(1H-pyrazol-1-yl)pyridazine (Ru1, Ru2, and Ru5) and 3-chloro-6-(3,5-dimethyl-1H-pyrazol-1-yl)pyridazine (Ru3-4) N,N' heterocyclic and η6-arene (cymene (Ru1-4) or toluene (Ru 5)) have been synthesized. The ruthenium(II) complexes have common "three-legged piano-stool" pseudo-octahedral structures known for half-sandwich complexes. Evolution of their UV–Visible absorption spectra in PBS buffer or DMSO over 24 h confirmed their good solvolysis stability. Titrations of the complexes with the calf thymus DNA (CT-DNA) were monitored using UV–Visible absorption and fluorescence spectroscopies. The complexes interact moderately with CT-DNA and their binding constants are in the order of 104 M−1. Competitive binding of the complexes to a DNA-Hoechst 33,258 depicted competitive displacement of Hoechst from DNA's minor grooves. These complexes bind to glutathione forming GSH-adducts through S coordination by replacement of a halide, with the iodo-analogues having higher binding constants than the chloro-complexes. Cyclic voltammograms of the complexes exhibited one electron-transfer quasi-reversible process. Trends in the molecular docking data of Ru1-5/DNA were similar to those for DNA binding constants. Of the five, only Ru1, Ru3 and Ru5 showed some activity (moderate) against the MCF-7 breast cancer cells with IC50 values in the range of 59.2–39.9 for which Ru5 was the most active. However, the more difficult-to-treat cell line, MDA-MB 231 cell was recalcitrant to the treatment by these complexes. Molecular docking simulations visualized the interactions of arene Ru(II) complexes with CT-DNA via minor grooving. The trends were corroborated by electrochemical and cytotoxicity data. [ABSTRACT FROM AUTHOR]

Two diphenyl formamidine ligands, four dirhodium(II,II) complexes, and three axially modified low-valent dirhodium(II,II) metallodendrimers were synthesized and evaluated as anticancer agents against the A2780, A2780cis, and OVCAR-3 human ovarian cancer cell lines. The dirhodium(II,II) complexes show moderate cytotoxic activity in the tested tumor cell lines, with acetate and methyl-substituted formamidinate compounds displaying increased cytotoxicity that is relative to cisplatin in the A2780cis cisplatin resistant cell line. Additionally, methyl- and fluoro-substituted formamidinate complexes showed comparable and increased cytotoxic activity in the OVCAR-3 cell line when compared to cisplatin. The low-valent metallodendrimers show some activity, but a general decrease in cytotoxicity was observed when compared to the precursor complexes in all but one case, which is where the more active acetate-derived metallodendrimer showed a lower IC50 value in the OVCAR-3 cell line in comparison with the dirhodium(II,II) tetraacetate. [ABSTRACT FROM AUTHOR]

The feasibility of implicitly assessing medical student burnout was explored, using the Implicit Relational Assessment Procedure (IRAP), to measure longitudinal student burnout over the first two years of medical school and directly comparing it with an existing explicit measure of burnout (Maslach Burnout Inventory; MBI). Three successive cohorts of medical students completed both implicit and explicit measures of burnout at several time points during their first two years of medical school. Both assessments were conducted via the internet within a one-week period during the first week of medical school, the end of the first year of medical school, and the end of the second year, though not all cohorts were able to complete the assessments at all time points. Mixed linear models were used to compare the two measures directly, as well as to evaluate changes over time in each measure separately. Minimal correspondence was observed between the implicit and explicit measures of burnout on a within-subject basis. However, when analyzed separately, all subscales of both measures detected significant change over time in the direction of greater levels of burnout, particularly during the first year of medical school. These results provide preliminary evidence the IRAP is able to assess implicit attitudes related to burnout among medical students, though additional research is needed. The IRAP detected consistent improvements in positive implicit attitudes toward medical training during students' second year of medical school, which was not detected by the MBI. Possible implications of these findings are discussed. [ABSTRACT FROM AUTHOR]

Implicit biases held by professionals, functioning outside conscious awareness, can negatively affect client outcomes and professional well-being. Purpose: This systematic review evaluated evidence in the literature of Implicit Relational Assessment Procedure (IRAP) utility for assessing implicit biases held by professionals toward client populations. Method: Included studies were those published 2000 through 2020 using IRAP to measure implicit biases in professionals toward consumers. Results: Eight studies met inclusion criteria, with two meeting borderline requirements. Results support IRAP reliability and validity for identifying implicit biases. Variation presents across studies in reporting and analysis of IRAP effects. Discussion: Convergence and divergence between implicit and explicit measures are discussed in terms of relational responding. Results are limited by the relative paucity of studies meeting inclusion criteria and by inconsistencies in data reporting and analysis. Methods for selecting IRAP stimuli are discussed, with a call for a more function-driven approach. Standardization of IRAP methodology is recommended to facilitate extension. [ABSTRACT FROM AUTHOR]

A new ditopic, quinoline-based ligand L (7-chloro-4-(pyridin-4-yl)quinoline) was synthesized via a Suzuki cross-coupling reaction. The ligand was utilized to synthesize the corresponding half-sandwich iridium(III) and ruthenium(II) binuclear complexes (1c and 1d) and the subsequent metallarectangles (2c, 2d, 3c, and 3d), via [2 + 2] coordination-driven self-assembly. Single-crystal X-ray diffraction confirmed the proposed molecular structure of the binuclear complex [{IrCl2(Cp*)}2(μ-L)] (1c) and DFT calculations were used to predict the optimized geometry of the rectangular nature of [{Ir(μ-Cl)(Cp*)}4(μ-L)2](CF3SO3)4 (2c). All of the metallarectangles were isolated as their triflate salts and characterized using various spectroscopic (1H, 13C{1H}, DOSY NMR, and IR spectroscopy) and analytical techniques (ESI-MS). The synthesized compounds were screened against the NF54 chloroquine-sensitive (CQS) and K1 chloroquine-resistant (CQR) strains of Plasmodium falciparum. Incorporation of the ubiquitous quinoline core and metal complexation significantly enhanced the in vitro biological activity, with an increase in the nuclearity correlating with an increase in the resultant antiplasmodial activity. This was observed across both parasitic strains, alluding to the potential of supramolecular metallarectangles to act as antiplasmodial agents. Inhibition of haemozoin formation was considered a potential mechanism of action and selected metallarectangles exhibit β-haematin inhibition activity with near comparable activity to chloroquine. [ABSTRACT FROM AUTHOR]

Iridium(III) half-sandwich complexes containing 7-chloroquinoline-1,2,3-triazole hybrid ligands were synthesised and their inhibitory activities evaluated against the Plasmodium falciparum malaria parasite. Supporting computational analysis revealed that metal coordination to the quinoline nitrogen occurs first, forming a kinetic product that, upon heating over time, forms a more stable cyclometallated thermodynamic product. Single crystal X-ray diffraction confirmed the proposed molecular structures of both isolated kinetic and thermodynamic products. Complexation with iridium significantly enhances the in vitro activity of selected ligands against the chloroquine-sensitive (NF54) Plasmodium falciparum strain, with selected complexes being over one hundred times more active than their respective ligands. No cross-resistance was observed in the chloroquine-resistant (K1) strain. No cytotoxicity was observed for selected complexes tested against the mammalian Chinese Hamster Ovarian (CHO) cell line. In addition, speed-of-action assays and β-haematin inhibition studies were performed. Through preliminary qualitative and quantitative cell-free experiments, it was found that the two most active neutral, cyclometallated complexes can act as transfer hydrogenation catalysts, by reducing β-nicotinamide adenine dinucleotide (NAD+) to NADH in the presence of a hydrogen source, sodium formate. [ABSTRACT FROM AUTHOR]

A highly efficient multitasking FeOCN composite was synthesized in a single step by the fast heating of an Fe(III) salt and urea. The composite was confirmed by various spectroscopic and analytical techniques which include XRD, FTIR, Raman, FESEM, and XPS analysis. The composite was then investigated for various organic transformations and it was found to be excellent for the hydroformylation of 1‐octene in toluene under 50 bar syngas pressure at 95 °C. The composite was also found to be significantly active for the hydration reactions of alkynes and nitriles under acid‐ and base‐free conditions. The hydration reactions were performed in aqueous methanol at 120 °C and an excellent yield of regioselective products was obtained under optimized reaction conditions. [ABSTRACT FROM AUTHOR]

A series of 2-phenyl and 2-pyridyl tris-benzimidazole ligands was reacted with the [Ru(p-cymene)Cl2]2 dimer to yield the corresponding neutral cyclometallated and cationic organoruthenium(II) complexes. All of the synthesized compounds were characterized using an array of spectroscopic and analytical techniques, including 1H, 13C nuclear magnetic resonance (NMR), infrared spectroscopy and mass spectrometry. The trinuclear compounds were screened for their cytotoxicy against the MCF-7 breast cancer cell line and the triple negative MDA-MB-231 breast cancer cell line at concentrations of 10 and 20 μM. Overall, the 2-pyridyl ligands 10 and 11, and their corresponding trinuclear complexes [16][PF6]3 and [17][PF6]3, show the most promising activity as these compounds significantly reduce the percentage cell survival of MCF-7 and MDA-MB-231 breast cancer cell lines at the aforementioned fixed concentrations. It was observed that 10 and [16][PF6]3 show potency greater than that of cisplatin against the MCF-7 breast cancer cell line, and [17][PF6]3 shows potency comparable to that of cisplatin against the MCF-7 cell line. Additionally, the synthesized compounds were observed to have relatively low cytotoxicty towards MCF-12A breast epithelial cells and relatively higher selectivity towards MCF-7 breast cancer cells compared to cisplatin. [ABSTRACT FROM AUTHOR]

Excessive fear and avoidance in relatively safe situations can lead to a narrowing of one's behavioral repertoire and less engagement with valued aspects of living. Ultimately, these processes can reach clinical levels, as seen in anxiety, trauma, and obsessive–compulsive disorders. Research on the basic behavioral processes underlying successful treatment with exposure therapy is growing, yet little is known about the mechanisms contributing to clinical relapse. Until recently, these mechanisms have largely been conceptualized in terms of Pavlovian return of fear, with relatively little research into operant processes. In the current paper, we briefly review translational research in anxiety disorders and the connections between fear and avoidance, focusing on recent work in the acquisition, extinction, and relapse of avoidance behavior and the generalization of this learning through arbitrary symbolic relations. We then introduce one possible treatment approach to mitigating clinical relapse, acceptance and commitment therapy (ACT), and provide a conceptual analysis for why ACT may be especially well‐situated to address this issue. Finally, we end with potential directions for future research on treatment and relapse of anxiety disorders. [ABSTRACT FROM AUTHOR]

Atomistic molecular dynamics (MD) simulations and contrast variation small angle neutron scattering (SANS) have been combined to investigate the Generation-5 polyelectrolyte polyamidoamine starburst dendrimer. This work reveals the dendrimer conformational dependence on counterion association at different levels of molecular charge. The accuracy of the simulations is verified through satisfactory comparison between modeled results, such as excess intra-dendrimer scattering length density distribution and hydration level, and their experimental counterparts. While the counterion distributions are not directly measureable with SANS, the spatial distribution of the counterions and their dendrimer association are extracted from the validated MD equilibrium trajectories. It is found that the conformation of the charged dendrimer is strongly dependent on the counterion association. Sensitivity of the distribution of counterions around charged amines to the counterion valency is qualitatively explained by adopting Langmuir adsorption theory. Moreover, via extending the concept of electrical double layer for compact charged colloids, we define an effective radius of a charged dendrimer including the spatial distribution of counterions in its vicinity. Within the same framework, the correlation between the strength of intra-dendrimer electrostatic repulsion and the counterion valency and dynamics is also addressed. [ABSTRACT FROM AUTHOR]

Based on atomistic molecular dynamics (MD) simulations, the small angle neutron scattering (SANS) intensity behavior of a single generation-4 polyelectrolyte polyamidoamine starburst dendrimer is investigated at different levels of molecular protonation. The SANS form factor, P(Q), and Debye autocorrelation function, γ(r), are calculated from the equilibrium MD trajectory based on a mathematical approach proposed in this work. The consistency found in comparison against previously published experimental findings (W.-R. Chen, L. Porcar, Y. Liu, P. D. Butler, and L. J. Magid, Macromolecules 40, 5887 (2007)) leads to a link between the neutron scattering experiment and MD computation, and fresh perspectives. The simulations enable scattering calculations of not only the hydrocarbons but also the contribution from the scattering length density fluctuations caused by structured, confined water within the dendrimer. Based on our computational results, we explore the validity of using radius of gyration RG for microstructure characterization of a polyelectrolyte dendrimer from the scattering perspective. [ABSTRACT FROM AUTHOR]

Spin-echo small angle neutron scattering (SESANS) provides a new experimental tool for structural investigation. Due to the action of spin-echo encoding, SESANS measures a spatial correlation function in real space, as opposed to the structure factor S(Q), I(Q), in momentum (Q) space measured by conventional small angle neutron scattering. To establish the usefulness of SESANS in structural characterization, particularly for interacting colloidal suspensions, we have previously conducted a theoretical study of the SESANS correlation functions for model systems consisting of particles with uniform density profiles [X. Li, C.-Y. Shew, Y. Liu, R. Pynn, E. Liu, K. W. Herwig, G. S. Smith, J. L. Robertson, and W.-R. Chen J. Chem. Phys. 132, 174509 (2010)]. Within the same framework, we explore in the present paper the prospect of using SESANS to investigate the structural characteristics of colloidal systems consisting of particles with nonuniform intraparticle mass distribution. As an example, a Gaussian model of interacting soft colloids is used to investigate the manifestation of structural softness in a SESANS measurement. The exploration shows a characteristically different SESANS correlation function for interacting soft colloids, in comparison to that of a uniform hard sphere system. The difference arises from the Abel transform imbedded in the mathematical formalism bridging the SESANS spectra and the spatial autocorrelation function. [ABSTRACT FROM AUTHOR]

We develop an experimental approach to analyze the water distribution around a core-shell micelle formed by polystyrene-block-poly[styrene-g-poly(ethylene oxide (PEO)] block copolymers in aqueous media at a fixed polymeric concentration of 10 mg/ml through contrast variation small angle neutron scattering (SANS) study. Through varying the D2O/H2O ratio, the scattering contributions from the water molecules and the micellar constituent components can be determined. Based on the commonly used core-shell model, a theoretical coherent scattering cross section incorporating the effect of water penetration is developed and used to analyze the SANS I(Q). We have successfully quantified the intramicellar water distribution and found that the overall micellar hydration level increases with the increase in the molecular weight of hydrophilic PEO side chains. Our work presents a practical experimental means for evaluating the intramacromolecular solvent distributions of general soft matter systems. [ABSTRACT FROM AUTHOR]

The application of the spin-echo small angle neutron scattering (SESANS) technique for structural characterization of interacting colloidal suspensions is considered in this work. The framework to calculate the theoretical SESANS correlation function is briefly laid out. A general discussion regarding the features of the SESANS correlation functions obtained from different model systems is presented. In comparison with conventional elastic scattering tools operating at the same length scale, our mean-field calculations, based on a monodisperse spherical colloidal system, show that the real-space measurement provided by SESANS presents a powerful probe for studying the intercolloid potential. The reason of this sensitivity is discussed from the standpoint of way, in which how the spatial correlations are manifested in different neutron scattering implementations. This study leads to a better understanding regarding the distinction between SANS and SESANS. [ABSTRACT FROM AUTHOR]

An accurate determination of the structure characteristics of protonated generation 5 polyamidoamine dendrimers in aqueous solution has been conducted by analyzing the small angle neutron scattering databased on a statistical mechanics model. In our investigation, the primary focus is to elucidate the effect of counterion valence on the counterion association and its impact on the intramolecular density profile within a dendrimer. In the range of our study for molecular protonation, a strong dependence of the structural properties of charged dendrimers on counterion valence is revealed. Our findings indicate that the association of a large amount of divalent counterions significantly reduces the effective charge of a dendrimer molecule. Surprisingly, no discernible transition of the density distribution profile is observed for the dendrimer charged by D2SO4, as opposed to our previous observation of a pronounced transition in intramolecular density profile for the dendrimer charged by DCl. These findings may be understood from the thermodynamic processes of counterions. [ABSTRACT FROM AUTHOR]

Palmitic acid (PA) and 1-hexadecanol (HD) strongly affect the phase transition temperature and molecular packing of dipalmitoylphosphatidylcholine (DPPC) monolayers at the air–water interface. The phase behavior and morphology of mixed DPPC/PA as well as DPPC/HD monolayers were determined by pressure-area-isotherms and fluorescence microscopy. The molecular organization was probed by synchrotron grazing incidence x-ray diffraction using a liquid surface diffractometer. Addition of PA or HD to DPPC monolayers increases the temperature of the liquid-expanded to condensed phase transition. X-ray diffraction shows that DPPC forms mixed crystals both with PA and HD over a wide range of mixing ratios. At a surface pressure (π) of 40 mN/m, increasing the amount of the single chain surfactant leads to a reduction in tilt angle of the aliphatic chains from nearly 30° for pure DPPC to almost 0° in a 1:1 molar ratio of DPPC and PA or HD. At this composition we also find closest packing of the aliphatic chains. Further increase of the amount of PA or HD does not change the lattice or the tilt. © 2002 American Institute of Physics. [ABSTRACT FROM AUTHOR]

Reaction engineering kinetics for the hydroformylation of the post-metathesis product 7-tetradecene using a heterobimetallic rhodium-ferrocenyl Schiff base derived precatalyst was investigated with variation of reaction temperature (85–105 °C), precatalyst loading (0.25–0.52 mM), carbon monoxide partial pressures (20–40 bar) and hydrogen partial pressures (20–40 bar). The experimental product-time distributions for the parallel hydroformylation and isomerization reaction system are well described by four interdependent pseudo first-order differential mole balance equations. The effects of temperature in the Arrhenius equation, precatalyst concentration, carbon monoxide and hydrogen partial pressures have been incorporated into a phenomenological mechanism-based rate equation. The rate of hydroformylation is first order in alkene, carbon monoxide and hydrogen, with fractional dependence in precatalyst concentration. The activation energy for the hydroformylation reaction was calculated to be 62 kJ mol−1, which is comparable to that determined for the commercialized phosphorus-modified catalyst systems. [ABSTRACT FROM AUTHOR]

Two Rh(III) and Ir(III) half-sandwich quinoline-based complexes were synthesised and evaluated for their in vitro antiplasmodial activity against the chloroquine-sensitive NF54 and multi-drug resistant K1 strains of the human malaria parasite, Plasmodium falciparum. These half-sandwich organometallic complexes can also facilitate transfer hydrogenation, by converting β-nicotinamide adenine dinucleotide (NAD+) to its reduced form (NADH) in the presence of sodium formate. Co-administration of the iridium(III) complex with sodium formate enhances the antiplasmodial activity in the chloroquine-resistant (K1) strain of Plasmodium falciparum, intimating that metal-mediated transfer hydrogenations can be achieved in malarial parasitic cells. [ABSTRACT FROM AUTHOR]

The synthesis and characterisation of two new water‐soluble RhI mononuclear 1,4‐diazabutadiene (DADs) complexes of general formula: [Rh(DADs‐R)(COD)], where (DADs = sulfonated‐tagged–1,4‐diazabutadiene, COD = cyclooctadiene; and R = H or C10H8), are described. The rhodium(I) complexes were obtained via a complexation reaction of [Rh(COD)(MeCN)2]BF4 with the sulfonated α‐diimine (DAD) ligands, which were previously obtained from a Schiff base condensation reaction of 4‐aminophenol with either 1,2‐ethanedione or acenapthenequinone. All rhodium complexes and their precursor ligands were characterised using 1H NMR, 13C NMR, FT‐IR spectroscopy and mass spectrometry. Their performance as catalyst precursors in the hydroformylation of 1‐octene was assessed and compared to those of the non‐sulfonated RhI mononuclear 1,4‐diazabutadiene (DAD) complexes. Utilisation of the water soluble [Rh(DADs‐R)(COD)] lead to high conversions and regioselectivity (linear/branched aldehyde ratio) in the aqueous biphasic hydroformylation of 1‐octene. Additionally, the catalysts were recovered by phase separation and are reusable over four consecutive catalytic runs without significant loss in catalytic activity. [ABSTRACT FROM AUTHOR]

The content of insoluble substance in guar gum solution is high and its temperature resistance is poor. A novel anionic guar gum (GG) derivative was developed and grafted by modification with maleic anhydride. Compared with guar gum, the insoluble content of MAG solution decreased from 13 to 5%, the decomposition temperature of MAG increased from 285 to 308, and the viscoelasticity of MAG gel has been enhanced, especially elasticity. The rheological tests show that the corresponding fracturing fluid belongs to a non-Newtonian pseudoplastic one and the viscosity could maintain 50 mPa∙s for 2 h under conditions of 150 °C and 170 s−1, which can be applied in a high-temperature well. It is noteworthy that the synthetic protocol of maleate esters guar gum (MAG) is easily available, low cost, and practical. It is conducive to the industrial application of MAG. The work showed a great significance to the modification of GG with acid anhydride for fracturing fluid. [ABSTRACT FROM AUTHOR]

Carbon fiber (CF)‐embedded acrylonitrile butadiene styrene polymer composites printed on the large‐scale printer at Oak Ridge National Laboratory were investigated by small‐angle neutron scattering to correlate the microstructure of the composites with their mechanical strength. The microstructure of the polymer domains and the alignment of CF were characterized across the interfaces between layers of the hot‐melt extruded material and were compared with CF‐free ABS. The small‐angle neutron scattering data show that the CF‐containing material displays strong anisotropic scatterings suggesting molecular alignment along the printing direction that is not present in the CF‐free ABS. Scattering data analysis across the interfacial layer revealed enhanced molecular alignment along the printing direction near the boundaries and inhomogeneous size distribution of polymer domains upon the addition of CF. We attribute the compromised strength across interfacial layers from CF‐containing material to this inhomogeneous size distribution which prevents effective lateral interaction between layers. POLYM. ENG. SCI., 59:E65–E70, 2019. © 2018 Society of Plastics Engineers [ABSTRACT FROM AUTHOR]

Motivative augmentals are rules or statements that temporarily change the effectiveness of a consequence, similar to establishing operations for nonverbal consequences (Hayes, Barnes-Holmes, & Roche, 2001). Many communications by an organization's leadership may function as such and alter the function of stimuli in the workplace, which in turn may influence employee behaviors (Houmanfar & Rodrigues, Journal of Applied Radical Behavior Analysis, N1, 22-27, 2012). There is a lack of experimental research regarding this, however, particularly under different organizational pay systems (i.e., financial contingencies), which have been repeatedly shown to influence performance (e.g., Gupta & Shaw, Compensation and Benefits Review, 30(2), 26-32, 1998; Locke, Feren, McCaleb, Shaw, & Denny, 1980). The current study sought to compare the two by measuring the effect of motivational statements on individual versus cooperative responding under two different pay-for-performance contingencies in an organizational analogue. Stimuli for the motivational statements were selected utilizing an Implicit Relational Assessment Procedure (IRAP) with one group of participants, and these statements were then tested under piece-rate and profit-share conditions with a second group of participants in a counterbalanced reversal design. Results indicated that the financial contingencies had more of an effect on responding, but that motivational statements influenced behavior as well. In particular, motivational statements affected whether a participant chose to cooperate or behave individually more under financially neutral conditions (i.e., profit share) when there was no financial cost for doing so. As such, organizations can utilize memos or speeches to increase performance, but it is important for the content to align with financial contingencies in order to maximize performance. [ABSTRACT FROM AUTHOR]

The application of conventional hydraulic fracturing technology has been greatly restricted especially in areas with water shortage and traffic inconvenience. At the same time, concern grows about water resources and environmental protection. More environmentally friendly new fracturing technologies, such as waterless fracturing technologies, can also make an important contribution to oil and gas exploitation. This paper reviews several kinds of waterless fracturing fluid technologies, including their working mechanisms, technical features, advantages, and disadvantages. This paper then explores the economics of the various technologies, and prioritizes them based on their advantages and disadvantages. It provides a reference point for theoretical research on and the practical application of waterless fracturing. [ABSTRACT FROM AUTHOR]

This review provides an overview of recent developments in the area of aqueous biphasic hydroformylation of higher olefins using metal catalysts and surfactants, cosolvents, thermoregulated ligands, cyclodextrins, and most importantly emerging water-soluble nonphosphine ligands. Water-soluble phosphine ligands have been widely explored for aqueous biphasic hydroformylation; however, phosphines are generally expensive and are prone to oxidation hence the recent interest in exploring other ligands. Various approaches have been used to introduce hydrophilicity to the ligands. The catalytic activity of monometallic and heterobimetallic systems containing nonphosphine ligands in aqueous biphasic media is emphasized in this review. [ABSTRACT FROM AUTHOR]

Fundamental understanding of microphase separation in ABC miktoarm copolymers is vital to access a plethora of nonconventional morphologies. Miktoarm stars based on poly(cis 1,4‐isoprene) (I), poly(styrene) (S), and poly(2‐vinylpyridine) (V) are model systems, which allow systematic studies of the effects of composition, chemical microstructure, and temperature on the thermodynamics of microphase separation. Eleven ISV‐x (I:S:V = 1:1:x, v:v:v) miktoarm copolymers were synthesized by anionic polymerization affording well‐defined copolymers with a variable V arm. Equilibrium bulk morphologies of all samples, as evidenced by small‐angle X‐ray scattering, transmission electron microscopy (TEM), and self‐consistent field theory, showed a systematic transition from lamellae (x ≈ 0–0.2) to [8.8.4] tiling (x ≈ 0.6–0.9) to cylinders in undulating lamellae (x ≈ 2–4) and, finally, to hexagonally packed core–shell cylinders (x ≈ 5–8). Chemical microstructure of the I arm [poly(cis 1,4‐isoprene)] versus poly(3,4‐isoprene) is shown to play important role in affecting morphological behavior. To reconcile differences between ISV‐x star morphologies reported in the literature and those reported herein, even for the same composition, effects of the microstructure of I arm on the Flory–Huggins parameter between I and V arms were taken into account in a qualitative manner. © 2018 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2018, 56, 1491–1504 A deeply integrated study of poly(styrene‐b‐cis‐1,4‐isoprene‐b‐2‐vinylpyridine) miktoarm star terpolymers interweaving transmission electron microscopy, small‐angle X‐ray scattering, self‐consistent field theory, and rheology, paints a coherent picture of this model system on the intricate self‐assembly forming many nonconventional morphologies like, for example, Archimedean tilings. Variation of the P2VP chain length (x) provides access to a plethora of experimental morphologies consistent with simulations. The simulations also reconcile differences encountered between morphologies formed by stars containing cis‐1,4‐PI studied here, and 3,4‐PI reported previously. [ABSTRACT FROM AUTHOR]

A series of organometallic dendrons containing N,O-salicylaldimine entities at the focal point were synthesised by reacting the N,O-salicylaldimine-functionalised Fréchet dendrons (G0, G1 and G2) with a [Rh(μ-Cl)(η2:η2-COD)]2 dimer to yield the corresponding Rh(COD) [COD = cyclooctadiene] complexes. These Rh(COD) complexes were exposed to an atmosphere of CO to yield a new class of rhodium carbonyl organometallic dendrons with Rh(CO)2 units at the focal point. All the compounds were characterised using standard spectroscopic and analytical techniques, these include nuclear magnetic resonance, infrared spectroscopy, mass spectrometry and single-crystal X-ray diffraction for compounds 1, 4 and 7. All of the complexes were evaluated in the hydroformylation of 1-octene, with excellent conversion and chemoselectivity towards aldehydes. The G0-(CO)2 catalyst precursor (7) was active in the hydroformylation of 1-octene, styrene, 7-tetradecene, methyl oleate, triolein, d-limonene and R-citronellal. The conversion and chemoselectivity towards aldehydes for 7-tetradecene, methyl oleate, triolein and d-limonene were promising. Across a particular dendron series, an increase in chemoselectivity was observed due to the dendritic effect. Mercury drop tests were performed for the G0-analogues and these confirm that the hydroformylation can be attributed to a combination of homogeneous and heterogeneous catalysis. [ABSTRACT FROM AUTHOR]

Abstract: A series of bidentate salicylaldimine ligands was prepared and reacted with either [RuCl(µ-Cl)(p-cymene)]2, [RhCl(µ-Cl)(Cp*)]2 or [IrCl(µ-Cl)(Cp*)]2. All of the compounds were characterised using an array of spectroscopic and analytical techniques, namely, nuclear magnetic resonance (NMR) spectroscopy, infrared (IR) spectroscopy and mass spectrometry. Single crystal X-ray diffraction (XRD) was used to confirm the bidentate coordination mode of the salicylaldimine ligand to the metal centre. The platinum group metal (PGM) complexes were screened against the MCF7 breast cancer cell line. The ruthenium and iridium salicylaldimine complexes showed comparable or greater cytotoxicity than cisplatin against the MCF7 cancer cells, as well as greater cytotoxicity than their rhodium counterparts. Three of the salicylaldimine complexes showed potent activity in the range 18-21 µM. Two of these complexes had a greater affinity for cancerous cells than for CHO non-cancerous cells (SI > 4). Preliminary mechanistic studies suggest that the ruthenium complexes undergo solvation prior to 5′-GMP binding, whereas the iridium complexes were inert to the solvation process.Graphical abstract: [ABSTRACT FROM AUTHOR]

The synthesis of water-soluble rhodium(I) salicylaldiminato and salicylhydrazonic complexes has been achieved employing two preparative routes. Schiff base condensation between 6A-deoxy-6A-amino-β-CD or 6A-deoxy-6A-hydrazino-β-CD and 5-sodiosulfonato-2-hydroxybenzaldehyde (sulfonated salicylaldehyde) (1) or 5-sodiosulfonato-3-tert-butyl-2-hydroxybenzaldehyde (sulfonated tBu-salicylaldehyde) (2) led to the formation of the corresponding imine or hydrazone ligands (3, 4, 5 and 6). Reaction of [Rh(COD)2+BF4−] with these new ligands in an alkaline solution formed the corresponding rhodium complexes quantitatively. These rhodium(I) complexes could also be prepared in one-pot by mixing, in stoichiometric proportions, the modified β-CDs with the sulfonated salicylaldehyde and with the rhodium precursor in an alkaline solution at room temperature. These rhodium complexes were applied as catalysts in the aqueous biphasic hydroformylation of 1-decene as a model reaction. [ABSTRACT FROM AUTHOR]

Recent computational and theoretical studies have shown that the deformation of colloidal suspensions under a steady shear is highly heterogeneous at the particle level and demonstrate a critical influence on the macroscopic deformation behavior. Despite its relevance to a wide variety of industrial applications of colloidal suspensions, scattering studies focusing on addressing the heterogeneity of the non-equilibrium colloidal structure are scarce thus far. Here, we report the first experimental result using small-angle neutron scattering. From the evolution of strain heterogeneity, we conclude that the shear-induced deformation transforms from nearly affine behavior at low shear rates, to plastic rearrangements when the shear rate is high. [ABSTRACT FROM AUTHOR]

In light of the widely used platinum anticancer drugs showing high toxicity and poor selectivity, the quest to develop new anticancer agents is increasing. This study investigated the synthesis of mononuclear and trinuclear RhIII and IrIII sulfonatecontaining pyridinyl complexes that have been fully characterized using NMR and IR spectroscopy, HR-ESI-mass spectrometry and elemental analysis. The cytotoxicities of all sulfonated pyr-idinyl compounds were investigated against a WHCO1 oesophageal cancer cell line and the metal complexes showed moderate activity, while the uncomplexed ligands were inactive. Several of the trinuclear complexes are of comparable activity to that of the clinical cancer drug cisplatin. 1H NMR model studies demonstrated the in vitro DNA binding ability of the most active complex. [ABSTRACT FROM AUTHOR]

Research aimed at enhancing the efficacy of organometallic complexes against cancer, has shown that attaching bio-active molecules to (metallo)drugs often enhances their biological properties. New salicylaldimine and 2-pyridylimine ligands (L2 and L3), containing a bio-active acridine scaffold, were synthesized and complexed to Rh(III), Ir(III), Ru(II) and Os(II) metal ion centers. The resulting acridine-containing half-sandwich complexes have been characterized fully by elemental analysis, FT-IR and NMR spectroscopy, HR-ESI mass spectrometry as well as single crystal X-ray diffraction, for the Rh(III) N^N bidentate complex [RhCp*Cl(L3)][BPh4]. The antiproliferative activity of the ligands (L2 and L3) and complexes (C1 to C9) were evaluated in vitro against human promyelocytic leukemia cells (HL60) and normal skin fibroblast cells (FG0). The compounds exhibit good activities against HL60 cells and are consistently selective towards cancerous cells over non-tumorous cells. This study demonstrates the potential of such hybrid compounds to target cancer cells specifically. The most active complex, [RhCp*Cl(L2)], exhibited binding to DNA model guanosine-5’-monophosphate (5’-GMP) which suggests a mode of action involving interaction of the complex with 5’-GMP found on DNA backbone. [ABSTRACT FROM AUTHOR]

This study investigates the structure of films spin-coated from blends of the semiconducting polymers poly(3-hexylthiophene-2,5-diyl) (P3HT) and poly{2,6-[4,4-bis-(2-ethylhexyl)-4 H-cyclopenta[2,1- b;3,4- b′]dithiophene]- alt-4,7(2,1,3-benzothiadiazole)} (PCPDTBT). Such blends are of potential use in all-polymer solar cells in which both the acceptor and the donor material generate excitons to contribute to the photocurrent. Prompted by threefold performance gains seen in polymer/fullerene and polymer blend solar cells upon addition of pristine graphene, devices are prepared from P3HT/PCPDTBT blends both with and without graphene. This report focuses on the morphology of the active layer since this is of critical importance in determining performance. Small-angle neutron scattering (SANS) is utilized to study this polymer blend with deuterated P3HT to provide contrast and permit the investigation of buried structure in neat and graphene-doped films. SANS reveals the presence of P3HT crystallites dispersed in an amorphous blend matrix of P3HT and PCPDTBT. The crystallites are approximately disc shaped and do not show any evidence of higher-order structure or aggregation. While the structure of the films does not change with the addition of graphene, there is a perceptible effect on the electronic properties and energy conversion efficiency in solar cells made from such films. Determination of the active layer morphology yields crucial insight into structure-property relationships in organic photovoltaic devices. [ABSTRACT FROM AUTHOR]

The Implicit Relational Assessment Procedure (IRAP, Barnes-Holmes et al. in Psychol Rec 60:527-542, 2010) was utilized as a relatively new tool to measure implicit weight bias in first- and third-year medical students. To date, only two studies (Miller et al. in Acad Med 88:978-982, 2013; Phelan et al. in Med Educ 49:983-992, 2015) have investigated implicit weight bias with medical students and both have found pro-thin/anti-fat implicit attitudes, on average, using the Implicit Association Test (IAT, Greenwald and Banaji in Psychol Rev 102:4-27, 1995) as the assessment tool. The IRAP, however, allows for a deeper analysis of implicit attitudes with respect to both thin and fat in isolation, and it was found that medical students are, on average, actually both pro-thin and pro-fat, and on average are more pro-thin than pro-fat, as opposed to anti-fat. Additionally, it was found that medical students' implicit weight bias against fat/obese individuals improved over the first 2 years of medical training, and this improvement was specifically driven by improved implicit attitudes toward overweight and obese, while implicit attitudes toward thin remained constant over that time. The implications of more sensitive implicit bias assessment and specific changes in bias over time are discussed within the context of medical education curriculum development. [ABSTRACT FROM AUTHOR]

A series of mono- and multimeric polyamine-containing ferrocenyl complexes containing a quinoline motif were prepared. The complexes were characterised by standard techniques. The molecular structure of the monomeric salicylaldimine derivative was elucidated using single crystal X-ray diffraction and was consistent with the proposed structure. The antiplasmodial activity of the compounds were evaluated in vitro against both the NF54 (chloroquine-sensitive) and K1 (chloroquine-resistant) strains of Plasmodium falciparum. The polyamine derivatives exhibit good resistance index values suggesting that these systems are beneficial in overcoming the resistance experienced by chloroquine. Mechanistic studies suggest that haemozoin formation may be the target of these quinoline complexes in the parasite. Some of the complexes exhibit moderate to high cytotoxicity against WHCO1 oesophageal cancer cells in vitro. The monomeric ferrocenyl-amine complexes exhibit potent activity against this particular cell line. The complexes were also screened against the G3 strain of Trichomonas vaginalis and the salicylaldimine complexes demonstrated promising activity at the tested concentration. All of these compounds show no inhibitory effect on several common normal flora bacteria, indicative of their selectivity for eukaryotic pathogens and cancer. [ABSTRACT FROM AUTHOR]

Tricarbonylrhenium(I) metallodendrimers functionalized with N,N-2-picolylamino chelates have been synthesized by the [2+1] approach. Methanol substitution reactions of the first- and second-generation poly(propylene amine) tetra- and octanuclear rhenium metallodendrimers by a range of monodentate nucleophiles (i.e. 4-dimethylaminopyridine, pyridine, and bromide ions) were investigated and compared to the substitution reactions of an analogous monomeric complex, fac-[Re(CO)3(N,N-bidentate)(CH3OH)]+. These detailed kinetic studies reveal that a greater activation is achieved using the metallodendrimers with no direct interactions between the metal centers. [ABSTRACT FROM AUTHOR]

Isonicotinyl and pyrazinyl ferrocenyl-derived complexes were prepared using various hydrazides and ferrocenyl aldehydes. Three heterobimetallic complexes were also synthesized from the Schiff base-derived isonicotinyl ferrocene complex using various platinum group metal dimers based on ruthenium, rhodium and iridium. All complexes were evaluated in vitro for antimycobacterial and antiparasitic activity. Against Mycobacterium tuberculosis H37Rv, the platinum group metal complexes showed glycerol-dependent antimycobacterial activity. The antiplasmodial activities against the NF54 chloroquine-sensitive strain of Plasmodium falciparum of some compounds were moderate, while some complexes also showed promising activity against Trichomonas vaginalis. Incorporation of the ferrocenyl-salicylaldimine moiety resulted in enhanced antimicrobial activity compared to the non-ferrocenyl compound in some cases. The bimetallic iridium-ferrocene isonicotinyl complex exhibited superior antitrichomonal activity relative to its organic counterpart, isoniazid. Furthermore, all these compounds, when screened on several normal flora bacteria of humans, showed no effect on the microbiome, emphasizing the selection of these compounds for these pathogens. The promising antimicrobial activities of the complexes thus supports incorporation of ferrocene as part of existing antimicrobial therapies in order to alter their biological activities favorably. [ABSTRACT FROM AUTHOR]

The effect of three nucleoside analogue antimetabolites (5-fluorouracil, floxuridine, and gemcitabine) on the structure of Pluronic L62 copolymer micelles was investigated using small-angle neutron scattering. These antimetabolites used for cancer chemotherapy have analogous molecular structures but different molecular sizes and aqueous solubilities. It was found that the addition of the three antimetabolites slightly reduced the micellar size and aggregation number, and the micellar anisotropy. The added antimetabolites also changed the internal molecular distribution of the micelles as measured by the scattering length densities, resulting in enhanced hydration of the hydrophobic core region of the micelle. The strength of the effect was found to correlate with the molecular properties of the model drugs, i.e. a larger molecular size and a higher aqueous solubility lead to enhanced hydration of the micellar core. [ABSTRACT FROM AUTHOR]

Monometallic and heterobimetallic complexes of Rh(I) bearing chelating N, O-bidentate aryl- and ferrocenyl-derived ligands have been synthesised via Schiff base condensation reactions, and characterised fully using 1H NMR, 13C{1H} NMR and Fourier transform infrared spectroscopies, elemental analysis and mass spectrometry. The new monometallic and heterobimetallic complexes were evaluated as potential catalyst precursors in the hydroformylation of 1-octene at 95°C and 40 bar. The ferrocenylimine mononuclear compounds were inactive in the hydroformylation experiments. The Rh(I) monometallic and the ferrocene-Rh(I) heterobimetallic pre-catalysts displayed good activity and conversion of 1-octene as well as outstanding chemoselectivity towards aldehydes in the hydroformylation reaction. [ABSTRACT FROM AUTHOR]

A series of rhodium(I)-1,2,3-triazol-5-ylidene (trz) complexes are described, containing either a novel triarylated trz ligand A' (N1, N3-arylated, C4-ferrocenyl) {complexes 1, [Rh(A')Cl(cod)]; 4, [Rh(A')Cl(CO)2]}, or N3-alkylated triazolylidenes with a C4-ferrocenyl {2, [Rh(B')Cl(cod)]; 5, [Rh(B')Cl(CO)2]} or C4-phenyl substituent {3, [Rh(C')Cl(cod)]; 6, [Rh(C')Cl(CO)2]}. The free mesoionic carbene (MIC) A' is structurally characterized and its electronic properties evaluated by employing the complex [Pd(Br)2(iPr2-bimy)(A')] (7) in an NMR spectroscopic analysis method. The redox activity of A' is exploited, and the chemically oxidized precursor Aox and complex 4ox are isolated. The mesoionic carbene complexes 1-3, as well as in situ oxidized 1ox, are used as homogeneous catalysts for the hydroformylation of 1-octene for the first time, and the influence of chemical oxidation of the catalyst on the activity and chemoand regioselectivity of the catalyst precursor 1 is evaluated. [ABSTRACT FROM AUTHOR]

A series of ferrocenyl-containing benzothiazoles with amine side-chains, both organosilane and carbon analogues, were prepared and fully characterised. The compounds were screened for their antiplasmodial activity against chloroquine-sensitive (NF54) and chloroquine-resistant (Dd2) strains of P. falciparum, displaying activities in the low micromolar range (0.1-1.9 µ m). The moderate cytotoxicity of the benzothiazoles against a Chinese hamster ovarian (CHO) cell line demonstrated selective antiparasitic activity. [ABSTRACT FROM AUTHOR]

Despite the success of exposure-based psychotherapies in anxiety treatment, relapse remains problematic. Resurgence, the return of previously eliminated behavior following the elimination of an alternative source of reinforcement, is a promising model of operant relapse. Nonhuman resurgence research has shown that higher rates of alternative reinforcement result in faster, more comprehensive suppression of target behavior, but also in greater resurgence when alternative reinforcement is eliminated. This study investigated rich and lean rates of alternative reinforcement on response suppression and resurgence in typically developing humans. In Phase 1, three groups (Rich, n = 18; Lean, n = 18; Control, n = 10) acquired the target response. In Phase 2, target responding was extinguished and alternative reinforcement delivered on RI 1 s, RI 3 s, and extinction schedules, respectively. Resurgence was assessed during Phase 3 under extinction conditions for all groups. Target responding was suppressed most thoroughly in Rich and partially in Lean. Target responding resurged in the Rich and Lean groups, but not in the Control group. Between groups, resurgence was more pronounced in the Rich group than the Lean and Control groups. Clinical implications of these findings, including care on the part of clinicians when identifying alternative sources of reinforcement, are discussed. [ABSTRACT FROM AUTHOR]

Bioisosteric ferrocenyl-containing quinolines and ferrocenylamines containing organosilanes and their carbon analogues, were prepared and fully characterised. The molecular structures of two ferrocenyl-containing quinolines, determined using single-crystal X-ray diffraction, revealed that the compounds crystallise in a folded conformation. The compounds were screened for their antiplasmodial activity against the chloroquine-sensitive (NF54) and CQ-resistant (Dd2) strains of P. falciparum, as well as for their cytotoxicity against Chinese Hamster Ovarian (CHO) cells. The ferrocenyl-containing quinolines displayed activities in the low nanomolar range (6–36 nM), and showed selectivity towards parasites. β-Haematin inhibition assays suggest that the compounds may in part act via the inhibition of haemozoin formation, while microsomal metabolic stability studies reveal that the ferrocenyl-containing quinolines are rapidly metabolised in liver microsomes. Further, antitrichomonal screening against the metronidazole-sensitive (G3) strain of the mucosal pathogen T. vaginalis revealed that the quinoline-based compounds displayed superior parasite growth inhibition when compared to the ferrocenylamines. The library was also tested E. coli and on Lactobacilli spp. found as part of the normal flora of the human microbiome and no effect on growth in vitro was observed, supporting the observation that these compounds are specific for eukaryotic pathogens. [ABSTRACT FROM AUTHOR]

A series of mono- and multimeric polyamine-containing ferrocenyl complexes containing a quinoline motif were prepared. The complexes were characterised by standard techniques. The molecular structure of the monomeric salicylaldimine derivative was elucidated using single crystal X-ray diffraction and was consistent with the proposed structure. The antiplasmodial activity of the compounds were evaluated in vitro against both the NF54 (chloroquine-sensitive) and K1 (chloroquine-resistant) strains of Plasmodium falciparum. The polyamine derivatives exhibit good resistance index values suggesting that these systems are beneficial in overcoming the resistance experienced by chloroquine. Mechanistic studies suggest that haemozoin formation may be the target of these quinoline complexes in the parasite. Some of the complexes exhibit moderate to high cytotoxicity against WHCO1 oesophageal cancer cells in vitro. The monomeric ferrocenyl-amine complexes exhibit potent activity against this particular cell line. The complexes were also screened against the G3 strain of Trichomonas vaginalis and the salicylaldimine complexes demonstrated promising activity at the tested concentration. All of these compounds show no inhibitory effect on several common normal flora bacteria, indicative of their selectivity for eukaryotic pathogens and cancer. [ABSTRACT FROM AUTHOR]

A new series of eight first- and second-generation heterometallic ferrocenyl-derived metal–arene metallodendrimers, containing ruthenium(ii)–p-cymene, ruthenium(ii)–hexamethylbenzene, rhodium(iii)–cyclopentadienyl or iridium(iii)–cyclopentadienyl moieties have been prepared. The metallodendrimers were synthesized by first reacting DAB-(NH2)n (where n = 4 or 8, DAB = diaminobutane) with salicylaldehyde, and then the Schiff-base dendritic ligands were reacted in a one-pot reaction with the appropriate [(η6-p-iPrC6H4Me)RuCl2]2, [(η6-C6Me6)RuCl2]2, [(η5-C5Me5)IrCl2]2 or [(η5-C5Me5)RhCl2]2 dimers, in the presence of 4-pyridylferrocene. Heterometallic binuclear analogues were prepared as models of the larger metallodendrimers. All complexes have been characterized using analytical and spectroscopic methods. The cytotoxicity of the heterometallic metallodendrimers and their binuclear analogues were evaluated against A2780 cisplatin-sensitive and A2780cisR cisplatin-resistant human ovarian cancer cell lines and against a non-tumorigenic HEK-293 human embryonic kidney cell line. The second generation Ru(ii)-η6-C6Me6 metallodendrimer is the most cytotoxic and selective compound. DNA binding experiments reveal that a possible mode-of-action of these compounds involves non-covalent interactions with DNA. [ABSTRACT FROM AUTHOR]