3-(1H-Benzimidazol-2-yl)-2-chloro-8-methyl­quinoline

Two independent mol­ecules of the title compound, C17H12ClN3, are present in the structure. The angle between the planes defined by the atoms of the benzimidazole unit and the quinoline unit are 45.2 (3) and 44.0 (3)°, indicating an essentially identical conformation for both mol­ecules. Each of the independent mol­ecules is linked with a symmetry equivalent by an inter­molecular N—H⋯N hydrogen bond involving the two benzimidazole N atoms, to form chains in the crystallographic c direction

2-{2-[3-(1H-Benzimidazol-2-yl)quinolin-2-yl­oxy]eth­oxy}ethanol

In the title compound, C20H19N3O3, the inter­planar angle between the benzimidazole unit and the quinoline unit is 25.1 (2)°. Two different hydrogen bonds involving the hydr­oxy group and the imidazole unit are present. An intra­molecular N—H⋯O hydrogen bond links the hydr­oxy group of the side chain with the imidazole unit, forming a 12-membered ring, and an inter­molecular O—H⋯N hydrogen bond links the mol­ecules, forming chains in the crystallographic b direction

Nonequilibrium evolution of volatility in origination and extinction explains fat-tailed fluctuations in Phanerozoic biodiversity

Fluctuations in biodiversity, large and small, pervade the fossil record, yet we do not understand the processes generating them. Here, we extend theory from nonequilibrium statistical physics to describe the fat-tailed form of fluctuations in Phanerozoic marine invertebrate richness. Using this theory, known as superstatistics, we show that heterogeneous rates of origination and extinction between clades and conserved rates within clades account for this fat-tailed form. We identify orders and families as the taxonomic levels at which clades experience interclade heterogeneity and within-clade homogeneity of rates, indicating that families are subsystems in local statistical equilibrium, while the entire system is not. The separation of timescales between within-clade background rates and the origin of major innovations producing new orders and families allows within-clade dynamics to reach equilibrium, while between-clade dynamics do not. The distribution of different dynamics across clades is consistent with niche conservatism and pulsed exploration of adaptive landscapes.Fil: Rominger, Andrew J.. No especifíca;Fil: Fuentes, Miguel Angel. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Filosóficas. - Sociedad Argentina de Análisis Filosófico. Instituto de Investigaciones Filosóficas; Argentina. Universidad San Sebastián; ChileFil: Marquet, Pablo A.. Pontificia Universidad Católica de Chile; Chile. Instituto de Ecología y Biodiversidad; Chile. Universidad Nacional Autónoma de México; Méxic

Phantom study for 90Y post-treatment dosimetry with a long axial field-of-view PET/CT

Purpose: The physical properties of yttrium-90 (90Y) allow for imaging with positron emission tomography/computed tomography (PET/CT). The increased sensitivity of long axial field-of-view (LAFOV) PET/CT scanners possibly allows to overcome the small branching ratio for positron production from 90Y decays and to improve for the post-treatment dosimetry of 90Y of selective internal radiation therapy. Methods: For the challenging case of an image quality body phantom, we compare a full Monte Carlo (MC) dose calculation with the results from the two commercial software packages Simplicit90Y and Hermes. The voxel dosimetry module of Hermes relies on the 90Y images taken with a LAFOV PET/CT, while the MC and Simplicit90Y dose calculations are image independent. Results: The resulting doses from the MC calculation and Simplicit90Y agree well within the error margins. The image-based dose calculation with Hermes, however, consistently underestimates the dose. This is due to the mismatch of the activity distribution in the PET images and the size of the volume of interest. Furthermore, there are likely limitations of Hermes' dose calculation algorithm for 90Y. We found that only for the smallest phantom sphere there is a statistically significant dependence of the Hermes dose on the image reconstruction parameters and scan time. Conclusion: Our study shows that Simplicit90Y's local deposition model can provide a reliable dose estimate. On the other hand, the image based dose calculation requires further benchmarks and verification in order to take full advantage of LAFOV PET/CT systems

EARL compliance measurements on the biograph vision Quadra PET/CT system with a long axial field of view.

BACKGROUND Our aim was to determine sets of reconstruction parameters for the Biograph Vision Quadra (Siemens Healthineers) PET/CT system that result in quantitative images compliant with the European Association of Nuclear Medicine Research Ltd. (EARL) criteria. Using the Biograph Vision 600 (Siemens Healthineers) PET/CT technology but extending the axial field of view to 106 cm, gives the Vision Quadra currently an around fivefold higher sensitivity over the Vision 600 with otherwise comparable spatial resolution. Therefore, we also investigated how the number of incident positron decays-i.e., exposure-affects EARL compliance. This will allow estimating a minimal acquisition time or a minimal applied dose in clinical scans while retaining data comparability. METHODS We measured activity recovery curves on a NEMA IEC body phantom filled with an aqueous 18F solution and a sphere to background ratio of 10-1 according to the latest EARL guidelines. Reconstructing 3570 image sets with varying OSEM PSF iterations, post-reconstruction Gaussian filter full width at half maximum (FWHM), and varying exposure from 59 kDecays/ml (= 3 s frame duration) to 59.2 MDecays/ml (= 1 h), allowed us to determine sets of parameters to achieve compliance with the current EARL 1 and EARL 2 standards. Recovery coefficients (RCs) were calculated for the metrics RCmax, RCmean, and RCpeak, and the respective recovery curves were analyzed for monotonicity. The background's coefficient of variation (COV) was also calculated. RESULTS Using 6 iterations, 5 subsets and 7.8 mm Gauss filtering resulted in optimal EARL1 compliance and recovery curve monotonicity in all analyzed frames, except in the 3 s frames. Most robust EARL2 compliance and monotonicity were achieved with 2 iterations, 5 subsets, and 3.6 mm Gauss FWHM in frames with durations between 30 s and 10 min. RCpeak only impeded EARL2 compliance in the 10 s and 3 s frames. CONCLUSIONS While EARL1 compliance was robust over most exposure ranges, EARL2 compliance required exposures between 1.2 MDecays/ml to 11.5 MDecays/ml. The Biograph Vision Quadra's high sensitivity makes frames as short as 10 s feasible for comparable quantitative images. Lowering EARL2 RCmax limits closer to unity would possibly even permit shorter frames

Chlorido[3,3′-dibutyl-5,5′-(pyridine-2,6-di­yl)dipyrazol-1-ido]gold(III)

The Au atom in the C2-symmetric pincer-type title complex, [AuCl(C19H23N5)], is in the +3 oxidation state. The ligand is composed of one pyridine unit and two n-butyl-substituted pyrazoles (pyrz). Both pyrazoles are deprotonated, thus forming a neutral compound. To the best of our knowledge, this is the first AuIII–bis­pyrazolate complex. According to the special geometry in the N,N′,N′′-tridentate ligand, containing two five-membered heterocycles, the complex deviates from an ideal square-planar coordination geometry; the Npyrz—Au—Npyrz angle is 160.8 (3)°, indicating a distortion of nearly 20°

Homogeneous and heterogenised new gold C-scorpionate complexes as catalysts for cyclohexane oxidation

Gold(III) complexes of type [AuCl2{eta(2)-RC(R'pz)(3)}]Cl [R = R' = H (1), R = CH2OH, R' = H (2) and R = H, R' = 3,5-Me-2(3), pz = pyrazol-1-yl] were supported on carbon materials (activated carbon, carbon xerogel and carbon nanotubes) and used for the oxidation of cyclohexane to cyclohexanol and cyclohexanone, with aqueous H2O2, under mild conditions

The propargyl rearrangement to functionalised allyl-boron and borocation compounds

A diverse range of Lewis acidic alkyl, vinyl and aryl boranes and borenium compounds that are capable of new carbon–carbon bond formation through selective migratory group transfer have been synthesised. Utilising a series of heteroleptic boranes [PhB(C6F5)2 (1), PhCH2CH2B(C6F5)2 (2), and E-B(C6F5)2(C6F5)C=C(I)R (R=Ph 3 a, nBu 3 b)] and borenium cations [phenylquinolatoborenium cation ([QOBPh][AlCl4], 4)], it has been shown that these boron-based compounds are capable of producing novel allyl- boron and boronium compounds through complex rearrangement reactions with various propargyl esters and carbamates. These reactions yield highly functionalised, synthetically useful boron substituted organic compounds with substantial molecular complexity in a one-pot reaction