etho Prevention through Design methods can make solar panel installation safer: CPWR report By www.safetyandhealthmagazine.com Published On :: Tue, 12 Dec 2017 00:00:00 -0500 Silver Spring, MD — As the use of solar energy panels continues to increase, Prevention through Design methods may help keep contractors safe during installation of the panels on small residential buildings, according to a recent report from the Center for Construction Research and Training, also known as CPWR. Full Article
etho New method of detecting combustible dust uses real-time imaging By www.safetyandhealthmagazine.com Published On :: Wed, 21 Oct 2020 00:00:00 -0400 West Lafayette, IN — Using newly developed algorithms, researchers from Purdue University have designed an image- and video-based application to detect combustible dust concentrations suspended in the air. Full Article
etho EPA requests comment on lead-based paint methodology By www.safetyandhealthmagazine.com Published On :: Fri, 08 Aug 2014 00:00:00 -0400 Washington – The Environmental Protection Agency is seeking comment on whether renovation, repair and painting activities in public and commercial buildings create lead-based health hazards. Full Article
etho Reviving Ancient Ingredients, Methods for Food Preservation By www.preparedfoods.com Published On :: Tue, 16 Nov 2021 18:00:00 -0500 From lactic acid fermentations of produce (such as kimchi and sauerkraut), to fermenting of dairy (cheese, yogurt, etc.), to the curing and smoking of fish and meat are all proven, effective methods and technologies humans have relied on through the ages to alter the intrinsic properties of foods and extend their consumability. Full Article
etho Two Recent Rulings Support Current Method for Assessing Prop 65 Exposure By www.foodengineeringmag.com Published On :: Wed, 22 May 2024 08:00:00 -0400 If the plaintiff’s theories were adopted during recent attempts to use California’s Proposition 65 to sue food manufacturers, it could've dealt a major blow to food manufacturers, distributors and retailers who sell products in the state. Full Article
etho Bavarian brewery testing a method to upcycle protein from spent brewers’ grains By www.foodengineeringmag.com Published On :: Mon, 07 Feb 2022 09:15:00 -0500 Spent brewers’ grains not only provide a source of energy for a brewery, but can also provide a salable, high-value protein. Full Article
etho Intergenerational place-based digital storytelling: a more-than-visual research method. By ezproxy.scu.edu.au Published On :: Tue, 01 Feb 2022 00:00:00 -0500 Children's Geographies; 02/01/2022(AN 154441560); ISSN: 14733285Academic Search Premier Full Article LEBANON DIGITAL storytelling GEOGRAPHICAL perception RESEARCH methodology SOCIAL processes CITIES & towns
etho Creating an ethos for learning: classroom seating and pedagogical use of space at a Chinese suburban middle school. By ezproxy.scu.edu.au Published On :: Fri, 01 Apr 2022 00:00:00 -0400 Children's Geographies; 04/01/2022(AN 155952639); ISSN: 14733285Academic Search Premier Full Article CHINA MIDDLE schools SEATING (Furniture) CLASSROOMS LEARNING
etho Children’s cartographies of the world: mapping Brazilian modes, methods and moments. By ezproxy.scu.edu.au Published On :: Wed, 06 Apr 2022 00:00:00 -0400 Children's Geographies; 04/06/2022(AN 156178709); ISSN: 14733285Academic Search Premier Full Article
etho Found childhood as a practice of child as method. By ezproxy.scu.edu.au Published On :: Wed, 01 Jun 2022 00:00:00 -0400 Children's Geographies; 06/01/2022(AN 156867988); ISSN: 14733285Academic Search Premier Full Article URBAN geography HUMAN geography PUBLIC spaces
etho Using methods across generations: researcher reflections from a research project involving young people and their parents. By ezproxy.scu.edu.au Published On :: Sat, 01 Oct 2022 00:00:00 -0400 Children's Geographies; 10/01/2022(AN 159948777); ISSN: 14733285Academic Search Premier Full Article YOUNG adults ADOLESCENT idiopathic scoliosis PARENTS PARTICIPATORY design FOCUS groups
etho Intergenerational solidarities for climate healing: the case for critical methodologies and decolonial research practices. By ezproxy.scu.edu.au Published On :: Tue, 09 Jan 2024 00:00:00 -0500 Children's Geographies; 01/09/2024(AN 174729549); ISSN: 14733285Academic Search Premier Full Article
etho Youth dis/comforts in everyday spaces: an intersectional and mixed methods approach in Catalonia. By ezproxy.scu.edu.au Published On :: Thu, 01 Aug 2024 00:00:00 -0400 Children's Geographies; 08/01/2024(AN 178911408); ISSN: 14733285Academic Search Premier Full Article YOUNG adults TOPOGRAPHIC maps SOCIAL status PUBLIC spaces PERCEIVED discrimination
etho Reflections on enabling intergenerational dialogue about climate interventions through deliberative methods. By ezproxy.scu.edu.au Published On :: Wed, 30 Oct 2024 00:00:00 -0400 Children's Geographies; 10/30/2024(AN 180543848); ISSN: 14733285Academic Search Premier Full Article YOUNG adults RESEARCH personnel CLIMATE change DEMOCRATIZATION RESPECT
etho Addressing integration in the organization of palliative care in belgium: a multilevel ecosystems approach using the analytic hierarchy process (AHP) method By ifp.nyu.edu Published On :: Sat, 02 Nov 2024 10:06:19 +0000 Palliative care is becoming an essential component of healthcare, but there is insufficient research on how integration across different levels of care (micro, meso, and macro) is realized in practice. Without… Read the full article › The post Addressing integration in the organization of palliative care in belgium: a multilevel ecosystems approach using the analytic hierarchy process (AHP) method was curated by information for practice. Full Article Open Access Journal Articles
etho Using Legitimation Code Theory to explore knowledge building in English medium higher education teaching: methodological challenges and innovations By ifp.nyu.edu Published On :: Tue, 05 Nov 2024 09:29:38 +0000 Volume 29, Issue 7, October 2024. Read the full article › The post Using Legitimation Code Theory to explore knowledge building in English medium higher education teaching: methodological challenges and innovations was curated by information for practice. Full Article Journal Article Abstracts
etho Call for expression of interest: National Centre for Research Methods (NCRM) By ifp.nyu.edu Published On :: Mon, 14 Oct 2024 00:03:48 +0000 The post Call for expression of interest: National Centre for Research Methods (NCRM) was curated by information for practice. Full Article Calls & Consultations
etho The Study Explores the Impact of Sterilization Methods on Aronia Juice Quality By www.newswise.com Published On :: Wed, 13 Nov 2024 02:10:18 EST A research team has conducted a comprehensive study on the effects of various sterilization methods on the quality of Aronia melanocarpa juice (AMJ). Full Article
etho The Study Explores the Impact of Sterilization Methods on Aronia Juice Quality By www.newswise.com Published On :: Wed, 13 Nov 2024 02:10:18 EST A research team has conducted a comprehensive study on the effects of various sterilization methods on the quality of Aronia melanocarpa juice (AMJ). Full Article
etho Lean Hypotheses and Effectual Commitments: An Integrative Framework Delineating the Methods of Science and Entrepreneurship By www.newswise.com Published On :: Wed, 13 Nov 2024 06:15:47 EST Full Article
etho A Scientific Method for Startups By www.newswise.com Published On :: Fri, 08 Nov 2024 08:50:53 EST Full Article
etho The seventh blind test of crystal structure prediction: structure generation methods By journals.iucr.org Published On :: The results of the seventh blind test of crystal structure prediction are presented, focusing on structure generation methods. Full Article text
etho The seventh blind test of crystal structure prediction: structure ranking methods By journals.iucr.org Published On :: The results of the seventh blind test of crystal structure prediction are presented, focusing on structure ranking methods. Full Article text
etho The seventh blind test of crystal structure prediction: structure ranking methods By journals.iucr.org Published On :: 2024-10-17 A seventh blind test of crystal structure prediction has been organized by the Cambridge Crystallographic Data Centre. The results are presented in two parts, with this second part focusing on methods for ranking crystal structures in order of stability. The exercise involved standardized sets of structures seeded from a range of structure generation methods. Participants from 22 groups applied several periodic DFT-D methods, machine learned potentials, force fields derived from empirical data or quantum chemical calculations, and various combinations of the above. In addition, one non-energy-based scoring function was used. Results showed that periodic DFT-D methods overall agreed with experimental data within expected error margins, while one machine learned model, applying system-specific AIMnet potentials, agreed with experiment in many cases demonstrating promise as an efficient alternative to DFT-based methods. For target XXXII, a consensus was reached across periodic DFT methods, with consistently high predicted energies of experimental forms relative to the global minimum (above 4 kJ mol−1 at both low and ambient temperatures) suggesting a more stable polymorph is likely not yet observed. The calculation of free energies at ambient temperatures offered improvement of predictions only in some cases (for targets XXVII and XXXI). Several avenues for future research have been suggested, highlighting the need for greater efficiency considering the vast amounts of resources utilized in many cases. Full Article text
etho The seventh blind test of crystal structure prediction: structure generation methods By journals.iucr.org Published On :: 2024-12-01 A seventh blind test of crystal structure prediction was organized by the Cambridge Crystallographic Data Centre featuring seven target systems of varying complexity: a silicon and iodine-containing molecule, a copper coordination complex, a near-rigid molecule, a cocrystal, a polymorphic small agrochemical, a highly flexible polymorphic drug candidate, and a polymorphic morpholine salt. In this first of two parts focusing on structure generation methods, many crystal structure prediction (CSP) methods performed well for the small but flexible agrochemical compound, successfully reproducing the experimentally observed crystal structures, while few groups were successful for the systems of higher complexity. A powder X-ray diffraction (PXRD) assisted exercise demonstrated the use of CSP in successfully determining a crystal structure from a low-quality PXRD pattern. The use of CSP in the prediction of likely cocrystal stoichiometry was also explored, demonstrating multiple possible approaches. Crystallographic disorder emerged as an important theme throughout the test as both a challenge for analysis and a major achievement where two groups blindly predicted the existence of disorder for the first time. Additionally, large-scale comparisons of the sets of predicted crystal structures also showed that some methods yield sets that largely contain the same crystal structures. Full Article text
etho The single-atom R1: a new optimization method to solve crystal structures By journals.iucr.org Published On :: 2024-03-18 A crystal structure with N atoms in its unit cell can be solved starting from a model with atoms 1 to j − 1 being located. To locate the next atom j, the method uses a modified definition of the traditional R1 factor where its dependencies on the locations of atoms j + 1 to N are removed. This modified R1 is called the single-atom R1 (sR1), because the locations of atoms 1 to j − 1 in sR1 are the known parameters, and only the location of atom j is unknown. Finding the correct position of atom j translates thus into the optimization of the sR1 function, with respect to its fractional coordinates, xj, yj, zj. Using experimental data, it has been verified that an sR1 has a hole near each missing atom. Further, it has been verified that an algorithm based on sR1, hereby called the sR1 method, can solve crystal structures (with up to 156 non-hydrogen atoms in the unit cell). The strategy to carry out this calculation has also been optimized. The main feature of the sR1 method is that, starting from a single arbitrarily positioned atom, the structure is gradually revealed. With the user's help to delete poorly determined parts of the structure, the sR1 method can build the model to a high final quality. Thus, sR1 is a viable and useful tool for solving crystal structures. Full Article text
etho Optimizing crucible geometry to improve the quality of AlN crystals by the physical vapor transport method By journals.iucr.org Published On :: The growth quality of AlN single crystals was improved by optimizing the crucible structure for Al vapor transport with the help of finite element simulation. Full Article text
etho Optimizing crucible geometry to improve the quality of AlN crystals by the physical vapor transport method By journals.iucr.org Published On :: 2024-10-16 In the conventional crucible structure for AlN crystal growth by physical vapor transport, owing to the long molecular transport path of Al vapor and the disruption of the gas flow by the presence of a deflector, the Al vapor easily forms polycrystals in the growth domain. The result is increased internal stress in the crystals and increased difficulty in growing large-sized crystals. On this basis, with the help of finite element simulations, a novel crucible structure is designed. This crucible not only optimizes the gas transport but also increases the radial gradient of the AlN crystal surface, making the enhanced growth rate in the central region more obvious. The thermal stresses between the deflector and the crystal are also reduced. High-quality AlN crystals with an FWHM of 79 arcsec were successfully grown with this structure, verifying the accuracy of finite element simulation of the growth of AlN crystals. Our work has important guiding significance for the growth of high-quality AlN crystals. Full Article text
etho An alternative method to the Takagi–Taupin equations for studying dark-field X-ray microscopy of deformed crystals By journals.iucr.org Published On :: 2024-09-26 This study introduces an alternative method to the Takagi–Taupin equations for investigating the dark-field X-ray microscopy (DFXM) of deformed crystals. In scenarios where dynamical diffraction cannot be disregarded, it is essential to assess the potential inaccuracies of data interpretation based on the kinematic diffraction theory. Unlike the Takagi–Taupin equations, this new method utilizes an exact dispersion relation, and a previously developed finite difference scheme with minor modifications is used for the numerical implementation. The numerical implementation has been validated by calculating the diffraction of a diamond crystal with three components, wherein dynamical diffraction is applicable to the first component and kinematic diffraction pertains to the remaining two. The numerical convergence is tested using diffraction intensities. In addition, the DFXM image of a diamond crystal containing a stacking fault is calculated using the new method and compared with the experimental result. The new method is also applied to calculate the DFXM image of a twisted diamond crystal, which clearly shows a result different from those obtained using the Takagi–Taupin equations. Full Article text
etho Crystal structures of two polymorphs for fac-bromidotricarbonyl[4-(4-methoxyphenyl)-2-(pyridin-2-yl)thiazole-κ2N,N']rhenium(I) By journals.iucr.org Published On :: 2024-11-08 Crystallization of the title compound, fac-[ReBr(ppt-OMe)(CO)3] (ppt-OMe = C15H12N2OS), from CH2Cl2/n-pentane (1:5 v/v) at room temperature gave two polymorphs, which crystallize in monoclinic (P21/c; α form) and orthorhombic (Pna21; β form) space groups. The ReI complex molecules in either polymorph adopt a six-coordinate octahedral geometry with three facially-oriented carbonyl ligands, one bromido ligand, and two nitrogen atoms from one chelating ligand ppt-OMe. In the crystal, both polymorph α and β form di-periodic sheet-like architectures supported by multiple hydrogen bonds. In polymorph α, two types of hydrogen bonds (C—H...O) are found while, in polymorph β, four types of hydrogen bonds (C—H...O and C—H...Br) exist. Full Article text
etho A method with ultra-high angular resolution for X-ray diffraction experiments By journals.iucr.org Published On :: 2024-01-01 In X-ray diffraction measurements, the angular resolution has a detection limit due to the receiving size of the detector. In many cases this detection limit is too large and must be breached to obtain the desired information. A novel method is proposed here by making the detector simultaneously measuring and moving. Using the deconvolution algorithm to remove the convolution effect, the pixel size limitation is finally broken. The algorithm used is not a common one, and suppresses signals at high frequencies, ensuring the reliability of the peak shape after restoration. The feasibility of this method is verified by successfully measuring the crystal truncation rod signal of SrTiO3 single crystal, and the resolution is nearly ten times higher than that of a single pixel. Moreover, this method greatly reduces the noise and improves the signal-to-noise ratio. Full Article text
etho A thermal deformation optimization method for cryogenically cooled silicon crystal monochromators under high heat load By journals.iucr.org Published On :: 2024-01-22 A method to optimize the thermal deformation of an indirectly cryo-cooled silicon crystal monochromator exposed to intense X-rays at a low-emittance diffraction-limited synchrotron radiation source is presented. The thermal-induced slope error of the monochromator crystal has been studied as a function of heat transfer efficiency, crystal temperature distribution and beam footprint size. A partial cooling method is proposed, which flattens the crystal surface profile within the beam footprint by modifying the cooling contact area to optimize the crystal peak temperature. The optimal temperature varies with different photon energies, which is investigated, and a proper cooling strategy is obtained to fulfil the thermal distortion requirements over the entire photon energy range. At an absorbed power up to 300 W with a maximum power density of 44.8 W mm−2 normal incidence beam from an in-vacuum undulator, the crystal thermal distortion does not exceed 0.3 µrad at 8.33 keV. This method will provide references for the monochromator design on diffraction-limited synchrotron radiation or free-electron laser light sources. Full Article text
etho GIWAXS experimental methods at the NFPS-BL17B beamline at Shanghai Synchrotron Radiation Facility By journals.iucr.org Published On :: 2024-06-25 The BL17B beamline at the Shanghai Synchrotron Radiation Facility was first designed as a versatile high-throughput protein crystallography beamline and one of five beamlines affiliated to the National Facility for Protein Science in Shanghai. It was officially opened to users in July 2015. As a bending magnet beamline, BL17B has the advantages of high photon flux, brightness, energy resolution and continuous adjustable energy between 5 and 23 keV. The experimental station excels in crystal screening and structure determination, providing cost-effective routine experimental services to numerous users. Given the interdisciplinary and green energy research demands, BL17B beamline has undergone optimization, expanded its range of experimental methods and enhanced sample environments for a more user-friendly testing mode. These methods include single-crystal X-ray diffraction, powder crystal X-ray diffraction, wide-angle X-ray scattering, grazing-incidence wide-angle X-ray scattering (GIWAXS), and fully scattered atom pair distribution function analysis, covering structure detection from crystalline to amorphous states. This paper primarily presents the performance of the BL17B beamline and the application of the GIWAXS methodology at the beamline in the field of perovskite materials. Full Article text
etho A distributed software system for integrating data-intensive imaging methods in a hard X-ray nanoprobe beamline at the SSRF By journals.iucr.org Published On :: 2024-08-22 The development of hard X-ray nanoprobe techniques has given rise to a number of experimental methods, like nano-XAS, nano-XRD, nano-XRF, ptychography and tomography. Each method has its own unique data processing algorithms. With the increase in data acquisition rate, the large amount of generated data is now a big challenge to these algorithms. In this work, an intuitive, user-friendly software system is introduced to integrate and manage these algorithms; by taking advantage of the loosely coupled, component-based design approach of the system, the data processing speed of the imaging algorithm is enhanced through optimization of the parallelism efficiency. This study provides meaningful solutions to tackle complexity challenges faced in synchrotron data processing. Full Article text
etho Redetermined structure of methyl 3-{4,4-difluoro-2-[2-(methoxycarbonyl)ethyl]-1,3,5,7-tetramethyl-4-bora-3a,4a-diaza-s-indacen-6-yl}propionate By journals.iucr.org Published On :: 2024-09-17 In the title compound, C21H27BF2N2O4, a highly fluorescent boron–dipyrromethene dye, the methylpropionate moieties have different conformations. In the crystal, weak C—H⋯F and C—H⋯O interactions link the molecules. Some optical properties are presented. Full Article text
etho Relationship between synthesis method–crystal structure–melting properties in cocrystals: the case of caffeine–citric acid By journals.iucr.org Published On :: 2024-05-07 The influence of the crystal synthesis method on the crystallographic structure of caffeine–citric acid cocrystals was analyzed thanks to the synthesis of a new polymorphic form of the cocrystal. In order to compare the new form to the already known forms, the crystal structure of the new cocrystal (C8H10N4O2·C6H8O7) was solved by powder X-ray diffraction thanks to synchrotron experiments. The structure determination was performed using `GALLOP', a recently developed hybrid approach based on a local optimization with a particle swarm optimizer, particularly powerful when applied to the structure resolution of materials of pharmaceutical interest, compared to classical Monte-Carlo simulated annealing. The final structure was obtained through Rietveld refinement, and first-principles density functional theory (DFT) calculations were used to locate the H atoms. The symmetry is triclinic with the space group Poverline{1} and contains one molecule of caffeine and one molecule of citric acid per asymmetric unit. The crystallographic structure of this cocrystal involves different hydrogen-bond associations compared to the already known structures. The analysis of these hydrogen bonds indicates that the cocrystal obtained here is less stable than the cocrystals already identified in the literature. This analysis is confirmed by the determination of the melting point of this cocrystal, which is lower than that of the previously known cocrystals. Full Article text
etho Methods in molecular photocrystallography By journals.iucr.org Published On :: 2024-09-04 Over the last three decades, the technology that makes it possible to follow chemical processes in the solid state in real time has grown enormously. These studies have important implications for the design of new functional materials for applications in optoelectronics and sensors. Light–matter interactions are of particular importance, and photocrystallography has proved to be an important tool for studying these interactions. In this technique, the three-dimensional structures of light-activated molecules, in their excited states, are determined using single-crystal X-ray crystallography. With advances in the design of high-power lasers, pulsed LEDs and time-gated X-ray detectors, the increased availability of synchrotron facilities, and most recently, the development of XFELs, it is now possible to determine the structures of molecules with lifetimes ranging from minutes down to picoseconds, within a single crystal, using the photocrystallographic technique. This review discusses the procedures for conducting successful photocrystallographic studies and outlines the different methodologies that have been developed to study structures with specific lifetime ranges. The complexity of the methods required increases considerably as the lifetime of the excited state shortens. The discussion is supported by examples of successful photocrystallographic studies across a range of timescales and emphasises the importance of the use of complementary analytical techniques in order to understand the solid-state processes fully. Full Article text
etho Protonation of histidine rings using quantum-mechanical methods By journals.iucr.org Published On :: 2024-07-25 Histidine can be protonated on either or both of the two N atoms of the imidazole moiety. Each of the three possible forms occurs as a result of the stereochemical environment of the histidine side chain. In an atomic model, comparing the possible protonation states in situ, looking at possible hydrogen bonding and metal coordination, it is possible to predict which is most likely to be correct. A more direct method is described that uses quantum-mechanical methods to calculate, also in situ, the minimum geometry and energy for comparison, and therefore to more accurately identify the most likely protonation state. Full Article text
etho Cryo2RT: a high-throughput method for room-temperature macromolecular crystallography from cryo-cooled crystals By journals.iucr.org Published On :: 2024-07-25 Advances in structural biology have relied heavily on synchrotron cryo-crystallography and cryogenic electron microscopy to elucidate biological processes and for drug discovery. However, disparities between cryogenic and room-temperature (RT) crystal structures pose challenges. Here, Cryo2RT, a high-throughput RT data-collection method from cryo-cooled crystals that leverages the cryo-crystallography workflow, is introduced. Tested on endothiapepsin crystals with four soaked fragments, thaumatin and SARS-CoV-2 3CLpro, Cryo2RT reveals unique ligand-binding poses, offers a comparable throughput to cryo-crystallography and eases the exploration of structural dynamics at various temperatures. Full Article text
etho Solving protein structures by combining structure prediction, molecular replacement and direct-methods-aided model completion By journals.iucr.org Published On :: 2024-01-13 Highly accurate protein structure prediction can generate accurate models of protein and protein–protein complexes in X-ray crystallography. However, the question of how to make more effective use of predicted models for completing structure analysis, and which strategies should be employed for the more challenging cases such as multi-helical structures, multimeric structures and extremely large structures, both in the model preparation and in the completion steps, remains open for discussion. In this paper, a new strategy is proposed based on the framework of direct methods and dual-space iteration, which can greatly simplify the pre-processing steps of predicted models both in normal and in challenging cases. Following this strategy, full-length models or the conservative structural domains could be used directly as the starting model, and the phase error and the model bias between the starting model and the real structure would be modified in the direct-methods-based dual-space iteration. Many challenging cases (from CASP14) have been tested for the general applicability of this constructive strategy, and almost complete models have been generated with reasonable statistics. The hybrid strategy therefore provides a meaningful scheme for X-ray structure determination using a predicted model as the starting point. Full Article text
etho Benchmarking predictive methods for small-angle X-ray scattering from atomic coordinates of proteins using maximum likelihood consensus data By journals.iucr.org Published On :: 2024-07-10 Stimulated by informal conversations at the XVII International Small Angle Scattering (SAS) conference (Traverse City, 2017), an international team of experts undertook a round-robin exercise to produce a large dataset from proteins under standard solution conditions. These data were used to generate consensus SAS profiles for xylose isomerase, urate oxidase, xylanase, lysozyme and ribonuclease A. Here, we apply a new protocol using maximum likelihood with a larger number of the contributed datasets to generate improved consensus profiles. We investigate the fits of these profiles to predicted profiles from atomic coordinates that incorporate different models to account for the contribution to the scattering of water molecules of hydration surrounding proteins in solution. Programs using an implicit, shell-type hydration layer generally optimize fits to experimental data with the aid of two parameters that adjust the volume of the bulk solvent excluded by the protein and the contrast of the hydration layer. For these models, we found the error-weighted residual differences between the model and the experiment generally reflected the subsidiary maxima and minima in the consensus profiles that are determined by the size of the protein plus the hydration layer. By comparison, all-atom solute and solvent molecular dynamics (MD) simulations are without the benefit of adjustable parameters and, nonetheless, they yielded at least equally good fits with residual differences that are less reflective of the structure in the consensus profile. Further, where MD simulations accounted for the precise solvent composition of the experiment, specifically the inclusion of ions, the modelled radius of gyration values were significantly closer to the experiment. The power of adjustable parameters to mask real differences between a model and the structure present in solution is demonstrated by the results for the conformationally dynamic ribonuclease A and calculations with pseudo-experimental data. This study shows that, while methods invoking an implicit hydration layer have the unequivocal advantage of speed, care is needed to understand the influence of the adjustable parameters. All-atom solute and solvent MD simulations are slower but are less susceptible to false positives, and can account for thermal fluctuations in atomic positions, and more accurately represent the water molecules of hydration that contribute to the scattering profile. Full Article text
etho Crystal structure of [1,3-bis(2,4,6-trimethylphenyl)imidazolidin-2-ylidene]dichlorido(2-{[(2-methoxyethyl)(methyl)amino]methyl}benzylidene)ruthenium By journals.iucr.org Published On :: 2024-01-01 The title compound, [RuCl2(C33H43N3O)], is an example of a new generation of N,N-dialkyl ruthenium catalysts with an N—Ru coordination bond as part of a six-membered chelate ring. The Ru atom has an Addison τ parameter of 0.244, which indicates a geometry intermediate between square-based pyramidal and trigonal–bipyramidal. The complex shows the usual trans arrangement of the two chlorides, with Ru—Cl bond lengths of 2.3515 (8) and 2.379 (7) Å, and a Cl—Ru—Cl angle of 158.02 (3)°. One of the chlorine atoms and the atoms of the 2-methoxy-N-methyl-N-[(2-methylphenyl)methyl]ethane-1-amine group of the title complex display disorder over two positions in a 0.889 (2): 0.111 (2) ratio. Full Article text
etho (S)-(+)-1-(4-Bromophenyl)-N-[(4-methoxyphenyl)methylidene]ethylamine and bis{(S)-(+)-1-(4-bromophenyl)-N-[(4-methoxyphenyl)methylidene]ethylamine-κN}dichloridopalladium(II) By journals.iucr.org Published On :: 2024-01-26 The (S)-(+)-1-(4-bromophenyl)-N-[(4-methoxyphenyl)methylidene]ethylamine ligand, C16H16BrNO, (I), was synthesized through the reaction of 4-methoxyanisaldehyde with (S)-(−)-1-(4-bromophenyl)ethylamine. It crystallizes in the orthorhombic space group P212121 belonging to the Sohncke group, featuring a single molecule in the asymmetric unit. The refinement converged successfully, achieving an R factor of 0.0508. The PdII complex bis{(S)-(+)-1-(4-bromophenyl)-N-[(4-methoxyphenyl)methylidene]ethylamine-κN}dichloridopalladium(II), [PdCl2(C16H16BrNO)2], (II), crystallizes in the monoclinic space group P21 belonging to the Sohncke group, with two molecules in the asymmetric unit. The central atom is tetracoordinated by two N atoms and two Cl atoms, resulting in a square-planar configuration. The imine moieties exhibit a trans configuration around the PdII centre, with average Cl—Pd—N angles of approximately 89.95 and 90°. The average distances within the palladium complex for the two molecules are ∼2.031 Å for Pd—N and ∼2.309 Å for Pd—Cl. Full Article text
etho Crystal structure of (S)-5-(3-acetyl-5-chloro-2-ethoxy-6-fluorophenyl)-2-oxazolidinone By journals.iucr.org Published On :: 2024-03-19 The structure of (S)-5-(3-acetyl-5-chloro-2-ethoxy-6-fluorophenyl)-2-oxazolidinone, C13H13ClFNO4, at 100 K has monoclinic (P21) symmetry. The compound has a polymeric structure propagated by a screw axis parallel to the b axis with N—H⋯O hydrogen bonding. It is of interest with respect to efforts in the synthesis of a candidate anticancer drug, parsaclisib. Full Article text
etho Synthesis, crystal structure and anticancer activity of the complex chlorido(η2-ethylene)(quinolin-8-olato-κ2N,O)platinum(II) by experimental and theoretical methods By journals.iucr.org Published On :: 2024-04-30 The complex [Pt(C9H6NO)Cl(C2H4)], (I), was synthesized and structurally characterized by ESI mass spectrometry, IR, NMR spectroscopy, DFT calculations and X-ray diffraction. The results showed that the deprotonated 8-hydroxyquinoline (C9H6NO) coordinates with the PtII atom via the N and O atoms while the ethylene coordinates in the η2 manner and in the trans position compared to the coordinating N atom. The crystal packing is characterized by C—H⋯O, C—H⋯π, Cl⋯π and Pt⋯π interactions. Complex (I) showed high selective activity against Lu-1 and Hep-G2 cell lines with IC50 values of 0.8 and 0.4 µM, respectively, 54 and 33-fold more active than cisplatin. In particular, complex (I) is about 10 times less toxic to normal cells (HEK-293) than cancer cells Lu-1 and Hep-G2. Furthermore, the reaction of complex (I) with guanine at the N7 position was proposed and investigated using the DFT method. The results indicated that replacement of the ethylene ligand with guanine is thermodynamically more favorable than the Cl ligand and that the reaction occurs via two consecutive steps, namely the replacement of ethylene with H2O and the water with the guanine molecule. Full Article text
etho Synthesis, crystal structure and Hirshfeld surface analysis of sulfamethoxazolium methylsulfate monohydrate By journals.iucr.org Published On :: 2024-09-24 The molecular salt sulfamethoxazolium {or 4-[(5-methyl-1,2-oxazol-3-yl)sulfamoyl]anilinium methyl sulfate monohydrate}, C10H12N3O3S+·CH3O4S−·H2O, was prepared by the reaction of sulfamethoxazole and H2SO4 in methanol and crystallized from methanol–ether–water. Protonation takes place at the nitrogen atom of the primary amino group. In the crystal, N—H⋯O hydrogen bonds (water and methylsulfate anion) and intermolecular N—H⋯N interactions involving the sulfonamide and isoxazole nitrogen atoms, link the components into a tri-dimensional network, additional cohesion being provided by face-to-face π–π interactions between the phenyl rings of adjacent molecules. A Hirshfeld surface analysis was used to verify the contributions of the different intermolecular interactions, showing that the three most important contributions for the crystal packing are from H⋯O (54.1%), H⋯H (29.2%) and H⋯N (5.0%) interactions. Full Article text
etho Multi-segment cooling design of a reflection mirror based on the finite-element method By journals.iucr.org Published On :: Through numerical optimization of cooling lengths and cooling groove positions for the first reflection mirror of a free-electron laser [OK?], the root mean square of the height error of the mirror's thermal deformation was minimized. The optimized mirror design effectively mitigated stray light and enhanced the peak intensity of the focus spot at the sample, thereby enhancing the optical performance of the high-heat-load mirror under high repetition rates at beamline FEL-II of the SHINE facility. Full Article text
etho Quantitative selection of sample structures in small-angle scattering using Bayesian methods By journals.iucr.org Published On :: 2024-06-18 Small-angle scattering (SAS) is a key experimental technique for analyzing nanoscale structures in various materials. In SAS data analysis, selecting an appropriate mathematical model for the scattering intensity is critical, as it generates a hypothesis of the structure of the experimental sample. Traditional model selection methods either rely on qualitative approaches or are prone to overfitting. This paper introduces an analytical method that applies Bayesian model selection to SAS measurement data, enabling a quantitative evaluation of the validity of mathematical models. The performance of the method is assessed through numerical experiments using artificial data for multicomponent spherical materials, demonstrating that this proposed analysis approach yields highly accurate and interpretable results. The ability of the method to analyze a range of mixing ratios and particle size ratios for mixed components is also discussed, along with its precision in model evaluation by the degree of fitting. The proposed method effectively facilitates quantitative analysis of nanoscale sample structures in SAS, which has traditionally been challenging, and is expected to contribute significantly to advancements in a wide range of fields. Full Article text
etho Practical courses on advanced methods in macromolecular crystallization: 20 years of history and future perspectives By journals.iucr.org Published On :: 2024-08-30 The first Federation of European Biochemical Societies Advanced Course on macromolecular crystallization was launched in the Czech Republic in October 2004. Over the past two decades, the course has developed into a distinguished event, attracting students, early career postdoctoral researchers and lecturers. The course topics include protein purification, characterization and crystallization, covering the latest advances in the field of structural biology. The many hands-on practical exercises enable a close interaction between students and teachers and offer the opportunity for students to crystallize their own proteins. The course has a broad and lasting impact on the scientific community as participants return to their home laboratories and act as nuclei by communicating and implementing their newly acquired knowledge and skills. Full Article text
etho Thermal analysis of a reflection mirror by fluid and solid heat transfer method By journals.iucr.org Published On :: 2024-10-15 High-repetition-rate free-electron lasers impose stringent requirements on the thermal deformation of beamline optics. The Shanghai HIgh-repetition-rate XFEL aNd Extreme light facility (SHINE) experiences high average thermal power and demands wavefront preservation. To deeply study the thermal field of the first reflection mirror M1 at the FEL-II beamline of SHINE, thermal analysis under a photon energy of 400 eV was executed by fluid and solid heat transfer method. According to the thermal analysis results and the reference cooling water temperature of 30 °C, the temperature of the cooling water at the flow outlet is raised by 0.15 °C, and the wall temperature of the cooling tube increases by a maximum of 0.5 °C. The maximum temperature position of the footprint centerline in the meridian direction deviates away from the central position, and this asymmetrical temperature distribution will directly affect the thermal deformation of the mirror and indirectly affect the focus spot of the beam at the sample. Full Article text