ram Forrest Frank, CeCe Winans among Christian artists nominated for Grammys By www.christianpost.com Published On :: Mon, 11 Nov 2024 11:05:38 -0500 The Recording Academy announced nominations for the 67th annual Grammy Awards on Thursday, with Christian and gospel artists such as Bethel Music, Brandon Lake, CeCe Winans and newcomer Forest Frank receiving nods. Full Article
ram Ceramicist Shares His Joy With New Collection At The Currier By www.nhpr.org Published On :: Fri, 14 May 2021 13:53:04 +0000 The Currier Museum of Art 's latest exhibition features the work of Philadelphia-based potter Roberto Lugo. Lugo finds inspiration for his work in his upbringing and his cultural heritage. His new collection, Te traigo mi le lo lai -- I bring you my joy , will be on display at the Currier Museum through September. Lugo will also be in Manchester this summer for a residency with the museum, where he'll be teaching pottery classes. Below are some excerpts from Robert Lugo's conversation with NHPR's Rick Ganley. On Lugo’s inspiration: “ I've always found that it's important for me as a person to not forget where I'm from. I'm from Philadelphia in a really impoverished neighborhood, mostly made up of Black and Latinx people. And so I identify and associate that as a culture and as almost its own society. And so in the tradition that people have represented their cultures in pottery, I do that.” On his new exhibition, Te traigo mi le lo lai -- I bring you my joy : “ One of the reasons why I Full Article
ram Nombramiento del Jefe Estatal de Bomberos By www.tdi.texas.gov Published On :: Mon, 14 Aug 2023 00:00:00 CDT El Departamento de Seguros de Texas anuncia un nuevo liderazgo para la Oficina del Jefe Estatal de Bomberos. Full Article
ram Drama on ice: Kamila Valieva fails, Alexandra Trusova breaks down By english.pravda.ru Published On :: Thu, 17 Feb 2022 19:44:00 +0300 Kamila Valieva, Russian figure skating phenomenon, failed her performance and was ranked fourth in the free skating program at the 2022 Olympic Games in Beijing. When Kamila finished her performance, Tutberidze asked her why she stopped fighting during the performance. "Well, why did you let go of everything? Well, explain, you let go somewhere after the axel,” said the coach to her 15-year-old athlete. Full Article Sport
ram Roman Abramovich buys another football club By english.pravda.ru Published On :: Tue, 05 Apr 2022 19:44:00 +0300 Roman Abramovich, a Russian billionaire entrepreneur, bought Turkey's Goztepe football club (Göztepe S. K.), D-Smar Spor reported via Twitter. Abramovich, the owner of London's Chelsea and the Turkish side have agreed on the details of the deal. Göztepe's acquisition by Abramovich is to be officially announced on April 8. Reports about Roman Abramovich's interest in another football club first appeared on March 23. After 31 matches, Göztepe was ranked 18th in the Turkish Super League. The team faced the risk of leaving the elite division. Full Article Sport
ram Roman Abramovich sells Chelsea By english.pravda.ru Published On :: Thu, 26 May 2022 19:40:00 +0300 Russian entrepreneur Roman Abramovich has closed the deal to sell London's Chelsea Football Club, RIA Novosti reports with reference to the British government. Chelsea, an English Premier League (EPL) club, owned by Russian billionaire Roman Abramovich, has been sold to American businessman Todd Boeli's consortium. It was earlier reported that the deal was evaluated at 5.33 billion dollars. Full Article Sport
ram MandM unveils interactive Live Shopping experience on Facebook and Instagram By www.retailtechnologyreview.com Published On :: MandM, the online retailer specialising in discounted fashion, sports and outdoor brands, has launched the first of a series of live shopping events on Facebook and Instagram in collaboration with Sprii. Full Article Digital Signage Internet Retailing Retail Supply Chain
ram German Lillevali and tumbled pyramids of grand strategists By english.pravda.ru Published On :: Wed, 15 Sep 2021 20:55:00 +0300 How do famous film directors and athletes become baits for pyramid schemes? How are such prominent figures as Anatoly Karpov, Nikita Mikhalkov and other renowned personalities in Russia involved with the scammers from Anchor-Invest? Scarcely ever it is possible to catch and put into jail big-time operators of financial pyramids how it happened with Mavrodi, the famous "financier of Russia". Apart from Mavrodi, a variety of pyramids existed and continue to operate in Russia that have the same backbone; to take your money. Full Article Business
ram Renovotec launches fast-improvement manufacturing programme By www.retailtechnologyreview.com Published On :: Supply chain hardware, software and services company Renovotec is launching a ‘fast improvement manufacturing programme’ designed to deploy those technologies that have the greatest impact on supply chain manufacturing. Full Article Retail Supply Chain RFID
ram Brother UK named as leader in sustainability programs and services in new report By www.retailtechnologyreview.com Published On :: Brother UK has been named as a 'leader' in sustainability programs and services in the most recent IDC Sustainability MarketScape assessment. Full Article Print and Label
ram SUV rams into crowd of joggers in China, over 20 hurt By english.pravda.ru Published On :: Mon, 11 Nov 2024 21:27:00 +0300 In the Chinese city of Zhuhai, a car rammed into a crowd of people near a sports center. The 62-year-old driver fled the scene of the accident but was later detained. The victims were hospitalized, China Daily said with reference to local authorities. WARNING: The videos are extremely graphic! Click here to see more photos and videos from the scene. Full Article Incidents
ram Elon Musk's Starlink satellite Internet raises Russian combat capability dramatically By english.pravda.ru Published On :: Tue, 12 Nov 2024 20:02:00 +0300 Russian military correspondent Alexander Kots said that the Russian Armed Forces use Elon Musk's technology in military actions. According to Kots, the Russian military use Starlink satellites in the special military operation zone. "The troops actively use Starlink in the SVO (SVO is a Russian abbreviation for special military operation — ed.). We use it, among other things, for broadcast to command posts, to get images from reconnaissance UAVs,” the military correspondent said. This has significantly raised the level of Russian intelligence, the military correspondent added. Full Article Incidents
ram Datalogic Memor 30/35 achieves rugged Certification under Android Enterprise Recommended (AER) Program By www.retailtechnologyreview.com Published On :: Datalogic, the global provider of automatic data capture and industrial automation solutions, has announced that the Memor 30/35 has been officially certified as a rugged device under the prestigious Android Enterprise Recommended (AER) program, meeting and surpassing key standards set by Android. Full Article Mobile Computers Data Capture
ram Expert Available: Beyonce leads Grammy nominations with 11 nods By www.newswise.com Published On :: Fri, 08 Nov 2024 12:00:34 EST Beyonce received 11 Grammy Award nominations, notching more citations than any other artist this year, "Cowboy Carter." ... Full Article
ram 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
ram The Lean Impact Start-Up Framework: Fueling Innovation for Positive Societal Change By www.newswise.com Published On :: Wed, 06 Nov 2024 10:15:12 EST Full Article
ram United Nations Ratifies Framework to Protect People on Cash Apps By www.newswise.com Published On :: Fri, 08 Nov 2024 09:05:00 EST University of Florida cybersecurity professor Kevin Butler developed the framework, which spells out guidance for countries to prevent fraud and abuse on mobile cash apps. Full Article
ram S. Korea, US to Conduct Joint Studies for Artemis Moon Exploration Program By world.kbs.co.kr Published On :: Wed, 30 Oct 2024 15:25:17 +0900 [Science] : South Korea and the United States will conduct joint studies related to the Artemis moon exploration program. According to the Korea AeroSpace Administration on Wednesday, it has signed a study agreement on the Artemis program with U.S. National Aeronautics and Space Administration(NASA). The agreement ...[more...] Full Article Science
ram Pianist Lim Yun-chan Wins Gramophone Award By world.kbs.co.kr Published On :: Thu, 03 Oct 2024 11:28:19 +0900 [Culture] : Pianist Lim Yun-chan has won the prestigious Gramophone Classical Music Award in the piano category. Lim received the award for his album, "Chopin: Etudes" during a ceremony on Wednesday in London, becoming the first South Korean to win the award in the piano category. Lim also won the special award of ...[more...] Full Article Culture
ram Korean Pianist Lim Yunchan Wins Gramophone Classical Music Award By world.kbs.co.kr Published On :: Thu, 03 Oct 2024 14:20:12 +0900 [Culture] : Anchor: South Korean Pianist Lim Yunchan has won the Gramophone Classical Music Award in the piano category. This marks the first time that a Korean pianist has received the prestigious prize, often called the Oscars of the classical music world. Kim Bum-soo has more. Report: [Sound bite: Lim ...[more...] Full Article Culture
ram KBS Hit Drama 'Winter Sonata' to be Released as Film in Japan Next Year By world.kbs.co.kr Published On :: Mon, 07 Oct 2024 15:10:36 +0900 [Culture] : KBS hit drama "Winter Sonata" which led the Korean Wave in the 2000s will be released as a theatrical film in Japan next year. Pan Entertainment, which produced the show, announced Monday that it had decided to release a film version after receiving continuous requests from Japanese distributors and ...[more...] Full Article Culture
ram What Does RAM Do to Speed Up Your Computer? By computer.howstuffworks.com Published On :: Tue, 28 May 2024 11:46:42 -0400 If you need a faster computer, adding more RAM may help. Learn about the benefits and drawbacks of making your computer faster with RAM memory. Full Article
ram How to Get More RAM (Random-access Memory) By electronics.howstuffworks.com Published On :: Thu, 06 Jun 2024 11:34:06 -0400 You can upgrade RAM on your computer at home without the need of a specialist. Take a look at these easy steps to upgrade RAM on your PC. Full Article
ram Coordination geometry flexibility driving supramolecular isomerism of Cu/Mo pillared-layer hybrid networks By journals.iucr.org Published On :: The hydrothermal synthesis and structural characterization of four novel 3D pillared-layer metal–organic frameworks are studied, revealing how the malleability of copper coordination geometries drives diverse supramolecular isomerism. The findings provide new insights into designing advanced hybrid materials with tailored properties, emphasizing the significant role of reaction conditions and metal ion flexibility in determining network topologies. Full Article text
ram Parameterized absorptive electron scattering factors By journals.iucr.org Published On :: 2024-01-25 In electron diffraction, thermal atomic motion produces incoherent scattering over a relatively wide angular range, which appears as a diffuse background that is usually subtracted from measurements of Bragg spot intensities in structure solution methods. The transfer of electron flux from Bragg spots to diffuse scatter is modelled using complex scattering factors f + if' in the Bloch wave methodology. In a two-beam Einstein model the imaginary `absorptive' scattering factor f' can be obtained by the evaluation of an integral containing f over all possible scattering angles. While more sophisticated models of diffuse scatter are widely used in the electron microscopy community, it is argued in this paper that this simple model is appropriate for current structure solution and refinement methods. The two-beam model is a straightforward numerical calculation, but even this simplistic approach can become time consuming for simulations of materials with large numbers of atoms in the unit cell and/or many incident beam orientations. Here, a parameterized form of f' is provided for 103 elements as neutral, spherical atoms that reduces calculation time considerably. Full Article text
ram Universal parameters of bulk-solvent masks By journals.iucr.org Published On :: 2024-02-09 The bulk solvent is a major component of biomacromolecular crystals that contributes significantly to the observed diffraction intensities. Accurate modelling of the bulk solvent has been recognized as important for many crystallographic calculations. Owing to its simplicity and modelling power, the flat (mask-based) bulk-solvent model is used by most modern crystallographic software packages to account for disordered solvent. In this model, the bulk-solvent contribution is defined by a binary mask and a scale (scattering) function. The mask is calculated on a regular grid using the atomic model coordinates and their chemical types. The grid step and two radii, solvent and shrinkage, are the three parameters that govern the mask calculation. They are highly correlated and their choice is a compromise between the computer time needed to calculate the mask and the accuracy of the mask. It is demonstrated here that this choice can be optimized using a unique value of 0.6 Å for the grid step irrespective of the data resolution, and the radii values adjusted correspondingly. The improved values were tested on a large sample of Protein Data Bank entries derived from X-ray diffraction data and are now used in the computational crystallography toolbox (CCTBX) and in Phenix as the default choice. Full Article text
ram GraphT–T (V1.0Beta), a program for embedding and visualizing periodic graphs in 3D Euclidean space By journals.iucr.org Published On :: 2024-04-29 Following the work of Day & Hawthorne [Acta Cryst. (2022), A78, 212–233] and Day et al. [Acta Cryst. (2024), A80, 258–281], the program GraphT–T has been developed to embed graphical representations of observed and hypothetical chains of (SiO4)4− tetrahedra into 2D and 3D Euclidean space. During embedding, the distance between linked vertices (T–T distances) and the distance between unlinked vertices (T⋯T separations) in the resultant unit-distance graph are restrained to the average observed distance between linked Si tetrahedra (3.06±0.15 Å) and the minimum separation between unlinked vertices is restrained to be equal to or greater than the minimum distance between unlinked Si tetrahedra (3.713 Å) in silicate minerals. The notional interactions between vertices are described by a 3D spring-force algorithm in which the attractive forces between linked vertices behave according to Hooke's law and the repulsive forces between unlinked vertices behave according to Coulomb's law. Embedding parameters (i.e. spring coefficient, k, and Coulomb's constant, K) are iteratively refined during embedding to determine if it is possible to embed a given graph to produce a unit-distance graph with T–T distances and T⋯T separations that are compatible with the observed T–T distances and T⋯T separations in crystal structures. The resultant unit-distance graphs are denoted as compatible and may form crystal structures if and only if all distances between linked vertices (T–T distances) agree with the average observed distance between linked Si tetrahedra (3.06±0.15 Å) and the minimum separation between unlinked vertices is equal to or greater than the minimum distance between unlinked Si tetrahedra (3.713 Å) in silicate minerals. If the unit-distance graph does not satisfy these conditions, it is considered incompatible and the corresponding chain of tetrahedra is unlikely to form crystal structures. Using GraphT–T, Day et al. [Acta Cryst. (2024), A80, 258–281] have shown that several topological properties of chain graphs influence the flexibility (and rigidity) of the corresponding chains of Si tetrahedra and may explain why particular compatible chain arrangements (and the minerals in which they occur) are more common than others and/or why incompatible chain arrangements do not occur in crystals despite being topologically possible. Full Article text
ram Understanding secondary order parameters in perovskites with tilted octahedra By journals.iucr.org Published On :: A symmetry guide for the secondary structural degrees of freedom and related physical properties generated by tilts of BX6 octahedra in perovskites is proposed. Full Article text
ram Understanding secondary order parameters in perovskites with tilted octahedra By journals.iucr.org Published On :: 2024-10-16 In the family of perovskite materials, the tilts of BX6 octahedra are the most common type of structural distortion. Conventionally, the formation of low-symmetry perovskite phases with tilted octahedra is analyzed by considering only primary order parameters. However, octahedral tilting also gives rise to secondary order parameters which contribute to additional atomic displacements, ordering and lattice distortions. Our study highlights the significant impact of secondary order parameters on the structural formation and emergent physical properties of perovskites. Through group-theoretical and crystallographic analyses, we have identified all secondary order parameters within Glazer-type tilt systems and clarified their physical manifestations. We explore the fundamental symmetry relationships among various structural degrees of freedom in perovskites, including tilt-induced ferroelasticity, correlations between displacements and ordering of atoms occupying different positions, and the potential for rigid unit rotations and unconventional octahedral tilts. Particular emphasis is placed on the emergence of secondary order parameters and their coupling with primary order parameters, as well as their symmetry-based hierarchy, illustrated through a modified Bärnighausen tree. We applied our theoretical insights to elucidate phase transitions in well known perovskites such as CaTiO3 and RMnO3 (where R = La and lanthanide ions), thereby demonstrating the significant influence of secondary order parameters on crystal structure formation. Our results serve as a symmetry-based guide for the design, identification and structural characterization of perovskites with tilted octahedra, and for understanding tilt-induced physical properties. Full Article text
ram A new modular framework for high-level application development at HEPS By journals.iucr.org Published On :: 2024-02-01 As a representative of the fourth-generation light sources, the High Energy Photon Source (HEPS) in Beijing, China, utilizes a multi-bend achromat lattice to obtain an approximately 100 times emittance reduction compared with third-generation light sources. New technologies bring new challenges to operate the storage ring. In order to meet the beam commissioning requirements of HEPS, a new framework for the development of high-level applications (HLAs) has been created. The key part of the new framework is a dual-layer physical module to facilitate the seamless fusion of physical simulation models with the real machine, allowing for fast switching between different simulation models to accommodate the various simulation scenarios. As a framework designed for development of physical applications, all variables are based on physical quantities. This allows physicists to analytically assess measurement parameters and optimize machine parameters in a more intuitive manner. To enhance both extensibility and adaptability, a modular design strategy is utilized, partitioning the entire framework into discrete modules in alignment with the requirements of HLA development. This strategy not only facilitates the independent development of each module but also minimizes inter-module coupling, thereby simplifying the maintenance and expansion of the entire framework. To simplify the development complexity, the design of the new framework is implemented using Python and is called Python-based Accelerator Physics Application Set (Pyapas). Taking advantage of Python's flexibility and robust library support, we are able to develop and iterate quickly, while also allowing for seamless integration with other scientific computing applications. HLAs for both the HEPS linac and booster have been successfully developed. During the beam commissioning process at the linac, Pyapas's ease of use and reliability have significantly reduced the time required for the beam commissioning operators. As a development framework for HLA designed for the new-generation light sources, Pyapas has the versatility to be employed with HEPS, as well as with other comparable light sources, due to its adaptability. Full Article text
ram DOMAS: a data management software framework for advanced light sources By journals.iucr.org Published On :: 2024-02-01 In recent years, China's advanced light sources have entered a period of rapid construction and development. As modern X-ray detectors and data acquisition technologies advance, these facilities are expected to generate massive volumes of data annually, presenting significant challenges in data management and utilization. These challenges encompass data storage, metadata handling, data transfer and user data access. In response, the Data Organization Management Access Software (DOMAS) has been designed as a framework to address these issues. DOMAS encapsulates four fundamental modules of data management software, including metadata catalogue, metadata acquisition, data transfer and data service. For light source facilities, building a data management system only requires parameter configuration and minimal code development within DOMAS. This paper firstly discusses the development of advanced light sources in China and the associated demands and challenges in data management, prompting a reconsideration of data management software framework design. It then outlines the architecture of the framework, detailing its components and functions. Lastly, it highlights the application progress and effectiveness of DOMAS when deployed for the High Energy Photon Source (HEPS) and Beijing Synchrotron Radiation Facility (BSRF). Full Article text
ram The role of carboxylate ligand orbitals in the breathing dynamics of a metal-organic framework by resonant X-ray emission spectroscopy By journals.iucr.org Published On :: 2024-02-16 Metal-organic frameworks (MOFs) exhibit structural flexibility induced by temperature and guest adsorption, as demonstrated in the structural breathing transition in certain MOFs between narrow-pore and large-pore phases. Soft modes were suggested to entropically drive such pore breathing through enhanced vibrational dynamics at high temperatures. In this work, oxygen K-edge resonant X-ray emission spectroscopy of the MIL-53(Al) MOF was performed to selectively probe the electronic perturbation accompanying pore breathing dynamics at the ligand carboxylate site for metal–ligand interaction. It was observed that the temperature-induced vibrational dynamics involves switching occupancy between antisymmetric and symmetric configurations of the carboxylate oxygen lone pair orbitals, through which electron density around carboxylate oxygen sites is redistributed and metal–ligand interactions are tuned. In turn, water adsorption involves an additional perturbation of π orbitals not observed in the structural change solely induced by temperature. Full Article text
ram Optimization of synchrotron radiation parameters using swarm intelligence and evolutionary algorithms By journals.iucr.org Published On :: 2024-02-22 Alignment of each optical element at a synchrotron beamline takes days, even weeks, for each experiment costing valuable beam time. Evolutionary algorithms (EAs), efficient heuristic search methods based on Darwinian evolution, can be utilized for multi-objective optimization problems in different application areas. In this study, the flux and spot size of a synchrotron beam are optimized for two different experimental setups including optical elements such as lenses and mirrors. Calculations were carried out with the X-ray Tracer beamline simulator using swarm intelligence (SI) algorithms and for comparison the same setups were optimized with EAs. The EAs and SI algorithms used in this study for two different experimental setups are the Genetic Algorithm (GA), Non-dominated Sorting Genetic Algorithm II (NSGA-II), Particle Swarm Optimization (PSO) and Artificial Bee Colony (ABC). While one of the algorithms optimizes the lens position, the other focuses on optimizing the focal distances of Kirkpatrick–Baez mirrors. First, mono-objective evolutionary algorithms were used and the spot size or flux values checked separately. After comparison of mono-objective algorithms, the multi-objective evolutionary algorithm NSGA-II was run for both objectives – minimum spot size and maximum flux. Every algorithm configuration was run several times for Monte Carlo simulations since these processes generate random solutions and the simulator also produces solutions that are stochastic. The results show that the PSO algorithm gives the best values over all setups. Full Article text
ram MLgrating: a program for simulating multilayer gratings for tender X-ray applications By journals.iucr.org Published On :: 2024-08-01 Multilayer gratings are increasingly popular optical elements at X-ray beamlines, as they can provide much higher photon flux in the tender X-ray range compared with traditional single-layer coated gratings. While there are several proprietary software tools that provide the functionality to simulate the efficiencies of such gratings, until now the X-ray community has lacked an open-source alternative. Here MLgrating is presented, a program for simulating the efficiencies of both multilayer gratings and single-layer coated gratings for X-ray applications. MLgrating is benchmarked by comparing its output with that of other software tools and plans are discussed for how the program could be extended in the future. Full Article text
ram 3-[(Benzo-1,3-dioxol-5-yl)amino]-4-methoxycyclobut-3-ene-1,2-dione: polymorphism and twinning of a precursor to an antimycobacterial squaramide By journals.iucr.org Published On :: 2024-07-05 The title compound, 3-[(benzo-1,3-dioxol-5-yl)amino]-4-methoxycyclobut-3-ene-1,2-dione, C12H9NO5 (3), is a precursor to an antimycobacterial squaramide. Block-shaped crystals of a monoclinic form (3-I, space group P21/c, Z = 8, Z' = 2) and needle-shaped crystals of a triclinic form (3-II, space group P-1, Z = 4, Z' = 2) were found to crystallize concomitantly. In both crystal forms, R22(10) dimers assemble through N—H⋯O=C hydrogen bonds. These dimers are formed from crystallographically unique molecules in 3-I, but exhibit crystallographic Ci symmetry in 3-II. Twinning by pseudomerohedry was encountered in the crystals of 3-II. The conformations of 3 in the solid forms 3-I and 3-II are different from one another but are similar for the unique molecules in each polymorph. Density functional theory (DFT) calculations on the free molecule of 3 indicate that a nearly planar conformation is preferred. Full Article text
ram Characterization of novel mevalonate kinases from the tardigrade Ramazzottius varieornatus and the psychrophilic archaeon Methanococcoides burtonii By journals.iucr.org Published On :: 2024-02-27 Mevalonate kinase is central to the isoprenoid biosynthesis pathway. Here, high-resolution X-ray crystal structures of two mevalonate kinases are presented: a eukaryotic protein from Ramazzottius varieornatus and an archaeal protein from Methanococcoides burtonii. Both enzymes possess the highly conserved motifs of the GHMP enzyme superfamily, with notable differences between the two enzymes in the N-terminal part of the structures. Biochemical characterization of the two enzymes revealed major differences in their sensitivity to geranyl pyrophosphate and farnesyl pyrophosphate, and in their thermal stabilities. This work adds to the understanding of the structural basis of enzyme inhibition and thermostability in mevalonate kinases. Full Article text
ram STOPGAP: an open-source package for template matching, subtomogram alignment and classification By journals.iucr.org Published On :: 2024-04-12 Cryo-electron tomography (cryo-ET) enables molecular-resolution 3D imaging of complex biological specimens such as viral particles, cellular sections and, in some cases, whole cells. This enables the structural characterization of molecules in their near-native environments, without the need for purification or separation, thereby preserving biological information such as conformational states and spatial relationships between different molecular species. Subtomogram averaging is an image-processing workflow that allows users to leverage cryo-ET data to identify and localize target molecules, determine high-resolution structures of repeating molecular species and classify different conformational states. Here, STOPGAP, an open-source package for subtomogram averaging that is designed to provide users with fine control over each of these steps, is described. In providing detailed descriptions of the image-processing algorithms that STOPGAP uses, this manuscript is also intended to serve as a technical resource to users as well as for further community-driven software development. Full Article text
ram Refining short-range order parameters from the three-dimensional diffuse scattering in single-crystal electron diffraction data By journals.iucr.org Published On :: 2024-01-01 Our study compares short-range order parameters refined from the diffuse scattering in single-crystal X-ray and single-crystal electron diffraction data. Nb0.84CoSb was chosen as a reference material. The correlations between neighbouring vacancies and the displacements of Sb and Co atoms were refined from the diffuse scattering using a Monte Carlo refinement in DISCUS. The difference between the Sb and Co displacements refined from the diffuse scattering and the Sb and Co displacements refined from the Bragg reflections in single-crystal X-ray diffraction data is 0.012 (7) Å for the refinement on diffuse scattering in single-crystal X-ray diffraction data and 0.03 (2) Å for the refinement on the diffuse scattering in single-crystal electron diffraction data. As electron diffraction requires much smaller crystals than X-ray diffraction, this opens up the possibility of refining short-range order parameters in many technologically relevant materials for which no crystals large enough for single-crystal X-ray diffraction are available. Full Article text
ram Toward a quantitative description of solvation structure: a framework for differential solution scattering measurements By journals.iucr.org Published On :: 2024-05-01 Appreciating that the role of the solute–solvent and other outer-sphere interactions is essential for understanding chemistry and chemical dynamics in solution, experimental approaches are needed to address the structural consequences of these interactions, complementing condensed-matter simulations and coarse-grained theories. High-energy X-ray scattering (HEXS) combined with pair distribution function analysis presents the opportunity to probe these structures directly and to develop quantitative, atomistic models of molecular systems in situ in the solution phase. However, at concentrations relevant to solution-phase chemistry, the total scattering signal is dominated by the bulk solvent, prompting researchers to adopt a differential approach to eliminate this unwanted background. Though similar approaches are well established in quantitative structural studies of macromolecules in solution by small- and wide-angle X-ray scattering (SAXS/WAXS), analogous studies in the HEXS regime—where sub-ångström spatial resolution is achieved—remain underdeveloped, in part due to the lack of a rigorous theoretical description of the experiment. To address this, herein we develop a framework for differential solution scattering experiments conducted at high energies, which includes concepts of the solvent-excluded volume introduced to describe SAXS/WAXS data, as well as concepts from the time-resolved X-ray scattering community. Our theory is supported by numerical simulations and experiment and paves the way for establishing quantitative methods to determine the atomic structures of small molecules in solution with resolution approaching that of crystallography. Full Article text
ram Many locks to one key: N-acetylneuraminic acid binding to proteins By journals.iucr.org Published On :: 2024-07-04 Sialic acids play crucial roles in cell surface glycans of both eukaryotic and prokaryotic organisms, mediating various biological processes, including cell–cell interactions, development, immune response, oncogenesis and host–pathogen interactions. This review focuses on the β-anomeric form of N-acetylneuraminic acid (Neu5Ac), particularly its binding affinity towards various proteins, as elucidated by solved protein structures. Specifically, we delve into the binding mechanisms of Neu5Ac to proteins involved in sequestering and transporting Neu5Ac in Gram-negative bacteria, with implications for drug design targeting these proteins as antimicrobial agents. Unlike the initial assumptions, structural analyses revealed significant variability in the Neu5Ac binding pockets among proteins, indicating diverse evolutionary origins and binding modes. By comparing these findings with existing structures from other systems, we can effectively highlight the intricate relationship between protein structure and Neu5Ac recognition, emphasizing the need for tailored drug design strategies to inhibit Neu5Ac-binding proteins across bacterial species. Full Article text
ram Texture tomography, a versatile framework to study crystalline texture in 3D By journals.iucr.org Published On :: 2024-07-24 Crystallographic texture is a key organization feature of many technical and biological materials. In these materials, especially hierarchically structured ones, the preferential alignment of the nano constituents heavily influences the macroscopic behavior of the material. To study local crystallographic texture with both high spatial and angular resolution, we developed Texture Tomography (TexTOM). This approach allows the user to model the diffraction data of polycrystalline materials using the full reciprocal space of the crystal ensemble and describe the texture in each voxel via an orientation distribution function, hence it provides 3D reconstructions of the local texture by measuring the probabilities of all crystal orientations. The TexTOM approach addresses limitations associated with existing models: it correlates the intensities from several Bragg reflections, thus reducing ambiguities resulting from symmetry. Further, it yields quantitative probability distributions of local real space crystal orientations without further assumptions about the sample structure. Finally, its efficient mathematical formulation enables reconstructions faster than the time scale of the experiment. This manuscript presents the mathematical model, the inversion strategy and its current experimental implementation. We show characterizations of simulated data as well as experimental data obtained from a synthetic, inorganic model sample: the silica–witherite biomorph. TexTOM provides a versatile framework to reconstruct 3D quantitative texture information for polycrystalline samples; it opens the door for unprecedented insights into the nanostructural makeup of natural and technical materials. Full Article text
ram Solvent organization in the ultrahigh-resolution crystal structure of crambin at room temperature By journals.iucr.org Published On :: 2024-08-27 Ultrahigh-resolution structures provide unprecedented details about protein dynamics, hydrogen bonding and solvent networks. The reported 0.70 Å, room-temperature crystal structure of crambin is the highest-resolution ambient-temperature structure of a protein achieved to date. Sufficient data were collected to enable unrestrained refinement of the protein and associated solvent networks using SHELXL. Dynamic solvent networks resulting from alternative side-chain conformations and shifts in water positions are revealed, demonstrating that polypeptide flexibility and formation of clathrate-type structures at hydrophobic surfaces are the key features endowing crambin crystals with extraordinary diffraction power. Full Article text
ram Supramolecular synthons in hydrates and solvates of lamotrigine: a tool for cocrystal design By journals.iucr.org Published On :: 2024-05-10 The molecule of anti-epileptic drug lamotrigine [LAM; 3,5-diamino-6-(2,3-dichlorophenyl)-1,2,4-triazine] is capable of the formation of multicomponent solids. Such an enhanced tendency is related to the diverse functionalities of the LAM chemical groups able to form hydrogen bonds. Two robust synthons are recognized in the supramolecular structure of LAM itself formed via N—H⋯N hydrogen bond: homosynthon, so-called aminopyridine dimer or synthon 1 [R22(8)] and larger homosynthon 2 [R32(8)]. The synthetic procedures for a new hydrate and 11 solvates of LAM (in the series: with acetone, ethanol: two polymorphs: form I and form II, 2-propanol, n-butanol, tert-butanol, n-pentanol, benzonitrile, acetonitrile, DMSO and dioxane) were performed. The comparative solid state structural analysis of a new hydrate and 11 solvates of LAM has been undertaken in order to establish robustness of the supramolecular synthons 1 and 2 found in the crystal structure of LAM itself as well as LAM susceptibility to build methodical solid state supramolecular architecture in the given competitive surrounding of potential hydrogen bonds. The aminopyridine dimer homosynthon 1 [R22(8)] has been switched from para-para (P-P) topology to ortho-ortho (O-O) topology in all crystal structures, except in LAM:n-pentanol:water solvate where it remains P-P. Homosynthon 2 [R32(8)] of the LAM crystal structure imitates in the LAM solvates as a heterosynthon by replacing the triazine nitrogen proton acceptor atoms of LAM with the proton acceptors of solvates molecules. Full Article text
ram Supramolecular architectures in multicomponent crystals of imidazole-based drugs and trithiocyanuric acid By journals.iucr.org Published On :: 2024-07-01 The structures of three multicomponent crystals formed with imidazole-based drugs, namely metronidazole, ketoconazole and miconazole, in conjunction with trithiocyanuric acid are characterized. Each of the obtained adducts represents a different category of crystalline molecular forms: a cocrystal, a salt and a cocrystal of salt. The structural analysis revealed that in all cases, the N—H⋯N hydrogen bond is responsible for the formation of acid–base pairs, regardless of whether proton transfer occurs or not, and these molecular pairs are combined to form unique supramolecular motifs by centrosymmetric N—H⋯S interactions between acid molecules. The complex intermolecular forces acting in characteristic patterns are discussed from the geometric and energetic perspectives, involving Hirshfeld surface analysis, pairwise energy estimation, and natural bond orbital calculations. Full Article text
ram Crystal structure, Hirshfeld surface analysis, intermolecular interaction energies, energy frameworks and DFT calculations of 4-amino-1-(prop-2-yn-1-yl)pyrimidin-2(1H)-one By journals.iucr.org Published On :: 2023-11-21 In the title molecule, C7H7N3O, the pyrimidine ring is essentially planar, with the propynyl group rotated out of this plane by 15.31 (4)°. In the crystal, a tri-periodic network is formed by N—H⋯O, N—H⋯N and C—H⋯O hydrogen-bonding and slipped π–π stacking interactions, leading to narrow channels extending parallel to the c axis. Hirshfeld surface analysis of the crystal structure reveals that the most important contributions for the crystal packing are from H⋯H (36.2%), H⋯C/C⋯H (20.9%), H⋯O/O⋯H (17.8%) and H⋯N/N⋯H (12.2%) interactions, showing that hydrogen-bonding and van der Waals interactions are the dominant interactions in the crystal packing. Evaluation of the electrostatic, dispersion and total energy frameworks indicates that the stabilization is dominated by the electrostatic energy contributions. The molecular structure optimized by density functional theory (DFT) calculations at the B3LYP/6–311 G(d,p) level is compared with the experimentally determined structure in the solid state. The HOMO–LUMO behaviour was also elucidated to determine the energy gap. Full Article text
ram Synthesis, structure and Hirshfeld surface analysis of 2-oxo-2H-chromen-6-yl 4-tert-butylbenzoate: work carried out as part of the AFRAMED project By journals.iucr.org Published On :: 2024-01-05 In the title compound, C20H18O4, the dihedral angle between the 2H-chromen-2-one ring system and the phenyl ring is 89.12 (5)°. In the crystal, the molecules are connected through C—H⋯O hydrogen bonds to generate [010] double chains that are reinforced by weak aromatic π–π stacking interactions. The unit-cell packing can be described as a tilted herringbone motif. The H⋯H, H⋯O/O⋯H, H⋯C/C⋯H and C⋯C contacts contribute 46.7, 24.2, 16.7 and 7.6%, respectively, to its Hirshfeld surface. Full Article text
ram Crystal structure, Hirshfeld surface analysis and energy frameworks of 1-[(E)-2-(2-fluorophenyl)diazan-1-ylidene]naphthalen-2(1H)-one By journals.iucr.org Published On :: 2024-01-12 The title compound, C16H11N2OF, is a member of the azo dye family. The dihedral angle subtended by the benzene ring and the naphthalene ring system measures 18.75 (7)°, indicating that the compound is not perfectly planar. An intramolecular N—H⋯O hydrogen bond occurs between the imino and carbonyl groups. In the crystal, the molecules are linked into inversion dimers by C—H⋯O interactions. Aromatic π–π stacking between the naphthalene ring systems lead to the formation of chains along [001]. A Hirshfeld surface analysis was undertaken to investigate and quantify the intermolecular interactions. In addition, energy frameworks were used to examine the cooperative effect of these intermolecular interactions across the crystal, showing dispersion energy to be the most influential factor in the crystal organization of the compound. Full Article text
ram (E)-N,N-Diethyl-4-{[(4-methoxyphenyl)imino]methyl}aniline: crystal structure, Hirshfeld surface analysis and energy framework By journals.iucr.org Published On :: 2024-01-26 In the title benzylideneaniline Schiff base, C18H22N2O, the aromatic rings are inclined to each other by 46.01 (6)°, while the Car—N= C—Car torsion angle is 176.9 (1)°. In the crystal, the only identifiable directional interaction is a weak C—H⋯π hydrogen bond, which generates inversion dimers that stack along the a-axis direction. Full Article text
ram Crystal structure, Hirshfeld surface analysis, crystal voids, interaction energy calculations and energy frameworks and DFT calculations of ethyl 2-cyano-3-(3-hydroxy-5-methyl-1H-pyrazol-4-yl)-3-phenylpropanoate By journals.iucr.org Published On :: 2024-01-31 The title compound, C16H17N3O3, is racemic as it crystallizes in a centrosymmetric space group (Poverline{1}), although the trans disposition of substituents about the central C—C bond is established. The five- and six-membered rings are oriented at a dihedral angle of 75.88 (8)°. In the crystal, N—H⋯N hydrogen bonds form chains of molecules extending along the c-axis direction that are connected by inversion-related pairs of O—H⋯N into ribbons. The ribbons are linked by C—H⋯π(ring) interactions, forming layers parallel to the ab plane. A Hirshfeld surface analysis indicates that the most important contributions for the crystal packing are from H⋯H (45.9%), H⋯N/N⋯H (23.3%), H⋯C/C⋯H (16.2%) and H⋯O/O⋯H (12.3%) interactions. Hydrogen bonding and van der Waals interactions are the dominant interactions in the crystal packing. The volume of the crystal voids and the percentage of free space were calculated to be 100.94 Å3 and 13.20%, showing that there is no large cavity in the crystal packing. Evaluation of the electrostatic, dispersion and total energy frameworks indicates that the stabilization is dominated by the electrostatic energy contributions in the title compound. Moreover, the DFT-optimized structure at the B3LYP/6–311 G(d,p) level is compared with the experimentally determined molecular structure in the solid state. The HOMO–LUMO behaviour was elucidated to determine the energy gap. Full Article text
ram Crystal structure, Hirshfeld surface analysis, crystal voids, interaction energy calculations and energy frameworks, and DFT calculations of 1-(4-methylbenzyl)indoline-2,3-dione By journals.iucr.org Published On :: 2024-01-31 The indoline portion of the title molecule, C16H13NO2, is planar. In the crystal, a layer structure is generated by C—H⋯O hydrogen bonds and C—H⋯π(ring), π-stacking and C=O⋯π(ring) interactions. The Hirshfeld surface analysis of the crystal structure indicates that the most important contributions for the crystal packing are from H⋯H (43.0%), H⋯C/C⋯H (25.0%) and H⋯O/O⋯H (22.8%) interactions. Hydrogen bonding and van der Waals interactions are the dominant interactions in the crystal packing. The volume of the crystal voids and the percentage of free space were calculated to be 120.52 Å3 and 9.64%, respectively, showing that there is no large cavity in the crystal packing. Evaluation of the electrostatic, dispersion and total energy frameworks indicate that the stabilization is dominated by the dispersion energy contributions in the title compound. Moreover, the DFT-optimized structure at the B3LYP/6-311G(d,p) level is compared with the experimentally determined molecular structure in the solid state. Full Article text