rom US Experts: Uranium Enrichment Facility Images Released by N. Korea Differs from that of 2010 By world.kbs.co.kr Published On :: Thu, 19 Sep 2024 17:55:20 +0900 [Science] : Two U.S. experts who inspected North Korea’s uranium enrichment facility at the Yongbyon nuclear complex in 2010 have analyzed recent images of a similar facility in the North and pointed out differences. Stanford University professor emeritus Siegfried Hecker and Robert Carlin, a scholar at the ...[more...] Full Article Science
rom S. Korea’s Telecom Satellite Koreasat-6A Launched from US Space Center By world.kbs.co.kr Published On :: Tue, 12 Nov 2024 09:48:52 +0900 [Science] : A telecommunication satellite from the South Korean telecom giant KT has been launched into space and is now in orbit. According to a launch video from SpaceX, the Koreasat-6A, a geostationary satellite for communication services, was launched aboard SpaceX’s Falcon 9 rocket from the Kennedy Space ...[more...] Full Article Science
rom Navy Flies Fixed-Wing Drone from Vessel for First Time By world.kbs.co.kr Published On :: Wed, 13 Nov 2024 13:47:24 +0900 [Politics] : The Navy flew a fixed-wing drone from one of its vessels for the first time as part of its efforts to advance technology for unmanned aerial vehicles. The Navy said a prototype of the Mojave drone, developed by the U.S. firm General Atomics Aeronautical Systems, took off Tuesday from the 14-thousand-ton ...[more...] Full Article Politics
rom J-Hope of BTS to be Discharged from Army Thursday By world.kbs.co.kr Published On :: Mon, 14 Oct 2024 18:44:12 +0900 [Culture] : J-Hope of K-pop sensation BTS will complete his 18 months of mandatory military service and be discharged from the Army on Thursday. The singer’s agency, BigHit Music, revealed the date on Monday in the group’s fan community platform, saying no event will be held to mark the occasion while urging ...[more...] Full Article Culture
rom Seoul City Campaigns to Promote Standardized Korean Dish Names in Foreign Languages By world.kbs.co.kr Published On :: Thu, 24 Oct 2024 15:27:03 +0900 [Culture] : The Seoul Metropolitan Government will run a campaign to promote standardized naming of Korean dishes in foreign languages. According to city officials on Thursday, the campaign, in cooperation with the Seoul Tourism Organization and the Korea Food Service Industry Association, is set to continue through ...[more...] Full Article Culture
rom What Exactly Is Jell-O Made From? By recipes.howstuffworks.com Published On :: Fri, 29 Mar 2024 11:15:12 -0400 "Watch it wiggle, see it jiggle" Remember that jingle? We're talking about Jell-O, or gelatin. But just how does how does it do that? And what is this stuff made of? Full Article
rom Stromboli vs. Calzone: Different Branches of Pizza Lineage By recipes.howstuffworks.com Published On :: Mon, 08 Apr 2024 11:30:33 -0400 Ordering a stromboli vs. calzone is a matter of personal preference, but the difference between them is clear. One is folded in half like an apple turnover, and the other is rolled up like a jelly roll cake. Full Article
rom How to Remove Deodorant Stains From Clothing By home.howstuffworks.com Published On :: Tue, 23 Jan 2024 17:35:32 -0500 You've noticed that your deodorant leaves stains on your shirt and you don't know how to take the deodorant out of your clothing. Well have no fear, you're at the right spot to learn how. Full Article
rom How to Export Bookmarks From Chrome By computer.howstuffworks.com Published On :: Wed, 29 May 2024 12:43:11 -0400 You love your Chrome browser bookmarks but your computer is on the verge of dying. Is there any way you can save them so they appear on your new computer? Full Article
rom How to Create Your Own Podcast: From Concept to Launch By computer.howstuffworks.com Published On :: Thu, 25 Jul 2024 10:14:02 -0400 Podcasting may be the ultimate democratization of radio. Anyone with an Internet connection and some inexpensive audio equipment can produce their own podcast and make it available online. Full Article
rom Extracting formation temperatures from stalagmites - British Geological Survey By news.google.com Published On :: Wed, 14 Aug 2024 07:00:00 GMT Extracting formation temperatures from stalagmites British Geological Survey Full Article
rom Studying multi-hazards from space - British Geological Survey By news.google.com Published On :: Fri, 31 May 2024 08:09:03 GMT Studying multi-hazards from space British Geological Survey Full Article
rom Monitoring coastal change from space - British Geological Survey By news.google.com Published On :: Thu, 10 Oct 2024 14:36:15 GMT Monitoring coastal change from space British Geological Survey Full Article
rom Electromagnetic geophysics in Japan: a conference experience - British Geological Survey By news.google.com Published On :: Wed, 23 Oct 2024 07:00:00 GMT Electromagnetic geophysics in Japan: a conference experience British Geological Survey Full Article
rom 2-Amino-5-oxo-4-(thiophen-2-yl)-5,6,7,8-tetrahydro-4H-chromene-3-carbonitrile By journals.iucr.org Published On :: In the crystal structure of the title compound, intermolecular N—H⋯N and N—H⋯O hydrogen bonds form a two-dimensional supramolecular network along the ac plane, contributing to the cohesion of the crystal. Full Article text
rom From `crystallographic accuracy' to `thermodynamic accuracy': a redetermination of the crystal structure of calcium atorvastatin trihydrate (Lipitor®) By journals.iucr.org Published On :: The crystal structure of calcium atorvastatin trihydrate was redetermined from previously published synchrotron powder diffraction data to give a much-improved agreement with two independent density-functional theory calculations. Full Article text
rom Atypical phase transition, twinning and ferroelastic domain structure in bis(ethylenediammonium) tetrabromozincate(II) bromide, [NH3(CH2)2NH3]2[ZnBr4]Br2 By journals.iucr.org Published On :: A unique phase transition, twinning and ferroelastic domain structure in [NH3(CH2)2NH3]2[ZnBr4]Br2 is found. The new additional domain structure is observed at the phase transition on heating, which is preserved after cooling to room temperature. Full Article text
rom Morphological control for hollow rod crystals of a photochromic diarylethene on spherulites by surface properties of substrates By journals.iucr.org Published On :: 1,2-Bis(3,5-dimethyl-2-thienyl)perfluorocyclopentene formed its own spherulites by sublimation onto the hydrophilic surfaces of the (0001) planes of α-quartz and sapphire substrates. The formation of different morphologies of these spherulites was attributed to the surface properties of each substrate. Depending on the morphology of the spherulites, hollow rod crystals with cross sections of different sizes and shapes and branching structures were generated on the surfaces of the spherulites. Full Article text
rom Crystal structure predictions for molecules with soft degrees of freedom using intermonomer force fields derived from first principles By journals.iucr.org Published On :: Full Article text
rom Atypical phase transition, twinning and ferroelastic domain structure in bis(ethylenediammonium) tetrabromozincate(II) bromide, [NH3(CH2)2NH3]2[ZnBr4]Br2 By journals.iucr.org Published On :: 2024-11-04 Single-crystal growth, differential thermal analysis (DTA), derivative thermogravimetry (DTG), differential scanning calorimetry (DSC), X-ray structural studies and polarized microscopy observations of bis(ethylenediammonium) tetrabromozincate(II) bromide [NH3(CH2)2NH3]2[ZnBr4]Br2 are presented. A reversible phase transition is described. At room temperature, the complex crystallizes in the monoclinic system. In some cases, the single crystals are twinned into two or more large domains of ferroelastic type with domain walls in the (100) crystallographic plane. DTA and DTG measurements show chemical stability of the crystal up to ∼538 K. In the DSC studies, a reversible isostructural phase transition was revealed at ∼526/522 K on heating/cooling run, respectively. Optical observation on the heating run reveals that at the phase transition the plane of twinning (domain wall) does not disappear and additionally the appearance of a new domain structure of ferroelastic type with domain walls in the planes (101), (101), (100) and (001) is observed. The domain structure pattern is preserved after cooling to the room-temperature phase and the symmetry of this phase is unchanged. Full Article text
rom Morphological control for hollow rod crystals of a photochromic diarylethene on spherulites by surface properties of substrates By journals.iucr.org Published On :: 2024-10-31 Sublimation methods utilizing the surface properties of substrates can address the challenge of controlling hollow morphologies in rod crystals. Spherulites were formed on the hydrophilic surface of the (0001) planes of α-quartz and sapphire substrates by sublimation of 1,2-bis(3,5-dimethyl-2-thienyl)perfluorocyclopentene (1a). Various types of hollow morphologies, distinguished by the size and shape of their cross sections and by the presence or absence of branching structures, were formed separately on α-quartz and sapphire substrates. Such precise control of the hollow morphologies was attributed to the wettability of each substrate, leading to the formation of spherulites of 1a. In addition, it was indicated that the formation process of the surface morphologies of spherulites was associated with the hollow morphologies of rod crystals of 1a. Full Article text
rom From `crystallographic accuracy' to `thermodynamic accuracy': a redetermination of the crystal structure of calcium atorvastatin trihydrate (Lipitor®) By journals.iucr.org Published On :: 2024-10-08 With ever-improving quantum-mechanical computational methods, the accuracy requirements for experimental crystal structures increase. The crystal structure of calcium atorvastatin trihydrate, which has 56 degrees of freedom when determined with a real-space algorithm, was determined from powder diffraction data by Hodge et al. [Powder Diffr. (2020), 35, 136–143]. The crystal structure was a good fit to the experimental data, indicating that the electron density had been captured essentially correctly, but two independent quantum-mechanical calculations disagreed with the experimental structure and with each other. Using the same experimental data, the crystal structure was redetermined from scratch and it was shown that it can be reproduced within a root-mean-square Cartesian displacement of 0.1 Å by two independent quantum-mechanical calculations. The consequences for the calculated energies and solubilities are described. Full Article text
rom Crystal structures of three uranyl–acetate–bipyridine complexes crystallized from hydraulic fracking fluid By journals.iucr.org Published On :: 2024-01-01 Hydraulic fracking exposes shale plays to acidic hydraulic fracking fluid (HFF), releasing toxic uranium (U) along with the desired oil and gas. With no existing methods to ensure U remains sequestered in the shale, this study sought to add organic ligands to HFF to explore potential U retention in shale plays. To test this possibility, incubations were set up in which uranyl acetate and one organic bipyridine ligand (either 2,2'-, 2,3'-, 2,4'-, or 4,4'-bipyridine) were added to pristine HFF as the crystallization medium. After several months and complete evaporation of all volatiles, bulk yellow crystalline material was obtained from the incubations, three of which yielded crystals suitable for single-crystal analysis, resulting in two novel structures and a high-quality structure of a previously described compound. The UO2VI acetate complexes bis(acetato-κ2O,O')(2,2'-bipyridine-κ2N,N')dioxidouranium(VI), [U(C2H3O2)2O2(C10H8N2)2] or [2,2'-bipyridine]UVIO2(CH3CO2)2, (I), and bis(acetato-κ2O,O')(2,4'-bipyridine-κN1')dioxidouranium(VI), [U(C2H3O2)2O2(C10H8N2)2] or [2,4'-bipyridine]2UVIO2(CH3CO2)2, (III), contain eight-coordinate UVI in a pseudo-hexagonal bipyramidal coordination geometry and are molecular, packing via weak C—H...O/N interactions, whereas catena-poly[bis(2,3'-bipyridinium) [di-μ-acetato-μ3-hydroxido-μ-hydroxido-di-μ3-oxido-hexaoxidotriuranium(VI)]–2,3'-bipyridine–water (1/1/1)], (C10H9N2)2[U3(C2H3O2)2O8(OH)2]·C10H8N2·H2O or {[2,3'-bipyridinium]2[2,3'-bipyridine][(UVIO2)3(O)2(OH)2(CH3CO2)2·H2O]}n, (II), forms an ionic one-dimensional polymer with seven-coordinate pentagonal bipyramidal UVI centers and hydrogen-bonding interactions within each chain. The formation of these crystals could indicate the potential for bipyridine to bind with U in shale during fracking, which will be explored in a future study via ICP-MS (inductively coupled plasma mass spectrometry) analyses of U concentration in HFF/bipyridine/shale incubations. The variation seen here between the molecular structures may indicate variance in the ability of bipyridine isomers to form complexes with U, which could impact their ability to retain U within shale in the context of fracking. Full Article text
rom ClusterFinder: a fast tool to find cluster structures from pair distribution function data By journals.iucr.org Published On :: 2024-02-29 A novel automated high-throughput screening approach, ClusterFinder, is reported for finding candidate structures for atomic pair distribution function (PDF) structural refinements. Finding starting models for PDF refinements is notoriously difficult when the PDF originates from nanoclusters or small nanoparticles. The reported ClusterFinder algorithm can screen 104 to 105 candidate structures from structural databases such as the Inorganic Crystal Structure Database (ICSD) in minutes, using the crystal structures as templates in which it looks for atomic clusters that result in a PDF similar to the target measured PDF. The algorithm returns a rank-ordered list of clusters for further assessment by the user. The algorithm has performed well for simulated and measured PDFs of metal–oxido clusters such as Keggin clusters. This is therefore a powerful approach to finding structural cluster candidates in a modelling campaign for PDFs of nanoparticles and nanoclusters. Full Article text
rom Structure of the outer membrane porin OmpW from the pervasive pathogen Klebsiella pneumoniae By journals.iucr.org Published On :: 2024-01-01 Conjugation is the process by which plasmids, including those that carry antibiotic-resistance genes, are mobilized from one bacterium (the donor) to another (the recipient). The conjugation efficiency of IncF-like plasmids relies on the formation of mating-pair stabilization via intimate interactions between outer membrane proteins on the donor (a plasmid-encoded TraN isoform) and recipient bacteria. Conjugation of the R100-1 plasmid into Escherichia coli and Klebsiella pneumoniae (KP) recipients relies on pairing between the plasmid-encoded TraNα in the donor and OmpW in the recipient. Here, the crystal structure of K. pneumoniae OmpW (OmpWKP) is reported at 3.2 Å resolution. OmpWKP forms an eight-stranded β-barrel flanked by extracellular loops. The structures of E. coli OmpW (OmpWEC) and OmpWKP show high conservation despite sequence variability in the extracellular loops. Full Article text
rom Expression, purification and crystallization of the photosensory module of phytochrome B (phyB) from Sorghum bicolor By journals.iucr.org Published On :: 2024-02-20 Sorghum, a short-day tropical plant, has been adapted for temperate grain production, in particular through the selection of variants at the MATURITY loci (Ma1–Ma6) that reduce photoperiod sensitivity. Ma3 encodes phytochrome B (phyB), a red/far-red photochromic biliprotein photoreceptor. The multi-domain gene product, comprising 1178 amino acids, autocatalytically binds the phytochromobilin chromophore to form the photoactive holophytochrome (Sb.phyB). This study describes the development of an efficient heterologous overproduction system which allows the production of large quantities of various holoprotein constructs, along with purification and crystallization procedures. Crystals of the Pr (red-light-absorbing) forms of NPGP, PGP and PG (residues 1–655, 114–655 and 114–458, respectively), each C-terminally tagged with His6, were successfully produced. While NPGP crystals did not diffract, those of PGP and PG diffracted to 6 and 2.1 Å resolution, respectively. Moving the tag to the N-terminus and replacing phytochromobilin with phycocyanobilin as the ligand produced PG crystals that diffracted to 1.8 Å resolution. These results demonstrate that the diffraction quality of challenging protein crystals can be improved by removing flexible regions, shifting fusion tags and altering small-molecule ligands. Full Article text
rom Preliminary X-ray diffraction and ligand-binding analyses of the N-terminal domain of hypothetical protein Rv1421 from Mycobacterium tuberculosis H37Rv By journals.iucr.org Published On :: 2024-06-27 Mycobacterium tuberculosis can reside and persist in deep tissues; latent tuberculosis can evade immune detection and has a unique mechanism to convert it into active disease through reactivation. M. tuberculosis Rv1421 (MtRv1421) is a hypothetical protein that has been proposed to be involved in nucleotide binding-related metabolism in cell-growth and cell-division processes. However, due to a lack of structural information, the detailed function of MtRv1421 remains unclear. In this study, a truncated N-terminal domain (NTD) of MtRv1421, which contains a Walker A/B-like motif, was purified and crystallized using PEG 400 as a precipitant. The crystal of MtRv1421-NTD diffracted to a resolution of 1.7 Å and was considered to belong to either the C-centered monoclinic space group C2 or the I-centered orthorhombic space group I222, with unit-cell parameters a = 124.01, b = 58.55, c = 84.87 Å, β = 133.12° or a = 58.53, b = 84.86, c = 90.52 Å, respectively. The asymmetric units of the C2 or I222 crystals contained two or one monomers, respectively. In terms of the binding ability of MtRv1421-NTD to various ligands, uridine diphosphate (UDP) and UDP-N-acetylglucosamine significantly increased the melting temperature of MtRv1421-NTD, which indicates structural stabilization through the binding of these ligands. Altogether, the results reveal that a UDP moiety may be required for the interaction of MtRv1421-NTD as a nucleotide-binding protein with its ligand. Full Article text
rom The structure of a pectin-active family 1 polysaccharide lyase from the marine bacterium Pseudoalteromonas fuliginea By journals.iucr.org Published On :: 2024-06-27 Pseudoalteromonas fuliginea sp. PS47 is a recently identified marine bacterium that has extensive enzymatic machinery to metabolize polysaccharides, including a locus that targets pectin-like substrates. This locus contains a gene (locus tag EU509_03255) that encodes a pectin-degrading lyase, called PfPL1, that belongs to polysaccharide lyase family 1 (PL1). The 2.2 Å resolution X-ray crystal structure of PfPL1 reveals the compact parallel β-helix fold of the PL1 family. The back side of the core parallel β-helix opposite to the active site is a meandering set of five α-helices joined by lengthy loops. A comparison of the active site with those of other PL1 enzymes suggests a catalytic mechanism that is independent of metal ions, such as Ca2+, but that substrate recognition may require metal ions. Overall, this work provides the first structural insight into a pectinase of marine origin and the first structure of a PL1 enzyme in subfamily 2. Full Article text
rom Crystallographic fragment screen of the c-di-AMP-synthesizing enzyme CdaA from Bacillus subtilis By journals.iucr.org Published On :: 2024-08-23 Crystallographic fragment screening has become a pivotal technique in structure-based drug design, particularly for bacterial targets with a crucial role in infectious disease mechanisms. The enzyme CdaA, which synthesizes an essential second messenger cyclic di-AMP (c-di-AMP) in many pathogenic bacteria, has emerged as a promising candidate for the development of novel antibiotics. To identify crystals suitable for fragment screening, CdaA enzymes from Streptococcus pneumoniae, Bacillus subtilis and Enterococcus faecium were purified and crystallized. Crystals of B. subtilis CdaA, which diffracted to the highest resolution of 1.1 Å, were used to perform the screening of 96 fragments, yielding data sets with resolutions spanning from 1.08 to 1.87 Å. A total of 24 structural hits across eight different sites were identified. Four fragments bind to regions that are highly conserved among pathogenic bacteria, specifically the active site (three fragments) and the dimerization interface (one fragment). The coordinates of the three active-site fragments were used to perform an in silico drug-repurposing screen using the OpenEye suite and the DrugBank database. This screen identified tenofovir, an approved drug, that is predicted to interact with the ATP-binding region of CdaA. Its inhibitory potential against pathogenic E. faecium CdaA has been confirmed by ITC measurements. These findings not only demonstrate the feasibility of this approach for identifying lead compounds for the design of novel antibacterial agents, but also pave the way for further fragment-based lead-optimization efforts targeting CdaA. Full Article text
rom Glucose-6-phosphate dehydrogenase and its 3D structures from crystallography and electron cryo-microscopy By journals.iucr.org Published On :: 2024-09-11 Glucose-6-phosphate dehydrogenase (G6PD) is the first enzyme in the pentose phosphate pathway. It has been extensively studied by biochemical and structural techniques. 13 X-ray crystal structures and five electron cryo-microscopy structures in the PDB are focused on in this topical review. Two F420-dependent glucose-6-phosphate dehydrogenase (FGD) structures are also reported. The significant differences between human and parasite G6PDs can be exploited to find selective drugs against infections such as malaria and leishmaniasis. Furthermore, G6PD is a prognostic marker in several cancer types and is also considered to be a tumour target. On the other hand, FGD is considered to be a target against Mycobacterium tuberculosis and possesses a high biotechnological potential in biocatalysis and bioremediation. Full Article text
rom First crystal structure of the DUF2436 domain of virulence proteins from Porphyromonas gingivalis By journals.iucr.org Published On :: 2024-09-26 Porphyromonas gingivalis is a major pathogenic oral bacterium that is responsible for periodontal disease. It is linked to chronic periodontitis, gingivitis and aggressive periodontitis. P. gingivalis exerts its pathogenic effects through mechanisms such as immune evasion and tissue destruction, primarily by secreting various factors, including cysteine proteases such as gingipain K (Kgp), gingipain R (RgpA and RgpB) and PrtH (UniProtKB ID P46071). Virulence proteins comprise multiple domains, including the pro-peptide region, catalytic domain, K domain, R domain and DUF2436 domain. While there is a growing database of knowledge on virulence proteins and domains, there was no prior evidence or information regarding the structure and biological function of the well conserved DUF2436 domain. In this study, the DUF2436 domain of PrtH from P. gingivalis (PgDUF2436) was determined at 2.21 Å resolution, revealing a noncanonical β-jelly-roll sandwich topology with two antiparallel β-sheets and one short α-helix. Although the structure of PgDUF2436 was determined by the molecular-replacement method using an AlphaFold model structure as a template, there were significant differences in the positions of β1 between the AlphaFold model and the experimentally determined PgDUF2436 structure. The Basic Local Alignment Search Tool sequence-similarity search program showed no sequentially similar proteins in the Protein Data Bank. However, DaliLite search results using structure-based alignment revealed that the PgDUF2436 structure has structural similarity Z-scores of 5.9–5.4 with the C-terminal domain of AlgF, the D4 domain of cytolysin, IglE and the extracellular domain structure of PepT2. This study has elucidated the structure of the DUF2436 domain for the first time and a comparative analysis with similar structures has been performed. Full Article text
rom Crystal structure of guanosine 5'-monophosphate synthetase from the thermophilic bacterium Thermus thermophilus HB8 By journals.iucr.org Published On :: 2024-09-18 Guanosine 5'-monophosphate (GMP) synthetase (GuaA) catalyzes the last step of GMP synthesis in the purine nucleotide biosynthetic pathway. This enzyme catalyzes a reaction in which xanthine 5'-monophosphate (XMP) is converted to GMP in the presence of Gln and ATP through an adenyl-XMP intermediate. A structure of an XMP-bound form of GuaA from the domain Bacteria has not yet been determined. In this study, the crystal structure of an XMP-bound form of GuaA from the thermophilic bacterium Thermus thermophilus HB8 (TtGuaA) was determined at a resolution of 2.20 Å and that of an apo form of TtGuaA was determined at 2.10 Å resolution. TtGuaA forms a homodimer, and the monomer is composed of three domains, which is a typical structure for GuaA. Disordered regions in the crystal structure were obtained from the AlphaFold2-predicted model structure, and a model with substrates (Gln, XMP and ATP) was constructed for molecular-dynamics (MD) simulations. The structural fluctuations of the TtGuaA dimer as well as the interactions between the active-site residues were analyzed by MD simulations. Full Article text
rom X-ray crystal structure of proliferating cell nuclear antigen 1 from Aeropyrum pernix By journals.iucr.org Published On :: 2024-10-09 Proliferating cell nuclear antigen (PCNA) plays a critical role in DNA replication by enhancing the activity of various proteins involved in replication. In this study, the crystal structure of ApePCNA1, one of three PCNAs from the thermophilic archaeon Aeropyrum pernix, was elucidated. ApePCNA1 was cloned and expressed in Escherichia coli and the protein was purified and crystallized. The resulting crystal structure determined at 2.00 Å resolution revealed that ApePCNA1 does not form a trimeric ring, unlike PCNAs from other domains of life. It has unique structural features, including a long interdomain-connecting loop and a PIP-box-like sequence at the N-terminus, indicating potential interactions with other proteins. These findings provide insights into the functional mechanisms of PCNAs in archaea and their evolutionary conservation across different domains of life. A modified medium and protocol were used to express recombinant protein containing the lac operon. The expression of the target protein increased and the total incubation time decreased when using this system compared with those of previous expression protocols. Full Article text
rom Exploiting Friedel pairs to interpret scanning 3DXRD data from complex geological materials By journals.iucr.org Published On :: A new processing technique for synchrotron scanning 3D X-ray diffraction data is introduced, utilizing symmetric Bragg reflections hkl and hkl, known as Friedel pairs. This technique is designed to tackle the difficulties associated with large, highly deformed, polyphase materials, especially geological samples. Full Article text
rom Towards expansion of the MATTS data bank with heavier elements: the influence of the wavefunction basis set on the multipole model derived from the wavefunction By journals.iucr.org Published On :: This study examines the quality of charge density obtained by fitting the multipole model to wavefunctions in different basis sets. The complex analysis reveals that changing the basis set quality from double- to triple-zeta can notably improve the charge density related properties of a multipole model. Full Article text
rom Small-angle scattering and dark-field imaging for validation of a new neutron far-field interferometer By journals.iucr.org Published On :: A neutron far-field interferometer is under development at NIST with the aim of enabling a multi-scale measurement combining the best of small-angle neutron scattering (SANS) and neutron imaging and tomography. We use the close relationship between SANS, ultra-SANS, spin-echo SANS and dark-field imaging and measurements of monodisperse spheres as a validation metric, highlighting the strengths and weaknesses of each of these neutron techniques. Full Article text
rom Optimal operation guidelines for direct recovery of high-purity precursor from spent lithium-ion batteries: hybrid operation model of population balance equation and data-driven classifier By journals.iucr.org Published On :: This study proposes an operation optimization framework for impurity-free recycling of spent lithium-ion batteries. Using a hybrid population balance equation integrated with a data-driven condition classifier, the study firstly identifies the optimal batch and semi-batch operation conditions that significantly reduce the operation time with 100% purity of product; detailed guidelines are given for industrial applications. Full Article text
rom Effect of thickness and noise on angular correlation analysis from scanning electron nanobeam diffraction of disordered carbon By journals.iucr.org Published On :: The impact of sample thickness and experimental noise on angular correlation analysis from scanning electron nanobeam diffraction patterns of disordered carbon are investigated and analyzed regarding the interpretability of the analysis results. Full Article text
rom Crystal structure, Hirshfeld surface analysis, DFT and molecular docking studies of ethyl 5-amino-2-bromoisonicotinate By journals.iucr.org Published On :: Theoretical and experimental structural studies of the title compound were undertaken using X-ray and DFT methods. The interactions present in the crystal were analyzed using Hirshfeld surface and MEP surface analysis. Docking studies with a covid-19 main protease (PDB ID: 6LU7) as the target receptor indicate that the synthesized compound may be a potential candidate for pharmaceutical applications. Full Article text
rom Crystal structure of a solvated dinuclear CuII complex derived from 3,3,3',3'-tetraethyl-1,1'-(furan-2,5-dicarbonyl)bis(thiourea) By journals.iucr.org Published On :: In the title compound, [Cu2(L)2]·2CH2Cl2, the CuII ions coordinate two (S,O)-chelating aroylthiourea moieties of doubly deprotonated furan-2,5-dicarbonylbis(N,N-diethylthiourea) (H2L) ligands. The coordination geometry of the metal centers is best described as a flat isosceles trapezoid with a cis arrangement of the donor atoms. Full Article text
rom 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 :: Crystallization of the title compound 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. Full Article text
rom Crystal structure, Hirshfeld surface, DFT and molecular docking studies of 2-{4-[(E)-(4-acetylphenyl)diazenyl]phenyl}-1-(5-bromothiophen-2-yl)ethanone; a bromine⋯oxygen type contact By journals.iucr.org Published On :: The title compound is a non-liquid crystal molecule. The molecular crystal is consolidated by C—Br⋯O&z-dbnd;C type contacts running continuously along the [001] direction. Full Article text
rom Small-angle scattering and dark-field imaging for validation of a new neutron far-field interferometer By journals.iucr.org Published On :: 2024-11-08 The continued advancement of complex materials often requires a deeper understanding of the structure–function relationship across many length scales, which quickly becomes an arduous task when multiple measurements are required to characterize hierarchical and inherently heterogeneous materials. Therefore, there are benefits in the simultaneous characterization of multiple length scales. At the National Institute of Standards and Technology, a new neutron far-field interferometer is under development that aims to enable a multi-scale measurement combining the best of small-angle neutron scattering (SANS) and neutron imaging and tomography. Spatially resolved structural information on the same length scales as SANS (0.001–1 µm) and ultra-small-angle neutron scattering (USANS, 0.1–10 µm) will be collected via dark-field imaging simultaneously with regular attenuation radiography (>10 µm). The dark field is analogous to the polarization loss measured in spin-echo SANS (SESANS) and is related to isotropic SANS through a Hankel transform. Therefore, we use this close relationship and analyze results from SANS, USANS, SESANS and dark-field imaging of monodisperse spheres as a validation metric for the interferometry measurements. The results also highlight the strengths and weaknesses of these neutron techniques for both steady-state and pulsed neutron sources. Finally, we present an example of the value added by the spatial resolution enabled by dark-field imaging in the study of more complex heterogeneous materials. This information would otherwise be lost in other small-angle scattering measurements averaged over the sample. Full Article text
rom Exploiting Friedel pairs to interpret scanning 3DXRD data from complex geological materials By journals.iucr.org Published On :: 2024-11-08 The present study introduces a processing strategy for synchrotron scanning 3D X-ray diffraction (s3DXRD) data, aimed at addressing the challenges posed by large, highly deformed, polyphase materials such as crystalline rocks. Leveraging symmetric Bragg reflections known as Friedel pairs, our method enables diffraction events to be precisely located within the sample volume. This method allows for fitting the phase, crystal structure and unit-cell parameters at the intra-grain scale on a voxel grid. The processing workflow incorporates several new modules, designed to (i) efficiently match Friedel pairs in large s3DXRD datasets containing up to 108 diffraction peaks; (ii) assign phases to each pixel or voxel, resolving potential ambiguities arising from overlap in scattering angles between different crystallographic phases; and (iii) fit the crystal orientation and unit cell locally on a point-by-point basis. We demonstrate the effectiveness of our technique on fractured granite samples, highlighting the ability of the method to characterize complex geological materials and show their internal structure and mineral composition. Additionally, we include the characterization of a metal gasket made of a commercial aluminium alloy, which surrounded the granite sample during experiments. The results show the effectiveness of the technique in recovering information about the internal texture and residual strain of materials that have undergone high levels of plastic deformation. Full Article text
rom Periodic diffraction from an aperiodic monohedral tiling – the Spectre tiling. Addendum By journals.iucr.org Published On :: 2024-10-08 This article describes the diffraction pattern (2-periodic Fourier transform) from the vertices of a large patch of the recently discovered `Spectre' tiling – a strictly chiral aperiodic monotile. It was reported recently that the diffraction pattern of the related weakly chiral aperiodic `Hat' monotile was 2-periodic with chiral plane-group symmetry p6 [Kaplan et al. (2024). Acta Cryst. A80, 72–78]. The diffraction periodicity arises because the Hat tiling is a systematic aperiodic deletion of vertices from the 2-periodic hexagonal mta tiling. Despite the similarity of the Hat and Spectre tilings, the Spectre tiling is not aligned with a 2-periodic lattice, and its diffraction pattern is non-periodic with chiral point symmetry 6 about the origin. Full Article text
rom 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
rom Crystal structure, Hirshfeld surface analysis, DFT and molecular docking studies of ethyl 5-amino-2-bromoisonicotinate By journals.iucr.org Published On :: 2024-11-08 In the title compound, C8H9BrN2O2, the C—O—C—C torsion angle between isonicotine and the ethyl group is 180.0 (2)°. Intramolecular N—H...O and C—H...O interactions consolidate the molecular structure. In the crystal, N—H...N interaction form S(5) zigzag chains along [010]. The most significant contributions to the Hirshfeld surface arise from H...H (33.2%), Br...H/H...Br (20.9%), O...H/H...O (11.2%), C...H/H...C (11.1%) and N...H/H...N (10%) contacts. The topology of the three-dimensional energy frameworks was generated using the B3LYP/6–31 G(d,p) model to calculate the total interaction energy. The net interaction energies for the title compound are Eele = 59.2 kJ mol−1, Epol = 15.5 kJ mol−1, Edis = 140.3 kJ mol−1 and Erep = 107.2 kJ mol−1 with a total interaction energy Etot of 128.8 kJ mol−1. The molecular structure was optimized by density functional theory (DFT) at the B3LYP/6–311+G(d,p) level and the theoretical and experimentally obtained parameters were compared. The frontier molecular orbitals HOMO and LUMO were generated, giving an energy gap ΔE of 4.0931 eV. The MEP was generated to identify active sites in the molecule and molecular docking studies carried out with the title compound (ligand) and the covid-19 main protease PDB ID: 6LU7, revealing a moderate binding affinity of −5.4 kcal mol−1. Full Article text
rom Crystal structure of a solvated dinuclear CuII complex derived from 3,3,3',3'-tetraethyl-1,1'-(furan-2,5-dicarbonyl)bis(thiourea) By journals.iucr.org Published On :: 2024-11-08 Reaction between equimolar amounts of 3,3,3',3'-tetraethyl-1,1'-(furan-2,5-dicarbonyl)bis(thiourea) (H2L) and CuCl2·2H2O in methanol in the presence of the supporting base Et3N gave rise to a neutral dinuclear complex bis[μ-3,3,3',3'-tetraethyl-1,1'-(furan-2,5-dicarbonyl)bis(thioureato)]dicopper(II) dichloromethane disolvate, [Cu2(C16H22N4O3S2)2]·2CH2Cl2 or [Cu2(L)2]·2CH2Cl2. The aroylbis(thioureas) are doubly deprotonated and the resulting anions {L2–} bond to metal ions through (S,O)-chelating moieties. The copper atoms adopt a virtually cis-square-planar environment. In the crystal, adjacent [Cu2(L)2]·2CH2Cl2 units are linked into polymeric chains along the a-axis direction by intermolecular coordinative Cu...S interactions. The co-crystallized solvent molecules play a vital role in the crystal packing. In particular, weak C—Hfuran...Cl and C—Hethyl...Cl contacts consolidate the three-dimensional supramolecular architecture. Full Article text
rom Angle-resolved X-ray emission spectroscopy facility realized by an innovative spectrometer rotation mechanism at SPring-8 BL07LSU By journals.iucr.org Published On :: 2024-02-01 The X-ray emission spectrometer at SPring-8 BL07LSU has recently been upgraded with advanced modifications that enable the rotation of the spectrometer with respect to the scattering angle. This major upgrade allows the scattering angle to be flexibly changed within the range of 45–135°, which considerably simplifies the measurement of angle-resolved X-ray emission spectroscopy. To accomplish the rotation system, a sophisticated sample chamber and a highly precise spectrometer rotation mechanism have been developed. The sample chamber has a specially designed combination of three rotary stages that can smoothly move the connection flange along the wide scattering angle without breaking the vacuum. In addition, the spectrometer is rotated by sliding on a flat metal surface, ensuring exceptionally high accuracy in rotation and eliminating the need for any further adjustments during rotation. A control system that integrates the sample chamber and rotation mechanism to automate the measurement of angle-resolved X-ray emission spectroscopy has also been developed. This automation substantially streamlines the process of measuring angle-resolved spectra, making it far easier than ever before. Furthermore, the upgraded X-ray emission spectrometer can now also be utilized in diffraction experiments, providing even greater versatility to our research capabilities. Full Article text
rom Combination of XEOL, TR-XEOL and HB-T interferometer at the TPS 23A X-ray nanoprobe for exploring quantum materials By journals.iucr.org Published On :: 2024-01-19 In this study, a combination of X-ray excited optical luminescence (XEOL), time-resolved XEOL (TR-XEOL) and the Hanbury-Brown and Twiss (HB-T) interferometer at the Taiwan Photon Source (TPS) 23A X-ray nanoprobe beamline for exploring quantum materials is demonstrated. On the basis of the excellent spatial resolution rendered using a nano-focused beam, emission distributions of artificial micro-diamonds can be obtained by XEOL maps, and featured emission peaks of a selected local area can be obtained by XEOL spectra. The hybrid bunch mode of the TPS not only provides a sufficiently high peak power density for experiments at each beamline but also permits high-quality temporal domain (∼200 ns) measurements for investigating luminescence dynamics. From TR-XEOL measurements, the decay lifetime of micro-diamonds is determined to be approximately 16 ns. Furthermore, the XEOL spectra of artificial micro-diamonds can be investigated by the HB-T interferometer to identify properties of single-photon sources. The unprecedented strategy of combining XEOL, TR-XEOL and the HB-T interferometer at the X-ray nanoprobe beamline will open new avenues with significant characterization abilities for unraveling the emission mechanisms of single-photon sources for quantum materials. Full Article text