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.

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.

The article presents a non-invasive nanoscale imaging technique that can be used in screening crystallization conditions for protein micro- and nanocrystals.

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.

In this work, Ce-doped yttria-stabilized zirconia (YSZ) and pure YSZ phases were subjected to irradiation with 14 MeV Au ions. Irradiation studies were performed to simulate long-term structural and microstructural damage due to self-irradiation in YSZ phases hosting alpha-active radioactive species. It was found that both the Ce-doped YSZ and the YSZ phases had a reasonable tolerance to irradiation at high ion fluences and the bulk crystallinity was well preserved. Nevertheless, local microstrain increased in all compounds under study after irradiation, with the Ce-doped phases being less affected than pure YSZ. Doping with cerium ions increased the microstructural stability of YSZ phases through a possible reduction in the mobility of oxygen atoms, which limits the formation of structural defects. Doping of YSZ with tetravalent actinide elements is expected to have a similar effect. Thus, YSZ phases are promising for the safe long-term storage of radioactive elements. Using synchrotron radiation diffraction, measurements of the thin irradiated layers of the Ce-YSZ and YSZ samples were performed in grazing incidence (GI) mode. A corresponding module for measurements in GI mode was developed at the Rossendorf Beamline and relevant technical details for sample alignment and data collection are also presented.

The normalization of X-ray absorption near-edge structure (XANES) spectra is required for comparing spectral features and extracting quantitative information in analytical techniques such as linear combination analysis, principal component analysis and multivariate curve resolution. Most published data are normalized to the edge-jump, but normalization to the spectral area has also been applied. The latter is particularly attractive if only a small energy range around the absorption can be recorded reliably. Here, the two normalization methods are compared at the L3-edge of Pt, Pd and Rh, and at the Ni K-edge using experimental and calculated spectra. Normalization to the spectral area is found to be a viable approach if the range for the area normalization is sufficiently large.

Using a 1:1 cocrystal of (E)-N-(3,4-di­fluoro­phen­yl)-1-(pyridin-4-yl)methanimine with acetic acid, C12H8F2N2·C2H4O2, we investigate the influence of F atoms introduced to the aromatic ring on promoting π–π inter­actions. The cocrystal crystallizes in the triclinic space group P1. Through crystallographic analysis and com­putational studies, we reveal the mol­ecular arrangement within this co­crystal, demonstrating the presence of hydrogen bonding between the acetic acid mol­ecule and the pyridyl group, along with π–π inter­actions between the aromatic rings. Our findings highlight the importance of F atoms in promoting π–π inter­actions without necessitating full halogenation of the aromatic ring.

Herein we report the crystal structures of two ben­zo­di­az­e­pines obtained by reacting N,N'-(4,5-di­amino-1,2-phenyl­ene)bis­(4-methyl­ben­zene­sul­fon­am­ide) (1) or 4,5-(4-methyl­ben­zene­sul­fon­am­ido)­ben­zene-1,2-diaminium dichloride (1·2HCl) with acetone, giving 2,2,4-trimethyl-8,9-bis­(4-methyl­ben­zene­sul­fon­am­ido)-2,3-di­hydro-5H-1,5-ben­zo­di­az­e­pine, C26H30N4O4S2 (2), and 2,2,4-tri­methyl-8,9-bis­(4-methyl­ben­zene­sul­fon­am­ido)-2,3-di­hydro-5H-1,5-ben­zo­di­az­e­pin-1-ium chloride 0.3-hydrate, C26H31N4O4S2+·Cl−·0.3H2O (3). Compounds 2 and 3 were first obtained in attempts to recrystallize 1 and 1·2HCl using acetone as solvent. This solvent reacted with the vicinal di­amines present in the mol­ecular structures, forming a 5H-1,5-ben­zo­di­az­e­pine ring. In the crystal structure of 2, the seven-membered ring of ben­zo­di­az­e­pine adopts a boat-like conformation, while upon protonation, observed in the crystal structure of 3, it adopts an envelope-like conformation. In both crystalline com­pounds, the tosyl­amide N atoms are not in resonance with the arene ring, mainly due to hy­dro­gen bonds and steric hindrance caused by the large vicinal groups in the aromatic ring. At a supra­molecular level, the crystal structure is maintained by a combination of hy­dro­gen bonds and hydro­phobic inter­actions. In 2, amine-to-tosyl N—H⋯O and amide-to-imine N—H⋯N hy­dro­gen bonds can be observed. In contrast, in 3, the chloride counter-ion and water mol­ecule result in most of the hy­dro­gen bonds being of the amide-to-chloride and ammonium-to-chloride N—H⋯Cl types, while the amine inter­acts with the tosyl group, as seen in 2. In conclusion, we report the synthesis of 1, 1·2HCl and 2, as well as their chemical characterization. For 2, two synthetic methods are described, i.e. solvent-mediated crystallization and synthesis via a more efficient and cleaner route as a polycrystalline material. Salt 3 was only obtained as presented, with only a few crystals being formed.

Cryo-electron microscopy (cryo-EM) has witnessed radical progress in the past decade, driven by developments in hardware and software. While current software packages include processing pipelines that simplify the image-processing workflow, they do not prioritize the in-depth analysis of crucial metadata, limiting troubleshooting for challenging data sets. The widely used RELION software package lacks a graphical native representation of the underlying metadata. Here, two web-based tools are introduced: relion_live.py, which offers real-time feedback on data collection, aiding swift decision-making during data acquisition, and relion_analyse.py, a graphical interface to represent RELION projects by plotting essential metadata including interactive data filtration and analysis. A useful script for estimating ice thickness and data quality during movie pre-processing is also presented. These tools empower researchers to analyse data efficiently and allow informed decisions during data collection and processing.

A considerable bottleneck in serial crystallography at XFEL and synchrotron sources is the efficient production of large quantities of homogenous, well diffracting microcrystals. Efficient high-throughput screening of batch-grown microcrystals and the determination of ground-state structures from different conditions is thus of considerable value in the early stages of a project. Here, a highly sample-efficient methodology to measure serial crystallography data from microcrystals by raster scanning within standard in situ 96-well crystallization plates is described. Structures were determined from very small quantities of microcrystal suspension and the results were compared with those from other sample-delivery methods. The analysis of a two-dimensional batch crystallization screen using this method is also described as a useful guide for further optimization and the selection of appropriate conditions for scaling up microcrystallization.

A key prerequisite for the successful application of protein crystallography in drug discovery is to establish a robust crystallization system for a new drug-target protein fast enough to deliver crystal structures when the first inhibitors have been identified in the hit-finding campaign or, at the latest, in the subsequent hit-to-lead process. The first crucial step towards generating well folded proteins with a high likelihood of crystallizing is the identification of suitable truncation variants of the target protein. In some cases an optimal length variant alone is not sufficient to support crystallization and additional surface mutations need to be introduced to obtain suitable crystals. In this contribution, four case studies are presented in which rationally designed surface modifications were key to establishing crystallization conditions for the target proteins (the protein kinases Aurora-C, IRAK4 and BUB1, and the KRAS–SOS1 complex). The design process which led to well diffracting crystals is described and the crystal packing is analysed to understand retrospectively how the specific surface mutations promoted successful crystallization. The presented design approaches are routinely used in our team to support the establishment of robust crystallization systems which enable structure-guided inhibitor optimization for hit-to-lead and lead-optimization projects in pharmaceutical research.

AlphaFold2 has revolutionized structural biology by offering unparalleled accuracy in predicting protein structures. Traditional methods for determining protein structures, such as X-ray crystallography and cryo-electron microscopy, are often time-consuming and resource-intensive. AlphaFold2 provides models that are valuable for molecular replacement, aiding in model building and docking into electron density or potential maps. However, despite its capabilities, models from AlphaFold2 do not consistently match the accuracy of experimentally determined structures, need to be validated experimentally and currently miss some crucial information, such as post-translational modifications, ligands and bound ions. In this paper, the advantages are explored of collecting X-ray anomalous data to identify chemical elements, such as metal ions, which are key to understanding certain structures and functions of proteins. This is achieved through methods such as calculating anomalous difference Fourier maps or refining the imaginary component of the anomalous scattering factor f''. Anomalous data can serve as a valuable complement to the information provided by AlphaFold2 models and this is particularly significant in elucidating the roles of metal ions.

A group of three deep-learning tools, referred to collectively as CHiMP (Crystal Hits in My Plate), were created for analysis of micrographs of protein crystallization experiments at the Diamond Light Source (DLS) synchrotron, UK. The first tool, a classification network, assigns images into categories relating to experimental outcomes. The other two tools are networks that perform both object detection and instance segmentation, resulting in masks of individual crystals in the first case and masks of crystallization droplets in addition to crystals in the second case, allowing the positions and sizes of these entities to be recorded. The creation of these tools used transfer learning, where weights from a pre-trained deep-learning network were used as a starting point and repurposed by further training on a relatively small set of data. Two of the tools are now integrated at the VMXi macromolecular crystallography beamline at DLS, where they have the potential to absolve the need for any user input, both for monitoring crystallization experiments and for triggering in situ data collections. The third is being integrated into the XChem fragment-based drug-discovery screening platform, also at DLS, to allow the automatic targeting of acoustic compound dispensing into crystallization droplets.

Fatty acid-derivative prodrugs have been utilized extensively to improve the physicochemical, biopharmaceutical and pharmacokinetic properties of active pharmaceutical ingredients. However, to our knowledge, the crystallization behavior of prodrugs modified with different fatty acids has not been explored. In the present work, a series of paliperidone aliphatic prodrugs with alkyl chain lengths ranging from C4 to C16 was investigated with respect to crystal structure, crystal morphology and crystallization kinetics. The paliperidone derivatives exhibited isostructural crystal packing, despite the different alkyl chain lengths, and crystallized with the dominant (100) face in both melt and solution. The rate of crystallization for paliperidone derivatives in the melt increases with alkyl chain length owing to greater molecular mobility. In contrast, the longer chains prolong the nucleation induction time and reduce the crystal growth kinetics in solution. The results show a correlation between difficulty of nucleation in solution and the interfacial energy. This work provides insight into the crystallization behavior of paliperidone aliphatic prodrugs and reveals that the role of alkyl chain length in the crystallization behavior has a strong dependence on the crystallization method.

A series of events underscoring the significant advancements in micro-crystallization and in vivo crystallography were held during the 26th IUCr Congress in Melbourne, positioning microcrystallography as a pivotal field within structural biology. Through collaborative discussions and the sharing of innovative methodologies, these sessions outlined frontier approaches in macromolecular crystallography. This review provides an overview of this rapidly moving field in light of the rich dialogues and forward-thinking proposals explored during the congress workshop and microsymposium. These advances in microcrystallography shed light on the potential to reshape current research paradigms and enhance our comprehension of biological mechanisms at the molecular scale.

Single-crystal X-ray diffraction analysis of small molecule active pharmaceutical ingredients is a key technique in the confirmation of molecular connectivity, including absolute stereochemistry, as well as the solid-state form. However, accessing single crystals suitable for X-ray diffraction analysis of an active pharmaceutical ingredient can be experimentally laborious, especially considering the potential for multiple solid-state forms (solvates, hydrates and polymorphs). In recent years, methods for the exploration of experimental crystallization space of small molecules have undergone a `step-change', resulting in new high-throughput techniques becoming available. Here, the application of high-throughput encapsulated nanodroplet crystallization to a series of six di­hydro­pyridines, calcium channel blockers used in the treatment of hypertension related diseases, is described. This approach allowed 288 individual crystallization experiments to be performed in parallel on each molecule, resulting in rapid access to crystals and subsequent crystal structures for all six di­hydro­pyridines, as well as revealing a new solvate polymorph of nifedipine (1,4-dioxane solvate) and the first known solvate of nimodipine (DMSO solvate). This work further demonstrates the power of modern high-throughput crystallization methods in the exploration of the solid-state landscape of active pharmaceutical ingredients to facilitate crystal form discovery and structural analysis by single-crystal X-ray diffraction.

The mol­ecular and crystal structure of a discrete [Ni8(μ4-OH)6(μ-4-Rpz)12]2− (R = H; pz = pyrazolate anion, C3H3N2−) cluster with an unprecedented, perfectly cubic arrangement of its eight Ni centers is reported, along with its lower-symmetry alkyl-functionalized (R = methyl and n-oct­yl) derivatives. Crystals of the latter two were obtained with two identical counter-ions (Bu4N+), whereas the crystal of the complex with the parent pyrazole ligand has one Me4N+ and one Bu4N+ counter-ion. The methyl derivative incorporates 1,2-di­chloro­ethane solvent mol­ecules in its crystal structure, whereas the other two are solvent-free. The compounds are tetra­butyl­aza­nium tetra­methyl­aza­nium hexa-μ4-hydroxido-dodeca-μ2-pyrazolato-hexa­hedro-octa­nickel, (C16H36N)(C4H12N)[Ni8(C3H3N2)12(OH)6] or (Bu4N)(Me4N)[Ni8(μ4-OH)6(μ-pz)12] (1), bis­(tetra­butyl­aza­nium) hexa-μ4-hydroxido-dodeca-μ2-(4-methyl­pyrazolato)-hexa­hedro-octa­nickel 1,2-di­chloro­ethane 7.196-solvate, (C16H36N)2[Ni8(C4H5N2)12(OH)6]·7.196C2H4Cl2 or (Bu4N)2[Ni8(μ4-OH)6(μ-4-Mepz)12]·7.196(ClCH2CH2Cl) (2), and bis­(tetra­butyl­aza­nium) hexa-μ4-hydroxido-dodeca-μ2-(4-octylpyrazolato)-hexa­hedro-octa­nickel, (C16H36N)2[Ni8(C11H19N2)12(OH)6] or (Bu4N)2[Ni8(μ4-OH)6(μ-4-nOctpz)12] (3). All counter-ions are disordered (with the exception of one Bu4N+ in 3). Some of the octyl chains of 3 (the crystal is twinned by non-merohedry) are also disordered. Various structural features are discussed and contrasted with those of other known [Ni8(μ4-OH)6(μ-4-Rpz)12]2− complexes, including extended three-dimensional metal–organic frameworks. In all three structures, the Ni8 units are lined up in columns.

Single crystals of two basic cadmium phosphates, dicadmium orthophosphate hydroxide, Cd2(PO4)OH, and penta­cadmium bis­(orthophosphate) tetra­kis­(hydroxide), Cd5(PO4)2(OH)4, were obtained under hydro­thermal conditions. Cd2(PO4)OH adopts the triplite [(Mn,Fe)2(PO4)F] structure type. Its asymmetric unit comprises two Cd, one P and five O sites, all situated at the general Wyckoff position 8 f of space group I2/a; two of the O atoms are positionally disordered over two sites, and the H atom could not be localized. Disregarding the disorder, distorted [CdO6] polyhedra form a tri-periodic network by edge-sharing with neighbouring [CdO6] units and by vertex-sharing with [PO4] units. The site associated with the OH group is coordinated by four Cd atoms in a distorted tetra­hedral manner forming 1∞[(OH)Cd4/2] chains parallel to [001]. The oxygen environment around the OH site suggests multiple acceptor atoms for possible O—H⋯O hydrogen-bonding inter­actions and is the putative reason for the disorder. Cd5(PO4)2(OH)4 adopts the arsenoclasite [Mn5(AsO4)2(OH)4] structure type. Its asymmetric unit comprises five Cd, two P, and twelve O sites all located at the general Wyckoff position 4 a of space group P212121; the H atoms could not be localized. The crystal structure of Cd5(PO4)2(OH)4 can be subdivided into two main sub-units. One consists of three edge-sharing [CdO6] octa­hedra, and the other of two edge- and vertex-sharing [CdO6] octa­hedra. Each sub-unit forms corrugated ribbons extending parallel to [100]. The two types of ribbons are linked into the tri-periodic arrangement through vertex-sharing and through common [PO4] tetra­hedra. Qu­anti­tative structure comparisons are made with isotypic M5(XO4)2(OH)4 crystal structures (M = Cd, Mn, Co; X = P, As, V).

The title complex, (1,4,7,10,13,16-hexa­oxa­cyclo­octa­decane-1κ6O)(μ-oxalato-1κ2O1,O2:2κ2O1',O2')triphenyl-2κ3C-potassium(I)tin(IV), [KSn(C6H5)3(C2O4)(C12H24O6)] or K[18-Crown-6][(C6H5)3SnO4C2], was synthesized. The complex consists of a potassium cation coordinated to the six oxygen atoms of a crown ether mol­ecule and the two oxygen atoms of the oxalatotri­phenyl­stannate anion. It crystallizes in the monoclinic crystal system within the space group P21. The tin atom is coordinated by one chelating oxalate ligand and three phenyl groups, forming a cis-trigonal–bipyramidal geometry around the tin atom. The cations and anions form ion pairs, linked through carbonyl coordination to the potassium atoms. The crystal structure features C—H⋯O hydrogen bonds between the oxygen atoms of the oxalate group and the hydrogen atoms of the phenyl groups, resulting in an infinite chain structure extending along a-axis direction. The primary inter-chain inter­actions are van der Waals forces.

A host–guest supra­molecular inclusion complex was obtained from the co-crystallization of A1/A2-bromo­but­oxy-hy­droxy difunctionalized pillar[5]arene (PilButBrOH) with adipo­nitrile (ADN), C47H53.18Br0.82O10·C6H8N2. The adipo­nitrile guest is stabilized within the electron-rich cavity of the pillar[5]arene host via multiple C—H⋯O and C—H⋯π inter­actions. Both functional groups on the macrocyclic rim are engaged in supra­molecular inter­actions with an adjacent inclusion complex via hydrogen-bonding (O—H⋯N or C—H⋯Br) inter­actions, resulting in the formation of a supra­molecular dimer in the crystal structure.

Hendrickson & Lattman [Acta Cryst. (1970), B26, 136–143] introduced a method for representing crystallographic phase probabilities defined on the unit circle. Their approach could model the bimodal phase probability distributions that can result from experimental phase determination procedures. It also provided simple and highly effective means to combine independent sources of phase information. The present work discusses the equivalence of the Hendrickson–Lattman distribution and the generalized von Mises distribution of order two, which has been studied in the statistical literature. Recognizing this connection allows the Hendrickson–Lattman distribution to be expressed in an alternative form which is easier to interpret, as it involves the location and concentration parameters of the component von Mises distributions. It also allows clarification of the conditions for bimodality and access to a simplified analytical method for evaluating the trigonometric moments of the distribution, the first of which is required for computing the best Fourier synthesis in the presence of phase, but not amplitude, uncertainty.

The suitability of point focus X-ray beam and area detector techniques for the determination of the uniaxial symmetry axis (fibre texture) of the natural mineral satin spar is demonstrated. Among the various diffraction techniques used in this report, including powder diffraction, 2D pole figures, rocking curves looped on φ and 2D X-ray diffraction, a single simple symmetric 2D scan collecting the reciprocal plane perpendicular to the apparent fibre axis provided sufficient information to determine the crystallographic orientation of the fibre axis. A geometrical explanation of the `wing' feature formed by diffraction spots from the fibre-textured satin spar in 2D scans is provided. The technique of wide-range reciprocal space mapping restores the `wing' featured diffraction spots on the 2D detector back to reciprocal space layers, revealing the nature of the fibre-textured samples.

X-ray crystallography is an established tool to probe the structure of macromolecules with atomic resolution. Compared with alternative techniques such as single-particle cryo-electron microscopy and micro-electron diffraction, X-ray crystallography is uniquely suited to room-temperature studies and for obtaining a detailed picture of macromolecules subjected to an external electric field (EEF). The impact of an EEF on proteins has been extensively explored through single-crystal X-ray crystallography, which works well with larger high-quality protein crystals. This article introduces a novel design for a 3D-printed in situ crystallization plate that serves a dual purpose: fostering crystal growth and allowing the concurrent examination of the effects of an EEF on crystals of varying sizes. The plate's compatibility with established X-ray crystallography techniques is evaluated.

Characterization of crystallization processes in situ is of great importance to furthering knowledge of how nucleation and growth processes direct the assembly of organic and inorganic materials in solution and, critically, understanding the influence that these processes have on the final physico-chemical properties of the resulting solid form. With careful specification and design, as demonstrated here, it is now possible to bring combined X-ray diffraction and Raman spectroscopy, coupled to a range of fully integrated segmented and continuous flow platforms, to the laboratory environment for in situ data acquisition for timescales of the order of seconds. The facility used here (Flow-Xl) houses a diffractometer with a micro-focus Cu Kα rotating anode X-ray source and a 2D hybrid photon-counting detector, together with a Raman spectrometer with 532 and 785 nm lasers. An overview of the diffractometer and spectrometer setup is given, and current sample environments for flow crystallization are described. Commissioning experiments highlight the sensitivity of the two instruments for time-resolved in situ data collection of samples in flow. Finally, an example case study to monitor the batch crystallization of sodium sulfate from aqueous solution, by tracking both the solute and solution phase species as a function of time, highlights the applicability of such measurements in determining the kinetics associated with crystallization processes. This work illustrates that the Flow-Xl facility provides high-resolution time-resolved in situ structural phase information through diffraction data together with molecular-scale solution data through spectroscopy, which allows crystallization mechanisms and their associated kinetics to be analysed in a laboratory setting.

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.

Energy-dispersive Laue diffraction (EDLD) is a powerful method to obtain position-resolved texture information in inhomogeneous biological samples without the need for sample rotation. This study employs EDLD texture scanning to investigate the impact of two salivary peptides, statherin (STN) and histatin-1 (HTN) 21 N-terminal peptides (STN21 and HTN21), on the crystallographic structure of dental enamel. These proteins are known to play crucial roles in dental caries progression. Three healthy incisors were randomly assigned to three groups: artificially demineralized, demineralized after HTN21 peptide pre-treatment and demineralized after STN21 peptide pre-treatment. To understand the micro-scale structure of the enamel, each specimen was scanned from the enamel surface to a depth of 250 µm using microbeam EDLD. Via the use of a white beam and a pixelated detector, where each pixel functions as a spectrometer, pole figures were obtained in a single exposure at each measurement point. The results revealed distinct orientations of hydroxyapatite crystallites and notable texture variation in the peptide-treated demineralized samples compared with the demineralized control. Specifically, the peptide-treated demineralized samples exhibited up to three orientation populations, in contrast to the demineralized control which displayed only a single orientation population. The texture index of the demineralized control (2.00 ± 0.21) was found to be lower than that of either the STN21 (2.32 ± 0.20) or the HTN21 (2.90 ± 0.46) treated samples. Hence, texture scanning with EDLD gives new insights into dental enamel crystallite orientation and links the present understanding of enamel demineralization to the underlying crystalline texture. For the first time, the feasibility of EDLD texture measurements for quantitative texture evaluation in demineralized dental enamel samples is demonstrated.

Compared with batch and vapor diffusion methods, counter diffusion can generate larger and higher-quality protein crystals yielding improved diffraction data and higher-resolution structures. Typically, counter-diffusion experiments are conducted in elongated chambers, such as glass capillaries, and the crystals are either directly measured in the capillary or extracted and mounted at the X-ray beamline. Despite the advantages of counter-diffusion protein crystallization, there are few fixed-target devices that utilize counter diffusion for crystallization. In this article, different designs of user-friendly counter-diffusion chambers are presented which can be used to grow large protein crystals in a 2D polymer microfluidic fixed-target chip. Methods for rapid chip fabrication using commercially available thin-film materials such as Mylar, propyl­ene and Kapton are also detailed. Rules of thumb are provided to tune the nucleation and crystal growth to meet users' needs while minimizing sample consumption. These designs provide a reliable approach to forming large crystals and maintaining their hydration for weeks and even months. This allows ample time to grow, select and preserve the best crystal batches before X-ray beam time. Importantly, the fixed-target microfluidic chip has a low background scatter and can be directly used at beamlines without any crystal handling, enabling crystal quality to be preserved. The approach is demonstrated with serial diffraction of photoactive yellow protein, yielding 1.32 Å resolution at room temperature. Fabrication of this standard microfluidic chip with commercially available thin films greatly simplifies fabrication and provides enhanced stability under vacuum. These advances will further broaden microfluidic fixed-target utilization by crystallographers.

Online courses and innovative teaching methods have triggered a trend in education, where the integration of multimedia, online resources and interactive tools is reshaping the view of both virtual and traditional classrooms. The use of interactive tools extends beyond the boundaries of the physical classroom, offering students the flexibility to access materials at their own speed and convenience and enhancing their learning experience. In the field of crystallography, there are a wide variety of free online resources such as web pages, interactive applets, databases and programs that can be implemented in fundamental crystallography courses for different academic levels and curricula. This paper discusses a variety of resources that can be helpful for crystallographic symmetry handling and visualization, discussing four specific resources in detail: the Bilbao Crystallographic Server, the Cambridge Structural Database, VESTA and Jmol. The utility of these resources is explained and shown by several illustrative examples.

Elizabeth Harper, a relics expert, at Mountain View Cemetery in Altadena; Credit: John Rabe

"Reach a certain moment in your life, and you discover that your days are spent as much with the dead as they are with the living." – Paul Auster

This has been one of my favorite quotes for a long time. To me it means that when you get older and your friends, relatives, and heroes start dying, you have a choice. You can either stop thinking about them because they're dead, giving up, as it were, the pleasure of their company; or you can keep them in your life. To me, that's not denial; it's being realistic.

So, it makes sense that I felt a kindred spirit with Elizabeth Harper, who keeps the website All the Saints You Should Know, when we met at a beautiful mausoleum at Mountain View Cemetery in Altadena to talk about the history of cemeteries, relics, castrated Italian avuncular mummies, and the best spots in Los Angeles to commune healthily with death.

Elizabeth will be part of the team when Atlas Obscura leads tours of The Cathedral of Our Lady of the Angels on Saturday, July 1. It's billed as "A celebration of life, death, architecture, and the patron saint of Los Angeles."

Here are some highlights of my mausoleum conversation with Elizabeth Harper:

At first glance, she says, all of the tombs are very similar.

And that was one of the things, when we started making modern cemeteries, outside the city lines, they wanted them to be regular and not so expressive and macabre. But people leave little things behind. On a lot of these (crypts), you can see a little emblem of something that was important to them. If they were a Mason or if they served in the Army. I like the (cremains) urns that are shaped like books. I have a friend who is a librarian and she was very taken with the idea of being in a book.

Napoleon instituted the Edict of Saint-Cloud, which mandated that cemeteries must be outside city limits (for health reasons) and must be toned-down (for no good reason).

People did not like the edict. There's a very famous poem called Sepulchers by Ugo Foscolo that was written in protest, that said, essentially, looking upon the graves of strong men strengthens the mind and the spirit.

From Slate: Photographing the Real Bodies of Incorrupt Saints, by Elizabeth Harper

Elizabeth often writes about cemeteries and tombs and sometimes posts photos of bodies, which causes a "certain segment" to assume she has no experience with death, or she wouldn't presume to do such a thing.

What I want to put out there is that we have this pervasive idea that we grieve and move on, and this moving on is very important, and I think there are multiple ways to incorporate the idea of death in your life, to get used to the idea, without forgetting, that's more of a way of memorializing. When I take these pictures, I'm very aware that these are real people, and I think of myself, what I will be one day, and people I love, who are already there.

Make sure to listen to our entire interview in the audio player to hear Elizabeth's 3 top spots in Los Angeles to consider the place of death in our lives, and to hear about poor old Uncle Vincent, a neutered naked mummy in a small town in Italy who has a large fan base.

This content is from Southern California Public Radio. View the original story at SCPR.org.

Source: Streetwise Reports 11/06/2024

Golden Cariboo Resources Ltd. (GCC:CSE; GCCFF:OTC; A0RLEP:WKN; 3TZ:FSE) has reported encouraging results from its 2024 field campaign. During the exploration, the company collected 16 rock samples from the Halo zone, North Hixon zone, and Pioneer area. These samples revealed promising gold mineralization in the region. Notable highlights from the Halo zone include grab samples from newly exposed outcrops, with assays reaching 8.47 g/t Au (grams per tonne, gold), 6.59 g/t Au, and 2.39 g/t Au. These samples were taken from altered andesite tuff with quartz-carbonate veins located approximately 101 meters northeast of the nearest drill collar.

Sampling near the Pioneer showing, situated one-kilometer north-northwest of the Halo zone, also returned assays of 1.13 g/t Au and 0.40 g/t Au. The fieldwork's findings have significantly extended the strike length of known gold mineralization by one kilometer and expanded the surface footprint of mineralization to the northeast. Despite challenging glacial cover, Golden Cariboo's team continues to uncover significant gold-bearing outcrops.

The report also underscored the strategic advantages of the property's location, infrastructure, and proximity to Highway 97, which reduces exploration and operational costs. Wortel detailed Golden Cariboo's drilling campaign, which includes results such as Hole QGQ24-013, which intersected 136.51 meters at 1.77 g/t gold, including a higher-grade interval of 23.89 meters at 3.32 g/t gold.

Valuation metrics from the report included a projected fair value of CA$0.40 per share, representing a 74% potential upside from the current trading price of CA$0.23, and doesn't include the added value from recent, significant exploration success. Despite acknowledging the high risks associated with early-stage exploration projects, Couloir Capital emphasized the long-term value potential in a Tier 1 mining jurisdiction, reinforced by the company's experienced management team and promising geological trends.

Frank Callaghan, President and CEO of Golden Cariboo, stated in the news release, "Although there is a lot of glacial cover on this project, our geologists still managed to find new gold-bearing outcrops in areas of great significance. We have now expanded the surface footprint of gold mineralization at the Halo zone to the northeast and increased the strike length of our gold trend. We're in a very large gold system that is being demonstrated by multiple, varied work programs."

Mining and Metals Market

On October 29, Kitco reported that gold prices had reached nearly US$2,800. This price represents a 35% increase for the year. The rise was attributed to multiple factors, including "geopolitical conflicts, Federal Reserve interest rate normalization, continued strong demand from global central banks, and uncertainties about the upcoming presidential election and potential fiscal stimulus." Analysts at Kitco described this combination of elements as a "perfect storm." They noted it had driven investor sentiment and reinforced gold's value as a hedge against economic turmoil.

LiveMint, on October 30, highlighted the substantial returns seen in gold over the past year. Despite this impressive performance, some analysts expressed caution regarding gold's future trajectory. Ajay Kedia, Director of Kedia Advisory, suggested that while gold prices may see a short-term rally, "investors may have to remain cautious on the yellow metal in the second half of 2025." Kedia noted that gold prices could experience profit-taking and a slowdown if interest rate cuts by the Federal Reserve do not materialize as quickly as expected. Nonetheless, gold has continued to serve as a preferred asset for those seeking stability, especially in times of economic and political uncertainty.

In a November 4 report, Egon von Greyerz, Founder and Chairman of Matterhorn Asset Management, provided a historical perspective on gold's role in preserving wealth. Von Greyerz discussed how gold had consistently retained value, even as fiat currencies depreciated over time. He emphasized, "Gold held in the investor's name in safe vaults and jurisdictions outside the financial system is the ultimate form of wealth preservation." Von Greyerz also pointed to gold's outperformance since the 1970s, stating that gold had increased 78 times since President Nixon ended the gold standard in 1971. He argued that gold's journey was "only starting now," citing the ongoing destruction of fiat money value through global debt expansion and monetary policies.

Cariboo Catalysts

According to Golden Cariboo Resources' Q1 2024 investor presentation, the company is advancing exploration on its 3,814-hectare Quesnelle Gold Quartz Mine property, located in British Columbia's historic Cariboo Mining District. The asset benefits from 160 years of mining history and is road-accessible, facilitating year-round exploration. The 2024 exploration program, including trenching and a proposed 2,500-5,000m Phase 2 drilling campaign, aims to delineate the gold system further and complete a National Instrument 43-101 compliant resource estimate.

The property, encircled by Osisko Development Corp. on three sides, holds the potential for high-grade, multi-ounce gold targets. Management is focusing on a multi-phase exploration strategy. This includes trenching to assess shallow overburden and mapping and sampling to refine drill targets. The team's experience and the property's historical and geological significance position Golden Cariboo as a promising exploration venture.

The proposed drilling and development efforts reflect a systematic approach to unlocking value in this underexplored yet historically significant gold camp as the company progresses toward realizing a resource estimate.

Expert Analysis

Golden Cariboo Resources Inc. received favorable coverage from Couloir Capital in a report released on September 3, 2024. Senior Mining Analyst Ron Wortel issued a Buy recommendation for the company, noting the significant potential for discovering a large gold resource at the Quesnelle Gold Quartz property. Wortel highlighted that the property, located in British Columbia's historic Cariboo Mining District, lies along the same geological trend as Osisko Development's projects, suggesting the possibility of tapping into similar high-grade mineralization systems.

The report also underscored the strategic advantages of the property's location, infrastructure, and proximity to Highway 97, which reduces exploration and operational costs. Wortel detailed Golden Cariboo's drilling campaign, pointing out positive early results, such as Hole QGQ24-08, which intersected 263 meters at 0.29 g/t gold, including a higher-grade interval of 200 meters at 0.58 g/t gold. The analyst described these findings as indicative of "bulk-tonnage targets," with visible gold observed in several drill cores, bolstering the outlook for continued exploration success. [OWNERSHIP_CHART-11131]

Valuation metrics from the report included a projected fair value of CA$0.40 per share, representing a 286% potential upside from the current trading price of CA$0.14. Despite acknowledging the high risks associated with early-stage exploration projects, Couloir Capital emphasized the long-term value potential in a Tier 1 mining jurisdiction, reinforced by the company's experienced management team and promising geological trends.

Ownership and Share Structure

According to Golden Cariboo, management and insiders own 30% of Golden Cariboo Resources. President and CEO Frank Callaghan owns 16.45% or 6.93 million shares; Elaine Callaghan has 0.97% or 0.41 million shares; Director Andrew Rees has 0.79% or 0.33 million shares; and Director Laurence Smoliak has 0.3% or 0.13 million shares.

Retail investors hold the remaining. There are no institutional investors.

The company said it has 50.3 million shares outstanding, 24.83 million warrants, and 3.8 million options.

Its market cap is CA$9.7 million. Over the past 52 weeks, Golden Cariboo has traded between CA$0.08 and CA$0.36 per share.

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Important Disclosures:

1. Golden Cariboo Resources Ltd. has a consulting relationship with Street Smart an affiliate of Streetwise Reports. Street Smart Clients pay a monthly consulting fee between US$8,000 and US$20,000.
2. As of the date of this article, officers and/or employees of Streetwise Reports LLC (including members of their household) own securities of Golden Cariboo Resources Ltd.
3. James Guttman wrote this article for Streetwise Reports LLC and provides services to Streetwise Reports as an independent contractor.
4. This article does not constitute investment advice and is not a solicitation for any investment. Streetwise Reports does not render general or specific investment advice and the information on Streetwise Reports should not be considered a recommendation to buy or sell any security. Each reader is encouraged to consult with his or her personal financial adviser and perform their own comprehensive investment research. By opening this page, each reader accepts and agrees to Streetwise Reports' terms of use and full legal disclaimer. Streetwise Reports does not endorse or recommend the business, products, services or securities of any company.

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( Companies Mentioned: GCC:CSE; GCCFF:OTC; A0RLEP:WKN;3TZ:FSE, )

Don't fear the 'shrooms.; Credit: /iStockphoto.com

California on Tuesday moved another step closer to decriminalizing psychedelics — amid a debate over whether their prohibition is an outdated remnant of the War on Drugs — after the author removed a substance (ketamine) from the bill that opponents said can be used as a date-rape drug.

The bill would allow those 21 and older to possess for personal use and “social sharing” psilocybin, the hallucinogenic component of so-called magic mushrooms. It also covers psilocybin, dimethyltryptamine (DMT), ibogaine, mescaline excluding peyote, lysergic acid diethylamide (LSD) and 3,4-methylenedioxymethamphetamine (MDMA, often called ecstasy).

The bill bars sharing with those under age 21 or possessing the substances on school grounds. It would remove the state’s ban on cultivating or transferring mushroom spores or other material containing psilocybin or psilocybin.

Even if California makes the bill law, the drugs would still be illegal under federal law.

With files from the Associated Press.

Guests:

Scott Wiener, author of SB 519; California State Senator representing Senate District 11, which includes all of the city and county of San Francisco, Broadmoor, Colma, Daly City, and part of South San Francisco; he tweets @Scott_Wiener

John Lovell, legislative director of the California Narcotics Officers Association

This content is from Southern California Public Radio. View the original story at SCPR.org.

President Biden signed a memorial bill to recognize the victims of the 2016 Pulse nightclub shooting and offered his condolences to people who are awaiting news on their loved ones in the wake of the deadly Surfside, Fla., partial condo collapse.

Biden — who was vice president when a 29-year-old man killed 49 people and wounded 53 more in the nightclub mass shooting — signed the bill to enshrine a monument to the dozens killed in the Latin Night massacre.

The shooting occurred at a gay nightclub in Orlando, Fla., in June 2016. The month of June is celebrated annually as LGBTQ Pride Month in the United States.

"May a president never have to sign another monument like this," Biden said.

Biden also offered his thoughts to the victims and loved ones of those affected by the catastrophic collapse this week of a Miami-Dade County condo. Authorities say four people have been declared dead and an additional 159 are considered missing in the rubble.

"I just want to say, I've spoken to Gov. [Ron] DeSantis, and we've provided all the help that they have, they need," Biden said. "We sent the best people from FEMA down there. We're going to stay with them."

This content is from Southern California Public Radio. View the original story at SCPR.org.

On-Demand Webinar >  Watch Now!>> SPONSORED BY: VM6 SoftwareWatch this FREE on-demand webinar now and you’ll discover:Why virtualization is important How to achieve a scala...

Architectural plans have been finalized for the new Sherrills Ford branch of Catawba County Library. The 10,000 square foot facility, to be erected on 2.5 acres near the intersection of Highway 150 and Sherrills Ford Road, is expected to be completed in 2014.

A new report from the National Academies of Sciences, Engineering, and Medicine outlines a research agenda for improving the commercial viability of technologies that turn greenhouse gases from the burning of fossil fuels into useful products such as fuels, construction materials, and chemicals.

At colleges and universities around the nation, scientists and graduate students are seeking out ways to bring their knowledge, skills, and resources to bear in the struggle against COVID-19.

If combined with public transit and increased in scale, shared modes of transportation, such as ride-hailing, scooter sharing, and bike sharing, can enhance mobility, equity, and sustainability in metropolitan areas, according to a new report from the National Academies of Sciences, Engineering, and Medicine.

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Urban freeways and transit infrastructure projects — often paid for in large part by federal transportation funds — have disproportionately displaced and isolated people living in minority neighborhoods, tearing at the fabric of vibrant communities and compounding issues of equity and access to jobs and essential services.

Every year, nearly 5 million Americans are evaluated for traumatic brain injury (TBI). But many individuals and their caregivers don’t get needed follow-up support after initial injury. A new report recommends structural changes to improve TBI research and care over the next decade.

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As part of the shift to a net-zero carbon emissions economy, industry and government should begin planning for the deployment of carbon dioxide utilization systems to turn captured CO2 into useful products, such as aviation fuel and aggregates for construction.

Strengthening and expanding critical safety net programs is necessary to address the COVID-19 pandemic’s effects on children and families, says a new report that examines the substantial toll the pandemic has taken on their health and well-being, especially those in marginalized communities.

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As the digital economy expands, so does the volume of data generated and stored within India. This presents an opportunity for the government to implement data localization policies to safeguard sensitive data, protect national security, and promote the growth of the domestic IT industry and related sectors.

The transport of food and health/sanitary items such as cleaning supplies and paper towels have placed significant strains on the supply chain. Food distributors have to scrutinize significant preventative measures needed to ensure the health and safety of customers, drivers, and everyone that is in contact with goods that are transported and delivered.

St-Méthode Bakery has chosen the UTrakk platform to empower its managers in the application of good management practices, including coaching and active supervision tours.

These days, you can have your cake and eat it, too. Today's sweet bakery treats like cakes, pies, cheesecakes, and cookies often combine the best of multiple worlds, bridging apparent gaps between indulgence, better-for-you and specialized dietary choices, clean label, sound functionality, and globally minded sustainability.