tall Application of a high-throughput microcrystal delivery system to serial femtosecond crystallography By scripts.iucr.org Published On :: 2020-03-25 Microcrystal delivery methods are pivotal in the use of serial femtosecond crystallography (SFX) to resolve the macromolecular structures of proteins. Here, the development of a novel technique and instruments for efficiently delivering microcrystals for SFX are presented. The new method, which relies on a one-dimensional fixed-target system that includes a microcrystal container, consumes an extremely low amount of sample compared with conventional two-dimensional fixed-target techniques at ambient temperature. This novel system can deliver soluble microcrystals without highly viscous carrier media and, moreover, can be used as a microcrystal growth device for SFX. Diffraction data collection utilizing this advanced technique along with a real-time visual servo scan system has been successfully demonstrated for the structure determination of proteinase K microcrystals at 1.85 Å resolution. Full Article text
tall Protein crystal structure determination with the crystallophore, a nucleating and phasing agent By journals.iucr.org Published On :: The unique nucleating and phasing capabilities of the crystallophore, Tb-Xo4, are illustrated through challenging cases. Full Article text
tall Significant texture improvement in single-crystalline-like materials on low-cost flexible metal foils through growth of silver thin films By journals.iucr.org Published On :: Single-crystalline-like thin films composed of crystallographically aligned grains are a new prototype of 2D materials developed recently for low-cost and high-performance flexible electronics as well as second-generation high-temperature superconductors. In this work, significant texture improvement in single-crystalline-like materials is achieved through growth of a 330 nm-thick silver layer. Full Article text
tall The competition between cocrystallization and separated crystallization based on crystallization from solution By journals.iucr.org Published On :: Because researchers do not understand the formation mechanism of cocrystals, the preparation of cocrystals is mostly done by trial and error. This study focuses on the cocrystal formation mechanism to improve the efficiency of cocrystal preparation. Full Article text
tall Handbook of Industrial Crystallization. Third edition. Edited by Allan S. Myerson, Deniz Erdemir and Alfred Y. Lee. Cambridge University Press, 2019. Pp. 538. Price GBP 145 (hardcover). ISBN 9780521196185. By journals.iucr.org Published On :: Book review Full Article text
tall 3D-printed holders for in meso in situ fixed-target serial X-ray crystallography By journals.iucr.org Published On :: The design and assembly of two 3D-printed holders for high-throughput in meso in situ fixed-target crystallographic data collection are described. Full Article text
tall Calculation of total scattering from a crystalline structural model based on experimental optics parameters By journals.iucr.org Published On :: A calculation procedure for X-ray total scattering and the pair distribution function from a crystalline structural model is presented. It allows one to easily and precisely deal with diffraction-angle-dependent parameters such as the atomic form factor and the resolution of the optics. Full Article text
tall Optimization of crystallization of biological macromolecules using dialysis combined with temperature control By journals.iucr.org Published On :: This article describes rational strategies for the optimization of crystal growth using precise in situ control of the temperature and chemical composition of the crystallization solution through dialysis, to generate crystals of the specific sizes required for different downstream structure determination approaches. Full Article text
tall Pattern matching indexing of Laue and monochromatic serial crystallography data for applications in Materials Science By journals.iucr.org Published On :: An algorithm, based on the matching of q-vectors pairs, is combined with three-dimensional pattern matching using a nearest-neighbors approach to index Laue and monochromatic serial crystallography data recorded on small unit cell samples. Full Article text
tall Forthcoming article in Journal of Applied Crystallography By journals.iucr.org Published On :: Full Article Still image
tall Crystal structures of two furazidin polymorphs revealed by a joint effort of crystal structure prediction and NMR crystallography By scripts.iucr.org Published On :: 2020-04-16 This work presents the crystal structure determination of two elusive polymorphs of furazidin, an antibacterial agent, employing a combination of crystal structure prediction (CSP) calculations and an NMR crystallography approach. Two previously uncharacterized neat crystal forms, one of which has two symmetry-independent molecules (form I), whereas the other one is a Z' = 1 polymorph (form II), crystallize in P21/c and P1 space groups, respectively, and both are built by different conformers, displaying different intermolecular interactions. It is demonstrated that the usage of either CSP or NMR crystallography alone is insufficient to successfully elucidate the above-mentioned crystal structures, especially in the case of the Z' = 2 polymorph. In addition, cases of serendipitous agreement in terms of 1H or 13C NMR data obtained for the CSP-generated crystal structures different from the ones observed in the laboratory (false-positive matches) are analyzed and described. While for the majority of analyzed crystal structures the obtained agreement with the NMR experiment is indicative of some structural features in common with the experimental structure, the mentioned serendipity observed in exceptional cases points to the necessity of caution when using an NMR crystallography approach in crystal structure determination. Full Article text
tall Crystallization of chiral molecular compounds: what can be learned from the Cambridge Structural Database? By scripts.iucr.org Published On :: 2020-04-10 A detailed study on chiral compound structures found in the Cambridge Structural Database (CSD) is presented. Solvates, salts and co-crystals have intentionally been excluded, in order to focus on the most basic structures of single enantiomers, scalemates and racemates. Similarity between the latter and structures of achiral monomolecular compounds has been established and utilized to arrive at important conclusions about crystallization of chiral compounds. For example, the fundamental phenomenon of conglomerate formation and, in particular, their frequency of occurrence is addressed. In addition, rarely occurring kryptoracemates and scalemic compounds (anomalous racemates) are discussed. Finally, an extended search of enantiomer solid solutions in the CSD is performed to show that there are up to 1800 instances most probably hiding among the deposited crystal structures, while only a couple of dozen have been previously known and studied. Full Article text
tall Crystallization of chiral molecular compounds: what can be learned from the Cambridge Structural Database? By journals.iucr.org Published On :: A study on chiral monomolecular compound structures found in the Cambridge Structural Database is presented. Full Article text
tall Synthesis and crystallographic, spectroscopic and computational characterization of the effects of O—R substituents on the torsional[torsion] angle of 3,3',4,4'-substituted biphenyls By journals.iucr.org Published On :: The synthesis, characterization and study of structures from a series of biphenyls substituted at positions 3, 3', 4 and 4' with groups connected to the biphenyl core through oxygen atoms are presented here. The molecular conformation is extensively studied both in the solid as well as in the liquid state, and the effect of different actors (such as packing and chain length) on the torsion angle between aromatic rings is analyzed. Full Article text
tall A new ZnII metallocryptand with unprecedented diflexure helix induced by V-shaped diimidazole building blocks By journals.iucr.org Published On :: A new ZnII metallocryptand is presented, with an unprecedented diflexure helix. Full Article text
tall Forthcoming article in Acta Crystallographica Section B Structural Science, Crystal Engineering and Materials By journals.iucr.org Published On :: Full Article Still image
tall Crystallographic snapshots of the EF-hand protein MCFD2 complexed with the intracellular lectin ERGIC-53 involved in glycoprotein transport By journals.iucr.org Published On :: This article reports conformational polymorphisms of the EF-hand protein MCFD2 which is involved in glycoprotein transport.. Full Article text
tall Structure of the dihydrolipoamide succinyltransferase catalytic domain from Escherichia coli in a novel crystal form: a tale of a common protein crystallization contaminant By scripts.iucr.org Published On :: 2019-08-29 The crystallization of amidase, the ultimate enzyme in the Trp-dependent auxin-biosynthesis pathway, from Arabidopsis thaliana was attempted using protein samples with at least 95% purity. Cube-shaped crystals that were assumed to be amidase crystals that belonged to space group I4 (unit-cell parameters a = b = 128.6, c = 249.7 Å) were obtained and diffracted to 3.0 Å resolution. Molecular replacement using structures from the PDB containing the amidase signature fold as search models was unsuccessful in yielding a convincing solution. Using the Sequence-Independent Molecular replacement Based on Available Databases (SIMBAD) program, it was discovered that the structure corresponded to dihydrolipoamide succinyltransferase from Escherichia coli (PDB entry 1c4t), which is considered to be a common crystallization contaminant protein. The structure was refined to an Rwork of 23.0% and an Rfree of 27.2% at 3.0 Å resolution. The structure was compared with others of the same protein deposited in the PDB. This is the first report of the structure of dihydrolipoamide succinyltransferase isolated without an expression tag and in this novel crystal form. Full Article text
tall An extracellular domain of the EsaA membrane component of the type VIIb secretion system: expression, purification and crystallization By scripts.iucr.org Published On :: 2019-11-20 The membrane protein EsaA is a conserved component of the type VIIb secretion system. Limited proteolysis of purified EsaA from Staphylococcus aureus USA300 identified a stable 48 kDa fragment, which was mapped by fingerprint mass spectrometry to an uncharacterized extracellular segment of EsaA. Analysis by circular dichroism spectroscopy showed that this fragment folds into a single stable domain made of mostly α-helices with a melting point of 34.5°C. Size-exclusion chromatography combined with multi-angle light scattering indicated the formation of a dimer of the purified extracellular domain. Octahedral crystals were grown in 0.2 M ammonium citrate tribasic pH 7.0, 16% PEG 3350 using the hanging-drop vapor-diffusion method. Diffraction data were analyzed to 4.0 Å resolution, showing that the crystals belonged to the enantiomorphic tetragonal space groups P41212 or P43212, with unit-cell parameters a = 197.5, b = 197.5, c = 368.3 Å, α = β = γ = 90°. Full Article text
tall Engineering the Fab fragment of the anti-IgE omalizumab to prevent Fab crystallization and permit IgE-Fc complex crystallization By scripts.iucr.org Published On :: 2020-03-02 Immunoglobulin E (IgE) plays a central role in the allergic response, in which cross-linking of allergen by Fc∊RI-bound IgE triggers mast cell and basophil degranulation and the release of inflammatory mediators. The high-affinity interaction between IgE and Fc∊RI is a long-standing target for therapeutic intervention in allergic disease. Omalizumab is a clinically approved anti-IgE monoclonal antibody that binds to free IgE, also with high affinity, preventing its interaction with Fc∊RI. All attempts to crystallize the pre-formed complex between the omalizumab Fab and the Fc region of IgE (IgE-Fc), to understand the structural basis for its mechanism of action, surprisingly failed. Instead, the Fab alone selectively crystallized in different crystal forms, but their structures revealed intermolecular Fab/Fab interactions that were clearly strong enough to disrupt the Fab/IgE-Fc complexes. Some of these interactions were common to other Fab crystal structures. Mutations were therefore designed to disrupt two recurring packing interactions observed in the omalizumab Fab crystal structures without interfering with the ability of the omalizumab Fab to recognize IgE-Fc; this led to the successful crystallization and subsequent structure determination of the Fab/IgE-Fc complex. The mutagenesis strategy adopted to achieve this result is applicable to other intractable Fab/antigen complexes or systems in which Fabs are used as crystallization chaperones. Full Article text
tall Rv0100, a proposed acyl carrier protein in Mycobacterium tuberculosis: expression, purification and crystallization. Corrigendum By scripts.iucr.org Published On :: 2020-04-02 The true identity of the protein found in the crystals reported by Bondoc et al. [(2019), Acta Cryst. F75, 646–651] is given. Full Article text
tall Open-access and free articles in Acta Crystallographica Section F: Structural Biology and Crystallization Communications By journals.iucr.org Published On :: Full Article Still image
tall Obese marmosets are more developmentally advanced as infants, study shows By insider.si.edu Published On :: Wed, 10 Apr 2013 15:35:46 +0000 Marmosets on track for obesity appeared to be more efficient in their feeding behavior. “Although all animals consumed the same amount of liquid, the ones […] The post Obese marmosets are more developmentally advanced as infants, study shows appeared first on Smithsonian Insider. Full Article Animals Research News Science & Nature mammals primates Smithsonian's National Zoo veterinary medicine
tall Windows Server 2019, autounattend install fails, No images are available.. By www.bleepingcomputer.com Published On :: 2020-04-23T16:30:52-05:00 Full Article
tall Macromolecular X-ray crystallography: soon to be a road less travelled? By scripts.iucr.org Published On :: 2020-04-30 The number of new X-ray crystallography-based submissions to the Protein Data Bank appears to be at the beginning of a decline, perhaps signalling an end to the era of the dominance of X-ray crystallography within structural biology. This letter, from the viewpoint of a young structural biologist, applies the Copernican method to the life expectancy of crystallography and asks whether the technique is still the mainstay of structural biology. A study of the rate of Protein Data Bank depositions allows a more nuanced analysis of the fortunes of macromolecular X-ray crystallography and shows that cryo-electron microscopy might now be outcompeting crystallography for new labour and talent, perhaps heralding a change in the landscape of the field. Full Article text
tall Accidentally deleting all data By www.bleepingcomputer.com Published On :: 2019-09-07T17:22:44-05:00 Full Article
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tall Windows 98 SE Installation Issues By www.bleepingcomputer.com Published On :: 2019-11-11T17:47:36-05:00 Full Article
tall Trouble installing Windows 98SE By www.bleepingcomputer.com Published On :: 2020-03-01T09:40:16-05:00 Full Article
tall A new method for in situ structural investigations of nano-sized amorphous and crystalline materials using mixed-flow reactors By scripts.iucr.org Published On :: 2019-08-23 Structural investigations of amorphous and nanocrystalline phases forming in solution are historically challenging. Few methods are capable of in situ atomic structural analysis and rigorous control of the system. A mixed-flow reactor (MFR) is used for total X-ray scattering experiments to examine the short- and long-range structure of phases in situ with pair distribution function (PDF) analysis. The adaptable experimental setup enables data collection for a range of different system chemistries, initial supersaturations and residence times. The age of the sample during analysis is controlled by adjusting the flow rate. Faster rates allow for younger samples to be examined, but if flow is too fast not enough data are acquired to average out excess signal noise. Slower flow rates form older samples, but at very slow speeds particles settle and block flow, clogging the system. Proper background collection and subtraction is critical for data optimization. Overall, this MFR method is an ideal scheme for analyzing the in situ structures of phases that form during crystal growth in solution. As a proof of concept, high-resolution total X-ray scattering data of amorphous and crystalline calcium phosphates and amorphous calcium carbonate were collected for PDF analysis. Full Article text
tall Cluster-mining: an approach for determining core structures of metallic nanoparticles from atomic pair distribution function data By scripts.iucr.org Published On :: 2020-01-01 A novel approach for finding and evaluating structural models of small metallic nanoparticles is presented. Rather than fitting a single model with many degrees of freedom, libraries of clusters from multiple structural motifs are built algorithmically and individually refined against experimental pair distribution functions. Each cluster fit is highly constrained. The approach, called cluster-mining, returns all candidate structure models that are consistent with the data as measured by a goodness of fit. It is highly automated, easy to use, and yields models that are more physically realistic and result in better agreement to the data than models based on cubic close-packed crystallographic cores, often reported in the literature for metallic nanoparticles. Full Article text
tall Freer Gallery opening projection art installation By insider.si.edu Published On :: Tue, 17 Oct 2017 18:08:16 +0000 A Projection Art Installation from the Smithsonian’s Freer Gallery of Art, “IlluminAsia Festival of Asian Art and Cultures” during the reopening celebration held in Oct. […] The post Freer Gallery opening projection art installation appeared first on Smithsonian Insider. Full Article Art History & Culture Video
tall Installation of the Obama portraits By insider.si.edu Published On :: Thu, 22 Feb 2018 12:49:23 +0000 On February 12, 2018, the Smithsonian’s National Portrait Gallery unveiled its commissioned portraits of former President Barack Obama and Mrs. Michelle Obama by artists Kehinde […] The post Installation of the Obama portraits appeared first on Smithsonian Insider. Full Article Art History & Culture Video National Portrait Gallery
tall How To Resize Animated GIFs Without Installing Software By www.bleepingcomputer.com Published On :: 2008-08-20T00:01:15-05:00 Full Article
tall installation stuck on Windows is loading files By www.bleepingcomputer.com Published On :: 2020-02-21T20:31:22-05:00 Full Article
tall How to uninstall external hard drives By www.bleepingcomputer.com Published On :: 2020-03-21T07:51:14-05:00 Full Article
tall Removing Chrome Extension Installed By Virus By www.bleepingcomputer.com Published On :: 2020-05-08T19:15:01-05:00 Full Article
tall Forthcoming article in Acta Crystallographica Section E Crystallographic Communications By journals.iucr.org Published On :: Full Article Still image
tall Gjønnes Medal in Electron Crystallography – call for nominations By scripts.iucr.org Published On :: 2019-01-01 Full Article text
tall Selling reduction versus Niggli reduction for crystallographic lattices By scripts.iucr.org Published On :: 2019-01-01 The unit-cell reduction described by Selling and used by Delone (whose early publications were under the spelling Delaunay) is explained in a simple form. The transformations needed to implement the reduction are listed. The simplicity of this reduction contrasts with the complexity of Niggli reduction. Full Article text
tall How To Make A Horizontally Centered Box With Xhtml/css By www.bleepingcomputer.com Published On :: 2006-06-06T00:28:03-05:00 Full Article
tall How To Make A Horizontally Centered Box With Drop Shadows Using Xhtml/css By www.bleepingcomputer.com Published On :: 2006-06-16T03:07:52-05:00 Full Article
tall Uninstalling Garage Band By www.bleepingcomputer.com Published On :: 2020-03-23T06:56:49-05:00 Full Article
tall Stuck using bootcamp to install Windows 10 on a Macbook Pro By www.bleepingcomputer.com Published On :: 2020-04-22T04:23:24-05:00 Full Article
tall Crystallographic curiosities: polymorphism and structures with Z' > 1 By scripts.iucr.org Published On :: 2019-06-24 Full Article text