scholarly journals (R)-10-Hydroxystearic Acid: Crystals vs. Organogel

2020 ◽  
Vol 21 (21) ◽  
pp. 8124
Author(s):  
Fioretta Asaro ◽  
Carla Boga ◽  
Rita De Zorzi ◽  
Silvano Geremia ◽  
Lara Gigli ◽  
...  
Keyword(s):  
Structural Information ◽  
Hydroxystearic Acid ◽  
Structural Determinants ◽  
Oh Groups ◽  
X Ray ◽  
Hydrogen Bonding Interactions ◽  
Low Molecular Weight Organogelators ◽  
Its Polymorphism

The chiral (R)-10-hydroxystearic acid ((R)-10-HSA) is a positional homologue of both (R)-12-HSA and (R)-9-HSA with the OH group in an intermediate position. While (R)-12-HSA is one of the best-known low-molecular-weight organogelators, (R)-9-HSA is not, but it forms crystals in several solvents. With the aim to gain information on the structural role of hydrogen-bonding interactions of the carbinol OH groups, we investigated the behavior of (R)-10-HSA in various solvents. This isomer displays an intermediate behavior between (R)-9 and (R)-12-HSA, producing a stable gel exclusively in paraffin oil, while it crystallizes in other organic solvents. Here, we report the X-ray structure of a single crystal of (R)-10-HSA as well as some structural information on its polymorphism, obtained through X-ray Powder Diffraction (XRPD) and Infrared Spectroscopy (IR). This case study provides new elements to elucidate the structural determinants of the microscopic architectures that lead to the formation of organogels of stearic acid derivatives.

scholarly journals Chest CT as a Complement to RT-PCR to Confirm and Follow-up COVID-19 Patients

Medicinus ◽  
2021 ◽  
Vol 8 (1) ◽  
pp. 31
Author(s):  
Aziza Ghanie Icksan ◽  
Muhammad Hafiz ◽  
Annisa Dian Harlivasari
Keyword(s):  
Chest Ct ◽  
Rt Pcr ◽  
High Resolution Computed Tomography ◽  
X Ray ◽  
First Case ◽  
Chest X Ray ◽  
Polymerase Chain

<p><strong>Background : </strong>The first case of COVID-19 in Indonesia was recorded in March 2020. Limitation of reverse-transcription polymerase chain reaction (RT-PCR) has put chest CT as an essential complementary tool in the diagnosis and follow up treatment for COVID-19. Literatures strongly suggested that High-Resolution Computed Tomography (HRCT) is essential in diagnosing typical symptoms of COVID-19 at the early phase of disease due to its superior sensitivity  (97%) compared to chest x-ray (CXR).</p><p>The two cases presented in this case study showed the crucial role of chest CT with HRCT to establish the working diagnosis and follow up COVID-19 patients as a complement to RT-PCR, currently deemed a gold standard.<strong></strong></p>

Who’s Teaching Whom? Disability and Deaf Studies Approaches to the Health Humanities

2019 ◽  
pp. 207-229 ◽  
Author(s):  
Rebecca Garden
Keyword(s):  
Inclusive Education ◽  
Disability Studies ◽  
Determinants Of Health ◽  
Deaf Studies ◽  
Structural Determinants ◽  
Health Humanities ◽  
The Social ◽  
Basic Approaches

This chapter contributes to health humanities pedagogy by addressing the social and structural dimensions of health and healthcare through the theories and practices of disability studies. It begins by discussing the role of disability studies in health humanities approaches to social and structural determinants of health, as well as the sometimes vexed relationship between the two fields. It discusses shared commitments to the pedagogical use of narrative and provides a case study of inclusive education in practice. This chapter represents disability studies critiques of health humanities as welcome challenges to deepen its pedagogy and practices. It also maps out arguments for and some basic approaches to access in the classroom, describing pedagogy that is accountable to the claims of disability justice in practice as well as theory.

Multi-wavelength flares and magnetic field in blazars: a case study of IBL S5 0716+714

2016 ◽  
Vol 12 (S324) ◽  
pp. 203-206
Author(s):  
S. Chandra ◽  
K. P. Singh ◽  
K. S. Baliyan
Keyword(s):  
Magnetic Field ◽  
Energy Distribution ◽  
Spectral Index ◽  
Particle Energy ◽  
X Ray ◽  
Peak Flux ◽  
Multi Wavelength

AbstractWe present a study performed to understand the role of magnetic field during a historical outburst of IBL S5 0716+714 witnessed in early 2015. The two month long profile of the outburst reveals several episodes of sub-flares superimposed over the diminishing trend of the peak-flux. The broadband X-ray spectrum from Swift + Nustar exhibits a break at 4.9+0.4−0.5 keV which is consistent with the valley in the SED predicted by model. The spectral index variations, closely correlated to the flux variations during the first prominent sub-flare, indicate the alterations in the particle energy distribution coinciding the onset of the flare. The PA rotations approximately at the same epoch are used to constrain the field and its geometry.

scholarly journals Exploring the atomic structure and conformational flexibility of a 320 Å long engineered viral fiber using X-ray crystallography

2014 ◽  
Vol 70 (2) ◽  
pp. 342-353 ◽  
Author(s):  
Anshul Bhardwaj ◽  
Sherwood R. Casjens ◽  
Gino Cingolani
Keyword(s):  
High Resolution ◽  
Quaternary Structure ◽  
Structural Information ◽  
Repeat Unit ◽  
Three Dimensional ◽  
Structural Determinants ◽  
X Ray ◽  
Fiber Assembly ◽  
Protein Fibers ◽  
Protein Fiber

Protein fibers are widespread in nature, but only a limited number of high-resolution structures have been determined experimentally. Unlike globular proteins, fibers are usually recalcitrant to form three-dimensional crystals, preventing single-crystal X-ray diffraction analysis. In the absence of three-dimensional crystals, X-ray fiber diffraction is a powerful tool to determine the internal symmetry of a fiber, but it rarely yields atomic resolution structural information on complex protein fibers. An 85-residue-long minimal coiled-coil repeat unit (MiCRU) was previously identified in the trimeric helical core of tail needle gp26, a fibrous protein emanating from the tail apparatus of the bacteriophage P22 virion. Here, evidence is provided that an MiCRU can be inserted in frame inside the gp26 helical core to generate a rationally extended fiber (gp26-2M) which, like gp26, retains a trimeric quaternary structure in solution. The 2.7 Å resolution crystal structure of this engineered fiber, which measures ∼320 Å in length and is only 20–35 Å wide, was determined. This structure, the longest for a trimeric protein fiber to be determined to such a high resolution, reveals the architecture of 22 consecutive trimerization heptads and provides a framework to decipher the structural determinants for protein fiber assembly, stability and flexibility.

scholarly journals HDX-MS reveals structural determinants for RORγ hyperactivation by synthetic agonists

eLife ◽  
2019 ◽  
Vol 8 ◽  
Author(s):  
Timothy S Strutzenberg ◽  
Ruben D Garcia-Ordonez ◽  
Scott J Novick ◽  
HaJeung Park ◽  
Mi Ra Chang ◽  
...  
Keyword(s):  
Small Molecules ◽  
Structural Dynamics ◽  
Site Directed Mutagenesis ◽  
Chemical Probes ◽  
Structural Determinants ◽  
X Ray ◽  
Synthetic Ligand ◽  
Hdx Ms

Members of the nuclear receptor (NR) superfamily regulate both physiological and pathophysiological processes ranging from development and metabolism to inflammation and cancer. Synthetic small molecules targeting NRs are often deployed as therapeutics to correct aberrant NR signaling or as chemical probes to explore the role of the receptor in physiology. Nearly half of NRs do not have specific cognate ligands (termed orphan NRs) and it’s unclear if they possess ligand dependent activities. Here we demonstrate that ligand-dependent action of the orphan RORγ can be defined by selectively disrupting putative endogenous—but not synthetic—ligand binding. Furthermore, the characterization of a library of RORγ modulators reveals that structural dynamics of the receptor assessed by HDX-MS correlate with activity in biochemical and cell-based assays. These findings, corroborated with X-ray co-crystallography and site-directed mutagenesis, collectively reveal the structural determinants of RORγ activation, which is critical for designing RORγ agonists for cancer immunotherapy.

Structural and functional properties of mouse proNGF

2006 ◽  
Vol 34 (4) ◽  
pp. 605-606 ◽  
Author(s):  
F. Paoletti ◽  
P.V. Konarev ◽  
S. Covaceuszach ◽  
E. Schwarz ◽  
A. Cattaneo ◽  
...  
Keyword(s):  
Structural Determinants ◽  
Compact Structure ◽  
X Ray ◽  
Neurotrophic Activity ◽  
X Ray Scattering ◽  
Structural And Functional Properties ◽  
Physicochemical Methods ◽  
Pro Region

The unprocessed pro-form of the NGF (nerve growth factor), proNGF (NGF precursor, without signal peptide), has been suggested to have additional functions distinct from its role as a promoter of protein folding, i.e. apoptosis and/or neurotrophic activity. Aiming to gain insights into the specific molecular interactions that mediate proNGF biological activity and into the structural determinants stabilizing its pro-region, rm-proNGF (recombinant mouse proNGF) was expressed in Escherichia coli, refolded in vitro and characterized by physicochemical methods. X-ray solution scattering measurements (small angle X-ray scattering) revealed that rm-proNGF is dimeric in solution and appears to be anisometric when compared with the compact structure of the NGF dimer. Two structural models, a globular crab-like shape and an elongated rod-like shape, equally fit to the experimental results, pointing to an intrinsically structural disordered pro-region of NGF. The models obtained allowed the interpretation of TrkA (tropomyosin receptor kinase A) binding and activation assays in cell cultures, shedding new light on the key role of proNGF in neuronal survival and neurodegeneration.

scholarly journals Probing the Structural Determinants of Amino Acid Recognition: X-Ray Studies of Crystalline Ditopic Host-Guest Complexes of the Positively Charged Amino Acids, Arg, Lys, and His with a Cavitand Molecule

Molecules ◽  
2018 ◽  
Vol 23 (12) ◽  
pp. 3368 ◽  
Author(s):  
Giovanna Brancatelli ◽  
Enrico Dalcanale ◽  
Roberta Pinalli ◽  
Silvano Geremia
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Water Molecule ◽  
Rational Design ◽  
Structural Information ◽  
Amino Acid Side Chain ◽  
Structural Determinants ◽  
X Ray ◽  
Charged Amino Acids ◽  
Positively Charged

Crystallization of tetraphosphonate cavitand Tiiii[H, CH3, CH3] in the presence of positively charged amino acids, namely arginine, lysine, or histidine, afforded host-guest complex structures. The X-ray structure determination revealed that in all three structures, the fully protonated form of the amino acid is ditopically complexed by two tetraphosphonate cavitand molecules. Guanidinium, ammonium, and imidazolium cationic groups of the amino acid side chain are hosted in the cavity of a phosphonate receptor, and are held in place by specific hydrogen bonding interactions with the P=O groups of the cavitand molecule. In all three structures, the positively charged α-ammonium groups form H-bonds with the P=O groups, and with a water molecule hosted in the cavity of a second tetraphosphonate molecule. Furthermore, water-assisted dimerization was observed for the cavitand/histidine ditopic complex. In this 4:2 supramolecular complex, a bridged water molecule is held by two carboxylic acid groups of the dimerized amino acid. The structural information obtained on the geometrical constrains necessary for the possible encapsulation of the amino acids are important for the rational design of devices for analytical and medical applications.

{[(PhCH2Sn)12(μ3-O)14(μ-OH)6](F3CSO3)2}: A New Dodecanuclear Organostannoxane

2011 ◽  
Vol 66 (3) ◽  
pp. 262-268
Author(s):  
Laurent Plasseraud ◽  
Hélène Cattey ◽  
Philippe Richard
Keyword(s):  
Mass Spectrometry ◽  
Hydrogen Bonding ◽  
Room Temperature ◽  
Bond Cleavage ◽  
Trifluoromethanesulfonic Acid ◽  
Two Dimensional ◽  
X Ray Diffraction ◽  
Oh Groups ◽  
X Ray ◽  
Hydrogen Bonding Interactions

The new dodecanuclear organostannoxane {[(PhCH2Sn)12(μ3-O)14(μ-OH)6](F3CSO3)2} (2) has been isolated as single crystals from the reaction of trifluoromethanesulfonic acid (F3CSO3H) with the decanuclear dibenzyltin(IV)-oxo cluster, [(PhCH2)2SnO]6{[(PhCH2)2SnOH]2(CO3)}2 (1), in [D3]acetonitrile, at room temperature. Compound 2 was structurally characterized by X-ray diffraction analysis, multinuclear NMR and IR spectroscopy, mass spectrometry, and thermogravimetry. The structure of 2 can be described as a football cage framework containing twelve tin atoms, exhibiting two distinct coordination geometries, penta- and hexacoordinated respectively, and linked together through μ3-O and μ-OH ligands. Resulting from Sn-C bond cleavage, all tin atoms are only connected to one benzyl ligand. Furthermore, two of the three oxygen atoms of each trifluoromethanesulfonate counteranions are involved in hydrogen bonding interactions with bridging μ-OH groups of two distinct Sn12 cations leading to the propagation of a two-dimensional polymeric network.

scholarly journals Norbert Elias o muzyce i społeczeństwie — możliwości aplikacyjne społeczno-muzycznych figuracji

2015 ◽  
Vol 59 (1) ◽  
pp. 51-70
Author(s):  
Barbara Jabłońska
Keyword(s):  
Human Life ◽  
Structural Determinants ◽  
Professional Musicians ◽  
Musical Life ◽  
Political Factors ◽  
Norbert Elias ◽  
Human Practices ◽  
And Gender

The first aim of the article is to show the Elias perspective on phenomena connected with the musical life of society and to consider the figuration processes connected with human practices directed at music. The author reflects on the dual feedback of the activities of individuals and the structural determinants conditioning those activities. As an example, she discusses Elias’s case study of the socio-cultural and historical-economic background of Wolfgang Amadeus Mozart’s creativity. The second aim of the article is to show the possibility of applying socio-musical figuration to various areas of human life associated with music, beginning with the question of the role of professional musicians and gender questions, through the political factors connected with musical creativity, and ending with the presence of music in the religious sphere and the rules governing the sacral context. Her reflections are premised on the idea that socio-musical life based on social norms and rules established during the civilization process is simultaneously undergoing a constant modification and transformation on account of the subjective activities of individuals.

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