40 research outputs found
Pulmonary Metastases of Alveolar Soft-Part Sarcoma: CT Findings in Three Patients
Alveolar soft-part sarcoma is a rare soft tissue sarcoma of young adults with unknown histogenesis, and the organ most frequently involved in metastasis is the lung. We report the CT findings of three patients of pulmonary metastases of alveolar soft-part sarcoma, which manifested as clearly enhanced pulmonary nodules or masses. On enhanced scans, some of the masses were seen to contain dilated and tortuous intratumoral vessels
Glueballs, Hybrids, Multiquarks. Experimental facts versus QCD inspired concepts
The spectroscopy of light and heavy mesons is reviewed with emphasis on
glueballs, hybrids, and tetraquarks.Comment: 266 pages, 117 figures, 39 tables. to be published in Physics Report
Economic- environmental Foresight Modeling In Support To The Integrated Management Paradigm. A Framework Based On Green Accounting
info:eu-repo/semantics/nonPublishe
Breaking the Aliphatic Wall: Iridium-Catalyzed Direct Reductive Amination of Ketones and Secondary Amines
International audienceDirect reductive amination (DRA) is a ubiquitous reaction in organic chemistry. This transformation between a carbonyl group and an amine is most often achieved using super stoichiometric amount of hazardous hydride reagents, thus being incompatible with many sensitive functional groups. DRA could also be achieved by means of chemo- or bio-catalysis, thereby attracting the interest of industry as well as academic laboratories due to their virtually perfect atomeconomy. Although DRA are well-established for substrate pairs such as aldehydes with either 1 o or 2 o amines as well as ketones with 1 o amines, the current methodologies are limited in the case of ketones with 2 o amines. Herein, we present a general DRA protocol that overcomes this major limitation by means of iridium catalysis. The applicability of the methodology is demonstrated by accessing an unprecedented range of biologically relevant tertiary amines starting from both aliphatic ketones and aliphatic amines. The choice of a disphosphane ligand (Josiphos A or Xantphos) is essential for the success of the transformation
Iridium-Catalyzed Direct Reductive Amination of Ketones and Secondary Amines: Breaking the Aliphatic Wall
International audienceInvited for the cover of this issue are Matthieu Jouffroy from Discovery Process Research at Janssen Pharmaceutica N.V. and the group of Rafael Gramage-Doria at the University of Rennes. The image depicts an Ir-based catalytic system "fueled" by hydrogen for the direct reductive amination of ketones and secondary amines, allowing complex aliphatic tertiary amines to be prepared and, so, new chemical space to be reached. Read the full text of the article at 10.1002/chem.202201078
Combined Intrathoracic and Intraperitoneal Splenosis after Splenic Injury: Case Report and Review of the Literature
Strategy for supplementing structure calculations using limited data with hydrophobic distance restraints
Analysis of proton NMR in hydrogen bonds in terms of lone-pair and bond orbital contributions
NMR spectroscopic parameters of the proton involved in hydrogen bonding are studied theoretically. The set of molecules includes systems with internal resonance-assisted hydrogen bonds, internal hydrogen bonds but no resonance stabilization, the acetic acid dimer (AAD), a DNA base pair, and the hydrogen succinate anion (HSA). Ethanol and guanine represent reference molecules without hydrogen bonding. The calculations are based on zero-point vibrationally averaged molecular structures in order to include anharmonicity effects in the NMR parameters. An analysis of the calculated NMR shielding and J-coupling is performed in terms of chemists orbitals, that is, localized molecular orbitals (LMOs) representing lone-pairs, atomic cores, and bonds. The LMO analysis associates some of the strong de-shielding of the protons in resonance-assisted hydrogen bonds with delocalization involving the Ï€-backbone. Resonance is also shown to be an important factor causing de-shielding of the OH protons for AAD and HSA, but not for the DNA base pair. Nitromalonamide (NMA) and HSA have particularly strong hydrogen bonds exhibiting signs of covalency in the associated J-couplings. The analysis results show how NMR spectroscopic parameters that are characteristic for hydrogen bonded protons are influenced by the geometry and degree of covalency of the hydrogen bond as well as intra- and intermolecular resonance.Fil: Sutter, Kiplangat. State University of New York at Bufalo; Estados UnidosFil: Aucar, Gustavo Adolfo. Consejo Nacional de Investigaciones CientÃficas y Técnicas. Centro CientÃfico Tecnológico Conicet - Nordeste. Instituto de Modelado e Innovación Tecnológica. Universidad Nacional del Nordeste. Facultad de Ciencias Exactas Naturales y Agrimensura. Instituto de Modelado e Innovación Tecnologica; ArgentinaFil: Autschbach, Jochen. State University of New York at Bufalo; Estados Unido
Comparative computational analysis of prion proteins reveals two fragments with unusual structural properties and a pattern of increase in hydrophobicity associated with disease-promoting mutations
Prion diseases are a group of neurodegenerative disorders associated with conversion of a normal prion protein, PrPC, into a pathogenic conformation, PrPSc. The PrPSc is thought to promote the conversion of PrPC. The structure and stability of PrPC are well characterized, whereas little is known about the structure of PrPSc, what parts of PrPC undergo conformational transition, or how mutations facilitate this transition. We use a computational knowledge-based approach to analyze the intrinsic structural propensities of the C-terminal domain of PrP and gain insights into possible mechanisms of structural conversion. We compare the properties of PrP sequences to those of a PrP paralog, Doppel, and to the distributions of structural propensities observed in known protein structures from the Protein Data Bank. We show that the prion protein contains at least two sequence fragments with highly unusual intrinsic propensities, PrP(114–125) and helix B. No segments with unusual properties were found in Doppel protein, which is topologically identical to PrP but does not undergo structural rearrangements. Known disease-promoting PrP mutations form a statistically significant cluster in the region comprising helices B and C. Due to their unusual properties, PrP(114–125) and the C terminus of helix B may be considered as primary candidates for sites involved in conformational transition from PrPC to PrPSc. The results of our study also show that most PrP mutations associated with neurodegenerative disorders increase local hydrophobicity. We suggest that the observed increase in hydrophobicity may facilitate PrP-to-PrP or/and PrP-to-cofactor interactions, and thus promote structural conversion