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Comprehensive approach to diagnostic cytology within endometrial pathology (overview of books).
© 2020 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.Copper-oxo clusters exchanged in zeolite mordenite are active in the stoichiometric conversion of methane to methanol at low temperatures. Here, we show unprecedented methanol yield per Cu of 0.6, with a 90-95 % selectivity, on a MOR solely containing [Cu3(μ-O)3]2+ active sites. DFT calculations, spectroscopic characterization and kinetic analysis show that increasing the chemical potential of methane enables the utilization of two µ-oxo bridge oxygen out of the three available in the tricopper oxo cluster structure. Methanol and methoxy groups are stabilized in parallel, leading to methanol desorption in the presence of water. © 2020 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.A general and efficient strategy for synthesis of tri-, hexa- and heptasaccharidic substructures of the lipopoly-saccharide of Providencia rustigianii O34 is described. For the heptasaccharide seven different building blocks were employed. Special features of the structures are an α-linked galactosamine and the two embedded α fucose units which are either branched at positions 3 and 4 or further linked at their 2 position. Convergent strategies focused on [4+3], [3+4], and [4+2+1] couplings. Whereas the [4+3] and [3+4] coupling strategies failed the [4+2+1] strategy was successful. As monosaccharidic building blocks trichloroacetimidates and phosphates were employed. Global deprotection of the fully protected structures was achieved by Birch reaction. © 2020 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.The gold-catalyzed cyclization of 1,5-diynes with ketones as reagents and solvent provides diversely substituted vinyl ethers under mild conditions. The regioselectivity of such gold-catalyzed cyclizations is usually controlled by the scaffold of the diyne. Herein we report the first solvent-controlled switching of regioselectivity from a 6-endo-dig- to 5-endo-dig-cyclisation in these transformations, providing fulvene derivatives. With respect to the functional group tolerance, aryl fluorides, chlorides, bromides and carboxylates are tolerated, Furthermore, the mechanism and selectivity are put to scrutiny by experimental studies and a thermodynamic analysis of the product. Additionally, 6-(vinyloxy)fulvenes are a hitherto unknown class of compounds. Their reactivity is briefly evaluated, to give insights into their potential applications. © 2020 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.Nostoc sp. PCC 7120 are filamentous cyanobacteria capable of both oxygenic photosynthesis and nitrogen fixation, with the latter taking place in specialized cells known as heterocysts that terminally differentiate from vegetative cells under conditions of nitrogen starvation. Cyanobacteria have existed on earth for more than 2 billion years and are thought to be responsible for oxygenation of the earth's atmosphere. Filamentous cyanobacteria such as Nostoc sp. PCC 7120 may also represent the oldest multicellular organisms on earth that undergo cell differentiation. BGB-16673 ic50 Pentapeptide repeat proteins (PRPs), which occur most abundantly in cyanobacteria, adopt a right-handed quadrilateral β-helical structure, also referred to as a repeat five residue (Rfr) fold, with four-consecutive pentapeptide repeats constituting a single coil in the β-helical structure. PRPs are predicted to exist in all compartments within cyanobacteria including the thylakoid and cell-wall membranes as well as the cytoplasm and thylakoid periplasmic space. Despite their intriguing structure and importance to understanding ancient cyanobacteria, the biochemical function of PRPs in cyanobacteria remains largely unknown. Here we report the crystal structure of Alr1298, a PRP from Nostoc sp. PCC 7120 predicted to reside in the cytoplasm. The structure displays the typical right-handed quadrilateral β-helical structure and includes a four-α-helix cluster capping the N-terminus and a single α-helix capping the C-terminus. A gene cluster analysis indicated that Alr1298 may belong to an operon linked to cell proliferation and/or thylakoid biogenesis. Elevated alr1298 gene expression following nitrogen starvation indicates that Alr1298 may play a role in response to nitrogen starvation and/or heterocyst differentiation. © 2020 Wiley Periodicals, Inc.Polydopamine (PD) and melanin species are chemically complex systems whose formation and properties are incompletely understood. Inspired by the role of functional amyloids in melanin biosynthesis, this paper examines influences of amyloid supramolecular structures on oxidation polymerization of dopamine. Kinetic analyses on the formation of PD species in the presence of Hen Egg White Lysozyme (HEWL) fibers or soluble HEWL revealed that the both forms gave rise to the total quantity of PD species, but the rate of their formation could be accelerated only by the amyloid form. PD species formed with HEWL fibers showed a morphology of bundled fibers, whereas those with soluble HEWL had a mesh-like structure. Amyloid fibers of recombinant Pmel17 had a similar property with HEWL fibers in modulating PD formation. The results presented here suggests a way how nature designs functionality with an amyloid structure and would help understand or engineer chemistries of other functional amyloids. © 2020 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.NEW FINDINGS What is the topic of this review? This review concerns the negative impact of pulmonary hypertension (PH) on the pulmonary haemodynamic and gas exchange responses to exercise, considering the mechanisms by which PH plays a role in exercise intolerance in heart failure (HF) patients. What advances does it highlight? The hallmark limited pulmonary vascular 'reserve' and impaired pulmonary gas exchange responses to exercise in HF are worsened by the development of PH; these are key determinants of exercise intolerance. Even HF patients who present with 'normal' pulmonary vascular function experience exercise-induced PH, which plays a role in exercise intolerance. ABSTRACT Patients with heart failure universally complain of exertional intolerance, but the underlying cause(s) of this intolerance may differ between patients with different disease phenotypes. Exercise introduces an impressive stress to the lungs, where elevations in venous return and cardiac output engender substantial increases in pulmonary blood volume and flow.
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