Commercially available coumarin 343 in combination with reducible Sm(III) ions catalyzed divalent lanthanide-mediated C═O, C-halogen, P-Cl, and N═N reductions at ambient temperature in aqueous solvent mixtures. The catalyst absorbs visible light efficiently. The active divalent species is formed by photoinduced electron transfer from coumarin 343 to the stable trivalent precursor, and the coumarin could be regenerated by strictly 1 equiv of ascorbic acid.
View Article and Find Full Text PDFUnlabelled: To elaborate expert consensus patient pathways to guide patients and physicians toward efficient diagnostics and management of patients with venous malformations.
Methods: VASCERN-VASCA (https://vascern.eu/) is a European network of multidisciplinary centers for Vascular Anomalies.
Lymphatic malformations (LMs) are developmental defects of lymphatic vessels. LMs are histologically benign lesions, however, due to localization, size, and unexpected swelling, they may cause serious complications that threaten vital functions such as compression of the airways. A large swelling of the face or neck may also be disfiguring and thus constitute a psychological strain for patients and their families.
View Article and Find Full Text PDFThe European Reference Network on Rare Multisystemic Vascular Diseases (VASCERN), is dedicated to gathering the best expertise in Europe and provide accessible cross-border healthcare to patients with rare vascular diseases. Infantile Hemangiomas (IH) are benign vascular tumors of infancy that rapidly growth in the first weeks of life, followed by stabilization and spontaneous regression. In rare cases the extent, the localization or the number of lesions may cause severe complications that need specific and careful management.
View Article and Find Full Text PDFAnalysis of C NMR spectroscopic data of the phlegmarine subset of Lycopodium alkaloids revealed spectral patterns that allowed the stereochemical arrangement of the four stereogenic carbons in the decahydroquinoline core to be established. A relatively simple predictive set of chemical shift combinations is reported, providing a tool for the challenging stereochemical assignment of phlegmarine-type alkaloids. Based on the chemical shifts in their NMR spectroscopic profiles, the alkaloids huperzine K and huperzine M, formally reported as cis derivatives, were structurally reassigned as trans-decahydroquinolines.
View Article and Find Full Text PDFThe synthesis and self-assembly of a water-soluble bolaamphiphilic cyclopenta[hi]aceanthrylene derivative is described. Self-assembly in aqueous medium leads to the formation of supramolecular vesicles with intense absorption bands over an extended range of the UV/vis spectral region and a narrow HOMO-LUMO bandgap of 1.65 eV.
View Article and Find Full Text PDFVesicle-shaped supramolecular polymers are formed by self-assembly of a DNA duplex containing phenanthrene overhangs at both ends. In the presence of spermine, the phenanthrene overhangs act as sticky ends linking the DNA duplexes together. In aqueous solution, the assembly leads to vesicles with a diameter in the range of 50-200 nm.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
January 2018
An unprecedented C-C coupling reaction between alkenes and ketones by hydrogen-atom transfer, using Fe(acac) and PhSiH in EtOH, is described. This mild protocol features high site selectivity and allows the construction of sterically congested structures containing tertiary alcohols and quaternary centers. The overall process introduces a novel strategic bond disconnection for ring-closing reactions.
View Article and Find Full Text PDFObjectives: To define appropriate antibiotic use in hospitalized adults treated for a bacterial infection, we previously developed and validated a set of six generic quality indicators (QIs) covering all steps in the process of antibiotic use. We assessed the association between appropriate antibiotic use, defined by these QIs, and length of hospital stay (LOS).
Methods: An observational multicentre study in 22 hospitals in the Netherlands included 1890 adult, non-ICU patients using antibiotics for a suspected bacterial infection.
A straightforward, two-step asymmetric synthesis of octahydroindoles has been developed on the basis of two complementary strategies: (i) an organocatalyzed Michael reaction followed by a tandem Robinson-aza-Michael double cyclization catalyzed by PS-BEMP, and (ii) a diastereoselective cyclization, which formally constitutes a remote 1,6 asymmetric induction mediated by PS-BEMP. This allowed the construction of complex octahydroindoles with up to four stereocenters, excellent enantioselectivities (up to 95% ee), and complete diastereoselective control in a single-pot operation. DFT calculations were performed to understand the origin of this effect.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
August 2016
A 2,7-disubstituted phosphodiester-linked phenanthrene trimer forms tubular structures in aqueous media. Chromophores are arranged in H-aggregates. Incorporation of small quantities of pyrene results in the development of light-harvesting nanotubes in which phenanthrenes act as antenna chromophores and pyrenes as energy acceptors.
View Article and Find Full Text PDFA revised structure for the Lycopodium alkaloid huperzine N is proposed and confirmed by synthesis. The key synthetic steps involve an epimerization of a cis-5-oxodecahydroquinoline to the corresponding trans isomer and a coupling, followed by a diastereoselective hydrogenation using Wilkinson's catalyst to incorporate the pyridylmethyl moiety. This route allowed the alkaloid serralongamine A to be synthesized for the first time, and two additional steps led to the revised structure of huperzine N, both products bearing an unusual decahydroquinoline stereostructure.
View Article and Find Full Text PDFA unified strategy for the synthesis of the cis-phlegmarine group of alkaloids is presented, leading to the first synthesis of serratezomine E (1) as well as the putative structure of huperzine N (2). A contrasteric hydrogenation method was developed based on the use of Wilkinson's catalyst, which allowed the facial selectivity of standard hydrogenation to be completely overturned. Calculations were performed to determine the mechanism, and structures for huperzines M and N are reassigned.
View Article and Find Full Text PDFBackground: An important requirement for an effective antibiotic stewardship program is the ability to measure appropriateness of antibiotic use. The aim of this study was to develop quality indicators (QIs) that can be used to measure appropriateness of antibiotic use in the treatment of all bacterial infections in hospitalized adult patients.
Methods: A RAND-modified Delphi procedure was used to develop a set of QIs.
Background: Outcomes in patients with sepsis are better if initial empirical antimicrobial use is appropriate. Several studies have shown that adherence to guidelines dictating appropriate antimicrobial use positively influences clinical outcome, shortens length of hospital stay and contributes to the containment of antibiotic resistance.Quality indicators (QIs) can be systematically developed from these guidelines to define and measure appropriate antimicrobial use.
View Article and Find Full Text PDFA general method for the synthesis of amides involving the direct coupling of alkali metal carboxylate salts with amines is described. Amidation of a wide variety of carboxylate salts with either free amines or their ammonium hydrochloride salts can be achieved using HBTU as a coupling agent in combination with Hünig's base. The reaction is highly efficient and is generally complete in as little as 1-2 h, giving the products in good to excellent yields.
View Article and Find Full Text PDFAs in other countries, the growing resistance to antimicrobial drugs is also taking place in the Netherlands; the primary cause being the total consumption of antibiotics. Given the steady decline in the discovery of new antimicrobials, better use of agents currently available is warranted. Guidelines describing appropriate antimicrobial therapy play an important role; however, such guidelines are not optimally used in daily practice.
View Article and Find Full Text PDFPurpose: Urological characteristics of renal ectopia have been addressed previously but little is known about the functional consequences. We sought to study renal function, blood pressure, proteinuria and urological abnormalities in children with renal ectopia. As a secondary objective, we compared these parameters between simple and crossed ectopia.
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