Synthesis of ruthenium@graphene nanomaterials in propylene carbonate as re-usable catalysts for the solvent-free hydrogenation of benzene

Ruthenium nanoparticles (Ru-NPs) can be deposited on thermally reduced graphite oxide (TRGO) in propylene carbonate (PC). Propylene carbonate is a biodegradable and non-toxic solvent. Synthesis of Ru-NPs and deposition on TRGO were achieved by decomposition of ruthenium dodecacarbonyl, Ru3(CO)12, by microwave irradiation. Ru@graphene nanomaterials were identified and characterized by high resolution transmission electron microscopy (TEM, HR-TEM), energy-dispersive X-ray diffraction (EDX), selected area electron diffraction (SAED), X-ray photoelectron spectroscopy (XPS) and powder X-ray diffraction (PXRD) with a small diameter and size distribution of Ru-NPs on TRGO. These Ru@graphene nanomaterials are active catalysts for the solvent-free hydrogenation of benzene to cyclohexane under mild conditions (100 °C, 10 bar) with activities of and over 90% conversion in at least ten consecutive runs

Transient N ‐glycosylation abnormalities likely due to a de novo loss‐of‐function mutation in the delta subunit of coat protein I

Accurate glycosylation of proteins is essential for their function and their intracellular transport. Numerous diseases have been described, where either glycosylation or intracellular transport of proteins is impaired. Coat protein I (COPI) is involved in anterograde and retrograde transport of proteins between endoplasmic reticulum and Golgi, where glycosylation takes place, but no association of defective COPI proteins and glycosylation defects has been described so far. We identified a patient whose phenotype at a first glance was reminiscent of PGM1 deficiency, a disease that also affects N-glycosylation of proteins. More detailed analyses revealed a different disease with a glycosylation deficiency that was only detectable during episodes of acute illness of the patient. Trio-exome analysis revealed a de novo loss-of-function mutation in ARCN1, coding for the delta-COP subunit of COPI. We hypothesize that the capacity of flow through Golgi is reduced by this defect and at high protein synthesis rates, this bottleneck also manifests as transient glycosylation deficiency

Hybrid materials of platinum nanoparticles and thiol-functionalized graphene derivatives

Hybrid materials of platinum nanoparticles (Pt-NP) and thiol-functionalized thermally reduced graphite oxide (TRGO-SH), were synthesized by thermal decomposition of the organometallic precursor methylcyclopentadienyl-trimethylplatinum(IV) in dispersions of TRGO-SH in the ionic liquid 1-n-butyl-3-methyl-imidazolium tetrafluoroborate under microwave-assisted heating conditions. For the kinetic stabilization of Pt-NPs on TRGO-SH no additional donor ligands were necessary. The ionic liquid acts as separator of the TRGO-SH graphene sheets and as kinetic stabilizing template in the Pt-nanoparticle formation process. Thiol-functionalization of thermally reduced graphite oxide was carried out using three different synthetic procedures: (1) ring opening of propylene sulfide; (2) xanthate grafting and reduction to thiol; (3) reduction, thioesterfication under Mitsunobu conditions and ester hydrolysis. These three different TRGO-SH materials (1), (2) and (3) had different sulfur contents (1.2, 2.5 and 14 wt.%, respectively) and were used as support materials for platinum nanoparticles. The loading of Pt-NPs on TRGO-SH (1), (2) and (3) was 3.2, 3.5 and 8.8 wt.% with particle diameters determined from transmission electron microscopy of (9 ± 4), (2.5 ± 0.9) and (5 ± 2) nm, respectively. © 2013 Elsevier Ltd. All rights reserved

Parosmia as a predictor of a better olfactory function in COVID-19: a multicentric longitudinal study for upper respiratory tract infections

Purpose: This study aimed to evaluate the course of olfactory dysfunction [OD] due to upper respiratory tract infections [URTI] especially for COVID-19 [C19] in a multicentric design and to investigate possible predictors for the outcome. Methods: In a multicentric study, patients (n = 147, of which 96 were women) with OD due to URTI, including C19 and non-C19 were evaluated at two visits with a standardized medical history and "Sniffin' Sticks" extended psychophysical testing to examine the course and possible predictors for improvement of olfactory function. Results: C19 patients showed better overall olfactory function (p < 0.001) compared to non-C19. Olfactory function (p < 0.001) improved over 3.5 ± 1.2 months in a comparable fashion for C19 and non-C19 comparable over time (p = 0.20) except for a more pronounced improvement of odour threshold (p = 0.03) in C19. C19 patients with parosmia exhibited a higher probability of clinically relevant improvement of odour threshold, a better threshold in the second visit, and tended to have a better TDI-score at the second visit. Further possible predictors for an improving olfactory function were younger age, female gender, and had lower scores in olfactory tests at the first visit. Conclusions: Patients with C19 and non-C19 URTI exhibit a similar improvement over 3-4 months except for the odour threshold, with a better TDI in both visits for C19. For C19 a better prognosis in terms of olfactory recovery was found for younger patients with parosmia and lower olfactory scores at the first visit. Still, for many patients with olfactory loss, an improvement that is experienced as complete may only occur over months and possibly years

Group A Streptococcus strains causing meningitis without distinct invasive phenotype

Abstract Group A streptococcal (GAS; aka Streptococcus pyogenes) meningitis is a fulminant disease associated with high morbidity and mortality. To elucidate the mechanisms underlying the invasiveness of GAS in meningitis, we compared GAS isolates derived from five cases of meningitis to otitis and colonizing isolates. We did not observe differences in adherence to and invasion of human brain microvascular endothelial cells, virulence factors activity, or barrier disruption. Whole genome sequencing did not reveal particular invasiveness traits. Most patients previously suffered from otitis media suggesting that meningitis likely resulted from a continuous spread of the infection rather than being attributable to changes in the pathogen's virulence