Environmental Isolates of Azole-Resistant Aspergillus fumigatus in Germany

Azole antifungal drug resistance in Aspergillus fumigatus is an emerging problem in several parts of the world. Here we investigated the distribution of such strains in soils from Germany. At a general positivity rate of 12%, most prevalently, we found strains with the TR₃₄/L98H and TR₄₆/Y121F/T289A alleles, dispersed along a corridor across northern Germany. Comparison of the distributions of resistance alleles and genotypes between environment and clinical samples suggests the presence of local clinical clusters.     

Double orifice mitral valve; a coincidental finding.

A double orifice mitral valve (DOMV) represents a rare congenital malformation characterised by two valve orifices with two separate subvalvular apparatus. This case demonstrates the necessity of careful imaging of the mitral valve apparatus, not only in patients with atrioventricular septal defects, but also in patients with congenital left obstructive heart disease.     

A Pantetheinase-Resistant Pantothenamide with Potent,On-Target,and Selective Antiplasmodial Activity

Pantothenamides inhibit blood-stage Plasmodium falciparum with potencies (50% inhibitory concentration [IC₅₀], ∼20 nM) similar to that of chloroquine. They target processes dependent on pantothenate, a precursor of the essential metabolic cofactor coenzyme A. However, their antiplasmodial activity is reduced due to degradation by serum pantetheinase. Minor modification of the pantothenamide structure led to the identification of α-methyl-N-phenethyl-pantothenamide, a pantothenamide resistant to degradation, with excellent antiplasmodial activity (IC₅₀, 52 ± 6 nM), target specificity, and low toxicity.     

On the Ablation Behavior of Carbon Fiber-Reinforced Plastics during Laser Surface Treatment Using Pulsed Lasers

This contribution discusses the ablation phenomena observed during laser treatment of carbon fiber-reinforced plastics (CFRPs) with pulsed lasers observed employing laser sources with wavelengths of 355 nm, 1064 nm and 10.6 µm and pulse durations from picoseconds (11 ps) to microseconds (14 µs) are analyzed and discussed. In particular, the threshold fluence of the matrix material epoxy (EP) and the damage threshold of CFRP were calculated. Moreover, two general surface pretreatment strategies are investigated, including selective matrix removal and structure generation through indentation (ablation of both, matrix material and fibers) with a cross-like morphology. The surfaces obtained after the laser treatment are characterized by means of optical and scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy is employed for the analysis of composite and constituent materials epoxy and carbon fibers. As a result, different ablation mechanisms, including evaporation and delamination are observed, depending on the employed laser wavelength and pulse duration. For both 355 nm and 1064 nm wavelength, the laser radiation produces only partial ablation of the carbon fibers due to their higher absorption coefficient compared to the epoxy matrix. Although a selective matrix removal without residues is achieved using the pulsed CO₂ laser. Differently, both constituent materials are ablated with the nanosecond pulsed UV laser, producing indentations. The sum of the investigations has shown that existing theories of laser technology, such as the ablation threshold according to Liu et al., can be applied to composite materials only to a limited extent. Furthermore, it has been found that the pronounced heterogeneity of CFRP mostly leads to an inhomogeneous ablation result, both when creating grooves and during selective matrix removal, where the carbon fibers influence the ablation result by their thermal conductivity, depending on fiber direction. Finally, despite the material inhomogeneity, a scanning strategy has been developed to compensate the heterogeneous ablation results regarding structure depth, width and heat affected zone.     

Benzophenone assisted UV-activated synthesis of unique Pd-nanodendrite embedded reduced graphene oxide nanocomposite: a catalyst for C–C coupling reaction and fuel cell

In this work we report the use of benzophenone (BP) for the synthesis of a palladium (Pd) embedded on reduced graphene oxide (rGO) nanocomposite (Pd/rGO) using a simple aqueous solution and UV irradiation. The simple and facile evolution of thermodynamically unstable branched Pd(0) nanodendrites was achieved by BP photoactivation, circumventing the growth of more stable nanomorphologies. The synthesis of Pd(0)-embedded rGO nanosheets (PRGO-nd) was made possible by the simultaneous reduction of both the GO scaffold and PdCl₂ by introducing BP into the photoactivation reaction. The nanocomposites obtained in the absence of BP were common triangular and twinned Pd(0) structures which were also implanted on the rGO scaffold (PRGO-nt). The disparity in morphologies presumably occurs due to the difference in the kinetics of the reduction of Pd²⁺ to Pd⁰ in the presence and absence of the BP photoinitiator. It was observed that the PRGO-nd was composed of dense arrays of multiple Pd branches around nucleation site which exhibited (111) facet, whereas PRGO-nt showed a mixture of (100) and (111) facets. On comparing the catalytic efficiencies of the as-synthesized nanocatalysts, we observed a superiority in efficiency of the thermodynamically unstable PRGO-nd nanocomposite. This is due to the evolved active facets of the dendritic Pd(0) morphology with its higher surface area, as testified by Brunauer–Emmett–Teller (BET) analysis. Since both PRGO-nd and PRGO-nt contain particles of similar size, the dents and grooves in the structure are the cause of the increase in the effective surface area in the case of nanodendrites. The unique dendritic morphology of the PRGO-nd nanostructures makes them a promising material for superior catalysis, due to their high surface area, and the high density of surface atoms at their edges, corners, and stepped regions. We investigated the efficiency of the as-prepared PRGO-nd catalyst in the Suzuki–Miyaura coupling reaction and showed its proficiency in a 2 h reaction at 60 °C using 2 mol% catalyst containing 0.06 mol% active Pd. Moreover, the electrochemical efficiency for the catalytic hydrogen evolution reaction (HER) was demonstrated, in which PRGO-nd provided a decreased overpotential of 68 mV for a current density of 10 mA cm⁻², a small Tafel slope of 57 mV dec⁻¹ and commendable stability during chronoamperometric testing for 5 h.

Benzophenone photoinitiator aided synthesis of Pd-nanodendrite embedded rGO nanocatalyst possessing superior potential in C–C coupling reaction and fuel cell application.