Radiocaesium pollution of fly agaric Amanita muscaria in fruiting bodies decreases with developmental stage

Amanita muscaria collected from a forested area in northern Poland in 2015 were analysed for activity concentrations of ¹³⁷Cs and ⁴⁰K. Total K concentration values were calculated from ⁴⁰K data. Mushrooms were grouped in six fruiting bodies size classes regarding to their developmental stage. The ¹³⁷Cs activity concentrations declined in A. muscaria as the fruiting bodies maturated. The contents of ⁴⁰K/K activity remained constant in caps at different developmental stage, while for stipes an increase was around twofold (⁴⁰K from 925?±?55 Bq kg^?1 dry biomass in the baby individuals and 1600?±?63–1700?±?53 Bq kg^?1 dry biomass in two oldest classes). A. muscaria is a weak accumulator of ¹³⁷Cs, while a steep drop in activity concentrations of this nuclide in the fruiting bodies as they maturate has not been reported earlier for mushrooms. Clearly, a fate of ¹³⁷Cs in A. muscaria is highly different from that of ⁴⁰K/K that is an essential element to fungi. In parallel, an observed increase in the content of ⁴⁰K/K in stipes of fruiting bodies with developmental state can be related to its ‘hardening’ and more fibrous nature with age and basic function to support the cap, but this has not been studied.     

Cooling overall spin temperature: protein NMR experiments optimized for longitudinal relaxation effects

In experiments performed on protonated proteins at high fields, 80% of the NMR spectrometer time is spent waiting for the ¹H atoms to recover their polarization after recording the free induction decay. Selective excitation of a fraction of the protons in a large molecule has previously been shown to lead to faster longitudinal relaxation for the selected protons [K. Pervushin, B. Vögeli, A. Eletsky, Longitudinal ¹H relaxation optimization in TROSY NMR spectroscopy, J. Am. Chem. Soc. 124 (2002) 12898–12902; P. Schanda, B. Brutscher, Very fast two-dimensional NMR spectroscopy for real-time investigation of dynamic events in proteins on the time scale of seconds, J. Am. Chem. Soc. 127 (2005) 8014–8015; H.S. Attreya, T. Szyperski, G-matrix Fourier transform NMR spectroscopy for complete protein resonance assignment, Proc. Natl. Acad. Sci. USA 101 (2004) 9642–9647]. The pool of non-selected protons acts as a “thermal bath” and spin-diffusion processes (“flip-flop” transitions) channel the excess energy from the excited pool to the non-selected protons in regions of the molecule where other relaxation processes can dissipate the excess energy. We present here a sensitivity enhanced HSQC sequence (COST-HSQC), based on one selective E-BURP pulse, which can be used on protonated ¹⁵N enriched proteins (with or without ¹³C isotopic enrichment). This experiment is compared to a gradient sensitivity enhanced HSQC with a water flip-back pulse (the water flip-back pulse quenches the spin diffusion between ¹H^N and ¹H^α spins). This experiment is shown to have significant advantages in some circumstances. Some observed limitations, namely sample overheating with short recovery delays and complex longitudinal relaxation behaviour are discussed and analysed.     

Synchronized cluster formation in coupled laser networks

We experimentally investigate the phase dynamics of laser networks with homogenous time-delayed mutual coupling and establish the fundamental rules that govern their state of synchronization. We identified a specific substructure that imposes its synchronization state on the entire network and show that for any coupling configuration the network forms at most two synchronized clusters. Our results indicate that the synchronization state of the network is a nonlocal phenomenon and cannot be deduced by decomposing the network into smaller substructures, each with its individual synchronization state.     

Acylation of novobiocin by carboxylic acid anhydrides: preparation and characterization of semi-synthetic novenamines

The acylation of novobiocin by carboxylic acid anhydrides leading to preparation of three families of semi-synthetic acylated novenamine analogues is reported. ESI-MS was used to monitor the reaction progress and enabled the isolation of intermediate compounds that provided insights into the sequence of acylation steps during the reaction. The chemoselectivity of the reaction depends on the carboxylic acid anhydride. The potential of the acylated novenamine analogues as leads for the development of antibacterial agents is discussed.     

Highly enantioselective addition of phenylethynylzinc to aldehydes using aziridine-functionalized tridentate sulfinyl ligands

Diastereomerically pure tridentate heteroorganic ligands containing hydroxyl, sulfinyl and aziridine moieties as nucleophilic centers, capable of binding to various organometallic reagents, have been proven to be highly efficient catalysts in the enantioselective addition of phenylethynylzinc to aldehydes to give the desired products in very high yields (up to 95%) and with ee’s up to 90%. The influence of the stereogenic centers located on the sulfinyl sulfur atom and in the aziridine moiety on the stereochemical course of the reaction is also discussed.     

Digital holographic cameras and data processing for remote monitoring and measurements of mechanical parts

Fast growing technology and requirements for testing of different types of materials and devices require new methods and systems for investigation of their parameters. Among the quantities of high interest are shape, deformation, roughness, local materials constants, displacement, and strain fields of elements under load. In the paper, we present novel solutions for digital holographic cameras, which allow for remote monitoring and measurement of the above mentioned quantities at small mechanical objects or at restricted areas of interest at big structures. The systems have compact design, “black box” measurement approach, and allows for fast and accurate measurements performed directly at the element and often in outdoor environment. The principles of digital and optoelectronic reconstruction and phase manipulation are described together with the exemplary measurement results obtained by means of the cameras presented.     

Air-dispersion measurement by second-harmonic heterodyne interferometry

Interferometers with long optical paths in air usually require knowledge and control of air dispersion. In addition, the measurements at several wavelengths and the dispersion properties of air allow errors caused by air turbulence to be compensated for. An innovative technique for air-dispersion measurement is described for long-baseline ground-based stellar interferometers. The technique combines second-harmonic interferometry and heterodyne detection to permit high-resolution measurement even for low optical powers. Experimental results show measurements of air dispersion in good agreement with the values predicted from the Edlén equation.     

Diastereoselective synthesis of tetrahydrofurans via reaction of gamma,delta-epoxycarbanions with aldehydes

[reaction: see text] Hydroxymethyl-substituted tetrahydrofurans were prepared with high diastereoselectivity by reaction of the carbanion derived from 3,4-epoxybutyl phenyl sulfone with aldehydes in the presence of a mixture of lithium and potassium tert-butoxides. Initial formation of aldol-type adducts is a nondiastereoselective but reversible process; thus, subsequent formation of one main diastereoisomer is controlled by the relative rates of cyclization. The configuration of the carbon stereocenter at the oxirane ring is inverted in the course of the S(N)2 process, and two new centers are created diastereoselectively.     

Secure key from bound entanglement

We characterize the set of shared quantum states which contain a cryptographically private key. This allows us to recast the theory of privacy as a paradigm closely related to that used in entanglement manipulation. It is shown that one can distill an arbitrarily secure key from bound entangled states. There are also states that have less distillable private keys than the entanglement cost of the state. In general, the amount of distillable key is bounded from above by the relative entropy of entanglement. Relationships between distillability and distinguishability are found for a class of states which have Bell states correlated to separable hiding states. We also describe a technique for finding states exhibiting irreversibility in entanglement distillation.