Innovative synthetical and structural features of new aryltellurenyl iodides

The syntheses and the structural characterization of the compounds [(mes)₂Te–Te(I)mes], (PyH)[mesTeI₃(I₃)] (mes = mesityl = 2,4,6-trimethylphenyl; Py = pyridine), (PyH)₃[dmephTeI₂(I₂)]₂(I₃) (dmeph = 2,6-dimethylphenyl), (PyH)₂[RTeI₄]₂·(CH₃)CO(CH₃)·C₆H₅CH₃ (R = p-tert-butylphenyl) and (PyH)₂[PhTeI₄]₂ (Ph = phenyl) are presented. Some earlier analog preparations are compared and the influence of ortho substituents in the aryl group on the oxidation state of tellurium is discussed, as well as the observed conditions for the formation of poly-iodides chains.     

Passively Q-switched Tm:YLF laser

Stable passive Q-switching of a Tm: LiYF4 laser is obtained using polycrystalline Cr2+: ZnS as a saturable absorber. The achieved maximum pulse energy of 0.9 mJ and peak power of 65 kW for a pulse duration of ～14 ns represent substantial improvement and highest values for a passively Q-switched diode-pumped Tm laser operating at ～1.9 μm.     

Defining the Human-Biota Thresholds of Toxicological Concern for Organic Chemicals in Freshwater: The Proposed Strategy of the LIFE VERMEER Project Using VEGA Tools

Several tons of chemicals are released every year into the environment and it is essential to assess the risk of adverse effects on human health and ecosystems. Risk assessment is expensive and time-consuming and only partial information is available for many compounds. A consolidated approach to overcome this limitation is the Threshold of Toxicological Concern (TTC) for assessment of the potential health impact and, more recently, eco-TTCs for the ecological aspect. The aim is to allow a safe assessment of substances with poor toxicological characterization. Only limited attempts have been made to integrate the human and ecological risk assessment procedures in a “One Health” perspective. We are proposing a strategy to define the Human-Biota TTCs (HB-TTCs) as concentrations of organic chemicals in freshwater preserving both humans and ecological receptors at the same time. Two sets of thresholds were derived: general HB-TTCs as preliminary screening levels for compounds with no eco- and toxicological information, and compound-specific HB-TTCs for chemicals with known hazard assessment, in terms of Predicted No effect Concentration (PNEC) values for freshwater ecosystems and acceptable doses for human health. The proposed strategy is based on freely available public data and tools to characterize and group chemicals according to their toxicological profiles. Five generic HB-TTCs were defined, based on the ecotoxicological profiles reflected by the Verhaar classes, and compound-specific thresholds for more than 400 organic chemicals with complete eco- and toxicological profiles. To complete the strategy, the use of in silico models is proposed to predict the required toxicological properties and suitable models already available on the VEGAHUB platform are listed.     

Claisen Rearrangement of Hydroxynaphthoquinones: Selectivity toward Naphthofuran or α‐Xiloidone Using Copper Salts and Iodine

α‐xiloidone is an interesting chromene that are structurally related to lapachones; in this work, we selectively synthesized α‐xiloidone from the reaction of lawsone 1 with 3,3‐chloro‐3‐methylbut‐1‐yne under copper/I₂ catalysis via propargyl Claisen rearrangement.     

Reduction of evaporative flux in bean leaves due to chitosan treatment assessed by infrared thermography

Infrared thermography can be used as a tool for evaluating antitranspirant treatment through the measurement of evaporative fluxes. The aim of this work is to compare the leaf surface temperatures of plant treated with chitosan (CHT), a potential stomatal-closing antitranspirant, with temperatures of leaves treated with the commercially available antitranspirant Vapor Gard®, a film-forming polyterpene. The main problem in the correct evaluation of stomatal conductance at leaf level is due to the need of performing a measurement in a completely non-invasive method. The main advantage of thermographic method is the possibility to acquire information about instantaneous conditions of transpiration over a large number of plants, with no need of sampling and avoiding any contact with plants.Tests on bean plants (Phaseolus vulgaris) showed the applicability of the thermal imaging to discriminate plants with different evaporation rate due to treatment with different antitranspirant compounds. Quantitative evaluation of evaporative flux and stomatal conductance was obtained through reference measurements on standards with calibrated conductance. Non-destructive gravimetric measurements were used in order to get a reliable evaluation of evaporative fluxes. In conclusion, thermographic approach, in climatic chamber, seems to be a valid tool for rapidly screening the performance of different antitranspirant products.     

Convenient synthesis of furan-3-carboxylic acid and derivatives

A convenient synthesis of furan-3-carboxylic acid and derivatives from aromatization of 4-trichloroacetyl-2,3-dihydrofuran followed by nucleophilic displacement of the trichloromethyl group by hydroxide, alcohols, and amines, is presented.     

Dynamical suppression of 1/f noise processes in qubit systems

We investigate the capability of dynamical decoupling techniques to reduce decoherence from a realistic environment generating 1/f noise. The predominance of low frequency modes in the noise profile allows for decoherence scenarios where relatively slow control rates suffice for a drastic improvement. However, the actual figure of merit is very sensitive to the details of the dynamics, with decoupling performance which may deteriorate for non-Gaussian noise and/or high frequency working points. Our results are promising for robust solid-state qubits and beyond.     

Decoherence and 1/f noise in Josephson qubits

We propose and study a model of dephasing due to an environment of bistable fluctuators. We apply our analysis to the decoherence of Josephson qubits, induced by background charges present in the substrate, which are also responsible for the 1/f noise. The discrete nature of the environment leads to a number of new features which are mostly pronounced for slowly moving charges. Far away from the degeneracy this model for the dephasing is solved exactly.     

Non-Abelian holonomies,charge pumping,and quantum computation with Josephson junctions

Non-Abelian holonomies can be generated and detected in certain superconducting nanocircuits. Here we consider an example where the non-Abelian operations are related to the adiabatic charge dynamics of the Josephson network. We demonstrate that such a device can be applied both for adiabatic charge pumping and as an implementation of a quantum computer.