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The distribution and residue depletion of thiamphenicol (TAP) were studied in seabass (Dicentrarchus labrax L.) and seabream (Sparus aurata L.) reared in field conditions at temperatures of 20–28 °C. The drug was administered orally as medicated feed at the rate of 40 mg active ingredient (a.i.) kg−1 of biomass once a day for 5 days. Samples of muscle, liver, skin and vertebrae from 10 fishes were collected on the 2nd and 4th day of treatment and 1, 2, 3, 5, 7, 9, 12, 15, 18, 21, 24, 27 and 30 days after the last administration of the drug, and were stored at −20 °C. Quantitative analysis of TAP was performed by high performance liquid chromatography (HPLC) after liquid‐liquid extraction; the quantification limits of the HPLC method were 0.02 μg/g for muscle, and 0.05–0.10 μg/g for the other tissues. In seabass, TAP concentrations during treatment were higher in liver and muscle than in skin and vertebrae, and rapidly decreased after the end of medication. Three days after treatment ceased, TAP was still detectable in liver (0.41 ± 0.23 μg/g), vertebrae (0.09 ± 0.03 μg/g) and in three out of 10 samples of muscle (0.03 μg/g), but not in skin. All tissues were below the limits of quantification on the 5th day of withdrawal. In seabream the highest TAP concentrations during treatment were measured in liver and skin, and their reduction after the end of medication was as rapid as that of seabass: on the 3rd day after treatment ceased traces were found in only four out of 10 samples of muscle (0.03 ± 0.00 μg/g) and vertebrae (0.08 ± 0.02 μg/g).

Around 40 years have passed since the first pioneering works introduced the possibility of using quantum physics to enhance communications safety. Nowadays, quantum key distribution (QKD) exited the physics laboratories to become a mature technology, triggering the attention of States, military forces, banks, and private corporations. This work takes on the challenge of bringing QKD closer to a consumer technology: deployed optical fibers by telecommunication companies of different States have been used to realize a quantum network, the first-ever connecting three different countries. This work also emphasizes the necessity of networks where QKD can come up besides classical communications, whose coexistence currently represents the main limitation of this technology. This network connects Trieste to Rijeka and Ljubljana via a trusted node in Postojna. A key rate of over 3 kbps in the shortest link and a 7-hour-long measurement demonstrate the system's stability and reliability. The network has been used to present the QKD at the G20 Digital Ministers' Meeting in Trieste. The experimental results, together with the interest that one of the most important events of international politics has attracted, showcase the maturity of the QKD technology bundle, placing it in the spotlight for consumer applications in the near term.

Use of random DNA amplification to generate specific molecular probes for hybridization tests and PCR-based diagnosis of Yersinia ruckeri ABSTRACT We have developed a fast and convenient detection method for the etiological agent of enteric redmouth disease in rainbow trout, the bacterium Yersinia ruckeri, using the random amplification of polymorphic DNA (RAPD) technique to design specific primers for a polymerase chain reaction (PCR)-based diagnosis. In the RAPD genomic fingerprint of Y ruckeri, a specific band was observed which gave no cross-hybridization with the genomes of other bacteria in Southern blot analysis. This band was cloned, sequenced, and found to bear no homology with known DNA sequences. Two primers were then synthesized to amplify by PCR the fragment lying between the terminal RAPD primer sequences of the band. The PCR assay detected specifically 3 serotypes of Y ruckeri (serotypes 01, 0 2 , and unknown) in samples with whole bacteria. It also detected the bacterium in kidney tissue from infected trout after brief digestion with proteinase K. Sample preparation was kept simple to minimize the risk of false positives due to inter-sample contamination. Because of its speed, inherent sensitivity, and apparent specificity we concluded that this diagnostic system was preferable to conventional bacteriological diagnostic tests.