Photodynamic Inactivation of Legionella pneumophila Biofilm Formation by Cationic Tetra- and Tripyridylporphyrins in Waters of Different Hardness

The bacterium Legionella pneumophila is still one of the probable causes of waterborne diseases, causing serious respiratory illnesses. In the aquatic systems, L. pneumophila exists inside free-living amoebae or can form biofilms. Currently developed disinfection methods are not sufficient for complete eradication of L. pneumophila biofilms in water systems of interest. Photodynamic inactivation (PDI) is a method that results in an antimicrobial effect by using a combination of light and a photosensitizer (PS). In this work, the effect of PDI in waters of natural origin and of different hardness, as a treatment against L. pneumophila biofilm, was investigated. Three cationic tripyridylporphyrins, which were previously described as efficient agents against L. pneumophila alone, were used as PSs. We studied how differences in water hardness affect the PSs’ stability, the production of singlet oxygen, and the PDI activity on L. pneumophila adhesion and biofilm formation and in biofilm destruction. Amphiphilic porphyrin showed a stronger tendency for aggregation in hard and soft water, but its production of singlet oxygen was higher in comparison to tri- and tetracationic hydrophilic porphyrins that were stable in all water samples. All three studied porphyrins were shown to be effective as PDI agents against the adhesion of the L. pneumophila to polystyrene, against biofilm formation, and in the destruction of the formed biofilm, in their micromolar concentrations. However, a higher number of dissolved ions, i.e., water hardness, generally reduced somewhat the PDI activity of all the porphyrins at all tested biofilm growth stages

La vida está “al otro lado del mar”

Libro reseñado: Al otro lado del mar. María Cristina Restrepo. Bogotá, Alfaguara, 2017, 253 pp

Unconditionally secure digital signatures implemented in an eight-user quantum network

The ability to know and verifiably demonstrate the origins of messages can often be as important as encrypting the message itself. Here we present an experimental demonstration of an unconditionally secure digital signature (USS) protocol implemented for the first time, to the best of our knowledge, on a fully connected quantum network without trusted nodes. We choose a USS protocol which is secure against forging, repudiation and messages are transferrable. We show the feasibility of unconditionally secure signatures using only bi-partite entangled states distributed throughout the network and experimentally evaluate the performance of the protocol in real world scenarios with varying message lengths

Deploying an Inter‐European Quantum Network

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

PERFORMANCE ASSESSMENT TOOL FOR QUALITY IMPROVEMENT IN HOSPITALS (PATH): FIRST EXPERIENCES IN CROATIA

PATH (Performance Assessment Tool for Quality Improvement in Hospitals), projekt Regionalnog ureda Svjetske zdravstvene organizacije (SZO) za Europu pruža bolnicama sveobuhvatan i standardiziran alat za vrednovanje vlastitih rezultata i razvoj mjera za unapređenje kvalitete. Program PATH pokrenut je 2008. godine i u Hrvatskoj, a od 2009. godine provodi se u bolnicama koje su se dobrovoljno odlučile u njega uključiti. U ovom radu prikazujemo prva iskustva probne faze uspostavljanja programa PATH, utemeljena na podacima koji su prikupljani u 22 hrvatske bolnice. Analiza prvih rezultata upozorila je na postojanje izraženih razlika među bolnicama, koje su se na primjeru postotka carskih rezova kretale od najmanje 1,1% do najviše 21,4% zabilježenih carskih rezova u pojedinim bolnicama tijekom razdoblja prikupljanja podataka. Stopa smrtnosti infarkta miokarda kretala se od 1,9 do 21,4%, dok se smrtnost moždanog udara kretala od 12,5 do 45,5%. Najviši postotak prijavljenih ubodnih ozljeda za liječnike iznosio je 16,2% osoblja tijekom jedne godine, 6,1% za medicinske sestre i 4,6% za spremačice. Ovo istraživanje upućuje na postojanje mnogih problema i ograničenja u prikupljanju pokazatelja na bolničkoj razini, njihovoj analizi i stvaranju preporuka za unapređenje kvalitete koje se moraju uzeti u obzir prilikom usporedbe bolnica na nacionalnoj ili međunarodnoj razini.PATH (Performance Assessment Tool for Quality Improvement in Hospitals), a project of the World Health Organization (WHO) for Europe offers hospitals a comprehensive and standardized tool (a set of indicators) to evaluate their own performance and development of measures for quality improvement. PATH Program was launched in Croatia in 2008, and it was conducted in 2009 in hospitals that have voluntarily decided to be involved. Here we present the results of the first phase of pilot experience of establishing the program, based on data collected in 22 Croatian hospitals. Analysis of the first results indicated the existence of marked differences among the hospitals that have taken the example of the percentage of cesarean sections ranging from 1.1% to 21.4%. The mortality rate of myocardial infarction ranged from 1.9 to 21.4%, while the mortality of stroke ranged from 12.5 to 45.5%. The highest percentage of needle-stick injuries reported for physicians was 16.2% of entire hospital staff in one year, 6.1% for nurses and 4.6% for the supportive staff. The result suggests the existence of many problems and limitations in data collection at hospital level, limitations in their analysis and creates recommendations for quality improvements, which must be taken into account when hospitals are compared on the national or international level