Uticaj aeromonas salmonicida na obrastanje i mikrobijalnu koroziju prevlake od legure nikla i bakra na kavezne sisteme u moru

Biofouling acts one of the most serious problems to marine industry and aquaculture development. In the marine environment, surfaces immersed in seawater are colonized by micro-biofoulers such as marine bacteria, algae, and protozoa (Callow and Callow, 2002; Dobretsov et al., 2006). Biofouling of sea cages is a great concern for the salmon growers. When a sea cage is first immersed, there will be a succession of organisms that colonize the cage (Hodson et al., 1997). Bacteria produce an exo-polysaccharide layer (EPS), which act as a protective barrier from the treated surface but also harmful to the lower substratum, in case of the physical degradation or bio-deterioration of the metal surface. This situation is called Microbial corrosion (Yuan and Pehkonen, 2009). In addition, there is a possibility that cage can act as a reservoirs for some disease-causing organisms so one of these bacteria is Aeromonas salmonicida. This bacterium is an aquatic Gram-negative bacterium causing lethal disease furunculosis in salmonid fish. Along with other members of the family Vibrionaceae (V. anguillarum, V. ordalii, A. hydrophila), diseases caused by these organisms can rapidly decimate populations of farmed marine or freshwater fish (Garduna et al., 1994). To reduce the amount of fouling, increase the water quality and decrease the chance of disease occurrence, cage can be coated with antifouling copper alloys and paints (Hodson and Burke, 1994). On the other hand, the tremendous applications of Ni-Cu alloys in different industries, especially in ships where chloride containing waters are always used, making the corrosion processes under the influence of chloride ions understandable and the control of these processes important subject of intensive investigations (Badawy et al., 2005). Therefore this study examines the effects of A. salmonicida in biofouling on Ni-Cu cage coating and its microbial corrosion influence. This study was performed using pure cultures of the A. salmonicida, isolated from water samples. The isolated bacterium was characterized on the basis of 16S rRNA sequences and submitted to NCBI under Accession No. GU907676 (San et al., 2010). The bacterium was cultured then centrifuged and used for bio-corrosion experiments. Electrochemical measurements were carried out in a conventional three-electrode cell. The polarization curves were measured using CompactStat Potentiostat (IviumStat, The Netherlands). Mild steel was used as a working electrode in electrochemical studies. The Ag/AgCl (sat. KCl) electrode (CHI111, CH Instrument, USA) was used as the reference electrode and a platinum wire (CHI115, CH Instrument, USA) was used as counter electrode for all experiments. Ni-Cu alloy was electrodeposited from a nickel-copper bath. The corrosion potential of Ni-Cu electrodes was -0.08 V (vs. Ag/AgCl) but, the corrosion potential of Ni-Cu electrodes in the medium inoculated with the bacterium shifted to cathodic site, -0.63 V (vs. Ag/AgCl) means the increased rate of corrosion. In addition, increase of corrosion current and corrosion current densities with an increase in presence of bacterium means the increased rate of corrosion. Besides, pH values of the medium did not change throughout the experiment (6.8) but after immersion, the pH value decreased to acidic value, 5.5 Furthermore, SEM micrographs show influence of biofouling by bacterium to Ni-Cu alloy. As a consequence, A. salmonicida colonize, strongly adhere and biofouling on alloy surfaces. This situation results in causing the lethal disease in salmon fish and microbial corrosion of cage material

Pharmacological Elevation of Cellular Dihydrosphingomyelin Provides a Novel Antiviral Strategy against West Nile Virus Infection

The flavivirus life cycle is strictly dependent on cellular lipid metabolism. Polyphenols like gallic acid and its derivatives are promising lead compounds for new therapeutic agents as they can exert multiple pharmacological activities, including the alteration of lipid metabolism. The evaluation of our collection of polyphenols against West Nile virus (WNV), a representative medically relevant flavivirus, led to the identification of N,N'-(dodecane-1,12-diyl)bis(3,4,5-trihydroxybenzamide) and its 2,3,4-trihydroxybenzamide regioisomer as selective antivirals with low cytotoxicity and high antiviral activity (half-maximal effective concentrations [EC50s] of 2.2 and 0.24 μM, respectively, in Vero cells; EC50s of 2.2 and 1.9 μM, respectively, in SH-SY5Y cells). These polyphenols also inhibited the multiplication of other flaviviruses, namely, Usutu, dengue, and Zika viruses, exhibiting lower antiviral or negligible antiviral activity against other RNA viruses. The mechanism underlying their antiviral activity against WNV involved the alteration of sphingolipid metabolism. These compounds inhibited ceramide desaturase (Des1), promoting the accumulation of dihydrosphingomyelin (dhSM), a minor component of cellular sphingolipids with important roles in membrane properties. The addition of exogenous dhSM or Des1 blockage by using the reference inhibitor GT-11 {N-[(1R,2S)-2-hydroxy-1-hydroxymethyl-2-(2-tridecyl-1-cyclopropenyl)ethyl]octanamide} confirmed the involvement of this pathway in WNV infection. These results unveil the potential of novel antiviral strategies based on the modulation of the cellular levels of dhSM and Des1 activity for the control of flavivirus infection.We thank Theodore C. Pierson (National Institutes of Health, USA) for the subgenomic replicon of WNV. This work was supported by the Spanish Ministry of Science and Innovation AEI/10.13039/501100011033 under grants PID2019-105117RR-C21 (to M.A.M.-A.), PID2019-105117RR-C22 (to M.-J.P.-P.), and PID2020-119195RJ-I00 (to N.J.d.O.) and by the AECSIC under grant PIE-201980E100 (to M.-J.P.-P. and A.S.-F.). This research work was also funded by the European Commission-NextGenerationEU (regulation EU 2020/2094) through CSIC’s Global Health Platform (PTI Salud Global). P.M.-C. was supported by an FPI fellowship (PRE2020-093374) from AEI/10.13039/501100011033. The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.Peer reviewe

Glycolytic shift during West Nile virus infection provides new therapeutic opportunities

Background Viral rewiring of host bioenergetics and immunometabolism may provide novel targets for therapeu‑ tic interventions against viral infections. Here, we have explored the effect on bioenergetics during the infection with the mosquito‑borne flavivirus West Nile virus (WNV), a medically relevant neurotropic pathogen causing out‑ breaks of meningitis and encephalitis worldwide. Results A systematic literature search and meta‑analysis pointed to a misbalance of glucose homeostasis in the cen‑ tral nervous system of WNV patients. Real‑time bioenergetic analyses confirmed upregulation of aerobic glycolysis and a reduction of mitochondrial oxidative phosphorylation during viral replication in cultured cells. Transcriptom‑ ics analyses in neural tissues from experimentally infected mice unveiled a glycolytic shift including the upregula‑ tion of hexokinases 2 and 3 (Hk2 and Hk3) and pyruvate dehydrogenase kinase 4 (Pdk4). Treatment of infected mice with the Hk inhibitor, 2‑deoxy‑D‑glucose, or the Pdk4 inhibitor, dichloroacetate, alleviated WNV‑induced neuroinflammation. Conclusions These results highlight the importance of host energetic metabolism and specifically glycolysis in WNV infection in vivo. This study provides proof of concept for the druggability of the glycolytic pathway for the future development of therapies to combat WNV pathology.This study was supported by the Spanish Ministry of Science and Innovation AEI/10.13039/501100011033 under Grants PID2019‑105117RR‑C21 (to MAMA) and PID2019‑105117RR‑C22 (to MJPP), PID2020‑119195RJ‑I00 (to NJO), by Synergistic Projects Community of Madrid under grant NUTRISION‑CM/Y2020/ BIO‑6350 (to ARM), and by the European Commission—NextGenerationEU through CSIC’s Global Health Platform (PTI Salud Global). PMC was sup‑ ported by an FPI fellowship from AEI/10.13039/501100011033 under Grant PRE2020‑093374. The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publicationPeer reviewe

Urartu Krallığı'nın kuzey ve kuzeydoğu yayılımı

Tez üzerinde özeti mevcut olmadığı için bu alan boş bırakılmıştır

Alinda. An ancient city with its remains and monumental tombs in Caria

A brief historical and topographical presentation of the Alinda site carried out during an extended archeological study on graveyards. Proposition for a typological classification of these funereal monuments.En introduction brève présentation historique et topographie du site d'Alinda à l'occasion d'une étude archéologique développée des tombes. Proposition pour un classement typologique de ces monuments funéraires.Özkaya Vecihi, San Oya. Alinda. An ancient city with its remains and monumental tombs in Caria. In: Revue des Études Anciennes. Tome 105, 2003, n°1. pp. 103-125