Saprolegnia parasitica Isolated from Rainbow Trout in Korea: Characterization, Anti-Saprolegnia Activity and Host Pathogen Interaction in Zebrafish Disease Model

( Sangyeop Shin ),( D. C. M. Kulatunga ),( S. H. S. Dananjaya ),( Chamilani Nikapitiya ),( Jehee Lee ),( Mahanama De Zoysa ) 한국균학회 2017 Mycobiology Vol.45 No.4

Saprolegniasis is one of the most devastating oomycete diseases in freshwater fish which is caused by species in the genus Saprolegnia including Saprolegnia parasitica. In this study, we isolated the strain of S. parasitica from diseased rainbow trout in Korea. Morphological and molecular based identification confirmed that isolated oomycete belongs to the member of S. parasitica, supported by its typical features including cotton-like mycelium, zoospores and phylogenetic analysis with internal transcribed spacer region. Pathogenicity of isolated S. parasitica was developed in embryo, juvenile, and adult zebrafish as a disease model. Host-pathogen interaction in adult zebrafish was investigated at transcriptional level. Upon infection with S. parasitica, pathogen/antigen recognition and signaling (TLR2, TLR4b, TLR5b, NOD1, and major histocompatibility complex class I), pro/anti-inflammatory cytokines (interleukin [IL]-1β, tumor necrosis factor α, IL-6, IL-8, interferon γ, IL-12, and IL-10), matrix metalloproteinase (MMP9 and MMP13), cell surface molecules (CD8⁺ and CD4⁺) and antioxidant enzymes (superoxide dismutase, catalase) related genes were differentially modulated at 3- and 12-hr post infection. As an anti-Saprolegnia agent, plant based lawsone was applied to investigate on the susceptibility of S. parasitica showing the minimum inhibitory concentration and percentage inhibition of radial growth as 200 μg/mL and 31.8%, respectively. Moreover, natural lawsone changed the membrane permeability of S. parasitica mycelium and caused irreversible damage and disintegration to the cellular membranes of S. parasitica. Transcriptional responses of the genes of S. parasitica mycelium exposed to lawsone were altered, indicating that lawsone could be a potential anti-S. parasitica agent for controlling S. parasitica infection.

Evaluation of steam pasteurization in controlling <i>Salmonella</i> serotype Enteritidis on raw almond surfaces

Chang, S.-S.,Han, A.R.,Reyes-De-Corcuera, J.I.,Powers, J.R.,Kang, D.-H. Blackwell Publishing Ltd 2010 Letters in applied microbiology Vol.50 No.4

<P>Abstract</P><P>Aim: </P><P>To investigate the efficacy of steam pasteurization for reducing <I>Salmonella</I> serotype Enteritidis on raw almond surfaces.</P><P>Methods and Results: </P><P>Nonpareil almonds were inoculated to 10<SUP>7–8</SUP> CFU g<SUP>−1</SUP> with a <I>Salm</I>.<I> </I>Enteritidis cocktail (<I>Salm. </I>Enteritidis 43353, ME-13, ME-14) or <I>Salm</I>.<I> </I>Enteritidis phage type 30, dried overnight and subjected to steam treatments through a pilot-sized vertical pasteurization machine for 5, 15, 25, 35, 45, 55 and 65 s to investigate the effect of steam on a single layer of almond. Survival of <I>Salm</I>.<I> </I>Enteritidis was evaluated with tryptic soy agar and xylose lysine desoxycholate overlay for total and healthy cells, respectively. No significant differences (<I>P</I> > 0·05) in reduction were observed between the <I>Salm. </I>Enteritidis cocktail and <I>Salm</I>. Enteritidis PT 30 inoculum. Reduction of <I>Salm. </I>Enteritidis increased as a function of treatment time, with 25 s being sufficient to achieve a 5-log reduction. Discolouration and visible formation of wrinkles were observed following steam pasteurization of more than 35 s.</P><P>Conclusions: </P><P>Steam pasteurization of 25 s is sufficient to achieve a 5-log reduction of <I>Salm. </I>Enteritidis inoculated on raw almonds without visual quality degradation.</P><P>Significance and Impact of the Study: </P><P>Steam pasteurization is an effective alternative to reduce or prevent <I>Salm. </I>Enteritidis contamination on raw almonds.</P>

ARRAKIS: atlas of resonance rings as known in the S⁴G

Comeró,n, S.,Salo, H.,Laurikainen, E.,Knapen, J. H.,Buta, R. J.,Herrera-Endoqui, M.,Laine, J.,Holwerda, B. W.,Sheth, K.,Regan, M. W.,Hinz, J. L.,Muñ,oz-Mateos, J. C.,Gil de Paz, A.,Men&eac Springer-Verlag 2014 Astronomy and astrophysics Vol.562 No.-

<P>Context. Resonance rings and pseudorings (here collectively called rings) are thought to be related to the gathering of material near dynamical resonances caused by non-axisymmetries in galaxy discs. This means that they are the result of secular evolution processes that redistribute material and angular momentum in discs. Studying them may give clues on the formation and growth of bars and other disc non-axisymmetries. Aims. Our aims are to produce a catalogue and an atlas of the rings detected in the Spitzer Survey of Stellar Structure in Galaxies (S<SUP>4</SUP>G) and to conduct a statistical study of the data in the catalogue. Methods. We traced the contours of rings previously identified and fitted them with ellipses. We found the orientation of bars by studying the galaxy ellipse fits from the S<SUP>4</SUP>G pipeline 4. We used the galaxy orientation data obtained by the S<SUP>4</SUP>G pipeline 4 to obtain intrinsic ellipticities and orientations of rings and the bars. Results. ARRAKIS contains data on 724 ringed galaxies in the S<SUP>4</SUP>G. The frequency of resonance rings in the S<SUP>4</SUP>G is of 16 ±1% and 35 ±1% for outer and inner features, respectively. Outer rings are mostly found in Hubble stages −1 ≤T≤ 4. Inner rings are found in a broad distribution that covers the range −1 ≤T≤7. We confirm that outer rings have two preferred orientations, namely parallel and perpendicular to the bar. We confirm a tendency for inner rings to be oriented parallel to the bar, but we report the existence of a significant fraction (maybe as large as 50%) of inner features that have random orientations with respect to the bar. These misaligned inner rings are mostly found in late-type galaxies (T ≥4). We find that the fraction of barred galaxies hosting outer (inner) rings is ~1.7 times (~1.3 times) that in unbarred galaxies. Conclusions. We confirm several results from previous surveys as well as predictions from simulations of resonant rings and/or from manifold flux tube theory. We report that a significant fraction of inner rings in late-type galaxies have a random orientation with respect to the bar. This may be caused by spiral modes that are decoupled from the bar and dominate the Fourier amplitude spectrum at the radius of the inner ring. The fact that rings are only mildly favoured by bars suggests that those in unbarred galaxies either formed because of weak departures from the axisymmetry of the galactic potential or that they are born because of bars that were destroyed after the ring formation.</P>

Cytomegalovirus Infection after Renal Transplantation: Occurrence, Clinical Features, and the Cutoff for Antigenemia in a University Hospital in Brazil

Sócrates Bezerra de Matos,Roberto Meyer,Fernanda Washington de Mendonça Lima 대한감염학회 2017 Infection and Chemotherapy Vol.49 No.4

Background: Cytomegalovirus (CMV) is the main infectious agent causative of morbidity and mortality in transplant recipients. This study aimed to describe the occurrence and clinical features of CMV infection, and the optimum antigenemia assay cutoff associated with symptomatic infection. Materials and Methods: This was a cohort study that investigated 87 patients undergoing renal transplantation. The patients were monitored with the CMV antigenemia assay performed weekly for the first 3 months post-transplantation and subsequently, when CMV infection was suspected clinically. Results: CMV infection was observed in 63.2% (55/87) of the recipients during the follow-up. Of the 65 episodes observed, 75% (49/65) occurred until 100 days after transplantation (D+100) and 25% (16/65) after D+100 with a median of 60 days. CMV infection was associated with age of the transplant recipients (P = 0.001) and use of deceased donor organ (P = 0.009). There were asymptomatic (34%) and symptomatic (66%) episodes of CMV infection, in which diarrhea was the most common symptom (22.6%), followed by elevated creatinine levels (14.5%), fever (12.9%) and leukopenia (10.5%). The optimum cutoff point associated with symptomatic infection was 5 positive cells/200,000 leukocytes (area under the curve = 0.87, positive predictive value = 88% and negative predictive value= 71%). Conclusion: The high occurrence and the risk factors for CMV infection such as the age of recipients, the number of positive cells in the antigenemia assay, and use of a deceased donor organ should be considered for appropriate monitoring and management of kidney recipients during the post-transplant period.

Aggressive unicystic ameloblastoma affecting the posterior mandible: late diagnosis during orthodontic treatment

Sérgio Lúcio Pereira de Castro Lopes,Isadora Luana Flores,Thiago de Oliveira Gamba,Rivea Ines Ferreira-Santos,Mari Eli Leonelli de Moraes,Aline Alvarez Cabello,Paula Nascimento Moutinho 대한구강악안면외과학회 2017 대한구강악안면외과학회지 Vol.43 No.2

Maxillofacial images must be examined to find pathologies not identified during clinical examination. Unicystic ameloblastoma (UA) extending to the mandibular body and ramus was neglected on initial panoramic radiographic examination. After orthodontic therapy, a huge lesion was observed clinically and through imaging exams. After the conservative surgery, no recurrence was observed during five years of follow-up. This case emphasized the need for careful evaluation of patient images focusing on the oral diagnosis before any dental treatment planning, including orthodontic therapy.

Lateral pterygoid muscle volume and migraine in patients with temporomandibular disorders

Sérgio Lúcio Pereira de Castro Lopes,André Luiz Ferreira Costa,Thiago de Oliveira Gamba,Isadora Luana Flores,Adriana Dibo Cruz,Li Li Min 대한영상치의학회 2015 Imaging Science in Dentistry Vol.45 No.1

Purpose: Lateral pterygoid muscle (LPM) plays an important role in jaw movement and has been implicated in Temporomandibular disorders (TMDs). Migraine has been described as a common symptom in patients with TMDs and may be related to muscle hyperactivity. This study aimed to compare LPM volume in individuals with and without migraine, using segmentation of the LPM in magnetic resonance (MR) imaging of the TMJ. Materials and Methods: Twenty patients with migraine and 20 volunteers without migraine underwent a clinical examination of the TMJ, according to the Research Diagnostic Criteria for TMDs. MR imaging was performed and the LPM was segmented using the ITK-SNAP 1.4.1 software, which calculates the volume of each segmented structure in voxels per cubic millimeter. The chi-squared test and the Fisher’s exact test were used to relate the TMD variables obtained from the MR images and clinical examinations to the presence of migraine. Logistic binary regression was used to determine the importance of each factor for predicting the presence of a migraine headache. Results: Patients with TMDs and migraine tended to have hypertrophy of the LPM (58.7%). In addition, abnormal mandibular movements (61.2%) and disc displacement (70.0%) were found to be the most common signs in patients with TMDs and migraine. Conclusion: In patients with TMDs and simultaneous migraine, the LPM tends to be hypertrophic. LPM segmentation on MR imaging may be an alternative method to study this muscle in such patients because the hypertrophic LPM is not always palpable.

Carrying Gas Influence and Fabrication Parameters Impact in 3D Manufacturing of In Situ TiN-Ti Composites by Direct Laser Deposition

C. Sánchez de Rojas Candela,A. Riquelme,P. Rodrigo,J. Rams 대한금속·재료학회 2023 METALS AND MATERIALS International Vol.29 No.3

The difficulty of getting a correct distribution of the reinforcement in the metal matrix and the complexity for achievinga good-metallurgy matrix-reinforcement bonding has limited the development of additive manufacturing of metal matrixcomposites. This research proposes the use of a reactive atmosphere during the fabrication process to obtain titanium matrixcomposites reinforced with TiN. The relation between the carrying gas and the process parameters used with the presence ofporous and defects, the microstructure, and microhardness has been obtained. Nitrogen was used as the carrying gas of thetitanium powder. Under laser irradiation, the particles melt and react with nitrogen, resulting in the formation of a titaniummatrix composite highly reinforced with TiN. The composite obtained had a microhardness increase between 50 and 100%in comparison with titanium samples fabricated in the same conditions in an argon atmosphere. Three reaction mechanismshave been proposed to take place in the microstructure, depending on the amount of nitrogen in the titanium particles, andits diffusion in them during the manufacture.

Ti6Al4V/SiC Metal Matrix Composites Additively Manufactured by Direct Laser Deposition

C. Sánchez de Rojas Candela,A. Riquelme,V. Bonache,P. Rodrigo,J. Rams 대한금속·재료학회 2022 METALS AND MATERIALS International Vol.28 No.12

Nowadays, research on additive manufacturing of Ti6Al4V alloy is growing exponentially but there are just a few studiesabout additive manufacturing of metal matrix composite components. In this work, highly reinforced Ti6Al4V matrix compositeswith SiC particles have been additively manufactured by direct laser deposition (DLD). Ti6Al4V powder and SiCparticles have been deposited layer by layer to form an additive thin wall structure. The geometry, microstructure, and microhardnessof the samples are strongly influenced by the laser scanning speed used during de fabrication process. In addition,the effect of the SiC increment in reinforcement concentrations and the influence of SiC particle sizes in the microstructurehave been evaluated, and the reaction mechanisms have been established. The percentage of reinforcement measured is lowerthan expected due to the reinforcement-matrix reactivity that results in partially dissolved SiC particles and the formationof a TiC and Si5Ti3ring around them. The size and number of particles and reaction products depend on the initial size andpercentage of reinforcement and the DLD scanning speed. The higher the size and percentage of SiC particles and reactionproducts in the matrix, the higher the hardening effect of the composite matrix.

Experimental and numerical study on the detection of fatigue failure in hydraulic turbines

Xavier Sánchez-Botello,Adolfo de la Torre,Rafel Roig,Esteve Jou,Oscar de la Torre,Javier Ayneto,Xavier Escaler 대한기계학회 2023 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.37 No.10

Detecting fatigue cracks in hydraulic turbine runners is costly, as it requires stopping the unit, emptying it of water and accessing the runner for inspection. Thus, an alternative way based on monitoring the changes of the structural modal response induced by the formation and growth of a crack was investigated. To do so, the crack propagation induced by a resonance was numerically predicted and experimentally machined on a disk-like structure that resembles a Kaplan turbine runner. The analysis of the results shows how the different stages of the fatigue crack growth can be monitored based on the change of the natural frequencies and mode shapes of several specific modes. Based on the obtained results, a structural health monitoring system is being designed to monitor the turbine runner modes of vibration without the need to stop and inspect the unit.

Numerical Analysis on the Spatiotemporal Characteristics of the Portevin–Le Chatelier Effect in Ti-12Mo Alloy

C. Sánchez de Rojas Candela,A. Riquelme,P. Rodrigo,J. Rams 대한금속ᆞ재료학회 2023 METALS AND MATERIALS International Vol.29 No.2

The difficulty of getting a correct distribution of the reinforcement in the metal matrix and the complexity for achievinga good-metallurgy matrix-reinforcement bonding has limited the development of additive manufacturing of metal matrixcomposites. This research proposes the use of a reactive atmosphere during the fabrication process to obtain titanium matrixcomposites reinforced with TiN. The relation between the carrying gas and the process parameters used with the presence ofporous and defects, the microstructure, and microhardness has been obtained. Nitrogen was used as the carrying gas of thetitanium powder. Under laser irradiation, the particles melt and react with nitrogen, resulting in the formation of a titaniummatrix composite highly reinforced with TiN. The composite obtained had a microhardness increase between 50 and 100%in comparison with titanium samples fabricated in the same conditions in an argon atmosphere. Three reaction mechanismshave been proposed to take place in the microstructure, depending on the amount of nitrogen in the titanium particles, andits diffusion in them during the manufacture.