Pub Date : 2023-08-28DOI: 10.18287/jbpe23.09.030310
Jayaprasad K. V., Titu Thomas, Manu Vaishakh, Sheenu Thomas
Concentration dependent thermal diffusivity measurement of Mn3O4 nanoparticles dispersed in ethylene glycol has been studied using dual beam mode mismatched thermal lens technique. The results reveal that the thermal diffusivity of the nanofluid depends on the concentration of Mn3O4 nanoparticles. The thermal diffusivity values were found to be greater than that of ethylene glycol for all sample concentrations. The samples with this high value of thermal diffusivity can be used as coolant for thermoelectric devices. The non-radiative decay process induced by defect states in the material, size and shape of nanoparticles etc. are the factors that control the thermal diffusivity of the nanoparticles dispersed in a solvent. The variation in thermal diffusivity of the Mn3O4 nanofluid is explained on the basis of changes in absorption and emission spectra with sample concentration. It is found that thermal diffusivity is inversely related with the emission intensity.
{"title":"Concentration Dependent Thermal Diffusivity of Mn3O4 Nanoparticles Using Dual Beam Thermal Lens Technique","authors":"Jayaprasad K. V., Titu Thomas, Manu Vaishakh, Sheenu Thomas","doi":"10.18287/jbpe23.09.030310","DOIUrl":"https://doi.org/10.18287/jbpe23.09.030310","url":null,"abstract":"Concentration dependent thermal diffusivity measurement of Mn3O4 nanoparticles dispersed in ethylene glycol has been studied using dual beam mode mismatched thermal lens technique. The results reveal that the thermal diffusivity of the nanofluid depends on the concentration of Mn3O4 nanoparticles. The thermal diffusivity values were found to be greater than that of ethylene glycol for all sample concentrations. The samples with this high value of thermal diffusivity can be used as coolant for thermoelectric devices. The non-radiative decay process induced by defect states in the material, size and shape of nanoparticles etc. are the factors that control the thermal diffusivity of the nanoparticles dispersed in a solvent. The variation in thermal diffusivity of the Mn3O4 nanofluid is explained on the basis of changes in absorption and emission spectra with sample concentration. It is found that thermal diffusivity is inversely related with the emission intensity.","PeriodicalId":52398,"journal":{"name":"Journal of Biomedical Photonics and Engineering","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-08-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135135075","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-12-01DOI: 10.18287/jbpe21.07.040101
Tsanislava Genova, L. Avramov, B. Kolev, A. Gisbrecht, I. Bliznakova, Lidiya Zaharieva, V. Mircheva, S. Ilyov, I. Angelov, V. Mantareva, P. Troyanova, P. Pavlova, T. Novikova, R. Ossikovski, D. Ivanov, V. Dremin, E. Rafailov, Sergey G. Sokolovsky, A. Bykov, I. Meglinski, I. Bratchenko, O. Semyachkina-Glushkovskaya, E. Genina, A. Bashkatov, A. Bucharskaya, V. Zakharov, J. Spigulis, Sindhoora Kaniyala Melanthota, S. K U, N. Mazumder, Shama Prasad K., P. Townsend, Luís Manuel Couto Oliveira, A. Priezzhev, D. Sterenborg, V. Tuchin
{"title":"A review of career devoted to Biophotonics – In memoriam to Ekaterina Borisova (1978–2021)","authors":"Tsanislava Genova, L. Avramov, B. Kolev, A. Gisbrecht, I. Bliznakova, Lidiya Zaharieva, V. Mircheva, S. Ilyov, I. Angelov, V. Mantareva, P. Troyanova, P. Pavlova, T. Novikova, R. Ossikovski, D. Ivanov, V. Dremin, E. Rafailov, Sergey G. Sokolovsky, A. Bykov, I. Meglinski, I. Bratchenko, O. Semyachkina-Glushkovskaya, E. Genina, A. Bashkatov, A. Bucharskaya, V. Zakharov, J. Spigulis, Sindhoora Kaniyala Melanthota, S. K U, N. Mazumder, Shama Prasad K., P. Townsend, Luís Manuel Couto Oliveira, A. Priezzhev, D. Sterenborg, V. Tuchin","doi":"10.18287/jbpe21.07.040101","DOIUrl":"https://doi.org/10.18287/jbpe21.07.040101","url":null,"abstract":"","PeriodicalId":52398,"journal":{"name":"Journal of Biomedical Photonics and Engineering","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49042310","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-11-10DOI: 10.18287/jbpe21.07.040307
N. Polukonova, M. Baryshnikova, Dmitry A. Khochankov, E. V. Stepanova, E. Solomko, A. Polukonova, D. A. Mudrak, A. M. Mylnikov, A. Bucharskaya, G. Maslyakova, N. Navolokin
. The problem of creating antitumor drugs with new mechanisms of action that predominantly induce apoptosis is still topical. The extract of Gratiola officinalis is a potential antitumor agent containing mainly flavonoids. The aim of this research is to study the effects of Gratiola officinalis extract on activation of apoptosis and autophagy in breast adenocarcinoma SK-BR-3 and kidney carcinoma A-498 lines. Apoptotic activity of the extract was studied by flow cytofluorometry using Hoechst stain and double staining with annexin V plus propidium iodide. There was 96.3% of cells in SK-BR-3 culture in late apoptosis phase detected by flow cytofluorometry method at the extract concentration of 0.88 mg/ml, 86.3% of cells were in apoptosis by Hoechst stain. The concentration of 0.82 mg/ml caused apoptosis in half of the cells. The extract has cytoprotective activity at low concentration (0.0352 mg/ml). The cytoprotection mechanism is realized through the activation of autophagy. The maximum number of autophagosomes in kidney carcinoma cells is observed at the extract concentration of 0.056 mg/ml. Thus, Gratiola officinalis extract is able to block cytoprotective autophagy with increasing the extract concentration and to activate apoptosis in 85% of tumor cells. Detailed research should be continued to understand the mechanisms of antitumor activity of Gratiola officinalis extract.
{"title":"Activation of Apoptosis and Autophagy by Gratiola Officinalis Extract in Human Tumor Cell Lines","authors":"N. Polukonova, M. Baryshnikova, Dmitry A. Khochankov, E. V. Stepanova, E. Solomko, A. Polukonova, D. A. Mudrak, A. M. Mylnikov, A. Bucharskaya, G. Maslyakova, N. Navolokin","doi":"10.18287/jbpe21.07.040307","DOIUrl":"https://doi.org/10.18287/jbpe21.07.040307","url":null,"abstract":". The problem of creating antitumor drugs with new mechanisms of action that predominantly induce apoptosis is still topical. The extract of Gratiola officinalis is a potential antitumor agent containing mainly flavonoids. The aim of this research is to study the effects of Gratiola officinalis extract on activation of apoptosis and autophagy in breast adenocarcinoma SK-BR-3 and kidney carcinoma A-498 lines. Apoptotic activity of the extract was studied by flow cytofluorometry using Hoechst stain and double staining with annexin V plus propidium iodide. There was 96.3% of cells in SK-BR-3 culture in late apoptosis phase detected by flow cytofluorometry method at the extract concentration of 0.88 mg/ml, 86.3% of cells were in apoptosis by Hoechst stain. The concentration of 0.82 mg/ml caused apoptosis in half of the cells. The extract has cytoprotective activity at low concentration (0.0352 mg/ml). The cytoprotection mechanism is realized through the activation of autophagy. The maximum number of autophagosomes in kidney carcinoma cells is observed at the extract concentration of 0.056 mg/ml. Thus, Gratiola officinalis extract is able to block cytoprotective autophagy with increasing the extract concentration and to activate apoptosis in 85% of tumor cells. Detailed research should be continued to understand the mechanisms of antitumor activity of Gratiola officinalis extract.","PeriodicalId":52398,"journal":{"name":"Journal of Biomedical Photonics and Engineering","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-11-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46564036","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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