Navegação por autor "SABINO, CAETANO P."

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  • IPEN-DOC 26453

    SABINO, CAETANO P.; WAINWRIGHT, MARK; ANJOS, CAROLINA dos; SELLERA, FABIO P.; BAPTISTA, MAURICIO S.; LINCOPAN, NILTON; RIBEIRO, MARTHA S. . Inactivation kinetics and lethal dose analysis of antimicrobial blue light and photodynamic therapy. Photodiagnosis and Photodynamic Therapy, v. 28, p. 186-191, 2019. DOI: 10.1016/j.pdpdt.2019.08.022

    Abstract: Background: Antimicrobial Photodynamic therapy (A-PDT) has been used to treat infections. Currently, microbial inactivation data is reported presenting survival fraction averages and standard errors as discrete points instead of a continuous curve of inactivation kinetics. Standardization of this approach would allow clinical protocols to be introduced globally, instead of the piecemeal situation which currently applies. Methods: To this end, we used a power-law function to fit inactivation kinetics and directly report values of lethal doses (LD) and a tolerance factor (T) that informs if inactivation rate varies along the irradiation procedure. A deduced formula was also tested to predict LD for any given survival fraction value. We analyzed the photoantimicrobial effect caused by red light activation of methylene blue (MB-APDT) and by blue light (BL) activation of endogenous microbial pigments against 5 clinically relevant pathogens. Results: Following MB- APDT, Escherichia coli and Staphylococcus aureus cells become increasingly more tolerant to inactivation along the irradiation process (T < 1). Klebsiella pneumoniae presents opposite behavior, i.e., more inactivation is observed towards the end of the process (T > 1). P. aeruginosa and Candida albicans present constant inactivation rate (T˜1). In contrast, all bacterial species presented similar behavior during inactivation caused by BL, i.e., continuously becoming more sensitive to blue light exposure (T > 1). Conclusion: The power-law function successfully fit all experimental data. Our proposed method precisely predicted LD and T values. We expect that these analytical models may contribute to more standardized methods for comparisons of photodynamic inactivation efficiencies.

    Palavras-Chave: antimicrobial agents; therapy; chemotherapy; inactivation; lethal doses; light sources; data analysis; candida; methylene blue

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  • IPEN-DOC 23888

    SOUSA, MARCELO V.P.; PRATES, RENATO ; KATO, ILKA T. ; SABINO, CAETANO P. ; YOSHIMURA, TANIA M. ; SUZUKI, LUIS C. ; MAGALHAES, ANA C.; YOSHIMURA, ELISABETH M.; RIBEIRO, MARTHA S. . Inhomogeneity in optical properties of rat brain: a study for LLLT dosimetry. In: HAMBLIN, MICHAEL R. (Ed.); ARANY, PRAVEEN R. (Ed.); CARROLL, JAMES D. (Ed.) MECHANISMS FOR LOW-LIGHT THERAPY, 8th, February 02, 2013, San Francisco, CA, USA. Proceedings... Bellingham, WA, USA: International Society for Optics and Photonics, 2013. p. 856905-1 - 856905-6. (SPIE Proceedings Series, 8569). DOI: 10.1117/12.2002836

    Abstract: Over the last few years, low-level light therapy (LLLT) has shown an incredible suitability for a wide range of applications for central nervous system (CNS) related diseases. In this therapeutic modality light dosimetry is extremely critical so the study of light propagation through the CNS organs is of great importance. To better understand how light intensity is delivered to the most relevant neural sites we evaluated optical transmission through slices of rat brain point by point. We experimented red (λ = 660 nm) and near infrared (λ = 808 nm) diode laser light analyzing the light penetration and distribution in the whole brain. A fresh Wistar rat (Rattus novergicus) brain was cut in sagittal slices and illuminated with a broad light beam. A high-resolution digital camera was employed to acquire data of transmitted light. Spatial profiles of the light transmitted through the sample were obtained from the images. Peaks and valleys in the profiles show sites where light was less or more attenuated. The peak intensities provide information about total attenuation and the peak widths are correlated to the scattering coefficient at that individual portion of the sample. The outcomes of this study provide remarkable information for LLLT dose-dependent studies involving CNS and highlight the importance of LLLT dosimetry in CNS organs for large range of applications in animal and human diseases.

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  • IPEN-DOC 18518

    SOUSA, MARCELO V.P.; PRATES, RENATO; KATO, ILKA T.; SABINO, CAETANO P.; SUZUKI, LUIS C.; RIBEIRO, MARTHA S. ; YOSHIMURA, ELISABETH M.. Laser scattering by transcranial rat brain illumination. In: POPP, JURGEN (Ed.); DREXLER, WOLFGANG (Ed.); TUCHIN, VALERY V. (Ed.); MATTHEWS, DENNIS L. (Ed.) BIOPHOTONICS: PHOTONIC SOLUTIONS FOR BETTER HEALTH CARE III, 2012, Proceedings... Society of Photho-optical Instrumentation Engineers, 2012. p. 842728-1 - 842728-7.

    Palavras-Chave: laser radiation; therapy; brain; near infrared radiation; hippocampus; biological models; rats

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  • IPEN-DOC 27394

    SABINO, CAETANO P.; BALL, ANTHONY R.; BAPTISTA, MAURICIO S.; DAI, TIANHONG; HAMBLIN, MICHAEL R.; RIBEIRO, MARTHA S. ; SANTOS, ANA L.; SELLERA, FABIO P.; TEGOS, GEORGE P.; WAINWRIGHT, MARK. Light-based technologies for management of COVID-19 pandemic crisis. Journal of Photochemistry and Photobiology B: Biology, v. 212, p. 1-8, 2020. DOI: 10.1016/j.jphotobiol.2020.111999

    Abstract: The global dissemination of the novel coronavirus disease (COVID-19) has accelerated the need for the implementation of effective antimicrobial strategies to target the causative agent SARS-CoV-2. Light-based technologies have a demonstrable broad range of activity over standard chemotherapeutic antimicrobials and conventional disinfectants, negligible emergence of resistance, and the capability to modulate the host immune response. This perspective article identifies the benefits, challenges, and pitfalls of repurposing light-based strategies to combat the emergence of COVID-19 pandemic.

    Palavras-Chave: visible radiation; coronaviruses; ultraviolet radiation; antimicrobial agents; inactivation; photosensitivity; modulation; radiobiology; epidemiology; lasers; viruses

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  • IPEN-DOC 25029

    SABINO, CAETANO P. ; BAPTISTA, MAURICIO da S.; RIBEIRO, MARTHA S. ; LINCOPAN, NILTON. Methylene blue uptake and intermolecular interactions in microbial cells through Fluorescence Lifetime Imaging Microscopy (FLIM). In: INTERNATIONAL PHOTODYNAMIC ASSOCIATION WORLD CONGRESS, 16th, June 08-13, 2017, Coimbra, Portugal. Abstract... 2017. p. 82-82.

    Abstract: Antimicrobial photodynamic therapy (APDT) is a promising tool to counterattack the emerging treat of drug-resistant pathogens. The technique combines low-intensity monochromatic light with a photosensitizer compound to produce reactive oxygen species (ROS) that can damage virtually any type of biomolecules and lead to rapid ce\l death. Since some ROS present diffusion-limited reactivity, most cell damage is co-localized with photosensitizer accumulation site. Hence, imaging photosensitizer accumulation and fluorescence lifetime in the nanoscale can bring a great levei of information to further understand the ultrastructural cellular damage caused by APDT. In this study, we used a FLIM system capable of single-molecule detection to observe the accumulation and interaction sites of methylene blue (MB), a very broadly-used photosensitizer, in yeast, and Gram-positive and Gram-negative bacterial cells, Our data shows fluorescence lifetime contrast, with nanometric resolution, among different cellular structures such as cell wall, membrane and DNA. The images evidentiate differential MB accumulation in microbial cells and the existence of two different populations of MB molecular species: those interacting mostly with the solvent (short-lived, - 0.8 ns) and those interacting with biomolecules (Iong-lived, -2 ns), The short-lived fluorescence predominates in the mucoid capsule of Gram-negative bacteria and cell-wall ofyeast and Gram-positive bacteria while longlived MB fluorescence shows preferential accumulation in DNA-rich sites 1 • It is marked in yeast nucleus and exclusively inside bacterial cells. In fact, literature supports that MB intercalation in nucleic acids stabilizes its excited-states leading to increased "fluorescence "lifetime and efficiency of singlet-oxygen production2 . Our data brings evidence that this sOli of phenomena can be observed by FLIM in the nanoscale and this should bring new insights to the photophysical, photochemical and biological mechanisms of photodynamic therapy.

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  • IPEN-DOC 27824

    SELLERA, FABIO P.; BARBOSA, BRUNA S.; GARGANO, RONALDO G.; RISPOLI, VIVIAN F.P.; SABINO, CAETANO P.; OLLHOFF, RUDIGER D.; BAPTISTA, MAURICIO S.; RIBEIRO, MARTHA S. ; SA, LILIAN R.M. de; POGLIANI, FABIO C.. Methylene blue-mediated antimicrobial photodynamic therapy can be a novel non-antibiotic platform for bovine digital dermatitis. Photodiagnosis and Photodynamic Therapy, v. 34, p. 1-8, 2021. DOI: 10.1016/j.pdpdt.2021.102274

    Abstract: Background Bovine digital dermatitis (BDD) is one of the most important diseases that effect dairy cows. Methylene blue-mediated antimicrobial photodynamic therapy (MB-APDT) emerges as a promising technique to treat superficial infections in bovines. Methods Twenty BDD lesions located at the skin horn transition of the claw of pelvic limbs of 16 cows were treated by MB-APDT, using a red LED cluster (λ = 660 nm, irradiance =60 mW/cm2, exposure time = 40 s) combined with topical application of MB at 0.01 %; or by topical application of OXY (500 mg in 20 % solution). Each lesion was treated twice with an interval of 14 days. Lesions were weekly evaluated until day 28 by clinical analysis and by histological examination on days 0 and 28. Results Both treatments led to a similar reduction of lesions area. At day 28, three lesions treated by OXY did not present completely recovery, whereas no lesions were observed in MB-APDT group. OXY resulted in a slight increase in type I and III collagen levels, while MB-APDT led to a significant increase in the total area of both collagen types. An abundant number of spirochetes were histologically observed in all lesions before treatments. On the 28th day, five lesions treated by OXY still presented a slight number of spirochetes, whereas in MB-APDT group no spirochetes were evidenced. Conclusion Our findings suggest that MB-APDT is more effective than OXY and could be used in Veterinary practice to fight BDD.

    Palavras-Chave: methylene blue; antimicrobial agents; cattle; inactivation; photosensitivity; therapy; dermatitis; infectious diseases

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  • IPEN-DOC 21874

    SABINO, CAETANO P. ; RIBEIRO, MARTHA S. . Modelo de estudo in vitro de infecções por biofilme de Candida albicans e sua inativação por terapia fotodinâmica. In: PROGRAMA INSTITUCIONAL DE BOLSAS DE INICIAÇÃO CIENTÍFICA, 19.; PROGRAMA DE BOLSAS E INICIAÇÃO CIENTÍFICA CNEN, 10.; PROGRAMA INSTITUCIONAL DE BOLSAS DE INICIAÇÃO DESENVOLVIMENTO TECNOLÓGICO E INOVAÇÃO, 3., 23-24 de outubro, 2013, São Paulo, SP. Resumo expandido... 2013.

    Palavras-Chave: in vitro; infectious diseases; candida; inactivation; therapy; lasers; films; teeth

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  • IPEN-DOC 24457

    SABINO, CAETANO P. ; HAMBLIN, MICHAEL R.. Molecular damage. In: SELLERA, FABIO P. (Ed.); NASCIMENTO, CRISTIANE L. (Ed.); RIBEIRO, MARTHA S. (Ed.). Photodynamic therapy in veterinary medicine: from basics to clinical practice. Gewerbestrasse, Switzerland: Springer, 2016. p. 45-56, DOI: 10.1007/978-3-319-45007-0_4

    Observação: Livro na íntegra disponível. Consulte a biblioteca do IPEN.

    Abstract: Photodynamic therapy (PDT) rapidly produces large amounts of reactive oxygen species (ROS) to induce death of photosensitized cells. As previously described in Chap. 2, excited photosensitizer (PS) molecules can either donate electrons (type 1) or energy (type 2) to ground-state oxygen to produce superoxide radicals (O2•−) or singlet oxygen (1O2). Each type of ROS has characteristic chemical reactivity and reacts with different types of chemical bonds present in biomolecules and, consequently, will lead to different types of cell damage. Once again, what determines the mechanism of cell death directly depends on both: the PS localization site within the cell and total extent of oxidative stress produced during therapy (i.e., light dosimetry and efficiency of ROS generation). To elucidate the mechanisms of photooxidative damage and the consequent biological effects, this chapter will cover the most relevant chemical reactions related to oxidative damage caused by 1O2 and free radicals.

    Palavras-Chave: veterinary medicine; photodynamic therapy; oxygen; molecular structure; photosensitivity

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  • IPEN-DOC 21613

    BAPTISTA, ALESSANDRA ; NUNEZ, SILVIA C. ; SABINO, CAETANO P. ; MIYAKAWA, WALTER ; RIBEIRO, MARTHA S. . Morphological evaluation of Candida albicans after phododynamic therapy. In: INTERNATIONAL PHOTODYNAMIC ASSOCIATION WORLD CONGRESS, May 23-26, 2015, Rio de Janeiro, RJ. Abstract... 2015. p. 355.

    Palavras-Chave: morphological changes; candida; therapy; antimicrobial agents; scanning electron microscopy; atomic force microscopy; photosensitivity

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  • IPEN-DOC 21600

    BAPTISTA, ALESSANDRA ; NUNEZ, SILVIA C. ; SABINO, CAETANO P. ; MIYAKAWA, WALTER ; RIBEIRO, MARTHA S. . Morphological evaluation of Candida albicans after phododynamic therapy. Photodiagnosis and Photodynamic Therapy, v. 12, p. 335, 2015.

    Palavras-Chave: morphological changes; candida; therapy; antimicrobial agents; scanning electron microscopy; atomic force microscopy; photosensitivity

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  • IPEN-DOC 24463

    RIBEIRO, MARTHA S. ; SABINO, CAETANO P. . Multimodality dosimetry. In: SELLERA, FABIO P. (Ed.); NASCIMENTO, CRISTIANE L. (Ed.); RIBEIRO, MARTHA S. (Ed.). Photodynamic therapy in veterinary medicine: from basics to clinical practice. Gewerbestrasse, Switzerland: Springer, 2016. p. 93-109, DOI: 10.1007/978-3-319-45007-0_7

    Observação: Livro na íntegra disponível. Consulte a biblioteca do IPEN.

    Abstract: PDT requires a multimodality approach for dosimetry because it works based on three essential components: light, photosensitizer, and molecular oxygen. Since these components are found in variable amounts inside target cells, PDT dosimetry is rather intricate. This chapter intends to address, with little mathematical complexity, the physical and chemical quantities that are most relevant for light and photosensitizer dosimetry as well as to present basic aspects of oxygen supply to achieve successful PDT interventions.

    Palavras-Chave: veterinary medicine; photodynamic therapy; dosimetry; light sources; lasers

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  • IPEN-DOC 29707

    ANJOS, CAROLINA dos; LEANSE, LEON G.; RIBEIRO, MARTHA S. ; SELLERA, FÁBIO P.; DROPA, MILENA; ARANA-CHAVEZ, VICTOR E.; LINCOPAN, NILTON; BAPTISTA, MAURÍCIO S.; POGLIANI, FABIO C.; DAI, TIANHONG; SABINO, CAETANO P.. New insights into the bacterial targets of antimicrobial blue light. Microbiology Spectrum, v. 11, n. 2, p. 1-13, 2023. DOI: 10.1128/spectrum.02833-22

    Abstract: Antimicrobial blue light (aBL) offers efficacy and safety in treating infections. However, the bacterial targets for aBL are still poorly understood and may be dependent on bacterial species. Here, we investigated the biological targets of bacterial killing by aBL (l = 410 nm) on three pathogens: Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa. Initially, we evaluated the killing kinetics of bacteria exposed to aBL and used this information to calculate the lethal doses (LD) responsible for killing 90 and 99.9% of bacteria. We also quantified endogenous porphyrins and assessed their spatial distribution. We then quantified and suppressed reactive oxygen species (ROS) production in bacteria to investigate their role in bacterial killing by aBL. We also assessed aBL-induced DNA damage, protein carbonylation, lipid peroxidation, and membrane permeability in bacteria. Our data showed that P. aeruginosa was more susceptible to aBL (LD99.9 = 54.7 J/cm2) relative to S. aureus (LD99.9 = 158.9 J/cm2) and E. coli (LD99.9 = 195 J/cm2). P. aeruginosa exhibited the highest concentration of endogenous porphyrins and level of ROS production relative to the other species. However, unlike other species, DNA degradation was not observed in P. aeruginosa. Sublethal doses of blue light (,LD90) could damage the cell membrane in Gram-negative species but not in S. aureus. In all bacteria, oxidative damage to bacterial DNA (except P. aeruginosa), proteins, and lipids occurred after high aBL exposures (.LD99.9). We conclude that the primary targets of aBL depend on the species, which are probably driven by variable antioxidant and DNA-repair mechanisms.

    Palavras-Chave: bacteria; germicides; chromosphere; lipids; oxidation; permeability; carbonylation; proteins; oxygen

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  • IPEN-DOC 24496

    SELLERA, FABIO P.; POGLIANI, FABIO C.; SABINO, CAETANO P. . Other practices in PDT. In: SELLERA, FABIO P. (Ed.); NASCIMENTO, CRISTIANE L. (Ed.); RIBEIRO, MARTHA S. (Ed.). Photodynamic therapy in veterinary medicine: from basics to clinical practice. Gewerbestrasse, Switzerland: Springer, 2016. p. 197-207, DOI: 10.1007/978-3-319-45007-0_13

    Observação: Livro na íntegra disponível. Consulte a biblioteca do IPEN.

    Abstract: In addition to clinical PDT applications regarding antimicrobial and antineoplastic activity, photodynamic reactions have also been used in several other practices such as for fish tank decontamination, water treatment, antiangiogenic therapy for age-related macular degeneration, decontamination of surfaces, and even inactivation of pathogens for blood transfusion. Nowadays, not all potentials of photodynamic reactions are commercially available yet, but they definitely deserve to be highlighted in this chapter as alternative applications of photodynamic reactions in veterinary medicine.

    Palavras-Chave: veterinary medicine; photodynamic therapy; sterilization; water treatment; decontamination

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  • IPEN-DOC 23124

    YOSHIMURA, TANIA M. ; SABINO, CAETANO P.; RIBEIRO, MARTHA S. . Photobiomodulation reduces abdominal adipose tissue inflammatory infiltrate of diet-induced obese and hyperglycemic mice. Journal of Biophotonics, v. 9, n. 11-12, p. 1255-1262, 2016. DOI: 10.1002/jbio.201600088

    Abstract: Systemic inflammation is closely related to the development of insulin resistance and type-2 diabetes, since the activation of pro-inflammatory pathways leads to inhibition of insulin signaling. Although photobiomodulation (PBM) has proven beneficial effects on the treatment of inflammatory disorders, the phototherapeutic approach to manage the chronic inflammatory component of obesity and hyperglycemia had never been explored. In this work, obese and hyperglycemic mice are treated with PBM, and their body mass, glycemia and inflammatory infiltrate of abdominal adipose tissue are evaluated. During four weeks, irradiated animals are exposed to six irradiation sessions using an 843 nm LED (5.7 J cm(-2) at 19 mW cm(-2) per session). Non-irradiated control animals display inflammatory areas almost five times greater than the treated group (p < 0.001). This result on inflammatory infiltrate may have caused impacts on the significant lower blood glucose level from irradiated animals (p = 0.04), twenty-four hours after the last irradiation session. PBM on obese and hyperglycemic mice reduced five times the areas of inflammatory infiltrate within abdominal adipose tissue (a, b), whereas dense inflammatory regions were a common finding amidst non-irradiated animals (c). The asterisks on (c) correspond to the inflammatory infiltrate permeating adipocytes.

    Palavras-Chave: abdomen; adipose tissue; diabetes mellitus; metabolic diseases; therapy; inflammation; low dose irradiation

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  • IPEN-DOC 19116

    CHIBEBE JUNIOR, JOSE; FUCHS, BETH B.; SABINO, CAETANO P.; JUNQUEIRA, JULIANA C.; JORGE, ANTONIO O.C.; RIBEIRO, MARTHA S. ; GILMORE, MICHAEL S.; RICE, LOUIS B.; TEGOS, GEORGE P.; HAMBLIN, MICHAEL R.; MYLONAKIS, ELEFTHERIOS. Photodynamic and antibiotic therapy impair the pathogenesis of enterococcus faecium in a whole animal insect model. PLoS ONE, v. 8, n. 2, p. e55926, 2013.

    Palavras-Chave: bacteria; streptococcus; therapy; antibiotics; infectious diseases; antimicrobial agents; insects; animal tissues; biological models; photosensitivity

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  • IPEN-DOC 24332

    BAPTISTA, ALESSANDRA ; SABINO, CAETANO P. ; NUNEZ, SILVIA C.; MIYAKAWA, WALTER; MARTIN, AIRTON A.; RIBEIRO, MARTHA S. . Photodynamic damage predominates on different targets depending on cell growth phase of Candida albicans. Journal of Photochemistry & Photobiology, B: Biology, v. 177, p. 76-84, 2017. DOI: 10.1016/j.jphotobiol.2017.10.013

    Abstract: Photodynamic inactivation (PDI) has been reported to be effective to eradicate a wide variety of pathogens, including antimicrobial-resistant microorganisms. The aim of this study was to identify the potential molecular targets of PDI depending on growth phase of Candida albicans. Fungal cells in lag (6 h) and stationary (48 h) phases were submitted to PDI mediated by methylene blue (MB) combined with a (662 +/- 21) nm-LED, at 360 mW of optical power. Pre-irradiation time was 10 min and exposure times were 12 min, 15 min and 18 min delivering radiant exposures of 129.6 J/cm(2), 162 J/cm(2) and 194.4 J/cm(2), respectively, on a 24-well plate of about 2 cm(2) at an irradiance of 180 mW/cm(2). Scanning electron microscopy (SEM), transmission electron microscopy (TEM), atomic force spectroscopy (AFS) and Fourier transform infrared spectroscopy (FT-IR) were employed to evaluate the photodynamic effect in young and old fungal cells following 15 min of irradiation. Morphological analysis revealed wrinkled and shrunk fungal cell membrane for both growth phases while extracellular polymeric substance (EPS) removal was only observed for old fungal cells. Damaged intracellular structures were more pronounced in young fungal cells. The surface nanostiffness of young fungal cells decreased after PDI but increased for old fungal cells. Cellular adhesion force was reduced for both growth phases. Fungal cells in lag phase predominantly showed degradation of nucleic acids and proteins, while fungal cells in stationary phase showed more pronounced degradation of polysaccharides and lipids. Taken together, our results indicate different molecular targets for fungal cells in lag and stationary growth phase following PDI.

    Palavras-Chave: fungal diseases; antibiotics; candida; adhesives; atomic force microscopy; spectroscopy; fourier transform spectrometers; flexibility; ultrastructural changes

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  • IPEN-DOC 20713

    SELLERA, FABIO P.; SABINO, CAETANO P. ; RIBEIRO, MARTHA S. ; FERNANDES, LORIE T.; POGLIANI, FABIO C.; TEIXEIRA, CARLOS R.; DUTRA, GUSTAVO H.P.; NASCIMENTO, CRISTIANE L.. Photodynamic therapy for pododermatitis in penguins. Zoo Biology, v. 33, n. 4, p. 353-356, 2014.

    Palavras-Chave: birds; dermatitis; antimicrobial agents; methylene blue; healing; wounds; photosensitivity; therapy

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  • IPEN-DOC 25031

    DIMMER, JESICA; CABRAL, FERNANDA V. ; SABINO, CAETANO P. ; NUNEZ MONTOYA, SUSANA C.; CABRERA, JOSE L.; RIBEIRO, MARTHA S. . Photoinactivation of Leishmania amazonesis by natural anthraquinones. In: INTERNATIONAL PHOTODYNAMIC ASSOCIATION WORLD CONGRESS, 16th, June 08-13, 2017, Coimbra, Portugal. Abstract... 2017. p. 195-195.

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  • IPEN-DOC 25291

    ANJOS, CAROLINA dos; SABINO, CAETANO P. ; BAPTISTA, MAURICIO da S.; RIBEIRO, MARTHA S. ; LINCOPAN, NILTON; POGLIANI, FABIO C.. Photoinactivation of pathogens in experimentally contaminated milk. In: DAI, TIANHONG (Ed.) LIGHT-BASED DIAGNOSIS AND TREATMENT OF INFECTIOUS DISEASES, January 27 - February 01, 2018, San Francisco, CA, USA. Abstract... Bellingham, WA, USA: Society of Photo-optical Instrumentation Engineers, 2018. (SPIE Proceedings Series, 10479).

    Abstract: Because milk is a highly nutritious food, it provides an excellent medium for growth of pathogenic microorganisms. Thus, dairy industry associates most of its processes and costs to keep contamination levels as low as possible. Thermal decontamination methods are the only antimicrobial strategies adopted, however, they are incapable to provide excellent organoleptic, nutritional and decontamination properties simultaneously. Microbial inactivation by exposure to blue light rises as a promising alternative in food industry due to its intrinsic antimicrobial properties without the harms of UV or ionizing radiation or the involvement of residual substances. Therefore, the aim of this study was to determine the inactivation kinetics of blue light (λLED = 413 nm) against Staphylococcus aureus, Escherichia coli, Listeria monocytogenes and Mycobacterium fortuitum cells suspended in whole milk or saline solution. The inactivation data was adjusted to the Weibull statistical model to extract theoretical values of lethal doses for any level of survival fraction. All species were sensitive to photoinactivation either suspended in milk or in saline solution. Inactivation kinetics significantly diverges according to the suspension medium and each species is differently affected. While S. aureus and E. coli are more sensitive to photoinactivation in milk, M. fortuitum and L. monocytogenes become more tolerant. Even though, more than 99,9% of any bacteria could be inactivated within less than 3 hours of irradiation. The organoleptic and nutritional properties of blue light irradiated milk still needs to be determined, however, photoinactivation presents great potential to microbial control in dairy industry.

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  • IPEN-DOC 24452

    SABINO, CAETANO P. ; HAMBLIN, MICHAEL R.. Photophysical and photochemical mechanisms. In: SELLERA, FABIO P. (Ed.); NASCIMENTO, CRISTIANE L. (Ed.); RIBEIRO, MARTHA S. (Ed.). Photodynamic therapy in veterinary medicine: from basics to clinical practice. Gewerbestrasse, Switzerland: Springer, 2016. p. 11-23, DOI: 10.1007/978-3-319-45007-0_2

    Observação: Livro na íntegra disponível. Consulte a biblioteca do IPEN.

    Abstract: Photodynamic therapy (PDT) harnesses the power of light in an elegant method to produce cytotoxic agents in a spatially and temporally controlled manner and specifically damage target cells and tissues. For photodynamic reactions to occur, the PS molecule must absorb at least one photon to be promoted to a sufficiently long-lived excited state and then induce photodynamic reactions in an oxygenated environment. Such properties guarantee that PDT has an exceptionally broad action spectrum against tumors or pathogens, and resistance occurrence is restricted to only a few exceptions that can be avoided using simple strategies. To fully understand the intricacies of the mechanisms by which PDT acts, it is clear that one must take advantage of all the basic sciences (e.g., physics, chemistry, and biology). In fact, such conceptual complexity still maintains constant scientific investigations to deeply understand the molecular basis of PDT. Curiously, it might also be one of the reasons to explain why this hundred-year-old technique is still not generally applied in clinics or taught in standard courses of pharmacology. In this chapter, we will attempt to use a multidisciplinary approach, with simple technical language and a minimum of mathematics and equations, to allow any student with minimal training in basic sciences to understand all the fundamental mechanisms of PDT.

    Palavras-Chave: photochemical reactions; photodynamic therapy; electromagnetic radiation; radiation sources

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✔ Para indexação dos documentos é utilizado o Thesaurus do INIS, especializado na área nuclear e utilizado em todos os países membros da International Atomic Energy Agency – IAEA , por esse motivo, utilize os termos de busca de assunto em inglês; isto não exclui a busca livre por palavras, apenas o resultado pode não ser tão relevante ou pertinente.

✔ 95% do RD apresenta o texto completo do documento com livre acesso, para aqueles que apresentam o significa que e o documento está sujeito as leis de direitos autorais, solicita-se nesses casos contatar a Biblioteca do IPEN, bibl@ipen.br .

✔ Ao efetuar a busca por um autor o RD apresentará uma relação de todos os trabalhos depositados no RD. No lado direito da tela são apresentados os coautores com o número de trabalhos produzidos em conjunto bem como os assuntos abordados e os respectivos anos de publicação agrupados.

✔ O RD disponibiliza um quadro estatístico de produtividade, onde é possível visualizar o número dos trabalhos agrupados por tipo de coleção, a medida que estão sendo depositados no RD.

✔ Na página inicial nas referências são sinalizados todos os autores IPEN, ao clicar nesse símbolo será aberta uma nova página correspondente à aquele autor – trata-se da página do pesquisador.

✔ Na página do pesquisador, é possível verificar, as variações do nome, a relação de todos os trabalhos com texto completo bem como um quadro resumo numérico; há links para o Currículo Lattes e o Google Acadêmico ( quando esse for informado).

ATENÇÃO!

ESTE TEXTO "AJUDA" ESTÁ SUJEITO A ATUALIZAÇÕES CONSTANTES, A MEDIDA QUE NOVAS FUNCIONALIDADES E RECURSOS DE BUSCA FOREM SENDO DESENVOLVIDOS PELAS EQUIPES DA BIBLIOTECA E DA INFORMÁTICA.

O gerenciamento do Repositório está a cargo da Biblioteca do IPEN. Constam neste RI, até o presente momento 20.950 itens que tanto podem ser artigos de periódicos ou de eventos nacionais e internacionais, dissertações e teses, livros, capítulo de livros e relatórios técnicos. Para participar do RI-IPEN é necessário que pelo menos um dos autores tenha vínculo acadêmico ou funcional com o Instituto. Nesta primeira etapa de funcionamento do RI, a coleta das publicações é realizada periodicamente pela equipe da Biblioteca do IPEN, extraindo os dados das bases internacionais tais como a Web of Science, Scopus, INIS, SciElo além de verificar o Currículo Lattes. O RI-IPEN apresenta também um aspecto inovador no seu funcionamento. Por meio de metadados específicos ele está vinculado ao sistema de gerenciamento das atividades do Plano Diretor anual do IPEN (SIGEPI). Com o objetivo de fornecer dados numéricos para a elaboração dos indicadores da Produção Cientifica Institucional, disponibiliza uma tabela estatística registrando em tempo real a inserção de novos itens. Foi criado um metadado que contém um número único para cada integrante da comunidade científica do IPEN. Esse metadado se transformou em um filtro que ao ser acionado apresenta todos os trabalhos de um determinado autor independente das variáveis na forma de citação do seu nome.

A elaboração do projeto do RI do IPEN foi iniciado em novembro de 2013, colocado em operação interna em julho de 2014 e disponibilizado na Internet em junho de 2015. Utiliza o software livre Dspace, desenvolvido pelo Massachusetts Institute of Technology (MIT). Para descrição dos metadados adota o padrão Dublin Core. É compatível com o Protocolo de Arquivos Abertos (OAI) permitindo interoperabilidade com repositórios de âmbito nacional e internacional.

1. Portaria IPEN-CNEN/SP nº 387, que estabeleceu os princípios que nortearam a criação do RDI, clique aqui.


2. A experiência do Instituto de Pesquisas Energéticas e Nucleares (IPEN-CNEN/SP) na criação de um Repositório Digital Institucional – RDI, clique aqui.

O Repositório Digital do IPEN é um equipamento institucional de acesso aberto, criado com o objetivo de reunir, preservar, disponibilizar e conferir maior visibilidade à Produção Científica publicada pelo Instituto, desde sua criação em 1956.

Operando, inicialmente como uma base de dados referencial o Repositório foi disponibilizado na atual plataforma, em junho de 2015. No Repositório está disponível o acesso ao conteúdo digital de artigos de periódicos, eventos, nacionais e internacionais, livros, capítulos, dissertações, teses e relatórios técnicos.

A elaboração do projeto do RI do IPEN foi iniciado em novembro de 2013, colocado em operação interna em julho de 2014 e disponibilizado na Internet em junho de 2015. Utiliza o software livre Dspace, desenvolvido pelo Massachusetts Institute of Technology (MIT). Para descrição dos metadados adota o padrão Dublin Core. É compatível com o Protocolo de Arquivos Abertos (OAI) permitindo interoperabilidade com repositórios de âmbito nacional e internacional.

O gerenciamento do Repositório está a cargo da Biblioteca do IPEN. Constam neste RI, até o presente momento 20.950 itens que tanto podem ser artigos de periódicos ou de eventos nacionais e internacionais, dissertações e teses, livros, capítulo de livros e relatórios técnicos. Para participar do RI-IPEN é necessário que pelo menos um dos autores tenha vínculo acadêmico ou funcional com o Instituto. Nesta primeira etapa de funcionamento do RI, a coleta das publicações é realizada periodicamente pela equipe da Biblioteca do IPEN, extraindo os dados das bases internacionais tais como a Web of Science, Scopus, INIS, SciElo além de verificar o Currículo Lattes. O RI-IPEN apresenta também um aspecto inovador no seu funcionamento. Por meio de metadados específicos ele está vinculado ao sistema de gerenciamento das atividades do Plano Diretor anual do IPEN (SIGEPI). Com o objetivo de fornecer dados numéricos para a elaboração dos indicadores da Produção Cientifica Institucional, disponibiliza uma tabela estatística registrando em tempo real a inserção de novos itens. Foi criado um metadado que contém um número único para cada integrante da comunidade científica do IPEN. Esse metadado se transformou em um filtro que ao ser acionado apresenta todos os trabalhos de um determinado autor independente das variáveis na forma de citação do seu nome.