Biophotonics South America最新文献_第3页

UV protection of euglenoids: computation of the electromagnetic response 类绿藻的紫外线防护:电磁响应的计算

Biophotonics South America Pub Date : 2015-06-19 DOI: 10.1117/12.2180935

A. Dolinko, C. Valencia, D. Skigin, M. Inchaussandague, Analía Tolivia, V. Conforti

{"title":"UV protection of euglenoids: computation of the electromagnetic response","authors":"A. Dolinko, C. Valencia, D. Skigin, M. Inchaussandague, Analía Tolivia, V. Conforti","doi":"10.1117/12.2180935","DOIUrl":"https://doi.org/10.1117/12.2180935","url":null,"abstract":"Euglenoids are a group of predominantly free-living unicellular microorganisms that mostly live in freshwater bodies but can also be found in marine and brackish waters. These organisms have a characteristic that distinguishes them form the other protists: they are covered by a surface pellicle formed by S-shaped overlapping bands which resemble a diffraction grating. These microorganisms have developed numerous protection mechanisms intended to avoid or reduce the damage produced by UV radiation, such as the production of pigments and the repair mechanisms in hours of darkness and during daylight. In a recent paper we have investigated the role played by the pellicle of Euglenoids in the protection of the cell against UV radiation, by means of an electromagnetic approach based on the approximation of the pellicle profile by a one-dimensional diffraction grating. This simplified model allowed us to confirm that under certain incidence conditions, the corrugation of the pellicle helps increase the UV reflection, and consequently, diminish the UV radiation that enters the cell. In order to analyze the electromagnetic response of the whole cell, we extend two different approaches to calculate the reflected response: a simulation method especially developed to deal with complex biological structures that permits the introduction of the scattering object via an electron microscopy image, and the integral method, which has been widely used to compute the electromagnetic response of finite structures. Numerical results of near and far fields are shown.","PeriodicalId":307847,"journal":{"name":"Biophotonics South America","volume":"3 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-06-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132328215","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}

引用次数: 2

Portable fluorescence microendoscope system for smartphones and its applications 智能手机便携式荧光显微内窥镜系统及其应用

Biophotonics South America Pub Date : 2015-06-19 DOI: 10.1117/12.2180987

Pablo Aurelio Gómez García, Ramon Gabriel Teixeira Rosa, S. Pratavieira, C. Kurachi

引用次数: 1

New speckle analysis algorithm for flow visualization in optical coherence tomography images 光学相干层析成像流显示的散斑分析新算法

Biophotonics South America Pub Date : 2015-06-19 DOI: 10.1117/12.2180811

L. D. De Pretto, G. Nogueira, A. Freitas

{"title":"New speckle analysis algorithm for flow visualization in optical coherence tomography images","authors":"L. D. De Pretto, G. Nogueira, A. Freitas","doi":"10.1117/12.2180811","DOIUrl":"https://doi.org/10.1117/12.2180811","url":null,"abstract":"Optical Coherence Tomography (OCT) is a noninvasive technique capable of generating in vivo high-resolution images. However, OCT images are degraded by a granular and random noise called speckle. Nevertheless, such a noise may be used to gather information regarding the sample, as is exploited by techniques like Speckle Variance – OCT (SV-OCT). SV-OCT is widely used in the literature, but the variance calculation is computationally expensive. Therefore, we propose a new algorithm to employ speckle in identifying flow based on the evaluation of intensity fluctuation between two consecutively acquired OCT images. Our results were compared to those obtained by traditional method of Speckle Variance to demonstrate the feasibility of the technique. Both algorithms were applied to series of OCT images from a microchannel flow phantom, as well as from a biological tissue with blood flow. The results obtained by our method are in good agreement with those from SV-OCT. We've also analyzed the performance of both algorithms, registering the processing time and memory use. Our method performed 31% faster with the same use of memory. Therefore, we demonstrated a new method to map flow on OCT images.","PeriodicalId":307847,"journal":{"name":"Biophotonics South America","volume":"78 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-06-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121331013","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}

引用次数: 0

Development of an in situ controllable polymerization tool and process for hydrogel used to replace nucleus pulposus 替代髓核的水凝胶原位可控聚合工具及工艺的研制

Biophotonics South America Pub Date : 2015-06-19 DOI: 10.1117/12.2180457

A. Schmocker, A. Khoushabi, P. Bourban, C. Schizas, D. Pioletti, C. Moser

引用次数: 0

Diffuse reflectance spectroscopy of liver tissue 肝组织漫反射光谱

Biophotonics South America Pub Date : 2015-06-19 DOI: 10.1117/12.2181008

N. Reistad, J. Nilsson, O. Vilhelmsson Timmermand, C. Sturesson, S. Andersson-Engels

引用次数: 16

Fluorescence spectroscopy for assessment of liver transplantation grafts concerning graft viability and patient survival 荧光光谱法评估肝移植移植物对移植物活力和患者生存的影响

Biophotonics South America Pub Date : 2015-06-19 DOI: 10.1117/12.2180730

J. D. Vollet Filho, M. D. da Silveira, O. Castro-e-Silva, V. Bagnato, C. Kurachi

引用次数: 3

In situ visualization of dermal collagen dynamics during skin burn healing using second-harmonic-generation microscopy 使用二次谐波显微镜观察皮肤烧伤愈合过程中真皮胶原动态的原位可视化

Biophotonics South America Pub Date : 2015-06-19 DOI: 10.1117/12.2180895

T. Yasui, E. Hase, R. Tanaka, S. Fukushima, T. Araki

{"title":"In situ visualization of dermal collagen dynamics during skin burn healing using second-harmonic-generation microscopy","authors":"T. Yasui, E. Hase, R. Tanaka, S. Fukushima, T. Araki","doi":"10.1117/12.2180895","DOIUrl":"https://doi.org/10.1117/12.2180895","url":null,"abstract":"Burn healing is a process to repair thermally damaged tissues. Although burn healing has many aspects, it is common for dynamics of collagen fiber, such as decomposition, production, or growth, to be closely related with burn healing. If such healing process can be visualized from the viewpoint of the collagen dynamics, one may obtain new findings regarding biological repairing mechanisms in the healing process. To this end, second-harmonic-generation (SHG) light will be an effective optical probe because of high selectivity and good image contrast to collagen molecules as well as high spatial resolution, optical three-dimensional (3D) sectioning, minimal invasiveness, deep penetration, the absence of interference from background light, and in situ measurement without additional staining. Furthermore, since SHG light arises from a non-centrosymmetric triple helix of three polypeptide chains in the collagen molecule, its intensity decreases and finally disappears when thermal denaturation caused by the skin burn changes the structure of this molecule to a centrosymmetric random coil. Therefore, optical assessment of skin burn has been investigated by SHG microscopy. In this paper, we applied SHG microscopy for in situ imaging of the healing process in animal skin burn and successfully visualized the decomposition, production, and growth of renewal collagen fibers as a series of time-lapse images in the same subject.","PeriodicalId":307847,"journal":{"name":"Biophotonics South America","volume":"7 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-06-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114241066","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}

引用次数: 0

Single LED-based device to perform widefield fluorescence imaging and photodynamic therapy 单led为基础的设备，执行宽视场荧光成像和光动力治疗

Biophotonics South America Pub Date : 2015-06-19 DOI: 10.1117/12.2185925

C. Grecco, H. Buzzá, M. D. Stringasci, C. T. Andrade, J. D. Vollet-Filho, S. Pratavieira, A. L. Zanchin, A. M. Tuboy, V. Bagnato

{"title":"Single LED-based device to perform widefield fluorescence imaging and photodynamic therapy","authors":"C. Grecco, H. Buzzá, M. D. Stringasci, C. T. Andrade, J. D. Vollet-Filho, S. Pratavieira, A. L. Zanchin, A. M. Tuboy, V. Bagnato","doi":"10.1117/12.2185925","DOIUrl":"https://doi.org/10.1117/12.2185925","url":null,"abstract":"Photodynamic therapy (PDT) is a treatment modality that can be indicated for several cancer types and pre-cancer lesions. One of the main applications of PDT is the treatment of superficial skin lesions such as basal cell carcinoma, Bowen’s disease and actinic keratosis. Three elements are necessary in PDT, a photosensitizer (PS); light at specific wavelength to be absorbed by the PS, and molecular oxygen. A typical PS used for skin lesion is protoporphyrin IX (PpIX), which is an intrinsic PS; its production is stimulated by a pro-drug, such as 5-aminolevulinic acid (ALA). Before starting a treatment, it is very important to follow up the PpIX production (to ensure that enough PS was produced prior to a PDT application) and, during a PDT session, to monitor its photodegradation (as it is evidence of the photodynamic effect taking place). The aim of this paper is to present a unique device, LINCE (MMOptics - São Carlos, Brazil), that brings together two probes that can, respectively, allow for fluorescence imaging and work as a light source for PDT treatment. The fluorescence probe of the system is optically based on 400 nm LED (light emitting diodes) arrays that allow observing the fluorescence emission over 450 nm. The PDT illumination probe options are constituted of 630 nm LED arrays for small areas and, for large areas, of both 630 nm and 450 nm LED arrays. Joining both functions at the same device makes PDT treatment simpler, properly monitorable and, hence, more clinically feasible. LINCE has been used in almost 1000 PDT treatments of superficial skin lesions in Brazil, with 88.4% of clearance of superficial BCC.","PeriodicalId":307847,"journal":{"name":"Biophotonics South America","volume":"667 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-06-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121999571","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}

引用次数: 30

Applications of Raman spectroscopy in life science 拉曼光谱在生命科学中的应用

Biophotonics South America Pub Date : 2015-06-19 DOI: 10.1117/12.2180653

A. Martin, Cláudio A. T. Soto, S. M. Ali, L. M. Neto, R. Canevari, L. Pereira, P. Fávero

{"title":"Applications of Raman spectroscopy in life science","authors":"A. Martin, Cláudio A. T. Soto, S. M. Ali, L. M. Neto, R. Canevari, L. Pereira, P. Fávero","doi":"10.1117/12.2180653","DOIUrl":"https://doi.org/10.1117/12.2180653","url":null,"abstract":"Raman spectroscopy has been applied to the analysis of biological samples for the last 12 years providing detection of changes occurring at the molecular level during the pathological transformation of the tissue. The potential use of this technology in cancer diagnosis has shown encouraging results for the in vivo, real-time and minimally invasive diagnosis. Confocal Raman technics has also been successfully applied in the analysis of skin aging process providing new insights in this field. In this paper it is presented the latest biomedical applications of Raman spectroscopy in our laboratory. It is shown that Raman spectroscopy (RS) has been used for biochemical and molecular characterization of thyroid tissue by micro-Raman spectroscopy and gene expression analysis. This study aimed to improve the discrimination between different thyroid pathologies by Raman analysis. A total of 35 thyroid tissues samples including normal tissue (n=10), goiter (n=10), papillary (n=10) and follicular carcinomas (n=5) were analyzed. The confocal Raman spectroscopy allowed a maximum discrimination of 91.1% between normal and tumor tissues, 84.8% between benign and malignant pathologies and 84.6% among carcinomas analyzed. It will be also report the application of in vivo confocal Raman spectroscopy as an important sensor for detecting advanced glycation products (AGEs) on human skin.","PeriodicalId":307847,"journal":{"name":"Biophotonics South America","volume":"48 22 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-06-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127776031","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}

引用次数: 2

3D Monte Carlo radiation transfer modelling of photodynamic therapy 光动力治疗的三维蒙特卡罗辐射转移模型

Biophotonics South America Pub Date : 2015-06-19 DOI: 10.1117/12.2180744

C. L. Campbell

引用次数: 4