Analysis of the alteration in the optical configuration of Raman spectrometer: Optimization of signal-to-noise ratio (SNR) in a specific wavelength range of clinical interest

Abstract. The present article is focused on the optimization of the optical parameters of a Raman spectrometer in order to obtain a minimum width of its spectral lines. In this way, using as reference the width of a fingerprint band of a calcified biological tissue, a spectral line without distortion or any loss of resolution was identified. This optimization is employed with the aim of improvement of the signal-to-noise ratio (SNR). A great improvement in the efficiency of the spectral collect was obtained, which can reduce significantly the time of diagnosis of target tissues, such as the calcified coronarian tissue. Therefore, the potential application of this new spectroscopic system increases the efficiency and precision, favoring the security of this technique to future in vivo applications. The excellent results obtained in this work become this spectroscopic system a powerful tool to the clinical diagnosis of several diseases

USE OF DISPERSIVE RAMAN SPECTROSCOPY IN THE DETERMINATION OF UNSATURATED FAT IN COMMERCIAL EDIBLE OIL- AND FAT-CONTAINING INDUSTRIALIZED FOODS

The present study aims at the use of Raman spectroscopy in the quantification of unsaturated fats in fat-containing foods, compared to the information available in the Nutritional Table, to obtain a non-destructive optical quantification of unsaturation. Raman spectra of edible oil, margarine, mayonnaise, hydrogenated fat, and butter were obtained with a near-infrared Raman spectrometer (830nm). By analyzing selected bands in the regions of 1750, 1660, 1440, 1300, and 1260cm-1, the amount of total and unsaturated fat of samples of oil, margarine, and mayonnaise were correlated with the information displayed in the Nutritional Table. The amount of unsaturated trans fat in selected samples was correlated to the Raman shift of 1660cm-1. Dispersive Raman spectroscopy was shown to be effective in quantifying the unsaturated fats in oil, margarine, and mayonnaise, and trans fat in hydrogenated oils and butter

Low-level light-emitting diode therapy increases mRNA expressions of IL-10 and type I and III collagens on Achilles tendinitis in rats

The present study investigated the effects of low-level light-emitting diode (LED) therapy (880 +/- 10 nm) on interleukin (IL)-10 and type I and III collagen in an experimental model of Achilles tendinitis. Thirty male Wistar rats were separated into six groups (n = 5), three groups in the experimental period of 7 days, control group, tendinitis-induced group, and LED therapy group, and three groups in the experimental period of 14 days, tendinitis group, LED therapy group, and LED group with the therapy starting at the 7th day after tendinitis induction (LEDT delay). Tendinitis was induced in the right Achilles tendon using an intratendinous injection of 100 mu L of collagenase. the LED parameters were: optical power of 22 mW, spot area size of 0.5 cm(2), and irradiation time of 170 s, corresponding to 7.5 J/cm(2) of energy density. the therapy was initiated 12 h after the tendinitis induction, with a 48-h interval between irradiations. the IL-10 and type I and III collagen mRNA expression were evaluated by real-time polymerase chain reaction at the 7th and 14th days after tendinitis induction. the results showed that LED irradiation increased IL-10 (p < 0.001) in treated group on 7-day experimental period and increased type I and III collagen mRNA expression in both treated groups of 7- and 14-day experimental periods (p < 0.05), except by type I collagen mRNA expression in LEDT delay group. LED (880 nm) was effective in increasing mRNA expression of IL-10 and type I and III collagen. Therefore, LED therapy may have potentially therapeutic effects on Achilles tendon injuries.Fundação de Amparo à Pesquisa do Estado de Minas Gerais (FAPEMIG)Univ Fed Vales Jequitinhonha & Mucuri, Dept Physiotherapy, Lab Res & Anim Experimentat, BR-39100000 Diamantina, MG, BrazilUniv Camilo Castelo Branco, Inst Biomed Engn, São Paulo, BrazilInst Fed Educ Ciencia & Tecnol Sul Minas Gerais, Grp Estudos & Pesquisa Ciencias Saude, Belo Horizonte, MG, BrazilUniversidade Federal de São Paulo, UNIFESP, São Paulo, BrazilNove de Julho Univ, UNINOVE, Dept Rehabil Sci, São Paulo, BrazilUniversidade Federal de São Paulo, UNIFESP, São Paulo, BrazilFAPEMIG: APQ-01733-11Web of Scienc

Near-infrared Raman spectroscopy to detect anti-Toxoplasma gondii antibody in blood sera of domestic cats: quantitative analysis based on partial least-squares multivariate statistics

Toxoplasmosis is an important zoonosis in public health because domestic cats are the main agents responsible for the transmission of this disease in Brazil. We investigate a method for diagnosing toxoplasmosis based on Raman spectroscopy. Dispersive near-infrared Raman spectra are used to quantify anti-Toxoplasma gondii (IgG) antibodies in blood sera from domestic cats. An 830-nm laser is used for sample excitation, and a dispersive spectrometer is used to detect the Raman scattering. A serological test is performed in all serum samples by the enzyme-linked immunosorbent assay (ELISA) for validation. Raman spectra are taken from 59 blood serum samples and a quantification model is implemented based on partial least squares (PLS) to quantify the sample's serology by Raman spectra compared to the results provided by the ELISA test. Based on the serological values provided by the Raman/PLS model, diagnostic parameters such as sensitivity, specificity, accuracy, positive prediction values, and negative prediction values are calculated to discriminate negative from positive samples, obtaining 100, 80, 90, 83.3, and 100%, respectively. Raman spectroscopy, associated with the PLS, is promising as a serological assay for toxoplasmosis, enabling fast and sensitive diagnosis. (C) 2010 Society of Photo-Optical Instrumentation Engineers. [DOI: 10.1117/1.3463006]Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq

Analysis of experimental tendinitis in rats treated with laser and platelet-rich plasma therapies by Raman spectroscopy and histometry

The objective of this controlled experimental study was to analyze the changes in the Achilles tendons of rats with experimentally induced tendinitis after treatment with platelet-rich plasma (PRP) and/or laser therapies by histometry to quantify fibroblasts and by Raman spectroscopy to determine the biochemical concentration of collagen types I and III. Fifty-four male Wistar rats were divided into six treatment groups: control (G1); PRP only (G2); irradiation with 660 nm laser (G3); irradiation with 830 nm laser (G4); PRP plus 660 nm laser irradiation (G5); and PRP plus 830 nm laser irradiation (G6). Injuries (partial tenotomy) were inflicted in the middle third of the Achilles tendon, with PRP added prior to suture in the appropriate experimental groups. A diode laser (model Laser Flash® III, DMC Equipamentos Ltda, São Carlos, SP, Brazil) that can be operated in two wavelengths 660 and 830 nm was used for irradiation treatments. The irradiation protocol was energy density of 70 J/cm(2), 20 s irradiation time, and 0.028 cm(2) spot area, per point in three points in the injured. The histometry was made in micrographical images of the H&E stained sections and evaluated by ImageJ (version 1.46r)®. Raman spectra were collected using a dispersive spectrometer at 830 nm excitation, 200 mW power, and 10 s integration time (P-1 Raman system, Lambda Solutions, Inc. MA, USA). The relative amount of type I collagen was significantly greater in the PRP plus 830 nm laser irradiation group (468 ± 188) than in the control (147 ± 137), 630 nm laser only (191 ± 117), and 830 nm laser only (196 ± 106) groups (p < 0.01), while the quantity of type III collagen was significantly greater in the PRP-only group compared to both irradiated groups without PRP (p < 0.05). Treatment with PRP combined with irradiation at 830 nm resulted in a larger number of fibroblasts and increased concentration of type I collagen, thus accelerating the healing of the injured tendon.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP