ABSTRACT
In this paper, we present an analysis of the performance of Raman spectroscopy, combined with feed-forward neural networks (FFNN), for the estimation of concentration percentages of glucose, sucrose, and fructose in water solutions. Indeed, we analysed our method for the estimation of sucrose in three solid industrialized food products: donuts, cereal, and cookies. Concentrations were estimated in two ways: using a non-linear fitting system, and using a classifier. Our experiments showed that both the classifier and the fitting systems performed better than a Support Vector Machine (SVM), a Linear Discriminant Analysis (LDA), a Linear Regression (LR), and interval Partial Least Squares (iPLS). The best-case obtained by an FFNN for water solutions was 93.33% of classification and 3.51% of Root Mean Square Error in Prediction (RMSEP), compared with 82.22% obtained by a LDA. Our proposed method got an RMSEP of 1% for the best-case obtained with the food products.
Subject(s)
Neural Networks, Computer , Spectrum Analysis, Raman , Sugars/analysis , Discriminant Analysis , Least-Squares Analysis , Linear Models , Support Vector Machine , Water/chemistryABSTRACT
The World Health Organization has declared the glycated hemoglobin (HbA1c) as a gold standard biomarker for diabetes diagnosis; this has led to relevant research on the spectral behavior and characterization of HbA1c. This paper presents an analysis of Raman peaks of commercial lyophilized HbA1c, diluted in distilled water, using concentrations of 4.76% and 9.09%, as well as pure powder (100% concentration). Vibrational Raman peak positions of HbA1c powder were found at 1578, 1571, 1536, 1436, 1311, 1308, 1230, 1222, 1114, 1106, 969, 799 and 665â¯cm-1; these values are consistent with results reported in other works. Besides, a nonlinear regression model based on a Feed-Forward Neural Network (FFNN) was built to quantify percentages of HbA1c for unknown concentrations. Using the Raman spectra as independent variables, the regression provided a Root Mean Square Error in Cross-Validation (RMSECV) of 0.08%⯱â¯0.04. We also include a detailed molecular assignment of the average spectra of lyophilized powder of HbA1c.
Subject(s)
Diabetes Mellitus , Spectrum Analysis, Raman , Glycated Hemoglobin/analysis , Humans , Neural Networks, Computer , Nonlinear DynamicsABSTRACT
In this study we compared the sensitivity of molecular, serologic and parasitologic methods for diagnosis of equine trichinellosis in two abattoirs, one rural and one federal inspection type. Diaphragm muscle samples were obtained from 170 slaughter horses and examined by artificial digestion and PCR. Serum samples from these horses were also analyzed by ELISA. No Trichinella muscle larvae were detected by artificial digestion. However, specific antibodies against Trichinella were detected in 17% and 7% of the serum samples examined from the rural and the federal abattoirs respectively. By PCR, 15% and 2% of the samples from these two abattoirs were Trichinella positive.
Subject(s)
Horse Diseases/diagnosis , Muscle, Skeletal/parasitology , Trichinellosis/veterinary , Abattoirs , Animals , DNA, Helminth/isolation & purification , Enzyme-Linked Immunosorbent Assay/methods , Horse Diseases/parasitology , Horses , Polymerase Chain Reaction/methods , Reproducibility of Results , Trichinella/isolation & purification , Trichinellosis/diagnosisABSTRACT
In order to determine the presence of Trichinella infections in horses slaughtered at an abattoir in Mexico, 147 serum samples were examined by two immunoenzymatic methods. Specific antibodies were detected by ELISA in 7% of the serum samples at a dilution 1:400 and in 10% at lower dilutions (1:20, 1:40) using Trichinella spiralis muscle larvae (ML) excretory/secretory (E/S) products. Serum samples from four naturally infected horses (confirmed by direct methods) gave negative O.D. values in an ELISA at a 1:400 dilution and only two of them were positive at a 1:20 and 1:40 dilutions. Serum samples from experimentally infected horses reacted by Western blotting with ML components with molecular weights of 47, 52, 59, 67, 72 and 105 kDa which correspond to the TSL-1 antigens. Serum samples from the four naturally infected horses and from the abattoir horses that were positive in ELISA using E/S antigens recognized several ML components, some of them reacted with all the TSL-1 antigens mentioned above and others recognized preferentially two or three of these molecules. Since the serologic assays may not offer the sensitivity required in the diagnosis of horses trichinellosis and the direct methods had not always been useful in the detection of larvae in horsemeat related to trichinellosis outbreaks in Europe, it is proposed that additional assays are performed to determine Trichinella infection in horses. These can include detection of parasite antigens by ELISA and Dot ELISA or PCR, which in turn may also help to determine the presence of the parasite in early and late infections of horses.
Subject(s)
Horse Diseases/diagnosis , Trichinella spiralis/isolation & purification , Trichinellosis/veterinary , Abattoirs , Animals , Antibodies, Helminth/blood , Antigens, Helminth/chemistry , Blotting, Western/veterinary , Diaphragm/parasitology , Enzyme-Linked Immunosorbent Assay/veterinary , Female , Horse Diseases/parasitology , Horses , Kinetics , Male , Mexico , Trichinellosis/diagnosisABSTRACT
Human trichinellosis outbreaks related to horsemeat consumption have been reported in France and Italy in recent years. In order to determine if Trichinella is present in horses slaughtered at an abattoir in the State of Mexico, diaphragm muscle tissue samples (22-37 g) from 80 horses were examined by artificial digestion. Four of these samples had larvae that were characterized as Trichinella sp. by morphological criteria and as Trichinella spiralis by the polymerase chain reaction.
