Fourier transform infrared spectrum pre-processing technique selection for detecting PYLCV-infected chilli plants

Pre-processing is a crucial step in analyzing spectra from Fourier transform infrared (FTIR) spectroscopy because it can reduce unwanted noise and enhance system performance. Here, we present the results of pre-processing technique optimization to facilitate the detection of pepper yellow leaf curl virus (PYLCV)-infected chilli plants using FTIR spectroscopy. Optimization of a range of pre-processing techniques was undertaken, namely baseline correction, normalization (standard normal variate, vector, and min–max), and de-noising (Savitzky-Golay (SG) smoothing, 1st and 2 derivatives). The pre-processing was applied to the mid-infrared spectral range (4000 – 400 cm−1) and the biofingerprint region (1800 – 900 cm−1) then the discrete wavelet transform (DWT) was used for dimension reduction. The pre-processed data were then used as an input for classification using a multilayer perceptron neural network, a support vector machine, and linear discriminant analysis. The pre-processing method with the highest classification model accuracy was selected for the further use in the processing. It was seen that only the SG 1st derivative method applied to both wavenumber ranges could produce 100% accuracy. This result was supported by principal component analysis clustering. Thus, we have demonstrated that by using the right pre-processing technique, classification success can be increased, and the process simplified by optimization and minimization of the technique used

Diagnostic Neuropathology of Brain Tumours using Biophotonics and Spectrometry

Classification of tumours such as gliomas, which are on a continuous spectrum of histology and malignancy into distinct categories is still a challenge using histopathology. There has been significant advances in the techniques used to fight cancer in the past two decades. A number of studies have looked at different approaches to improve the accuracy in diagnosis using histopathology. This study evaluated a number of techniques to compliment histopathology. One study looked at vibrational spectroscopy, Raman and attenuated total reflection-fourier transform infrared (ATR-FTIR) looking at brain tumour cell lines. This study investigated the potential application of vibrational spectroscopy in the segregation of different types of brain tumours using two tumour cell lines, U87MG, 1321N1 and a control, SVGP12. Another study looked at two approaches, elemental profiling of both tissue and serum using inductively coupled plasma-mass spectrometry. Trace elements increase or deficiency has been linked to cancer development and progression. The final study looked at the diagnostic application of Raman spectroscopy to distinguish between gliomas, meningiomas, medulloblastoma and several other brain tumours from histological normal brain tissue from brain tumour patients used as controls. The three cell lines U87MG, SVGP12 and 1321N1 were cultured and grown on calcium fluoride slides in triplicates. Spectra from each cell line was taken using both Raman and ATR-FTIR. The spectra was then analysed using multivariate statistics. In the elemental profiling study serum and tissue samples from 55 patients with brain tumours were collected and analysed using ICP-MS. The elemental data was then evaluated using multivariate statistics to investigate significant differences. In the analysis of human brain tumours tissue blocks of both tumour and histological normal brain that were formalin fixed and paraffin embedded (FFPE) were processed and mounted on low-E slides, dewaxed using Xylene, washed with alcohol and water before storage at room temperature until analysis. Raman and ATR-FTIR were able to separate U87MG, SVGP12 and 1321N1 with very high classification accuracy. All the brain tumour groups investigated showed a deficiency of Mg, Fe, Cu, and Zn concentrations against reported levels from healthy individuals in the literature. Raman spectroscopy coupled with multivariate statistics was able to distinguish between normal brain tissue and normal brain tumour tissue used as controls. Classification of gliomas based on the degree of malignancy was also apparent with very high classification accuracy. Spectral panels were developed that can be used as biomarkers in the diagnosis of brain tumours. Raman and Infrared spectroscopy are types of vibrational spectroscopy which have the potential to be used as diagnostic tools in neuropathology. They provide an intrinsic molecular fingerprint of the sample based on the interaction of light. The panels can accurately identify and classify specific brain tumours alleviating the need to use complex statistical models. Raman and ATR-FTIR were able to elucidate chemical information from the samples which was used to differentiate the three cell lines with very high classification accuracy. Diagnosis of a brain tumour is not always a straight forward process and the current techniques used lack the desired level of precision in diagnosis and cytoreductive surgery

Experimental and Model-based Terahertz Imaging and Spectroscopy for Mice, Human, and Phantom Breast Cancer Tissues

The goal of this work is to investigate terahertz technology for assessing the surgical margins of breast tumors through electromagnetic modeling and terahertz experiments. The measurements were conducted using a pulsed terahertz system that provides time and frequency domain signals. Three types of breast tissues were investigated in this work. The first was formalin-fixed, paraffin-embedded tissues from human infiltrating ductal and lobular carcinomas. The second was human tumors excised within 24-hours of lumpectomy or mastectomy surgeries. The third was xenograft and transgenic mice breast cancer tumors grown in a controlled laboratory environment to achieve more data for statistical analysis. Experimental pulsed terahertz imaging first used thin sections (10-30 μm thick) of fixed breast cancer tissue on slides. Electromagnetic inverse scattering models, in transmission and reflection modes, were developed to retrieve the tissue refractive index and absorption coefficient. Terahertz spectroscopy was utilized to experimentally collect data from breast tissues for these models. The results demonstrated that transmission mode is suitable for lossless materials while the reflection model is more suitable for biological materials where the skin depth of terahertz waves does not exceed 100 µm. The reflection model was implemented to estimate the polarization of the incident terahertz signal of the system, which was shown to be a hybridization of TE and TM modes. Terahertz imaging of three-dimensional human breast cancer blocks of tissue embedded in paraffin was achieved through the reflection model. The terahertz beam can be focused at depths inside the block to produce images in the x-y planes (z-scan). The time-of-flight analysis was applied to terahertz signals reflected at each depth demonstrating the margins of cancerous regions inside the block as validated with pathology images at each depth. In addition, phantom tissues that mimic freshly excised infiltrating ductal carcinoma human tumors were developed with and without embedded carbon nanometer-scale onion-like carbon particles. These particles exhibited a strong terahertz signal interaction with tissue demonstrating a potential to greatly improve the image contrast. The results presented in this work showed, in most cases, a significant differentiation in terahertz images between cancer and healthy tissue as validated with histopathology images

Proceedings of the Scientific-Practical Conference "Research and Development - 2016"

talent management; sensor arrays; automatic speech recognition; dry separation technology; oil production; oil waste; laser technolog

Applications and Experiences of Quality Control

The rich palette of topics set out in this book provides a sufficiently broad overview of the developments in the field of quality control. By providing detailed information on various aspects of quality control, this book can serve as a basis for starting interdisciplinary cooperation, which has increasingly become an integral part of scientific and applied research

XXIV congreso anual de la sociedad española de ingeniería biomédica (CASEIB2016)

En la presente edición, más de 150 trabajos de alto nivel científico van a ser presentados en 18 sesiones paralelas y 3 sesiones de póster, que se centrarán en áreas relevantes de la Ingeniería Biomédica. Entre las sesiones paralelas se pueden destacar la sesión plenaria Premio José María Ferrero Corral y la sesión de Competición de alumnos de Grado en Ingeniería Biomédica, con la participación de 16 alumnos de los Grados en Ingeniería Biomédica a nivel nacional. El programa científico se complementa con dos ponencias invitadas de científicos reconocidos internacionalmente, dos mesas redondas con una importante participación de sociedades científicas médicas y de profesionales de la industria de tecnología médica, y dos actos sociales que permitirán a los participantes acercarse a la historia y cultura valenciana. Por primera vez, en colaboración con FENIN, seJane Campos, R. (2017). XXIV congreso anual de la sociedad española de ingeniería biomédica (CASEIB2016). Editorial Universitat Politècnica de València. http://hdl.handle.net/10251/79277EDITORIA