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Full-Text Articles in Other Analytical, Diagnostic and Therapeutic Techniques and Equipment

Soft Lithographic Replication Of High Length-Scale Micropillars From Laser-Ablated Fused-Silica Templates, Jason Pitts Jun 2021

Soft Lithographic Replication Of High Length-Scale Micropillars From Laser-Ablated Fused-Silica Templates, Jason Pitts

University Honors Theses

Soft lithography is a well-established route to wafer-scale reproduction of micro- and nanoscale features in a wide variety of materials. Nevertheless, micron length scales have yet to be explored, despite the potential utility of such structures. Here, polymer micropillars of 6-12 μm length, approximately 0.5-1.5 μm wide at 10 μm spacing are reproduced from a polydimethylsiloxane (PDMS) mold made from patterned cellulose acetate (CA). The patterned CA was cast from a rigid fused silica template machined by a pulsed femtosecond laser. Pore topographic features were successfully reproduced in Norland Optical Adhesive (NOA), polycaprolactone (PCL), Nafion, acrylonitrile butadiene styrene (ABS), and …


Research Focus: Pattern Recognition May 2021

Research Focus: Pattern Recognition

In The Loop

A CDM health informatics team joins a global race to advance COVID-19 diagnostics through X-ray insights.


The Potential Of Raman Spectroscopy In The Diagnosis Of Dysplastic And Malignant Oral Lesions, Ola Ibrahim, M. Toner, Steven Flint, Hugh Byrne, Fiona Lyng Feb 2021

The Potential Of Raman Spectroscopy In The Diagnosis Of Dysplastic And Malignant Oral Lesions, Ola Ibrahim, M. Toner, Steven Flint, Hugh Byrne, Fiona Lyng

Articles

Early diagnosis, treatment and/or surveillance of oral premalignant lesions are important in preventing progression to oral squamous cell carcinoma (OSCC). The current gold standard is through histopathological diagnosis, which is limited by inter and intra observer and sampling errors. The objective of this work was to use Raman spectroscopy to discriminate between benign, mild, moderate and severe dysplasia and OSCC in formalin fixed paraffin preserved (FFPP) tissues. The study included 72 different pathologies from which 17 were benign lesions, 20 mildly dysplastic, 20 moderately dysplastic, 10 severely dysplastic and 5 invasive OSCC. The glass substrate and paraffin wax background were …


Biomedical Applications Of Vibrational Spectroscopy: Oral Cancer Diagnostics, Hugh Byrne, Isha Behl, Genecy Calado, Ola Ibrahim, M. Toner, Sheila Galvin, Claire M. Healy, Steven Flint, Fiona Lyng Feb 2021

Biomedical Applications Of Vibrational Spectroscopy: Oral Cancer Diagnostics, Hugh Byrne, Isha Behl, Genecy Calado, Ola Ibrahim, M. Toner, Sheila Galvin, Claire M. Healy, Steven Flint, Fiona Lyng

Articles

Vibrational spectroscopy, based on either infrared absorption or Raman scattering, has attracted increasing attention for biomedical applications. Proof of concept explorations for diagnosis of oral potentially malignant disorders and cancer are reviewed, and recent advances critically appraised. Specific examples of applications of Raman microspectroscopy for analysis of histological, cytological and saliva samples are presented for illustrative purposes, and the future prospects, ultimately for routine, chairside in vivo screening are discussed.


Biocompatible And Multifunctional Trityl Spin Probes For Electron Paramagnetic Resonance Spectroscopy, Teresa D. Gluth Jan 2021

Biocompatible And Multifunctional Trityl Spin Probes For Electron Paramagnetic Resonance Spectroscopy, Teresa D. Gluth

Graduate Theses, Dissertations, and Problem Reports (ETD)

The primary objective of my thesis was to develop and utilize a biocompatible multifunctional trityl spin probe for concurrent measurement of pO2, pHe, and [Pi] in vivo by electron paramagnetic resonance (EPR) spectroscopy (Chapter 2). My first goal was to synthesize the proposed probe we are terming HOPE71. Secondly, HOPE71 was characterized by X-band and L-band EPR spectroscopy. Next, the biocompatibility of HOPE71 was assessed through an albumin binding test, cytotoxicity assays, and in vivo intravenous tolerance. Then, the use of HOPE71 to measure the target parameters was demonstrated in a breast cancer …


Harnessing Acoustic Streaming For Bioanalysis In Microfluidics, Xiaojun Li Jan 2021

Harnessing Acoustic Streaming For Bioanalysis In Microfluidics, Xiaojun Li

Graduate Theses, Dissertations, and Problem Reports (ETD)

In the past few decades, microfluidic technology has been developed rapidly in both fabrication methods and multifunctionality integrations, making it a powerful tool for a wider variety of biological applications. The device fabrication method has expanded from conventional polymer-based micro devices to 3D-printed micro devices, and allows multiple functions such as electric, optic, magnetic and acoustic to be integrated on a single platform. This dissertation focuses on method development of acoustic streaming-based microfluidics in bioanalysis such as immunoassay, enzyme kinetics and DNA fragmentation analysis. In this dissertation, a micromixer was developed based on acoustic streaming generated from sharp-edge structure vibration …


Live Cell Biomass Tracking For Basic, Translational, And Clinical Research, Graeme Murray Jan 2021

Live Cell Biomass Tracking For Basic, Translational, And Clinical Research, Graeme Murray

Theses and Dissertations

Single cell mass is tightly regulated throughout generations and the cell cycle, making it an important marker of cell health. Abnormal changes in cell size can be the first indication of dysfunction in response to environmental stimuli such as cytotoxic drugs. Described here is the further development of high-speed live cell interferometry (HSLCI) to concurrently measure the changes in single cell mass of thousands of cells over time. Critically, the high-throughput nature of HSLCI provides realistic pictures of tumor heterogeneity. This throughput enabled HSLCI to correctly predict in vivo carboplatin sensitivity of three triple negative breast cancer patient derived xenografts, …


Carbon Dots As Artificial Peroxidases For Analytical Applications, Shih-Chun Wei, Yang-Wei Lin, Huan-Tsung Chang Dec 2020

Carbon Dots As Artificial Peroxidases For Analytical Applications, Shih-Chun Wei, Yang-Wei Lin, Huan-Tsung Chang

Journal of Food and Drug Analysis

Nanozymes have become attractive in analytical and biomedical fields, mainly because of their low cost, long shelf life, and less environmental sensitivity. Particularly, nanozymes formed from nanomaterials having high surface area and rich active sites are interesting since their activities can be tuned through carefully controlling their size, morphology, and surface properties. This review article focuses on preparation of carbon dots (C dots) possessing peroxidase-like activity and their analytical applications. We highlight the important roles of the oxidation states and surface residues of C dots and their nanocomposites with metal, metal oxides, or metal sulfides playing on determining their specificity …


Mapping Gadolinium Contrast In A Complex Ionic And Photosynthesis Environment Of Pineapple By Near-Infrared And X-Ray Imaging, Subhendra Sarkar, Zoya Vinokur, Chen Xu, Tetiana Soloviova, Amina Shahbaz, Aldona Gjoni Jul 2020

Mapping Gadolinium Contrast In A Complex Ionic And Photosynthesis Environment Of Pineapple By Near-Infrared And X-Ray Imaging, Subhendra Sarkar, Zoya Vinokur, Chen Xu, Tetiana Soloviova, Amina Shahbaz, Aldona Gjoni

Publications and Research

This work explores the diffusivity of a lanthanide complex, Eovist (Gadolinium-Ethoxy Benzyl Diethylenetriamine pentaacetate) that is stable in neutral media but is not in acidic environment. In the current work an acidic fruit model like pineapple that is rich in transition metals was used and a possible transmetallation reaction among Eovist and transition metal complexes was tested using X-ray imaging. Another goal of this work was to perturb the usual and the unusual photosynthesis systems that pineapple has maintained for millions of years during the evolution of circadian genes for efficient water conservation by dark photosynthesis. To detect such photosynthesis …


Optimal Multi-Stage Arrhythmia Classification Approach, Jianwei Zhang, Huimin Chu, Daniele Struppa, Jianming Zhang, Sir Magdi Yacoub, Hesham El-Askary, Anthony Chang, Louis Ehwerhemuepha, Islam Abudayyeh, Alexander Barrett, Guohua Fu, Hai Yao, Dongbo Li, Hangyuan Guo, Cyril Rakovski Feb 2020

Optimal Multi-Stage Arrhythmia Classification Approach, Jianwei Zhang, Huimin Chu, Daniele Struppa, Jianming Zhang, Sir Magdi Yacoub, Hesham El-Askary, Anthony Chang, Louis Ehwerhemuepha, Islam Abudayyeh, Alexander Barrett, Guohua Fu, Hai Yao, Dongbo Li, Hangyuan Guo, Cyril Rakovski

Mathematics, Physics, and Computer Science Faculty Articles and Research

Arrhythmia constitutes a problem with the rate or rhythm of the heartbeat, and an early diagnosis is essential for the timely inception of successful treatment. We have jointly optimized the entire multi-stage arrhythmia classification scheme based on 12-lead surface ECGs that attains the accuracy performance level of professional cardiologists. The new approach is comprised of a three-step noise reduction stage, a novel feature extraction method and an optimal classification model with finely tuned hyperparameters. We carried out an exhaustive study comparing thousands of competing classification algorithms that were trained on our proprietary, large and expertly labeled dataset consisting of 12-lead …


Adaptive Background Correction Of Crystal Image Datasets: Towards Automated Process Control, Luke Kiernan, Ian Jones, Lauri Kurki, Patrick J. Cullen, Toufic El Arnaout Jan 2020

Adaptive Background Correction Of Crystal Image Datasets: Towards Automated Process Control, Luke Kiernan, Ian Jones, Lauri Kurki, Patrick J. Cullen, Toufic El Arnaout

Articles

Improving the data descriptor calculation of crystal’s physical properties requires sophisticated imaging techniques and algorithms. It has been possible to construct 2D population balance models benefiting from characteristic measurements of both crystal’s length and width, compared to the single representative sizes used in 1D models. Our aim is to ameliorate the procedure of determining shape (and not only size) factors, in an automated fashion and directly from the process, for implementation in future models. Here, approaches suitable for real-time applications were employed including engineered imaging sensors and adaptive algorithms. We described the latter in detail for varying 2D image datasets. …


Image Restoration Using Automatic Damaged Regions Detection And Machine Learning-Based Inpainting Technique, Chloe Martin-King Dec 2019

Image Restoration Using Automatic Damaged Regions Detection And Machine Learning-Based Inpainting Technique, Chloe Martin-King

Computational and Data Sciences (PhD) Dissertations

In this dissertation we propose two novel image restoration schemes. The first pertains to automatic detection of damaged regions in old photographs and digital images of cracked paintings. In cases when inpainting mask generation cannot be completely automatic, our detection algorithm facilitates precise mask creation, particularly useful for images containing damage that is tedious to annotate or difficult to geometrically define. The main contribution of this dissertation is the development and utilization of a new inpainting technique, region hiding, to repair a single image by training a convolutional neural network on various transformations of that image. Region hiding is also …


In Vitro Evaluation Of Ovarian Cancer Tumorigenesis As A Function Of Quinone Oxidoreducatse-1 And Cell Phenotype, Milcah S. Jackson Jun 2019

In Vitro Evaluation Of Ovarian Cancer Tumorigenesis As A Function Of Quinone Oxidoreducatse-1 And Cell Phenotype, Milcah S. Jackson

LSU Doctoral Dissertations

In vitro multicellular spheroids are attractive model systems for assessing genetic and epigenetic changes that occur in diseased tissues. Understanding how such alterations in gene and subsequent protein expression affect disease progression and metastasis, drug resistance, and recurrence is of great interest in cancer research. In this regard, examining expression and activity of proteins, such as those with cytoprotective ability that are overexpressed in cancer cells, in addition to cell phenotype (i.e., stem-like, epithelial, mesenchymal, or mixed), are two ways to evaluate genetic and epigenetic changes. Moreover, determining the impact that cytoprotective proteins and cell phenotype have on tumor formation …


Seeing Eye To Eye: A Machine Learning Approach To Automated Saccade Analysis, Maigh Attre May 2019

Seeing Eye To Eye: A Machine Learning Approach To Automated Saccade Analysis, Maigh Attre

Honors Scholar Theses

Abnormal ocular motility is a common manifestation of many underlying pathologies particularly those that are neurological. Dynamics of saccades, when the eye rapidly changes its point of fixation, have been characterized for many neurological disorders including concussions, traumatic brain injuries (TBI), and Parkinson’s disease. However, widespread saccade analysis for diagnostic and research purposes requires the recognition of certain eye movement parameters. Key information such as velocity and duration must be determined from data based on a wide set of patients’ characteristics that may range in eye shapes and iris, hair and skin pigmentation [36]. Previous work on saccade analysis has …


Applications Of Supervised Machine Learning In Autism Spectrum Disorder Research: A Review, Kayleigh K. Hyde, Marlena N. Novack, Nicholas Lahaye, Chelsea Parlett-Pelleriti, Raymond Anden, Dennis R. Dixon, Erik Linstead Feb 2019

Applications Of Supervised Machine Learning In Autism Spectrum Disorder Research: A Review, Kayleigh K. Hyde, Marlena N. Novack, Nicholas Lahaye, Chelsea Parlett-Pelleriti, Raymond Anden, Dennis R. Dixon, Erik Linstead

Engineering Faculty Articles and Research

Autism spectrum disorder (ASD) research has yet to leverage "big data" on the same scale as other fields; however, advancements in easy, affordable data collection and analysis may soon make this a reality. Indeed, there has been a notable increase in research literature evaluating the effectiveness of machine learning for diagnosing ASD, exploring its genetic underpinnings, and designing effective interventions. This paper provides a comprehensive review of 45 papers utilizing supervised machine learning in ASD, including algorithms for classification and text analysis. The goal of the paper is to identify and describe supervised machine learning trends in ASD literature as …


On The Efficacy Of Moringa Oleifera As Anticancer Treatment: A Literature Survey, Florentin Smarandache, Victor Christianto Jan 2019

On The Efficacy Of Moringa Oleifera As Anticancer Treatment: A Literature Survey, Florentin Smarandache, Victor Christianto

Branch Mathematics and Statistics Faculty and Staff Publications

Medicinal plants are important elements of indigenous medical system that have persisted in developing countries. Many of the botanical chemo-preventions currently used as potent anticancer agents. However, some important anticancer agents are still extracted from plants because they cannot be synthesized chemically on a commercial scale due to their complex structures that often contain several chiral centers. The aim of this study was to test different extracts from the Moringa oleifera leaves. Previous studies have shown potentially antioxidant, antitumor promoter, anticlastogen and anticarcinogen activities both in vitro and in vivo. Emerging evidence indicates that efficacy of Moringa oleifera in cancer …


The Chapman Bone Algorithm: A Diagnostic Alternative For The Evaluation Of Osteoporosis, Elise Levesque, Anton Ketterer, Wajiha Memon, Cameron James, Noah Barrett, Cyril Rakovski, Frank Frisch Sep 2018

The Chapman Bone Algorithm: A Diagnostic Alternative For The Evaluation Of Osteoporosis, Elise Levesque, Anton Ketterer, Wajiha Memon, Cameron James, Noah Barrett, Cyril Rakovski, Frank Frisch

Mathematics, Physics, and Computer Science Faculty Articles and Research

Osteoporosis is the most common metabolic bone disease and goes largely undiagnosed throughout the world, due to the inaccessibility of DXA machines. Multivariate analyses of serum bone turnover markers were evaluated in 226 Orange County, California, residents with the intent to determine if serum osteocalcin and serum pyridinoline cross-links could be used to detect the onset of osteoporosis as effectively as a DXA scan. Descriptive analyses of the demographic and lab characteristics of the participants were performed through frequency, means and standard deviation estimations. We implemented logistic regression modeling to find the best classification algorithm for osteoporosis. All calculations and …


Analytical Models Of Neutron Spectral Fluence, Kerma And Absorbed-Dose For Proton Therapy, Suman Shrestha Aug 2018

Analytical Models Of Neutron Spectral Fluence, Kerma And Absorbed-Dose For Proton Therapy, Suman Shrestha

LSU Master's Theses

Abstract

Purpose: The accurate prediction of stray neutron dose has become increasingly important as it increases the risk of second cancer development after proton therapy. Previously reported analytical models predicted the quantity dose equivalent, which includes physical and biological considerations but does not explicitly take into account material dependence and variation in the radiation quality. The purpose of this study was to investigate the feasibility of an analytical model of absorbed dose to water from stray neutrons in proton therapy.

Methods: To calculate neutron absorbed dose and kerma in water, the authors developed analytical models of neutron spectral fluence and …


A Cyber-Physical System Framework For Early Detection Of Paroxysmal Diseases, Zuxing Gu, Yu Jiang, Min Zhou, Xiaoyu Song, Lui Sha Jul 2018

A Cyber-Physical System Framework For Early Detection Of Paroxysmal Diseases, Zuxing Gu, Yu Jiang, Min Zhou, Xiaoyu Song, Lui Sha

Computer Science Faculty Publications and Presentations

Paroxysmal diseases of inpatients are globally recognized as one of the top challenges in medicine. Poor clinical outcomes are primarily caused by delayed recognition, especially due to diverse clinical diagnostic criteria with complex manifestations, irregular episodes, and already overloaded clinical activities. With the proliferation of measuring devices and increased computational capabilities, cyber-physical characterization plays an increasingly important role in many domains to provide enabling technologies. This paper presents a cyber-physical system (CPS) framework to assist physicians in making earlier diagnoses of paroxysmal sympathetic hyperactivity based on existing medical knowledge. We propose a configurable diagnostic knowledge model to characterize clinical criteria …


Raman Spectral Analysis For Rapid Screening Of Dengue Infection, Tahir Mahmood, Haq Nawaz, A. Ditta, M.I. Majeed, M.A. Hanif, N. Rashid, H.N. Bhatti, H.F. Nargis, M. Saleem, Franck Bonnier, Hugh Byrne May 2018

Raman Spectral Analysis For Rapid Screening Of Dengue Infection, Tahir Mahmood, Haq Nawaz, A. Ditta, M.I. Majeed, M.A. Hanif, N. Rashid, H.N. Bhatti, H.F. Nargis, M. Saleem, Franck Bonnier, Hugh Byrne

Articles

Infection with the dengue virus is currently clinically detected according to different biomarkers in human blood plasma, commonly measured by enzyme linked immunosorbent assays, including non-structural proteins (Ns1), immunoglobulin M (IgM) and immunoglobulin G (IgG). However, there is little or no mutual correlation between the biomarkers, as demonstrated in this study by a comparison of their levels in samples from 17 patients. As an alternative, the label free, rapid screening technique, Raman spectroscopy has been used for the characterisation/diagnosis of healthy and dengue infected human blood plasma samples. In dengue positive samples, changes in specific Raman spectral bands associated with …


Use Of Excel Spreadsheet Calculators In Handling Data Generated From Uv- Spectrometer, Mercy Okezue, Kari Clase, Steve Byrn Mar 2018

Use Of Excel Spreadsheet Calculators In Handling Data Generated From Uv- Spectrometer, Mercy Okezue, Kari Clase, Steve Byrn

BIRS Symposium

To ease the complexities of handling data generated from different analytical procedures, validated excel spreadsheet containing relevant formulas are developed to ensure the process of data handling will consistently produce the expected results. This paper introduces the use of Excel spreadsheets in handling data generated from using a UV-Spectrometer in determination of analyte concentration in various dosage forms


Instituting Process Control Mechanisms In A Quality Control Analytical Chemistry Laboratory, Mercy Okezue, Kari Lynn Clase, Stephen Byrn Mar 2018

Instituting Process Control Mechanisms In A Quality Control Analytical Chemistry Laboratory, Mercy Okezue, Kari Lynn Clase, Stephen Byrn

BIRS Symposium

Statistical Process Control by means of using control charts was a means of monitoring performance of analytical equipment. Quality control checks on test items using these equipment generated data used for plotting X-bar charts. The charts generated had warning and control limits which helped monitor system performance


Motion-Induced Artifact Mitigation And Image Enhancement Strategies For Four-Dimensional Fan-Beam And Cone-Beam Computed Tomography, Matthew J. Riblett Jan 2018

Motion-Induced Artifact Mitigation And Image Enhancement Strategies For Four-Dimensional Fan-Beam And Cone-Beam Computed Tomography, Matthew J. Riblett

Theses and Dissertations

Four dimensional imaging has become part of the standard of care for diagnosing and treating non-small cell lung cancer. In radiotherapy applications 4D fan-beam computed tomography (4D-CT) and 4D cone-beam computed tomography (4D-CBCT) are two advanced imaging modalities that afford clinical practitioners knowledge of the underlying kinematics and structural dynamics of diseased tissues and provide insight into the effects of regular organ motion and the nature of tissue deformation over time. While these imaging techniques can facilitate the use of more targeted radiotherapies, issues surrounding image quality and accuracy currently limit the utility of these images clinically.

The purpose of …


Evaluation And Adaptation Of Live-Cell Interferometry For Applications In Basic, Translational, And Clinical Research, Kevin A. Leslie Jan 2018

Evaluation And Adaptation Of Live-Cell Interferometry For Applications In Basic, Translational, And Clinical Research, Kevin A. Leslie

Theses and Dissertations

Cell mass is an important indicator of cell health and status. A diverse set of techniques have been developed to precisely measure the masses of single cells, with varying degrees of technical complexity and throughput. Here, the development of a non-invasive, label-free optical technique, termed Live-Cell Interferometry (LCI), is described. Several applications are presented, including an evaluation of LCI’s utility for assessing drug response heterogeneity in patient-derived melanoma lines and the measurement of CD3+ T cell kinetics during hematopoietic stem cell transplantation. The characterization of mast cells during degranulation, the measurement of viral reactivation kinetics in Kaposi’s Sarcoma, and drug …


Rehabilitation Of An Injured Golden Eagle (Aquila Chrysaetos): A Case Study, Fida Muhammad Khan, Fakhar-I- Abbas, Abu Ul Hassan Faiz Sep 2017

Rehabilitation Of An Injured Golden Eagle (Aquila Chrysaetos): A Case Study, Fida Muhammad Khan, Fakhar-I- Abbas, Abu Ul Hassan Faiz

Journal of Bioresource Management

Habitat destruction and anthropogenic activities cause wild birds to migrate towards urban areas in search of food and sometimes nesting in high-roof buildings, where they are caught by local people using different techniques and are further used for hunting or recreational purposes. An injured Golden Eagle (Aquila chrysaetos) was found entangled in bushes near the vicinity of Balkasar Research Complex, Chakwal, Pakistan. After complete physical examination, a wound on the right wing and closed leg fracture was diagnosed. The successful treatment was done by anti-parasitic and anti-bacterial drugs with careful monitoring. Splint was adjusted after aligning the fractured …


Engineering Fret Biosensors For Microrna Presence/Absence Analysis, Nicholas E. Larkey, Sean M. Burrows Feb 2017

Engineering Fret Biosensors For Microrna Presence/Absence Analysis, Nicholas E. Larkey, Sean M. Burrows

Biomedical Engineering Western Regional Conference

No abstract provided.


Tau And Aβ Imaging, Csf Measures, And Cognition In Alzheimer's Disease, Matthew R. Brier, Brian Gordon, Karl Friedrichsen, John E. Mccarthy, Ari Stern, Jon Christensen, Christopher Owen, Patricia Aldea, Yi Su, Jason Hassenstab, Nigel J. Cairns, David M. Holtzman, Anne M. Fagan, John C. Morris, Tammie L.S. Benzinger, Beau M. Ances May 2016

Tau And Aβ Imaging, Csf Measures, And Cognition In Alzheimer's Disease, Matthew R. Brier, Brian Gordon, Karl Friedrichsen, John E. Mccarthy, Ari Stern, Jon Christensen, Christopher Owen, Patricia Aldea, Yi Su, Jason Hassenstab, Nigel J. Cairns, David M. Holtzman, Anne M. Fagan, John C. Morris, Tammie L.S. Benzinger, Beau M. Ances

Mathematics Faculty Research

Alzheimer’s disease (AD) is characterized by two molecular pathologies: cerebral β-amyloidosis in the form of β-amyloid (Aβ) plaques and tauopathy in the form of neurofibrillary tangles, neuritic plaques, and neuropil threads. Until recently, only Aβ could be studied in humans using positron emission tomography (PET) imaging owing to a lack of tau PET imaging agents. Clinical pathological studies have linked tau pathology closely to the onset and progression of cognitive symptoms in patients with AD. We report PET imaging of tau and Aβ in a cohort of cognitively normal older adults and those with mild AD. Multivariate analyses identified unique …


Partial Covariance Based Functional Connectivity Computation Using Ledoit-Wolf Covariance Regularization, Matthew R. Brier, Anish Mitra, John E. Mccarthy, Beau M. Ances, Abraham Z. Snyder Nov 2015

Partial Covariance Based Functional Connectivity Computation Using Ledoit-Wolf Covariance Regularization, Matthew R. Brier, Anish Mitra, John E. Mccarthy, Beau M. Ances, Abraham Z. Snyder

Mathematics Faculty Research

Highlights •We use the well characterized matrix regularization technique described by Ledoit and Wolf to calculate high dimensional partial correlations in fMRI data. •Using this approach we demonstrate that partial correlations reveal RSN structure suggesting that RSNs are defined by widely and uniquely shared variance. •Partial correlation functional connectivity is sensitive to changes in brain state indicating that they contain functional information. Functional connectivity refers to shared signals among brain regions and is typically assessed in a task free state. Functional connectivity commonly is quantified between signal pairs using Pearson correlation. However, resting-state fMRI is a multivariate process exhibiting a …


Facile Methods For The Analysis Of Lysophosphatidic Acids In Human Plasma, Jialu Wang Mar 2015

Facile Methods For The Analysis Of Lysophosphatidic Acids In Human Plasma, Jialu Wang

Dissertations and Theses

Lysophosphatidic acid (LPA) influences many physiological processes, such as brain and vascular development. It is associated with several diseases including ovarian cancer, breast cancer, prostate cancer, colorectal cancer, hepatocellular carcinoma, multiple myeloma atherosclerotic diseases, cardiovascular diseases, pulmonary inflammatory diseases and renal diseases. LPA plasma and serum levels have been reported to be important values in diagnosing ovarian cancer and other diseases. However, the extraction and quantification of LPA in plasma are very challenging because of the low physiological concentration and similar structures of LPA to other phospholipids. Many previous studies have not described the separation of LPA from other phospholipids, …


Vibrational Microspectroscopy For Cancer Screening, Fiona Lyng, Ines Ramos, Ola Ibrahim, Hugh Byrne Mar 2015

Vibrational Microspectroscopy For Cancer Screening, Fiona Lyng, Ines Ramos, Ola Ibrahim, Hugh Byrne

Articles

Vibrational spectroscopy analyses vibrations within a molecule and can be used to characterise a molecular structure. Raman spectroscopy is one of the vibrational spectroscopic techniques, in which incident radiation is used to induce vibrations in the molecules of a sample, and the scattered radiation may be used to characterise the sample in a rapid and non-destructive manner. Infrared (IR) spectroscopy is a complementary vibrational spectroscopic technique based on the absorption of IR radiation by the sample. Molecules absorb specific frequencies of the incident light which are characteristic of their structure. IR and Raman spectroscopy are sensitive to subtle biochemical changes …