Biological Engineering Commons^™

A Microfluidics-Based Cross-Flow Filtration Platform For Rapid Processing Of Amphiphilic Biomarkers From Blood, Kiersten D. Lenz

Biomedical Engineering ETDs

Early and accurate detection of bacterial infections can help save lives, prevent the spread of disease, and decrease the overuse of antibiotics. Our team at the Los Alamos National Laboratory has developed novel assays to detect bacterial biomarkers from patient blood at the point-of-care in order to facilitate a universal diagnostic platform. However, these biomarkers are amphiphilic in nature, and this biochemical property causes them to be sequestered by high-density and low-density lipoproteins (HDL and LDL) in the host’s blood. Extraction of the bacterial biomarkers from the lipoprotein complexes is thereby required for the development and deployment of a diagnostic …

Unravel The Cellular Biophysical Dynamics Of Spatial Constraint-Induced Membrane Blebbing And 3d Migration Using A Microfluidic Platform And Data-Driven Mathematical Modeling, Yu Huang

Funded Research Records

No abstract provided.

Developing A Control System To Better Understand The Effects Of Pyruvate Decarboxylase Activity On Clostridium Thermocellum Metabolism, Nicholas Cervenka

ENGS 88 Honors Thesis (AB Students)

In order for cellulosic biofuels from Clostridium thermocellum to be commercially viable, the ethanol yield and titer of the microbe must be increased. To accomplish this, it has been suggested to introduce the Pyruvate Decarboxylase (PDC) enzyme into C. thermocellum. In order to demonstrate effects on ethanol production by PDC prior to genetic modification, a cell free system (CFS) has been developed. A purified enzyme system was developed with the CFS to function as a control. Using the purified enzyme system, PDC from Saccharomyces cerevisiae was demonstrated to be a good candidate for further testing in the CFS.

Maximizing And Modeling Malonyl-Coa Production In Escherichia Coli, Tatiana Thompson Silveira Mello

LSU Master's Theses

In E. coli, fatty acid synthesis is catalyzed by the enzyme acetyl-CoA carboxylase (ACC), which converts acetyl-CoA into malonyl-CoA. Malonyl-CoA is a major building block for numerous of bioproducts. Multiple parameters regulate the homeostatic cellular concentration of malonyl-CoA, keeping it at a very low level. Understanding how these parameters affect the bacterial production of malonyl-CoA is fundamental to maximizing it and its bioproducts. To this end, competing pathways consuming malonyl-CoA can be eliminated, and optimal nutritional and environmental conditions can be provided to the fermentation broth. Most previous studies utilized genetic modifications, expensive consumables, and high-cost quantification methods, making …

Developing An Optomechanical Approach For Characterizing Mechanical Properties Of Single Adherent Cells, Ali Mehrnezhad

LSU Doctoral Dissertations

Mechanical properties of a cell reflect its biological and pathological conditions including cellular disorders and fundamental cellular processes such as cell division and differentiation. There have been active research efforts to develop high-throughput platforms to mechanically characterize single cells. Yet, many of these research efforts are focused on suspended cells and use a flow-through configuration. Therefore, adherent cells are detached prior to the characterization, which seriously perturbs the cellular conditions. Also, methods for adherent cells are limited in their throughput.

My study is aimed to fill the technical gap in the field of single cell analysis, which is a high-throughput …

Stackcbpred: A Stacking Based Prediction Of Protein-Carbohydrate Binding Sites From Sequence, Suraj Gattani

LSU New Orleans Theses and Dissertations

Carbohydrate-binding proteins play vital roles in many vital biological processes and study of these interactions, at residue level, are useful in treating many critical diseases. Analyzing the local sequential environments of the binding and non-binding regions to predict the protein-carbohydrate binding sites is one of the challenging problems in molecular and computational biology. Prediction of such binding sites, directly from sequences, using computational methods, can be useful to fast annotate the binding sites and guide the experimental process. Because the number of carbohydrate-binding residues is significantly lower than non-carbohydrate-binding residues, most of the methods developed are biased towards over predicting …

Immunofluorescence Image Feature Analysis And Clustering Pipeline For Distinguishing Epithelial-Mesenchymal Transition, Shreyas Hirway, Nadiah Hassan, Dr. Christopher Lemmon, Dr. Seth Weinberg

Biology and Medicine Through Mathematics Conference

No abstract provided.

Quantified Measurement Of The Tilt Effect In A Family Of Café Wall Illusions, Nasim Nematzadeh Dr., David Martin Powers Prof.

MODVIS Workshop

This abstract explores the tilt effect in a family of Café Wall illusions using a Classical Gaussian Receptive Field model (CRF). Our model constructs an intermediate representation called edge map at multiple scales (Fig. 1) that reveals tilt cues and clues involved in the illusory perception of the Café Wall pattern. We investigate a wide range of parameters of the stimulus including mortar width, luminance, tiles contrast, and phase of the tile displacement (the stimuli in Fig. 2). We show that this simple bioplausible model, simulating the contrast sensitivity of the retinal ganglion cells, can not only detect the tilts …

The 3d Scaffold Design Of De Novo Anterior Cruciate Ligament Graft, Dominique Angibeau

Honors Capstones

No abstract provided.

Volumetric Muscle Loss: The Role Of Physical Activity And Autologous Repair On Force Recovery And Signaling Pathways, Richard Perry

Graduate Theses and Dissertations

Volumetric muscle loss affects both military and civilian persons. The hallmark of this injury is incomplete muscle regeneration, excessive fibrosis, and chronic inflammatory signaling resulting in permanent functional loss. Since permanent functional loss drastically reduces quality of life, many studies have been conducted to improve force recovery. Current scientific literature considers a repair strategy of either devitalized scaffolds infused with growth factors or viable tissue plus activating factors to be the more promising interventions for optimal force recovery. PURPOSE The purpose of this study is to incorporate autologous repair and physical activity and observe the effects of muscle force recovery …

Stability Analysis Of A More General Class Of Systems With Delay-Dependent Coefficients, Chi Jin, Keqin Gu, Islam Boussaada, Silviu-Iulian Niculescu

SIUE Faculty Research, Scholarship, and Creative Activity

This paper presents a systematic method to analyse the stability of systems with single delay in which the coefficient polynomials of the characteristic equation depend on the delay. Such systems often arise in, for example, life science and engineering systems. A method to analyze such systems was presented by Beretta and Kuang in a 2002 paper, but with some very restrictive assumptions. This work extends their results to the general case with the exception of some degenerate cases. It is found that a much richer behavior is possible when the restrictive assumptions are removed. The interval of interest for the …

Assessing Commonly Used Methods In Measuring Yield Of Cellulose Nanocrystals, Marilyn Pharr

Biological and Agricultural Engineering Undergraduate Honors Theses

Cellulose is a ubiquitous, renewable biopolymer found in plants that can be broken down to isolate cellulose nanocrystals (CNCs). CNCs have been utilized in various applications that include biomedical technology, structural composites, and barrier films because of their unique mechanical, optical, and physicochemical properties. CNCs can be produced by a variety of approaches from cellulosic materials; however, strong acid hydrolysis is the most common and effective technique as it results in stable colloidal suspensions. Existing literature reveals a wide range of CNC yields, depending on the production process, raw material used, and the method of yield estimation. The yields of …

Predictive Modeling Of Fate And Transport Of Three Prevalent Contaminants In Midwest Agroecosystem Surface Waters: Nitrate-N, Atrazine, And Escherichia Coli, Samuel Hansen

Department of Agricultural and Biological Systems Engineering: Dissertations, Theses, and Student Research

The majority of streams and rivers in the United States (U.S.) are ecologically impaired, or threatened by anthropogenic stressors. Recent reports have found atrazine in drinking water to be associated with increased birth defects and incidences of Non-Hodgkin’s Lymphoma, with higher levels of significance from exposure to both atrazine and nitrate-N. In contrast, recent illnesses from E. coli contaminating vegetables that originated from irrigation water has increased awareness of identifying sources of E. coli entering irrigation reservoirs.

Methods to accurately predict atrazine and E. coli occurrence and potential sources in waterways continue to limit the identifying appropriate and effective prevention …

Ecological Co2 Flux Of A Green Roof Ecosystem And A Typical Grassland Ecosystem, Madeline Oxner

Biological and Agricultural Engineering Undergraduate Honors Theses

The Hillside Auditorium Green Roof is a low impact development feature on the University of Arkansas campus. It retains storm water and allows plants living on the roof to take up and transpire the water. Green roofs work to mimic natural ecosystems in urban environments. A key property is ecosystem respiration, which plays a large role in the global carbon cycle and is an important biologic activity indicator. The ecosystem respiration of Hillside Auditorium Green Roof was compared to a typical grassland ecosystem at the University of Arkansas farm to determine how closely the green roof is able to mimic …

Hydrodeoxygenation Of Pinyon-Juniper Catalytic Pyrolysis Oil, Hossein Jahromi

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Catalytic hydrodeoxygenation (HDO), is an effective process to convert oxygenated compounds to hydrocarbons. This process is widely used for improving the negative properties of biomass-derived pyrolysis oils (bio-oils) such as high acidity, poor stability, and low heating value. During this process oxygen is removed from the bio-oil in the form of water, thus the liquid product of HDO process consists of aqueous phase and hydrocarbon phase that can be easily separated. Synthesis of efficient HDO catalyst has been a major challenge in the field of bio-oil upgrading. Red mud, which is an alkaline waste from alumina industry was used to …

In Vitro Simulation Of Microgravity Induced Muscle Loss Successfully Increases Expression Of Key In Vivo Atrophy Markers, Charles P. Harding

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Muscle loss from lack of activity is a serious issue for immobilized patients on Earth and in human spaceflight, where the low gravity environment prevents normal muscle activity. Simulating muscle loss in cultured cells is an important step in understanding how this condition occurs. This work evaluates different means of simulating muscle loss and selects the one that most closely mimics the cellular responses seen in animals and humans.

To simulate the microgravity environment of spaceflight, mouse skeletal muscle cells were grown in a rotary cell culture system (RCCS). Growing the cells within a natural gelled substrate was compared against …

Incorporation Of Egfr And Ron Receptors Into Nanodiscs, Cristina Flores-Cadengo

Biomedical Engineering ETDs

Understanding the structure-function relationship of membrane receptors is essential to comprehend the crosstalk between key signaling pathways. Aberrant trans-activation between receptors can lead to tumorigenesis. Two of these receptors known to be involved in cancer development are receptor tyrosine kinases (RTKs), RON (Recepteur d'Origine Nantais) and EGFR (Epidermal Growth Factor Receptor). There has been evidence of heterodimerization and crosstalk between these two receptors based on co-immunoprecipitation, however the structural requirements behind these interactions remain unknown. Structural studies could provide insights into these RTKs’ modes of dimerization and structure-function relationship. However, structural studies of full-length membrane proteins are often difficult due …

Use Of Surface-Enhanced Raman Scattering (Sers) Probes To Detect Fatty Acid Receptor Activity In A Microfluidic Device, Han Zhang, Wei Zhang, Lifu Xiao, Yan Liu, Timothy A. Gilbertson, Anhong Zhou

Biological Engineering Faculty Publications

In this study, 4-mercaptobenzoic acid (MBA)-Au nanorods conjugated with a GPR120 antibody were developed as a highly sensitive surface-enhanced Raman spectroscopy (SERS) probe, and were applied to detect the interaction of fatty acids (FA) and their cognate receptor, GPR120, on the surface of human embryonic kidney cells (HEK293-GPRR120) cultured in a polydimethylsiloxane (PDMS) microfluidic device. Importantly, the two dominant characteristic SERS peaks of the Raman reporter molecule MBA, 1078 cm⁻¹ and 1581 cm⁻¹, do not overlap with the main Raman peaks from the PDMS substrate when the appropriate spectral scanning range is selected, which effectively avoided the …

Improved Production Of Antifungal Angucycline Sch47554 By Manipulating Three Regulatory Genes In Streptomyces Sp. Scc-2136, Ozkan Fidan, Riming Yan, Du Zhu, Jixun Zhan

Biological Engineering Faculty Publications

Sch47554 and Sch47555 are two angucyclines with antifungal activities against various yeasts and dermatophytes from Streptomyces sp. SCC‐2136. The schgene cluster contains several putative regulatory genes. Both schA4 and schA21were predicted as the TetR family transcriptional regulators, whereas schA16shared significant similarity to the AraC family transcriptional regulators. Although Sch47554 is the major product of Streptomyces sp. SCC‐2136, its titer is only 6.72 mg/L. This work aimed to increase the production of this promising antifungal compound by investigating and manipulating the regulatory genes in the Sch47554 biosynthetic pathway. Disruption of schA4and schA16 led to a significant increase …

3d-Printed Culture Plate Insert With Agarose Barrier For The Evaluation Of Stem-Cancer Cell Signaling., Erika M. Lewis

Honors Capstones

No abstract provided.