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Full-Text Articles in Biophysics

Analysis Of The Electrostatic Characteristics Of The Zika Virus Capsid Using Computational Methods, Cassandra Guadalupe Del Rio De Avila May 2023

Analysis Of The Electrostatic Characteristics Of The Zika Virus Capsid Using Computational Methods, Cassandra Guadalupe Del Rio De Avila

Open Access Theses & Dissertations

Zika virus (ZIKV) is a flavivirus that is usually transmitted through the bite of infected mosquitoes. This virus can cause a variety of neurological disorders, the most common being Guillain-Barré syndrome in adults. Moreover, it is of great concern in pregnant women, since can cause deformities in the brain and other organs of newborns.Studying the structural characteristics of the virus during its mature and infectious phase can provide crucial information on the mechanisms by which it enters and replicates within host cells, as well as its evolution, transmission, and interaction with other living organisms. The symmetric pattern present in the …


Microscopic And Spectroscopic Analysis Of Nordihydroguaiaretic Acid Effect On Astrocytes, Lizbeth Vanessa Martinez Lopez May 2023

Microscopic And Spectroscopic Analysis Of Nordihydroguaiaretic Acid Effect On Astrocytes, Lizbeth Vanessa Martinez Lopez

Open Access Theses & Dissertations

Astrocytes, one of the most abundant cell components in the central nervous system (CNS), have been a research target in the last few years. Several studies have found that astrocytes are not only mere supporters of neurons but also of essential processes developed in the CNS. Their malfunction could induce neurodegenerative diseases and brain tumors. Thus, further understanding of astrocytes and their role is of high interest to develop possible new treatments and methods of disease diagnosis, especially in brain cancer. The plant Larrea tridentata (La Gobernadora in Mexico or Creosote bush in the United States) is known to have …


Developing And Applying Computational Methods On Biomolecules, Shengjie Sun May 2023

Developing And Applying Computational Methods On Biomolecules, Shengjie Sun

Open Access Theses & Dissertations

Computational biophysics is an interdisciplinary subject that uses numerical algorithms to study the physical principles underlying biological phenomena and processes. Electrostatic interactions play an important role in computational molecular biophysics and their potential impact on disease mechanisms. At distances larger than several Angstroms, electrostatic interactions dominate all other forces, while the alteration of short-range electrostatic pairwise interactions can also have significant effects. The dual nature of electrostatic interactions, being dominant at long-range and specific at short-range, underscores their profound implications for wild-type structure and function. Any disruption of the complex electrostatic network of interactions may abolish wild-type functionality and could …


Utilizing Computational Methods To Study The Biomolecules, Wenhan Guo Jun 2022

Utilizing Computational Methods To Study The Biomolecules, Wenhan Guo

Open Access Theses & Dissertations

COVID-19 is increasingly affecting human health and global economy. Understanding the fundamental mechanisms of Severe Acute Respiratory Syndrome CoronaVirus 2 (SARS-CoV-2) is highly demanded to develop treatments for COVID-19. SARS-CoV and SARS-CoV-2 share 92.06% identity in their N protein RBDs' sequences, which results in very similar structures. However, the SARS-CoV-2 is more easily to spread. Utilizing multi-scale computational approaches, this work studied the fundamental mechanisms of the nucleocapsid (N) proteins of SARS-CoV and SARS-CoV-2, including their stabilities and binding strengths with RNAs at different pH values. Electrostatic potential on the surfaces of N proteins show that both the N proteins …


Developing And Applying Computational Algorithms To Reveal Health-Related Biomolecular Interactions, Yixin Xie May 2022

Developing And Applying Computational Algorithms To Reveal Health-Related Biomolecular Interactions, Yixin Xie

Open Access Theses & Dissertations

Computational biology is an interdisciplinary area that applies computational approaches in biological big data, including protein amino acid sequences, genetic sequences, etc., which is widely used to analyze protein-protein interactions, make predictions in drug discovery, develop vaccines, etc. Popular methods include mathematical modeling, molecular dynamics simulations, data science mythology, etc. With the help of computational algorithms and applications, drug development is much faster than traditional processes, as it reduces risks early on in a drug discovery process and helps researchers select target candidates that have the highest potential for success. In my doctoral research, I applied multi-scale computational approaches to …


The Electrostatic Features Of Dengue Virus Capsid Assembly, Alan Eduardo Lopez Hernandez May 2022

The Electrostatic Features Of Dengue Virus Capsid Assembly, Alan Eduardo Lopez Hernandez

Open Access Theses & Dissertations

Dengue virus causes serious diseases and considerable deaths each year all around the globe. Dengue virus undergoes assembly in a capsid, matures and becomes viral. Revealing mechanisms of the viral capsid protein may lead to the discovery of novel drugs that prevent this assembly to happen and stop the virus from spreading. Here I present a computational work which is focused on the stability and assembly of the dengue viral capsid. The E and M proteins conform a heterotetramer, which consists of two copies of E and M proteins. The heterotetramers form a highly ordered capsid. In the electrostatic analysis …


Utilizing Computational Approaches To Study Tubulin- Tubulin Electrostatic Interactions, Tolulope Ayodeji Ale Dec 2021

Utilizing Computational Approaches To Study Tubulin- Tubulin Electrostatic Interactions, Tolulope Ayodeji Ale

Open Access Theses & Dissertations

Microtubules play significant roles in transporting cargos within the cell, as well as the cell cycle. They are essentially the highway for the transportation of cell organelles. Understanding the interactions among microtubule components is crucial for the treatment of neurodegenerative diseases and cancer. In this study, we utilize a series of computational approaches to study the electrostatic interactions at the binding interfaces of interacting tubulin monomers. Our study revealed that the electrostatic attractive interactions in the αβ tubulin dimer is the strongest while the interaction between two αβ tubulin dimers in the longitude direction is the weakest. The result identified …


The Hybridizing Ions Treatment (Hit) Method Development And Computational Study On Sars-Cov-2 E Protein., Shengjie Sun May 2021

The Hybridizing Ions Treatment (Hit) Method Development And Computational Study On Sars-Cov-2 E Protein., Shengjie Sun

Open Access Theses & Dissertations

Fast and accurate calculations of the electrostatic features for highly charged biomolecules such as DNA, RNA, highly charged proteins, are crucial but challenging tasks. Traditional implicit solvent methods calculate the electrostatic features fast, but they are not able to balance the high net charges in the biomolecules effectively. Explicit solvent methods add unbalanced ions to neutralize the highly charged biomolecules in molecular dynamic simulations, which require more expensive computing resources. Here we developed a novel method, the Hybridizing Ions Treatment (HIT) method, which hybridizes the implicit solvent method with the explicit method to realistically calculate the electrostatic potential for highly …


Applying Computational Methods To Study The Interactions Between Sars-Cov-2 And Hace2, Yixin Xie May 2021

Applying Computational Methods To Study The Interactions Between Sars-Cov-2 And Hace2, Yixin Xie

Open Access Theses & Dissertations

The ongoing outbreak of COVID-19 has been a serious threat to human health worldwide. The virus SARS-CoV-2 initiates its infection to the human body via the interaction of its spike (S) protein with the human Angiotensin-Converting Enzyme 2 (ACE2) of the host cells. Here we implemented multi-scale computational approaches to study the binding mechanisms of human ACE2 and S proteins of both SARS-CoV and SARS-CoV-2. Electrostatic features, including electrostatic potential, electric field lines and electrostatic forces of SARS-CoV and SARS-CoV-2 were calculated and compared in detail. The results demonstrate that SARS-CoV and SARS-CoV-2 S proteins are both attractive to ACE2 …


Novel Methods For The Inactivation Of Cruzain For The Prevention And Treatment Of Chagas Disease, Veronica Gonzalez Jan 2019

Novel Methods For The Inactivation Of Cruzain For The Prevention And Treatment Of Chagas Disease, Veronica Gonzalez

Open Access Theses & Dissertations

Chagas Disease, also known as American Trypanosomiasis, is endemic to Latin American and is gradually making its way to other countries. The disease is caused by Trypanosoma cruzi, a protozoan parasite that causes lesions and inflammation of organs including the heart, esophagus, and colon. Over 30% of people infected will develop heart disease which can be fatal if untreated. While no vaccine is yet available, research is currently being conducted in finding new treatments for the disease. One target is an enzyme that is believed to help the progression of the disease. Cruzain, a cysteine protease expressed as a pro-enzyme, …


Computational Study Of Disease Related Proteins Form Electrostatic Point Of View, Chitra Bahadur Karki Jan 2019

Computational Study Of Disease Related Proteins Form Electrostatic Point Of View, Chitra Bahadur Karki

Open Access Theses & Dissertations

In the last three decades, many giant DNA viruses have been discovered. The giant viruses present a unique and essential research frontier for the study of self-assembly and regulation of supramolecular assemblies. The question on how these giant DNA viruses assemble thousands of proteins so accurately to form their protein shell, the capsids, remains largely unanswered. Revealing the mechanisms of giant virus assembly will help to discover the mysteries of many self-assembly biology problems. Paramecium Bursaria Chlorella Virus 1 (PBCV-1) is one of the most intensively studied giant viruses. Based on the high-resolution structure of PBCV-1, we implemented a multi-scale …


Non Linear Optics For Materials Fabrication And Medical Instrumentation, Aurelio Paez Jan 2019

Non Linear Optics For Materials Fabrication And Medical Instrumentation, Aurelio Paez

Open Access Theses & Dissertations

Two-photon absorption is a nonlinear optical process where two photons are absorbed by a molecule simultaneously. The probability of this quantum phenomenon is proportional to the quadratic excitation of light intensity. It has many applications in biomedical and materials research, such as two-photon fluorescence microcopy. The first project is to apply two-photon absorption induced bond cleavage in photoreactive materials for engineering 3D tissue scaffolds. The major challenge for growing thick 3D tissues is the lack of vasculature, where nutrients and oxygen can be delivered to the growing cells. Our collaborators have synthesized a novel polypeptide that is composed of 34-mer …


Computational Modeling Of Ring Dna-Carbon Nanotube Sensors, Aliasghar Alizadehmojarad Jan 2018

Computational Modeling Of Ring Dna-Carbon Nanotube Sensors, Aliasghar Alizadehmojarad

Open Access Theses & Dissertations

Non-covalent interactions between single-stranded DNA (ssDNA) oligonucleotides and carbon nanotubes have provided a unique class of tunable chemistries for applications in nanotube chirality purification, gene delivery, electrochemistry, and nanosensor development. However, mechanistic insight into both the photophysical and intermolecular phenomena underlying their utility in such applications is lacking, resulting in non-systematic approaches to producing DNAnanotube based technologies. In this work, we explore the molecular interactions between ssDNA polymers, in particular (GT)6, and single-walled carbon nanotubes (SWNT) in an ultrasensitive nanosensor for a modulatory neurotransmitters dopamine. Classical molecular dynamics simulations show that (GT)6 oligonucleotides adopt ordered, ring-like conformations around SWNT in …


Geant4 Study Of A Gamma Ray Collimator For Proton Therapy, Selim Romero Jan 2018

Geant4 Study Of A Gamma Ray Collimator For Proton Therapy, Selim Romero

Open Access Theses & Dissertations

This Thesis presents the results of an investigation of the use of collimators in proton therapy. The problem to solve is that in the proton therapy, we do not have the certainty if the target-tumor is receiving all the energy to destroy it or if we are really shooting at this one, so the remaining question is: where the beam is hitting? How to know it? to answer those questions our work has the propose of study proton therapy to determine where the proton interactions occur, these kinds of interactions usually produce gamma rays, and we simulated in GEANT4 the …


The Inverse And Direct Hofmeister Series Of Hen Egg White Lysozyme At Ph Below The Isoelectric Point (Pi) As Seen By Small Angle X-Ray Scattering(Saxs), Pawan Koirala Jan 2018

The Inverse And Direct Hofmeister Series Of Hen Egg White Lysozyme At Ph Below The Isoelectric Point (Pi) As Seen By Small Angle X-Ray Scattering(Saxs), Pawan Koirala

Open Access Theses & Dissertations

The structural changes of Hen Egg White Lysozyme (HEWL) in the intermediate stages leading up to Hofmeister anion-induced aggregation were measured using small-angle x-ray Scattering (SAXS). We used three concentrations of HEWL: 10mg/ml, 60mg/ml and 200mg/ml and two concentrations of salts: 0.1M and 1.0M, mostly in a Tris-buffer solution with a pH of 9.0. For 200mg/ml in Di-water solution, the scattering signal was best fit using an ellipsoidal form factor with equatorial radius of 28.4±0.1 Å and polar radius of 11.3±0.1 Å, and a screened Coulomb repulsive structure factor with an effective radius of 19.9±0.1 Å and protein surface charge …


Imaging Live Drosophila Brain With Two-Photon Fluorescence Microscopy, Syeed Ehsan Ahmed Jan 2017

Imaging Live Drosophila Brain With Two-Photon Fluorescence Microscopy, Syeed Ehsan Ahmed

Open Access Theses & Dissertations

Two-photon fluorescence microscopy is an imaging technique which delivers distinct benefits for in vivo cellular and molecular imaging. Cyclic adenosine monophosphate (cAMP), a second messenger molecule, is responsible for triggering many physiological changes in neural system. However, the mechanism by which this molecule regulates responses in neuron cells is not yet clearly understood. When cAMP binds to a target protein, it changes the structure of that protein. Therefore, studying this molecular structure change with fluorescence resonance energy transfer (FRET) imaging can shed light on the cAMP functioning mechanism. FRET is a non-radiative dipole-dipole coupling which is sensitive to small distance …


Two-Photon Excitation Based Photochemistry And Neural Imaging, Kevin Andrew Hatch Jan 2016

Two-Photon Excitation Based Photochemistry And Neural Imaging, Kevin Andrew Hatch

Open Access Theses & Dissertations

Two-photon microscopy is a fluorescence imaging technique which provides distinct advantages in three-dimensional cellular and molecular imaging. The benefits of this technology may extend beyond imaging capabilities through exploitation of the quantum processes responsible for fluorescent events. This study utilized a two-photon microscope to investigate a synthetic photoreactive collagen peptidomimetic, which may serve as a potential material for tissue engineering using the techniques of two-photon photolysis and two-photon polymerization. The combination of these techniques could potentially be used to produce a scaffold for the vascularization of engineered three-dimensional tissues in vitro to address the current limitations of tissue engineering. Additionally, …


Studying Cellular And Molecular Interaction With Two-Photon Fluorescence Microscopy, Arifur Rahaman Jan 2015

Studying Cellular And Molecular Interaction With Two-Photon Fluorescence Microscopy, Arifur Rahaman

Open Access Theses & Dissertations

Advances in microscopy and fluorescent probes provide new insight into studying cellular and molecular interactions. Two-photon fluorescence microscopy is one of the most important recent inventions in cellular and molecular study. This technology enables noninvasive study at cellular and molecular levels in three dimensions with submicrometer resolution. Two-photon excitation of fluorophores results from the simultaneous absorption of two photons. This excitation process has a number of unique advantages, such as reduced specimen photodamage and enhanced penetration depth. In this study, we used our two-photon microscope to observe predatorial behavior of fast moving bacterivorous marine organism Cafeteria roenbergensis and quantify Mycobacterium …


Furthering Our Understanding And Assessing The Effectiveness Of Scaling Patterns And Controls Of Land-Atmosphere Carbon Exchange In A Shrubland Of The Chihuahuan Desert With Novel Cyberinfrastructure, Aline Jaimes Jan 2014

Furthering Our Understanding And Assessing The Effectiveness Of Scaling Patterns And Controls Of Land-Atmosphere Carbon Exchange In A Shrubland Of The Chihuahuan Desert With Novel Cyberinfrastructure, Aline Jaimes

Open Access Theses & Dissertations

Over the last century, arid and semiarid regions have undergone intense desertification and in many regions, vegetation has shifted from grassland to shrubland dominated ecosystems. This land cover change has important implications for how desert ecosystems function - especially with regards to land-atmosphere exchange of carbon, water, and energy. Although the extent of desertified landscapes is expected to expand over the next 30 to 40 years, there is a relatively poor understanding of how this state transition will impact ecosystem function and feedbacks to other components of the earth system. Key to addressing this challenge is an improved understanding of …


Inhibition Of Calcium Oxalate Calculi By Ndga - A Spectroscopic Study, Preethi Dacha Jan 2011

Inhibition Of Calcium Oxalate Calculi By Ndga - A Spectroscopic Study, Preethi Dacha

Open Access Theses & Dissertations

Formation of calculi in urinary tract leads to kidney stones. This process is known as Urolithiasis. Some of the causes of urolithiasis are metabolic disorders, genetic factors, and anatomic abnormalities in the urinary system. Nowadays, urolithiasis is very common disease in population of all over the world. The present study strives to understand calcium oxalate calculi formation as well as its inhibition by using Nordihydroguaiaretic acid (NDGA), which is a chemical extract of the Larrea Tridentata bush, a plant that is traditionally employed in the El paso region as a natural treatment for kidney stones and bladder diseases. Thus, in …