Nanoscience and Nanotechnology Commons^™

Effects Of Three Dry Powder Inhalers On Deposition Of Aerosolized Medicine In The Human Oral-Pharyngeal-Laryngeal Regions, Mohammed Ali

Technology Faculty Publications and Presentations

The dry powder inhaler (DPI) is a popular, effective and convenient drug delivery device for inhalation therapy to treat asthma. However, a large quantity (approximately 54%) of inhaled aerosols deposit in the oropharyngeal region. Deposition in this region is undesirable because it provides minimum therapeutic benefits and has adverse localized or systemic side effects. This study reports a method of examining electrostatic charge effects on deposition of three DPI aerosols (Spiriva^™ Handihaler, Advair Diskus^™, and Pulmicort^™ Turbohaler) in a cadaver-based cast of the human oral-pharyngeal-laryngeal (OPL) regions. Experimental aerosols were generated from the three commercially available …

Highly-Selective Chemiresistive Sensing And Analysis Of Vapors Using Functionalized Nanotubes, Deon Hines

Dissertations, Theses, and Capstone Projects

Specifically, the project involves the development of a diversified array of nanostructured gas-sensors comprised of selectively, novel surface-functionalized carbon nanotubes (for analyte selectivity by virtue of functionality). Harnessing carbon nanotubes with various electron withdrawing and donating groups help in determining their affinity toward certain prognostic gaseous markers thus increasing specificity of such created sensors. We have devised synthetic routes that have led to the facile production of covalently polyfunctionalized nanotubes in high yield. Seven carbon nanotube analogues were systematically considered and then chemically synthesized, from pristine single-walled nanotubes (SWNT's), for use as the main component of sensory units that was …

Label-Free Detection Of Cancer Cells With Polysilicon Sensor Chips And Biomolecule-Assisted Synthesis Of Shape-Controlled Nanoparticles, Menglu Shi

Dissertations, Theses, and Capstone Projects

Constant effort has been made for the detection of cancer cells. Recently, ovarian and kidney cancer cell lines have been shown to have higher cellular elasticity as compared to normal cells assessed by monitoring the degree of deformation under hyposmotic pressure. This method has been modified and applied to various cases. In cancer cells, the oncogenic mutant p53 (mtp53) protein is present at high levels and contributes to tumor growth and metastasis. Herein the influence of mtp53 on the mechanical property of breast cancer cells was assessed by monitoring the swelling ratio of cells with time using the impedance measurements. …

Biomolecule Mediating Synthesis Of Inorganic Nanoparticles And Their Applications, Zengyan Wei

Dissertations, Theses, and Capstone Projects

Project 1.

The conventional phage display technique focuses on screening peptide sequences that can bind on target substrates, however the selected peptides are not necessary to nucleate and mediate the growth of the target inorganic crystals, and in many cases they only show moderate affinity to the targets. Here we report a novel phage display approach that can directly screen peptides catalytically growing inorganic nanoparticles in aqueous solution at room temperature. In this study, the phage library is incubated with zinc precursor at room temperature. Among random peptide sequences displayed on phages, those phages that can grow zinc oxide (ZnO) …

Efficacy Of A Magnetic Drug Delivery System And Development Of An Orthotopic Lung Tumor Imaging Model, Amber Mcbride

Nanoscience and Microsystems ETDs

The aim of this work was the development of a novel drug delivery vehicle termed nano-in-microparticles (NIMs) to evaluate the magnetic-field dependent targeting of dry powder NIMs administered endotracheally using an ex vivo and in vivo rodent model. NIMs are a novel dry powder drug delivery vehicle containing 70% lactose (w/w), 20% SPIONs (w/w) and 10% fluorescent nanospheres (w/w). Mice were insufflated with NIMs delivery vehicle in the presence of magnetic field dependent targeting to the left ventral lung after thoracotomy; controls were insufflated with the NIMs in the absence of magnetic field dependent targeting. Quantification of deposition of the …

On Thermal Aging Prevention In Polymer Core Composite Conductor Rods, Joe D. Hoffman

Electronic Theses and Dissertations

Increased energy usage in the United States and worldwide is driving the demand for new technologies to transmit electrical power in greater quantities and with reliable, safe, and more efficient methods. One recent innovation is to replace the standard Aluminum Conductor Steel Reinforced electrical transmission conductor with a new conductor design that utilizes a fiber reinforced polymer core rod to support a fully annealed aluminum conductor. This new technology that includes a hybrid carbon fiber/epoxy and glass fiber/epoxy support core allows for better efficiency and for greater current to be transmitted in the same size and weight line. These new …

Chloride Incorporation Process In Ch3Nh3Pbi3-XClX Perovskites Via Nanoscale Bandgap Maps, Jungseok Chae, Qingfeng Dong, Jinsong Huang, Andrea Centrone

Department of Mechanical and Materials Engineering: Faculty Publications

CH₃NH₃PbI_3-xCl_x perovskites enable fabrication of highly efficient solar cells. Chloride ions benefit the morphology, carrier diffusion length and stability of perovskite films; however, whether those benefits stem from the presence of Cl⁻ in the precursor solution or from their incorporation in annealed films is debated. In this work, the photothermal induced resonance (PTIR), an in situ technique with nanoscale resolution, is leveraged to measure the bandgap of CH₃NH₃PbI_3-xCl_x films obtained by a multicycle coating process that produces high efficiency (≈16 %) solar cells. Because chloride …

Role Of Interphase In The Mechanical Behavior Of Silica/Epoxy Resin Nanocomposites, Yi Hua, Linxia Gu, Sundaralingam Premaraj, Xiaodong Zhang

Department of Mechanical and Materials Engineering: Faculty Publications

A nanoscale representative volume element has been developed to investigate the effect of interphase geometry and property on the mechanical behavior of silica/epoxy resin nanocomposites. The role of interphase–matrix bonding was also examined. Results suggested that interphase modulus and interfacial bonding conditions had significant influence on the effective stiffness of nanocomposites, while its sensitivities with respect to both the thickness and the gradient property of the interphase was minimal. The stiffer interphase demonstrated a higher load-sharing capacity, which also increased the stress distribution uniformity within the resin nanocomposites. Under the condition of imperfect interfacial bonding, the effective stiffness of nanocomposites …

Biomimetic Oral Mucin From Polymer Micelle Networks, Sundar Prasanth Authimoolam

Theses and Dissertations--Chemical and Materials Engineering

Mucin networks are formed by the complexation of bottlebrush-like mucin glycoprotein with other small molecule glycoproteins. These glycoproteins create nanoscale strands that then arrange into a nanoporous mesh. These networks play an important role in ensuring surface hydration, lubricity and barrier protection. In order to understand the functional behavior in mucin networks, it is important to decouple their chemical and physical effects responsible for generating the fundamental property-function relationship. To achieve this goal, we propose to develop a synthetic biomimetic mucin using a layer-by-layer (LBL) deposition approach. In this work, a hierarchical 3-dimensional structures resembling natural mucin networks was generated …

Improving Practices In Nanomedicine Through Near Real-Time Pharmacokinetic Analysis, Isidro B. Magana

Doctoral Dissertations

More than a decade into the development of gold nanoparticles, with multiple clinical trials underway, ongoing pre-clinical research continues towards better understanding in vivo interactions. The goal is treatment optimization through improved best practices. In an effort to collect information for healthcare providers enabling informed decisions in a relevant time frame, instrumentation for real-time plasma concentration (multi-wavelength photoplethysmography) and protocols for rapid elemental analysis (energy dispersive X-Ray fluorescence) of biopsied tumor tissue have been developed in a murine model. An initial analysis, designed to demonstrate the robust nature and utility of the techniques, revealed that area under the bioavailability curve …

Ablation Of Myocardial Tissue With Nanosecond Pulsed Electric Fields, Fei Xie, Frency Varghese, Andrei G. Pakhomov, Iurii Semenov, Shu Xiao, Jonathan Philpott, Christian Zemlin

Bioelectrics Publications

Background

Ablation of cardiac tissue is an essential tool for the treatment of arrhythmias, particularly of atrial fibrillation, atrial flutter, and ventricular tachycardia. Current ablation technologies suffer from substantial recurrence rates, thermal side effects, and long procedure times. We demonstrate that ablation with nanosecond pulsed electric fields (nsPEFs) can potentially overcome these limitations.

Methods

We used optical mapping to monitor electrical activity in Langendorff-perfused New Zealand rabbit hearts (n = 12). We repeatedly inserted two shock electrodes, spaced 2–4 mm apart, into the ventricles (through the entire wall) and applied nanosecond pulsed electric fields (nsPEF) (5–20 kV/cm, 350 ns duration, …

Relevance Of Blood Vessel Networks In Blast-Induced Traumatic Brain Injury, Yi Hua, Shengmao Lin, Linxia Gu

Department of Mechanical and Materials Engineering: Faculty Publications

Cerebral vasculature is a complex network that circulates blood through the brain. However, the role of this networking effect in brain dynamics has seldom been inspected. This work is to study the effects of blood vessel networks on dynamic responses of the brain under blast loading. Voronoi tessellations were implemented to represent the network of blood vessels in the brain. The brain dynamics in terms of maximumprincipal strain (MPS), shear strain (SS), and intracranial pressure (ICP) weremonitored and compared. Results show that blood vessel networks significantly affected brain responses.The increased MPS and SS were observed within the brain embedded with …

In Situ Longitudinal Pre-Stretch In The Human Femoropopliteal Artery, Alexey Kamenskiy, Andreas Seas, Grant Bowen, Paul Deegan, Anastasia Desyatova, Nick Bohlim, William Poulson, Jason N. Mactaggart

Department of Mechanical and Materials Engineering: Faculty Publications

In situ longitudinal (axial) pre-stretch (LPS) plays a fundamental role in the mechanics of the femoropopliteal artery (FPA). It conserves energy during pulsation and prevents buckling of the artery during limb movement. We investigated how LPS is affected by demographics and risk factors, and how these patient characteristics associate with the structural and physiologic features of the FPA. LPS was measured in n=148 fresh human FPAs (14–80 years old). Mechanical properties were characterized with biaxial extension and histopathological characteristics were quantified with Verhoeff-Van Gieson Staining. Constitutive modeling was used to calculate physiological stresses and stretches which were then analyzed …

Asphalt Composition, David Allen, Flavio Souza, Yong-Rak Kim, Roberto Soares

Department of Mechanical and Materials Engineering: Faculty Publications

A computational method is provided for predicting roadway failure due to degradation of the roadway over time as a function of the input loads, the roadway geometry, the material properties of the constituents in the asphaltic pavement, the shape, distribution, orientation and volume fractions of the constituents, and environmental conditions. The unique and new feature of the method is that it employs several physically based predictive methodologies simultaneously.

Extracting Continuum-Like Deformation And Stress From Molecular Dynamics Simulations, Lili Zhang, John Jasa, George Gazonas, Antoine Jerusalem, Mehrdad Negahban

Department of Mechanical and Materials Engineering: Faculty Publications

We present methods that use results from molecular dynamics (MD) simulations to construct continuum parameters, such as deformation gradient and Cauchy stress, from all or any part of an MD system. These parameters are based on the idea of minimizing the difference between MD measures for deformation and traction and their continuum counterparts. The procedures should be applicable to non-equilibrium and inhomogeneous systems, and to any part of a system, such as a polymer chain. The resulting procedures provide methods to obtain first and higher order deformation gradients associated with any subset of the MD system, and associated expressions for …

Designed Synthesis Of Nanoporous Organic Polymers For Selective Gas Uptake And Catalytic Applications, Pezhman Arab

Theses and Dissertations

Design and synthesis of porous organic polymers have attracted considerable attentions during the past decade due to their wide range of applications in gas storage, gas separation, energy conversion, and catalysis. Porous organic polymers can be pre-synthetically and post-synthetically functionalized with a wide variety of functionalities for desirable applications. Along these pursuits, we introduced new synthetic strategies for preparation of porous organic polymers for selective CO₂ capture.

Porous azo-linked polymers (ALPs) were synthesized by an oxidative reaction of amine-based monomers using copper(I) as a catalyst which leads to azo-linkage formation. ALPs exhibit high surface areas of up to 1200 …

Molecular Dynamics Study On Defect Reduction Strategies Towards The Fabrication Of High Performance Cd1-Xznxte/Cds Solar Cells, Jose Juan Chavez

Open Access Theses & Dissertations

Cadmium Telluride is a material widely used in terrestrial thin film photovoltaic applications due to its nearly ideal band gap (~1.5 eV) and high absorption coefficient. Due to its low manufacturing cost, this technology has the potential to become a significant energy resource if higher energy conversion efficiencies are achieved. However, the module efficiencies (~14%) are still far from the theoretical maximum (~30%) for this material in a single junction configuration. The reason behind this low performance is attributed to the high number of defects that are present within the device materials. The physics behind the formation mechanisms of these …

Novel Techniques For Quasi Three-Dimensional Nanofabrication Of Transformation Optics Devices, Paul R. West

Open Access Dissertations

Current nanofabrication is almost exclusively limited to top-down, two-dimensional techniques. As technology moves more deeply into the nano-scale regime, fabrication of new devices with quasi three-dimensional geometries shows great potential. One excellent example of an emerging field that requires this type of non-conformal 3D fabrication technique is the field of Transformation Optics. This field involves transforming and manipulating the optical space through which light propagates. Arbitrarily manipulating the optical space requires advanced fabrication techniques, which are not possible with current two-dimensional fabrication technologies. One step toward quasi three-dimensional nanofabrication involves employing angled deposition allowing new growth mechanisms, and enabling a …

Electronic Structure Evolution Of Fullerene On Ch3Nh3Pbi3, Chenggong Wang, Congcong Wang, Xiaoliang Liu, John Kauppi, Yuchuan Shao, Zhengguo Xiao, Cheng Bi, Jinsong Huang, Yongli Gao

Department of Mechanical and Materials Engineering: Faculty Publications

The thickness dependence of fullerene on CH₃NH₃PbI₃ perovskite film surface has been investigated by using ultraviolet photoemission spectroscopy (UPS), X-ray photoemission spectroscopy (XPS), and inverse photoemission spectroscopy (IPES). The lowest unoccupied molecular orbital and highest occupied molecular orbital (HOMO) can be observed directly with IPES and UPS. It is observed that the HOMO level in fullerene shifts to lower binding energy. The XPS results show a strong initial shift of core levels to lower binding energy in the perovskite, which indicates that electrons transfer from the perovskite film to fullerene molecules. Further deposition of fullerene …

Improving The Sensitivity Of A Near-Infrared Nanocomposite Photodetector By Enhancing Trap Induced Hole Injection, Liang Shen, Yanjun Fang, Qingfeng Dong, Zhengguo Xiao, Jinsong Huang

Department of Mechanical and Materials Engineering: Faculty Publications

We report the enhancement of the photoconductive gain of nanocomposite near-infrared photodetectors by a zinc oxide nanoparticles (ZnO NPs) rich surface at the nanocomposite/cathode interface. An argon plasma etching process was used to remove polymer at the surface of nanocomposite films, which resulted in a ZnO NPs rich surface. The other way is to spin-coat a thin layer of ZnO NPs onto the nanocomposite layer. The ZnO NPs rich surface, which acts as electron traps to induce secondary hole injection under reverse bias, increased hole injection, and thus the external quantum efficiency by 2–3 times. The darkcurrent declined one order …