Eigenstrain As A Mechanical Set-Point Of Cells,
2018
University of Nebraska-Lincoln
Eigenstrain As A Mechanical Set-Point Of Cells, Shengmao Lin, Marsha C. Lampi, Cynthia A. Reinhart-King, Gary C.P. Tsui, Jian Wang, Carl A. Nelson, Linxia Gu
Department of Mechanical and Materials Engineering: Faculty Publications
Cell contraction regulates how cells sense their mechanical environment. We sought to identify the set-point of cell contraction, also referred to as tensional homeostasis. In this work, bovine aortic endothelial cells (BAECs), cultured on substrates with different stiffness, were characterized using traction force microscopy (TFM). Numerical models were developed to provide insights into the mechanics of cell–substrate interactions. Cell contraction was modeled as eigenstrain which could induce isometric cell contraction without external forces. The predicted traction stresses matched well with TFM measurements. Furthermore, our numerical model provided cell stress and displacement maps for inspecting the fundamental regulating mechanism of cell …
Interplay Of Molecular And Nanoscale Behaviors In Biological Soft Matter,
2018
University of Central Florida
Interplay Of Molecular And Nanoscale Behaviors In Biological Soft Matter, Nicholas Ciaffone
Electronic Theses and Dissertations
The complexity of biological soft matter at the sub-micrometer level is fundamentally correlated to the functionalities at the larger scale. Reflecting the level of heterogeneities in the properties of systems remains challenging when probing small scales, due to the mismatch between the area surveyed with the tools offering nanoscale resolution, such as atomic force microscopy (AFM), and the scale of natural variations inherent to biology. Hence, to understand the physiological and mechanical alterations that occur within a single cell relative to a cell population, a multiscale approach is necessary. In this work we show that it is possible to observe …
Tunable Effect Of Metal Ions On Polyelectrolyte Mechanics,
2018
University of Central Florida
Tunable Effect Of Metal Ions On Polyelectrolyte Mechanics, Angie Diaz
Electronic Theses and Dissertations
Polyelectrolyte based hydrogel fibers can mimic extracellular matrix and have applications such as drug delivery and tissue scaffolding. Metal ions play a critical role in hydrogel fiber stability via electrostatic interactions, but knowledge of how they modulate mechanical properties of individual polyelectrolyte polymers is lacking. In this study, electrospun polyacrylic acid with chitosan is used as a model system to evaluate ferric ion effect on nanofiber mechanics. Using dark field microscopy imaging and persistence length analysis, we demonstrate that ferric ions modulate the bending stiffness of nanofibers. Young's modulus of individual nanofibers is estimated at values of a few kilopascals, …
Size, Charge And Dose Dependent In-Vitro Kinetics Of Polystyrene Nanoparticles,
2018
University of Central Florida
Size, Charge And Dose Dependent In-Vitro Kinetics Of Polystyrene Nanoparticles, Yasmine Abdellatif
Electronic Theses and Dissertations
The aim of the study described herein is to quantify the in-vitro kinetics of internalization of polystyrene nanoparticles (PS NPs) by cells. We used different charges, sizes and doses of fluorescently labelled PS NPs. Nanoparticles were characterized with UV-Vis, Fluorescence emission Dynamic Light Scattering (DLS) and Zeta potential for knowing their absorption, fluorescence spectra, size, charge, respectively. Additionally, cell viability was tested to know the toxicity of PS NPs. The quantitative uptake, the kinetics profile and rate of uptake were studied by using a new in-vitro fluorescence assay. This was achieved quantitatively and qualitatively by fluorescent plate reader and confocal …
Engineered Nanomaterials And Human Health: Part 1. Preparation, Functionalization And Characterization (Iupac Technical Report),
2018
Medway School of Pharmacy, Chatham, United Kingdom
Engineered Nanomaterials And Human Health: Part 1. Preparation, Functionalization And Characterization (Iupac Technical Report), Vladimir Gubala, Linda J. Johnston, Harald Friedrich Krug, Colin J. Moore, Christopher K. Ober, Michael Schwenk, Michel R. Vert
Reports
Research on engineered nanomaterials (ENM) has progressed rapidly from the very early stages of studying their unique, size-dependent physicochemical properties and commercial exploration to the development of products that influence our everyday lives. We have previously reviewed various methods for synthesis, surface functionalization, and analytical characterization of ENM in a publication titled 'Engineered Nanomaterials: Preparation, Functionalization and Characterization'. In this second, inter-linked document, we first provide an overview of important applications of ENM in products relevant to human healthcare and consumer goods, such as food, textiles, and cosmetics. We then highlight the challenges for the design and development of new …
Engineered Nanomaterials And Human Health: Part 2. Applications And Nanotoxicology (Iupac Technical Report) (Review),
2018
Medway School of Pharmacy, Chatham, United Kingdom
Engineered Nanomaterials And Human Health: Part 2. Applications And Nanotoxicology (Iupac Technical Report) (Review), Vladimir Gubala, Linda J. Johnston, Harald Friedrich Krug, Colin J. Moore, Christopher K. Ober, Michael Schwenk, Michel R. Vert
Reports
Research on engineered nanomaterials (ENM) has progressed rapidly from the very early stages of studying their unique, size-dependent physicochemical properties and commercial exploration to the development of products that influence our everyday lives. We have previously reviewed various methods for synthesis, surface functionalization, and analytical characterization of ENM in a publication titled 'Engineered Nanomaterials: Preparation, Functionalization and Characterization'. In this second, inter-linked document, we first provide an overview of important applications of ENM in products relevant to human healthcare and consumer goods, such as food, textiles, and cosmetics. We then highlight the challenges for the design and development of new …
An Integrated Microstructural-Nanomechanical-Chemical Approach To Examine Material-Specific Characteristics Of Cementitious Interphase Regions,
2018
University of Nebraska-Lincoln
An Integrated Microstructural-Nanomechanical-Chemical Approach To Examine Material-Specific Characteristics Of Cementitious Interphase Regions, Mahdieh Khedmati, Yong-Rak Kim, Joseph A. Turner, Hani Alanazi, Charles Nguyen
Department of Mechanical and Materials Engineering: Faculty Publications
Effective properties and structural performance of cementitious mixtures are substantially governed by the quality of the interphase region because it acts as a bridge transferring forces between aggregates and a binding matrix and is generally susceptible to damage. As alternative binding agents like alkali-activated precursors have obtained substantial attention in recent years, there is a growing need for fundamental knowledge to uncover interphase formation mechanisms. In this paper, two different types of binding materials, i.e., fly ash-based geopolymer and ordinary portland cement, were mixed with limestone aggregate to examine and compare the microstructures and nanomechanical properties of interphase region. To …
Methods, Systems, And Devices For
Surgical Access And Procedures,
2018
University of Nebraska-Lincoln
Methods, Systems, And Devices For Surgical Access And Procedures, Shane M. Farritor, Mark Rentschler, Amy Lehman, Stephen R. Platt, Jeff Hawks
Department of Mechanical and Materials Engineering: Faculty Publications
The embodiments disclosed herein relate to various medical device components, including components that can be incorporated into robotic and/or in vivo medical devices. Certain embodiments include various actuation system embodiments, including fluid actuation systems, drive train actuation systems, and motorless actuation systems. Additional embodiments include a reversibly lockable tube that can provide access for a medical device to a patient's cavity and further provides a reversible rigidity or stability during operation of the device. Further embodiments include various operational components for medical devices, including medical device arm mechanisms that have both axial and rotational movement while maintaining a relatively compact …
Excess Charge-Carrier Induced Instability Of Hybrid
Perovskites,
2018
University of North Carolina
Excess Charge-Carrier Induced Instability Of Hybrid Perovskites, Yuze Lin, Bo Chen, Yanjun Fang, Jingjing Zhao, Chunxiong Bao, Zhenhua Yu, Yehao Deng, Peter N. Rudd, Yanfa Yan, Yongbo Yuan, Jinsong Huang
Department of Mechanical and Materials Engineering: Faculty Publications
Identifying the origin of intrinsic instability for organic–inorganic halide perovskites (OIHPs) is crucial for their application in electronic devices, including solar cells, photodetectors, radiation detectors, and light-emitting diodes, as their efficiencies or sensitivities have already been demonstrated to be competitive with commercial available devices. Here we show that free charges in OIHPs, whether generated by incident light or by current-injection from electrodes, can reduce their stability, while efficient charge extraction effectively stabilizes the perovskite materials. The excess of both holes and electrons reduce the activation energy for ion migration within OIHPs, accelerating the degradation of OIHPs, while the excess holes …
Visible Light Crosslinkable Human Hair Keratin Hydrogels,
2018
Harvard Medical School
Visible Light Crosslinkable Human Hair Keratin Hydrogels, Kan Yue, Yanhui Liu, Batzaya Byambaa, Vaishali Singh, Wanjun Liu, Xiuyu Li, Yunxia Sun, Yu Shrike Zhang, Ali Tamayol, Peihua Zhang, Kee Woei Ng, Nasim Annabi, Ali Khademhosseini
Department of Mechanical and Materials Engineering: Faculty Publications
Keratins extracted from human hair have emerged as a promising biomaterial for various biomedical applications, partly due to their wide availability, low cost, minimal immune response, and the potential to engineer autologous tissue constructs. However, the fabrication of keratin-based scaffolds typically relies on limited crosslinking mechanisms, such as via physical interactions or disulfide bond formation, which are time-consuming and result in relatively poor mechanical strength and stability. Here, we report the preparation of photocrosslinkable keratin-polyethylene glycol (PEG) hydrogels via the thiol-norbornene “click” reaction, which can be formed within one minute upon irradiation of visible light. The resulting keratin-PEG hydrogels showed …
Hydrophobic Surface Modification Of Polymethyl Methacrylate By Two-Dimensional Plasma Jet Array At Atmospheric Pressure,
2018
Nanjing Tech University
Hydrophobic Surface Modification Of Polymethyl Methacrylate By Two-Dimensional Plasma Jet Array At Atmospheric Pressure, Feng Liu, Meiling Cai, Bo Zhang, Zhi Fang, Chunqi Jiang, Kostya Ken Ostrikov
Bioelectrics Publications
Recently developed atmospheric pressure plasma jet (APPJ) is considered as a novel and efficient technique for uneven surfaces processing and APPJ array effectively expands the treatment area of a single APPJ. In this paper, a two-dimensional (2D) APPJ array in Ar/tetramethylsilane (TMS) is used to improve the surface hydrophobicity of polymethyl methacrylate (PMMA) by depositing polymerized silicalike clusters on the jet-PMMA interface. The electrical and optical characteristics of the 2D Ar/TMS APPJ array are measured to optimize experimental conditions. The wettability of jet-PMMA interface is assessed by measuring water contact angle, which increases from 65° to a maximum value of …
Methods, Systems, And Devices
Relating To Force Control
Surgical Systems,
2018
University of Nebraska-Lincoln
Methods, Systems, And Devices Relating To Force Control Surgical Systems, Shane M. Farritor, Thomas Frederick, Kearney Lackas, Joe Bartels, Jacob Greenburg
Department of Mechanical and Materials Engineering: Faculty Publications
The various embodiments herein relate to robotic surgical systems and devices that use force and/or torque sensors to measure forces applied at various components of the system or device. Certain implementations include robotic surgical devices having one or more force/torque sensors that detect or measure one or more forces applied at or on one or more arms. Other embodiments relate to systems having a robotic surgical device that has one or more sensors and an external controller that has one or more motors such that the sensors transmit information that is used at the controller to actuate the motors to …
Frequency Dependent Deformation Reversibility
During Cyclic Loading,
2018
Louisiana State University
Frequency Dependent Deformation Reversibility During Cyclic Loading, Shuai Shao, Michael M. Khonsari, Jian Wang, Nima Shamsaei, Nan Li
Department of Mechanical and Materials Engineering: Faculty Publications
High-frequency testing (HFT) is useful for accelerated fatigue testing of conventional materials that typically serve under low-frequency loading conditions, as well as for the assessment of the robustness of microelectromechanical systems which typically experience high-frequency service conditions. Using discrete dislocation dynamics, we attempt to elucidate the effect of loading frequency on the reversibility of cyclic deformation. We demonstrate that the HFT induces a higher fraction of reversible cyclic deformation because of a larger portion of elastic/anelastic deformation due to limited dislocation mobility, and a higher degree of reversibility in plastic deformation owing to the less occurrence of cross-slip.
An Integrated Microstructural-Nanomechanical-Chemical Approach To Examine Material-Specific Characteristics Of Cementitious Interphase Regions,
2018
University of Nebraska-Lincoln
An Integrated Microstructural-Nanomechanical-Chemical Approach To Examine Material-Specific Characteristics Of Cementitious Interphase Regions, Mahdieh Khedmati, Yong-Rak Kim, Joesph A. Turner, Hani Alanazi, Charles Nguyen
Department of Mechanical and Materials Engineering: Faculty Publications
Effective properties and structural performance of cementitious mixtures are substantially governed by the quality of the interphase region because it acts as a bridge transferring forces between aggregates and a binding matrix and is generally susceptible to damage. As alternative binding agents like alkali-activated precursors have obtained substantial attention in recent years, there is a growing need for fundamental knowledge to uncover interphase formation mechanisms. In this paper, two different types of binding materials, i.e., fly ash-based geopolymer and ordinary portland cement, were mixed with limestone aggregate to examine and compare the microstructures and nanomechanical properties of interphase region. To …
Neuroprotective And Anti-Inflammatory Effects Of
Rhus Coriaria Extract In A Mouse Model Of Ischemic
Optic Neuropathy,
2018
Università degli Studi di Milano
Neuroprotective And Anti-Inflammatory Effects Of Rhus Coriaria Extract In A Mouse Model Of Ischemic Optic Neuropathy, Saba Khalilpour, Ghazaleh Behnammanesh, Fouad Suede, Mohammed O. Ezzat, Jayadhisan Muniandy, Yasser Tabana, Mohamed B. K. Ahamed, Ali Tamayol, Amin Malik Shah Majid, Enrico Sangiovanni, Mario Dell'agli, Aman Shah Majid
Department of Mechanical and Materials Engineering: Faculty Publications
Modulating oxidative stresses and inflammation can potentially prevent or alleviate the pathological conditions of diseases associated with the nervous system, including ischemic optic neuropathy. In this study we evaluated the anti-neuroinflammatory and neuroprotective activities of Rhus coriaria (R. coriaria) extract in vivo. The half maximal inhibitory concentration (IC50) for DPPH, ABTS and B-carotene were 6.79 ± 0.009 µg/mL, 10.94 ± 0.09 µg/mL, and 6.25 ± 0.06 µg/mL, respectively. Retinal ischemia was induced by optic nerve crush injury in albino Balb/c mice. The anti-inflammatory activity of ethanolic extract of R. coriaria (ERC) and linoleic acid (LA) on …
Molecular Doping Enabled Scalable Blading Of
Efficient Hole-Transport-Layer-Free Perovskite Solar
Cells,
2018
University of North Carolina
Molecular Doping Enabled Scalable Blading Of Efficient Hole-Transport-Layer-Free Perovskite Solar Cells, Wu-Qiang Wu, Qi Wang, Yanjun Fang, Yuchuan Shao, Shi Tang, Yehao Deng, Haidong Lu, Ye Liu, Tao Li, Zhibin Yang, Alexei Gruverman, Jinsong Huang
Department of Mechanical and Materials Engineering: Faculty Publications
The efficiencies of perovskite solar cells (PSCs) are now reaching such consistently high levels that scalable manufacturing at low cost is becoming critical. However, this remains challenging due to the expensive hole-transporting materials usually employed, and difficulties associated with the scalable deposition of other functional layers. By simplifying the device architecture, hole-transport-layer-free PSCs with improved photovoltaic performance are fabricated via a scalable doctor-blading process. Molecular doping of halide perovskite films improved the conductivity of the films and their electronic contact with the conductive substrate, resulting in a reduced series resistance. It facilitates the extraction of photoexcited holes from perovskite directly …
Photonic Grating Coupler Designs For Optical Benching,
2018
University at Albany, State University of New York
Photonic Grating Coupler Designs For Optical Benching, Eng Wen Ong
Legacy Theses & Dissertations (2009 - 2024)
Background: Silicon Photonics has been rapidly developing as a field. The primary reason for this is its lower operating costs and faster switching rates for use in big data centres. Instead of microns-wide copper lines to transmit signals, silicon photonic chips use waveguides, usually of silicon or silicon nitride. Photonic signals bypass the issues of resistive-capacitance lag (RC-lag) and resistive-heating encountered by copper lines. Additionally, a single waveguide may transmit multiple signals along different carrier wavelengths.
Economics Of R&D Specialization In The Semiconductor Industry,
2018
University at Albany, State University of New York
Economics Of R&D Specialization In The Semiconductor Industry, Kyun Kim
Legacy Theses & Dissertations (2009 - 2024)
Starting in the 1970s, specialized suppliers have entered the semiconductor industry to supply capital equipment, or tools, used in semiconductor manufacturing to downstream semiconductor companies. After the entry of these external suppliers, semiconductor chip producers began to rely in varying degrees on them for the R&D to improve the quality of capital equipment, while they themselves began to focus on design and production of chips. In my dissertation, I conduct an empirical and theoretical investigation to support my hypothesis that the difference in R&D incentives between the upstream suppliers and downstream chip manufacturers was the important reason for the emergence …
Investigation Of The Ms2 Bacteriophage Capsid As An Mri-Capable, Brain-Targeted Nanoparticle Platform,
2018
University at Albany, State University of New York
Investigation Of The Ms2 Bacteriophage Capsid As An Mri-Capable, Brain-Targeted Nanoparticle Platform, Stephanie M. Curley
Legacy Theses & Dissertations (2009 - 2024)
Novel methods are needed to traverse the blood-brain barrier (BBB) and deliver drugs to specific targets in the brain. To this end, MS2 bacteriophage was explored as a multifunctional transport and targeting vector. The MS2 capsid exterior was modified with two different targeting moieties for delivery across the BBB and targeting specific regions of interest in the brain. Successful modification of MS2 capsids with a brain targeting peptide and NMDAR2D-targeting antibody was confirmed by immunoblotting and fluorescence detection. To measure transport efficiency of MS2 particles across an in vitro BBB model, a highly sensitive RT-qPCR protocol was developed and implemented. …
The Microfluidic Intravital Window : A Tool For Manipulation And Imaging Of The Tumor Microenvironment,
2018
University at Albany, State University of New York
The Microfluidic Intravital Window : A Tool For Manipulation And Imaging Of The Tumor Microenvironment, Logan William Butt
Legacy Theses & Dissertations (2009 - 2024)
The tumor microenvironment (TME) is a heterogeneous collection of both healthy and pathological cells, whose complex interactions hold the key for understanding and overcoming cancer. Metastasis leverages these complex interactions into a sophisticated process by which single cells from the tumor disseminate into the blood and form new colonies in other organ systems. Subsequent formation of tumors throughout the body, as a direct result of metastatic events, is responsible for most deaths related to cancer, making metastasis a necessary target for cancer therapy.
