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Open Access Publications from the University of California

Scholarly Works (226 results)

  • Multimedia
CMPM 80K (2018)
This is a game where players compete against each other by rolling and jumping with balls. There is a race track mode where players race to reach the end first, and an arena mode where players try to knock each other off. Tons more to find out when you play it!
  • 1 supplemental ZIP
  • Thesis
  • Peer Reviewed
UC San Diego Electronic Theses and Dissertations (2013)
Lafora Disease (LD) is a fatal neurodegenerative disease that is correlated with mutation of the human phosphatase, Laforin. While Laforin has been shown to dephosphorylate phosphoglucans, little is known about the mechanism of dephosphorylation and Laforin's structure. Laforin consists of two domains: a carbohydrate binding module (CBM) and a dual specificity phosphatase (DSP) domain. The absence of Laforin function results in hyperphosphorylated and poorly branched sugar accumulations. It is hypothesized that these insoluble sugar deposits lead to neurodegeneration and pre-mature death in LD patients. We utilized hydrogen/deuterium exchange mass spectrometry (DXMS) to define Laforin's structural components and to probe Laforin's substrate interactions. DXMS analysis was performed on wild-type (WT) Laforin and LD mutants : W32G, G240S, and Y294N. The analysis of WT Laforin revealed the strongest substrate interaction with glycogen, when compared to interactions with the carbohydrates amylopectin and [Beta]-cyclodextrin. WT data revealed that regions of the CBM were protected from deuteration when bound to glucans. Similarly, structurally important regions of the DSP showed deuteration protection. W32G data confirmed the lack of protection from deuteration in the absence of substrate binding, whereas G240S data confirmed deuteration protection due to substrate binding. Lastly, the Y294N data revealed surprisingly strong substrate interactions in the DSP mutation region, despite weak CBM interaction. Our results confirm the role of Laforin's CBM in glucan binding and highlight the significance of structural DSP elements in the dephosphorylation of phosphoglucans
    Cover page: Hydrogen/Deuterium Exchange Mass Spectrometry (DXMS) Analysis of the Human Carbohydrate Phosphatase, Laforin /
    • Article
    • Peer Reviewed
    UC Irvine Previously Published Works (2013)
    This study presents an analytical investigation into the mechanical behavior of a cartilage-polydioxanone (PDS) plate composite grafts. Numerical methods are used to provide a first-order, numerical model of the flexural stiffness of a cartilage-PDS graft. Flexural stiffness is a measure of resistance to bending and is inversely related to the amount of deformation a structure may experience when subjected to bending forces. The cartilage-PDS graft was modeled as a single composite beam. Using Bernoulli-Euler beam theory, a closed form equation for the theoretical flexural stiffness of the composite graft was developed. A parametric analysis was performed to see how the flexural properties of the composite model changed with varying thicknesses of PDS foil. The stiffness of the cartilage-PDS composite using 0.15-mm-thick PDS was four times higher than cartilage alone. The composite with a 0.5-mm-thick PDS graft was only 1.7 times stiffer than the composite with the 0.15-mm-thick PDS graft. Although a thicker graft material will yield higher flexural stiffness for the composite, the relationship between composite stiffness and PDS thickness is nonlinear. After a critical point, increments in graft thickness produce gradually smaller improvements in flexural stiffness. The small increase in stiffness when using the thicker PDS foils versus the 0.15 mm PDS foil may not be worth the potential complications (prolonged foreign body reaction, reduction in nutrient diffusion to cartilage) of using thicker artificial grafts.
      Cover page: Analysis of Cartilage-Polydioxanone Foil Composite GraftsCreative Commons 'BY' version 4.0 license
      • Peer Reviewed
      UC Irvine Previously Published Works (2016)
      Optical coherence tomography (OCT) is a minimally invasive, light-based imaging modality which produces high-resolution, three-dimensional (3D) images of biological tissues. A major focus of biophotonics research over the last 10 years is OCT-based evaluation of subepithelial laryngeal microanatomy, vocal fold vibration, and differentiation between benign and malignant disease processes of the larynx. With utility in both operative and office-based settings, OCT has potential as an adjunct diagnostic imaging modality to assist clinicians in the evaluation of normative and benign laryngeal processes and vibration parameters of the vocal cords. This chapter describes OCT-based delineation of vocal fold microanatomy, evolution of OCT technology, and OCT research to study normative anatomy, benign pathology, and functionality of the larynx.
        Cover page: Optical Coherence Tomography of the Larynx: Normative Anatomy and Benign ProcessesCreative Commons 'BY' version 4.0 license
        • Article
        • Peer Reviewed
        UC Irvine Previously Published Works (2020)
        • 1 supplemental video
        Cover page: Smoke Evacuator Use with Ultra-Low Particulate Air Filtration in Rhinoplasty and Sinus SurgeryCreative Commons 'BY' version 4.0 license
        • Article
        • Peer Reviewed
        UC Irvine Previously Published Works (2011)

        Objectives

        Costal cartilage is becoming increasingly popular as a graft source for facial reconstruction. However, carving methods have not changed in decades and continue to primarily rely on detailed maneuvers with a scalpel. There are few reports of mechanical devices for shaping costal cartilage, and to our knowledge their accuracy and precision have not been reported. We describe a simple costal cartilage slicing device that facilitates the production of sections having uniform, user-defined thicknesses.

        Methods

        The design included laboratory research using 200 porcine and 2 cadaveric human ex vivo costal cartilage slices. A 2-component apparatus was constructed consisting of a mechanism to secure the costal cartilage and a double-bladed device to cut the rib graft through a central cross-section. Optimizing blade characteristics and static forces that secure the cartilage were critical design challenges. The device was used to obtain slices 0.8, 2.1, and 4.1 mm in thickness, with lengths up to 4.0 cm and a width of 1.0 cm. To confirm uniformity, thickness was measured at 8 fixed regions per section using a digital micrometer.

        Results

        All costal cartilage slices appeared to be extremely uniform on visual and manual inspection. The absolute difference between the largest and smallest thickness measured for each individual sample ranged from 0.04 to 0.13 mm, 0.06 to 0.14 mm, and 0.10 to 0.21 mm for the 0.8-, 2.1-, and 4.1-mm-thick groups, respectively.

        Conclusions

        Our study demonstrates the precision of using a mechanical slicing device to section costal cartilage to a clinically relevant and uniform thickness. This mechanized technology may increase accuracy and reduce carving time required for using costal cartilage tissue in head and neck reconstruction.
          Cover page: Practical Device for Precise Cutting of Costal Cartilage Grafts to Uniform ThicknessCreative Commons 'BY' version 4.0 license
          • Peer Reviewed
          UC Irvine Previously Published Works (2020)
          In this chapter, we introduce the working theory of cartilage reshaping and highlight landmark papers in the development and refinement of this technique. We discuss the tissue and mechanical properties of cartilage and define how optical techniques may be utilized to manipulate these properties. The goal of cartilage reshaping is to ultimately reduce the need for more invasive traditional approaches with scalpel and suture, in favor of much less invasive techniques. Therefore, we discuss the challenges associated with its development and delineate its translation toward clinical applications.
            Cover page: Cartilage ReshapingCreative Commons 'BY' version 4.0 license
            • Peer Reviewed
            UC Irvine Previously Published Works (2016)
            Optical coherence tomography (OCT) is a minimally invasive optical imaging modality which produces three-dimensional (3D) images of biological tissue. In the last 10 years, technological innovation and research in biophotonics have led to advancements in OCT-based diagnostic evaluation of head and neck anatomy and pathology. With near-histologic resolution of mucosal epithelial and subepithelial tissues, OCT has the potential for in vivo diagnosis of oral and pharyngeal lesions. This chapter focuses on OCT technology, research and clinical applications in anatomical imaging of the pharynx, and OCT-based diagnosis of benign and precancerous lesions of the oral cavity (OC) and pharynx.
              Cover page: Optical Coherence Tomography of the Oral Cavity and Pharynx: Normative Anatomy and Benign ProcessesCreative Commons 'BY' version 4.0 license
              • Thesis
              • Peer Reviewed
              UC Irvine Electronic Theses and Dissertations (2023)

              The transparent outer layer of the eye, known as the cornea, has a vital function inbending and directing light onto the retina, which is essential for achieving clear vision. Current methods of correcting refractive errors that are becoming increasingly popular include LASIK and PRK surgeries; however, these invasive techniques come with downsides as well such as permanent thinning of the cornea. This thesis proposes the use of a non-invasive technique called electromechanical reshaping (EMR) that can be applied to the cornea to induce curvature change. EMR was performed on New Zealand white rabbit globes using a concave platinum lens as the working electrode in a 3-electrode setup. The primary outcomes to be measured include the aforementioned curvature change of the cornea and the change in distribution of collagen orientation: to observe such changes the advanced imaging modalities of optical coherence tomography (OCT) and second harmonic generation (SHG) have been employed. The curvature data can be analyzed through a developed MATLAB approach that reconstructs the 3D surface of the cornea from 2D cross-sectional OCT images and sphere-fits the surface to extract the radius of curvature. The collagen structural change can be analyzed in FIJI software using OrientationJ to quantify the orientation of collagen fibers. These methods serve as a sound quantitative way to analyze the outcomes of EMR. This thesis found that the mean curvature increased from 5193.73 µm ± 597.09 µm to 5429.16 µm ± 736.08 µm following EMR application. Regarding collagen structural change, most of the eyes did not show a statistically significant difference following EMR application. Due to experimental error because of the lack of standardization of pressure, however, the corneal curvature did not consistently increase and the corneas did not resemble the radius of curvature of the platinum lens used in EMR (7.486 mm). Future directions include standardization of the pressure applied on the cornea by the platinum lens, simultaneous OCT imaging during EMR application, seeing if corneas post-EMR retain curvature changes, and transitioning to applying EMR on eyes intact in New Zealand white rabbit heads.

                Cover page: Ex Vivo Corneal Electromechanical Reshaping
                • Article
                • Peer Reviewed
                UC Irvine Previously Published Works (2024)
                  Cover page: Before and After Rhinoplasty Photography on Online PlatformsCreative Commons 'BY' version 4.0 license
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