1. Kyle Nadeau
  2. http://www.igert.org/profiles/5368
  3. Graduate Student
  4. Presenter’s IGERT
  5. University of California at Irvine
  1. Julie Hsu
  2. http://www.igert.org/profiles/5340
  3. Graduate Student
  4. Presenter’s IGERT
  5. University of California at Irvine
  1. Joe Jing
  2. http://www.igert.org/profiles/5378
  3. Graduate Student
  4. Presenter’s IGERT
  5. University of California at Irvine
  1. Joanna Laird
  2. http://www.igert.org/profiles/5342
  3. Graduate Student
  4. Presenter’s IGERT
  5. University of California at Irvine
  1. Justin Luo
  2. http://www.igert.org/profiles/5407
  3. Graduate Student
  4. Presenter’s IGERT
  5. University of California at Irvine

Judges’ Queries and Presenter’s Replies

  • Icon for: Jon Kellar

    Jon Kellar

    Judge
    May 20, 2013 | 11:58 a.m.

    What is the mechanism by which HUVECs release Ca++ from the endoplasmic reticulum?

  • Icon for: Justin Luo

    Justin Luo

    Co-Presenter
    May 20, 2013 | 02:47 p.m.

    Hello Professor Kellar,

    The cavitation bubble will expose HUVECs to mechanical deformation and stimulate G-protein coupled receptors on the cell membrane. Stimulation of the G-protein coupled receptor will lead to production of inositol triphosphate (IP3). IP3 is produced from the protein phospholipase C (PLC) cleaving phosphatidylinositol 4,5-biphosphate (PIP2). IP3 diffuses and binds to the IP3 receptor on the endoplasmic reticulum surface which then induces Ca++ release.

    Thank you for your question.

    Sincerely,
    Justin

  • Icon for: Marc Porter

    Marc Porter

    Judge
    May 20, 2013 | 12:43 p.m.

    What is the specific structure-function relationship(s)you are attempting to examine the cornea project? That is, what are the minor changes (not clear what you mean by “arrangement”) in the corneal lamella you are attempting to connect to cornea function?

  • Icon for: Julie Hsu

    Julie Hsu

    Co-Presenter
    May 21, 2013 | 09:09 a.m.

    Hello Dr. Porter,
    Structurally, type I collagen is known to be composed of fibrils which align in a parallel or antiparallel fashion to produce collagen fibers and lamellae. It has been observed through methods such as electron microscopy and second harmonic generation how the collagen lamellae orient themselves in three-dimensional space within the cornea, forming layers which run in different directions depending on the region within the cornea. Fibers of one lamella may interweave with adjacent lamellae, forming a pattern that is believed to provide structural support for the cornea as well as functional importance. However, although methods such as these can image the physical orientation of lamellae and the fibers within them, they are unable to provide information on the polarity of the molecules. Therefore, one can not distinguish between parallel and antiparallel fibers within lamellae. The sum frequency generation microscope that we use has the capability to resolve these structural questions through implementation of an interferometric setup providing phase-sensitive detection and enabling polarization studies. It is of interest to us whether more understanding of how the cornea functions can be obtained from studying the polarity orientations of fibers within lamellae, particularly those that participate in interweaving.
    Thank you for your question.
    Sincerely,
    Julie

  • May 20, 2013 | 03:49 p.m.

    For any of the five presenters…or all…how would this approach apply to a study of the various heart-related illnesses?

  • Icon for: Joe Jing

    Joe Jing

    Co-Presenter
    May 21, 2013 | 05:10 a.m.

    Hello Dr. Ludwick,

    Cardiovascular studies are a very popular field within biophotonics. Fiber optic technologies allow for the delivery of light to many locations including the heart. Our group is actually actively studying cardiovascular plaques using Optical Coherence Tomography. We have built miniature fiber probes that can be inserted from the femoral artery and guided to lesions of interest for precise imaging. We can then measure different properties such as the elastic properties and wall thickness to better assess possibly plaque rupture. Multiphoton imaging can further improve upon these diagnostics as well by specifically targeting for molecular contrast such as lipids which form the interior of plaques. With these techniques, we can asses plaques at far higher resolutions and with higher specificity than compared to current techniques such as intravascular ultrasound.

    Thank you for your question,

    Joe

  • May 21, 2013 | 10:08 a.m.

    Are there potential applications for the IRI technology for stroke, either for basic research or clinical applications?

  • Icon for: Kyle Nadeau

    Kyle Nadeau

    Presenter
    May 21, 2013 | 01:09 p.m.

    Hi Dr. Gannett,
    Thanks for your question. We are in fact interested in monitoring stroke using our technology, and have published work pertaining to a preclinical rat model for stroke. Since most strokes are a result of ischemia, we can monitor this process in a similar fashion to how we monitor IRI shown in our presentation. In our stroke model, we perform an open vascular occlusion on the middle cerebral artery. Using SFDI, we can monitor light absorption and scattering in the rat brain. By interrogating the brain at several wavelengths of light, we are able to derive values for oxy/deoxy hemoglobin, from which we can quantify oxygen saturation, and thus tissue metabolism. In a similar manner to our kidney IRI study, we can also use light scattering changes to infer micro-scale changes such as cellular swelling and tissue edema.
    Sincerely,
    Kyle Nadeau

  • Icon for: Antal Jakli

    Antal Jakli

    Judge
    May 22, 2013 | 09:35 p.m.

    Can you explain how non-centrosymmetry leads to a sum-frequency generation?

  • Icon for: Julie Hsu

    Julie Hsu

    Co-Presenter
    May 23, 2013 | 06:24 p.m.

    Hi Dr. Jakli,
    When a sample is driven by waves of frequency w1 and w2, the molecules in the sample act like anharmonic oscillators, producing oscillations at frequency w1+w2. The induced dipole can be expressed as P(w1+w2)=X*E(w1)E(w2), X being the nonlinear susceptibility. For a centrosymmetric sample that has inversion symmetry, if the sample were driven by -E(w1) and -E(w2) instead, the induced dipole should be -P(w1+w2). However, the equation shows us that X-E(w1)*-E(w2) still produces P(w1+w2). In order for this to be true, X must be zero. Therefore, the sum frequency generation only exists for samples with non-centrosymmetry.
    Thank you for your question.
    Sincerely,
    Julie

  • Further posting is closed as the competition has ended.

Presentation Discussion
  • Icon for: Brian Drayton

    Brian Drayton

    Faculty
    May 23, 2013 | 11:30 p.m.

    I found your video interesting — beyond the specifics, all of which were new to me, what came across was a pretty dynamic and creative lab!

  • Icon for: Joanna Laird

    Joanna Laird

    Co-Presenter
    May 24, 2013 | 02:11 a.m.

    Thank you! We had a lot of fun putting it together and sharing our love for imaging technologies.

  • Further posting is closed as the competition has ended.