159 research outputs found
High-resolution spatial light modulation for holographic video
Thesis (S.M.)--Massachusetts Institute of Technology, School of Architecture and Planning, Program in Media Arts and Sciences, 2008.Vita.Includes bibliographical references (p. 87-89).The goal of the proposed research is to further the fabrication of a high-bandwidth two-axis scanning device. The device is intended for use in a holographic video geometry built specifically to take advantage of the new modulator's high-bandwidth and vertical-deflection capabilities, but it could also be used in many developing 3D display systems which currently require high-bandwidth light modulation. The modulator will have a spatial frequency bandwidth one order-of-magnitude greater than current light modulation technologies and be two orders of magnitude less expensive.by Daniel E. Smalley.S.M
Integrated optics for holographic video
Thesis (M. Eng.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2006.Includes bibliographical references (leaves 83-85).The goal of this research is to fabricate a guided-wave, two-axis scanner and to modify the design of the MIT holovideo system to take full advantage of the scanner's high bandwidth and two-dimensional deflection. The new display geometry will be designed to use the guided-wave scanner coupled with a holographic optical element to perform a solid-state horizontal de-scan. The development of the guided-wave scanner and the improvements made to the holovideo geometry, will enable the construction of a third generation holovideo display that is higher bandwidth, more solid-state and at least an order of magnitude less expensive than previous generations.by Daniel E. Smalley.M.Eng
Novel Materials Containing Single-Wall Carbon Nanotubes Wrapped in Polymer Molecules
In this design, single-wall carbon nanotubes (SWNTs) have been coated in polymer molecules to create a new type of material that has low electrical conductivity, but still contains individual nanotubes, and small ropes of individual nanotubes, which are themselves good electrical conductors and serve as small conducting rods immersed in an electrically insulating matrix. The polymer is attached through weak chemical forces that are primarily non-covalent in nature, caused primarily through polarization rather than the sharing of valence electrons. Therefore, the electronic structure of the SWNT involved is substantially the same as that of free, individual (and small ropes of) SWNT. Their high conductivity makes the individual nanotubes extremely electrically polarizable, and materials containing these individual, highly polarizable molecules exhibit novel electrical properties including a high dielectric constant
Progress in off-plane computer-generated waveguide holography for near-to-eye 3D display
Waveguide holography refers to the use of holographic techniques for the control of guided-wave light in integrated optical devices (e.g., off-plane grating couplers and in-plane distributed Bragg gratings for guided-wave optical filtering). Off-plane computer-generated waveguide holography (CGWH) has also been employed in the generation of simple field distributions for image display. We have previously depicted the design and fabrication of a binary-phase CGWH operating in the Raman-Nath regime for the purposes of near-to-eye 3-D display and as a precursor to a dynamic, transparent flat-panel guided-wave holographic video display. In this paper, we describe design algorithms and fabrication techniques for multilevel phase CGWHs for near-to-eye 3-D display
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Cellular response to collagen-elastin composite materials.
Collagen is used extensively in tissue engineering due to its biocompatibility, near-universal tissue distribution, low cost and purity. However, native tissues are composites that include diverse extracellular matrix components, which influence strongly their mechanical and biological properties. Here, we provide important new findings on the differential regulation, by collagen and elastin, of the bio-response to the composite material. Soluble and insoluble elastin had differing effects on the stiffness and failure strength of the composite films. We established that Rugli cells bind elastin via EDTA-sensitive receptors, whilst HT1080 cells do not. These cells allowed us to probe the contribution of collagen alone (HT1080) and collagen plus elastin (Rugli) to the cellular response. In the presence of elastin, Rugli cell attachment, spreading and proliferation increased, presumably through elastin-binding receptors. By comparison, the attachment and spreading of HT1080 cells was modified by elastin inclusion, but without affecting their proliferation, indicating indirect modulation by elastin of the response of cells to collagen. These new insights highlight that access to elastin dominates the cellular response when elastin-binding receptors are present. In the absence of these receptors, modification of the collagen component and/or physical properties dictate the cellular response. Therefore, we can attribute the contribution of each constituent on the ultimate bioactivity of heterogeneous collagen-composite materials, permitting informed, systematic biomaterials design. Statement of Significance In recent years there has been a desire to replicate the complex extracellular matrix composition of tissues more closely, necessitating the need for composite protein-based materials. In this case both the physical and biochemical properties are altered with the addition of each component, with potential consequences on the cell. To date, the different contributions of each component have not been deconvolved, and instead the cell response to the scaffold as a whole has been observed. Instead, here, we have used specific cell lines, that are sensitive to specific components of an elastin-collagen composite, to resolve the bio-activity of each protein. This has shown that elastin-induced alteration of the collagen component can modulate early stage cell behaviour. By comparison the elastin component directly alters the cell response over the short and long term, but only where appropriate receptors are present on the cell. Due to the widespread use of collagen and elastin, we feel that this data permits, for the first time, the ability to systematically design collagen-composite materials to promote desired cell behaviour with associated advantages for biomaterials fabrication.This work was supported by the ERC Advanced Grant 320598 3D-E, EPSRC fellowship EP/N019938/1, and British Heart Foundation Special ProjectSP/15/7/31561 D. V. Bax was funded by the Peoples Programme of the EU 7th Framework Programme (RAE no: PIIF-GA-2013-624904)
The future of mammary stem cell biology: the power of in vivo transplants
The recent review by Smith and Medina [1] of in vivo transplantation models and their role in investigating mammary stem cell (MaSC) biology provides comprehensive coverage of the history and complexity of the ‘gold standard ’ MaSC assay in mice. This includes a description of the pioneering studies that showed that mammary epithelial outgrowths can be generated in cleared mammary fat pads transplanted with explants or admixtures of mammary cells [2]. However, this approach clearly does not lend itself to prospective analysis of isolated subpopulations in order to identify which cells possess in vivo regenerative activity. More recently, success in obtaining complex mammary gland structures from transplanted suspensions of single cells has now made this possible [3-7]. Moreover, the regenerated structures have been shown to contain daughter cells with the same in viv
High-frequency A-type pulsators discovered using SuperWASP
We present the results of a survey using the WASP archive to search for high-frequency pulsations in F-, A- and B-type stars. Over 1.5 million targets have been searched for pulsations with amplitudes greater than 0.5 millimagnitude. We identify over 350 stars which pulsate with periods less than 30 min. Spectroscopic follow-up of selected targets has enabled us to confirm 10 new rapidly oscillating Ap stars, 13 pulsating Am stars and the fastest known δ Scuti star. We also observe stars which show pulsations in both the high-frequency domain and the low-frequency δ Scuti range. This work shows the power of the WASP photometric survey to find variable stars with amplitudes well below the nominal photometric precision per observation
Approaches and challenges to the study of loess—Introduction to the LoessFest Special Issue
In September 2016, the annual meeting of the International Union for Quaternary Research's Loess and Pedostratigraphy Focus Group, traditionally referred to as a LoessFest, met in Eau Claire, Wisconsin, USA. The 2016 LoessFest focused on thin loess deposits and loess transportation surfaces. This LoessFest included 75 registered participants from 10 countries. Almost half of the participants were from outside the United States, and 18 of the participants were students. This review is the introduction to the special issue for Quaternary Research that originated from presentations and discussions at the 2016 LoessFest. This introduction highlights current understanding and ongoing work on loess in various regions of the world and provides brief summaries of some of the current approaches/strategies used to study loess deposits
Minimum Technical Data Elements for Liquid Biopsy Data Submitted to Public Databases
Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/154656/1/cpt1747.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/154656/2/cpt1747-sup-0001-FigS1.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/154656/3/cpt1747_am.pd
Clinical Efficacy and Safety of Bevacizumab Monotherapy in Patients with Metastatic Melanoma: Predictive Importance of Induced Early Hypertension
Background: VEGF driven angiogenesis plays a key role in cancer progression. We determined the clinical efficacy of bevacizumab monotherapy in patients with metastatic melanoma. Methods and Findings: Thirty-five patients with metastatic melanoma in progression were enrolled in this phase II, single arm clinical trial. Each patient received bevacizumab monotherapy 10 mg/kg q14 d until intolerable toxicity or disease progression occurred. Clinical efficacy was evaluated as objective response, disease control (DC), and survival. We observed one complete (3%) and 5 partial (14%) responses. In addition, 5 patients experienced stable disease >6 months (14%) while 24 patients had progressive disease (PD, 69%), corresponding to a total DC at 6 months in 11 out of 35 patients (31%). Median progression free survival (PFS) was 2.14 months and median overall survival (OS) was 9 months (1.12–49). Seven of the 11 patients experiencing DC developed early hypertension (<2 months) compared to 3/24 of patients with PD (P = 0.001), and hypertension was associated with PFS (P = 0.005) and OS (P = 0.013). Conclusion: Bevacizumab monotherapy demonstrated promising clinical efficacy in patients with metastatic melanoma with disease control in 31% of the patients. Induced early hypertension was a marker for clinical efficacy of bevacizumab
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