Matching Items (4)

Filtering by

Clear all filters

132526-Thumbnail Image.png

Time-Lapse Visualization of Microglia Cell Processes using Fluorescent Miniature (Miniscope) Imaging

Description

In the United States, an estimated 2 million cases of traumatic brain injury (TBI) resulting in more than 50,000 deaths occur every year. TBI induces an immediate primary injury resulting in local or diffuse cell death in the brain. Then

In the United States, an estimated 2 million cases of traumatic brain injury (TBI) resulting in more than 50,000 deaths occur every year. TBI induces an immediate primary injury resulting in local or diffuse cell death in the brain. Then a secondary injury occurs through neuroinflammation from immune cells in response to primary injury. Microglia, the resident immune cell of the central nervous system, play a critical role in neuroinflammation following TBI. Microglia make up 10% of all cells in the nervous system and are the fastest moving cells in the brain, scanning the entire parenchyma every several hours. Microglia have roles in both the healthy and injured brain. In the healthy brain, microglia can produce neuroprotective factors, clear cellular debris, and organize neurorestorative processes to recover from TBI. However, microglia mediated neuroinflammation during secondary injury produces pro-inflammatory and cytotoxic mediators contributing to neuronal dysfunction, inhibition of CNS repair, and cell death. Furthermore, neuroinflammation is a prominent feature in many neurodegenerative diseases such as Alzheimer’s, and Parkinson’s disease, of which include overactive microglia function. Microglia cell morphology, activation, and response to TBI is poorly understood. Currently, imaging microglia can only be performed while the animal is stationary and under anesthesia. The Miniscope technology allows for real-time visualization of microglia in awake behaving animals. The Miniscope is a miniature fluorescent microscope that can be implanted over a craniectomy to image microglia. Currently, the goals of Miniscope imaging are to improve image quality and develop time-lapse imaging capabilities. There were five main sub-projects that focused on these goals including surgical nose cone design, surgical holder design, improved GRIN lens setup, improved magnification through achromatic lenses, and time-lapse imaging hardware development. Completing these goals would allow for the visualization of microglia function in the healthy and injured brain, elucidating important immune functions that could provide new strategies for treating brain diseases.

Contributors

Agent

Created

Date Created
2019-05

133517-Thumbnail Image.png

Image Analysis for Registration, Segmentation, and Intensity Measurement of 2-Photon Microscope Images using MATLAB

Description

Traumatic brain injury (TBI) is a major concern in public health due to its prevalence and effect. Every year, about 1.7 million TBIs are reported [7]. According to the According to the Centers for Disease Control and Prevention (CDC), 5.5%

Traumatic brain injury (TBI) is a major concern in public health due to its prevalence and effect. Every year, about 1.7 million TBIs are reported [7]. According to the According to the Centers for Disease Control and Prevention (CDC), 5.5% of all emergency department visits, hospitalizations, and deaths from 2002 to 2006 are due to TBI [8]. The brain's natural defense, the Blood Brain Barrier (BBB), prevents the entry of most substances into the brain through the blood stream, including medicines administered to treat TBI [11]. TBI may cause the breakdown of the BBB, and may result in increased permeability, providing an opportunity for NPs to enter the brain [3,4]. Dr. Stabenfeldt's lab has previously established that intravenously injected nanoparticles (NP) will accumulate near the injury site after focal brain injury [4]. The current project focuses on confirmation of the accumulation or extravasation of NPs after brain injury using 2-photon microscopy. Specifically, the project used controlled cortical impact injury induced mice models that were intravenously injected with 40nm NPs post-injury. The MATLAB code seeks to analyze the brain images through registration, segmentation, and intensity measurement and evaluate if fluorescent NPs will accumulate in the extravascular tissue of injured mice models. The code was developed with 2D bicubic interpolation, subpixel image registration, drawn dimension segmentation and fixed dimension segmentation, and dynamic image analysis. A statistical difference was found between the extravascular tissue of injured and uninjured mouse models. This statistical difference proves that the NPs do extravasate through the permeable cranial blood vessels in injured cranial tissue.

Contributors

Agent

Created

Date Created
2018-05

137469-Thumbnail Image.png

Novel siloxane nanoprobes for molecular and cellular imagin

Description

Oxygen delivery is crucial for the development of healthy, functional tissue. Low tissue oxygenation, or hypoxia, is a characteristic that is common in many tumors. Hypoxia contributes to tumor malignancy and can reduce the success of chemotherapy and radiation treatment.

Oxygen delivery is crucial for the development of healthy, functional tissue. Low tissue oxygenation, or hypoxia, is a characteristic that is common in many tumors. Hypoxia contributes to tumor malignancy and can reduce the success of chemotherapy and radiation treatment. There is a current need to noninvasively measure tumor oxygenation or pO2 in patients to determine a personalized treatment method. This project focuses on creating and characterizing nanoemulsions using a pO2 reporter molecule hexamethyldisiloxane (HMDSO) and its longer chain variants as well as assessing their cytotoxicity. We also explored creating multi-modal (MRI/Fluorescence) nanoemulsions.

Contributors

Agent

Created

Date Created
2013-05

157900-Thumbnail Image.png

A Low Cost, High Dynamic Range, Versatile Digital Readout Integrated Circuit Unit Cell Prototype for Infrared Imaging Applications

Description

Readout Integrated Circuits(ROICs) are important components of infrared(IR) imag

ing systems. Performance of ROICs affect the quality of images obtained from IR

imaging systems. Contemporary infrared imaging applications demand ROICs that

can support large dynamic range, high frame rate, high output data rate,

Readout Integrated Circuits(ROICs) are important components of infrared(IR) imag

ing systems. Performance of ROICs affect the quality of images obtained from IR

imaging systems. Contemporary infrared imaging applications demand ROICs that

can support large dynamic range, high frame rate, high output data rate, at low

cost, size and power. Some of these applications are military surveillance, remote

sensing in space and earth science missions and medical diagnosis. This work focuses

on developing a ROIC unit cell prototype for National Aeronautics and Space Ad

ministration(NASA), Jet Propulsion Laboratory’s(JPL’s) space applications. These

space applications also demand high sensitivity, longer integration times(large well

capacity), wide operating temperature range, wide input current range and immunity

to radiation events such as Single Event Latchup(SEL).

This work proposes a digital ROIC(DROIC) unit cell prototype of 30ux30u size,

to be used mainly with NASA JPL’s High Operating Temperature Barrier Infrared

Detectors(HOT BIRDs). Current state of the art DROICs achieve a dynamic range

of 16 bits using advanced 65-90nm CMOS processes which adds a lot of cost overhead.

The DROIC pixel proposed in this work uses a low cost 180nm CMOS process and

supports a dynamic range of 20 bits operating at a low frame rate of 100 frames per

second(fps), and a dynamic range of 12 bits operating at a high frame rate of 5kfps.

The total electron well capacity of this DROIC pixel is 1.27 billion electrons, enabling

integration times as long as 10ms, to achieve better dynamic range. The DROIC unit

cell uses an in-pixel 12-bit coarse ADC and an external 8-bit DAC based fine ADC.

The proposed DROIC uses layout techniques that make it immune to radiation up to

300krad(Si) of total ionizing dose(TID) and single event latch-up(SEL). It also has a

wide input current range from 10pA to 1uA and supports detectors operating from

Short-wave infrared (SWIR) to longwave infrared (LWIR) regions.

Contributors

Agent

Created

Date Created
2019