While machine learning-based image restoration techniques have been the focus in recent years, these algorithms are not adequate to address the effects of a degraded visual environment. An algorithm that successfully mitigates these issues is proposed. The algorithm is built upon the state-of-the-art DeblurGAN algorithm but overcomes several of its deficiencies. The key contributions of the proposed techniques include: 1)Development of an effective framework to generate training datasets typical of a degraded visual environment; 2) Adopting a correntropy based loss function to integrate with the original VGG16 based perceptual loss function and an L1 loss function; 3) Conducting substantial experiments against images from the artificial training datasets and demonstrate the effectiveness of the proposed algorithm.
Light-Assisted Drying (LAD) is a novel biopreservation technique which allows proteins to be immobilized in a dry, amorphous solid at room temperature. Indicator proteins are used in a variety of diagnostic assays ranging from highthroughput 96-well plates to new microfluidic devices. A challenge in the development of protein-based assays is preserving the structure of the protein during production and storage of the assay, as the structure of the protein is responsible for its functional activity. Freeze-drying or freezing are currently the standard for the preservation of proteins, but these methods are expensive and can be challenging in some environments due to a lack of available infrastructure. An inexpensive, simple processing method that enables supra-zero temperature storage of proteins used in assays is needed. Light-assisted drying offers a relatively inexpensive method for drying samples. Proteins suspended in a trehalose solution are dehydrated using near-infrared laser light. The laser radiation speeds drying and as water is removed the sugar forms a protective matrix. In this set of studies we investigate the effect varying protein concentration and protein size on EMC. We also test the functionality of a model protein, lysozyme, after LAD processing compared to air drying, samples incubated at a temperature comparable to LAD, and a control solution kept at 8°C.
A light-based processing method to create an amorphous trehalose matrix for the stabilization of proteins is discussed. This method has potential applications in the stabilization of protein-based therapeutics and diagnostics. During light-assisted drying (LAD), proteins suspended in a trehalose solution are dehydrated using near-infrared (NIR) laser light. The goal of this study was to determine processing parameters that resulted in fast processing times and low end moisture contents (EMC), while maintaining the functionality of embedded proteins. We compared the effect of changing processing wavelength, power and resulting sample temperature, and substrate material on the EMC for two NIR laser sources (1064 and 1850 nm). The 1850-nm laser resulted in the lowest EMC (0.03 ± 0.01 gH2O / gDryWeight) after 20 min of processing on glass microfiber paper. This suggests a storage temperature of 68.3°C. We also tested the functionality of a model protein, lysozyme, after LAD processing using a standard assay. LAD showed no significant effect on the functionality of lysozyme when processed at a maximum temperature of ∼44 ° C to an EMC of 0.17 ± 0.06 gH2O / gDryWeight. LAD is a promising technique for forming amorphous trehalose solids that could stabilize proteins at ambient temperatures.
Light-Assisted Drying (LAD) is a novel biopreservation technique which allows proteins to be immobilized in a dry, amorphous solid at room temperature. Indicator proteins are used in a variety of diagnostic assays ranging from highthroughput 96-well plates to new microfluidic devices. A challenge in the development of protein-based assays is preserving the structure of the protein during production and storage of the assay, as the structure of the protein is responsible for its functional activity. Freeze-drying or freezing are currently the standard for the preservation of proteins, but these methods are expensive and can be challenging in some environments due to a lack of available infrastructure. An inexpensive, simple processing method that enables supra-zero temperature storage of proteins used in assays is needed. Light-assisted drying offers a relatively inexpensive method for drying samples. Proteins suspended in a trehalose solution are dehydrated using near-infrared laser light. The laser radiation speeds drying and as water is removed the sugar forms a protective matrix. The goal of this study is optically characterize samples processed with LAD. We use polarized light imaging (PLI) to look at crystallization kinetics of samples and determine optimal humidity. PLI shows a 62.5% chance of crystallization during LAD processing and negligible crystallization during low RH storage.
In this study, a novel light-based processing method to create an amorphous trehalose matrix for the stabilization of proteins is discussed. Near-IR radiation is used to remove water from samples, leaving behind an amorphous solid with embedded protein. This method has potential applications in the stabilization of protein-based therapeutics and diagnostics that are becoming widely used in the treatment and diagnosis of a variety of diseases. Freeze-drying or freezing are currently the standard for the preservation of proteins, but these methods are expensive and can be challenging in some environments due to a lack of available infrastructure. Light-assisted drying offers a relatively inexpensive method for drying samples. Proteins suspended in a trehalose solution are dehydrated using near-infrared laser light. The laser radiation speeds drying and as water is removed the sugar forms a protective matrix. The goal of this study is to determine processing parameters that result in fast processing times and low end moisture contents (EMC), while maintaining the functionality of embedded proteins. We compare the effect of changing processing wavelength, power and resulting sample temperature, and substrate material on the EMC for two NIR laser sources (1064 nm and 1850 nm). The 1850 nm laser resulted in the lowest EMC (0.1836±0.09 gH2O/gDryWeight) after 10 minutes of processing on borosilicate glass microfiber paper. This suggests a storage temperature of ~3°C.
Protein therapeutics have been developed to treat diseases ranging from arthritis and psoriasis to cancer. A challenge in the development of protein-based drugs is maintaining the protein in the folded state during processing and storage. We are developing a novel processing method, light-assisted drying (LAD), to dehydrate proteins suspended in a sugar (trehalose) solution for storage at supra-zero temperatures. Our technique selectively heats the water in small volume samples using near-IR light to speed dehydration which prevents sugar crystallization that can damage embedded proteins. In this study, we compare the end moisture content (EMC) as a function of processing time of samples dried with two different light sources, Nd:YAG (1064 nm) and Thulium fiber (1850 nm) lasers. EMC is the ratio of water to dry weight in a sample and the lower the EMC the higher the possible storage temperature. LAD with the 1064 and 1850 nm lasers yielded 78% and 65% lower EMC, respectively, than standard air-drying. After 40 minutes of LAD with 1064 and 1850 nm sources, EMCs of 0.27±.27 and 0.15±.05 gH2O/gDryWeight were reached, which are near the desired value of 0.10 gH2O/gDryWeight that enables storage in a glassy state without refrigeration. LAD is a promising new technique for the preparation of biologics for anhydrous preservation.
Lumpectomy coupled with radiation therapy and/or chemotherapy is commonly used to treat breast cancer patients. We are developing an enhanced thermal IR imaging technique that has the potential to provide real-time imaging to guide tissue excision during a lumpectomy by delineating tumor margins. This enhanced thermal imaging method is a combination of IR imaging (8 to 10 μm) and selective heating of blood (∼0.5°C) relative to surrounding water-rich tissue using LED sources at low powers. Postacquisition processing of these images highlights temporal changes in temperature and the presence of vascular structures. In this study, fluorescent, standard thermal, and enhanced thermal imaging modalities, as well as physical caliper measurements, were used to monitor breast cancer tumor volumes over a 30-day study period in 19 mice implanted with 4T1-RFP tumor cells. Tumor volumes calculated from fluorescent imaging follow an exponential growth curve for the first 22 days of the study. Cell necrosis affected the tumor volume estimates based on the fluorescent images after day 22. The tumor volumes estimated from enhanced thermal imaging, standard thermal imaging, and caliper measurements all show exponential growth over the entire study period. A strong correlation was found between tumor volumes estimated using fluorescent imaging, standard IR imaging, and caliper measurements with enhanced thermal imaging, indicating that enhanced thermal imaging monitors tumor growth. Further, the enhanced IR images reveal a corona of bright emission along the edges of the tumor masses associated with the tumor margin. In the future, this IR technique might be used to estimate tumor margins in real time during surgical procedures.
Lumpectomy coupled with radiation therapy and/or chemotherapy comprises the treatment of breast cancer for many patients. We are developing an enhanced thermal IR imaging technique that can be used in real-time to guide tissue excision during a lumpectomy. This novel enhanced thermal imaging method is a combination of IR imaging (8- 10 μm) and selective heating of blood (~0.5 °C) relative to surrounding water-rich tissue using LED sources at low powers. Post-acquisition processing of these images highlights temporal changes in temperature and is sensitive to the presence of vascular structures. In this study, fluorescent and enhanced thermal imaging modalities were used to estimate breast cancer tumor volumes as a function of time in 19 murine subjects over a 30-day study period. Tumor volumes calculated from fluorescent imaging follow an exponential growth curve for the first 22 days of the study. Cell necrosis affected the tumor volume estimates based on the fluorescent images after Day 22. The tumor volumes estimated from enhanced thermal imaging show exponential growth over the entire study period. A strong correlation was found between tumor volumes estimated using fluorescent imaging and the enhanced IR images, indicating that enhanced thermal imaging is capable monitoring tumor growth. Further, the enhanced IR images reveal a corona of bright emission along the edges of the tumor masses. This novel IR technique could be used to estimate tumor margins in real-time during surgical procedures.
In this study we test the feasibility of using low-cost LEDs to selectivity heat blood for enhanced thermal imaging of vascular structures. Applications of this new imaging technique include mapping blood vessels during surgeries such as tumor removal and vascular repair. In addition, this technique could potentially be used to determine the location of increased vascular density, and thus breast cancer tumors. Porcine blood, skeletal muscle, skin and fat were illuminated with LEDs that emit at 405 nm and 530 nm (near the blood absorption peaks) and the increase in temperature as a function of time was recorded using a thermal camera. In the studies with the 530 nm LED, blood heated more than other tissue types and the heating rate for the blood was significantly faster than other tissues. Illumination of blood with the 530 nm LED at low powers (tissue irradiance <500 mW/cm2) will selectively heat blood with no damage to surrounding tissue. Illumination with the 405 nm LED produced large temperature changes (up to 15°C) at low LED powers (tissue irradiance <500 mW/cm2). The heating and heating rates measured with this LED were higher than those measured for the 530nm LED. However, blood, skin and fat showed comparable amounts of heating and heating rates. The amount of heating in muscle tissue was dependent on the skeletal muscle type, but most samples showed heating comparable to or larger than blood. This LED was not effective at selectively heating blood relative to the other tissue types. The results of the preliminary studies suggest that the best contrast can be achieved with pulsed 530 nm LED illumination and an image analysis method that highlights rapid changes in temperature.
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