Publications by authors named "Samana Shrestha"

Gold nanoparticles are a potential method for enhancing radiation therapy, causing extra damage to tumors when irradiated through the Auger effect. One of the major obstacles to using gold nanoparticles in human trials is the relatively large amount of gold required. This paper details an experiment where a relatively small amount of gold (200 g) was used to significantly reduce tumor volume in mice, as well as the results of an inter-tissue biodistribution experiment.

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Photodynamic therapy (PDT), a treatment that uses a photosensitizer, molecular oxygen, and light to kill target cells, is a promising cancer treatment method. However, a limitation of PDT is its dependence on light that is not highly penetrating, precluding the treatment of tumors located deep in the body. Copper-cysteamine nanoparticles are a new type of photosensitizer that can generate cytotoxic singlet oxygen molecules upon activation by X-rays.

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Idiopathic pulmonary fibrosis (IPF) is a fatal disease that destroys the structure and function of the lungs. Risk factors include advanced age and genetic predisposition. However, tobacco use is the chief modifiable risk factor.

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Biological indicators would be of use in radiation dosimetry in situations where an exposed person is not wearing a dosimeter, or when physical dosimeters are insufficient to estimate the risk caused by the radiation exposure. In this work, we investigate the use of gene expression as a dosimeter. Gene expression analysis was done on 15,222 genes of Drosophila melanogaster (fruit flies) at days 2, 10, and 20 postirradiation, with X-ray exposures of 10, 1000, 5000, 10,000, and 20,000 roentgens.

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People often have erroneous intuitions about the results of uncertain processes, such as scientific experiments. Many uncertainty visualizations assume considerable statistical knowledge, but have been shown to prompt erroneous conclusions even when users possess this knowledge. Active learning approaches been shown to improve statistical reasoning, but are rarely applied in visualizing uncertainty in scientific reports.

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Enhancing the effect of radiation on tumors would be a significant improvement in radiation therapy. With radiation enhancement, less radiation could be used to achieve the same goals, lessening damage to healthy tissue and lessening side effects. Gold nanoparticles are a promising method for achieving this enhancement, particularly when the gold nanoparticles are targeted to cancer.

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Previous research has shown that gold nanoparticles can increase the effectiveness of radiation on cancer cells. Improved radiation effectiveness would allow lower radiation doses given to patients, reducing adverse effects; alternatively, it would provide more cancer killing at current radiation doses. Damage from radiation and gold nanoparticles depends in part on the Auger effect, which is very localized; thus, it is important to place the gold nanoparticles on or in the cancer cells.

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