New anti-cancer drugs are constantly being developed and tested. Effectiveness of these drugs is currently assessed by measuring the reduction in number of cancer cells cultured in experiments as a function of the applied drug dose. These measurements determine the drug dose needed to achieve half of the maximum reduction in cells (IC50) and the maximum effect of the drug (εmax). However, the technique that measures values of IC50 and εmax depends on the time chosen to make the measurements. We have developed a method to analyze the growth of cancer cells in different concentrations of drugs that will provide estimates of both parameters that are independent of measurement time. Here, we computationally simulated the growth of cancer cells according to a logarithmic model, adding different levels of noise. And, we found the error in IC50 and εmax as a function of the level of noise. Development of this new technique will lead to more consistent measurement of the efficacy of known and novel anti-cancer therapies.

High-power laser excitation systems are critical in observing and studying nanomaterials and their optoelectronic properties on a single specie level. These systems enable inducing fluorescence and observing emission microscopically from individual flakes and or molecules. As the fluorescence of nanomaterials is often excitation dependent, multiple laser with different frequencies are needed to probe their optical properties. In this work we construct such multi-laser setup to use for a microscopy system to enable imaging nanocarbons: flakes of functional derivatives of graphene, carbon nanotubes, and graphene quantum dots.
The system is composed of four lasers of varying wavelength: blue at 450 nm, green at 532 nm, red at 637 nm, and near-infrared (NIR) at 808 nm. An additional near-infrared laser at 980 nm is included for special applications with deep NIR imaging. These lasers were set up to be turned on and off remotely and traverse through a system of dichroic and regular mirrors and a periscope coupled to a fluorescence microscope. A neutral density filter wheel designed and set up in the light path enables altering the intensity of the lasers leading to optimized fluorescence and imaging. The resulting laser set up allowed effective imaging of graphene oxide flakes, graphene quantum dots, and carbon nanotubes both on a microscope slide and in biological cells and tissues.

The goal of this project was to engineer complexes of antibiotics and nanomaterials that address gram negative bacteria more efficiently than antibiotics alone. The gram-negative class of bacteria has two cell membranes, as opposed to the gram-positive class which has only one; this second membrane poses an additional challenge for antibiotic cell entry. Theoretically, the amphiphilic nanomaterials may aid the antibiotics by assisting them through both membranes and masking their entry. A number of nanomaterials were tested including graphene quantum dots, single-walled carbon nanotubes, and graphene oxide, and antibiotics including Penicillin, Methicillin, Amoxicillin, Norfloxacin and Linezolid were tested as well. Carbon nanotubes were supplemented with polyethylene-glycol coating agent, while water-soluble GQDs and graphene oxide were used as synthesized in our laboratory. The complex of the antibiotic Norfloxacin and Graphene Quantum Dots (GQDs) was selected as the most efficacious. It allowed killing of the gram-negative bacteria E. Coli at moderate concentrations significantly more efficiently than unaccompanied Norfloxacin. Its colocalization with bacteria was verified via high quantum yield (over 62%) intrinsic fluorescence of GQDs in the visible. This may lead to substantial improvement of antibacterial techniques against gram negative bacteria, increase in antibiotic efficacy, and potentially the recycling of antibiotics to which bacteria exhibit resistance.

Terror management theory is a theory that proposes mortality salience, or the awareness of the inevitability of death, is a motivating factor for maintaining faith in cultural worldviews and personal growth in value and self-esteem. Following mortality salience, people are more likely to interact with others and express satisfaction in relationships. Meaning in life (MIL) research is interested in examining the purpose and significance one feels in relation to their personal lives. Research has found that high MIL is associated with increased feelings of social connectedness and sense of belonging. (Baumeister & Vohs, 2002) The present research examined the link between mortality concerns, relationship MIL, and satisfaction/commitment within people’s romantic partners. In the research 369 participants ranging from ages 17-43 were asked to complete a lexical decision task that could be filled with death or neutral related words. Participants also completed a 5- item measure of relationship-specific MIL. Finally, participants completed a measure recording their relationship satisfaction. It was hypothesized that increased death awareness would lead to greater pursuit in MIL in people’s relationship with their romantic partner. The results showed that people with elevated DTA also have higher scores on relationship specific meaning in life. That is, higher DTA was related to greater search for meaning from relationships. This, in turn, was related to increased relationship satisfaction and commitment scores.

From the perspective of terror management theory, reminders of death are problematic because they lead individuals to defend their cultural beliefs. Given that police officers are trained to see persons and situations as potentially dangerous (i.e., naturally occurring mortality salience), this may result in greater acceptance of the use of force. The current study examined police officers’ reactions to arrest vignettes and fear of death. Results suggest that increased death awareness predicted greater use of unnecessary force. These effects held while controlling for several individual differences that have previously been shown to influence use of force. These findings suggests that death concerns play an important role in how police officers respond to crime.