Ab initio studies of counterion effects in molecular quantum-dot cellular automata.

Molecular quantum-dot cellular automata (QCA) is a low-power computing paradigm that may offer ultra-high device densities and THz-speed switching at room temperature. A single mixed-valence (MV) molecule acts as an elementary QCA device known as a cell. Cells coupled locally via the electrostatic field form logic circuits. However, previously-synthesized ionic MV molecular cells are affected by randomly-located, nearby neutralizing counterions that can bias device states or change device characteristics, causing incorrect computational results. This ab initio study explores how non-biasing counterions affect individual molecular cells. Additionally, we model two novel neutral, zwitterionic MV QCA molecules designed to avoid biasing and other undesirable counterionic effects. The location of the neutralizing counterion is controlled by integrating one counterion into each cell at a well-defined, non-biasing location. Each zwitterionic QCA candidate molecule presented here has a fixed, integrated counterion, which neutralizes the mobile charges used to encode the device state.

Pivot to prevent bowel cancer: Reflections on adapting an Aboriginal bowel cancer screening awareness program to a digital call to action-A commentary.

ISSUE ADDRESSED: The Sydney Local Health District (SLHD) Health Promotion Unit was awarded a Cancer Institute NSW grant to raise awareness of bowel cancer and promote the National Bowel Cancer Screening Program (NBCSP) among Aboriginal communities in SLHD. The COVID-19 pandemic thwarted initial plans for face-to-face workshops and plans pivoted to digital products and dissemination of messages on a range of communication platforms. DISCUSSION: The coronavirus (COVID-19) pandemic provided staff with the freedom, flexibility, and ability to be creative in ways not possible prior to the pandemic and ultimately ended up with a superior product with a reach further than anticipated. A more comprehensive suite of digital resources addressing barriers to bowel cancer screening in the Aboriginal community was produced that is able to be used more broadly. These resources have reached a much larger population group through websites, social media, as well as TV and radio advertisements, and have the potential to be used and adapted in other local health districts and states across Australia. CONCLUSION: Adapting an Aboriginal bowel cancer screening awareness program to a digital platform is a promising approach. SO WHAT?: COVID-19 provided an opportunity to create new long-lasting partnerships and to be creative beyond the scope of the original grant. This in turn produced a product with a reach further than anticipated that can also be built on and sustained.

Clinical evaluation of the potential utility of computational modeling as an HIV treatment selection tool by physicians with considerable HIV experience.

The HIV Resistance Response Database Initiative (RDI), which comprises a small research team in the United Kingdom and collaborating clinical centers in more than 15 countries, has used antiretroviral treatment and response data from thousands of patients around the world to develop computational models that are highly predictive of virologic response. The potential utility of such models as a tool for assisting treatment selection was assessed in two clinical pilot studies: a prospective study in Canada and Italy, which was terminated early because of the availability of new drugs not covered by the system, and a retrospective study in the United States. For these studies, a Web-based user interface was constructed to provide access to the models. Participating physicians entered baseline data for cases of treatment failure and then registered their treatment intention. They then received a report listing the five alternative regimens that the models predicted would be most effective plus their own selection, ranked in order of predicted virologic response. The physicians then entered their final treatment decision. Twenty-three physicians entered 114 cases (75 unique cases with 39 entered twice by different physicians). Overall, 33% of treatment decisions were changed following review of the report. The final treatment decisions and the best of the RDI alternatives were predicted to produce greater virologic responses and involve fewer drugs than the original selections. Most physicians found the system easy to use and understand. All but one indicated they would use the system if it were available, particularly for highly treatment-experienced cases with challenging resistance profiles. Despite limitations, the first clinical evaluation of this approach by physicians with substantial HIV-experience suggests that it has the potential to deliver clinical and economic benefits.