Background Despite more aggressive screening across all demographics and gradual declines in mortality related to prostate cancer (PCa) in the United States, disparities among populations persist. A substantial proportion of African American men (AAM) have a higher overall incidence, earlier age of onset, increased proportion of clinically advanced disease, and increased bone metastases and mortality from PCa compared to European American men (EAM). Limited early evidence indicates that underlying causes for disparities may be observed in tumor-specific gene expression programs. Methods This study used microarray-based methods to measure expression levels for 517 genes that were previously associated with PCa in archived formalin-fixed paraffin embedded (FFPE) specimens; testing the hypothesis that gene expression features of functional consequence to cancer distinguish PCa from AAM and EAM. A t test was conducted comparing AAM to EAM expression levels for each probe on the array. Results Analysis of 639 tumor samples (270 AAM, 369 EAM) showed that 95 genes were overexpressed specifically in PCa from AAM relative to EAM and 132 were overexpressed in PCa from EAM relative to AAM. Furthermore, systems-level analyses highlight the relevant signaling pathways and functions associated with the EAM- or AAM-specific overexpressed gene sets, for example, inflammation and lipid metabolism. Conclusions Results here bring further understanding to the potential for molecular differences for PCa in AAM versus EAM. Impact The results support the notion that therapeutic benefits will be realized when targeted treatments are designed to acknowledge and address a greater spectrum of PCa subtypes and molecular distinctions.

Electrical operation of room-temperature (RT) single dopant atom quantum dot (QD) transistors, based on phosphorous atoms isolated within nanoscale SiO2 tunnel barriers, is presented. In contrast to single dopant transistors in silicon, where the QD potential well is shallow and device operation limited to cryogenic temperature, here, a deep (~2 eV) potential well allows electron confinement at RT. Our transistors use ~10 nm size scale Si/SiO2/Si pointcontact tunnel junctions, defined by scanning probe lithography and geometric oxidation.'Coulomb diamond' charge stability plots are measured at 290 K, with QD addition energy ~0.3 eV. Theoretical simulation gives a QD size of similar order to the phosphorous atom separation ~2 nm. Extraction of energy states predicts an anharmonic QD potential, fitted using a Morse oscillator-like potential. The results extend single-atom transistor operation to RT, enable tunnelling spectroscopy of impurity atoms in insulators, and allow the energy landscape for P atoms in SiO2 to be determined.

Single-electron devices operating at room temperature require sub-5 nm quantum dots having tunnel junctions of comparable dimensions. Further development in nanoelectronics depends on the capability to generate mesoscopic structures and interfacing these with complementary metal–oxide–semiconductor devices in a single system. The authors employ a combination of two novel methods of fabricating room temperature silicon single-electron transistors (SETs), Fowler–Nordheim scanning probe lithography (F-N SPL) with active cantilevers and cryogenic reactive ion etching followed by pattern-dependent oxidation. The F-N SPL employs a low energy electron exposure of 5–10 nm thick high-resolution molecular resist (Calixarene) resulting in single nanodigit lithographic performance [Rangelow et al., Proc. SPIE 7637, 76370V (2010)]. The followed step of pattern transfer into silicon becomes very challenging because of the extremely low resist thickness, which limits the etching depth. The authors developed a computer simulation code to simulate the reactive ion etching at cryogenic temperatures (−120 °C). In this article, the authors present the alliance of all these technologies used for the manufacturing of SETs capable to operate at room temperatures.