Band offsets of metal oxide contacts on TlBr radiation detectors

Metal oxides are investigated as an alternative to metal contacts on thallium bromide (TlBr) radiation detectors. X-ray photoelectron spectroscopy studies of SnO 2/TlBr and ITO/TlBr devices indicate that a type-II staggered heterojunction forms between TlBr and metal oxides upon contacting. By using the Kraut method of valence band offset (VBO) determination, the VBOs of SnO 2/TlBr and ITO/TlBr heterojunctions are determined to be 1.05 ± 0.17 and 0.70 ± 0.17 eV, respectively. The corresponding conduction band offsets are then found to be 0.13 ± 0.17 and 0.45 ± 0.17 eV, respectively. The I-V response of symmetric In/SnO 2/TlBr and In/ITO/TlBr planar devices is almost Ohmic with a leakage current of less than 2.5 nA at 100 V

Band offsets of metal oxide contacts on TlBr radiation detectors

Metal oxides are investigated as an alternative to metal contacts on thallium bromide (TlBr) radiation detectors. X-ray photoelectron spectroscopy studies of SnO 2/TlBr and ITO/TlBr devices indicate that a type-II staggered heterojunction forms between TlBr and metal oxides upon contacting. By using the Kraut method of valence band offset (VBO) determination, the VBOs of SnO 2/TlBr and ITO/TlBr heterojunctions are determined to be 1.05 ± 0.17 and 0.70 ± 0.17 eV, respectively. The corresponding conduction band offsets are then found to be 0.13 ± 0.17 and 0.45 ± 0.17 eV, respectively. The I-V response of symmetric In/SnO 2/TlBr and In/ITO/TlBr planar devices is almost Ohmic with a leakage current of less than 2.5 nA at 100 V

Socializing One Health: an innovative strategy to investigate social and behavioral risks of emerging viral threats

In an effort to strengthen global capacity to prevent, detect, and control infectious diseases in animals and people, the United States Agency for International Development’s (USAID) Emerging Pandemic Threats (EPT) PREDICT project funded development of regional, national, and local One Health capacities for early disease detection, rapid response, disease control, and risk reduction. From the outset, the EPT approach was inclusive of social science research methods designed to understand the contexts and behaviors of communities living and working at human-animal-environment interfaces considered high-risk for virus emergence. Using qualitative and quantitative approaches, PREDICT behavioral research aimed to identify and assess a range of socio-cultural behaviors that could be influential in zoonotic disease emergence, amplification, and transmission. This broad approach to behavioral risk characterization enabled us to identify and characterize human activities that could be linked to the transmission dynamics of new and emerging viruses. This paper provides a discussion of implementation of a social science approach within a zoonotic surveillance framework. We conducted in-depth ethnographic interviews and focus groups to better understand the individual- and community-level knowledge, attitudes, and practices that potentially put participants at risk for zoonotic disease transmission from the animals they live and work with, across 6 interface domains. When we asked highly-exposed individuals (ie. bushmeat hunters, wildlife or guano farmers) about the risk they perceived in their occupational activities, most did not perceive it to be risky, whether because it was normalized by years (or generations) of doing such an activity, or due to lack of information about potential risks. Integrating the social sciences allows investigations of the specific human activities that are hypothesized to drive disease emergence, amplification, and transmission, in order to better substantiate behavioral disease drivers, along with the social dimensions of infection and transmission dynamics. Understanding these dynamics is critical to achieving health security--the protection from threats to health-- which requires investments in both collective and individual health security. Involving behavioral sciences into zoonotic disease surveillance allowed us to push toward fuller community integration and engagement and toward dialogue and implementation of recommendations for disease prevention and improved health security

Intraperitoneal delivery of human natural killer cells for treatment of ovarian cancer in a mouse xenograft model

BACKGROUND AIMS: There is an urgent need for novel therapeutic strategies for relapsed ovarian cancer. Dramatic clinical antitumor effects have been observed with interleukin (IL)-2 activated natural killer (NK) cells; however, intravenous delivery of NK cells in patients with ovarian cancer has not been successful in ameliorating disease. We investigated in vivo engraftment of intraperitoneally (IP) delivered NK cells in an ovarian cancer xenograft model to determine if delivery mode can affect tumor cell killing and circumvent lack of NK cell expansion. METHODS: An ovarian cancer xenograft mouse model was established to evaluate efficacy of IP-delivered NK cells. Tumor burden was monitored by bioluminescent imaging of luciferase-expressing ovarian cancer cells. NK cell persistence, tumor burden and NK cell trafficking were evaluated. Transplanted NK cells were evaluated by flow cytometry and cytotoxicity assays. RESULTS: IP delivery of human NK cells plus cytokines led to high levels of circulating NK and was effective in clearing intraperitoneal ovarian cancer burden in xenografted mice. NK cells remained within the peritoneal cavity 54 days after injection and had markers of maturation. Additionally, surviving NK cells were able to kill ovarian cancer cells at a rate similar to pre-infusion levels, supporting that in vivo functionality of human NK cells can be maintained after IP infusion. CONCLUSIONS: IP delivery of NK cells leads to stable engraftment and antitumor response in an ovarian cancer xenograft model. These data support further pre-clinical and clinical evaluation of IP delivery of allogeneic NK cells in ovarian cancer