We discuss high-angular resolution observations of ammonia toward four candidate high-mass starless cores (HMSCs). The cores were identified by the Balloon-borne Large Aperture Submillimeter Telescope (BLAST) during its 2005 survey of the Vulpecula region where 60 compact sources were detected simultaneously at 250, 350, and 500 µm. Four of these cores, with no IRAS-PSC or MSX counterparts, were mapped with the NRAO Very Large Array (VLA) and observed with the Effelsberg 100 m telescope in the NH 3 (1,1) and (2,2) spectral lines. Our observations indicate that the four cores are cold (T k < 16 K) and show a filamentary and/or clumpy structure. They also show a significant velocity substructure within ∼ 1 km s −1 . The four BLAST cores appear to be colder and more quiescent than other previously observed HMSC candidates, suggesting an earlier stage of evolution.

Calcium sulfide (CaS) nanostructures have the potential to play an important role as cadmium‐free nanoscaled semiconductors with applications in bioimaging, in vivo labeling, and sensing, and for drug delivery systems. The objective of this work is to establish the effect of CaS nanostructures on cell replication rate and survival of human mammary adenocarcinoma cell lines. Human adenocarcinoma cell lines are grown in eagle’s minimum essential medium (EMEM). Single doses of dispersions containing traces of CaS nanostructures were added to human mammary adenocarcinoma cell lines with a 70 % confluence. After a 24 hour period, 200,000 cancer cells were subculture in T‐75 treated flasks. The number of dead cells in the cell culture media supernatant was determined in intervals of 24 hours using a Biorad T10 cell counter. The number of dead cells in the supernatant is found to increase from 2,000 in control cell cultures to over 70,000 in cancer cell cultures exposed to a single dose of the CaS dispersion in the first 24 hours: this represents 35 % of the initial cell seeding. The number of dead cells remains in the range of 60,000 to 30,000 in measurements performed between 48 and 72 hours following the single dose of the dispersion containing the CaS nanostructures. The number of replicating cells is found to decrease in the first 72 hours and to increase thereafter. We conclude that the CaS nanostructures affect the replication rate and survival of human adenocarcinoma cells and demonstrate the role CaS nanostructures may play to treat localized cancers. Grant Funding Source: NIH NIGMS‐R25GM088023 and NIGMS‐R25GM096955

Microgravity effect on the electrochemical oxidation of ammonia at platinum nanoparticles modified mesoporous carbon (MPC) substrates, with three different pore diameters, e.g. 64, 100, and 137 Å, have been studied in a parabolic flight between 24,000 and 32,000 ft. Microgravity effects on the chronoamperometric ammonia oxidation current density was a function of the mesoporous carbon support used. This support may be described as graphitic multilayer hollow globules, even though the carbon globules do not present a specific shape as seen in the HRTEM images.  Platinum nanoparticles were successfully chemically deposited, with a high dispersion, throughout the support’s topography.  An onboard accelerometer was the trigger in order to start each chronoamperomtric ammonia oxidation experiments when the microgravity condition of less than 0.02g (i.e. gravitational force) was achieved. Pt/MPC64 sustained the current density between terrestrial and microgravity conditions by a slight margin over Pt/MPC100. However, Pt/MPC137 resulted with the smallest current density decrease under microgravity conditions versus ground based experiments.  Pt/MPC137 has the largest pore diameter and shows a better capacity to sustain the oxidation current, which involves N2 formation.  This effect can be ascribed to an easier diffusional process obtained by the larger pore diameter, which improves the access for the mobility of the ammonia molecules towards the electroactive sites and the corresponding detachment of the gaseous N2molecules (bubbles) from the MPC cavities. Pt/MPC137 catalyst resulted with the smallest current density decrease under microgravity conditions versus ground based experiments. This MPC support has the largest average pore diameter (137 Å) and shows a better capacity to sustain the oxidation current. This effect can be ascribed to an easier diffusional process facilitated by the larger pore diameter, which improves the access for the mobility of the ammonia molecules towards the electroactive sites and the corresponding detachment of the gaseous N2 molecules (bubbles) away from them. In conclusion, it was demonstrated that under microgravity environment a porous infrastructure for a catalyst support has an impact on the mass transfer process of electroactive species, and a current density decreasing factor of ca. 50 - 67% must be taken into account. The lowest being the MCP average pore diameter 137 Å. In order to improve the current densities for ammonia oxidation, (100) faceted Pt nanoparticles need to be achieved.

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