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The Italian Space Agency, in line with its scientific strategies and the National Utilization Plan for the International Space Station (ISS), contracted Thales Alenia Space Italia to design and build a spaceflight payload for rodent research on ISS: the Mice Drawer System (MDS). The payload, to be integrated inside the Space Shuttle middeck during transportation and inside the Express Rack in the ISS during experiment execution, was designed to function autonomously for more than 3 months and to involve crew only for maintenance activities. In its first mission, three wild type (Wt) and three transgenic male mice over-expressing pleiotrophin under the control of a bone-specific promoter (PTN-Tg) were housed in the MDS. At the time of launch, animals were 2-months old. MDS reached the ISS on board of Shuttle Discovery Flight 17A/STS-128 on August 28th, 2009. MDS returned to Earth on November 27th, 2009 with Shuttle Atlantis Flight ULF3/STS-129 after 91 days, performing the longest permanence of mice in space. Unfortunately, during the MDS mission, one PTN-Tg and two Wt mice died due to health status or payload-related reasons. The remaining mice showed a normal behavior throughout the experiment and appeared in excellent health conditions at landing. During the experiment, the mice health conditions and their water and food consumption were daily checked. Upon landing mice were sacrificed, blood parameters measured and tissues dissected for subsequent analysis. To obtain as much information as possible on microgravity-induced tissue modifications, we organized a Tissue Sharing Program: 20 research groups from 6 countries participated. In order to distinguish between possible effects of the MDS housing conditions and effects due to the near-zero gravity environment, a ground replica of the flight experiment was performed at the University of Genova. Control tissues were collected also from mice maintained on Earth in standard vivarium cages.

Charge transfer complexes of substituted thiophens as donors with tetracyanoethylene, 2,3dichloro-5,6-dicyano-p-benzoquinone, chloranil and iodine have been studied spectrophotometricall y. From the energies of the charge transfer transitions, the ionization potentials of the donors have been obtained. Comparison with those measured by electron-impact mass spectrometry, shows that the thiophens behave as T donors with all four acceptors. In the case of iodine the stability constants of the complexes support a T+U* interaction. Some evidence is given for the role of inner valence orbitals in the complexes.

No abstract

The oxidation kinetics of HF-etched n- and p-doped silicon in air at room temperature have been studied by electron spectroscopy for chemical analysis. No great differences have been found between the n- and p-type oxidation kinetics at the low doping level of the studied samples. The rate of oxide growth on the HF-etched surface is much lower than that on a silicon surface obtained by fracture in air of a silicon monocrystal. The behavior of a silicon sample fractured in de-ionized water and then oxidized in air at room temperature is intermediate. The above findings have been interpreted on the basis of surface reactions involving the plasticizers of the HF and water containers. These reactions produce carbon-rich hydrophobic surfaces which retard the silicon oxide growth. A mechanism for the involved surface reactions is proposed.