Space radiation measurements were made on the International Space Station (ISS) with the Bulgarian Liulin-E094 instrument, which contains 4 Mobile Dosimetry Units (MDU), and the NASA ) during the time period May 11–July 26, 2001. In the time span 11–27 May 2001 four MDUs were placed at fixed locations: one unit (MDU #1) in the ISS “Unity” Node-1 and three (MDU #2–#4) units were located in the US Laboratory module. The MDTissue Equivalent Proportional Counter (TEPCU #2 and the TEPC were located in the US Laboratory module Human Research Facility (rack #1, port side). In this paper we discuss the flight observed asymmetries in different detectors on the ascending and descending parts of the ISS orbits. The differences are described by the shielding differences generated by different geometry between the predominating eastward drifting protons and the orientation and placement of the MDUs within the ISS. Shielding distributions were generated for the combined ISS and detector shielding models. The AP8MAX and AE8MAX trapped radiation models were used to compute the daily absorbed dose for the five detectors and are compared with the flight measurements. In addition, the trapped proton incident spectra inside of ISS were calculated using calibration curve of MDU obtained during the tests with protons at the Louvain-la-Neuve cyclotron facility. The energy of incident spectra maximums were analyzed against L value for the individual passes through the South Atlantic Anomaly.
Research Containing: Spectrometry
We studied the growth of metal-ion silicate chemical gardens under Earth gravity (1 g) and microgravity (mug) conditions. Identical sets of reaction chambers from an automated system (the Silicate Garden Habitat or SGHab) were used in both cases. The mug experiment was performed on board the International Space Station (ISS) within a temperature-controlled setup that provided still and video images of the experiment downlinked to the ground. Calcium chloride, manganese chloride, cobalt chloride, and nickel sulfate were used as seed salts in sodium silicate solutions of several concentrations. The formation and growth of osmotic envelopes and microtubes was much slower under mug conditions. In 1 g, buoyancy forces caused tubes to grow upward, whereas a random orientation for tube growth was found under mug conditions.
Dynamic Cultivation of Human Mesenchymal Stem Cells in a Rotating Bed Bioreactor System Based on the Z (R) RP Platform
Because the regeneration of large bone defects is limited by quantitative restrictions and risks of infections, the development of bioartificial bone substitutes is of great importance. To obtain a three-dimensional functional tissue-like graft, static cultivation is inexpedient due to limitations in cell density, nutrition and oxygen support. Dynamic cultivation in a bioreactor system can overcome these restrictions and furthermore provide the possibility to control the environment with regard to pH, oxygen content, and temperature. In this study, a three-dimensional bone construct was engineered by the use of dynamic bioreactor technology. Human adipose tissue derived mesenchymal stein cells were cultivated on a macroporous zirconium dioxide based ceramic disc called Sponceram (R). Furthermore, hydroxyapatite coated Sponceram (R) was used. The cells were cultivated under dynamic conditions and compared with statically cultivated cells. The differentiation into osteoblasts was initiated by osteogenic supplements. Cellular proliferation during static and dynamic cultivation was compared measuring glucose and lactate concentration. The differentiation process was analysed determining AP-expression and using different specific staining methods. Our results demonstrate much higher proliferation rates during dynamic conditions in the bioreactor-system compared to static cultivation measured by glucose consumption and lactate production. Cell densities on the scaffolds indicated higher proliferation on native Sponceram (R) compared to hydroxyapatite coated Sponceram (R). With this study, we Present an excellent method to enhance cellular proliferation and bone lineage specific growth of tissue like structures comprising fibrous (collagen) and globular (mineral) extracellular components. (C) 2009 American Institute of Chemical Engineers Biotechnol. Prog., 25: 1762-1771 2009
<Go to ISI>://WOS:000273152000025