Generation and characterisation of gallium titanate surfaces through hydrothermal ion-exchange processes

Infection negation and biofilm prevention are necessary developments needed for implant materials. Furthermore, an increase in publications regarding gallium (Ga) as an antimicrobial ion has resulted in bacterial-inhibitory surfaces incorporating gallium as opposed to silver (Ag). The authors present the production of novel gallium titanate surfaces through hydrothermal ion-exchange reactions. Commercially-pure Ti (S0: Cp-Ti) was initially suspended in NaOH solutions to obtain sodium titanate (S1: Na2TiO3) layers ca. 0.5–1 μm in depth (2.4 at.% Na). Subsequent suspension in Ga(NO3)3 (S2: Ga2(TiO3)3), and post-heat-treatment at 700 °C (S3: Ga2(TiO3)3-HT), generated gallium titanate layers (9.4 and 4.1 at.% Ga, respectively). For the first time, RHEED analysis of gallium titanate layers was conducted and demonstrated titanate formation. Degradation studies in DMEM showed S2: Ga2(TiO3)3 released more Ga compared to S3: Ga2(TiO3)3-HT (2.76 vs. 0.68 ppm) over 168 h. Furthermore, deposition of Ca/P in a Ca:P ratio of 1.71 and 1.34, on S2: Ga2(TiO3)3 and S3: Ga2(TiO3)3-HT, respectively, over 168 h was seen. However, the study failed to replicate the antimicrobial effect presented by Yamaguchi who utilised A. baumannii, compared to S. aureus used presently. The authors feel a full antimicrobial study is required to assess gallium titanate as a candidate antimicrobial surface

SOST Inhibits Prostate Cancer Invasion.

Inhibitors of Wnt signaling have been shown to be involved in prostate cancer (PC) metastasis; however the role of Sclerostin (Sost) has not yet been explored. Here we show that elevated Wnt signaling derived from Sost deficient osteoblasts promotes PC invasion, while rhSOST has an inhibitory effect. In contrast, rhDKK1 promotes PC elongation and filopodia formation, morphological changes characteristic of an invasive phenotype. Furthermore, rhDKK1 was found to activate canonical Wnt signaling in PC3 cells, suggesting that SOST and DKK1 have opposing roles on Wnt signaling in this context. Gene expression analysis of PC3 cells co-cultured with OBs exhibiting varying amounts of Wnt signaling identified CRIM1 as one of the transcripts upregulated under highly invasive conditions. We found CRIM1 overexpression to also promote cell-invasion. These findings suggest that bone-derived Wnt signaling may enhance PC tropism by promoting CRIM1 expression and facilitating cancer cell invasion and adhesion to bone. We concluded that SOST and DKK1 have opposing effects on PC3 cell invasion and that bone-derived Wnt signaling positively contributes to the invasive phenotypes of PC3 cells by activating CRIM1 expression and facilitating PC-OB physical interaction. As such, we investigated the effects of high concentrations of SOST in vivo. We found that PC3-cells overexpressing SOST injected via the tail vein in NSG mice did not readily metastasize, and those injected intrafemorally had significantly reduced osteolysis, suggesting that targeting the molecular bone environment may influence bone metastatic prognosis in clinical settings

MinXSS CubeSat On-Orbit Performance and the First Flight of the Blue Canyon Technologies XACT 3- axis ADCS

The Miniature X-ray Solar Spectrometer (MinXSS) 3U CubeSat was launched to the International Space Station (ISS) on 2015 December 6. Its deployment from the ISS is scheduled for 2016 March. MinXSS was designed and developed at the University of Colorado Boulder through a graduate project class, with significant professional support from the Laboratory for Atmospheric and Space Physics (LASP). The 3- axis attitude determination and control system (ADCS) is the Blue Canyon Technologies (BCT) XACT. This is the first flight of the XACT unit, which is the most capable commercially available 3-axis ADCS for CubeSats on the market today. MinXSS is a science mission funded by NASA\u27s Heliophysics division and is the first CubeSat to be flown from NASA Science Mission Directorate\u27s new CubeSat Implementation Panel. The primary objective for the MinXSS mission is to better understand the energy distribution of solar soft x-ray (SXR) emissions and their impact on earth\u27s ionosphere, thermosphere, and mesosphere (ITM). MinXSS observes the solar SXR spectrum between 0.5 to 30 keV with an energy resolution of 0.15 keV full width half maximum at 5.9 keV. Very few prior spectrally-resolved solar observations exist in the SXR range, leaving a critical gap in our ability to determine the spectral energy distribution for ITM modeling and solar flare studies. These issues can be addressed with new MinXSS data. This paper will provide details of the on-orbit performance of MinXSS and first-light observations from the primary science instrument, which is a commercially available system that was modified for flight. First light observations will include the first solar SXR spectrum from MinXSS and comparisons between quiet-Sun and flare spectra as observed by MinXSS. MinXSS represents the first opportunity for on-orbit characterization of BCT\u27s XACT ADCS. Performance of star tracker-based attitude determination, 3-axis reaction wheel-based attitude control, and torque rod-based momentum control will be assessed using on-orbit telemetry. This system is being used by several NASA centers, the DoD, many universities, and commercial entities for a multitude of upcoming missions that require precision attitude control at low cost. The exceptionally simple design of the LASP PPPT will be reviewed. The addition of a single fixed-value resistor mitigates the high current draw from the battery, which prevents the solar cell voltage from dropping below buck converter input requirements. The PPPT was successful in increasing the power output of the electrical power system by nearly a factor of 2 in mission simulations. The on-orbit power performance will be analyzed. In addition to thermal vacuum testing, MinXSS underwent thermal balance, which is dedicated to tuning the thermal model. The thermal balance procedure and model will be briefly overviewed and predictions compared to on-orbit temperatures. The results of this analysis have been generalized such that other CubeSat programs, who may not have the means to perform the test, may apply the results to their models and get improved model predictions. Thermal control of CubeSats is important to their lifetime and few if any prior results on this topic have been previously presented

The netrin receptor DCC is required in the pubertal organization of mesocortical dopamine circuitry

Netrins are guidance cues involvedinneural connectivity.Wehave shownthat the netrin-1 receptor DCC (deletedin colorectal cancer) is involvedinthefunctionalorganizationofthemesocorticolimbic dopamine(DA)system.Adult micewithaheterozygousloss-of-function mutation in dcc exhibit changes in indexes of DA function, including DA-related behaviors. These phenotypes are only observed after puberty,acritical periodinthe maturationofthe mesocortical DAprojection. Here, weexamined whether dcc heterozygous mice exhibit structural changes in medial prefrontal cortex (mPFC) DA synaptic connectivity, before and after puberty. Stereological counts of tyrosine-hydroxylase (TH)-positive varicosities were increased in the cingulate 1 and prelimbic regions of the pregenual mPFC. dcc heterozygous mice also exhibited alterations in the size, complexity, and dendritic spine density of mPFC layer V pyramidal neuron basilar dendritic arbors. Remarkably, these presynaptic and postsynaptic partner phenotypes were not observed in juvenile mice, suggesting that DCC selectively influences the extensive branching and synaptic differentiation that occurs in the maturing mPFC DA circuitatpuberty.Immunolabelingexperimentsinwild-typemice demonstratedthat DCCissegregatedtoTH-positivefibersinnervating the nucleus accumbens, with only scarce DCC labeling in mPFC TH-positive fibers. Netrin had an inverted target expression pattern. Thus, DCC-mediated netrin-1 signaling may influence the formation/maintenance of mesocorticolimbic DA topography. In support of this, we report that dcc heterozygous mice exhibit a twofold increase in the density of mPFC DCC/TH-positive varicosities. Our results implicate DCC-mediated netrin-1 signaling in the establishment of mPFC DA circuitry during puberty

Functional gene analysis of individual response to challenge of SIVmac239 in M. mulatta PBMC culture

AbstractIt has previously been shown in macaques that individual animals exhibit varying responses to challenge with the same strain of SIV. We attempted to elucidate these differences using functional genomics and correlate them to biological response. Unfractionated PBMC from three rhesus macaques were isolated, activated, and infected with SIVmac239. Interestingly, one of the three animals used for these experiments exhibited a completely unique response to infection relative to the other two. After repeated attempts to infect the PBMC from this animal, little or no infectivity was seen across the time points considered, and corresponding to this apparent lack of infection, few genes were seen to be differentially expressed when compared to mock-infected cells. For the remaining two animals, gene expression analysis showed that while they exhibited responses for the same groups of pathways, these responses included differences specific to the individual animal at the gene level. In instances where the patterns of differential gene expression differed between these animals, the genes being differentially expressed were associated with the same categories of biological process, mainly immune response and cell signaling. At the pathway level, these animals again exhibited similar responses that could be predicted based on the experimental conditions. Even in these expected results, the degree of response and the specific genes being regulated differed greatly from animal to animal. The differences in gene expression on an individual level have the potential to be used as markers in identification of animals suitable for lentiviral infection experiments. Our results highlight the importance of individual variation in response to viral challenge