The impact of size-selected Ag clusters on graphite: anSTM study S J Carroll, P Weibel, B von Issendorff et al. - Recent citations

a non discriminative way and thus selected the un-expressed cII gene in LIZ transgenes of Big Blue ™ (BB) mice to study. Because the available BB mice were on B6 genetic background, which has profound effect on tumor susceptibility, we generated B6 BB Gpx1/2-DKO mice and studied their phenotype. The B6 BB Gpx1/2-DKO mice had fewer inflammatory cells, milder ileocolitis, low mortality before 7 weeks of age, and only 2.5% of them developed tumors between 6-8 months old. Whether these Gpx1/2-DKO mice have LIZ transgenes or not does not affect these phenotype. We have then generated B6.129 BB Gpx1/2-DKO mice by breeding the B6 BB Gpx1/2-DKO mice with 129 mice. We then studied spontaneous gene mutations in the ileal and colonic epithelium, as well as the non-affected liver in the cII gene in both B6 and B6.129 BB Gpx1/2-DKO mice and their control. RESULTS AND CONCLUSIONS: The mutant frequency of a cII reporter gene was about 2-3 fold higher in 28-day-old Gpx1/2-DKO mouse ileal epithelia and 4-fold higher in 8-month-old Gpx1/2-DKO ileal epithelium than in controls in both genetic backgrounds. In contrast, mutant frequencies in the unaffected B6 liver were not different between wildtype and Gpx1/2-DKO mice. The mutant frequency of 8-month-old B6.129 Gpx1/2-DKO ileum was 38.94Ϯ15.5 -5 , which was higher than the age-matched B6 ileum, 25.54Ϯ10.33 -5 , although not statistically significant. The mutation spectra analysis has shown that B6 Gpx1/2-DKO ileum had a 3-fold increase in small nucleotide deletions at mononucleotide repeats over control B6, which are a signature mutation associated with oxidative stress. Unexpectedly, B6 Gpx1/2-DKO mice had fewer C to T transitions at CpG dinucleotides than the wildtype B6 (18.0% versus 40.1%; PϽ0.001). Our results suggest inflammation drives gene mutations, which by themselves are not sufficient for neoplastic transformation of intestinal epithelial cells.

A 3D reconstruction solution to ultrasound Joule heat density tomography based on acousto-electric effect by deconvolution is proposed for noninvasive imaging of biological tissue. Compared with ultrasound current source density imaging, ultrasound Joule heat density tomography doesn't require any priori knowledge of conductivity distribution and lead fields, so it can gain better imaging result, more adaptive to environment and with wider application scope. For a general 3D volume conductor with broadly distributed current density field, in the AE equation the ultrasound pressure can't simply be separated from the 3D integration, so it is not a common modulation and basebanding (heterodyning) method is no longer suitable to separate Joule heat density from the AE signals. In the proposed method the measurement signal is viewed as the output of Joule heat density convolving with ultrasound wave. As a result, the internal 3D Joule heat density can be reconstructed by means of Wiener deconvolution. A series of computer simulations set for breast cancer imaging applications, with consideration of ultrasound beam diameter, noise level, conductivity contrast, position dependency and size of simulated tumors, have been conducted to evaluate the feasibility and performance of the proposed reconstruction method. The computer simulation results demonstrate that high spatial resolution 3D ultrasound Joule heat density imaging is feasible using the proposed method, and it has potential applications to breast cancer detection and imaging of other organs.