Highly nonlinear current-voltage characteristics are measured, displaying a clear transition from a high-resistance state near zero applied bias to a low-resistance state as the voltage is increased. The measurement results,
including their temperature dependence and the variations in turn-on voltage with subband structure and bias polarity are in full agreement with a picture of sequential tunneling through the ground-state subbands of adjacent coupled quantum wells. Scattering-assisted tunneling due to interface roughness or structural defects appears to be the dominant transport mechanism. The potential role of photon-assisted tunneling is also investigated. (C) 2010 American Institute of Physics. [doi:10.1063/1.3511334]“
“Objective. Reconstructing irradiated mandibles with biomaterials is still a challenge but little investigated. We collected data that could help us understand studies in the field of regeneration with Fer-1 ic50 biomaterials and irradiated bone.
Study design. Systematic review of the literature.
Results. Delay and duration of radiation delivery and total equivalent dose are the most variable parameters in the various studies, selleck chemical resulting in confusion when interpreting the literature. Most reproducible experiments show that radiation reduces osteogenic cell numbers, alters cytokine capacity, and delays and damages bone remodeling. Interindividual variations and how such changes
become irreversible lesions are still uncertain. In the case of regeneration using biomaterials, most studies have addressed the question of reconstruction in previously irradiated bone. The results
show that osseointegration is often possible, although the failure rate is higher. The sooner the implantation takes place after the end of the radiation, the higher the likelihood of failure. Few studies have focused on primary reconstruction followed by early irradiation, and most of the currently available engineering models would be altered by radiation. Good outcomes have been obtained with bone morphogenetic protein and with total bone marrow transplanation.
Conclusion. This review points out the difficulties in achieving reproducible experiments R428 in vivo and interpreting literature in this underinvestigated field. ( Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2010; 109: 173-184)”
“Functionalized dendrimer-entrapped gold nanoparticles (Au DENPs) are of scientific and technological interest in biomedical applications. In this study, Au DENPs prepared with amine-terminated generation 5 (G5) poly(amido amine) dendrimers as templates were subjected to acetylation to neutralize the positive surface charge of the particles. By varying the molar ratio of Au salt to G5 dendrimer, we prepared acetylated Au DENPs with a size range of 2-4 nm. Meanwhile, we attempted to add glucose to the dialysis liquid of the acetylated Au DENPs to prevent possible particle aggregation after lyophilization.