(C) 2014 Elsevier Ltd. All rights reserved.”
“The use of tandem mass spectrometry (MS/MS) for screening of inherited metabolic disease in newborns has afforded many unique opportunities
in the understanding of the benefits early their early detection, diagnosis and treatment. From the standpoint of the laboratory and 4EGI-1 nmr modern analytical methods, the use of MS based analysis demonstrated that a multiple metabolite-multiple disease screen-one method approach expanded screening significantly. MS/MS and newborn screening has served as a model of one type of approach in preventative health care that has shown proven benefits. It has been nearly 20 years since the introduction of MS/MS analysis of dried blood spots from newborns. There have been many lessons learned in both the analytical approach as well as follow-up at the bedside. These lessons can be applied to future applications of MS/MS in newborn screening as well as other areas of metabolism and metabolic profiles such as that from acquired disease, environmental disease and other factors such as nutrition and age. The use of a highly specific, sensitive phosphatase inhibitor library and multiplex platform such as MS/MS will continue to grow and experience in the newborn screening application will insure this outcome.”
“The transport characteristics
of low dimensional semiconductors like silicon nano-wires (SiNWs)
rarely conform to expectations from geometry and dopant density, exhibiting significant variations as a function of different surface terminations/conditions. The association of these mechanisms with surface states and their exact Galardin influence on practical SiNW devices still remains largely unclear. Herein, we report on the influence of surface state charge distributions on SiNW transport characteristics. For this study, p-type SiNW devices with widths of 50, 100, and 2000 nm are fabricated from 25, 50, and 200 nm-thick SOI wafers. A similar to five order difference in effective carrier concentration was observed in the initial SiNWs characteristics, when comparing SiNWs fabricated with and without a thermal oxide. The removal of the surface oxide by a hydrogen fluoride (HF) treatment results in a SiNW conductance drop up to similar to six orders of magnitude. This effect is from a surface depletion of holes in the SiNW induced by positive surface charges deposited as a result of the HF treatment. However, it is observed that this charge density is transient and is dissipated with the re-growth of an oxide layer. In summary, the SiNW conductance is shown to vary by several orders of magnitude, while comparing its characteristics for the three most studied surface conditions: with a native oxide, thermal oxide and HF induced H-terminations.