35 research outputs found
N-type field-effect transistors using multiple Mg-doped ZnO nanorods
Nanorod field-effect transistors (FETs) that use multiple Mg-doped ZnO nanorods and a SiO2 gate insulator were fabricated and characterized. The use of multiple nanorods provides higher on-currents without significant degradation in threshold voltage shift and subthreshold slopes. It has been observed that the on-currents of the multiple ZnO nanorod FETs increase approximately linearly with the number of nanorods, with on-currents of similar to 1 mu A per nanorod and little change in off-current (similar to 4 x 10(-12)). The subthreshold slopes and on-off ratios typically improve as the number of nanorods within the device channel is increased, reflecting good uniformity of properties from nanorod to nanorod. It is expected that Mg dopants contribute to high n-type semiconductor characteristics during ZnO nanorod growth. For comparison, nonintentionally doped ZnO nanorod FETs are fabricated, and show low conductivity to compare with Mg-doped ZnO nanorods. In addition, temperature-dependent current-voltage characteristics of single ZnO nanorod FETs indicate that the activation energy of the drain current is very low (0.05-0.16 eV) at gate voltages both above and below threshold
Malabsorption in cirrhosis of the liver
Gastrointestinal function of absorption has been studied in twenty biopsy proved cases of cirrhosis of the liver. The gastro-intestinal function was assessed by means of glucose and lactose tolerance tests and by fecal fat, d-Xylose and Co<sup> 57</sup> B<sub> 12</sub> excretion tests. Steatorrhoea and lactose intolerance are common in cir-rhotics. The etiopathogenesis of this malabsorption in cirrhotics is discussed and appears multifactorial in origin
Experimental and Computational Studies on Remote γ‑C(sp<sup>3</sup>)–H Silylation and Germanylation of Aliphatic Carboxamides
A PdÂ(II)-catalyzed
protocol for highly regioselective distal γ-C–H
silylation and germanylation of aliphatic carboxylic acids is reported.
Bidentate 8-aminoquinoline as the directing group was found to stabilize
the six-membered palladacycle. A variety of aliphatic carboxylic acids
and amino acids were silylated and germanylated in good yields and
high diasteroselectivities. Detailed mechanistic studies involving
isolation of a PdÂ(II) intermediate, determination of the reaction
rate and order, control experiments, and isotopic labeling and DFT
studies were found to be crucial for elucidating the elementary steps
involved in this distal aliphatic functionalization