We have discovered a mechanism which can significantly reduce the dislocation density during the growth of GaN single crystals in the Na flux method. The significant reduction of the dislocation density occurs in the later stage of LPE growth, rather than solely at the seed-LPE interface for which we have already reported evidence indicating the presence of bundling dislocations. The two-step dislocation reduction is the key in achieving extremely low dislocation density using this method. 相似文献
The efficiency of microwave irradiation at low temperature for glycosylations is described. Although oligosaccharide synthesis usually requires reactive donors for glycosylations, which have leaving groups on the anomer positions, i.e., trichloroacetoimidates, halogenates, thioalkyl glycosides, etc., the suitable donors in our microwave supported synthesis of Lewis X oligosaccharide were very stable acetate derivatives. Regarding glycosylation with a fucosyl acetate donor and a glucosamine acceptor, microwave irradiation with simultaneous cooling improved yields. Moreover, further synthesis to Lewis X derivatives was achieved only with microwave irradiation at low temperatures. Without microwave irradiation, we could only obtain byproducts and none of the designed product at any reaction temperature. 相似文献
Pharmacological effects (catalepsy, hypothermia, pentobarbital-induced sleep prolongation, anticonvulsant and analgesic effects) of delta 8- and delta 9-tetrahydrocannabinols, and their 11-hydroxy-metabolites were evaluated and compared in mice. delta 9-Tetrahydrocannabinol and 11-hydroxy-delta 9-tetrahydrocannabinol exhibited somewhat greater effects than did delta 8-tetrahydrocannabinol and 11-hydroxy-delta 8-tetrahydrocannabinol, respectively, in all pharmacological indices tested. Greater effects of 11-hydroxy-metabolites than those of tetrahydrocannabinols were also demonstrated. 相似文献
The nuclear spin-lattice relaxation rate, 1/T1, has been measured in weak itinerant ferromagnets Y(Co1−xAlx)2. The temperature and magnetic field dependence of 1/T1T has been found to be well described by the self-consistent renormalization (SCR) theory of spin fluctuations. The parameters characterizing spin fluctuations in this system were estimated from NMR and magnetic measurements. The temperature dependence of susceptibility calculated from these parameters well reproduces the experimental results. 相似文献
On the basis of the results of thermal expansion and NMR measurements, the stability of Mn moments and spin fluctuations in RMn2 are discussed. It has been shown that the interatomic distance of RMn2 plays a crucial role in determining the Mn magnetism in RMn2. 相似文献
Recently, measuring the complexity of body movements during sleep has been proven as an objective biomarker of various psychiatric disorders. Although sleep problems are common in children with autism spectrum disorder (ASD) and might exacerbate ASD symptoms, their objectivity as a biomarker remains to be established. Therefore, details of body movement complexity during sleep as estimated by actigraphy were investigated in typically developing (TD) children and in children with ASD. Several complexity analyses were applied to raw and thresholded data of actigraphy from 17 TD children and 17 children with ASD. Determinism, irregularity and unpredictability, and long-range temporal correlation were examined respectively using the false nearest neighbor (FNN) algorithm, information-theoretic analyses, and detrended fluctuation analysis (DFA). Although the FNN algorithm did not reveal determinism in body movements, surrogate analyses identified the influence of nonlinear processes on the irregularity and long-range temporal correlation of body movements. Additionally, the irregularity and unpredictability of body movements measured by expanded sample entropy were significantly lower in ASD than in TD children up to two hours after sleep onset and at approximately six hours after sleep onset. This difference was found especially for the high-irregularity period. Through this study, we characterized details of the complexity of body movements during sleep and demonstrated the group difference of body movement complexity across TD children and children with ASD. Complexity analyses of body movements during sleep have provided valuable insights into sleep profiles. Body movement complexity might be useful as a biomarker for ASD. 相似文献
In our photo‐induced immobilization technique for an antibody (IgG) using azopolymers, the introduction of COOH and NMe2 into the azopolymers, which can introduce surface charges, strongly affected the immobilization properties such as the efficiency of immobilization and the activity of the immobilized IgG (i.e., the orientation of the immobilized IgG). The introduction of COOH promoted a more active orientation of the immobilized IgG. The orientation was determined during the adsorption process onto the azopolymer surface in solution before photo‐immobilization, and was maintained during the photo‐immobilization. The surface charge of the azopolymer appears to be an important factor for IgG orientation, which involves electrostatic interactions between its Fab and the azopolymer surface.