1.3-Dipolar cycloaddition products of 8-azidotetrazol[1,5a][1,8]naphthyridines with alkynes

A series of new 1,2,3-triazol derivatives, obtained by reaction of 8-azidotetrazol[1,5-a][1,8]naphthyridine with alkynes, is described. Some of the tested compounds showed activity against hypoxia in mice.     

On the various stages of spinodal decomposition in an Al-38 at % Zn alloy

Spinodal decomposition of an Al-38 at % Zn alloy in the temperature range 293 to 573 K has been studied by transmission electron microscopy. Microstructural evidences for the existence of various stages of spinodal decomposition, namely, the initial, the corsening and the particulate stages have been established. The morphological characteristics and the different diffusion regimes under which these stages are operative are explained.     

Predictive Model for Optimized Design Parameters in Flip-Chip Packages and Assemblies

An analytical model is developed to predict the out-of- plane deformation and thermal stresses in multilayered thin stacks subjected to temperature. Coefficient of thermal expansion mismatches among the components (chip, substrate, underfill, flip-chip interconnect or C4s) are the driving force for both first and second levels interconnect reliability concerns. Die cracking and underfill delamination are the concerns for the first level interconnects while the ball grid array solder failure is the primary concern for the second level interconnects. Inadvertently, many researchers use the so-called rule of mixture in its effective moduli for the flip chip solder (C4)/underfill layer. In this study, a proper formula for effective moduli of solder (C4)/underfill layer, is presented. The classical lamination theory is used to predict the out-of-plane displacement of the chip substrate structure under temperature variation (DeltaT). The warpage and stresses resulting from the analytical formulation are compared with the 3-D finite element analysis. The study helps to design more reliable components or assemblies with the design parameters being optimized in the early stage of the development using closed form analytical solutions.     

Internal auditory artery infarction: clinicopathologic correlation

Immunocytochemical examination for mitochondrial protein and cytochrome oxidase was performed to demonstrate oncocytes in normal adenohypophysis obtained from 28 patients of various age. A small number of solitary large epithelial cells showed intense cytoplasmic granular immunoreactivities for mitochondrial protein and cytochrome oxidase. The proportions of the cells positive for the former and the latter ranged from 0% to 5.9% (mean+/-SD; 1.5+/-1.7%) and from 0% to 4.9% (1.4+/-1.6%), respectively. These cells were either absent or extremely rare in young patients (under 10 years) but tended to increase in number with age (P < 0.0001). On the other hand, the mirror section technique showed that most of these cells were negative for adenohypophysial hormones, but a few of them were faintly positive for: alpha-subunit (8.0%), beta-subunits of follicle-stimulating hormone (4.8%), luteinizing hormone (2.5%), thyroid-stimulating hormone (1.0%), and growth hormone (0.5%), and were negative for prolactin and adrenocorticotropic hormone. We considered that these cells represent oncocytes that exist in varying numbers in normal adenohypophysis. It was suggested that oncocytes in normal adenohypophysis share various common features with tumorous oncocytes of pituitary oncocytomas.