1-Benzhydryl -4- (5-nitro-2-furfurylideneamino) piperazine and 11 substituted analogs were prepared and examined for in vitro antimicrobial activity. The compounds were active against Bacillus cereus ...7, Bacillus megaterium 122, Bacillus subtilis 104, Clostridium perfringens 13, and the tetracycline-resistant Clostridium perfringens 37. Regression analyses on the antibacterial activity data based on the Hansch approach, using pi, pi2, and sigma parameters, yielded several statistically significant correlation equations. 1-Benzhydryl-4-(5-nitro-2-furfurylideneamino) piperazine stopped the protein and DNA syntheses in C. perfringens 13, as indicated by precipitable radioactivity. The compound, however, showed no effect on the cell wall synthesis in the bacteria.
Reflection artifacts may complicate the diagnosis of intracranial hemorrhage in preterm neonates. A linear focus of bright echoes in the region of the germinal matrix at or anterior to the ...caudothalamic grooves, often seen on parasagittal scans, may be mistaken for a germinal matrix hemorrhage but is actually a reflection of the ultrasound beam at the wall of the lateral ventricle. Cranial sonograms of 100 preterm infants were retrospectively analyzed and categorized with regard to presence and size of specular reflection. Eight cases demonstrated a bright echogenic focus; seven of these potentially could have been mistaken for hemorrhages.
On screening fecal organisms for hydroxysteroid dehydrogenase activities applicable to bile acid metabolism studies, we have isolated a gram negative "Bacteroides-like" anaerobe which yields both ...12alpha- and 7alpha-hydroxysteroid dehydrogenase (HSDH) activities in cell-free preparation. At the optimal harvest time of 36 hours, approximately 4500 units 12alpha-HSDH and 360 units 7alpha-HSDH were produced per 10(10) viable cells. The two enzymes appear to be separate entities in the basis of their stabilities on freezing, and prolonged storage at room temperature and elution volumes on Sephadex G 200. Thin layer chromatography studies on oxidation products confirmed the respective sites of oxidation to be the 12alpha-OH and 7alpha-OH position. No 3alpha-OH oriented activity was measurable. Preliminary kinetic studies of the 12alpha-HSDH revealed a broad pH curve with optimal activity at pH 9.5. Michaelis constants for glycodeoxycholate and NADP were estimated at 1.5 x 10(-4)M and 3.3 x 10(-5)M respectively.
Mobile ad hoc networks by their nature are highly adaptive systems that can come into existence on an as needed basis. They can grow, reduce in size, fragment, and dismantle as desired. The dynamic ...and very flexible nature of ad hoc networks can be taken to a further level of sophistication by allowing these networks to retune and adapt themselves according to prevailing network conditions. We are interested in scenarios in which ad hoc nodes must reconfigure as part of a network-wide adaptation process such that network-wide consensus is needed before any change can take place. We present an elegant solution for attaining global consensus in MANETs based on the social science theory of the diffusion of innovations. We present results of the application of this novel approach to an ad hoc network with an adaptive reconfigurable network layer.
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