Comparison of the effectiveness of four linearizing techniques used in SiGe HBT LNA at 1900 MHz and low-bias voltage

In this article, four linearizing techniques are compared with each other when they are used in a common-emitter SiGe HBT LNA. Finally, when all of them are employed together, improved linearity of the LNA is observed and more than 10 dBm of IIP3 and −5 dBm of 1-dB gain input compression point are realized when the circuit is fed with 2.4 V. © 2004 Wiley Periodicals, Inc. Int J RF and Microwave CAE 14, 144–152, 2004.     

A PNA-array platform for the detection of hidden allergens in foodstuffs

A duplex PCR method was developed to simultaneously detect the presence of hazelnut and peanut in raw materials and commercial products. It was found to be able to specifically detect traces of the investigated products down to 50 pg of their target DNA.A PNA array device has been designed and implemented to be used in combination with the duplex PCR in order to investigate the presence of traces of potentially allergenic nuts in foodstuffs. A PNA probe for each target amplified by the duplex PCR was designed, synthesized and characterized. The PNA probes were then deposited on commercial slides in order to build a PNA array to be used for recognizing the PCR products; the concentration of the probes as function of the concentration of the target DNA, together with the specificity of the probes were investigated.The conditions optimized during the setting of the experiment were used to obtain the final version of the PNA array which was then used to test several commercially available foodstuffs claiming to contain or not to contain the targeted nuts.     

Compositional SOS and beyond: a coalgebraic view of open systems

In this paper we address the issue of providing a structured coalgebra presentation of transition systems with algebraic structure on states determined by an equational specification Γ. More precisely, we aim at representing such systems as coalgebras for an endofunctor on the category of Γ-algebras. The systems we consider are specified by using arbitrary SOS rules, which in general do not guarantee that bisimilarity is a congruence. We first show that the structured coalgebra representation works only for systems where transitions out of complex states can˜be derived from transitions out of corresponding component states. This decomposition property of transitions indeed ensures that bisimilarity is a congruence. For a system not satisfying this requirement, next we propose a closure construction which adds context transitions, i.e., transitions that spontaneously embed a state into a bigger context or vice versa. The notion of bisimulation for the enriched system coincides with the notion of dynamic bisimilarity for the original one, i.e., with the coarsest bisimulation which is a congruence. This is sufficient to ensure that the structured coalgebra representation works for the systems obtained as result of the closure construction.     

The human gallbladder increases cholesterol solubility in bile by differential lipid absorption: a study using a new in vitro model of isolated intra-arterially perfused gallbladder

In this study, we first developed and validated a new in vitro isolated, intra-arterially perfused, gallbladder model and then applied the method to investigate the absorption of biliary lipids by the gallbladder wall and the effect of this process on the composition of human bile. Oxygenated and glucose-added buffer was perfused through the cystic artery to maintain organ viability. A standard pooled natural bile, radiolabeled with H3-cholesterol and C14-palmitoyl-linoleoyl-phosphatidylcholine, was instilled in the lumen via a cystic duct catheter. Changes in bile volume and lipid concentrations were monitored at time intervals to evaluate the disappearance of lipids from bile caused by gallbladder absorptive function. Organ viability was demonstrated by stable lactate dehydrogenase (LDH) organ release and oxygen consumption throughout the experiments. In the pig, disappearance rates of lipids from bile were similar in vitro and in vivo, demonstrating the validity of the isolated in vitro model for functional studies. By applying our in vitro isolated preparation to the human gallbladder, we found that 23% of cholesterol and 32% of phosphatidylcholine, but only 9% of bile salts, disappeared from bile in 5 hours. As a consequence, at the end of the experiments, cholesterol (P < .05) and phospholipid (P < .05) molar percentages were significantly reduced, while the bile salt (P < .05) molar percentage was significantly increased with respect to values at the beginning of the studies. Our findings are of pathophysiological relevance and support the concept that the human gallbladder modifies the relative composition of biliary lipids in such a way as to increase cholesterol solubility in bile.     

Physical and functional characterization of PHASCL membranes

Dense semicrystalline membranes of polyhydroxyalkanoates with medium change length (PHA_SCL), polyhydroxybutyrate (PHB) and poly β (hydroxybutyrate-co-hydroxyvalerate) [P(βHB-co-XβHV)] were characterized using wide-angle X-ray (WAXS) and scanning electron microscopy. PHB membranes showed a more rugged surface than those of copolymers (0-22%HV). Properties such as swelling capacity, vapor permeability and selectivity were investigated. Swelling percentage in water-ethanol mixtures was 34% for PHB as compared to 14% for copolymers membranes. The ethanol/water selectivity (α_s) of PHB was 5.8 which shows that it is more selective than copolymers.The water vapor and ethanol vapor permeability were determined by a gravimetric technique at different temperatures by static and dynamic methods. PHB permeability was 69.5 Barrer at 30 °C and a discreet increment was observed at temperatures (30-50 °C). The difference in permeability between PHB and [P(βHB-co-X%βHV)] could be interpreted in terms of the crystallization rate, crystallite size and distribution which impact to transport properties of amorphous phase.     

Effects of pimozide on escape and discrimination performance in a water-escape task.

Three experiments studied the effects of pimozide (0.2 and 0.4 mg/kg) on discrimination learning of 255 male CD1 mice in a water-escape paradigm in which the degree of motor difficulty was manipulated by varying water temperature. The drug marginally affected escape latencies in relatively warm water (25°C) but markedly disrupted escape latencies when the task was more demanding (e.g., 15 and 20°C water). The escape deficits, however, were not accompanied by disturbances in the acquisition of position discrimination or cue discrimination responses when Ss were required to make the highly prepared response of swimming to light or the contraprepared response of swimming to dark. Data suggest that in tasks involving aversive motivation, pimozide influences performance through its effects on response maintenance but does not appear to affect either associative or motivational processes. (20 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

SECT: An effective coding technique for polygonal geographic data

Memory occupation of geographic data and efficiency of the selection and elaboration algorithms are challenging problems in designing a system for polygonal data processing. They arise basically from the large number of polygon vertices necessary to properly approximate territory maps. Since the number of vertices is determined by the expected resolution, data compression can only be achieved by reducing the memory occupation of each point. On the other hand, more efficient algorithms are obtained if unnecessary operations are carefully avoided: in geographic data processing this is done by precisely delimiting the territory areas to be processed. In this paper, the SECT coding technique is presented, which meets both the above requirements. Its data compression capability is proved with reference to points, lines and regions coding, having considered geographic data of different density. Furthermore, the benefits it ensures in terms of both CPU time and I/O operation savings are discussed.     

Laser monitoring of non‐Newtonian liquids during dip coating

Dip coated films, widely used in the coating industry, are usually measured by capacitive methods with micrometric precision. In this work, interferometric determination of thickness evolution in real time, for the first time to our best knowledge, is applied to volatile non‐Newtonian liquids with several viscosities and distinct dip withdrawing speeds. Thickness evolution during the process depends on time as predicted by a power law model. Comparison with measured results (uncertainty of ± 0.007 μm) showed very good agreement after initial steps of the process. © 2009 American Institute of Chemical Engineers AIChE J, 2009