Adenosine receptor mediates motility in human melanoma cells

Cell motility is an essential component of tumor progression and metastasis. A number of factors, both autocrine and paracrine, have been found to influence cell motility. In the present study, adenosine and adenine nucleotides directly stimulated chemotaxis of A2058 melanoma cells in the absence of exogenous factors. Three adenosine receptor agonists stimulated motility in the melanoma cells and two adenosine receptor antagonists strongly inhibited the chemotactic response to both adenosine and AMP. The chemotactic stimulation by adenosine and AMP was pertussis toxin sensitive. Otherwise unresponsive Chinese hamster ovary cells which were transfected with the adenosine A1 receptor cDNA acquired the direct, pertussis toxin sensitive, chemotactic response to adenosine, and this response was inhibited by adenosine receptor antagonists. These findings demonstrate that adenosine and adenine nucleotides are capable of stimulating chemotaxis of tumor cells mediated through an adenosine receptor, probably of the A1 subtype. The possibility of antimetastatic therapies based on inhibition of adenosine receptor activity is raised.     

Parametric graph drawing

A diagram is a drawing on the plane that represents a graph like structure, where nodes are represented by symbols and edges are represented by curves connecting pairs of symbols. An automatic layout facility is a tool that receives as input a graph like structure and is able to produce a diagram that nicely represents such a structure. Many systems use diagrams in the interaction with the users; thus, automatic layout facilities and algorithms for graphs layout have been extensively studied in the last years. We present a new approach in designing an automatic layout facility. Our approach is based on a modular management of a large collection of algorithms and on a strategy that, given the requirements of an application, selects a suitable algorithm for such requirements. The proposed approach has been used for designing the automatic layout facility of Diagram Server, a network server that offers to its clients several facilities for managing diagrams     

Mobile Agent-Based Performance Management for the Virtual Home Environment

Virtual Home Environment (VHE) encompasses the deployment and management of adaptable services that retain any personalized service aspects, irrespective of terminal, network' and geographic location. We assert that the dynamic nature of the VHE requires management capabilities that can be suitably provided through the use of mobile agent technology. We examine four different engineering solutions for the realization of a VHE performance management component that allows service adaptation in relation to the available network Quality-of-Service (QoS). The mobile agent approach is compared with competing technologies in order to identify the benefits of this novel application of mobile agents, discuss its drawbacks' and finally focus on the lessons learned from our prototype system. Although mobile agents are typically associated with increased performance costs, it is through agent migration that we were able to address the VHE requirements of universality, dynamic programmability, and network technology independence.     

Probing the cybotactic region in gas-expanded liquids (GXLs)

Gas-expanded liquids (GXLs) are a new and benign class of liquid solvents, which may offer many advantages for separations, reactions, and advanced materials. GXLs are intermediate in properties between normal liquids and supercritical fluids, both in solvating power and in transport properties. Other advantages include benign nature, low operating pressures, and highly tunable properties by simple pressure variations. The chemical community has only just begun to exploit the advantages of these GXLs for industrial applications. This Account focuses on the synergism of experimental techniques with theoretical modeling resulting in a powerful combination for exploring chemical structure and transport in the cybotactic region of GXLs (at the nanometer lengthscale).     

Selective alkylation of acidic hydroxyl groups in coal

The organic molecules which make up coal are held together not only by covalent bonds, but also by a substantial network of hydrogen bonds as well as certain other weak intermolecular associations, which together are called the secondary structure. It is believed that acidic hydroxyl groups are responsible for most of the secondary structure. These attractive forces have been diminished traditionally by solvent swelling the coal, then permanently removed by selective silylation or acetylation of the polar functionalities. A new selective alkylation procedure has been developed which converts polar hydroxyls into relatively non-polar ethers and esters, and has been successfully tested on a bituminous and sub-bituminous coal. This selective O-alkylation proceeds rapidly under very mild conditions and renders the coal essentially free from its secondary structure.     

Catalytic Removal of Toluene over Co3O4–CeO2 Mixed Oxide Catalysts: Comparison with Pt/Al2O3

The catalytic oxidation of toluene, chosen as VOC probe molecule, was investigated over Co₃O₄, CeO₂ and over Co₃O₄–CeO₂ mixed oxides and compared with the catalytic behavior of a conventional Pt(1 wt%)/Al₂O₃ catalyst. Complete toluene oxidation to carbon dioxide and water was achieved over all the investigated systems at temperatures below 500 °C. The most efficient catalyst, Co₃O₄(30 wt%)–CeO₂(70 wt%), showed full toluene conversion at 275 °C, comparing favorably with Pt/Al₂O₃ (100% toluene conversion at 225 °C).     

First Principles Modeling of Pd‐doped (La,Sr)(Co,Fe)O3 Complex Perovskites

(La,Sr)(Co,Fe)O₃ (LSCF) perovskites are well known promising materials for cathodes of solid oxide fuel cells. In order to reduce cathode operational temperature, doping on B‐sublattice with different metals was suggested. Indeed, as it was shown recently experimentally, doping with low Pd content increases oxygen vacancy concentration which is one of factors controlling oxygen transport in fuel cells. In this Communication, we modeled this material using first principles DFT calculations combined with supercell model. The charge density redistribution, density of states, and local lattice distortion around palladium ions are analyzed and reduction of the vacancy formation energy confirmed.     

Preoperative bowel cleansing: outpatient versus inpatient preparation

This study investigated the safety and efficacy of preoperative outpatient bowel preparation (OBP) and compared it with inpatient bowel preparation (IBP). Records of patients who underwent OBP and IBP for elective colorectal surgery from January 1995 to December 1997 were compared. All patients were instructed to take during the three days before surgery metronidazole (1.5 g pro die) while an oral polyethylene glycol solution was used for the oral lavage during the 12 hours before operation. The two groups, 65 patients, were uniform for age, sex, diagnosis and operations performed. The OBP group had a shorter length of hospital stay (median 9 vs 10 days; p = ns) whereas the complication rate was similar including infectious complications. Data on operating time, perioperative fluid and blood requirements, perioperative diuresis were not significantly different in the two groups. Outpatient bowel preparation for elective colorectal surgery is safe and effective while offering short hospital stay and therefore reduction in medical care cost.