Refractory ascites: a fifteen-year experience with the peritoneovenous shunt

The authors consider the various causes of ascites and they also develop the concept of refractory ascites. They consider the various possibilities of medical and dietary therapy whose failure constitutes the basis for a surgical approach. In the latter case it is being considered the Peritoneo Venous Shunt (PVS) that employs different types of valves. In the light of their personal experience, matured over a period of 15 years, in which 75 valves were positioned in 64 patients and precisely: 55 valves of Le Veen, 15 Hakim and 5 Denver, it is emphasized that the best results, as for as mortality and morbidity goes, were obtained through careful attention in the preoperative stage and during surgery itself with the privileged use of a Le Veen's valve. For such motives, since in a high percentage of these patients there persists a poor prognosis a year away from the onset of refractory ascites, a PVS seems proposable anyway and even though this will not alter the pathological outcome, there's a clear improvement in the quality of life without precluding any other surgical approach. Finally, the authors outline the possibilities offered by the Transjugular Intrahepatic Portosystemic Shunt (TIPS), as a new original approach for the resolution of refractory ascites.     

Low Replicative Stress Triggers Cell-Type Specific Inheritable Advanced Replication Timing

DNA replication timing (RT), reflecting the temporal order of origin activation, is known as a robust and conserved cell-type specific process. Upon low replication stress, the slowing of replication forks induces well-documented RT delays associated to genetic instability, but it can also generate RT advances that are still uncharacterized. In order to characterize these advanced initiation events, we monitored the whole genome RT from six independent human cell lines treated with low doses of aphidicolin. We report that RT advances are cell-type-specific and involve large heterochromatin domains. Importantly, we found that some major late to early RT advances can be inherited by the unstressed next-cellular generation, which is a unique process that correlates with enhanced chromatin accessibility, as well as modified replication origin landscape and gene expression in daughter cells. Collectively, this work highlights how low replication stress may impact cellular identity by RT advances events at a subset of chromosomal domains.     

Using short-circuit currents to perform a protective devicecoordination study

The article provides a brief background on the fundamentals of short-circuit analysis. Following that background is a discussion of how various types of phase overcurrent protective devices respond to the short-circuit current waveform. Based on this discussion, the short-circuit currents which are necessary to perform a protective device coordination study are specified. A comparison of the two types of short-circuit studies follows, based on the complex impedance network representation of the power system. The results of the comparison are then used to present recommendations for how the results of a computer-aided study to compute short-circuit current duties can be applied to determine the short-circuit currents necessary to select the settings of phase overcurrent protective devices. Finally, a sample industrial power system is provided to clarify the recommendations     

Industry-sponsored student projects to promote power qualityeducation

The authors present the results of two industry-sponsored senior design projects on power quality: effect of harmonic current distortion on power transformer capability, sponsored by the Philadelphia Electric Company (PECO); and power quality survey of a commercial system, sponsored by BCM engineers. The objective of the first project was to investigate the effect of harmonic current distortion on the capabilities of critical power transformers that service computing equipment in the corporate headquarters of PECO. The objective of the second project was to conduct a power quality survey of the BCM system to ascertain whether power line disturbances were the causes of outages and failures of essential BCM computing facilities. Each project had its own power line monitor. The success of these student projects has promoted interest in power engineering as a career for many of the group members and generated enrollment in the senior-level power program     

TREND OF ATMOSPHERIC BENZO[ a ]PYRENE IN ITALY BEFORE THE ADOPTION OF THE EUROPEAN DIRECTIVE ON PAHs

The benzo[a]pyrene temporal trend was investigated in 11 towns where at least five annual means were available. The overall number of stations was 22, of which 12 were traffic-oriented, 6 background and 4 industrial. The trend was generally declining at traffic-oriented sites and roughly stable at background sites. The annual means in 2004 still exceeded the forthcoming European target value of 1 ng/m ³ in two towns (up to 1.9 ng/m ³ ). The background means (up to 1.4 ng/m ³ in 2004) accounted for approximately 40–90% of those at the traffic-oriented sites in the same town. The presence of a coke plant was incompatible with the attainment of the target value, while the adoption of technical measures on a carbon electrode plant was successful in attaining concentrations lower than the target value. In heavy traffic areas in Italy, the attainment of the target value hardly appears feasible under the current conditions of traffic congestion.     

Analysis of interlaboratory comparisons affected by correlations of the reference standards and drift of the travelling standards

The paper describes a method for analysing interlaboratory comparison results among accredited laboratories. Interlaboratory comparisons are used in order to achieve or to maintain the accreditation following the ISO/IEC 17025 standard. The used approach permits an evaluation of the reference value and of the degree of equivalence in the cases in which the laboratories participating are mutually dependent and the travelling standards are not stable during the comparison. This approach, as an example, was applied to analyse the SIT (Servizio di Taratura in Italia) interlaboratory comparisons carried out for the pressure quantity in the range from 10 MPa to 100 MPa (gage mode and liquid medium) and in the range from 0.15 MPa to 7 MPa (gage mode and gas medium).