Statin intensity and postoperative mortality following open repair of intact abdominal aortic aneurysm.

BackgroundThere is a lack of evidence for the association between intensive statin therapy and outcomes following vascular surgery. The aim of this study was to evaluate the association between perioperative statin intensity and in-hospital mortality following open abdominal aortic aneurysm (AAA) repair.MethodsPatients undergoing open AAA repair between 2009 and 2015 were identified from the Premier Healthcare Database. Statin use was classified into low, moderate and high intensity, based on American College of Cardiology/American Heart Association guidelines. Supratherapeutic intensity was defined as doses higher than the recommended guidelines. Multivariable logistic regression analyses were undertaken to assess the association between statin intensity and postoperative major adverse events and in-hospital mortality.ResultsOf 6497 patients undergoing open AAA repair, 3217 (49·5 per cent) received perioperative statin. Statin users were more likely to present with three or more co-morbidities than non-users (26·5 versus 21·8 per cent; P < 0·001). Unadjusted postoperative mortality was significantly lower in statin users (2·6 versus 6·3 per cent; P < 0·001); however, there was no difference in the risk of developing major adverse events. Multivariable analysis showed that statin use was associated with lower odds of death (odds ratio 0·41, 95 per cent c.i. 0·31 to 0·54). Moderate, high and supratherapeutic statin intensities were not associated with lower odds of death or major adverse events compared with low-intensity statin therapy.ConclusionStatin use is associated with lower odds of death in hospital following open AAA repair. High-intensity statins were not associated with lower morbidity or mortality

Bio-extraction of metal ions from laterite ore by Penicillium chrysogenum

The main objective of this study was to find a more feasible and economical method to extract metal ions from laterite ore by Penicillium chrysogenum. The effect of different substrates on microbial recovery of metal ions from laterite ore using indigenous strain of P. chrysogenum was observed. Maximum recovery of aluminum (86.78%), iron (97.78%), manganese (77.61%), nickel (57.31%) and chromium (34.32%) was recorded in case of shaking flasks experiments up to 24 days of incubation. Metal ions solubilization was also compared with the samples, which were not shaken and maximum recovery of Al (83.54 %), Fe (96.12 %), Mn (88.56 %), Ni (46.53 %) and Cr (37.82 %), were attained up to 24 days of incubation period. Enhanced recovery of Fe and Al may be due to the result of the acidic effect of the environment and the chelating capacity of organic acids.Key words: Bioleaching, Penicillium chrysogenum, agriculture wastes, laterite ore

A Multistage Stochastic Programming Approach to the Dynamic and Stochastic VRPTW - Extended version

We consider a dynamic vehicle routing problem with time windows and stochastic customers (DS-VRPTW), such that customers may request for services as vehicles have already started their tours. To solve this problem, the goal is to provide a decision rule for choosing, at each time step, the next action to perform in light of known requests and probabilistic knowledge on requests likelihood. We introduce a new decision rule, called Global Stochastic Assessment (GSA) rule for the DS-VRPTW, and we compare it with existing decision rules, such as MSA. In particular, we show that GSA fully integrates nonanticipativity constraints so that it leads to better decisions in our stochastic context. We describe a new heuristic approach for efficiently approximating our GSA rule. We introduce a new waiting strategy. Experiments on dynamic and stochastic benchmarks, which include instances of different degrees of dynamism, show that not only our approach is competitive with state-of-the-art methods, but also enables to compute meaningful offline solutions to fully dynamic problems where absolutely no a priori customer request is provided.Comment: Extended version of the same-name study submitted for publication in conference CPAIOR201

Synthesis of bacteriophage lytic proteins against Streptococcus pneumoniae in the chloroplast of Chlamydomonas reinhardtii.

There is a pressing need to develop novel antibacterial agents given the widespread antibiotic resistance among pathogenic bacteria and the low specificity of the drugs available. Endolysins are antibacterial proteins that are produced by bacteriophage-infected cells to digest the bacterial cell wall for phage progeny release at the end of the lytic cycle. These highly efficient enzymes show a considerable degree of specificity for the target bacterium of the phage. Furthermore, the emergence of resistance against endolysins appears to be rare as the enzymes have evolved to target molecules in the cell wall that are essential for bacterial viability. Taken together, these factors make recombinant endolysins promising novel antibacterial agents. The chloroplast of the green unicellular alga Chlamydomonas reinhardtii represents an attractive platform for production of therapeutic proteins in general, not least due to the availability of established techniques for foreign gene expression, a lack of endotoxins or potentially infectious agents in the algal host, and low cost of cultivation. The chloroplast is particularly well suited to the production of endolysins as it mimics the native bacterial expression environment of these proteins while being devoid of their cell wall target. In this study the endolysins Cpl-1 and Pal, specific to the major human pathogen Streptococcus pneumoniae, were produced in the C. reinhardtii chloroplast. The antibacterial activity of cell lysates and the isolated endolysins was demonstrated against different serotypes of S. pneumoniae, including clinical isolates and total recombinant protein yield was quantified at ~1.3 mg/g algal dry weight. This article is protected by copyright. All rights reserved

Influence of a Wall Close to a Vent Outlet

It is well known that the US NFPA 68 (2013) and the EU standard (EN14994:2007), based on the work of Bartknecht (1993), for gas venting do not agree and the EU standard will require a much larger vent area for the same Pred. The present work offers a possible explanation of the difference in these guidelines: the experimental results of. Bartknecht (1993) were carried out with the bottom of the vented vessel on the ground, so that the vent exit was relatively close to the ground and the interaction increased Pred. In the present work a 0.2 m3 cylinder of 0.5m diameter with end wall ignition was free vented into a large dump vessel with a 0.5m diameter connecting pipe. The wall of the 0.5m connecting pipe was close to the vent and the results showed that there was a wall interaction that gave Pred close to those of Bartknecht (1993) at low Kv. In the vented explosion work of Fakandu (2016b) using a 10L vessel, the discharge area was connected to a dump vessel with a 0.5m diameter pipe, which was much bigger than the 162mm diameter of the vented vessel and this gave overpressures close to those predicted in NFPA 68 (2013) with the turbulence parameter λ set to unity. The critical ratio of the centerline distance of the vented vessel to the external surface (ground in most cases) as a ratio of the distance from the edge of the vent to the external surface (DR) was shown to be 1.8 in this work, with lower values indicating no interaction. The present results show that Bartknecht’s experimental results had high Pred probably due to the presence of the ground as a nearby surface

Mixture Reactivity Effects on Explosion Venting

Free vented explosions were investigated for 10% methane, 4.2 and 4.5% propane, 6.5 and 7.5% ethylene, 30% and 40% hydrogen in a 10 litre cylindrical explosion vessel for vent coefficients of 4.3 and 21.7. The cylindrical vessel volume was 10L and had a diameter of 162mm and an L/D of 2.8. End ignition was used on the wall opposite the vent. The results are presented against KG and the laminar burning velocity as measures of the mixture reactivity. It is shown that the correlation of the KG effect by Bartknecht does not agree with other experimental data, although the hydrogen results are closer to the present results than the other gases. In contrast the laminar flame venting theory, as used in NFPA68 (2013), does correlate the data well, even though it is not supposed to apply to hydrogen explosions. There was evidence of very fast flames at the vent for hydrogen explosions. Acceleration of the flames towards the vent was demonstrated, due to the expansion of the burnt gases in the direction of the vent. The laminar flame venting theory that is used in NFPA68 (2013) over predicts the measured Pred due to the assumption of the vessel surface area as the area of the flame at Pred. It was shown that the flame arrives at the wall after the flame has vented the vessel and well after the time that Pred occurs. At Kv 4.3 the external overpressure was responsible for Pred, although the difference from Pfv was small for methane, propane and ethylene but for hydrogen the flow through the vent Pfv was the highest overpressure. At Kv = 21.7 the pressure loss due to the unburnt gas flow through the vent was the largest overpressure. For hydrogen sonic flow at the vent occurs and at high Kv sonic flow is predicted to occur using the laminar flame venting equation modified for sonic flow at the vent. Sonic flow at the vent is not taken into account in current venting guidance

Particle size emissions from PVC electrical cable fires

Electrical cables are in every building and form a significant part of fire loads and can through electrical faults be the first item burnt in some fires. PVC insulated cables are still quite common in buildings and this work investigates Prysmian PVC cables. Deaths and injuries in fires are dominated by the influence of toxic smoke emissions and most of the work on the hazards of smoke are concerned with the toxic gases such as CO. However, fires are large producers of particulate material at levels over 1000 times that in controlled combustion and there is little knowledge of the role of ultra-fine particles in fires and none at all for electrical cable fires. The cone calorimeter fire material testing equipment was used in the present work, which is an ideal test procedure for particle size measurement, as controlled dilution (100/1) of the fire products occurs which enabled diluted samples to be used for particulate number measurement. The Cambustion DMS500 transient particle size analyser was used to determine the particle size distribution. The cone calorimeter uses a 100mm square test specimen and this was filled with 10 100mm lengths of the PVC cable. The test specimen was on a load cell so that the mass burn rate was determined. The cone calorimeter ignites the specimen using a conical electrical heater that is calibrated to achieve a control radiant heat flux on the test specimen, which was 35 kW/m2 in the present work. The fire occurred in a restricted air supply with an insulated air box around the 100mm square test fire. A chimney on the conical heater exit was used to obtain a raw gas sample for toxic gas analysis using a heated Gasmet FTIR. For gases dilution is undesirable as oxidation of the toxic gases may occur. For particles the chimney temperature was too low for carbon oxidation to be significant. The dilution process also condenses unburned hydrocarbons and carbonyl species, which may form nano aerosols and these may be the source of the 10nm particles measured in the present work. HCl is a major product of PVC fires and hence hydrochloric acid aerosols are likely in the particulate measurements. In previous work of the authors, PVC cable fires were investigated with free ventilation and HCl yields of about 50% were measured with Acrolein at 5% yield and Formaldyhyde at 3%. Thus there are plenty of liquid aerosol possible in the diluted products of PVC fires. The results showed a large nuclei number peak at about 10nm. The coarse particle peak only started after flaming combustion occurred and this was initially at 200nm, which increased to 300nm after 1000s. The 10nm peak was high for the first 200s, then dropped dramatically and slowly reformed later in the fire and at the end of the fire was very high with a low coarse particle peak. The FTIR gas species will be used to speculate on the likely composition of the nanoaerosols as a function of time in the fire

Ordered Mesoporous to Macroporous Oxides with Tunable Isomorphic Architectures: Solution Criteria for Persistent Micelle Templates

Porous and nanoscale architectures of inorganic materials have become crucial for a range of energy and catalysis applications, where the ability to control the morphology largely determines the transport characteristics and device performance. Despite the availability of a range of block copolymer self-assembly methods, the conditions for tuning the key architectural features such as the inorganic wall-thickness have remained elusive. Toward this end, we have developed solution processing guidelines that enable isomorphic nanostructures with tunable wall-thickness. A new poly(ethylene oxide-b-hexyl acrylate) (PEO-b-PHA) structure-directing agent (SDA) was used to demonstrate the key solution design criteria. Specifically, the use of a polymer with a high Flory-Huggins effective interaction parameter, χ, and appropriate solution conditions leads to the kinetic entrapment of persistent micelle templates (PMT) for tunable isomorphic architectures. Solubility parameters are used to predict conditions for maintaining persistent micelle sizes despite changing equilibrium conditions. Here, the use of different inorganic loadings controls the inorganic wall-thickness with constant pore size. This versatile method enabled a record 55 nm oxide wall-thickness from micelle coassembly as well as the seamless transition from mesoporous materials to macroporous materials by varying the polymer molar mass and solution conditions. The processing guidelines are generalizable and were elaborated with three inorganic systems, including Nb2O5, WO3, and SiO2, that were thermally stable to 600 °C for access to crystalline materials

Josephson effects in MgB2 meta masked ion damage junctions

Ion beam damage combined with nanoscale focused ion beam direct milling was used to create manufacturable SNS type Josephson junctions in 100 nm thick MgB$_{2}$ with T$_{C}$ of 38 K. The junctions show non-hysteretic current - voltage characteristics between 36 and 4.2 K. Experimental evidence for the dc and ac Josephson effects in MgB$_{2}$ metal masked ion damage junctions are presented. This technique is particularly useful for prototyping devices due to its simplicity and flexibility of fabrication and has a great potential for high-density integration.Comment: 12 pages, 4 figures, RevTeX4, submitted to AP