On the mechanisms governing gas penetration into a tokamak plasma during a massive gas injection

A new 1D radial fluid code, IMAGINE, is used to simulate the penetration of gas into a tokamak plasma during a massive gas injection (MGI). The main result is that the gas is in general strongly braked as it reaches the plasma, due to mechanisms related to charge exchange and (to a smaller extent) recombination. As a result, only a fraction of the gas penetrates into the plasma. Also, a shock wave is created in the gas which propagates away from the plasma, braking and compressing the incoming gas. Simulation results are quantitatively consistent, at least in terms of orders of magnitude, with experimental data for a D 2 MGI into a JET Ohmic plasma. Simulations of MGI into the background plasma surrounding a runaway electron beam show that if the background electron density is too high, the gas may not penetrate, suggesting a possible explanation for the recent results of Reux et al in JET (2015 Nucl. Fusion 55 093013)

The Cholecystectomy As A Day Case (CAAD) Score: A Validated Score of Preoperative Predictors of Successful Day-Case Cholecystectomy Using the CholeS Data Set

Background Day-case surgery is associated with significant patient and cost benefits. However, only 43% of cholecystectomy patients are discharged home the same day. One hypothesis is day-case cholecystectomy rates, defined as patients discharged the same day as their operation, may be improved by better assessment of patients using standard preoperative variables. Methods Data were extracted from a prospectively collected data set of cholecystectomy patients from 166 UK and Irish hospitals (CholeS). Cholecystectomies performed as elective procedures were divided into main (75%) and validation (25%) data sets. Preoperative predictors were identified, and a risk score of failed day case was devised using multivariate logistic regression. Receiver operating curve analysis was used to validate the score in the validation data set. Results Of the 7426 elective cholecystectomies performed, 49% of these were discharged home the same day. Same-day discharge following cholecystectomy was less likely with older patients (OR 0.18, 95% CI 0.15–0.23), higher ASA scores (OR 0.19, 95% CI 0.15–0.23), complicated cholelithiasis (OR 0.38, 95% CI 0.31 to 0.48), male gender (OR 0.66, 95% CI 0.58–0.74), previous acute gallstone-related admissions (OR 0.54, 95% CI 0.48–0.60) and preoperative endoscopic intervention (OR 0.40, 95% CI 0.34–0.47). The CAAD score was developed using these variables. When applied to the validation subgroup, a CAAD score of ≤5 was associated with 80.8% successful day-case cholecystectomy compared with 19.2% associated with a CAAD score >5 (p < 0.001). Conclusions The CAAD score which utilises data readily available from clinic letters and electronic sources can predict same-day discharges following cholecystectomy

Effective delivery and selective insecticidal activity of double-stranded RNA via complexation with diblock copolymer varies with polymer block composition

BACKGROUND Chemical insecticides are an important tool to control damaging pest infestations. However, lack of species specificity, the rise of resistance and the demand for biological alternatives with improved ecotoxicity profiles means that chemicals with new mode-of-actions are required. RNA interference (RNAi)-based strategies using double-stranded RNA (dsRNA) as a species-specific bio-insecticide offer an exquisite solution that addresses these issues. Many species, such as the fruit pest Drosophila suzukii, do not exhibit RNAi when dsRNA is orally administered, due to degradation by gut nucleases and slow cellular uptake pathways. Thus, delivery vehicles that protect and deliver dsRNA are highly desirable. RESULTS In this work, we demonstrate the complexation of D. suzukii-specific dsRNA for degradation of vha26 mRNA with bespoke diblock copolymers. We study the ex vivo protection of dsRNA against enzymatic degradation by gut enzymes, which demonstrates the efficiency of this system. Flow cytometry then investigates the cellular uptake of Cy3-labelled dsRNA, showing a 10 fold increase in the mean fluorescence intensity of cells treated with polyplexes. The polymer/dsRNA polyplexes induced a significant 87% decrease in the odds of survival of D. suzukii larvae following oral feeding, only when formed with a diblock copolymer containing a long neutral block length (1:2 cationic block/neutral block). However, there was no toxicity when fed to the closely related D. melanogaster. CONCLUSION Thus, we provide evidence that dsRNA complexation with diblock copolymers is a promising strategy for RNAi-based species-specific pest control, however, optimisation of polymer composition is essential for RNAi success

An outbreak of drug-resistant tuberculosis caused by a Beijing strain in the Western Cape, South Africa

During October 2005, four children in a school in Cape Town were identified with multidrug-resistant tuberculosis (MDR-TB). Genetic analysis confirmed that these isolates belonged to a single cluster (Beijing cluster 220) and that all harboured a -15 inhAC-T promoter mutation demonstrating transmission. Genetic analysis of isolates cultured from patients from the Boland-Overberg-South Cape-Karoo and Cape Town regions showed that 28% (58/209) of patients infected with a Beijing strain had the cluster 220 genotypes and that all harboured the same -15 inhAC-T promoter mutation. The presence of these transmissible MDR-TB strains may pose a threat to the community, and rigorous infection control measures are needed to ensure the safety of those exposed. © 2006 The Union.Articl

Recombinant activated factor VII: a solution to refractory haemorrhage in vascular surgery?

ObjectivesPost-operative haemorrhage is a recognised complication and independent predictor of outcome in complex vascular surgery. The off-license administration of activated Recombinant Factor VII (rFVIIa) to treat haemorrhage in other surgical settings has been investigated, but concerns over potential adverse events have limited its use in vascular surgery. This article reports rFVIIa's method of action and systematically reviews rFVIIa's role in complex vascular surgery.MethodsA systematic literature search identified articles reporting on rFVIIa administration within vascular surgery patients. Patient-specific data regarding transfusion requirements was extracted and pooled statistical analysis performed.Results15 articles reporting 43 patients were identified. RFVIIa has been administered in open and endovascular procedures and in both elective and emergency settings. Major aortic surgery accounted for 75% of cases. The range of rFVIIa administered as a cumulative dose was large, as was the variation in initial dose. Transfusion data from 9 patients was pooled and analysed. Significant differences were found between pre- and post- rFVIIa for packed red cell transfusions (mean 29.2 vs. 8.2, p=0.015). Intra-arterial thrombosis was reported in 3 cases.ConclusionsRFVIIa may reduce haemorrhage in selected vascular surgical patients. Randomized controlled trials are justified to definitively investigate its role within this setting