An optimised PCR/T-RFLP fingerprinting approach for the investigation of protistan communities in groundwater environments.

Due to the scarcity or complete absence of higher organisms, protists may represent an important higher trophic level (above Prokaryotes) in the food webs of groundwater habitats. Nevertheless, the importance of aquifer protists, especially in contaminated groundwater environments, is poorly understood. Partly, this may be due to a lack of adequate PCR and fingerprinting approaches for protists in aquifers, which can be considered low in protistan or high in non-target rRNA gene copy numbers. Therefore, we have validated the suitability of distinct eukaryote-targeted primer pairs and restriction endonucleases for T-RFLP fingerprinting of protistan communities. By in silico predictions, and by fingerprinting, cloning and sequencing of microeukaryote amplicons from hydrocarbon-contaminated aquifer sediment DNA, we show that the Euk20f/Euk516r primer set in combination with Bsh1236I digestion is best suited for the recovery of diverse protistan 18S rRNA lineages. In contrast to other tested primer sets, a preferred recovery of fungal and archaeal non-target amplicons was not observed. In summary, we present an optimised microeukaryote-targeted PCR/T-RFLP fingerprinting approach which may be of value for the characterisation of protistan communities in groundwater and other habitats

Selective elimination of bacterial faecal indicators in the <em>Schmutzdecke</em> of slow sand filtration columns.

Slow sand filtration (SSF) is an effective low-tech water treatment method for pathogen and particle removal. Yet despite its application for centuries, it has been uncertain to which extent pathogenic microbes are removed by mechanical filtration or due to ecological interactions such as grazing and competition for nutrients. In this study, we quantified the removal of bacterial faecal indicators, Escherichia coli and Enterococcus faecalis, from secondary effluent of a wastewater treatment plant and analysed the microbial community composition in compartments of laboratory model SSF columns. The columns were packed with different sand grain sizes and eliminated 1.6-2.3 log units of faecal indicators, which translated into effluents of bathing water quality according to the EU directive (&lt;500 colony forming units of E. coli per 100&nbsp;ml) for columns with small grain size. Most of that removal occurred in the upper filter area, the Schmutzdecke. Within that same zone, total bacterial numbers increased however, thus suggesting a specific elimination of the faecal indicators. The analysis of the microbial communities also revealed that some taxa were removed more from the wastewater than others. These results accentuate the contribution of biological mechanisms to water purification in SSF

Distal aortic reintervention after surgery for acute DeBakey type I or II aortic dissection: open versus endovascular repair.

OBJECTIVES: Aortic dissection DeBakey type I and II may require distal reinterventions after initial proximal repair. We evaluated outcomes following open versus endovascular approaches to distal aortic pathologies after surgery for acute dissection. METHODS: One hundred and forty-one consecutive patients underwent 152 distal reinterventions after previous type I or II dissection repair [63 (first quartile, 55; third quartile, 72) years old; initially 86% DeBakey type I; 54% hemiarch, 39% isolated ascending, 7% total arch replacement] at two tertiary centres in the USA and Europe over the last 14 years. Among them, 56 and 85 required reintervention for the aortic arch and the descending aorta, respectively. The median follow-up was 2.1 (first quartile, 0.8; third quartile, 5.8) years (439 patient-years). RESULTS: The median time between acute aortic dissection repair and descending aortic reintervention was longer in the open group (2.7 (first quartile, 0.8; third quartile, 6.7) vs 0.6 (first quartile, 0.1; third quartile, 3.5) years, P \u3c 0.01). There was one irreversible spinal ischaemia in the open and one stroke in the endovascular group. Two patients in the open and none in the endovascular group required re-exploration for bleeding. Two open and 4 endovascular patients required more than 1 distal reintervention (6 vs 8%, P = 1). Descending aortic open-repair patients experienced higher in-hospital mortality (23 vs 0%, P \u3c 0.01) and lower survival at 1 and 5 years (74 ± 8% vs 96 ± 3%, 65 ± 9% vs 92 ± 5%, P \u3c 0.01, respectively). CONCLUSIONS: Endovascular intervention for descending aortic pathologies after DeBakey type I or II dissection surgical repair is associated with lower in-hospital mortality and better survival, and does not raise the likelihood of later reinterventions at the mid-term follow-up

Low-dose vs high-dose paclitaxel-coated balloons for femoropopliteal lesions: 2-Year results from the COMPARE Trial.

Background: So far only 1-year data have been reported for direct comparisons of paclitaxel-coated balloons (PCBs) using different coating technologies. Objectives: The aim of this study was to report the 24-month results on the efficacy and safety of low-dose vs high-dose PCBs with nominal paclitaxel densities of 2.0 and 3.5 μg/mm2 and different coating technologies for femoropopliteal interventions from the COMPARE (Compare I Pilot Study for the Treatment of Subjects With Symptomatic Femoropopliteal Artery Disease) trial. Procedural characteristics of clinically driven (CD) target lesion revascularization (TLR) were analyzed. Methods: Within a prospective, multicenter, clinical trial, 414 patients with symptomatic femoropopliteal lesions (Rutherford categories 2-4, maximum lesion length 30 cm) were randomly assigned in a 1:1 ratio to endovascular treatment with either a low-dose (Ranger) or a high-dose (IN.PACT) PCB after stratification for lesion length. Two-year follow-up included assessment of primary patency (defined as absence of CD TLR or binary restenosis with a peak systolic velocity ratio &gt;2.4 by duplex ultrasound), safety, and functional and clinical outcomes. Results: At 2 years, the Kaplan-Meier estimates of primary patency were 70.6% and 71.4% for the low-dose and high-dose PCBs (log-rank P = 0.96), respectively. One major amputation occurred in the high-dose group, and rates of all-cause mortality (3.6% vs 2.2%; P = 0.55) and CD TLR (17.3% vs 13.0%; P = 0.31) were similar between the groups. Among a total of 57 CD TLRs, 44.6% were performed for reocclusion and 28.1% for in-stent restenosis. Functional and clinical benefits over baseline were sustained in both groups. Conclusions: The 2-year results of the COMPARE trial demonstrate a sustained treatment benefit of both low-dose and high-dose PCBs for femoropopliteal interventions including a wide range of lesion lengths. (Compare I Pilot Study for the Treatment of Subjects With Symptomatic Femoropopliteal Artery Disease; NCT02701543

Helium removal and transport studies in TEXTOR

Experiments demonstrating direct control of the He{sup 2+} density in a tokamak plasma have been performed in the TEXTOR tokamak with the Advanced Limiter Test-II pump limiter. Helium is injected in a short gas puff from the outside of the plasma, is observed to reach the plasma core, and then is readily from the plasma. Active He pumping is found to be a valuable technique for discriminating the actual He confinement time from {tau}*{sub He}, which is strongly dependent on recycling. Active charge-exchange spectroscopy is used to study the exhaust and transport of He{sup 2+} within the plasma, and the density evolution is modeled with the diffusive/convective transport code, MIST. 8 refs., 3 figs