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Background Transcranial alternating current stimulation (tACS) is a non-invasive brain stimulation modality that may modulate cognition by enhancing endogenous neocortical oscillations by application of sine-wave electric fields. Yet, the role of endogenous network activity in enabling and shaping the effects of tACS has remained unclear. Objective We combined optogenetic stimulation and multichannel slice electrophysiology to elucidate how the effect of a weak sine-wave electric field depends on the ongoing cortical oscillatory activity. We hypothesized that endogenous cortical oscillations constrain neuromodulation by tACS. Methods We studied the effect of weak sine-wave electric fields on oscillatory activity in mouse neocortical slices. Optogenetic control of the network activity enabled the generation of in vivo -like cortical oscillations for studying the temporal relationship between network activity and sine-wave electric field stimulation. Results Weak electric fields enhanced endogenous oscillations but failed to induce a frequency shift of the ongoing oscillation for stimulation frequencies that were not matched to the endogenous oscillation. This constraint on the effect of electric field stimulation imposed by endogenous network dynamics was limited to the case of weak electric fields targeting in vivo -like network dynamics. Together, these results suggest that the key mechanism of tACS may be enhancing, but not overriding, intrinsic network dynamics. Conclusion Our results contribute to understanding the inconsistent tACS results from human studies and propose that stimulation precisely adjusted in frequency to the endogenous oscillations is key to rational design of non-invasive brain stimulation paradigms. [ABSTRACT FROM AUTHOR]

Objectives The European C3 module of the Global Registry for Endovascular Aortic Treatment (GREAT) provides "real-world" outcomes for the new C3 Gore Excluder stent-graft, and evaluates the new deployment mechanism. This report presents the 1-year results from 400 patients enrolled in this registry. Methods Between August 2010 and December 2012, 400 patients (86.8% male, mean age 73.9 ± 7.8 years) from 13 European sites were enrolled in this registry. Patient demographics, treatment indication, case planning, operative details including repositioning and technical results, and clinical outcome were analyzed. Results Technical success was achieved in 396/400 (99%) patients. Two patients needed intraoperative open conversion, one for iliac rupture, the second because the stent-graft was pulled down during a cross-over catheterization in an angulated anatomy. Two patients required an unplanned chimney renal stent to treat partial coverage of the left renal artery because of upward displacement of the stent-graft. Graft repositioning occurred in 192/399 (48.1%) patients, most frequently for level readjustment with regard to the renal arteries, and less commonly for contralateral gate reorientation. Final intended position of the stent-graft below the renal arteries was achieved in 96.2% of patients. Thirty-day mortality was two (0.5%) patients. Early reintervention (≤30 days) was required in two (0.5%) patients. Mean follow-up duration was 15.9 ± 8.8 months (range 0-37 months). Late reintervention (>30 days) was required in 26 (6.5%) patients. Estimated freedom from reintervention at 1 year was 95.2% (95% CI 92.3-97%), and at 2 years 91.5% (95% CI 86.8-94.5%). Estimated patient survival at 1 year was 96% (95% CI 93.3-97.6%) and at 2 years 90.6% (95% CI 85.6-93.9%). Conclusions Early real-world experience shows that the new C3 delivery system offers advantages in terms of device repositioning resulting in high deployment accuracy. Longer follow-up is required to confirm that this high deployment accuracy results in improved long-term durability. [ABSTRACT FROM AUTHOR]

Objectives Remote ischaemic preconditioning (RIPC) is a physiological mechanism to protect against ischaemia-reperfusion injury. It is a technique in which short pre-emptive periods of ischaemia and reperfusion are thought to protect against ischaemia-reperfusion injury during procedures requiring longer periods of ischaemia. Discovered in the 1980s, its clinical application has been investigated heavily since the first human study in 2006. The aim of this paper was to provide a review of this rapidly expanding subject. Methods This study consists of a narrative review of the literature focusing on previous meta-analyses and randomised control trials. Results Five small randomised trials have been published on the effects of RIPC in vascular surgery. Several randomised trials have been published in cardiac surgery and percutaneous coronary intervention. Meta-analysis shows a significant reduction in troponin levels and biomarkers of renal dysfunction in RIPC patients, but as yet no convincing clinical benefit. The largest powered randomised trial in cardiac surgery showed no benefit to RIPC. Conclusions Current trials and therefore meta-analyses are generally underpowered. The technique is physiologically sound but remains lacking in clear clinical benefit. [ABSTRACT FROM AUTHOR]

Very high temperature reactors (VHTRs) and high temperature gas-cooled reactors (HTGRs) can develop extreme temperatures in excess of 900°C that make them theoretically very efficient, potentially in the range of 45% to 50%. The high temperatures, however, can also lead to a corresponding increase in fission product transport out of the fuel, which is potentially a source term-related safety issue. The aim of this work was to develop a repeatable, accurate, and cost-effective process to measure the diffusion coefficients of fission products in graphitic VHTR materials, particularly those materials used in the fabrication of TRISO [tristructural isotropic] fuel pellets'. Specifically, this work has focused on the diffusion of silver in graphite. We constructed graphite cells that could be filled with a silver diffusant in the form of silver flakes, silver powder, or a preloaded, silver-laden graphite powder. The cells were hermetically sealed and heated to temperatures comparable to those that will be found in VHTRs. After being kept at various amounts of time and temperature, these cells were imaged using microtomography and electron microscopy. Concentration profiles were measured by sectioning the heat-treated cells and analyzing them using neutron activation analysis. Estimated diffusion coefficients for silver in a commercial grade of graphite are reported, but the method is easily adapted to any grade of graphite material including nuclear grades and to a variety of other fission product species. [ABSTRACT FROM AUTHOR]

Background: The use of thoracic endovascular aneurysm repair (TEVAR) is increasing. Similar to open repair, TEVAR carries a risk of spinal cord ischemia (SCI). We undertook a systematic review to determine whether preoperative cerebrospinal fluid (CSF) drainage reduces SCI. Methods: PubMed, the Cochrane Library, and conference abstracts were searched using the keywords thoracic endovascular aortic repair, cerebrospinal fluid, spinal cord ischaemia, TEVAR, and aneurysm. Studies reporting SCI rates and CSF drain rates for TEVAR patients were eligible for inclusion. SCI rates across studies were pooled using random-effects modeling. Study quality was evaluated using the Downs and Black score. Results: Study quality was generally poor to moderate (median Downs and Black score, 9). The systematic review identified 46 eligible studies comprising 4936 patients; overall, SCI affected 3.89% (95% confidence interval, 2.95.05%-4.95%). Series reporting routine prophylactic drain placement or no prophylactic drain placement reported pooled SCI rates of 3.2% and 3.47%, respectively. The pooled SCI rate from 24 series stating that prophylactic drainage was used selectively was 5.6%. Conclusions: Spinal chord injury is uncommon after TEVAR. The role of prophylactic CSF drainage is difficult to establish from the available literature. High-quality studies are required to determine the role of prophylactic CSF drainage in TEVAR. [ABSTRACT FROM AUTHOR]

The article discusses the approaches to predicting future influenza epidemics in Queensland based on emergency department data collected from 2005 to the 2009 influenza season. These models include surveillance monitoring of influenza presentations using adaptive cumulative sum (CUSUM) plan analysis, historical data forecasts and use of Internet search data. It concludes that a combination of routine forecasting methods and an adaptive CUSUM methodology can determine unusual events and predict expected presentation rates.

Introduction: Recent studies suggest an increased risk of neurologic complications after coverage of the left subclavian artery (LSA) during thoracic endovascular aortic repair (TEVAR). The preventative role of preoperative revascularization of the LSA using carotid–subclavian bypass or transposition remains controversial. We assessed this increased risk and the role of revascularization by undertaking a systematic review and meta-analysis of the literature. Methods: In the absence of any randomized controlled trials, the Pubmed and Embase databases were searched to identify all series reporting TEVAR without LSA coverage compared with LSA coverage with and without revascularization. The incidence of neurologic complications, namely cerebrovascular accident (CVA) and spinal cord ischemia (SCI), were recorded for each group. Pooled odds ratios (POR) were then calculated for postoperative CVA and SCI. Results: Compared with patients without LSA coverage, the risk of CVA was increased both in patients with LSA coverage alone (4.7% vs 2.7%; POR, 2.28; 95% confidence interval [CI], 1.28-4.09; P = .005) and in those with LSA coverage after revascularization (4.1% vs 2.6%; POR, 3.18; 95% CI, 1.17-8.65; P = .02). The risk of SCI was also increased in patients requiring LSA coverage (2.8% vs 2.3%; POR, 2.39; 95% CI, 1.30-4.39; P = .005) but not for LSA coverage after revascularization (0.8% vs 2.7%; POR, 1.69; 95% CI, 0.56-5.15; P = .35). Conclusion: The risk of neurologic complications is increased after coverage of the LSA during TEVAR. Preemptive revascularization offers no protection against CVA, perhaps indicating a heterogeneous etiology. Revascularization may reduce the risk of SCI, although limited data tempers this conclusion. Improved or perhaps compulsory reporting to registries of a minimum data set may help further assess the exact etiology of these complications and identify a higher-risk subset of patients in whom revascularization might prove protective. [Copyright &y& Elsevier]

The article presents a study that deals with trophodynamics in Cubin Sands, a shallow lagoon off northwestern Europe. It focuses on the spatial and temporal variability of epibenthic communities, their diets, and consumption efficiency. The epibenthic communities include the brown shrimp Crangon crangon, the shore crab Carcinus maenas, and teleost fish, sticklebacks Gasterosteus aculeatus and Spinachia spinachia, seascorpion Myoxocephalus scorpius, gobies Pomatoschistus microps and Pomatoschistus minutus, flounder Platichthys fesus, and plaice. Based on their findings, the diets of the epibenthic predators were insect larvae for shrimp, amphipods Bathyporeia pilosa for shrimp and gobies, harpacticoids for plaice and gobies, and bivalves for plaice.

Objective: To compare the results of emergency open repair of acute (ruptured or symptomatic intact) abdominal aortic aneurysms with that of endovascular repair. Methods: A systematic literature search was performed to identify series that reported comparative outcomes. PubMed, Embase, the randomized controlled trial (RCT) register, and all relevant major journals were searched independently by two researchers. The outcome measures were 30-day mortality, intensive care unit (ICU) stay, hospital stay, blood loss, and operative time. Results: Twenty-three studies were identified. Of these, only one was a randomized controlled trial, which is now halted. The total number of patients in the pooled data was 7040 (730 emergency endovascular aneurysm repair [eEVAR]). Emergency EVAR was associated with a significant reduction in mortality (pooled odds ratio 0.624; 95% confidence interval [CI] 0.518 to 0.752; P < .0001). The eEVAR group''s ICU stay was reduced by 4 days (pooled effect size estimate −0.70; 95% CI −1.05 to −0.35; P < .0001) and hospital stay with eEVAR was reduced by 8.6 days (pooled effect size estimate −0.33; 95% CI −0.50 to −0.16; P = .0001). In addition, eEVAR was also associated with a significant reduction in blood loss (pooled effect size estimate −1.88 liters; 95% CI −2.49 to −1.27; P < .0001) and reduced procedure time (pooled effect size estimate −0.65; 95% CI −0.95 to −0.36; P < .0001). Conclusion: This meta-analysis suggests benefits to the selected group of patients undergoing this minimally invasive procedure. There is a reduction in the high mortality, prolonged intensive care requirement and total hospital stay, which are historically associated with open repair. It also indicates that most patients are fit enough to undergo computerized tomography (CT) scanning in acute settings. However, because of heterogeneity and bias in the outcomes these results should be interpreted with caution. [Copyright &y& Elsevier]

Background: Suprarenal fixation is widely used in endovascular aneurysm repair. Numerous small, underpowered studies have concluded that it does not increase the risk of renal impairment compared with infrarenal fixation. A recent meta-analysis demonstrated that renal infarction is more common with suprarenal fixation, but the effect on renal function remains unclear. Methods: Electronic abstract databases, article reference lists, and conference proceedings were searched for series reporting renal function data after suprarenal fixation. There was considerable study heterogeneity with respect to key factors such as pre-existing renal dysfunction and length of follow-up. Authors were contacted to obtain individual patient data for a pooled reanalysis using standardized criteria. Results: Of 46 potentially relevant citations, only 11 were eligible for inclusion in the meta-analysis. Complete data sets were available for four studies (1065 patients), with a median follow-up of 33 months. Kaplan-Meier curves were constructed for postoperative renal impairment in the suprarenal fixation and infrarenal fixation groups and compared by the log-rank test. Median time free of renal impairment was 38.5 months in the infrarenal fixation group compared with 32.4 months in the suprarenal fixation group (P = .0038). However, to account for significant methodologic differences, further analysis was required using a Weibull regression model fitted in open Bayesian inference using Gibbs sampling (BUGS). The pooled hazard ratio for deterioration of renal function after suprarenal fixation was 0.6 (95% confidence interval, 0.3-10). Conclusion: Currently available data are insufficient to determine the precise effect of suprarenal fixation on medium-term renal function. Conventional Kaplan-Meier analysis of the pooled data set suggested that suprarenal fixation increased the risk of renal dysfunction; however, the effect disappeared when sophisticated statistical modelling was performed to account for study heterogeneity. A randomised controlled trial of suprarenal fixation may resolve this issue. [Copyright &y& Elsevier]