Extractability and mobility of mercury from agricultural soils surrounding industrial and mining contaminated areas

This study focussed on a comparison of the extractability of mercury in soils with two different contamination sources (a chlor-alkali plant and mining activities) and on the evaluation of the influence of specific soil properties on the behaviour of the contaminant. The method applied here did not target the identification of individual species, but instead provided information concerning the mobility of mercury species in soil. Mercury fractions were classified as mobile, semi-mobile and non-mobile. The fractionation study revealed that in all samples mercury was mainly present in the semi-mobile phase (between 63 and 97%). The highest mercury mobility (2.7 mg kg-1) was found in soils from the industrial area. Mining soils exhibited higher percentage of non-mobile mercury, up to 35%, due to their elevated sulfur content. Results of factor analysis indicate that the presence of mercury in the mobile phase could be related to manganese and aluminum soil contents. A positive relation between mercury in the semi-mobile fraction and the aluminium content was also observed. By contrary, organic matter and sulfur contents contributed to mercury retention in the soil matrix reducing the mobility of the metal. Despite known limitations of sequential extraction procedures, the methodology applied in this study for the fractionation of mercury in contaminated soil samples provided relevant information on mercury's relative mobility

Locoregional therapies in cholangiocarcinoma

Cholangiocarcinoma is a rare and aggressive malignancy of the biliary tract. Complete surgical resection can be curative, but the majority of patients are diagnosed with advanced disease and usually die within a year of diagnosis. Most deaths are attributable to local disease progression rather than distant metastases, supporting the use of locoregional therapies. There is evidence that locoregional therapies can provide local tumor control resulting in increased survival while avoiding some of the side effects of systemic treatments, increasing potential treatment options for patients who may be unsuitable for systemic palliative treatments. This review considers the evidence for locoregional therapies in cholangiocarcinoma, which can be classified into endoscopic, vascular, percutaneous and radiation oncological therapies. Current guidelines do not recommend the routine use of locoregional therapies due to a lack of prospective data, but the results of ongoing trials are likely to increase the evidence base and impact on clinical practice

Overview and challenges of mercury fractionation and speciation in soils

Analytical procedures to assess mercury speciation in soils still lack consensus. This article presents an overview of the mercury fractionation and speciation procedures used in soils. Mercury fractionation is the most common approach despite the operational definition of the fractions. Application of single extraction procedures that target the water-soluble, exchangeable and acid-soluble fractions and the application of EPA method 3200 for mercury sequential extraction are examined in soils with different physicochemical characteristics. A step forward in mercury speciation is thermo-desorption, a useful tool to rapidly obtain needed information about contaminated soils. The advantages and limitations of these procedures are compared; the importance of soils’ physicochemical characteristics highlighted. Criteria to be considered when choosing a suitable method are given - assessing total mercury concentration, soil physicochemical characteristics, environmental conditions, and legislation. It is recommended that the interpretation of results is done wisely, to correctly support decisions concerning intervention strategies at contaminated sites

Interventions for necrotising pancreatitis

BACKGROUND: Acute necrotising pancreatitis carries significant mortality, morbidity, and resource use. There is considerable uncertainty as to how people with necrotising pancreatitis should be treated. OBJECTIVES: To assess the benefits and harms of different interventions in people with acute necrotising pancreatitis. SEARCH METHODS: We searched the Cochrane Central Register of Controlled Trials (CENTRAL, 2015, Issue 4), MEDLINE, EMBASE, Science Citation Index Expanded, and trials registers to April 2015 to identify randomised controlled trials (RCT). We also searched the references of included trials to identify further trials. SELECTION CRITERIA: We considered only RCTs performed in people with necrotising pancreatitis, irrespective of aetiology, presence of infection, language, blinding, or publication status for inclusion in the review. DATA COLLECTION AND ANALYSIS: Two review authors independently identified trials and extracted data. We calculated the odds ratio (OR) and mean difference with 95% confidence intervals (CI) using Review Manager 5 based on an available-case analysis using fixed-effect and random-effects models. We planned a network meta-analysis using Bayesian methods, but due to sparse data and uncertainty about the transitivity assumption, performed only indirect comparisons and used Frequentist methods. MAIN RESULTS: We included eight RCTs with 311 participants in this review. After exclusion of five participants, we included 306 participants in one or more outcomes. Five trials (240 participants) investigated the three main treatments: open necrosectomy (121 participants), minimally invasive step-up approach (80 participants), and peritoneal lavage (39 participants) and were included in the network meta-analysis. Three trials (66 participants) investigated the variations in the main treatments: early open necrosectomy (25 participants), delayed open necrosectomy (11 participants), video-assisted minimally invasive step-up approach (12 participants), endoscopic minimally invasive step-up approach (10 participants), minimally invasive step-up approach (planned surgery) (four participants), and minimally invasive step-up approach (continued percutaneous drainage) (four participants). The trials included infected or sterile necrotising pancreatitis of varied aetiology.All the trials were at unclear or high risk of bias and the overall quality of evidence was low or very low for all the outcomes. Overall, short-term mortality was 30% and serious adverse events rate was 139 serious adverse events per 100 participants. The differences in short-term mortality and proportion of people with serious adverse events were imprecise in all the comparisons. The number of serious adverse events and adverse events were fewer in the minimally invasive step-up approach compared to open necrosectomy (serious adverse events: rate ratio 0.41, 95% CI 0.25 to 0.68; 88 participants; 1 study; adverse events: rate ratio 0.41, 95% CI 0.25 to 0.68; 88 participants; 1 study). The proportion of people with organ failure and the mean costs were lower in the minimally invasive step-up approach compared to open necrosectomy (organ failure: OR 0.20, 95% CI 0.07 to 0.60; 88 participants; 1 study; mean difference in costs: USD -11,922; P value < 0.05; 88 participants; 1 studies). There were more adverse events with video-assisted minimally invasive step-up approach group compared to endoscopic-assisted minimally invasive step-up approach group (rate ratio 11.70, 95% CI 1.52 to 89.87; 22 participants; 1 study), but the number of interventions per participant was less with video-assisted minimally invasive step-up approach group compared to endoscopic minimally invasive step-up approach group (difference in medians: 2 procedures; P value < 0.05; 20 participants; 1 study). The differences in any of the other comparisons for number of serious adverse events, proportion of people with organ failure, number of adverse events, length of hospital stay, and intensive therapy unit stay were either imprecise or were not consistent. None of the trials reported long-term mortality, infected pancreatic necrosis (trials that included participants with sterile necrosis), health-related quality of life at any time frame, proportion of people with adverse events, requirement for additional invasive intervention, time to return to normal activity, and time to return to work. AUTHORS' CONCLUSIONS: Low to very low quality evidence suggested that the minimally invasive step-up approach resulted in fewer adverse events, serious adverse events, less organ failure, and lower costs compared to open necrosectomy. Very low quality evidence suggested that the endoscopic minimally invasive step-up approach resulted in fewer adverse events than the video-assisted minimally invasive step-up approach but increased the number of procedures required for treatment. There is currently no evidence to suggest that early open necrosectomy is superior or inferior to peritoneal lavage or delayed open necrosectomy. However, the CIs were wide and significant benefits or harms of different treatments cannot be ruled out. The TENSION trial currently underway in Netherlands is assessing the optimal way to perform the minimally invasive step-up approach (endoscopic drainage followed by endoscopic necrosectomy if necessary versus percutaneous drainage followed by video-assisted necrosectomy if necessary) and is assessing important clinical outcomes of interest for this review. Implications for further research on this topic will be determined after the results of this RCT are available

On rigidly rotating perfect fluid cylinders

The gravitational field of a rigidly rotating perfect fluid cylinder with gamma- law equation of state is found analytically. The solution has two parameters and is physically realistic for gamma in the interval (1.41,2]. Closed timelike curves always appear at large distances.Comment: 10 pages, Revtex (galley