One of the main challenges for the implementation of electrocoagulation (EC) in water treatment are fouling and passivation of the electrodes, especially for applications with high contaminant ...concentrations. For the first time, we investigated in this study the process of fouling mitigation by polarity reversal during the EC treatment of boiler blowdown water from oil-sands produced water, characterized by high silica concentrations (0.5-4 g L
). This effluent is typically obtained from an evaporative desalination process in oil production industries. Potentiodynamic characterisation was used to study the impact of passivation on the anode dissolution. Although a charge loading of 4,800 C L
was found to remove about 98% of silica from a 1 L batch of 4 g L
Si solution, fouling reduced the performance significantly to about 40% in consecutive cycles of direct current EC (DC-EC) treatment. Periodic polarity reversal (PR) was found to reduce the amount of electrode fouling. Decreasing the polarity period from 60 to 10 s led to the formation of a soft powdery fouling layer that was easily removed from the electrodes. In contrast, with DC operation, a hard scale deposit was observed. The presence of organics in the field samples did not significantly affect the Si removal, and organics with high levels of oxygen and sulfate groups were preferentially removed. Detailed electrochemical and economic investigations suggest that the process operating at 85 °C achieves 95% silica removal (from an initial concentration of 481 mg L
) with an electrical energy requirement of 0.52 kWh m
, based on a charge loading of 1,200 C L
, an inter-electrode gap of 1.8 cm and a current density of 16 mA cm
.
Objective.
The study objective was to conduct a systematic review of the effectiveness of integrated workplace interventions that combine health promotion with occupational health and safety.
Data ...Source.
Electronic databases (n = 8), including PsychInfo and MEDLINE, were systematically searched.
Study Inclusion and Exclusion Criteria.
Studies included were those that reported on workplace interventions that met the consensus definition of an “integrated approach,” published in English, in the scientific literature since 1990.
Data Extraction.
Data extracted were occupation, worksite, country, sample size, intervention targets, follow-up period, and results reported. Quality was assessed according to American College of Occupational and Environmental Medicine Practice Guidelines.
Data Synthesis.
Heterogeneity precluded formal meta-analyses. Results were classified according to the outcome(s) assessed into five categories (health promotion, injury prevention, occupational health and safety management, psychosocial, and return-on-investment). Narrative synthesis of outcomes was performed.
Results.
A total of 31 eligible studies were identified; 23 (74%) were (quasi-)experimental trials. Effective interventions were most of those aimed at improving employee physical or mental health. Less consistent results were reported from integrated interventions targeting occupational health and safety management, injury prevention, or organizational cost savings.
Conclusion.
Integrated approaches have been posed as comprehensive solutions to complex issues. Empirical evidence, while still emerging, provides some support for this. Continuing investment in, and evaluation of, integrated approaches are worthwhile.
Summary
The subsurface microbiology of an Athabasca oil sands reservoir in western Canada containing severely biodegraded oil was investigated by combining 16S rRNA gene‐ and polar lipid‐based ...analyses of reservoir formation water with geochemical analyses of the crude oil and formation water. Biomass was filtered from formation water, DNA was extracted using two different methods, and 16S rRNA gene fragments were amplified with several different primer pairs prior to cloning and sequencing or community fingerprinting by denaturing gradient gel electrophoresis (DGGE). Similar results were obtained irrespective of the DNA extraction method or primers used. Archaeal libraries were dominated by Methanomicrobiales (410 of 414 total sequences formed a dominant phylotype affiliated with a Methanoregula sp.), consistent with the proposed dominant role of CO2‐reducing methanogens in crude oil biodegradation. In two bacterial 16S rRNA clone libraries generated with different primer pairs, > 99% and 100% of the sequences were affiliated with Epsilonproteobacteria (n = 382 and 72 total clones respectively). This massive dominance of Epsilonproteobacteria sequences was again obtained in a third library (99% of sequences; n = 96 clones) using a third universal bacterial primer pair (inosine‐341f and 1492r). Sequencing of bands from DGGE profiles and intact polar lipid analyses were in accordance with the bacterial clone library results. Epsilonproteobacterial OTUs were affiliated with Sulfuricurvum, Arcobacter and Sulfurospirillum spp. detected in other oil field habitats. The dominant organism revealed by the bacterial libraries (87% of all sequences) is a close relative of Sulfuricurvum kujiense – an organism capable of oxidizing reduced sulfur compounds in crude oil. Geochemical analysis of organic extracts from bitumen at different reservoir depths down to the oil water transition zone of these oil sands indicated active biodegradation of dibenzothiophenes, and stable sulfur isotope ratios for elemental sulfur and sulfate in formation waters were indicative of anaerobic oxidation of sulfur compounds. Microbial desulfurization of crude oil may be an important metabolism for Epsilonproteobacteria indigenous to oil reservoirs with elevated sulfur content and may explain their prevalence in formation waters from highly biodegraded petroleum systems.
To evaluate the feasibility and pathologic complete response rate of induction bevacizumab + modified infusional fluorouracil, leucovorin, and oxaliplatin (FOLFOX) 6 regimen followed by concurrent ...bevacizumab, oxaliplatin, continuous infusion 5-fluorouracil (5-FU), and radiation for patients with rectal cancer.
Eligible patients received 1 month of induction bevacizumab and mFOLFOX6. Patients then received 50.4 Gy of radiation and concurrent bevacizumab (5 mg/kg on Days 1, 15, and 29), oxaliplatin (50 mg/m(2)/week for 6 weeks), and continuous infusion 5-FU (200 mg/m(2)/day). Because of gastrointestinal toxicity, the oxaliplatin dose was reduced to 40 mg/m(2)/week. Resection was performed 4-8 weeks after the completion of chemoradiation.
The trial was terminated early because of toxicity after 26 eligible patients were treated. Only 1 patient had significant toxicity (arrhythmia) during induction treatment and was removed from the study. During chemoradiation, Grade 3/4 toxicity was experienced by 19 of 25 patients (76%). The most common Grade 3/4 toxicities were diarrhea, neutropenia, and pain. Five of 25 patients (20%) had a complete pathologic response. Nine of 25 patients (36%) developed postoperative complications including infection (n = 4), delayed healing (n = 3), leak/abscess (n = 2), sterile fluid collection (n = 2), ischemic colonic reservoir (n = 1), and fistula (n = 1).
Concurrent oxaliplatin, bevacizumab, continuous infusion 5-FU, and radiation causes significant gastrointestinal toxicity. The pathologic complete response rate of this regimen was similar to other fluorouracil chemoradiation regimens. The high incidence of postoperative wound complications is concerning and consistent with other reports utilizing bevacizumab with chemoradiation before major surgical resections.
Inflammatory bowel disease (IBD) is characterised by chronic intestinal inflammation, resulting from dysregulation of the mucosal immune system and compromised intestinal epithelial barrier function. ...The bile salt, nuclear farnesoid X receptor (FXR), was recently implicated in intestinal antibacterial defence and barrier function. The aim of this study was to investigate the therapeutic potential of FXR agonists in the treatment of intestinal inflammation in complementary in vivo and in vitro models.
Colitis was induced in wild-type (WT) and Fxr-null mice using dextran sodium sulfate, and in WT mice using trinitrobenzenesulfonic acid. Mice were treated with vehicle or the FXR agonist INT-747, and colitis symptoms were assessed daily. Epithelial permeability assays and cytokine expression analysis were conducted in mouse colon and enterocyte-like cells (Caco-2/HT29) treated with medium or INT-747. Inflammatory cytokine secretion was determined by ELISA in various human immune cell types.
INT-747-treated WT mice are protected from DSS- and TNBS-induced colitis, as shown by significant reduction of body weight loss, epithelial permeability, rectal bleeding, colonic shortening, ulceration, inflammatory cell infiltration and goblet cell loss. Furthermore, Fxr activation in intestines of WT mice and differentiated enterocyte-like cells downregulates expression of key proinflammatory cytokines and preserves epithelial barrier function. INT-747 significantly decreases tumour necrosis factor α secretion in activated human peripheral blood mononuclear cells, purified CD14 monocytes and dendritic cells, as well as in lamina propria mononuclear cells from patients with IBD.
FXR activation prevents chemically induced intestinal inflammation, with improvement of colitis symptoms, inhibition of epithelial permeability, and reduced goblet cell loss. Furthermore, FXR activation inhibits proinflammatory cytokine production in vivo in the mouse colonic mucosa, and ex vivo in different immune cell populations. The findings provide a rationale to explore FXR agonists as a novel therapeutic strategy for IBD.
Summary
Endospore‐forming bacteria make up an important and numerically significant component of microbial communities in a range of settings including soils, industry, hospitals and marine sediments ...extending into the deep subsurface. Bacterial endospores are non‐reproductive structures that protect DNA and improve cell survival during periods unfavourable for bacterial growth. An important determinant of endospores withstanding extreme environmental conditions is 2,6‐pyridine dicarboxylic acid (i.e. dipicolinic acid, or DPA), which contributes heat resistance. This study presents an improved HPLC‐fluorescence method for DPA quantification using a single 10‐min run with pre‐column Tb3+ chelation. Relative to existing DPA quantification methods, specific improvements pertain to sensitivity, detection limit and range, as well as the development of new free DPA and spore‐specific DPA proxies. The method distinguishes DPA from intact and recently germinated spores, enabling responses to germinants in natural samples or experiments to be assessed in a new way. DPA‐based endospore quantification depends on accurate spore‐specific DPA contents, in particular, thermophilic spores are shown to have a higher DPA content, meaning that marine sediments with plentiful thermophilic spores may require spore number estimates to be revisited. This method has a wide range of potential applications for more accurately quantifying bacterial endospores in diverse environmental samples.
Randomized trials demonstrated that chromoendoscopy is superior to white light endoscopy with random biopsy sampling (WLE) for the detection of dysplasia in patients with inflammatory bowel disease ...(IBD). Whether implementing chromoendoscopy can increase the detection of dysplasia in clinical practice is unknown.
Patients with ulcerative colitis (UC) and Crohn's disease (CD) undergoing colonoscopic surveillance between January 2000 and November 2013 in three referral centers were identified using the patients' medical records. In recent years, the use of high-definition chromoendoscopy was adopted in all three centers using segmental pancolonic spraying of 0.1% methylene blue or 0.3% indigo carmine (chromoendoscopy group). Previously, surveillance was performed employing WLE with random biopsies every 10 cm (WLE group). The percentage of colonoscopies with dysplasia was compared between both groups.
A total of 440 colonoscopies in 401 patients were performed using chromoendoscopy and 1,802 colonoscopies in 772 patients using WLE. Except for a higher number of CD patients with extensive disease and more patients with a first-degree relative with colorectal cancer (CRC) in the chromoendoscopy group, the known risk factors for IBD-associated CRC were comparable between both groups. Dysplasia was detected during 48 surveillance procedures (11%) in the chromoendoscopy group as compared with 189 procedures (10%) in the WLE group (P=0.80). Targeted biopsies yielded 59 dysplastic lesions in the chromoendoscopy group, comparable to the 211 dysplastic lesions detected in the WLE group (P=0.30).
Despite compelling evidence from randomized trials, implementation of chromoendoscopy for IBD surveillance did not increase dysplasia detection compared with WLE with targeted and random biopsies.
The ability to mitigate toxicity of oil sands process-affected water (OSPW) for return into the environment is an important issue for effective tailings management in Alberta, Canada. OSPW toxicity ...has been linked to classical naphthenic acids (NAs), but the toxic contribution of other acid-extractable organics (AEOs) remains unknown. Here, we examine the potential for in situ bioremediation of OSPW AEOs by indigenous algae. Phosphate biostimulation was performed in OSPW to promote the growth of indigenous photosynthetic microorganisms and subsequent toxicity and chemical changes were determined. After 12 weeks, the AEO fraction of phosphate-biostimulated OSPW was significantly less toxic to the fission yeast Schizosaccharomyces pombe than unstimulated OSPW. Fourier transform ion cyclotron resonance mass spectrometry (FTICR-MS) analysis of the AEO fraction in phosphate-biostimulated OSPW showed decreased levels of SO3 class compounds, including a subset that may represent linear arylsulfonates. A screen with S. pombe transcription factor mutant strains for growth sensitivity to the AEO fraction or sodium dodecylbenzenesulfonate revealed a mode of toxic action consistent with oxidative stress and detrimental effects on cellular membranes. These findings demonstrate a potential algal-based in situ bioremediation strategy for OSPW AEOs and uncover a link between toxicity and AEOs other than classical NAs.
Summary
Background
There are plausible mechanisms for how dietary docosahexaenoic acid (DHA), an n−3 polyunsaturated fatty acid, could prevent Crohn's disease (CD).
Aim
To conduct a prospective study ...to investigate the association between increased intake of DHA and risk of CD.
Methods
Overall, 229 702 participants were recruited from nine European centres between 1991 and 1998. At recruitment, dietary intakes of DHA and fatty acids were measured using validated food frequency questionnaires. The cohort was monitored through to June 2004 to identify participants who developed incident CD. In a nested case–control analysis, each case was matched with four controls; odds ratios (ORs) were calculated for quintiles of DHA intake, adjusted for total energy intake, smoking, other dietary fatty acids, dietary vitamin D and body mass index.
Results
Seventy‐three participants developed incident CD. All higher quintiles of DHA intake were inversely associated with development of CD; the highest quintile had the greatest effect size (OR = 0.07; 95% CI = 0.02–0.81). The OR trend across quintiles of DHA was 0.54 (95% CI = 0.30–0.99, Ptrend = 0.04). Including BMI in the multivariate analysis, due to its correlation with dietary fat showed similar associations. There were no associations with the other dietary fatty acids studied.
Conclusion
There were inverse associations, with a biological gradient between increasing dietary docosahexaenoic acid intakes and incident Crohn's disease. Further studies in other populations should measure docosahexaenoic acid to determine if the association is consistent and the hypothesis tested in randomised controlled trials of purely docosahexaenoic acid supplementation.
During the Deepwater Horizon (DwH) oil spill, an excessive production of marine snow was observed, and it was estimated that as much as 14% of the oil was transferred to the ocean floor by MOSSFA ...(Marine Oil Snow Sedimentation and Flocculent Accumulation). MOSSFA is an important pathway of transferring oil to the ocean floor. We performed experiments at laboratory scale in 15 aquaria, representing 5 exposures of marine snow with or without oil, only oil, and controls with only clay or sediment. We developed a method to produce artificial marine snow, which resembles the natural marine snow. Results showed 40% less biodegradation of alkanes in “marine snow with oil” compared to “only oil.” Most probably, this is due to preferred biodegradation of marine snow organics comparing to oil alkanes. Biodegradation of marine snow reduces the dissolved oxygen concentration, which might result in anaerobic conditions in the sediment layer. This finding can be projected to a potential ocean floor effect.
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