Mao X.,Northeastern University |
Mao X.,Wuhan University |
Wang J.,Geosyntec Consultants |
Ciblak A.,Northeastern University |
And 5 more authors.
Journal of Hazardous Materials | Year: 2012
Successful bioremediation of contaminated soils is controlled by the ability to deliver bioremediation additives, such as bacteria and/or nutrients, to the contaminated zone. Because hydraulic advection is not practical for delivery in clays, electrokinetic (EK) injection is an alternative for efficient and uniform delivery of bioremediation additive into low-permeability soil and heterogeneous deposits. EK-enhanced bioaugmentation for remediation of clays contaminated with chlorinated solvents is evaluated. Dehalococcoides (Dhc) bacterial strain and lactate ions are uniformly injected in contaminated clay and complete dechlorination of chlorinated ethene is observed in laboratory experiments. The injected bacteria can survive, grow, and promote effective dechlorination under EK conditions and after EK application. The distribution of Dhc within the clay suggests that electrokinetic transport of Dhc is primarily driven by electroosmosis. In addition to biodegradation due to bioaugmentation of Dhc, an EK-driven transport of chlorinated ethenes is observed in the clay, which accelerates cleanup of chlorinated ethenes from the anode side. Compared with conventional advection-based delivery, EK injection is significantly more effective for establishing microbial reductive dechlorination capacity in low-permeability soils. © 2012 Elsevier B.V. Source
Steffensen C.,Aarhus University Hospital |
Maegbaek M.L.,Aarhus University Hospital |
Laurberg P.,Aalborg Hospital |
Andersen M.,University of Southern Denmark |
And 4 more authors.
Journal of Clinical Endocrinology and Metabolism | Year: 2012
Background: Increased risk of heart valve disease during treatment with certain dopamine agonists, such as cabergoline, has been observed in patients with Parkinson's disease. The same compound is used to treat hyperprolactinemia, but it is unknown whether this also associates with heart valve disease. Objectives: The objective of the study was to assess the incidence of diagnosed heart valve disease and cardiac valve surgery among patients with hyperprolactinemia, compared with a general population cohort in Denmark. Design: This was a nationwide, population-based, cohort study based on a nationwide hospital registry. Methods: We identified 2381 hyperprolactinemia patients with a first-time diagnosis recorded from 1994 through 2010 in the registry, with no previous hospital diagnosis of heart valve disease. Each patient was compared with 10 age- and gender-matched comparison cohort members from the general population. The association between hyperprolactinemia and heart valve disease was analyzed with Cox's proportional hazards regression, controlling for potential confounding factors. To assess the risk of cardiac valve surgery and avoid ascertainment bias, a subanalysis was made in a cohort of 2,387 hyperprolactinemia patients with no previous cardiac valve surgery and 23,870 comparison cohort members. Results: Nineteen hyperprolactinemic patients (0.80%) were diagnosed with heart valve disease during a total of 17,759.8 yr of follow-up, compared with 75 persons (0.31%) in the comparison cohort during 179,940.6 yr of follow-up [adjusted hazard ratio 2.27 (95% confidence interval 1.35-3.82)]. Seven of the 10 patients treated with cabergoline and diagnosed with heart valve disease were asymptomatic and diagnosed on the basis of an echocardiography performed as a safety measure. However, only two patients with hyperprolactinemia (0.08%) underwent surgery, compared with 28 persons in the general population cohort (0.12%) [adjusted hazard ratio 0.55 (95% confidence interval 0.13-2.42)]. Conclusions: Data from the present register-based study do not support that hyperprolactinemia or its treatmentis-associated with an increased risk of clinically significant heart valve disease. Copyright © 2012 by The Endocrine Society. Source
Thomsen N.I.,Miljoevej |
Binning P.J.,Miljoevej |
McKnight U.S.,Miljoevej |
Tuxen N.,Capital Region of Denmark |
And 2 more authors.
Journal of Contaminant Hydrology | Year: 2016
A key component in risk assessment of contaminated sites is in the formulation of a conceptual site model (CSM). A CSM is a simplified representation of reality and forms the basis for the mathematical modeling of contaminant fate and transport at the site. The CSM should therefore identify the most important site-specific features and processes that may affect the contaminant transport behavior at the site. However, the development of a CSM will always be associated with uncertainties due to limited data and lack of understanding of the site conditions. CSM uncertainty is often found to be a major source of model error and it should therefore be accounted for when evaluating uncertainties in risk assessments. We present a Bayesian belief network (BBN) approach for constructing CSMs and assessing their uncertainty at contaminated sites. BBNs are graphical probabilistic models that are effective for integrating quantitative and qualitative information, and thus can strengthen decisions when empirical data are lacking. The proposed BBN approach facilitates a systematic construction of multiple CSMs, and then determines the belief in each CSM using a variety of data types and/or expert opinion at different knowledge levels. The developed BBNs combine data from desktop studies and initial site investigations with expert opinion to assess which of the CSMs are more likely to reflect the actual site conditions. The method is demonstrated on a Danish field site, contaminated with chlorinated ethenes. Four different CSMs are developed by combining two contaminant source zone interpretations (presence or absence of a separate phase contamination) and two geological interpretations (fractured or unfractured clay till). The beliefs in each of the CSMs are assessed sequentially based on data from three investigation stages (a screening investigation, a more detailed investigation, and an expert consultation) to demonstrate that the belief can be updated as more information becomes available. © 2016 Elsevier B.V. All rights reserved. Source
Baelum J.,Geological Survey of Denmark |
Baelum J.,Technical University of Denmark |
Scheutz C.,Technical University of Denmark |
Chambon J.C.,Technical University of Denmark |
And 10 more authors.
Environmental Pollution | Year: 2014
A molecular study on how the abundance of the dechlorinating culture KB-1 affects dechlorination rates in clay till is presented. DNA extracts showed changes in abundance of specific dechlorinators as well as their functional genes. Independently of the KB-1 added, the microbial dechlorinator abundance increased to the same level in all treatments. In the non-bioaugmented microcosms the reductive dehalogenase gene bvcA increased in abundance, but when KB-1 was added the related vcrA gene increased while bvcA genes did not increase. Modeling showed higher vinyl-chloride dechlorination rates and shorter time for complete dechlorination to ethene with higher initial concentration of KB-1 culture, while cis-dichloroethene dechlorination rates were not affected by KB-1 concentrations. This study provides high resolution abundance profiles of Dehalococcoides spp. (DHC) and functional genes, highlights the ecological behavior of KB-1 in clay till, and reinforces the importance of using multiple functional genes as biomarkers for reductive dechlorination. © 2013 Elsevier Ltd. All rights reserved. Source
Rytter L.,Glostrup University Hospital |
Jakobsen H.N.,Capital Region of Denmark |
Ronholt F.,Herlev University Hospital |
Hammer A.V.,Metropolitan University College |
And 3 more authors.
Scandinavian Journal of Primary Health Care | Year: 2010
Objectives. Many hospital admissions are due to inappropriate medical treatment, and discharge of fragile elderly patients involves a high risk of readmission. The present study aimed to assess whether a follow-up programme undertaken by GPs and district nurses could improve the quality of the medical treatment and reduce the risk of readmission of elderly newly discharged patients. Design and setting. The patients were randomized to either an intervention group receiving a structured home visit by the GP and the district nurse one week after discharge followed by two contacts after three and eight weeks, or to a control group receiving the usual care. Patients. A total of 331 patients aged 78 years discharged from Glostrup Hospital, Denmark, were included. Main outcome measures. Readmission rate within 26 weeks after discharge among all randomized patients. Control of medication, evaluated 12 weeks after discharge on 293 (89%) of the patients by an interview at home and by a questionnaire to the GP. Results. Control-group patients were more likely to be readmitted than intervention-group patients (52% v 40%; p=0.03). In the intervention group, the proportions of patients who used prescribed medication of which the GP was unaware (48% vs. 34%; p=0.02) and who did not take the medication prescribed by the GP (39% vs. 28%; p=0.05) were smaller than in the control group. Conclusion. The intervention shows a possible framework securing the follow-up on elderly patients after discharge by reducing the readmission risk and improving medication control. © 2010 Informa Healthcare. Source