| 11. |
- Adlerberth, Ingegerd, 1959, et al.
(author)
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Toxin-producing Clostridium difficile strains as long-term gut colonizers of healthy infants.
- 2014
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In: Journal of clinical microbiology. - 1098-660X. ; 52:1, s. 173-179
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Journal article (peer-reviewed)abstract
- Clostridium difficile is a colonizer of the human gut, and toxin-producing strains may cause diarrhea if infectious burden is heavy. Infants are more frequently colonized than adults, but rarely develop C. difficile disease. It is not known whether strains of C. difficile differ in capacity to colonize and persist in the human gut microbiota. Here, we strain-typed isolates of C. difficile colonizing 42 healthy infants followed from birth to ≥12 months of age, using PCR ribotyping of the 16S-23S rRNA intergenic spacer region. The isolates were also characterized regarding carriage of the toxin genes tcdA, tcdB and cdtA/B, and capacity to produce toxin B in vitro. Most strains (71%) were toxin-producers, and 51% belonged to the 001 or 014 ribotypes, that often cause disease in adults. These ribotypes were significantly more likely than other ones to persist for ≥6 months in the infant micobiota, and were isolated from 13/15 children carrying such long-term colonizing strains. Ribotype 001 strains were often acquired in the first week of life and attained higher population counts than other C. difficile ribotypes in newborn infants' faeces. Several toxin-negative ribotypes were identified, two of which (GI and GIII) were long-term colonizers, each in one infant. Our results suggest that the toxin-producing C. difficile ribotypes 001 and 014 have special fitness in the infantile gut microbiota. Toxin-producing strains colonizing young children for long time periods may represent a reservoir for strains causing disease in adults.
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| 12. |
- Alsterholm, Mikael, 1977, et al.
(author)
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Establishment and utility of SwedAD : a nationwide Swedish registry for patients with atopic dermatitis receiving systemic pharmacotherapy
- 2023
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In: Acta Dermato-Venereologica. - : Medical Journals Sweden AB. - 0001-5555 .- 1651-2057. ; 103
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Journal article (peer-reviewed)abstract
- SwedAD, a Swedish nationwide registry for patients with atopic dermatitis receiving systemic pharmacotherapy, was launched on 1 September 2019. We describe here the establishment of a user-friendly registry to the benefit of patients with atopic dermatitis. By 5 November 2022, 38 clinics had recorded 931 treatment episodes in 850 patients with an approximate national coverage rate of 40%. Characteristics at enrolment included median Eczema Area and Severity Index (EASI) 10.2 (interquartile range 4.0, 19.4), Patient-Oriented Eczema Measure (POEM) 18.0 (10.0, 24.0), Dermatology Life Quality Index (DLQI) 11.0 (5.0, 19.0) and Peak Itch Numerical Rating Scale-11 (NRS-11) 6.0 (3.0, 8.0). At 3 months, median EASI was 3.2 (1.0, 7.3) and POEM, DLQI, and NRS-11 were improved. Regional coverage varied, reflecting the distribution of dermatologists, the ratio of public to private healthcare, and difficulties in recruiting certain clinics. This study highlights the importance of a nationwide registry when managing systemic pharmacotherapy of atopic dermatitis.
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| 13. |
- Anbalagan, Anbarasan, 1988-
(author)
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A passage to wastewater nutrient recovery units : Microalgal-Bacterial bioreactors
- 2018
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Artistic work (other academic/artistic)abstract
- In recent years, the microalgal–bacterial process has been considered to be a very attractive engineering solution for wastewater treatment. However, it has not been widely studied in the context of conventional wastewater treatment design under Swedish conditions. The technology holds several advantages: as a CO2 sink, ability to withstand cold conditions, ability to grow under low light, fast settling without chemical precipitation, and reducing the loss of valuable nutrients (CO2, N2, N2O, PO4). The process also provides the option to be operated either as mainstream (treatment of municipal wastewater) or side stream (treatment of centrate from anaerobic digesters) to reduce the nutrient load of the wastewater. Furthermore, the application is not only limited to wastewater treatment; the biomass can be used to synthesise platform chemicals or biofuels and can be followed by recovery of ammonium and phosphate for use in agriculture.In the present study, the feasibility of applying the process in Swedish temperature and light conditions was investigated by implementing microalgae within the activated sludge process. In this context, the supporting operational and performance indicators (hydraulic retention time (HRT), sludge retention time (SRT) and nutrients removal) were evaluated to support naturally occurring consortia in photo-sequencing and continuous bioreactor configuration. Furthermore, CO2 uptake and light spectrum-mediated nutrient removal were investigated to reduce the impact on climate and the technical challenges associated with this type of system.The results identified effective retention times of 6 and 4 days (HRT = SRT) under limited lighting to reduce the electrical consumption. From the perspective of nitrogen removal, the process demands effective CO2 input either in the mainstream or side stream treatment. The incorporation of a vertical absorption column demonstrated effective CO2 mass transfer to support efficient nitrogen and phosphorus removal as a side stream treatment. However, the investigation of a continuous single-stage process as the mainstream showed a requirement for a lower SRT in comparison to semi-continuous operation due to faster settlability, regardless of inorganic carbon. Furthermore, the process showed an effective reduction of influent phosphorus and organic compounds (i.e. COD/TOC) load in the wastewater as a result of photosynthetic aeration. Most importantly, the operation was stable at the temperature equivalent of wastewater (12 and 13 ˚C), under different lighting (white, and red-blue wavelengths) and retention times (6 and 1.5 d HRT) with complete nitrification. Additionally, the biomass production was stable with faster settling properties without any physiochemical separation.The outcomes of this thesis on microalgal–bacterial nutrient removal demonstrates that (1) photosynthesis-based aeration at existing wastewater conditions under photo-sequential and continuous photobioreactor setup, (2) flocs with rapid settling characteristics at all studied retention times, (3) the possibility of increasing carbon supplementation to achieve higher carbon to nitrogen balance in the photobioreactor, and (4) most importantly, nitrification-based microalgal biomass uptake occurred at all spectral distributions, lower photosynthetic active radiation and existing wastewater conditions.
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| 14. |
- Anbalagan, Anbarasan, et al.
(author)
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Continuous microalgae-activated sludge flocs for remediation of municipal wastewater under low temperature
- 2017
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Conference paper (peer-reviewed)abstract
- The operational performance of indigenous microalgae-activated sludge was evaluated regarding the nutrient removal efficiency using raw wastewater collected from Västerås wastewater treatment plant, Sweden at limited artificial surface lighting (290 μmol m-1 sec-1) and Nordic wastewater conditions (13°C). Additionally, the oxygen production and consumption, biomass concentration and its settling was evaluated during the symbiotic algal-bacterial interaction. The results confirmed oxygenic organic compound removal (COD removal of 65-94%) at higher (31-45 d) and lower (13-18 d) sludge retention time (SRT). Also, a complete removal of ammonium throughout the process and partial nitrite-nitrate removal at all SRTs (total nitrogen removal of 41- 62%) were observed. Likewise, a partial phosphorus (P)removal was observed in the effluent which provides an opportunity to capture free P fromthe effluent for recovery as fertiliser. Further, the microalgal growth was slower due to lightor inorganic carbon limitation or ammonium repression caused by higher internal recirculationas observed from ammonium and nitrite-nitrate levels in the PBR. Most importantly, effectivePBR biomass concentration based nutrient removal and relative sludge recirculation have tobe considered in the PBR design to avoid light limitation and activate symbiosis.
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| 15. |
- Anbalagan, Anbarasan, 1988-
(author)
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Indigenous microalgae-activated sludge cultivation system for wastewater treatment
- 2016
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Licentiate thesis (other academic/artistic)abstract
- The municipal wastewater is mainly composed of water containing anthropogenic wastes that are rich in nutrients such as carbon, nitrogen and phosphorous. The cost for biological treatment of wastewater is increasing globally due to the population growth in urban cities. In general, the activated sludge (AS) process is a biological nutrient removal process used in wastewater treatment plants (WWTPs). The AS is composed of different microorganisms in which bacteria play a crucial role in wastewater treatment (WWT). During the process, air is bubbled to supply oxygen and methanol is added to improve nitrogen removal, which is released as a gas. Phosphorous is removed in the expense of precipitation chemicals. Altogether, the current process requires electrical energy, precipitation chemicals, handling of excess sludge and it emits carbon dioxide (CO2) as a by-product. This process is still in practise in the WWTPs since 1914 although numerous modifications are implemented to meet the stringent regulations in the European Union and globally.Microalgae are microorganisms that perform photosynthesis like plants. They are green and reproduce fast using available nutrients (nitrogen and phosphorous) and CO2 from their environment in the presence of light. As a result of photosynthesis, oxygen is released as waste gas. The synthesised oxygen during this process can be implemented to support the AS bacteria that leads to the microalgae activated sludge (MAAS) process. The main advantage is combined removal of nutrients.The vision of the research is to implement the indigenous microalgae cultivation in activated sludge process to consume CO2 and recover the nutrients from wastewater. This study is performed to improve the understanding of the process such as: light utilisation, nutrient removal and recovery of the biomass from wastewater in closed photo-bioreactors. Photo-bioreactors are vessels where the cultivation is carried out in the presence of light. At first, the influence of the light spectrum on micro-algal cultivation is investigated for photosynthetic growth. This is followed by operational challenges of the microalgae cultivation during the AS process. The process is experimentally performed in the photo-bioreactors with different treatment time of the raw wastewater. The results showed that 2 - 6 days of treatment time can be used for reducing nutrients in wastewater if the process is optimised further. Also, nutrient ratio is analysed for the availability of the micro-algal growth. Furthermore, the biogas potential of MAAS showed a biogas yield of about 60-80% within 5 to 9 days.At last, the experimental verification of chemically precipitated wastewater showed limitation of phosphorous for micro-algal growth. Additionally, the optimal oxygen supply through light response is verified for photo-bioreactors. The outcome of this study shows that knowing the right conditions can lower the treatment time. By doing so, a stable nutrient removal and reduction of precipitation chemicals can be established as well as a better recovery of valuable nutrients as phosphorous and nitrogen.
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| 16. |
- Anbalagan, Anbarasan, et al.
(author)
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Influence of hydraulic retention time on indigenous microalgae and activated sludge process
- 2016
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In: Water Research. - : Elsevier BV. - 0043-1354 .- 1879-2448. ; 91, s. 277-284
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Journal article (peer-reviewed)abstract
- Integration of the microalgae and activated sludge (MAAS) process in municipal wastewater treatment and biogas production from recovered MAAS was investigated by studying the hydraulic retention time (HRT) of semi-continuous photo-bioreactors. An average total nitrogen (TN) removal efficiency (RE) of maximum 81.5 ± 5.1 and 64.6 ± 16.2% was achieved at 6 and 4 days HRT. RE of total phosphorous (TP) increased slightly at 6 days (80 ± 12%) HRT and stabilized at 4 days (56 ± 5%) and 2 days (55.5 ± 5.5%) HRT due to the fluctuations in COD and N/P mass ratio of the periodic wastewater. COD and organic carbon were removed efficiently and a rapidly settleable MAAS with a sludge volume index (SVI_10) of less than 117 mL g-1 was observed at all HRTs. The anaerobic digestion of the untreated MAAS showed a higher biogas yield of 349 ± 10 mL g VS-1 with 2 days HRT due to a low solids retention time (SRT). Thermal pretreatment of the MAAS (120 °C, 120 min) did not show any improvement with biogas production at 6 days (269 ± 3 (untreated) and 266 ± 16 (treated) mL gVS-1), 4 days (258 ± 11(untreated) and 263 ± 10 (treated) mL gVS-1) and 2 days (308 ± 19 mL (treated) gVS-1) HRT. Hence, the biogas potential tests showed that the untreated MAAS was a feasible substrate for biogas production. Results from this proof of concept support the application of MAAS in wastewater treatment for Swedish conditions to reduce aeration, precipitation chemicals and CO2 emissions.
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| 17. |
- Anbalagan, Anbarasan, et al.
(author)
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Influence of iron precipitated condition and light intensity on microalgae activated sludge based wastewater remediation
- 2017
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In: Chemosphere. - : Elsevier. - 0045-6535 .- 1879-1298. ; , s. 1523-1530
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Journal article (peer-reviewed)abstract
- The indigenous microalgae-activated sludge (MAAS) process during remediation of municipal wastewater was investigated by studying the influence of iron flocculation step and light intensity. In addition, availability of total phosphorous (P) and photosynthetic activity was examined in fed-batch and batch mode under northern climatic conditions and limited lighting. This was followed by a semi-continuous operation with 4 d of hydraulic retention time and mean cell residence time of 6.75 d in a photo-bioreactor (PBR) with varying P availability. The fed-batch condition showed that P concentrations of 3–4 mg L−1 were effective for photosynthetic chl. a development in iron flocculated conditions. In the PBR, the oxygen evolution rate increased with increase in the concentration of MAAS (from 258 to 573 mg TSS L−1) at higher surface photosynthetic active radiation (250 and 500 μmol m−2 s−1). Additionally, the rate approached a saturation phase at low MAAS (110 mg L−1) with higher light intensities. Semi-continuous operation with luxury P uptake and effective P condition showed stable average total nitrogen removal of 88 and 92% respectively, with residual concentrations of 3.77 and 2.21 mg L−1. The corresponding average P removal was 68 and 59% with residual concentrations of 2.32 and 1.75 mg L−1. The semi-continuous operation produced a rapidly settleable MAAS under iron flocculated condition with a settling velocity of 92–106 m h−1 and sludge volume index of 31–43 ml g−1 in the studied cases.
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| 18. |
- Axelsson, Lena, et al.
(author)
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Unmet Palliative Care Needs Among Patients With End-Stage Kidney Disease : A National Registry Study About the Last Week of Life
- 2018
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In: Journal of Pain and Symptom Management. - : Elsevier. - 0885-3924 .- 1873-6513. ; 55:2, s. 236-244
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Journal article (peer-reviewed)abstract
- Context. End-stage kidney disease (ESKD) is characterized by high physical and psychological burden, and therefore, more knowledge about the palliative care provided close to death is needed. Objectives. To describe symptom prevalence, relief, and management during the last week of life, as well as end-of-life communication, in patients with ESKD. Methods. This study was based on data from the Swedish Register of Palliative Care. Patients aged 18 or older who died from a chronic kidney disease, with or without dialysis treatment (International Classification of Diseases, Tenth Revision, Sweden; N18.5 or N18.9), during 2011 and 2012 were selected. Results. About 472 patients were included. Of six predefined symptoms, pain was the most prevalent (69%), followed by respiratory secretion (46%), anxiety (41%), confusion (30%), shortness of breath (22%), and nausea (17%). Of patients with pain and/or anxiety, 32% and 44%, respectively, were only partly relieved or not relieved at all. Of patients with the other symptoms, a majority (55%-84%) were partly relieved or not relieved at all. End-of-life discussions were reported in 41% of patients and 71% of families. A minority died in specialized palliative care: 8% in hospice/inpatient palliative care and 5% in palliative home care. Of all patients, 19% died alone. Bereavement support was offered to 38% of families. Conclusion. Even if death is expected, most patients dying with ESKD had unmet palliative care needs regarding symptom management, advance care planning, and bereavement support. (C) 2017 American Academy of Hospice and Palliative Medicine. Published by Elsevier Inc. All rights reserved.
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| 19. |
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| 20. |
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