| 1. |
- Alföldy, B., et al.
(författare)
-
Measurements of air pollution emission factors for marine transportation in SECA
- 2013
-
Ingår i: Atmospheric Measurement Techniques. - : Copernicus GmbH. - 1867-1381 .- 1867-8548. ; 6:7, s. 1777-1791
-
Tidskriftsartikel (refereegranskat)abstract
- The chemical composition of the plumes of seagoing ships was measured during a two week long measurement campaign in the port of Rotterdam, Hoek van Holland The Netherlands, in September 2009. Altogether, 497 ships were monitored and a statistical evaluation of emission factors (g kg(-1) fuel) was provided. The concerned main atmospheric components were SO2, NO2, NOx and the aerosol particle number. In addition, the elemental and water-soluble ionic composition of the emitted particulate matter was determined. Emission factors were expressed as a function of ship type, power and crankshaft rotational speed. The average SO2 emission factor was found to be roughly half of what is allowed in sulphur emission control areas (16 vs. 30 g kg(-1) fuel), and exceedances of this limit were rarely registered. A significant linear relationship was observed between the SO2 and particle number emission factors. The intercept of the regression line, 4.8 x 10(15) (kg fuel)(-1), gives the average number of particles formed during the burning of 1 kg zero sulphur content fuel, while the slope, 2 x 10(18), provides the average number of particles formed with 1 kg sulphur burnt with the fuel. Water-soluble ionic composition analysis of the aerosol samples from the plumes showed that similar to 144 g of particulate sulphate was emitted from 1 kg sulphur burnt with the fuel. The mass median diameter of sulphate particles estimated from the measurements was similar to 42 nm.
|
|
| 2. |
- Anheden, Marie, et al.
(författare)
-
Value chain for production of bio-oil from kraft lignin for use as bio-jet fuel
- 2017
-
Ingår i: The 7th Nordic Wood Biorefinery Conference held in Stockholm, Sweden, 28-30 Mar. 2017. - Stockholm : RISE Bioekonomi. - 9789186018207 ; , s. 104-109
-
Konferensbidrag (refereegranskat)abstract
- The LignoJet project aimed to achieve an intermediate lignin-oil product miscible with fossil feedstock and with a significantly reduced oxygen content. A technical concept for production has been studied that involves combined catalysed depolymerisation and hydrodeoxygenation, so called hydrogenolytic depolymerisation, of kraft lignin. Kraft lignin was separated through membrane ultrafiltration from softwood and eucalyptus black liquor followed by precipitation through LignoBoost technology. A difference in lignin properties was observed between ultrafiltration of softwood and eucalyptus black liquor through 15 and 150kDa ceramic membranes. Lignin-oils with similar oxygen content were produced regardless of origin and fractionation technique. A lignin-oil with favourable properties as precursor for refinery integration for jet fuel production as produced in small-scale batch experiments using nickel-based catalyst. Stable pumpable oils with melting point of less than 25-50 deg C and with 20-30% lower oxygen content and aromatic content were obtained that would be suitable as jet fuel precursors. The estimated production cost was found to be competitive with that of other liquid biofuels, while additional revenues could potentially be achieved by also producing chemical and materials from suitable fractions of the lignin-oil.
|
|
| 3. |
- Arkblad, Eva L, et al.
(författare)
-
Multiplex ligation-dependent probe amplification improves diagnostics in spinal muscular atrophy
- 2006
-
Ingår i: Neuromuscular disorders : NMD. - : Elsevier BV. - 0960-8966 .- 1873-2364. ; 16:12, s. 830-8
-
Tidskriftsartikel (refereegranskat)abstract
- Spinal muscular atrophy (SMA) is an autosomal recessive disease caused by decreased levels of survival motor neuron protein (SMN). In the majority of cases, this decrease is due to absence of the SMN1 gene. Multiplex ligation-dependent probe amplification (MLPA) is a modern quantitative molecular method. Applied in SMA cases, it improves diagnostics by simultaneously identifying the number of copies of several target sequences in the SMN1 gene and in nearby genes. Using MLPA in clinical diagnostics, we have identified a previously unreported, partial deletion of SMN1 (exons 1-6) in two apparently unrelated Swedish families. This mutation would not have been detected by conventional diagnostic methods. This paper illustrates the broad clinical and genetic spectrum of SMA and includes reports of MLPA results and clinical descriptions of a patient with homozygous absence of SMN1 and only one SMN2 (prenatal onset SMA type 1), an asymptomatic woman with five SMN2 (lacking SMN1) and representative patients with SMA types 1, 2 and 3.
|
|
| 4. |
|
|
| 5. |
- Berg, Niklas, 1980
(författare)
-
Remote Measurements of Ship Emissions
- 2011
-
Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The combustion of sulphur-containing fossil fuels gives rise to emissions of sulphurdioxide. Nitrogen oxides are also emitted when fuels are burned. The InternationalMaritime Organization (IMO) has ratified regulations regarding Sulphur Fuel Content(SFC) and NOx emissions from the shipping sector. There is economic incentive to ignorelegislation and run with cheaper residual fuel that contains high concentrations of sulphur.In open waters, there is no effective method of controlling whether ships are running onlow or high sulphur fuel.A surveillance system, denoted Identification of Gross Polluting Ships (IGPS), has beendeveloped and used with the objective of enforcing the use of low sulphur fuel and NOxabatement equipment according to the new conventions within the IMO.The system is foremost an airborne system consisting of an optical remote measuringsystem for total emission measurements of SO2 or NO2 from ships. When the emissionvalues reach a certain threshold, an aircraft flies into the ship’s exhaust and takes in situmeasurements, denoted the sniffer system, from which SFC and NOx g/kg fuelmeasurements are obtained.The uncertainty for the optical measurements is estimated to be approximately 45% withoptical and wind as the largest uncertainty sources. Estimates of the overall uncertaintyfor the sniffer measurements, derived during a campaign in Rotterdam, corresponds to14% for SO2 (S%) and 33% for NO (g/kg fuel). For the emission factors of NOx versusaxial power, g/kWh, the uncertainty is 37%. It should be noted that the NO uncertaintywas unusually high due to instrument problems.Measurement campaigns have been carried out in the Baltic and North Seas using aCASA-212 aeroplane and a Dauphin helicopter. Optical measurements show thepossibility to detect SO2 and NO2 emission from ships. Many of the ocean going shipshad a total emission of 60 kg/h SO2. The sniffer measurements showed good agreementwith the current IMO regulations for the majority of ships. When the strictest IMOregulation of 0.1% SFC is introduced, ships using fuels with 0.5-4.5% SFC will be easilydetected with the current uncertainties.
|
|
| 6. |
- Berg, Niklas, 1980, et al.
(författare)
-
Ship emissions of SO2 and NO2: DOAS measurements from airborne platforms
- 2012
-
Ingår i: Atmospheric Measurement Techniques. - : Copernicus GmbH. - 1867-1381 .- 1867-8548. ; 5:5, s. 1085-1098
-
Tidskriftsartikel (refereegranskat)abstract
- A unique methodology to measure gas fluxes of SO2 and NO2 from ships using optical remote sensing is described and demonstrated in a feasibility study. The measurement system is based on Differential Optical Absorption Spectroscopy using reflected skylight from the water surface as light source. A grating spectrometer records spectra around 311 nm and 440 nm, respectively, with the telescope pointed downward at a 30A degrees angle from the horizon. The mass column values of SO2 and NO2 are retrieved from each spectrum and integrated across the plume. A simple geometric approximation is used to calculate the optical path. To obtain the total emission in kg h(-1) the resulting total mass across the plume is multiplied with the apparent wind, i.e. a dilution factor corresponding to the vector between the wind and the ship speed. The system was tested in two feasibility studies in the Baltic Sea and Kattegat, from a CASA-212 airplane in 2008 and in the North Sea outside Rotterdam from a Dauphin helicopter in an EU campaign in 2009. In the Baltic Sea the average SO2 emission out of 22 ships was (54 +/- 13) kg h(-1), and the average NO2 emission was (33 +/- 8) kg h(-1), out of 13 ships. In the North Sea the average SO2 emission out of 21 ships was (42 +/- 11) kg h(-1), NO2 was not measured here. The detection limit of the system made it possible to detect SO2 in the ship plumes in 60% of the measurements when the described method was used. A comparison exercise was carried out by conducting airborne optical measurements on a passenger ferry in parallel with onboard measurements. The comparison shows agreement of (-30 +/- 14)% and (-41 +/- 11)%, respectively, for two days, with equal measurement precision of about 20%. This gives an idea of the measurement uncertainty caused by errors in the simple geometric approximation for the optical light path neglecting scattering of the light in ocean waves and direct and multiple scattering in the exhaust plume under various conditions. A tentative error budget indicates uncertainties within 30-45% but for a reliable error analysis the optical light path needs to be modelled. A ship emission model, FMI-STEAM, has been compared to the optical measurements showing an 18% overestimation and a correlation coefficient (R-2) of 0.6. It is shown that a combination of the optical method with modelled power consumption can estimate the sulphur fuel content within 40%, which would be sufficient to detect the difference between ships running at 1% and at 0.1%, limits applicable within the IMO regulated areas.
|
|
| 7. |
- Carroll, Christopher, et al.
(författare)
-
Hypoxia Generated by Avian Embryo Growth Induces the HIF-α Response and Critical Vascularization
- 2021
-
Ingår i: Frontiers in Ecology and Evolution. - : Frontiers Media SA. - 2296-701X. ; 9, s. 1-15
-
Tidskriftsartikel (refereegranskat)abstract
- Cancer research has transformed our view on cellular mechanisms for oxygen sensing. It has been documented that these mechanisms are important for maintaining animal tissues and life in environments where oxygen (O2) concentrations fluctuate. In adult animals, oxygen sensing is governed by the Hypoxia Inducible Factors (HIFs) that are stabilized at low oxygen concentrations (hypoxia). However, the importance of hypoxia itself during development and for the onset of HIF-driven oxygen sensing remains poorly explored. Cellular responses to hypoxia associates with cell immaturity (stemness) and proper tissue and organ development. During mammalian development, the initial uterine environment is hypoxic. The oxygenation status during avian embryogenesis is more complex since O2 continuously equilibrates across the porous eggshell. Here, we investigate HIF dynamics and use microelectrodes to determine O2 concentrations within the egg and the embryo during the first four days of development. To determine the increased O2 consumption rates, we also obtain the O2 transport coefficient (DO2) of eggshell and associated inner and outer shell membranes, both directly (using microelectrodes in ovo for the first time) and indirectly (using water evaporation at 37.5°C for the first time). Our results demonstrate a distinct hypoxic phase (<5% O2) between day 1 and 2, concurring with the onset of HIF-α expression. This phase of hypoxia is demonstrably necessary for proper vascularization and survival. Our indirectly determined DO2 values are about 30% higher than those determined directly. A comparison with previously reported values indicates that this discrepancy may be real, reflecting that water vapor and O2 may be transported through the eggshell at different rates. Based on our obtained DO2 values, we demonstrate that increased O2 consumption of the growing embryo appears to generate the phase of hypoxia, which is also facilitated by the initially small gas cell and low membrane permeability. We infer that the phase of in ovo hypoxia facilitates correct avian development. These results support the view that hypoxic conditions, in which the animal clade evolved, remain functionally important during animal development. The study highlights that insights from the cancer field pertaining to the cellular capacities by which both somatic and cancer cells register and respond to fluctuations in O2 concentrations can broadly inform our exploration of animal development and success.
|
|
| 8. |
- Efe, Cumali, et al.
(författare)
-
Tacrolimus and Mycophenolate Mofetil as Second-Line Therapies for Pediatric Patients with Autoimmune Hepatitis
- 2018
-
Ingår i: Digestive Diseases and Sciences. - : SPRINGER. - 0163-2116 .- 1573-2568. ; 63:5, s. 1348-1354
-
Tidskriftsartikel (refereegranskat)abstract
- We studied the efficacy and safety of mycophenolate mofetil (MMF) and tacrolimus as second-line therapy in pediatric patients with autoimmune hepatitis (AIH) who were intolerant or non-responders to standard therapy (corticosteroid and azathioprine). We performed a retrospective study of data from 13 centers in Europe, USA, and Canada. Thirty-eight patients (< 18 years old) who received second-line therapy (18 MMF and 20 tacrolimus), for a median of 72 months (range 8-182) were evaluated. Patients were categorized into two groups: Group 1 (n = 17) were intolerant to corticosteroid or azathioprine, and group 2 (n = 21) were non-responders to standard therapy. Overall complete response rates were similar in patients treated with MMF and tacrolimus (55.6 vs. 65%, p = 0.552). In group 1, MMF and tacrolimus maintained a biochemical remission in 88.9 and 87.5% of patients, respectively (p = 0.929). More patients in group 2 given tacrolimus compared to MMF had a complete response, but the difference was not statistically significant (50.0 vs. 22.2%, p = 0.195). Biochemical remission was achieved in 71.1% (27/38) of patients by tacrolimus and/or MMF. Decompensated cirrhosis was more commonly seen in MMF and/or tacrolimus non-responders than in responders (45.5 vs. 7.4%, p = 0.006). Five patients who received second-line therapy (2 MMF and 3 tacrolimus) developed side effects that led to therapy withdrawal. Long-term therapy with MMF or tacrolimus was generally well tolerated by pediatric patients with AIH. Both MMF and tacrolimus had excellent efficacy in patients intolerant to corticosteroid or azathioprine. Tacrolimus might be more effective than MMF in patients failing previous therapy.
|
|
| 9. |
- Eggens, Veerle Rc, et al.
(författare)
-
EXOSC3 mutations in pontocerebellar hypoplasia type 1: novel mutations and genotype-phenotype correlations.
- 2014
-
Ingår i: Orphanet journal of rare diseases. - : Springer Science and Business Media LLC. - 1750-1172. ; 9:1
-
Tidskriftsartikel (refereegranskat)abstract
- Pontocerebellar hypoplasia (PCH) represents a group of neurodegenerative disorders with prenatal onset. Eight subtypes have been described thus far (PCH1-8) based on clinical and genetic features. Common characteristics include hypoplasia and atrophy of the cerebellum, variable pontine atrophy, and severe mental and motor impairments. PCH1 is distinctly characterized by the combination with degeneration of spinal motor neurons. Recently, mutations in the exosome component 3 gene (EXOSC3) have been identified in approximately half of the patients with PCH subtype 1.
|
|
| 10. |
|
|
