97 research outputs found
The risk of HCV RNA contamination in serology screening instruments with a fixed needle for sample transfer
AbstractBackgroundHepatitis C diagnostics involve antibody screening and confirmation of current infection by detection of HCV RNA positivity. In screening instruments with fixed pipetting needle, there is a risk of sample carry-over contamination.ObjectivesThe aim of this study was to evaluate the risk of such contamination in a proposed clinical setting.Study designIn the present study, known HCV RNA positive (n=149) and negative (n=149) samples were analysed by anti-HCV Abbott in an Architect instrument in an alternating fashion in order to test for contamination.ResultsIn subsequent retesting of the previously HCV RNA-negative samples, six samples (4%) were positive by the Cobas Taqman assay with a maximum level of 33IU/mL. The results show that there is a risk for transfer of HCV in the Architect instrument but they also show that the levels of HCV RNA observed are low.ConclusionsWe conclude that complementary HCV RNA testing on samples identified as anti-HCV positive by screening can be recommended because the complementary results are reliable in the majority of cases when either HCV RNA is negative or HCV RNA is positive with a level >1000IU/mL. In a minority of cases, with low HCV RNA after anti-HCV antibody screening, cross-contamination should be suspected and a new sample requested for HCV RNA testing. This strategy would reduce the need for obtaining a new sample from the vast majority of patients with a newly discovered HCV antibody positivity
Decrease of core 2 O-glycans on synovial lubricin in osteoarthritis reduces galectin-3 mediated crosslinking
The synovial fluid glycoprotein lubricin (also known as proteoglycan 4) is a mucin-type O-linked glycosylated biological lubricant implicated to be involved in osteoarthritis (OA) development. Lubricin\u27s ability to reduce friction is related to its glycosylation consisting of sialylated and unsialylated Tn-antigens and core 1 and core 2 structures. The glycans on lubricin have also been suggested to be involved in crosslinking and stabilization of the lubricating superficial layer of cartilage by mediating interaction between lubricin and galectin-3. However, with the spectrum of glycans being found on lubricin, the glycan candidates involved in this interaction were unknown. Here, we confirm that the core 2 O-linked glycans mediate this lubricin-galectin-3 interaction, shown by surface plasmon resonance data indicating that recombinant lubricin (rhPRG4) devoid of core 2 structures did not bind to recombinant galectin-3. Conversely, transfection of Chinese hamster ovary cells with the core 2 GlcNAc transferase acting on a mucin-type O-glycoprotein displayed increased galectin-3 binding. Both the level of galectin-3 and the galectin-3 interactions with synovial lubricin were found to be decreased in late-stage OA patients, coinciding with an increase in unsialylated core 1 O-glycans (T-antigens) and Tn-antigens. These data suggest a defect in crosslinking of surface-active molecules in OA and provide novel insights into OA molecular pathology
Large and prolonged food-borne multistate hepatitis A outbreak in Europe associated with consumption of frozen berries, 2013 to 2014
Concentration of antibodies against Porphyromonas gingivalis is increased before the onset of symptoms of rheumatoid arthritis
Effekter av en havsbaserad vindkraftpark på fördelningen av bottennära fisk
Den här studien baserar sig på fältundersökningar utförda vid Lillgrund vindkraftpark i Öresund och syftar till att klargöra hur anläggningen kan ha påverkat förekomsten av bottennära fisk, det vill säga fisk som lever på eller nära havsbotten. Studien är framförallt fokuserad på effekter i närområdet för enskilda vindkraftverk. Hos flera av fiskarterna noterades en högre förekomst i närområdet för vindkraftverken i jämförelse med på längre avstånd. Effekten syntes från och med det första året av drift och var av likartad omfattning under samtliga tre studerade år. En aggregation nära vindkraftverken noterades hos tånglake, ål, torsk, stensnultra och rötsimpa. Effekten noterades inte hos oxsimpa och skrubbskädda, som också var relativt vanliga i provfisket. Hos strandkrabba noterades en förändrad fördelning, som var olika mellan år. Under de två första åren noterades en lägre förekomst av strandkrabba nära vindkraftverken men under det sista året noterades en aggregation. De observerade effekterna berodde sannolikt på en omfördelning av fisk inom vindkraftparksområdet, snarare än på en ökad produktivitet eller en ansamling av fisk från ett större område. Provfisken inom denna studie och inom kontrollprogrammet för Lillgrund vindkraftpark visar sammantaget att den totala mängden fisk inte ökade i vindkraftparken inom den studerade treårsperioden, och att mängden fisk i området inte heller var högre än före anläggningen, i relation till utvecklingen i referensområden. Mängden fisk hade dock inte heller minskat. Avståndsintervallet inom vilket en ökad förekomst av fisk kunde observeras skattades till mellan 0-50 och 0-160 meter från vindkraftverket, beroende på art. Hos vissa arter sågs därtill en minskad täthet av fisk på längre avstånd från kraftverken, vilket skulle kunna återspegla att fisken attraherades därifrån till närområdet för vindkraftverket. Vindkraftverkens fundament på Lillgrund är omgivna av erosionsskydd. Dessa strukturer erbjuder en omväxlande livsmiljö där det sannolikt finns goda möjligheter för fisk att söka skydd och hitta föda. Det relativt starka samband som noterades mellan mängden fisk och avstånd till vindkraftverk för ett flertal fiskarter antyder att vindkraftverken i första hand attraherar fisk, och att eventuella negativa effekter på fiskens förekomst, orsakad till exempel av elektromagnetiska fält eller yttre ljudmiljö, sannolikt har en i sammanhanget underordnad betydelse
Optimisation of the slag formation in a blast furnace charged with 100% pellets
This work is based on experiences from industrial blast furnaces. Process irregularities when testing self-fluxed pellets Process disturbances when charging increased proportions of coarse pellets Laboratory tests to evaluate the effect of basic fluxes on the slag formation in the bosh and in the raceway have been carried out. Pilot scale tests have been performed to verify the effect of coarse pellets. The effect of reduction degree and the reduction behaviour on the slag formation and blast furnace performance have been evaluated It was found that decreased degree of reduction of pellets or lowly reduced core of coarse pellets decrease the melting temperature and increase the softening and melting temperature interval. Basic fluxes have a negative effect on the melting properties of the self-fluxed pellets and a positive effect on the melting properties of the olivine pellets. Basic fluxes have a positive effect on the melting properties of tuyere slags.Godkänd; 2001; 20070313 (ysko
Co-injection of basic fluxes or BF flue dust with PC into a BF charged with 100% pellets : effects on slag formation and coal combustion
Based on 100% pellets operation at BF No. 3 at SSAB Tunnplåt in Luleå a new pellet with CaO/SiO2=1 was developed during early nineties. The pellet showed good results in metallurgical laboratory test but caused slag formation problems in the bosh. A high basicity slag was formed during interaction with basic fluxes and its melting point was increased when the slag was finally reduced. By injection of basic fluxes, the slag formation problems in the bosh can be avoided. Without a sinter plant, dusts have to be recycled in a cold bonded briquette. Injection of some of BF flue dust would improve the properties of the briquette and may be beneficial for the BF process. Based on top charging or tuyere-injection of basic fluxes and the injection of BF flue dust studies have been done. The studies carried out will clarify some phenomena of slag formation and the effect of co- injection on coal combustion in the blast furnace, including the effect of: 1) basic fluxes on slag formation in the blast furnace, if they are top- charged; 2) basic fluxes on slag formation in the blast furnace, if they are tuyere injected; 3) chemical composition and metallurgical properties of pellet and fluxes on slag formation; 4) reduction conditions on (reduction temperature, reducing gas composition) on bosh slag formation; 5 co- injection of BOF slag or BF flue dust on coal combustion efficiency and BF performance. From the results, it can be concluded that the interaction between pellets and fluxes starts when softening and melting starts in the cohesive layer. By choosing fluxes of a high melting point the dissolution of them in the bosh slag can be delayed and the excessive basicity of the bosh slag can be limited. A basic flux with a low melting point will easily dissolve into the bosh slag causing its basicity to increase, which is beneficial to S refining when acid pellets are used. The formation of a bosh slag of excessive basicity (which causes BF operation disturbances, because its high melting point, increases further during reduction) can be avoided by tuyere injection of basic fluxes with the coal. The positive effect is greatest when a fluxed pellet of basicity B21 and with a high Fe content is used as ferrous burden. In this case, the slag amount can be significantly decreased. BOF slag has suitable high-temperature properties for use as a basic flux in combination with e.g., olivine pellets. It has a low softening and melting temperature, does not shrink, is slowly reduced in the BF shaft and its properties are almost unaffected by the partial reduction occurring in the shaft of the BF. BOF slag absorbs a low content of alkalies, which causes volume increase at elevated temperatures, when the basicity is still high. The results indicate that co-injection of BOF slag or BF flue dust with PC has positive effects on the BF operation. The injection of BOF slag decreases the Si content in HM by an increased basicity of the slag formed during combustion leading to a decreased activity of SiO2 in the slag and by an increased FeO content in the tuyere slag that will be reduced by SiFe in the metal at the tuyere level, if the SiFe is initially high. The consumption of reducing agents can be reduced because of a decreased Si content in HM and a decreased slag amount. The permeability is improved by prohibiting the formation of a shell at the raceway end because of improved melting properties of tuyere slag caused by an increased basicity and FeO content, consumption of coal and coke fines by FeO and improved radial transport of tuyere slag. The injection of BOF slag improves the bosh slag because an excessive basicity caused by top-charged fluxes added for neutralisation of coal and coke ashes and non-uniform slag formation caused by uneven distribution of top-charged fluxes are avoided. The productivity increases because of the possibility to decrease the slag amount. The injection of BOF slag can be done without negative effects on combustion efficiency by using very finely ground BOF slag and because of improved total consumption of coal and coke fines by direct reduction in the coke bed. The injection of BF flue dust decreases the Si content in HM by an increased FeO content of the tuyere slag that will be reduced by SiFe in the metal at the tuyere level, if the SiFe is initially high. The consumption of coal and coke is decreased because of a high of C content in BF flue dust and the decreased Si content in HM. The permeability is improved by prohibiting the formation of a shell at the raceway end because of consumption of coal and coke fines by FeO and improved melting properties of tuyere slag promoting the radial transport of the tuyere slag. The injection of BF flue dust can be done without negative effects on the total consumption of coal and coke fines by direct reduction in the coke bed. Injected BF flue dust supplies oxygen for combustion, but because of endothermic reactions as reduction of hematite and calcination of limestone occurring in the BF flue dust at the same temperatures as release and disintegration of VM, it will have a negative effect on the combustion of HV coal. SSAB Luleå and SSAB Oxelösund have started up projects aiming to make tuyere- injection of BF flue dust part of the standard BF operation.Godkänd; 2004; 20070416 (ysko
Specialpedagogik och måluppfyllelse : En intervjustudie som belyser processer som leder till att kunskapsmålen i svenska uppnås
Sammanfattning Studien initierades av att det är många elever i dagens grundskola som inte uppnår målen i svenska trots specialpedagogiska insatser. Syftet med studien är att undersöka hur det specialpedagogiska stödet ges till de elever som inte når målen i svenska och dessutom att belysa de processer som leder till att det specialpedagogiska stödet ger positiva resultat. Studien är en kvalitativ intervjustudie där datainsamlingen gjordes genom nio halvstrukturerade intervjuer på fyra olika skolor i en svensk kommun. Respondenterna är utvecklingsledare, rektorer, specialpedagoger och klasslärare som sammantaget representerar organisations-, grupp- och individnivå. Sammanlagt genomfördes nio intervjuer. Resultatet av studien pekar åt att tidiga insatser, goda metoder, motiverade elever, god självkänsla och bra hjälpmedel är framgångsfaktorer som enligt respondenterna leder till att många elever i behov av särskilt stöd når grundskolans kunskapsmål i svenska
På andra sidan strecket? : Andelen godkända elevers avgångsbetyg i ämnena engelska, matematik, svenska och teckenspråk i specialskolan under åren 2002 till 2017.
Denna studie undersöker avgångsbetyg i specialskolan för döva och hörselskadade elever i syfte att belysa hur stor andel av specialskolans elever som nått godkänt betyg eller högre i ämnena engelska, matematik, svenska och teckenspråk, under åren 2002 till 2017. Vår kvantitativa metodansats bygger på avgångsbetyg tagna ur registerutdrag från Specialpedagogiska skolmyndigheten (SPSM) och den tidigare myndigheten Specialskolemyndigheten (SPM). Studien baseras på samtliga 860 elevers avgångsbetyg från de fem regionala specialskolorna; Birgitta-, Kristina-, Manilla-, Väner- samt Östervångskolan. Eleverna har avidentifierats till pojkar respektive flickor och deras avgångsbetyg har tilldelats varsin sifferkod. Därefter har andelen godkända betyg eller högre i varje ämne beräknats, sammanställts per år och slutligen presenterats i form av linjediagram. I resultatet framstår tydligt i huvudsak två distinkta tendenser. Den ena presenterar en mycket låg måluppfyllelse att nå godkänt i samtliga kärnämnen; matematik, svenska och engelska, där pojkarnas extremt låga resultat utmärker sig. Det andra resultatet pekar på andelen godkända betyg i respektive ämne, där teckenspråket når en påtagligt hög måluppfyllelse, till exempel 96 procent år 2017. Efter år 2013 och framåt då det nya betygssystemet tillämpades, syns tendenser till viss ökning av andelen godkända betyg i respektive ämne. I ämnet engelska ökande andelen med 10 procent och i teckenspråk ökade andelen med 16 procent, från år 2002 till år 2017, däremot når båda ämnena sina högsta resultat efter att Lspec11 implementerats. Sett över hela perioden presterar resultatmässigt flickorna högre än pojkarna i varje ämne, men fler utav pojkarna tenderar att nå godkänt de sista åren. En slutsats kan vara att bytet av läroplan både har och inte har haft en inverkan på andelen godkända betyg. Ser vi till att få godkänt i alla de tre kärnämnena så syns läroplansbytet inte ha haft någon tydlig effekt, men ser vi till måluppfyllelsen inom varje enskilt ämne finns tendenser till en viss ökning, vilket tyder på att eleverna verkar nå godkänt i ett eller två av kärnämnena. En annan möjlig slutsats är att trots den höga andelen godkända betyg i teckenspråk, når både fler pojkar och flickor ett godkänt betyg i teckenspråk efter läroplansbytet. Nyckelord Avgångsbetyg, måluppfyllelse, specialskola för döva och hörselskadade, engelska, matematik, svenska, teckensprå
Experiences of Bio-Coal Applications in the Blast Furnace Process—Opportunities and Limitations
Metal production, and especially iron ore-based steel production, is characterized by high fossil CO2 emissions due of the use of coal and coke in the blast furnace. Steel companies around the world are striving to reduce the CO2 emissions in different ways, e.g., by use of hydrogen in the blast furnace or by production of iron via direct reduction. To partially replace fossil coal and coke with climate neutral bio-coal products that are adapted for use in the metal industry, e.g., at the blast furnace, is a real and important opportunity to significantly lower the climate impact in a short-term perspective. Top-charging of bio-coal directly to the blast furnace is difficult due to its low strength but can be facilitated if bio-coal is added as an ingredient in coke or to the mix when producing residue briquettes. Bio-coal can also be injected into the lower part of the blast furnace and thereby replace a substantial part of the injected pulverized coal. Based on research work within Swerim, where the authors have been involved, this paper will describe the opportunities and limitations of using bio-coal as a replacement for fossil coal as part of coke, as a constituent in residue briquettes, or as replacement of part of the injected pulverized coal. Results from several projects studying these opportunities via technical scale, as well as pilot and industrial scale experiments and modelling will be presented
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