| 1. |
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| 2. |
- Karlsson, Klas-Göran, et al.
(författare)
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Inledning
- 2006
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Ingår i: Historieforskning på nya vägar. - 9789189116825 ; , s. 9-11
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Bokkapitel (övrigt vetenskapligt/konstnärligt)
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| 3. |
- Raoof, Mustafa, 1966-, et al.
(författare)
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Health-Related Quality-of-Life (HRQoL) on an Average of 12 Years After Gastric Bypass Surgery
- 2015
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Ingår i: Obesity Surgery. - : Springer Science and Business Media LLC. - 0960-8923 .- 1708-0428. ; 25:7, s. 1119-1127
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Tidskriftsartikel (refereegranskat)abstract
- It is evident that morbidly obese patients have a low health-related quality-of-life (HRQoL), and this low HRQoL has become a common reason for them to seek bariatric surgery. Several HRQoL studies demonstrate a dramatic postoperative improvement, but most of these have had a short follow-up period.An observational, cross-sectional study for HRQoL was conducted to study 486 patients (average age of 50.7 +/- 10.0 years, with 84 % of them being female) operated with gastric bypass (GBP) in the period 1993 to 2003 at the University Hospitals of A-rebro and Uppsala. Mean follow-up after gastric bypass was 11.5 +/- 2.7 years (range 7-17). Two HRQoL instruments were used, SF-36 and the Obesity-related Problems scale (OP). The study group was compared with two control groups, both matched for age and gender, one from the general population and one containing morbidly obese patients evaluated and awaiting bariatric surgery.The study group scored better in the SF-36 domains (all four physical domains and the vitality subscore) and OP scale compared to obese controls, but their HRQoL scores were lower than those of the general population. HRQoL was better among younger patients and in the following subgroups: men, patients with satisfactory weight loss, satisfied with the procedure, free from co-morbidities and gastrointestinal symptoms, employment, good oral status and those not hospitalised or regularly followed up for non-bariatric reasons.Long-term follow-up after GBP for morbid obesity showed better scores in most aspects of HRQoL compared to obese controls but did not achieve the levels of the general population. Patients with better medical outcome after gastric bypass operation had better HRQoL.
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| 4. |
- Abayneh, Sisay A, et al.
(författare)
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Sensitivity of HIV-1 primary isolates to human anti-CD40 antibody-mediated suppression is related to co-receptor use
- 2008
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Ingår i: AIDS Research and Human Retroviruses. - : Mary Ann Liebert Inc. - 1931-8405 .- 0889-2229. ; 24:3, s. 447-452
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Tidskriftsartikel (refereegranskat)abstract
- The effect of CD40 ligation on infection by HIV-1 primary isolates with different R5 phenotypes was evaluated with a novel set of anti-CD40 monoclonal antibodies originating from a human phage display library. Five human monoclonal anti-CD40 antibodies of IgG1 subtype characterized by the ability to activate B cells via CD40 were tested for induction of the CC-chemokines RANTES and MIP-1alpha and inhibition of HIV-1 replication in primary monocyte-derived macrophages (MDM). All activating anti-CD40 antibodies were able to induce CC-chemokines in MDM. We chose the most potent antibody, clone B44, for further experiments. This antibody had a suppressive effect on HIV-1 isolates of the R5 phenotype with limited use of CCR5/CXCR4 chimeric receptors. In comparison, HIV-1 isolates with broader use of CCR5/CXCR4 chimeric receptors or with CXCR4 use were less sensitive to anti-CD40-induced suppression. The results indicate that HIV-1 replication is inhibited by human anti-CD40 monoclonal antibodies through the mechanism of CC-chemokine induction. This effect is thus restricted to HIV-1 isolates sensitive to inhibition by CC-chemokines.
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| 5. |
- Abou Hachem, Maher, et al.
(författare)
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Carbohydrate-binding modules from a thermostable Rhodothermus marinus xylanase : Cloning, expression and binding studies
- 2000
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Ingår i: Biochemical Journal. - : Portland Press Ltd.. - 0264-6021. ; 345:1, s. 53-60
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Tidskriftsartikel (refereegranskat)abstract
- The two N-terminally repeated carbohydrate-binding modules (CBM4-1 and CBM4-2) encoded by xyn10A from Rhodothermus marinus were produced in Escherichia coli and purified by affinity chromatography. Binding assays to insoluble polysaccharides showed binding to insoluble xylan and to phosphoric-acid-swollen cellulose but not to Avicel or crystalline cellulose. Binding to insoluble substrates was significantly enhanced by the presence of Na+ and Ca2+ ions. The binding affinities for soluble polysaccharides were tested by affinity electrophoresis; strong binding occurred with different xylans and β-glucan. CBM4-2 displayed a somewhat higher binding affinity than CBM4-1 for both soluble and insoluble substrates but both had similar specificities. Binding to short oligosaccharides was measured by NMR; both modules bound with similar affinities. The binding of the modules was shown to be dominated by enthalpic forces. The binding modules did not contribute with any significant synergistic effects on xylan hydrolysis when incubated with a Xyn10A catalytic module. This is the first report of family 4 CBMs with affinity for both insoluble xylan and amorphous cellulose.
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| 6. |
- Ahlgren, Erik, 1962, et al.
(författare)
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Biokombi Rya - slutrapporter från ingående delprojekt
- 2007
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Inom projektet Biokombi Rya har ett flertal olika forskargrupper samarbetat för att studera system¬effekterna av förgasning av biobränsle ur olika aspekter. Syftet med projektet är att öka kunskapen om biobränsleförgasning i Sverige samt att utreda förutsättningar för att sådana anläggningar ska vara ekonomiskt och miljömässigt intressanta. En referensgrupp har varit kopplad till projektet där förutsättningar, resultat och slutsatser har behandlats.I denna underlagsrapport har slutrapporterna från projektets delprojekt samlats. De beskriver förutsättningar, metodansatser, använda data och resultat utförligt och utgör på så sätt ett viktigt komplement till den mer övergripande beskrivningen i projektets syntesrapport. De delrapporter som ingår har valts för att täcka in samtliga delar av projektet som är av allmänt intresse. Projektresultat som publicerats på annat sätt berörs dock mer kortfattat.Projektet Biokombi Rya har pågått under två år (2005-2006) och drivits av Chalmers EnergiCentrum. Förutom de omfattande analysinsatser som författarna till denna rapport står för, har Avdelningen för kemisk teknologi vid KTH, Siemens Industrial Turbines AB och Göteborg Energi AB bidragit med expertstöd. CIT Industriell Energianalys, med undertecknad som projektledare, har stått för projektledning och koordination.Projektet har finansierats av Energimyndigheten, Göteborg Energis forsknings¬stiftelse samt Göteborg Energi AB.
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| 7. |
- Alijagic, Andi, 1992-, et al.
(författare)
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Particle Safety Assessment in Additive Manufacturing : From Exposure Risks to Advanced Toxicology Testing.
- 2022
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Ingår i: Frontiers in Toxicology. - : Frontiers Media S.A.. - 2673-3080. ; 4
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Forskningsöversikt (refereegranskat)abstract
- Additive manufacturing (AM) or industrial three-dimensional (3D) printing drives a new spectrum of design and production possibilities; pushing the boundaries both in the application by production of sophisticated products as well as the development of next-generation materials. AM technologies apply a diversity of feedstocks, including plastic, metallic, and ceramic particle powders with distinct size, shape, and surface chemistry. In addition, powders are often reused, which may change the particles' physicochemical properties and by that alter their toxic potential. The AM production technology commonly relies on a laser or electron beam to selectively melt or sinter particle powders. Large energy input on feedstock powders generates several byproducts, including varying amounts of virgin microparticles, nanoparticles, spatter, and volatile chemicals that are emitted in the working environment; throughout the production and processing phases. The micro and nanoscale size may enable particles to interact with and to cross biological barriers, which could, in turn, give rise to unexpected adverse outcomes, including inflammation, oxidative stress, activation of signaling pathways, genotoxicity, and carcinogenicity. Another important aspect of AM-associated risks is emission/leakage of mono- and oligomers due to polymer breakdown and high temperature transformation of chemicals from polymeric particles, both during production, use, and in vivo, including in target cells. These chemicals are potential inducers of direct toxicity, genotoxicity, and endocrine disruption. Nevertheless, understanding whether AM particle powders and their byproducts may exert adverse effects in humans is largely lacking and urges comprehensive safety assessment across the entire AM lifecycle-spanning from virgin and reused to airborne particles. Therefore, this review will detail: 1) brief overview of the AM feedstock powders, impact of reuse on particle physicochemical properties, main exposure pathways and protective measures in AM industry, 2) role of particle biological identity and key toxicological endpoints in the particle safety assessment, and 3) next-generation toxicology approaches in nanosafety for safety assessment in AM. Altogether, the proposed testing approach will enable a deeper understanding of existing and emerging particle and chemical safety challenges and provide a strategy for the development of cutting-edge methodologies for hazard identification and risk assessment in the AM industry.
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| 8. |
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| 9. |
- Bengtsson, Eva-Lena, et al.
(författare)
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A Royal Family Reunited
- 1999
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Ingår i: Art Bulletin of Nationalmuseum Stockholm. - : Stockholm, Nationalmuseum. - 1401-2987. ; 5, s. 29-31
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)
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| 10. |
- Blomstrand, Peter, et al.
(författare)
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Pulsed tissue Doppler imaging for the detection of myocardial ischaemia, a comparison with myocardial perfusion SPECT
- 2004
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Ingår i: Clinical Physiology and Functional Imaging. - : John Wiley & Sons. - 1475-0961 .- 1475-097X. ; 24:5, s. 289-295
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Tidskriftsartikel (refereegranskat)abstract
- In order to compare the diagnostic ability of pulsed tissue Doppler and myocardial perfusion Single Photon Emission Computed Tomography (SPECT) in patients with a history of unstable coronary artery disease, CAD, 26 patients, 22 men and four women, age 47-76 years, were investigated in a prospective study, 5-10 day after an episode of unstable angina. Tissue Doppler and two-dimensional echocardiography were performed during dobutamine stress testing and myocardial scintigraphy after bicycle exercise and at rest. Patients with a normal SPECT had higher peak systolic velocity during dobutamine infusion, 18.9 ± 4.1 cm s-1, than patients with ischaemia, 12.2 ± 3.8 cm s-1 (P<0.001) or scar, 8.8 ± 3.0 cm s-1 (P<0.01). In a territorial analysis the difference in peak systolic velocity between areas with a normal and abnormal SPECT was less apparent. Failure to achieve ≥13 cm s-1 in mean-peak systolic velocity was the most accurate criterion for detection of significant CAD on SPECT. We conclude that pulsed tissue Doppler can be used for objective quantification of left ventricular wall motion during dobutamine stress testing and for identification of patients with CAD on SPECT but not for identification of regional ischaemia.
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| 11. |
- Cawthon, P. M., et al.
(författare)
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Putative Cut-Points in Sarcopenia Components and Incident Adverse Health Outcomes: AnSDOCAnalysis
- 2020
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Ingår i: Journal of the American Geriatrics Society. - : Wiley. - 0002-8614 .- 1532-5415. ; 68:7, s. 1429-1437
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVES Analyses performed by the Sarcopenia Definitions and Outcomes Consortium (SDOC) identified cut-points in several metrics of grip strength for consideration in a definition of sarcopenia. We describe the associations between the SDOC-identified metrics of low grip strength (absolute or standardized to body size/composition); low dual-energy x-ray absorptiometry (DXA) lean mass as previously defined in the literature (appendicular lean mass [ALM]/ht(2)); and slowness (walking speed <.8 m/s) with subsequent adverse outcomes (falls, hip fractures, mobility limitation, and mortality). DESIGN Individual-level, sex-stratified pooled analysis. We calculated odds ratios (ORs) or hazard ratios (HRs) for incident falls, mobility limitation, hip fractures, and mortality. Follow-up time ranged from 1 year for falls to 8.8 +/- 2.3 years for mortality. SETTING Eight prospective observational cohort studies. PARTICIPANTS A total of 13,421 community-dwelling men and 4,828 community-dwelling women. MEASUREMENTS Grip strength by hand dynamometry, gait speed, and lean mass by DXA. RESULTS Low grip strength (absolute or standardized to body size/composition) was associated with incident outcomes, usually independently of slowness, in both men and women. ORs and HRs generally ranged from 1.2 to 3.0 for those below vs above the cut-point. DXA lean mass was not consistently associated with these outcomes. When considered together, those who had both muscle weakness by absolute grip strength (<35.5 kg in men and <20 kg in women) and slowness were consistently more likely to have a fall, hip fracture, mobility limitation, or die than those without either slowness or muscle weakness. CONCLUSION Older men and women with both muscle weakness and slowness have a higher likelihood of adverse health outcomes. These results support the inclusion of grip strength and walking speed as components in a summary definition of sarcopenia.
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| 12. |
- Dahlén, Eva, et al.
(författare)
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Development of interleukin-1 receptor antagonist mutants with enhanced antagonistic activity in vitro and improved therapeutic efficacy in collagen-induced arthritis.
- 2008
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Ingår i: Journal of Immunotoxicology. - : Informa UK Limited. - 1547-6901 .- 1547-691X. ; 5:2, s. 189-199
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Tidskriftsartikel (refereegranskat)abstract
- Interleukin-1 receptor antagonist (IL-1Ra) is a naturally occurring inhibitor of the pro-inflammatory interleukin-1-mediated activation of the interleukin-1 receptor (IL-1R). Although wild-type IL-1Ra is used for treatment of inflammatory diseases, its effect is moderate and/or short-lived. The objective of this study was to generate IL-1Ra mutants with enhanced antagonistic activity for potential therapeutic use. Using a directed evolution approach in which libraries of IL-1Ra gene mutants were generated and screened in functional assays, mutants with desired properties were identified. Initially, diversity was introduced into the IL-1Ra using random mutagenesis. Mutations resulting in enhanced antagonistic activity were identified by screening in a reporter cell assay. To further enhance the antagonistic activity, selected mutations were recombined using the DNA recombination technology Fragment-INduced Diversity (FIND). Following three rounds of FIND recombination, several mutants with up to nine times enhanced antagonistic activity (mean IC50 +/- SEM value: 0.78 +/- 0.050 vs. 6.8 +/- 1.1 ng/ml for mutant and wild-type, respectively) were identified. Sequence analysis identified the mutations D47N, E52R and E90Y as being most important for this effect, however, the mutations P38Y, H54R, Q129L and M136N further enhanced the antagonistic function. Analysis of identified mutations in protein models based on the crystal structure of the IL-1Ra/IL-1R complex suggested that mutations found to enhance the antagonistic activity had a stabilizing effect on the IL-1Ra mutants or increased the affinity for the IL-1R. Finally, the therapeutic effect of one mutant was compared to that of wild-type IL-1Ra in collagen-induced arthritis in mice. Indeed, the enhanced antagonistic effect of the mutants observed in vitro was also seen in vivo. In conclusion, these results demonstrate that directed evolution of IL-1Ra is an effective means of generating highly potent therapeutic proteins.
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| 13. |
- Darwich, Adam S., et al.
(författare)
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IMI - Oral biopharmaceutics tools project - Evaluation of bottom-up PBPK prediction success part 3 : Identifying gaps in system parameters by analysing In Silico performance across different compound classes
- 2017
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Ingår i: European Journal of Pharmaceutical Sciences. - : Elsevier BV. - 0928-0987 .- 1879-0720. ; 96, s. 626-642
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Tidskriftsartikel (refereegranskat)abstract
- Three Physiologically Based Pharmacokinetic software packages (GI-Sim, Simcyp (R) Simulator, and GastroPlus (TM)) were evaluated as part of the Innovative Medicine Initiative Oral Biopharmaceutics Tools project (OrBiTo) during a blinded "bottom-up" anticipation of human pharmacokinetics. After data analysis of the predicted vs. measured pharmacokinetics parameters, it was found that oral bioavailability (F-oral) was underpredicted for compounds with low permeability, suggesting improper estimates of intestinal surface area, colonic absorption and/or lack of intestinal transporter information. Foralwas also underpredicted for acidic compounds, suggesting overestimation of impact of ionisation on permeation, lack of information on intestinal transporters, or underestimation of solubilisation of weak acids due to less than optimal intestinal model pH settings or underestimation of bile micelle contribution. F-oral was overpredicted for weak bases, suggesting inadequate models for precipitation or lack of in vitro precipitation information to build informed models. Relative bioavailability was underpredicted for both high logP compounds as well as poorly water-soluble compounds, suggesting inadequate models for solubility/dissolution, underperforming bile enhancement models and/or lack of biorelevant solubility measurements. These results indicate areas for improvement in model software, modelling approaches, and generation of applicable input data. However, caution is required when interpreting the impact of drug-specific properties in this exercise, as the availability of input parameters was heterogeneous and highly variable, and the modellers generally used the data "as is" in this blinded bottom-up prediction approach.
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| 14. |
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| 15. |
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| 16. |
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| 17. |
- Ekstrand, Eva-Maria, et al.
(författare)
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High-rate anaerobic co-digestion of kraft mill fibre sludge and activated sludge by CSTRs with sludge recirculation
- 2016
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Ingår i: Waste Management. - : Elsevier. - 0956-053X .- 1879-2456. ; 56, s. 166-172
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Tidskriftsartikel (refereegranskat)abstract
- Kraft fibre sludge from the pulp and paper industry constitutes a new, widely available substrate for thebiogas production industry, with high methane potential. In this study, anaerobic digestion of kraft fibresludge was examined by applying continuously stirred tank reactors (CSTR) with sludge recirculation.Two lab-scale reactors (4L) were run for 800 days, one on fibre sludge (R1), and the other on fibre sludgeand activated sludge (R2). Additions of Mg, K and S stabilized reactor performance. Furthermore, theCa:Mg ratio was important, and a stable process was achieved at a ratio below 16:1. Foaming was abatedby short but frequent mixing. Co-digestion of fibre sludge and activated sludge resulted in more robustconditions, and high-rate operation at stable conditions was achieved at an organic loading rate of 4 gvolatile solids (VS) L1 day1, a hydraulic retention time of 4 days and a methane production of230 ± 10 Nm L per g VS.
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| 18. |
- Ekstrand, Eva-Maria, 1985-, et al.
(författare)
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Identifying targets for increased biogasproduction through chemical and organicmatter characterization of digestate from full‑scale biogas plants : what remains and why?
- 2022
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Ingår i: Biotechnology for Biofuels and Bioproducts. - London, United Kingdom : BioMed Central. - 2731-3654. ; 15:1
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Tidskriftsartikel (refereegranskat)abstract
- Background: This study examines the destiny of macromolecules in different full-scale biogas processes. From previousstudies it is clear that the residual organic matter in outgoing digestates can have significant biogas potential,but the factors dictating the size and composition of this residual fraction and how they correlate with the residualmethane potential (RMP) are not fully understood. The aim of this study was to generate additional knowledge of thecomposition of residual digestate fractions and to understand how they correlate with various operational and chemicalparameters. The organic composition of both the substrates and digestates from nine biogas plants operating onfood waste, sewage sludge, or agricultural waste was characterized and the residual organic fractions were linked tosubstrate type, trace metal content, ammonia concentration, operational parameters, RMP, and enzyme activity.Results: Carbohydrates represented the largest fraction of the total VS (32–68%) in most substrates. However, inthe digestates protein was instead the most abundant residual macromolecule in almost all plants (3–21 g/kg). Thedegradation efficiency of proteins generally lower (28–79%) compared to carbohydrates (67–94%) and fats (86–91%).High residual protein content was coupled to recalcitrant protein fractions and microbial biomass, either from thesubstrate or formed in the degradation process. Co-digesting sewage sludge with fat increased the protein degradationefficiency with 18%, possibly through a priming mechanism where addition of easily degradable substrates alsotriggers the degradation of more complex fractions. In this study, high residual methane production (> 140 L CH4/kgVS) was firstly coupled to operation at unstable process conditions caused mainly by ammonia inhibition (0.74 mgNH3-N/kg) and/or trace element deficiency and, secondly, to short hydraulic retention time (HRT) (55 days) relative tothe slow digestion of agricultural waste and manure.Conclusions: Operation at unstable conditions was one reason for the high residual macromolecule content andhigh RMP. The outgoing protein content was relatively high in all digesters and improving the degradation of proteinsrepresents one important way to increase the VS reduction and methane production in biogas plants. Post-treatment
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| 19. |
- Ekstrand, Eva-Maria, 1985-, et al.
(författare)
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The route towards stable and efficient anaerobic digestion of fibrous wastewater from pulp and paper mills in high-rate CSTRs with sludge recirculation
- 2015
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- The pulp and paper industry carries high costs in wastewater treatment. By combining present techniques with anaerobic digestion (AD), expenses for electricity use and sludge disposal can be reduced. The large wastewater volumes require high-rate systems sensitive to suspended solids, and this has so far excluded treatment of the energy-rich wood fibres. In this study, AD of fibrous wastewater was examined in high-rate CSTRs with sludge recirculation. Two lab-scale reactors (4L) were run for 780 days. Once a day, reactor sludge was withdrawn and centrifuged. The main part of the supernatant was discarded, while the pellet was suspended with the substrate and returned to the reactor. This gave a sludge retention time of 10-16 days and a hydraulic retention time of 4-8 days. One reactor (denoted R1) was fed with fibre sludge, and the second reactor (denoted R2) was co-digesting fibre sludge and activated sludge. Both substrates were taken from a Kraft mill in Sweden. Initially, both reactors experienced frequent drops in pH, and continuous alkali supplements were necessary for process stability. Additions of magnesium and potassium were also needed to obtain stable process performance at an OLR of 3 g VS L-1·day-1. R1 and R2 behaved similarly, but R2 (co-digestion) was more robust with less or no fluctuations in VFA and pH. Addition of activated sludge also to R1 allowed an increase in OLR to 4 g VS L-1·day-1. In summary, stable and efficient operation of a high-rate CSTR with sludge recirculation digesting fibre sludge was achieved at an OLR of 4 g VS L-1·day-1, a HRT of 4 days and a methane production of 260±20 Nml. In addition, co-digestion with activated sludge stabilized the performance at increased OLR and thus gave more methane produced per reactor volume.
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| 20. |
- Falck, Eva, et al.
(författare)
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Loss of Glutathione peroxidase 3 expression is correlated with epigenetic mechanisms in endometrial adenocarcinoma
- 2010
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Ingår i: Cancer Cell International. - : BioMed Central (BMC). - 1475-2867. ; 10
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Tidskriftsartikel (refereegranskat)abstract
- Glutathione peroxidase 3 (GPX3) is one of the key enzymes in the cellular defense against oxidative stress and the hepatocyte growth factor receptor, (MET) has been suggested to be influenced by the GPX3 gene expression. In a previous microarray study performed by our group, Gpx3 was identified as a potential biomarker for rat endometrial adenocarcinoma (EAC), since the expression was highly downregulated in rat EAC tumors. Herein, we have investigated the mRNA expression and Gpx3 and Met in rat EAC by real time quantitative PCR (qPCR), and the methylation status of Gpx3. In addition we have examined the expression of GPX3 and MET in 30 human EACs of different FIGO grades and 20 benign endometrial tissues. We found that the expression of GPX3 was uniformly down regulated in both rat and human EAC, regardless of tumor grade or histopathological subtype, implying that the down-regulation is an early event in EAC. The rate of Gpx3 promoter methylation reaches 91%, where biallelic methylation was present in 90% of the methylated tumors. The expression of the Met oncogene was slightly upregulated in EACs that showed loss of expression of Gpx3, but no tumor suppressor activity of Gpx3/GPX3 was detected. Preliminary results also suggest that the production of H2O2 is higher in rat endometrial tumors with down-regulated Gpx3 expression. A likely consequence of loss of GPX3 protein function would be a higher amount of ROS in the cancer cell environment. Thus, the results suggest important clinical implications of the GPX3 expression in EAC, both as a molecular biomarker for EAC and as a potential target for therapeutic interventions.
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| 21. |
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| 22. |
- Hedberg, Yolanda S., et al.
(författare)
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Electrochemical surface oxide characteristics of metal nanoparticles (Mn, Cu and Al) and the relation to toxicity
- 2016
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Ingår i: Electrochimica Acta. - : Elsevier BV. - 0013-4686 .- 1873-3859. ; 212, s. 360-371
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Tidskriftsartikel (refereegranskat)abstract
- Most metal nanoparticles (NPs), except noble metal NPs, rapidly form a thin surface oxide in ambient conditions. The protective properties of these oxides improve or worsen depending on the environment, e.g., the human lung. Several properties, including the chemical/electrochemical stability and defect density, determine the capacity of these surface oxides to hinder the bulk metal from further oxidation (corrosion). The aim of this study was to investigate whether electrochemical surface oxide characterization of non-functionalized base metal NPs of different characteristics (Al, Mn and Cu) can assist in understanding their bioaccessibility (metal release) in cell media (DMEM+) and their cytotoxic properties following exposure in lung epithelial (A549) cells. The composition and valence states of surface oxides of metal NPs and their electrochemical activity were investigated using an electrochemical technique based on a graphite paste electrode to perform cyclic voltammetry in buffer solutions and open circuit potential measurements in DMEM+. The electrochemical surface oxide characterization was complemented and verified by Raman spectroscopy, X-ray diffraction, and X-ray photoelectron spectroscopy. The open circuit potential trends in DMEM+ correlated well with metal release results in the same solution, and provided information on the kinetics of oxide dissolution in the case of Cu NPs. Extensive particle agglomeration in cell medium (DMEM+) was observed by means of photon-cross correlation spectroscopy for all metal NPs, with sedimentation taking place very quickly. As a consequence, measurements of the real dose of added non-functionalized metal NPs to cell cultures for cytotoxicity testing from a sonicated stock solution were shown necessary. The cytotoxic response was found to be strongly correlated to changes in physico-chemical and electrochemical properties of the surface oxides of the metal NPs, the most potent being Cu NPs, followed by Mn NPs. No cytotoxicity was observed for Al NPs. The electrochemical surface oxide characterization corresponded well with other tools commonly used for nanotoxicological characterization and provided additional information.
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| 23. |
- Jiang, Zheshun, et al.
(författare)
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Hexavalent chromium still a concern in Sweden : Evidence from a cross-sectional study within the SafeChrom project
- 2024
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Ingår i: International journal of hygiene and environmental health. - : Elsevier. - 1438-4639 .- 1618-131X. ; 256
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Tidskriftsartikel (refereegranskat)abstract
- ObjectivesHexavalent chromium (Cr(VI)) is classified as a human carcinogen. Occupational Cr(VI) exposure can occur during different work processes, but the current exposure to Cr(VI) at Swedish workplaces is unknown.MethodsThis cross-sectional study (SafeChrom) recruited non-smoking men and women from 14 companies with potential Cr(VI) exposure (n = 113) and controls from 6 companies without Cr(VI) exposure (n = 72). Inhalable Cr(VI) was measured by personal air sampling (outside of respiratory protection) in exposed workers. Total Cr was measured in urine (pre- and post-shift, density-adjusted) and red blood cells (RBC) (reflecting Cr(VI)) in exposed workers and controls. The Bayesian tool Expostats was used to assess risk and evaluate occupational exposure limit (OEL) compliance.ResultsThe exposed workers performed processing of metal products, steel production, welding, plating, and various chemical processes. The geometric mean concentration of inhalable Cr(VI) in exposed workers was 0.15 μg/m3 (95% confidence interval: 0.11–0.21). Eight of the 113 exposed workers (7%) exceeded the Swedish OEL of 5 μg/m3, and the Bayesian analysis estimated the share of OEL exceedances up to 19.6% for stainless steel welders. Median post-shift urinary (0.60 μg/L, 5th-95th percentile 0.10–3.20) and RBC concentrations (0.73 μg/L, 0.51–2.33) of Cr were significantly higher in the exposed group compared with the controls (urinary 0.10 μg/L, 0.06–0.56 and RBC 0.53 μg/L, 0.42–0.72). Inhalable Cr(VI) correlated with urinary Cr (rS = 0.64) and RBC-Cr (rS = 0.53). Workers within steel production showed the highest concentrations of inhalable, urinary and RBC Cr. Workers with inferred non-acceptable local exhaustion ventilation showed significantly higher inhalable Cr(VI), urinary and RBC Cr concentrations compared with those with inferred acceptable ventilation. Furthermore, workers with inferred correct use of respiratory protection were exposed to significantly higher concentrations of Cr(VI) in air and had higher levels of Cr in urine and RBC than those assessed with incorrect or no use. Based on the Swedish job-exposure-matrix, approximately 17 900 workers were estimated to be occupationally exposed to Cr(VI) today.ConclusionsOur study demonstrates that some workers in Sweden are exposed to high levels of the non-threshold carcinogen Cr(VI). Employers and workers seem aware of Cr(VI) exposure, but more efficient exposure control strategies are required. National strategies aligned with the European strategies are needed in order to eliminate this cause of occupational cancer.
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| 24. |
- Jiang, Zheshun, et al.
(författare)
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P-205 THE SAFECHROM PROJECT - EVIDENCE FROM A CROSS-SECTIONAL STUDY SHOWS THAT HEXAVALENT CHROMIUM IS STILL A CONCERN IN SWEDEN
- 2024
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Ingår i: Occupational Medicine. - 0962-7480. ; 74:Suppl 1, s. 291-292
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Hexavalent chromium Cr(VI) is a human carcinogen, but the current exposure to Cr(VI) at Swedish workplaces is unknown.Recruitment of 113 workers with potential Cr(VI) exposure and 72 controls was combined with measurements of inhalable Cr(VI) (only exposed workers) and total Cr in urine and red blood cells (RBC), Bayesian analysis of occupational exposure limit (OEL) compliance was used, as well as the Swedish job-exposure-matrix.Exposed workers performed processing of metal products, steel production, welding, and plating. The geometric mean concentration of inhalable Cr(VI) in exposed workers was 0.15 μg/m3. Eight workers (7\ exceeded the Swedish OEL (5 μg/m3), and the share of OEL exceedances was estimated to be up to 19.6\ and RBC-Cr were significantly higher in exposed workers compared with controls. Workers with inferred non-acceptable local exhaustion ventilation showed significantly higher inhalable Cr(VI), urine- and RBC-Cr than those with acceptable ventilation. Workers with inferred correct use of respiratory protection had higher inhalable Cr(VI), and, paradoxically, higher urine- and RBC-Cr concentrations than workers with incorrect use. We estimate that ~17 900 Swedish workers are occupationally exposed to Cr(VI) today.Our study showed that although most air measurements were relatively low, 7\ and particularly stainless steel workers are at risk for exceeding the OEL. The existing protective measures implemented at workplaces are still inadequate and insufficient.Some workers in Sweden are exposed to high levels of the non-threshold carcinogen Cr(VI). National strategies aligned with European strategies are needed to eliminate occupational cancer.
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| 25. |
- Karlsson, Eva Nordberg, et al.
(författare)
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Cloning and sequence of a thermostable multidomain xylanase from the bacterium Rhodothermus marinus
- 1997
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Ingår i: Biochimica et Biophysica Acta - Gene Structure and Expression. - 0167-4781. ; 1353:2, s. 118-124
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Tidskriftsartikel (refereegranskat)abstract
- The gene (xyn1) encoding a Rhodothermus marinus xylanase has been cloned and expressed in Escherichia coli. The gene comprises 5 different domains in an unusual combination. The cellulose binding domains (CBDs) encoded by xyn1 are repeated in tandem at the N-terminus and show similarity with the CBD family IV. The xyn1-gene is the first example encoding a CBD family IV in combination with a xylan hydrolyzing catalytic domain of the glycosyl hydrolase family 10.
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