| 1. |
- Sundell, Nicklas, et al.
(författare)
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PCR detection of respiratory pathogens in asymptomatic and symptomatic adults.
- 2019
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Ingår i: Journal of clinical microbiology. - 1098-660X. ; 57:1
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Tidskriftsartikel (refereegranskat)abstract
- The frequency of viral respiratory pathogens in asymptomatic subjects is poorly defined. The aim of this study was to explore the prevalence of respiratory pathogens in the upper airways of asymptomatic adults, as compared with a reference population of symptomatic patients sampled in the same centres during the same period. Nasopharyngeal (NP) swab samples were prospectively collected from adults with and without ongoing symptoms of respiratory tract infection (RTI) during 12 consecutive months, in primary care centres as well as hospital emergency departments, and analysed for respiratory pathogens by a PCR panel detecting 16 viruses and four bacteria. Altogether, 444 asymptomatic and 75 symptomatic subjects completed sampling as well as follow-up (FU) at day 7. In the asymptomatic subjects the detection rate of viruses was low (4.3%) and the most common virus detected was rhinovirus (3.2%). Streptococcus pneumoniae was found in 5.6% of the asymptomatic subjects and Haemophilus influenzae in 1.4%. The only factor independently associated with low viral detection rate in asymptomatic subjects was age ≥65 (p=0.04). An increased detection rate of bacteria was seen in asymptomatic subjects who were currently smoking (p<0.01) and who had any chronical condition (p<0.01). We conclude that detection of respiratory viruses in asymptomatic adults is uncommon, suggesting that a positive PCR result from a symptomatic patient likely is relevant for ongoing respiratory symptoms. Age influences the likelihood of virus detection among asymptomatic adults and smoking as well as co-morbidity may increase the prevalence of bacterial pathogens in the upper airways.
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| 2. |
- Deshpande, Raghe, et al.
(författare)
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Initial phase of sodium bisulphite pulping of spruce. Part I
- 2016
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Ingår i: Cellulose Chemistry and Technology. - : Editura Academiei Romane. - 0576-9787. ; 50:2, s. 293-300
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Tidskriftsartikel (refereegranskat)abstract
- A sodium bisulphite cooking study has been performed on spruce chips with the aim of monitoring the impregnation and the initial phase of such a cook performed at pH 4.5. Both pulp and liquor analyses have been carried out and the experiments have been done with a laboratory-prepared cooking acid, in comparison with a mill cooking acid. The pulping experiments have been performed down to a total pulp yield of 60%. The objective was to verify and extend the current knowledge of bisulphite pulping with a focus on the initial phase of the cook. With the help of a kinetic model that has been developed in the project, the pulp composition during the cook with respect to cellulose, lignin, glucomannan and xylan can now be predicted. The side reactions with respect to thiosulphate formation were also analyzed in this study.
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| 3. |
- Deshpande, R., et al.
(författare)
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Lignin carbohydrate complex studies during kraft pulping for producing paper grade pulp from birch
- 2020
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Ingår i: TAPPI Journal. - : Technical Assoc. of the Pulp and Paper Industry Press. - 0734-1415. ; 19:9, s. 447-460
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Tidskriftsartikel (refereegranskat)abstract
- Paper grade pulp production across the globe is dominated by the kraft process using different lig-nocellulosic raw materials. Delignification is achieved around 90% using different chemical treatments. A bottleneck for complete delignification is the presence of residual covalent bonds that prevail between lignin and carbohydrate even after severe chemical pulping and oxygen delignification steps. Different covalent bonds are present in native wood that sustain drastic pulping conditions. In this study, 100% birch wood was used for producing paper grade pulp, and the lignin carbohydrate bonds were analyzed at different stages of the kraft cook. The lignin carbohydrate bonds that were responsible for residual lignin retention in unbleached pulp were compared and analyzed with the original lignin-carbohydrate complex (LCC) bonds in native birch wood. It was shown that lignin remaining after pulping and oxygen delignification was mainly bound to xylan, whereas the lignin bound to glucomannan was for the most part degraded. Application: One central problem for the pulp and paper industry is efficiency in delignification during the chemical pulping and bleaching processes. It has been believed that one limiting factor is the covalent bonds between lignin and polysaccharides. We present data on presence of such LCC bonds in paper grade birch pulp and its development during the processes. Hopefully, this research data will be useful for the development of more effi-cient processes.
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| 4. |
- Deshpande, Raghu, 1979-, et al.
(författare)
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New findings in sulfite pulping of softwood dissolving pulps
- 2015
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Ingår i: 5th Avancell Conference Chalmers University of Technology Gothenburg Sweden, October 6-7 2015.
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Karlstads University has for a long time done research on sulfite pulping with the purpose to increase the knowledge on sulfite pulping, to verify old fundamental results an to keep the knowledge on sulfite pulping alive. The basic objective during the last years has been to increase the value of the products produced in such a process and the vision is to make sulfite pulps the preferred pulp grade for dissolving pulps. These studies have so far included spruce and pine. Domsjö Fabriker and MoRe Research in Örnsköldsvik, Sweden have been industry partners in this project.
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| 5. |
- Deshpande, Raghu, 1979-, et al.
(författare)
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Some process aspects on acid sulphite pulping of softwood
- 2016
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Ingår i: Journal of Science & Technology for Forest Products and Processes. - Montreal : Pulp and Paper Technical Association of Canada. - 1927-6311 .- 1927-632X. ; 6:2, s. 48-54
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Tidskriftsartikel (refereegranskat)
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| 6. |
- Deshpande, Raghu, 1979-, et al.
(författare)
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Some process aspects on single-stage bisulfite pulping of pine
- 2016
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Ingår i: Nordic Pulp & Paper Research Journal. - : AB SVENSK PAPPERSTIDNING. - 0283-2631 .- 2000-0669. ; 31:3, s. 379-385
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Tidskriftsartikel (refereegranskat)abstract
- Sulfite pulping of pine is well-known to be a risky process because problematic lignin conden-sation reactions can occur resulting in poor pulp quality. However, sulfite pulping of pine is interesting of economic reasons as pine wood is cheaper than spruce. Therefore it has become interesting to investigate sulfite pulping again to determine if old data are still valid. Thus sodium bisulfite pulping of pine was carried out to investigate the influence of time, temperature and cooking acid quality. A small comparison of spruce pulping was also included. By using different cooking temperatures the activation energies for delignification and for degradation of cellulose and hemicelluloses could be determined. The results showed no lignin condensation reactions, thus it was not problematic to carry out these pine cooking experiments. It was found that glucomannan had higher activation energy than xylan and the activation energies of these hemicelluloses were lower than the corresponding value for the lignin degradation. It was found that the activation energy for bisulfite pulping of pine was slightly lower than the activation energy for bisulfite pulping of spruce.
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| 7. |
- Deshpande, Roghe, et al.
(författare)
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Some process aspects on single-stage bisulfite pulping of pine
- 2016
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Ingår i: Nordic Pulp & Paper Research Journal. - : SPCI. - 0283-2631 .- 2000-0669. ; 31:3, s. 379-385
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Tidskriftsartikel (refereegranskat)abstract
- Sulfite pulping of pine is well-known to be a risky process because problematic lignin conden-sation reactions can occur resulting in poor pulp quality. However, sulfite pulping of pine is interesting of economic reasons as pine wood is cheaper than spruce. Therefore it has become interesting to investigate sulfite pulping again to determine if old data are still valid. Thus sodium bisulfite pulping of pine was carried out to investigate the influence of time, temperature and cooking acid quality. A small comparison of spruce pulping was also included. By using different cooking temperatures the activation energies for delignification and for degradation of cellulose and hemicelluloses could be determined. The results showed no lignin condensation reactions, thus it was not problematic to carry out these pine cooking experiments. It was found that glucomannan had higher activation energy than xylan and the activation energies of these hemicelluloses were lower than the corresponding value for the lignin degradation. It was found that the activation energy for bisulfite pulping of pine was slightly lower than the activation energy for bisulfite pulping of spruce.
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| 8. |
- Deshpande, Raghu, et al.
(författare)
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Structural basis for lignin recalcitrance during sulfite pulping for production of dissolving pulp from pine heartwood
- 2022
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Ingår i: Industrial crops and products (Print). - : Elsevier. - 0926-6690 .- 1872-633X. ; 177
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Tidskriftsartikel (refereegranskat)abstract
- Dissolving pulps are technically produced by prehydrolysis kraft, one-stage or two-stage acid sulfite pulping. Like other pulping methods, the delignification process is incomplete and bleaching is required for complete lignin removal. Here, we explored the molecular aspects of lignin recalcitrance during the pulping, in order to gain insights that could inform future pulping efforts. For this purpose, we adopted a protocol for the controlled fractionation of pulp into soluble fractions that could be analyzed by spectroscopic methods including size exclusion chromatography (SEC) and 2D NMR methods. In addition, lignosulfonates (i.e. technical lignin) was analysed as a reference to gain insights on the structural basis for dissolution. Overall, the results identify a sequence of reactions responsible for the dissolution of lignin. In the first stage, the sulfonation of lignin begins and occurs at the alpha-carbon of beta-O-4 and beta-5 sub-structures. In the second stage the cleavage of lignin carbohydrate bonds (LCC) of benzyl ether, gamma ester and phenylglycosides types, all of which were detected in the residual lignin of the earlier phases, occurs and enhances lignin dissolution. Finally, condensation reactions of benzylic cations with activated positions on aromatic ring were detected in lignosulfonates. This suggest that a competing reaction mode to the sulfonation at C-alpha position in lignin was occurring at prolonged pulping conditions, here considered to be unproductive.
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| 9. |
- Deshpande, Raghu, 1979-, et al.
(författare)
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The influence of different types of bisulfite cooking liquors on pine wood components
- 2016
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Ingår i: BioResources. - Raleigh : North Carolina State University. - 1930-2126. ; 11:3, s. 5961-5973
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Tidskriftsartikel (refereegranskat)abstract
- In this laboratory study, the initial phase of a single-stage sodium bisulfite cook was observed and analyzed. The experiments were carried out using either a lab- or a mill-prepared cooking acid, and the cooking temperature used in these experiments was 154 °C. Investigated parameters were the chemical consumption, the pH profile, and the pulp yield with respect to cellulose, lignin, glucomannan, xylan, and finally extractives. Cooking was extended down to approximately 60% pulp yield and the pulp composition during the cook, with respect to carbohydrates and lignin, was summarized in a kinetic model. The mill-prepared cooking acid had a higher COD (Chemical Oxygen Demand) and TOC (Total Organic Carbon) content than the lab-prepared cooking acid and this influenced the pH and the formation of thiosulfate during the cook. It was found that the presence of dissolved carbohydrates and lignin in the bisulfite cooking liquor affected the extractives removal and the thiosulfate formation.
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| 10. |
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| 11. |
- Deshpande, Raghu, et al.
(författare)
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The influence of the temperature on the initial phase of sodium bisulfite pulping of spruce
- 2015
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Ingår i: O Papel. - : Assoc. Tecnica Brasileira de Celulose e Papel. - 0031-1057. ; 76:4, s. 56-61
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Tidskriftsartikel (refereegranskat)abstract
- The initial phase of a bisulfite cook, here defined as the first part of the cook down to 20% lignin, is highly influenced by the temperature and it can therefore be used to control the initial pulping rate with respect to lignin. However, the influence of the temperature is different for the degradation of lignin, hemicellulose and cellulose and for the formation of the by-product thiosulfate. The temperature is therefore a powerful tool to control several mechanisms in a bisulfite cook. Additionally, if the cooking acid is taken from a pulp mill, where the ionic strength, the content of by-products and COD in the liquor phase are much higher than in a lab prepared cooking acid, this will also influence the kinetics of the different chemical reactions and, thus, the composition of the pulp after a certain cooking time. Earlier literature references, which are based on lab prepared cooking acids, are therefore not completely reliable as tools to predict the final composition of the pulp in a pulp mill.
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| 12. |
- Deshpande, Raghu, 1979-, et al.
(författare)
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The Initial Phase of Sodium Bisulfite Pulping of Pine, Part II
- 2016
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Ingår i: Nordic Pulp & Paper Research Journal. - Härnösand : Mittuniversitetet. - 0283-2631 .- 2000-0669. ; 31:3, s. 379-385
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Tidskriftsartikel (refereegranskat)abstract
- Single stage sodium bisulfite cooking of pine was carried out to investigate the influence of time and temperature in the initial phase of the cook. The cooking experiments were carried out using either a lab or a mill prepared cooking acid and the initial stage of the cook was extended up to 5 h cooking time. The impact of temperature on wood components and side reactions was analyzed between 142°C and 165°C. Arrhenius equation was used to determine the influence of temperature on wood components during the initial phase of bisulfite cooking and the activation energy was calculated for delignification rate, cellulose degradation and hemicellulose dissolution with regard to glucomannan and xylan. The extent of extractives removal at different temperature and time was also analyzed.
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| 13. |
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| 14. |
- Deshpande, Raghu, 1979-, et al.
(författare)
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The magic of sulphite pulping : The critical first stage of a dissolving pulp cook
- 2013
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- A PhD project was started in 2012 with the purpose to in depth examine the first and second part of a sodium sulfite dissolving pulp cook including a following extraction stage. The experimental study started with the first part of the cook when using spruce or pine as the wood raw material and when using lab or mill cooking liquors. A large number of cooking experiments have been performed and a lot of data has been obtained and the risk for obtaining a black cook has been especially observed. In the latter case the thiosulphate content is very critical as it can both lead to a black cook and to decomposition reactions in the cooking liquor. How to avoid problematic cooking conditions will be especially highlighted in the project but ways to produce new pulp grades and new chemicals will be equally important
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| 15. |
- Deshpande, Raghu, 1979-, et al.
(författare)
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The reactivity of lignin carbohydrate complex (LCC) during manufacture of dissolving sulfite pulp from softwood
- 2018
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Ingår i: Industrial crops and products (Print). - : Elsevier B.V.. - 0926-6690 .- 1872-633X. ; 115, s. 315-322
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Tidskriftsartikel (refereegranskat)abstract
- The presence of covalent bonds between lignin and polysaccharides was investigated in dissolving pulps made with one-stage and two-stage acidic sulfite pulping for 100% pine heartwood raw material. The covalent bonds between lignin and pulp polysaccharides occurred mainly to xylan and glucomannan and were of the phenyl glycosides and γ–esters types. The α-ethers that are common in wood were missing in the studied pulp samples. Based on these findings and known lignin reactions during sulfite pulping, a mechanism explaining the absence of the α-ethers is discussed. It is suggested that the lignin carbohydrate bonds may play a vital role in lignin recalcitrance.
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| 16. |
- Gullers, Per, et al.
(författare)
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Track condition analyser – assessment of need for track maintenance based on instrumented wheelset measurements
- 2010
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Ingår i: Proceedings 16th International Wheelset Congress. ; , s. 12 pp-
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Konferensbidrag (refereegranskat)abstract
- Vertical wheel-rail contact forces with high magnitudes are generated in vehicle operation on track sections with periodic (rail corrugation) or discrete (rail joints, crossings) surface defects and/or in operations with out-of-round wheels. This may result in severe wheel damage, such as subsurface rolling contact fatigue and deep shelling. Based on input data in the form of contact forces measured by an instrumented wheelset, including contributions with frequencies up to about 2 kHz, Interfleet Technology Sweden has developed a Track Condition Analyser (TCA). The dominating and most frequently occurring types of track irregularity can be detected, their location along the line can be determined and their detrimental effect on the fatigue life of wheels can be estimated. This means that the TCA can be used as a tool for assessment of current track quality and to determine the need for immediate and planned track maintenance. Using the instrumented wheelset on a Swedish high-speed train, the 450 km line Stockholm-Gothenburg can be measured in both directions during an eight hour test campaign.
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| 17. |
- Kanberg, Nelly, et al.
(författare)
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Neurochemical signs of astrocytic and neuronal injury in acute COVID-19 normalizes during long-term follow-up.
- 2021
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Ingår i: EBioMedicine. - : Elsevier BV. - 2352-3964. ; 70
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Tidskriftsartikel (refereegranskat)abstract
- Neurologic manifestations are well-recognized features of coronavirus disease 2019 (COVID-19). However, the longitudinal association of biomarkers reflecting CNS impact and neurological symptoms is not known. We sought to determine whether plasma biomarkers of CNS injury were associated with neurologic sequelae after COVID-19.Patients with confirmed acute COVID-19 were studied prospectively. Neurological symptoms were recorded during the acute phase of the disease and at six months follow-up, and blood samples were collected longitudinally. Healthy age-matched individuals were included as controls. We analysed plasma concentrations of neurofilament light-chain (NfL), glial fibrillary acidic protein (GFAp), and growth differentiation factor 15 (GDF-15).One hundred patients with mild (n=24), moderate (n=28), and severe (n=48) COVID-19 were followed for a median (IQR) of 225 (187-262) days. In the acute phase, patients with severe COVID-19 had higher concentrations of NfL than all other groups (all p < 0·001), and higher GFAp than controls (p < 0·001). GFAp was also significantly increased in moderate disease (p < 0·05) compared with controls. NfL (r=0·53, p < 0·001) and GFAp (r=0·39, p < 0·001) correlated with GDF-15 during the acute phase. After six months, NfL and GFAp concentrations had normalized, with no persisting group differences. Despite this, 50 patients reported persistent neurological symptoms, most commonly fatigue (n=40), "brain-fog" (n=29), and changes in cognition (n=25). We found no correlation between persistent neurological symptoms and CNS injury biomarkers in the acute phase.The normalization of CNS injury biomarkers in all individuals, regardless of previous disease severity or persisting neurological symptoms, indicates that post COVID-19 neurological sequelae are not accompanied by ongoing CNS injury.The Swedish State Support for Clinical Research, SciLifeLab Sweden, and the Knut and Alice Wallenberg Foundation have provided funding for this project.
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| 18. |
- Otnes, Gaute, et al.
(författare)
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Understanding InP Nanowire Array Solar Cell Performance by Nanoprobe-Enabled Single Nanowire Measurements
- 2018
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Ingår i: Nano Letters. - : American Chemical Society (ACS). - 1530-6984 .- 1530-6992. ; 18:5, s. 3038-3046
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Tidskriftsartikel (refereegranskat)abstract
- III-V solar cells in the nanowire geometry might hold significant synthesis-cost and device-design advantages as compared to thin films and have shown impressive performance improvements in recent years. To continue this development there is a need for characterization techniques giving quick and reliable feedback for growth development. Further, characterization techniques which can improve understanding of the link between nanowire growth conditions, subsequent processing, and solar cell performance are desired. Here, we present the use of a nanoprobe system inside a scanning electron microscope to efficiently contact single nanowires and characterize them in terms of key parameters for solar cell performance. Specifically, we study single as-grown InP nanowires and use electron beam induced current characterization to understand the charge carrier collection properties, and dark current-voltage characteristics to understand the diode recombination characteristics. By correlating the single nanowire measurements to performance of fully processed nanowire array solar cells, we identify how the performance limiting parameters are related to growth and/or processing conditions. We use this understanding to achieve a more than 7-fold improvement in efficiency of our InP nanowire solar cells, grown from a different seed particle pattern than previously reported from our group. The best cell shows a certified efficiency of 15.0%; the highest reported value for a bottom-up synthesized InP nanowire solar cell. We believe the presented approach have significant potential to speed-up the development of nanowire solar cells, as well as other nanowire-based electronic/optoelectronic devices.
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| 19. |
- Sundvall, Pär-Daniel, et al.
(författare)
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Antimicrobial resistance in urinary pathogens among Swedish nursing home residents remains low: a cross-sectional study comparing antimicrobial resistance from 2003 to 2012
- 2014
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Ingår i: BMC Geriatrics. - : Springer Science and Business Media LLC. - 1471-2318. ; 14
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Tidskriftsartikel (refereegranskat)abstract
- Background: There are several risk factors for the colonisation, infection and spreading of antibiotic resistant bacteria among elderly residents of nursing homes. An updated estimate of the native prevalence of antimicrobial resistance in uropathogens among Swedish nursing home residents is needed. Methods: Urine specimens were collected for culture and antimicrobial susceptibility testing against mecillinam, ampicillin, cefadroxil, trimethoprim, nitrofurantoin and quinolones from the residents of 32 and 22 nursing homes, respectively. The residents were capable of providing a voided urine sample in 2003 and 2012. In 2012 urine specimens were also collected from residents with urinary catheters. Any antibiotic treatment during the previous month was registered in 2003 as well as hospitalisation and any antibiotic treatment during the previous six months in 2012. Results: The proportion of positive urine cultures was 32% (207/651) in voided urine specimens in 2003, 35% (147/421) in 2012, and 46% (27/59) in urine samples from catheters in 2012. Escherichia coli (E. coli) was the most commonly occurring bacteria. Resistance rates in E. coli (voided urine specimens) in 2012 were; ampicillin 21%, trimethoprim 12%, mecillinam 7.7%, ciprofloxacin 3.4%, cefadroxil 2.6% and nitrofurantoin 0.85%. There were no significant changes in the average resistance rates in E. coli for antibiotics tested 2003-2012. In 2012, two isolates of E. coli produced extended spectrum beta-lactamase enzymes (ESBL) and one with plasmid mediated AmpC production. Any antibiotic treatment during the previous month increased the risk for resistance in E. coli, adjusted for age and gender; for mecillinam with an odds ratio (OR) of 7.1 (2.4-21; p = 0.00049), ampicillin OR 5.2 (2.4-11; p = 0.000036), nalidixic acid OR 4.6 (1.4-16; p = 0.014) and trimethoprim OR 3.9 (1.6-9.2; p = 0.0023). Hospitalisation during the previous six months increased the risk for antibiotic resistance in E. coli to ampicillin, ciprofloxacin and any antimicrobial tested, adjusted for age, gender and antibiotic treatments during the previous six months. Conclusions: The average rates of antimicrobial resistance were low and did not increase between 2003 and 2012 in E. coli urinary isolates among Swedish nursing home residents. Antibiotic treatment during the previous month and hospitalisation during the previous six months predicted higher resistance rates.
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| 20. |
- Sundvall, Pär-Daniel, et al.
(författare)
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Interleukin-6 concentrations in the urine and dipstick analyses were related to bacteriuria but not symptoms in the elderly: a cross sectional study of 421 nursing home residents
- 2014
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Ingår i: BMC Geriatrics. - : Springer Science and Business Media LLC. - 1471-2318. ; 14
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Tidskriftsartikel (refereegranskat)abstract
- Background: Up to half the residents of nursing homes for the elderly have asymptomatic bacteriuria (ABU), which should not be treated with antibiotics. A complementary test to discriminate between symptomatic urinary tract infections (UTI) and ABU is needed, as diagnostic uncertainty is likely to generate significant antibiotic overtreatment. Previous studies indicate that Interleukin-6 (IL-6) in the urine might be suitable as such a test. The aim of this study was to investigate the association between laboratory findings of bacteriuria, IL-6 in the urine, dipstick urinalysis and newly onset symptoms among residents of nursing homes. Methods: In this cross sectional study, voided urine specimens for culture, urine dipstick and IL-6 analyses were collected from all residents capable of providing a voided urine sample, regardless of the presence of symptoms. Urine specimens and symptom forms were provided from 421 residents of 22 nursing homes. The following new or increased nonspecific symptoms occurring during the previous month were registered; fatigue, restlessness, confusion, aggressiveness, loss of appetite, frequent falls and not being herself/himself, as well as symptoms from the urinary tract; dysuria, urinary urgency and frequency. Results: Recent onset of nonspecific symptoms was common among elderly residents of nursing homes (85/421). Urine cultures were positive in 32% (135/421), Escherichia coli was by far the most common bacterial finding. Residents without nonspecific symptoms had positive urine cultures as often as those with nonspecific symptoms with a duration of up to one month. Residents with positive urine cultures had higher concentrations of IL-6 in the urine (p < 0.001). However, among residents with positive urine cultures there were no differences in IL-6 concentrations or dipstick findings between those with or without nonspecific symptoms. Conclusions: Nonspecific symptoms among elderly residents of nursing homes are unlikely to be caused by bacteria in the urine. This study could not establish any clinical value of using dipstick urinalysis or IL-6 in the urine to verify if bacteriuria was linked to nonspecific symptoms.
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