| 1. |
- Adam, A, et al.
(författare)
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Abstracts from Hydrocephalus 2016.
- 2017
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Ingår i: Fluids and Barriers of the CNS. - : Springer Science and Business Media LLC. - 2045-8118. ; 14:Suppl 1
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Tidskriftsartikel (refereegranskat)
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| 2. |
- Feletti, A., et al.
(författare)
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Ventriculoperitoneal Shunt Complications in the European Idiopathic Normal Pressure Hydrocephalus Multicenter Study
- 2019
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Ingår i: Operative neurosurgery. - : Ovid Technologies (Wolters Kluwer Health). - 2332-4260 .- 2332-4252. ; 17:1, s. 97-102
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Ventriculoperitoneal shunt (VP-shunt) is the standard of treatment for idiopathic normal pressure hydrocephalus (iNPH). However, a thorough investigation of VP-shunt complications in this population is lacking. OBJECTIVE: To present the analysis and the rates of complications progressively occurring during the first year after shunt surgery in the patients with iNPH included in the European multicenter (EU-iNPH) study. METHODS: Patients (n=142) were prospectively included in the EU-iNPH study by 13 institutions. All patients received a programmable VP-shunt. One hundred fifteen patients completed the 12-mo follow-up. Reexaminations were performed 1, 3, and 12 mo after surgery. Data regarding symptomatic over- or underdrainage, infections, malposition, subdural collections, and shunt surgery were collected and analyzed. RESULTS: Thirty patients (26%) experienced symptoms due to shunt underdrainage. Symptomatic overdrainage was reported in 10 (9%). Shunt adjustments were made in 43 (37%). Shunt malposition was recognized as the primary cause of shunt malfunction in 8 (7%), while only 1 infection (0.9%) occurred. Subdural hematoma was diagnosed in 7 (6%) and was treated by increasing the opening pressure of the valve in 5 patients. Hygroma was diagnosed in 10 (9%), requiring surgery in 1 patient. Overall, 17 patients (15%) underwent 19 shunt surgeries. CONCLUSION: The advances in valve technology, a careful opening pressure setting, and rigorous follow-up allow a significant reduction of complications, which can be usually managed nonsurgically within the first 3 to 6 mo. Copyright © 2018 by the Congress of Neurological Surgeons.
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| 3. |
- Hogberg, L, et al.
(författare)
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The impact of active intervention on the spread of penicillin-resistant streptococcus pneumoniae in Swedish day-care centres
- 2004
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Ingår i: Scandinavian Journal of Infectious Diseases. - : Informa UK Limited. - 1651-1980 .- 0036-5548. ; 36:9, s. 629-635
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Tidskriftsartikel (refereegranskat)abstract
- Policies for handling cases of penicillin-non-susceptible Streptococcus pneumoniae (PNSP) in day-care groups vary between different counties in Sweden. The aim of this study was to evaluate the epidemiological effect of excluding PNSP-carriers from children's day-care centres (DCC). We followed the incidence in 14 DCC groups with ongoing PNSP-spread, by repeated group screens until no further cases could be identified. All identified carriers were excluded from DCC attendance in study area A (Skane region) while they remained in the group in study area B (Goteborg and Orebro), according to local policies. The intervention effect was evaluated by comparing the number of additional cases after the baseline screen (start of the intervention period) between the 2 study areas. All PNSP-isolates were characterized by resistance pattern, serotype and pulse-field gel electrophoresis. The relative risk for children in DCCs without active intervention was 6.4 (95% CI: 2.0-20.7). Each prevented case in area A can be estimated to have demanded the exclusion of 2 other children from day care for approximately 4 weeks each. The total cost-benefit outcome of this action has to be seen in the light of the local situation with regard to the population prevalence and the distribution of other risk factors.
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| 4. |
- Feugnet, G., et al.
(författare)
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Improved laser-induced fluorescence method for bio-attack early warning detection system
- 2008
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Ingår i: Proceedings of SPIE - The International Society for Optical Engineering. - : SPIE.
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Konferensbidrag (refereegranskat)abstract
- Laser Induced Fluorescence (LIF) could permit fast early warning systems either for point or standoff detection if a reliable classification of warfare biological agents versus biological or non-biological fluorescing background can be achieved. In order to improve LIF discrimination capability, a new system is described in which the fluorescence pattern is enriched by the use of multiple wavelength delayed excitation while usual spectral fluorescence analysis is extended to time domain to use both aspects as criteria for classification. General considerations and guidelines for the system design are given as well as results showing good discrimination between background and simulants.
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| 5. |
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| 6. |
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| 7. |
- Roos, A.-K., et al.
(författare)
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Discrepancy in prevalence of Huntington's disease in two Swedish regions
- 2017
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Ingår i: Acta Neurologica Scandinavica. - : WILEY. - 0001-6314 .- 1600-0404. ; 136:5, s. 511-515
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Tidskriftsartikel (refereegranskat)abstract
- Background: Huntington's disease (HD) is a neurodegenerative disease with an autosomal dominant pattern of inheritance. The prevalence varies between different geographical regions with an estimated average in Europe of about 6/100 000. Parts of northern Sweden are known to have an accumulation of HD, but no prevalence studies have been undertaken for 50 years. Object: The aim of this study was to estimate the prevalence of HD in the two different Swedish counties of Jamtland and Uppsala and compare them with the reported prevalence in Europe. Method: Patients registered with the diagnosis of HD were identified through medical records in each county. Presymptomatic patients were excluded. We also compared the annual number of individuals with HD registered in the database of the National Board of Health and Welfare in these regions, with all of Sweden. Results: The prevalence of HD was found to be 22.1/100 000 in Jamtland and 4.9/100 000 in Uppsala county. The mean age was 62.2 years and 61.8 years, respectively. The annual average of patients with HD registered at inpatient care was 1.5/100 000 in Jamtland, 0.44/100 000 in Uppsala county, and 0.56/100 000 in all of Sweden. Conclusion: The prevalence of patients with the diagnosis of HD is four times higher in the county of Jamtland than in the county of Uppsala, where the prevalence is more similar to the average in Europe. Our results support earlier findings of regional variations of HD prevalence with an accumulation in certain parts of northern Sweden.
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| 8. |
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| 9. |
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| 10. |
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| 11. |
- Agate, B, et al.
(författare)
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Efficient frequency-doubling of femtosecond pulses in waveguide and bulk nonlinear crystals - Design, fabrication, theory and experiment
- 2006
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Ingår i: FRONTIERS IN PLANAR LIGHTWAVE CIRCUIT TECHNOLOGY DESIGN, SIMULATION, AND FABRICATION. - : Springer Nature. ; , s. 189-
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Konferensbidrag (refereegranskat)abstract
- We investigate efficient frequency-doubling of low energy femtosecond pulses in bulk and waveguide nonlinear crystals, thereby demonstrating how to achieve a compact and portable ultrafast blue light Source. Using a femtosecond Cr:LiSAF laser (fundamental wavelength 860 nm) we examine the relative merits of the process of second harmonic generation (SHG) using bulk potassium niobate, bulk aperiodically-poled KTP, periodically-poled and aperiodically-poled KTP waveguide crystals. While SHG conversion efficiencies LIP to 37% were achieved using the waveguides, non-traditional strong focusing in the bulk samples yielded efficiencies of 30%. We have developed several theoretical models to accurately describe the temporal and spectral properties of the generated blue light, as well as the observed saturation behavior of the conversion process in the waveguide structures.
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| 12. |
- Agate, B., et al.
(författare)
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Portable ultrafast blue light sources
- 2004
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Ingår i: OSA Trends Opt. Photonics Series. - 1557527709 ; , s. 651-652
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Konferensbidrag (refereegranskat)abstract
- An effective means of achieving a portable, ultrafast blue-light source using a variety of nonlinear media is demonstrated. We investigate the relative merits of aperiodically-poled bulk and waveguide nonlinear crystals in comparison to periodically-poled structures.
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| 13. |
- Agate, B., et al.
(författare)
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Portable ultrafast blue light sources designed with frequency doubling in KTP and KNbO3
- 2004
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Ingår i: IEEE Journal of Selected Topics in Quantum Electronics. - : Institute of Electrical and Electronics Engineers (IEEE). - 1077-260X .- 1558-4542. ; 10:6, s. 1268-1276
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Tidskriftsartikel (refereegranskat)abstract
- We demonstrate an effective means of achieving compact, truly portable, and entirely self-contained ultrafast blue light sources. Using a variety of nonlinear media to achieve simple second-harmonic generation of a femtosecond Cr:LiSAF laser, we investigate the relative merits of aperiodically poled bulk and waveguide nonlinear crystals in comparison to periodically poled structures. Such a compact and convenient source of ultrashort laser pulses in the blue spectral region could be of great interest for on-site applications spanning a host of disciplines, such as biomedical imaging, optical micromanipulation, and high-resolution spectroscopy.
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| 14. |
- Ahlberg, Alexander, et al.
(författare)
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ESOPHAGEAL STRICTURE AFTER RADIOTHERAPY IN PATIENTS WITH HEAD AND NECK CANCER : EXPERIENCE OF A SINGLE INSTITUTION OVER 2 TREATMENT PERIODS
- 2010
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Ingår i: Head and Neck. - : Wiley. - 1043-3074 .- 1097-0347. ; 32:4, s. 452-461
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Tidskriftsartikel (refereegranskat)abstract
- Background. Risk factors for development of a stricture of the upper esophagus after radiotherapy for head and neck cancer are poorly defined. Methods. This was a retrospective case-control study of patients diagnosed and treated for esophageal stricture after radiotherapy for head and neck cancer. Results. The incidence of esophageal stricture after external beam radiation therapy (EBRT) was 3.3%. Seventy patients with stricture and 66 patients without stricture were identified. A multivariate analysis showed that there was increased risk of stricture in receiving enteral feeding during EBRT or in receiving a mean dose of >45 By to the upper esophagus. Conclusions. Enteral feeding during EBRT is strongly associated with the development of stricture of the esophagus, as is a mean dose of >45 Gy to the upper esophagus. Treatment of the stricture with Savary-Gilliard bougienage or through scope balloon dilatation is safe and successful but often has to be repeated.
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| 15. |
- Alevronta, Eleftheria, et al.
(författare)
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Dose-response relations for stricture in the proximal oesophagus from head and neck radiotherapy
- 2010
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Ingår i: Radiotherapy and Oncology. - : Elsevier BV. - 0167-8140 .- 1879-0887. ; 97:1, s. 54-59
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Tidskriftsartikel (refereegranskat)abstract
- Background and purpose: Determination of the dose-response relations for oesophageal stricture after radiotherapy of the head and neck. Material and methods: In this study 33 patients who developed oesophageal stricture and 39 patients as controls are included. The patients received radiation therapy for head and neck cancer at Karolinska University Hospital, Stockholm, Sweden. For each patient the 3D dose distribution delivered to the upper 5 cm of the oesophagus was analysed. The analysis was conducted for two periods, 1992-2000 and 2001-2005, due to the different irradiation techniques used. The fitting has been done using the relative seriality model. Results: For the treatment period 1992-2005, the mean doses were 49.8 and 33.4 Gy, respectively, for the cases and the controls. For the period 1992-2000, the mean doses for the cases and the controls were 49.9 and 45.9 Gy and for the period 2001-2005 were 49.8 and 21.4 Gy. For the period 2001-2005 the best estimates of the dose-response parameters are D-50 = 61.5 Gy (52.9-84.9 Gy), gamma = 1.4 (0.8-2.6) and s = 0.1 (0.01-0.3). Conclusions: Radiation-induced strictures were found to have a dose response relation and volume dependence (low relative seriality) for the treatment period 2001-2005. However, no dose response relation was found for the complete material.
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| 16. |
- Antfolk, M., et al.
(författare)
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An integrated acousto- and dielectrophoresis device for tumor cell separation, concentration, and single-cell trapping
- 2016
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Ingår i: 20th International Conference on Miniaturized Systems for Chemistry and Life Sciences, MicroTAS 2016. - 9780979806490 ; , s. 1657-1658
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Konferensbidrag (refereegranskat)abstract
- Many microfluidic devices have been developed to separate rare cells, e.g. circulating tumor cells. The collection and analysis of the separated rare cells pose a challenge as it may lead to loss of target cells since extremely small number of cells are usually suspended in a large volume after separation. Here, we present an integrated device that allows acoustophoretic target cell separation and concentration, followed by dielectrophoretic single-cell trapping. We show that the human prostate cancer cell line DU145 were efficiently separated from peripheral blood mononuclear cells (PBMCs), and 81.7% of DU145 were trapped, with a contamination of 1.7% PBMC.
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| 17. |
- Augustsson, Per, et al.
(författare)
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Buffer medium exchange in continuous cell and particle streams using ultrasonic standing wave focusing
- 2009
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Ingår i: Microchimica Acta. - : Springer Science and Business Media LLC. - 1436-5073 .- 0026-3672. ; 164:3-4, s. 269-277
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Tidskriftsartikel (refereegranskat)abstract
- A microfluidic strategy to perform buffer exchange of particle and cell suspensions in a continuous flow format on, chip is presented. Ultrasonic standing wave technology is utilized to confine particulate matter to the centre of a buffer exchange channel while particle free buffer is sequentially aspirated via capillaries that branch off from the buffer exchange channel. At each such branch, clean buffer is supplied at an equal flow-rate from a capillary at the opposing channel wall, generating a sideways translation of the original buffer, laminated with a wash buffer stream. Each such junction increases the buffer exchange ratio accordingly. The reported buffer exchange system provides means to adjust buffer exchange conditions on-line by tuning the ratio of the cross-flow wash buffer relative the sample suspension flow, rate. The system performance was evaluated using 5 mu m polystyrene microbeads and a dye as the model contaminant. Wash efficiencies up to 96.4% were accomplished with a 0.2% solid content bead suspension, using eight cross-flow junctions, effectively exchanging the carrier buffer twice. The corresponding data for erythrocyte washing was recorded to be 98.3% at a haematocrit of 2%.
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| 18. |
- Campbell, S., et al.
(författare)
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Frequency-doubling in femtosecond laser inscribed periodically-poled potassium titanyl phosphate waveguides
- 2007
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Ingår i: Optics Express. - 1094-4087. ; 15:25, s. 17146-17150
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Tidskriftsartikel (refereegranskat)abstract
- Frequency doubling has been achieved in femtosecond-laser-inscribed single-mode waveguides written in two periodically-poled potassium titanyl phosphate crystals. A conversion efficiency of 0.22 %W-1 was obtained for first-order quasi-phase matching at 980 nm and an efficiency of 0.02 %W-1 for third-order quasi-phase matching at 800 nm.
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| 19. |
- Campbell, S., et al.
(författare)
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Frequency doubling in femtosecond-written periodically-poled potassium titanyl phosphate waveguides
- 2007
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Ingår i: Lasers and Electro-Optics, 2007 European Conference on and the International Quantum Electronics Conference. - 1424409306 - 9781424409303 ; , s. 4386106-
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Konferensbidrag (refereegranskat)abstract
- The second-harmonic conversion efficiency within the PPKTP waveguide is investigated using two separate tunable CW Ti:sapphire lasers at 800 nm and 980 nm. Results show strong conversion efficiency which imply that the local damage-induced index modification does not adversely affect the periodic domain structure in the material.
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| 20. |
- Campbell, S., et al.
(författare)
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Frequency doubling in femtosecond-written periodically-poled potassium titanyl phosphate waveguides
- 2007
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Ingår i: Conference on Lasers and Electro-Optics, 2007, CLEO 2007. - 9781557528346 ; , s. 4452462-
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Konferensbidrag (refereegranskat)abstract
- Frequency doubling is demonstrated in femtosecond-laser-created single-mode waveguides written in a periodically-poled potassium titanyl phosphate crystal. Conversion efficiencies of 0.22%/W (0.02%/W) were obtained for first (third) order phasematching at 980nm (800nm).
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| 21. |
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| 22. |
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| 23. |
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| 24. |
- de Flon, P., et al.
(författare)
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Changes of cerebrospinal fluid cytokine profile as a result of switching from first line MS-therapies to rituximab
- 2016
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Ingår i: Multiple Sclerosis Journal. - : Sage Publications. - 1352-4585 .- 1477-0970. ; 22:Suppl. 3, s. 622-622
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Tidskriftsartikel (refereegranskat)abstract
- Background: New treatment strategies in multiple sclerosis provide insights not only in the clinical effects but also, by their differences in mechanisms of action, in the immunopathological mechanisms behind disease activity.Objective: This study describes the change in cyto- and chemokine profile over a two-year period in a cohort of patients with clinically stable RRMS after treatment shift from ongoing first-line injectable disease modifying therapy (iDMT), e.g. interferon beta or glatirameracetat, to the anti-CD20 depleting agent rituximab and the differences compared with a cohort of healthy controls.Method: CSF from 73 patients with clinically stable RRMS was analysed by an elektrochemiluminiscens-based ELISA for a panel of 22 cytokines before and one and two year after treatment shift to rituximab and compared with 55 healthy controls.Results: During the first year of treatment it was a significant reduction (p< 0.005) in levels of IL-6, IL-8, IL-10, IL-12, IL-15, IP-10, MCP-1, MDC, TARC, sICAM, sVCAM and a significant elevation (p< 0,005) in levels of IL-7 and MIP-1b.Compared to healthy controls it was a significantly higher (p< 0,005) level of IFN-gamma, IL-6, IL-8, IL-10, IL-12, IL-15, TNF, IP-10, MDC, MIP-1a, MIP-1b, TARC, SAA, sICAM and sVCAM in patients with RRMS before treatment shift. Levels of IL-5 and IL-7 were significantly lower. One year after treatment shift the levels of IFN-gamma, IL-6, IL-7, IL-15, MIP-1a and SAA did not differ significantly between patients with RRMS and healthy controls.Conclusion: This study demonstrates significant changes in cyto- and chemokine profile in patients with RRMS after treatment shift from iDMT to rituximab and compared with healthy controls.
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| 25. |
- Drott, J, et al.
(författare)
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Pore morphology influence on catalytic turn-over for enzyme activated porous silicon matrices
- 1998
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Ingår i: THIN SOLID FILMS. - : ELSEVIER SCIENCE SA. - 0040-6090. ; 330:2, s. 161-166
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- The enzyme glucose oxidase (GOx) was coupled to porous silicon of different morphologies and the catalytic turn-over of glucose was recorded for the samples. The recorded catalytic turn-over of the samples clearly indicated the influence of morphology, wi
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| 26. |
- Drott, J, et al.
(författare)
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Porous silicon as the carrier matrix in microstructured enzyme reactors yielding high enzyme activities
- 1997
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Ingår i: JOURNAL OF MICROMECHANICS AND MICROENGINEERING. - : IOP PUBLISHING LTD. - 0960-1317. ; 7:1, s. 14-23
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- Miniaturization and silicon integration of micro enzyme reactors for applications in micro total analysis systems (mu TASs) require new methods to achieve structures with a large surface area onto which the enzyme can be coupled. This paper describes a me
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| 27. |
- Drott, J, et al.
(författare)
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Porous silicon carrier matrices in micro enzyme reactors-influence of matrix depth
- 1999
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Ingår i: MIKROCHIMICA ACTA. - : SPRINGER-VERLAG WIEN. - 0026-3672. ; 131:1-2, s. 115-120
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- The influence of the carrier matrix depth was investigated for porous silicon enzyme reactors. For the experiments, [110] oriented silicon, p-type (20-70 Ohm cm), was used. Porous silicon was generated on planar surfaces and on anisotropically pre-etched
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| 28. |
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| 29. |
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| 30. |
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| 31. |
- Farnebo, Jacob, et al.
(författare)
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Volumetric FDG-PET predicts overall and progression- free survival after 14 days of targeted therapy in metastatic renal cell carcinoma
- 2014
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Ingår i: BMC Cancer. - : Springer Science and Business Media LLC. - 1471-2407. ; 14, s. 408-
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Tidskriftsartikel (refereegranskat)abstract
- Background: To determine whether changes in the metabolism of metastatic renal cell carcinoma (mRCC) assessed by F18-FDG-PET after 14 and 28 days of treatment with tyrosine kinase inhibitors can predict overall and progression-free patient survival. Methods: Thirty-nine consecutive patients with mRCC were included prospectively and underwent PET examinations prior to and after 14 and 28 days of standard treatment with sunitinib (n = 18), sorafenib (n = 19) or pazopanib (n = 2). The PET response was analyzed in terms of SUVmax, SULpeak, and total lesion glycolysis and a positive response (defined as a 30% reduction) compared to overall and progression-free survival. Results: Thirty-five patients with at least one metabolically active metastatic lesion prior to treatment underwent additional FDG-PET examinations after 14 (n = 32) and/or 28 days (n = 30) of treatment. Changes in either SULpeak or total lesion glycolysis were correlated to both progression-free and overall survival (for TLG2.5 responders, HR = 0.38 (95% CI: 0.18-0.83) and 0.22 (95% CI: 0.09-0.53), and for TLG50 responders, HR = 0.25 (0.10-0.62) and 0.25 (95% CI: 0.11-0.57) and for SULpeak responders, HR = 0.39 (95% CI: 0.17-0.91) and 0.38 (95% CI: 0.15-0.93), respectively). In contrast SUVmax response did not predict progression-free or overall survival (HR = 0.43 (95% CI: 0.18-1.01) and 0.50 (95% CI: 0.21-1.19), respectively). Conclusions: Assessment of early changes in SULpeak and total lesion glycolysis undergoing treatment with tyrosine kinase inhibitors by FDG-PET can possibly predict progression-free and overall survival in patients with mRCC.
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| 32. |
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| 33. |
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| 34. |
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| 35. |
- Hemachandran, E., et al.
(författare)
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Bulk Acoustic Wave Activated Droplet Generation and Isolation
- 2023
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Ingår i: Fluid Mechanics and Fluid Power (Vol. 3)- Select Proceedings of FMFP 2021. - 2195-4364 .- 2195-4356. - 9789811962691 ; , s. 145-150
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Konferensbidrag (refereegranskat)abstract
- On-demand droplet generation from a continuously flowing stream of aqueous phase has profound applications in dropletbased microfluidics for rare event encapsulation studies. Here, we present acoustic relocation-based droplet generation from co-flowing immiscible fluids in an on-demand manner using bulk acoustic wave (BAW). After on-demand droplet generation, droplets are isolated using the same acoustic force resulted from BAW. Two different acoustic relocation regimes are observed, namely, stream to droplet relocation and stream to stream relocation regime. Our experimental observation reveals that to generate droplets from co-flowing fluids, the following conditions must be satisfied. First, the co-flowing immiscible stream should be maintained in acoustic relocation conditions (Cac > 1); Second, the capillary instability should be triggered during the relocation process, which happens at capillary numbers of the co-flowing fluids should be less than 0.2 (CaL and CaH < 0.2). Finally, using BAW microfluidic chip, droplets containing microparticle were produced ondemand from co-flowing streams wherein the microparticles are added in one of the phases.
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| 36. |
- Hemachandran, E., et al.
(författare)
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Continuous Droplet Coalescence in a Microchannel Coflow Using Bulk Acoustic Waves
- 2019
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Ingår i: Physical Review Applied. - 2331-7019. ; 12:4
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Tidskriftsartikel (refereegranskat)abstract
- The coalescence of liquid droplets with a liquid stream has profound importance in various emerging applications, such as biochemical assays. Acoustic force-based droplet manipulation, which offers unique advantages, is consequently gaining attention. However, the physics of acoustics-driven coalescence of liquid droplets with a liquid stream is not well understood. Here, we unravel the mechanism of coalescence of aqueous droplets flowing in an immiscible (oil) phase with a coflowing aqueous stream, when the system is exposed to acoustic radiation force due to bulk acoustic waves. Our study reveals that the acoustic coalescence phenomenon is governed by the interplay between two important timescales, acoustic migration timescale (τac) and advection timescale (τadv), that underpin the phenomenon. We find that the phenomenon is also governed by the acoustic capillary number (Cac) and relative widths of the coflowing oil and aqueous streams (i.e., Waq and Woil). Our results show that, if Cac<0.9 and Waq>Woil are satisfied to ensure the stability of the streams and positioning of the acoustic node in the aqueous phase, respectively, continuous coalescence is observed for (τadv/τac)≥0.85. We exploit the phenomenon for the extraction of droplet contents (beads and cells) into an aqueous stream.
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| 37. |
- Hemachandran, E., et al.
(författare)
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Relocation of coflowing immiscible liquids under acoustic field in a microchannel
- 2019
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Ingår i: EPL. - : IOP Publishing. - 1286-4854. ; 125:5
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Tidskriftsartikel (refereegranskat)abstract
- We report the dynamics of coflowing immiscible liquid streams exposed to an acoustic standing wave in a microchannel. Relocation of the liquid streams is experimentally demonstrated and a theoretical model that explains the underlying phenomena is presented. Our experiments and theoretical model suggest that the relocation phenomena are governed by the interplay between the primary acoustic radiation force F ac and the interfacial tension force F int-which is represented in terms of a new dimensionless number called "acoustocapillary number", . Using various combinations of immiscible liquids, we show that relocation of the higher acoustic impedance liquid stream to the pressure node occurs above a critical acoustocapillary number . The understanding of the above phenomena provides a new paradigm related to the manipulation of immiscible liquids under acoustic field.
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| 38. |
- Hemachandran, E., et al.
(författare)
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Reversible Stream Drop Transition in a Microfluidic Coflow System via on Demand Exposure to Acoustic Standing Waves
- 2021
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Ingår i: Physical Review Letters. - 0031-9007. ; 127:13
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Tidskriftsartikel (refereegranskat)abstract
- Transition between stream and droplet regimes in a coflow is typically achieved by adjusting the capillary numbers (Ca) of the phases. Remarkably, we experimentally evidence a reversible transition between the two regimes by controlling exposure of the system to acoustic standing waves, with Ca fixed. By satisfying the ratio of acoustic radiation force to the interfacial tension force, , experiments reveal a reversible stream drop transition for , and stream relocation for . We explain the phenomenon in terms of the pinching, advection, and relocation timescales and a transition between convective and absolute instability from a linear stability analysis [P. Guillot, Phys. Rev. Lett.99, 104502 (2007)PRLTAO0031-900710.1103/PhysRevLett.99.104502].
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| 39. |
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| 40. |
- Johansson, S., et al.
(författare)
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Coherent light source based on sum-frequency mixing
- 2005
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Patent (populärvet., debatt m.m.)abstract
- A method and a device for generating visible coherent radiation is disclosed. The visible coherent radiation is generated by sum-frequency mixing of a first fundamental beam from a diode laser and a second fundamental beam from a diode-pumped solid-state laser. The mixing is performed by means of a quasi-phasematching element provided within the resonant cavity of the solid-state laser. The first fundamental beam is stabilized by providing feedback to the diode laser.
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| 41. |
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| 42. |
- Kim, J. W., et al.
(författare)
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High-power and wavelength-tunable operation of an Er, Yb fiber laser using a volume Bragg grating
- 2008
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Ingår i: Optics Letters. - 0146-9592 .- 1539-4794. ; 33:11, s. 1204-
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Tidskriftsartikel (refereegranskat)abstract
- Efficient high-power operation of double-clad Er,Yb-doped fiber lasers with fixed-wavelength and wavelength-tunable resonator configurations using volume Bragg gratings for wavelength selection are reported. The fixed-wavelength laser yielded a maximum output power of 103 W at 1552.6 nm with a linewidth of ∼0.4 nm (FWHM) for a launched pump power of 290 W at 976 nm. The wavelength-tunable laser could be tuned from 1528 to 1550 nm with a linewidth of 0.2 nm (FWHM) and with output power in the range 30-38 W for a launched pump power of 120 W. The prospects for further improvement in performance are considered.
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