| 1. |
- Akner, Gunnar, et al.
(författare)
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Styrningen har blivit ett hot
- 2016
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Ingår i: Svenska Dagbladet. - 1101-2412. ; 25 jul
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Tidskriftsartikel (populärvet., debatt m.m.)
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| 2. |
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| 3. |
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| 4. |
- Felton, Adam, et al.
(författare)
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The tree species matters : Biodiversity and ecosystem service implications of replacing Scots pine production stands with Norway spruce.
- 2020
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Ingår i: Ambio. - : Springer. - 0044-7447 .- 1654-7209. ; 49:5, s. 1035-1049
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Forskningsöversikt (refereegranskat)abstract
- The choice of tree species used in production forests matters for biodiversity and ecosystem services. In Sweden, damage to young production forests by large browsing herbivores is helping to drive a development where sites traditionally regenerated with Scots pine (Pinus sylvestris) are instead being regenerated with Norway spruce (Picea abies). We provide a condensed synthesis of the available evidence regarding the likely resultant implications for forest biodiversity and ecosystem services from this change in tree species. Apart from some benefits (e.g. reduced stand-level browsing damage), we identified a range of negative outcomes for biodiversity, production, esthetic and recreational values, as well as increased stand vulnerability to storm, frost, and drought damage, and potentially higher risks of pest and pathogen outbreak. Our results are directly relevant to forest owners and policy-makers seeking information regarding the uncertainties, risks, and trade-offs likely to result from changing the tree species in production forests.
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| 5. |
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| 6. |
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| 7. |
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| 8. |
- Petersson, Christer, et al.
(författare)
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Ett kvartssekel med föräldragrupper i barnhälsovården - var står vi idag?
- 2005
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Ingår i: Läkartidningen. - 0023-7205. ; 102:39, s. 6-2754
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Tidskriftsartikel (refereegranskat)abstract
- En trygg föräldrarelation, präglad av värme och rimliga gränser, är en viktig förutsättning för barns hälsa och välfärd och för att de senare i livet ska kunna samspela förtroendefullt med omgivningen. Inom hälso- och sjukvården finns idag en omfattande verksamhet, exempelvis öppna föräldragrupper, vars syfte är att ge stöd i föräldraskapet. En aktuell rapport från Folkhälsoinstitutet visar att en stor del av denna verksamhet fortfarande saknar vetenskaplig evidens, men också att tillgången på evidens ökat dramatiskt under de senaste 10–15 åren. Här redovisas resultaten från tre lokala studier av föräldragrupper inom barnhälsovården, vilka exemplifierar resultaten i Folkhälsoinstitutets rapport.
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| 9. |
- Petersson, Kerstin, et al.
(författare)
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What is good parental education?
- 2004
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Ingår i: Scandinavian Journal of Caring Sciences. - : Wiley. - 1471-6712 .- 0283-9318. ; 18:1, s. 82-89
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Tidskriftsartikel (refereegranskat)abstract
- The aim of the study was to highlight the experiences and expectations of Swedish parents with respect to general parental education within child healthcare. Interviews were carried out with 25 parents who had attended education sessions. With a few exceptions the fathers did not take part, and those mothers who did comprised a relatively highly educated group; their views therefore predominate in this study. Socially vulnerable parents such as the unemployed and immigrants took part more sporadically in the meetings, which is why less material is available from these groups. The arrangement and analysis of the material was done using qualitative content analysis. We identified two main categories of importance: 'parental education content' and 'parental education structure'. The parents were on the whole satisfied with the content with respect to the child's physical and psychosocial development. On the other hand, first-time parents expressed a degree of uncertainty with respect to the new parent roles and parent relation and they thought that the education should place more emphasis on the interplay between the parents and between child and parents. The degree of confidence in the nurse as group leader was mainly high. The parents thought that the groups functioned well socially and were satisfied with the organization of the meetings. They did, however, demand clearer structure and framework with respect to the content. Since the aim of legally established parental education is to improve the conditions of childhood growth and to provide support to parents, it must be considered especially important to provide resources so that the socially vulnerable groups in the community may also be reached.
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| 10. |
- Redéen, Stefan, 1961-
(författare)
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Chronic Gastritis : Diagnosis, natural history and consequences
- 2010
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Background & alms: The main cause of chronic gastritis is Helicobacter pylori (H. pylori). Clinical manifestations of chronic gastritis are ulcer disease, gastric cancer and mucosa-associated lymphoma tissue (MALT) lymphoma in the stomach. It is uncertain whether gastritis can be diagnosed macroscopically at endoscopy. H. pylori infection may be diagnosed by several different methods, the accuracy of which needs to be explored. Some individuals with H. pylori related chronic gastritis will develop atrophy of the gastric mucosa. This condition is the main risk factor for cancer development and may also be associated with vitamin B12 deficiency leading to hyperhomocysteinaemia. The natural history of chronic gastritis in terms of development of atrophy and ulcer disease in the adult general population is largely unknown.Material & methods: A sample of 50 I volunteers from the general population in the municipality of Linköping was examined with esophago-gastro-duodenoscopy (EGD) with biopsy. Blood samples were collected in the fasting state and the subjects answered a questionnaire about lifestyle factors, medications and disease history. In-hospital diagnoses and causes of death during follow-up of the population were extracted from local and national patient files. Re-examination was done in 314 subjects after a median follow-up interval of 8.4 years. Five diagnostic tests (serology UBT, RUT, culture and microscopic examination) for H. pylori infection were used at re-examination.Results: The best values of sensitivity and specificity were for visible vessels in relation to microscopic presence of severe atrophy in the gastric corpus mucosa (80% and 87%, respectively). There was a positive relation of S-homocysteine to male gender, age, S-cystatin C (renal function), methylenetetrahydrofolate reductase 677TT genotype and atrophic gastritis. Logistic regression analysis showed an association of S-homocysteine higher than 14.5 Ilmol/L to cardiovascular diseases (OR 2.05), but not to dementia overall.The incidence ofulcer was 0.45 per 100 person years and was associated with weekly NSAID use, weekly alcohol consumption (OR 19.4) and smoking (OR 31.0), but not with H. pylori status. Among subjects with chronic gastritis, the incidence of atrophy of the corpus mucosa was 1.4 per 100 person years. Considering diagnostic test for H. pylori infection the accuracy was 0.86 for serology, 0.94 for UBT, 0.94 for RUT, 0.93 for culture, and 0.93 for histological examination. There was a strong correlation between the results of UBT and the histological scores of H. pylori colonisation as well as between the results of UBT and scores of RUT.Conclusions: The occurrence of chronic gastritis or H. pylori infection is not evaluable macroscopically at gastroscopy, except for the absence of rugae or visible vessels in the gastric corpus mucosa. Serum Hcy concentrations are dependent on gender, age, the levels of vitamin B12 and folate, renal function, the occurrence of atrophic gastritis and the MTHFR 677 TT genotype. Elevated S-Hcy is a risk factor for cardiovascular disease. The incidence of atrophy of the corpus mucosa is 1.4 per 100 person years for chronic gastritis overall. Chronic gastritis with or without H. pylori infection is a variable process in which milder degrees of atrophy of the corpus mucosa may appear or disappear. In contrast, moderate-to-severe atrophy of the corpus mucosa rarely regresses. Age and the degree of chronic inflammation in the gastric corpus mucosa are major risk factors for the development of atrophy. The incidence of ulcer was 0.45 per 100 person years. There are only minor differences in accuracy between the three invasive tests for H. pylori infection. The UBT is recommended for situations where endoscopy is not required. RUT may be recommended as the first non-invasive method of choice in the diagnosis of H. pylori infection.
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| 11. |
- Thulesius, Hans, et al.
(författare)
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Learner-centred education in end-of-life care improved well being in home care staff: a prospective controlled study.
- 2002
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Ingår i: Palliative Medicine. - : SAGE Publications. - 1477-030X .- 0269-2163. ; 16:4, s. 54-347
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Tidskriftsartikel (refereegranskat)abstract
- The aim of this controlled study was to evaluate a 1-year learner-centred educational project in end-of-life care for home care staff in a rural district of Sweden. Another rural district in the same region served as a control area. A 20-item questionnaire measuring attitudes towards end-of-life care was designed, and the Hospital Anxiety and Depression (HAD) scale was used to measure mental well being. Increased agreement to 18 of 20 attitude statements was seen in the education group, while 2 of 20 items showed a decreased agreement in the control group. Test retest reliability of the 20-item questionnaire was good (r =0.92). The total HAD score decreased from 8.3 pretest to 5.3 post-test in the education group (95% CI=2.1– 3.7; P<0.001), and was 6.8 for both years in the control group. Our study shows that a comprehensive educational programme not only improved attitudes towards end-of-life care, but also the mental well being of the home care staff.
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| 12. |
- Abdalla, Munir A, et al.
(författare)
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A CMOS APS for dental X-ray imaging using scintillating sensors
- 2001
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Ingår i: Nuclear Instruments and Methods in Physics Research Section A. - 0168-9002 .- 1872-9576. ; 460:1, s. 197-203
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Tidskriftsartikel (refereegranskat)abstract
- In this paper we present an integrating CMOS Active Pixel Sensor (APS) circuit to be used with scintillator type X-ray sensors for intra oral dental X-ray imaging systems. Different pixel architectures were constructed to explore their performance characteristics and to study the feasibility of the development of such systems using the CMOS technology. A prototype 64 x 80 pixel array has been implemented in a CMOS 0.8 mum double poly n-well process with a pixel pitch of 50 mum. A spectral sensitivity measurement for the different pixels topologies, as well as measured X-ray direct absorption in the different APSs are presented. A measurement of the output signal showed a good linearity over a wide dynamic range. This chip showed that the very low sensitivity of the CMOS APSs to direct X-ray exposure adds a great advantage to the various CMOS advantages over CCD-based imaging systems,
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| 13. |
- Abdalla, Munir A, et al.
(författare)
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A new biasing method for CMOS preamplifier-shapers
- 2000
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Ingår i: ICECS 2000: 7TH IEEE INTERNATIONAL CONFERENCE ON ELECTRONICS, CIRCUITS & SYSTEMS, VOLS I AND II. ; , s. 15-18
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Konferensbidrag (refereegranskat)
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| 14. |
- Abdalla, Munir A, et al.
(författare)
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An integrating CMOS APS for X-ray imaging with an in-pixel preamplifier
- 2001
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Ingår i: Nuclear Instruments and Methods in Physics Research Section A. - 0168-9002 .- 1872-9576. ; 466:1, s. 232-236
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Tidskriftsartikel (refereegranskat)abstract
- We present in this paper an integrating CMOS Active Pixel Sensor (APS) circuit coated with scintillator type sensors for intra-oral dental X-ray imaging systems. The photosensing element in the pixel is formed by the p-diffusion on the n-well diode. The advantage of this photosensor is its very low direct absorption of X-rays compared to the other available photosensing elements in the CMOS pixel. The pixel features an integrating capacitor in the feedback loop of a preamplifier of a finite gain in order to increase the optical sensitivity. To verify the effectiveness of this in-pixel preamplification, a prototype 32 x 80 element CMOS active pixel array was implemented in a 0.8 mum CMOS double poly, n-well process with a pixel pitch of 50 mum. Measured results confirmed the improved optical sensitivity performance of the APS. Various measurements on device performance are presented.
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| 15. |
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| 16. |
- Aboelfotoh, M. O., et al.
(författare)
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Schottky-barrier behavior of metals on n- and p-type 6H-SiC
- 2003
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Ingår i: Physical Review B. Condensed Matter and Materials Physics. - 1098-0121 .- 1550-235X. ; 67:7, s. 075312-
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Tidskriftsartikel (refereegranskat)abstract
- The Schottky-barrier height of a number of metals (Ti, Ni, Cu, and Au) on n- and p-type Si-terminated 6H-SiC has been measured in the temperature range 150-500 K. It is found that the barrier height to n-type 6H-SiC does not exhibit a temperature dependence, while for p-type 6H-SiC the change in the barrier height with temperature follows very closely the change in the indirect energy gap in 6H-SiC. These results are inconsistent with models of Schottky-barrier formation based on the concept of a charge neutrality level. Furthermore, the present results cannot be reconciled with a defect pinning mechanism, contrary to the conclusions of earlier studies on III-V compound semiconductors. We suggest that chemical bonding at the metal-semiconductor interface plays an important role in determining the Schottky-barrier height.
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| 17. |
- Akner, Gunnar, 1953-, et al.
(författare)
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Vi står gärna bakom en utfallsbaserad vård
- 2017
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Ingår i: Dagens Samhälle. - 1652-6511.
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Tidskriftsartikel (populärvet., debatt m.m.)abstract
- Jörgen Nordenström försöker få det till att vår kritik av värdebaserad vård egentligen handlar om att vi vill ha mer resurser. Han har helt missuppfattat oss, skriver 26 specialistläkare i en replik.
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| 18. |
- Albertsson, Daniel M, 1957, et al.
(författare)
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Hip and fragility fracture prediction by 4-item clinical risk score and mobile heel BMD: a women cohort study
- 2010
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Ingår i: BMC Musculosceletal disorders. - : Springer Science and Business Media LLC. - 1471-2474. ; 11
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Tidskriftsartikel (refereegranskat)abstract
- Background One in four Swedish women suffers a hip fracture yielding high morbidity and mortality. We wanted to revalidate a 4-item clinical risk score and evaluate a portable heel bone mineral density (BMD) technique regarding hip and fragility fracture risk among elderly women. Methods In a population-based prospective cohort study we used clinical risk factors from a baseline questionnaire and heel BMD to predict a two-year hip and fragility fracture outcome for women, in a fracture preventive program. Calcaneal heel BMD was measured by portable dual X-ray laser absorptiometry (DXL) and compared to hip BMD, measured with stationary dual X-ray absorptiometry (DXA) technique. Results Seven women suffered hip fracture and 14 women fragility fracture/s (at hip, radius, humerus and pelvis) among 285 women; 60% having heel BMD ≤ -2.5 SD. The 4-item FRAMO (Fracture and Mortality) Index combined the clinical risk factors age ≥80 years, weight <60 kg, prior fragility fracture, and impaired rise-up ability. Women having 2-4 risk factors showed odds ratio (OR) for hip fracture of 5.9 and fragility fracture of 4.4. High risk group hip fracture risk was 2.8% annually compared to 0.5% for the low risk majority (69%). Heel BMD showed hip fracture OR of 3.1 and fragility fracture OR of 2.6 per SD decrease. For 30 DXA assessed participants mean hip BMD at -2.5 SD level corresponded to a lower BMD at the heel. Five of seven hip fractures occurred within a small risk group of 32 women, identified by high FRAMO Index + prior fragility fracture + heel T-score ≤-3.5 SD. Conclusions In a follow-up study we identified high risk groups for hip and fragility fracture with our plain 4-item risk model. Increased fracture risk was also related to decreasing heel BMD in calcaneal bone, measured with a mobile DXL technique. A combination of high FRAMO Index, prior fragility fracture, and very low BMD restricted the high risk group to 11%, among whom most hip fractures occurred (71%). These practical screening methods could eventually reduce hip fracture incidence by concentrating preventive resources to high fracture risk women.
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| 19. |
- Albertsson, Daniel M, 1957, et al.
(författare)
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Validation of a 4-item score predicting hip fracture and mortality risk among elderly women.
- 2007
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Ingår i: Annals of family medicine. - : Annals of Family Medicine. - 1544-1717 .- 1544-1709. ; 5:1, s. 48-56
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Tidskriftsartikel (refereegranskat)abstract
- PURPOSE: One in 4 Swedish women experiences a hip fracture, an event that has high concomitant morbidity and mortality. We developed and validated a clinical predictor of fracture and mortality risk, the Fracture and Mortality (FRAMO) Index. METHODS: This was a population-based prospective cohort study with a baseline questionnaire and 2-year outcomes of hip fracture, fragility fracture, and death. The questionnaire was sent to 1,498 women aged 70 years or older in 3 rural populations, asking them about their age, weight, height, mobility, previous fractures, smoking, medication use, and housing. Some women were also asked about previous vertebral radiographs. We defined 2 risk models before outcome data collection and subsequently renamed 1 model (age =80 years, weight <60 kg, previous fragility fracture, and the need to use arms to rise from the sitting position) the FRAMO Index. We used logistic regression analysis to study the association between the FRAMO Index and outcomes in all participants. RESULTS: The participation rate was 83% in this elderly female population (N = 1,248). The 63% of women with 0 to 1 risk factor had a 2-year hip fracture risk of 0.8% and mortality risk of 3.2%. In contrast, women with 2 to 4 risk factors had a 2-year hip fracture risk of 5.4% (odds ratio = 7.5; 95% confidence interval, 3.0-18.4) and mortality risk of 23.7% (odds ratio = 9.5; 95% confidence interval, 6.0-14.9). These differences remained significant after adjustment for age as a continuous variable. Mortality increased with the number of risk factors. The proportion of women reporting previous vertebral fractures was higher among the group specifically questioned about vertebral radiographs (P <.001). CONCLUSIONS: The FRAMO Index identified the majority of women who experienced hip fractures during a 2-year follow-up, who might have been candidates for intensified preventive measures. The FRAMO Index, based on 4 binary risk factors, would be practical for routine use in primary care.
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| 20. |
- André, Malin, et al.
(författare)
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More physician consultations and antibiotic prescriptions in families with high concern about infectious illness-adequate response to infection-prone child or self-fulfilling prophecy?
- 2007
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Ingår i: Family Practice. - : Oxford University Press (OUP). - 0263-2136 .- 1460-2229. ; 24:4, s. 302-307
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Tidskriftsartikel (refereegranskat)abstract
- Background. Respiratory tract infections (RTI) in children is the most common cause of prescription of antibiotics. It is important to describe and analyse non-medical factors in order to develop more rational use of antibiotics. Objectives. To compare families with high and low concern about infectious illness with regard to social variables, perception of infection proneness and beliefs in antibiotics and to relate the concern for infectious illness to reported morbidity, physician consultations and antibiotic prescriptions for the 18-month-old child in the family. Methods. A prospective, population-based survey was performed. During 1 month, all infectious symptoms, physician consultations and antibiotic treatments for 18-month-old children were noted. The 818 families also answered questions about their socio-economic situation, illness perception and concern about infectious illness. Results. High concern about infectious illness was associated with more frequent physicians consultations and more prescriptions of antibiotics. There was no significant difference in reported days with symptoms of RTI, but the parents more often experienced their children with RTI without fever as being ill. The variables of infection proneness in the child, inadequate beliefs in antibiotics and the factor of being the only child were important explanatory factors for concern about infectious illness. Conclusions. High concern about infectious illness is an important determining factor for physician consultations and antibiotic prescription for small children. An adequate consultation, where the doctor deals with the parents' worries and gives appropriate information about symptoms and disease, might contribute to less antibiotic prescribing with preserved parental satisfaction.
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| 21. |
- Badel, Xavier, et al.
(författare)
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Improvement of an X-ray imaging detector based on a scintillating guides screen
- 2002
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Ingår i: Nuclear Instruments and Methods in Physics Research Section A. - 0168-9002 .- 1872-9576. ; 487:1-2, s. 129-135
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Tidskriftsartikel (refereegranskat)abstract
- An X-ray imaging detector has been developed for dental applications. The principle of this detector is based on application of a silicon charge coupled device covered by a scintillating wave-guide screen. Previous studies of such a detector showed promising results concerning the spatial resolution but low performance in terms of signal to noise ratio (SNR) and sensitivity. Recent results confirm the wave-guiding properties of the matrix and show improvement of the detector in terms of response uniformity, sensitivity and SNR. The present study is focussed on the fabrication of the scintillating screen where the principal idea is to fill a matrix of Si pores with a CsI scintillator. The photoluminescence technique was used to prove the wave-guiding property of the matrix and to inspect the filling uniformity of the pores. The final detector was characterized by X-ray evaluation in terms of spatial resolution, light output and SNR. A sensor with a spatial resolution of 9 LP/mm and a SNR over 50 has been achieved using a standard dental X-ray source and doses in the order of those used at the moment by dentists (around 25 mR).
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| 22. |
- Badel, Xavier, et al.
(författare)
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Metallized and oxidized silicon macropore arrays filled with a scintillator for CCD-based X-ray imaging detectors
- 2004
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Ingår i: IEEE Transactions on Nuclear Science. - : IEEE. - 0018-9499 .- 1558-1578. ; 51:3, s. 1001-1005, s. 1006-1010
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Tidskriftsartikel (refereegranskat)abstract
- Silicon charge-coupled devices (CCDs) covered with a scintillating film are now available on the market for use in digital medical imaging. However, these devices could still be improved in terms of sensitivity and especially spatial resolution by coating the CCD with an array of scintillating waveguides. In this paper, such waveguides were fabricated by first etching pores in silicon, then performing metallization or oxidation of the pore walls and finally filling the pores with CsI(TI). The resulting structures were observed using scanning electron microscopy and tested under X-ray exposure. Theoretical efficiencies of macropore arrays filled with CsI(TI) were also calculated, indicating that the optimal pore depth for metallized macropore arrays is about 80 mum while it is around 350 mum for oxidized ones. This result, together with the roughness of the metal coating, explains why lower SNR values were measured with the metallized macropores. Indeed, the macropore arrays had depths in the range of 210-390 mum, which is favorable to oxidized structures.
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| 23. |
- Brofelth, Mattias, et al.
(författare)
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Site-specific photocoupling of pBpa mutated scFv antibodies for use in affinity proteomics
- 2017
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Ingår i: Biochimica et Biophysica Acta - Proteins and Proteomics. - : Elsevier BV. - 1570-9639. ; 1865:8, s. 985-996
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Tidskriftsartikel (refereegranskat)abstract
- Recombinant antibody libraries can provide a source of renewable and high-performing binders tailored for use in affinity proteomics. In this context, the process of generating site-specific 1:1 tagging/functionalization and/or orientated surface immobilization of antibodies has, however, proved to be challenging. Hence, novel ways of generating such engineered antibodies for use in affinity proteomics could have a major impact on array performance. In this study, we have further tailored the design of human recombinant scFv antibodies for site-specific photocoupling through the use of an unnatural amino acid (UAA) and the Dock'n'Flash technology. In more detail, we have generated the 2nd generation of scFvs carrying the photoreactive UAA p-benzoyl-l-phenylalanine (pBpa). Based on key properties, such as expression levels, activity, and affinity, a preferred choice of site for pBpa, located in the beginning of the C-terminal affinity-tag, was for the first time pin-pointed. Further, the results showed that pBpa mutated antibody could be site-specifically photocoupled to free and surface immobilized β-cyclodextrin (an affinity ligand to pBpa). This paves the way for use of scFv antibodies, engineered for site-specific photochemical-based tagging, functionalization, and orientated surface immobilization, in affinity proteomics.
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| 24. |
- Duan, M., et al.
(författare)
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Deposition of Scintillating Layers of Bismuth Germanate (BGO) Films for X-ray detector applications
- 1998
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Ingår i: IEEE Transactions on Nuclear Science. - : Institute of Electrical and Electronics Engineers (IEEE). - 0018-9499 .- 1558-1578. ; 45:3, s. 525-527
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Tidskriftsartikel (refereegranskat)abstract
- Bi4Ge3O12 films were deposited by pulsed laser ablation on glass and SiO2/Si substrates. The crystal structures of the films depend on the deposition temperature. XRD patterns indicate that the films deposited at substrate temperature less than 400°C are amorphous. The as deposited amorphous films can be crystallized by post rapid thermal annealing (RTA) in the temperature window from 750°C to 800°C for 2 minutes in a oxygen ambient environment. RBS measurements confirm that the films have the same chemical composition as that of the target. The surface morphology of the films were characterized by atomic force microscopy (AFM)
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| 25. |
- Dubaric, Ervin, et al.
(författare)
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Resolution and noise properties of scintillator coated X-ray detectors
- 2001
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Ingår i: Nuclear Instruments and Methods in Physics Research Section A. - 0168-9002 .- 1872-9576. ; 466:1, s. 178-182
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Tidskriftsartikel (refereegranskat)abstract
- The imaging properties of X-ray pixel detectors depend on the quantum efficiency of X-rays, the generated signal of each X-ray photon and the distribution of the generated signal between pixels. In a scintillator coated device the signal is generated both by X-ray photons captured in the scintillator and by X-ray photons captured directly in the semiconductor. The Signal-to-Noise Ratio in the image is then a function of the number of photons captured in each of these processes and the yield, in terms of electron-hole pairs produced in the semiconductor, of each process. The spatial resolution is primarily determined by the light spreading within the scintillator. In a pure semiconductor detector the signal is generated by one process only. The Signal-to-Noise Ratio in the image is proportional to the number of X-ray photons captured within the sensitive layer. The spatial resolution is affected by the initial charge cloud generated in the semiconductor and any diffusion of carriers between the point of interaction and the readout electrode. In this paper we discuss the theory underlying the imaging properties of scintillator coated X-ray imaging detectors. The model is verified by simulations using MCNP and by experimental results. The results from the two-layer detector are compared with those from a pure semiconductor X-ray detector.
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| 26. |
- Eberbeck, Dietmar, et al.
(författare)
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AC susceptometry and magnetorelaxometry for magnetic nanoparticle based biomolecule detection
- 2009
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Functionalized magnetic nanoparticles are increasingly used as probes in biomolecule detection. We compared two different techniques, which provide information on the state of the magnetic particle system. The dynamics of an ensemble of magnetic nanoparticles was probed measuring the response its magnetisation both on an alternating magnetic field by AC-susceptometry and on a jump of external magnetic field by magnetorelaxometry. In order to compare both techniques, we studied the binding of streptavidin functionalized nanoparticles (fluidMAG/BC-SAV) to biotin-agarose beads and to biotinylated prostate specific antigens (PSA-10). By both techniques we observed specific changes in shape and amplitude of the characteristic signals due the binding of the particles. Therewith the signals of bound and unbound probes can be discriminated and a homogeneous assay without time-comsuming washing steps is realized. The AC susceptometry method provides a robust and sensitive measurement technology. Magnetorelaxometry, utilizing superconducting quantum interference devices (SQUIDs) as magnetic field sensors, owns a much shorter measurement time and has the potential of an even higher sensitivity, at the expense of a considerably increased technological effort.
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| 27. |
- Ehn, Andreas, et al.
(författare)
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Setup for microwave stimulation of a turbulent low-swirl flame
- 2016
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Ingår i: Journal of Physics D: Applied Physics. - : IOP Publishing. - 0022-3727 .- 1361-6463. ; 49:18
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Tidskriftsartikel (refereegranskat)abstract
- An experimental setup for microwave stimulation of a turbulent flame is presented. A low-swirl flame is being exposed to continuous microwave irradiation inside an aluminum cavity. The cavity is designed with inlets for laser beams and a viewport for optical access. The aluminum cavity is operated as a resonator where the microwave mode pattern is matched to the position of the flame. Two metal meshes are working as endplates in the resonator, one at the bottom and the other at the top. The lower mesh is located right above the burner nozzle so that the low-swirl flame is able to freely propagate inside the cylinder cavity geometry whereas the upper metal mesh can be tuned to achieve good overlap between the microwave mode pattern and the flame volume. The flow is characterized for operating conditions without microwave irradiation using particle imaging velocimetry (PIV). Microwave absorption is simultaneously monitored with experimental investigations of the flame in terms of exhaust gas temperature, flame chemiluminescence (CL) analysis as well as simultaneous planar laser-induced fluorescence (PLIF) measurements of formaldehyde (CH2O) and hydroxyl radicals (OH). Results are presented for experiments conducted in two different regimes of microwave power. In the high-energy regime the microwave field is strong enough to cause a breakdown in the flame. The breakdown spark develops into a swirl-stabilized plasma due to the continuous microwave stimulation. In the low-energy regime, which is below plasma formation, the flame becomes larger and more stable and it moves upstream closer to the burner nozzle when microwaves are absorbed by the flame. As a result of a larger flame the exhaust gas temperature, flame CL and OH PLIF signals are increased as microwave energy is absorbed by the flame.
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| 28. |
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| 29. |
- Felton, Adam, et al.
(författare)
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Forest biodiversity and ecosystem services from spruce-birch mixtures : The potential importance of tree spatial arrangement
- 2022
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Ingår i: Environmental Challenges. - : Elsevier BV. - 2667-0100. ; 6
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Forskningsöversikt (refereegranskat)abstract
- There is increasing empirical support for the biodiversity and ecosystem service (ES) benefits of mixed-species production forests. However, few studies control for the spatial arrangement of the trees within mixtures to determine the influence that clustering the tree species (patch scale mixtures), versus evenly dispersing them (intimate scale mixtures), may have for biodiversity and ES outcomes. To highlight the potential implications of altering tree spatial arrangement in mixtures, and the need to fill related knowledge gaps, here we provide a qualitative multi-disciplinary overview of ecological and socio-economic drivers with the potential to alter biodiversity, ecosystem services, and management-related outcomes from patch versus intimate scale mixtures. We focused our overview on even-aged mixtures of Norway spruce (Picea abies) and birch (Betula pendula or B. pubescens) in Sweden, which enabled us to contrast findings within a biogeographical and silvicultural setting. Specifically, we targeted implications for biodiversity (understory vascular plants, epiphytic lichens, saproxylic beetles, birds), biomass production, harvesting costs, management ease, recreation and aesthetics, cervid game, as well as abiotic and biotic risks (wind, fire, pathogens, pests, browsing damage). In the absence of direct empirical evidence, we primarily relied on expert inference from theory and relevant empirical studies sourced from the Fennoscandian region, and further afield if needed. Collectively these efforts allowed us to develop a number of informed hypotheses indicating that for spruce-birch mixtures in this region, patch scale mixtures may have the potential to favour the diversity of several forest dependant taxonomic groups, cervid game and reduce harvesting costs, whereas intimate mixtures may have the potential to reduce pathogen and pest damage, and likewise, potentially benefit production outcomes. Current knowledge was too limited, inconsistent or context dependant to even tentatively infer outcomes for fire risk, wind damage, browsing damage, management ease, recreational and aesthetic outcomes. We emphasize that our hypotheses require testing, but are sufficient to (1) highlight the likely importance of spatial-scale to biodiversity and ecosystem services outcomes in mixed-species production forests, (2) caution against generalization from mixture studies that lack scale considerations, and (3) motivate the targeted consideration of spatial grain in future mixture studies.
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| 30. |
- Fornara, Andrea, et al.
(författare)
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Tailored Magnetic Nanoparticles for Direct and Sensitive Detection of Biomolecules in Biological Samples
- 2008
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Ingår i: Nano letters (Print). - : American Chemical Society (ACS). - 1530-6984 .- 1530-6992. ; 8:10, s. 3423-3428
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Tidskriftsartikel (refereegranskat)abstract
- We developed nanoparticles with tailored magnetic properties for sensitive detection of biomolecules directly in biological samples in a single step. Thermally blocked nanoparticles obtained by thermal hydrolysis are mixed with sample solutions and the variation of the magnetic relaxation due to surface binding is used to detect the presence of biomolecules. The binding events significantly increase the hydrodynamic volume of nanoparticles, thus changing their Brownian relaxation frequency which is measured by a specifically developed AC-susceptometer.The system was tested for the presence of Brucella antibodies in serum samples from infected cows and the surface of the nanoparticles was functionalized with lipopolysaccarides (LPS) from Brucella abortus. The hydrodynamic volume of functionalized particles increased by 25-35% as a result of the binding of the antibodies, as measured by changes in the susceptibility in an alternating magnetic field. The method has shown high sensitivity, with detection limit of 7 nmol·L-1 in serum without any pre-treatment of the biological samples.The detection method is very sensitive, cost-efficient and versatile, giving a direct indication if the animal is infected or not, making it suitable for point-of care applications. The functionalization of tailored magnetic nanoparticles can be modified to suit numerous homogenous assays for a wide range of applications.
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| 31. |
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| 32. |
- Fröjdh, Anna, et al.
(författare)
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An alpha particle detector for measuring radon levels
- 2010
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Ingår i: Proceedings of Nuclear Science Symposium Conference Record (NSS/MIC), 2010. - : IEEE conference proceedings. - 9781424491063 ; , s. 460-461
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Konferensbidrag (refereegranskat)abstract
- An alpha particle detector for measuring radon levels through measurement of radon progeny concentration has been developed. The detector is a silicon diode optimized for these measurements. Different alternating and non-alternating guard ring structures and different doping profiles have been investigated.
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| 33. |
- Fröjdh, Anna, et al.
(författare)
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An optimized system for measurement of radon levels in buildings by spectroscopic measurement of radon progeny
- 2011
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Ingår i: Journal of Instrumentation. - 1748-0221. ; 6:12, s. art. no. C12018-
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Tidskriftsartikel (refereegranskat)abstract
- Radon gas, Rn-222, is a problem in many buildings. The radon gas is not harmful in itself, but the decay chain contains charged elements such as Po-218, and Po-214 ions which have a tendency to stick to the lungs when inhaled. Alpha particles from the decay of these ions cause damages to the lungs and increase the risk of lung cancer. The recent reduction in the limits for radon levels in buildings call for new simple and efficient measurement tools [1]. The system has been optimized through modifications of the detector size, changes to the filters and the design of the chamber. These changes increase the electric field in the chamber and the detection efficiency.
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| 34. |
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| 35. |
- Fröjdh, Christer, 1952-, et al.
(författare)
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New sensors for dental X-ray imaging
- 1999
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Ingår i: Nuclear Instruments and Methods in Physics Research Section A. - 0168-9002 .- 1872-9576. ; 434:1, s. 24-29
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Tidskriftsartikel (refereegranskat)
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| 36. |
- Fröjdh, Christer, et al.
(författare)
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Processing and characterisation of an etched groove Permeable
- 1994
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Ingår i: Physica scripta. T. - 0281-1847. ; T54, s. 56-59
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Tidskriftsartikel (refereegranskat)abstract
- The Permeable Base Transistor (PBT) is generally considered as an interesting device for high speed applications. PBTs have been fabricated on Silicon and Gallium Arsenide by a number of groups. In this paper we reported on the fabrication of an etched groove PBT structure on 6H-SiC using Ti as contact metal for all electrodes. The devices have been characterised by DC-measurements. The transistors show the normal IV-characteristics for a such a device except for a parasitic series diode at the drain electrode. The breakdown voltage of the gate-drain diode is generally as high as around 60 V even without passivation of the sidewalls of the grooves.
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| 37. |
- Fröjdh, Christer, et al.
(författare)
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Schottky Barriers on 6H-SiC
- 1999
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Ingår i: Physica scripta. T. - 0281-1847. ; T79, s. 297-302
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Tidskriftsartikel (refereegranskat)abstract
- Schottky diodes have been fabricated by deposition of Ti, Ni, Cu on epitaxial layers of p-type and n-type 6H-SiC. The fabricated devices have been characterised by CV, IV and photoelectric measurements. The results from the different characterisations are compared. The effect of incomplete ionisation of dopants and high series resistance on the results from CV-measurements is discussed. In addition to the results obtained from the experiments presented in this paper data has also been collected from other research groups in order to investigate the mechanism of Schottky barrier formation on Silicon Carbide. The results show that for a number of metals the barrier height is strongly correlated to the difference between the electron affinity of the semiconductor and the metal work function, while other metals show significant deviation from the Schottky-Mott theory.
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| 38. |
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| 39. |
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| 40. |
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| 41. |
- Gustafsson, Stefan, 1976, et al.
(författare)
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Evolution of Structural and Magnetic Properties of Magnetite Nanoparticles for Biomedical Applications
- 2010
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Ingår i: Crystal Growth & Design. - : American Chemical Society (ACS). - 1528-7483 .- 1528-7505. ; 10:5, s. 2278-2284
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Tidskriftsartikel (refereegranskat)abstract
- We have investigated the evolution of microstructure and magnetic properties of thermally blocked magnetite nanoparticles, aimed for immunoassay applications, during their synthesis. High-resolution transmission electron microscopy (HRTEM) investigations of the size, size distribution, morphology, and crystal structure of particles reveal that particles at an early stage of the reaction process are either single crystals or polycrystals containing planar faults and they grow via a combination of reactant (monomer) consumption and oriented attachment at specific crystallographic surfaces because of the strong dipolar character of the < 111 > surfaces of magnetite. At a later stage of the synthesis reaction, the magnetic attraction strives to align contacting particles with their < 111 > axis of easy magnetization in parallel and this may also be an active driving force for crystal growth. At latter stages, the crystal growth is dominated by Ostwald ripening leading to smoother crystalline particles with a mean diameter of 16.7 +/- 3.5 nm and a narrow size distribution. The magnetic properties of the particles measured using static and dynamic magnetic fields are consistent with the evolution of particle size and structure and show the transition from superparamagnetic to thermally blocked behavior needed for magnetic relaxation-based immunoassay applications.
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| 42. |
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| 43. |
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| 44. |
- Hatzikonstantinidou, S., et al.
(författare)
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Process Optimisation and Characterisation of PBT structures
- 1994
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Ingår i: Physica scripta. T. - 0281-1847. ; T54, s. 226-229
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Tidskriftsartikel (refereegranskat)abstract
- The Permeable Base Transistor (PBT) is considered to be a high frequency device with simulated fT and fmax values in the order of 100 GHz. In this work we present several PBT devices in silicon. The fabrication process steps have been developed and optimised in order to meet the demands of a future integration in a standard CMOS processing. Cobalt disilicide is used for the emitter metallization and base metallisation in order to form a good Schottky contact. The important issues of a fabrication process reliability and controllability are discussed in this paper. The process steps had been analysed by standard analysis methods. Electrical (DC) characterisation of the devices has been performed. The obtained results are in a good agreement with the 2D simulations.
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| 45. |
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| 46. |
- Hazarika, Pompi, et al.
(författare)
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Photopatterning of self assembled monolayers on oxide surfaces for the selective attachment of biomolecules
- 2014
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Ingår i: Biosensors & Bioelectronics. - : Elsevier BV. - 1873-4235 .- 0956-5663. ; 53, s. 82-89
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Tidskriftsartikel (refereegranskat)abstract
- The immobilization of functional biomolecules to surfaces is a critical process for the development of biosensors for disease diagnostics. In this work we report the patterned attachment of single chain fragment variable (scFv) antibodies to the surface of metal oxides by the photodeprotection of self-assembled monolayers, using near-UV light. The photodeprotection step alters the functionality at the surface; revealing amino groups that are utilized to bind biomolecules in the exposed regions of the substrate only. The patterned antibodies are used for the detection of specific disease biomarker proteins in buffer and in complex samples such as human serum. (C) 2013 Elsevier B.V. All rights reserved.
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| 47. |
- Hedin, Katarina, et al.
(författare)
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A population-based study of different antibiotic prescribing in different areas
- 2006
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Ingår i: British Journal of General Practice. - London, UK : Royal College of General Practitioners. - 0960-1643 .- 1478-5242. ; 56:530, s. 680-685
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Tidskriftsartikel (refereegranskat)abstract
- Background: Respiratory tract infections are the most common reason for antibiotic prescription in Sweden as in other countries. The prescription rates vary markedly in different countries, counties and municipalities. The reasons for these variations in prescription rate are not obvious. Aim: To find possible explanations for different antibiotic prescription rates in children. Design of study Prospective population based study. Setting All child health clinics in four municipalities in Sweden which, according to official statistics, had high antibiotic prescription rates, and all child health clinics in three municipalities which had low antibiotic prescription rates. Method: During one month, parents recorded all infectious symptoms, physician consultations and antibiotic treatments, from 848 18-month-old children in a log book. The parents also answered a questionnaire about socioeconomic factors and concern about infectious diseases. Results: Antibiotics were prescribed to 11.6% of the children in the high prescription area and 4.7% in the low prescription area during the study month (crude odds ratio [OR] = 2.67; 95% confidence interval [CI] = 1.45 to 4.93). After multiple logistic regression analyses taking account of socioeconomic factors, concern about infectious illness, number of symptom days and physician consultations, differences in antibiotic prescription rates remained (adjusted OR = 2.61; 95% CI = 1.14 to 5.98). The variable that impacted most on antibiotic prescription rates, although it was not relevant to the geographical differences, was a high level of concern about infectious illness in the family. Conclusions: The differences in antibiotic prescription rates could not be explained by socioeconomic factors, concern about infectious illness, number of symptom days and physician consultations. The differences may be attributable to different prescription behaviour.
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| 48. |
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| 49. |
- Hedin, Katarina, et al.
(författare)
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Infectious morbidity in 18-month-old children with and without older siblings
- 2010
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Ingår i: Family Practice. - : Oxford University Press (OUP). - 0263-2136 .- 1460-2229. ; 27:5, s. 507-512
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Infections are the most commonly reported health problems in children. Younger age and day care outside the home are two factors of importance for infectious morbidity. The influence of siblings on infectious symptoms is not clear. OBJECTIVES: To compare families with one child and families with more than one child in terms of reported infectious symptoms, physician consultations and antibiotic prescriptions. METHODS: A prospective population-based survey was performed. During 1 month, all infectious symptoms, physician consultations and antibiotic prescriptions for 18-month-old children were noted by the parents. The 789 families also answered questions about socio-economic factors, numbers of siblings in the family and type of day care. RESULTS: No difference in number of symptom days was found between children with and without older siblings. Neither could we find any significance in terms of having older siblings in relation to physician consultations and antibiotic prescriptions. CONCLUSIONS: The results of our study indicate that having older siblings not was important in relation to number of symptoms days, physician consultations or antibiotic prescriptions for 18-month-old children in Sweden today. Changes in social activities and attitudes towards antibiotic prescription may explain our different findings as compared with previous Swedish studies and studies from other countries.
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| 50. |
- Hedin, Katarina, et al.
(författare)
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Physician consultation and antibiotic prescription in Swedish infants : population-based comparison of group daycare and home care.
- 2007
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Ingår i: Acta Paediatrica. - : Wiley. - 0803-5253 .- 1651-2227. ; 96:7, s. 1059-1063
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Tidskriftsartikel (refereegranskat)abstract
- Background: Daycare infants have more infectious episodes, see a physician more often, and are prescribed antibiotics more often than home care infants. Aim: To compare physician consultations and antibiotic prescription in daycare children and home care children taking number of symptom days, sociodemographic factors, concern about infectious illness and antibiotic knowledge into account. Methods: For a cohort of Swedish 18-month-old children all infectious symptoms, physician consultation and antibiotic prescriptions were registered during 1 month. Results: 561 infants with daycare outside the home and 278 with daycare at home were included. Of the daycare infants, 23.2% saw a physician and 11.4% were prescribed antibiotics, as compared with 10.8% physician consultations and 5.0% antibiotic prescription for the home care infants. For daycare infants the crude odds ratio for physician consultation were 2.49 (1.63–3.82) and for antibiotic prescription 2.43 (1.34–4.41) compared with home care infants. However, these differences were no longer statistically significant when background data, concern about infectious illness and reported symptoms were taken into account. Conclusion: When background data, concern about infectious illness and reported infectious symptoms were taken into account daycare infants saw a physician and was prescribed antibiotics in the same way as home care infants.
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