| 1. |
- Bodén, Ida, 1977-, et al.
(author)
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NIR and skin impedance spectroscopic measurements for studying the effect of coffee and alcohol on skin, and dysplastic naevi
- 2012
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In: Skin research and technology. - : Wiley-Blackwell. - 0909-752X .- 1600-0846. ; 18:4, s. 486-494
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Journal article (peer-reviewed)abstract
- Background/purpose: Near infrared (NIR) and impedance spectroscopy can be used for clinical skin measurements and need to be evaluated for possible confounding factors; (a) are skin conditions of the patient and the subsequent skin measurements influenced by alcohol and/or coffee consumption and (b) are measurements of dysplastic naevi (DN) reproducible over time and significantly different compared to reference skin.Methods: NIR and skin impedance spectroscopic data were analysed multivariately. In the first study, the skin characteristics of 15 healthy individuals were examined related to body location, gender, individual differences, and consumption of coffee or alcohol. The second study included five patients diagnosed with dysplastic naevi syndrome (DNS). Measurements were taken on DN and reference skin over time.Results: In the first study, body location and gender had a major influence on measurement scores. Inter-individual skin characteristics and coffee or alcohol effects on skin characteristics were of minor importance. In the second study, it was shown that DN can be differentiated from reference skin and the measurements are stable over time.Conclusions: Moderate consumption of alcohol and coffee did not influence the results of the measurements. It is possible to follow, stable or changed, characteristics of DN over time.
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| 2. |
- Bodén, Ida, 1977-, et al.
(author)
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Non-invasive identification of melanoma with near-infrared and skin impedance spectroscopy
- 2013
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In: Skin research and technology. - : John Wiley & Sons. - 0909-752X .- 1600-0846. ; 19:1, s. e473-e478
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Journal article (peer-reviewed)abstract
- Background/purpose: An early diagnosis of cutaneous malignant melanoma is of high importance for good prognosis. An objective, non-invasive instrument could improve the diagnostic accuracy of melanoma and decrease unnecessary biopsies. The aim of this study was to investigate the use of Near infrared and skin impedance spectroscopy in combination as a tool to distinguish between malignant and benign skin tumours.Methods: Near infrared and skin impedance spectra were collected in vivo on 50 naevi or suspect melanomas prior to excision. Received data was analysed with multivariate techniques and the results were compared to histopathology analyses of the tumours. A total of 12 cutaneous malignant melanomas, 19 dysplastic naevi and 19 benign naevi were included in the study.Results: The observed sensitivity and specificity of the proposed method were 83% and 95%, respectively, for malignant melanoma.Conclusions: The results indicate that the combination of near infrared and skin impedance spectroscopy is a promising tool for non-invasive diagnosis of suspect cutaneous malignant melanomas.
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| 3. |
- Geladi, Paul, et al.
(author)
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A multivariate NIR study of skin alterations in diabetic patients as compared to control subjects
- 2000
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In: Journal of Near Infrared Spectroscopy. - 0967-0335 .- 1751-6552. ; 8:4, s. 217-227
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Journal article (peer-reviewed)abstract
- A group of 15 diabetic persons with different degrees of diabetes complications, including skin changes, was studied by Fourier Transform Near Infrared (FT-NIR) spectroscopy. Skin reflectance spectra were measured with a fibre-optic probe in four locations (sites): hand, arm, leg and foot. For reference, a group of 28 healthy controls was also measured. Multivariate analysis of the NIR spectra obtained shows a high potential for classification and discrimination of the skin conditions. Valuable indications for future experiments can be observed.
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| 4. |
- Geladi, Paul, et al.
(author)
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Chemometrics in spectroscopy : Part 2. Examples
- 2004
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In: SPECTROCHIMICA ACTA PART B-ATOMIC SPECTROSCOPY. - : Elsevier BV. - 0584-8547. ; 59:9, s. 1347-57
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Journal article (peer-reviewed)abstract
- Some of the principles and main methods of chemometrics are illustrated by examples. The examples are from electrochemistry, process analytical chemistry and multivariate imaging. Principal component analysis, partial least squares regression and multivariate image analysis are used to illustrate the power of chemometrical thinking. The emphasis is on plotting and visualization for showing the salient features of a model or data set.
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| 5. |
- Grimm, Alejandro, et al.
(author)
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Novel drying treatment to stabilize bilberry, blackcurrant, and cloudberry press cakes: Dryer performance and product quality characteristics
- 2020
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In: Food Science and Technology. - : Elsevier BV. - 0023-6438 .- 1096-1127. ; 128
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Journal article (peer-reviewed)abstract
- In this paper, continuous cyclone drying was compared to conventional batch fixed-bed convective drying of bilberry (Vaccinium myrtillus L.), blackcurrant (Ribes nigrum L.), and cloudberry (Rubus chamaemorus L.) press cakes from berry juice production. When the cyclone dryer was operated at a low feeding rate (2 kg/h), a drying air temperature of similar to 90 degrees C, and an inlet-air velocity of similar to 110 m/s, the dry matter content of the press cakes increased from 23.9 to 85.3 wt% for bilberry, 44.3 to 80.6 wt% for blackcurrant, and 36.4 to 68.4 wt% for cloudberry. The residence/drying time of feedstock particles inside the cyclone dryer when using the process variables mentioned above was approximately 2 s. The product from cyclone drying of cloudberry consisted mainly of seeds; therefore, only bilberry and blackcurrant press cakes were tested in fixed-bed drying. Average convective fixed-bed drying rates were lower than those for cyclone drying. The total polyphenol contents in fixed-bed and cyclone dried samples at the same drying air temperature was close. For bilberry similar to 8.6 freeze-dried, similar to 7 at 40 degrees C, similar to 5 at 90 degrees C, and for blackcurrant similar to 8 freeze-dried, similar to 7 at 40 degrees C, similar to 6 at 90 degrees C given as g GAE/100 g press cake d.b.
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| 6. |
- Lindholm-Sethson, Britta, et al.
(author)
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Are biosensor arrays in one membrane possible? A combination of multifrequency impedance measurements and chemometrics
- 2003
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In: Analytical and Bioanalytical Chemistry. - : Springer Science and Business Media LLC. - 1618-2642 .- 1618-2650. ; 377:3, s. 478-85
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Journal article (peer-reviewed)abstract
- A novel concept of a membrane-based micro-array biosensor is presented. The methodology is based on a single lipid membrane interrogated with electrochemical impedance techniques followed by multivariate data analysis. A single membrane is designed so that relaxation processes with a range of time constants can be probed at different potentials. A range of other approaches cited in the literature is reviewed.
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| 7. |
- Lindholm-Sethson, Britta, et al.
(author)
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Electrochemical impedance spectroscopy in label-free biosensor applications : multivariate data analysis for an objective interpretation
- 2010
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In: Analytical and Bioanalytical Chemistry. - : Springer Science and Business Media LLC. - 1618-2642 .- 1618-2650. ; 398:6, s. 2341-2349
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Research review (peer-reviewed)abstract
- Electrochemical impedance spectroscopy plays an important role in biosensor science thanks to the possibility of finding specific information from processes with different kinetics at a chosen electrode potential in one experiment. In this paper we briefly discuss label-free impedimetric biosensors described in the literature. A novel method for neutral interpretation of impedance data is presented that includes complex number chemometrics. Three examples are given based on impedance measurements on synthetic biomembranes, in this case a lipid monolayer deposited on a mercury electrode. The interaction of various compounds with the monomolecular lipid layer is illustrated with the following: (1) different concentrations of magainin (Geladi et al. in Proc. Int. Fed. Med. Biomed. Eng. 9:219-220, 2005); (2) different derivatives of gramicidin A (Lindholm-Sethson et al. in Langmuir 24:5029-5032, 2007), and (3) an antimicrobial peptide (Ringstad et al. in Langmuir 24:208-216, 2008).
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| 8. |
- Lindholm-Sethson, Britta, et al.
(author)
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Gramicidin A interaction at a dioleoyl phosphatidylcholine monolayer on a mercury drop electrode
- 2003
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In: Analytical and Bioanalytical Chemistry. - : Springer Science and Business Media LLC. - 1618-2642. ; 375:3, s. 350-5
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Journal article (peer-reviewed)abstract
- A biosensor where the sensing surface is a fluid dioleyl phosphatidylcholine monolayer (DOPC) deposited on a mercury drop was used. The lipid monolayer was held in 0.1 M NaCl and a concentration of gramicidin A in the range 0-12 nM was used. Electrochemical impedance spectroscopy in the frequency range 0.1-65 kHz was employed to investigate how the defect-free monolayer responds to interactions of gramicidin A in solution.The data was analyzed both with multivariate data analysis and classical electrochemical methods. The principal component analysis of the resulting impedance spectra gave a linear dependence on the concentration of gramicidin A. An increasing permittivity was observed in the low-frequency regime with increasing concentration of gramicidin A in solution.
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| 9. |
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| 10. |
- Lindqvist, Josefina, et al.
(author)
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Intelligent Dual-Responsive Cellulose Surfaces via Surface-Initiated ATRP
- 2008
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In: Biomacromolecules. - : American Chemical Society (ACS). - 1525-7797 .- 1526-4602. ; 9:8, s. 2139-2145
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Journal article (peer-reviewed)abstract
- Novel thermo-responsive cellulose (filter paper) surfaces of N-isopropylacrylamide (NIPAAm) and pH-responsive cellulose surfaces of 4-vinylpyridine (4VP) have been achieved via surface-initiated ATRP. Dual-responsive (pH and temperature) cellulose surfaces were also obtained through the synthesis of block-copolymer brushes of PNIPAAm and P4VP. With changes in pH and temperature, these "intelligent" surfaces showed a reversible response to both individual triggers, as indicated by the changes in wettability from highly hydrophilic to highly hydrophobic observed by water contact angle measurements. Adjusting the composition of the grafted block-copolymer brushes allowed for further tuning of the wettability of these "intelligent" cellulose surfaces.
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