| 121. |
|
|
| 122. |
- Andersson Trojer, Markus, 1981, et al.
(författare)
-
Directed self-assembly of silica nanoparticles in ionic liquid-spun cellulose fibers
- 2019
-
Ingår i: Journal of Colloid and Interface Science. - : Elsevier BV. - 1095-7103 .- 0021-9797. ; 553, s. 167-176
-
Tidskriftsartikel (refereegranskat)abstract
- The application range of man-made cellulosic fibers is limited by the absence of cost- and manufacturing-efficient strategies for anisotropic hierarchical functionalization. Overcoming these bottlenecks is therefore pivotal in the pursuit of a future bio-based economy. Here, we demonstrate that colloidal silica nanoparticles (NPs), which are cheap, biocompatible and easy to chemically modify, enable the control of the cross-sectional morphology and surface topography of ionic liquid-spun cellulose fibers. These properties are tailored by the silica NPs’ surface chemistry and their entry point during the wet-spinning process (dope solution DSiO2 or coagulation bath CSiO2). For CSiO2-modified fibers, the coagulation mitigator dimethylsulphoxide allows for controlling the surface topography and the amalgamation of the silica NPs into the fiber matrix. For dope-modified fibers, we hypothesize that cellulose chains act as seeds for directed silica NP self-assembly. This results for DSiO2 in discrete micron-sized rods, homogeneously distributed throughout the fiber and for glycidoxy-surface modified DSiO2@GLYEO in nano-sized surface aggregates and a cross-sectional core-shell fiber morphology. Furthermore, the dope-modified fibers display outstanding strength and toughness, which are both characteristic features of biological biocomposites.
|
|
| 123. |
- Andersson, Yvonne, et al.
(författare)
-
Lactoferrin is responsible for the fungistatic effect of human milk.
- 2000
-
Ingår i: Early Human Development. - 0378-3782 .- 1872-6232. ; 59:2, s. 95-105
-
Tidskriftsartikel (refereegranskat)abstract
- Human milk has recognized anti-microbial effects and it has been repeatedly shown that breast-fed infants have fewer and less severe infections than formula-fed infants. While most studies have focused on anti-bacterial and anti-viral activities few have focused on the anti-fungal effect of human milk. Dermal and other infections caused by fungi are common in very low birth weight (VLBW) infants. Using a liquid culturing method and Candida albicans and Rhodotorula rubra as representative fungi, we studied the anti-fungal effect of human milk and certain human milk proteins. In vitro, human milk showed potent inhibitory effect on fungal growth. Most, if not all of this effect was caused by lactoferrin via its iron-binding capacity; increasing the iron content of the incubation medium abolished the inhibitory effect. In contrast, other human milk proteins with known or suggested anti-microbial effects rather increased fungal growth. Viability test and electron microscopy revealed that the growth inhibitory effect of human milk, i.e. mediated by lactoferrin, is fungistatic rather than fungicidal.
|
|
| 124. |
- Ankarberg-Lindgren, Carina, 1963, et al.
(författare)
-
Determination of estrone sulfate, testosterone, androstenedione, DHEAS, cortisol, cortisone, and 17 alpha-hydroxyprogesterone by LC-MS/MS in children and adolescents
- 2020
-
Ingår i: Scandinavian Journal of Clinical & Laboratory Investigation. - : Informa UK Limited. - 0036-5513 .- 1502-7686. ; 80:8, s. 672-680
-
Tidskriftsartikel (refereegranskat)abstract
- Quantitation of endogenous steroids and their precursors is essential for diagnosis of a wide range of endocrine disorders. Usually, these analyses have been carried out using immunoassays. However, immunoassays often overestimate concentrations due to assay interference by other endogenous steroids, especially for low concentrations. Mass spectrometry based methods offer superior specificity, accuracy, and sensitivity. We therefore present a liquid chromatography-tandem mass spectrometry (LC-MS/MS) method with automated sample preparation for determination of 17 alpha-hydroxyprogesterone (17OHP), cortisol, cortisone, dehydroepiandrosterone sulfate (DHEAS), androstenedione (A(4)), testosterone (T), and estrone sulfate (E1S). Samples were prepared using protein precipitation and 96-well filter plates, fully automated in a pipetting robot and analyzed by LC-MS/MS. Serum samples from 187 healthy children and adolescents aged 5-18 years were used to study hormone changes in relation to sex and pubertal stage. Lower limit of quantification for 17OHP was 0.7 nmol/L, for cortisol 11 nmol/L, for cortisone 2 nmol/L, for DHEAS 0.1 mu mol/L, and for A(4), T, and E1S, 0.2 nmol/L. This study showed a general increase in 17OHP, DHEAS, A(4), T and E1S in both genders during puberty. In boys, A(4)and T increased significantly throughout pubertal development. Girls had significantly higher A(4)and E1S concentrations, while boys had higher T concentrations. No sex- or puberty-specific differences were seen in cortisol or cortisone concentrations. To the best of our knowledge, this is the first presentation of changes in serum E1S concentrations during pubertal development in healthy children.
|
|
| 125. |
- Ankarberg-Lindgren, Carina, 1963, et al.
(författare)
-
High-sensitivity quantification of serum androstenedione, testosterone, dihydrotestosterone, estrone and estradiol by gas chromatography-tandem mass spectrometry with sex- and puberty-specific reference intervals.
- 2018
-
Ingår i: The Journal of steroid biochemistry and molecular biology. - : Elsevier BV. - 1879-1220 .- 0960-0760. ; 183, s. 116-124
-
Tidskriftsartikel (refereegranskat)abstract
- Androgen and estrogen determinations serve as important diagnostic markers in a variety of clinical conditions. However, one challenge is to enhance assay sensitivity for determination in the lowest range, such as in prepubertal children. We here present a recently developed gas chromatography-tandem mass spectrometry (GC-MS/MS) method for determination of androstenedione (A4), dihydrotestosterone (DHT), testosterone (T), estrone (E1), and estradiol (E2) in children, which we have compared with the sensitive radioimmunoassays; E2 extraction-RIA and T-RIA.Steroids were extracted in ethyl acetate n-hexane solution from serum spiked with isotopically labeled internal standard and derivatized sequentially with pentafluorobenzyl bromide, pentafluorobenzyl hydroxylamine and pentafluoropropionic acid anhydride and analyzed by GC-MS/MS using a triple quadrupole mass spectrometer operated in negative chemical ionization mode. Leftover routine samples (n=414) were used to evaluate the concordance between GC-MS/MS and RIAs and the validity of GC-MS/MS for pediatrics; of these samples, 101 were from seemingly healthy children. Pubertal stage was recorded for reference interval evaluation.Lower limit of detection for A4, T, DHT, E1, and E2 were 0.1nmol/L, 0.1nmol/L, 27pmol/L, 9pmol/L, and 2pmol/L, respectively. Good agreement was found between GC-MS/MS and T-RIA (r=0.98) as well as between GC-MS/MS and E2 extraction-RIA (r=0.98, for E2 concentrations above 14pmol/L). In boys, T and DHT increased significantly from prepuberty throughout pubertal development, and in girls the same increase was observed for E1 and E2. The greatest increase in A4 for both genders, as well as E1 and E2 in boys and T and DHT in girls, occurred in mid to late puberty.We report the development of a GC-MS/MS method sensitive enough to accurately determine serum levels of androgens and estrogens in children.
|
|
| 126. |
- Areljung, Sofie, 1983-, et al.
(författare)
-
Two children, one paper, two pencils : co-drawing science explanations
- 2022
-
Ingår i: 30<sup>th</sup> EECERA Annual Conference. ; , s. 19-19
-
Konferensbidrag (refereegranskat)abstract
- This presentation examines how children (7-9 years) negotiate scientific and visual meaning when they co-draw a science explanation. Research has shown that the process of drawing is beneficial for students’ meaning-making (Ainsworth et al. 2011) and reasoning (Tytler et al. 2019) in science. Still, previous studies predominately focus on drawing as product - not as process. As Wilmes and Siry (2021), we assume that science learning unfolds in interaction. Moreover, we employ a socio-material perspective on learning and communication (Barad 2007). Acting within a qualitative interpretative paradigm, we analyse video data from six primary school classrooms. Children’s task was to draw a science explanation in pairs. Our analysis focuses on how children engage in the drawing process. First, we excluded the video sound, focusing on whether children participate with pencil, gestures and gaze in the drawing. Second, we added sound, to identify children's discussions about visual and scientific meaning. We informed children and parents about the project before we asked for their consent to participate. During classroom visits, we recurrently asked for children’s consent prior to recording an event.Our preliminary findings show two ways of enacting the task: (1) Both children draw or (2) One child is the main “drawer”, while the other (2a) occasionally breaks in with their pencil, (2b) engages in the process with gaze and gesture but does not draw, or (2c) is not involved in the drawing process. The findings raise questions about how teacher can scaffold children to make co-drawing exercises a joint venture.
|
|
| 127. |
- Avgerinou, M. D., et al.
(författare)
-
Perceptions of qualities, roles, and functions : The online teacher perspective
- 2006
-
Ingår i: IADIS International Conference on Cognition and Exploratory Learning in Digital Age, CELDA 2006. - 9781627483315 ; , s. 35-44
-
Konferensbidrag (refereegranskat)abstract
- This qualitative study focuses on perceptions of emerging instructional roles and performance of online teachers from Sweden, and the USA. The purpose is to explore, understand, and perhaps explain how teachers experience, create, and establish their teaching personas, but also how they perceive and perform their role online. Qualitative data from participating teachers' surveys and interviews point at significant common threads running within and across the two groups despite the fact their respective academic environments are at critically different points on the online education continuum. Teachers' perceptions are in complete alignment with the four major roles of the online instructor, pedagogical, social, managerial, and technological (Bonk et al., 2001).
|
|
| 128. |
|
|
| 129. |
- Axelsson, Lena, et al.
(författare)
-
Clustering of β2-integrins on human neutrophils activates dual signaling pathways to Ptdlns 3-kinase
- 2000
-
Ingår i: Experimental Cell Research. - : Elsevier BV. - 0014-4827. ; 256:1, s. 257-263
-
Tidskriftsartikel (refereegranskat)abstract
- The β2-integrins on leukocytes can serve as a signaling unit during cell adhesion and locomotion, and to further clarify this important property we investigated the possible mechanisms of β2-integrin-induced activation of PtdIns 3-kinase. It has previously been demonstrated that clustering of β2-integrins activates p21(ras) by a tyrosine kinase-dependent pathway, and here we show that active p21(ras) interacts with its downstream target, PtdIns 3-kinase. Engagement of β2-integrins also activates the tyrosine kinases p58(c-fgr) and p59/61(hck) and causes them to associate with the p85 subunit of PtdIns 3-kinase. These findings suggest a mechanism whereby p58(c- fgr) and p59/61(hck) are directly involved in the activation of PtdIns 3- kinase. No coupling between p58(c-fgr) and p59/61(hck) could be detected; hence these kinases probably trigger independent but parallel signals to PtdIns 3-kinase. The effect of β2-integrin clustering on PtdIns 3-kinase activity was monitored as the activation of protein kinase B (PKB). Stimulation of PKB by β2-integrins was abolished by genistein and wortmannin but not by using methyl transferase inhibitors to abrogate the influence of p21(ras)-related proteins. Thus, even if PtdIns 3-kinase is not activated by p21(ras), it can maintain full enzyme activity due to the mentioned interaction with p58(c-fgr) or p59/61(hck). These tyrosine kinases apparently activate similar pathways that operate in parallel and therefore have the potential to substitute for each other in mediating adhesion and regulating cell locomotion. (C) 2000 Academic Press.
|
|
| 130. |
- Backteman, Karin, et al.
(författare)
-
Lymphocyte Subpopulations in Lymph Nodes and Peripheral Blood: A Comparison between Patients with Stable Angina and Acute Coronary Syndrome
- 2012
-
Ingår i: PLOS ONE. - : Public Library of Science. - 1932-6203. ; 7:3
-
Tidskriftsartikel (refereegranskat)abstract
- Objective: Atherosclerosis is characterized by a chronic inflammatory response involving activated T cells and impairment of natural killer (NK) cells. An increased T cell activity has been associated with plaque instability and risk of acute cardiac events. Lymphocyte analyses in blood are widely used to evaluate the immune status. However, peripheral blood contains only a minor proportion of lymphocytes. In this study, we hypothesized that thoracic lymph nodes from patients with stable angina (SA) and acute coronary syndrome (ACS) might add information to peripheral blood analyses. less thanbrgreater than less thanbrgreater thanMethods: Peripheral blood and lymph nodes were collected during coronary by-pass surgery in 13 patients with SA and 13 patients with ACS. Lymphocyte subpopulations were assessed by flow cytometry using antibodies against CD3, CD4, CD8, CD19, CD16/56, CD25, Foxp3, CD69, HLA-DR, IL-18 receptor (R) and CCR4. less thanbrgreater than less thanbrgreater thanResults: Lymph nodes revealed a lymphocyte subpopulation profile substantially differing from that in blood including a higher proportion of B cells, lower proportions of CD8(+) T cells and NK cells and a 2-fold higher CD4/CD8 ratio. CD4(+)CD69(+) cells as well as Foxp3(+) regulatory T cells were markedly enriched in lymph nodes (p andlt; 0.001) while T helper 1-like (CD4(+)IL-18R(+)) cells were more frequent in blood (p andlt; 0.001). The only significant differences between ACS and SA patients involved NK cells that were reduced in the ACS group. However, despite being reduced, the NK cell fraction in ACS patients contained a significantly higher proportion of IL-18R(+) cells compared with SA patients (p andlt; 0.05). less thanbrgreater than less thanbrgreater thanConclusion: There were several differences in lymphocyte subpopulations between blood and lymph nodes. However, the lymphocyte perturbations in peripheral blood of ACS patients compared with SA patients were not mirrored in lymph nodes. The findings indicate that lymph node analyses in multivessel coronary artery disease may not reveal any major changes in the immune response that are not detectable in blood.
|
|
