| 1. |
|
|
| 2. |
- Fager, Cecilia, 1990, et al.
(författare)
-
3D high spatial resolution visualisation and quantification of interconnectivity in polymer films
- 2020
-
Ingår i: International Journal of Pharmaceutics. - : Elsevier B.V.. - 0378-5173 .- 1873-3476. ; 587
-
Tidskriftsartikel (refereegranskat)abstract
- A porous network acts as transport paths for drugs through films for controlled drug release. The interconnectivity of the network strongly influences the transport properties. It is therefore important to quantify the interconnectivity and correlate it to transport properties for control and design of new films. This work presents a novel method for 3D visualisation and analysis of interconnectivity. High spatial resolution 3D data on porous polymer films for controlled drug release has been acquired using a focused ion beam (FIB) combined with a scanning electron microscope (SEM). The data analysis method enables visualisation of pore paths starting at a chosen inlet pore, dividing them into groups by length, enabling a more detailed quantification and visualisation. The method also enables identification of central features of the porous network by quantification of channels where pore paths coincide. The method was applied to FIB-SEM data of three leached ethyl cellulose (EC)/hydroxypropyl cellulose (HPC) films with different weight percentages. The results from the analysis were consistent with the experimentally measured release properties of the films. The interconnectivity and porosity increase with increasing amount of HPC. The bottleneck effect was strong in the leached film with lowest porosity.
|
|
| 3. |
- Fager, Cecilia, 1990, et al.
(författare)
-
Correlating 3D porous structure in polymer films with mass transport properties using FIB-SEM tomography
- 2021
-
Ingår i: Chemical Engineering Science: X. - : Elsevier BV. - 2590-1400. ; 12
-
Tidskriftsartikel (refereegranskat)abstract
- Porous polymer coatings are used to control drug release from pharmaceutical products. The coating covers a drug core and depending on the porous structure, different drug release rates are obtained. This work presents mass transport simulations performed on porous ethyl cellulose films with different porosities. The simulations were performed on high spatial resolution 3D data obtained using a focused ion beam scanning electron microscope. The effective diffusion coefficient of water was determined using a diffusion chamber. Lattice Boltzmann simulations were used to simulate water diffusion in the 3D data. The simulated coefficient was in good agreement with the measured coefficient. From the results it was concluded that the tortuosity and constrictivity of the porous network increase with decreasing amount of added hydroxypropyl cellulose, resulting in a sharp decrease in effective diffusion. This work shows that high spatial resolution 3D data is necessary, and that 2D data is insufficient, in order to predict diffusion through the porous structure with high accuracy.
|
|
| 4. |
- Fager, Cecilia, 1990, et al.
(författare)
-
Optimization of FIB-SEM Tomography and Reconstruction for Soft, Porous, and Poorly Conducting Materials
- 2020
-
Ingår i: Microscopy and Microanalysis. - 1431-9276 .- 1435-8115. ; 26:4, s. 837-845
-
Tidskriftsartikel (refereegranskat)abstract
- Tomography using a focused ion beam (FIB) combined with a scanning electron microscope (SEM) is well-established for a wide range of conducting materials. However, performing FIB-SEM tomography on ion- and electron-beam-sensitive materials as well as poorly conducting soft materials remains challenging. Some common challenges include cross-sectioning artifacts, shadowing effects, and charging. Fully dense materials provide a planar cross section, whereas pores also expose subsurface areas of the planar cross-section surface. The image intensity of the subsurface areas gives rise to overlap between the grayscale intensity levels of the solid and pore areas, which complicates image processing and segmentation for three-dimensional (3D) reconstruction. To avoid the introduction of artifacts, the goal is to examine porous and poorly conducting soft materials as close as possible to their original state. This work presents a protocol for the optimization of FIB-SEM tomography parameters for porous and poorly conducting soft materials. The protocol reduces cross-sectioning artifacts, charging, and eliminates shadowing effects. In addition, it handles the subsurface and grayscale intensity overlap problems in image segmentation. The protocol was evaluated on porous polymer films which have both poor conductivity and pores. 3D reconstructions, with automated data segmentation, from three films with different porosities were successfully obtained.
|
|
| 5. |
|
|
| 6. |
- Hagberg, Cecilia, et al.
(författare)
-
Lättviktsgrindar av höghållfast stål för säkrare djurhantering och arbetsmiljö
- 2021
-
Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Lightweight gates of high-strength steel for improved worker safety and cattle handling This report presents the work with developing a lightweight gate of high-strength steel for the handling of cattle. The project was conducted as a European Innovation Partnership (EIP) project. The project group consisted of co-workers from the unit of Agriculture and Horticulture and the unit of Process and Environmental Engineering at Research Institutes of Sweden (RISE Jordbruk och trädgård och RISE Kretsloppsteknik), Parsteel AB (former Nilssons Plåtindustri AB), SSAB EMEA AB, Sophie Atkinson at Smart Animal Handling, Swedish University of Agricultural Sciences (SLU) in Skara and the cattle farmer Lars Olsson. The main objectives of the project were to develop a lightweight gate weighing at least 50% less and being three times as strong as a traditional gate for cattle handling. The main motive was to improve the ergonomic conditions and working environment for the animal handlers. Additionally, for the safety of both animals and handlers, the gate must withstand the loads from cattle. Other objectives were to design and construct a gate that does not exceed the price of a high-quality gate and not contribute to increased negative environmental impact. A lightweight gate can be made of various materials such as plastic, fiberglass or steel. Regarding the project group's participants and their competencies, in addition to the numerous requirements placed on a lightweight gate, the choice fell on high-strength steel. High-strength steel is characterized by having high yield strengths, up to 1300 MPa, in comparison with traditional construction steel with yield strength of 355 MPa. For the specific lightweight gate, steel pipes with a yield strength of approximately 750 MPa were chosen. These pipes are mainly used in the automotive and engine industry, where high demands are placed on strength while at the same time a light construction is desired. The gate itself was designed during the project and several details were examined and developed in regard to functionality and safety for both cattle and handlers. The work environment legislation states that gates must be dimensioned and anchored so that the animals cannot break out (AFS 2008:17). The gates must also not pose a risk of injury to the cattle. In order to work safely with cattle, knowledge of cattle behavior is essential and consequently the report contains a chapter describing cattle senses and behavior. Both the lightweight gates and the handling system, built up by the gates, must be adapted to the cattle. In the project, the bud box handling system was tested. The handling system was originally developed to make use of the behavioral characteristics of cattle to encourage forward movement in the desired direction. In the project the handling system's functionality and safety, by using lightweight gates and additional equipment and components, were further designed. The handling system was tested in two groups of heifers at the SLU Götala Beef and Lamb Research Centre. The lightweight gates were also tested in a dairy herd and a beef herd, while hoof trimming, and at a small-scale abattoir. Generally, the light weight of the gates was considered an advantage as the handling of the gates is simplified also resulting in more frequent use of the gates, increasing safety for both animals and humans. During the project, several strength tests were performed by building unique test rigs. In one test rig, the weld of the pipes of the lightweight gate was tested. In another test rig, the strength of lightweight gates, compared with traditional gates on the market, were tested. The outcome of the tests confirmed the original aim of the project, a lightweight gate made of high-strength steel, about 50% lighter and at least three times as strong as traditional gates, had been developed and designed during the project period.
|
|
| 7. |
- Jönsson, Göran B, et al.
(författare)
-
The retinoblastoma gene undergoes rearrangements in BRCA1-deficient basal-like breast cancer.
- 2012
-
Ingår i: Cancer Research. - 1538-7445. ; 72:16, s. 4028-4036
-
Tidskriftsartikel (refereegranskat)abstract
- Breast tumors from BRCA1 germ line mutation carriers typically exhibit features of the basal-like molecular subtype. However, the specific genes recurrently mutated as a consequence of BRCA1 dysfunction have not been fully elucidated. In this study, we utilized gene expression profiling to molecularly subtype 577 breast tumors, including 72 breast tumors from BRCA1/2 mutation carriers. Focusing on the RB1 locus, we analyzed 33 BRCA1-mutated, 36 BRCA2-mutated and 48 non-BRCA1/2-mutated breast tumors using a custom-designed high-density oligomicroarray covering the RB1 gene. We found a strong association between the basal-like subtype and BRCA1-mutated breast tumors and the luminal B subtype and BRCA2-mutated breast tumors. RB1 was identified as a major target for genomic disruption in tumors arising in BRCA1 mutation carriers and in sporadic tumors with BRCA1 promoter-methylation, but rarely in other breast cancers. Homozygous deletions, intragenic breaks, or microdeletions were found in 33% of BRCA1-mutant tumors, 36% of BRCA1 promoter-methylated basal-like tumors, 13% of non-BRCA1 deficient basal-like tumors, and 3% of BRCA2-mutated tumors. In conclusion, RB1 was frequently inactivated by gross gene disruption in BRCA1-related hereditary breast cancer and BRCA1-methylated sporadic basal-like breast cancer, but rarely in BRCA2-hereditary breast cancer and non-BRCA1-deficient sporadic breast cancers. Together, our findings demonstrate the existence of genetic heterogeneity within the basal-like breast cancer subtype that is based upon BRCA1-status.
|
|
| 8. |
|
|
| 9. |
|
|
| 10. |
- Lindblom, Cecilia, Universitetslektor, 1979-, et al.
(författare)
-
Challenges to Interdisciplinary teaching for nutrition and health in Swedish compulsory schools
- 2020
-
Ingår i: International Journal of Home Economics. - Bonn : International Federation for Home Economics. - 1999-561X. ; 13:1, s. 15-29
-
Tidskriftsartikel (refereegranskat)abstract
- The Swedish National Agency for Education states that educational provision should involve pupil opportunities for interdisciplinary work and the experience of learning in different ways. In this context, the current study aimed to explore the actual operation of interdisciplinary teaching (IDT) in Swedish compulsory schools, i.e. from preschool (6 years) to grade 9 (16 years) regarding nutrition and health. To investigate this, two web-based nationwide questionnaires were sent out in 2014 to compulsory schools in Sweden. One questionnaire was aimed at teachers in five subjects: Home and Consumer Studies (HCS), Natural Science Subjects (NSS) (Biology, Chemistry, Physics), and Physical Education and Health (PEH). The second questionnaire was for school principals. A total of 388 teachers and 216 principals answered the respective questionnaire. The study showed that 40% of the teachers and 59% of the principals reported that their school worked in an interdisciplinary way regarding nutrition and health education. Practical scheduling problems and a lack of time for planning were seen as the main barriers by both teachers and principals, but to a much larger extent by teachers. A prerequisite for successful IDT is that teachers have a chance to meet and plan, and this study indicates that frame factors have a critical impact on what is possible regarding IDT in Swedish schools. It is crucial that principals appreciate their part in facilitating IDT. Increased interdisciplinary teaching for nutrition and health (IDT-NH) might increase school potential for the better integration of knowledge and understanding about the importance of lifestyle for health, the environment and society.
|
|
