| 1. |
- Aberg, Jonas, et al.
(författare)
-
In vivo evaluation of an injectable premixed radiopaque calcium phosphate cement.
- 2011
-
Ingår i: International journal of biomaterials. - : Hindawi Limited. - 1687-8795 .- 1687-8787. ; 2011
-
Tidskriftsartikel (refereegranskat)abstract
- In this work a radiopaque premixed calcium phosphate cement (pCPC) has been developed and evaluated in vivo. Radiopacity was obtained by adding 0-40 % zirconia to the cement paste. The effects of zirconia on setting time, strength and radiopacity were evaluated. In the in vivo study a 2 by 3.5mm cylindrical defect in a rat vertebrae was filled with either the pCPC, PMMA or bone chips. Nano-SPECT CT analysis was used to monitor osteoblast activity during bone regeneration. The study showed that by adding zirconia to the cement the setting time becomes longer and the compressive strength is reduced. All materials evaluated in the in vivo study filled the bone defect and there was a strong osteoblast activity at the injury site. In spite of the osteoblast activity, PMMA blocked bone healing and the bone chips group showed minimal new bone formation. At 12 weeks the pCPC was partially resorbed and replaced by new bone with good bone ingrowth. The radiopaque pCPC may be considered to be used for minimal invasive treatment of vertebral fractures since it has good handling, radiopacity and allows healing of cancellous bone in parallel with the resorption of the cement.
|
|
| 2. |
- Andersson, Daniel, et al.
(författare)
-
Dynamic Modeling Of A Solid Oxide Fuel Cell System In Modelica
- 2010
-
Ingår i: Proceedings of the Asme 8th International Conference on Fuel Cell Science, Engineering, and Technology 2010, Vol 2. - 9780791844052 ; 2, s. 65-72
-
Konferensbidrag (refereegranskat)abstract
- In this study a dynamic model of a solid oxide fuel cell (SOFC) system has been developed. The work has been conducted in a cooperation between the Department of Energy Sciences, Lund University, and Mode Ion AB using the Modelica language and the Dymola modeling and simulation tool. Modelica is an equation based, object oriented modeling language, which promotes flexibility and reuse of code. The objective of the study is to investigate the suitability of the Modelica language for dynamic fuel cell system modeling. A cell electrolyte model including ohmic, activation and concentration irreversibilities is implemented and verified against simulations and experimental data presented in the open literature. A ID solid oxide fuel cell model is created by integrating the electrolyte model and a ID fuel flow model, which includes dynamic internal steam reforming of methane and water-gas shift reactions. Several cells are then placed with parallel flow paths and connected thermally and electrically in series. By introducing a manifold pressure drop, a stack model is created. The stack model is applied in a complete system including an autothermal reformer, a catalytic afterburner, a steam generator and heat exchangers. Four reactions are modeled in the autothermal reformer; two types of methane steam reforming, the water-gas shift reaction and total combustion of methane. The simulation results have been compared with those in the literature and it can be concluded that the models are accurate and that Dymola and Modelica are tools well suited for simulations of the transient fuel cell system behaviour.
|
|
| 3. |
- Bladh, Oscar, et al.
(författare)
-
Comparison of SARS-CoV-2 spike-specific IgA and IgG in nasal secretions, saliva and serum
- 2024
-
Ingår i: Frontiers in Immunology. - : FRONTIERS MEDIA SA. - 1664-3224. ; 15
-
Tidskriftsartikel (refereegranskat)abstract
- Introduction: Several novel vaccine platforms aim at mucosal immunity in the respiratory tract to block SARS-CoV-2 transmission. Standardized methods for mucosal sample collection and quantification of mucosal antibodies are therefore urgently needed for harmonized comparisons and interpretations across mucosal vaccine trials and real-world data. Methods: Using commercial electrochemiluminescence antibody panels, we compared SARS-CoV-2 spike-specific IgA and IgG in paired saliva, nasal secretions, and serum from 1048 healthcare workers with and without prior infection. Results: Spike-specific IgA correlated well in nasal secretions and saliva (r>0.65, p<0.0001), but the levels were more than three-fold higher in nasal secretions as compared to in saliva (p<0.01). Correlations between the total population of spike-specific IgA and spike-specific secretory IgA (SIgA) were significantly stronger (p<0.0001) in nasal secretions (r=0.96, p<0.0001) as opposed to in saliva (r=0.77, p<0.0001), and spike-specific IgA correlated stronger (p<0.0001) between serum and saliva (r=0.73, p<0.001) as opposed to between serum and nasal secretions (r=0.54, p<0.001), suggesting transudation of monomeric spike specific IgA from the circulation to saliva. Notably, spike-specific SIgA had a markedly higher SARS-CoV-2 variant cross-binding capacity as compared to the total population of spike specific IgA and IgG in both nasal secretions, saliva and serum, (all p<0.0001), which emphasizes the importance of taking potential serum derived monomeric IgA into consideration when investigating mucosal immune responses. Discussion: Taken together, although spike-specific IgA can be reliably measured in both nasal secretions and saliva, our findings imply an advantage of higher levels and likely also a larger proportion of SIgA in nasal secretions as compared to in saliva. We further corroborate the superior variant cross-binding capacity of SIgA in mucosal secretions, highlighting the potential protective benefits of a vaccine targeting the upper respiratory tract.
|
|
| 4. |
- López, Alejandro, 1983-, et al.
(författare)
-
1-Year pullout strength and degradation of ultrasound welded vs tapped craniomaxillofacial fixation screws
- 2022
-
Ingår i: Polymer testing. - : Elsevier BV. - 0142-9418 .- 1873-2348. ; 109, s. 107519-
-
Tidskriftsartikel (refereegranskat)abstract
- A knowledge on the pullout forces of degradable craniomaxillofacial screws is essential in designing pediatric cranial implants. Herein, four non-identical commercially available screws composed of different aliphatic polyesters were fixated to 3D-printed poly(L-lactide) screw hole test rig and onto a bone substitute material using manual tapping and ultrasonic welding fixation techniques. A method for mechanical testing was developed to determine and compare their quasi-static pullout strength. The degradation of the screws was followed for up to one year in three different degrading environments. While the screw size influences the initial pullout force, the degrading environment, size, and screw composition determine the degradation rate which in turn influences the pullout force over time. Given the limited availability of standard methods, the method developed herein can be used in determining the pullout forces of degradable craniomaxillofacial screws and comparing the effectiveness of various screw insertion techniques.
|
|
| 5. |
|
|
| 6. |
|
|
