| 1. |
- Jakobsson, Gunnar
(författare)
-
On Complications to Cataract Surgery
- 2015
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Cataract surgery, meaning exchange of the opaque lens in the eye with an artificial lens, is nowadays one of the most successful surgical procedures ever known. It is also the most frequent surgery performed in the Western world. In Sweden alone, more than 100,000 cataract operations are performed annually. Severe complications are rare, occurring only in a few percent of the patients, but owing to the large number of surgeries even infrequent complications amount to a substantial number of patients. The aim of this thesis was to study two different complications – retinal detachment (RD) and late artificial intraocular lens (IOL) dislocation – and to analyze inflammatory mediators in the vitreous of phakic (no previous cataract surgery) and pseudophakic (previous cataract surgery with IOL) eyes. Methods: Paper I is a multicenter case-control study evaluating the incidence and outcome of RD in eyes experiencing a perioperative complication with rupture of the lens capsule. Paper II and III are studies on patients with late IOL dislocation with a retrospective and a prospective observational design respectively. In paper IV the level of inflammatory immune mediators was measured in vitreous from phakic and pseudophakic patients. Results: The risk of developing RD after cataract surgery with a capsular rupture increased more than ten fold during the three-year follow-up period. Multivariate analyzes showed an odds ratio (OR) of 14.8 for RD. Additional risk factors were male sex (OR = 8.5) and lens remnants in the vitreous (OR = 14.4). The majority (62%) of eyes experiencing RD had a poor visual outcome of 0.1 or less. In patients with late IOL dislocation the median time to repositioning surgery was 6.5 years. This interval was significantly shorter in older patients and in eyes with perioperative complications (3.2 years). Pseudoexfoliations (PXF) were present in 60% of the patients and 36% had glaucoma. The annual incidence of late IOL dislocation in the pseudophakic population was calculated to 0.05%. Repositioning of the dislocated IOL with scleral sutures and a high frequency of pars plana vitrectomy procedures resulted in few complications and 59% of the patients obtained a visual acuity of ≥0.5. In patients with IOL dislocation and glaucoma, improved intraocular pressure (IOP) control was observed. Vitreous samples revealed significantly higher and sustained levels of immune mediators in pseudophakic eyes compared to phakic eyes. Conclusions: RD following capsule rupture results in profound visual loss in the majority of patients. Late IOL dislocation requiring reconstructive surgery occurs annually in 1/2000 pseudophakic patients. Risk factors are initially complicated cataract surgery, PXF and old age. The prognosis after repositioning surgery is good and IOP control in glaucoma patients is improved. Cataract surgery and pseudophakia induce elevated and sustained levels of inflammatory immune mediators in the vitreous.
|
|
| 2. |
- Vitt, Anton
(författare)
-
Clinical, microbiological and immunological effects of antiseptics in periodontal treatment
- 2020
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Periodontal diseases are characterized by high prevalence in many populations and the chronic and progressive course of the disease. A fundamental stage of treatment is mechanical debridement of the tooth surface. During debridement antimicrobial agents may be applied as adjunctive intrasulcular irrigants. There is lack of consensus as to the optimal type of antimicrobial therapy in treatment of periodontal disease. A new antiseptic solution, containing polyhexa- methylene guanidine phosphate (PHMG-P) as the active ingredient, has recently been marketed as an adjunctive irrigant in periodontal treatment. Since there is no sufficient history of oral application of this antiseptic, few scientific is evidence available to support its efficiency. The aim of the thesis was to investigate the effects of antiseptics on bacteria and human cells and to evaluate the efficacy of adjunctive (PHMG-P) irrigation of periodontal pockets during scaling and root planing (SRP). Clinical, microbiological and immunological parameters were evaluated. In the initial in vitro study (Paper I), the anti-microbial activity of antiseptics was investigated. Using a quantitative suspension method, PHMG-P was com- pared with chlorhexidine (CHX) on standard quality control bacterial strains of Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa and Candida albicans, the periopathogens Porphyromonas gingivalis, Aggregatibacter actino- mycetemcomitans and also Streptococcus mutans, and Lactobacillus acidophilus, microorganisms implicated in dental caries. In Paper II the cytotoxic and immune- modulatory effects of the antiseptics on human gingival fibroblasts were determined. In Paper III the clinical efficacy of intrasulcular irrigation with PHMG-P and CHX as adjunctives to periodontal debridement in patients with severe chronic peri- odontitis was investigated. Finally, Paper IV evaluated the impact of the antiseptics on microflora and cytokine profiles in periodontal pockets undergoing treatment. Papers I and II showed that PHMG-P had anti-microbial activity and cytotoxic- ity and expressed anti-inflammatory properties. In Paper III it was shown that adjunctive PHMG-P irrigation improved the short-term outcome of SRP, but had no significant long-term effect on the mean pocket depth. Paper IV showed that although antiseptic treatment caused changes in biomarkers and bacterial counts, no differences in these parameters were observed between the treatment groups at any of the follow-up examinations. Conclusion: In the in vitro studies, PHMG-P showed pronounced antimicrobial activity. The primary response to periodontal treatment was attributable to the mechanical debridement. The adjunctive antiseptic irrigants, applied in accord- ance with the study protocol, had only limited effects.
|
|
| 3. |
- Amavasai, Amardeep, 1988, et al.
(författare)
-
Particle Filter based on Jaya optimisation for Bayesian updating of nonlinear models
- 2024
-
Ingår i: Applied Soft Computing Journal. - 1568-4946. ; 158
-
Tidskriftsartikel (refereegranskat)abstract
- Particle filter (PF) is a powerful and commonly used filtering technique based on Sequential Monte Carlo framework. The main challenge in using PF for nonlinear state and parameter estimation is the degeneracy of particles. Although resampling techniques can solve this to some extent, it would still result in particle impoverishment when a limited number of particles are used thereby affecting the accuracy. Hence, a hybrid metaheuristic optimisation algorithm that combines the PF with Jaya optimisation, (PF-JAYA) has been proposed and implemented for joint state and parameter estimation for geotechnical engineering problems. The performance of PF-JAYA has been compared against the traditional Particle Filter with Sampling Importance Resampling (PF-SIR) technique. The synthetic examples show that PF-JAYA outperforms PF-SIR in terms of accuracy, rate of convergence, parameter identification and particle diversity. Furthermore, the performance of PF-JAYA is independent of the choice of prior distribution and due to its superior convergence proves to be efficient when working with sparse monitoring information. The performance of PF-JAYA on Bayesian updating of state and parameters of an elastoplastic model for a synthetic embankment case has also been evaluated where, along with PF-SIR, the Ensemble Kalman Filter (EnKF) is also chosen for comparison. Finally a further evaluation using the Lorenz ‘63 model, shows the superior performance of PF-JAYA in terms of accuracy and precision over the classical Data Assimilation techniques.
|
|
| 4. |
- Amavasai, Amardeep, 1988, et al.
(författare)
-
Towards consistent numerical analyses of embankments on soft soils
- 2022
-
Ingår i: European Journal of Environmental and Civil Engineering. - : Informa UK Limited. - 2116-7214 .- 1964-8189. ; 26:7, s. 2616 -2634
-
Tidskriftsartikel (refereegranskat)abstract
- A consistent automated parameter derivation method for an advanced constitutive model, Creep-SCLAY1S, which considers anisotropy, structure and creep in soft soil is presented. The algorithms are implemented in a general purpose numerical framework and are robust for noisy data. The accuracy of the derived parameters are benchmarked against a well known test case: the Haarajoki test embankment. The results show that using the proposed methodology, a consistent parameter set is derived that enables accurate laboratory data and boundary value level simulations with limited to no major user intervention. The only remaining user input relates to the adjustment of the pre-consolidation pressure with 3 kPa. This difference between the laboratory and boundary value simulations is attributed mainly due to somewhat low quality of the samples.
|
|
| 5. |
- Cabello, Adan
(författare)
-
The Contextual Computer
- 2013
-
Ingår i: Computable Universe. - Singapore : World Scientific Publishing. - 9789814374309 - 9789814374293 ; , s. 595-604
-
Bokkapitel (refereegranskat)abstract
- What kind of computer is the universe? Here we present three results. The first is a consequence of the Kochen-Specker theorem: If the predictions of quantum mechanics are correct, then the universe cannot be a non-contextual computer. We then show that, if we assume that the density of memory is bounded, then the universe cannot be a classical contextual computer. The third result singles out the universe among all possible contextual computers by exploiting a curious connection with graph theory: In the universe, the maximal contextuality of a set of propositions is given by the Lovasz number of the graph representing their mutual exclusiveness.
|
|
| 6. |
- Nguyen, Linh Anh, et al.
(författare)
-
A Horn Fragment with PTime Data Complexity of Regular Description Logic with Inverse
- 2014
-
Ingår i: VNU Journal of Computer Science and Communication Engineering. - Vietnam National University, Hanoi, Vietnam. - 0866-8612. ; 30:4, s. 14-28
-
Tidskriftsartikel (refereegranskat)abstract
- We study a Horn fragment called Horn-RegI of the regular description logic with inverse RegI, which extends the description logic ALC with inverse roles and regular role inclusion axioms characterized by finite automata. In contrast to the well-known Horn fragments EL, DL-Lite, DLP, Horn-SHIQ and Horn-SROIQ of description logics, Horn-RegI allows a form of the concept constructor "universal restriction" to appear at the left hand side of terminological inclusion axioms, while still has PTIME data complexity. Namely, a universal restriction can be used in such places in conjunction with the corresponding existential restriction. We provide an algorithm with PTIME data complexity for checking satisfiability of Horn-RegI knowledge bases.
|
|
| 7. |
|
|
| 8. |
- Stavrou, N., et al.
(författare)
-
The effect of moderate exercise on emotional state during hypoxic confinement
- 2014
-
Konferensbidrag (refereegranskat)abstract
- Normobaric hypoxic training is routinely used by athletes to improve their altitude and sea level performance. A multitude of schedules are being used, combining inactive and active exposure to hypoxic environments. The live high – train low regimen, in particular, requires athletes to spend a majority of time confined to a normobaric hypoxic environment. Despite the known positive effects of hypoxic training on physical performance, there is a lack of information regarding the influence of hypoxia and physical activity on emotional state. This was the principal aim of the current study. Specifically, we tested the hypothesis that physical activity alleviates the hypoxia-induced increases in negative feelings. Fourteen male subjects were confined to 10-day continuous hypoxia (fraction of inspired O2=0.139±0.003; 4000m simulated altitude). Subjects were assigned to either the Hypoxic Confinement: Exercise group (HCE: N=8, two 1 hour training sessions/day at 50% hypoxic peak power output) or the Hypoxic Confinement: Sedentary group (HCS: N=6, no exercise). Subjects were administered the Profile of Mood States (POMS) and the Positive and Negative Affect Schedule (PANAS) tests two days prior to hypoxic confinement (D-2), on days 3 (D3), 7 (D7) and 10 (D10) of hypoxic confinement and on the first day of recovery following the confinement period (R+1). The ANOVA repeated measure of the PANAS determined that positive affect differed significantly across the five time measures between HCS and HCE. Bonferroni post hoc analysis revealed that the HCS group elicited a reduction of positive emotion from D-2 to D7 and to D10 with a concomitant increase of negative emotion from D-2 to D10. In addition, an increase of tension from D-2 to D7 and to D10 was revealed in HCS, whereas an increase in tension on D10 was indicated in HCE. Based on the POMS, an increase of depression from D-2 to D7 was found in HCS, whereas no differences were revealed in HCE, among the five time measures. Finally, no significant differences revealed between D10 and R+1 in the PANAS or POMS in either HCS or HCE. The results indicate that in sedentary subjects hypoxic confinement increases tension and negative emotions, and decreases vigor and positive emotions. It is concluded that hypoxia negatively affects the emotional state, but that increasing the level of physical activity ameliorates such feelings.
|
|
| 9. |
|
|
| 10. |
|
|
