Exploring the precision of femtosecond laser-assisted descemetorhexis in Descemet membrane endothelial keratoplasty

Objective Descemet membrane endothelial keratoplasty (DMEK) remains a challenging technique. We compare the precision of femtosecond laser-assisted DMEK to manual DMEK. Methods and Analysis A manual descemetorhexis (DR) of 8 mm diameter was compared with a femtosecond laser-assisted DR of the same diameter (femto-DR) in 22 pseudophakic patients requiring DMEK. We used OCT images with a centred xy-diagram to measure the postoperative precision of the DR and the amount of endothelial denuded area. Endothelial cell loss (ECL) and best corrected visual acuity were measured 3 months after surgery. Results In the manual group, the median error of the DR was 7% (range 3%-16%) in the x-diameter and 8% (range 2%-17%) in the y-diameter. In the femto group, the median error in the respective x and y-diameters was 1% (range 0.4%-3%) and 1% (range 0.006%-2.5%), smaller than in the manual group (p=0.001). Endothelial denuded areas were larger in the manual group (11.6 mm(2), range 7.6-18 mm(2)) than in the femto group (2.5 mm(2), range 1.25.9 mm(2)) (p<0.001). The ECL was 21% (range 5%-78%) in the manual DR and 17% (range 6%-38%) in the femto-DR group (p=0.351). The median visual acuity increased from 0.4 logMAR (range 0.6-0.4 logMAR) in both groups to 0.1 logMAR (range 0.4-0 logMAR) in the manual group and to 0.1 logMAR (range 0.3-0 logMAR) in the femto group (p=0.461). Three rebubblings were required in the manual group, whereas the femto group required only one. Conclusion The higher precision of the femto-DR bears the potential to improve DMEK surgery

Pseudophakic corneal donor tissue in Descemet membrane endothelial keratoplasty (DMEK): implications for cornea banks and surgeons

Objective: Increasingly, cornea banks are recovering donor tissue from pseudophakic donors. Little is known about their suitability for Descemet membrane endothelial keratoplasty (DMEK) surgery in terms of endothelial cell density (ECD) and preparation failure. Methods and Analysis: We explored ECD during donor tissue preparation in 2076 grafts. Preparation failure was analysed in 1028 grafts used in DMEK surgery at our clinic. To monitor ECD and functional results, we matched 86 DMEK patients who received pseudophakic donor grafts with similar recipients of phakic donor grafts and followed them up for 36 months. Results: At recovery, mean ECD in pseudophakic donor grafts was 2193 cells/mm2 (SD 28.7) and 2364 cells/mm2 (SD 15.7) in phakic donor grafts (p<0.001). After cultivation, the difference increased as pseudophakic donor grafts lost 14% of ECD while phakic lost only 6% (p<0.001). At transplantation, mean ECD in pseudophakic donor grafts was 2272 cells/mm2 (SD 250) and 2370 cells/mm2 (SD 204) in phakic donor grafts (p<0.001). After transplantation, the difference in ECD increased as pseudophakic donor grafts lost 27.7% of ECD while phakic donor grafts lost only 13.3% (p<0.001). The risk of preparation failure in pseudophakic donor grafts was higher than in phakic donor grafts (OR 4.75, 95% CI 1.78 to 12.67, p=0.02). Visual acuity increased in both groups similarly. Conclusions: Pseudophakic donor grafts have a lower ECD, are more prone to endothelial cell loss during recovery and surgery and are associated with a higher risk of preparation failure. Cornea banks and surgeons should consider this in the planning of graft preparation and transplantation

Graft failure rate and complications after Descemet membrane endothelial keratoplasty in eyes with pre-existing glaucoma

Purpose: To evaluate the outcome of Descemet Membrane Endothelial Keratoplasty (DMEK) in eyes with pre-existing glaucoma. Design: In this retrospective, observational case series we included data of 150 consecutive DMEKs in eyes with pre-existing glaucoma of 150 patients after excluding data of the second treated eye of each patient and of re-DMEKs during follow-up. Cumulative incidences of IOP elevation (IOP > 21 mmHg or >= 10 mmHg increase in IOP from preoperative value), post-DMEK glaucoma (need of an additional intervention due to worsening of the IOP), graft rejection, and graft failure rate were analyzed using Kaplan-Meier survival analysis. COX regression analysis was used to evaluate independent risk factors. Results: The 36-month cumulative incidence of IOP elevation was 53.5% [95 CI 43.5-63.5%] and of post-DMEK glaucoma 36.3% [95 CI 26.3-46.3%]. Graft rejection occurred with a 36-month cumulative incidence of 9.2% [CI 95% 2.3-16.1]. None of the analyzed risk factors increased the risk for the development of graft rejection. The 36-month cumulative incidence of graft failure was 16.6% [CI 95% 8.4-24.8]. Independent risk factors for graft failure were the indication for DMEK "status after graft failure" (n = 16) compared to Fuchs' dystrophy (n = 74) (p = 0.045, HR 8.511 [CI 95% 1.054-68.756]) and pre-existing filtrating surgery via glaucoma drainage device (GDD) (n = 10) compared to no surgery/iridectomy (n = 109) (p = 0.014, HR 6.273 [CI 95% 1.456-27.031]). Conclusion: The risks of postoperative complications (IOP elevation, post-DMEK glaucoma, graft rejection, and graft failure) in patients with pre-existing glaucoma are high. In particular, pre-existing filtrating surgery via GDD implantation-but not trabeculectomy-and DMEK after graft failure increase the risk of graft failure

Genomic and strontium isotope variation reveal immigration patterns in a viking age town

Abstract: The impact of human mobility on the northern Euro- pean urban populations during the Viking and Early Middle Ages and its repercussions in Scandinavia it- self are still largely unexplored. Our study of the de- mographics in the final phase of the Viking era is the first comprehensive multidisciplinary investiga- tion that includes genetics, isotopes, archaeology, and osteology on a larger scale. This early Christian dataset is particularly important as the earlier com- mon pagan burial tradition during the Iron Age was cremation, hindering large-scale DNA analyses. We present genome-wide sequence data from 23 indi- viduals from the 10th to 12th century Swedish town of Sigtuna. The data revealed high genetic diversity among the early urban residents. The observed vari- ation exceeds the genetic diversity in distinct mod- ern-day and Iron Age groups of central and northern Europe. Strontium isotope data suggest mixed local and non-local origin of the townspeople..

Sweet spot of energy-level alignment in hyperfluorescent organic light-emitting diodes

We investigate loss mechanisms in hyperfluorescent organic light-emitting diodes (HF-OLEDs) with the emissive layer consisting of a host, a thermally activated delayed fluorescence (TADF) sensitizer, and a terminal emitter. We focus on understanding how the relative energy levels between the TADF sensitizer and terminal emitter impact device efficiency and roll-off through the formation and subsequent dissociation of an intermolecular state. Using a combined experimental and kinetic Monte Carlo (KMC) simulation-based approach, we analyzed HF-OLEDs incorporating either multiresonant (MR) or fluorescent (non-MR) terminal emitters. We find that selecting terminal emitters with ionization potential and electron affinity values that position the intermolecular state at least 150 meV above the singlet energy of the terminal emitter effectively suppresses the losses due to exciton dissociation. Furthermore, we show that using the MR emitter, which exhibits reverse intersystem crossing (RISC), significantly reduces residual triplet-related losses compared with the non-MR emitter. This further mitigates exciton dissociation losses, thereby improving the external quantum efficiency (EQE). These findings provide clear guidelines for selecting terminal emitters and optimizing energy level alignment to address intermolecular state-related loss pathways in HF-OLEDs

A Computational Statistics Approach to Evaluate Blood Biomarkers for Breast Cancer Risk Stratification

Breast cancer is the second leading cause of cancer mortality among women. Mammography and tumor biopsy followed by histopathological analysis are the current methods to diagnose breast cancer. Mammography does not detect all breast tumor subtypes, especially those that arise in younger women or women with dense breast tissue, and are more aggressive. There is an urgent need to find circulating prognostic molecules and liquid biopsy methods for breast cancer diagnosis and reducing the mortality rate. In this study, we systematically evaluated metabolites and proteins in blood to develop a pipeline to identify potential circulating biomarkers for breast cancer risk. Our aim is to identify a group of molecules to be used in the design of portable and low-cost biomarker detection devices. We obtained plasma samples from women who are cancer free (healthy) and women who were cancer free at the time of blood collection but developed breast cancer later (susceptible). We extracted potential prognostic biomarkers for breast cancer risk from plasma metabolomics and proteomics data using statistical and discriminative power analyses. We pre-processed the data to ensure the quality of subsequent analyses, and used two main feature selection methods to determine the importance of each molecule. After further feature elimination based on pairwise dependencies, we measured the performance of logistic regression classifier on the remaining molecules and compared their biological relevance. We identified six signatures that predicted breast cancer risk with different specificity and selectivity. The best performing signature had 13 factors. We validated the difference in level of one of the biomarkers, SCF/KITLG, in plasma from healthy and susceptible individuals. These biomarkers will be used to develop low-cost liquid biopsy methods toward early identification of breast cancer risk and hence decreased mortality. Our findings provide the knowledge basis needed to proceed in this direction

Ekologisk produktion som del av svensk livsmedelsberedskap

Den ekologiska produktionen i Sverige och internationellt har under de senaste 40 åren bidragit till att öka kunskapen om metoder och processer för livsmedelsproduktion utan bekämpningsmedel och mineralgödsel. Grunden för ekologisk produktion bygger på principer om hälsa, ekologi, rättvisa och omsorg. Principer som även är avsedda att inspirera och förbättra hela jordbrukssektorn. Utvärdering av forskning inom ekologisk produktion, både i Sverige och i Danmark, har pekat på att forskningen har bidragit till kunskap och inspiration för en mer hållbar användning av mark och andra naturresurser inom hela lantbruket. Det har fastslagits i den svenska Livsmedelsstrategin 2.0 att “ekologisk produktion kan driva utvecklingen av både maskiner och odlingsmetoder för minskad resursanvändning och ökad avkastning, vilket också kan inspirera den konventionella odlingen”

Visual outcomes and complications following posterior iris-claw aphakic intraocular lens implantation combined with penetrating keratoplasty

Abstract Background To evaluate the indication, visual outcome, and complication rate after implantation of a posterior iris-claw aphakic intraocular lens (IOL) during penetrating keratoplasty. Methods This retrospective study comprised 23 eyes (23 patients) without adequate capsule support undergoing posterior iris-claw aphakic IOL implantation (Verisyse™/ Artisan®) during penetrating keratoplasty between 2005 and 2010. Mean follow-up was 18 months (range from 12 to 37 months). Results The IOLs were inserted during an IOL exchange in 17 eyes and as a secondary procedure in six aphakic eyes. Pseudophakic bullous keratopathy with corneal scar after anterior chamber intraocular lens (ACIOL) was the main indication for penetrating keratoplasty in 16 eyes (69.6 %). The final corrected distance visual acuity (CDVA) in logMAR (mean 1.0 ± 0.46) improved significantly (p &lt; 0.05) compared to the preoperative CDVA (mean 1.8± 0.73). Twenty eyes (86.9 %) had a final visual acuity in logMAR better than the pre-operative CDVA. The mean postoperative IOP 16.3 mmHg±4.0 was not significantly (p &gt; 0.05) higher compared to the preoperative IOP 15.6 mmHg±5.1. Complications included slight temporary pupil ovalization in three eyes (13.0 %) and iris-claw IOL sublocation in three eyes (13.0 %); all IOLs could be easily repositioned. Cystoid macular edema occured in one eye (4.3 %) 8 weeks after primary surgery. All grafts remained clear without any sign of graft rejection. Conclusions Retropupillar iris-claw IOL during penetrating keratoplasty provides good visual outcomes with a favorable complication rate, and can be used for a wide range of indications in eyes without adequate capsule support