160 research outputs found
Wound healing in rabbit corneas after flapless refractive lenticule extraction with a 345 nm ultraviolet femtosecond laser
Purpose
To characterize corneal wound healing in a rabbit model after flapless refractive lenticule extraction with a 345âŻnm ultraviolet femtosecond laser.
Setting
Departments of Ophthalmology and Anatomy II, University of Erlangen-NĂŒrnberg and Wavelight GmbH, Erlangen, Germany.
Design
Methods
Flapless refractive lenticule extraction was performed in 1 eye each of 20 New Zealand white rabbits (â5.0 diopters). Groups of 4 animals were euthanized after 48âŻhours, 1âŻweek, 2âŻweeks, 4âŻweeks, and 3âŻmonths, respectively. Corneal samples were prepared for histology and fluorescence microscopy. To assess corneal cell death, proliferation, and myofibroblastic transdifferentiation, terminal uridine deoxynucleotidyl nick end-labeling (TUNEL) assay as well as immunostaining for Ki67 and α-smooth muscle actin (αSMA) were performed on sagittal cryosections.
Results
Histology revealed a zone of keratocyte depletion with a thickness of approximately 50âŻÎŒm around the extraction site. At 48âŻhours, pronounced TUNEL staining of keratocytes was detected around the interface (159.9âŻcells/mmâŻÂ±âŻ18.4 [SD]), which steadily decreased to 74.9âŻÂ±âŻ19.8âŻcells/mm at 1âŻweek and 5.7âŻÂ±âŻ4.8âŻcells/mm at 2âŻweeks. Ki67 staining of keratocytes was evident at 48âŻhours (10.0âŻÂ±âŻ3.8âŻcells/mm), which then decreased at 1âŻweek (5.2âŻÂ±âŻ1.7âŻcells/mm) and 2âŻweeks (0.4âŻÂ±âŻ0.5âŻcells/mm). From 4âŻweeks onward, no TUNEL or Ki67 staining was detected. The corneal stroma was αSMA-negative at all timepoints.
Conclusion
Application of the 345âŻnm laser showed no signs of problematic repair processes in the cornea, which supports the initiation of the clinical phase
Making Good Tenure Decisions
This article provides information on decision making on the granting or denial of tenure to a faculty member. It not only has an effect on the professional life of a colleague, it has a major influence on the direction and long-term quality of the department. The tenure decision in made in the sixth year of a tenure-track faculty appointment. If a faculty member has been on the tenure track at two institutions, the years of service at the first institution usually count toward those six years, unless the faculty member and his of her current institution agree in writing at the time of appointment that they will not or that only a certain number of them will. The sooner the person is terminated or helped to find another position, the better for him or her and for the department
Pancreatogastrostomy versus pancreatojejunostomy for RECOnstruction after partial PANCreatoduodenectomy (RECOPANC): study protocol of a randomized controlled trial UTN U1111-1117-9588
BACKGROUND: Pancreatoduodenectomy is one of the most complex abdominal operations, usually performed for tumors of the periampullary region and chronic pancreatitis. Leakage of pancreatic juice from the pancreatoenteric anastomosis, called postoperative pancreatic fistula, is the most prominent postoperative complication. Retrospective studies show a significant reduction of fistula rates with pancreatogastrostomy as compared to pancreatojejunostomy, the most frequently employed method of pancreatoenterostomy. Most single-center prospective trials, however, have not validated this finding. A large multicenter trial is needed for clarification. METHODS/DESIGN: RECOPANC is a prospective, randomized, controlled multicenter trial with two treatment arms, pancreatogastrostomy versus pancreatojejunostomy. The trial hypothesis is that postoperative pancreatic fistula rate is lower after pancreatogastrostomy when compared to pancreatojejunostomy. Fourteen academic centers for pancreatic surgery will participate to allocate 360 patients to the trial. The duration of the entire trial is four years including prearrangement and analyses. DISCUSSION: Postoperative pancreatic fistula is the main reason for clinically important postoperative morbidity after pancreatoduodenectomy. The primary goal of the chosen reconstruction technique for pancreatoenteric anastomosis is to minimize postoperative fistula rate. A randomized trial performed at multiple high-volume centers for pancreatic surgery is the best opportunity to investigate one of the most crucial issues in pancreatic surgery. TRIAL REGISTRATION: German Clinical Trials Register DRKS00000767 (2011/03/23), FSI 2011/05/31. Universal Trial Number U1111-1117-9588
Sex-Related Differences in Patient Selection for and Outcomes after Pace and Ablate for Refractory Atrial Fibrillation: Insights from a Large Multicenter Cohort.
Background: A pace and ablate strategy may be performed in refractory atrial fibrillation with rapid ventricular response. Objective: We aimed to assess sex-related differences in patient selection and clinical outcomes after pace and ablate. Methods: In a retrospective multicentre study, patients undergoing AV junction ablation were studied. Sex-related differences in baseline characteristics, all-cause mortality, heart failure (HF) hospitalizations, and device-related complications were assessed. Results: Overall, 513 patients underwent AV junction ablation (median age 75 years, 50% men). At baseline, men were younger (72 vs. 78 years, p < 0.001), more frequently had non-paroxysmal AF (82% vs. 72%, p = 0.006), had a lower LVEF (35% vs. 55%, p < 0.001) and more frequently had cardiac resynchronization therapy (75% vs. 25%, p < 0.001). Interventional complications were rare in both groups (1.2% vs. 1.6%, p = 0.72). Patients were followed for a median of 42 months in survivors (IQR 22-62). After 4 years of follow-up, the combined endpoint of all-cause death or HF hospitalization occurred more often in men (38% vs. 27%, p = 0.008). The same was observed for HF hospitalizations (22% vs. 11%, p = 0.021) and all-cause death (28% vs. 21%, p = 0.017). Sex category remained an independent predictor of death or HF hospitalization after adjustment for age, LVEF and type of stimulation. Lead-related complications, infections, and upgrade to ICD or CRT occurred in 2.1%, 0.2% and 3.5% of patients, respectively. Conclusions: Pace and ablate is safe with a need for subsequent device-related re-interventions in 5.8% over 4 years. We found significant sex-related differences in patient selection, and women had a more favourable clinical course after AV junction ablation
From Geometry to Numerics: interdisciplinary aspects in mathematical and numerical relativity
This article reviews some aspects in the current relationship between
mathematical and numerical General Relativity. Focus is placed on the
description of isolated systems, with a particular emphasis on recent
developments in the study of black holes. Ideas concerning asymptotic flatness,
the initial value problem, the constraint equations, evolution formalisms,
geometric inequalities and quasi-local black hole horizons are discussed on the
light of the interaction between numerical and mathematical relativists.Comment: Topical review commissioned by Classical and Quantum Gravity.
Discussion inspired by the workshop "From Geometry to Numerics" (Paris, 20-24
November, 2006), part of the "General Relativity Trimester" at the Institut
Henri Poincare (Fall 2006). Comments and references added. Typos corrected.
Submitted to Classical and Quantum Gravit
Findings from an in-depth annual tree-ring radiocarbon intercomparison
The radiocarbon (ÂčâŽC) calibration curve so far contains annually resolved data only for a short period of time. With accelerator mass spectrometry (AMS) matching the precision of decay counting, it is now possible to efficiently produce large datasets of annual resolution for calibration purposes using small amounts of wood. The radiocarbon intercomparison on single-year tree-ring samples presented here is the first to investigate specifically possible offsets between AMS laboratories at high precision. The results show that AMS laboratories are capable of measuring samples of Holocene age with an accuracy and precision that is comparable or even goes beyond what is possible with decay counting, even though they require a thousand times less wood. It also shows that not all AMS laboratories always produce results that are consistent with their stated uncertainties. The long-term benefits of studies of this kind are more accurate radiocarbon measurements with, in the future, better quantified uncertainties
The fundamental left-right asymmetry in the Germanic verb cluster
Cinque (2005, 2009, 2014a) observes that there is an asymmetry in the possible ordering of dependents of a lexical head before versus after the head. A reflection on some of the concepts needed to develop Cinqueâs ideas into a theory of neutral word order reveals that dependents need to be treated separately by class. The resulting system is applied to the problem of word order in the Germanic verb cluster. It is shown that there is an extremely close match between theoretically derived expectations for clusters made up of auxiliaries, modals, causative âletâ, a main verb, and verbal particles. The facts point to the action of Cinqueâs fundamental left-right asymmetry in language in the realm of the verb cluster. At the same time, not all verb clusters fall under Cinqueâs generalization, which, therefore, argues against treating all cases of restructuring uniformly
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