294 research outputs found
Enhancement of tissue lesion depth by dual wavelength irradiation with the Nd-YAG/KTP laser: Perspectives for laser prostatectomy
The Nd-YAG/KTP laser coagulates and vaporizes prostate tissue. The objective of this study was to investigate the combined effects of both wavelengths and to determine the irradiation parameters allowing the largest lesion volume. Chicken breast tissue was irradiated ex vivo. Consecutive 1064 and 532 nm Nd-YAG/KTP laser irradiations were performed for different combinations (30 W/10 W, 20 W/20 W, 10 W/30 W) with variable total fluence (1200 J, 2400 J, 3600 J) and compared to isofluent single wavelengths at 40 W irradiation. The depths, diameters and volumes of the total lesion as well as the vaporization effects of the 532 nm wavelength on normal and on priorly coagulated tissue were analysed. Maximum total lesion depths (p< 0.001) were found under combined Nd-YAG/KTP (20 W/20 W) irradiation conditions. Ablation efficacy of the 532 nm wavelength was reduced after prior 1064 nm irradiation, but crater depths were increased. Dual wavelength irradiation with the Nd-YAG/KTP laser induces a specific denaturation process. This may represent a new approach to increase the depth of coagulation necrosis, and thus the treated volume, thereby improving long-term result
Pacific variability reconciles observed and modelled global mean temperature increase since 1950
Global mean temperature change simulated by climate models deviates from the observed temperature increase during decadal-scale periods in the past. In particular, warming during the ‘global warming hiatus’ in the early twenty-first century appears overestimated in CMIP5 and CMIP6 multi-model means. We examine the role of equatorial Pacific variability in these divergences since 1950 by comparing 18 studies that quantify the Pacific contribution to the ‘hiatus’ and earlier periods and by investigating the reasons for differing results. During the ‘global warming hiatus’ from 1992 to 2012, the estimated contributions differ by a factor of five, with multiple linear regression approaches generally indicating a smaller contribution of Pacific variability to global temperature than climate model experiments where the simulated tropical Pacific sea surface temperature (SST) or wind stress anomalies are nudged towards observations. These so-called pacemaker experiments suggest that the ‘hiatus’ is fully explained and possibly over-explained by Pacific variability. Most of the spread across the studies can be attributed to two factors: neglecting the forced signal in tropical Pacific SST, which is often the case in multiple regression studies but not in pacemaker experiments, underestimates the Pacific contribution to global temperature change by a factor of two during the ‘hiatus’; the sensitivity with which the global temperature responds to Pacific variability varies by a factor of two between models on a decadal time scale, questioning the robustness of single model pacemaker experiments. Once we have accounted for these factors, the CMIP5 mean warming adjusted for Pacific variability reproduces the observed annual global mean temperature closely, with a correlation coefficient of 0.985 from 1950 to 2018. The CMIP6 ensemble performs less favourably but improves if the models with the highest transient climate response are omitted from the ensemble mean
Distribution of preoperative angle alpha and angle kappa values in patients undergoing multifocal refractive lens surgery based on a positive contact lens test
Purpose: To assess the preoperative objective angle alpha and angle kappa measurements of patients deciding to undergo multifocal refractive lens surgery based on a subjective positive multifocal contact lens test (MCLT).
Methods: Retrospective, consecutive case series. Alpha and kappa angles were measured using the iTrace aberrometer. All patients also performed a 1-week MCLT. Only patients with a positive MCLT underwent surgery. Visual outcome (UCVA) was obtained in the 1-year follow-up. We assessed the preoperative distribution of angle values within MCLT positive and negative patient groups.
Results: Two hundred seventeen eyes (111 patients) were included. Mean age was 56.4 years (SD 5.6) and 46.9% were female. In 71 eyes (38 patients), MCLT was positive. Of them, 12 eyes (17%) had an angle alpha and angle kappa ≥ 0.5mm. Of 146 eyes (73 patients) who refrained from surgery due to a negative MCLT, 71 eyes (48.6%) had both angles small (<0.5mm). In the 1-year follow-up, UCVA improved by 0.68 logMAR (SD 0.51; p<0.001) from baseline. Eyes with both small angle alpha and kappa sizes improved by 0.78 logMAR (SD 0.56), as did eyes with high (≥0.5mm) angle sizes (0.82 logMAR (SD 0.53). UCVA of eyes (n=24) with high alpha but low kappa sizes improved less (-0.31 logMAR (SD 0.13; p=0.019)).
Conclusion: Four out of five patients with a positive MCLT also had correspondingly small angle values. One-half of patients with low preoperative angle values refrained from surgery due to a negative MCLT result. One-year visual acuity improvement was substantial and independent from angle sizes.
Keywords: Angle alpha; Angle kappa; Decision-making; Multifocal intraocular lens; Refractive lens surgery
Deep Learning Models Used in the Diagnostic Workup of Keratoconus : A Systematic Review and Exploratory Meta-Analysis
Purpose
The prevalence of keratoconus in the general population is reported to be up to 1 of 84. Over the past 2 decades, diagnosis and management evolved rapidly, but keratoconus screening in clinical practice is still challenging and asks for improving the accuracy of keratoconus detection. Deep learning (DL) offers considerable promise for improving the accuracy and speed of medical imaging interpretation. We establish an inventory of studies conducted with DL algorithms that have attempted to diagnose keratoconus.
Methods:
This systematic review was conducted according to the recommendations of the PRISMA statement. We searched (Pre-)MEDLINE, Embase, Science Citation Index, Conference Proceedings Citation Index, arXiv document server, and Google Scholar from inception to February 18, 2022. We included studies that evaluated the performance of DL algorithms in the diagnosis of keratoconus. The main outcome was diagnostic performance measured as sensitivity and specificity, and the methodological quality of the included studies was assessed using QUADAS-2.
Results
Searches retrieved 4100 nonduplicate records, and we included 19 studies in the qualitative synthesis and 10 studies in the exploratory meta-analysis. The overall study quality was limited because of poor reporting of patient selection and the use of inadequate reference standards. We found a pooled sensitivity of 97.5% (95% confidence interval, 93.6%–99.0%) and a pooled specificity of 97.2% (95% confidence interval, 85.7%–99.5%) for topography images as input.
Conclusions
Our systematic review found that the overall diagnostic performance of DL models to detect keratoconus was good, but the methodological quality of included studies was modest
Evaluering av gratis skolemåltid på 1. – 4. trinn på en skole i Haugesund
Denne prosjektevalueringen har sett på elever, foresatte og ansatte sine erfaringer med en gratis skolematordning ved Austrheim skole i Haugesund kommune. I et toårig pilotprosjekt fikk elever fra 1. til 4. trinn et heldags skoletilbud som inkluderte et gratis skolemåltid i felles spisesal. Både sosiale aspekt ved måltidet og elevers matvalg ble evaluert. I tillegg ble eleverfaringer om sosiale aspekt ved måltidet innhentet fra en sammenlignbar kontrollskole med matpakkelunsj i klasserommet. Resultatene viste at elever på 3. og 4. trinn, ansatte og foresatte mente at de felles skolemåltidene bidro til trivsel og fremmet sosiale interaksjoner mellom elever og mellom elever og ansatte ved Austrheim skole. Både elever på Austrheim skole og kontrollskolen var opptatt av sosiale aspekt ved måltidet, men elever ved Austrheim skole følte et høyere nivå av medbestemmelse. Erfaringer fra Austrheim skole viste at for å få et rolig måltid med muligheter for samtaler mellom elever og ansatte, var det viktig å ha nok ansatte til stede. Selv om de ansatte var enig i at skolemåltidet var positivt for skolemiljøet, mente flertallet at det å måtte delta i skolemåltidene førte til en mer strevsom arbeidsdag. Foresatte mente derimot at å slippe å smøre matpakke var en stor hjelp i hverdagen. Elevene var mest fornøyd med varmmåltidene, som ble servert to-tre ganger i uken, men likte også godt å ha mange valgmuligheter i smørelunsjen. Selv om tilgjengeligheten av grønnsaker var god i smørelunsjen, viste kartleggingen at bare 41 % av elevene på 3. til 4. trinn forsynte seg med grønnsaker. Det var også svært få som valgte fiskepålegg. Funnene tyder på at et felles, gratis skolemåltid er positivt for skolemiljøet og fremmer sosiale interaksjoner. Et godt og variert gratis skolemåltid på 1. til 4. trinn har potensiale til å påvirke barns kosthold, men bør kombineres med påvirkningsarbeid dersom elevene skal endre sine matvaner. Det vil være viktig å se på langtidseffekter av gratis skolemåltid på trivsel, skolemiljø og elevers kosthold.Evaluering av gratis skolemåltid på 1. – 4. trinn på en skole i HaugesundpublishedVersio
50 years experience with Dupuytren's contracture in the Erlangen University Hospital – A retrospective analysis of 2919 operated hands from 1956 to 2006
<p>Abstract</p> <p>Background</p> <p>Dupuytren's disease (DD) is a hand disorder mainly among the northern population. In contrast it is rare in the mediterranean population. Therefore typical habits and dietetic influences have been discussed as well as genetic predisposition. Still, since the first description by Dupuytren in 1834 only little is known about the etiology and pathogenesis of this disease. Some hints were found for a higher prevalence among people with diabetes, alcohol abuse or smoking. Also, intensive manual work or hand injuries have been discussed to have an influence on DD. To our knowledge this is the largest retrospectively evaluated series of symptomatic patients published to date. The study includes patients from the last 50 years. It was performed to show possible correlations between DD and typical risk factors such as diabetes, alcohol consumption, and smoking.</p> <p>Methods</p> <p>We retrospectively analysed all patient records with DD documented between 1956 and 2006 in the Surgical University Hospital in Erlangen. Data acquisition was conducted by reviewing the medical records from 1956 to 2006 including data from all patients who were surgically treated because of DD.</p> <p>Results</p> <p>We reviewed 2579 male and 340 female surgically treated patients with DD. More than 80% of the patients were between 40 and 70 years old. In 28.9% only the right hand was effected by DD, in 25.3% only the left hand and in 45.8% both hands. In 10.3% of all Patients suffered from Diabetes mellitus. Statistical analysis revealed no significant correlation between diabetes, alcoholism or smoking on the degree of DD in our patients.</p> <p>Conclusion</p> <p>Most data are consistent with previously published results from smaller, comparable retrospective studies with regard to right- or left handedness. We could not confirm a statistically significant correlation of DD with diabetes mellitus, severe alcohol consumption, heavy smoking or epilepsy and the stage of the disease as described in other studies. However, in the whole cohort of our operated patients during the last 50 years the prevalence of the above mentioned risk factors is slightly higher than in the normal population.</p
From Sea to Sea: Canada's Three Oceans of Biodiversity
Evaluating and understanding biodiversity in marine ecosystems are both necessary and challenging for conservation. This paper compiles and summarizes current knowledge of the diversity of marine taxa in Canada's three oceans while recognizing that this compilation is incomplete and will change in the future. That Canada has the longest coastline in the world and incorporates distinctly different biogeographic provinces and ecoregions (e.g., temperate through ice-covered areas) constrains this analysis. The taxonomic groups presented here include microbes, phytoplankton, macroalgae, zooplankton, benthic infauna, fishes, and marine mammals. The minimum number of species or taxa compiled here is 15,988 for the three Canadian oceans. However, this number clearly underestimates in several ways the total number of taxa present. First, there are significant gaps in the published literature. Second, the diversity of many habitats has not been compiled for all taxonomic groups (e.g., intertidal rocky shores, deep sea), and data compilations are based on short-term, directed research programs or longer-term monitoring activities with limited spatial resolution. Third, the biodiversity of large organisms is well known, but this is not true of smaller organisms. Finally, the greatest constraint on this summary is the willingness and capacity of those who collected the data to make it available to those interested in biodiversity meta-analyses. Confirmation of identities and intercomparison of studies are also constrained by the disturbing rate of decline in the number of taxonomists and systematists specializing on marine taxa in Canada. This decline is mostly the result of retirements of current specialists and to a lack of training and employment opportunities for new ones. Considering the difficulties encountered in compiling an overview of biogeographic data and the diversity of species or taxa in Canada's three oceans, this synthesis is intended to serve as a biodiversity baseline for a new program on marine biodiversity, the Canadian Healthy Ocean Network. A major effort needs to be undertaken to establish a complete baseline of Canadian marine biodiversity of all taxonomic groups, especially if we are to understand and conserve this part of Canada's natural heritage
Change in auditory evoked potential index and bispectral index during induction of anesthesia with anesthetic drugs
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