Discover and publish cutting edge, open research.

Browse 18,025 multi-disciplinary research preprints

Most recent

Antunes FV

and 5 more

Hirokazu Miyashita

and 7 more

Objective: The implantation depth and membranous septum (MS) length are established as the predictors of new-onset conduction disturbance (CD) after transcatheter aortic valve replacement (TAVR) for tricuspid aortic valve (TAV) stenosis. However, little is known about the predictors with bicuspid aortic valve (BAV). This study investigated the role of MS length and implantation depth in predicting CD following TAVR with a balloon-expandable valve in patients with BAV. Methods and results: This retrospective study analyzed 169 patients who underwent TAVR for BAV with balloon-expandable valve, and TAV cohort was established as a control group using propensity score (PS) matching. The primary endpoint was in-hospital new-onset CD (new-onset left bundle branch block or new permanent pacemaker implantation). New-onset CD developed in 37 patients (21.9%). Multivariate analysis revealed severe LVOT calcification (Odds ratio [OR]: 5.83, 95% confidence interval [CI]: 1.08 – 31.5, p = 0.0407) and implantation depth – MS length (OR: 1.30, 95% CI: 1.12 – 1.51, p = 0.0005) as the predictors of new-onset CD within BAV cohort. The matched comparison between BAV and TAV groups showed similar MS length (3.0 vs 3.2mm, p = 0.5307), but valves were implanted deeper in BAV than TAV group (3.9 vs 3.0mm, p < .0001). New-onset CD was more frequent in patients having BAV (22.3% vs 13.9%, p = 0.0458). Conclusion: The implantation depth - MS length, and severe LVOT calcification predicted new-onset CD following TAVR in BAV with balloon-expandable valve. High implantation technique could be considered to avoid new-onset CD in BAV anatomy.
Restoration is the natural and intervention-assisted set of processes designed to promote and facilitate the recovery of an ecosystem that has been degraded, damaged, or destroyed. Therefore, the need to assess an ecological restoration project is a critical step to evaluate its success and identify best management practices. We performed a meta-analysis concerning the environmental outcomes during the years 2000 to 2015 resulting from the “Grain for Green” Project (GFGP) implementation in the Loess Plateau (LP). Data were collected in 48 English-language peer-reviewed papers selected from a pool of 332 papers. The results showed that, on average, GFGP increased forest coverage by 35.7% (95% CI: 24.15-47.52%), and grassland by 1.05% (95% CI: 0.8-1.28%). At the same time, GFGP has a positive impact on soil carbon (C) sequestration, net ecosystem production (NEP), and net primary production (NPP), from the years 2000 to 2015 by an average of 36% (95% CI: 28.96-43.18%), 22.7% (95% CI: 9.10-36.79%), and 13.5% (95% CI: 9.44-17.354%), respectively. Soil erosion, sediment load, runoff coefficient and water yield reduced by 13.3% (95% CI: 0.27%-25.76), 21.5% (95% CI: 1.50-39.99%), 22.4% (95% CI: 5.28-40.45%) and 43.3% (95% CI: 27.03%-82.86%), respectively, from the years 2000 to 2015. Our results indicate that water supply decreased with restoration age. Therefore, GFGP policies and strategies should be adjusted to balance the need for green space and grain trade by recovering, enhancing, and maintaining more resilient landscapes.

ibrahim dönmez

and 3 more

Purpose:Atrial fibrillation(AF) causes structural, electrical, and cellular remodeling in the atrium. Evaluation of intra- and interatrial conduction time, which is measured by tissue doppler echocardiography, indicates structural and electrical remodeling in the atrium. The aim of this study was to evaluate the effect of pulmonary vein isolation applied with RF ablation therapy on intra- and interatrial conduction time and to investigate the structural and electrically remodeling after treatment. Methods:Fifty-two patients with symptomatic PAF despite at least one antiarrhythmic drug and without structural heart disease were included in the study. Two patients were excluded because of complications developed during and after the operation. Fifty patients (28 female; mean age: 51.68 ± 11.731; mean left atrial diameter: 36.79 ± 4.318) who underwent CARTO® 3D pulmonary vein isolation applied with the RF ablation system were followed-up. Intra- and the inter-atrial electromechanical delay was measured in all patients by tissue doppler echocardiography before and three months after RF ablation. Results:All intra- and interatrial conduction times were significantly decreased 3 months after RF ablation procedure(PA lateral p = 0.022; PA septum p = 0.002; PA tricuspid p = 0.019, interatrial conduction delay p= 0,012, intra-atrial conduction delay p = 0.029). Conclusion:The results of our study suggest that providing stable sinus rhythm by the elimination of the AF triggering mechanisms with RF ablation of pulmonary vein isolation may slow down,stop or even improve structural remodeling at substrate level secondary to AF even in patients who did not yet develop atrial fibrosis and permanent structural changes.

Christina Moore

and 2 more

Background: Patients who undergo cardiac surgery are at increased risk of stroke, postoperative cognitive decline, and delirium. These neurocognitive complications have led to increased costs, intensive care unit stays, morbidity, and mortality. As a result, there is a significant push to mitigate any neurological complications in cardiac surgery patients. Near-infrared spectroscopy to measure regional cerebral oxygen saturations has gained consideration due to its non-invasive, user-friendly, and relatively inexpensive nature. Aim of Study: To provide a comprehensive summary of cerebral oximetry in cardiac surgery. The review interrogates multiple systematic reviews assessing different outcomes in cardiac surgery to assess if cerebral oximetry is effective. Further, the review analyzes all available interventions for an acute desaturation to determine the efficacy of individual interventions. Methods: A narrative review of randomized controlled trials, observational studies, and systematic reviews with metanalyses were performed through August 2021. Results: There is significant heterogeneity amongst studies regarding the definition of a clinically significant cerebral desaturation. In addition, the assessment of neurocognitive outcomes has large variability, making metanalysis challenging. To date, cerebral oximetry use during cardiac surgery has not been associated with improvements in neurocognitive outcomes, morbidity, or mortality. The evidence to support particular interventions for an acute desaturation is equivocal. Conclusions: Future research is needed to quantify a clinically significant cerebral desaturation and to determine which interventions for an acute desaturation effectively improve clinical outcomes.

Browse more recent preprints

Recently published in scholarly journals

Browse more published preprints

How it works

Upload or create your research work
You can upload Word, PDF, LaTeX as well as data, code, Jupyter Notebooks, videos, and figures. Or start a document from scratch.
Disseminate your research rapidly
Post your work as a preprint. A Digital Object Identifier (DOI) makes your research citeable and discoverable immediately.
Get published in a refereed journal
Track the status of your paper as it goes through peer review. When published, it automatically links to the publisher version.
Learn More
Featured communities
Explore More Communities

Other benefits of Authorea

Multidisciplinary

A repository for any field of research, from Anthropology to Zoology

Comments

Discuss your preprints with your collaborators and the scientific community

Interactive Figures

Not just PDFs. You can publish d3.js and Plot.ly graphs, data, code, Jupyter notebooks

Featured templates
Featured and interactive
Journals with direct submission
Explore All Templates