The introduction of transcatheter aortic valve replacement mandates attention to outcomes after surgical aortic valve replacement (SAVR) in low-risk, intermediate-risk, and very high-risk patients.
...The study population included 141,905 patients who underwent isolated primary SAVR from 2002 to 2010. Patients were risk-stratified by Society of Thoracic Surgeons (STS) predicted risk of mortality (PROM) <4% (group 1, n = 113,377), 4% to 8% (group 2, n = 19,769), and >8% (group 3, n = 8,759). The majority of patients were considered at low risk (80%), and only 6.2% were categorized as being at high risk. Outcomes were analyzed based on two time periods: 2002 to 2006 (n = 63,754) and 2007 to 2010 (n = 78,151).
The mean age was 65 years in group 1, 77 in group 2, and 77 in group 3 (p < 0.0001). The median STS PROM for the entire population was 1.84: 1.46% in group 1, 5.24% in group 2, and 11.2% in group 3 (p < 0.0001). Compared with PROM, in-hospital mean mortality was lower than expected in all patients (2.5% vs 2.95%) and when analyzed within risk groups was as follows: group 1 (1.4% vs 1.7%), group 2 (5.1% vs 5.5%), and group 3 (11.8% vs 13.7%) (p < 0.0001). In the most recent surgical era, operative mortality was significantly reduced in group 2 (5.4% vs 6.4%, p = 0.002) and group 3 (11.9% vs 14.4%, p = 0.0004) but not in group 1.
Nearly 80% of patients undergoing SAVR have outcomes that are superior to those by the predicted risk models. In the most recent era, early results have further improved in medium-risk and high-risk patients. This large real-world assessment serves as a benchmark for patients with aortic valve stenosis as therapeutic options are further evaluated.
The capture and concentration of CO2 from a dry ambient air stream by temperature vacuum swing adsorption (TVSA) have been experimentally demonstrated on a small scale by using a single bed system ...packed with 20 g of zeolite X. Initially seven different commercially available type X zeolites were investigated, and one of them was chosen for a more comprehensive study. Breakthrough experiments were carried out by perturbing the He saturated bed with compressed ambient air with CO2 of around 410–440 ppm. In the process studied, a basic four-step TVSA cycle was investigated first, comprising the following steps: pressurization, adsorption, blowdown, and desorption. Four different regeneration temperatures were tested along with four different gas space velocities. With this cycle configuration, CO2 was concentrated to 95% from 400 ppm with total capture fractions as high as 81%. The energy consumption per ton of CO2 captured in the system is discussed for the different process configurations. The results from this study are discussed on how to improve the possibility of using low Si/Al ratio faujasite-structured zeolites in direct air capture of CO2.
Objective
Regret is a powerful motivating factor in medical decision making among patients and surgeons. Regret can be particularly important for surgical decisions, which often carry significant ...risk and may have uncertain outcomes. We performed a systematic review of the literature focused on patient and physician regret in the surgical setting.
Methods
A search of the English literature between 1986 and 2016 that examined patient and physician self-reported decisional regret was carried out using the MEDLINE/PubMed and Web of Science databases. Clinical studies performed in patients and physicians participating in elective surgical treatment were included.
Results
Of 889 studies identified, 73 patient studies and 6 physician studies met inclusion criteria. Among the 73 patient studies, 57.5% examined patients with a cancer diagnosis, with breast (26.0%) and prostate (28.8%) cancers being most common. Interestingly, self-reported patient regret was relatively uncommon with an average prevalence across studies of 14.4%. Factors most often associated with regret included type of surgery, disease-specific quality of life, and shared decision making. Only 6 studies were identified that focused on physician regret; 2 pertained to surgical decision making. These studies primarily measured regret of omission and commission using hypothetical case scenarios and used the results to develop decision curve analysis tools.
Conclusion
Self-reported decisional regret was present in about 1 in 7 surgical patients. Factors associated with regret were both patient- and procedure related. While most studies focused on patient regret, little data exist on how physician regret affects shared decision making.
Updating the assignment of levels of evidence Marx, Robert G; Wilson, Sean M; Swiontkowski, Marc F
Journal of bone and joint surgery. American volume,
01/2015, Letnik:
97, Številka:
1
Journal Article
Knowledge of species' geographic distributions is critical for understanding and forecasting population dynamics, responses to environmental change, biodiversity patterns, and conservation planning. ...While many suggestive correlative occurrence models have been used to these ends, progress lies in understanding the underlying population biology that generates patterns of range dynamics. Here, we show how to use a limited quantity of demographic data to produce demographic distribution models (DDMs) using integral projection models for size-structured populations. By modeling survival, growth, and fecundity using regression, integral projection models can interpolate across missing size data and environmental conditions to compensate for limited data. To accommodate the uncertainty associated with limited data and model assumptions, we use Bayesian models to propagate uncertainty through all stages of model development to predictions. DDMs have a number of strengths: 1) DDMs allow a mechanistic understanding of spatial occurrence patterns; 2) DDMs can predict spatial and temporal variation in local population dynamics; 3) DDMs can facilitate extrapolation under altered environmental conditions because one can evaluate the consequences for individual vital rates. To illustrate these features, we construct DDMs for an overstory perennial shrub in the Proteaceae family in the Cape Floristic Region of South Africa. We find that the species' population growth rate is limited most strongly by adult survival throughout the range and by individual growth in higher rainfall regions. While the models predict higher population growth rates in the core of the range under projected climates for 2050, they also suggest that the species faces a threat along arid range margins from the interaction of more frequent fire and drying climate. The results (and uncertainties) are helpful for prioritizing additional sampling of particular demographic parameters along these gradients to iteratively refine projections. In the appendices, we provide fully functional R code to perform all analyses.
Aging infrastructure and growing interests in river restoration have led to a substantial rise in dam removals in the United States. However, the decision to remove a dam involves many complex ...trade-offs. The benefits of dam removal for hazard reduction and ecological restoration are potentially offset by the loss of hydroelectricity production, water supply, and other important services. We use a multiobjective approach to examine a wide array of trade-offs and synergies involved with strategic dam removal at three spatial scales in New England. We find that increasing the scale of decision-making improves the efficiency of trade-offs among ecosystem services, river safety, and economic costs resulting from dam removal, but this may lead to heterogeneous and less equitable local-scale outcomes. Our model may help facilitate multilateral funding, policy, and stakeholder agreements by analyzing the trade-offs of coordinated dam decisions, including net benefit alternatives to dam removal, at scales that satisfy these agreements.
Degraded DNA from suboptimal field sampling is common in molecular ecology. However, its impact on techniques that use restriction site associated next‐generation DNA sequencing (RADSeq, GBS) is ...unknown. We experimentally examined the effects of in situDNA degradation on data generation for a modified double‐digest RADSeq approach (3RAD). We generated libraries using genomic DNA serially extracted from the muscle tissue of 8 individual lake whitefish (Coregonus clupeaformis) following 0‐, 12‐, 48‐ and 96‐h incubation at room temperature posteuthanasia. This treatment of the tissue resulted in input DNA that ranged in quality from nearly intact to highly sheared. All samples were sequenced as a multiplexed pool on an Illumina MiSeq. Libraries created from low to moderately degraded DNA (12–48 h) performed well. In contrast, the number of RADtags per individual, number of variable sites, and percentage of identical RADtags retained were all dramatically reduced when libraries were made using highly degraded DNA (96‐h group). This reduction in performance was largely due to a significant and unexpected loss of raw reads as a result of poor quality scores. Our findings remained consistent after changes in restriction enzymes, modified fold coverage values (2‐ to 16‐fold), and additional read‐length trimming. We conclude that starting DNA quality is an important consideration for RADSeq; however, the approach remains robust until genomic DNA is extensively degraded.
Longitudinal sampling of the stool has yielded important insights into the ecological dynamics of the human gut microbiome. However, human stool samples are available approximately once per day, ...while commensal population doubling times are likely on the order of minutes-to-hours. Despite this mismatch in timescales, much of the prior work on human gut microbiome time series modeling has assumed that day-to-day fluctuations in taxon abundances are related to population growth or death rates, which is likely not the case. Here, we propose an alternative model of the human gut as a stationary system, where population dynamics occur internally and the bacterial population sizes measured in a bolus of stool represent a steady-state endpoint of these dynamics. We formalize this idea as stochastic logistic growth. We show how this model provides a path toward estimating the growth phases of gut bacterial populations in situ. We validate our model predictions using an in vitro Escherichia coli growth experiment. Finally, we show how this method can be applied to densely-sampled human stool metagenomic time series data. We discuss how these growth phase estimates may be used to better inform metabolic modeling in flow-through ecosystems, like animal guts or industrial bioreactors.
Intracellular Ca2+ signals are key for the regulation of cellular processes ranging from myocyte contraction, hormonal secretion, neural transmission, cellular metabolism, transcriptional regulation, ...and cell proliferation. Measurement of cellular Ca2+ is routinely performed using fluorescence microscopy with biological indicators. Analysis of deterministic signals is reasonably straightforward as relevant data can be discriminated based on the timing of cellular responses. However, analysis of stochastic, slower oscillatory events, as well as rapid subcellular Ca2+ responses, takes considerable time and effort which often includes visual analysis by trained investigators, especially when studying signals arising from cells embedded in complex tissues. The purpose of the current study was to determine if full-frame time-series and line-scan image analysis workflow of Fluo-4 generated Ca2+ fluorescence data from vascular myocytes could be automated without introducing errors. This evaluation was addressed by re-analyzing a published “gold standard” full-frame time-series dataset through visual analysis of Ca2+ signals from recordings made in pulmonary arterial myocytes of en face arterial preparations. We applied a combination of data driven and statistical approaches with comparisons to our published data to assess the fidelity of the various approaches. Regions of interest with Ca2+ oscillations were detected automatically post hoc using the LCPro plug-in for ImageJ. Oscillatory signals were separated based on event durations between 4 and 40 s. These data were filtered based on cutoffs obtained from multiple methods and compared to the published manually curated “gold standard” dataset. Subcellular focal and rapid Ca2+ “spark” events from line-scan recordings were examined using SparkLab 5.8, which is a custom automated detection and analysis program. After filtering, the number of true positives, false positives, and false negatives were calculated through comparisons to visually derived “gold standard” datasets. Positive predictive value, sensitivity, and false discovery rates were calculated. There were very few significant differences between the automated and manually curated results with respect to quality of the oscillatory and Ca2+ spark events, and there were no systematic biases in the data curation or filtering techniques. The lack of statistical difference in event quality between manual data curation and statistically derived critical cutoff techniques leads us to believe that automated analysis techniques can be reliably used to analyze spatial and temporal aspects to Ca2+ imaging data, which will improve experiment workflow.
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