258 research outputs found
Training in Robotic Surgery—an Overview
PURPOSE OF REVIEW:
There has been a rapid and widespread adoption of the robotic surgical system with a lag in the development of a comprehensive training and credentialing framework. A literature search on robotic surgical training techniques and benchmarks was conducted to provide an evidence-based road map for the development of a robotic surgical skills for the novice robotic surgeon.
RECENT FINDINGS:
A structured training curriculum is suggested incorporating evidence-based training techniques and benchmarks for progress. This usually involves sequential progression from observation, case assisting, acquisition of basic robotic skills in the dry and wet lab setting along with achievement of individual and team-based non-technical skills, modular console training under supervision, and finally independent practice.
SUMMARY:
Robotic surgical training must be based on demonstration of proficiency and safety in executing basic robotic skills and procedural tasks prior to independent practice
NLO-QCD corrections to e+ e- --> hadrons in models of TeV-scale gravity
We present results on NLO-QCD corrections to the process e+ e- --> hadrons
via photon-, Z- and graviton-exchange in the context of TeV-scale gravity
models. The quantitative impact of these QCD corrections for searches of extra
dimensions at a Linear Collider is briefly discussed.Comment: 10 pages, LaTeX, using axodraw.st
A statistical-mechanical explanation of dark matter halo properties
Cosmological N-body simulations have revealed many empirical relationships of
dark matter halos, yet the physical origin of these halo properties still
remains unclear. On the other hand, the attempts to establish the statistical
mechanics for self-gravitating systems have encountered many formal
difficulties, and little progress has been made for about fifty years. The aim
of this work is to strengthen the validity of the statistical-mechanical
approach we have proposed previously to explain the dark matter halo
properties. By introducing an effective pressure instead of the radial pressure
to construct the specific entropy, we use the entropy principle and proceed in
a similar way as previously to obtain an entropy stationary equation. An
equation of state for equilibrated dark halos is derived from this entropy
stationary equation, by which the dark halo density profiles with finite mass
can be obtained. We also derive the anisotropy parameter and pseudo-phase-space
density profile. All these predictions agree well with numerical simulations in
the outer regions of dark halos. Our work provides further support to the idea
that statistical mechanics for self-gravitating systems is a viable tool for
investigation.Comment: 5 pages, 4 figures, Accepted by A&
Comparing a new risk prediction model with prostate cancer risk calculator apps in a Taiwanese population
PURPOSE: To develop a novel Taiwanese prostate cancer (PCa) risk model for predicting PCa, comparing its predictive performance with that of two well-established PCa risk calculator apps. METHODS: 1545 men undergoing prostate biopsies in a Taiwanese tertiary medical center between 2012 and 2019 were identified retrospectively. A five-fold cross-validated logistic regression risk model was created to calculate the probabilities of PCa and high-grade PCa (Gleason score ≧ 7), to compare those of the Rotterdam and Coral apps. Discrimination was analyzed using the area under the receiver operator characteristic curve (AUC). Calibration was graphically evaluated with the goodness-of-fit test. Decision-curve analysis was performed for clinical utility. At different risk thresholds to biopsy, the proportion of biopsies saved versus low- and high-grade PCa missed were presented. RESULTS: Overall, 278/1309 (21.2%) patients were diagnosed with PCa, and 181 out of 278 (65.1%) patients had high-grade PCa. Both our model and the Rotterdam app demonstrated better discriminative ability than the Coral app for detection of PCa (AUC: 0.795 vs 0.792 vs 0.697, DeLong's method: P < 0.001) and high-grade PCa (AUC: 0.869 vs 0.873 vs 0.767, P < 0.001). Using a ≥ 10% risk threshold for high-grade PCa to biopsy, our model could save 67.2% of total biopsies; among these saved biopsies, only 3.4% high-grade PCa would be missed. CONCLUSION: Our new logistic regression model, similar to the Rotterdam app, outperformed the Coral app in the prediction of PCa and high-grade PCa. Additionally, our model could save unnecessary biopsies and avoid missing clinically significant PCa in the Taiwanese population
Evolution of spiral and scroll waves of excitation in a mathematical model of ischaemic border zone
Abnormal electrical activity from the boundaries of ischemic cardiac tissue
is recognized as one of the major causes in generation of ischemia-reperfusion
arrhythmias. Here we present theoretical analysis of the waves of electrical
activity that can rise on the boundary of cardiac cell network upon its
recovery from ischaemia-like conditions. The main factors included in our
analysis are macroscopic gradients of the cell-to-cell coupling and cell
excitability and microscopic heterogeneity of individual cells. The interplay
between these factors allows one to explain how spirals form, drift together
with the moving boundary, get transiently pinned to local inhomogeneities, and
finally penetrate into the bulk of the well-coupled tissue where they reach
macroscopic scale. The asymptotic theory of the drift of spiral and scroll
waves based on response functions provides explanation of the drifts involved
in this mechanism, with the exception of effects due to the discreteness of
cardiac tissue. In particular, this asymptotic theory allows an extrapolation
of 2D events into 3D, which has shown that cells within the border zone can
give rise to 3D analogues of spirals, the scroll waves. When and if such scroll
waves escape into a better coupled tissue, they are likely to collapse due to
the positive filament tension. However, our simulations have shown that such
collapse of newly generated scrolls is not inevitable and that under certain
conditions filament tension becomes negative, leading to scroll filaments to
expand and multiply leading to a fibrillation-like state within small areas of
cardiac tissue.Comment: 26 pages, 13 figures, appendix and 2 movies, as accepted to PLoS ONE
2011/08/0
Preoperative aerobic fitness and perioperative outcomes in patients undergoing cystectomy before and after implementation of a national lockdown
Abstract
Background
Lower fitness is a predictor of adverse outcomes after radical cystectomy. Lockdown measures during the COVID-19 pandemic affected daily physical activity. We hypothesised that lockdown during the pandemic was associated with a reduction in preoperative aerobic fitness and an increase in postoperative complications in patients undergoing radical cystectomy.
Methods
We reviewed routine preoperative cardiopulmonary exercise testing (CPET) data collected prior to the pandemic (September 2018 to March 2020) and after lockdown (March 2020 to July 2021) in patients undergoing radical cystectomy. Differences in CPET variables, Postoperative Morbidity Survey (POMS) data, and length of hospital stay were compared.
Results
We identified 267 patients (85 pre-lockdown and 83 during lockdown) who underwent CPET and radical cystectomy. Patients undergoing radical cystectomy throughout lockdown had lower ventilatory anaerobic threshold (9.0 [7.9–10.9] vs 10.3 [9.1–12.3] ml kg−1 min−1; P=0.0002), peak oxygen uptake (15.5 [12.9–19.1] vs 17.5 [14.4–21.0] ml kg−1 min−1; P=0.015), and higher ventilatory equivalents for carbon dioxide (34.7 [31.4–38.5] vs 33.4 [30.5–36.5]; P=0.030) compared with pre-lockdown. Changes were more pronounced in males and those aged >65 yr. Patients undergoing radical cystectomy throughout lockdown had a higher proportion of day 5 POMS-defined morbidity (89% vs 75%, odds ratio [OR] 2.698, 95% confidence interval [CI] 1.143–6.653; P=0.019), specifically related to pulmonary complications (30% vs 13%, OR 2.900, 95% CI 1.368–6.194; P=0.007) and pain (27% vs 9%, OR 3.471, 95% CI 1.427–7.960; P=0.004), compared with pre-lockdown on univariate analysis.
Conclusions
Lockdown measures in response to the COVID-19 pandemic were associated with a reduction in fitness and an increase in postoperative morbidity among patients undergoing radical cystectomy
Association between Insomnia Symptoms and Hemoglobin A1c Level in Japanese Men
Background: The evidence for an association between insomnia symptoms and blood hemoglobin A1c (HbA1c) level has been limited and inconclusive. The aim of this study was to assess whether each symptom of initial, middle, and terminal insomnia influences HbA 1c level in Japanese men. Methods: This cross-sectional study examined 1,022 male workers aged 22–69 years with no history of diabetes at a Japanese company’s annual health check-up in April 2010. High HbA1c was defined as a blood level of HbA1c $6.0%. Three types of insomnia symptoms (i.e., difficulty in initiating sleep, difficulty in maintaining sleep, and early morning awakening) from the previous month were assessed by 3 responses (i.e., lasting more than 2 weeks, sometimes, and seldom or never [reference group]). Results: The overall prevalence of high HbA1c was 5.2%. High HbA1c was positively and linearly associated with both difficulty in maintaining sleep (P for trend =.002) and early morning awakening (P for trend =.007). More specifically, after adjusting for potential confounding factors, high HbA1c was significantly associated with difficulty in maintaining sleep lasting more than 2 weeks (adjusted odds ratio, 6.79 [95 % confidence interval, 1.86–24.85]) or sometimes (2.33 [1.19–4.55]). High HbA1c was also significantly associated with early morning awakening lasting more than 2 weeks (3.96 [1.24–12.59]). Conclusion: Insomnia symptoms, particularly difficulty in maintaining sleep and early morning awakening, were found t
Hydrogen Peroxide Improves the Visibility of Ulcer Bases in Acute Non-variceal Upper Gastrointestinal Bleeding: A Single-Center Prospective Study
Geochemical characterization of oceanic basalts using Artificial Neural Network
The geochemical discriminate diagrams help to distinguish the volcanics recovered from different tectonic settings but these diagrams tend to group the ocean floor basalts (OFB) under one class i.e., as mid-oceanic ridge basalts (MORB). Hence, a method is specifically needed to identify the OFB as normal (N-MORB), enriched (E-MORB) and ocean island basalts (OIB)
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