Severe persistent hypocholesterolemia after emergency gastrointestinal surgery predicts in-hospital mortality in critically ill patients with diffuse peritonitis

<div><p>Background</p><p>Plasma cholesterol acts as a negative acute phase reactant. Total cholesterol decreases after surgery and in various pathological conditions, including trauma, sepsis, burns, and liver dysfunction. This study aimed to determine whether hypocholesterolemia after emergency gastrointestinal (GI) surgery is associated with in-hospital mortality in patients with diffuse peritonitis.</p><p>Methods</p><p>The medical records of 926 critically ill patients who had undergone emergency GI surgery for diffuse peritonitis, between January 2007 and December 2015, were retrospectively analyzed. The integrated areas under the curve (iAUCs) were calculated to compare the predictive accuracy of total cholesterol values from postoperative days (PODs) 0, 1, 3, and 7. Cox proportional hazard regression modeling was performed for all possible predictors identified in the univariate and multivariable analyses.</p><p>Results</p><p>The total cholesterol level measured on POD 7 had the highest iAUC (0.7292; 95% confidence interval, 0.6696–0.7891) and was significantly better at predicting in-hospital mortality than measurements on other days. The optimal total cholesterol cut-off value for predicting in-hospital mortality was 61 mg/dL and was determined on POD 7. A Cox proportional hazard regression analysis revealed that a POD 7 total cholesterol level < 61 mg/dL was an independent predictor of in-hospital mortality after emergency GI surgery (hazard ratio, 3.961; 95% confidence interval, 1.786–8.784).</p><p>Conclusion</p><p>Severe persistent hypocholesterolemia (<61 mg/dL) on POD 7 independently predicted in-hospital mortality, after emergency GI surgery, in critically ill patients with diffuse peritonitis.</p></div

Baseline characteristics of the total population.^a

<p>Baseline characteristics of the total population.<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0200187#t001fn002" target="_blank">^a</a></p

Estimated iAUC differences using a bootstrapping method.

<p>Estimated iAUC differences using a bootstrapping method.</p

Univariate and multivariable Cox proportional hazards model for in-hospital mortality.

<p>Univariate and multivariable Cox proportional hazards model for in-hospital mortality.</p

Flow diagram of the patient selection process.

<p>Flow diagram of the patient selection process.</p

Comparison of the changes in total cholesterol levels between survivors and nonsurvivors.

<p>The time variations in total cholesterol levels were significantly different between survivors and nonsurvivors (Greenhouse-Geisser corrected, <i>P</i> < 0.001, using repeated-measures analysis of variance).</p

Time-dependent receiver operating curve analysis to evaluate the predictive accuracy of each measurement day.

<p>Results in the top right-hand corner of the figure indicate the integrated area under the curve (iAUC) and 95% confidence interval. The iAUC is a measure of the predictive accuracy for in-hospital mortality on each measurement day. The cholesterol level measured on postoperative day 7 had the highest iAUC.</p

Kaplan–Meier curve based on hypocholesterolemia severity (total cholesterol level ≥61 mg/dL versus total cholesterol level <61 mg/dL; log-rank test, <i>P</i> < 0.0001).

<p>Kaplan–Meier curve based on hypocholesterolemia severity (total cholesterol level ≥61 mg/dL versus total cholesterol level <61 mg/dL; log-rank test, <i>P</i> < 0.0001).</p

Unusual Conversion-type Lithiation in LiVO₃ Electrode for Lithium-Ion Batteries

This work finds that LiVO₃ is lithiated by a conversion reaction at 25 °C, which is unusual for the family of vanadium oxides. The spectroscopic studies and first-principle calculations performed on the lithiation mechanism of LiVO₃ consistently propose that a two-phase insertion-type lithiation proceeds in the early stage of lithiation; LiVO₃ transforms into a rock-salt structured Li₂VO₃. The continuing single-phase Li⁺ insertion into the tetrahedral sites in the rock-salt Li₂VO₃ produces a more Li-rich phase (Li_2.5VO₃), which is highly distorted because of the unfavorable Li⁺ insertion into the tetrahedral sites such as to be vulnerable to lattice breakdown. Hence, a two-phase (nucleation/growth type) conversion reaction is followed along with a structural disintegration; the Li_2.5VO₃ phase decomposes into metallic vanadium and Li₂O. To determine the factors facilitating the conversion reaction of LiVO₃, galvanostatic intermittent titration technique (GITT) and electrochemical impedance spectroscopy (EIS) are performed on LiVO₃, the results of which are then compared to those observed with V₂O₅, which is not lithiated by the conversion reaction at 25 °C. The results show that the quasi-equilibrium potential for the conversion reaction is more positive for LiVO₃ (thermodynamically more feasible). Also, the conversion reaction is kinetically more facilitated for LiVO₃ due to faster solid-state diffusion of mobile ionic species during the two-phase growth stage of metallic vanadium and lithium oxide (Li₂O) in the conversion process

Stable Subloop Behavior in Ferroelectric Si-Doped HfO₂

The recent demand for analogue devices for neuromorphic applications requires modulation of multiple nonvolatile states. Ferroelectricity with multiple polarization states enables neuromorphic applications with various architectures. However, deterministic control of ferroelectric polarization states with conventional ferroelectric materials has been met with accessibility issues. Here, we report unprecedented stable accessibility with robust stability of multiple polarization states in ferroelectric HfO2. Through the combination of conventional voltage measurements, hysteresis temperature dependence analysis, piezoelectric force microscopy, first-principles calculations, and Monte Carlo simulations, we suggest that the unprecedented stability of intermediate states in ferroelectric HfO2 is due to the small critical volume size for nucleation and the large activation energy for ferroelectric dipole flipping. This work demonstrates the potential of ferroelectric HfO2 for analogue device applications enabling neuromorphic computing