Intercept Of Plot Research Articles

External validation and calibration of risk equations for prediction of diabetic kidney diseases among patients with type 2 diabetes in Taiwan

BackgroundMost existing risk equations for predicting/stratifying individual diabetic kidney disease (DKD) risks were developed using relatively dated data from selective and homogeneous trial populations comprising predominately Caucasian type 2 diabetes (T2D) patients. We seek to adapt risk equations for prediction of DKD progression (microalbuminuria, macroalbuminuria, and renal failure) using empiric data from a real-world population with T2D in Taiwan.MethodsRisk equations from three well-known simulation models: UKPDS-OM2, RECODe, and CHIME models, were adapted. Discrimination and calibration were determined using the area under the receiver operating characteristic curve (AUROC), a calibration plot (slope and intercept), and the Greenwood-Nam-D’Agostino (GND) test. Recalibration was performed for unsatisfactory calibration (p-value of GND test < 0.05) by adjusting the baseline hazards of risk equations to address risk variations among patients.ResultsThe RECODe equations for microalbuminuria and macroalbuminuria showed moderate discrimination (AUROC: 0.62 and 0.76) but underestimated the event risks (calibration slope > 1). The CHIME equation had the best discrimination for renal failure (AUROCs from CHIME, UKPDS-OM2 and RECODe: 0.77, 0.60 and 0.64, respectively). All three equations overestimated renal failure risk (calibration slope < 1). After rigorous updating, the calibration slope/intercept of the recalibrated RECODe for predicting microalbuminuria (0.87/0.0459) and macroalbuminuria (1.10/0.0004) risks as well as the recalibrated CHIME equation for predicting renal failure risk (0.95/-0.0014) were improved.ConclusionsRisk equations for prediction of DKD progression in real-world Taiwanese T2D patients were established, which can be incorporated into a multi-state simulation model to project and differentiate individual DKD risks for supporting timely interventions and health economic research.

Immune-mediated inflammatory diseases and periodontal disease: a bidirectional two-sample mendelian randomization study

BackgroundPrevious observational studies have shown a bidirectional association between immune-mediated inflammatory disorders (IMID) and periodontal disease. However, evidence regarding the causal role of IMID and periodontal disease is still lacking. Therefore, we conducted a bidirectional two-sample Mendelian randomization (MR) study to uncover the potential genetic causal effects between IMID and periodontal disease.MethodsBidirectional two-sample MR analysis was employed. Data for ten IMIDs were sourced from genome-wide association studies (GWAS) conducted by the FinnGen Consortium (range from 1023 to 36321 cases) and UK Biobank (UKB) (range from 150 to 17574 cases). Furthermore, GWAS data for periodontal disease were obtained from the FinnGen Consortium (87497 cases), UKB (458 cases), and Gene Lifestyle Interactions in Dental Endpoints (GLIDE) consortium (17,353 periodontitis cases). Subsequently, the causal relationships were analyzed by random effects inverse variance weighting, weighted median, and MR-Egger. Sensitivity analyses were performed using the Cochrane Q test, funnel plot, and Mr-Egger intercept test to ensure robustness. Eventually, replication analysis and meta-analysis across different databases were carried out.ResultsSystemic lupus erythematosus (SLE) [IVW: OR = 1.079 (95% CI: 1.032–1.128) and P < 0.001], Sjogren syndrome [IVW: OR = 1.082 (95% CI: 1.012–1.157) and P = 0.022] and hypothyroidism [IVW: OR = 1.52 (95% CI: 1.13–2.04) and P = 0.005] may increase the risk of periodontal disease. In addition, periodontal disease may reduce the risk of SLE [IVW: OR = 0.8079 (95% CI: 0.6764–0.9650) and P = 0.019] and hyperthyroidism [IVW: OR = 5.59*10–9 (95% CI: 1.43*10–15-2.18*10–2) and P = 0.014]. Meta-analysis indicated a causal correlation between SLE and an increased risk of periodontal disease: [OR = 1.08 (95% CI: 1.03–1.13), P = 0.0009]. No significant evidence suggests bilateral causal relationships between other IMIDs and periodontal disease. No significant estimation of heterogeneity or pleiotropy is detected.ConclusionsOur study has confirmed a genetic causal relationship between IMIDs and periodontal disease, thereby unveiling novel potential mechanisms underlying IMIDs and periodontal disease. This discovery is promising in fostering interdisciplinary collaboration between clinicians and stomatologists to facilitate appropriate and precise screening, prevention, and early treatment of IMIDs and periodontal disease.

Preliminary study of the effect of gut microbiota on the development of prostatitis

BackgroundDysbacteriosis of intestinal tract may cause systemic inflammation, making distant anatomical locations more susceptible to illness. Recent research has demonstrated that the microbiome can affect both prostatitis and the inflammation of the prostate that is linked to prostate cancer. It is still unclear, though, whether this relationship indicates causation. We conducted a Mendelian randomization investigation on two samples to fully uncover gut microbiota’s potential genetic causal role in prostatitis.MethodProstatitis (1859 prostatitis cases and 72,799 controls) was utilized as the outcome, while SNPs highly linked with 196 microbial taxa (18 340 people) were chosen as instrumental factors. Random effects, inverse variance weighting, weighted medians, and MR-Egger were used to analyze causal effects. The Cochran’s Q test, funnel plot, leave-one-out analysis, and MR-Egger intercept test were all used in the sensitivity analysis.ResultsA causal effect in lowering the incidence of prostatitis is anticipated for five gut microorganisms (Methanobacteria, Methanobacteriaceae, Erysipelatoclostridium, Parasutterella, and Slackia; P < 0.05). Four gut bacteria, including Faecalibacterium, LachnospiraceaeUCG004, Sutterella, and Gastranaerophilales, are predicted to play a causal role in increasing the risk of prostatitis (P < 0.05). There were no discernible estimates of pleiotropy or heterogeneity.ConclusionOur investigation established the genetic links between nine gut microorganisms and prostatitis, which may offer fresh perspectives and a theoretical framework for the future prevention and management of prostatitis.

The effects of psychiatric disorders on the risk of chronic heart failure: a univariable and multivariable Mendelian randomization study.

Substantial evidence suggests an association between psychiatric disorders and chronic heart failure. However, further investigation is needed to confirm the causal relationship between these psychiatric disorders and chronic heart failure. To address this, we evaluated the potential effects of five psychiatric disorders on chronic heart failure using two-sample Mendelian Randomization (MR). We selected single nucleotide polymorphisms (SNPs) associated with chronic heart failure and five psychiatric disorders (Attention-Deficit Hyperactivity Disorder (ADHD), Autism Spectrum Disorder (ASD), Major Depression, Bipolar Disorder and Schizophrenia (SCZ)). Univariable (UVMR) and multivariable two-sample Mendelian Randomization (MVMR) were employed to assess causality between these conditions. Ever smoked and alcohol consumption were controlled for mediating effects in the multivariable MR. The inverse variance weighting (IVW) and Wald ratio estimator methods served as the primary analytical methods for estimating potential causal effects. MR-Egger and weighted median analyses were also conducted to validate the results. Sensitivity analyses included the funnel plot, leave-one-out, and MR-Egger intercept tests. Additionally, potential mediators were investigated through risk factor analyses. Genetically predicted heart failure was significantly associated with ADHD (odds ratio (OR), 1.12; 95% CI, 1.04-1.20; p = 0.001), ASD (OR, 1.29; 95% CI, 1.07-1.56; p = 0.008), bipolar disorder (OR, 0.89; 95% CI, 0.83-0.96; p = 0.001), major depression (OR, 1.15; 95% CI, 1.03-1.29; p = 0.015), SCZ (OR, 1.04; 95% CI, 1.00-1.07; p = 0.024). Several risk factors for heart failure are implicated in the above cause-and-effect relationship, including ever smoked and alcohol consumption. Our study demonstrated ADHD, ASD, SCZ and major depression may have a causal relationship with an increased risk of heart failure. In contrast, bipolar disorder was associated with a reduced risk of heart failure, which could potentially be mediated by ever smoked and alcohol consumption. Therefore, prevention strategies for heart failure should also incorporate mental health considerations, and vice versa.

Recalibration of a Non-Laboratory-Based Risk Model to Estimate Pre-Diabetes/Diabetes Mellitus Risk in Primary Care in Hong Kong.

A non-laboratory-based pre-diabetes/diabetes mellitus (pre-DM/DM) risk prediction model developed from the Hong Kong Chinese population showed good external discrimination in a primary care (PC) population, but the estimated risk level was significantly lower than the observed incidence, indicating poor calibration. This study explored whether recalibrating/updating methods could improve the model's accuracy in estimating individuals' risks in PC. We performed a secondary analysis on the model's predictors and blood test results of 919 Chinese adults with no prior DM diagnosis recruited from PC clinics from April 2021 to January 2022 in HK. The dataset was randomly split in half into a training set and a test set. The model was recalibrated/updated based on a seven-step methodology, including model recalibrating, revising and extending methods. The primary outcome was the calibration of the recalibrated/updated models, indicated by calibration plots. The models' discrimination, indicated by the area under the receiver operating characteristic curves (AUC-ROC), was also evaluated. Recalibrating the model's regression constant, with no change to the predictors' coefficients, improved the model's accuracy (calibration plot intercept: -0.01, slope: 0.69). More extensive methods could not improve any further. All recalibrated/updated models had similar AUC-ROCs to the original model. The simple recalibration method can adapt the HK Chinese pre-DM/DM model to PC populations with different pre-test probabilities. The recalibrated model can be used as a first-step screening tool and as a measure to monitor changes in pre-DM/DM risks over time or after interventions.

Cheese consumption on atherosclerosis, atherosclerotic cardiovascular diseases and its complications: A two-sample Mendelian randomization study

Background and aimEvidence from prospective cohort studies has revealed an inverse association between cheese consumption and the development of atherosclerosis (AS), atherosclerotic cardiovascular diseases (ASCVD), and their complications. However, it remains unclear whether this observed association is influenced by potential confounding factors that may arise during the long-term development process of AS, ASCVD, and its complications. Therefore, to further clarify the causal relationship between cheese consumption and AS, ASCVD, and its complications, we conducted a two-sample Mendelian randomization (MR) analysis to explore the causal association between cheese intake and the aforementioned health outcomes. Methods and resultsWe employed a two-sample MR analysis based on publicly available genome-wide association studies (GWAS) to infer the causal relationship, with no overlap between their participating populations. The effect estimates were calculated using the random-effects inverse-variance-weighted method. Sensitivity analyses were conducted using Cochran's Q statistic, funnel plot, leave-one-out analysis, and MR-Egger intercept tests. The genetically predicted cheese intake was found to be associated with lower risks of coronary AS (odds ratio [OR] = 0.72, 95 % confidence interval [CI] 0.59–0.88, P = 0.001), peripheral vascular AS (OR = 0.56, 95 % CI 0.37–0.84, P = 0.006), other vascular AS (OR = 0.66, 95 % CI 0.44–0.99, P = 0.043), coronary artery disease (OR = 0.64, 95 % CI 0.56–0.74, P = 1.57e-09), angina pectoris (OR = 0.70, 95 % CI 0.58–0.84, P = 4.92e-05), myocardial infarction (OR = 0.63, 95 % CI 0.52–0.77, P = 3.56e-06), heart failure (OR = 0.62, 0.49–0.79, P = 1.20e-04), total ischemic stroke (OR = 0.76, 95 % CI 0.63–0.91, P = 0.003), peripheral artery disease (OR = 0.64, 95 % CI 0.43–0.95, P = 0.028), and cognitive impairment (OR = 0.65, 95 % CI 0.56–0.74, P = 3.40e-10). However, no associations were observed for cerebrovascular AS, arrhythmia, cardiac death, ischemic stroke (large artery AS), ischemic stroke (small vessel), ischemic stroke (cardioembolic), and transient ischemic attack. ConclusionThis two-sample MR analysis reveals a causally inverse association between cheese intake and multi-vascular AS (including coronary AS, peripheral vascular AS, and other vascular AS), as well as multiple types of ASCVD and its complications (such as coronary artery disease, angina pectoris, myocardial infarction, heart failure, total ischemic stroke, and peripheral artery disease). The findings from this study may lay a stronger theoretical foundation and present new opportunities for the dietary management of future atherosclerotic cardiovascular diseases.

A Risk Prediction Model for Long-term Prescription Opioid Use.

Tools are needed to aid clinicians in estimating their patients' risk of transitioning to long-term opioid use and to inform prescribing decisions. The objective of this study was to develop and validate a model that predicts previously opioid-naive patients' risk of transitioning to long-term use. This was a statewide population-based prognostic study. Opioid-naive (no prescriptions in previous 2 y) patients aged 12 years old and above who received a pill-form opioid analgesic in 2016-2018 and whose prescriptions were registered in the California Prescription Drug Monitoring Program (PDMP). A multiple logistic regression approach was used to construct a prediction model with long-term (ie, >90 d) opioid use as the outcome. Models were developed using 2016-2017 data and validated using 2018 data. Discrimination (c-statistic), calibration (calibration slope, intercept, and visual inspection of calibration plots), and clinical utility (decision curve analysis) were evaluated to assess performance. Development and validation cohorts included 7,175,885 and 2,788,837 opioid-naive patients with outcome rates of 5.0% and 4.7%, respectively. The model showed high discrimination (c-statistic: 0.904 for development, 0.913 for validation), was well-calibrated after intercept adjustment (intercept, -0.006; 95% confidence interval, -0.016 to 0.004; slope, 1.049; 95% confidence interval, 1.045-1.053), and had a net benefit over a wide range of probability thresholds. A model for the transition from opioid-naive status to long-term use had high discrimination and was well-calibrated. Given its high predictive performance, this model shows promise for future integration into PDMPs to aid clinicians in formulating opioid prescribing decisions at the point of care.

External Validation of the Prognostic Prediction Model for 4-Year Risk of Metabolic Syndrome in Adults: A Retrospective Cohort Study.

PurposeA prediction model for 4-year risk of metabolic syndrome in adults was previously developed and internally validated. However, external validity or generalizability for this model was not assessed so it is not appropriate for clinical application. We aimed to externally validate this model based on a retrospective cohort.Patients and MethodsA retrospective cohort design and a temporal validation strategy were used in this study based on a dataset from 1 January 2015 to 31 December 2018. Multiple imputation was used for missing values. Model performance was evaluated by using discrimination, calibration (calibration plot, calibration slope, and calibration intercept), overall performance (Brier score), and decision curve analysis.ResultsIn external validation, the C-statistic was 0.782 (95% CI, 0.771–0.793). The calibration plot shows good calibration, calibration slope was 1.006 (95% CI, −0.011–1.063), and calibration intercept was −0.045 (95% CI, −0.113–0.022). Brier score was 0.164.The discrimination and calibration of the prediction model were good in temporal external validation.ConclusionThe discrimination and calibration of the prediction model were satisfactory in the temporal external validation. However, clinicians should be aware that this prediction model was developed and validated in a tertiary setting. It is strongly recommended that further studies validate this model in international cohorts and large, prospective cohorts in different institutions.

82 Rb tissue kinetics in humans.

The study aim was to compare the kinetics of the potassium analogue, 82 Rb, between spleen, liver and kidney. Patients had myocardial stress/rest perfusion imaging using adenosine (n=45) or regadenoson (n=33) for stressing. Hepatic arterial (HAP), splenic (SP) and renal (RP) perfusions were measured from first-pass and blood 82 Rb clearances (Ki) from Gjedde-Patlak-Rutland graphical analysis of data between 1 and 2min postinjection, using regions of interest over left ventricular cavity or abdominal aorta to monitor arterial concentration. Tissue 82 Rb extraction efficiency (E) was calculated as [Ki/perfusion]*100. Tissue extracellular fluid volume (ECV) was derived from the GPR plot intercept. SP (24%) and RP (23%) increased after regadenoson but decreased (-41% and -19%) after adenosine. HAP increased after adenosine (91%) and regadenoson (68%). Resting E was high in kidney (69%) and low in spleen (26%). After adenosine, it increased to 91% in kidney and 49% in spleen. Assuming an arterial contribution of 25% to hepatic blood flow, resting E in liver was estimated as 23%. Relationships between Ki and perfusion in spleen and kidney were consistent with the Crone-Renkin equation (Ki = [1 - A.e-B/perfusion ]*perfusion), with respective values of A of 0.95 and 0.94 and B of 31 and 186ml/min/100ml. Splenic ECV decreased following adenosine from 62 to 39ml/100ml and showed a logarithmic correlation with SP. Kidney, spleen and liver display contrasting tissue kinetics. E is high in kidney and low in spleen and liver. Spleen is erectile, collapsing when perfusion decreases.

A Highly Sensitive Temperature Sensor Based on Au/Graphene-PVP/n-Si Type Schottky Diodes and the Possible Conduction Mechanisms in the Wide Range Temperatures

We report that the sensitive temperature response and possible Conduction Mechanisms (CMs) of Au/graphene-PVP/ ${n}$ -Si type Schottky diodes (SDs) are investigated using the standard Thermionic Emission (TE) theory at low temperatures (LTs) and high temperatures (HTs). The obtained results indicate that the zero-apparent barrier height ( $\phi _{\textit {Bo}}$ - $\phi _{\textit {ap}}$ ) increases while the ideality factor ( ${n}$ ), series and shunt resistances ( ${R} _{s}$ , ${R} _{\textit {sh}}$ ), rectifying rate (at ±2V) and surface states ( ${N} _{\textit {ss}}$ ) decrease with increasing temperature. The $\phi _{\textit {Bo}}$ , ${n}$ and ${R} _{s}$ values are also extracted from Cheung’s functions and, then compared with those obtained TE theory. The conventional Richardson plot ( $\ell {n}$ ( ${I} _{o}$ /T 2)- q/kT ) displays the deviation from the linearity at low-temperatures ( $T\le140$ K). Besides, the experimental value of Richardson constant ( ${A} ^{\ast }$ ) deduced from the intercept of plot was found to be several orders lower than the theoretical value. The discrepancies and higher values for the parameter of ${n}$ are important evidences for the deviation from TE theory. This is mainly attributed to the spatial inhomogeneities of the barrier height and potential fluctuations at the interface including low/high barrier areas. Hence the CMs across diode preferentially flows through these lower barriers/patches at the regions of LTs. The decrement in the ${N} _{\textit {ss}}$ with the enhancement in the temperature is in relation to the molecular restructuring-reordering under temperature and voltage effects. The SDs fabricated with graphene-PVP interlayer exhibit a higher sensitivity ( ${S}$ ) rather than many silicon/SOI-based structures. Numerically, the ${S}$ values are found to be in a range of 1.3 mV/K (LTs)/−1.93mV/K (HTs) in case of ${I} =0.1\,\,\mu \text{A}$ as against much greater values of −8.2 mV/K (LTs)/−7.9mV/K (HTs) for ${I} = 10\,\,\mu \text{A}$ .

Kinetics and equilibrium study for adsorptive removal of cationic dye using agricultural waste-raw and modified cob husk

ABSTRACT The adsorption efficiency of raw and modified cob husk to remove methylene blue (MB) dye was investigated in batch mode. The chemical modification of cob husk was done with citric acid to enhance the cationic dye removal from the aqueous solutions. Surface characterisation of the adsorbents was done through FTIR and SEM. The efficiency of raw and modified cob husk for dye removal was tested through adsorption in batch mode. The studies were carried out under optimised conditions of adsorbent dosage, dye concentration, pH and contact time. The concentration of dye before and after adsorption was estimated through spectrophotometric technique. The time taken to reach equilibrium was found to be 90 and 120 minutes for raw and modified cob husk, respectively. Langmuir, Freundlich, Temkin, and Dubinin–Radushkevich isotherm models were used to plot equilibrium data and slopes and intercept of respective plots were used to calculate the values of their corresponding constants. The isotherm data of cob husk and acid-modified cob husk could be best described by the Freundlich equation based on high correlation coefficient values. As a result of functionalization, the adsorption capacity of cob husk for methylene blue increased from 12.75 mgg−1 to 208.3 mgg−1 at 25 ֯C, respectively. Kinetic modelling of the experimental data showed that the sorption kinetics followed the pseudo-second-order kinetic model for both the adsorbents at different concentrations (25–250 mgL−1). Thermodynamic studies were carried out to assess the sorption behaviour of both the adsorbents. The values of different parameters viz.∆G֯, ∆S֯and ∆H֯were calculated for both the adsorbents which showed that the sorption process was endothermic and spontaneous in nature. The results showed that modified cob husk had better adsorption capacity than the raw cob husk due to an increase in the surface area of the adsorbent by chemical modification.

Silver and palladium nanoparticles produced using a plant extract as reducing agent, stabilized with an ionic liquid: sizing by X-ray powder diffraction and dynamic light scattering

Powder X-ray diffraction and dynamic light scattering (DLS) sizing of silver (Ag) and palladium (Pd) nanoparticles produced within aqueous plant extract and the effect of introducing of an ionic liquid are reported in this paper. The simple and novel synthesis of silver and palladium nanoparticles using the reducing power of Persea americana (Pa) bark extract is reported and the effect of adding 1-ethyl-3-methylimidazolium tosylate [EMIm][Tos] is described. Detailed powder X-ray interpretation allowed determination of the crystalline grain sizes of 16±4nm for Ag–Pa, 13±2nm for Ag–Pa[EMIm][Tos], 16±3nm for Pd–Pa and 9±1nm for Pd–Pa[EMIm][Tos] according to the Scherrer peak analysis. A size contraction occurs when moving from plant extract alone to plant extract/ionic liquid. These grain sizes are 9nm for Ag–Pa and for 9nm Ag–Pa[EMIm][Tos], 15nm for Pd–Pa and 7nm for Pd–Pa[EMIm][Tos] when the Williamson–Hall plot intercept is used. Modal hydrodynamic sizes were determined by DLS as 57nm for Ag–Pa, 72nm for Ag–Pa[EMIm][Tos], 390nm for Pd–Pa and 98nm for Pd–Pa[EMIm][Tos] providing indications on how the particles behave in solution. Intrinsic stresses of 0.177GPa for Ag–Pa, 0.219GPa for Ag–Pa[EMIm][Tos], 0.382GPa for Pd–Pa and 0.190GPa for Pd–Pa[EMIm][Tos] and dislocation densities of (6±3)×10−3nm−2 for Ag–Pa, (9±3)×10−3nm−2 for Ag–Pa[EMIm][Tos], (5±2)×10−3nm−2 for Pd–Pa and (16±4)×10−3nm−2 for Pd–Pa[EMIm][Tos] have been obtained.

Kinetics of V(V) extraction in V(V)-SO42− (Na+, H+)-primary amine N1923-sulfonated kerosene system using single drop technique

The kinetics of V(V) extraction from acidic sulfate medium by primary amine N1923(RNH2) dissolved in sulfonated kerosene has been investigated using a falling single drop technique. The time of drop formation and coalescence was determined and considered for calculating the V(V) transfer flux. The effects of aqueous pH, V(V) concentration and RNH2 concentration on the revised V(V)-transfer flux(F′) have been investigated with aim of obtaining the reaction orders for extraction rate. Activation energies (Ea) of extracted reaction for the aqueous pH of 2.0, 3.0 and 4.0 under the conditions of V(V) concentration of 0.24 mol/L, RNH2 concentration of 0.24 mol/L, temperature of 298 ± 0.5 K and an atmospheric pressure, were −8.04, −9.57 and −12.45 kJ/mol, respectively. The ΔH± for reactions under various operating conditions were also calculated according to the intercept of log(F′h/kT) versus (1/T) plots. The details studies on the kinetics of V(V) extraction from simulated industrial aqueous solution are significant to optimize its separation technology.

Efficacy of vitamin D supplementation in major depression: A meta-analysis of randomized controlled trials.

Background:There is a need to develop and periodically evaluate new treatment strategies in major depression due to the high burden of nonresponse and inadequate response to antidepressants.Aim:We aimed to assess the effect of vitamin D supplementation on depression symptom scores among individuals with clinically diagnosed major depression.Materials and Methods:Electronic search of databases was carried out for published randomized controlled trials in English language, peer-reviewed journals from inception till August 2017. Outcome measure used for effect size calculation was depression symptom scores. Effect sizes for the trials were computed using standardized mean difference (Cohen's d), and I2 test was used to assess sample heterogeneity. Pooled mean effect sizes were derived using both fixed and random-effects model. Critical appraisal of studies was done using the Cochrane risk of bias assessment tool.Results:A total of four trials involving 948 participants were included in the study. In three trials, the intervention group received oral vitamin D supplementation whereas in one parenteral vitamin D was given. Pooled mean effect size for vitamin D supplementation on depressive symptom ratings in major depression was 0.58 (95% confidence interval, 0.45–0.72). The I2 value for heterogeneity was 0 suggesting low heterogeneity among studies. Egger plot intercept indicated minimal publication bias.Conclusion:Vitamin D supplementation favorably impacted depression ratings in major depression with a moderate effect size. These findings must be considered tentative owing to the limited number of trials available and inherent methodological bias noted in few of them.

Prediction of postoperative myocardial infarction after suprainguinal bypass using the Vascular Quality Initiative Cardiac Risk Index

BackgroundThe Vascular Quality Initiative (VQI) Cardiac Risk Index (CRI) was developed to estimate the risk of postoperative myocardial infarction (POMI) for noncardiac vascular procedures. Whereas suprainguinal bypass carried the second highest odds of POMI, the performance of the all-procedure model declined when it was applied to the suprainguinal subset. We sought to improve the VQI CRI for application in this high-risk group undergoing open revascularization for aortoiliac occlusive disease. MethodsThe VQI Suprainguinal Bypass Registry was queried for elective procedures performed between January 2010 and March 2017. Logistic regression was used to create a model for estimating the risk of in-hospital POMI with preoperative variables including demographics, comorbidities, and planned inflow source. After adjustment for overfitting, internal validation was performed using both bootstrapping and 10-fold cross-validation methods. ResultsAmong 8157 procedures, the incidence of POMI was 3.2% (n = 258). After bootstrapping variable selection, age, graft inflow, preoperative stress test, American Society of Anesthesiologists class, indication for procedure, and coronary artery disease were chosen for inclusion as predictors in the final risk model. The final model demonstrated good discrimination (area under the curve = 0.725). On internal validation, the model discriminated well (area under the curve = 0.713), with good calibration (plot intercept = 0.0006 and slope = 1.001). Using this model, POMI risk estimates ranged from 0.6% to 30.4%. ConclusionsWhereas the incidence of POMI among all suprainguinal bypasses was 3%, model-based estimates ranged 50-fold, from 0.6% to 30.4%. This underscores the heterogeneity of this cohort and the need for patient-specific risk estimation. Although some of the strongest predictors were nonmodifiable (eg, age), the model provided specific estimates according to graft inflow and stress testing. This supraspecific VQI CRI module risk predictor may enhance preoperative counseling by influencing the decision to pursue preoperative stress testing and ultimately the type of revascularization strategy chosen.

Comparison of hydrocracking kinetic models based on SARA fractions obtained in slurry-phase reactor

Four kinetic models based on the SARA fractions were compared for the hydrocracking of heavy crude oil with mineral catalyst in slurry-phase. The reaction rate coefficients and activation energies were calculated with experimental information obtained at the following conditions: temperature range of 360–400 °C, pressure of 3.9 MPa and reaction times of 2–5 h. A sensitivity analysis was performed to ensure that the optimized kinetic parameters are the optimal. It was found that the reaction pathways from resins to saturate, aromatics to gases, and asphaltenes to gases are not carried out at the studied operating conditions. The number of negative and positive residuals, the maximum absolute error, the slope and the intercept of parity plots, and the Akaike and Bayesian criteria were used to select the model that fits better the experimental data.

Hospital Variation in Risk-Adjusted Pediatric Sepsis Mortality*

With continued attention to pediatric sepsis at both the clinical and policy levels, it is important to understand the quality of hospitals in terms of their pediatric sepsis mortality. We sought to develop a method to evaluate hospital pediatric sepsis performance using 30-day risk-adjusted mortality and to assess hospital variation in risk-adjusted sepsis mortality in a large state-wide sample. Retrospective cohort study using administrative claims data. Acute care hospitals in the state of Pennsylvania from 2011 to 2013. Patients between the ages of 0-19 years admitted to a hospital with sepsis defined using validated International Classification of Diseases, Ninth revision, Clinical Modification, diagnosis and procedure codes. None. During the study period, there were 9,013 pediatric sepsis encounters in 153 hospitals. After excluding repeat visits and hospitals with annual patient volumes too small to reliably assess hospital performance, there were 6,468 unique encounters in 24 hospitals. The overall unadjusted mortality rate was 6.5% (range across all hospitals: 1.5-11.9%). The median number of pediatric sepsis cases per hospital was 67 (range across all hospitals: 30-1,858). A hierarchical logistic regression model for 30-day risk-adjusted mortality controlling for patient age, gender, emergency department admission, infection source, presence of organ dysfunction at admission, and presence of chronic complex conditions showed good discrimination (C-statistic = 0.80) and calibration (slope and intercept of calibration plot: 0.95 and -0.01, respectively). The hospital-specific risk-adjusted mortality rates calculated from this model varied minimally, ranging from 6.0% to 7.4%. Although a risk-adjustment model for 30-day pediatric sepsis mortality had good performance characteristics, the use of risk-adjusted mortality rates as a hospital quality measure in pediatric sepsis is not useful due to the low volume of cases at most hospitals. Novel metrics to evaluate the quality of pediatric sepsis care are needed.

A new instrument for stable isotope measurements of &amp;lt;sup&amp;gt;13&amp;lt;/sup&amp;gt;C and &amp;lt;sup&amp;gt;18&amp;lt;/sup&amp;gt;O in CO&amp;lt;sub&amp;gt;2&amp;lt;/sub&amp;gt; – instrument performance and ecological application of the Delta Ray IRIS analyzer

Abstract. We used the recently developed commercially available Delta Ray isotope ratio infrared spectrometer (IRIS) to continuously measure the CO2 concentration c and its isotopic composition δ13C and δ18O in a managed beech forest in central Germany. Our objectives are (a) to characterize the Delta Ray IRIS and evaluate its internal calibration procedure and (b) to quantify the seasonal variability of c, δ13C, δ18O and the isotopic composition of nighttime net ecosystem CO2 exchange (respiration) Reco13C and Reco18O derived from Keeling plot intercepts. The analyzer's minimal Allan deviation (as a measure of precision) was below 0.01 ppm for the CO2 concentration and below 0.03 ‰ for both δ values. The potential accuracy (defined as the 1σ deviation from the respective linear regression that was used for calibration) was approximately 0.45 ppm for c, 0.24 ‰ for 13C and 0.3 ‰ for 18O. For repeated measurements of a target gas in the field, the long-term standard deviation from the mean was 0.3 ppm for c and below 0.3 ‰ for both δ values. We used measurements of nine different inlet heights to evaluate the isotopic compositions of nighttime net ecosystem CO2 exchange Reco13C and Reco18O in a 3-month measurement campaign in a beech forest in autumn 2015. During this period, an early snow and frost event occurred, coinciding with a change in the observed characteristics of both Reco13C and Reco18O. Before the first snow, Reco13C correlated significantly (p &lt; 10−4) with time-lagged net radiation Rn, a driver of photosynthesis and photosynthetic discrimination against 13C. This correlation became insignificant (p &gt; 0.1) for the period after the first snow, indicating a decoupling of δ13C of respiration from recent assimilates. For 18O, we measured a decrease of 30 ‰ within 10 days in Reco18O after the snow event, potentially reflecting the influence of 18O depleted snow on soil moisture. This decrease was 10 times larger than the corresponding decrease in δ18O in ambient CO2 (below 3 ‰) and took 3 times longer to recover (3 weeks vs. 1 week). In summary, we conclude that (1) the new Delta Ray IRIS with its internal calibration procedure provides an opportunity to precisely and accurately measure c, δ13C and δ18O at field sites and (2) even short snow or frost events might have strong effects on the isotopic composition (in particular 18O) of CO2 exchange on an ecosystem scale.

Cognitive Behavior Therapy for Medically Unexplained Symptoms: A Systematic Review and Meta-analysis of Published Controlled Trials.

Medically unexplained symptoms (MUS) commonly present across the board in medical specialties and are often challenging to treat. Our objective was to assess the efficacy for cognitive-behavior therapy (CBT) in MUS. Electronic search of databases was carried out for published controlled trials in English language peer-reviewed journals from inception till August 2016. Effect sizes for the trials were computed using standardized mean difference, and I2 test was used to assess sample heterogeneity. Pooled mean effect sizes were derived using a random-effects model. Critical appraisal of studies was done using the Cochrane risk of bias assessment tool. A total of 11 trials involving 1235 subjects were included in the study. Ten trials used standard CBT techniques while one studied the efficacy of mindfulness-based CBT technique. The control arms were treatment as usual in five trials, augmented care in four and waitlisted controls in two trials. The pooled mean effect size for CBT was 0.388 (range 0.055–0.806, 95% confidence intervals 0.316–0.461). The I2 value was 0 using a random effects model indicating low heterogeneity among studies. Risk of bias was noted in many included studies. Egger plot intercept indicated potential publication bias. CBT was superior to the waiting list, treatment as usual or enhanced usual care with moderate effect sizes in the treatment of MUS. These findings are impacted by the limited number of studies in this area and questionable methodological rigor of included studies.

Transport Properties of Short Alkyl Chain Length Dicationic Ionic Liquids—The Effects of Alkyl Chain Length and Temperature

Some transport properties of imidazolium-based short alkyl chain length dicationic ionic liquids (DILs) ([Cn(mim)2][NTf2]2), including shear viscosity, diffusion coefficient, and electrical conductivity, have been measured and analyzed as a function of temperature and alkyl chain length. Also, the dependence of viscosity on shear rate has been investigated. The small intercepts of plots of shear stress versus shear rate and also the small variations of the viscosity values with changing shear rate show that the studied DILs are moderately non-Newtonian fluids. Temperature dependence of the viscosity of these ILs shows non-Arrhenius behavior which can be fitted well using four well-known equations, namely, power law, Litovitz, Vogel–Fulcher–Tammann (VFT), and Ghatee et al. equations. The activation thermodynamic parameters of these DILs were calculated. The positive values of Gibbs free energy of activation show that the slip of two layers of the fluid is a nonspontaneous process. DOSY NMR spectroscopy was...