Effective heat dissipation has become a major concern with the rapid development of microelectronic devices. In general, thermally conductive fillers are incorporated into the polymeric matrix to increase the thermal conductivity of polymer composites. Herein, poly­(catechol-polyamine) (PCPA) is employed to modify boron nitride (BN) platelets, referred to as BN-PCPA, and improves the interfacial compatibility between a thermally conductive filler and elastomer matrix, resulting in carboxylated acrylonitrile-butadiene rubber (XNBR) composites filled with BN-PCPA platelets with enhanced thermal conductivity. The influence of PCPA thickness on the mechanical properties, thermal conductivity, and dielectric properties of BN-PCPA/XNBR composites is systematically studied. Briefly, the interfacial compatibility between the BN-PCPA filler and XNBR matrix increases with increasing PCPA thickness, leading to enhanced thermal conductivity. The maximum thermal conductivity of 0.399 W/(m·K) has been rendered by the BN-PCPA-12h/XNBR composite, which is about 2.5 times of pure XNBR. This work provides an easy route to develop polymer composites with a relatively high thermal conductivity and high dielectric constant for potential application in practical electronic packaging.

Background The discriminative ability of a point-of-care electroencephalogram (EEG)-derived pain index (Pi) for objectively assessing pain has been validated in chronic pain patients. The current study aimed to determine its feasibility in assessing labor pain in an obstetric setting. Methods Parturients were enrolled from the delivery room at the department of obstetrics in a tertiary hospital between February and June of 2018. Pi values and relevant numerical rating scale (NRS) scores were collected at different stages of labor in the presence or absence of epidural analgesia. The correlation between Pi values and NRS scores was analyzed using the Pearson correlation analysis. The receiver operating characteristic (ROC) curve was plotted to estimate the discriminative capability of Pi to detect labor pain in parturients. Results Eighty paturients were eligible for inclusion. The Pearson correlation analysis exhibited a positive correlation between Pi values and NRS scores in parturients (r = 0.768, P < 0.001). The ROC analysis revealed a cut-off Pi value of 18.37 to discriminate between mild and moderate-to-severe labor pain in parturients. Further analysis indicated that Pi values had the best diagnostic accuracy reflected by the highest area under the curve (AUC) of 0.857, with a sensitivity and specificity of 0.767 and 0.833, respectively, and a Youden index of 0.6. Subgroup analyses further substantiated the correlations between Pi values and NRS scores, especially in parturients with higher pain intensity. Conclusion This study indicates that Pi values derived from EEGs significantly correlate with the NRS scores, and can serve as a way to quantitatively and objectively evaluate labor pain in parturients.

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Background As type of surgery and opioids are suggested risk factors for the development of cognitive decline after surgery, we evaluated the effect of an opioid-sparing anesthesia regimen involving preoperative erector spinae block and continuous infusion of flurbiprofen on the incidence of cognitive decline after video-assisted thoracoscopic surgery. Methods In this observational study, patients over 18 years old presenting for elective video-assisted thoracoscopic surgery were divided into two groups, the erector spinae plane block group (ESPB group, who received preoperative single shot of bi-level ESPB at T4 and T6 levels) and the control group who received intercostal nerve blocks through T5 to T7 intercostal spaces along mid-axillary line after surgery. Continuous infusion of flurbiprofen (8 mg/h) and intravenous oxycodone rescue (1 mg/bolus, lockout time 10 minutes) were provided as postoperative analgesics. Cognitive function was measured one day before and 48 h after surgery with brief Cogstate computerized battery (CCB). Results There were 60 patients included with 30 in each group. Perioperative sufentanil dose was significantly reduced in ESPB group. Nine (30%) and 15 (50%) patients had delayed neurocognitive recovery in the ESPB group and the control group respectively. Psychomotor speed and visual attention tests were the two tests that patients showed cognitive decline. The results of multivariate regression revealed that patients who were more than 53.5 years of age (OR 9.213, 95% CI 1.789, 47.437, P = 0.008) and low levels of education (less than 9 years of complimentary education) (OR 6.829, 95% CI 1.068, 43.677, P = 0.042) were independent risk factors for postoperative delayed neurocognitive recovery. For subgroup analysis, ESPB could reduce the occurrence of delayed neurocognitive recovery in patients with both risk factors (6/10 (60%) vs. 11/11 (100%), P = 0.004) compared to the control group. Conclusions Middle-aged people and low levels of education are independent risk factors for delayed neurocognitive recovery after thoracoscopic surgery. ESPB has the potential to prevent cognitive decline in high-risk patients. Trial registration ChiCTR1800014508 (www.chictr.org.cn, January 17, 2018; Hong Zhao, M.D.). URL: http://www.chictr.org.cn/showproj.aspx?proj=24778. The date of the enrolment of the first participant to the trial was January 22, 2018.

Background: Ventricular septal rupture (VSR) is a rare but lethal complication occurring after acute myocardial infarction. The aim of our study was to review the single-center experience of surgery for VSR and seek a comprehensive evaluation process for early mortality. Methods: Patients undergoing surgical repair for postinfarction VSR in our institution retrospectively were evaluated from Jan. 2006 to Dec. 2019. The endpoint of the study was mortality within 30 days after VSR surgery, which was divided into survivors and nonsurvivors. The calibration and discrimination of two risk evaluation systems (European System for Cardiac Operative Risk Evaluation II (EuroSCORE II) and the Society of Thoracic Surgeons (STS) risk score) in total were compared by Hosmer-Lemeshow, and the area under the receiver operating characteristic curve (AUC). Risk factors in subsets were assessed by logistic regression analysis. Results: Twenty-three patients undergoing surgery for VSR repair were reviewed, and the early mortality after surgery was 34.8% (N = 8). The expected mortality predicted by EuroSCORE II was 24.3%, and that of the STS score was 12.2%. Both the EuroSCORE II and STS risk evaluation systems showed positive calibration in predicting mortality (H-L: P = 0.117 and P = 0.346, respectively) but poor discriminative power (AUC=0.633 and 0.575). Significant predictors determined by univariate analysis were concomitant coronary artery bypass grafting (CABG) (P = 0.035) and postoperative continuous renal replacement therapy (CRRT) (P = 0.008). Conclusion: Early mortality of VSR after surgery remains high, and the evaluation process is complicated. The performances of the two risk evaluation systems were not optimal, but EuroSCORE II was more accurate than STS. Patients with lower preoperation EuroSCORE II, concomitant CABG during repair, and no need for CRRT after surgery may have a better early survival rate.