Bright Structural-Phase-Pure CsPbI3 Core-PbSO4 Shell Nanoplatelets With Ultra-Narrow Emission Bandwidth of 77 meV at 630 nm.

Achieving a narrow emission bandwidth is long pursued for display applications. Among all primary colors, obtaining pure red emission with high visual perception is the most challenging. In this work, CsPbI3 halide perovskite nanoplatelets (NPLs) with rigorously controlled 2D  [PbI6]4- octahedron layer number (n) are demonstrated. A perovskite core-PbSO4 shell structure is designed to prevent aggregation and fusion between NPLs, enabling consistent thickness and quantum confinement strength for each NPL. Consequently, exact n = 4 CsPbI3 NPLs are demonstrated, exhibiting emission peaks around 630 nm, with very narrow spectral bandwidths of <24 nm and high absolute photoluminescence quantum yields up to 85%. The emission of n = 4 NPLs falls exactly within the pure-red region, closely aligning with the International Telecommunication Union Recommendation BT.2020  standard. Measurements suggest predominant stability and color homogeneity compared to traditional red-emitting CsPbIxBr3- x nanocrystals. Finally, proof-of-concept pure-red emissive light-emitting diodes (LEDs) are demonstrated by integrating n = 4 CsPbI3 NPLs films with a blue LED chip, showing an excellent external quantum efficiency of 18.3% and high brightness exceeding 3 × 106 nits. Stringent requirements for future display technologies, are satisfied based on the high color purity, stability, and brightness of CsPbI3 NPLs.

Angular color shift of micro-LED displays.

Sidewall emission of a micro-scale light emitting diode (micro-LED) improves the light extraction efficiency, but it causes mismatched angular distributions between AlGaInP-based red micro-LED and InGaN-based blue/green counterparts due to material difference. As a result, color shift of RGB micro-LED displays may become visually noticeable. To address this issue, we first analyze the angular distributions of RGB micro-LEDs and obtain good agreement between simulation and experiment. Next, we propose a device structure with top black matrix and taper angle in micro-LEDs, which greatly suppresses the color shift while keeping a reasonably high light extraction efficiency.

[Histopathological analysis of organs submitted by legal medicine experts in Baojii City: 358 forensic identification cases].

OBJECTIVE: To analyze pathological characteristics of organs recovered during forensic autopsy submitted by legal medicine experts. METHODS: From Baoji city, 358 cases of forensic autopsy specimens from a series of routine exams were collected. And histopathological diagnoses were reviewed. RESULTS: Majority of the 358 cases were young men. The major causes of death were trauma, sudden death and poisoning. The cause of death was determined with histology in 250 cases. No typical histological changes were noted in 101 cases. The tissue autolysis and decomposition were present in 7 cases. The major pathological diagnosis was cardiovascular disease, followed by diseases in respiratory, nervous, and digestive systems. CONCLUSION: Forensic autopsy with its professional characteristics, is different from regular autopsy. When diagnosing cause of death by histopathological examination, pathologists should collaborate with legal medicine experts to know the details of the cases, circumstances surrounding the death, and specific forensic pathological characteristics.

[Clinical significance of changes in T wave and ST segment amplitudes on electrocardiogram from supine to standing position among children with unexplained chest tightness or pain in resting stage].

OBJECTIVE: To investigate the clinical significance of changes in T wave and ST segment amplitudes on electrocardiogram (ECG) from supine to standing position in children with unexplained chest tightness or pain in resting stage. METHODS: A total of 122 6-14-year-old children with a chief complaint of unexplained chest tightness or pain (resting stage) underwent head-up tilt test (HUTT). According to HUTT results, these children were divided into HUTT-positive (n=61) and HUTT-negative groups (n=61). They underwent 12-lead ECG in the supine and standing positions, and heart rate and T wave and ST segment amplitudes in II, III, aVF and V5 leads were measured. RESULTS: In the HUTT-negative group, heart rates were significantly higher in the standing position than in the supine position (P<0.05), T wave amplitudes in II, III, aVF, and V5 leads were significantly lower in the standing position than in the supine position (P<0.05), and ST segment amplitudes in II, aVF and V5 leads were significantly higher in the standing position than in the supine position (P<0.05). In the HUTT-positive group, heart rates were significantly higher in the standing position than in the supine position (P<0.05), T wave amplitudes in II, III, aVF and V5 leads were significantly lower in the standing position than in the supine position (P<0.05), and ST segment amplitude in V5 lead was significantly higher in the standing position than in the supine position (P<0.05). There were no significant differences between the two groups with respect to ST segment amplitude and T wave amplitude in II, III and aVF leads of the supine or standing position (P>0.05). Compared with the HUTT-negative group, the HUTT-positive group had significantly greater T wave amplitude differences in II, III, aVF and V5 leads, and heart rate difference from supine to standing position (P<0.05). CONCLUSIONS: Among the children with unexplained chest tightness or pain in resting stage, T wave amplitude differences in II, III, aVF and V5 leads and heart rate difference from supine to standing position are greater in the HUTT-positive group than in the HUTT-negative group. This suggests that the changes in T wave amplitude on ECG from supine to standing position can indicate autonomic nervous system dysfunction.

[Investigation of 24-hour blood pressure monitoring for evaluating treatment outcome of nerve-mediated syncope in children].

OBJECTIVE: To investigate the clinical significance of 24-hour blood pressure monitoring (ABPM) for evaluating the treatment outcome of nerve-mediated syncope (NMS) in children. METHODS: Twenty-eight children with NMS confirmed by a head-up tilt table test (HUTT) (12 males and 16 females, aged 6-13 years) and with a chief complaint of unexplained syncope or pre-syncope between February 2010 and August 2012, were included in the study. These children received health education combined with therapy using oral rehydration salts solution and were then reexamined for clinical symptoms as well as HUTT and ABPM results. RESULTS: Of 28 NMS cases, 22 were vasodepressive type, 5 were mixed type, and 1 was cardioinhibitory type. The follow-up showed that 27 (96%) of all cases had improved clinical symptoms, and 18 (64%) had improved HUTT results. The ABPM follow-up revealed no significant changes in 24-hour mean systolic pressure, 24-hour mean diastolic pressure, daytime mean systolic pressure, daytime mean diastolic pressure, nighttime mean systolic pressure, nighttime mean diastolic pressure, day-night difference of systolic pressure, and day-night difference of diastolic pressure after treatment (P>0.05). The percentage of children with a dipper blood pressure pattern increased from 29% (8/28) before treatment to 50% (14/28) after treatment; the percentage of children with a non-dipper blood pressure pattern decreased from 71% (20/28) before treatment to 50% (14/28) after treatment. CONCLUSIONS: As an effective, objective and non-invasive monitoring means, ABPM is of some clinical significance for evaluating the treatment outcome of NMS in children.

Automated machine learning-based model for the prediction of delirium in patients after surgery for degenerative spinal disease.

OBJECTIVE: This study used machine learning algorithms to identify critical variables and predict postoperative delirium (POD) in patients with degenerative spinal disease. METHODS: We included 663 patients who underwent surgery for degenerative spinal disease and received general anesthesia. The LASSO method was used to screen essential features associated with POD. Clinical characteristics, preoperative laboratory parameters, and intraoperative variables were reviewed and were used to construct nine machine learning models including a training set and validation set (80% of participants), and were then evaluated in the rest of the study sample (20% of participants). The area under the receiver-operating characteristic curve (AUROC) and Brier scores were used to compare the prediction performances of different models. The eXtreme Gradient Boosting algorithms (XGBOOST) model was used to predict POD. The SHapley Additive exPlanations (SHAP) package was used to interpret the XGBOOST model. Data of 49 patients were prospectively collected for model validation. RESULTS: The XGBOOST model outperformed the other classifier models in the training set (area under the curve [AUC]: 92.8%, 95% confidence interval [CI]: 90.7%-95.0%), validation set (AUC: 87.0%, 95% CI: 80.7%-93.3%). This model also achieved the lowest Brier Score. Twelve vital variables, including age, serum albumin, the admission-to-surgery time interval, C-reactive protein level, hypertension, intraoperative blood loss, intraoperative minimum blood pressure, cardiovascular-cerebrovascular disease, smoking, alcohol consumption, pulmonary disease, and admission-intraoperative maximum blood pressure difference, were selected. The XGBOOST model performed well in the prospective cohort (accuracy: 85.71%). CONCLUSION: A machine learning model and a web predictor for delirium after surgery for the degenerative spinal disease were successfully developed to demonstrate the extent of POD risk during the perioperative period, which could guide appropriate preventive measures for high-risk patients.

Impact of viral replication inhibition by entecavir on peripheral T lymphocyte subpopulations in chronic hepatitis B patients.

BACKGROUND: To investigate dynamic fluctuations of serum viral load and peripheral T-lymphocyte subpopulations of chronic hepatitis B patients and their correlation during entecavir therapy. METHODS: Fifty-five patients received entecavir 0.5 mg/d therapy. Serum HBV DNA load was measured by Real-Time-PCR, and the levels of peripheral T-lymphocyte subpopulations by flow cytometry biweekly, every four weeks and every eight weeks during weeks 1-12, 13-24 and 24-48, respectively. Multilevel modelling was used to analyse the relationship between these variables. RESULTS: Of the 55 patients, all HBeAg positive and with detectable HBV DNA, the majority (81.8%) had serum levels of HBV DNA over 10(7) copies per milliliter. HBV viral load dropped sharply during the first two weeks. In 28 and 43 patients, the level became undetectable from week 24 and 48, respectively. Using pre-therapy level as the reference, a significant decrease in CD8+ T cells and increase in CD4+ T cells were found from week 12. Both parameters and CD4+/CD8+ ratio steadily improved throughout the 48 weeks. Multilevel analyses showed that the level of decrement of HBV DNA was associated with the increment of T-lymphocyte activities only in the later period (4-48 week). After 4 weeks of therapy, for each log10 scale decrement of HBV DNA, the percentage of CD4+ lymphocyte was increased by 0.49 and that of CD8+ decreased by 0.51. CONCLUSION: T-lymphocyte subpopulations could be restored partially by entecavir treatment in patients with chronic hepatitis B concurrently with reduction of viremia.