Predicting optimal endotracheal tube size and depth in pediatric patients using demographic data and machine learning techniques.

BACKGROUND: Use of endotracheal tubes (ETTs) with appropriate size and depth can help minimize intubation-related complications in pediatric patients. Existing age-based formulae for selecting the optimal ETT size present several inaccuracies. We developed a machine learning model that predicts the optimal size and depth of ETTs in pediatric patients using demographic data, enabling clinical applications. METHODS: Data from 37,057 patients younger than 12 years who underwent general anesthesia with endotracheal intubation were retrospectively analyzed. Gradient boosted regression tree (GBRT) model was developed and compared with traditional age-based formulae. RESULTS: The GBRT model demonstrated the highest macro-averaged F1 scores of 0.502 (95% CI 0.486, 0.568) and 0.669 (95% CI 0.640, 0.694) for predicting the uncuffed and cuffed ETT size (internal diameter [ID]), outperforming the age-based formulae that yielded 0.163 (95% CI 0.140, 0.196, P < 0.001) and 0.392 (95% CI 0.378, 0.406, P < 0.001), respectively. In predicting the ETT depth (distance from tip to lip corner), the GBRT model showed the lowest mean absolute error (MAE) of 0.71 cm (95% CI 0.69, 0.72) and 0.72 cm (95% CI 0.70, 0.74) compared to the age-based formulae that showed an error of 1.18 cm (95% CI 1.16, 1.20, P < 0.001) and 1.34 cm (95% CI 1.31, 1.38, P < 0.001) for uncuffed and cuffed ETT, respectively. CONCLUSIONS: The GBRT model using only demographic data accurately predicted the ETT size and depth. If these results are validated, the model may be practical for predicting optimal ETT size and depth for pediatric patients.

Forming Stable van der Waals Contacts between Metals and 2D Semiconductors.

High-performing 2D electrical and optical devices can be realized by forming an ideal van der Waals (vdW) metal contact with weak interactions and stable interface states. However, the methods for applying metal contacts while avoiding damage from metal deposition present challenges in realizing a uniform, stable vdW interface. To overcome this problem, this study develops a method for forming vdW contacts using a sacrificial Se buffer layer. This study explores this method by investigating the difference in the Schottky barrier height between the vdW metal contact deposited using a buffer layer, a transferred metal contact, and a conventional directly deposited metal contact using rectification and photovoltaic characteristics of a Schottky diode structure with graphite. Evidently, the Se buffer layer method forms the most stable and ideal vdW contact while preventing Fermi-level pinning. A tungsten diselenide Schottky diode fabricated using these vdW contacts with Au and graphite as the top and bottom electrodes, respectively, exhibits excellent operation with an ideality factor of ≈1, an on/off ratio of > 107 , and coherent properties. Additionally, when using only the vdW Au contact, the electrical and optical properties of the device can be minutely modulated by changing the structure of the Schottky diode.

Ferroelastic-Ferroelectric Multiferroicity in van der Waals Rhenium Dichalcogenides.

2D multiferroics with combined ferroic orders have gained attention owing to their novel functionality and underlying science. Intrinsic ferroelastic-ferroelectric multiferroicity in single-crystalline van der Waals rhenium dichalcogenides, whose symmetries are broken by the Peierls distortion and layer-stacking order, is demonstrated. Ferroelastic switching of the domain orientation and accompanying anisotropic properties is achieved with 1% uniaxial strain using the polymer encapsulation method. Based on the electron localization function and bond dissociation energy of the Re-Re bonds, the change in bond configuration during the evolution of the domain wall and the preferred switching between the two specific orientation states are explained. Furthermore, the ferroelastic switching of ferroelectric polarization is confirmed using the photovoltaic effect. The study provides insights into the reversible bond-switching process and potential applications based on 2D multiferroicity.

A High-Affinity Repebody for Molecular Imaging of EGFR-Expressing Malignant Tumors.

The accurate detection of disease-related biomarkers is crucial for the early diagnosis and management of disease in personalized medicine. Here, we present a molecular imaging of human epidermal growth factor receptor (EGFR)-expressing malignant tumors using an EGFR-specific repebody composed of leucine-rich repeat (LRR) modules. The repebody was labeled with either a fluorescent dye or radioisotope, and used for imaging of EGFR-expressing malignant tumors using an optical method and positron emission tomography. Our approach enabled visualization of the status of EGFR expression, allowing quantitative evaluation in whole tumors, which correlated well with the EGFR expression levels in mouse or patients-derived colon cancers. The present approach can be effectively used for the accurate detection of EGFR-expressing cancers, assisting in the development of a tool for detecting other disease biomarkers.

Alpha-lipoic acid treatment is neurorestorative and promotes functional recovery after stroke in rats.

The antioxidant properties of alpha-lipoic acid (aLA) correlate with its ability to promote neuroproliferation. However, there have been no comprehensive studies examining the neurorestorative effects of aLA administration after the onset of ischemia. The middle cerebral artery (MCA) of adult rats was occluded for 2 hours and then reperfused. aLA (20 mg/kg) was administered in 71 animals (aLA group) through the left external jugular vein immediately after reperfusion. An equivalent volume of vehicle was administered to 71 animals (control group). Functional outcome, levels of endogenous neural precursors with neurogenesis, glial cell activation, and brain metabolism were evaluated. Immediate aLA administration after reperfusion resulted in significantly reduced mortality, infarct size, and neurological deficit score (NDS) in the test group compared to the control group. Long-term functional outcomes, measured by the rotarod test, were markedly improved by aLA treatment. There was a significant increase in the number of cells expressing nestin and GFAP in the boundary zone and infarct core regions after aLA treatment. Furthermore, significantly more BrdU/GFAP, BrdU/DCX, and BrdU/NeuN double-labeled cells were observed along the boundary zone of the aLA group on days 7, 14, and 28 days, respectively. And brain metabolism using (18)F-FDG microPET imaging was markedly improved in aLA group. The effects of aLA was blocked by insulin receptor inhibitor, HNMPA (AM)3. These results indicate that immediate treatment with aLA after ischemic injury may have significant neurorestorative effects mediated at least partially via insulin receptor activation. Thus, aLA may be useful for the treatment of acute ischemic stroke.

Intratumoral Metabolic Heterogeneity for Prediction of Disease Progression After Concurrent Chemoradiotherapy in Patients with Inoperable Stage III Non-Small-Cell Lung Cancer.

PURPOSE: We evaluated the value of variable (18)F-FDG PET/CT parameters for the prediction of disease progression after concurrent chemoradiotherapy (CCRT) in patients with inoperable stage III non-small-cell lung cancer (NSCLC). METHODS: One hundred sixteen pretreatment FDG PET/CT scans of inoperable stage III NSCLC were retrospectively reviewed (stage IIIA: 51; stage IIIB: 65). The volume of interest was automatically drawn for each primary lung tumor, and PET parameters were assessed as follows: maximum standardized uptake value (SUVmax), metabolic tumor volume (MTV) using the boundaries presenting SUV intensity exceeding 3.0, and the area under the curve of the cumulative SUV-volume histograms (AUC-CSH), which is known to reflect the tumor heterogeneity. Progression-free survival (PFS), locoregional recurrence-free survival (LRFS), and distant metastasis-free survival (DMFS) were compared with each PET and clinical parameters by univariate and multivariate survival analysis. RESULTS: In the ROC analysis, the optimal cutoff values of SUVmax, MTV (cm(3)), and AUC-CSH for prediction of PFS were determined as 21.5, 27.7, and 4,800, respectively. In univariate analysis, PFS was statistically significantly reduced in those with AUC-CSH < 4,800 (p = 0.004). In multivariate analysis, AUC-CSH and SUVmax were statistically significant independent prognostic factors (HR 3.35, 95 % CI 1.79-6.28, p < 0.001; HR 0.25, 95 % CI 0.09-0.70, p = 0.008, respectively). Multivariate analysis showed that AUC-CSH was the most significant independent prognostic factor for LRFS and DMFS (HR 3.27, 95 % CI 1.54-6.94, p = 0.002; HR 2.79, 95 % CI 1.42-5.50, p = 0.003). CONCLUSIONS: Intratumoral metabolic heterogeneity of primary lung tumor in (18)F-FDG PET/CT can predict disease progression after CCRT in inoperable stage III NSCLC.

Evaluation of a mitochondrial voltage sensor, (18F-fluoropentyl)triphenylphosphonium cation, in a rat myocardial infarction model.

UNLABELLED: Radiolabeled lipophilic cationic compounds, such as (18)F-labeled phosphonium salt, accumulate in the mitochondria through a negative inner transmembrane potential. The purpose of this study was to develop and evaluate ((18)F-fluoropentyl)triphenylphosphonium salt ((18)F-FPTP) as a myocardial PET agent. METHODS: A reference compound of (18)F-FPTP was synthesized via 3-step nucleophilic substitution reactions and was radiolabeled via 2-step nucleophilic substitution reactions of no-carrier-added (18)F-fluoride. Accumulations of (18)F-FPTP, (3)H-tetraphenylphosphonium, and (99m)Tc-sestamibi were compared in a cultured embryonic cardiomyoblast cell line (H9c2). The biodistribution of (18)F-FPTP was assessed using BALB/c mice. The (18)F-FPTP small-animal PET study was performed in Sprague-Dawley rats with or without left coronary artery (LCA) ligation. RESULTS: (18)F-FPTP was synthesized with a radiochemical yield of 15%-20% and radiochemical purity of greater than 98%. Specific activity was greater than 6.3 TBq/µmol. Cell uptake of (18)F-FPTP was more than 15-fold higher in H9c2 than in normal fibroblasts (human normal foreskin fibroblasts). Selective collapse of mitochondrial membrane potential substantially decreased cellular uptake for (18)F-FPTP and (3)H-tetraphenylphosphonium, compared with that for (99m)Tc-sestamibi. The biodistribution data in mice (n = 24) showed rapid blood clearance and high accumulation in the heart. Heart-to-blood ratios at 10 and 30 min were 54 and 133, respectively. Heart-to-lung and heart-to-liver ratios at 10, 30, and 60 min were 4, 4, and 7 and 4, 5, and 7, respectively. Dynamic small-animal PET for 60 min after injection of (18)F-FPTP showed an initial spike of radioactivity, followed by retention in the myocardium and rapid clearance from the background. (18)F-FPTP small-animal PET images in LCA-occluded rats demonstrated sharply defined myocardial defects in the corresponding area of the myocardium. The myocardial defect size measured by (18)F-FPTP small-animal PET correlated closely with the hypoperfused area measured by quantitative 2,3,5-triphenyltetrazolium chloride staining (r(2) = 0.92, P < 0.001). CONCLUSION: The excellent pharmacokinetics of (18)F-FPTP and its correlation with 2,3,5-triphenyltetrazolium chloride staining in normal and LCA-occluded rats suggest that this molecular probe may have a high potential as a mitochondrial voltage sensor for PET. This probe may also allow high throughput, with multiple daily studies and a wide distribution of PET myocardial imaging in the clinic.

Chemical interaction of alexidine and sodium hypochlorite.

INTRODUCTION: Recent studies have reported the color change and formation of precipitates containing para-chloroaniline (PCA) after a reaction of sodium hypochlorite (NaOCl) and chlorhexidine (CHX). Alexidine (ALX), a biguanide disinfectant similar to CHX, has greater affinity for bacterial virulence factors than CHX. This study determined by electrospray ionization mass spectrometry (ESI-MS) and scanning electron microscopy (SEM) whether the chemical interaction between ALX and NaOCl results in PCA or precipitates. METHODS: ESI-MS was performed on 4 different concentrations of ALX (1%, 0.5%, 0.25%, and 0.125%) with 4% NaOCl to detect the presence of PCA. As control groups, 1% ALX, 0.5% PCA, and a mixture of 2% CHX and 4% NaOCl were analyzed. The formation of precipitates on the dentinal surfaces of premolar root canals treated with the solutions of ALX and NaOCl (AN) or CHX and NaOCl (CN) was observed by SEM and the color change in the reaction solutions was also analyzed. RESULTS: ESI-MS showed that the peak (mass/charge ratio = 128.026) in the PCA spectrum was not detected in any of the 4 AN solutions, whereas the peak was found in the CN solution. SEM revealed precipitates covering dentinal surfaces in the CN solution. The AN solutions produced no precipitate. The AN solutions changed in color from light yellow to transparent with decreasing ALX concentration, whereas peach-brown discoloration was observed in the CN solution. CONCLUSIONS: The interaction of ALX and NaOCl did not produce PCA or precipitates, and the color of the reacted solution changed transparent with decreasing ALX concentration.

Effects of sonicated Enterococcus faecalis extracts on interleukin-2 and interleukin-4 production by human T cells.

In the present authors' previous study, sonicated Enterococcus faecalis extracts were shown to suppress the cell cycle progression of human lymphocytes. To study the effect of this microorganism on the function of lymphocytes, the authors investigated the levels of interleukin-2 (IL-2) and interleukin-4 (IL-4) production by T lymphocytes before and after the addition of sonicated E. faecalis extracts. In this study, levels of IL-2 and IL-4 produced from T cells were evaluated by using the quantitative sandwich enzyme immunoassay technique. In response to phytohemagglutinin (PHA) stimulation, T cells produced increased levels of IL-2 and IL-4. However, the expressions of both cytokines were significantly inhibited when PHA-activated T cells were preexposed to 12.5 microg/ml and 25 microg/ml of sonicated E. faecalis extracts (p < 0.05). This effect was concentration-dependent, because the levels of IL-2 and IL-4 expressions were not affected by the addition of a low concentration (5 microg/ml) of sonicated extract. These findings suggest that Th1 and Th2 immunosuppression mediated by E. faecalis could be a part of the pathogenic mechanism of the endodontic failure associated with this microorganism.