Clinical Indications of Cultured Epithelial Autografts.

ABSTRACT: Cultured epithelial autografts (CEAs) have been used for decades as a treatment for massive burn injuries. Cultured epithelial autografts allow for wounds to heal by taking a small sample and growing a patient's own epithelium in culture to create large, graftable sheets. This technique is especially useful in large wounds where donor sites are limited compared with conventional skin grafting. However, CEAs have a variety of uses in wound healing and reconstruction and have the potential to aid in the closure of several types of defects. Cultured epithelial autografts have shown applicability in large burns, chronic nonhealing wounds, ulcerating wounds of various etiologies, congenital defects, wounds requiring specialized epithelium to replace like by like, and wounds in critically ill patients. Several factors must be considered when using CEAs, such as time, cost, and outcomes. In this article, we detail the various clinical applications of CEAs and how they can be situationally advantageous outside of their original purpose.

Tuning the threshold voltage from depletion to enhancement mode in a multilayer MoS2 transistor via oxygen adsorption and desorption.

Selective chemical doping in two-dimensional (2D) molybdenum disulfide (MoS2) is attractive for tailoring electrical properties according to device requirements. However, the ultra-thin 2D nature of MoS2 makes it difficult to realize effective doping by conventional ion implantation. Here, a simple method based on low-temperature (150 °C) annealing in air is developed for effective chemical doping in MoS2. We have demonstrated that the threshold voltage (V(th)) of multilayer MoS2 FET can be effectively tuned from depletion mode (V(th) = -1.8 V) to enhancement mode (V(th) = 1.1 V) by annealing in air at 150 °C. An energy band model based on electron trapping/detrapping due to oxygen adsorption on the MoS2 surface is proposed to explain the underlying mechanism. The model is consistent with an oxygen adsorption-desorption process evidenced by vacuum annealing that recovers the V(th) to its original value. These results can provide a simple approach for V(th) engineering and make a significant step toward 2D nanoelectronic device applications.

The utility and accuracy of ChatGPT in providing post-operative instructions following tonsillectomy: A pilot study.

OBJECTIVE: To investigate the utility of answers generated by ChatGPT, a large language model, to common questions parents have for their children following tonsillectomy. METHODS: Twenty Otolaryngology residents anonymously submitted common questions asked by parents of pediatric patients following tonsillectomy. After identifying the 16 most common questions via consensus-based approach, we asked ChatGPT to generate responses to these queries. Satisfaction with the AI-generated answers was rated from 1 (Worst) to 5 (Best) by an expert panel of 3 pediatric Otolaryngologists. RESULTS: The distribution of questions across the five most common domains, their mean satisfaction scores, and their Krippendorf's interrater reliability coefficient were: Pain management [6, (3.67), (0.434)], Complications [4, (3.58), (-0.267)], Diet [3, (4.33), (-0.357)], Physical Activity [2, (4.33), (-0.318)], and Follow-up [1, (2.67), (-0.250)]. The panel noted that answers for diet, bleeding complications, and return to school were thorough. Pain management and follow-up recommendations were inaccurate, including a recommendation to prescribe codeine to children despite a black-box warning, and a suggested post-operative follow-up at 1 week, rather than the customary 2-4 weeks for our panel. CONCLUSION: Although ChatGPT can provide accurate answers for common patient questions following tonsillectomy, it sometimes provides eloquently written inaccurate information. This may lead to patients using AI-generated medical advice contrary to physician advice. The inaccuracy in pain management answers likely reflects regional practice variability. If trained appropriately, ChatGPT could be an excellent resource for Otolaryngologists and patients to answer questions in the postoperative period. Future research should investigate if Otolaryngologist-trained models can increase the accuracy of responses.

Antimicrobial Prescription Patterns for Acute Sinusitis 2015-2022: A Comparison to Published Guidelines.

BACKGROUND: Acute rhinosinusitis (ARS) is one of the most encountered conditions in primary care and otolaryngology clinics. However, little is known about how antibiotic prescription practices following a diagnosis of ARS compare to guidelines set forth by the American Academy of Otolaryngology in 2015. OBJECTIVE: To investigate the epidemiology of ARS and the corresponding antibiotic prescribing practices by physicians and compare to published guidelines. METHODS: Using the TriNetX Live database, we identified all patients diagnosed with ARS using the ICD10 code J01 between April 2015 and December 2022 across the state of Tennessee. After investigating the demographics of this cohort, we compared the first prescribed antibiotic within one day of ARS diagnosis to published guidelines. Antibiotics were grouped into their respective classes. RESULTS: Of 81 310 patients diagnosed with ARS identified in the specified time frame, 66% were Female, 49% were African American, 44% were White, and the mean age was 47 ± 20 years. The six most common initial antibiotics prescribed for ARS were erythromycins/macrolides [14 609 (25.8%)], amoxicillin/clavulanate [14 322 (25.3%)], amoxicillin [9300 (16.4%)], third generation cephalosporins [7733 (13.6%)], quinolones [3648 (6.4%)] and tetracyclines [2235 (3.9%)]. Of this cohort, 56 719 patients (69.8%) of patients were prescribed an antibiotic within one day of diagnosis. CONCLUSION: Despite published guidelines recommending amoxicillin with or without clavulanic acid as first-line treatment for ARS, only 42.2% of prescribed antibiotics followed this guideline in our cohort. While accounting for patients with penicillin allergy, the second-most represented antibiotics were erythromycins/macrolides, which are specifically recommended against due to high rates of S. Pneumoniae resistance. Our results suggest that further investigation into the causes of erythromycin/macrolide prescriptions as first line treatment for ARS and practices at other institutions should be conducted. In addition, building awareness around published ARS guidelines for physicians may be useful in improving antibiotic stewardship in treatment of ARS.

Full factorial design of experiment-based and response surface methodology approach for evaluating variation in uniaxial compressive mechanical properties, and biocompatibility of photocurable PEGDMA-based scaffolds.

The goal of this study is to fabricate biocompatible and minimally invasive bone tissue engineering scaffolds that allowin situphotocuring and further investigate the effect on the mechanical properties of the scaffold due to the prevailing conditions around defect sites, such as the shift in pH from the physiological environment and swelling due to accumulation of fluids during inflammation. A novel approach of incorporating a general full factorial design of experiment (DOE) model to study the effect of the local environment of the tissue defect on the mechanical properties of these injectable and photocurable scaffolds has been formulated. Moreover, the cross-interaction between factors, such as pH and immersion time, was studied as an effect on the response variable. This study encompasses the fabrication and uniaxial mechanical testing of polyethylene glycol dimethacrylate (PEGDMA) scaffolds for injectable tissue engineering applications, along with the loss in weight of the scaffolds over 72 h in a varying pH environment that mimicsin vivoconditions around a defect. The DOE model was constructed with three factors: the combination of PEGDMA and nano-hydroxyapatite referred to as biopolymer blend, the pH of the buffer solution used for immersing the scaffolds, and the immersion time of the scaffolds in the buffer solution. The response variables recorded were compressive modulus, compressive strength, and the weight loss of the scaffolds over 72 h of immersion in phosphate-buffered saline at respective pH. The statistical model analysis provided adequate information in explaining a strong interaction of the factors on the response variables. Further, it revealed a significant cross-interaction between the factors. The factors such as the biopolymer blend and pH of the buffer solution significantly affected the response variables, compressive modulus and strength. At the same time, the immersion time had a strong effect on the loss in weight from the scaffolds over 72 h of soaking in the buffer solution. The biocompatibility study done using a set of fluorescent dyes for these tissue scaffolds highlighted an enhancement in the pre-osteoblasts (OB-6) cell attachment over time up to day 14. The representative fluorescent images revealed an increase in cell attachment activity over time. This study has opened a new horizon in optimizing the factors represented in the DOE model for tunable PEGDMA-based injectable scaffold systems with enhanced bioactivity.

Study of Carrier Mobilities in 4H-SiC MOSFETS Using Hall Analysis.

The channel conduction in 4H-SiC metal-oxide-semiconductor field effect transistors (MOSFETs) are highly impacted by charge trapping and scattering at the interface. Even though nitridation reduces the interface trap density, scattering still plays a crucial role in increasing the channel resistance in these transistors. In this work, the dominant scattering mechanisms are distinguished for inversion layer electrons and holes using temperature and body-bias-dependent Hall measurements on nitrided lateral 4H-SiC MOSFETs. The effect of the transverse electric field (Eeff) on carrier mobility is analyzed under strong inversion condition where surface roughness scattering becomes prevalent. Power law dependencies of the electron and hole Hall mobility for surface roughness scattering are determined to be Eeff-1.8 and Eeff-2.4, respectively, analogous to those of silicon MOSFETs. Moreover, for n-channel MOSFETs, the effect of phonon scattering is observed at zero body bias, whereas in p-channel MOSFETs, it is observed only under negative body biases. Along with the identification of regimes governed by different scattering mechanisms, these results highlight the importance of the selection of substrate doping and of Eeff in controlling the value of channel mobility in 4H-SiC MOSFETs.

Mechano-Immunomodulation in Space: Mechanisms Involving Microgravity-Induced Changes in T Cells.

Of the most prevalent issues surrounding long-term spaceflight, the sustainability of human life and the maintenance of homeostasis in an extreme environment are of utmost concern. It has been observed that the human immune system is dysregulated in space as a result of gravitational unloading at the cellular level, leading to potential complications in astronaut health. A plethora of studies demonstrate intracellular changes that occur due to microgravity; however, these ultimately fall short of identifying the underlying mechanisms and dysfunctions that cause such changes. This comprehensive review covers the changes in human adaptive immunity due to microgravity. Specifically, there is a focus on uncovering the gravisensitive steps in T cell signaling pathways. Changes in gravitational force may lead to interrupted immune signaling cascades at specific junctions, particularly membrane and surface receptor-proximal molecules. Holistically studying the interplay of signaling with morphological changes in cytoskeleton and other cell components may yield answers to what in the T cell specifically experiences the consequences of microgravity. Fully understanding the nature of this problem is essential in order to develop proper countermeasures before long-term space flight is conducted.

Electron beam-induced crystallization of Al2O3 gate layer on ß-Ga2O3 MOS capacitors.

Electron irradiation was observed to induce crystallization of amorphous Al2O3 films grown by atomic layer deposition on ß-Ga2O3 substrates. Growth of large, strongly oriented crystalline γ-Al2O3 regions was induced using conventional-mode transmission electron microscopy (TEM) and observed to propagate outward from the interface as well as from the previously crystallized Al2O3. A few nm of epitaxial Al2O3 was already visible at the beginning of the crystallization front propagation. The phenomenon is not explained by electron beam-induced heating, which amounted to less than 1 K at all times. Direct measurement of the beam current permitted quantitative correlation between electron dose rates and crystallization rates. Enlarging the electron beam to reduce current density was found to slow the propagation of the crystallization front. Furthermore, a factor of 4 smaller electron dose was required for a given rate using 100 keV electrons as compared to 200 keV, indicating that crystallization is driven by ionization-induced atomic rearrangement within the gate layer. Lattice spacing between the oxygen sub-lattices of ß-Ga2O3 and γ-Al2O3 are favorable for the nucleation of crystallites at the interface. Multivariate statistical analysis of electron energy loss spectroscopy (EELS) data also showed evidence of diffusion between Al and Ga in the substrates and gate oxides, respectively. These structural transformations at the semiconductor-insulator interface are expected to influence the device electrical behavior and are relevant to the continued refinement of ß-Ga2O3 device technology.

Chemical properties of oxidized silicon carbide surfaces upon etching in hydrofluoric acid.

Hydrogen termination of oxidized silicon in hydrofluoric acid results from an etching process that is now well understood and accepted. This surface has become a standard for studies of surface science and an important component in silicon device processing for microelectronics, energy, and sensor applications. The present work shows that HF etching of oxidized silicon carbide (SiC) leads to a very different surface termination, whether the surface is carbon or silicon terminated. Specifically, the silicon carbide surfaces are hydrophilic with hydroxyl termination, resulting from the inability of HF to remove the last oxygen layer at the oxide/SiC interface. The final surface chemistry and stability critically depend on the crystal face and surface stoichiometry. These surface properties affect the ability to chemically functionalize the surface and therefore impact how SiC can be used for biomedical applications.

Thermal characterization of gallium oxide Schottky barrier diodes.

The higher critical electric field of ß-gallium oxide (Ga2O3) gives promise to the development of next generation power electronic devices with improved size, weight, power, and efficiency over current state-of-the-art wide bandgap devices based on 4H-silicon carbide (SiC) and gallium nitride (GaN). However, it is expected that Ga2O3 devices will encounter serious thermal issues due to the poor thermal conductivity of the material. In this work, self-heating in Ga2O3 Schottky barrier diodes under different regimes of the diode operation was investigated using diverse optical thermography techniques including thermoreflectance thermal imaging, micro-Raman thermography, and infrared thermal microscopy. 3D coupled electro-thermal modeling was used to validate experimental results and to understand the mechanism of heat generation for the diode structures. Measured top-side and cross-sectional temperature fields suggest that device and circuit engineers should account for the concentrated heat generation that occurs near the anode/Ga2O3 interface and/or the lightly doped drift layer under both forward and high voltage reverse bias conditions. Results of this study suggest that electro-thermal co-design techniques and top-side thermal management solutions are necessary to exploit the full potential of the Ga2O3 material system.