Chemically Tailored Growth of 2D Semiconductors via Hybrid Metal-Organic Chemical Vapor Deposition.

Two-dimensional (2D) semiconducting transition-metal dichalcogenides (TMDCs) are an exciting platform for excitonic physics and next-generation electronics, creating a strong demand to understand their growth, doping, and heterostructures. Despite significant progress in solid-source (SS-) and metal-organic chemical vapor deposition (MOCVD), further optimization is necessary to grow highly crystalline 2D TMDCs with controlled doping. Here, we report a hybrid MOCVD growth method that combines liquid-phase metal precursor deposition and vapor-phase organo-chalcogen delivery to leverage the advantages of both MOCVD and SS-CVD. Using our hybrid approach, we demonstrate WS2 growth with tunable morphologies─from separated single-crystal domains to continuous monolayer films─on a variety of substrates, including sapphire, SiO2, and Au. These WS2 films exhibit narrow neutral exciton photoluminescence line widths down to 27-28 meV and room-temperature mobility up to 34-36 cm2 V-1 s-1. Through simple modifications to the liquid precursor composition, we demonstrate the growth of V-doped WS2, MoxW1-xS2 alloys, and in-plane WS2-MoS2 heterostructures. This work presents an efficient approach for addressing a variety of TMDC synthesis needs on a laboratory scale.

Network Analysis of Women in Otolaryngology and Demographic Trends.

OBJECTIVE: This study analyzes gender disparities between men and women otolaryngology faculty in the top 20 otolaryngology departments ranked by research output and discusses the implications of these disparities. METHODS: This was a cross-sectional study of all articles published by faculty from January 2020 to December 2021 at the top 20 otolaryngology departments as ranked by Doximity's 2022 research output report. Integrated data from Web of Science, faculty directories, and NIH RePORT were used to collect data on faculty. Social network analysis was performed using ORA-LITE. Student's and Welch's t-tests and Pearson chi-squared tests were used to evaluate gender differences in academic metrics. RESULTS: The findings revealed significant gender disparities, with men holding higher academic positions (men = 3.16, women = 2.69, p < 0.0001), higher H-indices (22.4, 13.8, p < 0.0001), more NIH grants (0.15, 0.07, p = 0.0032), and greater total degree centrality (3.98E-4, 2.4E-4, p < 0.0001) and betweenness centrality (4.47E-3, 3.00E-3, p = 0.0021). Men also had more publications (9.8, 6.8, p < 0.0001) with more distinct co-authors, both within (4, 3.1, p = 0.0074) and across (38.1, 25.8, p < 0.0001) institutions. Disparities persisted after accounting for career length. Notably, total degree centrality differences between men and women were statistically significant from 1991 to 2017 (p < 0.0001), but not from 2018 to 2022 (p = 0.83). CONCLUSIONS: This study highlights gender inequities in otolaryngology, encouraging mentors to foster new collaborations with female peers. Importantly, it identifies a trend toward narrowing the gender gap within the specialty, particularly over the past 5 years, emphasizing the need to sustain these positive changes for enhanced gender equity. LEVEL OF EVIDENCE: NA Laryngoscope, 2024.

Closing the Loop on Revision: The Impact of Emotional Well-Being on Elective Revision After Breast Reconstruction.

BACKGROUND: A diagnosis of breast cancer has a significant impact on a patient's physical and emotional health. Breast reconstruction improves quality of life and self-esteem following mastectomy. However, many patients undergo additional elective revision procedures after reconstruction. OBJECTIVES: This study aims to assess the relationship between perioperative emotional well-being and elective revisions in breast reconstruction. METHODS: A retrospective review was performed of patients who underwent breast reconstruction with a single surgeon from January 2007- December 2017. Revision procedures were defined as additional operations that fall outside the index reconstructive plan. Medical records were reviewed for a history of generalized anxiety disorder (GAD) and/or major depressive disorder (MDD). Multivariate analysis was performed to identify factors associated with revision. RESULTS: A total of 775 patients undergoing breast reconstruction were included, of which 121 (15.6%) underwent elective revision. Overall, a history of any psychiatric history (p<0.001), depression alone (p=0.001%), and GAD and depression together (p=0.003) were significantly associated with revision surgery. On multivariate logistic regression controlling for comorbidities and reconstruction modality, depression alone and GAD and depression together were significantly associated with increased likelihood of revision surgery (OR 3.20, p<0.001; OR 2.63, p<0.001). CONCLUSIONS: Peri-operative emotional well-being and reconstruction modality impact the rate of secondary revision surgery. An understanding of the surgical and patient-related risk factors for revision can provide more informed patient-decision making and improve surgical planning.

Impact of ciprofloxacin/dexamethasone on pediatric tracheostomy outcomes.

OBJECTIVE(S): To investigate the effectiveness of ciprofloxacin/dexamethasone in reducing granulation tissue post-tracheostomy in pediatric patients. METHODS: This cohort study examined pediatric patients with a tracheostomy at a single academic institution from 2016 to 2020. Exclusion criteria included: deceased within 1 year (n = 38), >16 years of age (n = 21), decannulated within 1 year (n = 15), lost to follow-up within 1 year (n = 6), and revision tracheostomy (n = 2). Logistic regression or Wilcoxon rank-sum (α = 0.05) were used to compare demographic and clinical characteristics between patients who did and did not receive ciprofloxacin/dexamethasone within 1 year of their tracheostomy. RESULTS: In this cohort, (n = 126, median age 5.2 months, 54.0 % male), 62.7 % received ciprofloxacin/dexamethasone within 1 year, with 27.8 % taking the nebulized form. Granulation tissue occurred in 81.0 % of cases, predominantly peristomal (69.8 %) and suprastomal (34.9 %). Notable complications included accidental decannulation (13.6 %), suprastomal collapse (11.2 %), and bleeding (7.2 %). Although granulation tissue was more common in ciprofloxacin/dexamethasone users (92.4 %) versus non-users (61.7 %) (OR: 7.55, 95 % CI: 2.73-20.9, p < 0.001), patients exhibited less frequent granulation tissue events after initiation (z = 3.88, p < 0.001). No significant differences in antibiotic resistance (p = 1.0) or endocrinology complications (p = 0.1) were found between those with and without ciprofloxacin/dexamethasone. CONCLUSIONS: We found a statistically significant reduction of granulation tissue incidence with ciprofloxacin/dexamethasone use and no significant differences in antibiotic resistance or endocrinology complications were noted. Future investigation is warranted to explore timing of ciprofloxacin/dexamethasone administration for granulation tissue and its role in managing and preventing tracheostomy complications.

Expanded Stability of Layered SnSe-PbSe Alloys and Evidence of Displacive Phase Transformation from Rocksalt in Heteroepitaxial Thin Films.

Bulk PbSnSe has a two-phase region, or miscibility gap, as the crystal changes from a van der Waals-bonded orthorhombic 2D layered structure in SnSe-rich compositions to the related 3D-bonded rocksalt structure in PbSe-rich compositions. This structural transition drives a large contrast in the electrical, optical, and thermal properties. We realize low temperature direct growth of epitaxial PbSnSe thin films on GaAs via molecular beam epitaxy using an in situ PbSe surface treatment and show a significantly reduced two-phase region by stabilizing the Pnma layered structure out to Pb0.45Sn0.55Se, beyond the bulk limit around Pb0.25Sn0.75Se at low temperatures. Pushing further, we directly access metastable two-phase films of layered and rocksalt grains that are nearly identical in composition around Pb0.50Sn0.50Se and entirely circumvent the miscibility gap. We present microstructural and compositional evidence for an incomplete displacive transformation from a rocksalt to layered structure in these films, which we speculate occurs during the sample cooling to room temperature after synthesis. In situ temperature-cycling experiments on a Pb0.58Sn0.42Se rocksalt film reproduce characteristic attributes of a displacive transition and show a modulation in electronic properties. We find well-defined orientation relationships between the phases formed and reveal unconventional strain relief mechanisms involved in the crystal structure transformation using transmission electron microscopy. Overall, our work adds a scalable thin film integration route to harness the dramatic contrast in material properties in PbSnSe across a potentially ultrafast crystalline-crystalline structural transition.

Magnetic Vortex Nanodiscs Enable Remote Magnetomechanical Neural Stimulation.

Magnetic nanomaterials in magnetic fields can serve as versatile transducers for remote interrogation of cell functions. In this study, we leveraged the transition from vortex to in-plane magnetization in iron oxide nanodiscs to modulate the activity of mechanosensory cells. When a vortex configuration of spins is present in magnetic nanomaterials, it enables rapid control over their magnetization direction and magnitude. The vortex configuration manifests in near zero net magnetic moment in the absence of a magnetic field, affording greater colloidal stability of magnetic nanomaterials in suspensions. Together, these properties invite the application of magnetic vortex particles as transducers of externally applied minimally invasive magnetic stimuli in biological systems. Using magnetic modeling and electron holography, we predict and experimentally demonstrate magnetic vortex states in an array of colloidally synthesized magnetite nanodiscs 98-226 nm in diameter. The magnetic nanodiscs applied as transducers of torque for remote control of mechanosensory neurons demonstrated the ability to trigger Ca2+ influx in weak (≤28 mT), slowly varying (≤5 Hz) magnetic fields. The extent of cellular response was determined by the magnetic nanodisc volume and magnetic field conditions. Magnetomechanical activation of a mechanosensitive cation channel TRPV4 (transient receptor potential vanilloid family member 4) exogenously expressed in the nonmechanosensitive HEK293 cells corroborated that the stimulation is mediated by mechanosensitive ion channels. With their large magnetic torques and colloidal stability, magnetic vortex particles may facilitate basic studies of mechanoreception and its applications to control electroactive cells with remote magnetic stimuli.